w estinghouse westinghouse electric company · 1.0 background 2.0 proposed changes 3.0 proposed dcd...

B W estinghouse Westinghouse Electric CompanyNuclear Power PlantsP.O. Box 355

Pittsburgh, Pennsylvania 15230-0355USA

U.S. Nuclear Regulatory Commission Direct tel: 412-374-6206ATTENTION: Document Control Desk Direct fax: 724-940-8505Washington, D.C. 20555 e-mail: [email protected]

Your ref: Docket Number 52-006Our ref: DCPNRC_002941

August 16, 2010

Subject: Information on Proposed Changes for the AP1000 Design Control Document Rev. 18

This letter is submitted in support of the AP 1000 Design Certification Amendment Application (DocketNo. 52-006). The information provided is generic and is expected to apply to all Combined License(COL) applicants referencing the AP 1000 Design Certification and the AP 1000 Design CertificationAmendment Application.

Westinghouse provided preliminary information on changes which it proposed to include in Revision 18of the AP 1000 Design Control Document (DCD-18) in a January 20, 2010 letter(Reference 1).Supplementary information on some of those changes requested by the NRC was provided in a March 12,2010 letter (Reference 2). Information was provided in an April 26, 2010 letter (Reference 3) for seven ofthe changes identified in the January 20, 2010 that were determined to meet one or more of the InterimStaff Guidance-i1 (ISG-1 1) criteria for reporting to the NRC staff. The remaining 50 "elective" items inthe January 20 letter are addressed in a letter dated May 21, 2010 (Reference 4). In a letter dated May 10,2010 (Reference 5), information was provided for seven design changes that met one or more of the ISG-11 criteria and which supported the AP1000 Licensing Finalization schedule. In a letter dated May 25,2010 (Reference 6), information was provided for two additional design changes that met one or more ofthe ISG-1 1 criteria and which supported the AP 1000 Licensing Finalization schedule. In letters datedJune 14, 2010 (Reference 7), June 18, 2020 (Reference 8), July 6, 2010 (Reference 9), July 8, 2010(Reference 10), July 28, 2010 (Reference 11) July 29, 2010 (Reference 12), and August 12, 2010,(Reference 13) information was provided for additional design changes.

This letter provides information on one additional design change (Change Number 74) which addressesimprovements to the design for containment external pressure. An "NRC Review Package" is provided inEnclosure 1.

As noted previously, the changes described in this and the referenced letters do not constitute all of thechanges which Westinghouse proposes to include in DCD-18. Rather, the changes in this letter are inaddition to those which Westinghouse either has submitted or will submit to the NRC as responses toRequests for Additional Information or Safety Evaluation Report Open Items.

DCPNRC_002941August 16, 2010

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Westinghouse will work with the NRC staff to disposition the changes described in this letter asexpeditiously as possible. Questions related to the content of this lettershould be directed toWestinghouse. Please send copies of such questions to the prospective COL applicants referencing theAP 1000 Design Certification. A representative for each applicant is included on the cc: list of this letter.

Very truly yours,

Robert Sisk, ManagerLicensing and Customer InterfaceRegulatory Affairs and Strategy

References:1. DCPNRC_002744, Re-submittal of Proposed Changes for AP 1000 Design

Control Document Rev. 18, January 20, 20102. DCPNRC_002818, Supplementary Information to DCPNRC_002744 -

Re-Submittal of Proposed Changes for AP 1000 Design Control Document Rev. 18,March 12, 2010

3. DCPNRC_002850, Final Information on Proposed Changes for the APlO1O Design ControlDocument Rev. 18, April 26, 2010

4. DCPNRC_002874, Final Information on Proposed Changes for the AP1000 Design ControlDocument Rev. 18, May 21, 2010

5. DCPNRC_002863, Information on Proposed Changes for the AP1OO0 Design ControlDocument Rev. 18, May 10, 2010

6. DCPNRC_002879, Information on Proposed Changes for the AP1000 Design ControlDocument Rev. 18, May 25, 2010

7. DCPNRC_002909, Information on Proposed Changes for the AP 1000 Design ControlDocument Rev. 18, June 14, 2010

8. DCP_NRC_002918, Information on Proposed Changes for the AP 1000 Design ControlDocument Rev. 18, June 18, 2010

9. DCPNRC_002925, Information on Proposed Changes for the AP1000 Design ControlDocument Rev. 18, July 6, 2010

10. DCPNRC_002932, Information on Proposed Changes for the AP1000 Design ControlDocument Rev. 18, July 8, 2010

11. DCPNRC_002939, Information on Proposed Changes for the AP1000 Design Control

Document Rev. 18, July 28, 201012. DCPNRC_002940, Information on Proposed Changes for the AP 1000 Design Control

Document Rev. 18, July 29, 201013. DCPNRC_002942, Information on Proposed Changes for the AP1000 Design Control

Document Rev. 18, August 12, 2010


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/Enclosure

1. AP 1000 Containment Vessel External Pressure Analysis and Design Information for ChangeNumber 74, NRC Review Package

cc: B. AndersonD. JaffeE. McKennaT. SpinkP. HastingsR. KitchenA. MonroeP. JacobsC. PierceE. SchmiechG. ZinkeR. GrumbirM. Melton

U.S. NRCU.S. NRCU.S. NRCTVADuke EnergyProgress EnergySCANAFlorida Power & LightSouthern CompanyWestinghouseNuStart/EntergyNuStartWestinghouse

1EIE1E1E1E1E1E

1E1E1E1E1E1E


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ENCLOSURE 1

AP 1000 Containment Vessel External Pressure Analysis and Design Information for

Change Number 74, NRC Review PackageNon-Proprietary

WESTINGHOUSE NON-PROPRIETARY CLASS 3

AP1000 CONTAINMENT VESSEL EXTERNAL PRESSUREANALYSIS AND DESIGN INFORMATION

FOR CHANGE NUMBER 74

NRC REVIEW PACKAGE

August 16, 2010

TABLE OF CONTENTS

TABLE OF NOTABLE REVISIONS TO PRIOR NRC PACKAGE

NRC COMMENT RECONCILIATION

1.0 BACKGROUND

2.0 PROPOSED CHANGES

3.0 PROPOSED DCD CHANGES AND JUSTIFICATION TABLE

4.0 DCD MARKUPS AND TECH SPEC MODIFICATIONS

5.0 CONTAINMENT VESSEL EXTERNAL PRESSURE ANALYSIS

6.0 CONTAINMENT ISOLATION CONSIDERATIONS

6.1 WEC RESPONSE TO BRANCH TECHNICAL POSITION 6-4

7.0 SETPOINTS AND CONTROLS

8.0 PRA/DRAP APPLICABILITY

9.0 VALVE INFORMATION

9.1 MECHANICAL DESIGN REQUIREMENTS

9.2 TESTING REQUIREMENTS

9.3 VALVE DESIGN SPECIFICATIONS AND DATASHEETS


Table of Notable Revisions to Prior NRC Package

1 Added Section 6.0: Containment Isolation Consideration

2 Added Section 6.1: WEC Stance on Branch Technical Position 6-4

3 Added Section 7.0: Setpoints and Controls

4 Added Section 8.0: PRA/DRAP Applicability

5 Added Section 9.0: Valve Information

6 Added Section 9.1: Valve Design Specifications and Datasheets

7 Added Section 9.2: Mechanical Design Requirements

8 Added Section 9.3: Testing Requirements

9 Modified Containment Vessel Design External Pressure to 1.7 psid

10 Table 3.7.3-1: Removed VFS Containment isolation valve from Room #12452

11 Table 3.9-16: Revised vacuum relief valve test requirements and frequencies

12 Text 6.2.1.1.4: Revised External Pressure Analysis inputs, assumption and containment pressure

transient response

,13 Table 6.2.3-1: Added valve stroke times for V800A/B

14 Text 6.2.3.5: Added statement addressing priority logic of the containment vacuum relief signal

15 Table 6.2.1.1-9: Added list of key parameters and assumptions used in the containment pressuretransient analysis.

16 Figure 6.2.1.1-11: Figure revised to reflect the new containment pressure transient analysis.

17 Figure 7.2-1: Updated functional diagram to identify signals for actuating the containment vacuumrelief isolation valves.

18 Text 9.4.7.2.1: Included statement addressing the impact of a radiological release through the 6"vacuum relief valves.

19 Text 9.427.2.3: Added a description of the vacuum relief valve operation during abnormal plant

operation.

20 Tech Spec Table 3.3.2-1: Added to address the Low-2 containment pressure ESF signal.

21 Added Tech Spec Bases 3.6.3: Containment Isolation Valves

22 Deleted Table 18.12.2-1


NRC Comments and WEC Resolutions to Prior NRC Package

NRC Staff Comments WEC Responses

I

Draft AP1000 Design Change Package (DCP)74 contains information specifying the logic

for the control of the vacuum relief valves.The draft specifies containment low pressuresignal takes priority over any containmentisolation signals, such as containment pressure

high or high radiation in containment, from

closing containment isolation valves VFS-V800A and V800B following a containmentlow pressure signal. An explanation for how

this meets the requirements of 10 CFR

50.34(f)(2)(xiv)(A) that that ensure that all

non-essential systems are isolatedautomatically by the containment isolationsystem and the requirements of 10 CFR

50.34(f)(2)(xiv)(E) that automatic closing on ahigh radiation signal be provided for all

systems that provide a path to theenvironment is required. In addition, see

GDC 54 & 56.

Valves VFS-V800A/B meet the 1OCFR50.34(f)(2)(xiv)(A) and 1OCFR50.34(f)(2)(xiv)(E) asfollows:

Valves VFS-V800A/B receive containment isolation and high radiation signals to automaticallyclose the valve, and low containment pressure to automatically open the valve. The Open signalhas priority over the Closed signal.The normally closed vacuum relief system motor operated valves (MOVs) are designed to openautomatically when containment pressure reaches -0.8 psig and remain open to precludeexceeding the containment external design pressure (1.7 psid). While the vacuum relief systemMOVs are open, the containment will be at a vacuum and flow will be into containment. Once

the vacuum condition inside containment is reduced to near ambient pressure conditions (-0.2psig), the Open signal is automatically cleared such that the vacuum relief system MOVs willthen be allowed to close automatically in the event that a containment isolation signal or highradiation signal is present. In addition check valves VFS-V803A/B are self actuated checkvalves which will also be closed if a vacuum does not exist inside containment. The checkvalves will not be open until a 0.2 psid differential pressure exists. This is consistent with thevacuum relief system clear signal as well as the -0.2 psig containment pressure Technical

Specification low alarm value.

See Section 6.0 for details.


2

Draft DCP 74 for the planned containment vacuum relief system includes two normally closed motor-operated butterfly valves that will bepowered by the IE battery supply, and signaled to open on a specific containment vacuum pressure. The DCP should provide additionalinformation to support the operational and sealing capability for these two motor-operated valves (MOVs). For example, the DCP should

address.the following:

2a

Butterfly valve design that provides a leak-tight

seal for its containment isolation function and

also maintains full closed position with design-

basis differential pressure from either flowdirection until signaled to open.

Valves VFS-V800A/B are 6" motor-operated valves designed to provide the following functions:

Design/Functional Requirement: These valves will be designed to meet the general requirementsof valve specification APP-PV 11 -ZO-001. The leak-tightness of the valves will be addressed byan air test in accordance with MSS-SP-61 and shall meet the 10 CFR 50 Appendix J leakagerequirements.

Valve features; Triple offset with bi-directional flow and leak tight sealing (FCI leak class V).Actuator example features; Locking gear sets shall be specified to ensure actuator and shaft areheld in position.

See attached design specification and representative data sheet contained in Sections 9.1.3 and9.1.4.

Functional design and qualification of these These valves will conform to the general design and qualification requirements as specified in thePV 11 valve specification APP-PV 1 -ZO-00 1. The system level design requirements for these

2b MOVs to satisfy their design-basis valves will be defined in a VFS system level valve calculation. An example of system levelrequirements for both containment isolation requirements is shown in datasheet APP-PV 11-ZOD-133. Note this datasheet does not reflect the

and vacuum relief functions. specific requirements of the vacuum relief check valves (V800A/B).

Operating control method using limit switch,torque switch, or a combination of these Close: Torque switch controlled.

2c switches to provide assurance of valve sealing

capability without overstroking the valve disk Open: Limit with torque switch backup.

through the seat.


2d

Power availability to operate these MOVs forthe required number of cycles considering the

valve, actuator, and motor sizes, stroke time,

and torque requirements to operate under theirdesign-basis conditions using the 1 E battery

supply over the time period which these valves

might need to function with lE power also

supplied to other plant equipment.

Based upon VFS-PL-V800A and V800B being required to be stroked twice for their design basisoperation, electrical design will consider these loads in the design calculations as follows.The valve(s) will be considered a RANDOM load within the methodology required in IEEE485

for each of the two operations and will therefore be added to the first and second worst one minutetime steps of the battery profile.Electrical calculations, i.e. battery sizing and cable, take into consideration both starting currentand stroke time rounded up to the whole minute(s) for all MOV operation(s). A computation hasbeen performed in evaluation of this design change and demonstrates that the existing componentrating requirements are adequate. This design change will be included in final design calculations

for the IDS system.

2e

Description of plan to satisfy applicable ASME

OM Code inservice testing (IST) provisions

and 10 CFR Part 50, Appendix J leak-testingrequirements.

Valves VFS-V800A/B are 6" motor operated butterfly Class 2 valves with open and closed safety

functions. The ASME OM Code was used to classify and categorize as well as specify the testrequirements and frequencies described below.The valves are considered Active and categorized as A in accordance with ASME OM Code,ISTC-1300. The valves are tested in accordance with ISTC-3500 and Table ISTC-3500-1. Thetesting regime and frequencies are listed below:

* Full Stroke Exercise - Refuel Shutdown

* Remote Position Indication - 2 Years

* Leakage Testing - In accordance with Appendix J frequency* Operability Test - In accordance with Power Operated Valve program

Periodic Verification to based on JOG Periodic Verification (PV) report, key contributors to

Description of plan to satisfy 10 CFR 50.55a periodic test frequency to be:1) Risk significance

supplemental requirements for periodic 2) Fion magin

verification of MOV design-basis capability, 2 ucinmriverifcludingappication of MOV odeign-b es c upai Risk significance to be established by WEC PRA (Refer to Section 8)2f OG) incud grapplicat fof JPeiodint O ers toup Functional margin to be based upon standard industry equations (EPRI), along with incorporating(JOG) Program for MOV Periodic Verification BRGD iigmtoooy

with program scope to include this butterfly

valve design and application. Valve and actuator components to be comprised of materials previously tested as part of the JOG

PV study.


Correction of valve size in draft DCP table 39 Table 19-16 has been updated to reflect the correct valves sizes for VFS-PL-V800A/B and VFS-2g 16. P1-V803A/B

In the event of a LOCA with these valves open, the releases of radioactivity during the maximumContainment isolation closing times time for valve closure (30 seconds) has been evaluated (APP-SSAR-GSC-1 13). The radiological

2h compliance with CSB BTP 6-4 to support ch consequences are bounded by those currently present in DCD 15.6.5.3.15 analysis. (see NUREG71793 chapter

6.2.4.13). See Section 6.0 for further details along with DCD markup provided in 9.4.7.2.1.

Draft DCP 74 includes two parallel check valves in series with the butterfly valves in the planned containment vacuum relief system. The3 DCP needs to provide additional information to support the operational and sealing capability of these two check valves. For example, the

DCP should address the following:

Valves VFS-V803A/B are 6" swing check valves designed to provide the following functions:

1) Function: Containment Isolation

Design Requirement: These valves will be designed to meet the general requirements of valvespecification APP-PV03-ZO-001. The leak-tightness of the valves will be addressed in the design

Check valve design that provides a leak-tight by an air leakage tested in accordance with MSS-SP-61.

seal for containment isolation function and will 2) Function: Vacuum Relief3aopen at a preset containment vacuum pressure Design Requirement: These valves will be provided with a balanced, and adjustable, angled seatthat supports the DCP analysis. design. The nominal cracking pressure will be set in accordance with the vacuum relief system

design requirements.

See attached design specification and representative data sheet contained in Sections 9.1.1 and

9.1.2These valves will conform to the general design and qualification requirements as specified in the

Functionalvdesign ad qualsf i theirdesign-ise PV03 valve specification APP-PV03-ZO-00 1. The system level design requirements for these

3b check valves to satisfy their design-basis valves will be defined in a VFS system level valve calculation. An example of system levelrequirements for both containment isolation and requirements is shown in datasheet APP-PV03-ZOD-192. Note this datasheet does not reflect thevacuum relief functions. specific requirements of these vacuum relief check valves (V803A/B).


Installation orientation for check valve that Per the PV03 valve specification APP-PV03-ZO-001, Section 3.2.13.2, check valves shall be

3c supports design assumptions for operating installed with the checking element closing with gravity in the reverse flow direction. These

differential pressure and sealing capability, valves will be installed in the horizontal direction in accordance with this design requirement.

Check valves VFS-V803A/B have a safety function in both the open and closed positions. Sincethe valves are classified as vacuum relief check valves, the requirements of ISTC and Appendix Iof the ASME OM Code will be applied.

Bidirectional Testing CapabilityASME OM Code, ISTC-5221 (a) requires the valves to have both an open and closed check

valve test. Since the valves have a safety function in both the open and closed directions, ISTC-

3d Capability for bidirectional testing of each check 5221(a) (1) applies.

valve. Open Test - The check valves will be exercised open using a mechanical exerciser inaccordance with ISTC-5221(b)(1) to verify the force required to open the valve is satisfied. Thevalve is designed with a mechanical exerciser to allow adjustment of the balancing deviceinherent to the valves. The valve is designed to begin to lift off the seat at 0.2 psid. This valuewill be used as the acceptance criteria.

Closed Test - The valves will be verified to close during the mechanical exercise test inaccordance with ISTC-5221(b)(3). The valves will be visually verified closed as well as leakagetested in accordance with the Appendix J program.Valves VFS-V8030A/B are 6" swing check valves designed as Class 2 with open and closedsafety functions. The ASME OM Code was used to classify, categorize as well as specify thetest requirements and frequencies described below.The valves are considered Active and categorized as AC in accordance with ASME OM Code,

Description of plan to satisfy applicable ASME ISTC-1300. The valves are tested in accordance with ISTC-3500 and Table ISTC-3500-1 as

OM Code IST provisions and 10 CFR Part 50, both check valves and vacuum relief devices. Appendix I of the ASME OM Code will be

3e Appendix J leak-testing requirements, including applied for vacuum relief devices. The testing regime and frequencies are listed below

appropriate provisions for vacuum relief devices * Full Stroke Exercise - Refuel Shutdown

in Appendix I to ASME OM Code. 0 Leakage Testing - In accordance with Appendix J frequency* Vacuum Relief Test - 2 Years

The full stroke exercise test of this valve will ensure that the open set point is met by using amechanical exerciser. The close test is performed in conjunction with the leakage test and visual

observation.


Correction of valve size in draft DCP table 3.9 Table 3.9-16 has been updated to reflect the correct valves sizes for VFS-PL-V800A/B and VFS-3f P1-V803A/B16 & inclusion of set pressure (Ch 6).

Refer to Section 5 (Page ) for set pressure details.

A discussion/explanation concerning the validity

of the minimum service metal analysis specifiedin Westinghouse Document APP-MV50-ZOC- Per NRC RAI - 381 3.8.1 CIB1-01 Revision 5, Westinghouse has agreed to revise APP-MV50-

4 039, as modified by Westinghouse letter dated ZOC-039, and it is still applicable as the basis for the determination of the Containment Vessel

July 9, 2010, is required. Explain why it is still lowest service metal temperature.valid (i.e., still bounding), and if it not valid,

provide the new analysis.

5 Draft DCP 74 does not contain any changes to Chapter 17 or 19 despite:

Cutsets are not provided in DCD Ch. 17. The only applicability for D-RAP and containmentThere was a single minimum cutset for this purge valves is whether or not they are required to be manipulated by the DAS. See section 8.0

5a system to fail containment, there are now nine. for description and calculation as to why DAS manipulation of the vacuum relief system is notThis may impact the Chapter 17 and possibly required. For Tier I Section 3.7 the system reliability calculation is included in Section 8.0 and

Tier 1 Section 3.7. demonstrates adequate reliability to not be included in Section 3.7.

Of the 8 cutsets for VFS failing, half of them5b increase the risk significance of the existing vent That is correct the values do increase slightly, but are within the same order of magnitude.

valves.

There appear to be two CCFs (CCF of MOVs to

open and CCF of check valves to open) that will5c prevent adequate venting when required (the Section 8.0 contains the calculation for assessing the risk of the multiple CCFs.

other system failure mode).

5d Preliminary analysis may not have recognized Section 8.0'contains the calculation and addresses latent failures.that these failures can be latent.

WESTINGHOUSE NON-P ROPRIETARY CLASS 3

6 A discussion of the following is required:

Analysis assumptions, including a description ofhow the relief valves are modeled (#, set points,

timing, etc), any sensitivity studies6a size' Section 5.0 of this report contains the requested information.

performed, and how initial conditions were

calculated with justification for the most limiting

case is required.

The containment external pressure analyses develop the acceptable range of operation for the

internal to external temperature differential. The Tech Specs are established to ensure that

operation of the AP 1000 is within the ranges analyzed for maximum external pressure. For

example, LCO 3.6. 10 requires the internal containment to external containment temperature

differential be:5 90 'F, and that if this cannot be achieved then containment temperature must be

reduced < 80 'F.

6b How tech specs are tied to analysis assumptions. The containment transients were performed to develop the 90'F internal to external temperaturedifferential operating band. The analyses show that with the application of the vacuum relief

system that no postulated mechanistic pressure excursion can occur that would cause the

containment external pressure to be greater than 1.7 psid while operating within the specified

range.

The < 80'F criteria allows for plant operation at cold conditions where the 90 'F differential

cannot be maintained. A run performed at -40 'F external temperature with a containment

internal temperature of -85 'F was mitigated by the performance of the vacuum relief system.

Tech Spec changes provided as part of this draft change package are only related to the revised

Tech spec changes incorporating changes to the external pressure analysis and the addition of the vacuum relief system. Additional changes to

6c containment air-only cooling calculation and <6 the affected Tech Specs will be compiled and one complete, comprehensive set of Tech Spec

MWt decay heat requirement (ILO 9MWt). changes will be provided in the final transmittal of the Change Notice in accordance with

W estinghouse procedures.


Operator expectations for valve operation

Normal Operation --During normal operation the vacuum relief system valves are normally

closed as testing will occur during shutdown operations. The valves are not required to be

opened for any normal operating evolution including testing. In addition, the motor operated

valve position is displayed in the control room with an alarm present to indicate when the valve

is not closed.

The operator is not expected to operate these valves during normal power operation.

Emergency Operation (Vacuum Relief) - During an event requiring vacuum relief the operator

is not expected to perform any actions. The motor operated vacuum relief valves openautomatically at a setpoint of -0.8 psig to mitigate the transient. After the event is mitigated and

pressure increases, the open signal is cleared automatically at -0.2 psig. Should a containment

isolation or high radiation signal be present, the valve will automatically close. Once the open

signal is cleared and pressure near ambient conditions, the operator may then close the vacuum

relief motor operated valve by remote manual operation to restore the system to normal

conditions.

The operator is not expected to operate these valves during emergency vacuum relief conditions.

Emergency Operation (Containment Isolation/High Containment Radiation) - During an event

requiring valve closure due to containment isolation or high contaim-nent radiation, the motor

operated valves receive a confirmatory close signal. Should the valves be in the open position

following a containment vacuum relief condition with a coincident containment isolation or

high radiation signal present, the valves will close automatically after the low containment

pressure signal is cleared (42 psig).

The operator is not expected to operate these valves to during a containment isolation or highradiation event as these will actuate automatically upon receipt of the safeguards signal.

6d I Operator expectations for valve operation.


Table 5-1 shows the comparison of the new fan cooler performance, and the performance of

those modeled for the negative pressure scenarios presented in APP-MV50-ZOC-039 R 0. The

difference in performance of the fan coolers is minimal, and the overall impact on the analysesChange to larger containment coolers & effect on would be negligible. However, an inadvertent actuation of a fan cooler at power conditions

6e possible negative pressure events - i.e. now would result in the setpoint (-0.8 psig) being reached for the vacuum relief system actuation.

possible at full power?

Refer to Section 5 for detailed analysis of containment pressure transients and representativeTables and Figures.

The DCD changes provided as part of this draft change package include only those DCDDCD change package including all relevant changes related to the revised external pressure analysis and the addition of the vacuum relief

7 changes from Rev 15, and a table that includes system. Additional changes that affect Revision 18 of the DCD sections will be compiled andpast RAI responses & DCD changes affected one comprehensive set of DCD changes will be provided in the final transmittal of the Change

by this change, is required. Notice in accordance with Westinghouse procedures.

TR-09 to be updated to include a summary of TR09 will be updated to include a summary of the new buckling analysis calculations and

8 the new buckling analysis calculations & thermal profile analysis. RAI TR09-008 Revision 6 will also be submitted to reflect thisthermal profile analysis. information.


1.0 BACKGROUND

DCD 6.2.1.1.4, External Pressure Analysis, describes the requirement for operator action to mitigate theconsequences of an event causing a vacuum to be developed inside containment. Evaluations have beenperformed that indicates a pressure reduction will be realized inside containment following low ambienttemperature (40 F) coincident with a loss of AC power. DCD 6.2.1.1.4 credits opening of the 16" ventand purge lines to mitigate the pressure reduction prior to reaching the containment shell design externalpressure (2.9 psig).

The DCD states that the vent and purge valves are powered from the IE batteries. The valve solenoidsare powered by the I E batteries however the valves are air operated valves such that loss of AC orpneumatic supply will cause the valves to close on spring force. Without AC power or pneumatic supply,the valves cannot be reopened.

2.0 PROPOSED CHANGES

The proposed change adds a Vacuum Relief System to the existing Containment Air Filtration System(VFS) vent line penetration as seen in Figure 1. The vent line was selected based on the ability to 1)provide enough flow area and 2) inherent to the containment venting system design the vent line will beunder a slight negative pressure (vacuum system check valves will tend to close) and will not short cyclethe normal containment air flow when the purge/vent system is in operation.

The proposed vacuum relief system consists of redundant vacuum relief devices inside and outsidecontainment sized to prevent differential pressure between containment and the shield building fromexceeding the design value of -1.7 psig.

Each relief flow path consists of a check valve (V803A/B) inside containment and motor operatedbutterfly valve (V80OA/B) outside of containment. The redundant relief devices outside containmentshare a common inlet line with redundant outside air flow entry points. The outlet lines downstream ofthe outside containment relief devices are routed to a common header connected to the vent linepenetration. The redundant relief devices inside containment share a common inlet line from the vent linepenetration and have independent discharge lines into containment. Each relief device is designed toprovide 100% of the required capacity to prevent a differential pressure across the containment vesselfrom exceeding the design value. Each relief flow path provides the required capacity, such that a singlefailure of any of the relief devices will not limit the required flow below what is required to mitigate acontainment vacuum relief event.

The butterfly valves are designed with motor operators that are powered from separate I E DC batterysources. They are designed to close within 30 seconds of receipt of either an automatic containmentisolation signal, or a manual isolation signal. The opening time is not significant when evaluating theperformance of the vacuum relief system, but is inherent to the actuator sizing of the valve. Each valve isqualified to provide 100% of the required capacity to mitigate the most bounding containment transientthat requires vacuum relief

The check valves are balanced to remain closed during non-nal operations, including containment vesselventing, to prevent inadvertent opening or chatter. Each valve is designed to provide 100% of therequired capacity at the vacuum relief set pressure -0.8 psig., The balanced design of the valve will causethe self actuated check valves to close when containment is at a slight negative pressure (on the order of0.2 psid), which ensures the containment becomes isolated prior to containment pressurization.


Figure 1: Proposed Vacuum Relief System Sketch

VF4S-16O

VFS-VO10 VFS-VO09

- - - - - - - - -- ------------

VFS Vent Line Penetration '

This change requires redundant outboard power operated valves along with self actuated swing checkvalves to meet the ASME Section III requirements for a Containment Vessel Vacuum Relief system. Inaddition, the design meets the ANSI 56.2 Containment Isolation Provisions for Fluid Systemsrequirements.


3.0 PROPOSED DCD CHANGES AND JUSTIFICATION TABLE

This section provides a detailed description of each DCD change required to implement this proposed design change.The actual DCD markups required to implement this proposed change are provided in Section 4.0.

DCD Title Reason for Change

Tier 1

Table 2.2.1-1 Containment System Valves VFS-V800A/B and VFS-V803A/B have been added to the Containment System equipment table.The valves are indicated with active functions to Transfer Closed and Transfer Open.

Figure 2.2.1 -1 Containment System The proposed vacuum relief system has been added to the Containment System figure on the vent linepenetration (Penetration #32).

Table 2.2.1-2 Containment System Line numbers L800, L801A/B, L803, L804, and L805A/B have been added to the Containment SystemPiping safety related line number list.

Text 2.7.6 Containment Air The proposed Vacuum Relief System safety function was added to the Containment Air Filtration SystemFiltration System Safety Function description.

Table 2.7.6-2 Inspections, Tests, The proposed Vacuum Relief System safety function was added to the Containment Air Filtration SystemAnalyses, and ITAAC Table description.Associated Criteria(ITAAC) Table forthe VFS

Tier 2

Table 3.2-3 AP1000 Valves VFS-V800A/B and VFS-V803A/B have been added to the table as Class B, Seismic Category 1, andClassification of ASME Section Ill Class 2 Construction Code.Mechanical andFluid Systems,Components, andEquipment

Table 3.7.3-1 Seismic Category IEquipment OutsideContainment byRoom Number

The VFS vacuum relief motor operated valves (VFS-V800A/B) are Seismic Category I and will be locatedoutside containment in the VAS Equipment Room (Room # 12651). Removed VFS containment isolationvalves from Room #12452.


3.0 PROPOSED DCD CHANGES AND JUSTIFICATION TABLE (CONTINUED)

Text 3.8.2.1.1 General The CV Design External Pressure is defined as 1.7 psid based upon the actuation point of the containmentvacuum relief system.

Text 3.8.2.4.1.1 Axisymmetric Transient analysis no longer determines the design external pressure of the CV; therefore this section isShell Analyses revised to remove references to analysis that defined external pressure.

Table 3.8.2-1 Load Combinations The CV load combinations table is updated based upon the new single design external pressure.and Service Limitsfor ContainmentVessel

Table 3.9-12 List of ASME Valves VFS-V800A/B and VFS-V803A/B have been added to the Active Valve List since they have an activeClass 1, 2, and 3 ESF function.Active Valves

Table 3.9-16 Valve In-service Valves VFS-V800A/B and VFS-V803A/B have been added to the Inservice Testing requirements Table.Test Requirements Valves VFS-V800A/B are categorized as A, with Active Safety Missions. Valves V800A/B will be full stroke

exercised during refueling shutdowns only, remote position indication tested, and receive a leakage rate test.In addition, Valves V800A/B will be included in the AP1000 POV Program and will be tested accordingly.Valves VFS-V803A/B are categorized as AC with Active Safety Missions. Valves V803A/B will be fullstroke exercised and receive a leakage rate test. In addition, these valves are categorized as vacuum reliefvalves and will receive a vacuum relief test in accordance with Appendix I of the ASME OM Code. All of therequirements of the ASME OM Code have been addressed.

Table 3.11-1 Environmentally Valves VFS-V800A/B and their respective motors and limit switches have been added to the table with theQualified Electrical ESF/PAMS functions and required Operating Times. Valves VFS-V803A/B have been added to the tableand Mechanical with and ESF Function and required Operating Times.Equipment

Table 31.6-2 List of Potential The motor operators for valves VFS-V800A/B have been added to the table as potential high frequencyHigh Frequency sensitive safety related components.Sensitive AP 1000Safety-RelatedElectrical andElectro-MechanicalEquipment



Table 31.6-3 List of AP1000 Valves VFS-V800A/B and VFS-V803A/B have been added to the table as not potential high frequencySafety-Related sensitive safety related components.Electrical andMechanicalEquipment NotHigh FrequencySensitive

Text 6.2.1.1.4 External Pressure This text defines the containment pressure transient that forms the basis for sizing the vacuum relief system.Analysis Previously, this text had been incorrect as it credited IE batteries to open the containment ventilation purge

isolation valves to mitigate a low containment pressure event. The text has been changed to reflect the revisedanalysis inputs, assumptions and containment pressure transient response. Using the results of this analysis,the vacuum relief system was sized to ensure that containment external pressure does not exceed thecontainment vessel design limit.

Table 6.2.1.1-9 External Pressure The new external pressure analysis figure was revised as well. New Table 6.2.1.1-9 was added to list keyAnalysis parameters and assumptions used in the transient analysis.

Figure 6.2.1.1-11 External Pressure Figure 6.2.1.1-11 has been revised to reflect the new containment pressure transient analysis.Analysis

Table 6.2.3-1 Containment Since the proposed vacuum relief system valves are included as part of the containment air filtration vent line,Mechanical valves VFS-V800A/B and VFS-V803A/B have been added to the table with the following actuation signals:Penetrations and Closes on Containment Isolation, High Radiation, and Opens on Low-2 Containment Pressure. Notes 8 and 9Isolation Valves were added to the Table. Note 8 addresses the Low-2 containment pressure to open the valve. Note 9

addresses testing of valves V800A/B in the reverse direction. Added stroke time of 30 seconds for valvesVFS-800A/B.

Text 6.2.3.5 Instrumentation Statement addressing the priority logic of the containment vacuum relief signal was added.

and ControlApplication



Figure 7.1-1 (Sheet 13 Functional This figure has been updated to identify the signals for actuating the containment vacuum relief isolationof 21) Diagram valves.

Containment andOther Protection

Figure 7.2-1 (Sheet 19 Functional This figure has been updated to identify the signals for actuating the containment vacuum relief isolationof 21) Diagram valves. The following signals will OPEN the Containment Isolation Relief valves: a 2oo4 "Low-2

Containment Containment Pressure", or one of two manual actuation controls. The following signals will CLOSE theVacuum Relief Containment Isolation Relief valves: Containment Isolation signal, High-1 Containment Radiation signal, orProtection one-of-two manual actuation controls.

Table 7.2-5 Figure 7.2-1 Cross This table has been updated to account for the additional Sheet 19 added to Figure 7.2-1. This table serves asReferences a cross reference to match the APP-PMS-J I drawing to its corresponding Figure 7.2-1 sheet.

Text 7.3.1 Engineered Safety This text has been updated to include Section 6.2 as a section that analyzes design basis events. The particularFeatures DCD paragraph is 6.2.1.1.4. DCD Chapter 15 contains the analyses of design basis events. Section 6.2Description contains the analyses of the Containment only.

Text 7.3.1.2.26 Containment DCD Section 7.3 describes the Engineered Safety Features. These features include "...providing containmentVacuum Relief integrity." The text of paragraph 7.3.1.2.26 describes the containment vacuum relief actuation signal. This

section has been added to explain the additions to Table 7.3-1.



Text 7.3.1.5.5 Design Basis: This text has been updated to include Section 6.2 as a section that analyzes design basis events. The particularEngineered Safety DCD paragraph is 6.2.1.1.4. DCD Chapter 15 contains the analyses of design basis events. Section 6.2Features for contains the analyses of the Containment only.Malfunctions,Accidents, NaturalPhenomena, orCredible Events

Table 7.3-1 Engineered Safety This, table lists the actuation signals for safety related features. The containment vacuum relief system hasFeatures Actuation been added to this table. Item 28 of this table lists the Containment Vacuum Relief signals, These signals areSignals Low-2 Containment Pressure or Manual Initiation. No permissives or interlocks are required for any of these

signals.

Table 7.3-3 System-Level The manual Containment Vacuum Relief Actuation Signals have been added to this table. Two PMSManual Input to the Divisions are used: A and C. The use of two separate divisions provides reliability against a single channelEngineered Safety failure.Features ActuationSystem

Table 7.5-1 Post-Accident The proposed containment vacuum relief motor operated valves have been included in the Post-AccidentMonitoring System Monitoring System table with Open/Closed status requirements. The variable is considered D2. The valves

are located outside contairunent (Mild Environment) and are seismically qualified. In addition as the tableindicated each valve will have remote position switches and be supplied with I E power.

Text 9.4.7. 1.1 Containment Air A functional description of the proposed vacuum relief system and the safety related basis of the proposedFiltration System vacuum relief system has been added to the Containment Air Filtration System Safety Design BasisSafety Design description.Basis



Text 9.4.7.2.1 Containment Air A general description of the proposed vacuum relief system has been added to the Containment Air FiltrationFiltration System System General Description. Included is a statement addressing the impact of a radiological release throughGeneral the 6" vacuum relief valves.Description

Text 9.4.7.2.2 Containment Air A description of the valve types and locations for the proposed vacuum relief system. Motor operatedFiltration System butterfly valves outside containment and self actuated swing check valves inside containment have been addedComponent to the Containment Air Filtration System Safety Evaluation.Description

Text 9.4.7.2.3 Containment Air A description of the vacuum relief valve operation during abnormal plant operation is provided.Filtration SystemAbnormal PlantOperation

Text 9.4.7.3 Containment Air A description of the proposed vacuum relief system piping and valves has been added to the Containment AirFiltration System Filtration System Safety Evaluation to describe the independent/redundant vacuum relief lines. A statementSafety Evaluation was also added describing that the independent and redundant lines share a common containment penetration.

Figure 9.4.7-1 Containment Air This DCD figure has been revised to include the proposed vacuum relief system.Filtration SystemPiping andInstrumentationDiagram

Table 9A-2 Safe Shutdown The motor operated valves (VFS-V80OA/B) included in the proposed vacuum relief system are located in FireComponents Area/Fire Zone 1200 AT 01. Valve VFS-V800A is powered from Division A and valve VFS-V80013 is

powered from Division C.

rech Spec 3.3.2 ESFAS Actuation The addition of a vacuum relief subsystem provides design basis protection during a containment overcoolingInstrumentation condition to protect the containment vessel integrity. Therefore, a TS is required to identify the

OPERABILITY requirements for the accident mitigation functions for this subsystem. Since this system isautomatically actuated, TS 3.3.2 requires identifying the actuation signals and their set points.



Tech Spec Table ESFAS Actuation Table added addresses Low-2 containment pressure ESF signal.3.3.2-1 Instrumentation

Tech Spec B 3.3.2 ESFAS Actuation Bases are required for each TS.Instrumentation

Tech Spec B 3.6.3 Containment Bases are required for each TS.Isolation ValvesBases

Tech Spec B 3.6.4 Containment In resolving an inconsistency between the VFS design in DCD Chapter 9 and the overcooling transientPressure Bases response in DCD Section 6.2.1.1.4, a vacuum relief system was required to be added to provide the mitigation

capability described in DCD 6.2.1.1.4.Tech Spec 3.6.10 Vacuum Relief The addition of a vacuum relief subsystem provides design basis protection during a containment overcooling

Valves condition to protect the containment vessel integrity. Therefore, a TS is required to identify theOPERABILITY requirements for the accident mitigation functions for this subsystem.

Tech Spec B 3.6.10 Vacuum Relief Bases are required for each TS.Valves Bases


4.0 DCD CHANGES

2. System Based Design.Descriptions and ITAAC AP1000 Design Control Document

Table 22.1-,1 (cont..):

ASME Class mE/ Los'sof:C 1deode ReinoteI IIy Q .au al folr, Safety-, Motive:

Section Seismic Operated Harsh Related , Control Active PowerCodeay RemotDly Functi. .o Paey ostioeEquipment Name Tag No. III Cat. I Valve Envir. Display 1PMS/AS Function Position

Integrated Leak Rate Testing VFS-PL-V008 Yes Yes No -/- No -N-. None .Vent Discharge ContainmentIsolation Valve - ORC

Containment Purge Discharge VFS-PL-V009 Yes Yes Yes Yes/Yes Yes: Ycs/Yes Transfer Closed

Containment Isolation Valve - (Val e Closed

IRC Position)

Containment Purge Discharge VFS-PL-VOIO Yes Yes Yes Yes/No Yes Yes/Yes Transfer Closed

Containment Isolation Valve- (Valve Closed

ORC Position)

VacuuM' Relief Containment VFS-PI>-VS00A Yes Yes Yes Yes/No Ves Yes/No Transfer As Is

Isolation A-- ORC (Valve Closed/Position), Transfer

Viacuumn1 Relief Containment VFS-PL-VS00B Yes Yes Y&s Ye-Js6 Yes ,Yes/No Transfer. As Is:

Isolation B - ORC -Val.e Closed/.o r Transfer.

bOpen

CaL]ulum Relief Containment VFS-PL-V80A Yes Yes No - .N'To-ranscfer

Isolation Check Valve A - IRC Closed&Tranmsfer•

N'acuuný Relief Containment VFS-PL-V80'3B Ys Ye s No _ No :L- Transfer

Isolation Check Valve B - IRC Closed/Transfer.

066n

Note: Dash (-) indicates not applicable.

Tier 1 Nlaterial 2.2. 1~6

Revision 18

Tier I Material -2.2.1-6: • Revision 18

2. System Based Design Descriptions and ITAAC API000 Design Control Document

3 3S - p

tL~ ~ t23 I

-S -

- 3 5

[ -

S S

Figure 2.2.1-1Containment System

Tier I Material 2.2.1-18 Revision 18

2:. System Based Design Descriptions andlTAAC AP1000 Design. Control Document.

Table-2.2t.-2ASME Code

:LineNamel Line.Number ::Section IHI

Instrument Air In CAS.PL-L01-5 Yes

Service Air In CAS-PL-L204:. Yes

Component Coohing Water Supply to Containment CCS-PL-L201 ýYes:

Component.Cooling Water Outlet from Containment CCS-PL-L207: Yes

Demineralized Water In DWS-PL4L245, L230 Yes

Fire Protection Supply toContainment FPS-PL-L107 'Yes

Spent Fuel Pool Cooling Discharge SFS-PL-L017 Yes;

•:SpenIt Fuel Pool CoolinigeSuction fromiCfitainment SFS-PL-L038 Yes,

ContainmenltPurge Inlet tO'Conta*menlt VFS-PL-L 104, L105, 1106 Yes

Containment Purge Discharge from Containment VFS-PL-L203,-L204, L205, Yes-IL(-800,L8L0 A 1, L803, L804,

Fan Cooler Supply Line to Contaimnent VWS-PL-L032 Yes.

FanCooler Retum Line from;Containment. VWS-PL-L055 Yes

RCDT Gas Out WLS-PL-L022 Yes

Waste Sump Out WLS-PLPL0731 Yes

Tier I Material 2.2.1-1.1

Revision 18

Tier I Material 2,1;1-11 Revision 18

•2.. SystemnBasWd DeshignDescriptions and ITAAC AP1.000Design Control Document

:2.7.6 Containiiment Air Filtration.System

Design Description

The contaifimenth aif-filtiation :system (VFS) provides intermittent flow of outdoor -air, to pu~rge.and filter the

.containmient atmfiosihedre6f,airborneradioactivity during n ormal plantloperation, and:Continuous flowduring h.otor-cold plant !shutdown conditions to reduce airbome radioactýivity, levels:foor personnel access.

The"VFs .can :also providefiltered exhauStforthe radiologically controlled area ventilation system (VAS)

during: abnrmnal conditions.

The ES is~asshown in Figure 2:,7.6-1 ,and the component locations of the VFSare as.shownwinTable 2.76-3.

1. The functional alrrangernentof the VFS is as described in theDesign Description 6f this Section 2..6.

2. The VFS pro6vides the safety-related function.s of preserving containment integrityby isolation of the.VFS lines penetrafing contaitment and providing vacuum re ief for tlhe conitadnent essel.

3. The VFS provides theintermittent flow of outdoor air to purge the containment atmosphere during

normal plant op'ration, and continuous flow:during hotor. cold plant shutdown conditions.

4. 'Controls existin the maincontrol room (MCR) to cause thecomponents identified in.Table 2.7.6-1 to

performlhe •listed :function.

5. Displays of the parameters in Table 2.7.6-1 can be retrieved in the MCR.

Inspections, 'fests, Analyses, and Acceptance Criteria

Table.2.7 . 2.6- specifies the inspections, tests, analyses, and-associated criteria for'the VFS.

Tier.1 Material :2:76:11 -Revision 18

2.System Based Design Descriptionsand ITAACeDgCor .AP1000 DesigniControl Documient.

Table 2.7.6-2

I1

Design Commitment inspections;.Tests, Analyses. j Acceptance Criteria

1. The fiinctionalarrangement of InJspectiono.f the as-built system The as-built VFS.conformswith thei

the VFS is as described in. the will be performed..: funictional:arrangement described in

Design Description of this thelDesignDescription of this

Section 2.7.6. T Seetion .27.6:

2I. The VFS provides the safety- See Tier i Material, Table 2.2.1-3, See Tieri' Material, Table 2.2..1-3,

related functions of preserving items I and 7., items I and 7.

contaiiment integrity by isolation of-t..he VFS lines penetratingcontainment !and p rovidln.1 vacuumSrelief for, the containment Vessel.

3. The VFS provides.the i) Testing willfbe.performed to i) The flow rate measured at eachintennittent flowof outdoor air to confirm that containmentsupply fan-isgreater thanor equal to

purge the containment atmosphere AFIUfan A when operated with 3,6100 scfm.

during normal plant operation,ý and 'containmentexhaust fan A provides

continuous flow durinig hot or cold a- flow of outd6orair.plant shutdown conditions.

ii) Testing will be performed to ii) Theflowrate measured at each

confirinithat contaiimient supply fan is greater than or. equal to.:

AHU fan B wien operated with 3,600 scfm.

containmmlent exhaust fan B providesa flow of outdoor air.

iii) Inspection will be conducted of iii) The nominal line size is Ž_>36 in.

the containment purge dischargeline:(VFS-L204) penetrating.the

containment,

4., Controls exist'inthe MCR to Testing will beperformed on. the Controls in the.MCR operate to

cause the components identified iH components in Table2.7.6-1 using: cause the components Iistedin

Table 2.7.6-1 to perform the listed controls in the MCR; Table 2.7.6-1 to perform the listed

function. functions.

5. Displays of the parameters Inspection will be performed for The displays identified in

,ideritifiedin Table 2.7.6-1 ean be retrievability of :the parametersin Table 2.7.6-1 can be retrieved in the

retrieved in the MCR. the MCR. MCR.

Tier I Material. 2.7.6-3

Revision 18

Tie~r I Material• 2.7ý6-3 Revision 18

3. Design of Structures, Components,Equipment and Systems AP1000 Design Control Document

Table 32-3 (Sheet7 of .

API000 CLASSIFICATION OF MECHANICAL ANDFLUID SYSTIEMS, COMPONENTS, AND EQUIPMENT

API000 f] Seismic, :Principail..Con-

TagNumber Description NClass Category struction Code Comments

Main Control Room Emergency Habitability System (Continued) _

V t S: M •DJ•_03r IFiltration Li in. Ntic 1 ,SMFA CI*ISunnl Damper ccS tion DA

VES-MY-VOI. MCRAirFihration Line Note I I ASME AG1Sil r •.. . Se tion SA.

VS-My-YR Air Filtaion Lin Note.l ASMEIAG-I,," .. . 'ilencer.. __________A

Containmenit Air Filtration System (VFS) Location:.AuXiliary Building•and Annex Building

VFS-PY-COlI Containment Supply DuPct B I ASME t11, 2Penetrati6n

VFS-PY-C02 Conitainment Exhaust Duct B I ASME 111, 2Penetration

VFS-MY-YOt Containment Air Supply, C I ASME Sec- Ill

Debris Screen Class 3

VFS-MY-Y02 Containment Air Exhaust C I ASME See. Ill

Debris Screen Class 3

CVFS-PL-V003 Containment Purge Supply B I ASMEIll-2.

Containimient Isolation Valve

VFS-PL-V004 Containment.Purge Supply B I ASME I11-2

Containment Isolation Valve.

VFS-PL-V008 Comtinmerit IsolationTest B I ASMEJII-2

Coniietioni

VFS-PL-V009ý Conainnent Prge Discharge B I ASME:IIl-2...... Cowantaient.th01ation Valve•

jYFS7PL-VOIO, ContinmentPurge Discharge B I ASME lil-2.'Containment isolation Valve/

VFS-PL-VO12 .ontainmeiit Isolation Test B ASME 111-2

ýY - LI015 Containi I solatiion Test IE 12Connectio "

,V.FS-P L-V8OOB3 vacuum RdiefCGintaiiimcnti I ASME.II1B2Isolation B -ORC

D e I etedi6 t

,Lýefeted: (is

Tier 1 Material 3.2-86 Revision 18

3. Design of Structures, Components,:Equipment and Systems APIO0O0Design Control Docurnent

Table 3.,2-3: (Sheet 6fý7I

AP1000 CLASSIFICATlON OF MECHANICALýANDFLUiD SYSTEMSI COMPONENTS, AND EQUIPMENT

.AP00 Seismic 1PrincipalCon- ,

1TagNumnber Description Class Category, s•t6iution.Code Comments

C•ontainmentAir Filtration :System,(continued)

VFS-PL-V_03A :4aiuuih ReliefCnitii.niinj. t .B 9 ASME.IH-2

IsolaionCheck ValveA RCMC

VFS-PL-V803B Vac•uim RciifCOxiitaiircntct.B ASME 111-2• , i•61lsoltion'Chieek ValiveB.13il• ~- IR .. ..

"/a Valves:ProvidingYFS D NS ANSI 16:34APiOO0 Equipment Class D j

Function,

n/a Dmunpersliin linsisoliating R NS ASME-'509radioactive contamination

n/a Shutoffj I•0iatiofn and L NS ANSItAMCA-Bitancing Danipier -s o0.0

n/a Fire Dampers Note:3 NS' U-5

n/a Supply Air.Handling:Units :L NS: ManufacturerStdd.

n/a Air Exhaust Filtration Units R NS. ASMEAG•.,,

n/a Fans, Ductwork I or R NS SMACNA orýASME:AG-I,

Note 4

Balance of system compon ents arc Class:L and Class R

Health Physics and Hot Machine Shop H-VAC.System (VHtS) Location: .Annex:Bu ildiiig

n/a Shutoff, Isolation, and L NS ANSI/AMCA-Balancing Damiper's 500

n/a Fire Dampers Note 3i NS UL-555S

n/a Air Handling Units:iw/ Filters. L NS MamnuacturerStd.

n/a Fans, Douctwork L NS SMACNA

Balance of system components are Class E or Class L

Containment Hydrogen Control System (VLS) Location: Containment

n/a Hlydrogen.igniters D NS Manufacturer ProvidesStd.. Hydrogen Control

Following-SevereAccidents,

7eD-

Deleted: 65,

Tier 2 Material T a.3.287 Revikio6l8

3. Design of:Structures, Compbnents,EqUipment :amdSystenms APIOOO Design Control DocUmenit

Table 3.7:3 I (Shcct 3 of 3)-

SEISMIC CATEGORY I EQUIPMENT OUITSIDE CONTAINMENT BY ROOM NUMBER

RoomNo.. Room Name Equipment Description

12421, Non:LE equipmnt/penetrationroom Divisional cabling

12422 Reactortrip switchgear Reactor hrip switchgear

12423 Reactortrip'stiitc.gearI Rcactor trip smitchgear

12452 V ýpenetration ro6om VFSc ntwinneifisoIationvalves.,divisional.cabling

12454 VFS/SFS/PSS pefietration room: SFS/PSS/VFS containment eisolatiot.valvcs,ýRNSP. p s•. ii'. ' , ,, .... . ....pressure bounary

12462 Cask-washdo~wn pit SFS. pipng

12504 'Upper MSIV'om'partmentB 1SGS CIVs, instrumentation and controls

12506 Upper MSIV compartiuent.A SGS.ClVs, instrumentation and controls

12541 Upperann.ulus, PCS piping'and cabling;

12553 Peronnellaccess area, Perionnel airl0k. (interlocks)

12555 Operating deck st agingiair'AES. air storage YES higiiprcssure:airfbottles

VFS eontainnert1tslation valves

12562 Fudl handliig area Spent fuel storage racks

12701 PCS valve room PCS~isolation.valves/instrumentation'

12 703 PCS watcr- storage• 'ahk' PCS piping, levetland temperature

instrumentation.

I.

Tier 2 Material 337-62 Revision !18

"3. Design of Structures, Components,Equipment and Systems APIOO Design:Control Document

3.8 Design of Category I Structures

3;8.1 Concrete ContainmentThis subsection iS not applicable to the AP 1o0o.

3.8.2 Steel Containment

3.8.2.1 Description ofthe.Containmenfit

318,121.1 GeneralThis Subsection describes the structural design of the steel containment vessel and iIs parts and

appurtenances. The steel containment Vessel is'aniintegral part of the containt .ncn istetn whose

Function is described in:Seetion 6.2. It serves both to limit releases in the event ofan accident and

to provide the safety-relatedjultimiate heat sink..

The containment vessel is an ASME mhetil .cortaininent.'The infonnation contained in' thissubsection is based on'ihedesigih specificationi aid preliminary design and analyses of the vessel;

Final detailed analyses will be documented in the ASME Design Report.

The containment arrangement is indicated in the general arrangeiient figuresin Section I.2. The

portion of the'vessel above elevation 132,'-31 is surrounded by the shield building but is exposed

to ambient, oditions as part of the passive cooling flow path: A flexible watertight and airtight

seal is provid•edat elevation 132'-3" between the containment vessel and the shield building. The

portion of the vessel below elevation 132%-3" isfully enclosed within the shield buildihg.

Figure 3.8.2-1 Ishows the contairiment vessel outl IineicI udWing the plate configuration and crane

girder. It is a free-standing, cylindrical steel ves el witth Oel'lipsoidal tupper"and Iower'heads. (The

containment vessel has the following design chtfracteristics:

Diameter: 130feetHeight: 215 feet ,4inchesDesign Code: ASME III, DwMaterial: SA738, Grade B

Design Pressire: 59psigDesign Temnperature: .300F Deted: 2.

Design Extrnal Pressure:" _.7.p...id - -

The wall, thickness in most of the cylinder is 1:75 inches; The&wallthicknessofthe lowest course,

of he cylindrical shell is increased to 1.875 inkhes to proyide margin in the event of corrosion in

the'embedinent transition region. The thickness:of the heads is 1.625inches.]* The heads are

ellipsoidal with a major diameter of 130 feet and a height of 37 feet, 7.5 inches.

The containment vessel includesthe:shell, hoop stiffeners and:cranc girder equipment hatches,

personnel airlocks, penetration assemblies, and miscellaneous appurtenances and-attachments. The

design for external pressure is dependent on the spacing of the hoop stiffeners, and crane girder,

which are shownon Figure 3.82-1 [Thespacngbetweeneachpairofringsupports (thebottom

INRC Staff approval is requircd prior to implemsenting a change in this infonnation see DC D iatroiduction S.ctioa 3.5,

Tier 2Material 3,8-1 Revision 18

3. Design of Structures, Components,Equipment and Systems: APi000 Design Control Documient

*V Wind loads* Thermal loads,:

The seismic analysis performed envelopes all soil conditions Thctdob~il susiidae i.,as e qdivaleht •itit.aceele~ 1s Usin thic inisiui aeeerations Shown in Table 3.8.2-S.!J These

aieeeleradi lnslare th~e ifximum aucelratmns from the npuclear island stick modll on hard ,roqek-

The accelerations are shown in Rene3 a consertiv desian by compaisn againstthe accelerations inl the more .ecent nuclearm isltad an dyses-for all s1oilLoniditidii.•desetihedbin-.Axpendix 3G. Th&"seismic analysis fi the nuclear island is discussed in Section 3ý7 and

AIpcndix 3GR The'torsional moments which include the cffects of the eccentric masses, are

increased to account:for accidental torsion and arc evaluated in a separate; alculation,.

The r!esults of these load eases are: factored and combined, in ,accordance with tlo16ad.combinations identified in Table3.8.2•-. These results are used to evaluatethe general shell away

from local penetrations and attachments' thacis, for areas 'of the shell represented ,by theaxisymmetiic geom&ry The results forthepolar crane wheel loadsare also used toestablish local

shell stiffnesses for inclusion in the containmeti vessel stick model described in.

subsection 3.7.123. Theresults of tihe analyses andevaluati6ns,are included in the ,6ntainimntn

vessel design report.

Desigh of, the containment shell is primarily controlled by the initeirnal pressure of 59 psig. The,meridional and circterent for the infernal r' re shown in Fi

h v l n dstein can t.his . adcas .otc .ontitn-.. .air r-"ons l ee

hoob tfeio 7) "fild n ac t onthe eti n ad: Inressregtn ionsths i.,ime iatel siy innrosled.i

thtae eteral ore"re isreieved it ih ni .

isated trno u ambientaconditi ons oad ons ryao t.ivo. adV sci tdhatsriioe al Peresitrnl-A

Dressureis~used;Designn emess t•ur isuainloia s defina-tias a t inlUdt e giteralthandl ih:xti-ni pressurde•i~e:vic3Jmiqzi~:Syte 6 winitigatc.'Il Th is apart 6gfýLhe containmenet aiyi.l4cailnls te

sh'~tion 9.4.7.7 1 [Jo0n ýiti--p h xcn~ rsue rni~tjr isV oenit r , ole •OC and:

evates.v .relievedAa 'hisn dessgn l external res is combined with sa coincidenti400Fg r t m erati reIo w hi ceh c re;on- ii~ ds 'to a -I 8 .'57F m]e tal tem per at urae Ifotr th ge C V s hell no.t ...,

initiiatidd frmfi iiinbiecht condition~s. The n~ortiOns d tile CV shell that are below tile-external-

siirfeuei.ari::in oln_~df'o"the cold'outside air. conditions and resutlt in a Inct'A l tenperatu •e, of*:

_eig•tfiaircssuire is uis.d'i•n ioad 'cornbinatio!n$ that, include thennal loads and tire us d~fo

.eva luate Service Level A and Q stress limits. Trhese ex tern al 'oressu re c0•nditiofs'sare included in

.tile loadiny combl ations'ia' FabW 3:8.l

Major loadsthat i compressive stresses in containment vessel are in I and external

pressure • nd cue and bsesic loads. Each icsc ds and the evaluat of the reiIiscussed below.

Tier2Material 3.8-7

Revision 18

Tier.2Material 3.8-7 Revision 18

3. Design of Structures, Components,Equipment and Systems AP1OO0 DesigntControl Document

Notes:I irnýý , are per -NE

ts I'll onstrateheýe.hqf load redUc e effects 6 1 1 ''I'll I I, I 'I I I,

that the 14d is always.p sent Or occur im. ta ýWith the othe loads

Temperature.of vessel is 70'F.Temperature. distribution for nornial opcratjoninadvefteat-aeý,

5. Wind load for the construction lbad combination ishased o1ya,70 mph wind, Wind load Cor the Service Lev

load combination is analyzed a,ý, a reduction io external ijrýssure;

empera li:4 11 c4prespo -'ý nVefa -e-.4,49J444-.14 w w4a4A t 4#4ý 0 t,,K

Tier 2 Material 318-73 Revision 18

3. Design of.Strdctures, Components,Equipment and Systems AP1J00:9Design Control Document

Table 3.9-12 (Sheet 7 of 7),

LIST OF ASME CLASS 1, 2, AND 3 ACTIVE VALVES

I

((

Valve No. Dsrpi Functiont 0

Main Control Room Habitability: System (Cont.)

VLS-FLl-VO4IA Air Tank Safety Relief Valve A3

VES-PL-V041 B Air.Tnk Safety Relief Valve B 3

VES-:.PL-V044 Main Air Flow Path Isolation Valve 3

E -P'-V45 ,Ed'uct6r H:ow' l'Path tsolntion Valve 3

VES-PL-V0460 L tI'ditr Bypass i'sojhtikValve 3

'Containment Air Filtration System_

VFS-PL-V003 Containmnat PurgeInletýContaimnent Isolation Valve R

VFS-PL-VO04 ContaiolmentPurge InSetyContainment Isolation Valve 2

VW-LV08 Contaimen gslto ThermalReliefn Va2

e" n ....

,WiL•-VSB VanCoouers Return Con tainment Isolatio] 2

Liquid~~adwasteý Sy tDi_ _ __ _ _

'V lS I t055 Sum•p e Containmnt Isolation IRC 2

VWS-PL-V062 Suap Containm e nt Isolation ORCh 2

VWS-PL-V058 Containment Isolation ThrlRelef Valve 2

VWS-PL-V082 Raco CoolantDrn Containnent Isolation IRC 2

VWS-PL-V085 R Fan Ctoolers S rn Gstainmett Isolation'. 2

WL-Lqu V0wst IA yChemiaanVoueCnrlSseCmptettoSp3

WLS-PL-V062 I ass Core Cooling System A somatio n to SumC 2'WS,'ft-V086 Sup Contaimnent Isolation ThrmlReleC av 2

WLS-PTL-V05F8 61esReu Containment I solation Rle av 2

WLS-PL-V067 FC a CoreCoola ing stem Ba Compatmment Itsoo Sum 2WLS-PL7V0-58 Sump.Coat ri.Tn a Containment Isolation ORC 2

WLSTPL-V071A Ghemical andSVolume Control System Conpartment ItolSumip 3WLS-PL-V067B Reassioe CoreColanring TanyGse AContiparment Isltion Sump 2

WLS-PL-V076C Reassioe CoreColan ring TanGste Compairtmnct Isltion Sump 3

WLS-PL-V072IA Chemical and Volur e Control Systemtem A Compartment to Sump 3

WLS-PL-V072C Passive Core Cooling System A Compartment to Sump 3

WLS-PL-V072C Passive Core Cooling System B Com1partment to'Sump 3

Note:a. Function: 1 - Reactor coolant system pressure boundary

2 - Containment isolation3 - Accident mitigation4- Safe shutdown

Tier 2 Material 319124 ýRevisio n'18

3. Design of Structures, Components,Equipment and Systems AP1000:Design Control D:ocument'

Table, 3.9-1.6 (SheetV o~f~f4)

VALVE INSERVICETEST REQU;IRM IENTS

Valve Taig Vall•Acita~ttor Safecy-Rl~eated . ASME;Ctaas• .

Number Description") " Tlyp Misslno• Safety Funutions S. IST Caitrgory Inscrice TestingType and FIreqauctyr -ST Notes

- " "• ...... ,',,,• ý,'•. ....q A2• . r. i,J q,w k's • " .

VFS-PL-j46 Edtictor Byrass Isido Valve Martutl .'tnia' Clos. Atiivc Cls. Evecise Full St'rot 0rears

VFS-PL-V003 Containment Purge Inlet Containment lsolation'Valvc RemoteAO Maintain Close. Aelive-to-Fsiled Class 2 RetiaBe Position Indication.Exercise/2 Years 27.31

Bsltrl~y Tranfer~ose oiiairment Isolation UateetA Contitainmentttlasi LeaT'Safety Seat Leaageae, -•cie Full Stroke/Qearterly

Remot Pesitioan ialn t!1tsý i-t(ed' *Operability Test

VFS-L•'VO04 Containment PFrge Inlet Contain'mit Isolation VMtle Remti AO Maintain Clos.e At'tive-to-Failed "Cl ss2 Remote Posutin Indication, Exereisc2.Years 27.31

-"bustrl~. Trainser Close Contaimincit Isolation Casrgoyky Conta•nment Isolation Lak TossSafety SeatLeakage Ex c Full Strokc)YQsartcly

Remote Position iýail 71,f tAcrri .

OPerability Test

VltS-Pl'VtOS: ConssairmentlIsolatioti Test Connsrtioit Manalh Maintain Close Ctn~iaiinenl isolation ' Category A Containmen Isolaition LeaksTtti 27

Safety Seat Lcak~g& :-

VFS-PLrV009 Containment Purge Discharge Containment Isolation Vnalve R"61ot AO Maintain Close Actitc-toeFailed.. Class 2 . Remote Position nliditatien, EaitcisYe2 ya27,31

BFtPorily,0 T sTran ,Roe• sfe Cloe iContainmment Islation Cate-igoy A Cots imic I soiti " .L c '2 TestSafety Seat Leakage . s Full cQ cry

Remnote Position ~ALs ifa Ts. Orrarteel's

VPS-PL-VOIo' Containment Purge Discharge onitaininentloututios Valve Remtote AO .Maintain Close Active to-Failed, Class 2 Rensos Position Inrdseautin. Eserc si~c2 Yeses

Butterfl y Tiransfer'Close Contasontent Isolation Category A Containmnot Isolation Leak Test... ..... ý ...... ..... Safety Secat Leaksc Ie xcrwci Fall Sýtokes Quasuerly

Re~ilia•: Pssiin;• Q.Oprabinlty Test . ...

.a.ct . rontetaisr, O, 'eraniFl t .w

V 5.P5. g-A;Q Vahcugrn Rtelief Casominneat Isrition rs V Salve A- IEC k -Mtlrimatui, 6l''t 39isels2 Crtiis sl rtrsi a'f

T stCnv Cns~gp lts. Crie-rA : EcjL-Ac Full ýIS kelP fueIin .% Stirtdo i -J:

T asc- 0 Safs art, S, rt: Mscrtoui lJýt livf"t2Yars

Tier2 Mterll Rvisin A

Tier 2 NiateililRevis ion 18

3.; Design of Structures, Components,rEquipment and Systems APt000 Design C6ntrol Documenat

Pbl 3.194IS(Shteell it

.V't). INSERVICE TEST., EQ IRENIENTS

Number: Desvription4• '.yp•e Missions, ýafiy'oUnctions l•-. , .,STrCategory n*rc etg'•p n rqec ISTNotes"

VWSPL-V062 FahCumlen Supply Consaiitoie Isolation Check Maintain bClose Active Class 2 ?oniammutIsolatiOn Leak Test 27.26"Trasfer Close Contiaiari- nt lsolti'l CategnrAC Cl 'E1,enisoturat , " " v

VWSPL.-VO2O Fanti o•lere Return Const iiaeosflsolation Thenalr. Relie fValve ::Relief: M.iu.isain Close .Active AC: C ont3ain .sen0t Isolation• Leak Test2 Years ,.27

Nmfr nfOpens Sae-TerLek

VWS.PL-VO0S2 Fan Coolers Return Containment Isolation Remote AO MaiMatain Close Acive-to-Failcd Class 2 RCmote Position Indication.-Exeisel2 Years 27,28.31

Buutrlly Transfer Close co tin Isrlatich Caitgoy A Containment Iolation Leak TeLrSafety Seat Leaka.e Exer-ise Full StLrkciQU.arte ly

R oc itailvafTti erst"

VWS-PL-V086 Fan Coolers Return Contaitsimcnt lsolation ReCihoteAO. Maintain Cloe :Activeto-Failed Class 2. Ceonitainion Indication, Exereit.est ara 27,28.31SBPtterily. Transfer Close .Containment Isolation Category A Contaient Isolaion Leak Teat.....

iS~~et~ eakatttig Exercise Full SieokeiQuaeiteel

.Operabilisy Tesi L

WLS-PL-VO55 Somp Discharge Containment Isolation IRC RemoteAOPlsg Maint i. Close .Activc-to-Failcd. Class 2 Remote Positioan ndieationExerci--Years: . 27,& 31

Trtfeetra Close Corit'aintieni Isolution Category A. Containment. Isolation Leak TestSafcty Seat L eakage ,. . Exercise Full. Steoke•itaeey OrpWrtion

• Rensul Positioni V. I. steiesU;Ovandv Oi• ition•Opoeability Test

WLS-PL-VO57 SFanp Discharge Containme nt Is. ORC. Reniote AO Maintain Close Activeto-Failed , Class 2 Remote Position ritdieation, Earcisei2 Yeses .278, 31

• PLUG - Tran.iferiClose Containment Isolation Category A Contoiitnmst Isolation Leak TestSafety Seat Leakage Exercise Full Strk urtrly OprtinRemote Position " ai sfai Te,-lct el Oestýtis .

Opcrability Test

WLS-PL-V055 Suonp Containment Isolation ThInoml Relief ValvC Relief Maintain Close ActiFe AC Continemoet IsolatimoLeak Teati2 Years' . 27Transfer'Close :Consai-• e• Isolastioiin ....

Transfer Open Safety.Seat Leakage Exercise ___________________________ ___Tierot 2oito hdAI1-1 5t'i5 3.9-01- 3Rvsot

I

Tier 2 Mlaterial3.9w183 Revision:18

3. Design of Structures, Components,Equipment and Systemns

AMlON Design Control Document

.38. The execrise stroke test for she.VES.pressurer regtlatirsg valvcs willconsias of 3t pressure dropseost across the yalve isaing ahe,

dosessatue test cosineclies. This meth~od ensurci adequate testing of the~valves.

\'y' Ti. foraisl h ~amtl~s tjti e aeaelt' VSx ii~~l ~ -S3/~ si

SU 55 t ie55 ete fytt~iisestlwrsrts itsss se 55 te' d5 ddriefltik

vi4 se VS ra s' s alia ale-sQg~njthse3i~esc sec aisisestil 5sal 'testts tutsvamatall~

Tier 2 Meterisil

3.9-191 RevisIon 18

Tier 2 Material19.9191 Reyision IS

3. Design of.Structures, Components,Equipment and Systems AP1 900 Design Control Document:

Table3.1 1-i (Sheet 31 of 5O1)

ENVIRONMENTALLY QUALIFIED ELECTRICAL AND MECHIANICAL EQUIPMENT-

nvr Operating

Envlr. Time QualificationAf1000 Zone Function Re'quired: Program:

Description Tag No. (Note 2) (Note. '1) (Note 5) (Note 6)

uRelief Containment Isolation, VFSPL-VWOA 7 .SF 24 hri, M.VailveA - ORG,'Limiit Switch. VFS-PL-v800A-L 7 PAMS I V tE

"M0tob0eirOttr VFS-PL-V800A\,M ESI 24 hr I E

]Vaihiij Relief Containment Isolatio -VFSPI-V800B 7 ESF, -24 hr MVal]Ve.B, ORC.Limit Switch VFS-PL-V801OB-L. 7 11.AMS r E

• Mot0O0erOator1 VFS-PL-.V 0OB-M 7 ESF 24 hr .

L%'... euUtn Rlief Containineiit isolation VFSI PL-VSO3A I ES . 5 min M

Check Valve A - IRC ....

lVacuum Reiici'Corntainincntlsi)lation VFS-PL-V803B I ESF 5 m.

Check Valve B - IlCFan .CoolerSupply Isolation VWS-PL-V058 2 ESF 5 mim, M S

ýLimit Switch VWS-PL-vOS8-L 2 PAMS: 2 wks El

Solenoid Valve VWS-PL-V058-S ý2 ESE 5 .min E.

Fan Cooler Supply Isolation VWS-PL-V062 1 IS, 5 min M*

VWS Containment Isolaijon Relief VWS-PL-V080 I ESF 24 hr M,**

Fan Cooler Return isolation VWS-PL-V082 I ESF 5 rmin M *

Limit Switch VWS-PL-V082-L I PAMS. I yrý E

Solenoid Valve: VWS-PL-V082-S I ESF 5 mm i *

Fan Cooler Return Isolation VWS-PL-V086 2 ESF, mim M S

Limit Switch VWS-PL-V086-L 2 PAMS: 2 Wks E

Solenoid Valve VWS-PL-V086-S 2 ESF :5 min mE

Sump Containment Isolation IRC WLS-PL-VO55 I ESF 5min M.*

Limit Switch WLS-PL-V055-L I PAMS I yr E *

Solenoid Valve WLS-PL-V055-SI I ESF 5rain E '

Sump Containment lsolation'ORC WLS-PL-V057 7 ESF 5 min S i*

Limit Switch WLS-PL-V057-L 7 PAMS 2 wks E**

Solenoid Valve WLS-PL-V057-SI 7 ESF 5 main E**

WLS Containment Isolation Relief WLS-PL-V058 I ESF 24 hr. M **

RCDT Gas Containment Isolation WLS-PL-V067 I ESF 5.min M;*

Limit Switch WLS-PL-V067-L I PAMS I yr E-*

Solenoid Valve WLS-PL-V067-S 1 ESF. 5 thin E *

RCDT Gas Containment Isolation WLS-PL-V068 7 ESF 5 min M'S **

Limit Switch WLS-PL-V068-L 7 PAMS .2 wks E **

Solenoid Valve WLS-PL-V068-S 7 ESE 5 min .E **

CVS ToSump WLS-PL-V071 A I ESF 2 wks M* _

PXS A To Sump WLS-PL-V071 B I ESF 2 wks M *

Tier 2 Material 3.11-36

Revision 18

Tier 2 Material 3.11-36 Reirisio n 18

.3. Design of Structures, Components,,Equipment 'and. Systems APIO00 Design Control Document

'Table 3L6-2 (Sheet 26 of 28)

LIST OF POTENTIAL HIGH FREQUENCY SENSITIVE

AP1000 SAFETY-RLATED ELECTRIICAL ANDELECTRO MECHANICAL EQUIPMENT

AP1OOO

Description Tag Number

Containment:Purge Discharge.Isblation

Limit Switch VFS-PL-V009-L

Solenoid Valve VFS-lPL-V009-S t

Containment Purge.Discharge Isolation

Limit Switch VFS:PL-V010-L

Solenoid Valve VFS-.PL-V.O 10-S I

ivacuum Relief ContaimnentI.lati6i Valve A - ORCG

Limnit Switch VFS-PL-VSOOA-L

Motor Operator VFS-PL-V800A-MNlacuunI Relief Contaiinen'iit :Isolition ValveB3- ORG•

Limit'Sitcth, VFS-PL-V80013-L

MotorOperator VFS-PLV001B-MI

Fan Cooler Supply .solation

Limit Switch VWSPLMV058-L

Solenoid'Valve VWS-PL-V058-S

Fan CoolerReturn Isolation

Limit Switch VWS-PL-V082-L

Solenoid Valve VWSTL-V082-S

Fan Cooler Return 1solation

Limit Switch VWS-PL-V086-L

Solenoid. Valve VWS-PL-V086-S

Sump Containment Isolation IRC

Limit Switch WLS-PL-V055-L

Solenoid Valve WLS-PL-V055-S1


3. Design ofStiructures,Coniponents,Equipment and Systems AP!000 Design Control Document

Table 31.6-3 (Slieet 1 f of 32)

LISTJDF AP!000 SAFETY-RELATED ELEECTRICAL

'AND MECHANICAL EQUIPMENT NOT fHIGTI FREQUENCY SENSITIVE

AP1000

Description TagNuimiber Comment

Air Tank ReliefA VES-PL V1040A 2

Air Ta Relief B VES-PL-V04B0 2

Air Tank Relief:A VES-PL-V041A .2

Air Tank Relief B VES-PL-V04•1B 2

Mza in Air Fl1oyw Path: Isolation Valve VES .PLNV044 2

-Containment Purge Inlet Isolation WVS-INPL003 2

coriiainmnentfPurge, Inlet Isolation VFS-PLNV004 2:

C6ntainment.Purge Discharge Isolation VFS-PL-V009 2

ContainmnfitPurge DisthargeIlsolatio"n VFS-PL.VQO~t 2'

Vacuuii ReliefCdntainment IsolAtion Valve A -ORC VFS-PL-VS00A 2_

.VacuutA Relief Containment Is61ati6n valve B - ORC VF.S-PI-Sb8l0 2'

lVacutni Relief Containment Isolation Check Vialve A - IRC VFS-PL-V803A .2

Vaum elief! Conta'inment lsola~tidn.Clieck ½hlve B - I RC V •FS-PLVOl3 20B

Fan COole I Supply Isolation. VWS-PLNV058 2

Fan Cooler'"Supply Isolation VWS-PL-V062 2

VWS Containment isolation Relief. VWS-PL-VO80 2

Fan Cooler Return Isolation VWS-PL-V082 2

Fan Cooler;ReturnIsolation VWS-PL-VO86 2

Sump Containment Isolation :IRC WLS-PL-\i055 2

Sump Containment Isolation ORC WLS-PL-V057 2

WLS Containment Isolation Relief WLS-PLNV058 2

RCDT Gas Containment Isolation WLS-PL-V067 2

RCDT Gas Containment Isolation WLS-PL-V068 2

CVS To Sump WLS-PL-V071 A 2

PXSATo Sump WLSTPL-V071 B 2

.Tier !2Material 31,50 Revision 18

6.• Engine~ered Sa fety Feattres AP1000.Delsign Control Documenti6. Engineered Safety Features APlOOO Design Control Document

For the LOCA, events, tWo double-ended guillotine reactor coolant: system pipe breaks are

.analIYzed. The breaks are postulated-to occur in.:either a hot or a cold legof the reactor-coolant

System. The hot leg break results in the highest blowdown peak:Jpressure..The cold leg breakresults in thehigher post-blowdown peak pressure, The cold legibreak analysis includes the long

termn contribution to containment pressurefroni the sources of storedenergy, such as the steam

generators. The LOCAmass and energy'releases described in subsection 6,21.A3 aremused for thesecalculations..

Fo.rthe MSLB eventia- representatiVe pipe.break spectrum is analyzed.. Various break sizes and

power.levels are-•fialyzed with the WGOTHIC-code. The MSLB mass, and energy releasesdescribed in subsection-6.2.1.4 are used for these calculations.

The results of the LOCA, andMSLB postulated accidents are -provided in Table 6.2.1.1-1. A

comparison of the cohtainment:integrity acceptance criteria to General Design Criteria is provided.in Table 6.2.1 .1-3.

The containmentp ressuie response--for the peak pressure steam line break case-is provided in

Figure 6.2.1.1-1. The containment temperature response for the peak temperature steam line break

case-,is provided in Figure,6.2.1.1-2.

The passive internal containment heat sink-data, used in the WGOTHICa an a lyses is presented in

Reference 20, Secti6n, 13.,.Data for both ýmetallic andconcrete heat sinks are presented. The

,containment pressure ý.nd: te6perature respohses to a double-enfded cold leg guillotine are

presented in Figures 612.1.1-5 .and 6.21.11-6: for the 24 hour portion of the transient and

Figures 6.2.11 27. and 6.-2..1 8.- for the 72 hour transient. A separate analysis for the double-ended

coldleg guillotine LOCA event, without considering heat conduction .from the dry to wet, section,

results in somewhat higher containment pressure in the long term, but still below 50 percent of

design pressure at 24 hours. This separate analysis confirms the assumption in

subsection 15.6.5.3.3 of reducingthe containment leakage to half its design value at 24,hours. The

containment pressure and temperature response to:a double-ended hot leg guillotine break-are

presented in Figures 6.2.1.1-9. and 6.2.1.1-10. The physical -properties of the materials

correspondingt the. heatsirik mformation are presented in Table 6.2.1.1-8.

The instrumentation provided ii4%doutside containment to monitor and record the containment,

pressure and the instrumentatiotjrovided inside containment to monitor and record temperature

is-arefiound in Section 7.5.

6.21.1.4 Extern ss=ure . sis

vcai essel. Th is event la stoan creiblt-i-eduto vin ve thes s interati conainent he p ntalto. lo s titI eacdrcola s stei and thrciv o oenstuse Vevuie in a te erte 0 edctiwihn dh conainetada copnigpesr euto.Eautosaepromd

determi e temxmmetra rsuet hc h otimn ab ujce itdeeopb llwhe1 oeaine reduear bin d- tsy Ills cntu'ain have61 o the -o hntial t e

Tier -2 Material 6.2-3 Revision 18

.6. Engineered Safety Features AP1000 Design Control Document

Til b6uniding scenario results froin a postulated.loss of ac power sources (statiotiblickoUt). This.

ýscenario, alongiwith bounding assiinpition• andginitiilconditions, will be used to deterutiie the

,maximum. cxpected external pressure transient. The csontainiii'V pi-dssure resp&nse from .the

:botunding transient will be used for sizing the containment vacuumfi relif'fsystemu:"iid;vil1 itiify

Athat the vacuum relief system is capabIe of mitigating the most boindfing external pressure

ýThe:,valuationl asstimed a 25TF ambibkit temoera'ture with no-oUtside, wind blo•ig tfo, niimize

the containment internal .temperatrareand eQ sni contduiniriient vssel shell temperatures,.The iniiti'al internal Containmcnt temperature is inlu ilibrium -at thC maxinium allowajj ble6valbeqof

1200K A 25° outside temperature coupled with a 120WF internal tIinperature ee'dws, the-

maximum allowable ni tll/exteral temp-atUredifferentijaldepictediii in the API 000 TechnicalSpecifidation s (LC.. 3.6.10), However, this is conservative and bounding, as described below,Pre-tiansient euilibrnuni iinalvses were pefolrmed to deteronine the Contain"ment eouilibrium

values for internal tcmperitcire and-6ntiliinent shell interna ILIexteraliemperatures to use to

inie d nsAlu the conditionslo uthe analysiS. Oncthe 1 puilibri-niII tedperatitWe values wevre

detemniihed, the boidini ilysiS, v.s Ierformed with coritainment iinternal relative humfidity setto 100 percenut This Crc iteIs thý largeyust potential for external pressure as this maximizes the partial

presure. of steam vaporvapor concentration, nad correspbiding condenisation rate. These

parameters represent the domrinant effectforlthe determination of th bounding externalpiessurescenario. ,A negative.0.2 psi: initial lontainment pressure is used for this evaluation. At tranSient

ihiitiaiin, the-cxteIal wind is -assumed to instantaneously accelerate :t'o 48 iptih (24:8 ,t/s inannuuti'siser region) and the extenal temperature is assumedi to begin decreasim-i basedt.o•tnhe

form ofa chopped cosine witha minimum value of 59F and bfriodic ity of 24 hourst iT s ,alsoonxservatively a ssumedthat no air-leakage occurs into the containment duirinnithe trahsienit. The

key assumptions for conta innient :initialconditions and containmeit transicnt conditions arielistedin Table 62.1L. L-9.4-e evaluations are perffnned Withi the a1 umptio of. • 40 0F. an~bient

tem.peratur with a steady 418 m-1ph ,.,id b.lo ., te. . a. . , ^ng ,h contniinent vesel.

With, no, aetive cooling in, use the initial4 intom'l m~ntumcn cos eense~ l

palculWate to4 be 69WF, ceateqing the largest -A5 Ab; tepr fr d,- ffrnnioma4mz the heatremloval rate through the containment ve'se! A w nga&.iOe p 0lp:ig in tki cenainrncntlpressureiso tsedfoihis evauaton. A e-11e1at .c I.- lnu iniia ctunpment relativem huidity o0.i4sdfrhis v, ain ,,o • . .... .+. ;.;: r• ... ;........ .. *..... -148..: ... r nn

ptveent-is used to lpredue te fle--e.t -fcue ix EK'intaimm ut o<ae Suic dUe to11 th S lo f'Steaffparti"l r b -n 'x o t i also conservatively-ass-mecl that no air ieakaie occurs into

the "containment during the hn 41,

Negative preps*iw-is-eva d b~ .,ui n aniavfstcu t4o the actve carimn

.ooli..g. For APIO• ss, the.p a onhiitarnteoolt g systcth rovidos heat ýemevai from thecantainhpent shello t renrnamnt ti ..... I . ir"u.ation aiOnw ... di, .,- ,iora", -. at-ioi.

Since the, passive containn, et coooixg-sysiem .... is r -ati ,l .. rm,(mi.imu .. 406 ).eeupae~~eheutike-~xexpe~iui atutin f thi ~c euti ii mmtmeten~orniefi

pre1s4ee and --adftnti h containmen Wia, ist e edibtle six

the API204, ewntaiensrr i .initicaxnt ku a ope tn to ahign the ,;YrtcmInadve"tent acuaio of the -otim nt fan ; - r tc liitn o_ nt L--m xt-,iaol pressure at

e&Ite-ndin4•


Revision 18

Tier 2Material 6.2-4 Revision, 18

6. Engineered Safety Features AP1000 Design Control Document

Thle; externial'p'ressure Vvaluations are performed using WGOTHIC with conservatively low

,estimates: of the :containment heat lOads and conservatively high heat removal through the

containment vessel consistent, with the liniiting assumptions stated: above. Results of t-heseevaluations ar6eusbd to develop thegmaximumndepressurization rate 6f c6'ntainment for use in'

sizing tihe4active.safety grade contaihuiefhtV,&•unctu 'rlief system. Figure 6.2. .1-11 :shows that the:

performanceiof the vacuum relief system is suffi'ient to mitigate thaemaximu 1un-xp ctedeiternal

:aftci- the inital, dcrea~ 14an F tre IS 9ffiint time fer tptr~eintPee h otimn

mnitigate th rssure redueticni 'y openingeth setof ntaiiineat Vetlý i uryiolto

.'lcwihae powre b~t batteiies.

6.2.1.2 Containment Subcompartments

6.2.1.2.1 Design Basis

Subco"mpa tments~within containment aredesigned to withstand thestransient differential pressures

of a postulited pipe break. These subcop0irtinfts are vented so that differential pressures remain

within structurallimits..The subcompartmentt walls are challengeddby the differential pressures

resulting, from.a break in a'high energy.line. Therefore, abhigh: energy line is postulated, with a

break size chosen consistent, with lth.e position presented in section 3.6, for analyzing the

maximum differential pressures-across Isubcompartment-walls.

Section 3.6 describesthe applicationof the mechanistic pipe break criteria, commonly referred to

as leak-before-break- (LBB), to the, evaluation of pipe ruptures. This eliminates the need to

consider the dynamic effects of postulated pipe.breaks forpipes.which qualify for LBB. However,the analyses. of contaimnent pressure and temperature, emergencycore cooling, and environmental

qualification'of equipment are basedon doublev-ended guillotine (DEG) reactor coolant system

breaks and through-wall cracks.

The pressurizer diameterand hei•ht were changed after the original subcompatmnent analysis was

performed., The subcompartment analysis has been evaluated for'the~changes in the~pressurizer.

The resultsbof this evaluation have shown tlihat.there is a small impact oni the analysis and the

conclusions remain valid. The output provided in this sectiohi for theanalysis is representative of

the transiefit phienomenon (Reference 34).

6.2.1.2.1.1 Summary of.Subcompartment Pipe: Break Analyses

Each subcompartment is analyzed for effects of differential pressures resulting from the break of

the most- limiting line in the subcompartment which has not been evaluated for LBB.

The subcompartment analysis demonstrates that the wall differential pressures resulting from the

most limiting high energy line break within the subcompartments'are within the design capability.

Tier:2Material 6.2-5. Revision 18

6. Engineered .Safety Features AP1000 Design Control Document

Table:6.2.1.1-9

CONTAINMENT EXTERNAL PRESSURE ANALYSIS MAJORASSUMPTIONS

Pre-Transieut-Conditions

Parameiter Value

Containment External Temperature 250F

Containment Wind .Speed Natural c6nVection

Containment Internal Temperaturel F20 0F

Co.ntaiirnent Initial Humidity 50%

IRWST Temperature 1200 F

•Coxitainment intemal Pressure 143i ia

Transient and Post-Transient Conditions

ContainmentExternal Tehperature. Chop•ed cosinle rampi to6,56F,:in 12 hours

Containmen~t Hunidity 100%

Contaimenit Wind Speed Forced convection at 24.8 ftVs in theriser region

Conitainmefit -l'eat Rate 0 decay heat, sensible-heat-addition ~-1/5, definýheatrate.attransient time t= 0 second

Tier 2 Material .6.2-58

Revision 18

Tierl2 Material 6.2-58 .Revision 18

6. Enginieered. Safety Features' APil000 Design Control Document,

Vacuum Relief-Vacuum Relief

14.6&

14.4LL0

D 14,CLE

13.8

0) 13.6E

.13.4.0

1.3.2

130 2000 4000 6000 8000 10000 12000

Time (sec)

Figure 6.2.1. 1-11

API 000 Desipn External Pressure AnalysisContainment Pressure ys. Time

'rier 2 Material .6.2-145

Revision 18

Tier 2 Material ý6.2-1415 :Revision 18

.6. Engineered Safety FeaturesAPIOOO Desian Control Document

Tabl6o1.3-1 (Shcct3 ofI 4)

CONTAINMNENT MECHIANICAL PENETRATIONS AND ISOLATION VALVES

syrro ir.e 60. .4S. "Mc, Vr . II... DCD S.. , . r... , d 6........ N~eQ %- W rie

VFS l~atra 'Muo roly in NO .OnV No9.4 CI-• T H!.R, Alt F , d

"tN Nq C.3.4.5 Air Fr rd

i ~F~a

11 Fe ,k rN.P . .. .... ....C-' 4. .3 , .... ., 'o rn

F•. 4 n in .9,7 0-0. C • 4 C-,4.5 Air F.... -rd

9/ nmo oe nnn ro e n N.. WLS-PL-V06S iS1I.L C-C-C T d" Ail

WILS-PL-vo$$cPS.;A

SP/ARE NA. N. PQ0 -25 C-C-C YXA H:A

SPARE / . 4 C-C-C A B Air fc,-040

SPRNA No P42. Ail Pore-e

CNIS M'Ll q.Proro h-. 2/A 140 t NSAIY-TQl 92 5 . c .-C4C. Nr NA BAir - Pror

S~i. or inNVA N. CS-Y-YO2 25CCC.NABAi

P/no..0n hard, N/A NO CNS.M'SYSSW t,.5 =I-CC N-n Air rod

Por~~oo lol, SA -.. NS.,1Y-O4 2.5C-(A N~m NA BAir Fo-erd

Tier 2Nleteriat

62-107 ReViSion 18

Tirr 2 Ma3terial62-107 Revislon Is

•6. Engineered. Safety FeaturesAPlOoOD•sipn •ntral D•enm•ni

6. Eginered afet FeauresAPfl0lf b~eisign Cnontrol DOtsumentr

Table 62.3-1 (Sheet 4,of4)

CONTAINMENT MECHANICALýPENETRAT.iNSANOD IsoLATION VALVES

Explanation offieading and Acronyms for Tablte 6.2.3-1

System:

Containment Penetration:

Line:Flow:Closed Sys IRC:

Isolation Device:Valv/Halotch ID:

Subsection Containing Figure:Position N-S-A:

Signal;

Fluid system penetrating containment

These fields refer to the penetration itself

Fluid system lineDirection of flow in or out ofcontainmcntClosed system inside contaimoent as defined in DCD Section 6.2.3.1.1

These fields refer to the isolation daviecs foat a given penetration

Identifieation number on P&ID orsystem figure

ý! njtniusfl tth atpi to.n t outboardl risstam"nt~n isolatvis salve. feet

Safety analysis report containing the system P&ID or figure

Deoice position for N (normal operation)

S (shutdown)A (post-accident)Dvice closure signal

MS: Main steam line isolationLSL: Low steam line pressureMF: Main foedwater isolationLTC: Low T'PPIIR: Passive residual heat removal actuation

T": Containment isolationS: Surety injection signalIIR: light containment radiationDAS: Diverse actiation system signal

PL2: Iligh 2 pressurizer level signal

S+PLI: Safety injection signal plus high I pressurioir teel

SGL: Hligh steam generator level

Closure Time:Required valve closure stroko time

§sW: Industry standard for valve type L< 60 seconds)

N/A: Not Applicable

Test: These fields rcfer to the penctration testing requirements

Type: Requirid test type

A: lntegratd Lo RualtTcstB: Local Leak Rate Tst- petnetration,C: Lal Leak Rare Test - fluid systems

Note: See notesn belowMedium: Test fluid on valve scatDirection: Pressurization direction

Forswad: .Iigh pressure on containment sido

Reverse: liighpressureonoutboard side ,

Notes-I1 Containment leak rate tests are designated Type A. B, or C according to IOCFR50, Appendix 1.

2. The secondary side of the steam generator, it•luding main sieam, feedwaer. strtup feedwater, blowdows and sampling piping from the steam generators to0thoentaioment peaetration, is considred an extmsion of •tcoatiinmcnanC Thei€ systems, ace not pa of the reactor

coolant pre ssure boundary and do not open directly to the containment atmosphere durinig post-accidort conditions:. During Type A tests, the seondary side ofthe steam generators is venid.to he atmosphere out ide eotttainmntto ensure ilia.It full test diffctisial pressuesi,

applied to this boundary.3. The cenwal chilled water sy-stCem remains water-filled and operational during the Type A tcst in orded ti maistain:stablc containiment atoosphcrie conditions.

4. The containmenis lC.ajion valves is enetration ato 4 duriitg the Type A test to facilitatestitg. Their leak futs arc measured separately

I

7, Refer to ThCD Table 15.0-4b " r PORV block vsac closure time.

'T elves rei a1 t it

'~l ~f~~/3o tu t ststrsrv ~s-int t.tetnrtit i cr'c. ciAqt reatt LIi irlt~v S

Tier 2 Material6.2-109 Revision 18

,6. Engineered Safety Features EAP1000 Design Control Document

main contro :room. Containment -isolation valves requiring isolation close automatically on receipt

of a safeguards actuation signal.

Contaixment isolation valvesjthat are,.equqipped with power Operators and are automatically

actuated may alsodbe controlled individually from -the: main-.control rTo0om. Also, in the case of

certain. valves with actuators (for cxample, samplingcontainment isolation valves), a manual.override of an automatic isolation signal is installed! to perinit manual control of-the. associated

valve. For allM alves exept the vacuum relief containment isolation,- alvcesLtheoverride control

function can beperfonned only subsequentto resetting of the actuation signal. That is, deliberate

manual action ..is required to change the position, ofcontainmiieit isolation valves in addition-to

resetting the original actuation signal. Resetting ofthe actuation signaldoes not cause-':any valve to

changeposition. The design does not allow.ganged reopenhigof the containment isolation valves.

Reopening :of the isolation valves is performed on: a valve-by-valve basis, or. on a line-by-line

basis. Safeguards actuation signals.take precedence over manual overrides of other isolation

signals. For- example, a containment isolation.signal causes islation valveclosure eventhough thehigh containment radiation signal is being overridden by ih&,0operator. Containment isolation

valves with power operators are provided With open/closed indication, which is displayed in the

:mainwcontrol room. The valvemechanism also provides a local mechanical indication of valve

position.

For the vacuum rielief containmPeit is6lation:valves, a containment vacuum .relief siznalt :ill

override the~iso1ation signal.

Power supplies and'control functions iecessary for containment isolation are Class. 1 E, as

described in Chapters .7 and 8.

6.2.4 Containment Hydrogen Control System

The containment hydrogen control system is provided to.limit the hydrogen.c6neentration in the

containment so that containment integrity is not endangered.

Following a severe accident, it is assumed that 100 percent of the fuel cladding reactswith water.

Although hydrogen production due to radiolysis and corrosion occurs, the cladding reaction with.

water dominates the production of hydrogen for this case. The hydrogen generation from the

zirconium-steam reaction could be sufficiently rapid that it may not :be possible to .prevent the

hydrogen concentration in the containment.from exceeding the lower flammability liimit. The

function of the containment hydrogen control system for. this case is to promote.hydrogen burning

soon after the lower flammability limnit is reached in the containment. Initiation of hydrogen

burning at the lower level of hydrogen flammability prevents accidental hydrogen bum initiation

at high hydrogen concentration levels and thus provides confidence that containment integrity can

be maintained during hydrogen bums. and that safety-related equipment can continue to operate

during and after the bums. /

The containment hydrogen control system serves the following functions:

Hydrogen concentration monitoring

Tiers2 Material 6.2-38 •Revision• 18

7. Instrumentation and Controls API000 Design Control Document

(MAIN0ANUAL TRIP(MNCONTROL B0ARO)

REACTOR TRIP(1M8 CONTROLS)

(NOTE 5)

8000 TRIP(APP PUs To2) .

HIGH-2

CONIANMENRT RNS SAECGUARDS 8100< CON180RADIOACITY (NOTE 3) MJANUA•. 1•CTUA10N FROU0ONTRMl BOARD

HWGH--2 CONTROL ROO MANUALAIR SUPPLY RADIOACITTAY 80C020AlON R04.N

CONTROL 8O088

LO SPENT FUJ0

A a C

NOTES:

1. M MOMENTARY CONTRO.2 OPERATING 0THERCONTROL WIL. ACITUAI ALL APPUJCA& DIMS1014S.

2. COMPONENTS ARE ALL INOIVIDUAY 5 IN (LS1O00), 501HAT LOSS O 1HE ACTUA.TON SIGNA•Ll.. NOT CAUSE THESECOUPOENTS TO RETURN TO THE CONDITIMON 8El PRIOR TO 1HEADVENT OF ONE 0CTUA080N SIGNA0

3. OEPARA11 MORMENTARY C00T180.. 08E FOR EACH APPUCAeLE

4. DIVSIONS A AND 8 ONLY.

S. T1O MOMENTARY CONTROL OPERATING 18TH CONTR0088082. CAUSE 1HE REACTOR TRIP FUNC10ON TO 8E ACTUA0EDIN EACH OF 0 E FOUR DIVISONS.

RNS CONTAINMENT 8SI0,A10I(APP PIS A 11g)

Figure 7.2-I (Sheet 13 of'201.)

Functional DiagramContainment and Other Protection

Tier 2 Material

7.2-52 Revision 18


7. Instrumentation and Controls APIOO Design Control Document

LOW-2 CONTAINMENT CONTAINMENT AIR INSIDE.CONTAINMENT PURGEPRESSURE FILTRATION SYSTEM EXHAUST ISOLATION VALVE

ISOLATION CLOSED(APP PMS JA 113)

NOTES:

1. TWO MOMENTARY CONTROLS. OPERATING EITHER CONTROL PILLACTUATE ALL APPUCABLE .DIVISONS.

2. COMPONENTS ARE ALL INDIVIDUALLY SEALED IN (LATCHED), SOTHAT LOSS OF THE ACTUATION SIGNAL VULL NOT CAUSE THESECOMPONENTS TO RETURN TO THE CONDITION HELD PRIOR TO THEADVENT OF THE ACTUATION•GNAL

3. SEPARATE MOMENTARY:CONTROLS. ONE FOR EACH APPUCABLE DIVISON.

FiTIurc 7.- (S ISc~l 1 (,)12 1


7. Instrumentation and Controls. .AP1000. Design Control Documenft

FIGURE 7.2-1 CROSS REFERENCES

.APP-PMS-JI Drawing Number Figure 7.2-l Sheet Number

APP-PMS-JI-101 1i

APP-ýPMS-J4I-02 2

APP-PMS-JI1-103 3,

.AP.P-PMS7 JT-•104 ,4

APP-PMS-i 1-105 .5

APP-PMS-J41-106 6

APP-TPMS-J1-107 .7

APP-PMS-J 1-108 8

APP-PMS-'J,1-109 9

APP-PM:S-J 1- 10 10

APP-PMS JI.- 11 11

APP-PMS-J1-1 12 12

APP-PMS4i-113 13

APP-PM.S-J -1 14 14

APP-PMS-J1-115 ý15

APPI-PMS-)1-11,6 1 6

APP-PMS-J 1 -119 18

LAPPRPMSJ.I -120 19

.APP-DAS-JI-102 4-920

APP-DAS-J/1-103 .201


Revision 18


7. Instrumentation and Controls APl000Design Control Document

Subsection 7.13.12 provides a functional escripnion of the: signals and initiating logic for

each. of the 1engineered safety features. Figure 7.2-1 presents the functional diagrams :for:

engineered saf'ety features actuation.

Table 7.3•1 summarizes thie :signalsando initiating,. ogic for each of the engineered safety

features initiated by the pr"tcction and safety monitoring system. Most of the functions

provide: protection: against design basis events which are analyZed in Chapter 6 and

Chapter 15• H6oWeVer, -not ail the :functions listed ii Table 7.3-1 are iecesSaty to 'meet:.the

assumptions used in. performing the safety-analysis.. For example; theý design provides features

which proyide automatic actuations which are not required for performing the safety analysis.

In: addition, some fuinctions are provided to suppct assumptions used in the probabilistic risk,

assessment, but are not used to itigate a design basis accident. Only those functions which.

meet the 0 CFR 50.36(c)(2)(ii) criteria 'are included iii the APIOQO DCD, Section 16.1-

Technical Specifications. This accounts for .any difference between functions listed, in

Table 7.3-1 mid functions which. are included-in:the Technical Specificati.ons.

7.3 1.1 Safeguards Actuation (S) Signal

A safeguards:' actuation (S) signal is, used in the initiation lOgic of many'"of the engineered

safety features. discussed in. subsection. 7.3.1.2. In addition, as descfibed in Section 7.2, the

safeguards, actuation signal also initiates a reactor trip. The:variables that are monitored and

used't generate.a safeguards..actuation ,signal are typicallythosedthat provide indication of a

significant plant transient that requires axresponse by several engineered safety features.

The safeguards actuation signal, i's generated from any of the following initiating conditions:

1. Low'pressurizer pressure2. Low lead-lag compensated steam line pressure3. Low cold leg temperature4. 'High-2 .containment pressure5. Manual initiation

Condition I results from the coincidence of pressurizer pressure below. the 'Low setpoint in

'any two of the four divisions.

Condition 2 results from the coincidence of two of the: four divisions of compensated steam

line pressure below the Low 'setpoint in either of the two steam lines. The steam line pressure

signal is lead-lag'compensated toimprove system response,

Condition 3 results from the coincidence of two of the four divisions of reactor coolant

system cold leg temperature below the Low setpoint inany loop.

Condition 4 results from the coincidence.of two of the four divisions of containment pressure

above the High-2 setpoint,

Condition 5 consists of two momentary 'controls. Manual actuation of either of the two

controls will trip the reactor and generatea safeguards actuation signal.

Tier 2 Maiterial 7.3 -2 Revision 18

7. Instrumentation and Controls AP1000 Design Control Document7. Instrumentation and Controls AP1000 Design Control Document

7.3.1.2.25 Component Coo1ing Svstem Containment Isolation Valve Closure

A sinal ito close thec0mponent coolici:Svstemncontainment isolation valves is derived fiom

*a .coincidencle of two of the four divisions 6f high reactor coolant punpbearin" xvater

temperatutre for any reactor coolant omum.. TIhe high te1mperature -setpoint and dynamic

compenisation arethe same as used in the ehigh reactor coolant p,,nmp bearing water

tejmperaturie 'reactor coolant ptrip (subsection 73.1.2.5. comdition 6). but with the

inchision of preset time delay.

'Ie Iunctiol reClatinlL in ~of t't- uMrctn- i us d i i;i Ii F'- ire .

liic 5'

A si;wnal1,01 reoim(nin the contawiment ,-ac.uunm relief valves Is genertetd fi'om the.olwin

conditions:

. Low-2 containment pressure

* ,MantIual initiationCondition I .resutts from thilei.nci(dence of containment prssurec the, Low2 ic t

in 'any Ltwo of the four divisions.

Conditmon 2 consists of two momentary controls. Manual actuation of either of the

two controls•will result'in opening of the conitainment vacUmn2relief valves.

Either 'signal will 'actuate two nnotor-operated containment isolation valves.to break the

containment Vacuum.

Thie fu-ietional ito c reClatin- to Containment ½& 'iti'r relief is ill I waed in. Fis ure . -

7.3.1'.3 o isesJck rdS r A 0

The interlocks used for engineered safety features actuation are designated as "P-xx"

permissives and are listed in-Taible 7.3-2.

7.3.1.4 Bypasses of Engineered Safety Features Actuation

The channels. used in engineered safety features, actuation that can be manually bypassed are

indicated in, Table 7.3-1. A description of this bypass capability is provided in

subsection 7.1.29. The actuation logic is not bypassed for test. During tests, the actuation

logic is., fully tested by blocking the actuation logic output before it results in component

actuation.

N

Tier 2 Material '7.3-20

Revision 18


7ý Instrumentation. and Control's AP1000 Design Control Document

for: an actuation signal to reach the necessary components. It is based on. f6lowing a step.

change in the applicable process parameter from 5 percent below -to 5*-percent above (or vice

versa) the actuation setpoint: withexternally adjustabl e time delays setrto OFF.

7.3.1.5.3 Design Basis: Spatially Depiendent Variables Used for Engincered Safety Features

Actuation (Paragraphi4.6 of IEEE 603-1991)

Spatially dependent:variables are discussed in subsection 7.2.1.2.3

7.3.1.5.4. Desgn. Basis: Limits for.Engineered'Safety Features Parameters in Various Reactor

Operating Modes (Paragraph 4.3 of IEEE 603-1991):

Duringstartup or shutdown, various engineered• safety features actuation can be manually

blocked. These functions are listed in Table 7.3-1.

During testing or maintenance of the, protection and safety monitoring system, certainchannels .used for engineered safety features may be bypassed. Although no setpoints are

changed fbr bypassihg, t•he lgic is automatically adjusted, as described in subsection 7.3.1.4.

The safeguards channelsthat can be bypassed in! the pfotection and safety monitoring system

are :listed in Table 7.3-1.

7.3.1.5.5 Design Basis: Engineered Safety Features for Malfunctions, Accidents, Natural

Phenomena, or Credible Events (Paragraph 4.7 and.4.8 of IEEE 603-1991)

The accidents that the various engineered safety features are designed to mitigate are detailed

in Chapter 6 and Chapter 15. Table 15.0-6 ,contains a summary listing of the engineered

safety features' actuated for various Condition II,. 111, or IV events. It relies on provisions

made to protect equipment against damage from natural phenomena and credible internal

events. Consequently,; there are no engineered safety, features actuated by the protection and

safety monitoring.system to mitigate the consequenes: of events such as fires.

Functional diversity is used in determining the actuation signals for engineered safety

features. For example, a safeguards actuation signal is generated from high containment

pressure, low pressurizer pressure, and low compensated steam line pressure. Engineered

safety features are not normally actuated by a single signal. The extent of this diversity is

seen from the initiating signals presented in.subsections 7.3.1.1 and 7.3.1.2. Table 7.3-1 also

lists the engineered safety features signals and the conditions thatvresult from-their actuation.

Redundancy provides confidence that engineered safety features are actuated on demand,

even when the protection and safety monitoring system is degraded by a single random

failure. The single-failure criterion is met even when engineered safety features channels are

bypassed.

7.3.1.6 System .Drawings

.Functional diagrams are provided in Figure 7.2-1.

Tier 2 Nlaterial 7.3-22

Revision 18


7. Instrumentation and Controls AP1000 Design Control Docuimento

Table 67.3-1 (Sheet 8 of 9)

ENGINEERED SAFETY FEATURES ACTUATION SIGNALS

No. ofDivisions/ Actuation.

Actuation Signal .Controls tLogic Permissives and Interlocks

c; :Manual initiation of ' i/1 None

auxiliary spray isolation I

1 8. Contai Inment Air :Filtration System Isolationt (Figure-7.2-1,I Sheets 1:1, and 13),

a. Cont6amentiioition (See items 2a through 2c)

b. High-I containment 4 2/4-BYP1 None

radioactivity

c. N/A 2 N/A For containment vacuumnrelIief valves,onl - close. in inside containment

biuiirke isolati6iyidalve :not closed'

19. NormaiResidual Heat Removal Systemnisolationu(Figure !,2-1, Sheets 13 and 18)

ýa.. Automatic or manual (See items la through le)

safeguards actuation signal

b. High-2 containment 4 1 24,-BYP' Manual block permitted below P4l

radioactivity Automatically. unblocked above P-I I

-c. Manual.initiation 4 controls 2/4 controls3 None

20. Refuefing Caivity Isolation'(Figure 7.2-1, Sheet.13)

a. .Lowspent fuel pool level 3 2/3 None

241. Open In-Containment Refueling Water Storage Tank (1RWST) Injection Line Valves

(Figure 7,2-1, Sheets 12 and 16)

a. Automatic reactor coolant (See items 3d and 3e)

system depressurization(fourth stage)

-b. Manual initiation 4.controls 2/4 controls3 None%

22. Open ContainmentRecirculation Valves In Series with Check Valves

(Figure 7:2-1, Sheet 15 and 16)•

a. Extended undervoltage to 2/charger 1/2 per charger None

Class I E battery chargers(8) and 2/4 chargers

23. Open AllContainment Recirculation Valves (Figure 7.2-1, Sheet 16)

a. Automaticreactor coolant (See items 3d through 30

system depressurization(fourth stage) coincidentwith


7. Instrumentation and Controls AP1O.O0 DesignRControl Docutment

Table:7.3•4:(Sh6et9 of 9)

ENGINEERED SAFETY.FEATURES ACTUATION-SIGNALS

No. ofDivisions/ Actuation

Actuation.Signal Controls . Logic Permissives andInterlocks

Lw. IRWST'level 4 2/4 BYP' None

(Low.-Isetpoi~n~t.) ______ _____________________

b'. Manualinitiation 4 controls 2/4 controls3 None

24. Chemical and.Volume Control:System:Letdown Isolation (Figure 7.2-, iSheet 16)

a. Low-I hot'leg level I pertloop 1/2 .Manul block permitted

above P-121 Automatically unblocked

below P712

25.: PressuriZer Heater Trip (Figure 7.2-1, Sheets,6 and :12)

a.. Core makeup tank injection (See items 6a through 6)

b. High-,3 pressurizer level 4 1 2/4 BYP' I Manual block permitted below P-19

_ _ _ _Automatically unblocked above P-19'

26. Steam Generator Relief Isolation (Figure,7.2-i, Sheet 9)

a. Manual initiation 2 controls 1/2 controls None

b. Low lead-lag compensated 4/steam line 2/4-BYP' in Manual block permitted below P-11

steam line pressUre 4, either steam line Automatically .unblocked above P-Il

27.- Close Component Coolin&SYstem Contain ment Isolation Valves (Figure 712-1, Sheet 5)

I .

2.3.4.5.

Any two channels from either tank not in samedivision.

Two associated controls must be actuated simultaneously.

Also, closes power-operated relief block valve of respective steam generator.

The two-out-of-four logic is based on undervoltage to the battery chargers for divisions A or C coincident with

an undervoltage to the battery chargers for divisions B or D.

Any two channels from either loop not in same division,.

Any two channels from either line not in same division.

This function does not meet the 10 CFR 50.36(c)(2)(ii) criteria and is not included in the Technical

Specifications.

6.7.8.


Revision 18


.7. Instrumentati~on ,andC~bhtrbls AP1000 Design Control Document

,Table7.3-3 (Sheet 2 of 2).

SYSTEM-LEVEL MANUAL INPUT TO THE

ENGINEEREDýSAFETY FEATURES ACTUATION.Y I SYSTEM

To Figure 7.2-1

Manual Control Divisions Sheet

Maniual p1assive containment cooling'"actuatio'n #I A B C D, 13

Maiiual passivecontainment cooli'g acation#2 A :B C D 13

Manual passive:containment isolatidn actuation #1 A B C D 13

Manual. passive.containment isolation actuatfion #2- A B ' C D 13

Manual depfessurization system Istages: 1, 2, and 3 actuation #1 &:#2: A B C D 15

Manual depressurization system stages 1, ,2 and 3 actuation #3 & #4 A B C D 15

Manual depressuriization systemistage 4:actuation #1 & #2 A B C D 15

Manual depressurization system stage 4 actuation #3:&#4 A B, C D 15

Manual IRWST injection actuation,#1 &*#2 A B, C D 16

Manual:iRWST injection actuation #3:& #4 A B C. D 16

Manual containment recirculktioriactuation # 1&#2 A B C 1 D 16

Manual c6ntainnieft recirculation-actuation#3 &%#4 A B C DJb 16

Manual control room isolation and air supply initIation#1. 1A B C D 13"

Manual control room isolation andair supply:initiation#2 A, B 3 C D 13

RCS pressure CVS/PRHR blockcontrol.# 1" A 6,

RCS pressure CVS/PRHRblock control #2 B. 6

RCS pressure CVS/PRHdR bl6cktcontrol #3 C 6

RCS pressure CVS/PRHR block:control #4 D 6

Normil residualbheat removal system isolation safeguards block control #1 A 13

Normal residual heat removal.system isolation safeguards block control #2 B 13

Boron dilution block control 1 A 3

Boron dilution block control #2 B 3

Boron dilution block control #3 C 3

Boron dilution block.control #4 D 3

ManuaLRNS isolation #1 & .A#3 3A B D 18

ManualRNS isolation #2 &-#4 A B D 18

CVS letdown isolation block control #1 A 16

CVS letdown isolation blockcontrol #2 D16

Manualcontainment vacuum relief actuation # l A C 19

Manual containment vacuum reiief'actuatioin #2. A C l 9.


Revision 18

Tier 2 Material •7.34 1 Revision 18

7. Instrumentation and Controls AP1000 Design Control Document

.Table'.5-1 (Sheet:3 of 12)

POST-ACCIDENT MONITORING:SYSTEM

Qr ficaltino Number of QPPS

R~IngCI Type! instruraentss Poir Indication

Variable Status Category Environmental seismic Required: Supply. (,Note2) Remarks

Startup feedwater 0"600 12 Mild. Yes ilstearn IE No

flow gpm" :gneratmr(Note 11),

Startup'feedwater. Open? 02. i3 iarsh Yes ,/valve iF Yes

controivalve status, :Closed. (Note 7),

C6ntaintirt -5 o .10 al.C21. 02, • oeelc. Ys 3 IE Yes

pressure psig F2 (Note 4)

Cdnlitinmcnt .0 t. 240 I i4i1Ik Yes 3. I E. . YeS

preskirec,(extended psig .(Note 4)'

range) _____ ___ ___

Con€ timsent are• s 16".Oto, R C1. 12' i2 Harshi Ye.s, 3 ii: Yes

radiation (high (Nse.)"

Reactor vessel hdt :0-10(0/ .B2,B3 Harsh Yes. I IE- Yes Two inlstruments

.leg Waeroevcl% 6.fspon are provided

Plantvent radiation '(Note 3) C2. E2 Mild None 1o Non-IE No

ARmotely oper'ated' Oper BI, D2. H~atrshmild Yes'. I/Valve' I E, Yes Separate divi Isions

•Hydrogen 0-20% 03 None None .N1 N•onIE No Three imasruments

concentration are provided


9.: Auxiliary Systems: AP1000 Design Control Document

9.4.6.5 Instrumentation Application:

The containment recirculation.:cooling system is& controlled by the plant control system. Process

indication and:'alarm signals are: 'locally accessible through ihe:plant control system:. Refer to

subsection 7.1.1 for a description of the plant control system..

Temperature: controllers: :are provided in the ring headers Of the corresponding containment

.recirculation fan coil ufit which provide an input signal to modulatethe ceentral chilled water

.system supply valvesto the cooling coils. Tlhe -containment vOlUmetric average .high and tow

temperature are monitored and alarmed when the temperature: is out of the normaltoperating range,

The ambienet temnperaturie inwa specific equipment compartment:or areas of the containment are

monitored and alarmed.

The discharge flowrate from each containment recirculation fan unit is monitored and:low flowcondition is alarmed to alert the operator for a manual start :of the spare fan unit. Flow to the

ýreactorcavity is also~monitored and lowflow condition is alarmed,

9.4;7 Containment Air Filtration System

The containment air filtration syStem (VFS) serves~thecontainment, the fuel handling area and the

other radiologically controlled areas of the auxiliary and annex buildings, except for the hot

machine shop and health physics 'areas which are served by a separate ventilation system.

9.4.7.1 Design Basis:

9.4.7.1.1 Safety Design Basis

The'containment air filtration system safety related fu.netin, , other- tl...i rois.h.

safetv-related functionsof cohtainment isolation and containment vacuum relief-, 4asn-- nuclear ..afot, l! ign 1-ThiS except bfr ontaimenot ialaiu n-. ze-ubzzzticn 6.23 for a

c-ou~ f~tl pci'ahity• of .safey clteI tm;i c" mc:;nent' airgd&longned te: •ei ismi

Gateg,..' f.. req . ..fenm. The . .emaini,, poi tion of the systen- n 'w-i, . The contaianient

isolation ftunction is described in subsection 6.2.3. The containment vaculium relict function

autonmatically adiusts the.internal contaimeni t pressure as it approaches the analyzed design

pmramneters described in subsection 6.2.1.1.4. This adjustment in the pressure across the"

containment shell preserves the structural integritynof the shell by maintaining the difterential

pressure within the allowable limits as defined by the structural analysis described in

subsection 3.8.2. The vacuum relief ftnction isactuatedon the Low-2 containmentpressuresignal

aniclimanually.

Ssecondary_ funiction of the containment air filtrati on system is to provid& containment vacumn

relief b automaticalldjusting the intenmal containment pressure once it approaches design

parameters reflected, in subsection 6.2.1.1 .4. This adiustment in pressure across the containment

shell preserves the structural integriY, tyofthe shell by maintaining the differential pressuircwithin

allowable limits as defined by structural analysis. The VFS also provides a vacuum relief system

1`r the containment vessel to prevent overpressurization from external pressLUre.


Revision 18

Tier 2.Material 9.4-43 :Revision 18

9- Auxiliary Systems AP1000 Design ControlDoeument

for :the radiologically control<area ventilation: system, and the containment air filtration system.

The intakeis not protected from tornado missiles. The containment air filtration system supply air

handling units dischargelthe supply air towards the east containment recirculation cooliig system

(VCS) recirculation unit to distribute: the purge air Within' the containment. Refer to

subsection 9.4.6 for a description of the containment recirculation cooling system.

The ekhaust air filtration units are located within the radiologically controlled area oftlie annex

building at'elevation 135'-3" and 146'-3". .Thefiltration units are connected to aducted systemwith:isolation dampers toprovide HEPA filtration and charcoal adsoiption ofexhaust air from the

containment, fuel handling area,.auxiliary and annex buildings. A gaseous radiation monitor is

located downstream of the exhaust air filtration units in the cormnon ductwork to providean alarm

ifabnormal.gaseous releases aredetected. The plant vent exhaust flow is monitored for gaseous,

particulate, and iodine releases to.the .environment. During containmenit purge, the exhaust air

filtration units satisfy 10 CFR.50 Appendix .1 guidelines (Reference20) for offsite releases and

meets '10 CFR 20 (Reference21)1allowable effluent concentration limits when combined with

gaseous releases from other sources. During conditiorinSof abnornal airborne radioactivity in the

fuel handling area,.auxiliary and/or annex buildings, the filtration units provide filtered exhaust to

minimize unfiltered offsite releases..

The size, of the containment aiifiltration 'system supply and exhaust air lines that penetrate the

containmentepressure boundary is 36 inclies in diameter. Each penetration includes an inboard and

outboard branch connection with 16 inlch diameter containment isolation valves that are opened

when the containment air filtration system dis connected to the containment. The ends:of the

36 inch containment penetrations are capped for possible fututre addition ofia~high volume purge

system.lIn the event of a loss-of-coolant accident (LOCA) while the containment air filtration

system is aligned.to containment, there willbn otbe a significant release ofradioactivity during:

closure of the 16 inch diameter supply. and exhaust Valves. The maximumn time for valve closure

(see Table 6.2.3-:1) is consistent with :the analysis assmptions-for radiological cmsequences•(see Table 15.6.'5-2). The closure time is also consistent witlithe basis (compliance with

1 0.CFR.Part [email protected]) for Branch Technical Position CSB.6-4 to Standard Review Plan 6U2.4

(Reference 23) or described in Subsection 6.2.1.5.

lhhJ exhaust air contai nmen penectration also includes fi containment ves~se vacUu-m relief function

or protect containment "Im reaching the 1ontainkentshell design extrnal design pressure. In the

event ofa LOCA, while these 6-iJch.1motor-opeaed vacuum hreliefvalves areopen, theOreleases

of radioactivity during the maximum time for Closure of thes valves (soeSTable 62.3-I have

been evaluated. The radio.l6iic(a dconsequences are bounded b;h currently prs.ented in

subsection 15.6.5.3.

The exhaust air containment penetrations also serve asa connection. for the containment integratedleak rate test system to pressurize and depressurize the containment during integrated:leak rate

testing. Otherwise, the containment air filtration exhaust subsystem is not. involved with the

containment integrated leak rate test andis isolatedfrom. the containment during~this time teriod.


Revision 18

Tier 2 .Material 9.4-45 kl~evision I1.8

,9. Auxiliary Systems. 9AP1000 Design Control:Document

Containment Penetirations

The containment penetrations include containment isolation valves, initerconnecting piping, and

vent .and.test connections with; mantuall test valves. The containment isolation: components that

maintain the integrity of the contairiment pressure bounidatyafter a LOCA are classified as Safety

Class B and: seismic Category 1. Seismic. CategoryI debris screens are mounted onSafety'Class C,

seismic Category pipe to prevententrainmeint of debris through the supply and exhaust openings

that may prevent .tight valve shutoff. The screefisare designedtowithstand post-LOCA pressures.

rhe en and purge line containmentisolation. valves inside and outside the containment have air

operators. The valIves are designed to fail closed in the event of, loss of electrical power or air

pressure. These valves:are controlled by:the protection ,and plant safety monitoring 'system .as

discussed in siubsection7.1.1. The valves shut tight against the containment pressuef6ellowing-a

design basis accident.

hlih, motor-operated Vacuum, relief',valves ,are controlled by theprotection and plant safety

monitorinýg.. system ,as discusselt; in',subsectiio 7.1 1. The valves inside containment are self-

:actuated check valves. These motor'operated valves and check valves shut tight against-the

contanmenit presswre following ia design basis-accident.

Ductwork and Accessories

Ductwork, duct supports:and accessories are constructed of galvanized steel. Ductwork subject to

fan shutoff pressures is structurallydesigned td.accormnodate fan shutoff pressures. The system

air d'uctwork inside'clontainmentl- meets seismic Category II criteriaso that it will not fall and

damage any safety-related equipment following: a safe shutdown earthquake. Ductwork, supports

and accessories meet the desigr and construction requirements of SMACNA Rectangular and

Round Industfial Duct Construction Standards (References, 16 and 34) and SMACNA HVAC

Duct Contruction Standard - Metal:and Flexible (Reference 17). The exhaust aii ductwork and

supports meet the design and construction requirements of ASME AG-I (Reference, 36),

Article SAA500.

Shutoff and Balancing Dampers

Multiblade, two-position remotely operated shutoff dampers.are parallel-blade type. Multiblade,

'balancing dampers are opposed-blade type. Air handling unit-and fan shutoff dampers are

designed for maximum fan static pressure at shutoff flow and meet the performance requirements

of AN SI/AMCA 500 '(Reference 1.4). The containment exhaust air dampers meet the design and

construction.criteria of ASME AG-1 (Reference 36), Section DA.

Fire Dampers

Fire dampers are provided where the ductwork penetrates a fire barrier to maintain the fire

resistance rating of the fire 'barriers. The fire dampers meet the design and installation

requirements of UL-555 (Reference 15).


Revision 18


.9.. Aupxiliary SystemsAP1000QDesign Control Document

Main controlroom operators,can~connect the containtment air filtration system to the containment

for cleanup of potential airborne radioactivity' while the containment remains isolated if a

containment high radiation signal is not present.

•fh. containment vacuum relief valves autonaticaillV olen whencontainment vacuum relief

sigLs ariinitiated:lbv the protection and safe ty monhitor inta system. Thesei valves iutbmaticall

close :when containinent isolation signals are initiated b) t rction and safety monitoring

system. Even though these valves are normally closed, th•e automatically receive aconfirinatory

ccldse signal if the containment isohition valve:inside the reactor containment buildinr ýis open.

-This interlockis perforfied to ensure the initeqrity of the :containment isolation function.

If high airb6hne radioactivity or highpi'essiute differential is' detected in the fuel handling area, the

auxiliary and/or annex buildings, the r.adiologically controlled.area ventilation system isolates the

affected. area from the outside env'ironment and Stats the 'containment air filtration exhaust

subsystem tomaintain a slight negative pressure differential in the isolated.zone(s). The airflow

rate through the exhaust fan is maintained at aiconstant value-by modulating thelfan inlet vanes.

Aneoutside air makeup damper modulates to. control the exhaust airflow rate through the HEPA

and charcoal filtersmto maintain the isolated area(s) at a: slightly negative pressure relative to the

clean areas. The contiiainment air filtratioinfsystem is automatically isolated-from the containment,

ifpurging is in progress and the standby exhaust filter train does not start. If both exhaust trains

are connectedto the containment one exhausttrainisautomaticallyisolated from the containment

and realigned to the. isolated area(S). The exhaust, subsystem can be manually connected tothe

onsite diesel generators if there i's ailoss of ac ppwer.

The containment air filtration system is not required to mitigate the consequences of a design basis

fuel handling accident or ,a loss of, coolant Accident. If the exhaust air filtration units are

operational and ac power isavailable, they may be used to support post-eventrecovery operationrs

The plant venthigh range radiation detectors monitorveffluents discharged into the plant vent.

If smoke:is detected in the:common,'supply'air duct,:an alarm is initiated. The system remains in

operation unless plant operators determineithat there is a need to manually shut, down the supply

air handling units. Fire dampers are. provided for HVAC ductwork that passes through a. fire

barrier in order to isolate each fire zone in the event of a fire.

9.4.7.3 Safety Evaluation

The containment air filtration system ia• iwe-thcsafety-related functions 6f-Ot4ef--i

contairment isolation and vacuum relieor es-no-an!ear tafsty e ittni The

containment isolation function is evaluated in subsection6.2,3. hC vacuunn relief systemconsists

of, redundant relief devices inside and outside containment. wo independetnt lines with an

automatic isolation valve are provided on the positivepressureside of the system along with two

maepndent lines with a check valve on the negitivc pressure side of the system penetrate

contaimnent. The linesshare acommon containment penetration. Therefore, there are no sile

active failures, which would prevent the system from perolrmiu its function.

The failure of equipment and ductwork will not reduce the functioning of safety-related systems,

structures or components that are required to close to maintain containment isolation integrity after

Tier. 2 Mater ial9.4-50

Revision 18

9. Auxiliarv Svstems APIO00 Design Control Document9. Auxiliary Systems AP1000 Design Control Document

-- - - --K1 AMCSrHERE

I OX>1 XV7Th> 1=1

'~ L " • L•

F • S• '..-; i _i • •-) - x. :--% . • ..

BJ

tilED > 1, F -

w15-1-- - - .- E.

.•...... L K• , .., h i

FigureI . 9..71 Sec IofI

T n I

T-.

Figure 9.4.7-1 (Sheet I of 2)

Containment Air Filtration SystemFigure represents system functional arrangement. Details internal to the system may Piping and Instrumentation Diagramdiffer as a result of implementation factors such as vendor-specific component requirements. (REF) VFS 001

Tier 2 Material

9.4-124 Revision 18


9. Auxiliary Systems :AP1.0600 DeignrControl Document.

I

Table 9A-2' (Sheet:8 of 14)

SAFE SHUTDOWN COMPONENTS

:Fire Area] Class IE.Division

Fire Zone System Description A C B D

1,200 AF 01 PSS Liquid Sample;Line Cont. VOl1,Iso0ation Valve

Sample Return Line.Cont. V023,Isolation Valve

SFS: Discharge Line Coit. isol, V038

iVFS. Vacuuhm Relief "V800A V8B

Containinent:-isoiation ::•ValveRNS •eischarge Cont. olation V I

SuVrctfion R Cant. V V022

Isolation Valve

Lcs Containment Pressure PTJ-00 Pt-O07

1200 AF 03 IDS Class IE CableTrays Note I Note I

1201 AF 02 IDSB 24.Hr Battery 1A DB,1A

24 Hr Battery lB DB-IB

72 Hr Battcry.2A DB-2A

72 Hr Battery 2B DB-2B

250 Vdc Distribution D D-1.Panel

208/.120 Vae Distribution EA- 1Panel

208/120 Vac Distribution EA-2

Panel

208/120 Vac Distribution EA-3Panel

250 Vdc Switchboard DS-1

Tier 2 Material 9A-137 Revision 18

ESFAS Instrumentation3.3.2

ACTIONS (continued)

CONDITION REQUiRED ACTION COMPLETION TIME.

AA.1.2.2 Verifythe affected flow Once per 7 dayspath :is isolated.

OR

AAM.2... Ifin MODE 4, be 'in 12 hours:MODE5.

AND

AA.2.2 If in MODE 4or(5., initiate. 12 hoursaction to establish a,pressurizer level >,20%.

AND

AA.21:3 If in MODE 6, initiate Immediatelyactionhto be in MODE 6with the water level:23 feet above the top *ofthe reactor vessel flange.

1BB. Onechannel BB.1 Place channel in bypass. 6 hours

inoperable.

AND

BB.2 Continuously monitor hot 6 hours.leg level.,

'CC. Required Action and CC. 1 'Be in MODE 3. 6 hours

associated CompletionTime not met. AND

C0.2 , Be in MOE'5 .or 6. 36 hours

AND

00.3 Open containment 44 hoursequipment hatch. orcontainment airlock.

AP1OW0 3.3.2 - 11 Amendment 0Revision 18

ESFAS Instrumentation3.3.2

Table 3.3.2-1 (page 13: of 13)Engineered Safeguards Actuation System Instrumentation

APPLICABLE MODES

OR OTHER SPECIFIED. REQUIRED SURVEILLANCE

FUNCTION CONDITIONS CHANNELS CONDITIONS 'REQUIREMENTS

-29., SG Powei Operated ReliefValve and Block ValvelIsolation

a. ManualInitiation

b. Steam Line. Pressure - Low

30. Coiponint Coolng.WaterSystem Containment IsolationValve Closure

a. Reactor Coolant PurmpBearinq WaterT emoterature - High

1.2.3,40)1,2,3,4,

2 switches

4 peristeam.line

E.N

B,N

SR 3.3.2.3.

SR 3.3.2.1SR 3.3.2.4SR .3' 2:5'SR 3.3•2:6

4 lier RCP SR:3.3.2.1SR ,3.3.2.4

SR 3.3.-2,5,SR 3112.6

a.. Containment.Pressure - 1 _2344 B CCSR 2 332;1

Low 2 5 SR 3.13124SR 3.312.5SR' 3.3.2.65

-Manual Initiation 1234 2 controls. ECC SR: 3:3.2:3

W) WththeoRCSnrtbeing cooled by the-Normal ResidualHeat Removal System (RNS).

(s) With both containment equipment hatches and both contahnmenvairlodks closed.

APIO00 3.3.2--27 Amendment 0Revision 18

Vacuum Relief Valves3.6.10

3:6 CONTAINMENT SYSTEMS

3.6.10 Vacuum Relief:Valves

LCO 3.61i0 Two vacuum relief flow paths shall be OPERABLE.LCO 3,6. 10

AND

Containment'inside tooutside differential air.temperature shall be •90 0 R.

'MODES 1:2,,3, anda4''MODES'5 and 6 with both containment equipment: hatchesahd both

APPLICABILITY:

containment airlocks closed

ACTIONS

CONDITION REQUIRED.ACTION COMPLETION TIME

A. One vacuumee relief. .A1 .Rest' vacuum relief'flowb -72 hoursflow path inoperable,: path to OPERABLE status.

OR

AA.2.1 :Open containment purqe 72 hoursdischargeisolation valves.

AND

A-2,2 Verfy containrmeht purge Once per 24 hoursdischarme isolation. valves aftersatisfyingare open. Required Action A.2.1

AND

A.2.3 Restore vacuum relief flow 7 dayspath to OPERABLE status.

APt.000 3.6.10- I Amendment 0Revision 18

Vacuum Relief Valves3.6.10

I AflTWThI5 h'r~ntiniu~-h

CONDITION REQUIRED ACTION C OMPLETION TIME

B1. Contaihnenhtihnside: .B.1 Restore.containment 8 Zhoursto outside differetial i nside to otsideb

air4temperature>: differential:air temperature-900F. to within limit.

OR,

B123 Reduce containment 8 hours.averafetemperature

_<80T,

OR

B.3.1 Open ,containment purge 8 hours':disdharge isolationval.Ves.

AND

B.B3.2 Vefif, containrmeht pur-e Once.Per 24 hoursdischarqe isolation valvesare open.

AND

8.3.3 Restore vacuum* relief daysflow Path to OPERABLEstatus.

C. Required Action, and C_. 1 Be in MODE 3. 6 hours

associated.Completion Time not ANDmet.

C.2 Be in MODE 5 or 6. 36 hours

AND

C.3 Open containment 44 hoursequipment hatch orcontainment airlock.

AP1000 3.6.10-2 Amendment 0Revision 18

Va&uum Relief ValVes3.6.10

SURVEILLANCE REQUIREMENTS_:

.SURVEILLANCE FREQUENCY

SR 3.,6.10.1 Verify cohtainmeht inside to outside differential air is 12 hours• !_900 F.

SR 316.10.2 Verify containment purge discharge isolation'valve 24 hours

VFS-PL.V009, is closed, or containment purgedischar-e isolationý valves, VFS-PL4V009 bndVFS•PL-V010, are both open with an operable flow.

SR 3.6.:0;.3. Verify each vacuum relief line is OPERABLE in In accordanceaccordance with the Inservice Testing Program,. with the Inservice,

Testing Program

AP1000 3.6.10 - 3 Amendment 0Revision 18

ESFAS InstrumentationB 3.3.2

BASES

APPLICABLE SAFETY ANALYSES, LCOs, and.APPLICABILITY (continued)

1,34 Containment Vacuum Relief Vave Actuation,

The Purpose of the vacuum relief lines is to protect the containmentVessel against damage due to a negative pressure (i.e., a, lowerpressure inside'than outside).

Manual-and'automahtic Containment Vacuum Relief'Valve actuationmust be: OPERABLE in MODES 1 through 4 and in MODES 5 :and 6:

with both containment equipment hat6hes and both containment.airlocks closed,.

!3i.a. :Containment Pressure- Low2

This siqnal provides protection against a,-negdtive pressure incontainmen iduje to loss of ac power or inadvertent actuation

of containmentcooling and a low outside ambient airtemperature in :combination with limited containment heatingthat reduces the atmospheric temperature (and hencepressure) inside dontainmen't.-

Four channels are provided ito permit.one ch6annel to:bef in tripor bypass iindefinitely and,,.still ensure no sintgle":random failur.e

will disable this trip Function.

!311.b. Manual Initiation

The operator can open the-vacUum relief valves at any.timefrom the~main control room by actuating either of-the twoVacuum relief actuation switches. There are two switches inthe main control room, either of which will actuate vacuumrelief. in all divisions.

ESFAS instrumentation satisfies Criterion 3 of *10CFR 50.36(c)(2)(ii).

ACTIONS A Note has been added in the ACTIONS to clarify the application ofCompletion Time rules. The Conditions of:this specification may beentered independently for each Function listed on Table 3.3.2-1. TheCompletion Time(s) of the inoperable equipment of a Functionvwill betracked separately for each Function starting from the time the Conditionwas ,entered for that Function..

A second Note. has been added to provide clarification that, more thanone Condition is listed for each of the Functions inTable 3:3.2-1. If theRequired Action and associated Completion Time of the first Conditionlisted in Table 3.3.2-1 is not met, the second Condition shall be entered.

AP1000 B 3.3.2 - 54 Amendment 0Revision 18

ESFAS InstrumentationB 3.3.2

BASES

ACTIONS :(Continued)

If the flow path cannot be isolated in accordance with RequiredActions AA.1I.1, .AAl. 2.1 anid AA.1.2.2, the: plantmust be placed in'a

MODE in which the likelihood and consequences of an event are:minimized,. .If in MODE 4, this is: accomplished by placing the plantin

MODE, 5within 12 hours. The 1:2 hours is a reasonable time to reach

MODE 5 from MODE 4 with RCS cooiing provided by the RNS(approximately 3506F) in an, orderly manner without challenging plant

systems.

If in mMODE 4 or 5, Required Action AA.2.2 requires initi ation of action,

within 1:2 hours, to establish> 20% pressurizer level. The 12 hour

Completion Time allows transition to MODE 5 in accordance with AA.2.1,

if needed, priortoinitiating action: to establish the pressurizer level.

Ifin'-MODE 6, Required:ActionAA.2.3 requires the plantto: be maintained

in MODE 6 and initiation of action to establish the reactor cavity water

level 23 ,feet: abovethe top of the reactor vessel flange.

Required Actions AA.2.2 and AA.2.3minimize the consequences of an

event by Optimizing conditions for RCS cooling in 'MODE 5 using the

PRHR HX or: in MODE 6 usihg :IRWST injection.

BB.13 and BB.12

With one channel inoperable, the inoperable channel must be placed in

bypass and ,lthe hot leg level continuously monitored.

lf:one channel is placed'in bypass, automatic,actuation will not occur.

Continuous monitoring of the hot leg level provides sufficient information

to permit ,timely operator action.to ensure that ADS Stage 4 actuati On can

occur, ifneeded to mitigate events requiring RCS makeup, boration, or

Core cooling. Operator action to manually initiate ADS Stage 4 actuation

is assumed in the analysis of shutdown events (Reference 140). It is also

credited.in theshutdown PRA (Reference 12-1) when automatic actuation

is L6 availab l ..........iCO. C C 2 ' an 3.

f the vacuum relief valve ,actuation function cannot be restored toOPERABLE istatus within the required Completion Time, the plant mu

placed ina condition in which the LCO-does not apply. To achieve this.status, the plant m ust be brought to at,-least MODE 3 within. 6 hours, and •to)

MO E 5 o iti .6 h u s The allowed Com pletion .Tim es are

treasonable, based, on operatingq experience, to reach the required: plan

-conditions, fromnfull power conditions in an orde-rly manner and without

AP1000 B :3.3.2 - 67 Amendment 0Revision 18.

ESFAS"InstrumentationB 3.3.2

BASES

,,ACTIONS (Continue

InJ OD 5or 6, a containment eauiDiment hatch or a conitainment airlockshalln be ocpnd within order rs. Oenl, itch or.an aimnockeProvides the: required Vacuum relief path .in the;.eVent::ofa' low pressure .-

, evenit, The allowed6 Completion Tifhe isý reasbnable,.for openingq a hatch

.SURVEILLANCE The 'Surveillance Req uirements: for each ESF: Function are identified byREQUIREMENTS the Surveillance Requirements column of Table 3.3.2ý-i. ANote has been

added to :the Surveillance Requirement tableto clarify; that Table 3.32-1determines which Surveillance Requirements aiPpy to which ESFFunctions.

SR 3.3.2.1

Performahce of the CHANNEL CHECK once every 12 hours:ensures thata gross failure of instrumentation. has not occurred. A CHANNEL CHECKis a6. comparison of the parameter indicated on one channel-toia similarparameter on other channels. It is based on'the assumption thatinstrument channels monitoring the same parameter should readapproximately the same value. Significant deviations. between the twoinstrument channels Could be an indication of excessiVe instrument drift inone of the channels or even something more serioUSA.CHANNEL

CHECK will detect gross. channel failure; thus, it-is key to verifying theinstrumentation continues to operate properly between each CHANNELCALIBRATION.

Agreement criteria are determined by the: plant staff, Abased on acombination of the channel instrument Uncertainties, including indicationand readability. If a channel. is outside the match criteria, it may be anindication that the sensor or the :signal processing equipment has driftedoutside •heir .correspondinqits limits.

The Surveillance Frequency is based on operating experience thatdemonstrates that channel failure is rare. Automated operator aids maybe used to: facilitate performance of the CHANNEL CHECK.

BASES

SURVEILLANCE, REQUIREMENTS (continued)

SR 3.3.2.2

SR 3.3.2.2 is the performance of'an ACTUATION LOGIC TEST. This test,in conjunction with the ACTUATION DEVICE TEST, demonstrates that the.actuated device responds to a simulated actuation signal. The ESFcoincidence logic and ESF actuation subsystems within a division are


Containment Isolation ValvesB 3.6.3

BASES

ACTIONS, (continued)

acceptable,. since,,the function of locking, sealing, or securing componentsis to ens!ure.that these: devices are not inadvertently repositioned.Therefore, the'probability of• misalignment: of these valves, once they

have been verified to be in the-proper position, is small.

D.1 and D.2

If the Required Actions and"associated Completion Times are;`notmet, the.

plant must be brought to'a MODE in which the lLCO does not apply. To

achieve this status,,the plant must be'brought to at least MODE -3:within6 hou'rs and to MODE:5 within 36 hours. The allowed Completion Times

are:reasonable, based on operating experience, to reach the requiredplant conditions from full power conditions in an orderly manner and

without challenging plant-systems.

SURVEILLANCE SR 3.6.31REQUIREMENTS.

This SR ensures that the 16: inch purge valves are closed as required or,

if open, open for an allowable reason. If a purge valve is open in violation

of lthis SR, the valveis considered inoperable. If the inoperable valve is

not otherwise known to have excessive leakage when closed, it is not

considered to:have leakage outside of limits. The.SR is not required tobe met when the 16 inch p.urge valves are open for the reasons stated.

The valves may be opened for pressure control, 16, prevent a containmentvacuum (according: to LCO 3.6.1 0, .Required Actions A.2 and B.3)•.ALARA

or air quality considerations for personnel entry, or for Surveillances that

require'the'valves to beopen. The. 16 inch purge valves are:capable of

closing in the environment following a LOCA. Therefore, these valves are;

allowed to be open for limited periods: of time. The 31 day Frequency is

consistent with other containment isolation valve requirements discussed

in SR 316.3.2.

SR 3.6.3.2

This SR requires verification that each containment isolation manualvalve and blind flange located outside containment and not locked,

sealed, or otherwise secured and required to be closed during accident

conditions is closed. The SR helps to ensure that post accident leakage

of radioactive fluids or gases outside of the containment boundary is

within design limits. This SR does not require any testing or valvemanipulation. Rather, it involves verification, through a system walkdown,

that those valves outside containment and capable of being mispositioned

are in the correct position. Since verification of valve position for valves

outside containment is relatively easy, the 31 day Frequency is based on.

AP1 000 B 3.6.3 - 7 Amendment 0Revision 18

Containment PressureB 3.6.4

B 3.6 CONTAINMENT:SYSTEMS

B13:16A.4 Containment Pressure

BASES.

BACKGROUND: The containment pressure is, limited during normal operation to-preserveIthe initial conditions assumed in the accident'analyses for a lossofcoolant accident (LOCA) or steam linie break: (SLB). These limits alsoprevent the containmenit press ure from exceeding the containment designnegative pressure differential with respectlto the outside atmospherepinthe event:of transients-which result:in a negative pressure.

Containment pressure is a process 'variable !that is monitored andcontrolled. The containment pressure limits arederived4rom theoperating band of conditiOis. used,in the containment pressure analysesfor the Design Basis Events which' result in internal.or external pressureloads on the containment vessel, Should operation occur outside theselimits, the initial containment pressure wouldbe outside the range Usedfor containmen fpressure analyses:

APPLICABLESAFETYANALYSES

Containment internal pressure is an 'initial condition used in the DBAanalyses to-establish the maximum peak 'oritainmeint; internalpressure.The limiting: DBAs considered, relative to containment pressure, arethe,LOCA and SLB. which are analyzed using computer pressure transients.The worst case LOCA generates larýer mass and ener release than theworst cast SLB. Thus, the LOCA event'bounds :the SLB event from thecontainment peak pressure standpoint (Ref. 1).

The initial pressure condition used in the containment analysis was15.7 psia (1.0 psig). This resulted: ina maximum peak pressure from aLOCA, Pa, of 57.8 psig. The containmentzanalysis (Ref. 1) shows that themaximum peak calculated containment pressure results from the limitinLOCASt-R. The maximum containment pressure resulting from the orst_case LOCASL-9, 57.!83 psig, does not exceed the containment designpressure, 59 psig.

The contai also designed for an external pressure loadequivalent- •1.7 tsig. The limiting negative prpessure transient.is-aloss of all At urces coincident with extreme-cold weatherconditions which cool the external .surface of'the containment vessel. Theinitial pressure condition used in this analysis was -0.2 psig. This resultedin a minimum pressure inside containment, as illustrated in Reference 1,

AP1000 B 3.6.4- 1 Amendment 0Revision 18

Containment PressureB 3.6.4

BASES

APPLICABLE SAFETY ANALYSES (continued)

which is less than the design load., Other external pressure load eventsevaluated include:

Failed :Containment Flan Ceooler (VFS) control

Malfunction of containment purge system

Inadvertent lncontainment Refueling Water Storage;,Tank (IRWST)drain

.Cont .. mentp ssure ... isfies§ iterion f 10 .50.3 2)(ii

LOO Maintaining containment pressure at less than or equal to the LCO upperpressure limit ensures that, in the event of a DBA, the resultant peakcontainment accident pressure will remain below the containment designpressure. Maintaining containment pressure at greater than orequal tothe LOO lower pressure limit ensures that the containment will not exceedthe design negative differential pressure following negative pressuretransients.

APPLICABILITY In.MODES 1:, 2, 3, and 4, a DBA could cause a release of. radioactivematerial to containment. Since maintaining containment pressurewithinlimits is essential-to ensure initial conditions assumed in the accidentanalyses'are maintained, the LCO is applicable in MODES 1, 2, 3, and 4.

In MODES 5 and 6, the probability and consequences of these events arereduced.due to the pressure and temperature limitations of theseMODES. Therefore, maintaining containment pressure within the limits ofthe LCO is not required in MODE 5 or 6.

ACTIONS A. 1

When containment pressure is not within the limits of the LCO, it must berestored within 1 hour. The Required Action is necessary to returnoperation to within the bounds of the containment analysis. The 1 hourCompletion Time is consistent with the ACTIONS of LCO 3.6.1,"Containment," which requires that containment be restored to

AP1000 B 3.6.4 - 2 Amendment 0Revision 1.8

Vacuum Relief ValvesB 316.10

B 3.6' CONTAINMENT SYSTEMS

B 3.6.110 Vacuum Relief Valves

BASES.

BACKGROUND The. purpose of the vacuum relief lines is to protect the containment

vessel from damaqe dueto.a.ne.ative pressure (that is, a lower pressureinside than outside). Excessive neiative pressure Inside containment can

occur, if there is:ajloss of ac:.power (VCS containment heating not,

available, reactor trip decay heating only) with.a: differential (inside to

outside) ambient-temperature>' 900 F. Inthisbecase, •the relativýelow

outside ambient temperature maycool containmeritfaster thaan the

available heat sources (prmarily, reactor decay heat) can heat

containment, resultingq:in a reduction of the containment temperature andpressure below the neglative pressure design.limnit since normal

non-safety-related pressure control me'ans are, nt available due t. loss of

ac power. In addition, .e xcessive negative pressure inside containmentcanmoccur, in-the:eveIntof malfunction of the Containment Fan'Codolers(VFS) control, i.,n' combination.:with low outside 'ambient tempierature,

which reduces .€containment itemperature.

The containment pressure. Vessel contains 'tWo 1 00-percent capacityvacuum relief flow pathsv with:a shared contairnment penetration that

protect the containment from excessive external piressure loadincq. Each

flow path outside containment contains: a nOrmally closed, motor-operatedd

valve (MOV). The 'MOVs receive an ESF "oben" signal on Containment

Pressure-Low2. The MOVs~close.:on an-ESFcontainmnent isolation

siqnal, as well as on Hiclh-i containment radioactivity. Each flow path

inside containment containsa normallv-closed, self-actuated checkvalve

inside containment that opens on a neqative differenbtial pressure of 0'.2

psi. A vacuum relief flow path consists of one MOV and one check valve

and the shared containment penetration.

The parallel vacuum relief MOVs are interlocked with the 16-inchcontainment purge discharge isolation valve inside containment,VFS-PL-V009, which shares the containment penetration.- The vacuumrelief 'MOVs are blocked from opening-if VFS-PL-V009 is not closed.. If

the 16-inch containment purge.discharge isolation valves -inside and

outside containment, VFS-PL-V009 and VFS-PL-VO10, are both open,

then an excessive negative.pressure-inhside containment cannot develop

since the containment is open to the outside.

AP1 000 B-3.6.10 - 1. Amendment 0Revision 18

Vacuum Relief Valves:B 3.6.1:0

BASES.

JAPPLICABLESAFETY

.ANALYSES

Design of the, vacuumreliefsystem.involves calculatinq..the effect: of loss,,.of ac power and an ambient air temp-erature in combination with limited,containment heatinq .that.reduces the atmospheric temperature (andhence pressure) inside containment(Ref. 1)., Chservative assumftionsaear.e used:for. relevant parameters in-the.calculation, for. example, inside€containment temperature and outside airtemperature. The resultincontainment pressure versus timeis calculated, ncludin the effect of theopening of the vacuum relief valves: when their negative pressure setpoint

,,,is reached. It is also .assumed'that one valve fails:to open,

The containment was.designed for n external presSure oad e0' alentto 1.7 psid-. The excessive containment cooling events were analyzed todete•imine theresultihq 'reduction in containment pressure. The initial,pressure condition used in this analysis was -0.2 psiq: This resulted in aminimum pressure, inside containment of -1:47 psig', which is less than thedesign load.

The vacuum relief valves must also perform the containment isolationfunction during a containment hi-gh pressure event. For this reason, thesystem is designed to take the full containment positivejdesign pressureand.the.enviroinmental conditions (temperature, pressure, humidity,

radiation, cI hemicaliattackk,.and the ,like) associated With the containmhen'tDBA.

The vacuum relief ValveWssatisfy Crite'rion 3 of 1O CFRm 50•.36(c)(2)(ii).

LCO The LCO establishes the maximum containment~temperature initialcondition and the: minimum eguipment required toaccomplish the-vacuumrelief function following !excessive containmentcooling events (Ref. 1).

Two 100.-percent vacuum rdelief flow pathsare required to be OPERABLEto ensure that at-least one is available, assuming one or both valves inthe other-flow path fail to open. A vacuum relief flow path is OPERABLE ifthe MOV opens on an ESF open signal and -the self-actuated checkvalves open on a neaative differential oressure of 0.2 Dsi:

The containment-insideto outside differential air temperature limit Ofý_90.F:ensuresgthat the initial condition.for the excessive cooling analysisis met. If the differential air temperature exceeds the limit, thecontainment vacuum: relief capacity of one flow path may not be adequateto preventa acontainment:pressure- below-the negative pressure designlimit


Vacuum Relief ValvesB 316.10

BASES

APPLICABILITY InNMODES 1 throuqh 6,.the potential exists for exceessive containmentcoolingq everts to produce a negative containment pressure below the

design limit. However, in MODE 5 or 6, a containment equipment hatch

or airlock may be openedj(LCO 3.6.8, Containment Penetrations),providcing a8vacuumrelief'path that is, sufficient to precludea negativecontainment pressure below'the desihn limit,

Therefore, the vacuum relief flow paths&are reguired to be OPERABLE in,MODES. 1 through 4 ,and'in "MODES 5.and 6with both containme.nt

equipment hatches: and both containment airlocks closed.

IACTIONS] A I, ,A.2. 1.2.2, and A.2.3

When one 0of the required vacuum relief flowzpaths is inoperable, the

inoperable flow path must be restored -to OPERABLE status within72 hours. The specified time periodI is consistent with other LCOsI for the

loss of one train.-of a systemreguired to mitigate the consequences 6of aLOCA or other.DBA.

.Alternatively,.Required Action A.2.i permitsopeningý the containrhentpurge6floW oath. Opening the containment purqe discharge isolation

val ves, VFS"PL- V009, and VFS-PLVO0 O, precludes, the possibility of anexcessive negative pressure inside the containment since thecontaini-ernt is open to the outside.

Once opened, .Required.Action A.2.2'requires Verification every 24 hoursthat the containment purge flow path is open:

RequiredAction A.2,3 limits the time forwhich the containment purgedischarge isolation valves may remain open, consistent with LCO'3.6.3,Containment Isolation Valves, by rejuiring restoration of the inoperablevacuum relief flow path to OPERABLE status within 7 days.

BA1, B.2, B3.1, B.3.2, and B.3.3

If the containment inside to outside differential air temperature is > 900F,then the 'differential air temperature shall be restored to within the limit

within 8 hours. The 8-hour COhipletion Time is reasonable, considering

that limit'is based on a worst case condition and the time needed toreduce the containment temperature while controlling pressure withinlimits of LCO: 3.6.4,gContainment.Pressure.

If the differential temperature cannot be restored, Required Action B.2

provides an alternate requirement. Reduction of the containment average

temperature to •<80 OF provides an initial condition for excessive cooling

events that ensures the vacuum relief system capacity is sufficient

(Refý 1).

APIo00 B 3.6.10- 3 Amendment 0Revision 18

Vacuum Relief ValvesB:3.6.10

.BASES.

IACTIONS (continued).

Altternatively, Re uired Action B.3.1 permits openin the containmentpurge46flow path. Openingothe containment purrqe discharqe isolationvalves, VFS-PL-V009 and VFS-PL-V0,1o precludes the possibility of an.excessive negative pressure inside containment since the co tainmerit is

open to the Outside.

Reqire•ldAdtion :B.32 reqUires verification evey t24 hours thatfthe,containment purqe flow path is open.

Required Action B .33limitsthe time for-which the containment purgedischarge isolation valves may remain ,open, consistent rwith LCO 36.3,.Containment Isolation:Valves, by requiring restoration of the inoperablevacuum relief flow path to OPERABLE status within 7 days.

C., C.2, and 03

If the vacuum relief flow path cannot be restored to OPERABLE Statuswithinthe required Completion Time, the plant must be: placed in aconditionfin nwhich .the LCO does not apply. To-achievethis status, theplantmust bebr,6ought to, at leastMODE 3.within 6 hours~and tV6MODE"'sor 6Within 36 hours. The allowed Completion Times are reasonable,based on operating experience, to reach the, required plant conditionsfrom full power conditions in an orderly manner and Without challengingplant systems.

In MODE5:or 6, a containment equipment hatch or a containment airlockshall be opened within 44 hours. Opening of a hatch or an airlockprovides the required vacuum relief:path in the event of a low ressureevent, .The allowed ComPletion Time is reasonable for openingqa.hatch oran airlock in an orderly manner.

AP1 000 B ý3.6.10 - 4 Amendment 0Revision 18

Vacuum Relief Valves.B 3.6.!10

I 'BASES

:SURVEILLANCEREQUIREMENTS

•SR 3.6.10.1

Verification that the containment inside t0ooutside differential .air.,temperature. is ._90'F is required every.12.hours. The containment inside

tooutside differential air temperature is determined by subtracting theoutside ambient air temperature (rneasdred by the site ýmeteoro logical.instrumentation or equivalent) .rfrom' thed inside containrment averaqe airtemperature:(measured usinq the sameinstrumentation-as used forSR :•:,1)

The Frequency is based on ,the normally stabl ,ontainment average air..temperature andc the relatively :small outside a mbient .i. tebfm6er8t"Wrechanges within this time.

SR 3.6.10.2

Verification that containment purge discharge isolation valve,VFS-PL-V009, is;closed ensures that .the vacuum relief MOWs are notblocked from openinq on a v.alidactuation signal.

Alternatively, if both containment purge, dischargeisolation-valves,VFS-PL- V009.and VFSPL-PVO10,. are verified to be open with an

operable flow path to the plant'vent, .a. 6e.qative pressure .caninot bedeveloped in the containment since'the containment is,!open.

The 24-hour Frequbency is required.since the purev.Valves are not locked

and may be operated at any time as permittedby SR3:6.3.,1.

SR 3.6.10.3

This SR cites the Inservice Testing: Program, Which :establishes the

requirement that inservice, testinqof the ASME Code. Class 1, 2, and 3valves shall be performed in accordance with the.ASME Code (Ref. 2).Therefore. SR Freouencv is aoverned by the lnservic'e Testino Proor~rm.

Therefore. SR Frenuencv is aoverhed;bv the Inservice Testino Procira

IREFERENCESI 1. Subsection 6.2.1.1.4, "External Pressure Analysis".

2. ASME OM Code, •Code for Operalti'on and Maintenance of. NOuclearPower Plants"..

AP1000 B 3,610 - 5 Amendment 0Revision 18


5.0 CONTAINMENT VESSEL EXTERNAL PRESSURE ANALYSIS

Ch. 6 Safety Analysis (6.2.1.1.4):

Table 5-1 documents the differences in key assumptions associated with the AP1000 DCD externalpressure analysis from Rev. 15 to the proposed version in Rev. 18.

Table 5-1: DCD Analysis Assumptions

Assumption Rev. 15 Rev. 18

Containment Heat Rate 0 Btu/s 469.2(Btu/s)l

Initial Humidity 100% 100%

Initial Containment Internal Temperature 120OF 120OF

Initial Containment External Temperature -40OF 250F 2

Initial Containment Shell Temperatures 60°F Equilibrium3

PCS Air-flow 24.8 ft/s 24.8 ft/s4

External Temperature (Transient) N/A Co sine

Distribution5

'For the proposed Rev. 18 analysis containment heat rate prior to transient initiation is assumed to be469.2 BTU/s. This value is approximately 1/5 the design heat rate of 2366.7 Btu/s used to size the heatremoval capability of the fan coolers without the 15% sizing margin required for the fan cooler sizing by

the Utility Requirements Document (URD). This value is calculated from CENTS which is a two-phasetransient analysis tool, and is based on conservative heat losses through RCS piping and components. Themain reason for the large difference in the heat rates is the CENTS code does not account for the heat

losses of major RCS component support anchors. These are the main supports for components such as

Steam Generators (SGs), Pressurizer (PZR)... etc. These supports cannot be insulated due to concrete

temperature concerns, but are rigidly attached metallic supports and will generate a substantial amount of

heat into the RCS.

2The containment external temperature of 25 'F is determined based on equilibrium transients performed

to determine the allowable operating band that will be presented in the Tech Specs. The equilibrium

transients assumed the required heat rate to bound the operating band presented in the Tech Specs and noactive containment cooling. The operating band determined from the transient runs is:

Containment Internal/External Temperature Differential must be maintained to be < 90 'F, and if that

cannot be achieved then containment temperature must be < 80 IF.


3The same equilibrium runs depicted in footnote 2 were used to determine the containment

internal/external equilibrium metal temperatures. This is still conservative as the assumptions on heat

transfer incorporated in the Rev. 15 DCD external pressure model were assumed for the proposed DCDRev. 18 model. This is conservative as the external pressure model minimizes the internal heat transfer

mechanisms, and maximizes the external heat transfer mechanisms.

4For the proposed analysis for Rev. 18, the PCS is assumed to be in natural convection during the pre-transient equilibrium phase. This minimizes heat transfer, and at transient initiation the wind is assumed

to step change to 24.8 ft/s forced convection. This corresponds to a 48 mph outside wind. This willmaximize heat transfer for the negative pressure excursion.

5For the proposed Rev. 18 analysis the external temperature is assumed to begin decreasing from 25°F at

transient initiation according to a chopped cosine distribution. The distribution proceeds to reducetemperature from 25°F to 5 'F in 12 hours. This is done to conservatively represent a change from day

and night meteorological attributes.

Sensitivities

Sensitivities were performed at various external temperatures and pressures to identify the dominanteffects associated with the external pressure analyses. Table 5-2 shows a synopsis of the key initialconditions used for the sensitivities along with the corresponding transient pressure at t=3600 secondsafter transient initiation to facilitate determination of the dominant effect.

Table 5-2: External Pressure Transient Initial Conditions and Pressures

Sensitivity Internal External Humidity Heat Rate PressureTemperature(0 F) Temperature(0 F) (psia)

(%) (Btu/s)

1 88 -40 50 Figure 1 13.35

2 88 -40 100 Figure 1 1131.12

3 88 -40 50 0 13.18

4 120 25 50 Figure 1 13.55

5 120 25 100 Figure 1 ,12.86

6 120 25 50 0 13.39

7 120 33 50 Figure 1 13.53

8 120 33 100 Figure 1 112.91

9 120 33 50 0 13.32

The highlighted sections represent the 100% humidity cases. Maximization of humidity provides thedominant effect for the external pressure analysis and will be implemented in the new analysis presented

in AP1000 DCD Section 6.2.1.1.4.


Valve Modelin•

Once the bounding transient is identified (25 'F at 100% humidity) that transient was used to verify theperformance of the vacuum relief system. The valve will actuate on a containment low-2 pressure signal.The low pressure setpoint is -0.8 psig. The associated instrument uncertainty was assumed to be +/- 0.4psig. So the safety analysis limit for the signal generation is assumed to be (-0.8) psig + (-0.4) psig = -1.2psig. When the pressure inside containment reaches -1.2 psig the trip signal is assumed to initiate theopening of the 6" MOV vacuum relief valves. A 20 second delay from setpoint being reached to valveactuation was assumed. The MOV's are assumed to have a max 30 second stroke time, but will becapable of full flow at 60% open. So,0.6*30 sec = 18 seconds. Two seconds were added for signalprocessing delay as is customary for safety analyses not using inputs from thermocouples or resistancetemperature detectors (RTDs). These instruments have a slower response time. The valves are assumed tostay closed until 20 seconds after the signal is generated to open. This means no flow is credited forpartial opening of the valve which is conservative. A summed total system resistance was converted intoan equivalent form loss value with a bias added for conservatism. The total system form loss modeled was25.

Summary

The proposed Rev. 18 analysis uses an equilibrium run to determine more credible initial conditions forcontainment internal/shell temperatures. Sensitivities performing the entire transient in one run wereperformed, however it is impossible to have 100% humidity and be in equilibrium, because thecontainment shell is always below the dew point temperature, and the humidity always equilibrates below50% within 1,000-2,000 seconds. The containment equilibrium temperature was achieved without theactive cooling system in operation. This is conservative, as it will maximize internal temperature.Additionally, the equilibrium runs account for humidity decrease associated with condensation on theshell this too will maximize the containment temperature. The containment temperature will rise whilehumidity is decreasing because the specific heat of steam is nearly twice that of air.

Figures 5-1 to 5-3 show a comparison of the transients performed at each external temperature. TheLOAC cases are the equilibrium runs. The equilibrium transients were allowed to run for 14,400 secondsprior to transient initiation. This means humidity, shell temperatures and containment internaltemperatures were in equilibrium prior to the start of the transient. The plots of the LOAC transients donot show the equilibrium portion so that they are in phase with the 100% humidity and zero heat loadtransients, which makes it easier to determine the bounding scenario for each temperature.

From Figures 5-1 to 5-3 it is easy to see that the 100% humidity cases dominate the external pressurescenarios. Figure 5-4 shows a comparison of the 100% humidity cases. The 25 'F cases results in themaximum negative pressure scenario. This makes sense as at 120 'F inside containment the vaporconcentration, partial pressure of steam contribution to total pressure, and the corresponding condensationrate are maximized. The 25 ° F case has a slightly larger heat transfer gradient than the 33 ° F case whichis why it is the dominant transient. Figure 5 shows the actuation of the vacuum relief system to mitigatethe 25 'F transient. From Figure 5-5 it can be concluded that the vacuum relief system actuates andmitigates the containment maximum expected external pressure scenario to approximately

-1.5 psid.


Containment Pressure:-40F Transients

G,

U.)SfCo

14.6

14.4

14.2

14

13.8

13.6

13.4

13.2

13

12.8

12.6

...... ........ .............. ............................... .... .......

AA'

LOAC

- 100% Humidity

NOHL

100000 5000 15000

Time (sec)

Figure 5- 1: Comparison -40 F Transients

Containment Pressure:25 F Transients

N

0._

'C

15

14.5

14

113.5

13

12.5

12

LOAC

100% Humidity

--- NOHL

0 2000 4000 6000 8000 10000 12000

Time (see)

Figure 5-2: Comparison of 25' F Transients


Containment Pressure: 33 F Transients

15

5;

U

14.5

14

13.5

13

12.5

12

LOAC

- - 100% Humidity

. NOHL

0 2000 4000 6000

Time (sec)

8000 10000 12000

Figure 5-3: Comparison of 330 F Transients

Containment Pressure: 100% Humidity

15

c,a

U,U)

E0~Q

.E

t-

O0

14.5

14

13.5

13

12.5

-Text=-40*F

- -- Text=25 0F---Text=330 F

120 2000 4000 6000

Time (sec)

8000 10000 12000

Figure 5-4: Comparison of 100% Humidity Transients


External Temp. (25'F) 100% Humidity

14.6

14.4

14.2

14

13.8 Pressure

13.6

13.4

13.2

13

0 2000 4000 6000 8000 10000 12000

Time (see)

Figure 5-5: Bounding External Pressure with Vacuum Relief System Actuation

6.0 CONTAINMENT ISOLATION CONSIDERATION

General Design Criteria 54 through 57 applies to the containment isolation function. The following

describes how the proposed vacuum relief system addresses each of the applicable General Design

Criteria.

Criterion 54, "Piping Systems Penetrating Containment"

"Piping systems penetrating primary reactor containment shall be provided with leak detection, isolation,

and containment capabilities having redundancy, reliability, and performance capabilities which reflect

the importance to safety of isolating these piping systems. Such piping systems shall be designed with a

capability to test periodically the operability of the isolation valves and associated apparatus and to

determine if valve leakage is within acceptable limits."

Position

The system is designed such that the proposed containment isolation valves may all be

individually tested such that their individual leakage rates may be determined. The vacuum relief

check valves inside containment will be reversed flow tested using temporary spool pieces

including test connections. The outboard butterfly valves will be tested using a temporary spool

piece and test connections. Testing of butterfly valves will be in the reverse direction of

containment leakage; however, this direction is more conservative since the butterfly valve will

be installed in the non-preferred direction. This test method meets the requirements of ANSI

56.8, Section 6.2, Direction of Testing. See sketch below:


Figure 6-1: Test Direction Sketch

Test Direction Containment

0.

Criterion 55, "Reactor Coolant Pressure Boundary Penetrating Containment""Each line that is part of the reactor coolant pressure boundary and that penetrates primary reactorcontainment shall be provided with containment isolation valves as follows, unless it can be demonstratedthat the containment isolation provisions for a specific class of lines, such as instrument lines areacceptable on some other defined basis."

Position

Does not apply.

Criterion 56, "Primary Containment Isolation"

"Each line that connects directly to the containment atmosphere and penetrates primary reactorcontainment shall be provided with containment isolation valves as follows, unless it can be demonstratedthat the containment isolation provisions for a specific class of lines, such as instrument lines, areaccepýable on some other defined basis:

I . One locked closed isolation valve inside and one locked closed isolation valve outsidecontainment; or

2. One automatic isolation valve inside and one locked closed isolation valve outsidecontainment; or

3. One locked closed isolation valve inside and one automatic isolation valve outsidecontainment. A simple check valve may not be used as the automatic isolation valve outsidecontainment; or

4. One automatic isolation valve inside and one automatic isolation valve outside containment.A simple check valve may not be used as the automatic isolation valve outside containment.

Isolation valves outside containment shall be located as close to the containment as practical and uponloss of actuating power, automatic isolation valves shall be designed to take the position that providesgreater safety."

Position

The proposed vacuum relief design satisfies criterion 56, #4 in that each pathway contains oneautomatic valve outside containment and one automatic valve inside containment. A check valveis used as the automatic valve inside containment. See figure below:


Figure 6-2: General Design Criteria 55 and 56 Isolation Valve Criteria

CONTAINMENTINSIDE OUTSIDE

The containment vessel vacuum relief isolation valves are placed in a different room than the containmentpenetration that they utilize. The addition of 2 large MOVs to the containment penetration room wouldhave reduced the serviceability of the valves existing in the room, while also causing difficultly for

personnel attempting to service the news valves. For this reason, the valves were placed to ensure thatthey are safely and readily available for maintenance and testing. This is in accordance with GDC 55which states that "...Isolation valves outside containment shall be located as close to containment as

practical....

Criterion 57, "Closed System Isolation Valves"

"Each line that penetrates primary reactor containment and is neither part of the reactor coolant pressure

boundary nor connected directly to the containment atmosphere shall have at least one containmentisolation valve which shall be either automatic, or locked closed, or capable of remote manual operation.This valve shall be outside containment and located as close to the containment as practical. A simple

check valve may not be used as the automatic isolation valve."

PositionDoes not apply.


6.1 WEC RESPONSE TO BRANCH TECHNICAL POSITION 6-4

WEC Position for AP1000 Vacuum Relief Power Operated Valves: VFS-V800A/B Stroke Time and

Control Logic

Normal Vent/Purge Operation

The VFS is designed such that the 16" purge isolation valves (V003/4) and vent isolation valves(V009/10) may be open during normal operation to filter the containment atmosphere and adjustcontainment pressure and temperature. It is anticipated that the system will be in operation(valves VFS-V003/4/9/10) open for approximately 20 hours per week. The VFS isolation valvesare fast closure air operated valves designed to close with 10 seconds upon receipt of a

Containment Isolation or High Radiation signal. This function prevents the release ofradioactivity to the environment and meets the requirements of Branch Technical Position 6-4 forgreater than 8" vent and purge lines.

Vacuum Relief Power Operated Valve Design

Valves VFS-V800A/B are the outboard vacuum relief power operated isolation valves. Thevalves are specified as ASME Section III Class 2, 6" butterfly valves with motor operators. Thevalve actuator is designed to close the valve upon receipt of a closure signal within 30 seconds.

This meets the containment isolation requirements for closure as specified in ANSI 56.2, Section

4.4.4.

Valve Functional Requirements

Open - The subject valves are normally closed and must open to provide a flow path of air fromthe outside atmosphere to containment in the event of vacuum conditions inside containment.This function provides protection of the containment vessel during the bounding event: a loss of

power event coincident with cold weather conditions, as well as normal expected transients. Thevalves open automatically upon receipt of a Low-2 containment pressure signal.

Closed - The valves must remain closed to isolate the containment atmosphere from the outsideenvironment. They provide redundant isolation because the power operated valves are placed inseries with check valves. This function preserves containment integrity and precludes the release

of radioactivity to the environment. The valves receive both confirmatory Containment Isolationand High-I Containment Radiation signals to close.

Control/Logic

These valves receive the following actuation signals:

Open - V800A/B open on the following signals


* Low-2 Containment Pressure* Manual Vacuum Relief System Actuation

Close - V800A/B close on the following signals

" Automatic Containment Isolation

" High-I Containment Radiation Signal* Manual Containment Isolation

* Manual Containment Cooling

Valves VFS-V800A/B are normally maintained closed during all modes of operation withposition indication and alarms in the main control room to indicate when they are open.

To preclude the alignment of purge line isolation valves (V009 and V010) being opened at the

same time as the vacuum relief valves (V800A/B), the following interlocks exist:

* V800A/B can not be opened unless V009 is closed.

* If open, V800A/B will close when V009 is opened.

This interlock feature eliminates the need for fast closure of these valves and ensures containmentintegrity at all times.

Valve Operation

During an event of a vacuum condition inside containment valves V800A/B receive an open

command based on a Containment Low-2 Pressure signal.

Valves V800A/B have priority logic such that the "Open-on-Low-2 Containment Pressure"

Signal has priority and is generated at a containment pressure of -0.8 psig. The valves openautomatically upon receipt of this Low-2 containment pressure signal. Once the containmentpressure increases above -0. 2 psid, the Containment Low-2 Pressure signal is no longer present.

The valve remains in the open position until one of the following occurs:

• Containment Isolation

" High-I Containment Radiation

" Manual Actuation

* Manual Containment Cooling

This functionality ensures that any event requiring vacuum relief inside containment can bemitigated to protect the containment vessel. In an event resulting in a LOCA, containmentisolation is also assured.


Summary

The 30 second stroke time is acceptable for the vacuum relief power operated isolation valves(VFS-V800A/B) for the following reasons:

" In the event of a LOCA with these valves open, the releases of radioactivity during themaximum time for closure (30 seconds) of these valves has been analyzed (APP-SSAR-GSC- 113). The radiological consequences are bounded by those currently present inDCD 15.6.5.3.

" For the calculation of the minimum backpressure for a LOCA, the mass loss through the6" vacuum relief system with a 30 second valve closure time was evaluated to ensure thatthe current methodology of modeling the 16" purge line performance remains limiting.The mass loss through the 16" purge line with a valve closure time of 12 seconds isgreater than the mass loss through the 6" vacuum relief line with a valve closure time of

30 seconds (APP-VFS-M3C-224)." The vacuum relief power operated valves (V80OA/B) are maintained closed during all

modes of operation and are not relied upon for vent/purge operation. An alarm exists inthe main control room to indicate when either V800A or V800B is open.

* An interlock exists to prevent opening of the vacuum relief power operated valves(V800A/B) if the vent valve (V009) inside containment is open.

• Tech Spec 3.6.10 requires action to be taken should the vacuum relief system be declared

inoperable in Modes 1-4.* Should failure of V009 to close occur simultaneously with a LOCA, the outboard valves

(V010, V800A/B) in the flow path will perform their safety related close functions.Valve V010 will close in 10 seconds. Valves V800A/B will already be in their closed

position." Should failure of V010 to close occur simultaneously with a LOCA, the inboard valves

(V009, V803A/B) in the flow path will perform their safety related close functions.Valve V009 will close in 10 seconds. Valves V803A/B will already be in their closedposition.


7.0 SETPOINTS AND CONTROLS

The VFS has two containment vacuum relief isolation valves located in the auxiliary building. Thesevalves are motor operated butterfly valves, which are normally closed. They are automatically controlled

from the PMS and powered by Divisions A and C. The valves will open automatically by a PMS low-2

containment pressure signal with a set point of-0.8 psig. The valves will close in the event of acontainment High-1 radiation signal or a containment isolation signal. Additionally, these valves can be

closed by a manual containment isolation or containment cooling signal.

Even though the containment vacuum relief isolation valves are closed at all times, except whenmitigating a vacuum condition or for testing, an interlock is provided to automatically close them if thecontainment purge isolation valve inside containment (VFS-V009) is open. This ensures the integrity of

the containment isolation function at all times.

Opening of the containment vacuum relief isolation valves on Low-2 containment pressure or manualactuation takes priority over all signals that cause the valves to close (automatic or manual containment

isolation, High-I containment radiation, and the closure interlock based on the containment purgeisolation valves being open).

Figure 7-1: System Level Actuation of Vacuum Relief Valves


8.0 PRA/DRAP APPLICABILITY

The following evaluation is used to confirm that no addition to DAS functional capabilities is required,

and that the system reliability is sufficient so that DCD Tier 1 Section 3.7 and DCD Tier 2 Chapter 17 arenot impacted. The following evaluation also considers the applicable CCF's, and latent failures.

Reliability of Vacuum Relief:Success: /2 Check Valves (V803A/B) open and ½ MOVs (V800A/B) openFailure: 2/2 Check Valves (V803A/B) fail to open or 2/2 MOVs (V800A/B) fail to open

Probability of failure of an MOV to open including contribution from power supply and I&C (PMS autoand Manual): 4.75E-03

Failure of a check valve to open: 1.3E-05/d

CCF of 2 MOVs to open: 1.07E-03/d x 2.26E-02 (P3 factor) = 2.4E-05/dCCF of 2 check valves to open: 1.3E-05/d x 8.5E-03 ([3 factor) = 1.1E-07/d

-4 Probability of failure to actuate the vacuum relief path is:

[(1.3E-05 x 1.3E-05) + 1.1E-07] + [(4.75E-03 x 4.75E-03) + 2.4E-05] = 4.7E-05

The probability of failure to close the vacuum relief path once actuated is in the same order of magnitude.

Adding a DAS function to open the MOVs would not have a significant impact on the overall reliability

of the system since the main contributor is the MOVs CCF.

Reliability of containment isolation:

Success: 2/2 Check Valves (V803A/B) close or 2/2 MOVs (V800A/B) close

Failure: 1/2 Check Valves (V803A/B) fails to remain closed and 1/2 MOVs (V800A/B) fails to remainclosed (and close when test occurs)

Probability of failure of an MOV to close including contribution from power supply and I&C (PMS auto

and Manual): 4.75E-03

Probability of spurious actuation of a normally closed MOV: 4.45E-08/hourLarge leakage of a check valve (>50 gpm): 2.96E-08/hour

CCF of 2 MOVs to close: 1.07E-03/d x 5.96E-03 (03 factor) = 6.4E-06/d

CCF of 2 MOVs to spuriously open: 4.45E-08/hour x (2190 /2) x 2.67E-02 (P3 factor) = 1.3E-06CCF of 2 check valves to leak: 2.96E-08/hour x (17520 / 2) x 3E-02 (P3 factor) = 7.8E-06

For the PRA evaluation, it was assumed that the 2 MOVs were quarterly cycled. If the two MOVs arecycled with a decreased frequency, then the PRA evaluation on system reliability would be improved,because this would decrease the amount of time the valves would be unavailable to perform theirdedicated safety function.

It is assumed in the following calculations that the 2 MOVs will be open for 1 hour a year (unavailabilityis thus 1E-04). In that case, if containment isolation is needed, the MOVs (V800A/B normally closed)

need to close.


9.0 VALVE DETAILED DESIGN

Based on ASME Section III requirements for containment vacuum relief systems and' ANSI 56.8requirements for containment isolation, the outboard valves must be power operated (i.e. air, electric, orelectro-hydraulic) with independent power sources. The inboard valves are required to be self actuated(i.e., simple check valve).

9.1 Outboard Motor Operated Valves VFS-V800A/B:9.1.1 Mechanical Design Requirements

Valves VFS-800A/B are specified as ASME Class 2, 6" motor operated butterfly valves, with open andclosed safety functions. They will be designed in accordance with the general requirements ofWestinghouse valve specification APP-PV 1 -ZO-001. A summary of mechanical design characteristics isprovided below:

- Valve Material: Carbon Steel

- Disk Style: Triple offset with bi-directional flow- Actuator: Motor Operated with locking gear sets to ensure actuator and shaft are held in

position.- Close: Torque switch controlled.- Open: Limit with torque switch backup.

- Leak-Tightness: FCI Class V- Open/Close Stroke time of 30 seconds (max)

9.1.2 Valve Electrical Requirements:

Based upon VFS-PL-V800A and V800B being required to be stroked twice for their design basisoperation, electrical design will consider these loads in the design calculations as follows: The valve(s)will be considered a RANDOM load within the methodology required in IEEE485 for each of the twooperations and will therefore be added to the first and second worst one minute time steps of the batteryprofile.

Electrical calculations, i.e. battery sizing and cable, take into consideration both starting current andstroke time rounded up to the whole minute(s) for all MOV operation(s). A computation has beenperformed in evaluation of this design change and demonstrates that the existing component ratingrequirements are adequate. This design change will be included in final design calculations for the IDS

system.

9.1.3 Testing Requirements

The ASME OM Code was used to classify and categorize as well as specify the test requirements and

frequencies described below:

The valves are considered Active and categorized as A in accordance with ASME OM Code, ISTC-1300.The valves are tested in accordance with ISTC-3500 and Table ISTC-3500-1. The testing regime and

frequencies are listed below:

" Full Stroke Exercise - Refuel Shutdown

• Remote Position Indication - 2 Years

" Leakage Testing - In accordance with Appendix J frequency,

" Operability Test - In accordance with Power Operated Valve program


Periodic verification will be based on JOG Periodic Verification (PV) report. The key contributors toperiodic test frequency will be:

3) Risk significance (established by WEC PRA)4) Function margin (based upon standard industry equations (EPRI), along with incorporating

BWROG DC sizing methodology)

9.2 Inboard Self Actuated Valves VFS-V803A/B:

9.2.1 Mechanical Design Requirements

Valves VFS-803A/B are specified as ASME Class 2, 6" swing check valves, with open and closed safetyfunctions. They will be designed in accordance with the general requirements of Westinghouse valvespecification APP-PV03-ZO-001. A summary of mechanical design characteristics is provided below:

- Valve Material: Carbon steel with soft seats- Disk Style: Balanced- 0.2 psi differential nominal cracking pressure- Leak-Tightness: Per MSS-SP-61

Valves shall be installed in the horizontal direction, such that the checking element will close with gravityin the reverse flow direction.

9.2.2 Testing Requirements

The ASME OM Code was used to classify and categorize as well as specify the test requirements andfrequencies described below:

The valves are considered Active and categorized as A in accordance with ASME OM Code, ISTC-1300.The valves are tested in accordance with ISTC-3500 and Table ISTC-3500-1. The testing regime andfrequencies are listed below:

* Full Stroke Exercise - Refuel Shutdown

• Leakage Testing - In accordance with Appendix J frequency* Vacuum Relief Test - Refuel Shutdown


9.3 Valve Design Specifications and Datasheets

This section provides the most recent revisions of the valve design documents referenced in the NRCComment Reconciliations and Section 9.0.

The following Documents will be available for review in the WEC Rockville, MD Office as they areWestinghouse Proprietary Class 2 documents.

9.3.1 APP-PV03-ZO-001 Rev 4:

9.3.2 APP-PV03-ZOD-192 Rev 2:

9.3.3 APP-PV1l-ZO-001 Rev 2:

Design Specification - 3" and Larger Manually Operated Gate,Stop Check, and Check Valves, ASME Boiler and Pressure VesselCode Section III Class 1, 2, and 3.

AP1000 Valve Data Sheet - Check Valves, 6", CL150, CarbonSteel, Butt Weld, Class 2, Active, Containment Isolation

Design Specification - Butterfly Valves, ASME Boiler andPressure Vessel Code Section III, Class 2 and 3

9.3.4 APP-PV211-ZOD-133 Rev 2: AP1000 Valve Data Sheet- Butterfly Valves, 16" CL 150, CarbonSteel, Air-Operated, Flanged Active, Sch. STD, Class 2, FailClosed, Containment Isol.