Crystal River Unit #3Containment Delamination

Investigation & Repair

March 9, 2010Garry Miller

• CR#3 Containment Design Features• SGR Opening Sequence & Identification of Delamination• Investigative Approach• Condition Assessment• Operational Experience (OE)• Root Cause Analysis (RCA)• Design Basis Analysis (DBA)• Repair Sequence• Summary Comments / Questions

Agenda

2

CRYSTAL RIVER #3 DESIGN FEATURES

3

Fission Product BarriersSimplified Schematic

Liner

Concrete

Tendons(horizontal)

Barrier # 1- Cladding Enclosing The Fuel

Barrier # 2 – Reactor Vessel & Coolant Piping

Barrier # 3 – Containment Liner

Tendon depiction is for illustrativepurposes and is not an exact scale 4

Dimension Value

Containment Outside Dimension (OD) 137 ft 0.75 in

Dome Thickness 36 in

Basemat Thickness 12 ft 6 in

Liner Thickness 0.375 in

Wall Thickness 42 in

Buttress Wall Thickness 5 ft 10 in

Vertical & Hoop Conduit OD 5.25 in

# of Vertical Tendons 144

# of Tendon Hoops 94

# of Tendons per Hoop 3

# of Prestressed Dome Tendons 123

CR3 Containment Dimensions

5

SGR OPENING SEQUENCE & IDENTIFICATION OF

DELAMINATION

6

Steam Generator Replacement (SGR) Opening (between Buttresses 3 and 4)

7

SGR OpeningDimensions

@ Liner23’ 6” x 24’ 9”

@ Concrete Opening25’ 0” x 27” 0”

Concrete Removal

8

Concrete & Liner Removal Sequence

1 2

3 4

9

Delamination Close-up

10

Location of the Delamination

11

Note - Tendon depiction is for illustrativepurposes and is not an exact scale

INVESTIGATION APPROACH

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Root Cause AnalysisPerformance Improvement International (PII)

(Dr Chong Chiu)

Design Basis AnalysisMPR Associates, Inc

Repair Alternatives AnalysisStructural Preservation Systems (SPS)

Analysis Cross Check

Implement RepairsSteam Generator Team, Inc (SGT)

Overall Work Flow SummaryAnalysis Cross Check

Condition AssessmentConstruction Technology

Laboratories (CTL)

13

• Condition Assessment & Laboratory Testing• NDT - Construction Technology Laboratories (CTL)• Labs - MacTec, Soil& Materials Engineers (S&ME)• Other Field Data - Sensing Systems, Inc; Core Visual Inspection

Services (Core VIS), Nuclear Inspection & Consulting, Inc; Precision Surveillance; Gulf West Surveying Inc; AREVA

• Root Cause Analysis• Lead - Performance Improvement International (PII)

• Numerous PhD's (11) with expertise in root cause investigation techniques, nuclear engineering, nuclear operations & maintenance, material science & testing, concrete standards & construction, concrete testing, concrete creep, concrete fracture, human performance, process analysis, containment analysis, reliability and computer modeling

• Owner’s Support - Worley Parsons, Bechtel

External Support

14

• Design Basis Analysis• Lead - MPR Associates, Inc.• Owner’s Support - Worley Parsons

• Repair Alternatives Analysis• Lead - Structural Preservation Systems (SPS)• Owner’s Support - Wiss, Janney, Elstner, Inc (WJE)

• Industry Peer Support• Exelon, SCANA, and Southern Company

External Support (cont)

15

Nuclear Safety Oversight Committee (NSOC)Containment Sub-Committee Membership

Member Title

John Elnitsky (PGN) VP - Nuclear Plant Development (Chairman)

Joe Donahue (PGN) VP - Nuclear Oversight

Chris Burton (PGN) VP - Harris

Greg Selby Technical Director - EPRI

Dr. Shawn Hughes VP - Shaw Stone & Webster

Dr. Paul Zia Civil Engineering Professor, NCSU

Hub Miller 33 years industry oversight experience

Darrell Eisenhut 41 years industry operation and oversight experience

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CONDITION ASSESSMENT

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• Determine Extent of Condition• Characterize the extent of delamination at the SGR opening• Determine condition of other portions of structure

• Non-Destructive Testing (NDT) of Containment Wall Surfaces• Use of Impulse Response (IR) Method• Comprehensive on external exposed surfaces• Accessible areas in adjacent buildings

Condition Assessment Activities

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• Concrete Cores• Used to confirm IR results (over 116 cores)• Visual examination of core bore holes with boroscope to identify if

delamination present

• ASME Section XI IWL Visual Inspection (affected areas)

• Containment Dome Inspections• NDT IR scans in segment above the SGR opening • Concrete cores with boroscope examination of bore holes• Physical survey with established benchmarks

Condition Assessment Activities (cont)

19

l IR Equipment• Primary test method used in

this evaluation

Condition Assessment TechniquesImpulse Response (IR)

l IR Performed in the Field

20

l Ground Penetrating Radar (GPR) Equipment

w Locates internal features (rebar, tendon conduits, etc.)

Condition Assessment TechniquesGround Penetrating Radar (GPR)

l GPR Performed in the Field

21

l IE Equipmentw Ability to determine depth of

delamination

Condition Assessment TechniquesImpact Echo (IE)

l IE Performed in the Field

22

Examination – Inward View

Condition Assessment TechniquesCore Bores & Boroscopic Examination

Examination – Side View

23

1

2

3

6

5

4

Plan View

Buttress #(typical)

Construction Opening

24

SeawaterAuxiliary

Bldg

Turbine Bldg

Intermediate Bldg

Control Complex

Heater Bay Bldg

Fuel Transfer

Bldg

Fuel Pool

Aux Bldg EDG Bldg

R

T

V W X

AAZ

S

P

M O

LKJ

FED

G IH

Pour 3

Pour 4

Pour 5

Pour 6

Pour 7

Pour 8

Pour 9

Pour 10

Pour 11

Pour 12

Pour 13

Pour 14

Pour 15

Pour 16

Pour 1

Pour 2

- - - - - - - - - - - EL 240’

- - - - - - - - - - - EL 250’

- - - - - - - - - - - EL 230’

- - - - - - - - - - - EL 220’

- - - - - - - - - - - EL 210’

- - - - - - - - - - - EL 200’

- - - - - - - - - - - EL 190’

- - - - - - - - - - - EL 180’

- - - - - - - - - - - EL 170’

- - - - - - - - - - - EL 160’

- - - - - - - - - - - EL 150’

- - - - - - - - - - - EL 140’

- - - - - - - - - - - EL 130’

- - - - - - - - - - - EL 120’

- - - - - - - - - - - EL 110’

- - - - - - - - - - - EL 100’

- - - - - - - - - - - EL 90’CL CL CL CL

Containment “Unfolded” – Buttress 2 to 5Mosaic IR Overlay scale is approximate

12

3

6

54

CL

Aux Bldg Roof EL 167’ 8”

Intermediate Bldg Roof EL 149’ 0”

SGR

Opening

Equipment Hatch

A B C

D F

G I

E

H

J K L

M O

P R

N

Q

S T U

V X

Y AA

W

Z

AB ADAC

A B C A B C

D F

G I

E

H

J K L

M O

P R

N

Q

S T U

V XW

Y

Z

AA

AB

25

AC

AE

AF

AG

SGR

Opening

Y

10’ x 60’ 13’ x 42’ 10’x 16’

IR scans completed

per PT-407T:

Blue = no delamination

Actual IR scan output

data:

Blue = no delamination

Yellow= transition

Red = delaminated

Drawing scale is not exact

EL 128’

EL 128’8’ x 15’

20’ x 22’10’ x 25’

6’ x 40’ @

EL 164’’

EL 150’’

14’

x

10’

14’

x

6’

Conclusion – IR scans with confirmation core bores identified delamination only in the Buttress 3-4 span above the Equipment Hatch, as shown in red aboveConclusion – IR scans with confirmation core bores identified delamination only in the Buttress 3-4 span above the Equipment Hatch, as shown in red above

Buttress # 3 Buttress # 4 Buttress # 5Buttress # 2

10’ x60’

Pour 3

Pour 4

Pour 5

Pour 6

Pour 7

Pour 8

Pour 9

Pour 10

Pour 11

Pour 12

Pour 13

Pour 14

Pour 15

Pour 16

Pour 1

Pour 2

- - - - - - - - - - - EL 240’

- - - - - - - - - - - EL 250’

- - - - - - - - - - - EL 230’

- - - - - - - - - - - EL 220’

- - - - - - - - - - - EL 210’

- - - - - - - - - - - EL 200’

- - - - - - - - - - - EL 190’

- - - - - - - - - - - EL 180’

- - - - - - - - - - - EL 170’

- - - - - - - - - - - EL 160’

- - - - - - - - - - - EL 150’

- - - - - - - - - - - EL 140’

- - - - - - - - - - - EL 130’

- - - - - - - - - - - EL 120’

- - - - - - - - - - - EL 110’

- - - - - - - - - - - EL 100’

- - - - - - - - - - - EL 90’CL CL CL CL

Containment “Unfolded” – Buttress 5 to 2

Intermediate Bldg Roof

EL 149’ 0”

Fuel Transfer Bldg Roof

EL 200’ 4”

Intermediate Bldg Roof

EL 149’ 0”

B C

D F

G I

E

H

J K L

M ON

A B C

D F

G I

E

H

J K L

M ON

A B C

D F

G I

E

H

J K L

M ON

P RQ

S T U

V X

Y AA

W

Z

AB ADAC

P RQ

S T U

V X

Y AA

W

Z

AB ADAC

26

12

3

6

54

CL

Q

R

P

8’ x 16’

9’ x 12’

EL 160’

EL 143’

EL 119’

8’ x 12’

Actual IR scan output

data:

Blue = no delamination

Yellow= transition

Red = delaminated

28’ x11’

EL 122’

6’ x 15’ 6’ x 24’3’ x 9’

EL 180’

Conclusion – No delamination identified in these Buttress spansConclusion – No delamination identified in these Buttress spans

Drawing scale is not exact

IR scans completed

per PT-407T:

Blue = no delamination

Buttress # 6 Buttress # 1 Buttress # 2Buttress # 5

Core Bores Buttress Spans 2 - 3 - 4 - 5 (as of February 5, 2010)

Buttress # 3 Buttress # 4 Buttress # 5Buttress # 2

27

12

3

6

54

CL

Conclusion – Delamination is confined between Buttresses 3-4 spanConclusion – Delamination is confined between Buttresses 3-4 span

Drawing scale is not exact

Buttress # 6 Buttress # 1 Buttress # 2Buttress # 5

Core Bores Buttress Spans 5 - 6 - 1 - 2 (as of February 5, 2010)

28

12

3

6

54

CL

Conclusion – Core bore hole(s) boroscopic exams on these Buttress spans confirm the IR results, that no delamination has occurredConclusion – Core bore hole(s) boroscopic exams on these Buttress spans confirm the IR results, that no delamination has occurred

Drawing scale is not exact

Core Borings

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Conclusion – Delamination has only been observed in core bore hole(s) boroscopic exams in the buttress 3-4 span, as accurately predicted by IR

Conclusion – Delamination has only been observed in core bore hole(s) boroscopic exams in the buttress 3-4 span, as accurately predicted by IR

Buttress # 3 Buttress # 4

Equipment Hatch area(tendons continue below)

Buttress(typical)

Tendon Pattern

CL CL

Removed Tendon

Energized Tendon

Tendon Pattern at time of cutting SGR Opening

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SGR Opening

OPERATIONAL EXPERIENCE (OE)

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• Worley Parsons• 1976 dome delamination investigation and repair (as Gilbert /

Commonwealth)

• Structural Preservation Systems (SPS)• Largest Concrete Repair Contractor in the US, 2nd largest Concrete

Contractor (of any type) in the US• Defects, Damage, and Deterioration

• Performs > 4,000 repair projects per year

• Wiss, Janney, Elstner, Inc (WJE)• Structural engineering and materials science firm specializing in

failure investigations and problem solving• Specialist in structural condition assessments and design of repairs

and retro-fits for reinforced and post tension concrete structures• Conducted original CR3 Structural Integrity Test (SIT)

Concrete OE

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ROOT CAUSE ANALYSIS

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l 75 potential failure modes considered

l Failure Mode Categories Included:w Design & Analysisw Concrete Constructionw Use of Concrete Materialsw Shrinkage, Creep and Settlementw Chemically or Environmentally Induced Distressw Concrete – Tendon – Liner Interactionsw SGR Containment Cuttingw Operational Eventsw External Events

Root Cause Analysis (RCA)

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• Impulse Response (IR) Scans • Boroscopic Inspections

• Core bore holes

• Inside the delaminated gap

• Visual Inspections • Delamination at SGR Opening

• Larger fragments from concrete removal process

• Containment external surface

Root Cause AnalysisField Data Acquisition

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• Nearby energized tendons lift-off (vertical and horizontal)

• Containment dimension measurements

• Strain gauge measurements

• Linear variable displacement transducer (LVDT) gap monitoring

• Building natural frequency

Root Cause AnalysisField Data Acquisition (continued)

36

• Core Bores Laboratory Analyses • Petrographic Examination• Modulus of Elasticity and Poisson’s Ratio• Density, Absorption, and Voids• Compressive Strength, Splitting Tensile Strength, and Direct

Tensile Strength• Accelerated Creep Test• Accelerated Alkali Silica Reaction (ASR) Test• Chemistry and Contamination Test• Scanning Electron Microscope (SEM) Examination of Micro-

Cracking

Root Cause AnalysisField Data Acquisition (continued)

37

l 65 Failure Modes Refuted

l Remaining 10 Failure Modes were Combined for Root Cause Analysis (with 3D Fracture Analysis and Various Special Tests) to Determine their Significance (if any)

l Delamination Occurred as a Result of Outage Activities to Create an Opening for Steam Generator Replacement

Root Cause Analysis

38

Yellow line denotes boundary of delamination

DESIGN BASIS ANALYSIS

39

MPR Design Basis AnalysisFinite Element Analysis (FEA) Model Details

Mesh at Ring Girder connection

Mesh at Foundation connection

Modeling of Tendons

Composite FEA Model

40

REPAIR SEQUENCE

41

Engineering & Repair Work Flow

De-tension Additional Tendons

ImplementCrack Arrest

Strategy

Delamination Removal

Re-tensioning & Post-Repair

Testing

EC ModPhase 1

Crack ArrestEC 75000

EC ModPhase 3RemovalEC 75219

RCA Failure Modes Analysis

Cross CheckFinal Root

Cause Analysis

MPR 3D Finite Element

Analysis

EC ModPhase 2

De-tensioningEC 75218

RCA Failure Modes Analysis

Cross Check

EC ModPhase 4

PlacementEC 75220

EC ModPhase 5

Re-TensioningEC 75221

Reinforcement & Concrete Placement

SGT Engineering & Construction Input (Permanent Repair)

MPR TendonAnalysis

Sequence

Permanent Repair

SGT Engineering & Construction Input

(Repair Preparations)

PII AbaqusAnalysis of

MPR Tendon (# and sequence)

Indicates Completed Task

42

MPR Calcon Tendon

(# and sequence)

Summary & Questions

43

l Design is Acceptable for Normal and Emergency Operations

l Construction was in Accordance with Design

l Delamination Occurred during the Outage

l Investigation was Thorough and Comprehensive

l New State-of-the-Art Analytical Methods Had to be Created to Analyze Containment Response