advanced sodium technological reactor … sodium technological reactor for industrial demonstration...
TRANSCRIPT
ASTRID
ADVANCED SODIUM TECHNOLOGICAL
REACTOR FOR INDUSTRIAL DEMONSTRATION
JUNE 2012
IIAEA TWG FR, Argonne USA, 20 – 22 June 2012 | Alfredo Vasile
| PAGE 1CEA | JUNE 2012
Presented by A. VASILE (CEA)
OUTLINE
| PAGE 2CEA | JUNE 2012
ASTRID objectives and organization of the project
General features of the reactor
Safety: Examples of major improvements
Conclusions
ASTRID OBJECTIVES
| PAGE 4CEA | JUNE 2012
Industrial prototype (could be a step before a Firs t Of A Kind)
Including French and international SFRs feedback
A GEN IV system
SafetyLevel at least equivalent to GEN III systemsProgress on specific Na reactors issuesIncluding FUKUSHIMA accident feedback
OperabilityLoad factor of 80% or more after first “learning” yearsSignificant progress concerning In Service Inspection & Repair (ISIR)
Waste transmutationDemonstration of minor actinides transmutation according to June 28, 2006 French Act on Waste Management
A mastered investment cost
Irradiation services and options test
PROJECT ORGANIZATION
| PAGE 5CEA | JUNE 2012
CEA/Nuclear Energy Division is the leader of the ASTRI D project
Industrial partnerships to cover main design engineeri ng batchesAREVA NP: nuclear island (core and fuel stays at CEA)Support to the owner by EDFALSTOM: turbine islandBOUYGUES:civil engineeringCOMEX NUCLEAIRE: batches in robotics and mechanicsTOSHIBA: development of large electromagnetic pumpsOn going discussions for other partnerships
Manpower: 300 CEA, 200 industry
For technical developments and experimental facilities , CEA iswilling to develop international partnerships
INTERNATIONAL COLLABORATIONS
RussiaMaterial irradiations in BOR-60, Neutronics in BFSPossibility of fuel irradiations in BN-600 ?
IndiaStrong collaboration, several Implementing Agreement on going on safety, including severe accidents
USASeveral STCsSafety benchmark on CFV core
JapanSeveral STCsEAGLE collaboration
EuropeCP-ESFR project, SOFIA proposalNext Framework program in preparation (2014-2020)
Korea, China, Argentina
CEA | JUNE 12th 2012 | PAGE 6
SCHEDULE FOR ASTRID AND ASSOCIATED FACILITIES
| PAGE 7CEA | JUNE 2012
2009 2010 2011 2012 2013 2014 2015 2016 2017
Decision to continue
Preliminary choice of options
Decision to build
Pre-conceptualdesign
Conceptualdesign
Basic design
Fuel loading
Detaileddesign
& Constructi
on
ASTRID
Facilities
Feasibility Report on minor
actinides partitioning
Position Report on minor actinides partitioning and transmutation
Core manufacturing
workshop (AFC)
MA bearing fuels fabrication facility
Commercial deployment: from 2040-2050
Mid of 2010: preliminary selection of ASTRID characteristics for launching the preconceptual design
Preconceptual design: 2010 to end of 2012: The preconceptual design is considering some open options. Innovation and technological breakthroughs are favored, while maintaining risk at an acceptable levelDuring the preconceptual design phase, start of the interactions with the Safety authorities on safety objectives and orientationFirst estimation of ASTRID investment cost, including the different open optionsSchedule of next steps and their associated costs Safety orientation report: report delivering and first advices of the French Safety Authorities
End 2014: Conceptual designSafety Options File
MAIN MILESTONES
CEA | JUNE 2012 | PAGE 9
1500 thMW - ~600 eMW pool type reactorWith an intermediate sodium circuit High level expectations in terms of safety demonstrationPreliminary strategy for severe accidents (core catcher…)Diversified decay heat removal systemsOxide fuel UO2-PuO2 for starting cores Transmutation capabilityFuel handling in sodium….
Main features Open options
Core designEnergy conversion systemReference : water/steamAlternative : N2 Number of loopsDevices to eliminate severe accidents (i.e. 3rd shutdown level)Core catcher technologySGs materials and technologyInnovative technologies for Na fires detection and masteringI&C
• …
Carbide fuel
SiC-SiC materials
…Many of these options will be decided during the pre-conceptual design up to end 2012,
Innovative options to be tested
PRELIMINARY DESIGN CHOISES / OPEN OPTIONS
CEA | JUNE 2012 | PAGE 11
MATERIAL SCOPE
Core structures400 – 700°C nominal850-900°C accidental
High irradiation No swelling
Fixed structuresLife time
40 �60 years
Vessel400°Cno deformationnegligeable creep
Cold structuresHeat exchanger, Pumps400°C + low irradiation no deformation
Hot structures550°C + low irradiation
creep, seal coef., weldings
SGs, Energy conversion System
350 – 525°Cageing, weldings, compatibility
Pipes and circuits350 – 550°C
creep, fatigue, creep-fatigue, thermal fatigue,ageing
weldings
First coreEM10->T91/T92 ?
AIM1->AIM2 ?
316 LN 316 LN
316 LNNi alloy
316 LN800H9 Cr ?
316 LN9 Cr ?
Specific field of investigation : long
term process, nuclear facilities…
Long term R & DF/M ODS->Base V ?Ceramics->SiC/SiC ?
To extend R&D programs on accidental conditions (fr om the Fukushima accident): high temperature material beha viour: creep, creep-fatigue,
Stellites replacements: aims to gain benefits for decommissioning,
Welded seals behaviour,
Material behaviour justification up to lifetimes of 60 years
MATERIAL SCOPE – ASTRID FOCUS
CEA | JUNE 2012 | PAGE 14
A progressive approachflexible to meet the decisions according to June 28, 2006 French Act on Wastes Management –1st milestone � end 2012
2 levels of demonstration:experimental stage� Pellets� A few pins� A subassemblyreserved positions for several subassemblies
2 ways considered : homogeneous and heterogeneous
Transmutation of Am, eventually Np and Cm
Specification for ASTRID in 2012
TRANSMUTATION CAPABILITY
CEA | JUNE 2012 | PAGE 16
A CORE WITH ENHANCED SAFETY
Feedback experiencefrom SPX and EFR :
� To reduce the fuel reactivity loss per cycle
� To reduce the sodium void worth
2009 : heterogeneities added to SFRv2 core
� Sodium void worth strongly reduced
� Quantification of the potentialbenefit from safety point of view ison going
Absorbing protection
Sodium plenumzone
Outer fissilezone
Inner fertile zone
Upper inner fissile zone
Lower inner fissile zone
Fertile blanket
Neutronic protection
Absorbing protection
Sodium plenumzone
Outer fissilezone
Inner fertile zone
Upper inner fissile zone
Lower inner fissile zone
Fertile blanket
Neutronic protection
CFV core
2008 : concept with larger pin and smaller-diameter spacing wire� Increase of the fuel fraction
� Low reactivity loss during cycle
� Decrease of the Na fraction ⇒ lower Na voiding effect
� Progress on control rod withdrawal
SFRv2 core
� Choice of the core: september 2012
CEA | JUNE 2012 | PAGE 19
SFRv2 – AIM1 – 1500 MWth CFV – V1 - AIM1 – 1500 MWth
Spatial distribution of the sodium void effect Spatial distribution
of Doppler
EA
NO
S/P
AR
IS C
ALC
ULA
TIO
NS
CORE DESIGN OPTIONS: SFRV2 AND CFV LAYOUTS
CEA | JUNE 2012 | PAGE 20
Core 1500 MWth SFRV2B CFV-V1Number of fuel pin / SA 169 217
Fuel pin diameter (mm) 9,43 8,45
Pu enrichment E1/ E2 (%) 13,9 / 17,6 23,5 / 20
Height H1 / H2 (cm) 110 80 / 90
Number of SA C1 / C2 144 / 144 177 / 114
Number batch / Fuel cycle lenght
4 x 390 JEPP
4 x 360 JEPP
Void effect ($) - RZ +5,1 -0,5
Breeding gain -0,05 -0,02
TCT average fissile C1/C2 (GWj/t)
76 / 67 105 / 69
∆ρ∆ρ∆ρ∆ρ / cycle (pcm/jepp) -2,2 -4,3
Number of CR 18 + 6 (*) 12 + 6
Core diameter (cm) 326 340
Plin max BOL (W/cm) 407 483
Amplification based on individual effects
CORE DESIGN OPTIONS: SFRV2 AND CFV CHARACTERISTICS
CEA | JUNE 2012 | PAGE 21
Best estimate calculations ⇒⇒⇒⇒ trends
(uncertainty analysis is on-going)
CFV V1 V2B
ULOSSP Margin to Na boiling of ≈≈≈≈ 55°C Na boiling in ≈≈≈≈ 100s
ULOF Na boiling in ≈≈≈≈ 3500s Na boiling in ≈≈≈≈ 100s
ULOHSTemperature of neutronic
shutdown : 700°CTemperature of neutronic
shutdown : 800°C
LIPOSO 680°C / 45%Pn 736°C / 43%Qn
• CFV core: a promising core for an improved intrinsi c behaviour in case of unprotected situations and control rod withdrawal
•Analysis of severe accidents conditions are on-goin g
•On-going definition of version 2 of CFV core for im proving inherent behaviour (with the objectives to increase the sodium boiling margin and robust demon stration of no fuel melting in case of CRW)
COMPARISON OF PRELIMINARY RESULTS ON UNPROTECTED LOSS OF FLOW SITUATIONS
CEA | JUNE 2012 | PAGE 22
Natural behavior favorable for transients of unprotec tedloss of flow and loss of heat sinkTarget criteria : no sodium boiling for a ULOSSP transient
Sodium void effect minimizedTarget criteria : Na void effect < 0
Natural behavior favorable for a complete control rodwithdrawal (with no detection) Target criteria : no fuel melt
Improved performancesTarget criteria : Cycle length ≈ 480 efpd, High fuel burnup, and breeding gain ≈ 0
Core design extrapolable to higher power
CORE DESIGN OBJECTIVES
CEA | JUNE 2012 | PAGE 23
2. Mitigation of the core meltdown To garantee that core meltdown accidents don’t lead to significant mechanical energy release, whatever ini tiator event
by a favorable natural core behavior (negative sodium void worth for CFV type core)by adding specific mitigation dispositions in case of natural behavior is not sufficient
Absorbing protection
Sodium plenumzone
Outer fissilezone
Inner fertile zone
Upper inner fissile zone
Lower inner fissile zone
Fertile blanket
Neutronic protection
Absorbing protection
Sodium plenumzone
Outer fissilezone
Inner fertile zone
Upper inner fissile zone
Lower inner fissile zone
Fertile blanket
Neutronic protection
ASTRID core design is mainly guided by safety objectives:1. Prevention of the core meltdown accident
by a natural behavior of the core and the reactor (as 3rd line of defense in case of no actuation of the two shutdown systems)• Natural behavior favorable for transients of unprot ected loss of flow and loss of heat sink
Target criteria : no sodium boiling for a ULOSSP transient for CFV type core (CFV = Low Na void worth core)• Sodium void effect minimized
Target criteria : Na void effect < 0 for CFV type core• Natural behavior favorable for a complete control r od withdrawal (with no detection)
Target criteria : no fuel fusion
by adding passive complementary systems if natural behavior is not sufficient for some transient cases
CORE DESIGN APPROACH
CEA | JUNE 2012 | PAGE 24
ISSUES TO BE INVESTIGATED BY EXPERIMENTS
Measures for In-Vessel-Retention (IVR) have priority but 3 options are open
External core-catcherCore-catcher between 2 vessels
Internal core-catcher
Design studies for ASTRID aim at preventing the risk of core melting.
However according to the WENRA 2010 « Safety Objectives for New Nuclear Power Plants », 4th level of in depth prevention request that this accident will be taken into account in the design process.
CEA | JUNE 2012 | PAGE 25
DECAY HEAT REMOVAL ARCHITECTURE
Sodium/air loop, using secondary circuit (connecte d circuit on secondary pipes, or dedicated heat exchanger integr ated in Intermediate Heat Exchanger)
Circulation of air along steam generators vessels
Dedicated circuit set outside ofreactor vessel, using vesselwall as heat exchange surface
Dedicated sodium/air loop,with its own heat exchangerlocated in the primary circuit
4 – Na/air loop, dedicated loop in the
main vessel
1 – Na/air loop, using secondary loop
3 – cooling through the vessel
2 – air circulation along steam generator
CEA | JUNE 2012 | PAGE 26
SODIUM WATER REACTIONS
Sodium – water reactionViolent and exothermic reactionMain reaction : Na + H2O � NaOH + ½ H2 + 162 kJ/ mole of water (at 500°C)
Effects of a sodium-water reaction in a Steam Generator
� Chemical effectsGlobal corrosion in polluted sodium environmentLocal erosion / corrosion (« wastage »)� self-evolution of the tube leak orifice� damage of the nearest tubes
� Mechanical effectsFor large leaks(>100 g/s)
� Fast over-pressure associated to pressurewave propagation
� Slow over-pressure associated to massive introduction of water in secondary sodium circuit
� Thermal effectsFor large leaks(>100 g/s) and due to exothermal reaction
� effects on tubes : heating, creeping, swelling, burst
2 ways to reduce the SWR risk:– Improve SG design of the steam PCS (Rankine cycle) in order to :
• reduce the risk of SWR occurrence• limit the consequences of an hypothetical violent reaction
– PCS (Brayton cycle with pure nitrogen at 180 bar) in place of steam cycle to eliminate de facto the SWR risk
• Feasibility to be demonstrated.CEA | JUNE 2012
STEAM POWER CONVERSION SYSTEM (1/2)
Innovation : modular SGsProtection of secondary piping and intermediate heat exchanger integrity in case of simultaneous failure of all the tubes of a SG module (accidental envelope case)
Imply a maximal SG power of about150 MWth
Improvement of detectionHydrogen detection by means of permeationthrough very sensitive nickel membrane but :Complicated fabrication and operationResponse time to be optimized An electro-chemical flow meter has been tested recently in PHENIXSimplerPossible optimization of response timeStudy of diversified detection method based on acoustic principle in progress
Protection against large sodium-water reactions ensured by :Passive fast draining of the sodium loop by means of rupture diskFast insulation and depressurization of the water-steam loop
CEA | JUNE 2012 | PAGE 28
STEAM POWER CONVERSION SYSTEM (2/2)
Reverse SG (sodium inside the tubes)� Innovative approach with SG no sensitive to wastage phenomena occurring in
classical SGs
Reduce the probability of crack to leak evolution (tubes with external pressure)
Speeds up the leak detection
Slow down drastically the propagation of a possible SWR
Feed-back : 2 designs of reverse SG operated in BOR-60 reactor
Preliminary design of 125 MWth modules achieved
Issues :Dimensioning of external pressurized shellModeling of the sodium-water reactionGeneral design of the reverse SGIn service inspection CEA | JUNE 2012 | PAGE 29
GAS POWER CONVERSION SYSTEM (1/2)
Very innovative concept with feasibility to be demonstrated Nitrogen selected as gas, at a pressure of 180 barsEncouraging first resultsNet efficiency of the reactor plant about 38% possibleTurbomachinery
TurbineTwo possible designs: single flow and split flow with high isentropic efficiency (94%)
Turbine design challenging but not unfeasible (no showstopper identified)
Compressor
Two technologies (axial and radial) with equivalent isentropic efficiency (90%)
Radial technology should be put forward : simpler, cheaper, no performance test required
HP and LP compressors with same technology
CEA | JUNE 2012 | PAGE 30
GAS POWER CONVERSION SYSTEM (2/2)
Key points on sodium/gas heat exchangersCompact heat exchangers
PCHE heat exchanger technology choosenTechnological issue of the gas PCS: codification,fabrication control and In Service Inspection
Tubes and shell heat exchangersMore robust back-up option, but very heavy components and largefloor space requirements, feasibility and integration to be detailed.
General architectureInvestigation in progress to optimizepiping layout, performance(pressure losses), accessibility,maintenance and operation.
CEA | JUNE 2012 | PAGE 31
SURVEILLANCE AND ISI&R: A FOUR LEVEL STRATEGY
AS
TR
ID IS
I&R
L1: Continuous monitoring
Statutory ISI
L2: Periodic examination
Statutory ISI
L3: Exceptional interventions
Doubts / warnings
L4: Repair
Investment protection
Looking for …* Operating parameters variation
* Abnormal deformation of structures
* Vibrations
* Leakage
* Safety …
Considered options•improve the prevention level
• Robust and redundant detection systems
•Innovative instrumentation
•Up to date technologies
* Excessive deformations
* Fatigue (or creep-fatigue) cracks next to the welded junction
* Corrosion / loss of thickness
* Erosion on rotating parts
* …
•ISI&R oriented design
•Under Na telemetry
•Under Na volumetric NDT
•Under sodium robotic carriers
• …
* The same type as for Level 2
• Localization : everywhere !• The same type as for Level 2
* Noxious cracks
* Loss of parts
* Stuck mechanisms
* Out of use primary components
* …
Repair …•Removable components
•Specific repair tools
• …
CEA | JUNE 2012 | PAGE 32
Inlet and outlet coretemperature∆T, CRW(TIB ?)
TC, optical fiber, flowmeter
Inlet and outlet coreflowrate
TIB, loss of flow
Surveillance ciel de pileGaseous FP Clad failure
Localisation in gazGaseous FPIonisation chamber,
Spectro g, (CRDS)
Neutronic monitoringFonctionnement, CRW
High Temperature FissionChambers with largedynamics
Clad Failure Detection
in Na Open CF, BTI
HTFC / IHX
Clad failure Localisation in Na
FP neutronic detection
FC with B
US telemetry under NaCore movment,(Temperature)
Acoustic DetectionAbnormal noise (TIB?)
Active Acoustic Det.Gas rate
SONAR, TUSHT…
CoreCFV
InnovativeLine of Defense A
( ) R&D
SURVEILLANCE AND PROTECTION OF THE CORE
CEA | JUNE 2012 | PAGE 33
R&D results [CEA-AREVA-EDF] obtained from 2007 to 2009 have contributed to ASTRID mid 2010 choice of options
ASTRID has the objective to demonstrate at the industrial scale progress in the identified domains of SFR weakness (safety, operability, economy) and to perform transmutation demonstrations
A lot of improvements are related to safety
The first very important milestone is 2012 (June 2006 French Act on wastes management) :
ASTRID pre-conceptual design studies : 2010-2012
First investment cost evaluation
First safety Authorities advice on the orientations for ASTRID safety
With the ASTRID program funded by the French government, France has the opportunity to develop a GEN IV Sodium Fast Reactor
CONCLUSIONS
CEA | JUNE 2012 | PAGE 34
FAVOURABLE CHARACTERISTICS OF SFR
Easy to operate: no pressurization of the primary coolant, high thermal inertia, control by single rod position, no xenon effect, no need of soluble neutron poisonRadiation protection : higher level of protection than LWRFew effluents and little radioactive waste High thermal efficiency Large sodium boiling marginNatural convectionDiversification of heat sink by using air
Rapsodie (1967-1983)
Phénix (1973-2010) Super-Phénix (1985-1998)
CEA | JUNE 2012 | PAGE 36