CORPUS : A MULTIPHYSICS SALOME APPLICATION FOR REACTOR MULTIPHYSICS ANALYSIS

Transcription

1 JUS 2016 EDF LAB, Saclay, December 09 CORPUS : A MULTIPHYSICS SALOME APPLICATION FOR REACTOR MULTIPHYSICS ANALYSIS COUPLINGBETWEENTHE NEUTRONICS(APOLLO3 ) THE THERMAL-HYDRAULICS (FLICA4) AND THE FUEL PERFORMANCE (ALCYONE/PLEIADES) FOR THE MODELING OF A PWR ROD EJECTION ACCIDENT (REA) Jean-Charles LE PALLEC 1,K. Mer-Nkonga 2, N. Crouzet 1 1 CEA France, DEN/DANS 2 CEA France, DEN/CAD PAGE 1

2 OUTLINE Context CORPUS multi physics platform REA Exercice Conclusion and Prospects PAGE 2 7 DÉCEMBRE 2016

3 CONTEXT REA phenomenology REA challenges CEA 10 AVRIL 2012 PAGE 3 7 DÉCEMBRE 2016

4 REA PHENOMENOLOGY Control rods ejection(0.1s) fast reactivity core transient(1s) 1. Core power especially around the ejected control rod assembly 2. Corepower due to the Doppler (1 st order) + moderator(2 nd order) feedbacks 3. Core power due to the control rods emergency shutdown( scram ) core Γ max P core max t F hot spot < 100 ms 10 P nom 200 ms 20 Integrity of the first containment barrier (cladding) SAFETY CRITERIA: fuel temperature, fuel enthalpy, clad temperature 7 DÉCEMBRE 2016 JUS EDF Lab, Saclay, December 09 PAGE 4

5 REA CHALLENGES Access to safety criteria = local responses(fuel) 3D modeling multiphysics approach Fuel performance Doppler feedback Neutronics Core power Safety criteria Thermalhydraulics Moderator feedback MODELING FOR SAFETY ANALYSIS : methodological evolution From conservatism to best-estimate (BE) approach 2D static/1d kinetic 3D cinétique BE modeling = CORPUS development framework JUS EDF Lab, Saclay, December 09 PAGE 5

6 CORPUS PRESENTATION Motivation Perimeter Architecture Current modeling development CEA 10 AVRIL 2012 PAGE 6 7 DÉCEMBRE 2016

7 CORPUS: OVERVIEW(1/2) A SALOME application for reactor multphysics analysis Core design: LWR (900MWe,1300MWe, N4, EPR, GEN3+) Accident scenarios: steady state and transient : RIA (MSLB, REA) 7 DÉCEMBRE 2016 JUS EDF Lab, Saclay, December 09 PAGE 7

8 CORPUS: OVERVIEW(2/2) CALCULATION SCHEMES Integral plant analysis (MSLB) Core analysis (REA) Th. limit conditions CRONOS2 (Access) FLICA4 (Access) CATHARE2 (ICoCo) APOLLO2 Cross-sections Library Interpolation process (INTERP2_5D) Mixing grid application (MELANGE) 7 DÉCEMBRE 2016 JUS EDF Lab, Saclay, December 09 PAGE 8

9 CORPUS: ARCHITECTURE (1/2) «Russian doll» structure based on SALOME environment Supervision of distributed components (implementation of multiphysics schemes). Codes C++ wrapper libraries (API). Generation of SALOME components with YACSGEN CODES Prerequisisites (C, C++ Fortran libraries) 7 DÉCEMBRE 2016 JUS EDF Lab, Saclay, December 09 PAGE 9

10 CORPUS: ARCHITECTURE(2/2) Typical API used for CODE supervision Method initialize(), terminate() solve(), interate() computetimestep () inittimestep (dt) solvetimestep () validatetimestep ()/aborttimestep () save()/restore() setinputfield(), getinputfield() definition Initilize/finalize the problem Resolution of steady problems Time step value estimation Initialise all the variables for the time step Start the calculation on the time step Validate/Abort the time step calculation Save the internal state, and restore it Field Exchange at MED format ICOCO : standard API for code coupling shared by a large range of SALOME codes (neutronics, thermalhydraulics, fuel, from core to system description) adopted notably by the EU NURESIM platform 7 DÉCEMBRE 2016 JUS EDF Lab, Saclay, December 09 PAGE 10

11 CORPUS : CURRENT MODELING DEVELOPMENT (1/4) BE fuel description challenges Doppler Feedback Fuel performance neutronic Power 1 f gamma f gamma Heat exchange Moderator Feedback thermohydraulique Existing modeling: internal fuel treatment in CRONOS2(C2) and FLICA4 (F4) Limitations = modeling limited to the thermal response calculation (heat conduction eq.) Dynamic fuel/clad gap: NO ( simplified H gap model) Fuel irradiation state (rim effect): NO Target modeling: go beyond those limitations use of a dedicated code = ALCYONE + CRONOS2 APOLLO3 switch JUS EDF Lab, Saclay, December 09 PAGE 11

12 CORPUS : CURRENT MODELING DEVELOPMENT (2/4) Development strategy STEP by STEP Final target: APOLLO3 /FLICA4/ALCYONE coupling Neutronics C2 AP3 AP3 Thermalhydraulics Starting point F4 AL F4 Fuel performance AL Intermediate modeling: APOLLO3 /ALCYONE coupling 7 DÉCEMBRE 2016 JUS EDF Lab, Saclay, December 09 PAGE 12

13 CORPUS : CURRENT MODELING DEVELOPMENT (3/4) REA scenario target PWR1300MWe GEMMES managment (193 UOx assemblies - 24 with Gd) modeling steps (APOLLO3 /ALCYONE coupling) STEP1 Irradiation state calculation (depletion) APOLLO3 /ALCYONE coupling STEP2 Control Rod specification APOLLO3 Internal simplified fuel/fluid description 0: Fresh fuel assembly 1: Assemblies batch 1 2: Assemblies batch 2 3: Assemblies batch 3 STEP3 REA transient APOLLO3 /ALCYONE coupling Ejection of the Control rods situated in H2 ass. Hot spot in the H1 ass. 7 DÉCEMBRE 2016 JUS EDF Lab, Saclay, December 09 PAGE 13

14 CORPUS : CURRENT MODELING DEVELOPMENT (4/4) Design simplification for calculation schemes development Principle: to make the developments on a small core (mini-core denomination) submitted to a REA scenario accident and update them progressively in the full core design Simplification of the coupling scheme analysis and the simulation in terms of computation time + data analysis APOLLO3 /FLICA4/ALCYONE coupling on a mini-core design 7 DÉCEMBRE 2016 JUS EDF Lab, Saclay, December 09 PAGE 14

15 REA EXERCICE Mini core presentation REA scenario Modeling First results CEA 10 AVRIL 2012 PAGE 15 7 DÉCEMBRE 2016

16 MINI-CORE PRESENTATION (ACCADEMIC CASE) MiniCore design 3D 3*3 fuel core with a reflector envelope Standard fuel assembly design Geometric data Assembly pitch m Fuel pins per assembly 264 Fuel Cell dimension m Active height m Reflector height m (bottom/top) Clad external radius 4, m Clad internal radius 4, m Fuel pellet radius 4, m isotopic data (fresh fuel) U 235 enrichment 4% Control Rod to be ejected JUS EDF Lab, Saclay, December 09 7 DÉCEMBRE 2016 PAGE 16

17 RIA SCENARIO STEP 1: cycle length calculation BU(x,y,z) at the beginning of the transient (EoC config.) STEP 2: characterization of the Control Rod to be ejected (CR worth) STEP 3: REA transient calculation STEP1 Core Power (Pcore) NOC * W/ HS ** W Average linear fuel NOC W.m -1 power (Plin) HS 1W.m -1 Initial core Burn-up 0 MWd/t (fresh core) Depletion duration STEP1 result HS to NOC transition 1 day STEP3 Initial Pcore/Plin HS level Initial core Burn-up STEP1 result Rod ejection duration 0.1s Transient duration 0.3 s STEP1/STEP3 (common data) Fast neutron Flux *** n.j -1. m -1 Plin Fuel cell mass flow kg.s -1 Outlet Pressure Pa Inlet fluid temp. 563 K 3 calculation steps Fuel/clad accomodation (*) NOC: Nominal Operating Condition (**) HS: Hot Shutdown (***) E neutron >1Mev 7 DÉCEMBRE 2016 JUS EDF Lab, Saclay, December 09 PAGE 17

18 APOLLO3-ALCYONE MODELING CALCULATION SCHEME (1/3) Models and data exchanges (+ simplified thermal hydraulics) P fuel INTERPOLATION Multi-threaded calculation ρ fluid /T fuel 7 DÉCEMBRE 2016 JUS EDF Lab, Saclay, December 09 PAGE 18

19 APOLLO3-ALCYONE MODELING CALCULATION SCHEME (2/3) import Queue, threading class ThreadOneAlcyoneStep(threading.Thread): CODE SAMPLE def init (self, queue_in, queue_out): threading.thread. init (self) self.queue = queue_in # resources self.queue_out = queue_out # results Code sample Initialization def run(self): while True: ressources = self.queue.get() pinid=ressource[0] alcyone_compo=ressource[1] # ETC alcyone_compo.inittimestep(currenttimestep) alcyone_compo.setinputfield( linpower", power) if alcyone_compo.iteratetimestep() : # send results in output queue fuel_temperature=alcyone_compo.getoutputfield("temperature") fcoolant_density=alcyone_compo.getoutputfield("rhok") output=[pinid, fuel_temperature, coolant_density] self.queue_out.put(output) else: # Stop computation self.queue.task_done() # signals to queue that the job is done Get the resources Compute one Time-step Get results and Put them in out queue 7 DÉCEMBRE 2016 CEA 26 SEPTEMBRE 2012 PAGE 19

20 APOLLO3-ALCYONE MODELING CALCULATION SCHEME (3/3) time marching management Depletion (STEP1) - Synchronous implicit Block Gauss-Seidel (BGS) coupling scheme with a relaxation method to improve efficiency - Time step ( t i, i+1 ) determined by ALCYONE (stability of the thermo-mechanical/thermalhydraulics resolution) If the current time step does not converged (due to a code or to the BGS coupling scheme), the time step is divided by two and the BGS computation is restarted REA transient (STEP3) - Synchronous explicit scheme - Time step ( t i, i+1 ) determined by APOLLO3 constant value during the transient ( t i = 1.e -3 s) AP3 t i t i+1 Kinetic 1 calculation 2 AP3 t i t i Depletion 5 calculation ALC Kinetic 7 DÉCEMBRE calculation 4 ALC BGS (CV criteria) Depletion 7 DÉCEMBRE calculation 4 1 = Stationary calculation JUS EDF Lab, Saclay, December 09 PAGE 20

21 APOLLO3-ALCYONE MODELING FIRST RESULTS (1/2) Depletion calculation (STEP 1) Limitation: each code runs its own depletion model that potentially lead to a drift in terms of BU comparison of the burn-up evolution obtained by APOLLO3 and ALCYONE: close behavior of the 2 models coherence between the two codes in terms of depletion Coupling effects Local effects Global effects CBoron BoD * BUEoD ** [MWd/t] [ppm] APOLLO APOLLO / ALCYONE 1499 (-22) (-21) (*) Boron concentration at the Begin of Depletion (**) Core Burn-up at the End of Depletion effect of a fine fuel description on a depletion calculation without invalidating the simplified fuel/fluid modeling currently used for cycle length calculations 7 DÉCEMBRE 2016 JUS EDF Lab, Saclay, December 09 PAGE 21

22 APOLLO3-ALCYONE MODELING FIRST RESULTS (2/2) REA transient (STEP 3) ρ = 1,55$ Fraction of delayed neutron [pcm] 568 Control rod worth [pcm $] Adiabatic model ALCYONE Max. linear fuel Power (Pmax) [W.m -1 ] linear fuel energy at t = 0.3s [J] Pulse width at Pmax/2 [ms] Max. Fxyz consistence between the 2 models that gives a good level of confidence of the coupling APOLLO3 /ALCYONE 7 DÉCEMBRE 2016 JUS EDF Lab, Saclay, December 09 PAGE 22

23 APOLLO3 - FLICA4- ALCYONE MODELING REA transient (STEP 3) Fuel: Fluid: proof of concept coupling effect to be analysed JUS EDF Lab, Saclay, December 09 PAGE 23

24 CONCLUSION AND PROSPECTS CEA 10 AVRIL 2012 PAGE 24 7 DÉCEMBRE 2016

25 CONCLUSION AND PROSPECTS (1/2) promising opening: first demonstration of the CORPUS capability to integrate a BE fuel description (ALCYONE) in a PWR core model for depletion and transient analysis in terms of calculation schemes Conclusion Prospects Numerical aspect: calculation time optimisation and robustness improvement Data exchanges: extension to the fast neutron flux from APOLLO3 to ALCYONE Feedback models: Fuel effective temperature formula from T Rowland to T Alcyone in terms of scenario calculation accademic case realistic REA bias analysis (typically simplified fuel description versus BE modeling) 7 DÉCEMBRE 2016 JUS EDF Lab, Saclay, December 09 PAGE 25

26 Thank you for your attention 7 DÉCEMBRE 2016

27 CORPUS: ARCHITECTURE(3/3) Standardized environment Exchanged codes format (MED) Code running interface (ICoCo) Why to use the SALOME plateform? adapted to CORPUS applications Supervision of complex modeling multi physics coupling YACS graphical interface «User friendly» calculation management (interactivity tools like stop and go) and CORPUS capabilities extension Modeling coupling extension Uncertainties analysis management 7 DÉCEMBRE 2016 JUS EDF Lab, Saclay, December 09 PAGE 27

28 Simulation tools to understand and predict fuel behavior under irradiation Dev. framework: the PLEIADES software env. C++ software architecture based on the SALOME norm for exchanges with other platforms (thermo-hydraulic and neutronic) Modeling perimeter Multidimensional approach (1D, 2D, 3D) Multiphysics modelling Thermal/mechanical behaviour Material modifications under irradiation Fission products inventory Simplified model for the fluid (coolant) flow Simplified model for the neutronic behavior Focus on 1D scheme 1 fuel pin/1 sub-chanel flow description Several axial slices (usually 30 slices) 1D radial calculation on every fuelslice 7 DÉCEMBRE 2016 PAGE 28

29 CURRENT MODELING DEVELOPMENT APOLLO3* for neutronic modeling Overview New generation code, shared project with industry (EDF and AREVA) 3D deterministic multi-purpose code for any kind of reactor concepts Neutronics at fuel pin to core scales High Performance Computing (different levels of parallelization) Focus on the Neutronic core calculation Approximate models of Boltzmann equation : Multigroup diffusion or SPN solver MINOS Finite Elements for 3D extruded hexahedral and hexagonal structured meshes Multigroup SN or SPN solver MINARET Finite Elements for 3D extruded unstructured meshes Bateman equations for isotopic evolution (depletion) (*) D. Schneider et al., APOLLO3 : CEA/DEN Deterministic Multi Purpose Code for Reactor Physics Analysis, PHYSOR2016 JUS EDF Lab, Saclay, December 09 PAGE 29 PWR