WP1.4: CORE PHYSICS BENCHMARKING OVERVIEW

Transcription

1 WP1.4: CORE PHYSICS BENCHMARKING OVERVIEW N.Kolev, N.Petrov, N.Zheleva, G.Todorova, M.Manolova, P.Ivanov, N.Mihaylov (INRNE), J-F.Vidal, F.Damian, P.Bellier, F-X.Hugot (CEA), C.Ahnert, JJ.Herrero, N.Garcia-Herranz, S.Sanchez-Cervera, JA.Lozano (UPM), G.Hegyi, A.Keresturi (KFKI), S.Canepa, H.Ferroukhi (PSI), U.Rohde, Y.Bilodid, S.Mittag (HZDR), J.Hadek (NRI), J.Dufek (KTH) 1

2 Outline 1. Objectives 2. Generic strategy for benchmarking 3. PWR benchmarking using APOLLO2 vs.tripoli4 4. PWR benchmarking using COBAYA3 and DYN3D pin-by-pin 5. VVER benchmarking using APOLLO2,TRIPOLI4 and COBAYA3 pin-by-pin 6. BWR benchmarking using APOLLO2, TRIPOLI4 and COBAYA3 pin-by-pin 7. Conclusions 2

3 Objectives Define the generic strategy for V&V A step-by-step validation process from lattice to core calculations, with the objective of pin-by-pin neutronics fidelity for safety margin analysis. Perform numerical and experimental validation of - New developments in the NURISP core physics codes - Advanced MOC based calculation schemes for XS library generation with APOLLO2 for LWR Take into account - LWR cell, lattice and core benchmarks with Monte Carlo and deterministic reference solutions - Well documented mock-up experiments 3

4 The VVQ process Definitions The verification answers the question: are the model equations correctly solved? The validation (numerical validation) answers the question: how approximate is the deterministic model used? The qualification (experimental validation) answers the question: how representative of the real world the model is? Focus on the pin-by-pin neutronics fidelity Parameters and metrics used to estimate the biases 4

5 Generic strategy of benchmarking Step-by-step validation process from cell to core geometry Consider - a set of numerical problems with Monte-Carlo or deterministic reference solutions, and - selected experimental problems based on mock-up data Use pin clusters and assembly clusters in the lattice step to take into account the influence of the environment while keeping the size of the problem manageable Perform the core physics benchmarking in coordination with the work done on multi-physics benchmarks - consistent specifications - testing of the XS libraries - static pin-by-pin calculations with simple t-h feedback 5

6 Codes and database Platform codes to be tested TRIPOLI4 APOLLO2.8e CRONOS2, COBAYA3, DYN3D JEFF3.1.1 database 281-group micro XS library in APOLLO2 6

7 New developments being tested APOLLO2-281-group micro-xs library based on JEFF Resonant mixture self-shielding treatment - Improved step MOC and LS MOC solvers (acceleration, higher-order MOC) - MOC based calculation schemes for LWR XS lib generation with APOLLO2: reference and industrial calculation schemes pin-cluster and assembly-cluster branch calculations accurate surface fluxes and currents for side-dependent Interface DF COBAYA3 nodal/pin-by-pin - Improved pbp MG diffusion solvers for Cartesian and hex geometry - Side-dependent Interface DF of GET and BBH type - Unstructured mesh at the pin level DYN3D nodal/pin-by-pin - Multi-group pbp SP3 solvers for Cartesian geometry (in progress) - SPH factors at the pin level - Pin-power reconstruction APOLLO2 MOC generated nodal and pbp XS libraries for LWR 7

8 Numerical validation of LWR calculation schemes APOLLO2 multi-group lattice calculation Scope: PWR, VVER, BWR Nuclear data (JEFF3) Multi-group micro XS lib Optimised two-step XS generation scheme using APOLLO2 MOC Point-wise XS APOLLO2 MOC fine 2D calculation with heterogeneous cells 2g-8g XS COBAYA/DYN3D/CRONOS 3D Nodal, pin/pin TRIPOLI4 Monte Carlo Keff, PD Reference deterministic scheme Keff, PD Industrial calculation schemes Keff, PD Monte Carlo reference 8

9 PWR benchmarking using APOLLO2 vs.tripoli4 1/ PWR lattice benchmark Specifications: 3x3 cells, UOX, MOX assemblies, colorset (UPM) Solutions - APOLLO2 MOC vs.tripoli4 (INRNE) - APOLLO2 LS MOC vs.tripoli4 (INRNE) - APOLLO2 MOC industrial vs. ref calculation scheme (INRNE) 2/ PWR cell depletion benchmark Specifications: UOX, MOX-1 and MOX3 models (PSI) Solutions - APOLLO2.8e Pij vs. CASMO5 MOC & MCNPX/CINDER (PSI) 9

10 PWR lattice benchmark Specifications based on the PWR MOX/UO 2 CTB 2D lattice calculations at HZP 3x3 pin clusters Fuel assemblies Color-set 10

11 Benchmarking APOLLO2 calculation schemes a: recommended MOC spatial mesh for b: recommended MOC spatial mesh for the UOX assembly standard calculation the UOX assembly reference calculation scheme. 0/12 sectors in fuel/moderator scheme, 8/12 sectors in fuel/moderator 1672 regions in 1/4 assembly 4129 regions in 1/4 assembly 11

12 PWR lattice benchmark: A2 UOX assembly solution UOX-GT assembly: A2 vs.t4 results for the windmill mesh, 1672 regions Error convergence with MOC parameters refinement N of groups MOC parameters Aniso tropy r Nφ Nψ K inf k, pcm max FRR * P1 0, , , P3 0, , , P1 0, , , P3 0, , /37 P1 0, , ,57 281/37 P3 0, , ,58 281/37 P0* 0, , ,69 281/37 P1 0, , ,50 281/37 P3 0, , ,54 12

13 PWR lattice benchmark: A2 colorset solution Code Solver/ MOC parameters K inf A2 281g MOC windmill Δr=0.06 cm, Nφ=24, Nψ=3 Bickley, P0* Δk (A2-T4) pcm max FRR * A2 281g LS MOC, Δr=0.06 cm, Nφ=48, Nψ=3, Bickley, P0*, N subd=4, threshold size 0.7cm

14 PWR lattice benchmark: COBAYA and DYN3D solutions T1.4.4 Objective: to test diffusion or SPn codes and conservation techniques such as Interface DF to be used in 3D pin-by-pin core calculations. Benchmarking APOLLO2 and TRIPOLI4 reference solutions (INRNE) Generate pbp few-group diffusion XS and DF with APOLLO2 (INRNE, UPM) Provide options for GET or BBH DF (UPM, INRNE) Compare COBAYA3 and DYN3D pin-by-pin vs. reference solutions (UPM, INRNE, HZDR) Results The COBAYA3 pbp transport-corrected few-group diffusion results are very close to the APOLLO2 and TRIPOLI4 reference solutions Preliminary DYN3D pin-by-pin diffusion and SP3 solutions were obtained with HELIOS/ENDFB6 XS and SPH factors The COBAYA3 solutions illustrate the target accuracy of pin-by-pin few-group diffusion theory solutions when using advanced XS libraries 14

15 PWR lattice benchmark: COBAYA3 pbp solutions The UOX and MOX assemblies are to be computed for 7 states, as defined for the calculation of reactivity effects: State1: Reference HZP state (560K, 560K, kg/m3, 1000 ppm) State2: Tm = 580K (coolant reactivity) State3: Tf = 900K (fuel Doppler reactivity) State4: HFP State5: 50% void State6: 100% void State7: Cb = 0 (boron reactivity) 15

16 PWR lattice benchmark: COBAYA3 pbp solutions COBAYA vs. APOLLO2 results for UOX-GT and MOX assemblies for the seven states UOX-GT MOX State Code k-inf Δk max Δk max (C3-A2) k-inf (C3-A2) ΔFRR*100 ΔFRR*100 pcm pcm S1a A2 MOC 281g P C3 8g S2 A2 MOC 281g P C3 8g S3 A2 MOC 281g P C3 8g S4 A2 MOC 281g P C3 8g S5 A2 MOC 281g P C3 8g S6 A2 MOC 281g P C3 8g S7 A2 MOC 281g P C3 8g

17 COBAYA3: Full core 3D pin-by-pin capability 17

18 Benchmarking for VVER T1.4.5 Part 1: Numerical validation (D1.4.5a) A VVER lattice benchmark including 19-cell clusters, assemblies and an assembly cluster was defined and solved with APOLLO2,TRIPOLI4 and COBAYA3 pin-by-pin MOC based calculation schemes in APOLLO2 were validated vs. TRIPOLI4 reference solutions (INRNE) APOLLO2 functionalities, incl. improved solvers (MOC, LS MOC) were tested vs.tripoli4 reference solutions (INRNE) COBAYA3 pbp multi-group diffusion vs. APOLLO2 vs.tripoli4 solutions were analyzed. The APOLLO2 generated pbp XS and DF library was numerically validated (INRNE, UPM) Part 2: Experimental validation (D1.4.5b, D1.4.5c) APOLLO2 MOC results were tested vs. ZR-6 critical assembly data (KFKI) DYN3D nodal/ppr results were tested vs. V1000-LR0-STAT data (NRI) 18

19 VVER lattice benchmark cases 19

20 VVER lattice benchmark: APOLLO2 solutions Part 1: Numerical validation a) MOC spatial mesh of 2254 reg/1/6 assembly b) LS MOC spatial mesh of 404 reg/1/6 assembly 20

21 VVER lattice benchmark: APOLLO2 solutions Part 1: Numerical validation 46 Keff Δ 1/K DEV to T4 427 pcm MAX DEV Fiss 1.66 % AVE DEV Fiss Biases of Pij 281g UP0 vs.t4 computed pin fission rates at Bu=0 404 regions in 1/6 UOX-GT assembly 21

22 VVER lattice benchmark: APOLLO2 solutions Part 1: Numerical validation Keff Deviation to T4 35 pcm Δ 1/k MAX Dev Fiss 0.12 % AVE DEV Fiss TIME / MOC 200 sec Biases of MOC 281g vs.t4 computed pin fission rates at Bu= regions in 1/6 UOX-GT assembly, 0.04, 24, 2, P0* 22

23 VVER lattice benchmark: APOLLO2 solutions Part 1: Numerical validation Keff Deviation to T4 169 pcm Δ 1/k MAX Dev Fiss 0.11 % AVE DEV Fiss TIME / MOC 27 sec Biases of MOC 281/37g vs.t4 computed pin fission rates at Bu= regions in 1/6 UOX-GT assembly, 0.04, 24, 2, P0* 23

24 VVER lattice benchmark: APOLLO2 solutions Part 1: Numerical validation 46 Keff Deviation to T4-20 pcm MAX Dev Fiss 0.27 % Averaged in Fiss TIME / MOC 102 sec Biases of LS MOC 281g vs.t4 computed pin fission rates at 31 MWd/kgHM 404 regions in 1/6 UOX-GT assembly, 0.04, 24, 2, P0* 24

25 VVER lattice benchmark: APOLLO2 solutions Part 1: Numerical validation 46 Keff Deviation to T4-44 pcm MAX Dev Fiss 0.25 % Averaged in Fiss TIME / MOC 14 sec Biases of LS MOC 281/37g vs.t4 computed pin fission rates at 31 MWd/kgHM 404 regions in 1/6 UOX-GT assembly, 0.04, 24, 2, P0* 25

26 VVER lattice benchmark: APOLLO2 solutions UOX-GT assembly at 39.8MWd/kgHM. Reactivity effects from HZP for the 5 states MOC 281g SHEM, dr= 0.01,Nφ=48, Nψ= 3, Bickley, P0*/P3, 2254 reg/1/6 assembly State Kinf Δk (A2-T4) pcm, Δk (A2-T4) pcm, A2, P0* A2, P3 T4 P0* P3 S1* at 574K ± 14 E S2* ± 14 E S3* ± 14 E S4* ± 14 E S5* ± 15 E Reactivity effects from HZP at 574K, 53 ppm A2, P0* A2, P3 T4 (A2-T4) P0* S2*-S1*: Doppler reactivity Δ(1/k), pcm (A2-T4) P3 S3*-S1*:Coolant reactivity Δ(1/k), pcm S4*-S1*: Void react. effect (100% void): Δk, pcm (-1.0%) -275 (-0.75%) S5*-S1*: Boron react effect: Δk, pcm

27 VVER assembly depletion solutions with APOLLO2/JEFF Pij 12r 15c 225 2L 37g δ1/k pcm Burnup MWd/kg Biases 1/kref-1/k (pcm) of the two-level 281/37g MOC and 281g Pij vs. reference 281g MOC P0* depletion calculation 27

28 VVER core benchmarks: APOLLO2 vs.tripoli4 solutions Part 1: Numerical validation Whole core benchmarks (V1000-2D-C1, V1000CT2-EXT1) were solved with APOLLO2 LS MOC and TRIPOLI4 V1000-2D-C1 fresh core benchmark, ARO APOLLO2 281/37g vs.tripoli4 computed assembly powers: Δk = 62pcm, max Δ fis r =2.1% 28

29 VVER core benchmarks: APOLLO2 vs.tripoli4 solutions V1000CT2-EXT1 depleted core benchmark, all rods out. APOLLO2/JEFF /37g vs. TRIPOLI4 solution Keff(T4)= ± , Δk=48 pcm, max Δfis r=1.8% 29

30 VVER lattice benchmark: COBAYA3 pin-by-pin solutions Transport-corrected diffusion pin-by-pin 2, 4 and 8 energy groups XS and Interface DF taking into account the cell environment Side-dependent GET or BBH Interface DF Structured and unstructured mesh calculation (unstructured mesh for the inter-assembly water gap) Fixed parameter state solutions 30

31 VVER lattice benchmark: COBAYA3 19-pin solution 1/6 19-pin UOX-CR cluster at 39.8 MWd/kg, 574K, 740 kg/m3, 53 ppm Comparison C3 versus A2 Comparison C3 versus T CR CR Dev Kinf (A2), pcm Dev Kinf (T4), pcm Max dev FRR, % Max dev FRR, % Average dev FRR, % Average dev FRR, % Kinf A Kinf T Kinf C Kinf C Biases of C3 8g vs. A2ref vs.t4ref solution when using A2 MOC P0* computed XS and side-dependent GET DF 31

32 VVER lattice benchmark: COBAYA3 19-pin solution 1/6 19-pin UOX-CR cluster at 39.8 MWd/kg, 574K, 740 kg/m3, 53 ppm Comparison C3 versus A2 0,00 4 0,00 0, CR 0,00 0, Comparison C3 versus T4 0,02 4-0,03 0, CR 0,02-0, Dev Kinf (A2), pcm 0,463 Max dev FRR, % 0,00 Average dev FRR, % 0,00 Kinf A2 Kinf C3 0, ,62091 Dev Kinf (T4), pcm 110 Max dev FRR, % 0,02941 Average dev FRR, % 0,01912 Kinf T4 Kinf C3 0, ,62091 Biases of C3 8g vs. A2ref vs.t4ref solution when using A2 MOC P3 computed XS and side-dependent GET DF 32

33 VVER lattice benchmark: COBAYA3 8g vs APOLLO2 solution C3 FRR A2 FRR FRR dev N 0,969 0,969-0, ,026 0,956 1,026 0,956-0,02 0, Max FRR deviation, % 0,28 0,995 1,018 0,950 Average FRR deviation, % 0,02 0,994 1,018 0,950 Delta K inf, pcm 2 0,01 0,02 0, ,001 0,993 1,015 0,948 1,001 0,992 1,015 0,948 0,03 0,02 0,03 0, ,005 1,007 0,996 1,014 0,947 1,005 1,006 0,996 1,014 0,947 0,01 0,02 0,01 0,04 0, ,017 1,009 1,002 0,997 1,014 0,948 1,018 1,009 1,002 0,997 1,013 0,947 0,00 0,00 0,00 0,03 0,04 0, ,025 1,019 0,000 1,001 0,996 1,015 0,951 1,025 1,019 0,000 1,001 0,996 1,015 0,950-0,01 0,00 0,00 0,00 0,02 0,02 0, ,000 1,023 1,018 1,009 1,006 0,992 1,018 0,956 0,000 1,024 1,019 1,009 1,006 0,992 1,018 0,956 0,00-0,03-0,02-0,01 0,01 0,03 0,03 0, ,038 1,029 1,031 1,014 1,004 1,000 0,995 1,026 0,969 1,038 1,029 1,031 1,014 1,004 1,000 0,994 1,026 0,969 0,00-0,03-0,01 0,00 0,01 0,00 0,01 0,00-0, ,048 1,037 1,029 1,019 0,000 0,998 1,000 1,004 0,939 0,963 1,048 1,037 1,030 1,020 0,000 0,998 1,000 1,004 0,939 0,965-0,02 0,00-0,04-0,02 0,00 0,00 0,02 0,01-0,05-0, UOX-GT assembly solution at 39.8MWd/kg, 53ppm. Unstructured mesh, BBH DF 33

34 Summary of VVER lattice and core benchmarking Part 1 Part 1: Numerical validation MOC based calculation schemes for nodal and pbp XS library generation with APOLLO2 were implemented and tested for VVER. The APOLLO2 vs. TRIPOLI4 results are in very good agreement The performance of the higher-order Linear Surface MOC is found very promising Based on this study, MOC calculation options of the industrial calculation schemes for VVER lattices were recommended These options include higher-order of anisotropy (P3, P1) in case of steep flux gradients The tested schemes in APOLLO2 were used to generate multi-parameter nodal and pbp few-group diffusion XS libraries for VVER transient analysis The comparison of COBAYA3 pbp vs. APOLLO2 vs.tripoli4 solutions shows very good agreement, both in structured and unstructured meshes COBAYA successfully tackles the irregular mesh at the assembly periphery (across the inter-assembly water gap) 34

35 APOLLO2 calculation of ZR-6 experiments T1.4.5 Part 2: Experimental validation D1.4.5b: Experimental validation of APOLLO2.8e for VVER on ZR-6 experiments (KFKI) VVER mock-up measurements at KFKI were solved with APOLLO2.8e MOC: Macro-cells containing different absorber rods in the center (especially different enrichments of Gd 2 O 3 in Al 2 O 3 ) 2D whole core configuration with point perturbations Fuel assembly imitators (macrocells surrounded by water gap) The MOC spatial mesh is as shown in the next slide. The MOC parameters are 0.04, 24, 8, Gauss, P0*. APOLLO2.8e is in good agreement with the measured data: Keff is slightly overestimated in 2D core calculations (consistent with CEA results on LWR mockups: such a trend due to JEFF3.1.1 XS is observed with TRIPOLI4 and APOLLO2) Gadolinium rod worth and pin-by-pin distributions are well reproduced 35

36 Experimental validation of APOLLO2 on ZR-6 MOC spatial mesh for K91 configuration 36

37 Experimental validation of APOLLO2 on ZR-6 Part 2: Experimental validation T1.4.5 Fission rate [arb. u.] Measured APOLLO28 APOLLO Radial position from the absorber pin [pitch units] Measured power distribution in I7 macro-cell and its simulation by APOLLO2.7/JEF2.2 and APOLLO2.8/JEFF3.1.1 codes 37

38 Experimental validation of APOLLO2 on ZR-6 Part 2: Experimental validation Comparison of measured and calculated fission rate for N7 type lattice Measured 1300 APOLLO Fission rate [-] Radial position [-] APOLLO2 vs measured intra macro-cell fission rate distribution along a central traverse of the ZR6 configuration N7 with Gd-pins 38

39 Experimental validation of DYN3D on LR0 data T1.4.5 D1.4.5c: V1000-LR0-STAT experimental benchmark (NRI) VVER-1000 mock-up in Rez (LR-0) 2g XS library generated with HELIOS /ENDFB6 DYN3D solutions: nodal and pin power reconstruction Reconstructed centre-of-node solution, and combination of reconstruction with pin-flux result from a lattice code The DYN3D calculations against Experiment show: good agreement in Keff : slight underestimation significant discrepancies in the radial fission rate distribution: need to compare with direct pin-by-pin calculations 39

40 VVER mock-up: LR0 Reactor Crane Loading mast Rotating cover Moderator level meter Reactor tank Absorption cluster Horizontal channels Supporting structure M oderator inlet tube Fuel as sembly Supporting plate Safety valve Moderator outlet tube 40

41 DYN3D LR0 calculation vs. experimental results Measurement 1 - calculation results FA # 1 axial layer #11 EC1 cluster node-averaged flux = x 10**5 reconstructed flux reconstructed x pin-wise flux Comparison of three computational models for measurement 1, fuel assembly No.1, 11. axial layer (EC1 cluster) 41

42 DYN3D LR0 calculation vs. experimental results Measurement 1 calculation results FA No axial layer C6 detector node-averaged flux = x 10**5 reconstructed flux reconstructed x pin-vise flux Comparison of three computational models for measurement 1, fuel assembly No.1, 7. axial layer (location of C6 detector) 42

43 BWR lattice benchmark T1.4.6: BWR benchmarking at HZP using APOLLO2, TRIPOLI4 and COBAYA3 pin-by-pin The objective is to test the codes on the BWR lattice benchmark (UPM): OECD/NEA BWR MOX assembly benchmark With six different Pu enrichments Specified in 2D at HZP and at the BOL Asymmetric water hole in the center of the array Covering the different states of BWR operation: CZP, HZP, HP with 0%, 40% and 80% void fraction Significant anisotropy 43

44 BWR lattice benchmark Specifications based on the Physics of Plutonium fuels BWR MOX benchmark from NEA Modern 10x10 fuel assembly ( conditions Different void fractions (cold and hot Simplified cruciform control rod (in reality more complex) + other geometrical simplifications 44 44

45 BWR lattice benchmarking APOLLO2 MOC geometries un-rodded rodded 45

46 BWR lattice benchmark: APOLLO2 solution APOLLO2 MOC 281g solutions Reactivity effects from HZP Δ(1/k), pcm T4-A2, pcm Effect from HZP to HP 0% void: (2)-(3) Effect from HZP to HP 40% void: (2)-(4) Effect from HZP to HP 80% void: (2)-(5)

47 BWR lattice benchmark: Impact of energy mesh collapsing State P3-281g 2L-P3-42g 2L-P3-70g CZP HZP HZP rodded HP 0% void HP 40% void HP 80% void

48 Summary of the BWR lattice benchmarking TRIPOLI4 reference solution (Chalmers) Calculation scheme for XS generation (PSI) Generation of XS & DF libraries with APOLLO2 (PSI) Analysis of the COBAYA3 and CRONOS2 pbp solutions (UPM,PSI) APOLLO2 MOC 281g and COBAYA3 were compared vs.tripoli4 - biases in Keff are significantly higher than those observed for PWR or VVER calculations, due to the strong heterogeneities of BWR assemblies - reactivity effects at HP including CR worth are well reproduced COBAYA3 pin-by-pin vs. APOLLO2 ref solutions show close agreement 48

49 Conclusions New developments in the NURISP core physics codes and new MOC based calculation schemes for LWR XS library generation with APOLLO2 were implemented and tested step-by-step. For numerical validation, LWR lattice benchmarks were defined and solved. The solutions were compared to deterministic and Monte Carlo reference solutions. For experimental validation, critical assembly experiments were calculated with APOLLO2 MOC and DYN3D. The benchmark results of APOLLO2 show that: The code is an accurate and reliable lattice physics tool and is a good choice for LWR applications The APOLLO2 reference scheme solutions are very close to the Monte Carlo results The industrial calculation schemes for XS generation with APOLLO2 give solutions close to the reference ones while the CPU time is reduced about 10 times The APOLLO2 solutions reproduce well the ZR-6 data for Gadolinium rod worth and pin-by-pin distributions, and slightly overestimate the Keff 49

50 Conclusions As a result of this work, APOLLO2 has been improved and advanced calculation routes for each type of LWR have been developed. Multiparameter XS libraries at the nodal and pin level have been generated and tested. The testing of the pin-by-pin core simulators shows that: the COBAYA3 pin-by-pin transport-corrected few-group diffusion solutions vs. APOLLO2 results are in very close agreement the results with side-dependent DF taking into account the cell neighbourhood illustrate the target accuracy when using advanced pin-by-pin XS libraries. The NURISP objective of pin level fidelity is met for subsets of the core, up to 2D mini-cores with unstructured mesh. 50