Evaluation of Sodium-cooled Fast Reactor Neutronic Benchmarks N.E. Stauff a, T.K. Kim a, T. Taiwo a, L. Buiron b, F. Varaine b, J. Gulliford c a Argonne National Laboratory, Nuclear Engineering Division, USA b CEA, DEN, DER, Cadarache, F-13108 Saint Paul lez Durance, France c OECD/NEA
Context: OECD/NEA Working Party on Reactor and System (WPRS) SFR benchmark taskforce GEN IV Sodium-cooled Fast Reactor: Flexible management of nuclear material Improved economic competitiveness Improved safety favorable transient behavior 4 steps benchmark study: 1. Compile a state of the art report 2. Perform a parametric neutronic study 3. Transient calculations 4. Synthesis of the work Study summarized Participants: CEA, ANL, PSI, IRSN, KIT, KFKI, SCK/CEN, OECD/NEA Results compared 1
Neutronic Benchmark Neutronic parameters evaluated: K-effective Reactivity swing Power distribution Safety parameters evaluated: Delayed Neutron Fraction Doppler coefficient Sodium-void worth MOX-1000 MET-1000 MOX-3600 CAR-3600 ANL - Burner CEA Breakeven Thermal Power [MW] 1000 3600 Type of fuel (U,Pu)O 2 UPuZr 10 (U,Pu)O 2 (U,Pu)C Fuel Avg. Temperature [ C] 1027 534 1227 987 Complete description available : http://www.oecdnea.org/science/wprs/sfr-taskforce/ 2
Large Cores Description CAR-3600 MOX-3600 3
Medium Cores Description MOX-1000 MET-1000 4
Methodologies used Deterministic codes: Multi-group cross-section generation MC 2-3/REBUS-3 System (ANL) ERANOS2.2 System (CEA) Code system MC 2-3/TWODANT ECCO Evaluated nuclear data file JEFF-3.1 & Groups in master library 2082 1968 Neutron flux solver Code system DIF3D (VARIANT) AVNM Solving equation Nodal transport Nodal transport Number of energy groups 33 33 Angular flux & scattering approx. P3 & P1 P3 & P1 Perturbations Code system PERSENT - transport perturbation solver Direct comparison of transport + MCNP5 calculations for BOC comparison 5
Results obtained (1/4) ERANOS and REBUS K-EFFECTIVE evaluation with : Good agreement for every cores between ERANOS / REBUS and MCNP Reactivity [pcm] 2500 2000 1500 1000 500 MET-1000 REBUS MET-1000 ERANOS MET-1000 MCNP MOX-1000 REBUS MOX-1000 ERANOS MOX-1000 MCNP Reactivity [pcm] 1500 1000 500 0 BOC EOC MOX-3600 REBUS MOX-3600 ERANOS MOX-3600 MCNP CAR-3600 REBUS CAR-3600 ERANOS CAR-3600 MCNP 0 BOC EOC -500 6
Results obtained (2/4) For MET-1000 at BOC: Good agreement on the power distribution with less than 3% of discrepancy ERANOS REBUS % of power difference 7
Results obtained (3/4) ERANOS and REBUS neutronic and safety for MET-1000: Good agreement except for the K-EFF between JEFF3.1 and calculations ERANOS JEFF3.1 ERANOS REBUS-3 MCNP BOC K eff 1.0335 1.0224 1.0237 1.0242 β eff [pcm] 334 337 332 330 ρ Na void [pcm] 2356 2358 2267 2238 K D [pcm] -397-420 -349 CR worth[pcm] 22120 22384 21367 21803 EOC K eff 1.0111 1.0063 1.0042 β eff [pcm] 333 334 330 ρ Na void [pcm] 2471 2409 2348 K D [pcm] -415-435 -358 8
Results obtained (4/4) Difference between and JEFF3.1: Consistent between the different codes used Varies from 500 to 1100pcm for the different core modeled Code MCNP ERANOS Libraries compared minus JEFF3.1 MET-1000-1232 ± 9-1068 MOX-1000-757 ± 9-655 MOX-3600-610 ± 9-547 CAR-3600-869 ± 9-779 Which isotope is responsible for this difference? Why is there a larger difference for MET-1000 than for MOX-3600? 9
Perturbation analysis with ERANOS ϕ' : perturbed flux with ϕ* : reference adjoint flux with JEFF3.1 K and K : reference and perturbed multiplication factors Fand F : production operator in the Boltzmann equation, Fitheir difference (with respect to isotope i) A and A : remaining operators (transport, collision, in-scattering), Ai their difference (with respect to isotope i) [pcm] minus JEFF3.1 MET-1000 MOX-1000 CAR-3600 MOX-3600 Σ i ρ i -1035-605 -734-502 Σ i ρ i 1558 1694 1452 1514 Observed difference Similar absolute difference 10
Isotope contribution to the reactivity discrepancy Large positive compensation effect of Pu-239 400 minus JEFF3.1 Reactivity [pcm] 300 200 100 0-100 -200-300 -400 MOX-3600 CAR-3600 MOX-1000 MET-1000 11
Energy breakdown for Pu-239 Normalized flux 0.15 0.10 0.05 MOX-3600 MET-1000 XS (barn) 10.0 8.0 6.0 4.0 2.0 : Pu-239 fission micro XS JEFF3.1: Pu-239 fission micro XS Reactivity impact MOX-3600 Reactivity impact MET-1000 0.00 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 Energy (MeV) 200 100 0-100 Reactivity impact [pcm] minus JEFF3.1 0.0-200 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 Energy (MeV) 12
Energy breakdown for Na-23 : Na-23 inelastic micro XS 1.0 JEFF3.1: Na-23 inelastic micro XS Reactivity impact MOX-3600 150 XS (barn) 0.8 0.6 0.4 0.2 Reactivity impact MET-1000 100 50 0-50 -100 Reactivity impact [pcm] minus JEFF3.1 0.0-150 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 Energy (MeV) 13
Conclusions Summary of the results obtained between ANL and CEA to model various SFR cores in the frame of the WPRS benchmark ANL used MC 2-3/REBUS-3 system with library CEA and ANL used the ERANOS system with JEFF3.1 and libraries MCNP was used at ANL for BOC benchmark with JEFF3.1 and libraries Very satisfactory agreement was obtained for reactivity, power distribution, burnup composition evolution Large difference observed for K-effective between JEFF3.1 and Main responsible: Pu-238, Pu-239, Pu-240, Na-23 Some other isotopes like U-238, Fe-56, O-16 might also have a large impact The smaller reactivity change (JEFF3.1 ), for MOX-3600 with respect to MET-1000, is due to the error cancelation and not to a better agreement between the two libraries 14
Acknowledgements Participants of the ECD/NEA WPRS SFR Task Force: E. Ivanov (IRSN, France) A. Kereszturi (KFKI, Hungary) Y. Lee (CEA-Saclay, France) N. Messaoudi (SCK/CEN, Belgium) A. Ponomarev (KIT, Germany) F. Michel-Sendis (OECD/NEA) A. Yamaji (OECD/NEA) ANL : G. Aliberti and L. Mynsberg 15
THANK YOU FOR YOUR ATTENTION! 16
APPENDIX 17
Results obtained (2/4) For MOX-1000 at BOC: Good agreement on the power distribution with less than 2% of discrepancy ERANOS REBUS % of power difference 18
Results obtained (3/4) ERANOS and REBUS neutronic and safety for MOX-1000: Good agreement except for the K-EFF between JEFF3.1 and calculations ERANOS JEFF3.1 ERANOS REBUS-3 MCNP BOC K eff 1.0265 1.0197 1.0218 1.0223 β eff [pcm] 326 327 323 326 ρ Na void [pcm] 2159 2130 2100 2002 K D [pcm] -850-858 -716 CR worth[pcm] 24217 24497 23304 23106 EOC K eff 1.0138 1.0139 1.01136 β eff [pcm] 323 324 321 ρ Na void [pcm] 2206 2122 2126 K D [pcm] -866-868 -720 19
Results obtained (2/4) For MOX-3600 at BOC: Good agreement on the power distribution with less than 3% of discrepancy ERANOS REBUS % of power difference 20
Results obtained (3/4) ERANOS and REBUS neutronic and safety for MOX-3600: Good agreement except for the K-EFF between JEFF3.1 and calculations ERANOS JEFF3.1 ERANOS REBUS-3 MCNP BOC K eff 1.0104 1.0050 1.0077 1.0075 β eff [pcm] 362 365 360 360 ρ Na void [pcm] 2152 2122 2044 2033 K D [pcm] -975-988 -915 CR worth[pcm] 7039 7087 7020 6952 EOC K eff 1.0152 1.0143 1.0144 β eff [pcm] 354 356 351 ρ Na void [pcm] 2190 2129 2082 K D [pcm] -937-943 -866 21
Results obtained (2/4) For CAR-3600 at BOC: Satisfactory agreement on the power distribution with less than 2% of discrepancy ERANOS REBUS % of power difference 22
Results obtained (3/4) ERANOS and REBUS neutronic and safety for CAR-3600: Good agreement except for the K-EFF between JEFF3.1 and calculations ERANOS JEFF3.1 ERANOS REBUS-3 MCNP BOC K eff 1.0043 0.9965 0.9991 0.9997 β eff [pcm] 372 375 369 365 ρ Na void [pcm] 2378 2365 2298 2289 K D [pcm] -1056-1079 -990 CR worth[pcm] 4853 4875 4834 4741 EOC K eff 1.0172 1.0144 1.0145 β eff [pcm] 362 364 359 ρ Na void [pcm] 2475 2419 2361 K D [pcm] -1005-1019 -928 23
Results obtained (4/4) Difference between and JEFF3.1: Consistent between the different codes used Varies from 500 to 1100pcm for the different core modeled Small difference between and ENDF/B-VII.1 Code MCNP MCNP ERANOS Libraries compared minus ENDF/B-VII.1 minus JEFF3.1 minus JEFF3.1 MET-1000 +146 ± 7-1232 ± 9-1068 MOX-1000-757 ± 9-655 MOX-3600-99 ± 6-610 ± 9-547 CAR-3600-869 ± 9-779 Which isotope is responsible for this difference? Why is there a larger difference for MET-1000 than for MOX-3600? 24
Energy breakdown for Pu-238 5.0 : Pu-238 fission micro XS JEFF3.1: Pu-238 fission micro XS Reactivity impact MOX-3600 Reactivity impact MET-1000 100 XS (barn) 4.0 3.0 2.0 1.0 50 0-50 Reactivity impact [pcm] minus JEFF3.1 0.0-100 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 Energy (MeV) 25
Energy breakdown for Pu-240 : Pu-240 fission micro XS 3.0 JEFF3.1: Pu-240 fission micro XS Reactivity impact MOX-3600 300 XS (barn) 2.0 1.0 Reactivity impact MET-1000 200 100 0-100 Reactivity impact [pcm] minus JEFF3.1-200 0.0-300 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 Energy (MeV) 26
Energy breakdown for U-238 1.6 1.4 : U-238 fission micro XS JEFF3.1: U-238 fission micro XS Reactivity impact MOX-3600 200 150 XS (barn) 1.2 1.0 0.8 0.6 0.4 Reactivity impact MET-1000 100 50 0-50 -100 Reactivity impact [pcm] minus JEFF3.1 0.2-150 0.0-200 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 Energy (MeV) 27