Evaluation of Sodium-cooled Fast Reactor Neutronic Benchmarks

Transcription

1 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 Saint Paul lez Durance, France c OECD/NEA

2 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

3 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] Type of fuel (U,Pu)O 2 UPuZr 10 (U,Pu)O 2 (U,Pu)C Fuel Avg. Temperature [ C] Complete description available : 2

4 Large Cores Description CAR-3600 MOX

5 Medium Cores Description MOX-1000 MET

6 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 Neutron flux solver Code system DIF3D (VARIANT) AVNM Solving equation Nodal transport Nodal transport Number of energy groups 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

7 Results obtained (1/4) ERANOS and REBUS K-EFFECTIVE evaluation with : Good agreement for every cores between ERANOS / REBUS and MCNP Reactivity [pcm] MET-1000 REBUS MET-1000 ERANOS MET-1000 MCNP MOX-1000 REBUS MOX-1000 ERANOS MOX-1000 MCNP Reactivity [pcm] BOC EOC MOX-3600 REBUS MOX-3600 ERANOS MOX-3600 MCNP CAR-3600 REBUS CAR-3600 ERANOS CAR-3600 MCNP 0 BOC EOC

8 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

9 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 β eff [pcm] ρ Na void [pcm] K D [pcm] CR worth[pcm] EOC K eff β eff [pcm] ρ Na void [pcm] K D [pcm]

10 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 ± MOX ± MOX ± CAR ± Which isotope is responsible for this difference? Why is there a larger difference for MET-1000 than for MOX-3600? 9

11 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 Σ i ρ i Observed difference Similar absolute difference 10

12 Isotope contribution to the reactivity discrepancy Large positive compensation effect of Pu minus JEFF3.1 Reactivity [pcm] MOX-3600 CAR-3600 MOX-1000 MET

13 Energy breakdown for Pu-239 Normalized flux MOX-3600 MET-1000 XS (barn) : Pu-239 fission micro XS JEFF3.1: Pu-239 fission micro XS Reactivity impact MOX-3600 Reactivity impact MET E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 Energy (MeV) Reactivity impact [pcm] minus JEFF E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 Energy (MeV) 12

14 Energy breakdown for Na-23 : Na-23 inelastic micro XS 1.0 JEFF3.1: Na-23 inelastic micro XS Reactivity impact MOX XS (barn) Reactivity impact MET Reactivity impact [pcm] minus JEFF E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 Energy (MeV) 13

15 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

16 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

17 THANK YOU FOR YOUR ATTENTION! 16

18 APPENDIX 17

19 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

20 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 β eff [pcm] ρ Na void [pcm] K D [pcm] CR worth[pcm] EOC K eff β eff [pcm] ρ Na void [pcm] K D [pcm]

21 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

22 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 β eff [pcm] ρ Na void [pcm] K D [pcm] CR worth[pcm] EOC K eff β eff [pcm] ρ Na void [pcm] K D [pcm]

23 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

24 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 β eff [pcm] ρ Na void [pcm] K D [pcm] CR worth[pcm] EOC K eff β eff [pcm] ρ Na void [pcm] K D [pcm]

25 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 ± ± MOX ± MOX ± ± CAR ± Which isotope is responsible for this difference? Why is there a larger difference for MET-1000 than for MOX-3600? 24

26 Energy breakdown for Pu : Pu-238 fission micro XS JEFF3.1: Pu-238 fission micro XS Reactivity impact MOX-3600 Reactivity impact MET XS (barn) Reactivity impact [pcm] minus JEFF E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 Energy (MeV) 25

27 Energy breakdown for Pu-240 : Pu-240 fission micro XS 3.0 JEFF3.1: Pu-240 fission micro XS Reactivity impact MOX XS (barn) Reactivity impact MET Reactivity impact [pcm] minus JEFF E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 Energy (MeV) 26

28 Energy breakdown for U : U-238 fission micro XS JEFF3.1: U-238 fission micro XS Reactivity impact MOX XS (barn) Reactivity impact MET Reactivity impact [pcm] minus JEFF E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 Energy (MeV) 27