Criticality analysis of ALLEGRO Fuel Assemblies Configurations

Transcription

1 Criticality analysis of ALLEGRO Fuel Assemblies Configurations Radoslav ZAJAC Vladimír CHRAPČIAK October th International Serpent User Group Meeting at Knoxville, Tennessee

2 ALLEGRO Core - Fuel Cross Section of MOX Starting Sub-Assembly Materials: Cladding/ Wrapper Tube: Ti Steel Coolant: He-4 Fuel: PuO 2 (MOX) 24 % Pu Number of Pins: 169 The Distance Wire was Integrated into the Cladding 2

3 ALLEGRO Core - Fuel Ceramic Pin Sub-Assembly Materials: Cladding/Wrapper Tube: SiC Coolant: He-4 Fuel: UPuC 27.5 % Pu Model: Sub-Assembly in Infinite Lattice Number of Fuel Pins: 90 3

4 k inf - infinite lattice ALLEGRO Core - Fuel 1.55 Maximum reserve of reactivity UPuC - SERPENT MOX - SERPENT UPuC - SCALE MOX - SCALE Burnup [MWd/kg hm ] 4

5 Assurance criteria of sub-criticality Assurance criteria of sub-criticality Regulation 57/2006 Coll. of Slovak Republic from 12. January, This regulation modifies the requirements details regarding to radioactive materials transport Regulation of the Slovak regulatory body 30/2012 Coll. from 30 January 2012 specifies the requirements shipment of nuclear materials, nuclear waste and spent fuel Multiplication coefficient k eff is equivalent to this requirement: k eff < 0.95 routine states k eff < 0.98 accident events The international requirements are listed in IAEA documents: SSG-15, SSG-27 a SSR-6. These documents recommends sub-criticality 5 % with note that national rules are binding. 5

6 Assurance criteria of sub-criticality The final value of multiplication coefficient is summary of conservative corrective positive factors, so the final equation: cal k eff = k eff tol + 2σ MC + 2σ + k eff where: cal k eff - calculated value of multiplication - standard deviation of Monte Carlo method (listed in output) - standard deviation between calculation and experiment tol k eff - maximum impact of manufactured tolerances, = 0.0 6

7 Calculated k eff for chosen experiments in fast spectrum Computer Code SCALE 6.1.2, Module KENO VI SERPENT XS Library v7-238 ce_v7_endf CE, ENDF/B-VII.0 Critical experiment k eff dev. k eff dev. k eff dev. pu-met-fast % % % pu-met-fast % % % pu-met-fast % % % pu-met-fast % % % pu-met-fast % % % pu-met-fast-044, case 1 = molybdenum % % % pu-met-fast-044, case 2 = iron % % % pu-met-fast-044, case 3 = beryllium % % % pu-met-fast-044, case 4 = aluminum % % % pu-met-fast-044, case 5 = graphite % % % Conservative element 2σ Determination of Conservative Element 2σ XS Library v7-238 (SCALE 6) CE (SCALE 6) CE (SERPENT ) Conservative element 2σ

8 Calculation Method KENO VI (SCALE 6.1.2) library of physical constants: used libraries v7-238 and ce_v7_endf, which are based on ENDF/B-VII.0 LIBRARY. v7-238 and ce_v7_endf libraries include cross sections and others physical parameters (concentration, density, albedos,...) for various materials (mixtures, nuclides, compounds, alloys,...). SERPENT CE continuous energy libraries of cross sections was used evaluated from the ENDF/B-VII.0 library existing ACE files were performed in SERPENT, 300K for materials Neutron Population - number of neutrons per cycle: number of non-active cycles: number of active cycles: 750 8

9 Sub-Criticality Configurations of 7 UPuC assemblies in water 72 UPuC assemblies in air 9

10 Sub-Criticality Configurations of Critical Calculation of UPuC Configurations in Water k eff assemblies_v assemblies_v assemblies_ce-scale 8 assemblies_ce-scale 7 assemblies_ce-serpent 8 assemblies_ce-serpent limit Pitch [cm] 10

11 Sub-Criticality Configurations of Critical Calculation of UPuC Configurations in Water Code SCALE SERPENT v7-238 vs. CE Library v7-238 CE CE (SCALE 6.1.2) [%] k eff v7-238 (SCALE) vs. CE (SERPENT) [%] CE (SCALE) vs. CE (SERPENT) [%] Pitch [cm] 7 assm. 8 assm. 7 assm. 8 assm. 7assm. 8 assm. 7 assm. 8 assm. 7 assm. 8 assm. 7 assm. 8 assm v7-238 library of SCALE was taken as reference limit 11

12 Sub-Criticality Configurations of 1.00 Critical Calculation of UPuC Configurations in Air k eff assemblies_v assemblies_v assemblies_ce-scale 73 assemblies_ce-scale 72 assemblies_ce-serpent 73 assemblies_ce-serpent limit Pitch [cm] 12

13 Sub-Criticality Configurations of Critical Calculation of UPuC Configurations in Air Code SCALE SERPENT v7-238 vs. CE Library v7-238 CE CE (SCALE 6.1.2) [%] k eff v7-238 (SCALE) vs. CE (SERPENT) [%] CE (SCALE) vs. CE (SERPENT) [%] Pitch [cm] 72assm. 73assm. 72assm. 73assm. 72assm. 73assm. 72assm. 73assm. 72assm. 73assm. 72assm. 73assm v7-238 library of SCALE was taken as reference limit 13

14 Sub-Criticality Configurations of Design of storage can for fresh and spent fuel assembly UPuC Fuel Assembly ATABOR Steel (Boron 1%) Aluminium 14

15 Sub-Criticality Configurations of Conservative storage can filled by water or air Code SCALE SERPENT Library v7-238 CE CE k eff limit Pitch [cm] water air water air water air v7-238 vs. v7-238 (SCALE) CE (SCALE) vs. CE (SCALE 6.1.2) vs. CE (SERPENT) 19.0 CE (SERPENT) [%] [%] [%] water air water air water air v7-238 library of SCALE was taken as reference 15

16 Sub-Criticality Configurations of Storage can filled by gas Gas N 2 Code KENO VI (SCALE 6.1.2) 16 SERPENT XS library v7-238 CE CE k eff Density [g/cm 3 ] limit 5.0x x x x Deviation [%] Density [g/cm 3 ] v7-238 vs. CE (SCALE 6.1.2) [%] v7-238 (SCALE) vs. CE (SERPENT) [%] CE (SCALE) vs. CE (SERPENT) [%] 5.0x x x x v7-238 library of SCALE was taken as reference

17 k eff, conservative assembly Sub-Criticality Configurations of Change of water density in the storage can CE - SERPENT v7-238, KENO VI CE - KENO VI limit Density of water [g/cm 3 ] 17

18 Sub-Criticality Configurations of Proposal of arrangements for criticality analyses of fuel assemblies configuration: With regard to the conclusions of the results and the differences in calculations of criticality configurations between KENO VI (SCALE 6.1.2) code and SERPENT code is necessary: - to obtain critical experiments documentation of existing fast reactors Phénix and SUPERPHENIX fast reactor, or any other fast reactor - to design and implement critical experiment for potential MOX fuel and UPuC of ALLEGRO reactor Proposal of arrangements for storage of fresh and spent fuel in the can: Addition the termohydraulical analyses to the can design Addition the shielding analyses and analyses of influence on environment to the can design. General arrangement: Recalculation of criticality analyses of fuel assemblies configurations and design of storage can by new version of SCALE 6.2 which will be available next year. 18

19 Thank you for your attention VUJE, a.s. Okružná Trnava Slovenská Republika Radoslav.Zajac@vuje.sk 19 VUJE, a. s. Okružná 5, Trnava