BEYOND 5 ENRICHMENT LIMIT FOR PWR 17X17 AND VVER-440 FUEL - CRITICALITY PROBLEMS

摘要

The fuel suppliers improve permanently fuel for commercial energetic nuclear reactors. One way is to increase initial enrichment of U235. Higher initial enrichment of U235 allows to increase burnup of assembly, to prolong stay in assembly in reactor and therefore decrease number of fresh assemblies loaded into reactor and decrease number of spent fuel assemblies for storage and disposal. In this article are some criticality analyses for fresh fuel PWR 17×17 and WER-440 for enrichment up to 6% of U235 without burnable absorber: 1. Criticality of fresh assembly (PWR 17×17 and VVER-440) in cold state in reactor 2. Critical number of fresh assemblies (PWR 17×17 and VVER-440) in water 3. Possible storage and transport of fresh fuel VVER-440 in existing facilities and transport cask The SCALE 6.1.2 system was used for all calculation. The KENO VI module was used with library v7-238 (continuous energy).