Comparison of the SCALE, SERPENT and MCNP Criticality Safety Calculation of the NPP Krško Spent Fuel Pool

Criticality safety reanalyzes of the NPP Krško spent fuel pool has been performed. Limiting criticality cases at optimal moderation conditions are calculated using different SCALE code versions (SCALE-4.4a, SCALE-5.1 and SCALE-6.1) with 44-group ENDF/B-V and 238-group ENDF/B-VII.0 derived cross section libraries. Relative small discrepancies are observed. Additional verification is provided with SERPENT and MCNP5 codes, which are capable to take into account neutron continuous energy cross section library based on ENDF/B-VII.0 files. Comparison has shown that the results of the pool design calculations are conservative, precluding racks criticality even at optimum moderation conditions.