Criticality Analysis of PWR Spent Fuel Storage Facilities Inside Nuclear Power Plants

Criticality safety design analysis of wet PWR storage pools with soluble boron in pool water at German nuclear power plants is based on the actinide plus fission product burnup credit method. A standard design procedure is used to conduct depletion analyses and to determine isotopic inventories of irradiated fuel for which burnup credit is awarded. Application of criticality calculation modules to spent LWR fuel assembly storage pools was verified by analysis of critical experiments that simulated such storage pools. The resulting burnup credit loading curve specifies the loading criterion by indicating the minimum burnup needed for the fuel assembly with a specific initial enrichment to be placed in storage racks designed for burnup credit.