Criticality Calculations Supporting PWR Spent Fuel Pool Activities

摘要

Two bounding analyses were performed to assess margin to criticality in PWR spent fuel pools. For fuel assemblies undergoing ultrasonic fuel cleaning for both the normal operating conditions as well as a postulated accident condition were evaluated to determine the effective multiplication factor of the configurations and soluble boron concentration required to mitigate the accident condition. The second analysis evaluated the margin to criticality for the physical situation of a 16x16 fuel assembly that has been dropped while residing in the new fuel elevator of a spent fuel pool. Through conservative assumptions and extensive analyses, it has been shown that the effective multiplication factor will remain less than the regulatory limit of 0.95 for these two activities in the spent fuel pool to maintain safe operation.