A Determination of Bias between Calculational Methods for the Criticality Safety Analysis of Spent Fuel Storage Pool with Burnup Credit

Abstract

A test is made for a method to determine reliable bias in the criticality safety analysis of spent fuel storage pool with burnup credit between the reference and rack criticality calculation methods. The spent fuel pool of Kori Unit: 1 is conceptually redesigned to the most compact rack with burnup credit, and its multiplication factors are calculated depending on fuel enrichment and burnup, by the Monte Carlo code KENO-IV as a reference and by a two-dimensional collision probability code FATAC as a practical method. Then, the computed values with the help of the above two computer codes are compared to evaluate the bias and its trend in terms of multiplication factor on fuel enrichment and burnup. The result indicates that the bias can be determined with reliability basis but without any disadvantage in criticality safety margin compared with the conventional method.