Consequence analysis of a postulated nuclear excursion in BWR spent fuel pool using 1/ spectrum model of randomization

Simanullang, I. ; Yamane, Yuichi  ; Kikuchi, Takeo ; Tonoike, Kotaro 

This study investigated a postulated criticality event that occurred in the fuel debris produced after the loss of the cooling function in a spent fuel pool. The 1/ spectrum model was introduced to overcome this situation considering the difficulties of predicting the random fuel debris distribution. The number of fissions in the first peak power was analyzed using the Nordheim Fuchs model. A total of 100 replicas were considered to investigate the fluctuation of the number of fissions. The results show that the number of fissions per volume varied from 3.78 10 to 1.49 10 (fissions/m). Moreover, the distribution of the number of fissions was positively skewed.