[3K06-09] Criticality Analysis of Fuel Debris 2

[3K06] Kinetics analysis to investigate effects of fuel debris particle size on criticality behavior in terms of thermal transfer

*Kodai Fukuda¹, Yuichi Yamane¹ (1. JAEA)

Keywords:Criticality safety, Criticality accident analysis, Kinetics analysis, Fukushima Dai-ichi Nuclear Power Station, Fuel debris

This study presents the results of kinetics analysis in a water-moderated fuel debris particle dispersion system to investigate effects of the fuel particle size on criticality behavior, e.g., the number of fissions. The analysis was performed using point kinetics equations and the one-dimensional unsteady heat conduction equation. Obtained results show a possibility that the number of fissions is larger when the fuel particle size is smaller under certain conditions. The importance of an appropriate setting of fuel particle size is implied by the results.