10:30 AM - 10:45 AM
[2B05] Effect of Neutron Generation Time on Supercritical Transient Analysis in Fuel Debris during Falling Down in Water
Keywords:Criticality safety, Prompt supercritical transient analysis, Neutron generation time, Fuel debris, Fukushima Daiichi NPS decommissioning
In previous studies, evaluations of released energy in criticality accidents have been conducted in accumulated fuel debris. However, it is suggested that reactivity during falling down in water could be higher than when accumulated on floor. In such cases, change of neutron generation time could be important for the evaluations. The purpose of this study is to clarify whether it is needed to consider change of neutron generation time for evaluation of released energy by supercritical accidents by fuel debris during falling down in water.
In this study, supercritical transient analysis based on PKM were performed in falling fuel debris system with some cases of neutron generation time. A necessity to consider change of neutron generation time was discussed.
In this study, supercritical transient analysis based on PKM were performed in falling fuel debris system with some cases of neutron generation time. A necessity to consider change of neutron generation time was discussed.