Intersubassembly Fuel Penetration into a Failed Blanket Subassembly

摘要

This work provides additional understanding of hypothetical core-disruptive accident issues involving LMFBRs. Intersubassembly molten fuel and steel penetration into a failed blanket subassembly was analyzed with the two-dimensional SIMMER-II code. Interaction of the fuel and steel with the blanket coolant was included in the investigation. The molten core material was injected through a prescribed opening in the blanket subassembly wall. Eighteen cases involving variations of parameters of importance to the subsequent flow were calculated. In general the resulting pressurization was a good figure of merit for rating the severity of the events. In turn, the pressurization depended on the wall opening size, the initial pool pressure, and the heat-transfer rates. However, only when the wall failure rate was large relative to the sodium expulsion rate, was sufficient pressure generated that could affect the reactor vessel containment. (ERA citation 07:063062)