Response of a Spent Nuclear Fuel Transportation Package to Regulatory Format Thermal Events

The objective of this work is to compare the response of intact and damaged versions of the 125-ton Multi-Purpose Canister (MPC) rail package conceptual design (OCRWM 1993) to a range of regulatory format fire/post-fire events. In this work we determine the critical fire duration which causes the spent fuel cladding to reach a containment-integrity temperature limit for a relevant range of fire temperatures and external neutron shield damage levels (Fischer et al. 1987). The sensitivity of these critical-duration versus fire temperature envelopes to differing assumptions regarding the fuel region effective thermal conductivity, and the fuel cladding containment-integrity critical temperature, is also determined. The resulting performance envelopes are compared to the conditions of the half-hour, 800°C regulatory fire specified in 1 0-CFR. 71 (US NRC 1992).