Fire durations of concern for a modern legal weight truck cask

The response of a truck package designed to transport four pressurized water reactor fuel assemblies to a range of fire durations is simulated using MSC Patran and Container Analysis Fire Environment computer code (CAFE).;A three-dimensional thermal finite element package model is constructed. Different fire models are employed and compared: (a) 10CFR71 Regulatory Format (specified fire temperature and emissivity), (b) Container Analysis Fire Environment (Computational Fluid Dynamics fire model);A model is developed to determine the fractional seal degradation from its temperature versus time history. This model is used to determine the minimum fire duration that causes the seal to lose containment integrity. The fire durations that cause the maximum cladding temperature to reach its long term creep deformation and burst rupture temperatures are determined and found to be longer than the duration that cause the seal to lose containment integrity. These simulations are repeated for package models without the compliant regions of the impact limiters, and for a package with the impact limiter completely removed. These simulations quantify the level of thermal protection the impact limiters provide to the seals and cladding during simulated fires.;Using the Container Analysis Fire Environment, three different wind boundary conditions are applied to the side walls of the computational domain in order to evaluate their effect on the thermal response of the package. The fire durations that cause seal and fuel cladding to reach their temperature of concern are calculated for No-Wind, typical Wind and Reverse Wind conditions and compared with regulatory format fires.