Estimation of Package Temperatures During Hypothetical Accident Thermal Test Conditions

Knowledge of package maximum temperatures during normal transport and hypothetical accident thermal test conditions is required to ensure that a package for the transportation of radioactive materials is designed adequately to meet the requirements specified m the Code of Federal Regulations, Tiile 10, Part 71 ( 10 CFR §71 ). The testing procedure for the hypothetical accident thermal event, specified in 10 CFR §71.73, is to expose the whole package to a radiation environment at soo·c (1475.F) for a period of 30 rnins, with the ambient temperature before and after the 30-min test held constant at 38·c ( l oo·F). To determine the temperatures of a package during the hypothetical accident thermal event, the designers and reviewers perform detailed analyses with computer codes. Because detailed modeling of the package and solving the thermal diffusion equation with computer codes require considerable time and effort, simple conservative estimating procedures are therefore preferred because the very detailed and time-consuming numencal computation can be avoided if the results of a simple conservative estimation can show that a package meets the requirements.