Basic tests on 48Y-Cylinder for Integrity Evaluation

The present IAEA regulations for transport have not yet required fire resistance (800~,30min) for packagings for natural uranium-hexafluoride. However , fire requirements will be implemented in accordance with the revision of the IAEA regulations in 1996. The integrity of 48Y-cylinder in fire conditions was evaluated using experimental and analytical data . When thermal analysis is performed, various thermal parameters are required. Among these parameters, the outer surface emissivity of the packaging is very important in evaluating heat input from the fire to the cylinder. The IAEA regulations require that the surface emissivity is either 0.8 or the value that the package may be demonstrated to possess if it is exposed to a specified fire . In this study, the emissivity of carbon steel used for 48Y-cylinders was measured to evaluate their fire resistance at the Central Research Institute of Electric Power Industry (CRIEPI) . Furthermore, when a 48Y-cylinder is involved in a fire accident , it is engulfed in the fire and the structural strength decreases. There is insufficient data on the structural materials at high temperature because the carbon steel used for 48Y-cylinders is for moderate- /lower-temperature service . Tension tests were carried out to obtain data on tensile strength , etc. at the CRIEPI under the contract from the Science and Technology Agency (STA) of Japan .