Indirect Measurement of Internal Container Pressure Using Real-Time Radiography

摘要

Special Nuclear Materials are being put into long-term storage at sites in the US nuclear weapons complex, including Los Alamos National Laboratory. The storage of these materials is subject to the possibility of internal pressurization of the storage containers arising via the radiolysis of adsorbed water or other contaminant materials along with the nuclear material. With proper treatment of the material before storage, by driving off the contaminants, pressurization is not a factor. However, as a precaution it is important to have a noninvasive method to confirm that there is no internal pressure buildup. Therefore, Los Alamos National Laboratory started a program to include a pressure sensitive bellows inside the containers; as the internal pressure increases the bellows responds by compressing. Since the cans are made of stainless steel, the bellows length is radiographically measured and, knowing the bellows spring rate, the internal container pressure is thus indirectly measured. Here we report the radiographic system configuration, system qualification effort, and production inspection results.