For the Storage of Plutonium Metal, Is a Surveillance Program for Pressurization Necessary?

As part of the U.S. Department of Energy’s (DOE) Materials Identification and Surveillance (MIS) program, gas generation issues for Pu metal stored in DOE-STD-3013-2000 containers were evaluated. This study was prompted in part by problems with lid thickness variabilities of “3013 containers” during initial quality assurance evaluations and to address issues with baseline radiographs in trying to detect pressurization in such containers at DOE packaging and storage facilities. If it is found that there is a credible mechanism for pressurization, then a research effort to show that we can detect such pressurization should be undertaken. If no such credible pressurization mechanism is identified, then there should be no need to implement mechanisms for the detection of pressurization in Pu-metal bearing containers. Elimination or minimization of surveillance activities to detect pressurization of Pu metal stored in 3013 cans for the fifty-year storage period would result in a significant cost savings. This work analyzes the published literature on Pu metal reactivity, presents calculations of pressure rise under credible storage conditions, and evaluates the results of recent Pu metal surveillance experiments. Based on this analysis, we conclude that a regular surveillance program to detect pressurization for the fifty-year term storage of metal items is not necessary.