Sampling Approach to Validate the Safe Storage of Plutonium-Bearing Materials

The 3013 surveillance sampling approach combines statistical and judgmental sampling to provide a powerful, cost-effective method for ensuring the safe storage of 3013 containers. To select the statistical sample, the population of containers is organized into three bins based on a container’s contents and estimated po- tential for degradation. Using pressure and corrosion as the po- tential degradation mechanisms, the three bins are Pressure and Corrosion, Pressure Only, and Innocuous. The requirement of 99.9 percent probability of observing at least one of the worst 5 percent (in terms of potential degradation) is used to guide the statistical sampling process for the Pressure and Corrosion and Pressure Only bins. The statistical sample for the Innocuous bin is based on evaluating the assumption that these containers will show no degradation; therefore, these containers will have almost no variability in the surveillance results. The judgmental sampling uses engineering judgment and results of the shelf-life studies to augment the statistical sample with additional containers that are judged to have the greatest potential for degradation.