Attractiveness to Theft of a Vitrified Plutonium Waste Form Relative to Commercial Spent Nuclear Fuel – A Pairwise Comparison Approach

This paper compares the potential attractiveness to theft of a lanthanide borosilicate (LaBS) glass vitrified plutonium waste form (VPWF) to a commercial spent nuclear fuel (CSNF) benchmark. The present study uses a pair-wise comparison approach that had been created previously by the Department of Energy (DOE) specifically to rank potential attractiveness to theft for the DOE Spent Nuclear Fuel (SNF) inventory representing hundreds of fuel types. The approach is now extended to address the theft potential of this additional candidate material for the repository at Yucca Mountain, and previously developed data is also used to compare this vitrified waste form with a broad spectrum of the DOE SNF inventory. This analytical tool may contribute towards a useful means for determining an appropriate level of safeguards and security at the monitored geologic repository. The current study extends an existing expert system model, and demonstrates that the vitrified plutonium waste form using lanthanide borosilicate glass cans exhibits the same attractiveness to theft as the commercial SNF benchmark. A major assumption is that the special nuclear material would be used for the purpose of creating a nuclear explosive device. The model is a decision support tool that employs the Analytic Hierarchy Process, a pair-wise comparison technique relying on elicitation of expert judgment. The approach decomposes the concept of relative attractiveness into four intrinsic characteristics: overall weight, fissile material content, relative difficulty of separation, and homogeneity and concentration of special nuclear material. The latter two characteristics were subsequently combined into a single component designated as chemical separability. By determining weights of importance for the resulting attractiveness factors, one can not only calculate the overall attractiveness score, but also observe the role that each factor would play in contributing to relative attractiveness of the vitrified plutonium waste form as well as this waste form’s major fissile material-bearing components.