Nuclear waste forms for actinides

TLDR

The disposition of long‑lived actinides such as 239Pu and 237Np from the nuclear fuel cycle requires waste forms that demonstrate long‑term chemical and mechanical durability, and mineralogic and geologic studies provide candidate phases for immobilization. The study aims to illustrate the mineralogic approach by discussing zircon as a phase for immobilizing excess weapons plutonium. The authors discuss zircon as a candidate phase for immobilizing excess weapons plutonium.

Abstract

The disposition of actinides, most recently 239Pu from dismantled nuclear weapons, requires effective containment of waste generated by the nuclear fuel cycle. Because actinides (e.g., 239Pu and 237Np) are long-lived, they have a major impact on risk assessments of geologic repositories. Thus, demonstrable, long-term chemical and mechanical durability are essential properties of waste forms for the immobilization of actinides. Mineralogic and geologic studies provide excellent candidate phases for immobilization and a unique database that cannot be duplicated by a purely materials science approach. The "mineralogic approach" is illustrated by a discussion of zircon as a phase for the immobilization of excess weapons plutonium.