Radiation effects in actinide host phases

Three crystalline ceramic materials, which occur as host phases for the long-lived actinides in many nuclear waste formulations, were doped with Cm-244, and the effects of self-radiation damage from alpha decay on microstructure and physical properties were investigated. The irradiation-induced micro- structure consists of individual amorphous tracks from both the alpha-recoil particles and the spontaneous fission fragments. The overlap of the tracks at higher doses leads to a completely amorphous state at a cumulative dose of 1.3–2.3 × 1025 alpha decays/m3. This radiation-induced amorphization process results in a stored energy of ∼ 128 J/g, 5–10% swelling, factor of 10–50 increase in leachability, and an increase in fracture toughness.