Chapter 13 - Actinide host phases as radioactive waste forms

Abstract

An effective strategy for dealing with high-level waste is to partition the short-lived fission product elements from the long-lived actinides, creating separate waste streams. Once there are two waste streams, the properties and durability of the waste form can be designed to a level appropriate to the toxicity and time required for isolation from the environment. With such a strategy the fission product elements may be incorporated into a borosilicate glass and the actinides into more durable crystalline ceramics. Although special glass compositions may be developed for actinide incorporation, their long-term durability is less easily assured, particularly on the time scales required for actinide immobilization and confinement. The final selection of any waste form should depend on its ability to incorporate the radionuclides of interest, its chemical durability, response to a radiation-field, and physical properties as well as the time required for isolation to protect the environment.