Performance Assessment of Glass As A Long-Term Barrier To The Release of Radionuclides Into The Environment

Abstract

AbstractPerformance assessment of high-level nuclear waste forms in a repository must cover periods of time on the order of hundreds of thousands of years. There has rarely been a need to extrapolate the properties of a material over such long periods of time (except in the geologic sciences, e.g., the evaluation of long-term weathering effects based on results from laboratory experiments) and there has never been a more important need to make accurate and -verifiable “predictions” of the long-term materials performance. The results of such extrapolations could affect decisions concerning the selection of a repository and the number and types of barriers that are required to insure isolation over long periods of time. In typical safety analyses [1,2] waste form corrosion is described by a single constant rate, and no effort is made to evluate whther the modal of the “source term” can be substantiated or verified by comparison similar or analogous processes [3].