Repository benefits of partitioning and transmutation.

Geologic repositories such as the one proposed for Yucca Mountain are designed to both safely store hazardous nuclear materials for very long periods of time and to minimise the release rate of these materials to the environment. To succeed in this mission, these repositories need to satisfy a number of design and operational constraints which usually take the form of temperature limits, restrictions on inventory, etc. In general, the ability of a repository to satisfy the constraints depends on the nature and characteristics of the emplaced materials. This paper reports the results of several studies into the benefits to a geologic repository that can be obtained by processing and partitioning spent nuclear fuel, and recycling certain chemical elements in nuclear reactors to transmute them into less hazardous materials. The modest benefits obtained using limited recycling in LWRs is discussed, along with the far greater benefits possible when continuous, or repeated, recycling approaches are employed.