Used Fuel Container Designs and Lifetime Prediction

Abstract

The Canadian method for long-term management of used nuclear fuel is Adaptive Phased Management, which consists of placing the fuel in a deep geological repository designed to contain and isolate the fuel for an extended period of time. This method involves encapsulating used-fuel bundles in durable containers and sealing the containers in the repository which would be built at a depth of about 500 m below ground. Several used-fuel container designs are being considered. Copper and carbon steel are candidate corrosion barrier materials for the used fuel containers. Over the past 20 years, many studies have been carried out to improve our understanding of the long-term behaviour of both materials in a deep geological repository in either a crystalline rock or a sedimentary rock environment. This paper presents an overview of recent work in used fuel container design and development in the Canadian program, including anticipated container performance and lifetime estimates based on our current knowledge of the relevant corrosion processes.