Sizing of canisters. - Stress analysis

Questions concerning the design and the mechanical integrity of the canisters for containment of the spent nuclear fuel is an important issue in connection with the storage of nuclear waste. Although the canister is only one of several barriers against undesired release and migration of nuclides, it is obviously of great benefit to the total safety of the storage system if integrity of the containers can be upheld during a large part of the intended design life. Activities to increase the amount of knowledge in this area have been under way for a considerable time. In 1990 SKB formed a reference group with the main objective to guide research and development on mechanical integrity of the canister. In this paper the current achievements of stress analysis and other sizing considerations of canisters initiated by SKB's reference group on canister integrity are illuminated. A number of different storage concepts have been subject to discussion. During the later years the alternatives have been reduced and the current main alternative is the KBS-3 concept with a canister consisting of an inner load carrying steel cylinder surrounded by a corrosion resistant copper cylinder. In this report only this alternative is to be discussed. 8 refs, 2 tabs