Analysis of the ultimate structural behaviour of Caorso NPP primary containment

Evaluation of severe accidents in the safety analysis of nuclear power plants requires that the performance of containment structures be analysed with regard to the actual material properties, either the actual strength of as-built structures or the non-linear stress-strain relationship up to failure. In the paper phase I of the study on the ultimate structural behaviour of the Caorso Nuclear Power Plant is described and the results are discussed. The structural analysis was performed using the non-linear computer program ADINA, and the principal result was the high structural capacity of the reinforced concrete structure. The critical structural element proved to be the drywell steel head, which reaches general yielding at about 3.3 times the design pressure. (author). 9 refs, 8 figs, 7 tabs