Probabilistic lifetime evaluation of the fusion first wall

This paper describes a numerical analysis used to evaluate the lifetime of a first wall of a fusion reactor based on a probabilistic approach. Very high heat flux is deposited on the first wall during a major plasma disruption. Melting, evaporation, and resolidification of the material result in metallurgical and mechanical deterioration with high residual stresses and small cracks. It is very important to investigate the severity of the consequences and to evaluate the lifetime of the wall. In this paper, the occurrence of plasma disruptions and the length of resulting cracks are determined by random numbers. More than 400 histories are analyzed to determine the probabilistic distribution of crack length. The prediction of the lifetime of the wall is also presented.