The first wall and plasma interactive components of a fusion power reactor are subjected to heavy irradiation of high energy neutrons and high heat flux during normal operation. An extremely high heat flux is deposited in the components during a major plasma disruption categorized as abnormal operation. As a consequence of the event the components melt and solidify resulting in deterioration of the material, high residual stress, metallurgical change and initiation of small cracks. Quantitative evaluation of the consequence of plasma disruption is required to maintain the structural integrity of the components and predict their lifetimes.In the present study the whole process of melting, evaporation and resolidification is analysed using a newly developed computer code based on FEM. In addition, the elastoplastic thermal stress in the heated region during the event is described including residual stress. An experiment was carried out to verify the validity of the code.