Elapsed change and thermal flow in nuclear power plant

This report is constructed by research results of two technical committee on 'elapsed degradation and thermal flow' and 'elapsed change and thermal flow'. In chapter 2 of this report, general consideration on present state of elapsed change in the nuclear power plant was shown. In chapter 3, relationship between degradation mechanism and thermal flow is described. In chapter 4, some items where thermal flow largely affected among research and development projects relating to elapsed degradation of the nuclear power plants conducted in Japan, were described. The projects picked up here were one conducted for cause elucidation or reoccurrence protection countermeasure on troubles formed actually in the nuclear power plants, and one conducted for confirming tolerance of design. (G.K.)