Inelastic analysis of high temperature structure

In high temperature, gas-cooled reactors, coolant temperature is very high, while it is up to about 4000C in conventional light water reactors. For example, the multi-purpose VHTR (Very High Temperature Reactor) being designed in JAERI aims at coolant temperature of 1,0000C. At such high temperature, the structural materials show inelastic behavior, so that a new approach is required to the structural analysis. The following matters are described: the theory of inelastic structure analysis as the basis for the finite element code PENTADEC developed for that purpose; and the applications of the code to the elasto-plastic analysis of a thick-walled cylinder, the thermal creep analysis of the fuel-sleeve bottom, and the elasto-plastic analysis of the core-barrel skirt of a VHTR. (Mori, K.)