ADVANCED VESSEL COOLING SYSTEM CONCEPT FOR HIGH-TEMPERATURE GAS-COOLED REACTORS

The high-temperature gas-cooled reactor (HTGR) program will be attract ive to a broad range of owner/operators and meet public acceptance if the future HTGRs would be completely free from accidents, which cause a significant release of radioactivity into the environment. An advanc ed vessel cooling system concept, in which there is no heat loss in no rmal operation and the decay heat is removed by the natural circulatio n of air in an accident, is proposed for the High-Temperature Engineer ing Test Reactor to meet this requirement. The depressurization accide nt, one of the severest accidents of the HTGR, is selected and the ana lysis shows no significant core heatup. Applicability to the future HT GR is also investigated.