Thermal analysis of heated cylinder simulating nuclear reactor during loss of coolant accident

Sato, Hiroyuki  ; Ohashi, Hirofumi ; Tachibana, Yukio ; Kunitomi, Kazuhiko ; Ogawa, Masuro

Transient analyses are presented of temperature behavior of reactor during loss-of-coolant accident with scram. The influence of reactor thermal properties, operating power density, geometry of active core and selection of fuel type on the capability of decay heat removal against the accident are studied. It is shown that the reactor design envelope is fully determined by the key parameters. The range of the envelope is shown to enlarge considerably by selecting high refractory fuel. High temperature gas-cooled reactor (HTGR), a graphite-moderated reactor with TRISO coated fuel particle, is the primary candidate which can fulfill the requirement to the design concept of nuclear reactor independent of coolant for decay heat removal.