CONCEPTUAL DESIGN OF AN EX-VESSEL MELT COOLING DEVICE

摘要

A helical ex-vessel cooling device is being designed and evaluated to insure retention of the molten corium that may discharge from the failed lower head of a reactor pressure vessel (RPV) during postulated severe accidents of a light water reactor. This conceptual design consists of four functional parts located in the reactor cavity, including an intermediate chamber for temporary retention of corium, an helical channel for corium spreading, cooling pipes embedded in the channel wall and venting system. The heat flux profile and steam generation along the cross section of the spreading channel T are analyzed under several conservative assumptions. The results show the melt coolability is achievable even under Benrenson film boiling regime.