DEVICE FOR COOLING THE MOLTEN CORE MATERIAL OF A NUCLEAR REACTOR EQUIPPED OUT OF THE NUCLEAR REACTOR

摘要

The purpose of the present invention is to provide an excore cooling apparatus of nuclear reactor corium melt capable of improving cooling efficiency of nuclear reactor corium melt by entirely and uniformly transferring heat to a core catcher body by melting a sacrificial material above the core catcher body almost at the same time and ensuring the time that cooling water can be supplied to a core catcher as making the time of melting the sacrificial material long. To achieve the objective of the present invention, the excore cooling apparatus of nuclear reactor corium melt comprises: a core catcher body (30) equipped in a lower side of a reactor vessel (2) and accommodating corium melt (20) in a serious accident; a cooling channel (60) equipped in an upper part, a lateral surface, and a lower part of the core catcher body (30), and in which cooling water (70, 70a) for cooling the corium melt (20) and the core catcher body (30) flows in the serious accident; a soft sacrificial material (50) equipped in the upper part of the core catcher body (30), and to promote melting by causing an exothermic reaction with the corium melt (20); and a general sacrificial material (40) equipped in the upper part of the soft sacrificial material (50). In the soft sacrificial material (50) and the general sacrificial material (40), a material thereof is selected so as that the melting erosion rate of the general sacrificial material (40) is slower than the melting erosion rate of the soft sacrificial material (50).