device for reducing the dangers, as the result of a nuclear reactor cores can arise niederschmelzens

摘要

Danger for the surrounding arising from the melting of a nuclear reactor provided with a core-catcher in the case of a failure of a water-, steam- or gas-cooling system(s) is reduced by providing the core-catcher with a layer of a substance preventing direct contact between the metallic part of the core melt and water or steam. This security system is esp. suitable for fast breeder reactors. The system reduces the formation of hydrogen as a layer of the protective matl. floats on the metl caught by the core-catcher. This layer bars also the radioactive decompsn. prods. and dangerous radiation emitted by the core melt (e.g. boron component of the protective matl. absorbes neutrons). The nuclera fuel can mix with the protective matl. so that the critical concn. is not reached. The protective substance can be an oxide(s) selected from MgO, CaO, B2O3 and/or SiO2, or a borate, phosphate, chromate and/or carbonate. The protective substance may contain an iodine binding matl., pref. Ag.