Method of and apparatus for shutting down a gas-cooled nuclear reactor

摘要

A gas-cooled nuclear reactor whose nuclear-fuel elements are constituted by graphite-encapsulated nuclear fuel particles and have graphite coatings is shut down in accordance with the present invention by introducing into the primary coolant gas circulation, a gadolinium-containing substance which is dispersed in the primary cooling gas before the latter enters the space between the fuel elements within the reactor core so that the gadolinium-containing substance is at least partly deposited on the free graphitic surfaces of the fuel elements.