PROCESS FOR LOWERING THE REACTIVITY OF A GAS-COOLED, GRAPHITE-MODERATED NUCLEAR REACTOR, AND GRAPHITE ELEMENT WITH SHUT -DOWN SUBSTANCE THEREIN

摘要

A method of operating a gas-cooled nuclear reactor having graphite fuel elements in which, to reduce the reactor, a quenching element is introduced which takes a particle of a reaction-reducing substance in a sheath which will melt or release the substance in vapor form so that the substance can penetrate in gaseous form through the surrounding graphite body and deposit upon fuel elements.