Core-catcher for reactor meltdown has heat absorbing reservoir - of salts with temp. limited by latent or conversion heat

摘要

A method of, and a device for, contg. a reactor core meltdown in a hypothetical nuclear accident comprises a "core-catcher" below the pressure vessel, sepd. by a barrier layer from the coolant and moderator. The core-cather contains a reservoir of a salt or salts mixt. intended for absorbing meltdown heat in the form of latent or conversion heat of the salt or salts mixt., thus preventing a temp. rise above a given value. After meltdown, penetrations through the reactor vessel, containment, concrete walls etc. are closed by foam. This foam, or suitable remeltable material such as thermoplastics, is produced from foam-forming substances by the meltdown heat. It prevents re-entry of coolant and moderator fluid. Specifically Boron salt or similar neutron-absorbing material is added to the salt to prevent criticality. There is improved absorption and removal of decay heat.