PASSIVE SYSTEM FOR COOLING THE CORE OF A NUCLEAR REACTOR

摘要

A system for passively cooling nuclear fuel in a pressurized water reactor during refueling that employs gravity and alignment of valves using battery reserves or fail in a safe position configurations to maintain the water above the reactor core during reactor disassembly and refueling. A large reserve of water is maintained above the elevation of and in fluid communication with the spent fuel pool and is used to remove decay heat from the reactor core after the reaction within the core has been successfully stopped. Decay heat is removed by boiling this large reserve of water, which will enable the plant to maintain a safe shutdown condition without outside support for many days.

主权项

1. A nuclear power generating facility comprising:
a containment building; an elongated reactor vessel housed within the containment building, the reactor vessel having a nuclear core having fissile material in which fission reactions take place and an open end axially spaced from the nuclear core, with the open end sealed by a head at a flange; a spent fuel pool supported outside the containment building at an elevation that extends substantially above the reactor vessel, the spent fuel pool being in fluid communication with an interior of the reactor vessel through a first valve; and an ultimate heat sink coolant reservoir whose upper coolant level under normal operation of the nuclear power generating facility is supported at an elevation substantially above the spent fuel pool, with a lower portion of the ultimate heat sink reservoir in fluid communication with the spent fuel pool through a second valve whose operation is controlled by a level of coolant in the spent fuel pool to maintain the coolant in the spent fuel pool at approximately a preselected level.