Abstract: A nuclear reactor and emergency core cooling system. A nuclear reactor is provided with a cylinder around the core barrel that defines an annular channel therebetween. An injection nozzle is provided through the reactor vessel for delivery of emergency coolant to the defined channel. Emergency coolant is supplied during a LOCA to the injection nozzles sequentially from a high pressure tank, a low pressure tank, gravity feed tanks inside the reactor building, and from sumps that collect coolant in the reactor building. Check valves in the upper portion of the cylinder vent steam to the reactor inlet lines during a LOCA. Bores around the upper circumference of the cylinder break any siphoning action that might occur at the injection nozzle if there is a break in the emergency coolant lines from the emergency coolant sources.

Abstract: In order to supply emergency coolant directly to the core inlet of a nuclear reactor, a separate and distinct channel is located within the reactor vessel. This channel flows downward along the perimeter of the core barrel and discharges its emergency coolant directly to the core inlet. Separate nozzles couple this channel to the supply of emergency coolant.