PRIMARY COOLANT SYSTEM OF A NUCLEAR POWER PLANT WITH ACCUMULATOR TANK FOR EMERGENCY AND LONG TERM COOLING

摘要

An accumulator tank (60) for containing water under a pressurized, gaseous atmosphere is attached to the primary loop via a coupling, which provides an oulet for the coolant from the accumulator tank to pass to the primary loop. A valve (120), which includes a pressure sensor (150) that senses the pressure in the accumulator tank (60) and opens or closes the coolant flow in the coupling in response to the sensed pressure, is attached to the coupling. The valve causes the coolant to pass substantially through the coupling at a substantially high flow rate when the pressure in the accumulator tank is relatively high and causes the coolant to pass from the accumulator tank to the circulation loop through the coupling at a substantially low rate when the pressure in the accumulator tank is relatively low which, in turn, provides long term cooling of the reactor vessel.