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AssigneeWestinghouse Electric Corp.
InventorsDaniel J. McDermott, Kenneth J. Schrader, Terry L. Schulz
Estimating the term…
The effects of steam generator tube ruptures in a pressurized water reactor are mitigated by reducing the pressure in the primary loop by diverting reactor coolant through the heat exchanger of a passive heat removal system immersed in the in containment refueling water storage tank in response to a high feed water level in the steam generator. Reactor coolant inventory is maintained by also in response to high steam generator level introducing coolant into the primary loop from core make-up tanks at the pressure in the reactor coolant system pressurizer. The high steam generator level is also used to isolate the start-up feed water system and the chemical and volume control system to prevent flooding into the steam header.
In a pressurized water reactor having a reactor core within a reactor vessel, a steam generator having a plurality of heat transfer tubes, a reactor coolant system circulating reactor coolant through said reactor core and said heat transfer tubes of said steam generator under pressure in a primary loop, a pressurizer maintaining reactor coolant pressure in said primary loop, a turbine generator, a feed water supply system supplying feed water to said steam generator which covers said heat transfer tubes and is converted to steam which in turn is circulated to said turbine generator in a secondary loop through a steam line near the top of the steam generator, steam generator level indicating means measuring feed water level in said steam generator, and safety systems maintaining cooling of said reactor core and including a passive heat removal system comprising a cold coolant storage tank, a heat exchanger immersed in said cold coolant storage tank, and first piping with first valve means which when opened diverts reactor coolant in said primary loop through said heat exchanger to remove decay heat, the improvement comprising steam generator heat transfer tube rupture mitigation means comprising means responsive to a selected high level of feed water in said steam generator as measured by said steam generator feed water level indicating means to open said first valve means.
A method of mitigating a steam generator tube leak in a pressurized water reactor having a reactor core within a reactor vessel, a steam generator having a plurality of heat transfer tubes, a reactor coolant system circulating reactor coolant through said reactor core and said heat transfer tubes of the steam generator under pressure in a primary loop, a pressurizer maintaining pressure in the primary loop, a turbine generator, a feed water supply system supplying feed water to said steam generator which covers said heat transfer tubes and is converted to steam which in turn is circulated to said turbine generator in a secondary loop through a steam line through the top of the steam generator and a steam generator level indicator system measuring feed water level in said steam generator, said method comprising maintaining cooling of said reactor core while reducing pressure in said primary loop including monitoring said steam generator feed water level and when said level is above a preselected high level diverting reactor coolant through a heat exchanger immersed in a tank of cold water to reduce reactor coolant pressure at least to steam pressure in said secondary loop.
Dependencies are inferred from the claim text.