Auxiliary feedwater is a backup
water supply system found in
pressurized water reactor nuclear power plant
A nuclear power plant (NPP) is a thermal power station in which the heat source is a nuclear reactor. As is typical of thermal power stations, heat is used to generate steam that drives a steam turbine connected to a electric generator, generato ...
s (PWRs). This system, sometimes known as emergency feedwater, can be used to cool the reactor, if normal feedwater to the
steam generators fails to work. It works by pumping water to the steam generators from reserve tanks or a larger body of water (e.g. lake, river, or ocean) to remove
decay heat from the
reactor by dumping non-radioactive steam to atmosphere or using this steam to drive turbine driven auxiliary feedwater pump(s). The auxiliary feedwater system in PWRs are often equipped with ''motor driven'' aux feedwater pumps, and, as an additional measure, ''turbine driven'' aux feedwater pump that is driven not by electricity but by steam generated by decay heat removal from the normal secondary side steam circuit of the plant. In contrast to
emergency core cooling systems for
loss-of-coolant accidents, the auxiliary feedwater system does not inject directly into the reactor core. Instead, it cools in an indirect manner by cooling the primary circuit with the reactor via the steam generators.
Nuclear technology
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