METHOD FOR CONTROLLING IRON CONCENTRATION IN FEED WATER OF NUCLEAR POWER PLANT

摘要

PURPOSE:To control the iron concn. in feed water and to decrease exposure dose by controlling the inflow rate of heater drain water into the feed water according to the iron concn. and nickel concn. in the feed water and the nickel concn. and cobalt concn. in reactor water. CONSTITUTION:The iron concn. of the feed water is controlled by controlling the opening degrees of a flow rate control valve 17 interposed in a low-pressure heater drain feed water return piping 15 and a flow rate control valve 18 interposed to a low-pressure heater drain condenser return piping 16 by the required iron concn. of the feed water calculated by the iron and nickel concns. in the feed water measured by a feed water sampling line 19 and the nickel and cobalt concns. in the reactor water measured by a reactor water sampling line 20. Since the heater drain water contg. iron clads is directly introduced into the feed water system in such a manner, the iron concn. in the feed water is rapidly and exactly controlled without increasing the load on the iron-component of a condensate desalting device and without taking the iron-component from the outside. The radioactivity of the nuclear power plant is thereby lowered and the exposure dose is decreased.