BWR type nuclear power plant

Purpose: To remove impurities such as Ni and Co in heater drain water thereby suppressing the rise of the radiation dose in pipeways and equipments. Constitution: A clean-up device for removing Ni, Co ions and the likes is disposed to a system for transporting heater drain water flowing in the heater drain pipeways to a portion in admixture with feedwater. In this case, if the temperature of the drain water is higher than 90 deg C in view of the system design, a device using metal oxide adsorbents or electrolytic metal ion removing device is employed. In the case where the drain temperature is lower than 90 deg C, a device using ion-exchange resins or chelate resins, or device using oxine added active carbon is used, so that a preferable ion removing method is selected depending on the temperature. As a result, the Ni and Co concentration in the feedwater can be reduced by about 2/3 as usual and the nuclides introduced into the reactor core are about 2/3. In this way, operators, the exposure upon in-service inspection can be reduced and the maintenance can be facilitated. (Kamimura, M.)