Method of operating BWR type power plants

Purpose: To suppress the increase of the dose rate by suppressing the corrosion to the structural materials in primary coolant circuits. Constitution: An acid is injected such that the pH value is within a range from 6 to 7 for the coolants in nuclear reactor, turbine generator, condensator, filter device using ion exchange resin and recycling system mainly composed of feedwater heater as the constituent elements, to thereby suppress the corrosion to structural materials and also suppress the deposition of Co-60 to stainless steels. The acid is injected at least to such an amount as capable of neutralizing alkaline components leaked from the ion exchange resin filtering device and other equipments. The acid may be injected by a method of injecting gaseous carbon dioxide and organic acid to coolant or feedwater, previously a portion of the anionic resins filled in the filter device as a carbonate type and forming an acid through the ionic reaction with anions, etc. (Sekiya, K.)