Condensate storage vessel cleaning device for nuclear power plant

An ordinary condensate storage vessel which is a water source of an ordinary water absorbing load and an emergency condensate storage vessel which is a water source such as of an emergency reactor core cooling facility are disposed separately and connected by a water feeding line, and there is disposed a returning line connecting a filtering desalting device of a fuel pool cleaning facility for cooling and cleaning spent fuel pool water and the emergency condensate storage vessel, a suppression pool. When condensate stored in the emergency condensate storage vessel is cleaned by the filtering desalting device of the fuel pool cleaning facility and returned to the emergency condensate storage vessel by the returning line, the condensate can be cleaned periodically. In addition, condensate after purification is optionally supplied from the ordinary condensate storage vessel to the emergency condensate storage vessel to store water. Then, the emergency condensate storage vessel can be reduced in the size, and the construction cost for the ordinary condensate storage vessel can be reduced. (N.H.)