JP2859199B

PROBLEM TO BE SOLVED: To enable an efficient test by injecting heated reactor water into a water supply line through a communicating line and an outside non-return valve, and putting pressurized pressure into the water supply line through a communicating line and an outside nonreturn valve to humidify and pressurize all the corners. SOLUTION: There are provided with a main steam piping side communicating line 102 communicated from a discharge part of a residual heat removing pump 5 operated for circulating and heating holding water in a nuclear reactor pressure container to the main steam drain piping drain line 20 when performing pressure resisting leakage test of a nuclear reactor coolant pressure boundary, a water supply line side connecting line 101 connected from the line 102 to a water supply system nuclear reactor storing receptacle outside nonreturn valve drain line 34 and a switching valve 104, whereby the main steam line 11 and the water supply line 30 in a pressure resisting leakage test for a nuclear reactor coolant pressure boundary can be heated efficiently and further pressurization from a water supply system unclear reactor storing receptacle inside non-return valve to the outside non-return valve can be performed efficiently.