Hamaoka Nuclear Power Station Reactor No. 4 Undergoes Periodic Inspection
January 24, 2012
Chubu Electric Power Co.,Inc.
This is to announce that Hamaoka Nuclear Power Station Reactor No. 4 (boiling water reactor; rated output: 1,137 MW) will begin its 13th periodic inspection on January 25, 2012.
During the periodic inspection, the reactor, cooling system equipment, containment structure, steam turbine equipment and so on will undergo inspection, and some of the total 764 fuel assemblies will be replaced with new ones (the number of the assemblies to be replaced is under consideration).
Major Inspections and Work Performed During Regular Inspection at Hamaoka Nuclear Power Station Reactor No. 4
(1) Major inspections
Inspection of reactor pressure vessel, structures inside reactor and fuel
b. Reactor cooling system equipment
Inspection of pipes, heat exchangers, pumps and valves
c. Measurement and control system equipment
Inspection of control rod drive hydraulic control system; inspection and calibration of various measurement devices
d. Radiation control equipment
Inspection and calibration of various radiation control measurement devices
e. Reactor containment equipment
Seal testing of reactor building, containment equipment
f. Steam turbines
Overhaul inspection of steam turbine equipment; disassembly and inspection of main valves; inspection of auxiliary equipment
Inspection of scrapped equipment, fuel equipment, emergency backup generator equipment, electrical equipment, etc.
(2) Major work and construction
a. Some of the total 764 fuel assemblies will be replaced (the number of the assemblies to be replaced is under consideration).
b. Work will continue on the construction of tsunami countermeasures*1 reflecting findings obtained from sources including studies of the accident at Tokyo Electric Power Co., Inc.'s Fukushima Daiichi Nuclear Power Station as a result of the Great East Japan Earthquake. As part of this work, during the periodic inspection of the facility, an emergency seawater intake system (EWS) will be connected to the existing seawater cooling system equipment.
c. The soundness of the cylinder liners*2 of the emergency diesel generators will be checked.
d. As a measure to prevent reoccurrence of damage to main condenser tubes in Hamaoka Nuclear Power Station Unit No. 5, any structures in which it is considered that the same phenomenon might occur will be subject to replacement work.
*1 Press release "Tsunami Countermeasures at Hamaoka Nuclear Power Station" (Reported on July 22, 2011)
*2 Cylindrical parts that form the combustion chambers of the emergency diesel generators. Pistons move up and down inside the cylinder liners, repeating a cycle of combustion and compression.