Hamaoka Nuclear Power Station Reactor No. 3 Undergoes Periodic Inspection
November 26, 2010
Chubu Electric Power Co.,Inc.
Chubu Electric will begin the 17th regular inspection of Hamaoka Nuclear Power Station, Reactor No. 3 (boiling water reactor; rated output 1,100 MW) on November 29, 2010.
The periodic inspection, including power adjustments, is scheduled to last about five months.
During the periodic inspection, the reactor, cooling system equipment, containment structure, steam turbine equipment and so on will undergo inspection, and 172 of the total 764 fuel assemblies will be replaced.
Major Inspections and Work Performed During Regular Inspection at Hamaoka Nuclear Power Station Reactor No. 3
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 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 turbine equipment
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
a. Of the total 764 fuel assemblies, some 172 are to be replaced.
b. Air purge pipes will be positioned in the reactor isolation cooling system as reactor pressure vessel head spray pipes.*1
c. The control unit for the automatic switching unit*2 for the control rod drive mechanisms will be replaced, and there will also be a detailed inspection of its ancillary equipment.
*1 The reactor pressure vessel head spray pipes in the reactor isolation cooling system are pipes that spray cooling water from the top of the reactor pressure vessel to cool steam, in order to efficiently cool the reactor pressure vessel when the plant shuts down.
*2 The automatic switching unit for the control rod drive mechanisms is a device that attaches and detaches the drive mechanisms used to insert and withdraw the control rods.
The control rod drive mechanisms are positioned in the lower part of the reactor pressure vessel, and are replaced by remote control using the automatic switching unit.