On August 23, 2011, we are going to commence the 10th regular inspection
for Unit 7 of Kashiwazaki Kariwa Nuclear Power Station (advanced boiling
water reactor type, 1,356 MW of rated output). The details are shown below.
1.Planned working period for the inspection
From August 23rd, 2011 (83 days)
2.Main equipment that will be inspected
(2) Reactor cooling system facility
(3) Instrumentation and control system facility
(4) Fuel facility
(5) Radiation control facility
(6) Disposal facility
(7) Primary containment facility
(8) Emergency reserve generation facility
(9) Steam turbine
3.Planned main works during the regular inspection
(1) Replacement of fuel assemblies
200 out of 872 fuel assemblies will be replaced.
(2) Replacement of control rods
25 hafnium flat tube-type control rods out of 205 control rods will
be replaced by boron carbide type control rods.
(3) Replacement of clean up water system pipes
New ventilation pipes that exhaust mixed gas (hydrogen and oxygen)
generated through radiation dissolution in the reactor will be
installed to clean up water system pipes to prevent the gas from
(4) Countermeasures against tsunami
The following equipment will be arranged or installed for the
countermeasures against tsunami
-Laying out cables from emergency high voltage distribution boards to
the that in the reactor building
-Arranging alternative seawater heat exchange equipment
-Installing top ventilation equipment in the reactor building
We will identify the fuel assembly where a pinhole, through which
radioactive materials in the form of gas leaked into the reactor coolant,
on a cladding tube of a fuel rod was potentially created.
We will conduct the shipping inspection to all the fuel assemblies, then
conduct visual check the whole of the identified fuel assembly using the
underwater camera as well as ultrasound scan to identify the leaking fuel
rod. We will observe it in details using the fiber scope.
During this regular inspection, we will clean up the reactor and systems
connecting to the reactor to further reduce the leaked fuel.
With respect to the start-up, we will consult the national and local
government adequately and deliberately.
<Reference> Status of Our Nuclear Power Stations
Fukushima Daiichi and Fukushima Daini
All the units are shut down due to the Tohoku Chihou Taiheiyou Oki
Earthquake of which epicenter is Sanriku Oki, which occurred on March
Unit 1 (1,100 MW) Under regular inspection
Unit 2 (1,100 MW) Under regular inspection
Unit 3 (1,100 MW) Under regular inspection
Unit 4 (1,100 MW) Under regular inspection
Unit 5 (1,100 MW) In operation
Unit 6 (1,356 MW) In operation
Unit 7 (1,356 MW) Scheduled to be inspected from August 23rd
The total output of the plants in operation will be 2,456 MW in 2 units.