On March 11 2011, Fukushima Daini Nuclear Power Station Units 1 to 4
(Boiling Water Reactors, rated output 1,100 Megawatts each) that we had
been operating at rated thermal output shutdown automatically at 2:48 pm,
due to the Tohoku-Chihou-Taiheiyou-Oki Earthquake (previously announced on
March 11).
At 7:15 pm on March 15, the reactor of Unit 4 achieved a cold shutdown. As
a result, all the Units of Fukushima Daini Nuclear Power Station achieved
the status of cold shutdown (previously announced on March 15).
As of 3:00 pm on July 16, the Units 1 to 4 remain in a cold shutdown
(please refer to the appendix). We will make our best efforts to stabilize
each plant.
<New items are underlined>
○At 11:11am today (on June 16), the Clean Up Water System* of Unit 1 has
been restored.
Currently Residual heat removal system (B) is in operation for cooling
and heat removal of Reactor. As the Clean Up Water System restored today
is expected to work as reactor cooling function, it is thought that the
reliability of Unit 1 cold shutdown status would be improved. We will
make every effort to retrieve the plant, aiming to further improvement
of cold shutdown status
*Clean Up Water System: The system removes impurities in the reactor
water and maintains the water quality. The system is also used to
control reactor water level by discharging redundant water from the
reactor during regular inspection or reactor shutdown.
So far, the Clean Up Water System of Unit 4 and Unit 3 were restored on
June 4 and June 6 respectively.
○Of the monitoring posts (7 in total) installed in the site boundary, we
are planning to clean the inside of the covers that veil the measuring
devices and the feet of the posts from No. 1 to 5, five in total in
order to improve sensitivity for detection
(Track Record of Cleaning Monitoring Posts)
· No. 1: July 11th From 4:05 pm to 5:15 pm
· No. 2: July 12th From 3:05 pm to 4:05 pm
· No. 3: July 13th From 4:05 pm to 5:00 pm
· No. 4: July 14th From 3:05 pm to 3:55 pm
· No. 5: July 15th From 3:05 pm to 4:00 pm
We will make our best efforts to stabilize each plant
Appendix: TEPCO Plant Status of Fukushima Daini Nuclear Power Station
(PDF 16.4KB)