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 am 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 30, Units 1 to 4 remain in a cold shutdown (please
refer to the appendix).
We will make our best efforts to stabilize each plant.
<Updates are underlined>
○Regular inspection of monitoring post
Among monitoring post (total of 7), which are installed at site boundary,
we are implementing regular inspection for No. 1 - 6 (1 monitoring post
per day) from July 29 to August 8.
In the period of inspection, although it is unable to measure radiation
dose by such monitoring post, we will continue to measure and confirm the
data by using remainder of 6 monitoring post.
Inspection date might be changed due to the weather.
(Operation Results of Regular Inspection)
○No. 6: July 29, 9:31 am - 6:30 pm in regular inspection
*No significant changes in the data were confirmed before and after the
inspection of monitoring posts.
○Inspection after the earthquake occurred July 31
- At 6:32 am on July 31, air leak was found at the weld zone of unit 4's
main emission duct by TEPCO employee. Radioactive materials in the air
were below measurable limits. No outlier at main emission monitor and
monitoring post. This is the same place repaired on June 7. The repair
work will be implemented soon.
- Results of main emission duct and monitoring post are within normal
range, There is no affect by radioactive material outside. 
Appendix: TEPCO Plant Status of Fukushima Daini Nuclear Power Station
(PDF 18.4KB)
