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 August 3, Units 1 to 4 remain in a cold shutdown (please
refer to the appendix).
We will make our best efforts to stabilize each plant.
<Updated items are underlined> ○Restoration of emergency diesel generator (A)of Unit 4
At 8:20 pm on August 3, an emergency diesel generator (A)of Unit 4 was
restored. ○Switching to the Residual Heat Removal System (A)
At 12:24 pm on August 2, we finished commissioning of the residual heat
removal system (A) of Unit 4, and then, it had been kept in standby
condition. At 11:00 pm on August 3, we completed switching from Residual
Heat Removal System (B) to (A)
○Regular inspection of monitoring posts
Among monitoring posts (7 in total), which are installed at site boundary,
we are implementing a regular inspection for those of No. 1 to 6 from
In the period of inspection, although it is impossible to measure
radiation dose at inspected monitoring posts, we will continue monitoring
and confirming data from remaining 6 ones.
Inspection dates might be changed due to weather.
(Operation Results of Regular Inspection)
No. 6: on July 29, from 9:31 am to 6:30 pm
No. 1: from 9:21 am, August 2 to 2:30 pm, August 3
*Slight changes in the data were confirmed before and after the
inspection. However, those changes are subject to the adjustments within
the range of measurement devices' allowable margin of errors and are not
caused by changes in environmental radiation dose or detectors' troubles.
No. 3: from9:31 am, August 4, we are conducting an inspection
Appendix: TEPCO Plant Status of Fukushima Daini Nuclear Power Station