On March 11 2011, turbines and reactors of Fukushima Daini Nuclear Power
Station Units 1 to 4 (Boiling Water Reactors, rated output 1,100 Megawatts)
that we had been constantly operating at rated thermal output were
automatically shut down 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 cold shutdown. As a
result, all reactors of Units 1 to 4 at Fukushima Daini Nuclear Power
Station achieved cold shutdown (previously announced on March 15).
As of 3:00 pm on June 7, the reactors of Unit 1 to 4 are in cold shutdown
(please refer to the appendix). We continue to make our endeavors to
stabilize each plant.
<Updates from previous press release are underlined.>
At 4:00 pm on June 7, air leak was found at the weld zone of unit 4's main
emission duct by TEPCO employee. (10cm×3cm 2 places ). Radioactive
materials in the air were below measurable limits.
We will implement the repair work and check similar points soon. No outlier
at main emission monitor and monitoring post was detected. No radiation
effect is found outside.
Appendix: TEPCO Plant Status of Fukushima Daini Nuclear Power Station
(PDF 16.3KB)