With regard to the accident at Fukushima Daiichi Nuclear Power Station due
to the Tohoku-Chihou-Taiheiyo-Oki Earthquake that occurred on March 11th,
2011, we are currently doing our best to bring the situation under control
and are proceeding with a factual investigation.
Amidst this backdrop, regarding the major time-line of seawater injection
to Unit 1 which was conducted on March 12th, we would like to announce
the facts identified so far as follows.
<Major time-line on March 12>
Approx.12:00pm President confirmed and approved the preparation for
seawater injection
Approx.2:50pm President confirmed and approved the implementation of
seawater injection
Approx.2:53pm Injection of freshwater stopped
(80,000l were injected at this point)
Approx.3:18pm Reported to the Nuclear and Industrial Safety Agency
(NISA) that we were scheduling to inject seawater once
ready.
Approx.3:36pm Hydrogen explosion
Approx.6:05pm Received instruction from the government regarding
seawater injection
Approx.7:04pm Seawater injection was started
Approx.7:06pm Reported to NISA about seawater injection
Approx.7:25pm Based on the situational decision by our staff
dispatched to the prime minister's office, the message
stating "Prime minister's approval is not obtained
regarding seawater injection here" was received at our
headquarters and the power station. As a result of the
discussion between headquarters and the power station,
we decided to suspend the injection.
However, seawater injection was continued per a decision
by the site superintendent at the power station.(*)
(*) As a result of the hearing conducted with relevant parties, we found
out that the seawater injection conducted at approximately 7:25pm was
not actually suspended and that the water was continually being
injected per a decision by the site superintendent. (In order to
prevent the accident from getting worse, continuous water injection
to the reactor is considered to be the most important measure)