As the investigation results regarding tsunami arrived in Fukushima
Daiichi and Daini Nuclear Power Stations generated by the Tohoku -
Taiheiyou - Oki - Earthquake occurred at around 2:46 pm on March 11,
2011, we have indicated each inundation height and area as well as we
have reported to Nuclear and Industrial Safety Agency (hereafter "NISA")
that the impact of the tsunami in Fukushima Daiichi Nuclear Power Station
was relatively larger than Fukushima Daini Nuclear Power Station.
(Announced on April 9th,2011)
And also, we have received directive that requires implementation of more
detailed analysis and evaluation on tsunami arrived in Fukushima Daiichi
Nuclear Power Station and Fukushima Daini Nuclear Power Station from NISA.
(Announced on April 13th,2011)
After that, based on this directive, we conducted tsunami investigation
at inside and outside of the site, and analyses of characteristics of the
tsunami and effects by inundation to the power station, etc. regarding
tsunami arrived in Fukushima Daiichi and Daini Nuclear Power Stations.
As results of tsunami investigation and numerical simulations, we
estimated that the height of the tsunami at the tidal observatory of both
power stations were approximately 13m in Fukushima Daiichi Nuclear Power
Station and approximately 9m in Fukushima Daini Nuclear Power Station
respectively.
As for the factor of this differential, we consider that it would be
caused by difference of the overlap level of the peak of the tsunami from
the large landslide area expected off the coast of Miyagi Prefecture and
Fukushima Prefecture.
And also, we summarized the impacts to main buildings such as reactor
building and turbine building as well as important facilities for seismic
safety of both power stations by this tsunami.
Today we reported to NISA on aforementioned contents.
End
Attachment:
Report on investigation results regarding tsunami generated by the Tohoku
- Taiheiyou - Oki - Earthquake in Fukushima Daiichi and Daini Nuclear
Power Stations (vol.2) [outline] (PDF 1.45MB)
We have provided a Japanese press release version of the instruction
document received from NISA. However, at this time we have reserved the
right to not provide an English version due to potential misunderstandings
that may arise from an inaccurate rendering of the original Japanese text.
We may provide the English translation that NISA releases in our press
releases. However, in principle we would advise you to visit the NISA
website for timely and accurate information.