We, Tokyo Electric Power Company, received an instruction notice*
"regarding the additional opinion of NISA for the analysis of reporting
the results of evaluation of earthquake-proof safety of existing reactor
facilities for power generation, referring to the new earthquake-proof
standards established based on the Tohoku-Chihou- Taiheiyo-Oki Earthquake,
2011 (Instruction)"(April 28th,, 2011).
(Previously announced on April 29, 2011)
As a consequence of the occurrence of Tohoku-Chihou-Taiheiyou-Oki
Earthquake ("the Earthquake"), where the huge crustal movement was
observed, we have reviewed and summarized the Information regarding fault,
which is necessary to take into consideration in the seismic design, which
is necessary to review the possibility of eligibility to take into
consideration in the seismic design of nuclear power station, for existing
nuclear power station with existing survey and submitted to NISA today.
In addition, we will collect information regarding the effect of crustal
movement with regards to the Earthquake, correlation between the
earthquake and fault which is happening after the Earthquake in the
surrounding area of Fukushima Daiichi Nuclear Power Station, Fukushima
Daini Nuclear Power Station and Kashiwazaki Kariwa Nuclear Power Station
and reflect these survey to the evaluation appropriately.
Attachment 1: Faults unconsidered in the seismic design of Fukushima
Daiichi Nuclear Power Station and Fukushima Daini Nuclear
Power Station
Attachment 2: Faults unconsidered in the seismic design of Kashiwazaki
Kariwa Nuclear Power Station
(Reference)Regarding the report on the response to the addition of opinions
upon considered by NISA in relation to the report of the evaluation results
on seismic safety of existing nuclear power reactor facilities etc. in
light of the new Seismic Regulatory Guide for based on the 2011 Tohoku
District -Off the Pacific Ocean Earthquake.
·The first half of the report (PDF 12.41MB)
·The second half of the report (PDF 11.46MB)
* Instruction Notice
Regarding the additional opinion of NISA for the analysis of reporting
the results of evaluation of earthquake-proof safety of existing reactor
facilities for power generation, referring to the new earthquake-proof
standards established based on the Tohoku-Chihou-Taiheiyo-Oki Earthquake,
2011 (Instruction)
NISA No.4, April 28th, 2011
April 28th, 2011
Today, Nuclear Safety Commission decided on the additional opinion of NISA
for the analysis of reporting the results of evaluation of earthquake-
proof safety of existing reactor facilities for power generation,
referring to the new earthquake-proof standards established based on the
Tohoku-Chihou-Taiheiyo-Oki Earthquake, 2011 and notified to Nuclear and
Industrial Safety Agency (hereinafter referred to as "NISA").
According to the decision, Nuclear Safety Commission defined the following
opinion and request analysis by NISA regarding the evaluation of
earthquake-proof safety of the existing reactor facilities for power
generation referring to the new earthquake-proof standards (hereinafter
referred to as "earthquake-proof back-check"), in the understanding that
more places are becoming seismically active triggered by the current
earthquake and normal-fault-type earthquakes are occurring as observed in
Hamadori in Fukushima Prefecture on April 11th.
·Accompanying the Tohoku-Chihou-Taiheiyo-Oki Earthquake, major crustal
movements were observed with a big impact in a wide area. In response
to this situation, it is necessary to analyze the possibilities that
the faults, displacements, and lineaments, which are already
investigated by the reactor owners, fall into the active faults that
require earthquake-proof measures.
·Earthquakes should be evaluated in case that earthquakes have been
observed in the area which previously was seismically inactive
accompanying the Tohoku-Chihou-Taiheiyo-Oki Earthquake or nearby faults
which do not fall into the faults which require earthquake-proof
measures.
·Based on the above analysis, if there are any faults which may
influence the site, the ground motion should be evaluated.
In response to the opinion, NISA request Tokyo Electric Power Company to
report on the following matter by May 31st, 2011.
Note
Information regarding the results of geological surveys or faults,
displacements, and lineaments, etc., which are necessary to analyze the
possibilities of existence of the faults which require earthquake-proof
measures, considering that major crustal movements were observed
accompanying the Tohoku-Chihou-Taiheiyo-Oki Earthquake.