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.