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Press Release (Aug 18,2011)
Submission of reports to NISA regarding results of earthquake response analysis using observed seismic data collected at Fukushima Daiichi and Daini Nuclear Power Station during the Tohoku-Taiheiyou-Oki Earthquake, etc. (Vol. 3)
TEPCO compiled a record of observed seismic data collected at Fukushima 
Daiichi Nuclear Power Station and Fukushima Daini Nuclear Power Station 
when the Tohoku-Taiheiyou-Oki Earthquake occurred at 2:46pm on March 11, 
2011, and reported it to NISA. 
                         (Previously announced on April 1 and May 16, 2011)

Subsequently, we received an instruction document* from NISA. Following the
instruction, we were meant to conduct detailed evaluation of the impact 
from the earthquake shake and implementation of countermeasures for 
malfunctions of seismometers, and to report the results to NISA. We have 
already compiled reports on the results of earthquake response analysis of 
reactor buildings, facilities and pipes important to earthquake safety in 
Unit 1 to 4 and the results of survey on the malfunctions of seismometers 
and their modifications made following the survey, and submitted them to 
NISA.
              (Previously announced on May 18, June 17, and, July 28 .2011)

We'd like to notify here that we compiled reports on the results of 
earthquake response analysis at Fukushima Daiichi and Daini Nuclear Power 
Station, and submitted them to NISA. 

· Results of earthquake response analysis of reactor building, 
  facilities and pipes important to earthquake safety in Unit 5 and 6 at 
  Fukushima Daiichi Nuclear Power Station.
· Results of earthquake response analysis of reactor building, 
  facilities and pipes important to earthquake safety in Unit 1 to 4 at 
  Fukushima Daini Nuclear Power Station.
· Results of earthquake response analysis of all turbine buildings, 
  facilities and pipes important to earthquake safety at Fukushima Daiichi 
  and Daini Nuclear Power Station

                                                                        END

The report and appendix are now being developed.
Due to the vast amount of data contained in the material,it will take a 
month before the whole translation is completed.
We will post the translated material one by one when it is prepared.
We apologize for the inconvenience caused.
At the moment, the report and appendix are prepared in Japanese.

Attachment 1: Report on results of earthquake response analysis of reactor
              building, facilities and pipes important to earthquake safety
              in Unit 5 at Fukushima Daiichi Nuclear Power Station using
              observed seismic data during the Tohoku-Taiheiyou-Oki
              Earthquake (Summary) (PDF 258KB)
Attachment 2: Report on results of earthquake response analysis of reactor
              building, facilities and pipes important to earthquake safety
              in Unit 6 at Fukushima Daiichi Nuclear Power Station using
              observed seismic data during the Tohoku-Taiheiyou-Oki
              Earthquake (Summary) (PDF 304KB)
Attachment 3: Report on results of earthquake response analysis of reactor
              building, facilities and pipes important to earthquake safety
              in Unit 1 at Fukushima Daini Nuclear Power Station using
              observed seismic data during the Tohoku-Taiheiyou-Oki
              Earthquake (Summary) (PDF 303KB)
Attachment 4: Report on results of earthquake response analysis of reactor
              building, facilities and pipes important to earthquake safety
              in Unit 2 at Fukushima Daini Nuclear Power Station using
              observed seismic data during the Tohoku-Taiheiyou-Oki
              Earthquake (Summary) (PDF 293KB)
Attachment 5: Report on results of earthquake response analysis of reactor
              building, facilities and pipes important to earthquake safety
              in Unit 3 at Fukushima Daini Nuclear Power Station using
              observed seismic data during the Tohoku-Taiheiyou-Oki
              Earthquake (Summary) (PDF 309KB)
Attachment 6: Report on results of earthquake response analysis of reactor
              building, facilities and pipes important to earthquake safety
              in Unit 4 at Fukushima Daini Nuclear Power Station using
              observed seismic data during the Tohoku-Taiheiyou-Oki
              Earthquake (Summary) (PDF 286KB)
Attachment 7: Report on results of earthquake response analysis of turbine
              building, facilities and pipes important to earthquake safety
              at Fukushima Daiichi and Daini Nuclear Power Station using
              observed seismic data during the Tohoku-Taiheiyou-Oki
              Earthquake (Summary) (PDF 172KB)

Appendix 1: Report on results of earthquake response analysis of reactor
            building, facilities and pipes important to earthquake safety
            in Unit 5 at Fukushima Daiichi Nuclear Power Station using
            observed seismic data during the Tohoku-Taiheiyou-Oki
            Earthquake (PDF 2.17MB)
Appendix 2: Report on results of earthquake response analysis of reactor
            building, facilities and pipes important to earthquake safety
            in Unit 6 at Fukushima Daiichi Nuclear Power Station using
            observed seismic data during the Tohoku-Taiheiyou-Oki
            Earthquake (PDF 1.55MB)
Appendix 3: Report on results of earthquake response analysis of reactor
            building, facilities and pipes important to earthquake safety
            in Unit 1 at Fukushima Daini Nuclear Power Station using
            observed seismic data during the Tohoku-Taiheiyou-Oki
            Earthquake (PDF 1.55MB)
Appendix 4: Report on results of earthquake response analysis of reactor
            building, facilities and pipes important to earthquake safety
            in Unit 2 at Fukushima Daini Nuclear Power Station using
            observed seismic data during the Tohoku-Taiheiyou-Oki
            Earthquake (PDF 1.33MB)
Appendix 5: Report on results of earthquake response analysis of reactor 
            building, facilities and pipes important to earthquake safety
            in Unit 3 at Fukushima Daini Nuclear Power Station using
            observed seismic data during the Tohoku-Taiheiyou-Oki
            Earthquake (PDF 2.14MB)
Appendix 6: Report on results of earthquake response analysis of reactor
            building, facilities and pipes important to earthquake safety
            in Unit 4 at Fukushima Daini Nuclear Power Station using
            observed seismic data during the Tohoku-Taiheiyou-Oki
            Earthquake (PDF 1.73MB)
Appendix 7: Report on results of earthquake response analysis of turbine
            building, facilities and pipes important to earthquake safety
            at Fukushima Daiichi and Daini Nuclear Power Station using
            observed seismic data during the Tohoku-Taiheiyou-Oki
            Earthquake (PDF 2.02MB)

*Actions following the analysis of seismic data collected at Fukushima 
 Daiichi nuclear power station and Fukushima Daini nuclear power station 
 during the Tohoku-Taiheiyou-Oki Earthquake (Instruction)
                                                     NISA No.6, 2011 May 16

On May 16, NISA received TEPCO's report of analysis of observed seismic 
data collected at Fukushima Daiichi nuclear power station and Fukushima 
Daini nuclear power station during the Tohoku-Taiheiyou-Oki Earthquake.

According to the report, acceleration response spectra of observed seismic 
data observed at free foundation point in the reactor buildings in 
Fukushima Daiichi nuclear power station was mostly below the acceleration 
response spectra for evaluation of basic earthquake ground motion Ss in 
most periods, however, spectra collected in Unit 2, 3, and 5 exceeded 
spectra for evaluation by 30% at maximum during 0.2 to 0.3 seconds. 
Based on TEPCO's analysis above, NISA considers that it is extremely 
important to evaluate the impacts from the earthquake on reactor buildings,
turbine buildings, and major facilities and pipes from earthquake 
resistance perspective in Fukushima Daiichi and Daini nuclear power station
in order to confirm the status of safety function of those facilities at 
the time of earthquake and following period.
The report also states that data recording was interrupted in several 
voluntary located seismometers during 130 to 150 seconds after the 
initiation of recoding due to the malfunction of recording devices.
The reason of malfunction was analyzed that 1) the program was coded to 
finish the recording once the seismometer detects the shake below threshold
even if it detects the shake above such threshold afterwards, 2) while the 
recording device was meant to restart the recording when the shake exceeds 
threshold even after the recording was interrupted, program didn't restart 
the recording due to the malfunction of recognition of recording material. 
NISA accordingly requests TEPCO to report following matters by the 
following due date.

1.Fukushima Daiichi and Diani nuclear power station
(1) Result of combining seismic response analysis of the impact from the 
shake of the earthquake on reactor building and their important facilities 
including PCV and RPV in Unit 2 and 4 of Fukushima Daiichi nuclear power 
station.

Due date: June 17, 2011

(2) Result of combining seismic response analysis of the impact from the 
shake of the earthquake on reactor building and their important facilities 
including PCV and RPV in Unit 1 and 3 of Fukushima Daiichi nuclear power 
station.

Due date: July 29, 2011

(3) Result of combining seismic response analysis of the impact from the 
shake of the earthquake on reactor building and their important facilities 
including PCV and RPV in Unit 5 and 6 of Fukushima Daiichi nuclear power 
station and in all units of Fukushima Daini nuclear power station and 
result of seismic response analysis of turbine buildings and major 
facilities and pipes from earthquake resistance perspective in both nuclear
power station regarding the impact from the shake of the earthquake.

Due date: August 17, 2011

2.Recording device allocated to collect seismic data
Survey of the malfunction revealed in the report regarding the recording 
devices of all kinds of voluntary located seismometers in TEPCO's all 
nuclear power station and result of modification made following the survey. 

Due date: June 17, 2011
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