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Press Release (Feb 17,2012)
Submission of a report on investigation of causes of damage situation of power facilities inside and outside of Fukushima Daiichi Nuclear Power Station to NISA (2nd release)
 On May 16, 2011, we received an instruction* from Nuclear and Industrial 
Safety Agency (NISA) of Ministry of Economy, Trade and Industry titled 
"Countermeasures based on a report on records of damage situation of power 
facilities inside and outside of Fukushima Daiichi Nuclear Power Station 
(instruction)" 
Thereafter we put together the contents in a report on the result of 
investigation of causes that brought about damage situation of power 
facilities inside and outside of Fukushima Daiichi Nuclear Power Station 
and those why protective devices of transmission lines worked and electric 
transmission was suspended (Countermeasures in the future are included in 
the result). We submitted the report to NISA on May 23. 
                         (Previously announced on May 17 and May 24, 2011) 
 
And we have organized a report with the result of seismic analysis based 
on presumption of seismic waveform from data of observation points located 
near the power station about the causes that brought about damage 
situation of power facilities inside and outside of the Power Station. We 
submitted the report to NISA on Jan 19, 2012. 
                                    (Previously announced on Jan 19, 2012) 
 
We assumed the causes that the steel towers collapsed by the collapse of 
fill inside of Fukushima Daiichi Nuclear Power Station in the report to 
NISA on May 23, 2011. Subsequently, we have examined an investigation or 
analysis about a cause of the collapse of fill still more. 
We announce we submitted the report to NISA today. 
 
                                                                      END 
 
○ Attachment(The attachment file will be posted later.) 
  Report on countermeasures based on a report on records of damage 
  situation to power facilities inside and outside of Fukushima Daiichi 
  Nuclear Power Station (instruction) 
 
* Countermeasures based on a report on records of damage to power 
  facilities inside and outside of Fukushima Daiichi Nuclear Power Station 
  (NPS) (instruction) 
                                                     2011.05.16 NISA no. 7 
 
Today on May 16, with regard to collection of a report pursuant to the 
provisions of Article106, paragraph 3 of the Electricity Business Act 
(Act No. 170 of 1964), we received a report from your company on damage 
situation of power facilities, electric transmission to NPS and 
restoration situation of off-site power by urgent measures inside and 
outside of NPS since the occurrence of the Tohoku-Chihou-Taiheiyou-Oki 
Earthquake (Earthquake). 
We, Nuclear and Industrial Safety Agency (NISA), determine we have to make 
clear causes that brought about damage situation of power facilities 
inside and outside of NPS in the report and those why protective device of 
transmission lines worked and electric transmission was suspended in order 
to utilize study to further enhance reliability of power supply to nuclear 
power stations. 
Hence, we request that you report the following items to us by May 23, 
2011.
 
Required Items 
 
1. Results of determination why the following items and other electric 
facilities inside and outside of NPS have caused damage situation since 
Earthquake occurred; especially, you should analyze whether damage 
situation was caused by Earthquake or the tsunami by operation records 
including those just after the earthquake occurred and accident records in 
nuclear reactor facilities stipulated in paragraph 1 of Article 7 of Order 
on Installation and Operation of Nuclear Reactors for Commercial Power 
Generation (Order No.77 of Ministry of International Trade and Industry of 
1978) regarding the current accident at NPS in accordance with the 
provisions of Article 67, paragraph 1 of Act on Regulation of Nuclear 
Source Material, Nuclear Fuel Material and Reactors (Act No. 166 of 1957) 
by records in the report and Nuclear No.1 on April 24, 2011 dated on April 
25, 2011. 
 
○ Fukushima Daiichi Nuclear Power Station 
 · Causes why power receiving circuit breakers and disconnecting switches 
   were damaged 
 · Causes of troubles on electric wires connecting Toden Genshiryoku Line 
 · Causes of collapse of a high tension tower of Yonomori Line No.27 
 · Causes why regular and emergent power distribution panels were damaged 
 
○Shin Fukushima Electric Power Substation 
 · Causes why major transformers were damaged 
 · Causes why circuit breakers were damaged 
 · Causes why disconnecting switches were damaged 
 · Causes why instrument transformers were damaged 
 · Causes why current transformers were damaged 
 
2. Results of determination why protective devices of the following 
transmission lines worked and electric transmission was suspended 
○ Fukushima Daiichi Nuclear Power Station 
 · Okuma Line No.1 
○ Shin Fukushima Electric Power Substation 
 · Okuma Line No.2, 3 and 4 
 · Yonomori Line No. 1 and 2  
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