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Corporate Information

 
Press Release (May 24,2011)
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
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)" 
                                (Previously announced on May 17, 2011)

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 announce we submitted the report to NISA 
yesterday on May 23. 
                                                                    END

○ Attachment 
 ·Our report on "Countermeasures based on a report on records of damages 
  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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