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Corporate Information

 
Press Release (Feb 17,2012)
Status of TEPCO's Facilities and its services after the Tohoku-Chihou-Taiheiyou-Oki Earthquake (as of 3:00 pm, February 17)
 Due to the Tohoku-Chihou-Taiheiyou-Oki Earthquake which occurred on March 
11, 2011, TEPCO's facilities including our nuclear power stations have 
been severely damaged. We deeply apologize for the anxiety and 
inconvenience caused. 
With regard to the accident at Fukushima Daiichi Nuclear Power Station, on 
April 17, 2011, we have compiled the roadmap towards restoration from the 
accident and on July 19 we accomplished the Step1 target "Radiation dose 
is in steady decline". Then on December 16 we confirmed the accomplishment 
of the Step 2 target "Release of radioactive materials is under control 
and radiation doses are being significantly held down". 
In addition, on December 21, 2011, we have compiled the "Mid-to-long-Term 
Roadmap toward the Decommissioning of Fukushima Daiichi Nuclear Power 
Units 1-4, TEPCO". 
In addition to the maintenance of the plant's stable condition, we will 
implement Mid-to-Long Term countermeasures towards the decommissioning of 
Fukushima Daiichi Nuclear Power Units 1-4 to enable evacuees to return to 
their homes as soon as possible and reduce the anxiety of the people in 
Fukushima and the whole nation as soon as possible.
 
Below is the status of TEPCO's major facilities. 
 
*Updates are underlined. 
 
 [Nuclear Power Station] 
 
 Fukushima Daiichi Nuclear Power Station: Unit 1 to 3: shut down due to 
 the earthquake: 
  (Units 4 to 6: outage due to regular inspections before the earthquake) 
 
 -At 8:46 am on February 17, since the treatment capacity of the 2nd 
  Cesium adsorption apparatus was declining gradually, we stopped it for 
  the reverse cleaning of the filters. At 10:59 am on the same day, we 
  restarted it, and at 11:05 am it reached to the rated flow (approx. 
  36.4 m3/h). 
 
 -At 11:33 on February 17, we reduced the water injection rate to Unit 3 
  by the core spray system from approx. 6.0m3/h to approx. 5.0m3/h in 
  order to transfer the accumulated water increased due to the increase of 
  the water injection rate to Unit 2 as well as to reduce the burden of 
  the water treatment, seeing that we had some margins in the volume of 
  water injection at that time against the rate equivalent to the delay 
  heat. We also adjusted the water injection rate from the feed water 
  system, which was fluctuating, from approx. 2.9 m3/h to approx. 3.0 m3/h. 
 
 -Regarding the Unit 2 the bottom of whose RPV showed the increasing trend 
  of the temperature rise, since the trend was still continuing, we 
  started the operation to increase the water injection rate*1 at 2:10 
  February 12. At 2:20 pm, we judged that it did not satisfy the condition 
  "the temperature is below 80 °C at the bottom of PCV", which is one of 
  operational limits stipulated in "the Reactor Facility safety 
  Regulation*2. We conducted measures to satisfy those operational limits, 
  and increased the volume of water injection. The trend of the 
  temperature rise was continued further, we investigated the thermometer 
  in the lower part of the RPV of Unit 2 on February 13. Through the 
  investigation, we considered the possibility that the wires of device 
  are broken, since the higher DC resistance value than normal was 
  measured. After the final evaluation, we concluded that the device was 
  broken. Therefore, at 2:00 pm on February 17, we judged that the 
  temperature at the bottom of PCV was not actually increasing, and we 
  corrected the judge of the deviation from the conditions of operations 
  stipulated in the management of facilities retrospectively back from 
  February 12. We also excluded this device from the items to be monitored 
  for the temperature at the bottom of PCV stipulated in the Reactor 
  Facility safety Regulation, and we decided to monitor the temperature 
  using other devices. 
 
  *1) Based on the management of facilities stipulated at the Article 12 
      "Mid-term safety securing" of Act of the Regulation of Nuclear 
      Source Material, Nuclear Fuel Material and Reactors, it provides 
      "Operational Limit" and "measures required in the case that does not 
      satisfy the Operational Limit", it is required to respond based on 
      the measures required in the case that does not satisfy the 
      Operational Limit. In this case, in order to implement the 
      preservation work, it was shifted to outside of operational limit 
      condition [the rate of the increase in the water injection volume is 
      less than 1.0m3/h in any 24 hour period] as planned (from 1:55 pm on 
      February 12), we change the water injection amount into the reactor 
      of Unit 2. Later at 2:00 pm on February 17, we judged that the 
      Operational Limit [the temperature at the bottom of PCV is below 80 
      °C] has been satisfied, and corrected the judge of the deviation 
      from Operational Limit. We also lifted the application of the 
      planned shift to the outside of operational limit condition. 
 
  *2) Reactor Facility Safety Regulation provides necessary conditions 
      such as the numbers of the permitted machines etc. or criteria of 
      temperatures and pressures for securing multiple safety function for 
      operating reactors and for keeping nuclear power stations stable and 
      these are treated as conditions for operation. When there happen 
      some malfunctions of equipment provided in the regulation and a 
      nuclear power station can not clear the conditions temporarily, 
      operators have to take required countermeasures. 
 
 -In order to conduct inspection of the strainer changeover valve of the 
  pump of the reactor sea water system of Unit 6 from February 14 to 
  February 17, at 10:02 am on February 14, we stopped cooling of the 
  spent fuel pool by the spent fuel pool cooling system (B) and at 10:06 
  am on the same day, we stopped the pump of the reactor sea water 
  system (A) (spent fuel pool water temperature during the stoppage: 
  approx. 23°C). Because the spent fuel pool cooling system isn't in 
  operation during the inspection, we conduct alternating cooling of the 
  reactor and the spent fuel pool by the residual heat removal system. 
  At 2:07 pm on February 17, we finished the inspection and started the 
  pump of the reactor sea water system (A), and at 2:53 pm on the same 
  day, we resumed the cooling of the spent fuel pool by the spent fuel 
  pool cooling system (B), back to normal cooling condition (the maximum 
  temperature during the alternative cooling period: 33.6°C(water in the 
  reactor), 29°C(water in ths spent fuel pool). 
 
・Fukushima Daini Nuclear Power Station: 
  (Units 1 to 4: shutdown due to the earthquake) 
 
・Kashiwazaki Kariwa Nuclear Power Station: Units 6: under normal operation 
  (Units 1 to 5 and 7: outage due to regular inspections) 
 
 [Thermal Power Station] 
・Power supply has returned to normal and the facilities damaged by the 
 earthquake are now being handled in a timely manner. 
 
 [Hydro Power Station] 
・Power supply has returned to normal and the facilities damaged by the 
 earthquake are now being handled in a timely manner. 
 
 [Impacts on Transmission Facilities] 
・Power supply has returned to normal and the facilities damaged by the 
 earthquake are now being handled in a timely manner. 
 
 [Impacts on Power Supply and Demand Balance] 
This winter, there are some minus factors such as the regular inspection 
of Unit 5 at Kashiwazaki-Kariwa Nuclear Power Station. On the other hand, 
there are several plus factors such as the recovery of the common thermal 
power stations which suffered the earthquake. As a result, we expect to 
secure 53.7 GW (at the end of February) supply power. 
Compared to the maximum demand in the last winter, which is 51.5 GW, we 
will have 2.2 GW generation reserve margin. 
 
We expect to maintain stable power supply this winter. However, as there 
remains possibilities of unplanned shutdowns at our power stations and 
growth in the demand according to the rapid change in the temperature, we 
would like to ask your reasonable effort to save electricity. 
 
We will continue to make our efforts to maintain stable operation and 
maintenance of the power facilities in order to "prevent in principle" the 
planned blackouts and secure power supply. 
 
 
Appendix: Past Progress (As of 3:00 pm on February 17, 2012) (PDF 434KB) 
Appendix: Past Progress (From March 11, 2011 to July 31, 2011) (PDF 225KB) 
 
* Revised past progress 
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