Corporate Information

Press Release (Jul 28,2012)
Status of TEPCO's Nuclear Power Stations after the Tohoku-Chihou-Taiheiyou-Oki Earthquake (Daily Report as of 3:00 PM, July 28)

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 nuclear power stations (Fukushima Daiichi and Fukushima Daini).

* The updates are underlined.

[Fukushima Daiichi Nuclear Power Station]
· Unit 1 to 4: Abolishment (April 19, 2012)
· Unit 5 to 6: Outage due to regular inspections before the earthquake

- On October 24, oil film was found on the accumulated water in the oil retaining wall of temporary oil tank for main transformer in the power plant premise (Wild Bird Forest). Later, since the water level fell in the retaining oil wall due to waste-water treatment and oil absorption treatment, as checking the status of the submerged tank, on June 25 2012, we found oil leak from the bottom of the oil gage of one of 9 tanks and oil level falling of other 4 tanks. Currently no oil leaks as the valve of the oil gage is closed, leaked oil accumulates in the retaining oil wall. The estimated amount of the oil that has leaked from the tank since we found the oil film on the surface of accumulated water in the retaining oil wall is approx.39kl. Oil leaks from other places are under investigation as well. As a result of reinvestigation of each tankage, we newly confirmed the leakage from 2 tanks. Total number of tanks of which the leak part was confirmed was 3, and total number of tanks which the oil surface fell was 6 out of 9. We revaluated that the amount of leaked oil was approx. 40kl. We conducted on-site investigation and spill test for the remaining 3 units, and did not find a leak part. However, since we confirmed the drop of oil surface, we assumed that the oil was leaked by some reason. We estimated the period of leakage utilizing the precipitation record of Japan Meteorological Agency. The accumulated water with oil in the retaining oil wall is assumed to have flowed out in around September 2011. Since the recovered oil in the retaining oil wall utilizing the adsorption mat etc. was approx. 4kl, we estimate finally that the leaked oil which flowed out of the retaining oil wall was approx. 36kl at a maximum. Most of the oil which flowed out the retaining oil wall (approx. 36kl at a maximum) penetrated into the soil surrounding the retaining oil wall. Although there was possibility that some of the rest flowed into the drain, since the drain near by the retaining oil wall was closed and there was no sign of oil leakage at the surrounding soil, we assumed that there was no leakage into the sea. The leaked oil from the tanks was the insulating oil which was withdrawn from the transformer before the Tohoku-Chihou-Taiheiyou-Oki Earthquake due to the Unit 4 main transformer replacing work at Fukushima Daiichi Nuclear Power Station. Since it contains a trace of PCB (polychlorinated biphenyl)*, we will deal with it in consultation with each place concerned.

* PCB: Polychlorinated biphenyl. It is not soluble in water, is stable scientifically, have high insulating performance and has a high boiling point. It is a chemical compound synthesized industrially. It was used as an insulating oil formerly. Since the toxicity for human body and the residual element for environment had come to problem, the production was halted in 1972.

[Fukushima Daini Nuclear Power Station]
· Unit 1 to 4: Shutdown due to the earthquake.

Appendix: Past Progress (As of 3:00 pm, on July 28, 2012) (PDF 463KB)
Appendix: Past Progress (From March 11, 2011 to December 31, 2011) (PDF 523KB)
* Revised past progress

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We apologize for any inconvenience this may cause.
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