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 3: shut down due to the earthquake
 ・Unit 4 to 6: outage due to regular inspections before the earthquake

*At 9:26 am on April 11, we started transferring of accumulated water from the basement of T/B of Unit 2 to the Centralized Radiation Waste Treatment Facility (Miscellaneous Solid Waste Volume Reduction Treatment Building [High Temperature Incinerator Building]). At 10:04 am on April 13, we stopped transferring.
 
*At 10:29 am on April 13, we started transferring of accumulated water from the basement of T/B of Unit 2 to the Centralized Radiation Waste Treatment Facility(Process Main Building).

*At 1:31 pm on April 10, we started transferring of accumulated water from the basement of T/B of Unit 3 to the Centralized Radiation Waste Treatment Facility (Miscellaneous Solid Waste Volume Reduction Treatment Building [High Temperature Incinerator Building]). Since there was other operation around transferring line, at 11:04 am on the same day, we stopped transferring. At 1:47pm on the same day, we restarted transferring.

*On April 13, we conducted the dust sampling at the open part of Unit 2 Reactor Building (Blowout panel).

*On April 13, we took samples at the charcoal filter and particulate filter of Unit 1 RCV gas control system.

*At around 12:20 pm on April 12, 2012, at the road between Unit2 and Unit3 reactor buildings, we found a leakage of fuel (diesel oil) of heavy machinery (grab bucket) which has been used for removing rubbles of upper part of Unit 3 reactor building on the iron plate under the vehicle in the area of approx. 1.5 m x 1m. At around 12:40 pm on the same day, we informed Tomioka fire station. Afterwards, Futaba wide-area fire-defense headquarters and Tomioka fire station checked the site and confirmed that this oil leakage came under the leakage from dangerous facilities stipulated in the Fire Services Act. This oil leakage was stopped when it was found, and there will be no radiation effects to the outside by this event. Regarding the cause, we estimated that fuel was dripping due to the damage of the fuel filter in the fuel supply line for heavy equipments. In By way of caution, an oil absorbent mat and a receiving can was set at the leaking point.

*At 2:44 pm on April 12, 2012, an alarm "excessive leaking flow amount from heat exchange unit" went off and the pumps of the system automatically stopped. As a result of site investigation on leakage from the system, the following events were confirmed. We are investigating their relevance with the automatic stop of cooling system of the spent fuel pool. The water temperature of the spent fuel pool was 28℃ and the temperature rising rate was estimated at approx. 0.5 ℃/h.
 1.During checking leakage from the system, at around 3:04 pm on the same day, we confirmed that hydrazine was leaking at a rate of one drop per 7 seconds from a check-valve installed in the hydrazine injection pipes of the cooling system. We closed the check-valve and the leakage stopped. (We injected hydrazine from 1:35 pm to 2:56 on the same day.) The amount of leaked hydrazine below the check-valve was approx. 20 cc (approx. 10cm x 20 cm x 1 mm).
 2.At 3:10 pm on the same day, at the east side of the 1 floor of Unit 4 Waste Treatment Building, we found water leaking at a rate of 1 drop per 2 seconds from the pipe flange of alternative cooling line for the spent fuel pool. Afterwards, at around 3:55 pm on the same day, we retorqued the flange and confirmed that the leakage stopped. We confirmed that the leakage was approx. 40liters (approx. 1m x 2m x 1-2 cm) around the funnel near the flange. The leaked hydrazine and water were only in the Waste Treatment Building and we confirmed no other leakage than these two places after the investigation.

*At 1:00 am on April 13, 2012, a TEPCO employee found the measurement flow volume of the nitrogen injection line to PCV of Unit 1-3 and RPV decreased. At 1:04am, we checked on the site. And at 1:30 am, we found the nitrogen supply system (nitrogen/gas separator B) was stopped due to failure alert of compressor. At 3:10 am, we started a stand-by nitrogen gas separator and we restarted the nitrogen supply to PCV of Unit 1-3 and RPV at 3:46 am. As for stopped nitrogen/gas separator B, we started to operate at 4:04 am. At 4:20, we started nitrogen injection from nitrogen/gas separator B. At 9:25, we stopped the operation of a stand-by nitrogen gas separator since no problem was found as a result of trial operation with regard to separator and compressor. We continue nitrogen injection with nitrogen supply system B. No significant changes of pressure of PCV of Unit 1-3 and density of hydrogen are confirmed

[Fukushima Daini Nuclear Power Station]
 ・Unit 1 to 4: shutdown due to the earthquake

Appendix: Past Progress (As of 3:00 pm, on April 13, 2012) (PDF 294KB)
Appendix: Past Progress (From March 11, 2011 to December 31, 2011) (PDF 460KB)
* Revised past progress