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 May 28, filling concrete in Unit 3 circulating water pump discharge valve pit was completed.

* At 10:00 AM on May 29, we started transferring the accumulated water in Unit 6 Turbine Building basement to the temporary tank.

* At 10:33 AM on May 29, we started up Unit 5 PCV fan which had been stopped after the earthquake in order to exhaust the air directly from PCV (Until now we have been opening the equipment hatch to exhaust the air).

* On May 28, the following Unit 2 PCV thermometers (monitored in accordance with Article 138 of the Technical Specification) indicated significant temperature changes (stepwise increase/decrease in temperature). Upon our temperature trend evaluation, we found that these temperature changes may have been caused by abnormality with the thermometers. On May 29, direct resistance measurement was done on these thermometers, and reliability evaluation will also be done. According to the radioactivity density of short half-life nuclides, there is no possibility of re-criticality.
RETURN AIR DRYWELL COOLER (TE-16-114A) [Monitored] 58.0°C→64.7°C
RETURN AIR DRYWELL COOLER (TE-16-114D) [Monitored] 43.7°C→47.6°C
SUPPLY AIR D/W COOLER HVH 2-16A (TE-16-114F #1) [Reference] 41.0°C→35.0°C
SUPPLY AIR D/W COOLER HVH 2-16C (TE-16-114H #1) [Monitored] 52.1°C→48.2°C
(Above data was acquired from 5:00 PM to 11:00 PM on May 28)

* At 12:30 PM on May 29, data reading was failing on the Main Anti-Earthquake Building monitoring panel of the portable monitoring post at the west entrance. The same issue was occurring on the Main Anti-Earthquake Building monitoring panel of the wireless monitoring post used for alternative monitoring. There is no problem with data monitoring at 12:30 PM and later, as a worker at the site has been measuring data.

* At 1:10 PM on May 29, an alarm went off at the measurement equipment (dust monitor which continuously measures the radioactivity density of radioactive materials in the air) located in front of the Main Anti-Earthquake Building. At 1:15 PM, an instruction was given to wear a full-face mask (based on an operation rule). After that we found that there was no significant change in monitoring post data. The filter of the measurement equipment was replaced. At 1:50 PM, the equipment was restarted by resetting. As a result of a manual measurement of radioactivity density of the air in front of the Main Anti-Earthquake Building, the radioactivity density was below the detection limit (1x10^-5[Bq/cm³]) and the standard value for requiring a full-face mask (1x10^-4[Bq/cm³]). At 1:53 PM, an announcement was given to allow taking off the mask.

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

* At 10:28 AM on March 6, Unit 2 PCV airlock (hatch for workers to go in and out of PCV) was opened for a soundness inspection of PCV and the equipments inside PCV. On May 29, the visual inspection was completed. As a result, we found no leakage of reactor coolant or deformation/damage of equipments and piping inside PCV and that there are no factors hindering the cold shutdown function. Though minor issues were found such as the paint inside PCV partially coming off and rust on the surface of some equipments (due to the temporary temperature/humidity rise until reaching the cold shutdown), these do not have impact on the cold shutdown function

Appendix: Past Progress (As of 3:00 pm, on May 29, 2012) (PDF 551KB)
Appendix: Past Progress (From March 11, 2011 to December 31, 2011) (PDF 460KB)
* Revised past progress