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
-At 12:00 AM on December 26, the common diesel generator (B) which had been recovered has been put in operation as a required common diesel generator to be used in times of abnormality which is stipulated by Article 131 of the technical specification along with the common diesel generator (A).
-At 1:52 PM on December 21, we started transferring the accumulated water in Unit 2 Turbine Building basement to Unit 3 Turbine Building basement. At 9:22 AM on December 26, the transfer was stopped.
-At 9:37 AM on October 23, continuous nitrogen injection into Unit 1 suppression chamber was started. At 10:37 AM on November 26, continuous nitrogen injection was stopped since most of the residual hydrogen in the suppression chamber was considered to have been replaced. At 9:10 AM on December 7, continuous nitrogen injection in the suppression chamber was restarted in order to let out as much residual hydrogen as possible. At 9:56 AM on December 26, continuous nitrogen injection into the suppression chamber was stopped since the hydrogen concentration in the PCV had been reduced down to 0.1%.
-At 10:00 AM on December 26, we started transferring the accumulated water in Unit 6 Turbine Building basement to the temporary tank. At 3:00 PM on the same day, the transfer was stopped.
-At around 10:10 AM on December 26, a cooperative company worker found water leakage in the temporary warehouse of the desalination system (reverse osmosis membrane) 3. At 10:16 AM on the same day, the desalination system 3 was suspended and the leakage was confirmed to have stopped. The area affected by the leakage was approx. 1m x 5m x 1-2mm. The leaked water remains in the dam and has not flowed outside the temporary warehouse. The atmosphere dose rates near the desalination system 3 were as follows. γ, βray: 2mSv/h, γ ray: 0.5mSv/h. The atmosphere dose rates measured in the leakage area were about the same. The radioactivity density analysis results of the leaked water were as follows. Cesium 134: 3.4×10-1 (Bq/cm3), cesium 137: 5.5×10-1 (Bq/cm3). The cause of the leakage is to be investigated. Considering that there is a sufficient amount of desalinated water available, the incident will not have an impact on reactor water injection.
[Fukushima Daini Nuclear Power Station]
·Unit 1 to 4: Shutdown due to the earthquake.
Past Progress (As of 3:00 pm, on December 26, 2012) (PDF 638KB)
Past Progress (From March 11, 2011 to December 31, 2011) (PDF 523KB)
* Revised past progress
The aforementioned attachments are only available in Japanese.
We apologize for any inconvenience this may cause.