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 2:02 PM on December 12, Unit 3 spent fuel pool cooling was suspended in order to install additional valves and inspect the check valves in the spent fuel pool alternative cooling system. At 2:35 PM on December 18, the spent fuel pool cooling was restarted (the spent fuel pool water temperatures when the cooling was stopped and restarted: approx. 11.0℃ and 23.7℃ respectively).
-At 10:00 AM on December 18, 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 9:50 AM on December 18, the air fin cooler of the common pool cooling purification system (A) secondary system was suspended in order to stop the main line of the common D/G (A) M/C. Cooling will be suspended until December 19. The pool water temperature when cooling was suspended was approx. 19.0℃. The pool water temperature increase rate during cooling suspension is approx. 0.23℃/h and the amount of pool water temperature increase is estimated to be approx. 8℃. There is no problem with the pool water temperature control considering the sufficient margin to the maximum allowed temperature (65℃).
-At 2:00 PM on December 18, we started transferring the accumulated water in Unit 3 Turbine Building basement to the Central Radioactive Waste Treatment Facility (Miscellaneous Solid Waste Volume Reduction Treatment Building [High Temperature Incinerator Building]).
-From 11:14 AM to 2:05 PM on December 10, Units 1-3 reactor water injection pump was switched from the regular reactor water injection pump on the hill to the reactor injection pump in the Turbine Building in order to prepare for newly building a shed for the regular reactor water injection pump on the hill during the period from December 10 to 17. Since the work was completed, the pump was switched back from the reactor water injection pump in the Turbine Building to the regular reactor water injection pump on the hill from 1:58 PM to 5:05 PM on December 17. The reactor injection water amounts at Units 1-3 were changed as follows so as to adjust Unit 1 reactor injection water target amount to be equal to the target reactor injection water amount for the regular reactor water injection pump on the hill (4.5m3/h (total flow rate)).
[Unit 1] Reactor core spray system: Decreased from approx. 2.5m3/h to approx. 2.0m3/h, Feed water system: Maintained at approx. 2.5m3/h.
[Unit 2] Feed water system: Increased from approx. 1.9m3/h to approx. 2.0m3/h, Reactor core spray system: Decreased from approx. 4.1m3/h to approx. 3.5m3/h.
[Unit 3] Increased from approx. 1.9m3/h to approx. 2.0m3/h, Reactor core spray system: Decreased from approx. 4.0m3/h to approx. 3.5m3/h.
[Fukushima Daini Nuclear Power Station]
･ Unit 1 to 4: Shutdown due to the earthquake.
Past Progress (As of 3:00 pm, on December 18, 2012) (PDF 634KB)
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.