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 June 6, sampling was conducted at Unit 2 PCV gas control system. Upon analysis, xenon 135 measured at the system entrance was below the detection limit (9.7×10-2Bq/cm3) and the re-criticality criteria (1Bq/cm3).
* At 10:00 AM on June 7, we started transferring the accumulated water in Unit 6 Turbine Building basement to the temporary tank. At 4:00 PM on the same day, we stopped transferring. At 10:00 AM on June 8, transferring was restarted.
* At 2:18 PM on June 7, hydrazine injection into Unit 4 spent fuel pool utilizing the circulation cooling system was started. At 4:00 PM on the same day, the injection was completed. Hydrazine injection into the spent fuel pool and the reactor well of each unit will be done as appropriate.
* At 8:21 AM on June 8, the second cesium absorption apparatus was temporarily stopped for filter backwash. At 12:05 PM on the same day, the apparatus was restarted and the steady flow rate (approx. 40m3) was achieved. The apparatus will be temporarily stopped for filter backwashing as appropriate.
* At around 10:14 AM on June 8, primary system pump (A) was manually stopped as an alarm indicating "the primary system pump (A) suction pressure low" went off at Unit 2 spent fuel pool alternative cooling system (the pool water temperature at the time the pump was stopped: 24.4°C). As no water leak or the suction strainer clogging was found as a result of site investigation, the pump was restarted at 11:32 AM and the cooling of the spent fuel pool was resumed (the pool water temperature at the time the pump was restarted: 24.5°C). The alarm is assumed to be caused by the temporary flow rate change and the suction pressure decrease of the pump due to the water filling operation after the resin replacement for Unit 2 spent fuel pool ion-exchange equipment.
[Fukushima Daini Nuclear Power Station]
Unit 1 to 4: Shutdown due to the earthquake
Appendix:
Past Progress (As of 3:00 pm, on June 8, 2012) (PDF 416KB)
Appendix:
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.
