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
-As for the installation of Unit 2 RPV alternative thermometer, the RPV pressure was found to be higher than that measured during the mockup testing. At 10:33 PM on October 1, the flow rate of the nitrogen injected into Unit 2 PCV was changed from 5m3/h to 0m3/h (the amount of nitrogen injection into the RPV remains the same). As the amount of nitrogen injection into the RPV has been maintained at 15m3/h (the necessary minimum flow rate: 9m3/h), there should be no impact on safety. Due to the change in nitrogen injection amount, the monitoring of the hydrogen concentration in the PCV, PCV pressure, PCV ambient temperature and reactor pressure has been enhanced. As the RPV pressure has decreased (6kPa as of 5:00 AM on October 2), insertion of the coil guide (functions as a guide for thermometer installation) started at 9:39 AM on October 2. The insertion was completed at 11:57 AM on the same day. The installation of the alternative thermometer was started at 8:30 AM on October 3 and completed at 11:03 AM on the same day. The temperature measured at 11:00 AM on the same day was 42.6°C, which is similar to the temperature indicated by the RPV bottom monitoring instrument (TE-2-3-69H3) currently in use at 11:00 AM (46.1°C).
-At 9:00 AM on October 3, the cesium absorption apparatus and the desalination system (reverse osmosis membrane) were stopped for switching to a different power source. The second cesium absorption apparatus is planned to be started on October 4. Considering that the suspension period of accumulated water treatment system will be short and there is a sufficient amount of desalinated water in the buffer tank, there should be no impact on reactor water injection.
-At 10:00 AM on October 3, 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 3:35 PM on October 3, a TEPCO employee found a burn on the relay block terminal of the desalination system under suspension (used for treating the accumulated water in Unit 5-6 buildings) during inspection. At 3:56 PM on the same day, the incident was reported to the fire department. This incident has caused no impact on the surrounding equipments.
[ Fukushima Daini Nuclear Power Station ]
·Unit 1 to 4: Shutdown due to the earthquake.
Past Progress (As of 4:00 pm, on October 3, 2012) (PDF 545KB)
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.