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 around 8:30 AM on August 14, a worker from cooperative company found a white smoke from the vessel ventilation vacuum pump*1 at the cesium adsorption tower temporary storage facility*2 at the outside of the central environment facility on the south side. We worked on digestion with a fire extinguisher immediately, and confirmed that the white smoke was stopped at 8:40 AM. At 9:17 AM, we reported to Tomioka fire department. At 2:20 PM, we received the judgment by the fire department that it was not fire. We replaced it to another unused vessel ventilation vacuum pump, and started up the pump at 2:50 PM on the same day. We will investigate the cause of the white smoke from the pump. For reference, there was no impact to the surrounding equipments, and no remarkable changes at the values of monitoring posts around the power station.
*1 Vessel ventilation vacuum pump
It is a pump which sucks the hydrogen caused by water radioactive decomposition in a vessel from the venting valve. Since the hydrogen generated in a vessel is minute amount, stopping of the pump would not cause safety hazard immediately.
*2 Cesium adsorption tower temporary storage facility
It is a facility to store the vessels which were used at the Cesium Adsorption Apparatus. There is no impact to water injection to reactor and accumulated water treatment.
- At around 11:15 AM on August 14, a worker of TEPCO found leaked water at the power center room on the Unit 4 Turbine Building first floor. The leaked water was spread to all area of the power center room and north side of the Unit 4 Turbine Building first floor corridor. The depth of water was approx. 1 cm, and there was no leak to the outside of the building. The water inflow into the room was continued. Since there is a pipe which is transferring the accumulated water from Unit 3 Turbine Building basement to the Miscellaneous Solid Waste Volume Reduction Treatment Building (High Temperature Incinerator Building), we stopped the transferring pump at 12:21 PM on the same day. At 12:58 PM on the same day, we confirmed that the inflow of water into the room was stopped. The result of nuclide analysis of the accumulated water in the power center room was as below.
Cesium 134: approx. 3.0 X 104 Bq/cm3
Cesium 137: approx. 4.7 X 104 Bq/cm3
We estimated that the leaked water was the accumulated water in Unit 3 Turbine Building. As for the accumulated water in the power center room, we will drain to the Unit 4 Turbine Building basement. We will investigate the cause continuously.
- At 10:00 AM on August 12, we started transferring the accumulated water from Unit 2 Turbine Building basement to Unit 3 Turbine Building basement. At 12:57 PM on August 14, we stopped transferring.
[Fukushima Daini Nuclear Power Station]
· Unit 1 to 4: Shutdown due to the earthquake.
Appendix:
Past Progress (As of 4:30 pm, on August 14, 2012) (PDF 488KB)
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.