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
- The isolated circulating operation of the decontaminant of water treatment facility was started on May 21. At 6:58 AM on June 14, an alarm indicating a "flow rate balance abnormality" went off. As a worker of our cooperative company checked the monitoring camera and suspected a possibility of water leak, the isolated cycle operation of the apparatus was suspended at 8:14 AM on the same day. Upon site investigation, water leak was found on the dam floor at 12:20 PM. The leak had already been stopped at the time of the investigation, and it was confirmed that the leaked water did not flow out of the dam. (The amount of the leaked water is estimated to be approx. 3m3.) The nuclides analysis result of the leaked water is as follows.
γ nuclides total density: 4.8x102Bq/cm3
Cs-134:1.8x102Bq/cm3
Cs-137:2.6x102Bq/cm3
The leaked water is assumed to have come from the coagulation-sedimentation equipment of the decontamination apparatus. As a result of site investigation on June 15, it is assumed that the leaking part is the interspace of the piping penetration hole on the top side of waste liquid strage tank. And also it is assumed that the water of the tank flowed out, since the water did not flow downstream by shutting down the flow regulating valve of downstream pipes due to instantaneous descent of the level meter of the tank and inflow from upper stream was continued. The integrity verification was conducted on the same day, and the problem was confirmed. The level meter has been decided to be fixed.
- At 10:00 AM on June 18, we started transferring the accumulated water in Unit 6 Turbine Building basement to the temporary tank.
- At 9:54 AM on June 18, Unit 5 Equipment Cooling Seawater System was stopped due to the fix of the strainer drive from June 18 to June 28. Since Spent Fuel Pool cooling system was stopped, cooling at Spent Fuel Pool will be conducted by the residual heat removal system during this period. Cooling of reactor and Spent Fuel Pool will be conducted by the residual heat removal system in alternate shifts. It is estimated that the water temperature will be approx. 60°C (Max.) at reactor, and 31°C (Max.) at Spent Fuel Pool. There is no problem with the temperature control.
- At 9:00 AM on June 18, a worker found the oil leakage from the hydraulic part of the backhoe arm which was used at the civil engineering work (breaking the concrete pavement) near the water intake equipment. The amount of the leaked oil is estimated to be approx. 1 - 2 liter, and leakage was stopped. As for the leaked oil, some was penetrated into the ground, but we wiped it as possible. We reported it to Tomioka fire department at around 10:40 AM on the same day. As a result of the verification at 12:30 PM on the same day by the fire department, it was judged that it was not a leakage from a hazardous material facility. We will investigate the cause.
[Fukushima Daini Nuclear Power Station]
· Unit 1 to 4: Shutdown due to the earthquake
Appendix:
Past Progress (As of 3:00 pm, on June 18, 2012) (PDF 423KB)
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.