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 major facilities.

* The updates are underlined.

[Nuclear Power Station]
・ Fukushima Daiichi Nuclear Power Station: Unit 1 to 3: shut down due to the earthquake:
   (Units 4 to 6: outage due to regular inspections before the earthquake)

-At 10:00 am on April 5, we started transferring the accumulated water from the basement of T/B of Unit 6 to the temporary tanks. At 4:00 pm on the same day, we stopped transferring.

-At 1:14 pm on April 6, we resumed operation of primary water circulating pump and cooling of spent fuel pool in order to conduct flashing to suction side strainer of the pump since suction pressure of the pump showed downward trend. (Water temperature in the pool at the time of stop of the operation: approx. 25 ℃).
 We assume the increase of water temperature will be approx. 0.5 ℃/h. (Outage time will be approx. 3 hours.) Therefore, it will not effect on control of water temperature in the pool.

-At around 1:10 am, because the amount of flow which transfer condensed water from the water desalinator (reverse osmosis membrane) to the condensed water storage tank increased at around 1:05 am on April 5, 2012, we stopped the operation of the desalinator manually considering the possibility of water leakage. At around 1:45 am, In order to prevent water leakage, we closed the valve located before and after the piping (pressure-proof hose) which transfer condensed water from the water desalinator to the condensed water storage tank. At around 1:50 am, TEPCO's employee checked the site and found water leakage from the piping. At around 2:20 am, the employee confirmed that the leakage stopped since the desalinator was stopped its operation and the valve was closed. Because it was confirmed that water leaked from the lagging material of the pressure-proof hose, the employee removed the material, confirming that the pressure-proof horse had been disconnected from the joint flange. Because there was possibility that condensed water amounting to approximately 12 m³ might have flown into sea via the ditch for general water discharge, we conducted sampling of the leaked water, water at the drainage ditch, and seawater around the exit of the ditch for general water discharge which locates around 300 m south from the water outlet of Unit 1 - 4. As a result, all gamma and beta nuclide was detected from the leaked water and water at the ditch, we confirmed the result was below the detection limit for the seawater around the exit of the ditch. Consequently, as the result of samplings conducted at coast of the plant etc, we confirmed the result was below the detection limit. Although the operation of the water desalinator (reverse osmosis membrane type and evaporative concentration apparatus type) was suspended, there is no significant influence to the water injection into the reactor because there are affluent amount of water which has been already desalinated.

-At 1:05 am on April 5, 2012: 2nd Cesium adsorption apparatus automatically stopped its operation triggered by the alarm. After checking the site, we confirmed there was no leakage. The cause of the stop is that an operator mistakenly touched the "button for switching modes" on the operation panel (touch panel) of the apparatus.

-At 1:20 pm on April 5, we started injection of hydrazine into reactor well of Unit4 through inside metering piping. At 4:25 pm on the same day, we stooped the injection.

-At 10:14 am on March 20, we started transferring of accumulated water from the basement of Unit 2 T/B to Centralized Radiation Waste Treatment Facility (Miscellaneous Solid Waste Volume Reduction Treatment Building [High Temperature Incinerator Building]).
 At 9:43 am on April 6, we finished the transferring.

-At 10:08 am on April 6, we started transferring of accumulated water from the basement of Unit 2 T/B to Centralized Radiation Waste Treatment Facility (Process Main Building).

・ Fukushima Daini Nuclear Power Station: 
   Units 1 to 4: shutdown due to the earthquake

-At 10:08 am on February 14, we opened the airlock for staff (hatch to come in and out of the primary containment vessel) and started visual inspection to confirm soundness of the primary containment vessel of Unit 3 and the inside facilities. On April 5, we finished visual inspection, As the result of the inspection, we confirmed there is no leakage of reactor coolant, no serious strain and damage etc at every equipments, devices and piping etc inside of the PCV, and no factors to effect on cold shutdown of the plant. In addition, we found peeling of paintworks inside the PCV due to effect of temporally high temperature environment after the plant stop and rusts at the surface of some devices due to effect of humidly environment etc. However, we assume they will not effect on cold shutdown of the plant. Hereafter, we plan to conduct detail inspection of the devices etc including inside of the PCV.

-At around 9:28 on April 28, on the 6th floor of Unit 1 reactor building (controlled area^*1), our partner company's employee who conducted preparation for inspection of stud tensioner^*2 found oil leakage on the floor where installed the facility. At around 9:42, we reported to Futaba Broad Area Fire Fighting Head Office. After on-site inspection by Fire Fighting Head Office,  at 12:40 pm on the same day, regarding this oil leakage, the head office judged it didn't fall under the leakage from dangerous facility as defined in the Fire Defense Law. In addition, the water leakage had stopped when the employee found the leakage. The leaked oil was operating oil of the facility and the amount of the leaked oil was approx.250L. We assumed that of approx. 32 L leaked to flour surface (inside floodgate) and that of approx,.218 L leaked to decontaminated waste liquid receiving tank^*4 through the funnel^*3. There is no outside leakage of radioactivity due to this accident.
 
*1 Controlled area
   An area which needs to be controlled in order to prevent unnecessary radiation exposure and radiation contamination by radioactive materials from spreading.

*2 Stud tensioner
   An apparatus handling check bolts for the cover of reactor pressure vessels

*3 Funnel
   Middle squares which lead drainage water from pipes of each of the buildings or equipment to the tank for the water

*4 Decontaminated waste liquid receiving tank
   Tank which receives waste fluid which decontaminates equipment and so forth

・ Kashiwazaki Kariwa Nuclear Power Station:
   Units 1 to 7: outage due to regular inspections

[Thermal Power Station]
・ Power supply has returned to normal and the facilities damaged by the earthquake are now being handled in a timely manner.

[Hydro Power Station]
・ Power supply has returned to normal and the facilities damaged by the earthquake are now being handled in a timely manner.

[Impacts on Transmission Facilities]
・ Power supply has returned to normal and the facilities damaged by the earthquake are now being handled in a timely manner.

[Impacts on Power Supply and Demand Balance]
We expect to maintain stable power supply in April.
Daily supply and demand balance is announced at our "TEPCO Electricity Forecast".

 

Appendix: Past Progress (As of 3:00 pm, on April 6, 2012) (PDF 528KB)
Appendix: Past Progress (From March 11, 2011 to July 31, 2011) (PDF 225KB)
* Revised past progress