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 around 8:30 on March 26, 2012, in the area of condensed water tanks for water desalinations (reverse osmosis membrane) of Fukushima Daiichi Nuclear Power Station, a partner company worker found that water was leaked from a pipeline (anti-pressure hose) which transferred the condensed water from the water desalinations to the condensed water tanks. In order to stop the water leakage, we stopped the transfer pumps of the water desalinations (reverse osmosis membrane) and then the leakage stopped. After that, we closed the valves at the both sides to the leakage point of the pipeline (anti-pressure hose). When we checked the leakage on the site later, we found that a part of the leaked water had been poured into a nearby drainage for general draining water. And then, we conducted sampling surveys on the leaked water, the water which was poured into the drainage, and the seawater around the exit of the drainage. As a result, we judged that some water including radioactive materials was poured into the sea from the exit of the drainage located at about 300 m south from the discharge channel of Unit 1-4 of Fukushima Daiichi Nuclear Power Station. At this moment, the water desalinations (reverse osmosis membrane and evaporative concentration apparatus) are not in service. However, because we have much treated fresh water, it does not affect water injection to the reactors. Total amount of leaked water is estimated to be approx 120 m3 in accordance with the operation hour of the pump. 80 L out of 120 m3 is estimated to flow into the sea at maximum. Thereafter, the cesium adsorption apparatus was stopped at 5:00 pm and the second cesium adsorption apparatus was stopped at 5:29 pm.
*At 10:00 am on March 26, we started transferring of accumulated water from the basement of Unit 6 T/B to the temporary tank. At 4:00 pm on the same day, the transfer was stopped. At 10:00 am on March 27, the transfer was restarted.
*At 10:10 am on March 26, we started transferring of accumulated water from the basement of Unit 3 T/B to Centralized Radiation Waste Treatment Facility (Miscellaneous Solid Waste Volume Reduction Treatment Building "High Temperature Incinerator Building"). At 4:34 pm on the same day, the transfer was stopped.
*From 9:40 am to 12:30 pm on March 26, the water level and water temperature inside the PCV of Unit 2 was investigated with the industrial endoscope. As a result, the water level was confirmed to be 60 cm from the bottom of the PCV and the water temperature was confirmed to be in the range of approx. 48.5 ℃ to 50.0 ℃.
*At 5:41 am on March 27, the cooling of the spent fuel pool of Unit 4 was stopped (water temperature at the time of stoppage: approx. 24 ℃) in order to implement the replacement of flexible hose in the primary coolant system and pump inlet strainer in the secondary coolant system. Stoppage is scheduled to continue till March 28. The increasing rate of the water temperature is estimated to be approx. 0.5 ℃/h, therefore no material issue in the management of the pool temperature is expected.
*At approx. 9:30 am on March 27, workers of the other company found the water leakage from the underground pipes (Anti-disaster pipe for Unit 4 transformer) during the removal work of such pipes using heavy machine to prepare the ground condition for the installation work of Unit 4 covering. After the inspection, it was confirmed that such pipes were already isolated and the leaked water was treated water remaining in the pipes. *Treated water (fresh water): water from the Sakashita Dam
*At 12:10 pm on March 27, the amount of injected nitrogen into the PCV was adjusted from 0 m3/h to approx. 5 m3/h as the internal investigation of the Unit 2 PCV was finished.
*At 2:00 pm on March 27, Hydrazine injection into the Unit 4 reactor well through the instrument pipes inside the reactor was started.
・Fukushima Daini Nuclear Power Station:
Units 1 to 4: shutdown due to the earthquake
*At 3:30 pm on March 26, malfunction in data transfer function of Emergency Response Support System occurred . At 4:10 pm on the same day, the malfunction was restored after the reboot of network termination unit. The malfunction is estimated to be a temporary phenomenon as the data transfer functions well thereafter.
*At 4:20 pm on March 26, Unit 4 residual heat removal system(A) was stopped due to the removal work of scaffolding materials inside the Unit 4 sea water heat exchanger building. At 4:26 pm on the same day, Unit 4 residual heat removal system(B) was activated.
*At 12:42 pm on March 27, in the Unit 3 and 4 Service Buildings when a TEPCO member was bringing in analysis samples from Fukushima Daiichi Nuclear Power Plant, he confirmed that there was contamination by radioactive materials on a desk beside a small object monitor (non-controlled area*) at the checkpoint for the confirmation of contamination of goods for workers exiting from controlled area. Currently we are investigating the cause of the contamination. The contaminated desk and other spots where there is a possibility of contamination are partitioned and under control now.
*Controlled area is the area which requires control for prevention of unnecessary exposure and prevention of increase of radioactive contamination. Non-controlled area is the area other than controlled area.
*Periodic inspection of the monitoring posts (7 in total: from No.1 to 7) located at the site boundary was started.
No. 1: From 10:11 am to 11:30 am on March 27
No. 2: From 2:21 pm on March 27
・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 March.
Daily supply and demand balance is announced at our "TEPCO Electricity Forecast".
Appendix:
Past Progress (As of 3:00 pm, on March 27, 2012)
Appendix:
Past Progress (From March 11, 2011 to July 31, 2011) (PDF 225KB)
*
Revised past progress
