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
-On June 20, sampling was conducted at Unit 2 PCV gas control system. Upon analysis, xenon 135 measured at the system entrance was below the detection limit (9.6×10-2Bq/cm3) and the re-criticality criteria (1Bq/cm3).
-At 10:00 AM on June 21, we started transferring the accumulated water in Unit 6 Turbine Building to the temporary tank. At 4:00 PM on the same day, we stopped transferring. We started transferring at 10:00 AM on June 22, and stopped at 10:45 AM on the same day due to the problem at the pump which connects the temporary tanks. We will conduct the inspection of the pump.
-At 12:05 PM on June 21, the operation was temporarily stopped at the Cesium Adsorption Apparatus in order to replace the valve. We will stop it for a month. During the work of replacing the valve, the operation will be conducted utilising the second Cesium Adsorption Apparatus, and there will be no problem with the accumulated water treatment and the water injection into the reactor.
-As the figure at a point of Unit 3 Pressure Suppression Room radiation monitor, it has been kept 0.20 Sv/h until 11:00 PM on June 20. The figure had risen in a stepwise manner, and reached at 17.59 Sv/h at 5:00 AM on June 21. It was the PCV atmosphere radiation monitor which measures 2 points at the containment vessel side and 2 points at the Pressure Suppression Room side. The figure rose at one of the Pressure Suppression Room side, there was no change at other 3 measure points. Since it was assumed the problem of instrumentation with the rising tendency, the inspection was conducted at 1:30 PM on June 21. As a result of the inspection, it was confirmed that there was the cause at the detector system side. The plan of treatment for the monitor is under consideration. For reference, it was not the data at the intended monitoring parameter in relation to Technical Specification.
-As a part of the foundation improvement work for installing the cover for Unit 4 fuel removing, we confirmed the site in order to remove Unit 4 disaster prevention pit, the accumulated water (approx. 90m3) which was assumed as sea water or rain water was confirmed at the pit. Since we had to transfer the accumulated water in order to pit removal, we started transferring the accumulated water to Unit 4 Turbine Building basement at 10:10 PM on June 22, and stopped it 12:40 PM on the same day (the amount of transferring water was 14 m3). We will transfer it for a week.
[Fukushima Daini Nuclear Power Station]
･ Unit 1 to 4: Shutdown due to the earthquake
* In our previous press release, we announced "Transferring which was planed on June 22 was not conducted due to the problem at the transferring pump motor. The cause is under investigation." We corrected it as "We started transferring at 10:00 AM on June 22, and stopped at 10:45 AM on the same day due to the problem at the pump which connects the temporary tanks. We will conduct the inspection of the pump." Please accept our apologies for this mistake. (As of June 23, 2012)
Appendix:
Past Progress (As of 3:00 pm, on June 22, 2012) (PDF 452KB)
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.
