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 6:17 PM on September 24, the reactor injection water amounts were adjusted as follows since the amounts had decreased.
[Unit 1] Feed water system: Increased from approx. 2.6m³/h to approx. 3.0m³/h, reactor core spray system: Increased from approx. 1.9m³/h to approx. 2.0m³/h.
[Unit 2] Feed water system: Increased from approx. 1.8m³/h to approx. 2.0m³/h, reactor core spray system: Increased from approx. 4.9m³/h to approx. 5.0m³/h.
[Unit 3] Feed water system: Increased from approx. 2.2m³/h to approx. 2.5m³/h, reactor core spray system: Increased from approx. 4.3m³/h to approx. 4.5m³/h.

-At around 11:07 AM on September 22, during debris removal from the upper part of Unit 3 Reactor Building, a steel beam (Approx. 300mmX200mmX7m, Approx. 470kg) which had been on the side of the spent fuel pool (SFP) slipped and fell into the pool when a worker was trying to grab it using an oil-pressure fork attached to the head of the crane. At around 11:45 AM on the same day, it was confirmed that there was no problem with the operation status of the spent fuel pool alternative cooling system and the skimmer surge water level. No significant change was found in the monitoring post data, the atmosphere dose rate around the spent fuel pool and the spent fuel water level. No injury was reported due to this matter. From 9:55 AM on September 24, we started investigating the condition (and location) of the steel beam which fell into the pool and the condition inside the pool using a remote control underwater camera. The investigation was finished at 1:55 PM on the same day. From around 7:00 AM on September 25, we started investigating the condition (and location) of the steel beam which fell into the pool and the condition inside the pool using a remote control underwater camera. The investigation was finished at 11:10 AM on the same day. Evaluation of the investigation results is to be done.

The nuclide analysis results of the spent fuel pool water are as follows. No significant change in the results has been found.

[September 21 (Before the incident)]
Cesium 134: 2.4X10³Bq/cm³, Cesium 137: 4.0X10³Bq/cm³, Iodine 131: Below the detection limit (3.4X10¹Bq/cm³)
[September 22 (After the incident)]
Cesium 134: 2.2X10³Bq/cm³, Cesium 137: 3.6X10³Bq/cm³, Iodine 131: Below the detection limit (1.4X10¹Bq/cm³)
[September 23]
Cesium 134: 2.5X10³Bq/cm³, Cesium 137: 4.2X10³Bq/cm³, Iodine 131: Below the detection limit (1.6X10¹Bq/cm³)
[September 24]
Cesium 134: 2.4X10³Bq/cm³, Cesium 137: 3.9X10³Bq/cm³, Iodine 131: Below the detection limit (1.6X10¹Bq/cm³)

-At 9:37 AM on September 25, Unit 1 spent fuel pool alternative cooling system was stopped for replacement of the secondary system pipe with polyethylene pipe (Pool water temperature when the system was stopped: 29.0℃). Though the system is planned to be suspended until September 28, there will be no problem with pool water temperature management as the temperature increase rate is estimated to be approx. 0.09℃/h.

-At 10:00 AM on September 25, we started transferring the accumulated water in Unit 6 Turbine Building basement to the temporary tank. At 3:00 PM on the same day, the transfer was stopped.

-As the second cesium absorption apparatus was planned to be stopped for a soundness inspection on its pipes, etc., the cesium absorption apparatus was started at 11:03 AM on September 25 taking into considerations the Turbine Building water level. At 12:59 PM on the same day, the second cesium absorption apparatus was stopped.

-At 12:20 PM on September 25, Unit 1 reactor injection water amounts were adjusted as follows since the amounts had decreased.
Feed water system: Increased from approx. 2.5m³/h to approx. 3.0m³/h, reactor core spray system: Increased from approx. 1.9m³/h to approx. 2.0m³/h

[Fukushima Daini Nuclear Power Station]
･ Unit 1 to 4: Shutdown due to the earthquake.

Appendix: Past Progress (As of 3:00 pm, on September 25, 2012) (PDF 536KB)
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.