The following is the known status as of Saturday morning of each of the six reactor at the Fukushima Daiichi nuclear power plant and the four reactors at the Fukushima Daini plant, both in Fukushima Prefecture, which were crippled by the magnitude 9.0 earthquake and ensuing tsunami on March 11.
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 8:55 AM on March 4, the nitrogen supply equipment (nitrogen gas separator on the hill) on standby (operable) has been excluded from standby state in order to perform a full-scale inspection*. At 9:52 AM on March 8, the inspection was completed. As no problem was found as a result of trial operation, the nitrogen gas separator on the hill has been put back in the standby state.
*The facility management policy based on Chapter 12 of the technical specification for
the nuclear reactor facility "Policy on the Mid-term Security" stipulates "operational requirements" and "necessary measures to be implemented in the case that the
operational requirements are not fulfilled" (When the operational requirements are not
fulfilled, the required measures must be implemented). In this case, the nitrogen gas
separator on the hill was excluded from standby state intentionally for maintenance from
8:55 AM on March 4 (transition out of the scope of operational requirements). As the inspection was completed at 9:52 AM on March 8 and no problem was found as a result of trial operation, the nitrogen gas separator on the hill has been put back in the standby state. Thus, at 9:52 AM on March 8, the transition out of the scope of operational requirements has been cancelled.
- At 10:00 AM on March 8, 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 for the hole drilled on the ceiling of Unit 6 Reactor Building on March 18, 2011 for the purpose of preventing hydrogen explosion, considering that cold shutdown is being maintained and the plant condition has been stable at Unit 6, work to close the hole has been started on March 8 in order to maintain the air tightness of the building.
[Fukushima Daini Nuclear Power Station]
･ Unit 1 to 4: Shutdown due to the earthquake.
- From February 28 to March 6, underwater visual inspection was performed in Unit 4 PCV suppression chamber to investigate the impact of the Tohoku Chihou Taiheiyou Oki Earthquake occurred in 2011. As a result, no abnormality such as deformation and damage due to the earthquake was found with the facilities in the suppression chamber pool. Though paint peels and rust were found on part of the surfaces of the walls, floor and equipment, etc. of the suppression chamber, these have been confirmed to have no impact on the function of the suppression chamber.