Status of TEPCO's Nuclear Power Stations after the Tohoku-Chihou-Taiheiyou-Oki Earthquake(Daily Report as of 3:00 PM, March 19)

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 6:35 AM on March 18, Unit 2 spent fuel pool alternative cooling system was suspended for power supply multiplication work (The pool water temperature when the system was suspended: 15.0℃). At 6:38 PM on the same day, the system was restarted since the work was completed. The pool water temperature when the system was restarted was 16.4℃. There is no problem with the spent fuel pool water temperature control considering that there is a sufficient margin to the maximum allowed temperature (65℃).

- At around 6:57 PM on March 18, there was an incident where the power supply facilities in the Main Anti-earthquake Building momentarily stopped. Upon investigation, it was found that part of the power supply facilities at Fukushima Daiichi Nuclear Power Station have stopped due to the incident and the following facilities were suspended accordingly.
- Cesium adsorption apparatus of the water treatment facility
- Unit 1 spent fuel pool alternative cooling system^* (Secondary system)
- Unit 3 spent fuel pool alternative cooling system (Primary and secondary systems)
- Unit 4 spent fuel pool alternative cooling system (Primary and secondary systems)
- Unit 3 PCV gas control system (A system)
- Common pool cooling purification system
- Nitrogen separator (B)
* The primary system of Unit 1 spent fuel pool alternative cooling system was manually stopped at 9:10 PM for the purpose of protecting the pumps of the system.
No problem was found with the following facilities due to the incident.
- Units 1-3 reactor water injection systems
- Monitoring posts
- Units 1-3 PCV gas control systems (being monitored)
- Unit 2 spent fuel pool alternative cooling system
- Units 1-3 nitrogen injection equipment
- Nitrogen separator (A)
The later updates on the incident are provided as below.
- Nitrogen separator (B) was started at 3:00 AM on March 19 and nitrogen supply was started at 3:10 AM on the same day.
- The regular M/C in the Process Building has received power from the backup M/C in the Process Building at 9:03 AM on March 19. The common M/C4A has received power from the regular M/C in the Process Building at 10:01 AM on the same day.
- The cesium adsorption apparatus of the water treatment facility was started at 12:01 PM on March 19 and the steady flow rate was achieved at 12:17 PM on the same day. No problem has been found with its operation.
- The primary system of Unit 4 spent fuel pool alternative cooling system was started at 1:20 PM on March 19. No problem has been found with its operation.
- The primary and secondary systems of Unit 1 spent fuel pool alternative cooling system were started at 2:20 PM on March 19. No problem has been found with its operation.

- At 10:04 AM on February 26, nitrogen injection into Unit 1 suppression chamber was started to discharge the residual hydrogen and confirm the impact of the radiolysis of water inside the suppression chamber. At 10:18 AM on March 19, continuous nitrogen injection has been stopped.

- As for the hole drilled on the ceiling of Unit 5 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 5, work to close the hole has been started on March 16 in order to maintain the air tightness of the building. At 1:00 PM on March 19, the work has been completed.

- At 10:27 AM on March 15, we started transferring the accumulated water in Unit 3 Turbine Building basement to the Central Radioactive Waste Treatment Facility (Process Main Building). At 10:34 AM on March 19, the transfer was stopped since the accumulated water level monitoring has been disabled after the power supply of the Main Anti-earthquake Building being momentarily stopped at around 6:57 PM on March 18.

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

* Revised past progress

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