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
-A TEPCO employee found a water leakage near the pipe joint area of Unit 5-6 accumulated water treatment system when the system pump was started at 4:28 PM on October 4. The pump was stopped at 4:30 PM on the same day and the leakage was confirmed to have stopped at around 4:35 PM. Upon investigation, a hole (3mm x 1mm) was found on the pipe joint where the leakage occurred. The leakage occurred outside in the north of Unit 5-6 (the ground surface is gravel). Since there is no side ditch in the surrounding area, it is considered that the leaked water remains under ground and did not flow out of the station. The amount of water leaked from the hole on the pipe joint is estimated to be approx. 12L. The radioactivity density analysis results of the leaked water sampled at the downstream of the leakage area are as follows.
Iodine 131: Below the detection limit (1.6×10-2Bq/cm3), Cesium 134: 1.5×10-1Bq/cm3, Cesium 137: 2.4×10-1Bq/cm3
The cause of the leakage is currently under investigation.
-At 9:22 AM on October 1, the regular nitrogen supply equipment (nitrogen gas separator B) was stopped for inspection and maintenance/repair since the cumulative operation hours exceeded 6,000 hours (adequate timing for inspection). While the equipment was under inspection, the nitrogen gas separator A and the temporary nitrogen gas separator*1 were in operation in parallel. Since the work was completed, the nitrogen supply equipment (nitrogen gas separator B) was started at 8:38 AM on October 5 and nitrogen gas injection utilizing this equipment was restarted at 10:17 AM on the same day. At 10:27 AM on the same day, the temporary nitrogen gas separator was stopped. The nitrogen gas separator A and B are currently in parallel operation.
*1 Nitrogen gas separator used for bubbling the filtrate water tank
-On October 5, dust sampling was conducted at the opening of Unit 2 Reactor Building (Blow-out panel).
-On October 5, sampling was conducted at the charcoal filter and the particulate filter of Unit 2 PCV gas control system
[ Fukushima Daini Nuclear Power Station ]
·Unit 1 to 4: Shutdown due to the earthquake.
-At around 2:25 PM on October 5, a TEPCO employee fell down from the opening of the ball collector pit*2 (approx. 4m high) located outside of Unit 4 (uncontrolled area) during repair/paint work of the pit frame. The injured worker was transported to the clinic in J-Village at 3:37 PM on the same day upon judgment by a doctor at the clinic in the power station. The worker is currently being examined at the clinic in J-Village. The worker is conscious and no radioactive material is attached on his body.
*2 Area where the sponge balls used for removing the marine organisms attached on the small tubes in the condenser (the sponge is a little larger than the tube).
Appendix:
Past Progress (As of 4:00 pm, on October 5, 2012) (PDF 563KB)
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.
