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Top > Releases ・ Announcements > Press Releases > 2013 > Status of TEPCO's Nuclear Power Stations after the Tohoku-Chihou-Taiheiyou-Oki Earthquake (Daily Report as of 3:00 PM, March 1)

Press Releases 2013

Press Release (Mar 01, 2013)Status of TEPCO's Nuclear Power Stations after the Tohoku-Chihou-Taiheiyou-Oki Earthquake (Daily Report as of 3:00 PM, March 1)

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 around 12:12 PM on February 23, a cooperative company worker found a puddle near the center of the Heater Room on the first floor of Unit 2 Turbine Building. The puddle was approx. 5m x 1m x 1mm. It was confirmed that water was dripping from some areas of the ceiling (a drop every 5 seconds) and that there was no leakage from the piping and temporary hose installed near the puddle. The radioactivity density analysis results of the water sampled from the puddle are as follows. Cesium 134: 1.3x102Bq/cm3, cesium 137: 2.5x102Bq/cm3. The contamination conditions (radioactivity densities) of the floor surface are as follows: Cesium 134: 1.2x102Bq/cm3, cesium 137: 2.1x102Bq/cm3. The atmosphere dose rates measured at the site are as follows: γ+β: 0.7mSv/h, γ: 0.7mSv/h. Also, a puddle (approx. 15m x 11m x 10mm) was found in the Turbine Exhaust Filter Room on the second floor of Unit 2 Turbine Building, which is located just above the site where a puddle was first found. On February 25, the puddle in the Turbine Exhaust Filter Room on the second floor of Unit 2 Turbine Building was identified to be the water dripping from the ceiling. The radioactivity density analysis results of the water dripping from the ceiling of the Turbine Exhaust Filter Room (obtained on February 26) are as follows. Cesium 134: 1.1×100Bq/cm3, cesium 137: 1.9x100Bq/cm3. The water is assumed to be rainwater. Upon site investigation, it was confirmed that water dripping onto the floor of the Heater Room on the first floor (a drop every 5 seconds) and onto the floor of the Turbine Exhaust Filter Room on the second floor (a drop every 2-3 seconds) had been continuing. Later, radioactivity density analysis was performed on the water dripping onto the floor of the Turbine Exhaust Filter Room on the second floor and the floor of the Heater Room on the first floor (water dripping from the ceiling of the Heater Room on the first floor). The results are as follows. [Puddle on the floor of the Turbine Exhaust Filter Room on the second floor]
Cesium 134: 2.7x100Bq/cm3, cesium 137: 5.1x100Bq/cm3
[Water dripping from the ceiling of the Heater Room on the first floor]
Cesium 134: 2.8x10-2Bq/cm3, cesium 137: 6.5x10-2Bq/cm3
Upon site investigation, no other possible source of water inflow was found in the Turbine Exhaust Filter Room on the second floor. Therefore, the puddle found near the center of the Heater Room on the first floor has been identified to be the water dripping from the ceiling of the Turbine Exhaust Filter Room on the second floor.

- At 8:00 AM on February 28, the second cesium absorption apparatus was suspended for power supply construction. At 4:45 PM on the same day, the apparatus was restarted after the work was completed. At 5:30 PM on the same day, the steady flow rate has been achieved.

- At around 8:50 AM on March 1, a worker driving a dump truck reported being sick near Fureai intersection in Fukushima Daiichi Nuclear Power Station. Upon medical examination at Units 5-6 emergency medical room, judgment was given by a doctor that the worker needs to be transported to a hospital immediately. The worker left Fukushima Daiichi Nuclear Power Station on an emergency transportation vehicle at 9:30 AM and was transferred onto an ambulance at Tomioka Fire Department to be transported to Iwaki Kyoritsu Hospital. At 11:15 AM, the worker arrived at Iwaki Kyoritsu Hospital. As a result of medical examination, it was judged that the worker needs to be hospitalized for a few days to have his condition monitored. No radioactive contamination was found on his body.

- At 9:50 AM on March 1, Unit 2 spent fuel pool alternative cooling system was suspended for valve inspection. At 12:42 PM on the same day, the spent fuel pool alternative cooling system was restarted after the inspection was completed. No problem has been found with its operation. Though the spent fuel pool water temperature increased from 12.3℃ to 12.5℃ during suspension, there is no problem with the spent fuel pool water temperature control considering the sufficient margin to the maximum allowed temperature (65℃).

- On March 1, sampling was conducted at the charcoal filter and the particulate filter of Unit 1 PCV gas control system.

- On March 1, dust sampling in the upper part of Unit 1 Reactor Building was conducted utilizing the exhaust filter system equipped on the Reactor Building cover.

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

*"Sampling at the charcoal filter and the particulate filter of Unit 1 PCV gas control system" and "dust sampling in the upper part of Unit 1 Reactor Building utilizing the exhaust filter system equipped on the Reactor Building cover" performed on March 1 were added as they were missing from the daily report previously announced. (Added on April 2, 2013)

 

* Revised past progress

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