Status of TEPCO's Nuclear Power Stations after the Tohoku-Chihou-Taiheiyou-Oki Earthquake (Daily Report as of 3:00 PM on July 17)

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 Fukushima Daiichi Nuclear Power Station.

* 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 10:53 AM on July 15, accumulated water transfer from the Unit 3 Turbine Building basement to the Central Radioactive Waste Treatment Facility (Miscellaneous Solid Waste Volume Reduction Treatment Building [High Temperature Incinerator Building]) was started. At 9:37 AM on July 17, the transfer was temporarily stopped. At 10:07 AM on the same day, the transfer was restarted.

-Contaminated water transfer from the underground reservoirs was all completed as of July 1. However, we are continuing to take measures to prevent the expansion of contaminated water, and to conduct sampling activities.

<Measures to prevent the expansion of contaminated water>
On June 19, since the decrease of all-β radioactivity density in the leakage detection hole (northeast) at the underground reservoirs No.1 has been slow, an operation to dilute the underground reservoir No.1 by transferring desalination-system (RO) treated water (the all-β radioactivity density: approx. 1×10¹Bq/cm³) into the reservoir was started (the all-β radioactivity density of residual water in the underground reservoir No.1: 6.6×10⁴Bq/cm³).
[Recent dilution operation] On July 5, approx. 40m³ of filtered water was injected.
On June 27, since the decrease of all-β radioactivity density in the leakage detection hole (northeast) at the underground reservoirs No.2 has been slow, an operation to dilute the underground reservoir No.2 by transferring filtered water into the reservoir was started.
[Recent dilution operation] On July 17, approx. 40m³ of desalination-system (RO) treated water was injected.

On July 17, leaked water in the leakage detection holes at the underground reservoirs No.1-No.3 was transferred to the temporary aboveground tank, and leaked water in the drain holes at the underground reservoir No.1 was transferred into this underground reservoir.

<Sampling>
On July 16, sampling was performed in the drain holes of the underground reservoirs No.1-No.7 (14 locations), the leakage detection holes of the underground reservoirs No.1-No.4 and No.6 (sample could not be collected at 2 out of 10 locations), the observation holes of the underground reservoirs (22 locations), the groundwater bypass investigation holes a-c (sample could not be collected at 1 out of 3 locations), the groundwater bypass pump wells No.1-No.4, and the observation holes on the sea side (1)-(4). No significant change was found with the analysis results compared to the analysis results from the sampling performed previously (on July 9 in the groundwater bypass investigation holes a-c, the groundwater bypass pump wells No.1-No.4, and the observation holes on the sea side (1)-(4), and on July 15 in the other locations). Further, analysis for tritium was performed on water sampled on July 8 and 9 in the groundwater bypass (investigation holes a-c and pump wells No.1-No.4; sample could not be collected at 1 investigation hole out of 3 investigation holes) and the observation holes on the sea side (1)-(8). As a result, no significant change was found compared to the previous analysis results (from the sampling on July 1 in the observation holes on the sea side (5)-(8), and on July 2 in the other locations).

-We installed observation holes east of the Unit 1-4 Turbine Buildings, and have been conducting sampling and analysis of groundwater from the observation holes. On June 19, we announced that tritium and strontium were detected at high densities in the observation hole located between Units 1 and 2. Therefore, we have been conducting intensified monitoring.

* Revised past progress

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