Status of TEPCO's Nuclear Power Stations after the Tohoku-Chihou-Taiheiyou-Oki Earthquake(Daily Report as of 3:00 PM on August 18)

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

-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>
·Since the decreases of all-β radioactivity densities in the leakage detection holes (at the northeast side of the underground reservoir No.1, the northeast side of the underground reservoir No.2, and the southwest side of the underground reservoir No.3) have been slow, operations to dilute the underground reservoirs No.1-No.3 by transferring filtered water or desalination-system (RO) treated water (the all-β radioactivity density: approx. 1×10¹Bq/cm³) into these reservoirs have been conducted as appropriate.
[Recent dilution operations]
Underground reservoir No.1 (since June 19): On August 3, approx. 60m³ of filtered water was injected.
Underground reservoir No.2 (since June 27): On August 1, approx. 60m³ of filtered water was injected.
Underground reservoir No.3 (since July 24): On August 11, approx. 51m³ of water in the drain hole (northeast) of this underground reservoir was injected.

·On August 17 and 18, 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 reservoirs No.1 and No.2 was transferred into these underground reservoirs.

<Sampling>
On August 17, 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), and the observation holes of the underground reservoirs (22 locations). The all-β density in water from the underground reservoir No.3 drain hole (northeast) showed increases after August 13 compared to 6.3×10^-2Bq/cm³ in the sample taken on August 12. We have monitored changes in the data because of the possibility of measurement irregularities. Based on the analysis result obtained on August 17 (an all-β density value of 6.6×10^-1Bq/cm³ in the sample taken on August 17), however, we have determined that the density is on an upward trend. The other analysis results showed no significant change compared to the results from the previous sampling (on August 16).

-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.

·Tritium analysis was conducted on accumulated water sampled on August 14 in the Unit 1 seawater pipe trench vertical shaft B.
<Accumulated water in the Unit 1 seawater pipe trench vertical shaft B>
Tritium Below the detection limit value (Detection limit value: 130Bq/L)

·At 11:35 AM on August 15, we started pumping up groundwater from one of the well points (pumping facilities using vacuum pumps, scheduled to be installed at 28 locations) installed east of Units 1 and 2 Turbine Buildings and transferring the pumped-up groundwater to the Unit 2 vertical shaft C. Later, we started to use additional12 locations at 11:10 AM on August 16, and additional 9 locations at 11:05 AM on August 17, thereby starting to pump up groundwater from a total of 22 well points and transfer pumped-up groundwater to the Unit 2 vertical shaft C. Meanwhile, a drilling machine became out of order on August 17 by running into a hard rock during drilling. Therefore, we expect that installation of all of the well points will be completed on August 19 or later. At 9:00 AM on August 18, we started pumping up groundwater from the 23rd well point, which had been dug up before the drilling machine became out of order. We are currently pumping up groundwater from this well point and transferring pumped-up water to the Unit 2 vertical shaft C.

-At 10:31 AM on August 18, accumulated water transfer from the Unit 2 Turbine Building basement to the Central Radioactive Waste Treatment Facility (Miscellaneous Solid Waste Volume Reduction Treatment Building [High Temperature Incinerator Building]) was stopped.

-At 11:25 AM on August 18, accumulated water transfer from the Unit 2 Turbine Building basement to Unit 3 Turbine Building basement was started.

* Revised past progress

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