Status of TEPCO's Nuclear Power Stations after the Tohoku-Chihou-Taiheiyou-Oki Earthquake (Daily Report as of 3:00 PM on July 9)

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 around 11:00 PM on June 15, during dew condensation check, a TEPCO employee found a trace of discolored (brown) water in the leaked water receiving pan under the batch treatment tank (2A) of the multi-nuclide removal equipment system A (currently in trial operation utilizing waste liquid treated at the water treatment facility). On June 18, after water was removed from the tank, a liquid penetrant inspection was performed in the surface investigation on the lower part of the tank. As a result, two very narrow holes (pinholes) were found in the welding line where discoloration was found. Later, a detailed investigation was conducted from the interior. As a result, we found out that these holes were caused by flaws in a stainless net, which are attributable to local corrosion of the stainless net due to the crevice environment. We consider that the crevice corrosion had developed to such a degree that penetrating holes were generated. Repair will be made on these locations.
On June 20, a liquid penetrant inspection on the batch treatment tank (1A), which has the same structure as the batch treatment tank (2A), was performed although no discolored water drop trace was found on the 1A tank. As a result, oozing of liquid was found at one location on the surface of the tank. We consider the oozing to have occurred by seeping of liquid having remained in a small amount on the inner surface of the tank, as in the case of the 2A tank. We consider that the 1A tank also has a pinhole as in the case of the 2A tank. We have been conducting a detailed investigation since then. As a result of the detailed investigation, we found out that the pinhole was caused by a flaw that is typically found in stainless steel and is attributable to its local corrosion due to the crevice environment, as in the case of the 2A tank. We consider that the crevice corrosion had developed to such a degree that a penetrating hole was generated. Repair will be made on the hole.

- At around 1:05 PM on July 4, a cooperative company worker found oil leaking from a 25 ton crane vehicle at the construction site of Miscellaneous Solid Waste Incinerator Building at the north side of Unit 6. The leakage spread over an area of approx. 1m × approx. 1m on a protective iron plate, and the oil was removed using an adsorption mat. Around 1:19 PM on the same day, we reported this incident to Tomioka Fire Station. Later, at around 1:38 PM, a TEPCO employee arrived at the site, and confirmed that the leaked oil spread over an area of approx. 2m × approx. 1m with a thickness of approx. 1mm. We previously announced that the oil was leaking at a pace of 1 drop per approx. 10 seconds, and that we placed a bucket to receive the oil. This oil leakage was categorized as "hazardous material leakage" by the fire department. It was later found out that the oil had been leaking from the cylinder box section. Therefore, on July 5, a hydraulic pressure hose of the cylinder box section was detached. As of July 8, we had confirmed that the leakage stopped. Repair will be made on the cylinder box section.

- At 10:08 AM on July 2, accumulated water transfer from the Unit 2 Turbine Building basement to the Unit 3 Turbine Building basement was started. At 10:08 AM on July 9, the transfer was stopped.

- At 10:25 AM on July 9, nitrogen injection into the 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 10:05 AM on July 7, 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 10:28 AM on July 9, the transfer was stopped.

- 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 8, approx. 40m³ of desalination-system (RO) treated water was injected.
On July 8, 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 July 8, 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), and the observation holes on the sea side (5)-(8). As a result of the analysis, no significant change was found compared to the analysis results from the sampling performed previously (on July 1 in the observation holes on the sea side (5)-(8) and July 7 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.
On July 8, analyses for the γ nuclides and all-β were conducted on water sampled on July 8 in the groundwater observation holes No.1-2 and No.2. As a result, cesium-134 and cesium-137 in the groundwater observation hole No.1-2 water were detected at 9,000Bq/L and 18,000Bq/L, respectively, which are higher than the past highest values (cesium-134 at 99Bq/L and cesium-137 at 210Bq/L in water sampled on July 5). In the groundwater observation hole No.2 water, all-β was detected at 1,700Bq/L, which is also higher than the past highest value (260Bq/L in water sampled on July 1).
On July 8, as a measure to prevent spread of contamination, foundation improvement work by means of chemical injection was started at the bank protection between the water intakes of Units 1 and 2.

* There has been a mistranslation in the part starting with "leaked water in the drain holes". This part has been corrected from "leaked water in the drain holes at the underground reservoir No.2 was transferred into this underground reservoir" (corrected on July 16). We apologize for the mistranslation.

* Revised past progress

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