Fukushima Daiichi NPS Prompt Report 2013

This is follow-up information regarding the water leak from the underground reservoirs at Fukushima Daiichi NPS.

We conducted additional nuclide analysis of the leakage detector hole water at the Underground Reservoir 3, which locates next to the east side of the Underground Reservoir 2 (previously announced).
The latest analyzed results are as follows.

[Underground Reservoir No.3: Leakage detector hole water, northeast side (sampled at 9:50PM, April 6)]
[Results]
-Chloride concentration: Below 1ppm
-I-131: N.D（Below detection limit）( Detection limit:2.7×10^-2Bq/cm3）
-Cs-134: N.D（Detection limit:5.2×10^-2Bq/cm3）
-Cs-137: N.D（Detection limit:6.7×10^-2Bq/cm3）
-All β: 1.8×10^-1Bq/cm3（Detection limit: 3.1×10^-2Bq/cm3）

[Underground Reservoir No.3: Leakage detector hole water, southwest side (sampled at 10:20PM, April 6)]
[Results]
-Chloride concentration: 350ppm
-I-131: N.D ( Detection limit:6.6×10^-2Bq/cm3）
-Cs-134: N.D（Detection limit:6.5×10^-2Bq/cm3）
-Cs-137: N.D（Detection limit:7.9×10^-2Bq/cm3）
- All β: 1.8×10^3Bq/cm3（Detection limit: 3.1×10^0q/cm3）

All βnuclide was detected at the leakage detector hole water (northeast side) and leakage detector hole water (southwest side) of Underground Reservoir No.3.
We have not confirmed water level decrease from the reservoir. However, we are assuming a possibility of a small leakage from the outside sheet (bentonite sheet) of the reservoir.

We will strengthen monitoring of the water level at the reservoir and conduct sampling at the following sites to search for the leakage place.
-Underground Reservoir 3 leakage detector hole water, southwest side
-Underground Reservoir 3 drain hole water, southwest side
We will announce the results as soon as they have been analyzed.

<Press Conference Announcement>
From 10:00AM, April 7, we will explain the situation of the Underground Reservoir 3 at Fukushima Daiichi NPS at the provisional press conference held at our headquarter office and Fukushima Office. We would like to announce the details individually.