Fukushima Daiichi NPS Prompt Report 2013

This is follow-up information on the latest situation concerning the detection of high densities of tritium and strontium in the observation hole located on the east of the Units 1-4 Turbine Buildings.

As a result of the measurement, it was found that the gross-β density in the groundwater observation hole No.0-3-2 obtained at the east of the Units 1-4 Turbine Buildings on December 16 (63,000Bq/L) were higher than the previous result.

<Measurement results on the groundwater observation hole No.0-3-2>
(Sampled on December 16)
- Cesium-134: Below the detection limit value (detection limit value: 0.62Bq/L)
- Cesium-137: Below the detection limit value (detection limit value: 0.64Bq/L)
- Gross-β: 63,000Bq/L
(Sampled on December 13: previously announced)
- Cesium-134: Below the detection limit value (detection limit value: 0.41Bq/L)
- Cesium-137: Below the detection limit value (detection limit value: 0.47Bq/L)
- Gross-β: Below the detection limit value (detection limit value: 18Bq/L)

The gross-β densities obtained in the groundwater observation holes No.0-3-1 and No.0-1-2 on December 15, which locate near the hole No.0-3-2, were below the detection limit value. It is supposed that the pumped water from the groundwater observation hole No.1-16 where 1,700,000Bq/L of gross-β was detected on December 16 has mixed into the water in the hole No.0-3-2. For more confirmation, we will conduct samplings and measurements today again at the hole No.0-3-2.

No significant change has been found in the measurement results obtained in the pumped water from the groundwater observation hole No.1-16 compared to the results from the previous sampling.

For the past sampling results, please refer to the following page on our website:
http://www.tepco.co.jp/en/nu/fukushima-np/f1/smp/index-e.html