Press Releases 2013

This is follow-up information on the latest situation concerning the detection of high densities of Tritium and Strontium in the observation hole at the east side of the Unit 1-4 Turbine Buildings of Fukushima Daiichi NPS.

As we have obtained measurement results for the γ nuclides and all-β in samples taken on July 11 from the groundwater observation holes No.1, No.1-2, No.1-4, No.2, and No.3, we would like to make an announcement on the results.

As a result, the detected all-β density in the groundwater observation hole No.3 was 1,400Bq/L, which is higher than the previous density (in the sample taken on July 4).

With the other measured densities, no significant change was found compared to the previous densities.

We are continuing to tackle this problem in such manners as to intensely bring forward implementation of contamination prevention measures such as foundation improvement work to the bank protection, and comprehensively intensify the monitoring by using the results of additional boring to drill additional locations, and the analyses results on seawater at such locations as the port interior and the water outlets.

<Groundwater observation hole No.1>
- Sampling on July 11:
Cesium-134 ND (0.61Bq/L)
Cesium-137 1.0Bq/L
All-β  1,600Bq/L
- Sampling on July 8 (previously announced):
Cesium-134 ND (0.50Bq/L)
Cesium-137 ND (0.47Bq/L)
All-β  1,800Bq/L

<Groundwater observation hole No.1-2>
- Sampling on July 11:
Cesium-134 8,200Bq/L
Cesium-137 17,000Bq/L
All-β  890,000Bq/L
- Sampling on July 9 (previously announced):
Cesium-134 11,000Bq/L
Cesium-137 22,000Bq/L
All-β  900,000Bq/L

<Groundwater observation hole No.1-4>
- Sampling on July 11:
Cesium-134 0.91Bq/L
Cesium-137 2.0Bq/L
All-β  250Bq/L
- Sampling on July 8 (previously announced):
Cesium-134 1.5Bq/L
Cesium-137 3.6Bq/L
All-β  330Bq/L

<Groundwater observation hole No.2>
- Sampling on July 11:
Cesium-134 ND (0.47Bq/L)
Cesium-137 1.2Bq/L
All-β  1,400Bq/L
- Sampling on July 9 (previously announced):
Cesium-134 0.50Bq/L
Cesium-137 0.74Bq/L
All-β  910Bq/L

<Groundwater observation hole No.3>
- Sampling on July 11:
Cesium-134 1.9Bq/L
Cesium-137 4.8Bq/L
All-β  1,400Bq/L
- Sampling on July 4 (previously announced):
Cesium-134 1.5Bq/L
Cesium-137 2.8Bq/L
All-β  ND (18Bq/L)

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