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 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 from sampling performed yesterday (on July 8) in the groundwater observation hole No.1, the groundwater observation hole No.1-1 (east of (on the sea side to) the groundwater observation hole No.1), the groundwater observation hole No.1-2 (south of the groundwater observation hole No.1), and the groundwater observation hole No.2, we release the results.

As a result, cesium-134 and cesium-137 in the groundwater observation hole No.1-2, and all-β in the groundwater observation hole No.2 were detected at high densities compared to the most recent previous analysis results.

Specifically, cesium-134 and cesium-137 in the groundwater observation hole No.1-2 were detected at 9,000Bq/L and at 18,000Bq/L, respectively, which are higher than the past highest values (cesium-134 at 99Bq/L and cesium-137 at 210Bq/L in the sample taken on July 5). All-β in the groundwater observation hole No.2 was detected at 1,700Bq/L, which is higher than the past highest value (260Bq/L in the sample taken on July 1).

No significant change was found with the other measurement results compared to the previous results.

Upon obtaining the measurement results for tritium in these locations, we will release them likewise.

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.1-2>
- Sampling on July 8:
Cesium-1349,000Bq/L
Cesium-13718,000Bq/L
All-β890,000Bq/L
- Sampling on July 5 (previously announced):
Cesium-13499Bq/L
Cesium-137210Bq/L
All-β900,000Bq/L

<Groundwater observation hole No.2^*>
- Sampling on July 8:
Cesium-134ND (0.49Bq/L)
Cesium-1370.74Bq/L
All-β1,700Bq/L
- Sampling on July 4 (previously announced):
Cesium-134ND (0.39Bq/L)
Cesium-1370.46Bq/L
All-β93Bq/L

For the past sampling results, please refer to the following page on our website:

*This sampling location has been corrected from "Groundwater observation hole No.1-1". We apologize for the mistake. (Corrected on July 10, 2013)