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.

Today (on July 7), as we have obtained measurement results for tritium from samples obtained on July 5 (in the groundwater observation holes No.1-1 and No.1-2), we release the results.

As a result of the measurement, tritium in the groundwater observation hole No.1-1 was detected at 600,000Bq/L, which is higher than past highest value (510,000Bq/L in the sample taken on July 1).

The measurement on the groundwater observation hole No.1-2 (on the south side to the groundwater observation hole No.1) resulted in 380,000Bq/L, which was lower than the density in the groundwater observation hole No.1-1 located nearby.

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.1-1>
- Sampling on July 5:
Cesium-134 ND (0.42Bq/L) (Previously announced)
Cesium-137 0.55Bq/L (Previously announced)
All-β  3,800Bq/L (Previously announced)
Tritium  600,000Bq/L
- Sampling on July 1 (previously announced):
Cesium-134 ND (0.44Bq/L)
Cesium-137 0.98Bq/L
All-β  4,300Bq/L
Tritium  510,000Bq/L

<Groundwater observation hole No.1-2>
- Sampling on July 5:
Cesium-134 99Bq/L (Previously announced)
Cesium-137 210Bq/L (Previously announced)
All-β  900,000Bq/L (Previously announced)
Tritium  380,000Bq/L

* ND indicates a case where the result is below the detection limit value. The detection limit value is shown in the parentheses.