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 holes at the east side of the Unit 1-4 Turbine Buildings of Fukushima Daiichi NPS.

Today (on June 29), as we have obtained measurement results for the γ nuclides and all-β from sampling performed yesterday (on June 28) in water of the groundwater observation hole No.1 and the groundwater observation hole No.1-1 (a new hole installed completely on June 27, on the east side (sea side) to the groundwater observation hole No.1) and in seawater inside the port, and measurement results for tritium in water sampled on June 26 in the groundwater observation holes No.2 and No. 3, we release those results.

No significant change was found with the γ nuclide and all-β densities in water of the groundwater observation hole No.1 and in seawater inside the port, compared to the previous results. Water of the groundwater observation hole No.1-1 (on the east side (sea side) to the groundwater observation hole No.1) was found with about the same levels of nuclide densities as water of the groundwater observation hole No.1, but was found with a relatively high all-β density of 3000Bq/L as compared to 1400Bq/L in water of the groundwater observation hole No.1.

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

The tritium density in water sampled on June 26 in the groundwater observation hole No.3 showed no significant increase from the previous result. On the other hand, the tritium measurement result in water sampled on June 26 in the groundwater observation hole No.2 showed a slight increase from the previous result, and has become subject to the intensified monitoring.

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 June 28:
Cesium-134 ND (0.40Bq/L)
Cesium-137 ND (0.43Bq/L)
All-β 1,400Bq/L
- Sampling on June 25 (previously announced):
Cesium-134 ND (0.39Bq/L)
Cesium-137 ND (0.49Bq/L)
All-β 1,400Bq/L

<(New) Groundwater observation hole No.1-1>
- Sampling on June 28:
Cesium-134 ND (0.41Bq/L)
Cesium-137 ND (0.51Bq/L)
All-β 3,000Bq/L

<Groundwater observation hole No.2>
-Sampling on June 26:
Tritium 850Bq/L
-Sampling on June 21(previously announced):
Tritium 560Bq/L

<Groundwater observation hole No.3>
- Sampling on June 26:
Tritium 1,600Bq/L
- Sampling on June 21 (previously announced):
Tritium 1,600Bq/L

<Seawater in the water intake north side>
- Sampling on June 28:
Cesium-134 15Bq/L
Cesium-137 33Bq/L
All-β 230Bq/L
- Sampling on June 26 (previously announced):
Cesium-134 6.1Bq/L
Cesium-137 13Bq/L
All-β 200Bq/L

<Seawater between the water intakes of Units 1 and 2 (near the surface)>
- Sampling on June 28:
Cesium-134 8.5Bq/L
Cesium-137 19Bq/L
All-β 180Bq/L
- Sampling on June 26 (previously announced):
Cesium-134 6.2Bq/L
Cesium-137 11Bq/L
All-β 260Bq/L

<Seawater between the water intakes of Units 1 and 2 (near the bottom)>
- Sampling on June 28:
Cesium-134 7.5Bq/L
Cesium-137 17Bq/L
All-β 180Bq/L
- Sampling on June 26 (previously announced):
Cesium-134 6.2Bq/L
Cesium-137 9.3Bq/L
All-β 210Bq/L