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.

On December 16, the measurement result for gross-β in the water sampled at the groundwater observation hole No.0-3-2 located on the east of the Units 1 to 4 Turbine Buildings was 63,000Bq/L, a higher measurement result compared to the last one.
We conducted a sampling again today (on December 17), but the measurement result of gross-β was below the detection limit value.

We attribute the increase in the measurement result of gross-β to the incorporation of radioactive material into the sample water, based on the following reasons.
· No high measurement results was found at the groundwater observation holes No.0-3-1 or No.0-1-2 which are located near the hole No.0-3-2.
· The sample obtained at the groundwater observation hole No.1-16 with a high measurement result was dealt at the same time.
· The measurement result was 'below the detection limit value' in the sampling today.

We will see to it that no incorporation occurs in the process from sampling to analysis, and continuously monitor the situation.

<Measurement results on the groundwater observation hole No.0-3-2>
(Sampled on December 17)
- Cesium-134: Below the detection limit value (detection limit value: 0.37Bq/L)
- Cesium-137: Below the detection limit value (detection limit value: 0.48Bq/L)
- Gross-β: Below the detection limit value (detection limit value: 17Bq/L)
- Tritium: Under analysis

(Sampled on December 16) (Reference)
- Cesium-134: Below the detection limit value (detection limit value: 0.62Bq/L) (Previously announced)
- Cesium-137: Below the detection limit value (detection limit value: 0.64Bq/L) (Previously announced)
- Gross-β: 63,000Bq/L (Previously announced)
- Tritium: 65,000Bq/L

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