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 27), as we obtained measurement results as follows on the sample taken on July 26 from the Unit 2 water intake power cable trench (seawater piping foundation part) where a new observation hole (B1-1) was newly installed for the survey conducted for purposes such as identification of the contamination source of high-density contaminated water inside the sea-side trench, we would like to make an announcement on the results.

These measurement results on the Unit 2 seawater piping foundation part cannot be compared directly since the location is a new observation point. However, high radioactivity densities were found compared to the sample taken on July 17 from the nearby water intake power cable trench.

These densities found this time are at the same levels as those found in water leaked into the Unit 2 water intake screen room in April 2011.

<B1-1: Unit 2 water intake power cable trench (seawater piping foundation part)>
- Sampling on July 26:
Chlorine 8,000ppm
Cesium-134 750,000,000Bq/L (750,000Bq/cm³)
Cesium-137 1,600,000,000Bq/L (1,600,000Bq/cm³)
All-β 750,000,000Bq/L (750,000Bq/cm³)

<B2: Unit 2 water intake power cable trench> (previously announced)>
- Sampling on July 17:
Chlorine 70ppm
Cesium-134 12,000,000Bq/L (12,000Bq/cm³)
Cesium-137 24,000,000Bq/L (24,000Bq/cm³)
All-β 23,000,000Bq/L (23,000Bq/cm³)

<Quality of water leaked into the Unit 2 water intake screen room in April 2011>
Cesium-134 1,800,000,000Bq/L (1,800,000Bq/cm³)
Cesium-137 1,800,000,000Bq/L (1,800,000Bq/cm³)

In addition, water levels in the seawater piping foundation part were measured on July 23 and 26, and were O.P.+3.150mm on both of these days.

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.

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