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 obtained measurement results for strontium in samples taken on June 7 from the groundwater observation holes No.1-No.3, and measurement results for tritium in samples taken on July 9 from the groundwater observation holes No.1-2 and No.2 today (on July 11), we would like to make an announcement on those results.

As a result, no significant change was found with the results obtained this time, as compared to the previous results.

In addition, as we obtained the all-β density (after filtering) in the sample taken on June 9 from the groundwater observation hole No.2 and having been under analysis, we would like to make an announcement on the density.

As a result, no significant difference was found compared to the value in the unfiltered sample.

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: Measured strontium density>
- Sampling on June 7 (the first measurement): 1,200Bq/L
- Sampling on June 7 (the second measurement): 1,200Bq/L
- Sampling on May 31: 890Bq/L (previously announced)

<Groundwater observation hole No.2: Measured strontium density>
- Sampling on June 7 (the first measurement): 5.2Bq/L
- Sampling on June 7 (the second measurement): 5.1Bq/L
- Sampling on May 31: 54Bq/L (previously announced)

<Groundwater observation hole No.3: Measured strontium density>
- Sampling on June 7 (the first measurement): ND (detection limit value: 0.24Bq/L)
- Sampling on June 7 (the second measurement): ND (detection limit value: 0.27Bq/L)
- Sampling on May 31: 0.25Bq/L (previously announced)

<Groundwater observation hole No.1-2: Measured tritium density>
- Sampling on July 9: 370,000Bq/L
- Sampling on July 8: 360,000Bq/L (previously announced)

<Groundwater observation hole No.2: Measured tritium density>
- Sampling on July 9: 670Bq/L
- Sampling on July 8: 730Bq/L (previously announced)

<Groundwater observation hole No.1-2: Measured all-β density (after filtering)>
- Sampling on July 9: 890,000Bq/L (in filtered sample)
- Sampling on July 9: 900,000Bq/L (in unfiltered sample; previously announced)

For the past sampling results, please refer to the following page on our website:
URL:http://www.tepco.co.jp/en/nu/fukushima-np/f1/smp/index-e.html