Fukushima Daiichi NPS Prompt Report 2013

This is follow-up information on the "water leak at a tank in the H4 area in Fukushima Daiichi Nuclear Power Station" found on August 19.

In connection with the water leaking from the drain valve at the H4 area tank dike, we conducted analysis on water in the groundwater bypass pump wells No.11-No.12 (2 locations) yesterday (on August 30), and we would like to announce the results.

<Pump well No.11>
(Sampling on August 30)
Tritium: 300Bq/L
All β: Below the detection limit value (16Bq/L)

(Previous value obtained on February 12, 2013)
Tritium: 57Bq/L
All β: Below the detection limit value (2.6Bq/L)

<Pump well No.12>
(Sampling on August 30)
Tritium: 900Bq/L
All β: Below the detection limit value (16Bq/L)

(Previous value obtained on February 16, 2013)
Tritium: 450Bq/L
All β: Below the detection limit value (2.6Bq/L)

* In a case where the result is below the detection limit value, the detection limit value is shown in the parentheses.

The results obtained this time are sufficiently low compared to the density limit by the announcement of Reactor Regulation (60,000Bq/L).

We will conduct analysis on water in the groundwater bypass pump wells No.7-No.12 tomorrow (on September 1).

We will continue to analyze the water and to investigate the influence of the water leak at a tank in the H4 area.

As for the position relation between the groundwater bypass pump wells and the H4 area, please refer to the page 10 of the following report (announced on August 23) on our website:
http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2013/images/handouts_130823_05-e.pdf