Fukushima Daiichi NPS Prompt Report 2013

This is follow-up information on "Water Leak at a Tank in the H4 area in Fukushima Daiichi Nuclear Power Station" and "Water Dropping from the Top Plate of the B area (South) Tank at Fukushima Daiichi NPS", which were respectively found on August 19, and October 2.

We analyzed the all-β radioactivity level of the samplings obtained at the junction of the drainage channels B and C (C-1), the junction of the drainage channel C and the side ditch beside the tank (C-1-1), the downstream of the drainage channel B (B-2), and the drainage channel C OP. 35m (C-2) on October 16. The all-β radioactivity level was relatively high compared to the samplings in the past. The measurement results were as follows.

<Measurement results of the samplings>
The junction of the drainage channels B and C (C-1): 2,100Bq/L
The junction of the drainage channel C and the side ditch beside the tank (C-1-1): 2,000Bq/L
The downstream of the drainage channel B (B-2): 2,300Bq/L
The drainage channel C OP. 35m (C-2): 1,400Bq/L

We attribute the higher all-β radioactivity level to the nearby pollution flooded into the drain ditch due to the typhoon.

As for other measurement results, no significant change was found.

We will continue to monitor the situation.

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