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.

There are 3 tanks, including Tank No.5 in Group I in the H4 area, found to have been initially installed in the H1 area.

Since ground subsidence occurred at the foundation on which these tanks had been set up, we planned to set up these tanks in the H2 area. However, we discovered that these tanks have been set up actually as Tank No.5 in Group I in the H4 area, Tank No.10 in Group I in the H4 area, and Tank No.3 in Group II in the H4 area.

On August 21, we completed transfer of water from inside Tank No.5 in Group I in the H4 area found to have leaked water.

(Above information was previously announced.)

Although it is still unclear whether there is a causal relationship between the water leaking of Tank No.5 in Group I in the H4 area and the tank's having experienced ground subsidence occurred at the foundation on which it had been set up, we started to transfer water from inside Tank No.10 in Group I in the H4 area to Tank No.10 in Group B in the H4 area at 3:57 PM today (on August 25) to reduce the risk of leakage.

We patrolled the site to check on the transfer, and found no abnormality such as leakage.