Fukushima Daiichi NPS Prompt Report 2013

At around 8:50 AM today (on November 15), an associated company worker found water was leaking from the second flange part from the bottom of the G6-C3 tank in the G6-south area at a pace of 1 drop per 4 seconds during a tank patrol.

Leakage location was identified to be the ninth bolt from the bottom out of 14 bolts located at the second vertical flange joint from the bottom, and water dropping was stopped after we tightened 7 bolts (1 bolt which is leakage location and 3 upper and lower bolts of this bolt).

The leaked water was confirmed to be remaining inside the dike.

The water level of this tank was 52cm from the top plate, which was the same level as the neighboring G6-C2 tank.

We are considering if we should transfer water in this tank.

Measurement result of dose equivalent rate at the location where water was spilled is as follows.
- G6-C3 tank (5cm distant) 35mSv/h (γ+β ray (70μm dose equivalent rate))
- G6-C3 tank (5cm distant) 0.03mSv/h (γ ray）

Also, at around 12:50 PM today (on November 15), a Nuclear Safety Inspector found a bleeding near dike drain valve of the G6-south area (north side of the G6-C8 tank) and a small paddle at the exit of drain valve, during a patrol of the G6 tank area.

The status of the site is currently being confirmed, and will be announced as soon as we know it.

* For the tank area map of Fukushima Daiichi NPS, please refer to the second page on the following URL.
http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2013/images/handouts_131021_07-e.pdf