Fukushima Daiichi NPS Prompt Report 2013

This is follow-up information regarding the water leak from the underground reservoirs at Fukushima Daiichi NPS.

All β nuclide was detected from a nuclide analysis of the leakage detector hole water (southwest side) and the drain hole water (southwest side) at the Underground Reservoir 3, which locates next to the east side of the Underground Reservoir 2 (previously announced at 9:01AM, April 7).
We have not confirmed water level decrease from the reservoir. However, we have assumed a possibility of a small leakage from the outside bentonite sheet of the reservoir.

We judged that this incident falls into the matter which would be applied as "A case when the nuclide materials etc. have leaked within the controlled area due to reactor facility failures or other contingent matters" under the provisions of the Rules on the Installation and Operation of Commercial Power Reactors Article 19-17 item 10.
 
Therefore, we will report this matter upon the Safety Regulations for Nuclear Reactor Facilities of Fukushima Daiichi NPS.
The results will be explained at the provisional press conference held from 10:00AM.