Fukushima Daiichi NPS Prompt Report 2013

This is follow-up information on influence of rainfall from the approaching typhoon on Fukushima Daiichi NPS.

With respect to the following areas where large amounts of rainwater have been accumulated inside the dikes due to rainfall from the approaching typhoon, we confirmed that the radioactivity densities (all-β) in accumulated water inside the dikes were below the density limit by the announcement of reactor regulation for strontium-90 (30Bq/L) and that the accumulated water inside the dikes are rainwater. Accordingly, we started to release rainwater accumulated inside the dikes of these areas as an emergency measure.

<Statuses as at 2:30 PM on September 16>
· C area (west): At 12:42 PM, water release through a dike drain valve was started
· G6 area (north): At 1:20 PM, water release through a dike drain valve was started
· E area: At 1:30 PM, water release through a dike drain valve was started
· G9 area: At 1:50 PM, water release through a dike drain valve was started
· G9 area (west): At 1:50 PM, water release through a dike drain valve was started
· C area (east): At 1:50 PM, water release using a temporary pump was started
· G4 area (south): At 2:20 PM, water release using a temporary pump was started

Here, we would like to make a correction in our previous announcement (in Follow-up Information 2) that we would release rainwater accumulated inside the dike to the outside through a dike drain valve. However, this does not apply to the C area (east) and the G4 area (south) since dike drain valves are not provided in these areas. In these areas, therefore, we are releasing the water to the outside of the dikes using temporary pumps.