Fukushima Daiichi NPS Prompt Report 2013

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

The following is the progress status of the measures to prevent the further leakage of the leaked water in the leakage detection holes as of today (April 13).

- Underground reservoir No.1
The temporary pump was put in operation twice to return the leaked water accumulated in the leakage detection hole (northeast/southwest) to the underground reservoir.

- Underground reservoir No.2
The temporary pump was put in operation once to return the leaked water accumulated in the leakage detection hole (northeast/southwest) to the underground reservoir.

- Underground reservoir No.3
The temporary pump was put in operation once to return the leaked water accumulated in the leakage detection hole (northeast/southwest) to the underground reservoir.

As for the leakage detection hole (northeast) of the underground reservoir No.3, since the pumping operation was not completed after putting the temporary pump in operation for 15 minutes, the pump was stopped manually. As a result of analyzing the water sampled at the location, no significant change was found with the results compared to the previous day.

- Leakage detection hole (northeast) of the underground reservoir No.3
Sampling performed at 9:45 AM on April 13
Chloride concentration: 10ppm (previously announced)
All β: 5.8×10^-2 Bq/cm³
(Reference) Sampling performed at 10:30 AM on April 12
Chloride concentration: 8ppm
All β: 1.6×10^-2 Bq/cm³

As for the underground reservoirs No.1-No.3, when the daily sampling of leaked water is performed, the temporary pump will be put in operation to return the leaked water accumulated in the leakage detection holes to the reservoirs.

The water transfer from the underground reservoir No.3 to No.6 utilizing the permanent facilities currently ongoing will be suspended on April 14 since the transfer of the planned amount of water is planned to be completed.