Fukushima Daiichi NPS Prompt Report 2013

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

The results of sampling performed in the underground reservoirs yesterday (May 10) are as follows.
- Drain holes of the underground reservoirs No.1-7
- Leakage detection holes of the underground reservoirs No.1-4 and 6
- Observation holes of the underground reservoirs (around reservoirs No.1-3): A1-A19
- Observation holes of the underground reservoirs (around reservoir No.6): B1-B3

No significant change was found with the results compared to the previous analysis results obtained on May 9.

As a result of all β analysis performed in the drain holes of the underground reservoirs No.1 and 2, the tendency of results obtained in the northeast side and the southwest side was found to be opposite to how it had been. Thus, it was judged that the samples may have been put in the wrong bottles.

Due to this, the sampling was performed again in all the drain holes of underground reservoirs using samples collected in the afternoon.

As for the sampling performed in the leakage detection holes of the underground reservoirs, it is considered that the similar mistake (putting samples in the wrong bottles) did not occur considering that the chloride concentration/all β analysis results indicate the same tendency as before.

The time of sampling performed in the drain holes of the underground reservoirs and the chloride analysis results announced in the follow-up report No.136 have been corrected as follows since reanalysis was done using samples collected in the afternoon.

Please visit our web page for the sampling results.
http://www.tepco.co.jp/en/nu/fukushima-np/f1/smp/2013/images/chosui_13051101-e.pdf

The water level, etc. of the underground reservoirs will continue to be intensively monitored.