Fukushima Daiichi NPS Prompt Report 2013

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

Today (April 27), chloride concentration analysis was performed in the drain holes of the underground reservoirs No.1-7 (at 14 locations) and the leakage detection holes (samples could not be collected at 2 out of 10 locations) of the underground reservoirs No.1-4 and 6. The results are as follows.

No significant change was found with the results compared to the previous results.

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

[Chloride concentration analysis results on April 27]

- Drain hole (northeast) of the underground reservoir No.1
Sampling performed at 5:30 AM on April 27
Chloride concentration: 17ppm

- Drain hole (southwest) of the underground reservoir No.1
Sampling performed at 5:30 AM on April 27
Chloride concentration: 6ppm

- Drain hole (northeast) of the underground reservoir No.2
Sampling performed at 5:35 AM on April 27
Chloride concentration: 9ppm

- Drain hole (southwest) of the underground reservoir No.2
Sampling performed at 5:35 AM on April 27
Chloride concentration: 7ppm

- Drain hole (northeast) of the underground reservoir No.3
Sampling performed at 5:40 AM on April 27
Chloride concentration: 7ppm

- Drain hole (southwest) of the underground reservoir No.3
Sampling performed at 5:40 AM on April 27
Chloride concentration: 4ppm

- Drain hole (northeast) of the underground reservoir No.4
Sampling performed at 5:45 AM on April 27
Chloride concentration: 10ppm

- Drain hole (southwest) of the underground reservoir No.4
Sampling performed at 5:45 AM on April 27
Chloride concentration: 8ppm

- Drain hole (northeast) of the underground reservoir No.5
Sampling performed at 5:50 AM on April 27
Chloride concentration: 8ppm

- Drain hole (southwest) of the underground reservoir No.5
Sampling performed at 5:50 AM on April 27
Chloride concentration: 7ppm

- Drain hole (northeast) of the underground reservoir No.6
Sampling performed at 5:55 AM on April 27
Chloride concentration: 10ppm

- Drain hole (southwest) of the underground reservoir No.6
Sampling performed at 5:55 AM on April 27
Chloride concentration: 7ppm

- Drain hole (northeast) of the underground reservoir No.7
Sampling performed at 6:00 AM on April 27
Chloride concentration: 5ppm

- Drain hole (southwest) of the underground reservoir No.7
Sampling performed at 6:00 AM on April 27
Chloride concentration: 10ppm

- Leakage detection hole (northeast) of the underground reservoir No.1
Sampling performed at 8:30 AM on April 27
Chloride concentration: 1200ppm

- Leakage detection hole (southwest) of the underground reservoir No.1
Sampling performed at 8:25 AM on April 27
Chloride concentration: 7ppm

- Leakage detection hole (northeast) of the underground reservoir No.2
Sampling performed at 8:40 AM on April 27
Chloride concentration: 18ppm

- Leakage detection hole (southwest) of the underground reservoir No.2
Sampling performed at 8:35 AM on April 27
Chloride concentration: 11ppm

- Leakage detection hole (northeast) of the underground reservoir No.3
Sampling performed at 8:55 AM on April 27
Chloride concentration: 10ppm

- Leakage detection hole (southwest) of the underground reservoir No.3
Sampling performed at 8:45 AM on April 27
Chloride concentration: 18ppm

- Leakage detection hole (northeast) of the underground reservoir No.4
Sampling performed at 9:10 AM on April 27
Chloride concentration: 9ppm

- Leakage detection hole (southwest) of the underground reservoir No.4
* Sampling was not performed since the amount of sample necessary for analysis could not be obtained.

- Leakage detection hole (northeast) of the underground reservoir No.6
Sampling performed at 9:25 AM on April 27
Chloride concentration: 7ppm

- Leakage detection hole (southwest) of the underground reservoir No.6
* Sampling was not performed since the amount of sample necessary for analysis could not be obtained.