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 chloride concentration analysis performed in the drain holes of the underground reservoirs No.1-7 (14 locations) and the leakage detection holes of the underground reservoirs No.1-4 and 6 (sample could not be collected at 2 out of 10 locations) today (May 8) are as follows.

The chloride concentration in the leakage detection hole (northeast) of the underground reservoir No.1 was found to have increased (from 46ppm to 120ppm). However, no significant change was found with the samples obtained in other leakage detection holes and the drain holes compared to the previous analysis results.

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

[Chloride concentration analysis results on May 8]

- Drain hole (northeast) of the underground reservoir No.1
Sampling performed at 5:40 AM on May 8
Chloride concentration: 10ppm

- Drain hole (southwest) of the underground reservoir No.1
Sampling performed at 5:35 AM on May 8
Chloride concentration: 6ppm

- Drain hole (northeast) of the underground reservoir No.2
Sampling performed at 5:45 AM on May 8
Chloride concentration: 8ppm

- Drain hole (southwest) of the underground reservoir No.2
Sampling performed at 5:45 AM on May 8
Chloride concentration: 7ppm

- Drain hole (northeast) of the underground reservoir No.3
Sampling performed at 5:55 AM on May 8
Chloride concentration: 8ppm

- Drain hole (southwest) of the underground reservoir No.3
Sampling performed at 5:50 AM on May 8
Chloride concentration: 4ppm

- Drain hole (northeast) of the underground reservoir No.4
Sampling performed at 6:05 AM on May 8
Chloride concentration: 9ppm

- Drain hole (southwest) of the underground reservoir No.4
Sampling performed at 6:00 AM on May 8
Chloride concentration: 8ppm

- Drain hole (northeast) of the underground reservoir No.5
Sampling performed at 6:15 AM on May 8
Chloride concentration: 7ppm

- Drain hole (southwest) of the underground reservoir No.5
Sampling performed at 6:10 AM on May 8
Chloride concentration: 8ppm

- Drain hole (northeast) of the underground reservoir No.6
Sampling performed at 6:25 AM on May 8
Chloride concentration: 10ppm

- Drain hole (southwest) of the underground reservoir No.6
Sampling performed at 6:20 AM on May 8
Chloride concentration: 8ppm

- Drain hole (northeast) of the underground reservoir No.7
Sampling performed at 6:35 AM on May 8
Chloride concentration: 6ppm

- Drain hole (southwest) of the underground reservoir No.7
Sampling performed at 6:30 AM on May 8
Chloride concentration: 7ppm

- Leakage detection hole (northeast) of the underground reservoir No.1
Sampling performed at 8:10 AM on May 8
Chloride concentration: 120ppm

- Leakage detection hole (southwest) of the underground reservoir No.1
Sampling performed at 8:15 AM on May 8
Chloride concentration: 6ppm

- Leakage detection hole (northeast) of the underground reservoir No.2
Sampling performed at 8:20 AM on May 8
Chloride concentration: 11ppm

- Leakage detection hole (southwest) of the underground reservoir No.2
Sampling performed at 8:25 AM on May 8
Chloride concentration: 12ppm

- Leakage detection hole (northeast) of the underground reservoir No.3
Sampling performed at 8:30 AM on May 8
Chloride concentration: 9ppm

- Leakage detection hole (southwest) of the underground reservoir No.3
Sampling performed at 8:35 AM on May 8
Chloride concentration: 12ppm

- Leakage detection hole (northeast) of the underground reservoir No.4
Sampling performed at 8:50 AM on May 8
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 9:00 AM on May 8
Chloride concentration: 6ppm

- 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.