Fukushima Daiichi NPS Prompt Report 2013

This is follow-up information on the "water leak at a tank in the H4 area in Fukushima Daiichi Nuclear Power Station" found on August 19.

We performed the analyses of water sampled on September 14 in the observation holes (E-1: in north of the tank No.5 in Group I in the H4 area (outside of a dike) where water leakage was found, E-2: in south of the tank No.5 in Group I in the H4 area (outside of a dike) where water leakage was found) around the H4 tank area.
The result of tritium obtained in E-1 (170,000Bq/L) was found to be on the upward trend as the previous day and was higher than the result obtained on September 13 (150,000Bq/L).
No significant change was found on the result of tritium obtained in E-2 compared with the result obtained on September 13.

In addition, the result of all β obtained in a newly analyzed observation hole (E-4) around H4 tank area on September 15 was 1,300Bq/L and was equivalent to E-1.
No significant change was found on the results of all β obtained in E-1 and E-2 on September 15 compared with the results obtained on September 14.

We will continue to investigate whether this incident is affected by the leakage from the H4 area tank or the leakage from the concentrated saltwater transfer pipe after treatment at the desalination system (reverse osmosis membrane method), which was happened on March 26 and April 5, 2012.

<Observation hole: E-1>
- Sampled on September 15
 All β: 1,100 Bq/L

- Sampled on September 14
 Tritium: 170,000 Bq/L
 All β: 1,100 Bq/L (previously announced)

- Sampled on September 13
 Tritium: 150,000 Bq/L (previously announced)
 All β: 1,300 Bq/L (previously announced)

- Sampled on September 12
 Tritium: 130,000 Bq/L (previously announced)
 All β: 1,600 Bq/L (previously announced)

- Sampled on September 11
 Tritium: 97,000 Bq/L (previously announced)
 All β: 1,500 Bq/L (previously announced)

- Sampled on September 10
 Tritium: 64,000 Bq/L (previously announced)
 All β: 2,000 Bq/L (previously announced)

<Observation hole: E-2>
- Sampled on September 15
 All β: 35 Bq/L

- Sampled on September 14
 Tritium: 360 Bq/L
 All β: 21 Bq/L (previously announced)

- Sampled on September 13
 Tritium: 410 Bq/L (previously announced)
 All β: Below the detection limit value (detection limit value: 15 Bq/L)
(previously announced)

- Sampled on September 12
 Tritium: 290 Bq/L (previously announced)
 All β: 29 Bq/L (previously announced)

- Sampled on September 11
 Tritium: 300 Bq/L
 All β: Below the detection limit value (detection limit value: 20Bq/L)
(previously announced)

<Observation hole: E-4>
- Sampled on September 15
 All β: 1,300 Bq/L