Fukushima Daiichi NPS Prompt Report 2013

This is follow-up information regarding the alarm indicating the high-high radioactivity level, which went off at the continuous dust monitor installed in front of the Main Anti-earthquake Building at Fukushima Daiichi NPS on August 19.

We would like to make an announcement on nuclides analysis result of the radioactive materials in the air at the upper part of Unit 3 Reactor Building, which was performed yesterday (on August 22) to investigate the cause when a debris removal work at the upper part of Unit 3 Reactor Building was not conducted.

As a result of the analysis, slightly high value compared to the past results was detected from the first sampling out of 2 samplings at the vertical direction of west-southwest side of a space above the reactor at Unit 3 Reactor Building as follows. As of the analysis results obtained at the other places, they were found to be within the past variation ranges.

<Analysis result at the upper part of Unit 3 Reactor Building (west-southwest side of a space above the reactor at Unit 3 Reactor Building (vertical direction)>
- From 11:35 AM to 12:05 PM on August 22 (date and time of sampling)
Cesium 134: 1.2 × 10^-3 [Bq/cm³]
Cesium 137: 2.6 × 10^-3 [Bq/cm³]

We will continue to investigate the cause of occurrence of the alarm indicating the high-high radioactivity level.

For the sampling results, please refer to the following page on our website:
http://www.tepco.co.jp/en/nu/fukushima-np/f1/smp/index-e.html