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 measurement results of dust densities sampled today (on August 20) at the site includes in front of the Main Anti-earthquake Building, as we obtained the results.

All results obtained this time were below the level requiring full-face (or half-face) mask (2.0 x 10^-4[Bq/cm³]), but the instruction to put on masks in the areas not requiring full-face (or half-face) masks in the power station site has been kept in force.

<West side of the construction area No.1 of the Main Anti-earthquake Building>
- From 11:40 AM to 12:00 PM (time of sampling)
Cesium-134:Below the detection limit value (3.3 x 10^-6[Bq/cm³])
Cesium-137:Below the detection limit value (4.7 x 10^-6[Bq/cm³])

<East side of switching station at Unit 1, 2>
- From 11:30 AM to 11:50 AM (time of sampling)
Cesium-134:4.6 x 10^-6[Bq/cm³]
Cesium-137:8.6 x 10^-6[Bq/cm³]

<Monitoring post-2>
- From 11:58 AM to 12:28 PM (time of sampling)
Cesium-134:3.1 x 10^-7[Bq/cm³]
Cesium-137:4.2 x 10^-7[Bq/cm³]

For the sampling results, please refer to the following page on our website:
http://www.tepco.co.jp/en/nu/fukushima-np/f1/smp/2013/images/air_130820_1-e.pdf