Fukushima Daiichi NPS Prompt Report 2013

An exhaust system is installed in Unit 2 Reactor Building at Fukushima Daiichi NPS, and its filter removes the radioactive materials from the air in the building.
There is a facility (A system, B system) which monitors dust in the air at the exit of the exhaust system while exhaust is performed. The following failure was found at the facility.

At around 9:03 AM today (July 23), an alarm went off indicating a failure of the suction pump installed at dust radiation monitor B system in the exhaust system exit of Unit 2 Reactor Building, and the pump was suspended.
Since dust radiation monitor A system is under repair, both A system and B system of dust radiation monitor cannot make measurement. However, the air in the building is exhausting through the filter continuously.

We are inspecting the site status and preparing to restart the dust radiation monitor B. We will announce the status as soon as we know it.

No abnormality was found in the plant data (temperature of the bottom of the RPV and inside the PCV, etc.), and no significant change was found in the monitoring post readings.