On October 15, 2012, a worker of a cooperative company found a water leakage in a corridor in the back of the large equipment hatch on the first floor of Unit 3 Turbine Building at Fukushima Daiichi Nuclear Power Station. At around 10:10 AM on the same day, a TEPCO employee confirmed the leakage. As we stopped the pump transferring the accumulated water from Unit 3 Turbine Building basement to the Central Radioactive Waste Treatment Facility (Miscellaneous Solid Waste Volume Reduction Treatment Building [High Temperature Incinerator Building]) at 10:18 AM, the leakage was stopped at 11:16 AM. The leaked water remained on the floor on the downside of the slope in the back of the large equipment hatch and there was no leakage to the outside of the building.
The area affected by the leakage was approx. 3m x approx. 6m and approx. 5mm in depth, and the leakage amount was estimated to be approx. 90L. As a result of nuclide analysis of the leaked water, cesium 134 density was approx. 1.0 x 104 Bq/cm3 and cesium 137 density was approx. 1.8 x 104 Bq/cm3. The leaked water was identified to be the accumulated water of the Turbine Building.
In response to this incident, we have received a directive document* "Radioactive Water Leakage in Unit 3 Turbine Building at TEPCO Fukushima Daiichi Nuclear Power Station (Direction)" from the Nuclear Regulatory Authority yesterday.
In accordance with the direction given, appropriate measures will be implemented.
* Directive document
"Radioactive Water Leakage in Unit 3 Turbine Building at TEPCO Fukushima Daiichi Nuclear Power Station (Direction)"
The aforementioned document is available only in Japanese. We apologize for the inconvenience this may cause.