This is follow-up information regarding the water leakage which occurred today (on October 9) near the desalination system (reverse osmosis membrane: RO-3) inside the temporary warehouse.
The leaked water has spread over the area of approx. 60m × 12m × the depth of several centimeters, i.e., over the entire inside of the dike, and has been staying inside the dike.
Further, we confirmed that the location where the leakage occurred is a pipe located upstream of the desalination system (reverse osmosis membrane: RO-3), and that the leaked water is water after treatment by the second cesium absorption apparatus (SARRY) (water before treatment by the desalination system).
We are currently conducting sampling of the leaked water.
Earlier analysis on a sample (taken on August 13) of water before treatment by the desalination system resulted in an all-β density of 3.7×107Bq/L (announced on October 4). Based on this density and the extent of the leakage, we determined at 11:10 AM today that this incident corresponds to "a case when nuclear fuel material (not in the form of gas) or the like has leaked within an area controlled by the company due to an unpredictable event such as a failure of a nuclear reactor facility for power generation" as per Article 18, item 12 of the regulations concerning the operational safety and the protection of specified nuclear fuel material at the TEPCO's Fukushima Daiichi NPS nuclear reactor facilities.