TEPCO is currently investigating the cause and the amount of overflow. The incident may have caused the landslides which occurred near the conduit and TEPCO is also investigating this possibility.

On December 18, at around 12:30 A.M., a TEPCO employee confirmed through remote monitoring equipment that the amount of water used had decreased at the plant.

TEPCO then investigated the plant and found no abnormalities in water intake facilities and water level indicators and was unable to identify the cause of the decrease of amount of water used.

As a result, TEPCO stopped the water intake activities at 6:20 P.M. for safety reasons.

At around 7:35 A.M. today, TEPCO accompanied Niigata prefecture in their investigation and confirmed through aerial photographs that there was melted snow around an inspection tunnel near the water conduit, pproximately 600 meters away from the roadblocks set after the landslide.

At around 11:00 A.M., TEPCO searched inside the conduit and confirmed there was residual water. The water is estimated to have overflowed from the inspection tunnel due to a blockage further downstream in the conduit.

Investigation of the nearby area via helicopter has been also conducted.
Water intake is currently suspended and the overflow is also assumed to have stopped.

TEPCO launched an emergency response center for the Tsunan-cho landslide at its head office at 10:20 A.M. today and is coordinating its response to the accident with local branch and authorities.