Aug 04 (NHK) - The operator of the Fukushima Daiichi nuclear power plant says the groundwater level briefly plummeted near a building that houses one of the crippled reactors.
Tokyo Electric Power Company, or TEPCO, says the fall was observed in a monitoring well about 11 meters southwest of the No.4 reactor building on Wednesday.
The utility says the groundwater level temporarily sank roughly 1 meter below the level of contaminated water inside the reactor building.
The firm says the groundwater rose above the usual level 23 minutes later.
A sharp fall in the groundwater level just outside reactor buildings could cause contaminated water to leak from inside the buildings.
TEPCO says it assessed the density of radioactive substances in the well water on Thursday and has confirmed no leak of contaminated water took place.
