Contaminated water may have leaked from the disaster-struck Fukushima No. 1 nuclear power plant since April, the owner said Thursday.
Tokyo Electric Power Company Holdings Inc. said it is still unknown, due to a problem with monitoring equipment, whether radiation-contaminated water actually leaked from the damaged reactor buildings.
In one of the world’s worst nuclear disasters, reactors 1, 2 and 3 experienced fuel meltdowns while reactors1, 3 and 4 units were also severely damaged by hydrogen explosions following a massive earthquake and tsunami in March 2011.
To prevent leakage of tainted water, Tepco has installed water-level indicators and kept groundwater levels in wells higher than the contaminated water levels inside the buildings.
The water level in the wells is usually kept a meter higher than the level of tainted water inside the buildings, according to Tepco.
But the water level in some wells has been found to be about 70 cm lower than indicated by …