The operator of a damaged nuclear power station said Tuesday that a chemical injected into gravel near a cracked concrete pit at a reactor had helped reduce the amount of highly radioactive water leaking into the ocean, DPA reported.
Tokyo Electric Power Co (TEPCO), the operator of the Fukushima Daiichi Nuclear Power Plant, put 1,500 litres of the chemical into gravel to harden it so that the radioactive water would not flow into the concrete pit near reactor number 2.
The plant was damaged by the March 11 earthquake and tsunami that rocked north-eastern Japan, killing more than 12,000.
TEPCO said it suspected the contaminated water was leaking from a cracked pipe and seeping through the gravel into the pit.
On Saturday, TEPCO found radioactive water coming out of the concrete pit, and tried unsuccessfully to seal it with concrete or to plug the leak with water-absorbing polymers.
TEPCO was to put up steel fences at the breached sections of an offshore dyke to prevent the contaminated water from spreading further into the sea, public broadcaster NHK said.
The operator was also to put up underwater silt barriers at three locations, NHK said.