Tokyo Electric Power Company (TEPCO), operator of Japan’s earthquake and tsunami-crippled Fukushima Daiichi nuclear plant, suspended its work over the weekend on a self-contained cooling system after a filter, which was expected to remove the radioactive cesium for several weeks, exceeded its capacity in just five hours.
Junichi Matsumoto, a spokesman for the company, said that oil and sludge in the water contained much more radiation than expected, according to The Japan Times.
The filter, used to purify contaminated waters in Fukushima’s No. 1 reactor, should be replaced when the radiation level reaches 4 millisieverts. Yet, the filter in question had reached 4.7 millisieverts.
The company has yet to find a solution for the filter and halted its efforts to decontaminate about 28 million gallons of water in the basements and trenches at the reactor.
Nevertheless, Matsumoto said that the company is confident that the setback will not delay its original plan to achieve a stable cool status by mid-July.