TEPCO Halts Filtering of Tainted Water at Japanese Plant

By Ken Belson, The New York Times

18 June 11

he Tokyo Electric Power Company said Saturday that the filtration system it had struggled to put into operation at the damaged Fukushima Daiichi nuclear power plant had broken down after just five hours, a disappointing setback in its efforts to cool the reactors.

The company said that the sprawling system, which is designed to siphon oil, radioactive materials and salt from the water used to cool the reactors, was shut down because it had filled up with radioactive cesium.

The filtration system was built ad hoc and rushed into service because Tokyo Electric, or TEPCO, is quickly running out of space to store the tens of thousands of tons of water that have been contaminated after being poured into the reactors and spent-fuel pools.

Some of the tanks, basements and other storage facilities at the power plant have inches to spare and could overflow within days. TEPCO hoped to reduce the amount of contaminated water by reusing the newly filtered water. The company is also bringing in hundreds of extra tanks.

A spokesman for TEPCO, Junichi Matsumoto, said that the company was working to find the cause of the problem and that it would restart the machines as soon as possible. The filtration system began operating at 8 p.m. Friday, and was shut down at 12:54 a.m. on Saturday.

NHK, the national broadcaster, said that in five hours the filters had accumulated four millisieverts of radioactive material, about as much as was expected to be collected in a month.

TEPCO has not discussed alternatives to its filtration strategy. But some nuclear experts believe that the utility may again be forced to dump thousands of tons of low-level contaminated water into the ocean. In April, TEPCO poured more than 11,000 tons of radioactive water into the Pacific Ocean, prompting protests from neighboring countries, environmentalists and fishermen.

Yasuko Kamiizumi contributed reporting.