JAPAN | Radioactive sludge crisis

Posted on June 15, 2011


JAPAN | JAPAN TIMES | Wednesday, June 15, 2011

Tokyo Electric Power Co., struggling to contain the world’s worst nuclear disaster in 25 years, has another crisis on its hands: finding storage for enough radioactive sludge to fill an Olympic-sized swimming pool.

Tepco has started decontaminating millions of liters of water poured over melting reactors to keep them from exploding. By the end of the year it expects to have 2,000 cu. meters of highly radioactive sludge separated from the water, said Teruaki Kobayashi, a nuclear facility management official at Tepco.

“We haven’t determined a final disposal site for the waste,” Kobayashi said Monday. “Our priorities are decontaminating radioactive water and maintaining cooling efforts.”

The sludge will be put in tanks at the Fukushima No. 1 station, where three reactors suffered meltdowns, and moved to a temporary storage unit in December, Kobayashi said. About 105 million liters lies in basements and trenches at Fukushima. Tepco expects the amount of contaminated water to be almost double that by the end of the year.

The utility delayed the start of operations of the decontamination unit supplied by Areva SA from Wednesday to Friday, Junichi Matsumoto, a general manager at Tepco, said Monday.

Radiation in the water is estimated at 720,000 terabecquerels, Matsumoto said at a media briefing June 3. That’s almost as much as the latest estimate of the radiation released into the air between March 11 and 16 at the height of the crisis.

When a reactor exploded at Chernobyl in 1986 in the world’s worst nuclear disaster, 5.2 million terabecquerels of radiation was discharged, the Nuclear and Industrial Safety Agency said April 12.

In the days after the earthquake and tsunami knocked out power and backup generators for the cooling system, Tepco used fire hoses and makeshift pumps. Much of the water has overflowed or leaked into basements, connecting tunnels and service trenches at the plant, which has six reactors housed in separate buildings.

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