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Japan's radiation cleanup is trial and error

By Mari Yamaguchi

Associated Press

Published: Monday, March 5 2012 1:55 a.m. MST

In this photo taken Monday, Feb. 20, 2012, a man washes a door in a bathtub, in an attempt to remove radioactive contamination, at a private house in Hirono, outside Japan's nuclear exclusion zone. A massive cleanup has begun in towns contaminated by radiation leaks from the Fukushima Dai-ichi nuclear plant, but experts say there is no successful example they can follow, and they don’t know how to judge the effectiveness of a process that is expected to last for years or even decades.

Greg Baker, Associated Press

FUKUSHIMA, Japan — Workers in rubber boots chip at the frozen ground, scraping until they've removed the top 2 inches (5 centimeters) of radioactive soil from the yard of a single home. Total amount of waste gathered: roughly 60 tons.

One down, tens of thousands to go. And since wind and rain spread radiation easily, even this yard may need to be dug up again.

The work is part of a monumental task: a costly and uncertain effort by Japan to try to make radiation-contaminated communities inhabitable again. Some contractors are experimenting with chemicals; others stick with shovels and high-pressure water. One government expert says it's mostly trial and error.

The radiation leak has slowed considerably at the Fukushima Dai-ichi nuclear plant, nearly one year after the March 11 earthquake and tsunami sent three of its reactors into meltdown. Work continues toward a permanent shutdown, but the Japanese government declared the plant stable in December, setting the stage for the next phase: decontaminating the area so that at least some of the 100,000 evacuated residents can return.

Experts leading the government-funded project cannot guarantee success. They say there's no prior model for what they're trying to do. Even if they succeed, they're creating another problem they don't yet know how to solve: where to dump all the radioactive soil and debris they haul away.

The government has budgeted $14 billion (1.15 trillion yen) through March 2014 for the cleanup, which could take decades.

The uncertainty plays out at many levels. One of the workers at the house with the frozen ground said they weren't sure how to measure 2 inches (5 centimeters) from the uneven ground or what to do with the snow on top of it.

"We often encounter situations that are not in the manual and wonder if we are doing the right thing," Takahiro Watanabe said as they wrapped up on a chilly February day. "Just to be safe, we packed the snow into the bags."

The 60 tons of radioactive waste sat in 60 waterproof bags, waiting to be carted away from the house in Fukushima city's Onami district. Some 40 miles (60 kilometers) from the nuclear plant, the neighborhood is a "hot spot" — an area with high radiation readings that is outside the 20-kilometer (12-mile) ring that has remained closed since the early days of the crisis. Residents of hot spots were encouraged, but not ordered, to leave, and some, including the residents of the house that was decontaminated, have not moved out.

In the fading late afternoon light, Watanabe took a dosimeter in his bare hand and placed it on the ground, now covered with a fresh layer of replacement soil. It read 0.24 microsieverts per hour — close to the target level of 0.2 and about one-fifth of what it had been before. "Looks like it has come down a bit," he said.

But for how long? With so much radiation in the area, workers probably will have to return to redo this neighborhood. And areas where children gather, such as parks, schools and playgrounds, will be held to an even stricter standard than homes and offices.

"You have to keep cleaning up," said Toshiaki Kusano, Fukushima city's top crisis management official. The city has a five-year decontamination plan, which he said could be extended.

For evacuees, a major step forward may come in the next few weeks, when officials hope to redefine the evacuation zone, possibly opening up some areas, based on radiation data.

Radiation accumulates in soil, plants and exterior building walls. Workers start cleaning a property by washing or chopping off tree branches and raking up fallen leaves. Then they clean out building gutters and hose down the roof with high-pressure water. Next come the walls and windows. Finally, they replace the topsoil with fresh earth.

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