Tons of tree bark pose new radiation hazard


At least 16,000 tons of radiation-contaminated tree bark and wood chips are piled up in unattended storage spots in lumber mills in Fukushima Prefecture, a local industry group said Wednesday.

The roughly 200 members of the prefectural wood-industry association, Fukushimaken Mokuren, are requesting compensation for storage and disposal costs by year’s end. Unlike quake rubble, the costs of handling such debris are not covered by state subsidies, the group said.

The companies have stopped shipment of bark and wood chips — commonly used for compost or to line the floors of livestock barns — after radiation above the state-set limit from the crisis-hit Fukushima No. 1 nuclear plant was detected by the group during voluntary monitoring that began in August, it said.

Compared with limit of 400 becquerels per kilogram for leaf mold, the levels on bark and wood chips averaged 400 to 500 becquerels and even passed 1,000 becquerels in some areas, while no detectable radioactivity was measured on debarked timber, it said.

The association asked Tepco to burn the tainted debris at its coal-fired thermal power plants, but the utility has rejected that request on grounds that such a move could cause its facilities to malfunction, it said.

Industrial waste disposal businesses have also refused to process the materials over public fears that radioactive ash or other material will concentrate at the incinerators, it added.

Some timber companies are trying to get rid of the tainted by-product by rinsing it off to reduce the radioactivity, but no one will even consider buying it, the group said.

As lumbering produces about 4,000 tons of bark per month in the prefecture, some companies have begun to switch to imported timber instead of local produce for business, so as not to further increase the odds of tainted products emerging, the group added.