Biomass plant tested for Belarus forest decontamination

Ten years after the world`s worst accident involving a nuclear reactor, a collaboration of private business and researchers from the US and Belarus is planning to test a way to decontaminate forests north of Chernobyl. The project will evaluate health, environmental and economic consequences of a pilot biomass power plant designed to burn timber harboring almost all the radioactive residue and capture radioactivity in the ash.

Belarus is an independent state just north of Chernobyl. It received about 70 percent of the radioactive fallout released during the Chernobyl explosion and subsequent fires. Regions severely contaminated in the April 26, 1986, accident represent approximately 25 percent of the total area of Belarus. The contamination is concentrated mainly in the heavily forested southeast portion of the country.

Researchers at the Institute of Power Engineering Problems, which was part of the Soviet Academy of Sciences under the former Soviet Union, will join with US-based Wheelabrator Environmental Systems Inc. to build the pilot plant to convert contaminated wood and litter from the forest floor into electrical energy. Wood and duff from the forest floor would be burned in this specially designed biomass power plant. Radionuclides, primarily cesium and strontium, would be captured in the ash and could then be disposed of as low-level or very low-level waste.

Wheelabrator, which operates five biomass and 16 trash-to-energy plants, is contributing half of the (US)$1.6 million expense for the two-year project. The remaining half will be contributed by Belarus and Sandia National Laboratories of the US.

The pilot plant could demonstrate a way to remediate contamination and reduce health risks posed by ingesting the radionuclides. A second benefit would be to potentially decrease Belarus` heavy dependence on imported energy.

“The prime consideration is to not make the situation worse,” said David Brekke, a Sandia health physicist. “If we can`t do this in a safe and environmentally sound manner, it won`t go.”

Wheelabrator will experiment by burning uncontaminated duff at its commercial plant in Anderson, Calif., USA, where about 2,000 tons of biomass are burned daily. At Sandia`s Combustion Research Facility, models will be run on combustion characteristics to determine via computer simulation which plant design would minimize the emission of small, hard-to-capture particles. The model will be benchmarked against Wheelabrator`s database for heavy metals and available radionuclide data.