Japanese Research Group Succeeds in Removal of Radioactive Cesium from Incinerator Ash

Prussian Blue (PB) nanoparticle absorbent (Left: granulated  Right: non-woven　fabric)
Copyright National Institute of Advanced Industrial Science and Technology
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The Nanosystem Research Institute of Japan's National Institute of Advanced Industrial Science and Technology (AIST) announced on November 20, 2013, that it had succeeded in field tests conducted jointly with private companies to extract and fix radioactive cesium contained in the incinerator ash of radiation-contaminated tree trunks and branches, which contains high concentrations of radioactive cesium, by using a Prussian Blue (PB) nanoparticle absorbent.

The test process comprised producing ash by burning radiation-contaminated materials, extracting radioactive cesium from the ash by using water, and collecting and fixing the cesium by adding the PB. The research team conducted a total of 11 incineration tests with different types of contaminated materials and using different incineration conditions, which produced some 80 kilograms of incineration ash from over 10 tons of radiation-contaminated material, and succeeded in removing 60 to 90% of the radioactive cesium from the ash under the optimally-adjusted incineration condition. The highly contaminated waste with 100 kBq/kg of radioactive cesium is decreased to 1/17,000,000 of the initial amount. The test plant for ash-decontamination can treat 24 tons of the ash from the incinerator per day.

It has been difficult to secure storage facilities for radioactive-contaminated waste generated from decontamination efforts following the nuclear accident triggered by the Great East Japan Earthquake. The research team aims to develop commercial plants in order to reduce the volume of contaminated material and contribute to the decontamination of incinerator ash from urban waste, disaster debris and biomass.