title: Dealing with the aftermath of Fukushima Daiichi nuclear accident: decontamination of radioactive cesium enriched ash.
abstract: Environmental radioactivity, mainly in the Tohoku and Kanto areas, due to the long living radioisotopes of cesium is an obstacle to speedy recovery from the impacts of the Fukushima Daiichi Nuclear Power Plant accident. Although incineration of the contaminated wastes is encouraged, safe disposal of the Cs enriched ash is the big challenge. To address this issue, safe incineration of contaminated wastes while restricting the release of volatile Cs to the atmosphere was studied. Detailed study on effective removal of Cs from ash samples generated from wood bark, household garbage, and municipal sewage sludge was performed. For wood ash and garbage ash, washing only with water at ambient conditions removed radioactivity due to (134)Cs and (137)Cs, retaining most of the components other than the alkali metals with the residue. However, removing Cs from sludge ash needed acid treatment at high temperature. This difference in Cs solubility is due to the presence of soil particle originated clay minerals in the sludge ash. Because only removing the contaminated vegetation is found to sharply decrease the environmental radioactivity, volume reduction of contaminated biomass by incineration makes great sense. In addition, need for a long-term leachate monitoring system in the landfill can be avoided by washing the ash with water. Once the Cs in solids is extracted to the solution, it can be loaded to Cs selective adsorbents such as Prussian blue and safely stored in a small volume.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, 305-8565, Japan.
authors.forename: Durga
authors.initials: D
authors.lastname: Parajuli
authors.forename: Hisashi
authors.initials: H
authors.lastname: Tanaka
authors.forename: Yukiya
authors.initials: Y
authors.lastname: Hakuta
authors.forename: Kimitaka
authors.initials: K
authors.lastname: Minami
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Fukuda
authors.forename: Kuniyoshi
authors.initials: K
authors.lastname: Umeoka
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Kamimura
authors.forename: Yukie
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Ouchi
authors.forename: Tohru
authors.initials: T
authors.lastname: Kawamoto
mesh_terms: D002586:Cesium / Q000302:isolation & purification*; D002588:Cesium Radioisotopes; D060729:Coal Ash / Q000737:chemistry*; D003666:Decontamination / Q000379:methods*; D062406:Fukushima Nuclear Accident; D005735:Garbage; D017745:Incineration; D011848:Radioactive Pollutants / Q000302:isolation & purification*; D012722:Sewage / Q000737:chemistry; D014197:Trees / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014934:Wood / Q000737:chemistry
chemical_list: D002588:Cesium Radioisotopes; D060729:Coal Ash; D011848:Radioactive Pollutants; D012722:Sewage; D014867:Water; D002586:Cesium