Overview of rehabilitation schemes for farmlands contaminated with radioactive cesium released from Fukushima power plant

Schemes for rehabilitation of farmlands contaminated with radioactive cesium are discussed based on the various pieces of information obtained to date from a series of validation trials in Fukushima, Japan. Decontamination of affected farmlands is to be achieved by scraper-removal of the very highly contaminated shallow top soil layer. In areas with very low contamination, the plans are to implement in-situ burial of the scraper-removed contaminated topsoil at depths greater than 2 m - meaning that the affected areas will be the burial sites. For disposal of the contaminated top-soils removed in the very highly contaminated areas, there will be a two-step procedure: (a) volume reduction and decontamination of the contaminated soil, and (b) disposal in a mulch barrier landfill system with encapsulating clay liners at selected sites. Volume reduction and decontamination of the contaminated soils will involve removal of the finer soil fractions through washing with water. For implementation of the schemes for rehabilitation, science-based verification of safety and public acceptance of the schemes are required.