Abstract
Among the removed soil and waste contaminated by radio-cesium after the accident at Japan’s Fukushima Daiichi Nuclear Power Station is now being transported into Interim Storage Facilities, those which are difficult to be recycled due to high radioactive density etc. have to be disposed outside Fukushima prefecture. Various studies on volume reduction technologies for its final disposal are being conducted and high temperature melting treatments are being adopted; actual facilities are also operating to handle radioactively contaminated incineration residue. This report explains volume-reduction technologies for fly ash that have been generated from the melting treatment and how mass balance calculation methods are being integrated. As a result of the mass balance calculation for some cases of the volume-reduction process, each of which is composed of different treatment technologies, the volume of stabilized waste has been reduced to around 1/1000 to 1/10000 of the incineration residue while its radioactivity measured in at around ten million to a handred million Bq/kg, in the process with fly ash washing. On the other hand, molten slag, washing residues, waste water, etc. are being generated and also need to be taken into consideration and managed. Hereinafter, these technologies must be verified through demonstration tests conducted by the State. The calculation methods and results for volume-reduction processes are expected to be used in the decision making of the State technical strategy.
