Radioactive waste treatment and disposal techniques

In Hitachi Ltd., the technical development has been advanced according to the basic policy to treat the low level radioactive wastes from nuclear power stations as compactly as possible and to enable to dispose them safely. As the compacting techniques, the technique of making powder pellets for reducing the volume of liquid waste up to the maximum limit and the technique of reducing the volume by cutting spent channel boxes and control rods small were developed and put to practical use, respectively. As the waste solidifying technique which enables the safe disposal of wastes, cement glass which is an inorganic solidifying material having excellent long period stability was developed. This cement glass was put to practical use as the material for solidifying pellets, and further, the application to the sludges of resins and others and miscellaneous incombustible solids is advanced. Moreover, the carrying-out management system which automatically carries out the nondestructive inspection on the strength, surface dose equivalent rate, the amount of radioactivity and so on of the solidified bodies of wastes was developed and put to practical use. In this report, these techniques are explained. (K.I.)