[en] Prompt countermeasure for an effective waste treatment should be taken to deal with a lots of wastes including concrete wastes generated by dismantling the retired nuclear facilities. The scenarios and the radiological safety assessment in the recycling of dismantled concrete wastes were established in order to resolve the problem. The volume reduction of dismantled concrete wastes were developed by thermal and mechanical treatment. The volume reduction and stabilization of fine concrete waste were developed. Lots of radioactive HEPA filter wastes are generated from high radioactive facilities in operation, improvement, repair, and decommissioning. However, the effective treatment for HEPA filter wastes has not been developed in Korea. In order to resolve the problem, the downgrading and volume reduction treatment of HEPA filter waste were developed. The downgrading and volume reduction system of HEPA filter waste were developed in order to treat the radioactive HEPA filter. The incineration for TBP and dodecane is not easy because corrosive phosphoric acid condenses on the inner surface of incinerator and off gas pipes. Therefore an advanced alternative technology that prevents potential corrosion by condensing phosphoric acid and that provides sufficient volume reduction effect like incineration. The characteristics of unit processes for the volume reduction treatment of alpha bearing organic mixed waste were evaluated and the performance of unit processes for the volume reduction treatment of alpha-bearing organic mixed waste were developed