In Korea, two decommissioning projects have been carried out due to retire of nuclear research facilities such as Korean research reactors (KRR-1 & KRR-2) and a uranium conversion plant (UCP). The decommissioning of the KRR-2 and a uranium conversion plant (UCP) at KAERI were finished completely by 2011, whereas the decommissioning of KRR-1 is currently underway. The large quantity of radioactive waste was generated during the decommissioning the KRR and UCF such as concrete waste, soil, combustible and non combustible waste. The volume reduction of the combustible wastes through the incineration technologies has merits from the view point of decrease in the amount of waste to be disposed of resulting in a reduction of the disposal cost. Incineration is generally accepted as a method of reducing the volume of radioactive waste. The incineration technology is effective treatment method that contains hazardous chemical as well as radioactive contamination. Incinerator burns waste at high temperatures. Incineration of a mixture of chemically hazardous and radioactive materials, known as“mixed waste,”has two principal goals: to reduce the volume and total chemical toxicity of the waste. Incineration itself does not destroy the metals or reduce the radioactivity of the waste. A proven melting technology is currently used for low-level waste (LLW) at several facilities worldwide. These facilities use melting as a means of processing LLW for unrestricted release of the metal or for recycling within the nuclear sector. Fig. 1 shows the schematic diagram of the oxygen-enriched incineration (OEI) and melting facility. The oxygen-enriched incinerator located at the KAERI. The system consists of a waste preparation system, incineration system, off-gas cooling system, and off-gas treatment system. Demonstration incineration facility took over the responsibilities of KHNP for decommissioned combustible waste. After taking over the demonstration incineration facility from KHNP, the facility was modified, and work toward the licensing procedure, and an extension of the object waste including alpha-bearing waste and increase incineration capacity, began in June 2011. The melt decontamination technology is the most effective treatment method for decommissioned metal waste. Melting for size reduction would require no prior surface decontamination and very little sorting of the waste material. Also, the recycling or volume reduction of the metallic wastes through the melt decontamination technologies has merits from the view point of an increase in resource recycling as well as a decrease in the amount of waste to be disposed of resulting in a reduction of the disposal cost and an enhancement of the disposal safety. Melt facility consist of four system such as preparation system, melting system, ingot treatment, and off-gas treatment system. The decommissioned combustible waste has been incineration by incinerator from last year. In case of metal waste, metal waste will be melt for self-disposal and volume reduction by induction furnace. Combustible wastes were treated by incinerator and ash dispose permanently site. In case of metal wastes is treated by induction furnace and slag dispose permanently site and ingot will be reuse.

This paper describes the domestic and international status for melt decontamination, which has been known as the most effective technology for the volume reduction and recycling of the metal wastes generated from nuclear facilities. The recycle or self disposal of metallic wastes can be considered as one of the waste management options under the circumstances of the capacity limitation of a waste disposal in Korea. The limited recycle or self disposal of the metal wastes through an melt decontamination have the merit from the positive view point of the increase in resource recyclability as well as the decrease in the amount of wastes to be disposed resulting the reduction of disposal cost and the enhancement of disposal safety. Among the scenarios for recycle and reuse of the radioactive metallic wastes, the most feasible and reasonable one is limited reuse option, in which the ingot can be recycled as the products such as the waste drums and ISO containers. Prior to recycle and reuse in the nuclear sector, however, the regulatory criteria for the recycle and reuse of metallic wastes should be established in parallel with the development of the recycling technology.