[en] The goal of this project is the safe and successful decommissioning of the inside reactor hall of the Korean Research Reactor No 2 (KRR-2) and convert to temporary storage facility for the radioactive waste produced during decommissioning. It's necessary to manage the overall decommissioning and decontamination project for the man-power, the progress of the work, etc. needed to works and to develop the suitable technology and equipment in order to perform the decommissioning works for the purpose of securing the safety and minimizing the radiation exposure for works. Also, the large amount of the liquid and solid wastes were generated from the dismantling works. The radioactivity of the waste was not high but the amount was large and the properties was very diverse, and therefore unique management technologies were required for the decommissioning waste. The operation experience of the uranium conversion plant as a nuclear cycle facility was contributed to the localization of nuclear fuels for HWR. It was shut down in 1993. And, in 2001 the decontamination and dismantlement program for the conversion plant has been launched to achieving radiation safety and environment restoration. Conversion plant environment restoration project will be contributed to developing the decontamination and dismantlement technologies related to other domestic nuclear facilities and to set new criteria in the D and D areas