[en] This reports described the activities of Department of Decommissioning and Waste Management (DDWM) in Nuclear Science Research Institute (NSRI) in the period from April 1, 2008 to March 31, 2009. The report covers organization and missions of DDWM, outline and operation/maintenance of facilities which belong to DDWM, treatment and management of radioactive wastes, decommissioning activities, and related research and development activities which were conducted in DDWM. In FY2008 radioactive wastes generated mainly from R and D activities in NSRI were treated safely. They were about 384 m³ of combustible solid wastes, 135 m³ of noncombustible solid wastes and 314 m³ of liquid wastes. After adequate treatment 2,391 waste packages (in 200L-drum equivalent) were generated and total accumulated waste packages amounted to 136,971 as of the end of FY2008. Two new approaches were conducted for radioactive waste management: development of record keeping system for land burial and a new management system for mid-level radioactive waste packages. Decommissioning activities were carried out as planned for the JAEA's Reprocessing Test Facility (JRTF), the Ceramic Fuel Laboratory, the Plutonium Laboratory No.2, the Metallurgical Laboratory, Isotope Separation Laboratory and Reprocessing Test Laboratory. As for the R and D activities, studies were conducted on radiochemical analyses of wastes for land burial, and JRFT decommissioning technologies and new waste management for land burial and waste volume reduction. The method of nuclide measuring for the clearance was approved. And as for the activity of safety was started removing of liquid waste pipeline. (author)