Investigation of applicable methods on safety verification of disposal facilities and waste packages

In this project, three subjects about safety verification were investigated in FY 2010. For radioactive waste disposal facilities, verification items and methods for trench disposal facility and verification method of permeability on cover of pit disposal facility were studied. For waste packages subject to near surface pit disposal, adequacy of continuous use of the scaling factor and average radioactivity concentration, and a new method for verifying waste packages were investigated. Those results were finalized in consideration of the opinion from advisory panel, and publicly opened as JNES-SS reports. In FY 2010, four JNES-SS reports were published and all of these reports have been used as standards of safety verification on waste packages. The characteristics and verification procedures of wastes subject to near-surface trench disposal were also studied. For radioactive waste which will be returned from overseas, verification items and methods for receiving were investigated. Knowledge accumulated in this subject was reflected in the report on the safety of low level vitrified waste (CSD-B), which is written by Radioactive Waste Safety Subcommittee. All results have been utilized in safety verification on waste disposal facility and radioactive waste conducted by NISA and JNES. (author)