High-level radwaste disposal technology development: geological disposal system development

The leaching behaviors of waste glass and spent fuel were investigated and the inventory of nuclides in gap and IRF(Instant Release Fraction) of the spent fuel were measured as a HLW source. The life time for the canister materials such as copper, titanium, carbonsteel, stainlesssteel and nickel alloy was evaluated and manufacturing methods for each material type had been surveyed. The engineering properties and chemical retardation properties of compacted bentonite as a candidate buffer material were investigated. In order to understand the behavior the rock mass around deep repository, mechanical as well as thermal-mechanical coupling analysis was carried out. Thermal analysis and the coupled thermal-hydrological-mechanical analysis were performed for for a repository, rock masses in the vicinity of a repository, and joints adjacent to a repository. For the safety assessment for a reference repository system, KAERI FEP list has been extensively extended and base case scenarios and alternative ones were created. To enhance the confidence on the MASCOT-K, the blind tests were attempted. This comparison work gived more confidence on the excellency of the MASCOT-K code and KAERI's ability on performance assessment. For the probabilistic TSPA approach, the key parameters were identified through so called system prioritization method. The first attempt was made to understand the features on the Korean reference biosphere. The Web base QA system adopted the US NRC concept of T2R3 was developed