< Information for this week’s seminar >

▶ Date: 2021.09.30(THU)

▶ Time: 16:30 ~ 17:30

▶ Speaker: Dr. Tae-Jin Park(KAERI)

▶ Title: Buffer characterization under the elevated temperature conditions for SNF disposal

▶ Abstract: In most countries, the upper limit of buffer temperature in the repository is set to below 100 ℃ due to the possible illitization. This smectite-to-illite transformation will likely be detrimental to the swelling functions of the buffer. However, if the upper limit increases, the disposal density and cost-effectiveness for the repository will dramatically increase. Thus, understanding characteristics and providing database related for the buffer under the elevated temperature conditions is of crucial importance. Here, we review and propose a strategy to investigate Korean bentonite under the elevated temperatures, from a mineral transformation and radionuclides retardation perspective. The long-term hydrothermal reactions provide bentonite samples required. The bentonites will be studied using in-situ synchrotron-based XRD technique to determine smectite-to-illite transformation. The ‘high-temperature and high-pressure mineral alteration measurement system’ based on Diamond Anvil Cell (DAC) will control and provide the elevated temperature and pressure conditions simultaneously during the measurements. Kinetic modellings will predict how and when the illitization becomes detrimental to the performance and safety of the repository. The sorption reactions planned for the bentonites to evaluate effects on retardation will provide the information required to expand our knowledge for repository optimization.