Unsaturated hydraulic conductivity of buffer material for spent nuclear fuel final disposal

• Main Authors: Chang, Yu-Hsin, 張育馨
• Other Authors: Yang, Shu-Rong
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/5t6v27

碩士 === 國立屏東科技大學 === 土木工程系所 === 105 === Clayey soils are used as buffer material in an engineered barrier system for isolation of high-level radioactive wastes (HLW) in a repository. In the current proposal for deep geological disposal of the high-level radioactive wastes in Taiwan, compacted bentonite is used to contain the metallic waste canisters and separate the waste from the host rock and backfill materials. The major roles of the buffer material are used to reduce the groundwater flow, to protect the overpack from degradation, and to minimizee the migration of radionuclides. The resaturation of the buffer considered as a hydro-process occurring at elevated temperatures in the near-field of a repository affects the migration of radionuclides. Hydraulic conductivity properties of buffer material affects this resaturation process. To evaluate the influence of temperature and dry density on hydraulic conductivity properties of buffer material, an equipment was designed to simulate the near-field environment of a repository and to measure the hydraulic conductivity at unsaturated condition.