报告题目：Cementation effect on swelling and permeability properties of bentonite
报告人：Daichi Ito 博士(日本早稻田大学土木环境工程系)
地点：宝山校区东区11号楼404
时间：2023年9月18日（周一）15:00-16:30
摘要：In geological disposal of high-level radioactive waste, bentonite is planned to be used as a buffer material surrounding the waste. Buffer material is required to have high swelling capacity and low water permeation for delaying the movement of radionuclide. Due to the high radioactivity and long half-lives of the radionuclide, buffer is required to maintain its integrity for a long period of time, tens of thousands of years. However, because buffer materials may be exposed to complex underground environments such as high temperature, high pressure, and contact with saline groundwater, there is concern that the properties related to barrier performance, such as swelling properties, may deteriorate due to cementation. In this study, bentonite ore mined from deposits was used to simulate the cemented buffer, and the effects of cementation on swelling and permeability properties were experimentally investigated. As results, swelling properties may be reduced to less than half, but permeability property may almost same under the effect of cementation. Also, X-ray diffraction and SEM-EDS analysis were conducted to elucidate the mechanism of cementation. Furthermore, an evaluation method for self-healing capability of buffer was proposed, considering the effect of degradation because of cementation.
报告人简介：He took a Doctor degree of Engineering in School of Creative Science and Engineering of Waseda University, Japan. His research areas are environmental geotechnics and energy geotechnics. In 2023, he received a research encouragement award from the Japan Geotechnical Society. Especially, he has been researching on the swelling characteristics evaluation of bentonite buffer material for geological disposal of high-level radioactive waste considering long-term alteration phenomena such as cementation.
