Thermal, hydraulic and swelling properties of bentonite pellet. Examine on calculating parameter assessment on PRP. Research document

In the Prototype Repository Project (PRP), an international collaborative research project using an underground research laboratory of SKB, we have been carrying out a prediction analysis and comparing the results of the prediction analysis with the monitoring data of the coupled Thermo-Hydro-Mechanical behaviors in and around the engineered barrier system. In PRP, the gap between bentonite blocks and rock mass are filled with bentonite pellet. Since our analytical code cannot handle the properties of bentonite pellet, we assume the gap filled with bentonite blocks to calculate. Then, we performed laboratory tests on thermal, hydraulic and swelling properties of bentonite pellet, and summarized the assessment of the bentonite pellet on calculation. In cases where the swollen bentonite pellet is considered to become uniform, the properties of bentonite pellet are similar to ones of bentonite block. In additions, since swelling of bentonite pellet is rapid, assumption that the region filled with bentonite pellet is bentonite block is justified. (author)