Numerical analysis of coupled thermo-hydro-mechanical behavior in single- and multi-layer repository concepts for high-level radioactive waste disposal

•Multi-layer repository design for high-level radioactive waste disposal is proposed.•Applicability of the multi-layer concept is analyzed by numerical simulations.•Multi-layer repositories meet the temperature criterion of 100 °C.•Stress evolutions in bentonite buffer materials are not significantly different from existing repository concept.•Rock mechanical behavior is different and potential for spalling failure exists.