High level radioactive waste disposal repository is faced thermos-hydro-mechanical-radioactive condition. Factors according to these complex conditions are measured using multiple sensors installed in the disposal repository to check integrity of the structure. Wires of the sensors can be potential pathways of groundwater and nuclide flow and these pathways accelerates bentonite saturation. Therefore, it is worth to developing wireless sensors buried in the bentonite buffer which can communicate without wires. In start of the study, widely-utilized wireless communication methods including WiFi and LoRa are tested using compacted bentonite blocks to estimate the performance of them. Compacted bentonite blocks are prepaired using di-press method with metal molds and the dry density of them are about 1.6 g/cm3. All wireless communication methods are well communicated through the bentonite blocks over 50 cm. The further experimental tests will be conducted with different dry density and water contents. The results of these experimental tests give a possibility of wireless communications in compacted bentonite buffer and will be utilized for the design of wireless sensor systems for the repository monitoring.

• Chang-Ho Hong(Korea Atomic Energy Research Institute (KAERI)) Corresponding author
• Jonghun Kim(Korea Atomic Energy Research Institute (KAERI))
• Jin-Seop Kim(Korea Atomic Energy Research Institute (KAERI))
• Joohyun Lee(M1 International Inc.)