Experimental Setup for Non-Contact Displacement Measurement of Nuclear Waste via Electromagnetic Waves

Spent nuclear fuel and high-level waste from fuel reprocessing are the most hazardous and long-lived radioactive wastes produced by the nuclear fuel cycle, and they must be contained and isolated for thousands of years at an acceptable safety level for human health and the environment. Recently, the authors have proposed a preliminary numerical investigation of possible non-contact techniques for displacement measurement in a geological nuclear waste disposal. In fact, cables used for the detection of measurement signals might be effectively substituted with wireless sensors, thus avoiding all the side effects produced in such a harsh environment (e.g. degradation due to temperature, humidity and radiation conditions). Previous works showed the feasibility of using an electromagnetic approach for the contactless displacement measurement of a canister immersed and suspended in bentonite, a material with a high degree of water retention. The results demonstrated that such an approach is possible provided that some strong requirements are imposed on the sensor design. Sure enough, new sensors must assure reliable transmission through the isolated areas of a repository without affecting the engineered barriers performance and reliable use of energy supply for the measuring equipment in the long term. This work proposes a possible experimental setup where the numerical models developed in previous works can be tested, so to arrive to a prototype sensor to be used in a demonstrator repository.