An energy supply unit for an autonomous remote sensor system monitoring stored nuclear waste

This paper proposes a system for monitoring nuclear waste stored in sealed underground repositories after a period of several decades. The focus of the work is on the selection and prototyping of a critical part of the system, the energy source. In order to select the energy source from a number of possible options, a trade-off study is implemented using a weighted decision matrix. From this trade-off study a system based on a magnetic spring to store energy is chosen, primarily due to its low number of parts and does not suffer from self-degrading effects. When required, some of this stored energy is converted to the electrical domain and supplied to a wireless sensor node in a conditioned form. A prototype of the concept is presented and the supply of energy to a wireless sensor node is demonstrated.