Design and Modeling of Magnetic Power and Signal Transmission Mechanism for Sensors in Nuclear Reactors

Nuclear reactors rely on constant observation from sensors to ensure safe and reliable operation. However, complications can arise due to wire penetrations for power and data transmission. Here, we design and optimize a low-frequency, inductive coupling transmission mechanism to wirelessly transmit power or signals through a test capsule wall. Inductive coupling was chosen because it can withstand the high pressures and temperatures in a nuclear environment. A model in ANSYS Maxwell was created and examined for different geometries and material properties as well as various loading conditions. Factors, such as operating frequency, radial size, choice of driving coil, core, and shielding material, were analyzed using parametric simulations. Primarily, the efficiency of the power transfer was evaluated to determine the best choice for each of these factors in the design. Then, we quantified how the efficiency of the system will change due to the high operating temperature of a reactor through the variation of the core permeability and coil conductivity. In addition, a physical prototype was manufactured and tested for validation of the simulations. Our results indicate that this is a viable technique to transmit power or signals for sensors in nuclear reactors.