Radiation Induced Currents in Mineral Insulated Cables

Mineral insulated (MI) cables used with self-powered flux detectors in CANDU reactors employ Inconel-600 as the sheath and core-wire material, and MgO as the insulation. A study was undertaken to obtain a more fundamental understanding of the current producing processes in such MI cables and to determine how these processes are related to cable geometry. A number of Inconel-Inconel cables were irradiated in the NRU and Pool Test reactors at CRNL, and a Gammacell-220 60CO irradiator. Additional data were obtained from the Bruce Nuclear Generating Station 'A'. The experimental results permit the selection of optimum cable geometries.