Pre- and post-service microhardness measurements of electrical contacts operating at Kozloduy NPP

Selected electrical equipment of different monitoring systems operating at Kozloduy NPP has been studied for identification of the changes occurring during its long use under the conditions of monitored radiation background. As a part of a complex research program, pre- and post-service microhardness measurements of Ag and Ag–Cd electrical contacts were undertaken. The interpretation of the experimental results led to formulas describing adequately the microhardness–depth profiles. The changes of material characteristics varied in the different types of the electrical components.