Accelerating test method of thermal aging considering heat generation of electric equipment

All electrical equipment of nuclear power plant (NPP) should be qualified for operating normally in the various conditions of heat, radiation and vibration. Because the design life of the NPP is as long as 30 or 40 years, the accelerating aging test is applied for qualification test of the electric equipment. Especially in thermal aging test, Arrhenius equation, which defines relationship between activation energy of a material and chemical reaction rate, is used as a tool calculating the accelerated condition of the thermal aging test. The equation enables to convert actual NPP condition of the working temperature in a long time into accelerated test condition of higher temperature of shortened period. Temperature of components of the electric equipment often increases by heat sources such as power supply, electrical circuit and coil. This heat-rise makes difficulty for deciding the accelerated condition of thermal aging test. In addition, the number of components composing of the equipment and different temperatures of each component are an additional consideration of the difficulty. We proposed the effective method and technology of accelerated thermal aging test for heat-rise equipment in NPP. (author)