Reliability analysis of a modern power supply under nuclear radiation effects

The nuclear radiation damage due to displacement and ionization effects on power devices is well known. This affects the performance of the systems, which use these power devices. This paper presents a study on the performance degradation of a modern power supply unit operating in a nuclear environment. In this paper, a buck-boost converter has been considered which is used for feeding DC power to various electronic systems, DC drives, etc. in nuclear power plant. The power devices, which constitute the buck-boost converter, were irradiated with gamma rays and the basic parameters were monitored to determine the deviations. The experimental results have been utilized to find out the probability of failure of each device of the power converter and subsequently the reliability evaluation of the buck-boost converter has been carried out using fault tree analysis. The experimental database has been used to mathematically model the gamma radiation effects, which helps in predicting the life of electronic systems in a nuclear environment. The polynomials derived are very useful for enhancing the availability of modern power supply system working in a nuclear environment. The buck-boost converter has been simulated using PSpice to analyse the overall effect of gamma radiation damage on the modern power supply system by feeding experimental results of individual power devices into the simulation. Detail experimental and analysis results are presented.