Hierarchical Bayesian Estimation on Truncated Zero-Failure Data of Pumps and Valves in Nuclear-Powered System

According to that zero-failure data of nuclear-powered equipment is truncated and small sample, failure rate and failure probability on demand of nuclear-powered pumps and valves were estimated by using hierarchical Bayesian method, and the recommended parameters of truncated distribution were given. The results show that the method is applicable and effective．