Test Interval for Engineered Safeguards Features of Nuclear Reactor

In this paper, based on the traditional average availability model of Engineered Safeguards Features（ESF） of the nuclear reactor, a component availability model has been established, which considers the states dependency in the standby, test and repair periods and uses less assumption. This model can be used in a more extensive field than the traditional one, and it is necessary to obtain the high-accuracy results for the large and complex system. The deduced model is applied for obtaining the TI of residual heat removal system as an example. The results can provide the guidance for the operation management and maintenance decision for ESF of the nuclear power plant.