Application of dynamic fault tree in reliability assessment of reactor protection system

The traditional static fault tree cannot accurately simulate the sequential failure behaviors of the RPS. [Purpose] This study aims to obtain the failure probability of related system of RPS and the sensitivity of each component by simulating the sequential failure behaviors of RPS, and provide suggestions for the optimal design and optimization of RPS in the future.

[Methods] First of all, the dynamic fault tree (DFT) modeling tools was employed to model the reliability of the RPS, a dynamic binary tree method was applied to quantitative analysis of the DFT model. Then, the Latin hypercube sampling method was adopted to quantitatively analyze the uncertainty of the RPS failure probability, and compared with the traditional static fault tree method under the same conditions. [Results] Simulation results show that the failure probability with 0.95 confidence interval of RPS is 0.015 306~0.015 721.