变送器冗余结构对紧急停堆系统可靠性影响分析

Impact of Transmitter Redundant Structure On Reactor Trip System Reliability

为优化紧急停堆系统的可靠性设计,采用故障树方法对某紧急停堆系统硬件进行可靠性建模,通过定量计算得到系统的薄弱环节在于变送器。进一步分析变送器冗余结构对可靠性的影响,探讨了冗余结构的两种基本改变方式下整体误动率和拒动率的变化规律;在所建故障树模型基础上,对不同变送器冗余结构下紧急停堆系统拒动率进行量化对比,四取二结构是最合理选择,其系统拒动率比三取二和二取一结构低了3个数量级,而五取二结构可靠性提升不大,不具备经济性。

To optimize the reliability design of the reactor trip system(RTS),the fault tree method is used to the reliability modeling of an RTS hardware. The weakness of the system lies in the transmitter. In the paper,the impact of transmitter redundant structure on RTS reliability is further analyzed,and the change rules of the mis-operation rate and the mal-operation rate after the two basic changes of the redundant structure is concluded. On the basis of the fault tree model built,quantitative comparisons are made for the refusal rates of RTS with different transmitter redundant structures. It’s confirmed that "2-out-of-4 " structure is an optimal choice,with which the RTS mis-operation rate is 3 orders of magnitude lower than that with "2-out-of-3"and "1-out-of-2". "2-out-of-5"structure has less promotion in reliability,and it is not economically efficient.