Abstract: The radiation monitoring system is onemain means of radioactivity monitoring in NPPs. Its operational status has always been highly valued by national regulatory authorities, especially relevant human events. Through practical case analysis, the common problems among these cases are studied. It’s found that the probability of occurrence of the error interval is obviously related to the nature of the work of the operator and the management attribution. And the equipment which is easy to be incorrect operated also has clear features. Based on these correlations and characteristics analysis,suggestions for improving the reliability of the operation of the radiation monitoring system are proposed.

Key words: NPP, Radiation monitoring system, Human error, Error interval