Study On The Cause Mechanism And Barrier System Of Human-Caused Events In Nuclear Power Commissioning

The development of nuclear power has great significance for solving the energy structural imbalance and ecological pollution in China.Nuclear safety is the lifeline of nuclear power generation.Numerous studies have shown that human failure has become an increasingly important factor that threatens nuclear safety.People participate in every stage of the life cycle of nuclear power systems,thus human reliability has a significant impact on the overall reliability of nuclear power plants.Commissioning and start-up is the last and most critical stage before putting into operation of nuclear power plant,and also the key link between construction and production.In the Commissioning stage,the incidence of human error events is quite high,and the risk of personal injury and major equipment damage is relatively high.Especially after nuclear fuel loading,the consequences of human error will directly affect nuclear safety.At present,the main means of preventing human errors in nuclear power commissioning site are still at the stage of improving personnel safety awareness and standardizing personnel safety behavior.There is no systematic cause analysis and effective technical means to prevent human errors.Therefore,it is necessary to combine the current mainstream human factor analysis theory to analyze the human factor events in nuclear power plant Commissioning,observe the personnel,organization,environment and operation mode in the field of Commissioning,study the main factors and mechanism of human factor errors in Commissioning,and on this basis,establish a human factor barrier system model for nuclear power plant Commissioning,and use this model to identify the risk of human factor errors in Commissioning.It should also be prevented and controlled to effectively improve the safety and quality management level of nuclear power plant commissioning.On the basis of fault tree analysis of 245 Commissioning human-caused failure events,questionnaire survey of Commissioning practitioners in a nuclear power plant under construction and face-to-face interviews with some debuggers who have experienced human-caused failure,this paper first re-identifies and classifies the fundamental failure factors of human-caused failure events in nuclear power Commissioning,and then combines Commissioning tests on the basis of general model.Through testing and Commissioning personnel characteristics,the paper constructs Commissioning human influence diagram,Commissioning framework of "social-human-technical system" and cognitive behavior model of debuggers.Then on this basis,the relationship among six failure factors is analyzed and elaborated.Combining with accident-causing theory,a regularity for reacting human-causedevents in nuclear power plant Commissioning is established,which can be used as human factors.Qualitative analysis of the causes of accidents provides theoretical basis for the prediction and prevention of human-caused events.Swiss cheese model is the theoretical basis for the construction of human factor barrier system.After analyzing the limitations and supplementary definitions of Swiss cheese model,combined with the concept of defense in depth,the theory of safety barrier and the extraction of fundamental failure factors,this paper attempts to build a Commissioning human factor barrier system which combines the elements of barrier layer,barrier layer and the implementation skills and skills of elements.Through the analysis of the limitations of Swiss cheese model,a Commissioning human factor barrier The hierarchical decomposition of the system can be further refined to the practical stage until it expands into a perfect human factor barrier network.At the same time,the limitations,failure probability and element importance of the human factor barrier system are analyzed and elaborated,which provides a path for failure detection and improvement optimization of the human factor barrier system layer.