The Research On Dynamic Assessment Of Accident Situation By Operators Of Digital Main Control Room Of Nuclear Power Plant

Today,The systems of digital main control room of NPP become more complex,The information of HMI display discontinuously,while performing an operation,The operators need to do many times interface management tasks,which have increased the workload of the operator's cognitive,and weaken their situation awareness.so the operators will be easy to make mistakes in information-monitoring,informationprocessing and decision-making.The assessment of accident scenarios is a skill that operators must master,Not only will have to do,but to achieve efficient.because in case of happening accident in the plant,it is necessary to confirm the type of incident in the shortest time,so that operators can take solutions to solve the problem,Otherwise extension will lead to disastrous consequences.The assessment process of accident scenarios is complex,operators must have a wealth of knowledge and operating experience,Also they must have excellent psychological quality,accurate mental model and situation model.This paper did the following in-depth studies for assessing accident situation:(1)In this paper,the characteristics of the digital main control room and man-machine interface had been described in detail.It is aimed illustrating something,With the development and application of digital main control room of NPP,The operating systems of main control roombecome more complex,the knowledge structure and cognitive abilities of the operators have become increasingly demanding,whether it is the operators' daily work tasks,psychological cognitive workload have increased a lot,it is necessary to conduct in-depth research on the cognitive workload of the operators,This paper proceed from the assessment of accident situation,the three stages of the assessment are studied.(2)The monitoring information stage,Through the analysis and description of the monitoring process,This paper proposed a monitoring information model; Information processing stage,Through the description of the type of information processing and analysis of the process of information processing,information processing model had been presented;Decision making stage,Through the analysis of situation awareness and drawing on the experience of cognitive information processing model proposed by Endsley,The qualitative assessment model of accident situation had been built.(3)By building mental model and situation model based on Bayesian theory,This paper studied the process of accident situation assessing,And simulated this process with the software of MSBNX combined the LOCA and SGTR accident cases, The simulation results were consistent with results of case analysis. By quantitative study of information search mechanism driven by knowledge, this paper got that the greater the amount of information provided by the source, the greater the probability of operator choose the source in the course of the accident situation assessing.(4)For the three stages(information monitoring, information processing and decision making stage) of the process of accident situation assessing, This paper presented some improved recommendations that prevent operators from making mistakes in the process of accident situation assessing.