Human cognitive task distribution model for maintenance support system of a nuclear power plant

Abstract

In human factors research, more attention has been devoted to the operation of nuclear power plants (NPPs) than to their maintenance. However, human error related to maintenance is 45% among the total human errors from 1990 to 2005 in Korean nuclear power plants. Therefore, it is necessary to study human factors in the maintenance of an NPP. There is a current trend toward introducing digital technology into both safety and non-safety systems in NPPs. A variety of information about plant conditions can be used digitally. In the future, maintenance support systems will be developed based on an information-oriented NPP. In this context, it is necessary to study the cognitive tasks of the personnel involved in maintenance and the interaction between the personnel and maintenance support systems. The fundamental purpose of this work is how to distribute the cognitive tasks of the personnel involved in the maintenance in order to develop a maintenance support system that considers human factors. The second purpose is to find the causes of errors due to engineers or maintainers and propose system functions that are countermeasures to reduce these errors. In this paper, a cognitive task distribution model of the personnel involved in maintenance is proposed using Rasmussen’s decision making model. First, the personnel were divided into three groups: the operators (inspectors), engineers, and maintainers. Second, human cognitive tasks related to maintenance were distributed based on these groups. The operators’ cognitive tasks are detection and observation; the engineers’ cognitive tasks are identification, evaluation, target state, select target, and procedure; and the maintainers’ cognitive task is execution. The case study is an analysis of failure reports related to human error in maintenance over a period of 15years. By using error classification based on the information processing approach, the human errors involved in maintenance were classified accordin...