Combining Neural Methods and Knowledge-Based Methods in Accident Management

Accident management became a popular research issue in the early 1990s. Computerized decision support was studied from many points of view. Early fault detection and information visualization are important key issues in accident management also today. In this paper we make a brief review on this research history mostly from the last two decades including the severe accident management. The author’s studies are reflected to the state of the art. The self-organizing map method is combined with other more or less traditional methods. Neural methods used together with knowledge-based methods constitute a methodological base for the presented decision support prototypes. Two application examples with modern decision support visualizations are introduced more in detail. A case example of detecting a pressure drift on the boiling water reactor by multivariate methods including innovative visualizations is studied in detail. Promising results in early fault detection are achieved. The operators are provided by added information value to be able to detect anomalies in an early stage already. We provide the plant staff with a methodological tool set, which can be combined in various ways depending on the special needs in each case. 1. Introduction Accident management grew into an own and popular research branch in the early 1990s. This trend was a kind of delayed reflection of the two serious industrial accidents in the 1980s in Bhopal (1984) and in Chernobyl (1986). It was noticed that most of the earlier studies about abnormal events did not cover very well the severe accident cases. Already the Three Mile Island accident (1979) made the nuclear power plant control room a major focus for the studies of human factors, human reliability, and man-machine interface technology [1]. The Fukushima accident in 2011 has risen the accident management issue up again, although the nature and origin of this accident were completely different. The problem area in the 1990s was identified to begin with information needs and reliability, to be completed with accident mitigation. The presentation methods and information structuring were located to central issues, as the human being was considered often to be the weakest link in the safety systems. The fault diagnosis of abnormal events and the support of operator decision making were naturally completing this entity [2]. Computerized accident management was studied in the 1990s, for instance, in OECD Halden Project, and prototyping systems including also strategic planning features in operator support or technical support