Summary of panel discussions at the international seminar on accident sequence modeling
✍ Scribed by G.E. Apostolakis; P. Kafka; G. Mancini
- Publisher
- Elsevier Science
- Year
- 1988
- Tongue
- English
- Weight
- 105 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0951-8320
No coin nor oath required. For personal study only.
✦ Synopsis
In Probabilistic Safety Assessment (PSA), accident sequence modeling represents the synthesis of expert judgment, operational evidence, and plant behavior. The aim of this two-day seminar, which was held in Munich in August 1987, was to provide a forum for in-depth discussion in a workshop atmosphere of the key elements of.the modeling process, such as operator actions and the response of the plant, and to discuss how such models may interact with the design of decision support systems in the form of expert systems or interactive man-computer structures. While this evaluation of the state of the art was done in the context of nuclear power reactor safety, most of the models and ideas advanced by the participants have wider applicability and could be useful to probabilistic safety assessments and reliability enhancement programs for other industries.
A major focus of the extensive discussions that followed the formal presentations was the difference in the approaches to human reliability modeling between PSA practitioners and modelers of cognitive human behavior. The main objective of PSA models is to provide guidance to practitioners in deriving human error rates for specific actions under accident conditions. Engineering judgment, as well as results from simulator exercises and actual experience, forms the basis for these numerical assessments.
The criticism that is raised against this engineering approach is that it lacks an appreciation of the internal mechanisms, e.g. reasoning, association, memory, that govern human behavior. It is argued that human errors can be understood only in the context of a cognitive model of the operators. The counterargument is that decisions regarding the safety of major industrial facilities cannot wait until satisfactory operator models become available.