Qualitative and quantitative methods for human factor analysis and assessment in NPP. Investigations and results

We consider here two basic groups of methods for analysis and assessment of the human factor in the NPP area and give some results from performed analyses as well. The human factor is the human interaction with the design equipment, with the working environment and takes into account the human capabilities and limits. In the frame of the qualitative methods for analysis of the human factor are considered concepts and structural methods for classifying of the information, connected with the human factor. Emphasize is given to the HPES method for human factor analysis in NPP. Methods for quantitative assessment of the human reliability are considered. These methods allow assigning of probabilities to the elements of the already structured information about human performance. This part includes overview of classical methods for human reliability assessment (HRA, THERP), and methods taking into account specific information about human capabilities and limits and about the man-machine interface (CHR, HEART, ATHEANA). Quantitative and qualitative results concerning human factor influence in the initiating events occurrences in the Kozloduy NPP are presented. (authors)