Impact Assessment of Eight Year Application of the SOL Safety Event Analysis Methodology in a Nuclear Power Plant

The objective of this paper was to summarize the measurable indicators of the impact of eight year application of the SOL safety event analysis methodology in the period of 2007 - 2015 in a nuclear power plant in Hungary. The theoretical framework of this paper consists of the (1) "Swiss-Cheese Model", (2) the "socio-technical system model", (3) the organizational learning approach, and (4) the concept of safety culture. The selected broad spectrum of methods corresponds to the approach of progressing from the actual state of the safety culture - via covering the SOL related experiences and opinions of the most involved employees, middle and top managers, and training experts as well towards the whole community of the NPP. As the results of widespread questionnaire surveys, focus group interviews and anonymous intranet-based inquiry methods it can be stated that the overwhelming majority of the respondents considered the application of the SOL methodology as useful and supporting the safety- related organizational learning. It was also found, however, that in the respondents' opinion the utilization of the - otherwise correct and deeply penetrating - results of SOL analyses is still to be improved.