Development of a System Dynamics Model for Assessing Nuclear Security Culture using Survey Data

A concept of nuclear security culture and its implementing guide are developed by the International Atomic Energy Agency in 2008 under the Nuclear Security Series No. 7. Many countries agree on the importance of nuclear security culture and actively seek ways to evaluate and improve the culture. This paper aims to propose a system dynamics model, which is developed to assess nuclear security culture in nuclear facilities such as nuclear power plants. System dynamics is an approach to understanding the nonlinear behavior of complex systems over time. This approach fits well with the cultural aspect of the issues including two main feedback loops on ‘policy level and work environment’, ‘workload and stress’ and ‘learning’. The model is presented in Casual Loop Diagram (CLD) and Stock and Flow Diagram (SFD). CLD is a logic flow chart of the elements in nuclear security culture showing their interactions. SFD demonstrates the transition phase of the main elements as time goes on. To investigate the relationships assumed in the model, two questionnaires targeting the personnel at NPPs and their regulator were developed. Each survey was made up of 39 and 6 questions, which are designed to evaluate awareness of nuclear security culture and existing infrastructure. The data was collected from 846 people at NPPs and 10 people at their regulatory agency and incorporated into the model. By this quantitative analysis, the model can assess the current and future levels of nuclear security culture in the facilities. The model also can be used to generate reliable estimates of the effects of additional relevant decisions or actions. With these simulation results, this paper suggests some improvement plans applicable to the policy and decision making process.