Analysis and Insights from a Dynamical Model of Nuclear Plant Safety Risk

In this paper, we expand upon previously reported results of a dynamical systems model for the impact of plant processes and programmatic performance on nuclear plant safety risk. We utilize both analytical techniques and numerical simulations typical of the analysis of nonlinear dynamical systems to obtain insights important for effective risk management. This includes use of bifurcation diagrams to show that period doubling bifurcations and regions of chaotic dynamics can occur. We also investigate the impact of risk mitigating functions (equipment reliability and loss prevention) on plant safety risk and demonstrate that these functions are capable of improving risk to levels that are better than those that are represented in a traditional risk assessment. Next, we analyze the system response to the presence of external noise and obtain some conclusions with respect to the allocation of resources to ensure that safety is maintained at optimal levels. In particular, we demonstrate that the model supports the importance of management and regulator attention to plants that have demonstrated poor performance by providing an external stimulus to obtain desired improvements. Equally important, the model suggests that excessive intervention, by either plant management or regulatory authorities, can have a deleterious impact on safety for plants that are operating with very effective programs and processes. Finally, we propose a modification to the model that accounts for the impact of plant risk culture on process performance and plant safety risk. We then use numerical simulations to demonstrate the important safety benefits of a strong risk culture.Nonlinear Dynamical Systems, Process Model, Risk Management

Facing differences with an open mind: Openness to Experience, salience of intra-group differences, and performance of diverse groups.

This study examined how the performance of diverse teams is affected by member openness to experience and the extent to which team reward structure emphasizes intragroup differences. Fifty-eight heterogeneous four-person teams engaged in an interactive task. Teams in which reward structure converged with diversity (i.e., "faultline" teams) performed more poorly than teams in which reward structure cut across differences between group members or pointed to a "superordinate identity." High openness to experience positively influenced teams in which differences were salient (i.e., faultline and "cross-categorized" teams) but not teams with a superordinate identity. This effect was mediated by information elaboration

Proceedings of the 13th annual conference of INEBRIA

CITATION: Watson, R., et al. 2016. Proceedings of the 13th annual conference of INEBRIA. Addiction Science & Clinical Practice, 11:13, doi:10.1186/s13722-016-0062-9.The original publication is available at https://ascpjournal.biomedcentral.comENGLISH SUMMARY : Meeting abstracts.https://ascpjournal.biomedcentral.com/articles/10.1186/s13722-016-0062-9Publisher's versio

Framework for risk-informed safety margin characterization,”

ABSTRACT The concept of safety margins has served as a fundamental principle in the design and operation of commercial nuclear power plants (NPPs). Defined as the minimum distance between a system's "loading" and its "capacity", plant design and operation is predicated on ensuring an adequate safety margin for safety-significant parameters (e.g., fuel cladding temperature, containment pressure, etc.) is provided over the spectrum of anticipated plant operating, transient and accident conditions. To meet the anticipated challenges associated with extending the operational lifetimes of the current fleet of operating NPPs, the United States Department of Energy (USDOE), the Idaho National Laboratory (INL) and the Electric Power Research Institute (EPRI) have developed a collaboration to conduct coordinated research to identify and address the technological challenges and opportunities that likely would affect the safe and economic operation of the existing NPP fleet over the postulated long-term time horizons. In this paper we describe a framework for developing and implementing a Risk-Informed Safety Margin Characterization (RISMC) approach to evaluate and manage changes in plant safety margins over long time horizons

The Role of Personality Factors in the Reduction of Intergroup Anxiety and Amelioration of Outgroup Attitudes via Intergroup Contact

Two studies investigated the role of personality factors in the amelioration of outgroup attitudes via intergroup contact. In study 1, the effect of extraversion on outgroup attitude operated via an increase in cross-group friendship, whereas openness to experience and agreeableness had a direct effect on outgroup attitude. In study 2, we included intergroup anxiety as a mediator explaining these relationships, and we ruled out ingroup friendship as a potential confound. We found that the relationships between openness to experience and agreeableness on the one hand and outgroup attitude on the other were mediated by reduced intergroup anxiety. In addition, the effect of extraversion on outgroup attitude operated via an increase in cross-group friendship that was in turn associated with lower levels of intergroup anxiety. Across both studies, the friendship-attitude relationship was stronger among those low in agreeableness and extraversion. We discuss the importance of integrating personality and situational approaches to prejudice reduction in optimizing the impact of contact-based interventions