Development of a risk screening method for credited operator actions

The US Nuclear Regulatory Commission (NRC) reviews the human factors aspects of proposed license amendments that impact human actions that are credited in a plants safety analysis. The staff is committed to a graded approach to these reviews that focus resources on the most risk-important changes. Therefore, a risk-informed screening method was developed based on an adaptation of existing guidance for risk-informed regulation and human factors. The method uses both quantitative and qualitative information to divide the amendment requests into different levels of review. The method was evaluated using a variety of tests. This paper summarizes the development of the methodology and the evaluations that were performed to verify its usefulness.