Deterministic criteria versus probabilistic analyses: examining the single failure and separation criteria

The primary purpose of design requirement criteria for reactor safety systems is to better ensure the adequacy of safety system design, the single failure and separation criteria being cases in point. However, strict adherence to these two criteria may actually result in a less than optimal design in terms of system reliability. Working within the spirit of these criteria, an integration of probabilistic analyses into the licensing review process for safety system design would result in a more reliable system, which is the intent of deterministic criteria