Application of phenomenological calculations to the N Reactor probabilistic risk assessment

A deterministic phenomenological calculation generates only a single best estimate result. However, probabilistic risk assessment (PRA) accident progression calculations require phenomenological data in the form of probability distributions. A three step process, to provide such distributions, consisting of issue identification, deterministic calculation specification, and the use of expert judgment to interpret the results, is described in this paper. The results of a sample expert judgment elicitation from the N Reactor PRA are included to demonstrate how the uncertainties associated with deterministic calculations are accounted for in the final probability distributions that are based on those calculations. 6 refs., 2 figs., 3 tabs