Publications

A phenomena identification and ranking table (PIRT) exercise for nuclear power plant fire model applications

Nowlen, Steven P.; Olivier, Tara J.; Dreisbach, Jason; Salley, Mark H.

This paper summarizes the results of a Phenomena Identification and Ranking Table (PIRT) exercise performed for nuclear power plant (NPP) fire modeling applications conducted on behalf of the U.S. Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research (RES). A PIRT exercise is a formalized, facilitated expert elicitation process. In this case, the expert panel was comprised of seven international fire science experts and was facilitated by Sandia National Laboratories (SNL). The objective of a PIRT exercise is to identify key phenomena associated with the intended application and to then rank the importance and current state of knowledge of each identified phenomenon. One intent of this process is to provide input into the process of identifying and prioritizing future research efforts. In practice, the panel considered a series of specific fire scenarios based on scenarios typically considered in NPP applications. Each scenario includes a defined figure of merit; that is, a specific goal to be achieved in analyzing the scenario through the application of fire modeling tools. The panel identifies any and all phenomena relevant to a fire modeling-based analysis for the figure of merit. Each phenomenon is ranked relative to its importance to the fire model outcome and then further ranked against the existing state of knowledge and adequacy of existing modeling tools to predict that phenomenon. The PIRT panel covered several fire scenarios and identified a number of areas potentially in need of further fire modeling improvements. The paper summarizes the results of the ranking exercise.