Use of expert judgement in the HLW regulatory program: US NRC staff draft guidance

As with other licensing decisions, the U.S. Nuclear Regulatory Commission's (NRC's) decision to grant or deny a license for a proposed repository at Yucca Mountain will be based on a combination of fact and judgment as set forth by the Department of Energy (DOE) in a license application. Subjective judgments of individual experts and, in some cases, groups of experts will be used by DOE to interpret data obtained during site characterization and to address the many technical issues and inherent uncertainties associated with predicting repository performance for thousands of years. The NRC has traditionally accepted expert judgment to evaluate and interpret the facts which support a license application. Recently, the Performance Assessment and High-level Waste Integration Branch of the NRC has developed regulatory guidance in the form of a draft branch technical position (BTP) that identifies circumstances which may warrant the use of a formal process for obtaining the judgments of more than one expert (i.e. expert elicitation) and describes acceptable procedures for conducting such expert elicitations