An analysis of operational experience during low power and shutdown and a plan for addressing human reliability assessment issues

Abstract

Recent nuclear power plant events (e.g., Chernobyl, Diablo Canyon, and Vogtle) and U.S. Nuclear Regulatory Commission (NRC) reports (e.g., NUREG-1449) have led to concerns regarding human reliability during low power and shutdown (LP&S) conditions and limitations of human reliability analysis (HRA) methodologies in adequately representing the LP&S environment. As a result of these concerns, the NRC initiated two parallel research projects to assess the influence of LP&S conditions on human reliability through an analysis of operational experience at pressurized water reactors (PWRs) and boiling water reactors (BWRs). These research projects, performed by Brookhaven National Laboratory for PWRs, and Sandia National Laboratories for BWRs, identified unique aspects of human performance during LP&S conditions and provided a program plan for research and development necessary to improve existing HRA methodologies. This report documents the results of the analysis of LP&S operating experience and describes the improved HRA program plan.

Multidisciplinary framework for human reliability analysis with an application to errors of commission and dependencies

“…In the event descriptions in LERs, there was insufficient information to identify separate unsafe actions, or the existence of dependence mechanisms. The limitations in LER reports as a basis for HRA modeling were discussed in NUREG/CR-6093 (Barriere et al, 1994b).…”

“…Several necessary improvements to the HACS database (Barriere et al, 1994b), have been identified, related principally to the evolution of the project, our current understanding of human performance, and the associated unanticipated needs of research and development (e.g., framework, EOCs, and dependencies). Consequently, it is important to update and improve the structure of the database scheme and user-interface to support current and future work.…”

“…As documented in NUREG/CR-6093 (Barriere et al, 1994b), interest in improving HRA modeling intensified several years ago (1991) when the NRC/RES-sponsored PRAs for LP&S modes of operation were undertaken. NRC/RES recognized that the development of new or improved HRA methodologies were needed to better represent human performance and to increase the utility of PRAs to more realistically represent the risk associated with all modes of plant operation.…”

“…The accomplishments of the Assessment Phase (including details of the BNL and SNL parallel efforts and the program plan outline) were documented in NUREG/CR-6093, "An Analysis of Operational Experience During LP&S and A Plan for Addressing Human Reliability Assessment Issues" (Barriere et al, 1994b).…”

Human events reference for ATHEANA (HERA) database description and preliminary user`s manual

“…The first database, the Human Action Classification Scheme (HACS) (Barriere, Luckas, Whitehead, and Ramey-Smith, 1994) pre-dates ATHEANA. It was patterned on existing databases, including the Human Performance Investigation Process (HPIP) (Paradies, Unger, Haas, and Terranova, 1993) and the Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) (Gilbert, Gertman, and Gilmore, 1990) , so represented the commonly accepted aspects of human performance such as performance shaping factors (PSFs), event time phases, and error types.…”