Computer-based procedures for nuclear power plant field workers: Design implications based on three evaluation studies

Procedures guide nearly all activities in a nuclear power plants; including control room operations and tasks carried out in the field such as surveillances, lockout tag out, and maintenance activities. These procedures are still executed using a paper-based process, which fails to take advantage of efficiencies that can be gained by transitioning to a computer-based procedure system. Computer-based systems have many potential advantages such as the ability to provide context-sensitive instructions that incorporate plant mode, equipment state, and other relevant conditions. Further, the CBP system can automate placekeeping, correct component verification, calculations, and provide access to relevant supporting information such as drawings, supplemental instructions, or just-in-time-training from within the procedure system. Although the potential advantages of CBP systems are clear, it is important to understand the impact that introducing such a technology may have before implementing them in plants. Technology often changes a human's task in unintended and unanticipated ways, and some of the consequences may cause errors rather than prevent them. A thorough understanding of these issues may help to mitigate any negative consequences so that the benefits of CBPs can be fully achieved. Researchers at Idaho National Laboratory (INL) have developed a CBP prototype for the purpose of investigating the impact of computer-based procedures on human performance, and developing human factors design guidance on the interface and interaction design. The researchers have conducted a series of three evaluation studies comparing CBP use to traditional paper based procedures. The evaluation studies took place at two partnering utilities where field workers conducted realistic proceduralized tasks using the CBP system. This paper describes the prototype development, the three studies, and the results of the three studies. Implications for CBP design are discussed.