An empirical study on the human error recovery failure probability when using soft controls in NPP advanced MCRs

• Published in: Annals of nuclear energy Vol. 73; pp. 373 - 381
• Main Authors: Jang, Inseok, Kim, Ar Ryum, Jung, Wondea, Seong, Poong Hyun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2014
• Subjects: Advanced MCR; Failure; Human; Human error; Mockups; Nuclear engineering; Nuclear power generation; Nuclear power plants; Recovery; Recovery failure probabilities; Soft control; Recovery failure probabilities; Advanced MCR; Soft control
• ISSN: 0306-4549; 1873-2100
• DOI: 10.1016/j.anucene.2014.07.004

•Many researchers have tried to understand human recovery process or step.•Modeling human recovery process is not sufficient to be applied to HRA.•The operation environment of MCRs in NPPs has changed by adopting new HSIs.•Recovery failure probability in a soft control operation environment is investigated.•Recovery failure probability here would be important evidence for expert judgment. It is well known that probabilistic safety assessments (PSAs) today consider not just hardware failures and environmental events that can impact upon risk, but also human error contributions. Consequently, the focus on reliability and performance management has been on the prevention of human errors and failures rather than the recovery of human errors. However, the recovery of human errors is as important as the prevention of human errors and failures for the safe operation of nuclear power plants (NPPs). For this reason, many researchers have tried to find a human recovery process or step. However, modeling the human recovery process is not sufficient enough to be applied to human reliability analysis (HRA), which requires human error and recovery probabilities. In this study, therefore, human error recovery failure probabilities based on predefined human error modes were investigated by conducting experiments in the operation mockup of advanced/digital main control rooms (MCRs) in NPPs. To this end, 48 subjects majoring in nuclear engineering participated in the experiments. In the experiments, using the developed accident scenario based on tasks from the standard post trip action (SPTA), the steam generator tube rupture (SGTR), and predominant soft control tasks, which are derived from the loss of coolant accident (LOCA) and the excess steam demand event (ESDE), all error detection and recovery data based on human error modes were checked with the performance sheet and the statistical analysis of error recovery/detection was then carried out to obtain the recovery failure probabilities.