Bruce P. Hallbert

Advantages and disadvantages of physiological assessment for next generation control room design

We propose using non-obtrusive physiological assessment (e.g., eye tracking,) to assess human information processing errors (e.g., loss of vigilance) and limitations (e.g., workload) for advanced energy systems early in the design process. This physiological approach for assessing risk will circumvent many limitations of current risk methodologies such as subjective rating (e.g., rater’s biases) and performance modeling (e.g., risk assessment is scripted and is based upon the individual modeler’s judgment). Key uses will be to evaluate (early in the design process) novel control room equipment and configurations as well as newly developed automated systems that will inevitably place a high information load on operators. The physiological risk assessment tool will allow better precision in pinpointing problematic design issues and will provide a “real-time” assessment of risk. Furthermore, this physiological approach would extend the state-of-the-art of human reliability methods from a “static” measure to more “dynamic.” This paper will discuss a broad range of the current popular online performance gauges as well as its advantages and disadvantages for use in next generation control room.

The Use of Empirical Data Sources in HRA

Abstract This paper presents a review of available information related to human performance to support Human Reliability Analysis (HRA) performed for nuclear power plants (NPPs). A number of data sources are identified as potentially useful. These include NPP licensee event reports, augmented inspection team reports, operator requalification data, results from the literature in experimental psychology, and the Aviation Safety Reporting System. The paper discusses how utilizing such information improves our capability to model and quantify human performance. In particular, the paper discusses how information related to performance shaping factors can be extracted from empirical data to determine their size effect, their relative effects, as well as their interactions. The paper concludes that appropriate use of existing sources can help addressing some of the important issues we are currently facing in HRA.

Capturing control room simulator data with the HERA System

The Human Event Repository and Analysis (HERA) system has been developed as a tool for classifying and recording human performance data extracted from primary data sources. This paper reviews the process of extracting data from simulator studies for use in HERA. Simulator studies pose unique data collection challenges, both in types and quality of data measures, but such studies are ideally suited to gather operator performance data, including the full spectrum of performance shaping factors used in a HERA analysis. This paper provides suggestions for obtaining relevant human performance data for a HERA analysis from a control room simulator study and for inputting those data in a format suitable for HERA.

HUMAN ERRORS DURING THE SIMULATIONS OF AN SGTR SCENARIO: APPLICATION OF THE HERA SYSTEM

Due to the need of data for a Human Reliability Analysis (HRA), a number of data collection efforts have been undertaken in several different organizations. As a part of this effort, a human error analysis that focused on a set of simulator records on a Steam Generator Tube Rupture (SGTR) scenario was performed by using the Human Event Repository and Analysis (HERA) system. This paper summarizes the process and results of the HERA analysis, including discussions about the usability of the HERA system for a human error analysis of simulator data. Five simulated records of an SGTR scenario were analyzed with the HERA analysis process in order to scrutinize the causes and mechanisms of the human related events. From this study, the authors confirmed that the HERA was a serviceable system that can analyze human performance qualitatively from simulator data. It was possible to identify the human related events in the simulator data that affected the system safety not only negatively but also positively. It was also possible to scrutinize the Performance Shaping Factors (PSFs) and the relevant contributory factors with regard to each identified human event.

Simplified plant analysis risk (SPAR) human reliability analysis (HRA) methodology: Comparisons with other HRA methods

The 1994 Accident Sequence Precursor (ASP) human reliability analysis (HRA) methodology was developed for the U.S. Nuclear Regulatory Commission (USNRC) in 1994 by the Idaho National Engineering and Environmental Laboratory (INEEL). It was decided to revise that methodology for use by the Simplified Plant Analysis Risk (SPAR) program. The 1994 ASP HRA methodology was compared, by a team of analysts, on a point-by-point basis to a variety of other HRA methods and sources. This paper briefly discusses how the comparisons were made and how the 1994 ASP HRA methodology was revised to incorporate desirable aspects of other methods. The revised methodology was renamed the SPAR HRA methodology.

Human factors issues for multi-modular reactor units

Smaller and multi-modular reactors (MMR) will be highly technologically-advanced systems allowing more system flexibility to reactor configurations (e.g., addition/removal of reactor units). While the technical and financial advantages of such systems may be numerous, MMR presents many human factors challenges that may pose vulnerabilities to plant safety. An important human factors challenge in MMR operation and performance is the monitoring of data from multiple plants from centralized control rooms where human operators are responsible for interpreting, assessing, and responding to different system states (e.g., simultaneously monitoring refueling at one plant while vigilant to another plant’s normal operating state). Furthermore, the operational, safety, and performance requirements for MMR can significantly change current staffing models and roles, the mode in which information is displayed, and the approach for conducting procedures and training. Consequently, addressing human factors concerns in MMR is essential in reducing plant risk.

Using Information from Operating Experience to Inform Human Reliability Analysis

This paper reports on efforts being sponsored by the U.S. NRC and performed by INEEL to develop a technical basis and perform work to extract information from sources for use in HRA. The objectives of this work are to: 1) develop a method for conducting risk-informed event analysis of human performance information that stems from operating experience at nuclear power plants and for compiling and documenting the results in a structured manner; 2) provide information from these analyses for use in risk-informed and performance-based regulatory activities; 3) create methods for information extraction and a repository for this information that, likewise, support HRA methods and their applications.

Developing static information displays: a case study on improving worker safety

A case study of a human factors effort to improve information displays at the Department of Energys Rocky Flats Plant is presented. The posted displays convey information about controls on process variables which are necessary to ensure safe operations. An independent assessment of criticality safety at this facility determined that human performance is key to achieving safety in processes involving fissile material and that analyses on its improvement were needed. Reviews conducted of past infractions and a sample of postings identified problems with legibility, complexity, readability, saliency, and usability. A discussion of issues related to each problem area and a comparison with applicable literature is offered. An improvement project was conducted which developed candidate display formats, and the results of efforts undertaken.<<ETX>>

Development of Job Performance Aids to Increase Human Performance Reliability: A Case Study in the Evaluation of Human Factors Principles

A study of criticality safety, commissioned by the U.S. Department of Energy, was conducted by Scientech Inc. at the Rocky Flats nuclear weapons facility. The study concluded that human performance is the driving factor in the risk of an inadvertent criticality incident at the Rocky Flats Plant (RFP). A study of the infractions which have occurred at this facility bears this point out. A human factors team was established to identify a means of reducing human error in every day operations. The team determined that the posted instructions near each work area are key to operators having a clear understanding of operating requirements. An evaluation of the posted instructions revealed that they were very complex, required operators to monitor multiple parameters, and resulted in the operators” attention being divided between operational tasks and the task of monitoring nuclear safety parameters. Alternative graphics, textual, and graphics and textual formats combined with color coding were developed to improve comprehensibility, understandability, controllability, and usability in the Job Performance Aids (JPAs). Results of field tests of the different formats provide clear indication that operators prefer short, concise textual statements summarizing important information over both other formats. Although operators indicated interest in the graphics formats, the magnitude of change in presentation techniques and the generalizability of the icons argued against their immediate use. Issues in the development of candidate JPAs and other usability requirements are discussed.

Advanced Instrumentation, Information, and Control Systems Technologies Technical Program Plan for 2014

Reliable instrumentation, information, and control (II&C) systems technologies are essential to ensuring safe and efficient operation of the U.S. light water reactor (LWR) fleet. These technologies affect every aspect of nuclear power plant (NPP) and balance-of-plant operations. In 1997, the National Research Council conducted a study concerning the challenges involved in modernization of digital instrumentation and control systems in NPPs. Their findings identified the need for new II&C technology integration.