Using a Power Plant Simulator to Enhance Human Factors Engineering Research

Today’s nuclear power industry is keen on collaboration. We count on government, university, and privately funded research to continually study how new technology and design affect safe, reliable operations and plant performance.

The nuclear industry is the largest source of zero-carbon energy. With its ability to provide on-demand baseload power, it is receiving more recognition and funding for research and development activities. The U.S. Department of Energy recently launched the GAIN (Gateway for Accelerated Innovation in Nuclear) initiative with an initial investment of $82 million and plans to invest more with the goal of advancing nuclear technology. Programs such as GAIN are designed to help the nuclear community conduct research, development and demonstration (RD&D). The goal is to reduce the risk of commercial deployment of new technologies and the time to bring them to market.

For a long time, research institutes have been performing human-factors research with pen and paper algorithms. Recently, a growing number of forward-thinking organizations have begun to utilize simulation as part of a complete human factors engineering (HFE) study. With the simulator serving as a “Virtual Plant”, researchers are provided with a dynamic platform. This enables them to test theories and develop tangible, validated results in a true-to-life environment.

Why do we need to study human factors engineering (HFE)?

Our industry is always striving to advance the safe operation of existing and new complex technical systems. We recognize, from evaluation of past events, the root cause is often a combination of human error, failure in technical systems, and/or organizational conditions. Safety can be enhanced by understanding and improving on the relationship between operators and technical systems within an organizational environment. This is the investigational theory Man-Technology-Organization (MTO) proposed by OECD Halden Reactor Project (Halden).

Most of the world’s nuclear power plants were built between 1967-1990. These Gen II and Gen III reactors are now or will soon be undergoing plant modernization projects that will fundamentally change the way operators view and interact with plant controls. These new “hybrid” control rooms introduce digital instrumentation and controls (I&C), large screen displays, advanced alarm systems, computerized procedures, and control room design for which best practices still need to be defined. Gen IV and beyond reactor designs will be working with future Human System Interface (HSI) technologies to be designed around users who aren’t even born yet. These future plant operators and engineers will be entirely unfamiliar with hard panel displays and digital control rooms will become the norm.

Other human factors engineering benefits exist in the form of testing performance efficiency with conventional versus innovative display features. Utilizing HFE findings, plants can increase efficiency in line with our industry’s strategic plan of Delivering the Nuclear Promise. This is an industry-wide initiative to ensure the commercial viability of nuclear power by increasing efficiency.

While the nuclear industry is undergoing a renaissance of new reactor technology and design innovations, we are still responding to lessons learned from the Fukushima event. Determining better ways to train and prepare operators for beyond design basis events is a high priority. Human factors engineering studies are being performed to determine how and why operators take the actions that they do and what changes can be made to the control displays. These changes would enable operators to make more effective decisions, faster.

How Simulation Can Enhance HFE Research Techniques

Data is a researcher’s friend. However, the simulator’s ability to run an unlimited number of scenarios, as many times as required, can collect a seemingly insurmountable amount of data to wade through. Here’s a tip from a seasoned HFE expert, “Start with simple, observable phenomena, and then gradually increase the types of measures as warranted by the study.”

The goal of human factors engineering studies is to optimize human and overall system performance through better situational awareness. A full-scope simulator provides a safe, reliable environment to carry out HFE studies. By performing, revising and further testing experiments on a fully operational nuclear power plant simulator, researchers can be confident that their results are valid in the real world.

Various human factors engineering (HFE) options to be studied:

• Human Reliability Analysis (HRA)
• Human System Interfaces (HSI) and Control Room Design & Evaluation
• Human Performance Measures

Human Reliability Analysis (HRA)

HRA is part of a complete probabilistic risk assessment (PRA) and is used to determine the potential for and probability of human failure events. Using a full-scope simulator, researchers are able to test and refine their techniques for validating HRA models. Including HRA data in an HFE study allows researchers to better focus on the scenarios, actions and interfaces identified as having the most potential for human failure.

Human System Interfaces (HSI) and Control Room Design & Evaluation

Nearly all US plants are ‘hybrids’ of digital and analog I&C. Our industry expects the use of digital I&C to increase significantly because it has key advantages over its analog counterparts. Digital I&Cs are easy to modify, offers greater precision and has reduced maintenance costs. The changes in HSI and control room design that accompanies these digital I&C upgrades need to be fully vetted for safety and efficiency.

Researchers need an environment to support the design, development and assessment of highly-integrated digital control rooms. Utilizing a full-scope simulator, researchers can put licensed operators into the driver seat of an operational nuclear power plant during normal, abnormal, and emergency operations to evaluate prototype HSI. The simulator also enables researchers to test HSI concepts and alternative approaches for future Gen IV plants.

Tying a full-scope replica simulator to large screen overview displays allows researchers at Halden to provide and test HSI concepts such as:

• Common frame of reference
• Overview panel
• Alerts
• Zones (safety, main process and auxiliary systems)
• Computerized procedures and procedures on hand-held devices
  – Innovative workstation displays
• Task based
• Function oriented
• Ecological
• Methods to reduce the keyhole effect

Human Performance Measures

Human performance undoubtedly has a strong correlation to nuclear power plant safety and efficiency; however, it can be difficult to assess. The ability to rerun scenarios on a simulator enables researchers to evaluate human performance measures against plant changes, be it organizational or plant design changes.

Dr. Nathan Lau of Virginia Tech’s Department of Industrial and Systems Engineering utilizes a full-scope PWR plant simulator to perform human performance measurement studies in a representative setting most relevant to the US nuclear industry.

The human performance measures assessed in conjunction with the plant simulator for Virginia Tech’s HFE study included:

Established Measures

• Plant performance (parameter logs)
• Task performance (event and operator action logs)
• Workload
• Self-Rating
• Process overview measure

Physiological Measures

Measurements and observations of the physiological effects of a variety of scenarios and actions on various plant personnel including Unit Supervisors, Reactor Operators (RO) and Balance of Plant (BOP) Operators.

• Eye-tracking glasses with respect to event difficulty, situational awareness (SA) and task performance
• Galvanic skin response/perspiration with respect to event difficulty, workload and task performance
• Respiration/Breathing rate with respect to event difficulty, workload and task performance

Conclusion

The nuclear power industry is serious about its responsibility to increase efficiency and ensure the safe operation of existing plants and new reactor designs. As researchers work hard to help our industry meet its goals, many are using a full-scope simulator for their human factors engineering research.

Are you using the best tools available to run your scenarios and validate your theories?  Consider a full-scope generic PWR with unlimited flexibility and configurability for performing HFE/HSI research to help move your work to the next level.