Dr. L. C. Geary
Westinghouse Savannah River Company
Aiken, SC 29808

Keywords: Human Factors Engineering, Human System Interface, NUREG-0700, Software Tool, Cost Reduction

The Westinghouse Savannah River Company, a contractor to the Department of Energy, has developed a new software tool for automating the Human Factors Engineering design review, analysis, and evaluation processes. The set of design guidelines, used in the tool, was obtained from the United States Nuclear Regulatory Commission Nuclear Regulatory Guide, NUREG- 0700 – Human System Interface Design Review Guideline. This tool has been described at a previous IEEE Conference on Human Factors and Power Plants. The original software tool in NUREG- 0700 was used to evaluate a facility and a separate independent evaluation was performed using the new tool for the same facility. A comparison was made between the two different tools; both in results obtained and cost and time to complete the evaluation. The results demonstrate a five to ten fold reduction in time and cost to complete the evaluation using the newly developed tool while maintaining consistent evaluation results. The time to perform the review was measured in weeks using the new software tool rather than months using the existing NUREG-0700 tool. The new tool has been so successful that it was applied to two additional facilities with the same reduced time and cost savings. Plans have been made to use the new tool at other facilities in order to provide the same savings.

It is the desire of all operating Process Control facilities to operate in an efficient and cost effective manner. The high priced supplier is doomed to extinction. One of the ways to reduce cost of facility operations is to replace present control rooms with modern human engineered control rooms. This paper will demonstrate how, with the use of a new Human Factors Engineering tool, a quick and cost effective review and analysis of the control room can be made. A review using this tool can be made on present control rooms even when an upgrade is not being planned or implemented. Examples of the software tool used to implement NUREG-0700 and a newly developed tool will be presented and comparisons of the effectiveness of these tools.

It is not the intention of this paper to describe previous Human Factors Guides IEEE #845 [1], #1023 [2], #1046 [3], and #1289 [4], nor NUREG-0700 [5] but to describe a tool developed and used by Westinghouse Savannah River Company to reduce the time and cost to perform a Human Factors Engineering analysis of control rooms. In particular, three facilities recently replaced and/or enhanced their control rooms. In all three cases, Windows based monitors were installed with high resolutions graphics. A mouse/trackball was the interface with the operator with limited keyboard actions. The keyboard is used to enter numerical information only, e.g. set points, alarm levels, etc. Two different Distributed Control System (DCS) suppliers implemented the upgraded and enhanced control rooms. In all three facilities graphical displays were utilized to depict the facility, its major sub-systems, and the process flow of material through the facility. In addition to the graphics, each monitor provided alarm display capability, trends, control actions, set point changing, and other normal control functions.

The importance of a well-designed human-system interface (HSI) to achieve reliable human performance and maintain plant safety is widely acknowledged. One of the first insights from studies of the Three Mile Island (TMI) accident was that errors resulting from human factors deficiencies in the control room were a significant contributing factor to Nuclear Power Plant (NPP) incidents and accidents. One significant outgrowth of the accident with respect to the human-system interface design was that the U.S. Nuclear Regulatory Commission (NRC) required all licensees and applicants for commercial NPP operating licenses to conduct detailed control room design reviews, including reviews of remote shutdown panels, to identify and correct human factors design deficiencies. Extensive guidelines published as NUREG-0700, "Guidelines for Control Room Design Reviews" (NRC, 1981b), were prepared in support of these reviews. Based on the above and the fact that the Savannah River Site is a nuclear facility, NUREG-0700 was used as a benchmark for Human Factors Engineering reviews.

NUREG-0700, Rev. 1, provides the Human Factors Engineering (HFE) guidelines, which can be used to review a specific HSI design and/or implementation. The HFE review guidelines address both advanced and conventional HSIs. The general contents of the individual sections of the guidelines are:

1. Information Display
2. User-System Interaction
3. Process Control and Input Devices
4. Alarms
5. Analysis and Decision Aids
6. Inter-Personnel Communication
7. Workplace Design
8. Local Control Stations

Although not all industries are required to use NUREG-0700, it does provide a baseline by which facilities can use to substantiate their control room designs and implementation, especially when queried by their respective regulatory agencies.

In 2001, a Wastewater Treatment Facility replaced its system consoles and data historian. As part of this upgrade, a Human Factors Engineering evaluation was performed to evaluate compliance with the Nuclear Regulatory Commission guidelines, NUREG 0700, Revision 1 utilizing the software tool provided with NUREG-0700. This review included plant graphic displays, linking between the displays, trending functions, alarm handling and display, error messages, control functions, event history, point select, system status, and any other general operations and functionality of the interface. This control system has greater than 40 graphical displays, greater than 350 controllers, multiple alarm displays, other operational aids and approximately 1300 I/O points. This review, per NUREG-0700, included 1648 guidelines. Of the 1648 guidelines, 496 were excluded during the preliminary review because they were not applicable to the upgrade project scope. Areas excluded were conventional control devices, speech-based communication, workplace design, and local control stations. Workplace design was excluded because a separate ergonomic study was performed on the existing control room. Workstation consoles were replaced as a result of this study.

The remaining 1152 guidelines were then used to review and validate the Wastewater Treatment Facility Upgrade Project for compliance. During this more intense review, an additional 415 guidelines were determined to be "NOT APPLICABLE", leaving 737 guidelines for the final evaluation. From the 737 guidelines, 670 were classified "OK" and therefore in compliance with the Guideline.

The number of criteria evaluated and discrepancies identified for each of the above eight major sections and associated sub-sections are shown in Attachment 1. In addition, the number of discrepancies and percent discrepancy within each section and sub-section are listed. Five sub-sections with percent deficiencies greater than 10% are highlighted in gray. A summary of the detail listing of Attachment 1 is shown below.

	NUREG 0700 Sections	Number of Criteria Evaluated	Number of Discrepancies Identified	% of Criteria with Discrepancies
Section
1	INFORMATION DISPLAY	322	21	7%
2	USER-SYSTEM INTERACTION	512	34	7%
3	PROCES CONTROL AND INPUT DEVICES	104	2	2%
4	ALARMS	149	10	7%
5	ANALYSIS AND DECISION AIDS		excluded
6	INTER-PERSONNEL COMMUNICATION	47	0	0%
7	WORKPLACE DESIGN		excluded *
8	LOCAL CONTROL STATIONS		excluded
	TOTAL	1152	67	6%

* - See information in text above for the exclusion reason

Attachment 2 identifies for each of the 67 discrepancies, the guideline number and associated description with the recommended action and implementation priority. This detail listing is summarized below.

The time required to perform this review and analysis, including interviewing and interfacing with operations and developer personnel was between four and five months.

A new tool utilizing the same NUREG-0700 Guidelines has been developed and has been previously presented [6]. Since this tool is based on the NUREG-0700 Guidelines, it is applicable to all types of control rooms – from panel boards to graphical based workstations. However, this tool has the benefit of eliminating many of the guidelines based on the type of control system classification and implementing technology. Specifically, whether the control system is safety based or non-safety based and whether the implementing technology is computer based or non-computer based. In addition specific guidelines were added for company specific procedures and standards. Finally, the tool allows four responses: Compliant, Not Applicable, Discrepancy-Use As Is, and Discrepancy-Modify to Comply; Analysis Required. The tool also statuses ones progress in the review process indicating one of the four above or either Not Statused or on Hold pending further review.

This new tool was utilized to perform the review on the same Wastewater Treatment Facility described above. Since this facility implemented a non-safety computer based HMI, the number of review questions was reduced from 1648 to 620. The remaining 620 guidelines were then used to review and validate the Wastewater Treatment Facility Upgrade Project for HFE compliance. During this more intense review, the following provides a summary of this review:

• 304 - "Compliant"
• 272 - "Not Applicable"
• 24 - "Discrepancy-Use As Is"
• 20 - "Discrepancy-Modify to Comply; Analysis Required"

The number of discrepancies differs from the first review because the new tool eliminates redundant and obsolete guidelines and reduces the number of questions from 1648 to 1471.

The time to complete this review was between three and four weeks.

A second facility, a Laboratory Information Management System, was reviewed and analyzed utilizing the new tool. Here again, the facility implemented a non-safety computer based HMI, and therefore the number of review questions was reduced. In this case the number of questions was reduced from 1648 to 542. The lower number, 542 versus 620 in the first facility, is because this second facility is less complex than the first. The following provides a summary of this review:

• 325 - "Compliant"
• 189 - "Not Applicable"
• 20 - "Discrepancy-Use As Is"
• 8 - "Discrepancy-Modify to Comply; Analysis Required"

This control system has greater than 30 graphical displays, 12 controllers, multiple alarm displays, other operational aids, and 400 I/O points. This review was completed in less than one month.

Finally a third facility, a batch mixing process to solidify low level waste, was reviewed and analyzed utilizing the new tool. This control system has greater than 25 graphical displays, greater than 50 controllers, multiple alarm displays, other operational aids and approximately 350 I/O points. Here again, the facility implemented a non-safety computer based HMI, and therefore the number of review questions was reduced from 1648 to 620. During this more intense review, the following provides a summary of this review:

• 372 - "Compliant"
• 224 - "Not Applicable"
• 22 - "Discrepancy-Use As Is"
• 2 - "Discrepancy-Modify to Comply; Analysis Required"

Competing this review required less than two weeks. Although, this review only documented the discrepancies it does demonstrate the efficiency of the newly developed tool.

Based on the results of the use of the newly developed software tool for Human Factors Engineering Evaluation, it has been demonstrated that a reduction of the review, analysis, and evaluation time from months to weeks with an efficiency factor from five to ten can be realized. In addition, consistent evaluation results are maintained because the same NUREG-0700 criteria are used.

Based on my experience using the tool three times, it is simple to use, with easy navigation and sorting capabilities, and flexible report generation.

1. IEEE Guide to Evaluation of Man-Machine Performance in Nuclear Power Generating Station Control Rooms and Other Peripheries, IEEE Std 845-1988, March 10, 1988.
2. IEEE Guide for the Application of Human Factors Engineering to Systems, Equipment, and Facilities of Nuclear Power Generating Stations, IEEE Std 1023-1988, December 12, 1988.
3. IEEE Application Guide for Distributed Control and Monitoring for Power Plants, IEEE Std 1046-1991, October 25, 1991.
4. IEEE Guide for the Application of Human Factors Engineering in the Design of Computer-Based Monitoring and control Displays for Nuclear Power Generating Stations, IEEE Std 1289-1998, May 27,1998.
5. NUREG-0700, Human-System Interface Design Review Guideline, Rev. 1, Vol. 1 & 2, June, 1996.
6. Charles R. Mastromonico and Richard D. Izard, Automating the Human Factors Engineering and Evaluation Processes, Proceedings of the 2002 IEEE Seventh Conference on Human Factors and Power Plants, September 15-19, 2002, IEEE Cat. No.: 02CH37355; ISBN: 0-7803-7450-9.