Human Performance Technology and the Accident at Three Mile Island
by
William H. Lowthert, Ph.D.
AIP Associates
mailto:BillisImproving@aol.com
home page: http://www.alwaysimproving.com/
ã William H. Lowthert, 1994

Companies operating nuclear power plants in the United States have invested heavily in human performance technology to improve the safety of nuclear operations. Many of these human performance technology investments were a direct result of lessons learned from the accident at the Three Mile Island Nuclear Power Plant (TMI). Prior to 1979 the American nuclear industry did not provide sufficient investment in human performance technology. Training was inadequate. Operating experiences were not shared. Operators had limited opportunity to experience simulation of plant operations. Often the simulation was not technically accurate.

Now American nuclear plants use effective human performance technology applications to achieve nuclear safety and high electric production. The nuclear industry and the National Academy for Nuclear Training have implemented performance based training programs through an industry wide accreditation program. All American nuclear plants have achieved accreditation of their training programs (Coakley, 1991). Nuclear plant staffs have become learning organizations by using operating experience from their own and other plants to identify potential operating problems. This program is coordinated by the Institute of Nuclear Power Operations (1989). Technically accurate control room simulations are in use at 82 American nuclear plant training centers (Smith, 1991).

The expanding demands of complex technologies outside the nuclear power industry bring new benefits, potential hazards, and additional human performance challenges. Industries using complex technologies could learn from historical research into the human performance technology related causes of the TMI accident. This research identified three areas of weakness in human performance technology that contributed to the TMI accident: training, learning from operating experience, and simulation.

On March 28, 1979 the most serious accident in the history of commercial nuclear power in the United States occurred at Unit 2 of the Three Mile Island Nuclear Plant. Even though environmental and radiological consequences were minor, the economic consequences were great (Kneif, 1992, p. 423). TMI unit 2 was unusable. Clean up costs were nearly one billion dollars. The plant's owner, the Metropolitan Edison Company, was prohibited from operating the undamaged reactor at TMI unit 1 for four and one-half years. The entire nuclear industry incurred extensive costs for plant modifications, staff increases, and administrative changes (Kneif, 1992, p. 442- 444). These changes included substantial improvements in human performance technology including establishing the Institute for Nuclear Power Operations and the National Academy for Nuclear Training.

Investigations of the accident on behalf of the President of the United States (Kemeny, 1979), and the Nuclear Regulatory Commission (Rogovin & Frampton, 1980) indicated that although the accident was initiated by equipment malfunctions, safety equipment operated properly to protect the public. The accident was made worse by human error and ineffective preparation. Human performance technology failed the operators.

Between January 1971 and March 1979 the nuclear industry experienced continual growth. Many large nuclear generating projects were started. More sophisticated equipment was installed and the knowledge required of operators and managers increased. There was a lack of trained and trainable personnel for the expanding nuclear industry. The competition for experienced nuclear personnel was increasing. The need for training was identified, but most nuclear companies did not increase the training effort as the size and complexity of the plants increased (Parker, 1979).

During this period nuclear training was primarily concerned with meeting the requirements of the Code of Federal Regulations (Barge, 1979). This law mandated the content of training programs for reactor operators and reactor operations supervisors (Flemming, 1979; Mau, 1979). It required proof that an operator had learned to operate the controls of the reactor. The Code of Federal Regulations (1976), the Standard for Selection and Training of Nuclear Power Plant Personnel (ANSI, 1971), and the Nuclear Regulatory Commission Operator Licensing Guide (NRC, 1976) identified the majority of the nuclear training efforts prior to 1979 (Flemming, 1979; Mau, 1979).

The Metropolitan Edison Company met all the requirements of The Code of Federal Regulations and the existing industry standards. When this training was challenged by a demanding situation, it proved to be inadequate (Rogovin & Frampton, 1980, p. 104; Kemeny, 1979, pp., 49-50). Inadequate training was not the fault of the Metropolitan Edison Company alone. Training in the entire nuclear industry was deficient (Rogovin & Frampton, 1980, p. 104). Training was a minor function of nuclear plant management. Training departments were understaffed both quantitatively and qualitatively. Supervisors, rather than professional trainers performed the majority of nuclear plant training (Flemming, 1979; Mau, 1979). The training staffs at nuclear power plants were small and grew slowly (Harris, 1979; Enzor, 1979; Flemming, 1979; Mau, 1979). Nuclear trainers felt that a training staff of eight full time instructors was too large to justify to company management (Harris, 1979).

In 1971 the American National Standard for Selection and Training of Personnel for Nuclear Power Plants was issued by The American National Standards Institute (ANSI, 1971) to provide criteria concerning training and qualification of nuclear power plant personnel. The standard provided guidance concerning training, but was not intended to take precedence over any government regulation. It relied heavily on experience gained at university reactors, government reactor facilities and navy nuclear powered ships (Palmer, 1979).

Compliance with this standard required the utility to develop and schedule a training program that would help ensure safe operation of the plant (ANSI, 1971, p. 9). It stated specific technical subjects that must be taught to reactor operators and their supervisors. These subjects included principles of reactor operation, safety, emergency systems, and radiation control. There was no requirement for formal technical training for craft and technical personnel. The standard discussed on-the-job training, participation in the initial plant startup program, or formal technical training as possible learning activities. Managers, supervisors, and professional personnel not requiring an Atomic Energy Commission operator license were not required to attend technical training about the plant at which they were employed. The only formal training required for personnel other than reactor operators and operations supervisors was General Employee Training. This general training was assigned to all regularly employed persons at the nuclear plant. It consisted of training in industrial and radiation safety, security procedures, and other administrative plans and procedures (ANSI, 1971, p. 10).

The American Nuclear Society revised the national standard for training of nuclear power plant personnel in 1978. This new standard increased the experience criteria for assignment to certain nuclear plant positions but did not increase any training requirements (Palmer, 1979; ANSI, 1978).

Inadequate training of personnel contributed significantly to the accident (Kemeny, 1979, p 49; Rogovin and Frampton, 1980, p 102). The plant owner, Metropolitan Edison, had the responsibility for training. Their training programs were low in quality and inadequate in scope (Kemeny, 1979, p, 50). The major learning activities of this training program were self-study, reading, and classroom instruction. The TMI training program did not emphasize principles of reactor safety (Kemeny, 1979,p, 49). It did not teach sufficient engineering and physics principles for operators to understand the thermal-hydraulic characteristics of the reactor system (Rogovin and Frampton, 1980, p. 104). This training did not emphasize the problems created when abnormal conditions occur in the reactor core as happened during the accident (Kemeny, 1979, pp. 43-44). TMI operators were trained only for normal power operations, not for accidents (Rogovin and Frampton, 1980, p. 103). There was no comprehensive on the job evaluation of operator performance to ensure the operators had the knowledge to operate the plant safely (Kemeny, 1979, p. 47).

According to The President's Commission on TMI, The Nuclear Regulatory Commission contributed to the accident because they did not prescribe a high enough standard for operator training, they did not require minimum training or education requirements for operators, and they did not provide qualification criteria for instructors and supervisors performing operator training (Kemeny, 1979, p. 49). The NRC required only a limited amount of engineering and physics training for reactor operators (Rogovin and Frampton, 1980, p. 104).

The NRC Office of Nuclear Reactor Regulation's Lessons Learned Task Force recommended that operations shift supervisors receive training that will "emphasize and reinforce the responsibility for safe operation" (NRC, 1979, NUREG-0578, p. A-48). They indicated that training and qualification of nuclear operations personnel was among the most important factors in reactor safety. Training for personnel other than reactor operators was also addressed. Utilities were required to review training programs for all personnel including maintenance and technical personnel to verify that their training was sufficient to ensure reactor safety. The suggested method for review was to perform a task analysis for the position, compare the present training program to the tasks performed by the position, and identify any tasks that are not included in the training program. The lessons learned report included a recommendation to include the expertise of professional educators in nuclear training programs. Corporate management involvement in training was encouraged. The vice president responsible for plant operations was assigned the responsibility to personally verify to the NRC that applicants for an operator license are competent to operate the reactor. In-plant drills to keep the plant staff proficient in emergency activities were suggested. The report recommended additional emphasis on instructors' ability to instruct and on supervisory skills training for supervisors (NRC, 1979, NUREG -0585).

After the accident in 1979 The American Nuclear Society began to write new standards for training and qualification of nuclear plant personnel (Palmer 1981). The training manager position was identified in the standard. This position is required to have a bachelor degree with some courses in education or some training in educational techniques and must have nuclear experience. Experience and training requirements for training coordinators and instructors were also identified (ANSI, 1981, ANSI/ANS 3.1).

These standards presented a major change in training requirements for supervisors, technicians, craftsmen, and non-licensed operators. A training program to ensure job duties that affect reactor safety are performed correctly was required. This training program must be based upon a task analysis of the position's assigned functions. Reactor operators must complete training on a reactor control room simulator. Supervisory skills training was required for some supervisors. This standard required a retraining program for all personnel to ensure proficiency of the entire staff is maintained. An independent evaluation of the training program's content, quality, and appropriateness was required annually (ANSI, 1981, ANSI/ANS 3.1).

Much can be learned from the experience of others. Prior to the accident at TMI the nuclear industry did not use operating experience information very effectively. At TMI the people who analyzed operating experience reports from other plants had no nuclear backgrounds. Analysts routed summaries of the operating reports. The routing took several months. The man in the training group who received the routings often did not review the summary until several months after he received them due to his other duties. TMI provided only two hours per year of training for operators on operational problems and experiences at other reactor plants (Kemeny, 1979, p.47).

Babcock and Wilcox, the TMI reactor supplier, shares some of the blame for the inadequate preparation of TMI operators. Babcock and Wilcox contributed to the inadequate performance because they failed to identify and communicate important factors concerning reactor safety to operators of Babcock and Wilcox designed plants (Kemeny, 1979, p. 43). They provided the services and functions required of them under formal operator training agreements, however they did not provide information about events and technical issues at other plants (Kemeny, 1979, p. 50).

Prior to the accident at TMI, pressure relief valves had stuck open at Babcock and Wilcox plants on nine different occasions. Babcock and Wilcox did not incorporate this malfunction into their operator training program (Kemeny, 1979, p. 43). This mechanical malfunction of the pressure relief valves was a significant contributor to the accident. It provided the path for loss of cooling water and caused the loss of pressure control for the reactor. This loss of water and pressure allowed conditions in the reactor core to deteriorate (Kemeny, 1979; Rogovin and Frampton, 1980). Operators were not prepared to properly investigate and analyze the impacts of this malfunction. Had they responded to the malfunction promptly the consequences would have been minor.

The President's Commission on Three Mile Island (Kemeny, 1979, p. 43) identified three situations that should have prompted Babcock and Wilcox to upgrade their operator training program. An accident with the same initiating sequence as at TMI occurred at the Davis-Besse Nuclear Plant in September 1977. This accident sequence was not incorporated into operator training at Babcock and Wilcox. A report written by a senior Babcock and Wilcox engineer 13 months before the accident was ignored. This report warned that operators must be given precise instruction on operations. The third warning situation was a 1978 Tennessee Valley Authority question to Babcock and Wilcox concerning operator response to the occurrence of a rising water level and a decreasing pressure in the reactor. Babcock and Wilcox never informed other plants with their reactor designs of the concerns identified in this report. This situation occurred during the TMI accident. The TMI operators responded incorrectly to the occurrence causing damage to the nuclear fuel (Kemeny, 1979; Rogovin and Frampton, 1980).

Operational training was provided by Babcock and Wilcox at their reactor simulator. TMI operators were normally trained for routine duties, not emergency situations. The simulator was not programmed to produce the conditions that occurred during the accident (Rogovin and Frampton, 1980, p. 104; Kemeny, 1979, p. 50). This simulator was not a model of TMI, but of a different plant. The Babcock and Wilcox simulator control room did not have the same characteristics as the TMI control room, "which is larger, more confusing, and less organized" than the simulator control room (Rogovin and Frampton, 1980, p. 105).

The NRC Special Inquiry Group (Rogovin and Frampton, 1980, pp. 103-105) recommended that utility training should include a comprehensive retraining program with regular training on a nuclear plant simulator. The NRC should administer certification examinations at the time of initial operator licensing and at the operator license renewal stage.

The President's Commission on The Accident at TMI recommended that each utility incorporate training on a control room simulator into its licensed operator training program and that issuance of a license by the NRC be contingent on satisfactory performance in a simulator examination (Kemeny, 1979, p. 71). The 1981 American National Standard for Selection, Qualification and Training of Personnel for Nuclear Power Plants required that training for operators include manipulating the controls of an applicable control room simulator (ANSI, 1981, ANSI/ANS 3.1, p. 12). This standard identifies an applicable simulator as a simulator with similar operating characteristics to the trainee's own plant (ANSI, 1981, ANSI/ANS 3.1, p. 18). A simulator that is a full scope replica of a nuclear plant control room cost six million dollars to procure in 1980 and developing the training program to support training on that simulator cost another four million dollars (Kriessman, 1981). Regardless of the costs, the simulator must meet the specific needs of the plant staff. It must be staffed with qualified instructors using well defined training programs (Brockhold, 1981).

Minimum standards for nuclear plant simulators were identified in the American National Standard for Nuclear Power Plant Simulators for Use in Operator Training (ANSI, 1981, ANSI/ANS 3.5) This standard addresses criteria for the hardware and software design of the simulator, such as the functional capability and the degree of simulation required, but does not address the use of the simulator in the training program.

Other industries can learn from the accident at TMI. An equipment malfunction can occur anywhere. People in key operating positions must be prepared to identify the causes and impacts of malfunctions and take appropriate actions. This preparation can be achieved through training and learning from the operating experience of others.

Line managers must be held accountable to provide training on necessary skills to operate the facility and on the fundamental science behind the technology. A professional training organization should manage the learning to support management. Managers must understand the importance of this training and support it. Realistic training environments must be provided. These environments could include simulators, mock ups and training laboratories.

Systems must be established to share information on hazardous operations and safety problems throughout industries to prevent accidents. Even in competitive situations companies must share lessons learned when health and safety to the public are concerned.

Equipment problems initiated the accident at TMI. Human error and inadequate information made the accident worse. Training had not prepared the operators and technicians for the challenge they faced. Operating experience and technical concerns were not shared among plants. No one at TMI expected the conditions that occurred during the accident. They had not reviewed information concerning similar situations at other plants. The control room simulator used to train TMI operators did not accurately model the TMI plant.

Applications of human performance technology that are routine activities in American nuclear plants today would have minimized the consequences of the TMI accident. The nuclear industry learned from the accident. Training is well done. Accurate control room simulators are used to train operating personnel in complex accident scenarios. Operating experience and technical information are freely exchanged between nuclear organizations. The Institute of Nuclear Power Operations and the National Academy for Nuclear Training were established to support the application of human performance technology.

Other industries with complex technologies should review the causes and lessons learned from the accident at TMI. The response by the nuclear industry to incorporate human performance technology applications into standard operation of the plants is noteworthy. Other industries could avoid the costs of learning the lesson through their own accidents. Human performance technology could avoid injury, loss and destruction. It could also improve safety and production.

References

ANSI, American National Standards Institute (1971). ANSI N18.1-1971 American national standard for qualification and training of personnel for nuclear power plants. Hinsdale, IL: American Nuclear Society.

ANSI, American National Standards Institute (1978). ANSI/ANS 3.1-1978 American national standard for selection, qualification and training of personnel for nuclear power plants. La Grange Park, IL: American Nuclear Society.

ANSI, American National Standards Institute (1981). ANSI ANS 3.1-1981 American national standard for the selection, qualification and training of personnel for nuclear power plants. La Grange Park, IL: American Nuclear Society.

ANSI, American National Standards Institute (1981). ANSI/ANS 3.5-1981 American national standard for nuclear simulators for use in operator training. La Grange Park, IL: American Nuclear Society.

Barge, R. (1979). Effective mechanic training. Proceedings of the Third Symposium on Training of Nuclear Facility Personnel. Springfield, VA: National Technical Information Service.

Brockhold, G. (1981). The best nuclear simulator. Proceedings of the Fourth Symposium on Training of Nuclear Facility Personnel. Springfield, VA: National Technical Information Service.

Coakley, W.J. (1991). Training and accreditation in the nuclear power industry. Nuclear News, 34,(5), 41-43.

Code of Federal Regulations Energy, Title 10 (1976). Washington, DC: US Government Printing Office.

Enzor, E. K.(1979). I&C training program development at the Brunswick Steam Electric Plant. The Third BWR Training Conference. San Diego, CA: General Electric Company.

Flemming, S. T. (1979). Training - a four factor formula. Proceedings of the Third Symposium on Training of Nuclear Facility Personnel. Springfield, VA: National Technical Information Service.

Harris, J. H. (1979). Eight is not enough. Proceedings of the Third Symposium on Training of Nuclear Facility Personnel. Springfield, VA: National Technical Information Service.

Institute of Nuclear Power Operations (1989). Annual Report. Atlanta, GA: Author.

Kemeny J. G. (1979). Report of the president's commission on the accident at Three Mile Island. Washington DC: US Government Printing Office.

Kneif, R.A. (1992). Nuclear engineering, theory and technology of commercial nuclear power. Washington DC: Hemisphere Publishing Corporation, Taylor & Francis Group.

Kriessman, C. A (1981). A spectrum of simulators for power plant training. Training and Development Journal 35 (9), 37-39.

Mau J. M. (1979). Staffing a training organization in a single unit nuclear plant. Proceedings of the Third Symposium on Training of Nuclear Facility Personnel. Springfield, VA: National Technical Information Service.

NRC, Nuclear Regulatory Commission (1976). NUREG-0094, NRC operator licensing guide. Washington, DC: Office of Nuclear Reactor Regulation, Nuclear Regulatory Commission.

NRC, Nuclear Regulatory Commission (1979). NUREG-0578, TMI-2 lessons learned task force status report and short term recommendations. Washington, DC: Author.

NRC, Nuclear Regulatory Commission (1979). NUREG-0585, TMI-2 lessons learned task force final report. Washington, DC: Author.

Palmer, F. A. (1979). The implications of ANSI/ANS 3.1-1978 on the nuclear industry. Proceedings of the Third Symposium on Training of Nuclear Facility Personnel. Springfield, VA: National Technical Information Service.

Palmer, F. A. (1981). Revisions to ANSI/ANS 3.1, 1978 resulting from TMI-2. Proceedings of the Fourth Symposium on Training of Nuclear Facility Personnel. Springfield, VA: National Technical Information Service.

Parker, W, O. (1979). View from the top. Proceedings of the Third Symposium on Training of Nuclear Facility Personnel. Springfield, VA: National Technical Information Service.

Rogovin, M. & Frampton, G. T. (1980). Three Mile Island. a report to the commissioners and to the public. Washington DC: Nuclear Regulatory Commission.

Smith, G. (1991). Nuclear training: a status report. Nuclear News, 34,(5), 41-43.

About William H. Lowthert, Ph.D.
AIP Associates
34 Willow Lane, Bloomsburg, PA 17815
home page: WWW.alwaysimproving.com
mail to: Bill Lowthert at mailto:BillisImproving@aol.com

APA reference citation: Lowthert, W. (1994). Human performance technology and the accident at three mile island (On-line). Available: www.alwaysimproving.com