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Radioactive and Toxic Waste Handling

Radioactive and toxic wastes represent special problems and require some innovative approaches. Given that about a dozen U.S. nuclear reactors are ready for decommissioning now and about 50 will be ready for retirement in the Western world before the end of the century the problem of handling nuclear wastes will be getting much more attention than it has in the past. Because very few nuclear reactors have yet been dismantled, the technology for this undertaking is still being developed.

Much attention will be focused on the cleanup of the Hanford site in the state of Washington, where weapons-grade radioactive materials have been produced since the days of the Manhattan Project in the early 1940s. This cleanup project alone is planned to take 30 years to complete. It is also expected to require resolution of many human factors issues. Among these will be issues having to do with the design of control facilities for a vitrification plant in which liquid wastes will be solidified and issues relating to the design and use of tele-operator systems for remote handling of radioactive materials. Because of the industry’s limited experience with dismantling and cleanup operations, there will need to be some innovative thinking about the allocation of functions to people and machines and the design of person-machine interfaces for this purpose

Designing for Error Prevention

Human error is known to be a major cause of industrial accidents. The accident at Chernobyl occurred because of an interaction of poor plant design, poor management decisions, and violations of procedures The Bhopal incident was caused by a combination of operator error, poor training, and bad policies, including the policy of storing large quantities of hazardous materials, thus increasing the chances that an accident, should it occur, would be on a very large scale . At Three Mile Island, inadequacies in training, operating procedures, control room interface design, and maintenance practice were all seen to be contributing factors. More generally, analyses of industrial accidents have revealed a great variety of human errors—in system design, regulation, operation, maintenance, communication and management

Inasmuch as industrial accidents can have—and have had—serious environmental consequences, work on the problem of designing industrial control stations and operating procedures so as to minimize the possibility of human error is very much in the spirit of what this chapter is intended to promote. The most difficult challenge here is to identify vulnerable points in an industrial process before any disastrous errors occur. Although thePage 169Suggested Citation:“5 Environmental Change.” National Research Council. 1995. Emerging Needs and Opportunities for Human Factors Research. Washington, DC: The National Academies Press. doi: 10.17226/4940.×SaveCancel

occurrence of a disaster should always be a stimulus to research on how to prevent a recurrence, the greatly preferred objective is to prevent the initial disaster from happening. Unfortunately, the successful prevention of accidents of a type that has never occurred is likely to go unrecognized; until an accident has happened, people tend to be unaware of its possibility.

It has become increasingly evident that the traditional ergonomics of control room design is insufficient to prevent large-scale accidents. Accidents occur because of complex interactions among people at all levels of an organization and between people and plant hardware; they occur despite regulations, training, and operating procedures that are intended to minimize accident potential. Attitudinal variables may play a more important role than has been realized. Management’s interest in developing a ”safety culture” within a company plant is also a key factor. To understand the causes of accidents and how to prevent them, we need to understand the psychology of a system in its entirety, from the ergonomics of design to the social dynamics of “whistle blowing.”

Automation is sometimes seen as a solution to the problem of human error because it removes human operators from the scene. But automation does not necessarily reduce the probability or severity of accidents. When highly skilled operators are removed from an industrial system, the system sometimes loses the protection against design errors that the workers’ skill may provide, and the hazardous implications of those design errors may be very difficult to discover before an actual incident. In automated systems, the day-to-day role of humans tends to be the performance of maintenance, and we know that accidents can occur because of faulty maintenance. has described how automation, if not introduced in an appropriate way, can reduce quality of performance.