A Model of Evacuation--Decision Making in a Nuclear Reactor Emergency

Abstract

A model for decision making about evacuation during a radiological emergency is tested by loglinear causal modeling and with data from a survey of households in the vicinity of the Shoreham nuclear power station on Long Island. The model incorporates intention to evacuate as a surrogate for actual behavior and attributes of both location and local residents as predictors of evacuation. The results strongly suggest that the model can forecast magnitude and spatial extent of spontaneous evacuation for any commercial nuclear installation, if a radiological emergency should occur. LICENSEES of commercial nuclear power plants in the United States are required to devise, in conjunction with state and local governments, plans to ensure protective measures during a radiological emergency.1 These plans must comply with prescribed federal guidelines, and final approval is the joint responsibility of the U.S. Nuclear Regulatory Commission (NRC) and the Federal Emergency Management Agency (FEMA).2 However, the criteria that are to be used in both the preparation and the evaluation of the plans are based almost solely on knowledge about human behavior in natural disasters and nonradiological technological emergencies.3 Studies conducted in the aftermath of the accident at the Three Mile Island nucleargenerating facility near Harrisburg, Pennsylvania, in March 1979 strongly implied that emergency plans, developed according to such criteria, are likely to be inadequate and ineffective for a major nuclear-reactor accident. During the Three Mile Island crisis, the advisory from the governor of Pennsylvania instructed the evacuation of pregnant women and preschoolaged children within a five-mile radius of the malfunctioning reactor and everyone else within a ten-mile radius to stay indoors. This advisory should have resulted in the evacuation of approximately 3,500 persons. However, it was estimated that 144,000 persons, or 39 percent of the population within * I wish to thank William A. V. Clark, J. Nicholas Entrikin, Bernard Logan, Melvin Oliver, Bruce W. Pigozzi, and Donald J. Zeigler for their comments on drafts of this article. Nuclear Regulatory Commission, Emergency Planning: Final Regulations, Federal Register, Vol. 45, 1980, p. 55402. 2 Criteria for Preparation and Evaluation of Radiological Emergency Response Plans and Preparedness in Support of Nuclear Power Plants (Washington, D.C.: U.S. Nuclear Regulatory Commission and Federal Emergency Management Agency, 1980). 3 Robert T. Jaske, Emergency Preparedness: Status and Outlook, Nuclear Safety, Vol. 24, 1983, pp. 1-11; James H. Johnson Jr., Planning for Spontaneous Evacuation during a Radiological Emergency, Nuclear Safety, Vol. 25, 1984, pp. 186-194; Susan L. Cutter, Emergency Preparedness and Planning for Nuclear Power Plants Accidents, Applied Geography, Vol. 4, 1984, pp. 235-245; and Richard T. Sylves, Nuclear Power Plants and Emergency Planning: An Intergovernmental Nightmare, Public Administration Review, Vol. 44, 1984, pp. 393-401. * DR. JOHNSON is an associate professor of geography at the University of California, Los Angeles, California 90024. This content downloaded from 207.46.13.113 on Thu, 06 Oct 2016 04:24:00 UTC All use subject to http://about.jstor.org/terms THE GEOGRAPHICAL REVIEW fifteen miles of the facility, departed.4 The process whereby individuals and families left their homes without official directive was called spontaneous evacuation.5 An analysis of responses to the accident from a geographical perspective used the term evacuation-shadow phenomenon to identify the tendency of people beyond or outside the designated dangerous zone to leave spontaneously or voluntarily.6 This behavior had occurred in other crisis situations but never at the magnitude observed during the Three Mile Island incident. The gap between expected and actual evacuation was so wide that it highlighted a need for improved methods to estimate the flow and extent of spontaneous evacuation movements.7 This article presents a causal model of evacuation-decision making during a nuclear reactor emergency. The model is tested by a modified version of path analysis and with data obtained from interviews in a survey of a representative sample of households in the vicinity of the Shoreham nuclear power station on Long Island, New York. The results of the test demonstrate that the model can be used to forecast for any commercial nuclear power plant both magnitude and geographical extent of spontaneous evacuation if a radiological emergency occurs.