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Comments on

"Nuclear Environmental Consequences" 

Duane Pendergast

Comments on

Nuclear Environmental Consequences” by Donald N. Dewees, Ontario Hydro at the Millennium
ISBN 0-7735-1426-0&9, McGill - Queen’s University Press, Montreal, 1996, pp 277-323.

Professor Dewees has initiated a broad review of the environmental consequences of nuclear energy in comparison with coal-fuelled generation. He has looked at the full range of the fuel cycle from the point where fuel comes from the ground to decommissioning of plants. 

The opening tone, even the title, of Professor Dewees' study faintly suggests a presumption that nuclear power is unfairly bearing a lesser share of social and environmental costs than coal-based electricity. However, as he proceeds through his step-by-step review he finds, in fact, that health and environmental costs of nuclear generation are probably very low relative to this competitor. 

He has found widely varying information on the costs associated with accidents, largely based on the major difference in estimates of, and actual, consequences of accidents at the Three Mile Island and Chernobyl reactors. He concludes that these costs have little effect on the cost of electricity in Ontario, as design differences between the Chernobyl and CANDU reactors result in much reduced probability and consequence of major CANDU accidents. 

Professor Dewees is less convinced that decommissioning and spent fuel disposal costs will be as low as current nuclear industry estimates. He points out that no Canadian reactors have been completely decommissioned. Canada has no spent fuel disposal facility. He believes that lack of practical experience with these activities poses a risk that actual costs will turn out to be greater than estimated. I can add only a little to the comments of Keith Dinnie and Stephen Allen on these issues. 

The environmental assessment of the Canadian spent fuel disposal concept is getting underway in 1995. Technical and economic issues have been thoroughly studied. A good measure of practical experience has been gained through the development of research facilities. A huge amount of information is available to the public. I repeat, for the reader,  Professor Dewees' reference to a document that provides a window to this information.[1] I speculate that when this concept is fully evaluated in this public forum that the nuclear industry may be accused of spending too much money on a simple problem. 

Professor Dewees cites lack of experience with decommissioning as a basis for projections that decommissioning costs will exceed estimates made by the nuclear industry. I believe the reports he has reviewed do not fully reflect Canadian experience with decommissioning of reactors and other nuclear facilities. In addition to the experience with Gentilly 1, cited by Professor Dewees, decommissioning has commenced at the Douglas Point and NPD reactors in Ontario. Additional information on these projects, and others, is available from the literature[2],[3],[4]· In view of this experience base, it seems unlikely cost overruns would be as great as the factor of 5 considered by Professor Dewees. Even with such a large cost overrun, Professor Dewees indicates the cost of decommissioning would not greatly increase the cost of electricity generated by nuclear power stations. 

Professor Dewees mentions the potential externality effects from carbon dioxide emissions, which are expected by many climate experts to lead to global warming. The information he cites pays scant attention to costs which may be incurred. Erik Haites raised a concern that proliferation of independent power producers might make the control of carbon dioxide emissions more difficult. I would also like to remind participants of this issue and introduce some illustrations which show the contribution nuclear electricity is making to the reduction of carbon dioxide emissions in Canada.


Figure 1 provides information on the basic cycle of life on earth. Our planes, trains, automobiles, and power plants are becoming a significant part of earth's life based on processing and circulation of carbon containing materials. The information presented shows that annual carbon dioxide from fossil fuels is several percent of that estimated to be processed annually by earth's plant life.



Figure 2 shows the strong correlation between our use of fossil fuels and levels of carbon dioxide measured in the atmosphere. 

Nuclear energy releases no carbon dioxide to the atmosphere during plant operation. Figure 3 shows the location of 32 CANDU and related reactors operating throughout the world. Eight more are under construction. Replacement of high carbon content fossil generation by one large CANDU can reduce Canada's carbon dioxide generation by as much as 1%.


The solid line of figure 4 shows Canada's total carbon dioxide emissions from 1950 to 1990. The dashed line diverging from the top indicates the extent of emissions had we not followed the nuclear option for electricity generation and had chosen the carbon-based fossil fuel option. This indicates Canada's 22 nuclear plants are reducing carbon dioxide about 15% from what might have been. This is equal to the magnitude of carbon dioxide emission reduction Canada has proposed in response to international concern with respect to global warming. 

In closing I should just like to say I am pleased you are contemplating changes of regulations required to ensure competitive, efficient, and safe electricity supply in the 21st century. The need to develop regulations which realistically reflect all environmental costs is emphasized by several of the contributors to this volume. Professor Dewees' preliminary assessment indicates that nuclear energy does not carry with it significant external environmental costs. Should the costs associated with carbon-dioxide-induced global warming turn out to be significant, carbon-dioxide-free nuclear energy will flourish.

[1] Atomic Energy of Canada, "Summary of the Environmental Impact Statement on the Concept for Disposal of Canada's Nuclear Fuel Waste," AECL 10721 COG-93-11, 1994. 
[2] Paul Denault and L. de Pabrita, "Gentilly 1 Nears Static State," Nuclear Engineering International (August 1985). 
[3] G. Pratapagirl, et al, "Cost Estimate for Decommissioning a CANDU 6 MKI Nuclear Generating Station," CNA/CNS Annual Conference, Ottawa, Ontario,June 4-7,1989. 
[4] B. Gupta, "Progress of Decommissioning Projects in Canada," Nuclear Decom '92: Decommissioning of Radioactive Facilities, Institute of Mechanical Engineers, London, February 17-19, 1992.


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