Panel Report

The Panel will also examine the general criteria for the management of nuclear fuel wastes as compared to those for wastes from other energy and industrial sources. In addition, the impact of recycling or other processes on the volume of wastes should be examined.

Terms of Reference

Comparable Wastes

Nuclear fuel wastes are the most concentrated wastes that arise from nuclear electricity generation, but there are others, including solid wastes from reactor operation and decommissioning, and gaseous and liquid emissions. A notable feature of nuclear fuel wastes is that they contain uranium and plutonium that could one day become economically valuable. The most closely analogous wastes from other energy sources-although their potential economic value is dubious-might be ash and residue from coal power generation. These solid hazardous wastes contain heavy metals, some of which are radioactive. However, the combustion of coal and other fossil fuels also releases substantial quantities of environmentally hazardous substances into the air. Comparable wastes from other industrial sources will be dealt with under the broad headings of hazardous wastes and chemical contaminants.

Characteristics

The characteristics of nuclear fuel wastes are described in section 2.1.5 of this report. Some constituents of nuclear fuel and hazardous wastes, particularly heavy metals, remain toxic essentially forever. Some of them are carcinogenic. Radioactivity, which at certain levels is carcinogenic and mutagenic, decreases over time. These periods are short for some radionuclides and very long for others. Gaseous emissions from fossil fuel combustion contribute to global warming and acid precipitation, which have the potential to harm the environment and biota.

In their present quantities, non-nuclear wastes may pose an even greater risk to human health and the environment than nuclear wastes do, but it is not possible to say with certainty which are, overall, more threatening. That question aside, the very long duration during which some elements of nuclear wastes are hazardous, and public perceptions and fears related to nuclear questions, require that nuclear wastes be managed at least as rigorously as other hazardous wastes. Indeed, the "dread factor" related to nuclear matters may well require more stringent standards if public concerns are to be met.

Regulation

The federal government regulates radioactive wastes, including uranium mine tailings and nuclear fuel wastes. The existing Atomic Energy Control Board (AECB) requirements for these wastes are not entirely equivalent to the requirements for managing other hazardous wastes. This is due, in part, to historical reasons: the AECB has been solely responsible for nuclear matters for a long time, whereas multiple federal, provincial and even municipal authorities share the regulatory responsibility for other wastes. In most cases, provincial regulations meet or exceed federal guidelines and regulations. The federal and provincial governments harmonize their regulations through such bodies as the Canadian Council of Ministers of the Environment (CCME), which develops hazardous waste management and other guidelines that form the basis of provincial regulations and practice. At the local level, municipal governments set the allowable limits for the discharge of hazardous wastes into their sanitary sewer systems. Even with a certain degree of co-ordination, these divisions of responsibility have led to a rather uneven approach to waste management.

Current Criteria

The principal federal criteria for managing nuclear fuel wastes and, in some cases, other radioactive wastes, are found in the regulations and regulatory documents (R-71, R-72, R-90 and R-104) issued by the AECB. Corresponding criteria for hazardous wastes are found in CCME guidelines, especially the National Guidelines for the Landfilling of Hazardous Wastes (1991); in Environment Canada's Toxic Substances Management Policy (1995); in Health Canada's Guidelines for Canadian Drinking Water Quality; and in commentary by senior government officials and other review participants. Although we did not receive information on criteria for emissions from fossil fuel combustion, we know various reduction targets and regulations exist. Regardless of which regulations, policies or guidelines are consulted, not all the criteria are explicitly stated. Some are implicit in the acceptance of a general approach for managing wastes, and of the quantities of wastes allowed to be produced and managed in that manner.

Both similarities and differences can be found in the criteria applied to different types of wastes. Without attempting an exhaustive analysis, we have noted a few of the more significant ones.

General Management Approaches

While all nuclear fuel wastes in Canada are currently being stored at the sites where they are generated, the long-term management method preferred by the regulator is deep geological disposal. [Atomic Energy Control Board, Regulatory Policy Statement: Regulatory Objectives, Requirements and Guidelines for the Disposal of Radioactive Wastes, Long-term Aspects (Atomic Energy Control Board, Regulatory Document R-104, June 5, 1987), p. 2; and Regulatory Guide: Geological Considerations in Siting a Repository for Underground Disposal of High-level Radioactive Waste (Atomic Energy Control Board, Regulatory Document R - 72, September 21, 1987), p. 5.] This represents a "contain and isolate" approach. Because the sites where the wastes are stored are not necessarily suitable for such disposal, managing the wastes would likely require transporting them to another site.

For hazardous wastes, the increasingly preferred approach is the 4Rs waste management hierarchy (reduce, re-use, recycle, recover), followed by disposal only as a last resort. This preferred approach stands in contrast to past and many current waste management practices. However, the costs of disposal and the difficulty of finding acceptable landfill or treatment sites, as well as public perception, are driving the trend towards waste reduction. The federal government has pledged to reduce the total quantity of hazardous wastes produced in Canada by 50 per cent by the year 2000, using a 1988 baseline measurement. [G.M. Cornwall, Paper presented at the Federal Environmental Assessment Panel for Nuclear Fuel Waste Management and Disposal Concept Review 11 March 1996 on Department of Environment Criteria for Hazardous Waste Management (Hull: Environment Canada, Environmental Protection Service, Hazardous Waste Branch, PHGov.005), p. 4.] In Canada, 60 per cent of hazardous wastes is either landfilled (a "contain and isolate" approach) or discharged to municipal sewers (a "dilute and disperse" approach), while 40 per cent is treated through either incineration or physical-chemical-biological means. [Government of Canada, Canada's Green Plan (Ottawa: Minister of Supply and Services Canada, 1990), p. 57.] Whichever approach is used, about 60 per cent of the wastes is dealt with at the generation site, while 40 per cent is sent elsewhere. [G.M. Cornwall, Paper presented at the Federal Environmental Assessment Panel, p. 4.]

Priority toxic substances are identified and managed according to the federal Toxic Substances Management Policy. Those that are toxic, persistent and bioaccumula-tive, and that result predominantly from human activity, are to be eliminated from the environment through either a ban or a phase-out. Other toxic substances or substances of concern are to be managed throughout their entire life cycles to prevent or minimize their release into the environment.

Attempts are being made to reduce emissions from the combustion of fossil fuels, but success has been mixed. Surprisingly large quantities are allowed to be released through this "dilute and disperse" approach.

Many participants in our hearings insisted that the 4Rs should apply in the nuclear field. They also felt it was essential to start by decreasing the nuclear generation of electricity in order to reduce or even halt the creation of nuclear fuel wastes. This would entail either significantly reducing overall electricity consumption or switching to other sources of generation. It would be necessary to analyze carefully the feasibility and the environmental and health impacts of switching to alternative sources to determine whether there would be a net benefit. One submission to the Panel indicated that, even with optimal use of renewable electricity sources such as solar and wind power, conventional energy sources would still be required. [Canadian Nuclear Association, Canadian Nuclear Association Presentation to the Federal Panel on Geologic Disposal of Canada's Used Nuclear Fuel (Canadian Nuclear Association, PH3Pub.218, March 27, 1997), pp. 9-10.] Other presenters believed that, if switching were to occur, Canada should move away from coal-fired generation rather than from nuclear generation, for both health and environmental reasons.

As for the rest of the 4Rs, re-use appears to be impractical at present, as the spent fuel cannot be used for any other purpose as is. Recycling and recovery can be achieved, at least in part, by reprocessing and recycling the wastes, as discussed in Appendix L. But this, too, would have many implications. For instance, high-level and other wastes would still require disposal, and mixed oxide (MOX) fuel would have to be fabricated and burned to make full use of the extracted products. Unfortunately, there is currently no proven method of reducing the volume or toxicity of nuclear wastes that is equivalent to methods for treating other hazardous wastes. Research on transmutation may lead to a comparable result, but it is impossible to predict whether a breakthrough in this regard will provide a clear alternative to storage or disposal.

Waste Quantities

It is difficult to predict the quantities of nuclear wastes to be dealt with in the future, since these quantities depend on future policy decisions on nuclear generation and, possibly, the importation of nuclear fuel wastes. Nuclear fuel wastes are currently removed from Canadian reactors at a rate of about 85,000 bundles, or about 2,040 metric tonnes, per year. Assuming that existing nuclear reactors are operated for 40 years, but that no new reactors are constructed, about 3.6 million bundles or 86,000 tonnes of spent fuel will exist in Canada by 2033. Atomic Energy of Canada Limited's (AECL's) reference case study repository was designed to accommodate 10 million bundles or 240,000 tonnes of spent fuel, which represents the amount that would exist by 2035 if nuclear generating capacity were to increase by three per cent per year, or the amount that would exist in 2073 if current capacity were maintained.

The quantities of hazardous wastes greatly exceed those of nuclear wastes. A hazardous waste landfill in the Sarnia area, for example, will contain 7.5 million tonnes when full. It has over 30 times the capacity of the nuclear waste repository in AECL's reference case study, and is only one of three major hazardous waste facilities in Canada. [Hans Tammemagi, in Nuclear Fuel Waste Environmental Assessment Panel Public Hearings Transcripts, June 20, 1996, p. 37.] An estimated total of 5.9 million tonnes of hazardous wastes was generated in Canada in 1991. [George Cornwall, in Nuclear Fuel Waste Environmental Assessment Panel Public Hearings Transcripts, March 11, 1996, p. 171.]

We compared some of the wastes generated by nuclear and thermal energy options. In 1994, equivalent amounts of electricity were produced from nuclear and fossil fuels, each comprising about 19 per cent of Canadian production. Nuclear generation required 1,740 tonnes of uranium [Canadian Electricity Association and Natural Resources Canada, Electric Power in Canada 1994, p. 64.] and produced about 2,200 tonnes of spent fuel (assuming 19 kilograms of uranium in a 24-kilogram fuel bundle); 917,000 tonnes of waste rock; 91,700 tonnes of tailings; 26,600 cubic metres of processed low-level wastes; and liquid and airborne effluents. [Waste quantities estimated according to values given in Standing Committee on Energy, Mines and Resources, B. Sparrow, Chairman, Nuclear Energy: Unmasking the Mystery, pp. 115-116.] Fossil fuel generation required about 46 million tonnes of coal and 5.6 million cubic metres of oil and natural gas, and produced approximately 4.2 million tonnes of ash containing 3,780 tonnes of heavy metals, some radioactive; 21,100 tonnes of escaped ash air emissions; [Ash yields and compositions were estimated according to values given in William R. Baarschers, On the Disposal of Nuclear Fuel Waste (PH3Pub.067), p. 3.] 95 million tonnes of carbon dioxide; 542,000 tonnes of sulphur dioxide; 168,000 tonnes of nitrogen oxide (NO_x) air emissions; [Canadian Electricity Association and Natural Resources Canada, Electric Power in Canada 1994, pp. 63-64 and p. 66.] and other wastes. To give an indication of the overall situation, a total of 475 million tonnes of carbon dioxide was emitted from all Canadian energy activities in that year.

Exposure Limits

According to a study recently completed by the Joint AECB Advisory Committees/Health Canada Working Group on Risk Assessment Methods for Chemical and Radiological Hazards, there are discrepancies in the manner in which exposure limits are set for chemical versus radioactive contaminants. While the final report was not completed in time for the Panel to consider it, the Panel did have access to a summary of draft 10. [David Myers, Assessment and Management of Cancer Risks from Chemical and Radiological Hazards .] To begin with, exposure limits for radiation normally refer to the sum from all radionuclides, the total number of which is known, and to all industrial sources and exposure pathways. They are often compared to natural background radiation levels. Limits for chemicals apply to individual toxins, not all of which have yet been recognized, and to natural and synthetic sources combined, but usually do not include all exposure pathways. Since not all chemicals are found in nature, background levels are usually not considered in setting limits. [David Myers, Assessment and Management of Cancer Risks from Chemical and Radiological Hazards, p. 2 and pp. 16-19.]

Risk management practices for both nuclear fuel wastes and chemicals are designed to minimize risks, yet balance the benefits of reducing risk with the costs and feasibility of controls. [David Myers, Assessment and Management of Cancer Risks from Chemical and Radiological Hazards, p. 17.] This is otherwise known as the ALARA principle: exposures shall be kept as low as reasonably achievable, economic and social factors being taken into account. However, the Panel was told that exposure limits for radiation are set such that the ALARA principle is to be applied to achieve exposures that are a small fraction of the specified limits, whereas the limits for chemicals are set to include a form of ALARA. [David Myers, Assessment and Management of Cancer Risks from Chemical and Radiological Hazards, p. 20, and J.A.L. Robertson, Some Additional Comments on Submissions to the Panel, p. 2.] Thus, there remains some inconsistency regarding the precise role of the ALARA principle in meeting or exceeding regulatory limits. For both types of substances, lower acceptable risk levels are specified for the general population than for workers.

As a result of the factors outlined above, as well as the fragmented responsibility for regulation, different levels of acceptable risk are inherent in the exposure limits for radioactive versus chemical contaminants, and even within contaminant categories. According to one interest group, acceptable lifetime risks for all cancers caused by chemical carcinogens range, in general, from a high of one in 10,000, to a low of one in 100,000,000, while those for fatal cancers caused only by radioactive carcinogens range from a high of one in 50 (today's legal limit for artificial public doses of radiation from nuclear facilities) to a low of one in 2,000 (today's Ontario Drinking Water Objective for tritium). [Norman Rubin, Risk Methodology and Criteria for a Nuclear Waste Disposal Facility, Part 4 of Energy Probe's Submission to the Nuclear Fuel Waste Environmental Assessment Panel (Toronto: Borealis Energy Research Association, March 1, 1996, PHPub.041), p. 22.] They argue even further that the ways used to calculate the figures and apply the limits add more discrepancies between the strict standards for chemicals and the lax standards for radionuclides.

Yet, we also received contradictory information indicating that the limits for continuous water consumption at maximum acceptable concentrations specified in the Guidelines for Canadian Drinking Water Quality correspond to estimated individual lifetime cancer risks of one in 2,500 for all radionuclides combined, versus about one in 1,000 for all designated chemicals combined. [David Myers, Assessment and Management of Cancer Risks from Chemical and Radiological Hazards, Table 4.] And, as we shall see in the next section, the acceptable risk designated for a nuclear fuel waste disposal facility for 10,000 years after closure corresponds to a lifetime risk of fatal cancers and serious genetic effects of about one in 14,286 (assuming a lifetime of 70 years).

Comparison of Disposal and Landfilling

Given the analogy between nuclear fuel waste disposal and hazardous waste landfilling, a more detailed look at the criteria for each is in order. According to AECB regulatory documents, disposal should occur deep underground (R-72); minimize the burden on future generations; not rely on long-term institutional controls as a necessary safety feature; and maintain the annual risk to individuals of fatal cancers and serious genetic effects from radiation below one in a million for 10,000 years after closure (R-104).

In contrast to deep geological disposal, landfilling takes place at or near the surface. Like the regime specified for disposal, the CCME National Guidelines for the Landfilling of Hazardous Waste recommend that a combination of natural and engineered barriers be used to minimize adverse environmental effects; barrier materials be selected according to their compatibility with site and waste characteristics; site assessments include the development of a contaminant transport model; and facility closure be executed in a manner that minimizes the need for further maintenance. [Canadian Council of Ministers of the Environment, National Guidelines for the Landfilling of Hazardous Waste (Report CCME-WM/TRE-028E, April 1991), pp. xii-xv.] However, the guide-lines do require some institutional controls in the postclosure period, including maintenance, monitoring and operation of a leachate collection and removal system; environmental monitoring; protection and maintenance of survey benchmarks; site access control; maintenance of facility records; provision of contingency financing; and legal registration of the facility on the land deed or title. [Canadian Council of Ministers of the Environment, National Guidelines, pp. xiv-xvi.]

One review participant noted that, generally, unlike the nuclear fuel waste regime, risk assessment and pathways analysis are not required for hazardous waste; rigorous consideration is not given to long-term, postclosure impacts; and design and regulation is focused on a few decades to a century or so after closure, failing to recognize that maintenance is required in perpetuity. [Hans Y. Tammemagi, The Wrong Wastes are on Trial: A Presentation to the Nuclear Fuel Waste Environmental Assessment Panel (St. Catharines: Oakhill Environmental, PH2Tec.023, June 20, 1996), p. 2, and Oakhill Environmental, A Comparison of How Nuclear and Non-nuclear Wastes are Managed and Disposed (St. Catharines: Oakhill Environmental, October 1996), p. 14 and pp. 31-32.] Hence, it can be said that the CCME recommendations place more emphasis on immediate postclosure controls and less on very long-term safety than those of the AECB, which rule out dependence on such controls in an attempt to ensure long-term passive safety.

These two disposal approaches lead to two types of disposal: either a facility deep underground that does not require maintenance and monitoring and from which waste retrieval would be difficult; or a facility at or near the surface that does require maintenance and monitoring and from which retrieval would be easy. A preference for one type over the other seems to boil down to the interpretation of and importance given to criteria relating to our obligations to future generations, as discussed in chapters 4 and 5.

A Common Approach for Nuclear Fuel Wastes and Other Hazardous Wastes?

Through both our public hearings and a lively exchange of written material, participants asked which criteria were or should be more strict, and whether a common set of criteria should apply to both nuclear and other hazardous wastes. One argument was that nuclear wastes are already subject to more stringent controls than most other hazardous substances, even though they are not more dangerous (in some ways, they are less dangerous, as their toxicity decreases over time). The opposing argument was that nuclear wastes are much more leniently controlled than other persistent toxic substances, and that they should be subject to the same regime, especially to a ban or phase-out. It is unlikely that these differences will be readily resolved, in part because they come from very different views about the future of nuclear energy in Canada.

It would nevertheless be desirable to work towards common methods for assessing and managing risk, as well as common and publicly accepted risk criteria, so that relative risks might be fairly judged, whether they arise from radioactivity or not. At this stage, common methods and criteria have neither been developed nor accepted.

The Panel has learned, however, that the AECB intends to work with Environment Canada and the provinces to establish an approach for regulating environmental protection from industrial radiation sources consistent with that used for other potentially toxic substances, which would include regulating effects on non-human species. To this end, the two federal agencies are conducting an ecological risk assessment of radionuclide releases from nuclear facilities, including waste management facilities, in accordance with the Toxic Substances Management Policy. If such releases are determined to be "toxic," then the agencies would develop regulatory and other options for reducing them, including banning them or phasing them out, in conformance with the Policy. [Patsy Thompson, Environment Canada, Assessment of Radionuclides under the Canadian Environmental Protection Act, oral presentation at the Symposium on Radiological Impacts from Nuclear Facilities on Non-human Species (Ottawa: Canadian Nuclear Society, December 2, 1996).] The recently completed study by the Joint AECB Advisory Commit-tees/Health Canada Working Group on Risk Assessment Methods for Chemical and Radiological Hazards may also lead to some convergence in this area.

Lessons Learned

Our examination of the general criteria for managing wastes from other energy and industrial sources did not provide explicit analogues to use in formulating our advice. We have therefore relied more on the specific characteristics of nuclear fuel wastes, and public views on those characteristics. In the course of our hearings, however, we gleaned much useful information about the general management of low-level radioactive wastes and hazardous wastes, and interim storage practices for nuclear fuel wastes. A number of the lessons learned and procedures adopted for good management-safe on-site storage, safe transportation, federal-provincial co-operation, selection of a facility site, postclosure measures, societal aspects and public involvement-should be given close attention when developing policy and procedures for managing nuclear fuel wastes. This information has proven valuable in framing the conclusions and recommendations provided elsewhere in this report.