4. Science and environment
Overview
4.1 Status of Biosphere Research related to High-level Radioactive Waste Management (HLRWM)
ECOMatters Inc., MB CAN
The biosphere is anywhere organisms live. Effects in the biosphere on humans or other biota are the ultimate performance criteria for the various HLWRM options, so related biosphere research is quite important. Historically, the emphasis in biosphere research related to nuclear environmental contamination was on the protection of humans, especially from contamination in agricultural settings. Since about 1996, there have been rapid developments worldwide to include predictions of effects on non human biota. Canada has at times been a leader in issues related to biosphere aspects of HLRWM, and continues to play a role with contributions to the scientific literature and involvement in international programs. The underlying scientific discipline, radioecology, has particular strengths in dealing with the transport and dispersion of radioactive contaminants in soil, water and air. It borrows from human health and safety research and is well advanced in the estimation of the additive effects of multiple radioactive contaminants. Radioecology is now adapting scientific methods from other ecological disciplines to deal with the multiple organisms present in natural settings. Although the biosphere is not usually conceived as a manageable barrier, biosphere research has additional importance because the public identifies with biosphere issues. This aspect is becoming increasingly more important as the HLWRM programs worldwide progress and facilities are built.
Resources:
- 4-1 Status of Biosphere Research related to High-level Radioactive Waste Management (HLRWM)
- Executive Summary
Author Biography
Dr. Steve Sheppard, ECOMatters Inc.
Dr. Steve Sheppard is Vice President and senior ecotoxicologist with ECOMatters Inc., and is a Professional Agrologist (P.Ag) and a Canadian Certified Environmental Practitioner (C.C.E.P.).
He is also the Editor-in-Chief of the Journal of Environmental Radioactivity and was previously Editor-in-Chief of the Canadian Journal of Soil Science. His research places emphasis on contaminant exposure pathways and ecotoxicology, much of it directed to support assessment modelling. He has over 100 referred journal publications in seven major topic areas: ecotoxicology, environmental assessment, radioecology, radionuclide behaviour, contaminant exposure pathways, soil science and agronomy. His book “Advances in Earthworm Ecotoxicology” is widely recognised as summarising the most recent developments on this topic. His Ph.D. and M.Sc. were in soil science and plant nutrition, and his B.Sc. was in physical sciences.
A few of his recent projects include: determining ecotoxicology endpoints for radionuclides for the French nuclear waste agency ANDRA; evaluating behaviour and impacts of U for the Canadian nuclear regulator CNSC; review and parameterisation of a dynamic model of 14C behaviour in the Loire River for Electricité de France; measurement and interpretation of dose to transport workers in Canada for the CNSC; quantitative risk assessments for decommissioning of Whiteshell labs for Atomic Energy of Canada Limited; radiological dose estimates for the ecological effects review of Ontario Power Generation (OPG) Darlington NGS; a model of terrestrial pathways for the revised OPG derived release limit model; a biosphere model of 36Cl using specific activity concepts for ANDRA; a revised soil model for nuclear waste disposal assessments for OPG; and review and parameterisation of a cold-biospheres model of nuclear fuel waste disposal assessments for ANDRA.
In addition to scientific work, Steve is the Executive Director of the Canadian Society of Agronomy and the Registrar and Office Manager of the Canadian Society of Soil Science.
4.2 Characterizing the Geosphere in High-Level Radioactive Waste Management
Jonathan Sykes, University of Waterloo, ON CAN
The rock surrounding a disposal or storage vault, any sediments overlying the rock and the groundwater in the rock and sediments is defined as the “Geosphere”. For subsurface disposal or storage systems for high-level radioactive waste, the geosphere can provide a buffer between the spent fuel and the biosphere. The importance of the geosphere and geospheric research is dependent on the approach, being least important for above ground storage, and most important for a below ground management system.
The degree to which the geosphere will be relied upon to minimize the impact on the biosphere of potential releases of radionuclides from a waste repository or vault determines the relative importance of the geosphere within the overall waste management system. For above ground short-term storage approaches, the waste repository or vault is in close proximity to the biosphere; the geosphere does not contribute to the isolation of the accessible repository from the human environment. Long-term disposal systems, located deep within the geosphere, are designed to be passive. The geosphere is an integral and important part of the high-level radioactive waste management system. It acts to isolate the repository from the human environment. Even if the waste canisters in the repository are breached, the slow rate of the groundwater flow and the range of geochemical immobilization and retardation processes help to ensure that radionuclides continue to be confined within the engineered barrier system and the immediately surrounding rock, so that further radioactive decay takes place. Therefore, a required attribute of the geosphere for a deep disposal system is that groundwater flow at repository depths be either stagnant or sluggish. The plutonic rock of the Canadian Shield has this attribute. Other geosphere formations that also have this property are bedded salts and shales. Within Ontario, there are significantly more potential disposal sites in plutonic rock than either salt or shale.
Plutonic rock is widespread throughout the Canadian Shield. The characteristics of plutonic rock have been studied at the Whiteshell Research Area (WRA) near Lac du Bonnet Manitoba. The fracture, hydraulic, thermal, mechanical and hydrogeochemical properties of the crystalline rock have been extensively studied at the Underground Research Laboratory at the WRA. The hydrogeochemical data indicate that below 500 m at the URL, groundwaters are very saline, reducing, and old. The groundwater can be considered as essentially stagnant over the period of concern for a waste facility (1,000,000 years). The very low permeability of the rock supports this conclusion.
From our understanding of the glaciation-deglaciation cycles that have occurred for the last 900,000 years, it is virtually certain that the geosphere above a deep repository will be covered by ice for a significant interval in the next 100,000 years. The impact of the thickness of the ice and remoteness of the biosphere are important factors that must be considered in safety assessment. The presence of the ice cover should significantly reduce the possible impact of a repository on the biosphere.
Author Biography
Dr. Jon F. Sykes
Dr. Jon Sykes is a Professor in the Department of Civil Engineering at the University of Waterloo. He has been a faculty member at the university for over 28 years during which time he has served as Associate Chair for Graduate Studies, Associate Chair for Undergraduate Studies and Department Chair. He teaches undergraduate and graduate courses on environmental modeling, landfill design, wastewater treatment and environmental management.
The research interests of Dr. Sykes focus on the simulation of subsurface flow and contaminant transport in natural and engineered environments. Current research projects include the forensic investigation of sites contaminated with carcinogens, the study of nuclear waste disposal concepts, the integration of groundwater and surface water models and the modeling of groundwater remedial technologies.
Dr. Sykes has extensive experience in the Canadian high-level radioactive waste program as a result of past work with Intera Technologies and Ontario Hydro, and current work with Ontario Power Generation.
He has been an expert witness on numerous contaminated groundwater cases including working for the plaintiffs in the Woburn Massachusetts Toxic Waste Trial (the case is described in the book and movie entitled Civil Action) and for the defendants in the Toms River New Jersey Cancer Cluster.
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4.3 Natural and Anthropogenic Analogues - Insights for Management of Spent Fuel
Paul McKee & Don Lush, Stantec Consulting
Spent nuclear fuel is highly radioactive when discharged from reactors, but the inventory of radioactive materials declines very rapidly over the first ten years, when used fuel is stored underwater at reactor sites, and over the next 50 to 100 years when used fuel is stored in dry storage facilities. Beyond this initial period, used fuel disposal in Canada will either be in surface or near-surface facilities, or in deep underground repositories. Over the first 100,000 years, used fuel remains significantly more radioactive than the equivalent mass of natural uranium from which it was derived; however, after this period, the radioactive inventory approaches the inventory present in the natural uranium used originally to make the fuel. Thus, the need for long-term containment and isolation of the waste diminishes over the very long term as radioactivity levels diminish.
Natural analogues are used by scientists and engineers to help develop and validate models of the performance of used fuel repositories over time, and provide examples of the behaviour of radioactive substances and structural materials pertinent to repositories over time scales of interest (thousands to billions of years). These analogues provide tangible indirect evidence supporting the long-term safety of repositories to the public and government agencies. This background paper provides a brief description of several analogues relevant to spent fuel management in Canada, including descriptions of the uranium ore bodies that were natural reactors, other natural deposits of uranium found around the world, as well as both natural and archaeological analogues for isolation and containment materials and systems.
Author Biographies
Paul McKee, M.Sc., Principal, Radiation Ecologist
Mr. McKee is a Principal at BEAK, with about 20 years of environmental consulting experience, with substantial expertise in the nuclear industry. Mr. McKee's experience includes extensive work with the nuclear industry and with Ontario Hydro.
Representative projects include work for the Atomic Energy Control Board (development of derived release limits for radioactive substances; risk assessment pertaining to radioactive soils near Port Hope; risk assessment pertaining to the disposal of incidental radioactive wastes by hospitals, university laboratories and private industry); for uranium mines (radiological assessments for Cigar Lake Mining Corporation, Madawaska Mines, the Cluff Lake Mine and various uranium properties in northern Saskatchewan, Ontario and Labrador as regulated by the province governments and the AECB); as well as for other nuclear energy agencies including Atomic Energy of Canada Limited (development of contaminant pathways models for tritium, carbon-14 and iodine-129;).
Mr. McKee's decommissioning experience includes source inventories and decommissioning of the Kitt's and Michelin radioactive waste rock dumps in northern Labrador for Consolidated Edison, an evaluation and comparative risk assessment for various disposal options for the Surrey Low-Level radioactive waste for Atomic Energy of Canada Limited, and a survey and cleanup of radium-contaminated soils in Scarborough, Ontario.
His experience for Ontario Hydro includes Project Management of the E15/E16 environmental assessments for proposed new CANDU generating stations at Darlington and the North Channel, and senior or project management responsibilities on several other environmental assessments.
His experience in the area of spent fuel management includes work on a project for Environment Canada assessing the AECL disposal concept presented to the Seaborn panel hearings.
Donald Lush, Ph.D., Stantec Consulting
Dr. Lush received his PhD in biology from the University of Waterloo in 1973. Following his graduation he entered the environmental consulting industry with Beak International and has been in the private sector ever since. He is presently a senior consultant with Stantec.
During his career he has worked for all of the major industrial sectors in Canada on a wide cross section of environmental issues. During the past decade he has spent the majority of his time in working with the nuclear industry in addressing environmental issues associated with the release of and investigating the various environmental pathways through which radionuclides migrate through the environment.
He has worked as a consultant for all sectors of the nuclear fuel cycle in Canada:
- In the mining area he has carried out numerous environmental assessments for new mines, upgrades for existing mines and decommissioning assessments for uranium mines in the process of being decommissioned;
- He has worked with Canada’s refiners of uranium in addressing a number of environmental issues ranging from the assessment of new refining facilities to addressing operational concerns;
- At the energy production stage he has worked with reactor operators in addressing many of the environmental issues associated with the operation of nuclear power plants;
In dealing with nuclear waste he has acted as a consultant to Environment Canada, AECL, OPG, NRCan and CNSC as well as the NEA and the IAEA.
Dr. Lush is currently serving as a special advisor to the IAEA addressing issues associated with the international application of safety assessment methodologies to the question of long term nuclear waste management.
In the more academic area Dr. Lush has worked with the National Sciences and Engineering Research Council (NSERC) in training a number of Industrial Post Doctoral students, participating on a number of NSERC grant review panels, chairing NSERC Industrial Research Chair committees and participating on PhD committees. He currently serves on NSERC’s industrial partnerships committee. He has also lectured at several Canadian Universities and to the US National Academy of Sciences on the future of technology and its role in society.
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4.4 The Chemical Toxicity Potential of CANDU Spent Fuel
Don Hart & Don Lush, Stantec Consulting
The purpose of this background paper is to identify elements in CANDU spent fuel that should be included in environmental assessments when demonstrating “safety” with respect to chemical toxicity in long-term storage or disposal of spent fuel. It should be noted that previous assessments have demonstrated the safety of specific storage/ disposal concepts with respect to radiotoxicity, and similar demonstrations can probably be made with respect to chemical toxicity. This paper is not intended to be a safety assessment. However, it is useful to develop a rationale by which such assessments can focus on the elements of greatest potential concern. The rationale presented herein involves very conservative assumptions such as rapid chemical release from fuel and unretarded transport to the biosphere. The resulting short list of chemicals of potential environmental concern provides a starting point for subsequent safety assessment, in that the onus is on the proponent to demonstrate why conditions in the long-term management facility and surrounding environment will be such that these chemical elements do not pose unacceptable environmental risk.
Author Biographies
Donald R. Hart, Ph.D., Stantec Consulting
Dr. Don Hart is an environmental biologist with Stantec Consulting Ltd. His expertise includes ecotoxicology, radioecology, risk assessment and contaminant pathways analysis.
He completed post-doctoral work on radiation effects at the Whiteshell Nuclear Research Establishment, and on genetic toxicology at the University of Ottawa, and began environmental consulting in 1983.
Over the past 20 years, he has participated in a wide variety of environmental assessments involving both chemical contaminants and radioactive materials. These studies have encompassed all aspects of the nuclear fuel cycle, from uranium mining and milling, to nuclear fuel fabrication and power generation, to radioactive waste disposal.
Donald Lush, Ph.D., Stantec Consulting
Dr. Lush received his PhD in biology from the University of Waterloo in 1973. Following his graduation he entered the environmental consulting industry with Beak International and has been in the private sector ever since. He is presently a senior consultant with Stantec.
During his career he has worked for all of the major industrial sectors in Canada on a wide cross section of environmental issues. During the past decade he has spent the majority of his time in working with the nuclear industry in addressing environmental issues associated with the release of and investigating the various environmental pathways through which radionuclides migrate through the environment.
He has worked as a consultant for all sectors of the nuclear fuel cycle in Canada:
- In the mining area he has carried out numerous environmental assessments for new mines, upgrades for existing mines and decommissioning assessments for uranium mines in the process of being decommissioned;
- He has worked with Canada’s refiners of uranium in addressing a number of environmental issues ranging from the assessment of new refining facilities to addressing operational concerns;
- At the energy production stage he has worked with reactor operators in addressing many of the environmental issues associated with the operation of nuclear power plants;
- In dealing with nuclear waste he has acted as a consultant to Environment Canada, AECL, OPG, NRCan and CNSC as well as the NEA and the IAEA.
Dr. Lush is currently serving as a special advisor to the IAEA addressing issues associated with the international application of safety assessment methodologies to the question of long term nuclear waste management.
In the more academic area Dr. Lush has worked with the National Sciences and Engineering Research Council (NSERC) in training a number of Industrial Post Doctoral students, participating on a number of NSERC grant review panels, chairing NSERC Industrial Research Chair committees and participating on PhD committees. He currently serves on NSERC’s industrial partnerships committee. He has also lectured at several Canadian Universities and to the US National Academy of Sciences on the future of technology and its role in society.
Resources
4.5 Review of the Possible Implications of Climate Change on the Long-Term Management of Spent Nuclear Fuel
Gordon A. McBean, Ph.D., FRSC
There is now strong evidence that the climate is changing and will change at an accelerating rate in the coming century. It will be several centuries before climate is stabilized. Changing climate will bring with it more intense weather events and changing groundwater, lake and sea levels. These weather-related events will change the risks to storage, disposal and transportation facilities for spent nuclear fuels. Over the next several hundred years, climate could stabilize but in the interim there are risks of rapid climatic changes or discontinuities. These risks become more likely if emissions of greenhouse gases continue at high levels and push the climate system far from that of the past few thousand years. Model studies indicate that the onset of the next ice age will be delayed to beyond the next 10,000 years but it will inevitably come with major impacts on any surface facilities and risks to deep geological disposal.
Climate change is a reality and it brings risks that must be factored into the long-term management of spent nuclear fuel. The scientific basis for the risk analysis is available and with an adaptive management approach, the new knowledge can be factored in as the decades pass. The broader impacts of climate change on society will increase risks to the stable governance systems needed for maintenance of facilities.
Author Biography
Gordon A. McBean
Professor and Research Chair, Institute for Catastrophic Loss Reduction and Departments of Geography & Political Science The University of Western Ontario.
Dr. Gordon McBean received his B.Sc. in Physics and Ph.D. in Oceanography from the University of British Columbia and a M.Sc. in Meteorology from McGill University. He was a scientist in Environment Canada from 1970 to 1988 when he was appointed Professor and Chair of the Atmospheric Science Program at UBC. In 1992, he was appointed Head, Department of Oceanography. From 1994 to 2000, he was Assistant Deputy Minister responsible for the Meteorological Service of Environment Canada. He was appointed to his present position in July, 2000.
Dr. McBean’s research interests are in atmospheric and climate sciences, ranging in scope from the natural sciences of the phenomena to the policies of governments and responses of people to them. He was Chair, international Scientific Committee for the World Climate Research Programme of the UN agencies from 1988 to 1994. He was a lead author for the First and Second Assessment Reports of the IPCC. As ADM for the Meteorological Service, he was responsible for climate science in the federal government and a member of the Canadian delegation to Kyoto and other meetings.
He is now undertaking research on changing climate and weather systems and the science-policy interface as Lead for the Integrating Theme of ArcticNet, a newly established research program on climate change and its impacts in the coastal Canadian Arctic. An area of interest is the changing occurrence of extreme weather events with climate change, their influence on public systems and strategies for adaptation.
In addition to his activities at UWO, Dr. McBean is active nationally and internationally. He is Chair of the Board of Trustees of the Canadian Foundation for Climate and Atmospheric Sciences, lead author for the Arctic Climate Impact Assessment’s chapter on the climate system and member of the International Council for Science Advisory Committee on the Environment. He has received the Patterson Medal for distinguish contributions to meteorology by a Canadian and is a Fellow of the Royal Society of Canada, the Canadian Meteorological and Oceanographic Society and the American Meteorological Society.
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4.6 Review of the Implications of Microbiological Factors on the Long-term Management of Used Nuclear Fuel
D. Roy Cullimore, Ph.D. R.M., Droycon Bioconcepts Inc.
This paper outlines the need to recognize and include factors relating to the subsurface biosphere in the design and establishment of any used nuclear fuel storage or disposal concepts which may be developed.
Following an introductory chapter, Chapter 2 gives an overview of the science of microbiology, particularly from the environmental and ecological perspectives. Chapter 3 considers the critical microbiological issues with respect to the storage and disposal of used nuclear fuel. The influences of natural phenomena on microbiological aspects of the containment are addressed in Chapter 4, and Chapter 5 summarizes the potential forms of microbiologically mediated movement of the radionuclides from containment.
The key points arising from this review include:
- Microbial populations (particularly the Archea) are found throughout the biosphere and several kilometers deep into the geosphere.
- These communities exist anywhere they can exploit an energy gradient (pH gradient, redox gradient,) that may be driven by radiation, temperature, etc.
- The introduction of a used-fuel disposal facility deep into the geosphere will create local gradients that will act as a source of energy for Archea and bacteria capable of exploiting these gradients.
- The consequences of this exploitation could involve increasing the rate at which radionuclides contained in the facility are solubilized, the chemical form of the solubilized radionuclides and as a consequence their potential mobility through the geosphere.
- This in turn may influence the flux of these radionuclides into the receiving surface biosphere where human beings and the ecosystem on which our species depends is adversely affected.
Author Biography
D. Roy Cullimore, Ph.D. R.M., Droycon Bioconcepts Inc.
Roy Cullimore has a Ph.D. in agricultural microbiology and taught at the University of Regina for 33 years.
An inventor, author of a series of books on sustainable water wells and is an applied microbial ecologist, he dove to conduct scientific experiments on the RMS Titanic in 1996, 98 and in 2003.
Now Roy is President of a biotechnology company in Regina.
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