6.4 RADIOACTIVITY

6.4.1 Nuclear Task Force Mandate

In 1995 IJC authorized a Nuclear Task Force to review, assess and report on the state of radioactivity in the Great Lakes and to carry out other activities IJC might direct. IJC requested the Task Force to complete its review and assessment by 1997 and recommend additional projects based in part on three criteria:

• the Task Force's findings, based on work performed in preparing its status report, would substantiate a priority list of nuclear problems requiring analysis and remediation;
• concerns of IJC Commissioners; and
• problems brought to the Task Force's attention in the course of its work.

The Task Force determined that an inventory of radionuclides for the Great Lakes was essential to address the state of radioactivity in the lakes, so undertook to produce such an inventory. Key material in the inventory report is summarized below. The full report is in the final stages of preparation.

What Is an Inventory of Radionuclides?

An inventory of radionuclides attempts to quantify and organize information on the sources, levels, distributions, receptors and repositories of radioactivity. It is numerical, but not theoretical modelling, part of a material balance study of radioactive substances found in the Great Lakes basin. An inventory is a natural starting point to evaluate many radioactivity issues. It organizes information on what exists and where. Without an inventory, basic risk assessment analysis cannot be performed, nor can the aspects of sources, distributions and pathways of radionuclides requiring special attention be determined.

The Agreement contains a specific objective for radioactivity. In the 25 years of the Agreement's existence, neither the objective nor the subject of radioactivity drew much IJC attention. With the impending decommissioning of nuclear power plants, the growing problems of nuclear waste and the signing of a Comprehensive Test Ban Treaty on September 24, 1996, posing a plutonium disposal problem, general concerns about the effects of radioactivity on humans and ecosystems have made the subject of radioactivity very timely. The Agreement also espouses an ecosystem approach, which the Task Force used to place in perspective the extent to which radionuclides may be environmental factors in the dynamics of Great Lakes ecosystems.

Historical Perspective

From 1945 to 1963, radioactive fallout from the atmospheric testing of nuclear weapons was the main source of artificial radioactivity to the Great Lakes. Following the Limited Test Ban Treaty in 1963, atmospheric testing continued sporadically through 1980. During the 30-year period of the treaty, the decay of residual nuclear debris from atmospheric testing has reduced nuclear fallout sufficiently to make it a secondary source of artificial radioactivity to the lakes.

Starting in 1962 with the commissioning of the Big Rock Point nuclear power plant, reactors in the basin added new sources of artificial radioactivity to the lakes. The number of nuclear power plant facilities increased rapidly until 1974, then more slowly until 1993. There are currently 19 nuclear power plants in, and with emissions to, the basin. Two other nuclear power plants operate in Great Lakes states near the basin, but their emissions enter other watershed and airshed regions. Decommissioning of reactors may begin as early as 2000 with expiration of the license for Big Rock Point.

Other large sources of radioactivity in the basin include a tritium ( ³ H) removal plant at Darlington (Lake Ontario), uranium mine and mill tailings entering the Serpent River region (North Channel), uranium refining and conversion at Blind River (North Channel) and Port Hope, Ontario, and weapons facilities and auxiliary operations at Ashtabula, Ohio. Not all of these facilities are currently operating but they remain sources of radioactivity to the basin.

Previous IJC reports have reviewed radioactivity in the Great Lakes basin, specifically those of the Water Quality Board in 1977, 1978, 1979, 1983 and 1987. Those reports discussed the routinely studied radionuclides: ³ H, strontium ( ⁹⁰ Sr), cesium ( ¹³⁷ Cs), radium ( ²²⁶ Ra), uranium ( ²³⁸ U) and iodine ( ¹³¹ I); and alpha, beta, and gamma radiation and a few occasionally reported nuclides: antimony ( ¹²⁵ Sb), cobalt ( ⁶⁰ Co) and thorium ( ²³² Th). The reported parameters can help assess the effects of radioactivity on the Great Lakes, but are inadequate to address such issues as ecosystem impacts of radioactivity, technology and resource needs for nuclear waste disposal, the decommissioning of nuclear reactors and interactions of toxic chemicals and radiation.

6.4.2 Sources of Radioactivity

Sources of radioactivity include natural background radiation from cosmogenic and terrestrial origin, residual debris from weapons testing in fallout, atmospheric deposition of nuclides emitted in gaseous discharges from various facilities, liquid emissions from various facilities, and many smaller sources that require identification. Facilities include nuclear power plants, mining and milling operations, refining, conversion and fuel fabrication and reprocessing operations, and tritium recovery operations. Smaller sources include research reactors and laboratories, hospital nuclear medicine departments and industrial operations. These are discussed in the Task Force's report, along with comments on data acquisition and analysis procedures. The material below focusses on emissions from nuclear power plants and secondary sources.

Emissions from Nuclear Power Plants

Table 14 presents information on licensed nuclear power plants in the Great Lakes basin. There are heavy water reactors (HWR) and two kinds of light water reactors (LWR), the pressurized water reactor (PWR) and boiling water reactor (BWR). U.S. facilities are all LWR systems and Canadian facilities all HWR systems. The names describe the reactor cooling and moderating systems used. A fourth type of reactor at university and hospital research laboratories is the gas cooled reactor, which is not used for electric power production. Under development is a fast breeder reactor (FBR). The Fermi 1 nuclear power plant had a FBR system but was decommissioned following an accident.

The relative quantities of radionuclides produced depend on the reactor type, including the technology and materials of construction, the amount of electricity generated, and the processes used to handle effluents and waste products. United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) documents present nuclear power plant data in a format based on reactor type and power production. UNSCEAR applies a special averaging technique, normalization, which puts nuclide production in a reactor on a unit energy basis averaged over all reactors worldwide of the given type. The Task Force calculated normalization of the data but did not find it useful.

Table 14 NUCLEAR POWER PLANT REACTORS IN THE GREAT LAKES BASIN ^a

Reactor	Start-Up (Year)	Net Electrical	Reactor Type b Power MW(e)	License Expiration (Year)
United States
Big Rock Point	1962	70	BWR	2000
Nine Mile Point 1	1969	625	BWR	2009
R.E. Ginna	1970	420	PWR	2009
Point Beach 1	1970	497	PWR	2010
Palisades	1971	700	PWR	2007
Point Beach 2	1972	497	PWR	2013
Zion 1,2	1973	2 x 1050	PWR	2013
D.C. Cook 1	1975	1050	PWR	2014
Kewaunee	1974	520	PWR	2013
J.A. Fitzpatrick	1975	800	BWR	2014
Davis-Besse 1	1977	910	PWR	2017
D.C. Cook 2	1978	1050	PWR	2017
Fermi 2	1985	1090	BWR	2025
Perry	1986	1205	BWR	2026
Nine Mile Point 2	1987	1070	BWR	2026
Canada
Douglas Point c	1966	220	HWR	1996
Pickering A	1971/1973	4 x 508	HWR	1996
Pickering B	1983/1984	4 x 508	HWR	1996
Bruce A	1976/1979	4 x 750	HWR	1996
Bruce B	1984/1987	4 x 840	HWR	1996
Darlington A	1990/1993	4 x 850	HWR	1996

^a. Sources of data: U.S. Nuclear Regulatory Commission, Information Digest, 1995 edition; Tracy and Ahier (1995), "Radionuclides in the Great Lakes Basin;" UNSCEAR 1977, 1982, 1988; Reporter, AECB Newsletter, Spring 1996. See the Task Force's report for full citations.

^b. BWR: boiling water reactor; PWR: pressurized water reactor; HWR: heavy water reactor

^c. No longer operating but not yet decommissioned.

Atmospheric emission data from nuclear power plants in the basin show varying degrees of completeness, specificity and descriptive information. All power plants report particulate matter, ³ H, total beta-emissions excluding ³ H, and ¹³¹ I. Some plants report "total noble gases," alpha and gamma radiation, and others list specific noble gas radionuclides (e.g. ⁴¹ Ar, ⁸⁵ Kr, ¹³³ Xe, ¹³⁵ Xe) and other radionuclides of iodine (e.g. ¹³³ I, ¹³⁴ I, ¹³⁵ I). The measurement of xenon nuclides depends on their energy spectrum; those emitting gamma radiation of less than 1 MeV (1 million electron volts) might not be reported. Canadian HWR plants generally report fewer radionuclides. Canadian regulation is based on the consideration of the effect of all radionuclides migrating through all pathways to humans. While reporting of many nuclides may not be required, sometimes power plant authorities do collect this information but without any consistency or regularity.

Emissions from Secondary Sources in the Great Lakes Basin

Sources not associated with releases from nuclear fuel cycle activities are designated as secondary sources. This does not imply that such sources of radioactivity or their emissions are secondary in importance. These are either military or civilian (e.g. hospitals, industrial and commercial users and universities) or activities that release a naturally occurring radioactive material from an otherwise trapped matrix (technological enhancement), provided that the technological enhancement did not result from an activity associated with the nuclear fuel cycle. Although emissions from a single source may be negligible, the large number of such sources in the basin may make their combined effect significant. The Task Force's report addresses open sources of radionuclides that may eventually be released to the atmosphere or to sewer systems draining into the lakes. Excluded are an even larger category of sealed source uses, which would not be expected to release radionuclides to the air or water. Sealed sources could become a problem only if disposed of indiscriminately in municipal landfills.

All users of radioisotopes must obtain a license from the national regulator, the Atomic Energy Control Board (AECB) in Canada or the Nuclear Regulatory Commission (NRC) in the U.S. Regular reporting of measured or estimated emissions is a condition of maintaining the licence. This information is available from the regulators, but not usually in a convenient or machine-readable format. The Task Force obtained information from most of the Canadian users but not the larger number of U.S. users. Although incomplete, these data indicate the magnitude of the emissions. A crude estimate of total secondary emissions to the basin can be obtained by considering the ratio of the total population in the basin to that on the Canadian side.

The Task Force inquiry on secondary sources emphasized research reactors at universities and industrial sites and the use of radioisotopes in hospitals, research facilities and medical facilities other than hospitals. The Canadian data, obtained with the cooperation of AECB, came through questionnaires asking licensees to estimate their emissions. Responses were obtained from 85 percent of the licensees, which was assumed to include virtually all those with significant emissions. The greatest users of radionuclides are nuclear medicine departments of hospitals, which administer radioisotopes to patients for diagnostic purposes. Lesser amounts of radionuclides are used for research or industrial purposes. About 75 percent of the radioisotopes administered to patients are assumed to be excreted to sewers.

The Task Force's report summarizes the results for secondary Canadian users of radioisotopes for 1993, 1994 and 1995. For most radionuclides emissions are a few megabecquerels per year, although a few can reach gigabecquerel per year levels. These are insignificant compared to the tera- and petabecquerel levels released from nuclear reactors. Furthermore radionuclides from secondary sources all have half lives significantly less than one year and therefore do not accumulate from year to year. (Note: Becquerel is a measure of the rate of decay of a radioactive substance; mega = 10 ⁶ , giga = 10 ⁹ , tera = 10 ¹² and peta = 10 ¹⁵ )

6.4.3 Environmental Monitoring Data from Nuclear Facilities

The Task Force collected and examined environmental monitoring data provided by the operators of the major nuclear facilities in the basin. Virtually all radionuclide activities or concentrations were reported as the lower limit of detection. This does not necessarily mean that various radionuclides were absent from the environment, nor that their environmental impacts were insignificant. Rather, it means that the radionuclides could not be detected by the instrumentation and procedures used.

Rather than reproducing the results from all station reports, the Task Force report presents three typical examples to illustrate the general significance and the limitations of these results:

• artificial radionuclides in shoreline sediment, fish and surface waters near the Nine Mile Point nuclear station (Oswego County, New York) during 1994;
• environmental monitoring results from the Donald G. Cook nuclear plant operated by the Indiana Michigan Power Company; and
• radionuclides in Lake Ontario fish in the vicinity of the Pickering nuclear generating station during 1988.

Although the Task Force examined a significant quantity of environmental data collected by nuclear facility operators, the analysis of open water data was constrained by the limited number of lakewide monitoring surveys conducted in the past, making environmental and biological assessments difficult to perform. IJC previously recommended (in 1987) that radionuclide monitoring be conducted in the open waters of the Great Lakes every five years in a manner similar to the surveys conducted by the National Water Research Institute, Environment Canada, between 1973 and 1983. The last open water surveillance program, in 1990 by Environment Canada, was limited to Lake Ontario. Its scope was to ensure that nuclear facilities and other sources of radioactive contamination were controlled in a manner that met the broad objectives of the Lake Ontario Toxics Management Plan and the Agreement.

6.4.4 Inventories for Biological Compartments

One of the most difficult components of an inventory is assessing the radionuclide content of biota. Organisms are continuously exposed to radiation and radioactivity, but the extent to which they act as repositories for radioactive isotopes of various elements involves a complex set of metabolic and physiological processes that has not been intensively studied for purposes of establishing an inventory. Most of the research entails use of radioactive versions of selected elements or compounds (tracers) that are important in the physiological functioning of various species in order to understand the pathways and mechanisms of those physiological processes and functions. Almost none of the studies extended the data from tracer studies to establish biological compartmental inventories of radionuclides.

Because most radionuclides entering the Great Lakes move to sediments as their final repositories, the need to study biological compartments and establish radionuclide inventories for biota must necessarily emphasize those nuclides that have known physiological functions because of their stable element versions, and those which can become available to biota through natural physical, chemical, geological and biological processes which modify their movement and reaction patterns. Still, it is very difficult to detect those elements in the water column unless very large water samples (300 litres) are taken. The major exceptions are tritium and isotopes of strontium and rubidium. The Task Force reviewed considerable data on physiological and metabolic behaviour in lake biota of various elements and realized that for the Great Lakes, the production of an inventory for radionuclides in biological compartments meant addressing several generic problems related to the lakes, their biota and the nature of available data. The Task Force report addresses individual elements and nuclides with respect to bioaccumulation and biomagnification factors for freshwater biota. The work emphasizes studies with stable nuclides, but some data derived from radionuclides appear, mainly cesium and potassium.

6.4.5 Conclusions

The Task Force's key conclusions, based on inventory work to date, are presented below.

Adequacy Of Monitoring

1. Monitoring meets the needs of the relevant atomic energy acts in the U.S. and Canada but is not designed to look at environmental cycling of radionuclides.
2. Quality assurance protocols are also designed for compliance monitoring. Therefore, it is not possible to tell if nuclear plant monitoring is satisfactory to meet the goals and objectives of the Agreement.

The information base used to assemble the inventories, notably emissions data from nuclear facilities and monitoring data off site of the facility but keyed to its activities, has many problems. The Task Force reviewed monitoring protocols (i.e. directives, instrumentation, sampling plans, chemical analysis techniques, station and monitoring site locations, quality assurance considerations, data reporting and statistical analysis procedures) and found the following.

• The primary goal of all monitoring is to show that a given nuclear facility complies with the environmental requirements of its license. In turn, the environmental requirements in the license are dictated by the atomic energy legislation of each country. The Task Force concluded that the current state of monitoring is that of compliance.
• The atomic energy legislation of each country prescribes a maximum annual allowable human exposure to radiation as the basis for setting environmental monitoring requirements for each individual radionuclide. Dose assessment models translate this exposure criterion into allowable discharges of specific radionuclides and types of energy.
• The dose assessment models used to derive allowable discharges have a very limited relationship to the cycling of radionuclides for development of an inventory. The models make assumptions about the distribution of the activity of a given nuclide in different environmental compartments and the fraction of that nuclide's activity that is taken up by biota, assimilated and retained as opposed to taken up and then released, excreted or otherwise removed. The models also make specific assumptions about the transfer of radioactivity from retained nuclides in other biological compartments and the movements of nuclides through various foodwebs. This includes direct uptake by humans through drinking water or through intermediate uptake and bioaccumulation through food species.
• When monitoring environmental media, a particular characteristic of radionuclide measurements is that the lower limit of detection for a given sample depends on the time lapse between collection and analysis. This arises because the radioactivity in the sample continues to decay after sample collection and all measured activities must be corrected back to the time of collection. Thus the reported lower limits of detection may vary considerably from one laboratory to another, or even for measurements carried out in the same laboratory at different times after collection. For this reason it is not practical to use reported lower limits of detection to derive an upper bound for radionuclide inventories in the Great Lakes, or in any environmental compartment within the lakes.

Need for Reassessment of Environmental Monitoring of Nuclear Facilities to Support the Agreement

The comments in the four bullets above are generic and address specific data problems associated with individual facilities in each country. This led the Task Force to conclude the following.

3. There is a strong need for a comprehensive review of all monitoring activities at nuclear facilities with a view toward making monitoring more accommodating to the needs of the Agreement.
4. Since there are policy and fiscal implications to any likely expansion or adjustment of monitoring efforts, the Task Force calls upon the relevant atomic energy and environmental agencies in each country to explore in detail the kinds of monitoring needed and changes to current protocols.

Reporting

The Task Force concludes the following.

5. There are significant differences in the scope of data reporting and analysis of U.S. states and Canadian nuclear power plant emissions.
6. The monitoring for toxic chemicals used in large quantities at nuclear power plants needs to be included in analyses of their impact on the Great Lakes ecosystem.
7. The monitoring of radionuclides does not include identification of radioactive forms of toxic chemicals.
8. The details of U.S. data reporting are greater and more helpful for the purpose of ecosystem impact analysis than is Canadian reporting, but U.S. data come in mixed formats which make them difficult to organize.
9. U.S. facilities historically have aggregated their data on an annual basis, but the contract to continue this aggregation has apparently been discontinued as a cost savings measure.
10. Current biological monitoring and reporting is neither consistent nor adequate for lakewide assessments.
11. Developing inventories for specific isotopes in biological compartments was difficult because no common reporting format is used to produce/present biological data.

Conclusions 5 - 11 describe problems associated with using specific data from individual nuclear facilities and associated monitoring sites. The conclusions address the scope of data collection, the completeness of such collection from specific sites and facilities, the methods of data reporting and aggregation, and the problems of handling data from variable formats. In addressing these specific data issues, the Task Force noted the following important considerations.

• Since all Canadian nuclear power plant facilities belong to one corporate entity, Canadian data are quite uniform in their scope, reporting and formats. U.S. nuclear power plant facilities, however, belong to 15 different corporate entities. Thus, while U.S. facilities report data that meet requirements set by NRC, these data often vary in scope, reporting and formats.
• To bring some semblance of order to the data from U.S. nuclear power plants, NRC had previously contracted with the Brookhaven National Laboratories to produce an annual document which assembled in a standardized format emissions data from these plants. These reports often appeared three years after the individual facilities reported their emissions for a given year and usually reflected the varying timetables and lag times in the submission of data from U.S. facilities. The termination of the Brookhaven contract in 1996 without a new contractual effort represents a serious reporting setback for those groups interested in the radionuclide emissions from U.S. nuclear power facilities.
• U.S. reporting tends to include a far greater number of radionuclides than Canadian reporting, although the Task Force could not always judge whether the more extensive reporting by U.S. sources is more comprehensive and useful than Canadian reporting. U.S. data often report nuclides at extremely low levels, basically levels of detection. The uncertainties in the reported data may call into question the information value of reporting selected radionuclides in certain emissions at levels of detection. On the other hand, the aggregated reporting of these radionuclides at trace levels reveals much about the performance of nuclear reactors and allows for a better understanding of the relationship between a particular reactor technology and the generation of its nuclear waste products.
• Biological data have multiple problems, ranging from sample descriptions to variable lower limits of nuclide detection. The latter problem is particularly troubling because, for many nuclides, the lower limit changes with every sample even when methodology and instrumentation do not change. This situation arises because of the need to back calculate and correct nuclide data to the original time of sampling. Radioactivity continues to decay in a sample after collection and through the period of storage, analysis and reporting. To place all measurements on a common basis, the nuclide levels must be corrected to those at the time of sample collection.
• The large-scale use of nonradioactive toxic chemicals at nuclear power plants is often overlooked in establishing toxic substance inventories and monitoring activities. Among the chemical problems are those related to weed control on roadways and fence areas in a facility and at its perimeter, calling for considerable use of herbicides and pesticides. Cooling towers require antifouling and water softening agents and a variety chemicals to maintain heat transfer surfaces at their highest heat exchange capacities. The corrosion and fouling of piping and cooling system components, including water intakes, has led to widespread use of anti-corrosion and fouling control agents. Zebra mussel problems have led to increased use of chlorine as a decontaminating agent. How these chemicals behave in contact with radioactivity is not assessed in any monitoring work.

Harmonization of Monitoring and Data Reporting

The Task Force concludes the following.

12. There is a need to harmonize the approaches used in the U.S. and Canada with respect to the scope of monitoring, the nuclides reported and the reporting of biological data. International cooperation among the nuclear agencies of both countries would accomplish much of this harmonization.

Biological Transfer Factors for Lake Systems

The Task Force concludes the following.

There is a special issue of the reporting of nuclear data that applies specifically to the Great Lakes. It has the serious possibility of rendering incorrect all dose assessment factors used in establishing the transfer of radionuclides from biota to humans in the region of interest. The issue relates to the transfer factors which estimate biotic uptake of radionuclides. These factors traditionally have been derived from work done in rivers and oceans, rather than fresh water lakes. The Task Force is concerned that the factors derived from riverine and oceanic systems are inappropriate for use in the Great Lakes.

In developing the inventory for radionuclides, the Task Force noted that the bioaccumulation, biomagnification and transfer factors used to describe the cycling of radionuclides and their transfer along exposure pathways to biota, including humans, came from the long history of work done in marine, estuarine and river environments. This work stemmed from interests in the deposition of radionuclides in the oceans and the transport of nuclides down rivers and estuaries from discharges to the oceans. The comparable studies for lakes were virtually nonexistent. Yet for the Great Lakes, the need for transfer factors that describe lake environments is critical.

To what extent can riverine, estuarine or oceanic data be used to infer lake situations for the cycling and transfer of radionuclides in environmental compartments? Where no data exist, it is the obvious approach. But why use marine data when lake data exist that can be used to develop the appropriate factors? The Task Force undertook such analysis after discovering the nuclear sciences literature was not extensive in its coverage of lake situations. To those who believe that the oceanic work, excellent as it was, should be used for the Great Lakes without confirmation, the Task Force cites two examples: nuclides of silver, specifically ^110,110m Ag, and nuclides of lanthanide elements (rare earths). These nuclides appear in the effluents of nuclear power plants from the Great Lakes.

Silver, in the presence of chloride (the main anionic constituent of estuaries and oceans) forms silver chloride, a compound with such a low water solubility that it is a basis for the quantitative analysis of silver. To reverse the solubility requires a large quantity of either ammonia or cyanide ion, such levels in environment being toxic in their own right. Because of nitrogen limitations of marine and estuarine environments, ammonia would not be present in these environments unless a specific pollutant source were present or an unusual algal species dominated plankton production. In lakes and rivers, however, where chloride is low and nitrogen is rarely limited, the presence of silver nuclides in soluble ionic form is expected. Only soluble silver is subject to biouptake, and biouptake factors for silver in fresh water systems are as high as 100,000. However, factors for silver do not exist for river biota, and thus the marine factors are used.

Rare earth elements have unusual biological uptake. Freshwater organisms can often selectively accumulate these elements and, except for yttrium, cerium, lanthanum and, in a few instances europium, usually only the even atomic numbered elements accumulate in freshwater biota. Thus it is not correct to assume that all lanthanides accumulate and to use the marine factors which rarely discriminate among lanthanides, but rather use cerium and lanthanum as surrogates for all the elements in this group.

Nuclides of Concern

Based on its studies, the Task Force concludes the following.

14. There are isotopes which merit separate studies and further reporting because of use and discharge patterns; physical, chemical and biological properties; and the special monitoring needs of lakes as opposed to estuaries, oceans and rivers. These include ³ H, ¹⁴ C, ¹²⁹ I, isotopes of plutonium and ²²⁶ Ra.
15. Other nuclides could be a potential concern in special situations: ^99,99m Tc, ³² P, ⁵¹ Cr, ^134,137 Cs, ^141,144 Ce, ^89,90 Sr, ^125,131 I and ⁶⁰ Co.

The isotopes listed in conclusion 14 are those that have exceptionally long half lives, arise from both natural (cosmogenic and primordial) sources and some aspect of the nuclear fuel cycle, and present long term toxicological and ecological problems. Except for ¹⁴ C and ¹²⁹ I, the isotopes are routinely monitored in the Great Lakes. The isotopes listed in conclusion 15 occur often in the discharges of sources other than nuclear power plants as well as in some cases in various components of the nuclear fuel cycle. Under conditions of large scale emission or abundance they merit special monitoring studies.

6.4.6 Membership

Dr. Murray Clamen (Cochair) Canadian Section International Joint Commission 100 Metcalfe Street, 18th floor Ottawa, Ontario K1P 5M1	Dr. Joel Fisher (Cochair) U.S. Section International Joint Commission 1250 23rd Street N.W., Suite 100 Washington, D.C. 20440
Dr. Rosalie Bertell 710-264 Queens Quay West Toronto, Ontario M5J 1B5	Dr. Walter Carey 2563 Snouffer Place West Worthington, Ohio 43235
Dr. Bliss Tracy Head, Radiological Impact Section Environmental Radiation Hazards Division Radiation Protection Bureau Health Canada 775 Brookfield Road (Room 276A) Postal Locator 6302D1 Ottawa, Ontario K1A 1C1	Dr. John Clark Great Lakes Regional Office International Joint Commission 100 Ouellette Avenue Windsor, Ontario N9A 6T3
Mr. Robert Krauel Head, Nuclear Programs and Contaminants Environment Canada 4905 Dufferin Street Downsview, Ontario M3H 5T4	Emilie Lepoutre (Coordinator) Canadian Section International Joint Commission 100 Metcalfe Street, 18th floor Ottawa, Ontario K1P 5M1