Submitted To: Ontario Power Generation Inc. Prepared By: SENES Consultants Limited and AMEC NSS

Transcription

1 RADIATION AND RADIOACTIVITY ENVIRONMENT ASSESSMENT OF ENVIRONMENTAL EFFECTS TECHNICAL SUPPORT DOCUMENT NEW NUCLEAR - DARLINGTON ENVIRONMENTAL ASSESSMENT NK054-REP Rev 000 Submitted To: Prepared By: SENES Consultants Limited and AMEC NSS August 2009

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3 EXECUTIVE SUMMARY Ontario Power Generation (OPG) was directed by the Ontario Minister of Energy in June 2006 to begin the federal approvals process, including an environmental assessment (EA), for new nuclear units at an existing site. OPG has begun this process, and in September 2006 submitted an application for a Site Preparation Licence to the Canadian Nuclear Safety Commission (CNSC) for a new nuclear power generating station at the Darlington nuclear site (DN site). Before any licensing decision can be made concerning a new nuclear generating station, an EA must be performed to meet the requirements of the Canadian Act (CEAA). This (TSD) describes the assessment of effects of the Project on the Radiation and Radioactivity component of the environment. It has been prepared by SENES Consultants Limited, the member firm of the EA Consulting Team with technical responsibility for the Radiation and Radioactivity Effects Assessment. The Radiation and Radioactivity environment is comprised of the following subcomponents where potential effects from the Project could occur: Radioactivity in the Atmospheric Environment (e.g., airborne concentrations); Radioactivity in the Surface Water and Aquatic Environment (e.g., concentrations in surface water, fish, etc.); Radioactivity in the Terrestrial Environment (e.g., external gamma radiation, concentrations in vegetation, etc.); Radioactivity in the Hydrogeology Environment (e.g., concentrations in sub-surface soil, groundwater); Radiation Doses to Members of the Public (including individuals who live, work and recreate in the vicinity of the DN site); and Radiation Doses to Workers (includes Nuclear Energy Workers (NEWs) and non-news on site). The likely effects to the four different environments (Atmospheric, Surface Water and Aquatic Environment, Terrestrial and Hydrogeology) are assessed to be minimized by the Project design and operation assumptions (Scope of Project TSD). No residual adverse environmental effects are anticipated for any of the four environments. The maximum dose for both cooling options (once through cooling and cooling towers) to a member of the public, a resident at a dairy farm is estimated at about 4 µsv/y (0.004 msv/y), which is well below the regulatory limit for members of the public of 1 msv/y (1000 µsv/y) (CNSC 2000). Furthermore, this maximum dose is a small fraction of the annual dose from natural background radiation (about 1,840 µsv/y in Canada). Therefore, based on the Project design and operation assumptions (Scope of Project TSD), no residual adverse effects to the members of the public are anticipated. ES-1

4 The assessment of doses to workers from the Project concluded that based on the implementation of ALARA and the Project design and operation assumptions (Scope of Project TSD), doses to individual workers will be within the regulatory criteria and similar or less than current individual worker doses at the DN site and thus, no residual adverse effects to the nuclear workers are anticipated. Although no residual adverse effects to the members of the public or workers are anticipated, since radiation dose is of great interest, estimated doses to members of the public and to workers are carried forward to the Human Health TSD for further assessment. ES-2

5 TABLE OF CONTENTS EXECUTIVE SUMMARY... ES-1 1 INTRODUCTION Background The New Nuclear Darlington Project The New Nuclear - Darlington (TSD) Description of the al Component EFFECTS ASSESSMENT METHODOLOGY Assessment Framework Assessment Basis, Spatial Boundaries, Methods and Criteria Project Basis for the Assessment Spatial Boundaries for the Assessment Analytical Methods for the Assessment Criteria for the Assessment Process Steps for Determination of Likely Environmental Effects Detailed Screening for Potential Project-Environment Interactions Evaluation for Likely Measurable Changes in the Environment Assessment of Likely Effects on the Environment Consideration of Mitigation and Determination of Likely Residual Effects ASSESSMENT AND MITIGATION OF ENVIRONMENTAL EFFECTS Detailed Screening for Potential Project-Environment Interactions Radioactivity in Atmospheric Environment Evaluation for Likely Change to the Environment Assessment of Likely Effects on the Environment Consideration of Mitigation and Determination of Likely Residual Effects Radioactivity in Surface Water and Aquatic Environment Evaluation for Likely Change to the Environment Assessment of Likely Effects on the Environment Consideration of Mitigation and Determination of Likely Residual Effects Radioactivity in Terrestrial Environment Evaluation for Likely Change to the Environment Assessment of Likely Effects on the Environment Consideration of Mitigation and Determination of Likely Residual Effects Radioactivity in Hydrogeology Environment Evaluation for Likely Change to the Environment Assessment of Likely Effects on the Environment Consideration of Mitigation and Determination of Likely Residual Effects Doses to Members of the Public i

6 3.6.1 Evaluation for Likely Change to the Doses to Members of the Public Assessment of Likely Effects on Doses to Members of the Public Consideration of Mitigation and Determination of Likely Residual Effects Doses to Workers Evaluation for Likely Change to the Doses to Workers Assessment of Likely Effects on the Doses to Workers Predicted Doses to Workers Consideration of Mitigation and Determination of Likely Residual Effects REFERENCES LIST OF APPENDICES APPENDIX A: BASIS FOR THE EA... A-1 APPENDIX B: BACKGROUND ON RADIATION AND RADIOACTIVITY...B-1 APPENDIX C: EXPOSURE PATHWAYS AND PARAMETERS... C-1 APPENDIX D: RADIONUCLIDE RELEASES... D-1 APPENDIX E: AIR DISPERSION MODELING AND UNIT AIR CONCENTRATION FACTORS...E-1 APPENDIX F: WATER DILUTION AND UNIT WATER CONCENTRATION FACTORS...F-1 APPENDIX G: ENVIRONMENTAL FATE... G-1 APPENDIX H: DOSE CONVERSION FACTORS... H-1 APPENDIX I: TRANSFER PARAMETERS AND DOSE CALCULATIONS...I-1 APPENDIX J: RESULTS OF DOSE CALCULATIONS FOR MEMBERS OF THE PUBLIC... J-1 APPENDIX K: MODEL PARAMETER VALUES... K-1 APPENDIX L: SAMPLE CALCULATIONS...L-1 APPENDIX M: OVERVIEW OF QUALITY ASSURANCE... M-1 APPENDIX N: EXISTING REACTOR... N-1 APPENDIX O: SENSITIVITY AND UNCERTAINTY... O-1 ii

7 LIST OF FIGURES Follows Page No Regional Study Area Local Study Area Site Study Area Conceptual Overview of Dose Calculation to Members of the Public Maximum Receptor Locations iii

8 LIST OF TABLES Page No Evaluation Criteria for the Valued Ecosystem Components (VECs) Potential Project-Environment Interactions in the Radiation And Radioactivity Environment Evaluation Criteria used for the Atmospheric Environment (Within the ) Evaluation Criteria used for the Surface Water and Aquatic Environment (within ) Evaluation Criteria used for the Terrestrial Environment (Within ) Evaluation Criteria used for the Hydrogeology Environment Within ) Evaluation Criteria Used for Assessing the Doses to Members of the Public Doses for Maximum Receptor for Each Scenario from Bounding Release With Once Through Cooling Doses for Maximum Receptor for Each Scenario from Bounding Release With Cooling Towers Evaluation Criteria Used for Assessing the Doses to Workers iv

9 SPECIAL TERMS UNITS Bq Bq/kg Bq/L Bq/m 2 Bq/m 3 Bq-MeV/week Bq-MeV/year Bq/month Bq/week Bq/y dw fw g/s Gy GW km L/s L/y m/s mgy msv msv/y MW P-Sv Sv µg/m 3 µgy µsv/y becquerel becquereal per kilogram becquerel per litre becquerel per square meter becquerel per cubic meter becquerel-megaelectron volt per week becquerel-megaelectron volt per year becquerel per month becquerel per week becquerel per year dry weight fresh weight grams per second gray gigawatt kilometre litres per second litres per year meters per second milligray millisievert millisievert per year megawatt person-sievert sievert micrograms per cubic meter microgray microsievert per year ABBREVIATIONS AND ACRONYMS ACR ALARA AP1000 CEAA CNSC CSA DN DNGS EA EIS EPR ICRP Advanced CANDU Reactor As Low As Reasonably Achievable Advanced Passive Reactor Canadian Act Canadian Nuclear Safety Commission Canadian Standards Association Darlington Nuclear Darlington Nuclear Generating Station Environmental Impact Statement Areva s US EPR Reactor International Commission on Radiological Protection v

10 MoE NEW NND OPG RLWMS TSD UNSCEAR VEC WPCP Ministry of the Environment Nuclear Energy Worker New Nuclear Darlington Ontario Power Generation Radioactive Liquid Waste Management System United Nations Scientific Committee on the Effects of Atomic Radiation Valued Ecosystem Component York-Durham Water Pollution Control Plant RADIONUCLIDES Ag-110 Silver-110 Ag-110m Silver-110m (metastable state) Ar-41 Argon-41 Ba-137m Barium-137m (metastable state) Ba-140 Barium-140 Br-84 Bromine-84 C-14 Carbon-14 Ce-141 Cerium-141 Ce-143 Cerium-143 Ce-144 Cerium-144 Co-57 Cobalt-57 Co-58 Cobalt-58 Co-60 Cobalt-60 Cr-51 Chromium-51 Cs-134 Cesium-134 Cs-136 Cesium-136 Cs-137 Cesium-137 Fe-55 Iron-55 Fe-59 Iron-59 H-3 Tritium HTO Tritiated Water I-131 Iodine-131 I-132 Iodine-132 I-133 Iodine-133 I-134 Iodine-134 I-135 Iodine-135 Kr-85 Krypton-85 Kr-85m Krypton-85 (metastable state) Kr-87 Krypton-87 Kr-88 Krypton-88 La-140 Lanthanum-140 Mn-54 Manganese-54 Mo-99 Molybdenum-99 Na-24 Sodium-24 vi

11 Nb-95 Niobium-95 Np-239 Neptunium-239 Pr-143 Praseodymium-143 Pr-144 Praseodymium-144 Rb-88 Rubidium-88 Rh-103m Rhodium-103 (metastable state) Rh-106 Rhodium-106 Ru-103 Ruthenium-103 Ru-106 Ruthenium-106 Sb-125 Antimony-125 Sr-89 Strontium-89 Sr-90 Strontium-90 Sr-91 Strontium-91 Tc-99m Technetium-99m (metastable state) Te-129 Tellurium-129 Te-129m Tellurium-129m (metastable state) Te-131 Tellurium-131 Te-131m Tellurium-131m (metastable state) Te-132 Tellurium-132 W-187 Tungsten-187 Xe-131m Xenon-131 (metastable state) Xe-133 Xenon-133 Xe-133m Xenon-133 (metastable state) Xe-135 Xenon-135 Xe-135m Xenon-135 (metastable state) Xe-138 Xenon-138 Y-91m Yttrium-91m (metastable state) Y-93 Yttrium-93 Zn-65 Zinc-65 Zr-95 Zirconium-95 GLOSSARY Absorbed Dose Air Dispersion Air Immersion ALARA The amount of radiation energy absorbed by a material (biological tissue or inanimate object) through exposure to radiation. The dispersion into the atmosphere of matter and gases that can be carried by air currents. Exposure to radiation emitted from radionuclides in the air. A principle in radiation protection according to which radiation exposures are kept as far below the regulatory limits as reasonable, taking into account social and economic factors. These factors could include, for example, the financial impact of protection measures as balanced against the benefit obtained. vii

12 Alpha Radiation Becquerel Beta Radiation Biota Bounding Release Collective Dose Collective Effective Dose Committed Effective Dose de minimis Derived Release Limit Deterministic Effect Distribution Coefficient (Kd) Dose Conversion Factor Dry Deposition Velocity Particles emitted by some radioactive nuclei, each particle consisting of two protons and two neutrons bound together. The standard international unit of radioactivity equal to one radioactive disintegration per second. High-energy electrons that are emitted by some radioactive nuclei. The animal and plant life of a region. Maximum annual release (airborne/waterborne) from the three potential reactor technologies. The total dose received by all the individuals exposed to a source of ionizing radiation. Collective dose is usually measured in units of person-sieverts. The sum of the effective doses to a group of people from a source of radiation. This term is intended to express the effective dose received during the 50 years after the substance is taken into the body of a person 18 years old or older, or during the period beginning at intake and ending at age 70, after it is taken into the body of a person less than 18 years old. An amount small enough to be of no concern. The release rate for a radionuclide or a group of radionuclides that would result in the average member of the critical group (most exposed group of members of the public) receiving an annual dose of 1 msv. Effects for which the severity increases with dose, and above a threshold dose below which no effects are observed. The distribution coefficient which is the ratio of the concentrations in two different environmental media (e.g., soil and water). Factor used to convert radionuclide exposure to dose. The velocity at which particles in the atmosphere deposit on the ground. viii

13 Effective Dose Elemental Tritium (HT) Environmental Fate Equivalent Dose Exposure pathway Farm Product Gamma Radiation Gross Beta Groundshine Groundwater Groundwater Infiltration Rate Half-Life Isotopic Discrimination Factor This term is intended to express radiation doses in a manner such that the long-term biological harm to humans will be approximately the same per unit of effective dose, regardless of the type of radiation involved or the parts of the body exposed to radiation. The gaseous form of tritium, which imparts a very low radiological dose relative to HTO since it is weakly absorbed by the body. The processes by which pollutants move through and are transformed in the environment. This term is intended to express the radiation dose to tissue incorporating the different biological effects of different types of radiation. To obtain equivalent dose in Sv, the absorbed radiation dose in Gy is multiplied by the appropriate radiation weighting factor. The path from sources of pollutants via soil, water, or food to human and other species or settings. This term represents animals and animal products. High-energy, short-wavelength electromagnetic radiation (similar to X-rays) emitted during radioactive decay. Gamma rays are very penetrating and require dense materials (such as lead or steel) for shielding. The total amount of beta radioactivity present in a medium, regardless of the specific radionuclide source. Exposure to radiation emitted from radionuclides deposited on the ground. Water beneath the earth s surface, accumulating as a result of infiltration and seepage, and serving as a source for springs and wells. The rate at which the water moves downward towards the intake zone of a well. The time in which half the atoms of a particular radioactive substance undergo radioactive decay. Account for the fact that tritium is incorporated more slowly into organic molecules than hydrogen. ix

14 Nuclear Energy Worker Organically Bound Tritium (OBT) Produce Radiation Radiation Dose A worker who might receive as a result of their work or occupation a radiation dose greater than the dose limit for the general public. A form of tritium that is bound to organic molecules where it replaces hydrogen and is bound to carbon. This term represents fruit, vegetables and animal feed. The emission and propagation of energy through space or matter in the form of electromagnetic waves (e.g., gamma rays) or fastmoving particles such as alpha or beta particles. A measure of the potential harm that may result from exposure to ionizing radiation. There are several distinct measures of radiation dose to quantify the effects on humans. Radioactive Decay The disintegration of the nucleus of an unstable radionuclide by the spontaneous emission of energy and/or particles. Radioactive Decay Constant Radioactivity Radionuclide Removal Constant from forage and crops Sievert Stochastic Effect Translocation Factor Tritiated Water (HTO) The fraction of a number of atoms of a radionuclide that decays in unit time. Spontaneous emission of particles and/or energy from unstable atomic nuclei. An isotope, which is radioactive as a result of the instability of the nucleus of its atom (e.g., radium or uranium). Accounts for the removal of contaminants from forage and crops based on physical processes such as wind, rain and plant growth. A unit of equivalent or effective dose. Equivalent and effective doses are frequently expressed as millisievert (msv), equal to onethousandth of a sievert, or as a microsievert (Sv), equal to onemillionth of a sievert. Effects that occur in a statistical manner and for which the chance of occurrence increases with the radiation dose received. An example is cancer. This factor is used to estimate the radionuclide concentrations that are present in the edible portion of a plant. Results from the substitution of ordinary hydrogen in H 2 O with tritium. x

15 Washout Ratio Water Dilution Water Immersion Fraction of airborne contamination that is removed from the air through interaction with precipitation (e.g., rain or snow). The dilution of radionuclides in water by normal water currents and flow. Exposure to radiation when immersed in water containing radionuclides. Examples of this exposure include taking baths in contaminated water and from swimming at beaches or pools. xi

16 LIST OF TECHNICAL SUPPORT DOCUMENTS (TSDs) Atmospheric Environment Existing Environmental Conditions TSD SENES Consultants Limited Atmospheric Environment TSD SENES Consultants Limited Surface Water Environment Existing Environmental Conditions TSD Golder Associates Limited Surface Water Environment TSD Golder Associates Limited Aquatic Environment Existing Environmental Conditions TSD SENES Consultants Limited and Golder Associates Limited Aquatic Environment TSD - SENES Consultants Limited and Golder Associates Limited Terrestrial Environment Existing Environmental Conditions TSD Beacon Environmental Terrestrial Environment TSD Beacon Environmental Geological and Hydrogeological Environment Existing Environmental Conditions TSD CH2M HILL Canada Limited and Kinectrics Incorporated Geological and Hydrogeological Environment TSD CH2M HILL Canada Limited Land Use Existing Environmental Conditions TSD MMM Group Limited Land Use TSD MMM Group Limited Traffic and Transportation Existing Environmental Conditions TSD MMM Group Limited Traffic and Transportation TSD MMM Group Limited Existing Environmental Conditions TSD AMEC NSS TSD SENES Consultants Limited and AMEC NSS Socio-Economic Environment Existing Environmental Conditions TSD - AECOM Socio-Economic Environment TSD - AECOM Physical and Cultural Heritage Resources Existing Environmental Conditions TSD Archaeological Services Incorporated Physical and Cultural Heritage Resources TSD Archaeological Services Incorporated Ecological Risk Assessment and Assessment of Effects on Non-Human Biota TSD SENES Consultants Limited Scope of Project for EA Purposes TSD SENES Consultants Limited Emergency Planning and Preparedness TSD SENES Consultants Limited and KLD Associates Incorporated Communications and Consultation TSD Ontario Power Generation Incorporated Aboriginal Interests TSD Ontario Power Generation Incorporated Human Health TSD SENES Consultants Limited Malfunctions, Accidents and Malevolent Acts TSD SENES Consultants Limited Nuclear Waste Management TSD Ontario Power Generation Incorporated xii

17 1 INTRODUCTION 1.1 Background Ontario Power Generation (OPG) was directed by the Ontario Minister of Energy in June 2006 to begin the federal approvals process, including an environmental assessment (EA), for new nuclear units at an existing site. OPG initiated this process, and in September 2006 submitted an application for a Licence to Prepare Site to the Canadian Nuclear Safety Commission (CNSC) for a new nuclear power generating station at the Darlington Nuclear site (DN site), located in the Municipality of Clarington on the north shore of Lake Ontario in the Region of Durham. The DN site is currently home to Darlington Nuclear Generating Station (DNGS), a 4-unit plant, the first unit of which was commissioned by OPG in It remains under OPG ownership and operational control. Before any licensing decision can be made concerning the new nuclear generating station, an EA must be performed to meet the requirements of the Canadian Act (CEAA) and be documented in an Environmental Impact Statement (EIS). An EIS is a document that allows a Joint Review Panel, regulators, members of the public and Aboriginal groups to understand the Project, the existing environment and the potential environmental effects of the Project. Guidelines for the preparation of the EIS were prepared by the Canadian Agency (the CEA Agency) and the CNSC (in consultation with Department of Fisheries and Oceans Canada (DFO) and the Canadian Transportation Agency). The Guidelines require that the proponent prepare the EIS and support it with detailed technical information which can be provided in separate volumes. Accordingly, OPG has conducted technical studies that will serve as the basis for the EIS. These technical studies are documented in s (see Section 1.2 below) The New Nuclear Darlington Project New Nuclear Darlington (NND) is proposed to be located primarily on the easterly one-third (approximately) of the DN site, with reactor buildings and other related structures located south of the CN rail line. The proposed Project involves the construction and operation of up to four nuclear reactor units supplying up to 4,800 MW of electrical capacity to meet the baseload electrical requirements of Ontario. The proposed Project will include: Preparation of the DN site for construction of the new nuclear facility; Construction of the NND nuclear reactors and associated facilities; Construction of the appropriate nuclear waste management facilities for storage and volume reduction of waste; Operation and maintenance of the NND nuclear reactors and associated facilities for approximately 60 years of power production (i.e., for each reactor); Operation of the appropriate nuclear waste management facilities; and Development planning for decommissioning of the nuclear reactors and associated facilities, and eventual turn-over of the site to other uses. For EA planning purposes, the following temporal framework has been adopted for the Project: 1-1

18 Project Phase Start Finish Site Preparation and Construction Operation and Maintenance Decommissioning and Abandonment The New Nuclear - Darlington The EA considers the three phases of the NND Project (i.e., Site Preparation and Construction, Operation and Maintenance, and Decommissioning and Abandonment) extending over approximately 140 years. In doing so, it addresses: The need for, and purpose of, the Project; Alternatives to the Project; Alternative means of carrying out the Project that are technically and economically feasible, and the environmental effects of such alternatives; The environmental effects of the Project including malfunctions, accidents and malevolent acts, and any cumulative effects that are likely to result from the Project in combination with other projects or activities that may be carried out; Measures to mitigate significant adverse environmental effects that are technically and economically feasible; The significance of residual (after mitigation) adverse environmental effects; Measures to enhance any beneficial environmental effects; The capacity of renewable resources that are likely to be significantly affected by the project, to meet the needs of the present and the future; The requirements of a follow-up program in respect of the Project; Consideration of community knowledge and Aboriginal traditional knowledge; and Comments that are received during the EA. 1.2 (TSD) The EA studies were carried out and are documented within a framework of individual aspects or components of the environment. The environmental components are: Atmospheric Environment; Surface Water Environment; Aquatic Environment; Terrestrial Environment; Geological and Hydrogeological Environment; Seismicity; Land Use; Traffic and Transportation; ; Socio-Economic Environment; Physical and Cultural and Heritage Resources; Aboriginal Interests; 1-2

19 Health Human; and Ecological Risk Assessment and Assessment of Effects on Non-Human Biota. This (TSD) describes the assessment of effects of the Project on the Radiation and Radioactivity component of the environment. It has been prepared by SENES Consultants Limited and AMEC NSS, the member firms of the EA Consulting Team with technical responsibility for the Radiation and Radioactivity component of the environment. This TSD is one of a series of related documents describing different aspects of the overall effects assessment, one for each environmental component. A separate series of TSDs (i.e., Existing Environmental Conditions TSDs), one for each environmental component, describes the baseline conditions throughout the study areas relevant to the Project, including Valued Ecosystem Components (VECs). A preliminary screening of potential Project-environment interactions for each environmental component was carried out during the baseline characterization program to focus those studies on relevant aspects of the existing environment. In most cases, separate TSDs have been prepared to describe existing conditions and likely effects of the Project. However, for some environmental components the description of existing environmental conditions and the assessment of environmental effects have been combined within one TSD. A number of other TSDs have also been prepared to address related subjects in support of the EA. These include, but are not necessarily limited to: Scope of the Project for EA Purposes; Emergency Planning and Preparedness; Communications and Consultation; Malfunctions, Accidents and Malevolent Acts; and Nuclear Waste Management System. 1.3 Description of the al Component Radiation is energy in the form of waves or particles that travel through material or space, while radioactivity is the spontaneous emission of radiation, either directly from unstable atomic nuclei or as a consequence of a nuclear reaction. Radiation and radioactivity are present throughout the environment due to natural and anthropogenic sources (e.g., fallout from atmospheric nuclear testing, nuclear facilities, etc.). The Radiation and Radioactivity environment is comprised of the following subcomponents where effects (e.g., changes in environmental concentrations, external gamma radiation or dose) from the Project could occur: Radioactivity in the Atmospheric Environment (e.g., changes in airborne concentrations); Radioactivity in the Surface Water and Aquatic Environment (e.g., changes in concentrations in surface water); 1-3

20 Radioactivity in the Terrestrial Environment (e.g., changes in external gamma radiation levels); Radioactivity in the Hydrogeology Environment (e.g., changes in groundwater concentrations); Radioactivity in Humans (e.g., changes in radiation doses to members of the public or radiation doses to workers). 1-4

21 2 EFFECTS ASSESSMENT METHODOLOGY At the time of completing this TSD, three vendors were being considered by the Province of Ontario for supplying and installing the reactors and associated equipment for the Project. Accordingly, the specific reactor to be constructed and operated had not yet been determined. Therefore, for purposes of the EA, the Project was defined in a manner that effectively incorporated the salient aspects of all of the considered reactors. Similarly, the existing environmental conditions and the likely environmental effects of the Project were also determined in a manner that considered the range of reactor types and number of units that may comprise the Project. The essential aspect of the method adopted for defining the Project for EA Purposes is the use of a bounding framework that brackets the variables to be assessed. This bounding framework is defined within a Plant Parameter Envelope (PPE). The PPE is a set of design parameters that delimit key features of the Project. The bounding nature of the PPE allows for appropriate identification of a range of variables within a project for the purpose of the environmental assessment while also recognizing the unique features of each design. For further information concerning the use of the PPE for this EA, the reader is directed to Section 2.1 of the EIS. The information presented in this TSD is deemed to be appropriately bounding so as to facilitate the assessment of environmental effects that may be associated with any of the considered reactors. As both the EA studies and the vendor selection programs continue, it may be that aspects of this TSD are updated to respond to these evolving programs, in which case the updated information will be presented in an addendum to this TSD or in the EIS. The EIS itself will remain subject to edits until it has been accepted by the JRP as suitable for the basis of the public hearing that will be convened to consider the Project. This TSD is a document prepared in support of the EIS. Where there may be differences in the information presented in the two documents, the EIS will take precedence for the reasons noted above. 2.1 Assessment Framework Details of the EA process and the assessment methods used throughout the EA are described in Section 3 of the Environmental Impact Statement (EIS) Report. This TSD focuses specifically on the assessment of effects of the Project on the environment and in doing so the following procedural steps were applied: Detailed screening for potential Project-environment interactions; Identification of likely changes to the environment; Identification and assessment of likely effects on the environment as a result of changes; and Consideration of mitigation measures and determination of likely residual effects. These steps are further described in Section

22 2.2 Assessment Basis, Spatial Boundaries, Methods and Criteria Project Basis for the Assessment A full description of the Project that is the subject of the EA is provided in the Scope of the Project for EA Purposes TSD. A summary description of the specific works and activities that collectively comprise the Project (i.e., Basis for the EA) is included in this TSD as Appendix A Spatial Boundaries for the Assessment Generic spatial boundaries (i.e., study areas) applied for the EA are described in the EIS Report in a context of Site Study Area, Local Study Area and Regional Study Area. These generic study areas were considered for their specific relevance to the Radiation and Radioactivity Environment and modified as appropriate to recognize the unique nature of this environmental component. The study areas applied for this assessment, including the rationale for their delineation, are described below and are illustrated in Figures 2.2-1, 2.2-2, and Site Study Area (): The area covers the entire DN site, including all facilities, buildings and infrastructure of DNGS and lands and portions of Lake Ontario under the care and control of OPG. This corresponds with the generic Site Study Area selected for the future EA Study. Local Study Area (): The generic Local Study Area is adopted for. It includes the DN site and immediate vicinity, generally corresponding to the 10 km emergency planning zone centred on the DN site as identified by Emergency Management Ontario. Regional Study Area (): This area includes lands, communities and portions of Lake Ontario around the DN site that may be affected by the off-site transport of radioactivity from the Project by air and water. The area is bounded by the westerly limit of the region of Durham in the west, Highway 28 to the east; Highways 47 and 7A to the north, and 1 km into Lake Ontario to the south. This corresponds with the generic Regional Study Area selected from the future EA Study Analytical Methods for the Assessment Assessment of effects across a wide range of environmental components and sub-components requires the use of a variety of different analytical methods (e.g., computer models, manual calculations, relevant project experiences, formal case studies, comparison against relevant benchmarks, professional judgement). The specific methods used in the assessment of environmental effects in the are described below. All of those project works and activities identified to have likely measurable effects on one of the environmental components (atmosphere, surface water, terrestrial, hydrogeology and humans) were assessed using the bounding release for each radionuclide (described in Appendix D), 2-2

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26 relevant criteria (Section 2.2.4), background on radiation and radioactivity (Appendix B) and comparison with other relevant project experience. The project works and activities identified to potentially result in increases to the radiation doses to members of the public were generally assessed following the methodology provided in the Canadian Standard Association s (CSA s) N document (2008). The general details of the methodology used in this assessment are provided in Appendices G (Environmental Fate) and I (Transfer Parameters and Dose Calculations). A conceptual overview of the calculation methodology is provided in Figure 2.2-4, with the details (including pathway selection) provided in Appendix C. It should be noted that CSA s N (2008) is, necessarily, generic in nature and that where site or local data were available, for example food consumption patterns from OPG surveys, such data was used in preference to the generic ( default ) assumptions reported by CSA (2008). In addition, amongst other differences from the assumptions reported by CSA (2008), unit air concentration factors (Appendix E) and water dilution factors, including unit water concentration factors (Appendix F) were based on analyses provided by the Atmospheric and Surface Water technical disciplines. The project works and activities identified to potentially result in increases to the radiation doses to workers were collectively assessed in details based on the comparison of historical data, and prediction taking into account the operational and safety features of the reactors under consideration Criteria for the Assessment To assess Project-related effects on the various components of the environment, it is necessary to identify the criteria against which the effects of the Project will be compared and judged. These criteria are collectively referred to as the criteria of assessment. The criteria relevant to assessment of the are provided in Table and are described in each corresponding section of Chapter

27 FIGURE CONCEPTUAL OVERVIEW OF DOSE CALCULATION TO MEMBERS OF THE PUBLIC RELEASES AND DOSE RATES DISPERSION/DILUTION MODELLING ENVIRONMENTAL FATE INTAKE DOSE AERMOD INPUTS Meteorological Data Land Use Data Receptor Locations PROJECT DESCRIPTION AIR RELEASES AERMOD DISPERSION MODEL AIR CONCENTRATION (Except Tritium/C-14) AIR IMMERSION INHALATION TRITIUM/C-14 AIR CONCENTRATION SOIL INGESTION SOIL CONCENTRATION DOSE CALCULATION GROUNDSHINE SPECIFIC ACTIVITY MODEL TRANSFER TO SOIL PRODUCE CONCENTRATION PRODUCE CONSUMPTION FARM PRODUCT CONCENTRATION FARM PRODUCT CONSUMPTION GROUNDWATER CONCENTRATION WATER USE WATER IMMERSION WATER INGESTION DOSE CALCULATION PROJECT DESCRIPTION WATER RELEASES WATER DILUTION MODEL LAKE WATER CONCENTRATION FISH INGESTION WATER MODEL INPUTS Current Flow Distance (alongshore and offshore NWMD FENCELINE GAMMA RADIATION DOSE RATES DOSE CALCULATION NOTE: Water concentrations for water immersion and water ingestion come from either lake water or groundwater depending on receptor location.

28 TABLE Evaluation Criteria for the Radiation and Radioactivity Sub-Component Evaluation Criteria a Radiation Doses to Humans Must be Below Regulatory Limits (CNSC Atmospheric Environment 2000) a Surface Water and Aquatic Environment a Drinking Water Standard (MoE 2007) OPG Commitment to Maintain Annual Average Tritium Levels at all Nearby WSPs below 100 Bq/L (OPG 2008) Radiation Doses to Humans Must be Below Regulatory Limits (CNSC 2000) a a Radiation Doses to Humans Must be Below Regulatory Limits (CNSC Terrestrial Environment 2000) a a Radiation Doses to Humans Must be Below Regulatory Limits (CNSC Hydrogeology Environment 2000) a Members of the Public Radiation Protection Regulations (CNSC 2000) Natural Background Radiation Dose in Canada b Workers Radiation Protection Regulations (CNSC 2000) a) The levels of radiation and radioactivity in this environmental sub-component are not directly limited by regulation, but are indirectly limited by this requirement. b) OPG Used for comparison and perspective, but they are not regulatory criteria. 2.3 Process Steps for Determination of Likely Environmental Effects Detailed Screening for Potential Project-Environment Interactions A preliminary screening for potential interactions was conducted during baseline characterization studies to ensure appropriate focus of those studies. A more detailed screening was subsequently conducted for each component of the environment based on the Description of the Project (as summarized in the Basis for the EA in Appendix A) to direct the effects assessment effort. The screening approach allows the EA studies to focus on the aspects of key importance, thus minimizing assessment effort where there is low potential for Project-related effect. Each of the relevant Project works and activities was considered individually to determine if there was a plausible mechanism for the Project to interact with the environment Evaluation for Likely Measurable Changes in the Environment Each potential interaction was evaluated to determine if it would be likely to result in a measurable change to the environment. For purposes of the EA, a measurable change to the 2-4

29 environment is defined as a change that is real, observable or detectable compared with existing (baseline) conditions. A predicted change that is trivial, negligible or indistinguishable from background conditions is not considered to be measurable Assessment of Likely Effects on the Environment Each Project interaction likely to result in a measurable change to the environment was further evaluated to identify the likely effect of the change on a Valued Ecosystem Component (VEC) selected for the, or on a pathway to other environmental components. VECs relevant to the are described in the Existing Conditions TSD and are provided in Table Each likely effect was identified and described as either beneficial or adverse. Where the likely effect was determined to be beneficial, no further assessment was conducted. Similarly, where the likely effect was determined to be adverse, but clearly not of concern, no further assessment was conducted. Rationale was provided in each case where further assessment was not considered to be warranted. All other likely adverse environmental effects were carried forward for consideration of mitigation opportunities. 2-5

30 TABLE Valued Ecosystem Components (VECs) Sub-Component VECs as Pathways Rationale Radioactivity in Pathway to human health the Atmospheric Environment Radioactivity in the Terrestrial Environment Radioactivity in the Surface Water and Aquatic Environments Radioactivity in the Geological and Hydrogeological Environments Radioactivity in Humans Pathway to non-human biota The is a pathway for potential effects on human health (i.e., of the general public and of workers) Changes in radiation and radioactivity levels in the environment (including dose to humans) are characterized and described within the Radiation and Radioactivity Environment as the basis for considering associated effects on humans. Potential effects on humans associated with changes in the Radiation and Radioactivity Environment are described in the Human Health component. The is a pathway for potential effects on non-human biota. Changes in radiation and radioactivity levels in the natural environment are characterized and described within the as the basis for considering associated effects on nonhuman biota. The potential effects on non-human biota associated with changes in the Radiation and Radioactivity Environment are described in the Ecological Risk Assessment and Assessment of Effects on Non-Human Biota TSD Consideration of Mitigation and Determination of Likely Residual Effects For each likely adverse effect (other than those clearly of no concern), possible means that were technically and economically feasible were identified and considered for mitigating (i.e., eliminating, reducing or controlling) the effect. Each likely adverse effect was re-evaluated assuming implementation of the identified mitigation measures, to determine the residual effect, if any, that would remain after mitigation. By advancing through the assessment in the methodical manner described above, the wider range of potential Project-environment interactions identified at the beginning of the process was progressively screened and evaluated to result in a narrower range of residual adverse effects identified as likely at the end of the process. This progression from potential interactions through to likely residual adverse effects is an important aspect of the overall assessment methodology used, especially as it relates to the subsequent determination of significance of the likely residual adverse effects. 2-6

31 3 ASSESSMENT AND MITIGATION OF ENVIRONMENTAL EFFECTS This section of the TSD describes the assessment conducted to determine the likely adverse effects of the Project on the environment, and more specifically, on the VECs selected as features of the to be the focus of the EA. The process followed in carrying out the assessment is described in Section 2. An evaluation of the significance of the residual adverse effects of the Project on the Environment is presented collectively for all likely environmental effects in all relevant environmental components, in the EIS. 3.1 Detailed Screening for Potential Project-Environment Interactions Each Project works and activity (see Appendix A) was screened to consider if there was a plausible mechanism for it to interface with the individual sub-components of the Radiation and Radioactivity Environment. The screening decisions were based on the experience and professional judgment of the specialists involved. The outcome of this detailed screening as it related to the Radiation and Radioactivity Environment is summarized in Table The table includes the rationale for each interaction determination identified. 3-1

32 TABLE Potential Project-Environment Interactions in the Project Works and Activities Atmospheric Environment Surface Water and Aquatic Environment Terrestrial Environment Hydrogeology Environment Humans Rationale SITE PREPARATION AND CONSTRUCTION PHASE Mobilization and Preparatory Works Excavation and Grading Marine and Shoreline Works Development of Administration and Physical Support Facilities Construction of Power Block Construction of Intake and Discharge Structures Construction of Ancillary Facilities Construction of Radioactive Waste Storage Facilities Mobilization and preparatory works are not expected to alter the radiation and radioactivity environment. Excavation and grading are may result in local changes to the groundwater flow, thus redistributing any existing radioactivity in groundwater and soil (from emissions of existing facility). Marine and shoreline works are not expected to alter the radiation and radioactivity environment. Administrative and physical support facilities are not expected to alter the radiation and radioactivity environment. Construction of power block is expected to interact with the terrestrial environment and workers due to the industrial radiography completed as part of this activity. Construction of intake and discharge channels is not expected to alter the radiation and radioactivity environment. Construction of ancillary facilities is not expected to alter the radiation and radioactivity environment. Construction of radioactive waste storage facilities is not expected to alter the radiation and radioactivity environment. 3-2

33 TABLE (Cont d) Potential Project-Environment Interactions in the Project Works and Activities Atmospheric Environment Surface Water and Aquatic Environment Terrestrial Environment Hydrogeology Environment Humans Rationale SITE PREPARATION AND CONSTRUCTION PHASE Management of Stormwater Supply of Construction Equipment, Material and Operating Plant Components Management of Construction Waste, Hazardous Materials, Fuels and Lubricants Workforce, Payroll and Purchasing OPERATION AND MAINTENANCE PHASE Operation of Reactor Core Operation of Primary Heat Transport System Management of stormwater is expected to interact with the hydrogeology environment from the redirection of precipitation surface flow, thus redistributing sub-surface soil radioactivity (from existing facility operations). Supply of construction equipment, material and operating plant components is not expected to alter the radiation and radioactivity environment. Management of construction waste, hazardous materials, fuels and lubricants is not expected to alter the radiation and radioactivity environment. Workforce is not expected to alter the radiation and radioactivity environment. Operation of the reactor core is expected to increase the radiation doses to workers. Operation of the primary heat transport system is not expected to alter the radiation and radioactivity environment; however, workers will be exposed to external gamma radiation and airborne emissions from this activity. 3-3

34 TABLE (Cont d) Potential Project-Environment Interactions in the Project Works and Activities Atmospheric Environment Surface Water and Aquatic Environment Terrestrial Environment Hydrogeology Environment Humans Rationale OPERATION AND MAINTENANCE PHASE Operation of Active Ventilation and Radioactive Liquid Waste Management Systems Operation of Safety and Related Systems Operation of Fuel and Fuel Handling Systems Operation of Secondary Heat Transport System and Turbine Generators Operation of Condenser and Condenser Circulating Water, Service Water and Cooling Systems Operation of Electrical Power Systems Operation of Site Services and Utilities Operation of active ventilation and radioactive liquid waste management systems is expected to interact with all components of the radiation and radioactivity environment through air and water emissions. Operation of safety and related systems is not expected to alter the radiation and radioactivity environment. Operation of fuel and fuel handling systems is expected to increase the radiation doses to workers. Operation of secondary heat transport system and turbine generators is not expected to alter the radiation and radioactivity environment. Operation of condenser and condenser circulating water, service water and cooling systems is expected to result in water emissions to surface water and members of the public. Operation of electrical power systems is not expected to alter the radiation and radioactivity environment. Operation of site services and utilities is not expected to alter the radiation and radioactivity environment. 3-4

35 TABLE (Cont d) Potential Project-Environment Interactions in the Project Works and Activities Atmospheric Environment Surface Water and Aquatic Environment Terrestrial Environment Hydrogeology Environment Humans Rationale OPERATION AND MAINTENANCE PHASE Management of Operational Low and Intermediate- Level Waste Transportation of Operational Low and Intermediate- Level Waste to a Licensed Off-site Facility Dry Storage of Used Fuel Management of Conventional Waste Replacement/Maintenance of Major Components and Systems Management of operational low and intermediate-level waste is expected to result in airborne tritium emissions from the L&ILW building, increase the gamma radiation (in the terrestrial environment) and increase the radiation doses to workers and members of the public. Transport of operational low and intermediatelevel waste to a licensed off-site facility is expected to increase the gamma radiation (in the terrestrial environment) and increase the radiation doses to workers and members of the public. Dry storage of used fuel is expected to increase the gamma radiation (in the terrestrial environment) and increase the radiation doses to workers and members of the public. Management of conventional waste is not expected to alter the radiation and radioactivity environment. Replacement/maintenance of major components and systems is expected to interact with all components of the radiation and radioactivity environment. 3-5

36 TABLE (Cont d) Potential Project-Environment Interactions in the Project Works and Activities Atmospheric Environment Surface Water and Aquatic Environment Terrestrial Environment Hydrogeology Environment Humans Rationale OPERATION AND MAINTENANCE PHASE Physical Presence of the Station Administration, Purchasing and Payroll The physical presence of the station is not expected to alter the radiation and radioactivity environment. This activity is not expected to alter the radiation and radioactivity environment. Note: A dot () in the table grid indicate a potential Project-Environment interaction. 3-6