The Safety of Ontario's Nuclear Power Reactors
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INIS-mf —1 rVW CA9200506 The Safety of Ontario's Nuclear Power Reactors A SCIENTIFIC AND TECHNICAL REVIEW Vol. 1 Report to the Minister, Technical Report and Annexes F. Kenneth Hare Commissioner Ontario Nuclear Safety Review Toronto, Ontario 29 February, 1988 THE SAFETY OF ONTARIO'S NUCLEAR POWER REACTORS A Scientific and Technical Review F. Kenneth Hare Commissioner Ontario Nuclear Safety Review Toronto 29 February 1988 Ontario Nuclear Safety Review 180 Bloor Street West. Suite 303, Toronto. Ontario M5S2V6 Toi.: (416) 923-5791 ENVOY/INET: ONSR.HKF Fax: (416) 923-9362 F. Kenneth Hare March 21, 1988 The Honourable Robert C. Wong Minister of Energy Government of Ontario Queen's Park Toronto, Ontario Dear Mr. Wong: I have the honour to present my report as Commissioner of the Ontario Nuclear Safety Review, as requested in December 1986 by your predecessor, the Honourable Vincent G. Kerrio. The report is in several volumes. In addition to my own short report to yourself as Minister (containing conclusions, recommendations and a summary) there is a technical report, a volume of appendices written by my colleagues, and a set of selected consultants' reports. Ontario Hydro's and Atomic Energy of Canada Limited's submissions are also presented as support documents. A large group of submissions from various public interest groups, individuals, professional bodies and the union movement has also been deposited with your staff. Obviously this is a record of work completed by many persons in a little over a year. I hope it will prove a valuable contribution to Ontario's picture of its own achievements. It has been a great privilege for me to have been allowed to undertake this Review. I am most grateful to your staff for help and above all to Ontario Hydro for its patience. Yours sincerely, F. Kenneth Hare Commissioner CONTENTS (i) Letters of Appointment and Transmittal (ii) Royal Society of Canada Reviewers' Report (iii) Biographical Sketches of Commissioner, Advisory Panel, and Royal Society of Canada Reviewers (iv) Minister's Report: I Conclusions and Recommendations i A. Scope i B. Major Conclusions and Recommendations i 1. Overall safety i 2. Ontario Hydro corporate affairs iii 3. Pressure tube issues vi C. Other Conclusions and Recommendations vii 4. Research and development vii 5. Other Ontario Hydro practices viii 6. Reactor performance ix 7. Operating system xi 8. Risk of accidents xii 9. Emergency measures xiv 10. Health matters xv 11. Regulation xvii 12. The role of government xxi (v) Minister's Report: II Summary of Technical Report xxiii A. General Questions xxiii B. Where are the Reactors? xxiv C. What are the Safety Issues? xxiv D. Safety Measures xxv E. The Pressure Tube Problem xxvii F. The Operating System xxix G. Exposure to Radioactivity: Health Questions xxxi H. Could a Severe Accident Happen in Ontario? xxxiv I. Ontario Hydro Corporate Affairs xxxvi J. Emergency Measures xxxvii K. Regulation and Public Awareness xxxviii L. Research and Development xxxix M. Women in Nuclear Power xli Contents (cont'd) Page (vi) Le rapport au ministre: I Conclusions et recommandations i* A. Objet i B. Conclusions et recommandations majeures ii 1. Sécurité générale ii 2. Administration générale d'Hydro-Ontario iv 3. Les problèmes avec les tubes de force vii C. Autres Conclusions et Recommandations ix 4. Recherche et développement ix 5. Autres pratiques d'Hydro-Ontario x 6. Bilan de fonctionnement des réacteurs xii 7. Système d'exploitation xiv 8. Risques d'accidents xv 9. Mesures d'urgence xviii 10. Questions de santé xix 11. Réglementation xxii 12. Le rôle du gouvernement xxvi (vii) Le rapport au ministre: II Sommaire du rapport technique xxvii A. Questions générales xxvii B. Où se trouvent les réacteurs? xxix C. Quelles sont les questions sur la sécurité? xxx D. Les mesures de sécurité xxxi E. Le problème des tubes de force xxxiii F. Le système d'exploitation xxxv G. L'exposition à la radioactivité: les questions de santé xxxviii H. Un accident grave pourrait-il se produire en Ontario? xli I. Administration générale d'Hydro-Ontario xliv J. Mesures d'urgence xlv K. Réglementation et sensibilisation du public xlvi L. Recherche et développement xlviii M. Les femmes et l'énergie nucléaire 1 The Roman numeralisation of pages begins again with the French text which is being presented in obverse form in separate editions. Contents (cont'd) The Technical Report Page CHAPTER I Introduction 1 A. The Problem Outlined 1 B. Origins of the Review 9 C. Restraints 10 D. Made in Ontario 12 E. Some General Comments 15 F. With Whom has the Review Dealt? 18 G. What is Safety? 20 H. Where, and of What Sort, are the Reactors? 24 I. The Framework of Regulation 28 CHAPTER II The CANDU Reactor System 31 A. Overall Characteristics 31 B. Where do Safety Problems Arise? 35 C. On Reactivity, Criticality, and Regulation 36 D. Special Safety Systems 42 E. Other Subsystems 47 CHAPTER III CANDU Operations: the Human Element 53 A. Method of Analysis 53 B. Organisation 55 C. Operating Systems at the Nuclear Generating Stations 58 D. Operating Staff and Station Support Groups 60 E. Training of Nuclear Staff 64 F. Head-office Support Groups 67 G. Role of Women in the Nuclear Power Industry 68 CHAPTER IV CANDU Operations: Safety Performance 69 A. The Problems Studied 69 B. Significant Event Reports 70 C. Special Safety System Performance 73 (a) Shut-down system performance 73 (b) Emergency core cooling system performance 75 (c) Containment performance 76 D. Process System Performance 78 E. The Fuel Channel (Pressure Tube) Problem 79 F. Reactor Research Funding 89 Contents (cont'd) Page CHAPTER V Radiological Performance 95 A. Background 95 B. Exposure to Radiation During Normal Operations 97 C. Radiological Performance at Nuclear Generating Stations Within Work Areas 99 D. Environmental Releases of Radioactive Substances due to Normal Reactor Operation 109 E. Epidemiological Evidence Bearing on Health Impact 118 F. The Carbon-14 Question 124 G. Monitoring 129 H. Relative Sensitivity of Women to Radiological Hazards 131 I. What Does ALARA Mean? 132 CHAPTER VI Safety and Accident Analysis 137 A. Introduction 137 B. Canadian Methods 138 C. Severe Accident Analyses: the Problem of Pickering A 146 D. Why are the Predicted Consequences at Pickering A so Different from Those Observed at Chernobyl? 157 E. Potential Consequences of Even More Severe Accidents 160 F. Would Other Types of Reactors Help Safety? 163 CHAPTER VII Emergency Measures for Nuclear Accidents 167 A. The Problem Defined 167 B. For What Accidents Should the Province Prepare? 171 C. Is There a Danger from US Reactors? 173 D. Meteorological Monitoring and Modelling 174 CHAPTER VIII Design, Quality Assurance, and Safety Culture 175 A. Preliminaries 175 B. Ontario Hydro's Design and Construction Processes 176 C. Ontario Hydro's Safety Culture 181 CHAPTER IX Regulation 189 A. Can AECB be an Effective Regulator of Ontario Hydro? 189 B. Is AECB Sufficiently Visible? 190 C. Should AECB Remain a Purely Technical Body? 191 D. Does AECB Have Sufficient Powers? 192 E. The Character of AECB 193 Contents (cont'd) Page Annex I List of Written Submissions from Consultants and Intervenors 197 Annex II Power Reactors In or Near Ontario and Research Reactors In Canada 203 Annex III Ontario Hydro Radiation Protection Regulations, Part I 209 Annex IV Comments on Special Interest Group Intervention 215 Annex V Brief on Nuclear Emergency Planning and Preparedness in Ontario 225 Annex VI Description of the Ontario Nuclear Safety Review 233 List 1 Site Visits 241 List 2 Contact Visits 242 List 3 Informal Meetings 244 List 4 Conferences Attended 245 List 5 Field Exercise Attended 245 List 6 Seminars Conducted for the ONSR 246 Annex VII Glossary 247 1. Technical Terms 247 2. Acronyms and Abbreviations 260 3. Scientific Units 264 References 267 Index 271 List of Appendices Preface F. Kenneth Hare Ontario Hydro's CANDU Nuclear Stations: An Outline of Safety-related Design Aspects Daniel A. Meneley II A Review of the Design-related Aspects of the Safety of Ontario Hydro's Nuclear Generating Stations Peter M. Fraser HI.l An Evaluation of Operational Safety in Ontario Hydro Nuclear Generating Facilities William J. Keough III.2 Operational Safety of Nuclear OSART Mission, Installations, Canada International Atomic Energy Agency III.3 Ontario Nuclear Safety Review Assessment of Ontario Hydro's Response to the IAEA/OSART Recommendations William J. Keough IV The Canadian Approach to Nuclear J.A.L. (Archie) Safety Robertson and Donald G. Hurst V La sûreté nucléaire en France après Tchernobyl Wladimir Paskievici VI Review of Nuclear Emergency Measures Affecting Ontario, and Other Related Matters Alan T. Prince VII The Legal, Regulatory, and Organisa- tional Framework Within Which Ontario's CANDU Reactors Operate Margaret C. Grisdale Biographical Sketches of Authors of Technical Appendices List of Acronyms and Abbreviations List of Figures Figure Page 1 Ontario's stake in nuclear power 2 2 Daily load curves, by source and hour of day, for Ontario Hydro's system, (a) 7 December 1987, (b) 18 May 1987 4-5 3 Fraction of respondents who supported the use of nuclear power 8 4 Sites and electric power ratings of reactors in and 13 near Ontario 5 Pickering Nuclear Generating Station, from nearby Lake Ontario 26 6 Bruce Nuclear Power Development, from Lake Huron 27 7 Main features of the CANDU reactor system 33 8 The regulating system of a CANDU reactor (much simplified) 40 9 The shut-down systems of a CANDU reactor 44 10 AECL's high-pressure emergency