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INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or wpy submittad. Thus, soma thesis and disseMion copies are in typemiter face, hile othen may be from any type of amputer pnnter. The quality of this reproduction is dependent upon the quality of the copy submittad. Broken or indistinct print, colored or poor quality illustrations and phatographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Ovenize materials (e.g., rnaps, drawings, charts) are reproduced by sedioning the original, beginning at the upper lefthand corner and continuing from left to right in equal sections with small overlaps. Photographs included in the original manuscript have been reproduced xerographically in mis copy. Higher quality 6" x 9" bhck and white photographie prints are available for any photographs or illustrations appeanng in this copy for an additional charge. Contact UMI diredy to order. Bell 8 Howell Information and Leaming 300 North Zeeb Road, Ann Amr, MI 481B1346 USA SAFETY CHARACTERISTICS OF A SUSPENDED-PELLET FISSION REACTOR SYSTEM BY DAVID ROSS KINGDON, BSng., M.Eng. A Thesis Submztted to the School of Graduate Studies in Partial Fulfrlment of the Requzrernents for the Degree Doctor of PhiIosophy McMaster University Ocopyright by David Ross Kingdon, September 1998 National Library Bibliothèque nationale of Canada du Canada Acquisitions and Acquisitions et Bibliographic Services services bibliographiques 395 Wellington Street 395, nie Wellington OttawaON K1AON4 Ottawa ON KIA ON4 Canada Canada Your hl8 Votre rderanca Our fi& Noire retetenm The author has granted a non- L'auteur a accordé une licence non exclusive licence allowing the exclusive permettant a la National Library of Canada to Bibliothèque nationale du Canada de reproduce, loan, distribute or sel1 reproduire, prêter, distribuer ou copies of ths thesis in rnicroform, vendre des copies de cette thèse sous paper or electronic formats. la fome de microfiche/film, de reproduction sur papier ou sur format électronique. The author retains ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor substantial extracts fiom it Ni la thèse ni des extraits substantiels may be printed or otherwise de celle-ci ne doivent être imprimés reproduced without the author's ou autrement reproduits sans son permission. autorisation. TITLE: Safety Characteristics of a Suspended-Pellet Fission Reaetor System AUTHOR: David Ross Kingdon, B .Eng., M.Eng. (McMaster University) SUPERVISOR: Professor AAHarms WEROF PAGES: smr, 197 ABSTRACT A new fission reactor system with passive safety characteristics to eliminate the ommence of loss-of-eoolant accidents, duce reactivity excursion effixb, and wbich also provides for closure of the nuclear fuel cyde tbugh on-site spent fuel management is emnaiined. The concept uses multi-coated fuel pellets which are suspended by an upwarà moving cmlant in vertical columns of the reacbr core and electro-rem elemental separation to remove selected fission products prior to acfinide recyciing. The possibility of fuel melt following a l~ssa~coolantis avoided as a decrease in codant flow results in the removal of fûel hmthe core through the action of gravity alone. Average fluid velocities in the columns which are necesaary to suspend the pellets are calcdated and found tn be consistent with the necessary heat extraction to yield -1-10 MW,, per column. The total output power of such suspended pellet-type reactors is compared to the power necessary to provide the suspending fluid flow, yielding favourable ratios of -1 o2 - 10'. The reduction of reactivity excursion tendencies is envisageci through an ablative layer of materiai in the pellets which sublimates at temperatures abme normal operating conditions. In the event of a power or temperature increase the particles migrnent and thereby change their hydrodynamic drag characteristics, thus leadhg to fuel removal fram the am by eIutriation. Cornparison of nuclear-*thexmai response tirnes and elutriation rates for Mting power transie- indicate that the present design assists in feacfivity excursion mitigation C!os.üïï ûf eh~-;2!ea- fiil qck is atddthrîgh a speilt hel nimagement strategy which requires ody onîite storage of a fraction of the fission pmducts produced during reactor operation. Eleclm-refïning separation of selected fission products combinecl with complete actinide recycling yields no isolation of plu~nium or highly enriched uranium during the pmcedure. The out-of-core waste stmam has a signiticantly reduced radioactivity, volume and lifetime oompared to the oncethrough waste management strategy and thus provides an alternative to Iong-term geological disposal of fission reactor wastes. The Pellet Suspension Reactor concept possesses some unique operating characteristics and, additiody, is shown to be similar to conventional fission reactors in terms of common performance features. This work arose, in part, hm a 1992-93 graduate course given in the Department of Engineering Physics at McMaster University by Dr. AAHm. The initial efforts of the other graduate students in the course, in particular J. Whitlock and W. Fundamenski, are gratefidy acknowledged, as is Dr. Harms' subsequent direction and encouragement as my PhB. supemisor. Feilow researchers Dr. AN. Kornilovsky and Dr. V.A Wotylev provided valuable assistance and suggestions, as did the members of my m.D. supervisory cornmittee, Dr. W.J.Garland and Dr. J. Vlachopoulos. Advice on ablative materials and their temperature dependence has ken provided by Dr. G.P. Johari and is ais0 gratefully acknowledged. Financial assistance hm the Nahual Science and Engineering Research Coucil, Ontario Ministry of Education and Training, National Chapter of Canada IODE, Canadian Fusion Fuels Technology Rqect, and McMaster Universiw is sincerely appreciated. To the few family and fiends who, despite clairning ignorance to most of this, trusted me to do it nonetkless. TABLE OF CONTENTS Abstract ......................................................... v kknowledgements ................................................ "i TableofContents ................................................. Q ListofFigures .................................................. xiii .. List of Tables ................................................... mi ListofSymbolç ................................................... Chapter 1: Introduction and Con- ...................................1 1.1 Fission Energy Fundamentals ............................... 1 1.2 Global Nuclear Power ..................................... 5 1.3 DecliningAcceptability .................................... 7 1.4 Evolution of a Technology ................................. 10 1.5 Component Substitution .................................. 12 1.6 Conditions For Renewal ................................... 13 1.7 Design Pmeess and Interactions ............................ 16 Chapter 2: Reactor Conœpt ........................................ 19 2.1 SafetyTerminology ....................................... 19 2.2 Similar Concepts ........................................20 2.3 PSR Core Concept ....................................... 26 2.4 lnherent Accident Avoidance ...............................38 2.5 Material Ymperties ...................................... 41 2.6 Aitemative Means of Pellet Suspension....................... 44 2.7 Advantages of Pellet Suspension ............................ 47 Chapter 3: Pellet Suspension and Power Ratio ..........................49 3.1 PackedBeds ........................................... 49 3.2 Minimum Fluidization Veldty ............................. 54 3.3 Types of Fluidization ..................................... 59 3.4 Terminal Velocie ....................................... 62 3.5 Suspension Vehities .....................................65 Table of Contents 3.6 Particle Distributions .................................... 70 3.7 Suspension Column Geometric Considemtiom .................. 73 3.8 Column Power Capacity ................................... 76 3.9 Pellet Power Ratio ....................................... 78 3.9.1 Geometric Modei ................................. 78 3.9.2 Individual Particle Formulation ..................... 81 3.9.3 Entire Coliimn Formuiation ........................ 87 Chapter 4: Fuel Pellets and Ablation ................................. 93 4.1 Pellet Fuel ............................................. 93 4.2 TRIS0 MimFuel Particles ................................94 4.3 Roposed Fuel Removal Mechanism ..........................98 4.4 Additional Reactivity EEcursion Avoidance Schemes ............ 102 4.5 Steady State Thermal Conditions ...........................105 4.6 Steady State Thermal Conditions for a Column ................ 109 4.7 Transient Analyses ..................................... 115 4.8 Removal of Pellet Fragments .............................. 121 Chapter 5: Waste Management and Fuel Recycling ...................... 131 5.1 Conventional Waste Management Strcttegies .................. 131 5.2 Fuel Recycling with EZectro-refining ........................ 133 5.3 Assessrnent of Reduced Wasîe Inventory .....................142