NOTICE s^BTIONS OF THIS REPORT ARE ILLEGIBLE' i> has been reproducer! from the best LA--102 00-IIS available copy to permit tits broadest possible availability. DE85 002351 Compact Reversed-Field Pinch Reactors (CRFPR): Preliminary Engineering Considerations R. L. Hagenson* R. A. Krakowski C. G. Bathke R. L Miller M. J. Embrechts" N. M. Schnurr M. E. Battat R. J. LaBauve J. W. Davidson DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsi- bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Refer- ence herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recom- mendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. •Consultant at Los Alamos. Technology International, Inc., 2515 Elmwood Dr., Suite 102, Ames, IA 50010. "Collaborator at Los Alamos. Department of Nuclear Engineering, Rensselacr Polytechnic Institute, Troy, NY 12184. Los Alamos National Laboratory Los Alamos, New Mexico 87545 DISTJIIBUOT or TABLE Of CONTENTS PAGE I. EXECUTIVE SUMMARY 1 A. Introduction 1 B. Background 3 C. Scope of Study 6 D. The Reversed-Field Pinch Confinement Principle 9 E. Reactor Design Overview 16 F. Technology Assessment 22 G. Conclusions ...... 27 II. BACKGROUND 29 A. Status of Experimental and Reactor Studies 29 B. Rationale for High-Power-Density Fusion 38 C. Simplified Reactor Model 46 D. The Reversed-Field Pinch 61 1. Confinement Principle and Application to Reactor Studies 61 2. Reactor Design-Point Update and Sensitivity 68 III. PRELIMINARY ENGINEERING DESIGN 77 A. Design Overview 77 B. Neutronics ..... 84 1. Calculational Procedure 84 2. Computational Results 86 a. Parametric Studies ..... 86 b. The Canonical Blanket 91 C. Materials 100 1. Overview 100 2. Materials Selection 103 a. First Wall 103 b. Blanket/Shield 108 c. Magnets 109 3. Radiation Effects 109 4. Summary 115 D. In-Vacuum Components (First Wall and Limiters) 117 1. General Thermal-Mechanical Considerations 117 2. Thermal-Hydraulic Analysis 122 a. First Wall - ... 122 b. Pumped Limiter 130 E. Blanket 134 1. General Considerations 134 2. Thermal-Hydraulic Analysis 138 a. Calculation of Blanket Pumping Power 139 b. Results 142 3. Thermal Analysis of Shield 146 4. First-Wall/Blanket/Shield Integration 148 F. Magnets 150 1. Toroidal-Field-Coil System 151 2. The Poloidal-Field-Coil System 158 a. Startup Operations 160 b. PFC (OHC + EFC) Conductor Locations 167 Ohmic-Heatlng Coil (OHC) 168 Equilbrium-Field Coil (EFC) 170 Combined OHC/EFC Magnetic Properties 172 c. PFC (OHC + EFC) Circuit Analysis 173 d. Resistive PFC Numerical Circuit Analysis 179 G. Plasma and Circuit Simulation 188 H. Particle Control by Pumped Liraiters 208 1. Scrapeoff and Limiter Model 209 2. Parametric Results 214 I. Magnetic Divertor 232 J. Vacuum and Fueling 236 K. Current Drive 249 VI L. Fusion-Power-Core Integration ..... 261 1. Power-Plant Energy Balance Integration 261 2. Thermal-Hydraulic Design Integration 265 a. Thermal-Conversion Efficiency 266 b. Thermal-Hydraulics Design Parametics Study 269 Limiter Analysis 270 First-Wall/Second-Wall Analysis 271 Shield Analysis 271 Pressurized-Water Manifold/Header Design 271 Blanket Analysis 272 Cycle Efficiency 272 c Thermal-Hydraulics Design Parametrics Study Results . 272 3. Mechanical Design Integration 281 IV. ASSESSMENT 301 A. Physics Assessment 301 B. Technology Assessment 303 1. Plasma Heating System 303 2. Particle Control Systems , . 304 a. Fueling 304 b. Particle Removal 305 c. Vacuum Pumping 306 3. Plasma Current-Drive System 307 4. Nuclear Systems 308 a. In-Vacuum Components 308 b. Blanket 310 c. Shield 312 d. Afterheat and Radwaste 313 5. Magnet Systems 315 a. Toroidal-Field Coils 315 b. Poloidal-Field Coils 316 6. Electrical and Mechanical Systems 316 a. Energy Transfer and Storage (ETS) 317 b. FPC Structural Support, Assembly, and Maintenance. 317 7. Tritium Systems 318 8. Balance-of-Plant Systems 318 vn C. Economic Assesssment 320 1. Parametric Systems Model 320 2. CRFPR Cost Tradeoffs 321 D. Conclusions 332 REFERENCES 334 ACRONYMS AND NOTATION 346 ACKNOWLEDGEMENTS 348 APPENDICES 349 Appendix A. CRFPR BURN MODEL AND REACTOR DESIGN CODE 349 A.I. Computer Model for Burn Simulation 351 A.2. Fokker-Planck Slowing-Down Calculation 355 A.3. Plasma Powers and Profile Averages 357 a. Heating by Energetic Particle 358 b. Ohmic Heating 359 c Radiation Power 359 d. Transport 361 A.4. Magnetic-Field, Density, and Temperature Profiles . 363 A.5. Equilibrium ai.d Stability 369 A.6. First-Wall The:-mal-Mechanical Response 371 A.7. Reactor Energy Balance 372 Appendix B. TABLE OF CRFPR DESIGN PARAMETERS 377 Appendix C. TWO DIMENSIONAL NEUTRONICS ANALYSES 387 C.I. Introduction 387 C.2. Two-Dimensional Model 388 C.3. Neutronics Calculations 388 a. Codes 388 b. Cross Sections 393 c. Calculational Specifications 393 C.4. Parametric Results 394 a. Reference (Canonical) FW/B/S Model 394 b. Modified Reference (Canonical) FW/B/S Model . 400 C.5. Conclusions and Recommendations 403 COMPACT REVERSED-FIELD PINCH REACTORS (CRFPR): PRELIMINARY ENGINEERING CONSIDERATIONS by R. L. Hagenson, R. A. Krakowski, C. G. Bathke, R. L. Miller, M. J. Embrechts, N. M. Schnurr, M. E. Battat, R. J. LaBauve, and J. W. Davidson ABSTRACT The unique confinement physics of the Reversed-Field Pinch (RFP) projects to a compact, high-power-density fusion reactor that promises a significant reduction in the cost of electricity. The compact reactor also promises a factor-of-two reduction in the fraction of total cost devoted to the reactor plant equipment [i.e., fusion power core (FPC) plus support systems]. In addition to operational and developmental benefits, these physically smaller systems can operate economically over a range of total power output. After giving an extended background and rationale for the compact fusion approaches, key FPC subsystems for the Compact RFP Reactor (CRFPR) are developed, designed, and integrated for a minimum-cost, lOOO-MWe(net) system. Both the problems and promise of the compact, high-power-density fusion reactor are quantitatively evaluated on the basis of this conceptual design. The material presented in this report both forms a framework for a broader, more expanded conceptual design as well as suggests directions and emphases for related research and development. I. EXECUTIVE SUMMARY A. Introduction The cost-optimized Compact Reversed-Field Pinch Reactor (CRFPR) design suggested by this study would operate with a fusion-power-core (FPC, i.e., first wall, blanket, shield, and coils) power density (MWt/m^) and mass utilization (tonne/MWt) that are comparable to fission power plants. These two measures of FPC performance couple with appropriately modified values for plant availability and operating cost to give a cost of electricity [COE (mills/kWeh)] that is 1.6-2.0 times less than that being projected for other approaches to fusion powei:; a similar basis is used in evaluating these cost differences, which are significant. Furthermore, the fraction of the total plant cost required for the reactor plant equipment (i.e., FPC and support systems) can be reduced from the 50-70 % generally considered necessary for fusion to - 30 % for the compact systems; the influence of plasma physics in the overall cost equation for fusion is reduced, thereby diminishing the risk of development and deployment. After the background and rationale for compact fusion reactors are reviewed, preliminary designs and related technology assessments of crucial FPC engineering subsystems are presented. Physics and engineering models for the RFP are developed, many for the first time, to describe parametrically key FPC subsystems required for all aspects of plasma initiation, startup, sustenance, and plasma power conversion. Once defined, these subsystems are integrated into a cost-optimized FPC design that is used for a physics, technology, and economic assessment while simultaneously providing a basis for future, more comprehensive power-plant design studies. The material contained herein, therefore, is both summary and interim in form and is intended to provide a framework for future work. B- Background The development and eventual commercialization of magnetic fusion energy (MFE) is pursued in the U. S. through two co-mainline concepts, the tokamak and the tandem mirror, with a number of promising but less-developed approaches being investigated as alternative or supporting fusion concepts (AFCs). The engineering development needs for the mainline tokamak have been quantified by detailed conceptual design studies of both first-generation engineering experiments1*2 and commercial power eactors.3 To a lesser extent, but nevertheless at a significant level of effort and conceptual design detail, are studies of the Tandem Mirror Reactor (TMR)1*"6 as well as nearer-term engineering devices7!3 based on the tandem-mirror confinement principle. Complementing and supporting both the tokamak and tandem-mirror mainline approaches are the