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Sequential charged-particle and neutron activation of Flibe in the HYLIFE-II inertial fusion energy power plant design

Description: Most radionuclide generation/depletion codes consider only neutron reactions and assume that charged particles, which may be generated in these reactions, deposit their energy locally without undergoing further nuclear interactions. Neglect of sequential charged-particle (x,n) reactions can lead to large underestimation in the inventories of radionuclides. PCROSS code was adopted for use with the ACAB activation code to enable calculation of the effects of (x,n) reactions upon radionuclide inventories and inventory-related indices. Activation calculations were made for Flibe (2LiF + BeF{sub 2}) coolant in the HYLIFE-II inertial fusion energy (IFE) power plant design. For pure Flibe coolant, it was found that (x,n) reactions dominate the residual contact dose rate at times of interest for maintenance and decommissioning. For impure Flibe, however, radionuclides produced directly in neutron reaction dominate the contact dose rate and (x,n) reactions do not make a significant contribution. Results demonstrate potential importance of (x,n) reactions and that the relative importance of (x,n) reactions varies strongly with the composition of the material considered. Future activation calculations should consider (x,n) reactions until a method for pre-determining their importance is established.
Date: June 14, 1996
Creator: Latkowski, J.F.; Tobin, M.T.; Vujic, J.L. & Sanz, J.
Partner: UNT Libraries Government Documents Department

Inertial fusion energy development approaches for direct and indirect-drive

Description: Consideration of different driver and target requirements for inertial fusion energy (IFE) power plants together with the potential energy gains of direct and indirect-drive targets leads to different optimal combinations of driver and target options for each type of target. In addition, different fusion chamber concepts are likely to be most compatible with these different driver and target combinations. For example, heavy-ion drivers appear to be well matched to indirect=drive targets with all-liquid-protected-wall chambers requiring two-sided illuminations, while diode-pumped, solid- state laser drivers are better matched to direct-drive targets with chambers using solid walls or flow-guiding structures to allow spherically symmetric illuminations. R&D on the critical issues of drivers, targets, and chambers for both direct and indirect-drive options should be pursued until the ultimate gain of either type of target for IFE is better understood.
Date: August 20, 1996
Creator: Logan, B.G.; Lindl, J.D. & Meier, W.R.
Partner: UNT Libraries Government Documents Department

Opportunities in the Fusion Energy Sciences Program [Includes Appendix C: Topical Areas Characterization]

Description: Recent years have brought dramatic advances in the scientific understanding of fusion plasmas and in the generation of fusion power in the laboratory. Today, there is little doubt that fusion energy production is feasible. The challenge is to make fusion energy practical. As a result of the advances of the last few years, there are now exciting opportunities to optimize fusion systems so that an attractive new energy source will be available when it may be needed in the middle of the next century. The risk of conflicts arising from energy shortages and supply cutoffs, as well as the risk of severe environmental impacts from existing methods of energy production, are among the reasons to pursue these opportunities.
Date: June 1, 1999
Partner: UNT Libraries Government Documents Department

A fusion power plant without plasma-material interactions

Description: A steady-state fusion power plant is described which avoids the deleterious plasma-material interactions found in D-T fueled tokamaks. It is based on driven p-{sup 11}B fusion in a high-beta closed-field device, the field-reversed configuration (FRC), anchored in a gas-dynamic trap (GDT). The plasma outflow on the open magnetic-field lines is cooled by radiation in the GDT, then channeled through a magnetic nozzle, promoting 3-body recombination in the expansion region. The resulting supersonic neutral exhaust stream flows through a turbine, generating electricity.
Date: April 1, 1997
Creator: Cohen, S.A.
Partner: UNT Libraries Government Documents Department

Fusion research at General Atomics annual report, October 1, 1993-- September 30, 1994

Description: In FY94, the General Atomics (GA) Fusion Group made significant contributions to the technology needs of the controlled fusion power program. The work was supported by the Office of Fusion Energy, Advanced Physics and Technology Division and ITER and Technology Division, of the US Department of Energy. The work is reported in the following sections on Fusion Power Plant Studies, Plasma Interactive Materials, RF Technology, and Diagnostics. Meetings attended and publications are listed in their respective sections. The overall objective of GA`s fusion technology research is to develop the technologies necessary for fusion to move successfully from present-day physics experiments to the next-generation fusion reactor experiments, Tokamak Physics Experiment (TPX) and ITER, and ultimately to fusion power plants. To achieve this overall objective, we carry out fusion systems design studies to evaluate the technologies needed for next-step experiments and power reactors, and we conduct research to develop basic knowledge about these technologies, including plasma technologies, fusion nuclear technologies, and fusion materials. We continue to be committed to the development of fusion power and its commercialization by US industry.
Date: November 1, 1995
Partner: UNT Libraries Government Documents Department

Advanced Fusion Power Plant Studies. Annual Report for 1999

Description: Significant progress in physics understanding of the reversed shear advanced tokamak regime has been made since the last ARIES-RS study was completed in 1996. The 1999 study aimed at updating the physics design of ARIES-RS, which has been renamed ARIES-AT, using the improved understanding achieved in the last few years. The new study focused on: Improvement of beta-limit stability calculations to include important non-ideal effects such as resistive wall modes and neo-classical tearing modes; Use of physics based transport model for internal transport barrier (ITB) formation and sustainment; Comparison of current drive and rotational flow drive using fast wave, electron cyclotron wave and neutral particle beam; Improvement in heat and particle control; Integrated modeling of the optimized scenario with self-consistent current and transport profiles to study the robustness of the bootstrap alignment, ITB sustainment, and stable path to high beta and high bootstrap fraction operation.
Date: January 1, 2000
Creator: Chan, V.S.; Chu, M.S.; Greenfield, C.M.; Kinsey, J.E. & al., et
Partner: UNT Libraries Government Documents Department

Plasma Profile and Shape Optimization for the Advanced Tokamak Power Plant, ARIES-AT

Description: An advanced tokamak plasma configuration is developed based on equilibrium, ideal-MHD stability, bootstrap current analysis, vertical stability and control, and poloidal-field coil analysis. The plasma boundaries used in the analysis are forced to coincide with the 99% flux surface from the free-boundary equilibrium. Using an accurate bootstrap current model and external current-drive profiles from ray-tracing calculations in combination with optimized pressure profiles, beta(subscript N) values above 7.0 have been obtained. The minimum current drive requirement is found to lie at a lower beta(subscript N) of 5.4. The external kink mode is stabilized by a tungsten shell located at 0.33 times the minor radius and a feedback system. Plasma shape optimization has led to an elongation of 2.2 and triangularity of 0.9 at the separatrix. Vertical stability could be achieved by a combination of tungsten shells located at 0.33 times the minor radius and feedback control coils located behind the shield. The poloidal-field coils were optimized in location and current, providing a maximum coil current of 8.6 MA. These developments have led to a simultaneous reduction in the power plant major radius and toroidal field.
Date: June 5, 2001
Creator: Kessel, C.E.; Mau, T.K.; Jardin, S.C. & Najmabadi, and F.
Partner: UNT Libraries Government Documents Department

Reference Scenario for an Advanced Deuterium Power Plant System

Description: The proposal is to make large deuterium (D-D) magnetic fusion power plants in which some (most) of the tritium produced by fusion is removed and stored. This tritium will ultimately decay to helium-3 that will be recycled to supplement the helium-3 produced by fusion. Thus the dominant fusion becomes that of deuterium and helium-3. The level of neutron damage is reduced very substantially from that for a D-T power plant.
Date: September 17, 2001
Creator: Sheffield, J.
Partner: UNT Libraries Government Documents Department

Overview of design activities for Li/V blankets

Description: Recent fusion power plant design studies in the US have been conducted within the ARIES project. The most recent design of Li/V blankets was conducted as part of the ARIES-RS design. The ARIES-RS fusion power plant design study is based on reversed-shear (RS) physics with a Li/V (lithium breeder and vanadium structure) blanket. The reversed-shear discharge has been documented in many large tokamak experiments. The plasma in the RS mode has a high beta, low current, and low current drive requirement. Therefore, it is an attractive physics regime for a fusion power plant. The blanket system based on a Li/V has high temperature operating capability, good tritium breeding, excellent high heat flux removal capability, long structural life time, low activation, low after heat and good safety characteristics. For these reasons, the ARIES-RS reactor study selected Li/V as the reference blanket. The combination of attractive physics and attractive blanket engineering is expected to result in a superior power plant design.
Date: December 31, 1997
Creator: Sze, D.K. & Mattas, R.F.
Partner: UNT Libraries Government Documents Department

The impact of pulsed irradiation upon neutron activation calculations for inertial and magnetic fusion energy power plants

Description: Inertial fusion energy (IFE) and magnetic fusion energy (MFE) power plants will probably operate in a pulsed mode. The two different schemes, however, will have quite different time periods. Typical repetition rates for IFE power plants will be 1-5 Hz. MFE power plants will ramp up in current for about 1 hour, shut down for several minutes, and repeat the process. Traditionally, activation calculations for IFE and MFE power plants have assumed continuous operation and used either the ``steady state`` (SS) or ``equivalent steady state`` (ESS) approximations. It has been suggested recently that the SS and ESS methods may not yield accurate results for all radionuclides of interest. The present work expands that of Sisolak, et al. by applying their formulae to conditions which might be experienced in typical IFE and MFE power plants. In addition, complicated, multi-step reaction/decay chains are analyzed using an upgraded version of the ACAB radionuclide generation/depletion code. Our results indicate that the SS method is suitable for application to MFE power plant conditions. We also find that the ESS method generates acceptable results for radionuclides with half-lives more than a factor of three greater than the time between pulses. For components that are subject to 0.05 Hz (or more frequent) irradiation (such as coolant), use of the ESS method is recommended. For components or materials that are subject to less frequent irradiation (such as high-Z target materials), pulsed irradiation calculations should be used.
Date: June 26, 1996
Creator: Latkowski, J.F.; Sanz, J. & Vujic, J.L.
Partner: UNT Libraries Government Documents Department

Nuclear heating, radiation damage, and waste management options for the HYLIFE-II final focus magnets

Description: Heavy-ion fusion (HIF) designs for inertial fusion energy (XFE) power plants typically require final focusing magnets just outside the reaction chamber and blanket. Due to penetrations within the chamber and blanket, the magnets are exposed to a radiation environment. Although the magnet bores would be sized to avoid line-of-sight irradiation, the magnets still would be susceptible to nuclear heating and radiation damage from neutrons and y-rays. Additionally, the magnets must be included in waste management considerations due to neutron activation. Modified versions of the HYLIFE-II IFE power plant featuring two-sided illumination by arrays of 32 or 96 beams from each side are presented. A simple, point-of-departure quadrupole magnet design is assumed, and a three-dimensional neutronics model is created for the Flibe pocket, first wall, blanket, shield, and final two focusing magnets. This work details state-of-the-art neutronics calculations and shows that the final focus system needs to be included in the economic and environmental considerations for the driver-chamber interface of any HIF IFE power plant design.
Date: August 9, 1999
Creator: Latkowski, J F; Moir, R W & House, P A
Partner: UNT Libraries Government Documents Department

HYLIFE-II: An approach to a long-lived, first-wall component for inertial fusion power plants

Description: The HYLIFE-II concept for IFE (inertial fusion energy) is based on nonflammable, renewable liquid-wall fusion target chambers formed with Flibe (Li{sub 2}BeF{sub 4}) molten-salt jets, a heavy-ion driver, and single-sided illumination of indirect drive targets. As a direct result of using thick renewable liquid walls, the predicted cost of electricity is reduced about 30% to 4.4{cents}/kWh at 1 GWe (3.2{cents}/kWh at 2 GWe). The development program for HYLIFE-II can be shortened and reduced in cost by not requiring expensive neutron sources to develop first-wall materials.
Date: August 1, 1994
Creator: Moir, R.W.; House, P.A. & Leber, R.L.
Partner: UNT Libraries Government Documents Department

Physics assessment of stellarators as fusion power plants

Description: Four different stellarator configurations (a Compact Torsatron, a new modular torsatron, Helias, and a new Modular Helias-like Heliac) were analyzed as fusion power plants and compared with the second-stability ARIES-IV tokamak. The device and plasma parameters were determined by minimizing the projected cost of electricity subject to various constraints. The stellarators were competitive with ARIES-IV for a range of assumptions on confinement models, alpha-particle losses, and beta. 1-D power balance equations were solved for both Lackner-Gottardi confinement scaling with an assumed n{sub e}(r) and for helical-ripple-induced transport with both assumed and calculated forms for n{sub e}(r) and E{sub r}(r).
Date: February 1, 1995
Creator: Lyon, J. F.; Rome, J. A.; Garabedian, P. R.; Anderson, D. T. & Painter, S. L.
Partner: UNT Libraries Government Documents Department

Evaluation of a committed fusion site. Final report

Description: This report is divided into five technical sections. Section 2 is a summary. In Section 3, which covers device and site analyses the major characteristics of devices that might be placed at the site, as envisioned by major fusion laboratories, are described; the characteristics of a site (baseline site) which would accommodate these devices are defined; and various approaches to a committed site meeting the baseline site requirements are discussed. Section 4 describes the scenarios selected to represent possible site development outcomes; these scenarios are evaluated with respect to comparative cost and schedule effects. Section 5 presents a brief evaluation of the effects fusion-fission hybrids might have on the committed site. Major conclusions and recommendations are discussed in Section 6.
Date: July 1, 1979
Partner: UNT Libraries Government Documents Department

Fusion facility siting considerations

Description: Inherent in the fusion program's transition from hydrogen devices to commercial power machines is a general increase in the size and scope of succeeding projects. This growth will lead to increased emphasis on safety, environmental impact, and the external effects of fusion in general, and of each new device in particular. A critically important consideration in this regard is site selection. The purpose of this paper is to examine major siting issues that may affect the economics, safety, and environmental impact of fusion.
Date: January 1, 1985
Creator: Bussell, G.T.
Partner: UNT Libraries Government Documents Department

Hot cell facility design for large fusion devices

Description: Large hot cell facilities will be necessary to support the operation of large fusion devices. The supporting hot cells will be needed to serve a variety of different functions and tasks, which include reactor component maintenance, tool and maintenance equipment repair, and preparation of radioactive material for shipment and disposal. This paper discusses hot cell facility functions, requirements, and design issues and techniques. Suggested solutions and examples are given.
Date: January 1, 1985
Creator: Barrett, R.J. & Bussell, G.T.
Partner: UNT Libraries Government Documents Department

Fusion technology development annual report, October 1, 1995--September 30, 1996

Description: In FY96, the General Atomics (GA) Fusion Group made significant contributions to the technology needs of the magnetic fusion program. The work is reported in the following sections on Fusion Power Plant Design Studies (Section 2), Plasma Interactive Materials (Section 3), SiC/SiC Composite Material Development (Section 4), Magnetic Diagnostic Probes (Section 5) and RF Technology (Section 6). Meetings attended and publications are listed in their respective sections. The overall objective of GA`s fusion technology research is to develop the technologies necessary for fusion to move successfully from present-day physics experiments to ITER and other next-generation fusion experiments, and ultimately to fusion power plants. To achieve this overall objective, the authors carry out fusion systems design studies to evaluate the technologies needed for next-step experiments and power plants, and they conduct research to develop basic knowledge about these technologies, including plasma technologies, fusion nuclear technologies, and fusion materials. They continue to be committed to the development of fusion power and its commercialization by US industry.
Date: March 1, 1997
Partner: UNT Libraries Government Documents Department

Prospects and status of low-aspect-ratio tokamaks

Description: The prospects for the low-aspect-ratio (A) tokamak to fulfill the requirements of viable fusion power plants are considered relative to the present status in data and modeling. Desirable physics and design features for an attractive Blanket Test Facility and power reactors are estimated for low-A tokamaks based on calculations improved with the latest data from small pioneering experiments. While these experiments have confirmed some of the recent predictions for low-A, they also identify the remaining issues that require verification before reliable projections can be made for these deuterium-tritium applications. The results show that the low-A regime of small size, modest field, and high current offers a path complementary to the standard and high A tokamaks in developing the full potential of fusion power.
Date: December 1994
Creator: Peng, Y. K. M.
Partner: UNT Libraries Government Documents Department

Time to pause before the next step

Description: Many scientists, who have staunchly supported ITER for years, are coming to realize it is time to further rethink fusion energy`s development strategy. Specifically, as was suggested by Grant Logan and Dale Meade, and in keeping with the restructuring of 1996, a theme of better, cheaper, faster fusion would serve the program more effectively than ``demonstrating controlled ignition...and integrated testing of the high-heat-flux and nuclear components required to utilize fusion energy...`` which are the important ingredients of ITER`s objectives. The author has personally shifted his view for a mixture of technical and political reasons. On the technical side, he senses that through advanced tokamak research, spherical tokamak research, and advanced stellarator work, scientists are coming to a new understanding that might make a burning-plasma device significantly smaller and less expensive. Thus waiting for a few years, even ten years, seems prudent. Scientifically, there is fascinating physics to be learned through studies of burning plasma on a tokamak. And clearly if one wishes to study burning plasma physics in a sustained plasma, there is no other configuration with an adequate database on which to proceed. But what is the urgency of moving towards an ITER-like step focused on burning plasma? Some of the arguments put forward and the counter arguments are discussed here.
Date: December 31, 1998
Creator: Siemon, R.E.
Partner: UNT Libraries Government Documents Department

Magnetic fusion commercial power plants

Description: Toroidal magnetic systems present the best opportunity to make a commercial fusion power plant. They offer potential solutions to the main requirements that confront a power plant designer. An ideal system may be postulated in which the coils are a very small part of the cost, and the cost stems primarily from the inescapable components: minimal plasma heating (and sustaining system), tritium breeding blanket, shield, particle input, removal and treatment system, heat transfer system, generators, buildings, and balance of plant. No present system meets the ideal standards; however, toroidal systems contain among them the elements required. Consequently, a logical program may be based upon an evolutionary development, building on the contributions of the tokamak, which has been the mainline of research for a number of years.
Date: December 31, 1994
Creator: Sheffield, J.
Partner: UNT Libraries Government Documents Department

Engineering options for the U.S. Fusion Demo

Description: Through its successful operation, the US Fusion Demo must be sufficiently convincing that a utility or independent power producer will choose to purchase one as its next electric generating plant. A fusion power plant which is limited to the use of currently-proven technologies is unlikely to be sufficient attractive to a utility unless fuel shortages and regulatory restrictions are far more crippling to competing energy sources than currently anticipated. In that case, the task of choosing an appropriate set of engineering technologies today involves trade-offs between attractiveness and technical risk. The design space for an attractive tokamak fusion power core is not unlimited; previous studies have shown that advanced low-activation ferritic steel, vanadium alloy, or SiC/SiC composites are the only candidates they have for the primary in-vessel structural material. An assessment of engineering design options has been performed using these three materials and the associated in-vessel component designs which are compatible with them.
Date: October 1, 1996
Creator: Tillack, M.S.; Billone, M.; Sze, D.K.; El-Guebaly, L.; Waganer, L.M. & Wong, C.
Partner: UNT Libraries Government Documents Department

Can inertial electrostatic confinement work beyond the ion-ion collisional time scale?

Description: Inertial electrostatic confinement systems are predicated on a non-equilibrium ion distribution function. Coulomb collisions between ions cause this distribution to relax to a Maxwellian on the ion-ion collisional time-scale. The power required to prevent this relaxation and maintain the IEC configuration for times beyond the ion-ion collisional time scale is shown to be at least an order of magnitude greater than the fusion power produced. It is concluded that IEC systems show little promise as a basis for the development of commercial electric power plants.
Date: January 1, 1995
Creator: Nevins, W.M.
Partner: UNT Libraries Government Documents Department

Development path of low aspect ratio tokamak power plants

Description: Recent advances in tokamak physics indicate the spherical tokamak may offer a magnetic fusion development path that can be started with a small size pilot plant and progress smoothly to larger power plants. Full calculations of stability to kink and ballooning modes show the possibility of greater than 50% beta toroidal with the normalized beta as high as 10 and fully aligned 100% bootstrap current. Such beta values coupled with 2--3 T toroidal fields imply a pilot plant about the size of the present DIII-D tokamak could produce {approximately} 800 MW thermal, 160 MW net electric, and would have a ratio of gross electric power over recirculating power (Q{sub PLANT}) of 1.9. The high beta values in the ST mean that E x B shear stabilization of turbulence should be 10 times more effective in the ST than in present tokamaks, implying that the required high quality of confinement needed to support such high beta values will be obtained. The anticipated beta values are so high that the allowable neutron flux at the blanket sets the device size, not the physics constraints. The ST has a favorable size scaling so that at 2--3 times the pilot plant size the Q{sub PLANT} rises to 4--5, an economic range and 4 GW thermal power plants result. Current drive power requirements for 10% of the plasma current are consistent with the plant efficiencies quoted. The unshielded copper centerpost should have an adequate lifetime against nuclear transmutation induced resistance change and the low voltage, high current power supplies needed for the 12 turn TF coil appear reasonable. The favorable size scaling of the ST and the high beta mean that in large sizes, if the copper TF coil is replaced with a superconducting TF coil and a shield, the advanced fuel D-He{sup 3} could ...
Date: March 1, 1997
Creator: Stambaugh, R.D.; Chan, V.S. & Miller, R.L.
Partner: UNT Libraries Government Documents Department

The ARIES-RS power core -- Recent development in Li/V designs

Description: The ARIES-RS fusion power plant design study is based on reversed-shear (RS) physics with a Li/V (lithium breeder and vanadium structure) blanket. The reversed-shear discharge has been documented in many large tokamak experiments. The plasma in the RS mode has a high beta, low current, and low current drive requirements. Therefore, it is an attractive physics regime for a fusion power plant. The blanket system based on a Li/V has high temperature operating capability, good tritium breeding, excellent high heat flux removal capability, long structural life time, low activation, low after heat and good safety characteristics. For these reasons, the ARIES-RS reactor study selected Li/V as the reference blanket. The combination of attractive physics and attractive blanket engineering is expected to result in a superior power plant design. This paper summarizes the power core design of the ARIES-RS power plant study.
Date: April 1, 1997
Creator: Sze, D.K.; Billone, M.C. & Hua, T.Q.
Partner: UNT Libraries Government Documents Department