Showing papers in "Fusion Technology in 1992"

Deuterium Transport and Trapping in Polycrystalline Tungstena

Abstract: Deuterium permeation studies for polycrystalline tungsten foil have been conducted to provide data for estimating tritium transport and trapping in tungsten-clad divertors proposed for advanced fus...

Conceptual design of the D-3He reactor artemis

Abstract: A comprehensive design study of the D-3He-fueled field-reversed configuration (FRC) reactor Artemis is carried out for the purpose of proving its attractive characteristics and clarifying the criti...

The Polywell: A Spherically Convergent Ion Focus Concept

Abstract: The Polywell™ spherically convergent ion focus concept for controlled thermonuclear fusion is described. The device magnetically confines electrons by a quasi-spherical-cusp magnetic field, forming a potential well. Ions are electrostatically confined by this well, converging to a dense focus in the center of the spherical potential, where the fusion rate is large because of the high local density of transient energetic ions. Power balance and critical physics issues are outlined, along with current experimental and theoretical work. The potential of the device for D-3He operation is described by the derivation of scaling laws for energy gain.

A KrF Laser Driven Inertial Fusion Reactor “SOMBRERO”

Abstract: The SOMBRERO inertial fusion reactor conceptual design study is of a 1000 MWe KrF laser driven near symmetric illumination system which utilizes a Li2O solid breeder moving bed in a blanket made en...

Space Propulsion by Fusion in a Magnetic Dipole

Abstract: The unique advantages of fusion rocket propulsion systems for distant missions are explored using the magnetic dipole configurations as an example. The dipole is found to have features well suited to space applications. Parameters are presented for a system producing a specific power of kW/kg, capable of interplanetary flights to Mars in 90 days and to Jupiter in a year, and of extra-solar-system flights to 1000 astronomical units (the Tau mission) in 20 years. This is about 10 times better specific power performance than nuclear electric fission systems. Possibilities to further increase the specific power toward 10 kW/kg are discussed, as is an approach to implementing the concept through proof-testing on the moon. 20 refs., 14 figs., 2 tabs.

A Review of 3He Resources and Acquisition for Use as Fusion Fuel

Abstract: This paper reports that a combination of man-made and natural resources on earth could provide sufficient {sup 3}He fuel for the technological development of D-{sup 3}He fusion reactors. Helium exists in natural gas wells; however, at the current rate of natural gas usage, this resource would provide {lt}5 kg/yr of {sup 3}He. The radioactive decay of {sup 3}H produced in fission production reactors could yield 110 kg of {sup 3}He by the year 2000 if it were retained. Apparently, a large amount of {sup 3}He exists within the earth's mantle, but it is inaccessible. A significant quantity of {sup 3}He, which could be imported to supply a fusion power industry on earth for hundreds of years, exists on the moon. The solar wind has deposited {gt}1 million tonnes of {sup 3}He in the fine regolith that covers the surface of the moon. The presence of this solar wind gas was confirmed by analyses of the lunar regolith samples brought to earth. A strong correlation is noted between the helium retained and the TiO{sub 2} content of the regolith; consequently, remote-sensing data showing high-titanium-bearing soils in the lunar maria areas have been used to locate potentially rich sites for helium extraction.more » Surface photographs of Mare Tranquillitatis have shown that nearly 50% of this mare may be minable and capable of supplying {approximately}7100 tonnes of {sup 3}He. A mobile mining vehicle is proposed for use in the excavation of the soil and the release of the helium and other solar wind gases. The evolved gases would be purified by a combination of permeators and cryogenic techniques to provide a rich resource of H{sub 2}, helium, CO{sub 2}, H{sub 2}O, and N{sub 2}, followed by helium isotopic separation systems.« less

A “SuperCode” for Systems Analysis of Tokamak Experiments and Reactors

Abstract: A new code, named SUPERCODE, has been developed to fill the gap between currently available zero dimensional systems codes and highly sophisticated, multidimensional plasma performance codes. The former are comprehensive in content, fast to execute, but rather simple in terms of the accuracy of their physics and engineering models. The latter contain state-of-the-art plasma physics modeling but are limited in engineering content and are time consuming to run. The SUPERCODE upgrades the reliability and accuracy of systems codes by calculating the self consistent 1 1/2-D plasma evolution in a realistic engineering environment. By a combination of variational techniques and careful formulation there is only a modest increase in CPU time over 0-D runs, thereby making the SUPERCODE suitable for use as a systems studies tool. In addition, we have expended considerable effort to make the code user- and programmer friendly, as well as operationally flexible, with the hope of encouraging wide usage throughout the fusion community.

Metal Hydride Based Isotope Separation -- Large-Scale Operations

Abstract: A program to develop a metal hydride based hydrogen isotope separation process began at the Savannah River Laboratory in 1980. This semi-continuous gas chromatographic separation process will be us...

Hylife-II Inertial Fusion Energy Power Plant Design

Abstract: The HYLIFE-II inertial fusion power plant design study uses a liquid fall, in the form of jets, to protect the first structural wall from neutron damage, x rays, and blast to provide a 30-y lifetime. HYLIFE-I used liquid lithium. HYLIFE-II avoids the fire hazard of lithium by using a molten salt composed of fluorine, lithium, and beryllium (Li2BeF4) called Flibe. Access for heavy-ion beams is provided. Calculations for assumed heavy-ion beam performance show a nominal gain of 70 at 5 MJ producing 350 MJ, about 5.2 times less yield than the 1.8 GJ from a driver energy of 4.5 MJ with gain of 400 for HYLIFE-I. The nominal 1 GWe of power can be maintained by increasing the repetition rate by a factor of about 5.2, from 1.5 to 8 Hz. A higher repetition rate requires faster re-establishment of the jets after a shot, which can be accomplished in part by decreasing the jet fall height and increasing the jet flow velocity. In addition, although not adequately considered for FIYLIFE-I, there is liquid splas...

Characterization of an Inertial-Electrostatic Confinement Glow Discharge (IECGD) Neutron Generator

Abstract: There is considerable demand in the scientific community for a neutron generator with an output of 105–106 n/s that can be turned on or off, emits fusion neutrons, is self-calibrating, and can offer portable operation [1,2]. This paper will describe how an IEC-based neutron generator could satisfy these demands. Experimental data and modeling is presented for operation to the 105 n/s range. Direct extrapolation of the results indicate that with modest extension of operating parameters operation can be achieved in the 106–107 n/s range; with more aggressive modifications operation in the 108–10 n/s range can be possible.

Fusion Power from Lunar Resources

Abstract: The moon contains an enormous energy source in 3He deposited by the solar wind. Fusion of only 100 kg of 3He with deuterium in thermonuclear fusion power plants can produce > 1000 MW(electric) of e...

The ARIES-II and ARIES-IV Second-Stability Tokamak Reactors

Abstract: The ARIES research program is a multi-institutional effort to develop several visions of tokamak reactors with enhanced economic, safety, and environmental features. Four ARIES visions are currentl...

In-Line Process Tritium Monitors

Abstract: This paper describes in-line process tritium monitors have been designed, fabricated, and tested for process and experimental applications in the Tritium Laboratory at Ontario Hydro. The monitors are uniquely simple and compact in design, ultrahigh vacuum compatible, and bakeable to 300{degrees}C. The low level and medium level tritium monitors with minimum detection limits of the order of 1 and 10 {mu}Ci m{sup {minus}3}, respectively, have linear responses spanning more than 6 decades in concentration, are flow independent to at least 0.5 L s{sup {minus}1}, and exhibit small memory effects with rapid recovery following short duration tritium exposures.

Stress analysis of hydride bed vessels used for tritium storage

Abstract: A prototype hydride storage bed was fitted with strain gages to measure strains occurring in the stainless steel bed vessel caused by expansion of the storage powder upon uptake of hydrogen. The st...

Sorption of Tritium and Trittated Water on Construction Materials

Abstract: In this paper, sorption and desorption of tritium (HT) and tritiated water (HTO) on materials to be used in the construction of fusion facilities are studied. In ca. 24-hour exposures in argon or room air, metal samples sorbed 8-200 {mu}Ci/m{sup 2} (1 Ci = 3.7 {times} 10{sup 10} Bq) of tritium form atmospheres of 5-9 Ci/m{sup 3} HT, and non-metallic samples sorbed 60-800 {mu}Ci/m{sup 2} from atmospheres of 14 Ci/m{sup 3} HT. Sorption of HTO varied much more widely than HT sorption for different samples, ranging from 4 {mu}Ci/m{sup 2} for glass to 1,300,000 {mu}Ci/m{sup 3} HTO in room air. Time dependence of desorption in dry air showed a rapid initial process and a slower secondary process.

Particle exhaust scheme using an in-vessel cryocondensation pump in the advanced divertor configuration of the DIII-D Tokamak

Abstract: A particle exhaust scheme using a cryocondensation pump in the advanced divertor configuration of the DIII-D tokamak is described. In this configuration, the pump is located inside a baffle chamber...

A Light Water Excess Heat Reaction Suggests That “Cold Fusion” May Be “Alkali-Hydrogen Fusion”

Abstract: This paper reports that Mills and Kneizys presented data in support of a light water excess heat reaction obtained with an electrolytic cell highly reminiscent of the Fleischmann-Pons cold fusion cell. The claim of Mills and Kneizys that their excess heat reaction can be explained on the basis of a novel chemistry, which supposedly also explains cold fusion, is rejected in favor of their reaction being, instead, a light water cold fusion reaction. It is the first known light water cold fusion reaction to exhibit excess heat, it may serve as a prototype to expand our understanding of cold fusion. From this new reactions are deduced, including those common to past cold fusion studies. This broader pattern of nuclear reactions is typically seen to involve a fusion of the nuclides of the alkali atoms with the simplest of the alkali-type nuclides, namely, protons, deuterons, and tritons. Thus, the term alkali-hydrogen fusion seems appropriate for this new type of reaction with three subclasses: alkali-hydrogen fusion, alkali-deuterium fusion, and alkali-tritium fusion. A new three-dimensional transmission resonance model (TRM) is sketched. Finally, preliminary experimental evidence in support of the hypothesis of a light water nuclear reaction and alkali-hydrogen fusion is reported. Evidence ismore » presented that appears to strongly implicate the transmission resonance phenomenon of the new TRM.« less

Small tokamaks for fusion technology testing

Abstract: Small steady-state tokamaks for testing divertors and fusion nuclear technologies are considered. Based on present physics and technology data and explanation to reduce R{sub 0}/a, H-D-fueled tokamaks with R{sub 0} {approximately} 0.6--0.75 m, R{sub 0}/a {approximately} 1.8--2.5, and B{sub t0} {approximately} 1.4--2.2 T can be driven with P{sub tot} {approximately} 4.5 MW to maintain I{sub p} {approximately} 0.5 MA and produce the ITER-level plasma edge and divertor conditions. Given an adequate steady-state divertor solution and Q{approximately}1 operation based on fusion through the suprathermal component, D-T-fueled tokamaks with R{sub 0} {approximately} 0.8 m, R{sub 0}/a {approximately} 2, and B{sub t0} {approximately} 4 T can be driven with P{sub tot} {approximately} 15 MW to maintain I{sub p} {approximately} 4.6 MA and produce an peak neutron wall load W{sub L} {approximately} 1 MW/m{sup 2}. Such devices appear possible if the plasma properties at the power R{sub 0}/a remain tokamak-like and, for the D-T case, can unshielded center core is feasible. The use of a single conductor as the inboard leg of the toroidal field coils for this purpose is discussed. The physics issues and the design features are identified for such tokamaks with a testing duty for factor goal of 10--20%.

On-line tritium process gas analysis by laser Raman spectroscopy at TSTA

Abstract: Laser Raman spectroscopy has been applied to the on-line analysis of the operation of the cryogenic Isotope Separation System (ISS) at the Tritium Systems Test Assembly (TSTA). A flow-through cell was employed to permit near real-time observation of the dynamic response of the 3-column ISS. Accurate analysis of hydrogen isotopic mixtures may be made in less than 2 minutes. Full response to a change in the sampling point is achieved in approximately one minute. In this paper, response measurements are shown as well as static column profiles and dynamic response to induced parameter changes. Cross check of analysis was performed with radio-gas chromatography.

Inert gas secondary enclosure clean-up system

Abstract: This paper reports on St 198 alloy which is attractive for glovebox clean-up systems operating with nitrogen cover gases, offering good tolerance to impurities which may permeate into the box from the environment and stable sorption speeds for alloy loadings as high as 360 mCi/g. At this loading the tritium concentration in the stream leaving the scavenger bed will be of the order of 400 {mu}Ci/m{sup 3}. The alloy operating conditions can be adjusted to increase the quantity of tritium stored in the alloy or to reduce the tritium concentration in the effluent. Methane can not be removed from a nitrogen stream with St 198. A glovebox clean-up system based on the use of this alloy is under evaluation.

Separation of Tritium Using Polyimide Membrane

Abstract: A polyimide membrane has a selective permeability for hydrogen gas and water vapor. A small scale experimental apparatus for reducing the tritium concentration of air was designed and fabricated at...

Overview of the Osiris IFE Reactor Conceptual Design

Abstract: The Osiris reactor concept is one of two that emerged from the DOE-sponsored IFE reactor design study. It uses a heavy ion beam driver, a carbon cloth first wall and blanket structure that is filled with Flibe, and a steam power conversion system. The driver energy is about 5 MJ and the target yield is about 430 MJ. A 1000 MW(e) net plant requires a rep rate of about 4.6 Hz. The reactor chamber is of a leak-tolerant design where Flibe permeates a carbon cloth first wall and provides a protective coating. A Flibe spray, which supplies the pool at the bottom, condenses blowoff vapor. All components are removed as an assembly from the top of a carbon composite vacuum vessel. The study included assessments of environmental and safety aspects, economics, and technology development requirements.

Separation of hydrogen isotopes by the cryogenic-wall thermal diffusion column

Abstract: In this paper experimental study for separation of hydrogen isotopes has been performed by using a cryogenic-wall thermal diffusion column refrigerated by liquid nitrogen. The column separated H-D system at total reflux and total recycle operational modes. The dependences of the separation factor on the column pressure and hot wire temperature were examined for the total reflux experiments. The optimum pressure observed was 30 kPa at 1273 K. The maximum separation factor at 473 K was larger than that at 1273 K since HD molecules were not produced on the hot wire by the isotope exchange reaction. The separation factor was exponentially proportion al to the hot wire temperature. In the total recycle experiments, the separation factor was measured under a variety of flow rates, positions and compositions of the feed stream. The increase in the feed flow rate deteriorated the separation factor appreciably.

Status and Plans for TFTR

Abstract: Recent research on TFTR has emphasized optimization of performance in deuterium plasmas, transport studies and studies of energetic ion and fusion product physics in preparation for the D-T experiments that will commence in July of 1993. TFTR has achieved full hardware design parameters, and the best TFTR discharges in deuterium are projected to QDT of 0.3 to 0.5.The physics phenomena that will be studied during the D-T phase will include: tritium particle confinement and fueling, ICRF heating with tritium, species scaling with tritium, collective alpha-particle instabilities, alpha heating of the plasma and helium ash buildup. It is important for the fusion program that these physics issues be addressed to identify regimes of benign alpha behavior, and to develop techniques to actively stabilize or control instabilities driver by collective alpha effects.

ETMOD: A New Environmental Tritium Model

Abstract: The ETMOD (Environmental Tritium Model) computer code calculates the potential radiological impact of short duration releases of HT and HTO. The code is now able to predict key input parameters, such as the deposition velocity of HT to soil and the rate of HTO exchange between terrestrial surfaces and the atmosphere, on the basis of weather conditions, land use, season and time of day. In this paper, these features are illustrated by presenting model simulations of an HT field release experiment.

HYLIFE-II Reactor Chamber Mechanical Design

Abstract: Mechanical design features of the reactor chamber for the HYLIFE-II inertial confinement fusion power plant are presented. A combination of oscillating and steady, molten salt streams are used for ...

Water-Cooled Lithium-Lead Blanket Design Studies for DEMO Reactor: Definition and Recent Developments of the Box-Shaped Concept

Abstract: Within the framework of the European DEMO blanket study programme, this paper describes the design work performed on the “box-shaped” concept for water-cooled Pb-17Li blankets in the past two years. The first part of the paper describes the general design, and the thermo-mechanical and neutronical analyses of the main segment structure leading to the optimization of the thickness of the various component. The second part describes specific analysis of particular segment regions, like water-and Pb-17Li-headers, box bottom and support, which have required detailed design development. All results indicate that the “box-shaped” concept is a very promising candidate for DEMO reactor blankets.

Excess Heat during the Electrolysis of a Light Water Solution of K2CO3 with a Nickel Cathode

Abstract: Experimental results of differential heat loss calorimetry measurements during the electrolysis of light water solutions of K2CO3 and Na2CO3 with a nickel cathode are presented. A significant incre...