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in subjects: "Fuel Pellets"

open access

Status of Oak Ridge National Laboratory fusion activities

This review covers the following research being carried out at ORNL: (1) confinement experiments such as ATF, EBT, and STX, (2) theory, (3) atomic physics, (4) shielding, (5) technology developments on superconducting magnets, pellet injection, rf plasma heating, and materials, and (6) fusion engineering design center. (MOW)

Date: January 1, 1985

Creator: Rosenthal, M.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Results of hydrogen pellet injection into ISX-B

High speed pellet fueling experiments have been performed on the ISX-B device in a new regime characterized by large global density rise in both ohmic and neutral beam heated discharges. Hydrogen pellets of 1 mm in diameter were injected in the plasma midplane at velocities exceeding 1 km/s. In low temperature ohmic discharges, pellets penetrate beyond the magnetic axis, and in such cases a sharp decrease in ablation is observed as the pellet passes the plasma center. Density increases of appro… more

Date: September 1, 1980

Creator: Milora, S. L.; Foster, C. A. & Thomas, C. E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Electrostatically driven plasma hydrodynamic instability. I. The failure of vacuum-insulated, long wavelength laser fusion pellets

Longer wavelength (e.g., lambda = 10.5 ..mu..m) laser radiation generates relatively large fluxes of superthermal electrons that penetrate and preheat the cores of such pellets at early times in their implosion history, precluding their efficient subsequent compression. It has been proposed to separate the outermost shell of such pellets (onto which the laser light is directed) from its inner regions by a vacuum layer, thereby ''insulating'' these inner portions from superthermal electron degra… more

Date: October 1, 1977

Creator: Levermore, C. D.; Caflisch, R. E. & Wood, L. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Compact nuclear power systems based on particle bed reactors

Compact, low cost nuclear power systems with an extremely low radioactive inventory are described. These systems use the Particle Bed Reactor (PBR), in which HTGR particle fuel is contained in packed beds that are changed daily. The small diameter particle fuel (500 ..mu..m) is directly cooled utilizing the large heat transfer area available (7.8 m/sup 2//liter), thus allowing high bed power densities (MW/liter).

Date: January 1, 1986

Creator: Horn, F. L.; Powell, J. R.; Steinberg, M. & Takahashi, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

In-Home Performance of Exempt Pellet Stoves in Medford, Oregon.

Pellet stoves that are considered exempt'' operate at an air-to-fuel ratio in excess of 35:1. They therefore qualify for exemption from the emissions certification process. A primary goal of this project was to determine how a sample of such stoves, operated in homes, would perform compared to their certified cousins,'' which were evaluated the previous year. In-home performance data documenting emissions from exempt stoves and net delivered efficiencies was particularly desired. This project e… more

Date: July 5, 1991

Creator: Barnett, Stockton G. & Fields, Paula G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Calculation of density profiles in tandem mirrors fueled by pellets

We have modified the LLNL radial transport code TMT to model reactor regime plasmas, fueled by pellets. The source profiles arising from pellet fueling are obtained from existing pellet ablation models. Because inward radial diffusion due to inverted profiles must compete with trapping of central cell ions in the transition region for tandem mirrors, pellets must penetrate fairly far into the plasma. In fact, based on our radial calculations, a pellet with a velocity of 10 km/sec cannot sustain… more

Date: December 2, 1983

Creator: Campbell, R. B. & Gilmore, J. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Parameters of the luminous region surrounding deuterium pellets in the PLT tokamak

The luminous region of the plasma cloud surrounding deuterium pellets injected into a tokamak is studied spectroscopically. At the time of peak luminosity the average electron density is 2.4 x 10/sup 17/ cm/sup -3/ to within 30% and the temperature is at most 2.0 eV. The intensity ratio of the Balmer alpha and beta light from the pellets, the total number of emitted photons, and the apparent size of the radiating region are consistent with local thermodynamic equilibrium at this temperature and… more

Date: August 1, 1985

Creator: McNeill, D. H.; Greene, G. J. & Schuresko, D. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Structured pellet design for laser fusion: a numerical determination of the optimum mass ratio

Structured pellets for laser fusion have been suggested in the past few years. Herein, numerical simulations are presented which demonstrate a departure from purely elastic collisions and illustrate the significance of temporal shaping of the incident laser energy.

Date: October 1, 1977

Creator: Stroscio, M.A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Development of annular-coated-pressurized and sphere-pac LWR fuels

Annular-coated (graphite)-pressurized and sphere-pac fuel rod designs, which are expected to exhibit improved PCI-failure resistance, and, thus, more reliable extended burnup performance, are being developed. Data sufficient to provide the technical bases needed to license lead test assemblies of the improved designs for irradiation in commercial LWRs are being obtained. Out-of-reactor experiments, in-reactor instrumented experiments, in-reactor power-ramp tests, and lead-rod demonstration irra… more

Date: December 1, 1981

Creator: Buckman, F. W.; Crouthamel, C. E.; Freshley, M. D. & Barner, J. O.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Effects of fill gas composition and pellet eccentricity. [BWR]

Data and an analysis are presented showing that when the operating pellet-cladding gap size of contemporary UO/sub 2/ fuel rods is carefully considered, the gap conductances are closely proportional to the thermal conductivities of the fill gases. Pellet-cladding gap eccentricity is shown to raise the gap conductance appreciably in cases of high thermal gradients across the gap. Ignoring the azimuthal heat flow can lead to an underestimation of the thermal time constant of the rod, resulting in… more

Date: July 1, 1977

Creator: Williford, R.E. & Hann, C.R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

End-of-irradiation data report for the instrumented fuel assembly (IFA)-527. [PWR; BWR]

This report presents data obtained during the irradiation of the six-rod instrumented fuel assembly (IFA)-527 in the Halden Boiling Water Reactor (HBWR), Halden, Norway. This assembly is the last in a series of US Nuclear Regulatory Commission (NRC)-sponsored tests to obtain data for the development and verification of steady-state fuel performance computer codes. IFA-527 contains five identical rods with high-density stable fuel pellets and 230-..mu..m diametral gaps and one rod with similar f… more

Date: May 1, 1982

Creator: Cunningham, M. E. & Lanning, D. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Tritium systems for the tokamak fusion core experiment, TFCX

Tritium systems, tritium needs and possible tritium release scenarios were assessed for a TFCX class of device, 250 MW, 2 x 10/sup 5/ s of burn, with burn times from 20 s to 300 s. On-site and off-site, continuous and batch processing modes were considered. A reference case, batch processing was developed which fulfills the requirements for plasma physics experiments.

Date: January 1, 1983

Creator: Finn, P.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

HYPERFUSE: a novel inertial confinement system utilizing hypervelocity projectiles for fusion energy production and fission waste transmutation

Parametric system studies of an inertial confinement fusion (ICF) reactor system to transmute fission products from an LWR economy have been carried out. The ICF reactors would produce net power in addition to transmuting fission products. The particular ICF concept examined is an impact fusion approach termed HYPERFUSE, in which hypervelocity pellets, traveling on the order of 100 to 300 km/sec, collide with each other or a target block in a reactor chamber and initiate a thermonuclear reactio… more

Date: January 1, 1980

Creator: Makowitz, H; Powell, J R & Wiswall, R

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Heat transfer in inertial confinement fusion reactor systems

The short time and deposition distance for the energy from inertial fusion products results in local peak power densities on the order of 10/sup 18/ watts/m/sup 3/. This paper presents an overview of the various inertial fusion reactor designs which attempt to reduce these peak power intensities and describes the heat transfer considerations for each design.

Date: April 23, 1980

Creator: Hovingh, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Economic model of a relativistic electron beam hybrid reactor

An optimization model of the economics of power generation using a relativistic electron beam hybrid reactor is briefly discussed. An assumed model structure is described. Projected plant costs vs. plant output are discussed. An optimization procedure is used to determine the lowest power and fissile fuel prices associated with a given model reactor concept. The levelized busbar energy cost is projected to be 30 m cents/kWh using the model. (RME)

Date: January 1, 1977

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Preparation of carbide-type, advanced LMFBR fuel pellets for irradiation testing

A carbothermic reduction process was established to fabricate single- and two-phase uranium-plutonium carbide fuel on a production basis. Sintering temperatures of 1550 and 1800/sup 0/C were used to prepare fuel densities of 98, 87, and 81% of theoretical.

Date: June 1, 1980

Creator: Gutierrez, R. L. & Herbst, R. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Application of the active well coincidence counter to the measurement of uranium

An Active Well Coincidence Counter has been developed to assay uranium fuel material in field inspection applications. The unit is used to measure bulk UO/sub 2/ samples, high enrichment uranium metals, LWR fuel pellets, and /sup 233/U-Th fuel materials which have very high gamma-ray backgrounds.

Date: January 1, 1980

Creator: Menlove, H. O.; Foley, J. E. & Bosler, G. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Secure Automated Fabrication: a system design description (SDD), section 1. [LMFBR]

Information is presented concerning the conversion system to convert purified mixed nitrate solution to MO/sub x/ powder; powder preparation and pellet fabrication; sintering and pin loading; assembly fabrication; and scrap recovery.

Date: unknown

Creator: Konze, G. M.; Thompson, M. L.; Wadekamper, D. C. & Zimmer, J. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Improved understanding of first-mall vaporization-condensation in inertial confinement fusion reactors. Revision 1

We report approximate x-ray and debris spectra emanating from a region of compressed DT fuel representing the imploded configuration of a generic direct-drive ICF reactor pellet. We show how the spectra are modified by spherical lead shields of various thicknesses placed near the pellet, and show that it is not possible to lessen the ablation of the first wall or blanket of a low-pressure ICF reactor chamber through use of such shields. Then we report that the calculated x-ray spectra alone (i.… more

Date: August 1, 1986

Creator: Orth, C.D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Diagnostic techniques for measuring temperature transients and stress transients in the first wall of an ICF reactor

The primary challenge in the design of an Inertial Confinement Fusion (ICF) power reactor is to make the first wall survive the frequent explosions of the pellets. Westinghouse has proposed a dry wall design consisting of steel tubes coated with tantalum. This report describes the design of a test chamber and two diagnostic procedures for experimentally determining the reliability of the Westinghouse design. The test chamber simulates the x-ray and ion pulse irradiation of the wall due to a pel… more

Date: January 1, 1983

Creator: Melamed, N. T. & Taylor, L. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Achieving higher count rates with EDX

An automated energy-dispersive x-ray spectrometer (EDX) was developed for the close-coupled analysis of mixed U, Pu oxide fuel pellets. (Close-coupled means the analytical glove box is closely adjacent to the production line.) The L ..cap alpha.. fluorescences of U and Pu were chosen. The advantages and disadvantages of the system are given. (DLC)

Date: January 1, 1980

Creator: Lambert, M. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Effects of fueling profiles on plasma transport

The effects of cold particle fueling profiles on particle and energy transport in an ignition sized tokamak plasma are investigated in this study with a one-dimensional, multifluid transport model. A density gradient driven trapped particle microinstability model for plasma transport is used to demonstrate potential effects of fueling profiles on ignition requirements. Important criteria for the development of improved transport models under the conditions of shallow particle fueling profiles a… more

Date: January 1, 1977

Creator: Houlberg, W. A.; Mense, A. T.; Attenberger, S. E. & Milora, S. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Liquid-metal fast-breeder-reactor program: reference fuel studies. Eighth quarterly report, August-October 1976. [LMFBR]

In FY-76, Task 3 of Contract E(04-3)-893 consisted of the following programs: fuel rod chemistry and thermodynamics; fuel rod engineering; fuel irradiations testing and analysis; and reference structural materials. Starting in FY-77, the Fuel Rod Engineering Program was reorganized into other existing G.E. programs under the E(04-3)-893 contract. Continuation of the reports on technical progress of this program can be found under 189 No. SG009, Task 3, or 189 No. SG023, Task 11.

Date: November 1, 1976

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

X-ray lines as a density diagnostic in DT plasmas near 100x solid density

The use of electron impact broadened resonance lines to diagnose near-term high density diagnostics is discussed. In particular, the question of how to choose seed and pusher materials to have discernible broadening effects while maintaining line visibility is discussed.

Date: October 19, 1977

Creator: Bailey, D.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department