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in creator/contributor: "Lackey, W.J."  
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Improved size uniformity of sol-gel spheres by imposing a vibration on the sol in dispersion nozzles

Description: A major part of the Th-- /sup 233/U fuel cycle program at ORNL has been concerned with the development of sol-gel processes to prepare ThO/sub 2/ and ThO/ sub 2/--/sup 233/UO/sub 2/ spheres. The formation of sol drops having a uniform and controlled diameter is important to any sol-gel process for preparing oxide kernels for High Temperature Gas-Cooled Reactor fuels. A recently developed technique that incorporates use of a sol disperser with vibration has met the dispersion requirements for OR… more
Date: May 1, 1973
Creator: Haas, P. A. & Lackey, W. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Improved gas distributor for coating HTGR fuel particles

Description: The important criteria to be considered in design of the gas distributor are: (1) The distributor should ideally spread or disperse the gas over the full area of the coating chamber to maximize the particle gas contact area and thereby increase both particle circulation and the percentage of the input gas that ends up as coating. (2) The gas should not heat up during its passage through the distributor. Otherwise the gas would partially decompose prematurely, causing excessive coating depositio… more
Date: January 1, 1977
Creator: Lackey, W. J.; Stinton, D. P. & Sease, J. D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Improved gas distributor for coating HTGR fuel particles

Description: A new and improved gas distributor was developed for use in coating fuel particles for the HTGR. The coating gas enters the coating furnace through multiple thin regions of a porous plate. This more uniformly disperses the gas and leads to improved coating properties. High-quality carbon and SiC coatings have been deposited with the new distributor in both 13- and 24-cm-diam coating furnaces.
Date: January 1, 1977
Creator: Lackey, W. J.; Stinton, D. P. & Sease, J. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Effect of deposition conditions on the properties of pyrolytic silicon carbide coatings for high-temperature gas-cooled reactor fuel particles

Description: Silicon carbide coatings on HTGR microsphere fuel act as the barrier to contain metallic fission products. Silicon carbide coatings were applied by the decomposition of CH/sub 3/SiCl/sub 3/ in a 13-cm-diam (5-in.) fluidized-bed coating furnace. The effects of temperature, CH/sub 3/SiCl/sub 3/ supply rate and the H/sub 2/:CH/sub 3/SiCl/sub 3/ ratio on coating properties were studied. Deposition temperature was found to control coating density, whole particle crushing strength, coating efficiency… more
Date: October 1, 1977
Creator: Stinton, D. P. & Lackey, W. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Coating crystalline nuclear waste forms to improve inertness

Description: Crystalline waste forms of high simulated waste loading were successfully coated with layers of pyrolytic carbon and silicon carbide. Sol-gel technology was used to produce microspheres that contained simulated waste. A separate process for cesium immobilization was developed, which loads 5 wt % Cs onto zeolite particles for subsequent coating. The chemical vapor deposition process was developed for depositing thin layers of carbon and silicon carbide onto particles in a fluidized-bed coater. P… more
Date: January 1, 1981
Creator: Stinton, D. P.; Angelini, P.; Caputo, A. J. & Lackey, W. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Determination of defective particle fraction in HTGR fuels

Description: The fuel for the High-Temperature Gas-Cooled Reactor (HTGR) consists of uranium and thorium species in the form of microspheres individually encapsulated in layers of pyrolytic carbon and silicon carbide. In the characterization of these particles, an important consideration is the fraction in a particular sample that may have defective coatings which would allow the release of gaseous and metallic fission products. A method for this determination, which has been in use for almost a decade, is … more
Date: November 1, 1976
Creator: LaValle, D. E.; Costanzo, D. A.; Lackey, W. J. & Caputo, A. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Device for sampling HTGR recycle fuel particles

Description: Devices for sampling High-Temperature Gas-Cooled Reactor fuel microspheres were evaluated. Analysis of samples obtained with each of two specially designed passive samplers were compared with data generated by more common techniques. A ten-stage two-way sampler was found to produce a representative sample with a constant batch-to-sample ratio.
Date: March 1, 1977
Creator: Suchomel, R. R. & Lackey, W. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Inspection of high-temperature gas-cooled reactor recycle fuel

Description: Inspection of recycle fuel for High Temperature Gas-Cooled Reactors (HTGRs) involves many operations which, because of the high radiation level associated with the presence of /sup 232/U, must be performed in shielded (5 cm of lead) glove boxes containing automated sample handling and analysis equipment. Equipment for obtaining representative fuel particle samples and for pneumatically transferring particles and fuel rods through long tubes has been developed. Schemes for cross checking inspect… more
Date: June 1, 1977
Creator: Pechin, W. H.; Lackey, W. J.; Sease, J. D. & Eatherly, W. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Influence of process variables on permeability and anisotropy of Biso-coated HTGR fuel particles

Description: The effect of several important process variables on the fraction of defective particles and anisotropy of the low-temperature isotropic (LTI) coating layer was determined for Biso-coated HTGR fuel particles. Process variables considered are deposition temperature, hydrocarbon type, diluent type, and percent diluent. The effect of several other variables such as coating rate and density that depend on the process variables were also considered in this analysis. The fraction of defective particl… more
Date: November 1, 1977
Creator: Stinton, D. P.; Lackey, W. J. & Thiele, B. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Development of silicon nitride composites with continuous fiber reinforcement

Description: The composites were fabricated using ultrafine Si powders prepared by attritor milling; the powders exhibits full conversion to Si nitride in < 3 h at {le} 1200 C (these conditions reduce degradation of the fibers compared to conventional). Effects of processing conditions on fiber properties and the use of fiber coatings to improve stability during processing as well as change the fiber-matrix interfacial properties were investigated. A duplex carbon-silicon carbide coating, deposited by CVD, … more
Date: October 1, 1993
Creator: Starr, T. L.; Mohr, D. L.; Lackey, W. J. & Hanigofsky, J. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Sol-Gel Technology Applied to Crystalline Ceramic Nuclear Waste Forms

Description: The sol-gel process is being developed for the solidification and isolation of high-level nuclear fuel waste. Three gelation methods are being developed for producing alternative waste forms. These include internal gelation for producing spheres of up to 1 mm diam suitable for coating, external gelation, and water extraction methods for producing material suitable for alternate ceramic processing. In this study internal gelation has been used to produce ceramic spheres of various alternative nu… more
Date: January 1, 1980
Creator: Angelini, P.; Bond, W. D.; Caputo, A. J.; Mack, J. E.; Lackey, W. J.; Lee, D. A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Grain structure and growth of dispersed phase BN-AlN coatings grown via chemical vapor deposition

Description: This paper discusses the variation in microstructures encountered during the separate depositions of boron nitride (BN) and aluminium nitride (AlN) as well as during the codeposition of BN-AlN dispersed phase ceramic coatings. This combination was chosen in order to take advantage of the self lubricating properties of hexagonal BN along with the hard, erosion resistance of AlN. Films were characterized using scanning and transmission electron microscopy (SEM and TEM), x-ray photoelectron spectr… more
Date: January 1, 1990
Creator: Freeman, Garth B.; Lackey, W. J.; Hanigofsky, J. A.; Lee, Woo Y. & More, Karren L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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