Deposition and characterization of pyrocarbon coatings produced by use of CO/sub 2/ dilution

Technical Report · Thu Oct 01 00:00:00 EDT 1981

DOI:https://doi.org/10.2172/6239077· OSTI ID:6239077

Stinton, D. P.; Lackey, W. J.

A Biso-coated fuel particle for the High-Temperature Gas-Cooled Reactor (HTGR) consists of a 500 ..mu..m ThO/sub 2/ kernel, an 85-..mu..m layer of low-density carbon, and a 75-..mu..m layer of high-density pyrocarbon. Coatings produced from mixtures of 50% propylene, 25% CO/sub 2/, and 25% Ar were found to be more gastight than were coatings produced from mixtures of propylene and argon, helium, or H/sub 2/. Higher concentrations of CO/sub 2/ in the gas mixture caused severe oxidation of graphite components within the coating furnace. The permeability of coatings deposited by use of CO/sub 2/ dilution was found to depend on the deposition temperature. Low deposition temperatures produced more gastight coatings. It was determined that CO/sub 2/ had little or no effect on coating anisotropy. 6 figures.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6239077
• Report Number(s): ORNL/TM-7853; ON: DE82000900; TRN: 81-017261
• Country of Publication: United States
• Language: English

Related Subjects

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COATED FUEL PARTICLES
COATINGS
HTGR TYPE REACTORS
PYROLYTIC CARBON
DEPOSITION
THORIUM OXIDES
SURFACE COATING
ANISOTROPY
CARBON DIOXIDE
PERMEABILITY
PROPYLENE
ACTINIDE COMPOUNDS
ALKENES
CARBON
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
ELEMENTS
FUEL PARTICLES
GAS COOLED REACTORS
GRAPHITE MODERATED REACTORS
HYDROCARBONS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTORS
THORIUM COMPOUNDS
210300* - Power Reactors
Nonbreeding
Graphite Moderated
050700 - Nuclear Fuels- Fuels Production & Properties
360201 - Ceramics
Cermets
& Refractories- Preparation & Fabrication