Characterization of SiC coatings on HTGR fuel particles: preliminary report

Technical Report · Wed Aug 01 04:00:00 EDT 1979

DOI:https://doi.org/10.2172/6073519· OSTI ID:6073519

Lauf, R. J.; Braski, D. N.; Tennery, V. J.

Fuel particles for the HTGR contain a layer of pyrolytic silicon carbide to act as a pressure vessel and fission product barrier. The SiC is deposited by the thermal decomposition of methyltrichlorosilane (CH/sub 3/SiC/sub 3/ or MTS) in an excess of hydrogen. Coatings deposited at temperatures from 1500 to 1700/sup 0/C and coating rates of 0.4 to 1.2 ..mu..m/min have been studied by optical microscopy, x-ray diffraction, electron microscopy, and density measurements. Transmission electron microscopy (TEM) has shown the microstructural features to be extremely complex and much finer than the ability of optical microscopy to resolve. X-ray diffraction has detected traces of ..cap alpha..-SiC in some coatings, and those conditions of deposition temperature and coating rate that give rise to this phase have been determined.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6073519
• Report Number(s): ORNL/TM-6940
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210300* -- Power Reactors
Nonbreeding
Graphite Moderated
CARBIDES
CARBON COMPOUNDS
COATED FUEL PARTICLES
CRYSTAL STRUCTURE
FUEL PARTICLES
GAS COOLED REACTORS
GRAPHITE MODERATED REACTORS
HTGR TYPE REACTORS
MICROSTRUCTURE
REACTORS
SILICON CARBIDES
SILICON COMPOUNDS