Accession Number DE2012-1044196
Title Ceramographic Examinations of Irradiated AGR-1 Fuel Compacts.
Publication Date Mar 2012
Media Count 84p
Personal Author J. Hunn P. Demkowicz S. Ploger
Abstract The AGR 1 experiment involved irradiating 72 cylindrical fuel compacts containing tri-structural isotropic (TRISO)-coated particles to a peak burnup of 19.5% fissions per initial metal atom with no in-pile failures observed out of almost 300,000 particles. Five irradiated AGR 1 fuel compacts were selected for microscopy that span a range of irradiation conditions (temperature, burnup, and fast fluence). These five compacts also included all four TRISO coating variations irradiated in the AGR experiment. The five compacts were cross-sectioned both transversely and longitudinally, mounted, ground, and polished after development of careful techniques for preserving particle structures against preparation damage. Approximately 40 to 80 particles within each cross section were exposed near enough to mid-plane for optical microscopy of kernel, buffer, and coating behavior. The microstructural analysis focused on kernel swelling and porosity, buffer densification and fracture, debonding between the buffer and inner pyrolytic carbon (IPyC) layers, and fractures in the IPyC and SiC layers. Three basic particle morphologies were established according to the extent of bonding between the buffer and IPyC layers: complete debonding along the interface (Type A), no debonding along the interface (Type B), and partial debonding (Type AB). These basic morphologies were subdivided according to whether the buffer stayed intact or fractured. The resulting six characteristic morphologies were used to classify particles within each cross section, but no spatial patterns were clearly observed in any of the cross-sectional morphology maps. Although positions of particle types appeared random within compacts, examining a total of 830 classified particles allowed other relationships among morphological types to be established.
Keywords Atoms
Bonding
Cross sections
Fractures
Irradiation
Particles
Porosity
Pyrolytic carbon
Swelling


 
Source Agency Technical Information Center Oak Ridge Tennessee
NTIS Subject Category 77I - Reactor Fuels & Fuel Processing
Corporate Author Idaho National Laboratory, Idaho Falls, ID.
Document Type Technical report
Title Note N/A
NTIS Issue Number 1302
Contract Number DE-AC07-05ID14517

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