Fission Product and Actinide Distribution in the SiC Layer of Fissioned Triso Fuel Particles

Journal Article · Sat Jul 01 00:00:00 EDT 2017 · Transactions of the American Nuclear Society

OSTI ID:23047422

Seibert, Rachel L.; Terry, Jeff ^[1]; Gerczak, Tyler; Hunn, J.; Baldwin, C.; Montgomery, F.; Leonard, K.; Terrani, Kurt ^[2]

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1. Illinois Institute of Technology, 3105 S. Dearborn St., Chicago, IL, 60616 (United States)
2. Oak Ridge National Laboratory, One Bethel Valley Road, Oak Ridge, TN, 37831 (United States)

Tri-structural Isotropic (TRISO) encapsulated fuel particles are used in next generation high-temperature gas-cooled nuclear reactors. The integrity of the fuel over a wide range of temperatures is integral to the safety of an operating nuclear reactor. It has been observed that fission products are released at high temperatures that simulate hypothesized accident scenarios. The particles under study were from the AGR-1 fuel development and qualification program. They consist of an enriched UCO fuel kernel surrounded by a dense carbon buffer layer (100 {mu}m), an inner pyrolytic carbon (IPyC) layer (40 {mu}m), a silicon carbide (SiC) layer (35 {mu}m), and an outer pyrolytic carbon (OPyC) layer (40 {mu}m). The SiC layer acts as the main diffusion barrier to fission products, but has been demonstrated to fail due to release of Ag through intact particles and local corrosion from metallic fission products such as Pd. In this work, we use transmission electron microscopy and diffraction techniques to study the structure and dispersion of release products within the SiC of TRISO particles as a function of annealing temperature used to simulate margin temperatures for in-reactor accident scenarios. In order to improve our understanding of fission product retention as a function of temperature, we have the unique opportunity to examine irradiated, fissioned TRISO particles to study post-irradiation effects on these materials. This data will contribute to current models used to predict the behavior of fission products in the SiC layer of TRISO fuels.

• OSTI ID: 23047422
• Journal Information: Transactions of the American Nuclear Society, Vol. 116; Conference: 2017 Annual Meeting of the American Nuclear Society, San Francisco, CA (United States), 11-15 Jun 2017; Other Information: Country of input: France; 10 refs.; available from American Nuclear Society - ANS, 555 North Kensington Avenue, La Grange Park, IL 60526 (US); ISSN 0003-018X
• Country of Publication: United States
• Language: English

Related Subjects

07 ISOTOPES AND RADIATION SOURCES
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
ACTINIDES
ANNEALING
CORROSION
DIFFRACTION
DIFFUSION BARRIERS
FISSION
FISSION PRODUCTS
FUEL PARTICLES
IRRADIATION
NUCLEAR FUELS
PYROLYTIC CARBON
REACTOR ACCIDENTS
REACTORS
SILICON CARBIDES
TEMPERATURE DEPENDENCE
TRANSMISSION ELECTRON MICROSCOPY