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Redistribution of radionuclides in irradiated AGR-1 UCO TRISO fuel after 1800 °C safety testing

Journal Article · · Journal of Nuclear Materials

Release of radionuclides from intact tristructural-isotropic (TRISO) coated particle fuel at normal and accident conditions is a primary metric of fuel performance. The distribution of fission products and actinides in the TRISO layers of individual particles provides insight on radionuclide transport and release behavior and was determined using scanning electron microscopy analysis. Particles were isolated from an irradiated fuel compact (AGR-1 Compact 4-4-2) and analyzed as-irradiated or after individual particle safety-testing at 1800 °C for 650 h. Particles were selected for comparison based on their remaining 110mAg fission product inventory. These comparisons corroborated the observation that the 110mAg inventory is a marker for relative irradiation temperature based on observed radionuclide distribution in the SiC layer. The comparison also indicated that the in-pile behavior influences the fission product and actinide species interactions with the TRISO layers during high temperature exposure after irradiation. The analysis confirms both palladium and uranium diffusion, as well as other species, are active in the UCO TRISO fuel system at 1800 °C and that palladium transport is active at lower temperatures relative to uranium. While diffusion across the SiC layer was observed, the intact nature of the SiC layer after the 1800 °C, 650-h exposure indicates the SiC layer maintained its functionality as a fission product barrier by mitigating release of radionuclides at beyond accident margin temperatures.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1661266
Journal Information:
Journal of Nuclear Materials, Journal Name: Journal of Nuclear Materials Journal Issue: 0 Vol. 542; ISSN 0022-3115
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (41)

Carbon monoxide-silicon carbide interaction in HTGR fuel particles journal January 1991
Thermodynamics of multi-component systems containing UC and PuC A review journal August 1969
Fission product palladium-silicon carbide interaction in htgr fuel particles journal July 1990
SIMS and RBS study of thermally annealed Pd/β-SiC interfaces journal December 2002
Interface reactions between silicon carbide and metals (Ni, Cr, Pd, Zr) journal March 2001
Preconceptual design of a fluoride high temperature salt-cooled engineering demonstration reactor: Core design and safety analysis journal May 2017
Determining the minimum required uranium carbide content for HTGR UCO fuel kernels journal June 2017
Assessment of SiC-CMC compatibility with components of actinide fuel systems journal June 2019
Electron microscopy study of Pd, Ag, and Cs in carbon areas in the locally corroded SiC layer in a neutron-irradiated TRISO fuel particle journal September 2018
The challenges associated with high burnup, high temperature and accelerated irradiation for TRISO-coated particle fuel journal September 2007
A novel approach to fabricating fuel compacts for the next generation nuclear plant (NGNP) journal October 2008
Microencapsulated fuel technology for commercial light water and advanced reactor application journal August 2012
The role of Pd in the transport of Ag in SiC journal January 2013
Ag transport in high temperature neutron irradiated 3C–SiC journal February 2014
Identification of silver and palladium in irradiated TRISO coated particles of the AGR-1 experiment journal March 2014
Chemical reactivity of CVC and CVD SiC with UO2 at high temperatures journal May 2015
Associations of Pd, U and Ag in the SiC layer of neutron-irradiated TRISO fuel journal May 2015
Grain boundary diffusion of Ag through polycrystalline SiC in TRISO fuel particles journal December 2015
STEM-EDS analysis of fission products in neutron-irradiated TRISO fuel particles from AGR-1 experiment journal July 2016
Fission products silver, palladium, and cadmium identification in neutron-irradiated SiC TRISO particles using a Cs-Corrected HRTEM journal August 2016
Local atomic structure of Pd and Ag in the SiC containment layer of TRISO fuel particles fissioned to 20% burn-up journal March 2018
Separate effects irradiation testing of miniature fuel specimens journal December 2019
Microstructure and fission products in the UCO kernel of an AGR-1 TRISO fuel particle after post irradiation safety testing journal January 2020
Investigation of the structure and chemical nature of Pd fission product agglomerations in irradiated TRISO particle SiC journal April 2020
Role of microstructure on CO corrosion of SiC layer in UO2-TRISO fuel journal August 2020
Palladium assisted silver transport in polycrystalline SiC journal October 2012
Electron microscopic evaluation and fission product identification of irradiated TRISO coated particles from the AGR-1 experiment: A preliminary review journal May 2014
Performance of AGR-1 high-temperature reactor fuel during post-irradiation heating tests journal September 2016
Silicon carbide grain boundary distributions, irradiation conditions, and silver retention in irradiated AGR-1 TRISO fuel particles journal April 2018
Analysis of fission product distribution and composition in the TRISO layers of AGR-2 fuel journal August 2020
High temperature interface reactions of TiC, TiN, and SiC with palladium and rhodium journal December 2008
Multi-tier Analysis of SiC Breaches in Safety-Tested AGR-1 TRISO Fuel Particles journal August 2014
Silver and Cesium Diffusion Dynamics at the β-SiC Σ5 Grain Boundary Investigated with Density Functional Theory Molecular Dynamics and Metadynamics journal January 2014
A Novel Dual-Step Nucleation Pathway in Crystalline Solids under Neutron Irradiation journal January 2018
Epitaxial carbon nanotube film self-organized by sublimation decomposition of silicon carbide journal November 1997
Thermodynamic Study of SiC Utilizing a Mass Spectrometer journal November 1958
Diffusion of Ag along Σ 3 grain boundaries in 3C-SiC journal December 2011
Stoichiometric Effects on Performance of High-Temperature Gas-Cooled Reactor Fuels from the U-C-O System journal September 1977
Silver Release from Coated Particle Fuel journal September 1977
PIE on safety-tested AGR-1 compact 4-2-2 report March 2015
PIE on Five Irradiated AGR-1 Compacts report September 2012

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