AGR-1 Post Irradiation Examination Final Report

Technical Report · Sat Aug 01 00:00:00 EDT 2015

DOI:https://doi.org/10.2172/1236801· OSTI ID:1236801

Demkowicz, Paul Andrew ^[1]

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1. Idaho National Lab. (INL), Idaho Falls, ID (United States)

The post-irradiation examination (PIE) of the Advanced Gas Reactor (AGR)-1 experiment was a multi-year, collaborative effort between Idaho National Laboratory (INL) and Oak Ridge National Laboratory (ORNL) to study the performance of UCO (uranium carbide, uranium oxide) tristructural isotropic (TRISO) coated particle fuel fabricated in the U.S. and irradiated at the Advanced Test Reactor at INL to a peak burnup of 19.6% fissions per initial metal atom. This work involved a broad array of experiments and analyses to evaluate the level of fission product retention by the fuel particles and compacts (both during irradiation and during post-irradiation heating tests to simulate reactor accident conditions), investigate the kernel and coating layer morphology evolution and the causes of coating failure, and explore the migration of fission products through the coating layers. The results have generally confirmed the excellent performance of the AGR-1 fuel, first indicated during the irradiation by the observation of zero TRISO coated particle failures out of 298,000 particles in the experiment. Overall release of fission products was determined by PIE to have been relatively low during the irradiation. A significant finding was the extremely low levels of cesium released through intact coatings. This was true both during the irradiation and during post-irradiation heating tests to temperatures as high as 1800°C. Post-irradiation safety test fuel performance was generally excellent. Silver release from the particles and compacts during irradiation was often very high. Extensive microanalysis of fuel particles was performed after irradiation and after high-temperature safety testing. The results of particle microanalysis indicate that the UCO fuel is effective at controlling the oxygen partial pressure within the particle and limiting kernel migration. Post-irradiation examination has provided the final body of data that speaks to the quality of the AGR-1 fuel, building on the as-fabricated fuel characterization and irradiation data. In addition to the extensive volume of results generated, the work also resulted in a number of novel analysis techniques and lessons learned that are being applied to the examination of fuel from subsequent TRISO fuel irradiations. This report provides a summary of the results obtained as part of the AGR-1 PIE campaign over its approximately 5-year duration.

• Research Organization: Idaho National Lab. (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• DOE Contract Number: AC07-05ID14517
• OSTI ID: 1236801
• Report Number(s): INL/EXT-15-36407; TRN: US1600270
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
AGR TYPE REACTORS
CESIUM
SILVER
IRRADIATION
FISSION PRODUCTS
POST-IRRADIATION EXAMINATION
COATED FUEL PARTICLES
PARTIAL PRESSURE
URANIUM CARBIDES
URANIUM OXIDES
TEMPERATURE RANGE 1000-4000 K
OXYGEN
PERFORMANCE
FAILURES
FISSION
HEATING
LAYERS
MICROANALYSIS
RADIONUCLIDE MIGRATION
SAFETY
FISSION PRODUCT RELEASE
COATINGS
TIME DEPENDENCE
MORPHOLOGY
TESTING
AGR
ART
HFEF
MFC
PIE