Implications of Results from the Advanced Gas Reactor Fuel Development and Qualification Program on Licensing of Modular HTGRs

Conference · Mon Oct 01 00:00:00 EDT 2001

OSTI ID:1167535

Petti, David

The high level of safety of modular high temperature gas-cooled reactor (HTGR) designs is achieved by passively maintaining core temperatures below fission product release thresholds under all envisioned accident scenarios. This level of fuel performance and fission product retention reduces the radioactive source term by many orders of magnitude relative to other reactor types but is predicated on exceptionally high coated-particle fuel fabrication quality and excellent fuel performance under normal operation and accident conditions. The Advanced Gas Reactor Fuel Development and Qualification (AGR) Program decided to qualify for uranium oxide/uranium carbide (UCO) TRISO coated-particle fuel in an operating envelope that would bound both pebble bed and prismatic modular HTGR options. By using a mixture of uranium oxide and uranium carbide, the kernel composition is engineered to minimize CO formation and fuel kernel migration, which is key to maintain to fuel integrity at the higher burnups, temperatures, and temperature gradients anticipated in prismatic HTGRs. Fuel fabrication conducted at both laboratory and engineering scale has demonstrated the ability to fabricate high quality UCO TRISO fuel with very low defects. The first irradiation (AGR 1) exposed about 300,000 TRISO fuel particles to a peak burnup of 19.6% FIMA, a peak fast-neutron fluence of about 4.3 × 10²⁵ n/m², and a maximum time-averaged fuel temperature of about 1,200°C without a single particle failure. The very low release of key metallic fission products (except silver) measured in post-irradiation examination (PIE) confirms the excellent performance measured under irradiation. Very low releases have been measured in accident simulation heatup testing (''safety testing'') after hundreds of hours at 1600 and 1700°C and no particle failures (no noble gas release measured) have been observed. Even after hundreds of hours at 1800°C, the releases are still very low indicative of only a small fraction of fuel failure. The implications of these results relative to safety design and analysis and licensing will be discussed to demonstrate the margins associated with UCO TRISO fuel.

• Research Organization: Idaho National Lab. (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• DOE Contract Number: DE-AC07-05ID14517
• OSTI ID: 1167535
• Report Number(s): INL/CON-14-32127; TRN: US1500003
• Resource Relation: Conference: 7. International topical meeting on high temperature reactor technology (HTR 2014), WeiHai (China), 27-31 Oct 2014
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
NUCLEAR FUELS
HTGR TYPE REACTORS
MODULAR STRUCTURES
PEBBLE BED REACTORS
PRISMATIC CONFIGURATION
FAST NEUTRONS
URANIUM CARBIDES
URANIUM OXIDES
CARBON MONOXIDE
COATED FUEL PARTICLES
SILVER
RARE GASES
REACTOR ACCIDENTS
REACTOR LICENSING
PERFORMANCE
SAFETY MARGINS
REACTOR SAFETY
BURNUP
FABRICATION
PERFORMANCE TESTING
FISSION PRODUCT RELEASE
FUEL INTEGRITY
POST-IRRADIATION EXAMINATION
RADIATION SOURCES
TEMPERATURE GRADIENTS
AMOEBA EFFECT
REACTOR ACCIDENT SIMULATION
NEUTRON FLUENCE
TEMPERATURE RANGE 1000-4000 K
EXPERIMENTAL DATA
Advanced Gas Reactor Fuel Development and Qualific
high temperature gas-cooled reactor (HTGR)
HTR 2014
NGNP
post-irradiation examination (PIE)
VHTR