Publications
Showing 172 results for Author: Jason M. Harp
Sep, 2026
Journal
Review and analysis of the high-burnup fuel fragmentation and dispersal data: Comparing LOCA test programs
A significant amount of data have been collected on high-burnup fuel fragmentation and dispersal; however, the data from various programs have been analyzed using different approaches. These approaches have led to differing observations, which regulators worldwide may interpret as uncertainties, and therefore, the regulators have to incorporate this uncertain transposabili…
Sep, 2026
ORNL Report
Analysis of ATR flux wires 284-116, 284-117, 284-124, 284-125, 284-126, and 284-127
Sep, 2026
Conference Paper
Radial Characterization of As-Irradiated and Post-LOCA Tested High Burnup UO2 Fuel Using SEM and S/TEM-EDS
Sep, 2026
Journal
Effect of spacer grids on high-burnup fuel fragmentation, relocation, and dispersal
Increasing the fuel burnup limit in light-water reactors to improve fuel cycle economics requires a strong technical foundation. Experimental observations from the Halden and Studsvik programs have revealed severe fuel fragmentation during loss-of-coolant accident (LOCA) conditions, highlighting the need for additional technical evaluation. Consequently, further LOCA test…
Sep, 2026
Journal
Identifying microstructures susceptible to pulverization in commercially irradiated high burnup UO2 under LOCA conditions
High burnup fuel fragmentation (HBFF) has been a concern in the nuclear industry for many years. When UO2 reaches and exceeds pellet average burnups around 55 GWd/tU, microstructural changes in the fuel pellet begin to occur that render the pellet susceptible to fine fragmentation under loss-of-coolant accident (LOCA) conditions. During a LOCA event, the cladding balloons…
Aug, 2026
Journal
Using X-ray spectrum imaging to quantify fission gas in high-burnup UO2 fuel
Analysis of fission gas bubbles (FGBs) in light-water reactor (LWR) fuel is needed to improve the understanding and predictive capability of fuel evolution under normal- and transient conditions. One of the most important parameters of a FGB is the pressure of the gas, primarily Xe, inside it. Bubble volume and location (inter- vs. intragranular) are important consideratio…
Aug, 2026
Journal
Irradiation of UC1+x kernels using the MiniFuel vehicle: Microstructure, phase analysis, and initial post-irradiation examination
Uranium carbide is a candidate fuel form for a wide range of advanced reactors, including larger Generation IV reactors as well as small modular reactors and microreactors. However, its commercial deployment timeline faces challenges via traditional qualification approaches. To address this issue, an accelerated fission rate irradiation test was performed to collect basic…