Publications
Showing 121 results for Author: Grant W. Helmreich
Feb, 2025
Journal
Investigation of UO2 Doped with Fe2O3 Sintered Under a Reducing Atmosphere
Nuclear fuel produced with trace amounts of transition metal additives is of potential interest for introducing intentional signatures for accelerating nuclear forensics. In this work, we investigate the effects on microstructure, grain size, crystal structure, and stoichiometry when trace amounts of Fe in the form of Fe2O3 are added to UO2. Sintering of compacts with diff…
Dec, 2024
Journal
Ordered Particle Packing in Dense TRISO/SiC Fuel Elements and Preliminary Assessment of Neutronic and Thermomechanical Characteristics
Detailed analysis of the particle distribution in Transformational Challenge Reactor fuel elements indicates that particle packing is not random; instead, it follows a relatively ordered structure near fuel element surfaces. Discrete particle neutronic simulations indicate that the core reactivity is not impacted when assuming homogenization of particles with the silicon c…
Sep, 2024
Journal
Interface stability of ultrasonic additively manufactured Zircaloy-4 during hydrothermal corrosion
Simulated pressurized water reactor conditions (330 °C, 15.6 MPa, ∼20 ppb oxygen) without irradiation were used to investigate the hydrothermal corrosion behavior of ultrasonic additively manufactured Zircaloy-4 up to 1000 h. X-ray computed tomography allowed for visualization of defects from processing and their progression after corrosion experiments. The specimens were…
Sep, 2024
ORNL Report
ROADRUNNER MiniFuel Experiment – Irradiation Target Design and Sample Characterization