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2026 Nuclear Energy Conference & Expo (NECX)
August 24–27, 2026
Dallas, TX|Hilton Anatole
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Launching into tomorrow: NRIC guides new era of research and deployment
In June 2025, the Department of Energy announced the Reactor Pilot Program, an authorization pathway that allowed reactor developers to partner with the DOE to get first-of-a-kind (FOAK) reactors built and tested. Soon after, the DOE rolled out a complementary Fuel Line Pilot Program, which aimed to fast-track fuel projects. In all, 20 projects were accepted into the new programs.
Yuqiao (Joy) Fan, Igor Bolotnov
Nuclear Science and Engineering | Volume 200 | Number 8 | August 2026 | Pages 1834-1861
Research Article | doi.org/10.1080/00295639.2025.2547485
Articles are hosted by Taylor and Francis Online.
In nuclear thermal-hydraulic studies, counter-current flow limitation (CCFL) typically refers to steam rising at a fast rate such that it prevents coolant from draining down within a confined channel. CCFL is a crucial issue in nuclear reactor safety analysis. This study investigates CCFL in debris bed channels using high-resolution interface-capturing simulations. A novel proportional-integral-derivative flow rate controller is developed to efficiently achieve the CCFL conditions. Verification studies confirm that CCFL occurs under the same conditions with or without the controller, demonstrating that PID control ensures accurate prediction. Three debris bed channel geometries were examined: a cylindrical channel, a channel with small obstacles, and a channel with large obstacles. Results show that obstacles significantly impact flow behavior, interfacial shear, wall shear, and pressure gradients required for CCFL. The comparison with experimental data confirmed that simulations incorporating geometric complexities align more closely with experimental CCFL conditions. A pressure gradient correlation was also developed for CCFL prediction.