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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.
Liam Carlson, Jean C. Ragusa, Paolo Balestra, Yaqi Wang
Nuclear Science and Engineering | Volume 200 | Number 1 | March 2026 | Pages S574-S594
Research Article | doi.org/10.1080/00295639.2025.2471722
Articles are hosted by Taylor and Francis Online.
The pebble tracking transport (PTT) algorithm offers a high-fidelity deterministic approach for neutron transport for pebble bed reactors (PBRs). This approach requires the mesh for the active-core region to consist exclusively of tetrahedral elements, where each node in the pebble-packing region represents a pebble centroid. This paper investigates the application of PTT for full-scale PBRs, considering both the isothermal and the temperature-dependent core conditions. Macroscopic cross sections are generated using Serpent 2 full-core eigenvalue simulations where pebbles are grouped into disjoint subsets using machine learning. To minimize the need for individual cross-section sets for each pebble in the core, K-means clustering is used to group pebbles by temperature and neutronic environment parameters. We compare the multiplication factor and power rate distributions between PTT simulations using the Griffin reactor physics software and reference solutions from Serpent 2. Our analysis shows that a full-core, high-fidelity PTT calculation produces accurate results with minimal local (pebblewise) errors. Additionally, timing results indicate that PTT simulations converge rapidly on modern supercomputing platforms.