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Fuel loading process begins at Palisades
The Palisades nuclear power plant has drawn closer to restart, as plant staff began the process of loading fuel into the reactor vessel on Sunday morning.
The commencement of fuel loading places the Covert, Mich., facility in Mode 6—or the refueling stage—under the plant’s technical specifications, plant owner and operator Holtec International said in a news release. The Palisades reactor core consists of 204 fuel assemblies that include new fuel and partially used fuel from the plant’s most recent operating cycles. According to Holtec, the fuel loading is being conducted in accordance with plant procedures and technical specifications.
Vidor H. Lujan, Bailey Painter, Dan Kotlyar
Nuclear Science and Engineering | Volume 200 | Number 6 | June 2026 | Pages 1425-1439
Research Article | doi.org/10.1080/00295639.2025.2526881
Articles are hosted by Taylor and Francis Online.
Traditional engineering-based core analyses generally rely on a two-stage approach, involving a transport code and a diffusion (e.g. nodal) solver. The accuracy and fidelity of the core solution strongly depend on the generation of few-group constants, which is a topic that has been extensively studied. However, the practice of calculating group constants with Monte Carlo (MC) codes is still relatively new. The main challenge of this approach is the generation of diffusion coefficients. A common approach adopted by many MC codes is the flux separability approximation (FSA). However, diffusion coefficients generated with FSA have trouble matching the heterogenous solution. This is due to a strong coupling between the energetic, spatial, and angular distributions of neutrons. This is a well-documented challenge, with some literature proposing consistent methods to handle energy-angle dependence and others proposing consistent methods to handle energy-space-angle dependence. Recently, the Cumulative Migration Method has been used to generate consistent diffusion coefficients using MC. However, these diffusion coefficients are valid only for infinite single region problems. As such, it is important to revisit the consistent group constant generation method to better handle the energy-space-angle dependence using MC. This paper will lay out the method to generate these consistent group constants using MC and then verify that they can then be used for a two-stage approach using a steady-state nodal expansion method.