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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.
S. Dargaville, R. P. Smedley-Stevenson, P. N. Smith, C. C. Pain
Nuclear Science and Engineering | Volume 198 | Number 6 | June 2024 | Pages 1235-1254
Research Article | doi.org/10.1080/00295639.2023.2240658
Articles are hosted by Taylor and Francis Online.
Previously, we developed an adaptive method in angle that is based on solving in Haar wavelet space with a matrix-free multigrid for Boltzmann transport problems. This method scalably mapped to the underlying P0 space during every matrix-free matrix-vector product; however, the multigrid method itself was not scalable in the streaming limit. To tackle this, we recently built an iterative method based on using an Approximate Ideal Restriction multigrid with GMRES polynomials (AIRG) for Boltzmann transport that showed scalable work with uniform P0 angle in the streaming and scattering limits. This paper details the practical requirements of using this new iterative method with angular adaptivity. Hence, we modify our angular adaptivity to occur directly in P0 space rather than the Haar space. We then develop a modified stabilization term for our Finite Element Method that results in scalable growth in the number of nonzeros in the streaming operator with P0 adaptivity. We can therefore combine the use of this iterative method with P0 angular adaptivity to solve problems in both the scattering and the streaming limits, with close to fixed work and memory use.We also present a coarse-fine splitting for multigrid methods based on element agglomeration combined with angular adaptivity, which can produce a semicoarsening in the streaming limit without access to the matrix entries. The equivalence between our adapted P0 and Haar wavelet spaces also allows us to introduce a robust convergence test for our iterative method when using regular adaptivity. This allows the early termination of the solve in each adapt step, reducing the cost of producing an adapted angular discretization.