A neutron noise solver based on a discrete ordinates method
The convergence rate of the accelerated and unaccelerated versions of the simulator is studied for the case of a perturbed infinite homogeneous system. The theoretical behavior predicted by the Fourier convergence analysis agrees well with the numerical performance of the simulator. The diffusion synthetic acceleration decreases significantly the number of numerical iterations, but its convergence rate is still slow, especially for perturbations at low frequencies.
The simulator is further tested on neutron noise problems in more realistic, heterogeneous systems and compared with the diffusion-based solver. The diffusion synthetic acceleration leads to a reduction of the computational burden by a factor of 20. In addition, the simulator shows results that are consistent with the diffusion-based approximation. However, discrepancies are found because of the local effects of the neutron noise source and the strong variations of material properties in the system, which are expected to be better reproduced by a higher-order transport method such as the one used in the new solver.
diffusion synthetic acceleration
nuclear reactor modelling
deterministic neutron transport methods
Chalmers, Fysik, Subatomär, högenergi- och plasmafysik
A discrete ordinates solver with diffusion synthetic acceleration for simulations of 2-D and 2-energy group neutron noise problems
International Conference on Mathematics and Computational Methods applied to Nuclear Science and Engineering - M&C 2019,; (2019)p. 2023-2032
Paper i proceeding
Neutron noise simulations in a heterogeneous system: A comparison between a diffusion-based and a discrete ordinates solver
International Conference on Mathematics and Computational Methods applied to Nuclear Science and Engineering - M&C 2019,; (2019)p. 439-448
Paper i proceeding
Core monitoring techniques and experimental validation and demonstration (CORTEX)
Europeiska kommissionen (EU) (EC/H2020/754316), 2017-09-01 -- 2021-08-31.
Övrig annan teknik
CTH-NT - Chalmers University of Technology, Nuclear Engineering: 341
PJ Lecture room, Fysik Origo, Fysikgården 2B, Chalmers University of Technology
Opponent: Dr. Vasily Arzhanov, KTH Royal Institute of Technology, Stockholm, Sweden