Method of Characteristics for 3D, Full-Core Neutron Transport on Unstructured Mesh

Abstract

A myriad of nuclear reactor designs are currently being considered for next-generation power production. These designs utilize unique geometries and materials and can rely on multiphysics effects for safety and operation. This work develops a neutron transport tool, MOCkingbird, capable of three-dimensional (3D), full-core reactor simulation for previously intractable geometries. The solver is based on the method of characteristics, utilizing unstructured mesh for the geometric description. MOCkingbird is built using the MOOSE multiphysics framework, allowing for straightforward linking to other physics in the future. A description of the algorithms and implementation is given, and solutions are computed for two-dimensional/3D C5G7 and the Massachusetts Institute of Technology BEAVRS benchmark. The final result shows the application of MOCkingbird to a 3D, full-core simulation utilizing 1.4 billion elements and solved using 12 000 processors.

Investigation and Validation of Unstructured Mesh Methodologies for Modeling Experimental Reactors

“…A previous attempt at modeling the core with PARCS is reported in [6], but the neutron flux comparison with the Serpent solution was not successful, especially in the outer fuel lattice region, due to the mismatch between PARCS mesh and the actual CROCUS fuel lattices. Furthermore, in line with the current efforts towards the use of more flexible numerical methodologies to implement deterministic neutron transport solvers capable of operating on unstructured meshes [7,8], the Laboratory for Reactor Physics and System Behaviour (LRS-EPFL) has started to develop new tools for reactor analysis based on the OpenFOAM finite-volume library [9,10], namely: the GeN-Foam multiphysics solver [11] and the OFFBEAT fuel behavior tool [12]. In particular, GeN-Foam is a multiphysics solver for the analysis of nuclear reactors that takes advantage of general finite-volume methodologies on unstructured meshes to provide enough flexibility for the study of non-conventional reactor designs, such as CROCUS.…”

High-fidelity multiphysics load following and accidental transient modeling of microreactors using NEAMS tools: Application of NEAMS codes to perform multiphysics modeling analyses of micro-reactor concepts

“…First and foremost, the assessment of new or existing NEAMS codes and capabilities is summarized in Section 2, providing a summary of the feedback and experience gathered through this work. This includes the use of Griffin for neutronics, BISON for thermo-mechanics, Sockeye for heat pipe modeling, SAM for 1D Fluid -3D solid modeling of coolant channels and system modeling of balance of plant components, SWIFT for hydrogen redistribution in hydride moderator, MOOSE Reactor Module and Mesh System for mesh generation [5], and the NEAMS Workbench for creating meshes or executing codes on the INL NCRC. The MOOSE MultiApp System was used in a wide range of multiphysics analyses on the HP-MR, GC-MR and KRUSTY models, for applications coupling of the Griffin, BISON, Sockeye or SAM, and SWIFT applications.…”

Investigation of discretization uncertainty in Monte Carlo neutron transport simulations of the Molten Salt Fast Reactor (MSFR)

“…The lack of sensitivity evaluation studies on MCNT calculations makes the researchers to perform their MCNT calculations neglecting mass errors due to mesh utilization, since the available works are related with deterministic methods [8,11,13].…”