Neutronics Modeling of the High Flux Isotope Reactor using COMSOL
- ORNL
The High Flux Isotope Reactor located at the Oak Ridge National Laboratory is a versatile 85 MWth research reactor with cold and thermal neutron scattering, materials irradiation, isotope production, and neutron activation analysis capabilities. HFIR staff members are currently in the process of updating the thermal hydraulic and reactor transient modeling methodologies. COMSOL Multiphysics has been adopted for the thermal hydraulic analyses and has proven to be a powerful finite-element-based simulation tool for solving multiple physics-based systems of partial and ordinary differential equations. Modeling reactor transients is a challenging task because of the coupling of neutronics, heat transfer, and hydrodynamics. This paper presents a preliminary COMSOL-based neutronics study performed by creating a two-dimensional, two-group, diffusion neutronics model of HFIR to study the spatially-dependent, beginning-of-cycle fast and thermal neutron fluxes. The 238-group ENDF/B-VII neutron cross section library and NEWT, a two-dimensional, discrete-ordinates neutron transport code within the SCALE 6 code package, were used to calculate the two-group neutron cross sections required to solve the diffusion equations. The two-group diffusion equations were implemented in the COMSOL coefficient form PDE application mode and were solved via eigenvalue analysis using a direct (PARDISO) linear system solver. A COMSOL-provided adaptive mesh refinement algorithm was used to increase the number of elements in areas of largest numerical error to increase the accuracy of the solution. The flux distributions calculated by means of COMSOL/SCALE compare well with those calculated with benchmarked three-dimensional MCNP and KENO models, a necessary first step along the path to implementing two- and three-dimensional models of HFIR in COMSOL for the purpose of studying the spatial dependence of transient-induced behavior in the reactor core.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 1042798
- Journal Information:
- Annals of Nuclear Energy, Vol. 38, Issue 11; ISSN 0306-4549
- Country of Publication:
- United States
- Language:
- English
Similar Records
Upgrading the HFIR Thermal-Hydraulic Legacy Code Using COMSOL
Evaluation of HFIR LEU Fuel Using the COMSOL Multiphysics Platform
Related Subjects
ALGORITHMS
CROSS SECTIONS
DIFFERENTIAL EQUATIONS
DIFFUSION
DIFFUSION EQUATIONS
DISCRETE ORDINATE METHOD
EIGENVALUES
HEAT TRANSFER
HFIR REACTOR
HYDRODYNAMICS
IRRADIATION
ISOTOPE PRODUCTION
NEUTRON ACTIVATION ANALYSIS
NEUTRON TRANSPORT
REACTOR CORES
RESEARCH REACTORS
SCATTERING
THERMAL HYDRAULICS
THERMAL NEUTRONS
TRANSIENTS
HFIR
COMSOL
Multiphysics
diffusion theory
neutronics
SCALE
NEWT