Neutron transport methods for multiphysics heterogeneous reactor core simulation in Griffin
Griffin is a reactor physics application based on the Multiphysics Object-Oriented Simulation Environment (MOOSE). This work discloses the methods, algorithms, and implementation for simulating heterogeneous reactor dynamics models. Griffin utilizes a discontinuous finite-element method with discrete ordinates (DFEM-SN) to discretize the multigroup neutron transport equation. Multiphysics feedback is handled using a two-step tabulated cross-section methodology. […]
Investigation of Ring-heterogeneous Geometry Approximation for Efficient and Practical SFR Analysis
A novel geometry approximation scheme named ring-heterogeneous approximation for intermediate resolution multiphysics analysis of SFRs is presented. This approach particularly targets neutronics coupled with thermo-mechanics feedback, which dominate the passive safety of SFR designs. The ring-heterogeneous approximation casts an array of pins into volume-preserving bands of materials that constitute the pins. It allows to efficiently […]
An equilibrium core depletion algorithm for pebble-bed reactors in the Griffin code
We present a novel deterministic equilibrium core pebble-bed depletion algorithm. It differs from most other algorithms by distinguishing pebble age directly by burnup instead of using the number of completed passes through the core. Using burnup allows for a more physically realistic modeling of the pebble discharge process, especially for low pass cores. The major […]
Layer dissolution in accumulative roll bonded bulk Zr/Nb multilayers under heavy-ion irradiation
The heavy-ion irradiation behavior of bulk zirconium-niobium multilayered composites was investigated up to large doses. Multilayers with an average individual layer thicknesses ranging between 15 and 80 nm were synthesized by accumulative roll bonding technique. The irradiation was performed with a defocused 7 MeV Zr2+ ion beam at 500°C. The maximum dose achieved was ~140 […]
Improvements in High Temperature Gas Cooled Reactor Modeling Capabilities in the Pronghorn Code
This report details the improvement of pebble bed reactor modeling capabilities in the Pronghorn code in fiscal year 2022. The following accomplishments are reported: • DeploymentofweaklycompressiblefinitevolumeformulationtotheHTR- PM reference plan model. • Enable modeling of stagnant gas gaps in the finite volume formulation. • Enable using all Pronghorn correlations available in the finite element version in […]
Validation of the Griffin Application for TREAT Transient Modeling and Simulation
The Transient Reactor Test Facility (TREAT) at Idaho National Laboratory is a graphite-moderated, air-cooled facility that was restarted in 2018 and is specifically built to conduct transient reactor tests. The Department of Energy focused modeling and simulation efforts between 2015 and 2019 on obtaining multiphysics solutions using the Griffin reactor physics application. This research has: […]