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Demonstration of a nuclear multiphysics workflow using Coreform Cubit, OpenMC, MOOSE, and Cardinal

Dr. April Novak

Assistant Professor University of Illinois Urbana-Champaign, lead developer of Cardinal

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Matt Sederberg

Coreform Chief Strategy Officer

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Dr. Patrick Shriwise

Assistant Computational Scientist at Argonne National Labs, OpenMC and DAGMC developer

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At last! An accessible high-fidelity nuclear multiphysics workflow

  • Opportunity: Multiphysics analysis is needed to account for interaction between radiation transport and other physics areas: temperature, density, geometry, nuclear heating

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  • Problem: industrial use of multiphysics is limited the nuclear industry because of
    • Tedious software dependencies
    • Incompatible data representations
    • Expert-only workflows

Motivation

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Learn how to run a multiphysics simulation with a ‘single source of truth’ geometry representation

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  • No tedious software dependencies
    • Short list of required software included at end of presentation

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  • No incompatible data representations
    • Coreform Cubit creates a “single source of truth” from OpenMC Constructive Solid Geometry (CSG) data
    • Full 3D data visualization - no more relying on 2D CSG slices

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  • Straightforward workflow
    • New step-by-step DAGMC toolbar in Coreform Cubit
    • Improved DAGMC documentation

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  • Today’s data and tutorial will be available for you to reproduce after the webinar

Learning objectives

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Today’s webinar

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  • Introduction of multiphysics software stack
    • Preprocessor: Coreform Cubit
      • Integrated DAGMC functionality
    • Solver: Cardinal
      • OpenMC and nekRS coupled within the MOOSE framework

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  • Demonstration on Kilopower Reactor Using Stirling Technology (KRUSTY) model

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Agenda

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Coreform Cubit

Advanced meshing for challenging simulations

  • CAD import and clean-up
  • Semi-automated hex meshing
  • Maximum control of mesh properties and quality
  • Python and scripting
  • Flexible licensing
  • Support for OpenMC and MCNP workflows

Prior webinar: OpenMC neutronics simulations of CAD-based geometry using DAGMC and Coreform Cubit (November 2023)

Introduction of multiphysics software stack

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DAGMC

Direct Accelerated Geometry Monte Carlo

  • Enables geometry queries on computer-aided design (CAD)-based tessellations
  • Eliminates the need to rebuild CAD as constructive solid geometry (CSG) in many Monte Carlo codes

CAD Model

Surface Tessellation

Tessellation Sealing

Ray Tracing Algs.

Supported codes

  • MCNP
  • OpenMC
  • FLUKA
  • Geant
  • Shift

Introduction of multiphysics software stack

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An open-source Monte Carlo particle transport code

• Programming interfaces (C/C++ and Python)

• Nuclear data interfaces and representation

• Depletion (Python)

• HPC support

• Hybrid CSG/CAD models

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Supported and developed primarily at Argonne National Laboratory and MIT

Introduction of multiphysics software stack

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Nuclear Energy Advanced Modeling and Simulation (NEAMS)

  • Couples OpenMC to MOOSE using CAD

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  • Can be used to predict fission and fusion integrated physics behavior, such as:
    • Nuclear heating → power deposition in thermal-fluid simulations
    • Material damage (dpa), gas production → material correlations
    • Diagnostics, sensor responses → digital twins

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  • Typical use cases for industry:
    • Fission and fusion system design
    • Provide “reference” solutions for confirmatory analysis/benchmarking
    • Create constitutive models for other codes

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MOOSE Navier-Stokes

Fluid temperature, velocity, …

OpenMC radiation transport

Nuclear heating, dpa, activation, …

MOOSE solid mechanics

Solid temperature, stress, strain, …

Introduction of multiphysics software stack

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Coreform Cubit Meshing for Cardinal

  • OpenMC geometry: CSG or triangulated surface meshes using Cubit DAGMC plugin
  • OpenMC tallies: volume mesh (any element type)
  • MOOSE geometry: volume mesh (any element type)

MOOSE geometry

Introduction of multiphysics software stack

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New Coreform Cubit feature: OpenMC CSG import

  • Reduce redundant effort in translating OpenMC CSG → CAD for
    • Multiphysics/meshing
    • 3D visualization
    • External engineering domains

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  • Partial model conversion supported for
    • Interactive model building
    • Geometry debugging of complex parts
    • Lost particle visualization

Introduction of multiphysics software stack

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KRUSTY: Kilopower Reactor Using Stirling Technology

  • Fission reactor from Los Alamos National Laboratory
  • Existing CSG model (developed by Michael Mendes, UIUC)

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Existing CSG model

D. Poston, M. Gibson, T. Godfroy, and P. McClure. “KRUSTY reactor design,” Nuclear Technology 206 (2020)

Demonstration of multiphysics simulation with a ‘single source of truth’ geometry representation

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Coreform Cubit demo

Existing CSG model

Objective:

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Couple OpenMC neutron transport to finite element heat conduction in the fuel region

Simplified version of the criticality benchmark

Demonstration of multiphysics simulation with a ‘single source of truth’ geometry representation

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Coreform Cubit demo

Existing CSG model

Load into Cubit as CAD

Demonstration of multiphysics simulation with a ‘single source of truth’ geometry representation

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Coreform Cubit demo

Existing CSG model

Load into Cubit as CAD

Conversion of 1 cell to DAGMC

Volume mesh for tallies and heat conduction

Demonstration of multiphysics simulation with a ‘single source of truth’ geometry representation

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Cardinal Coreform Cubit Demo

Demonstration of multiphysics simulation with a ‘single source of truth’ geometry representation

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Cardinal Model Demo

OpenMC model

Hybrid mesh + CSG geometry

MOOSE Heat conduction model

Unstructured mesh

power

temperature

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Cardinal Model Demo

On-the-fly regeneration of the OpenMC mesh geometry based on temperature contours

Cell 1

Cell 2

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Cardinal Model Demo

Cardinal input file structure

[Mesh]

# …

[]

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[Variables]

# …

[]

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[Kernels]

# …

[]

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[BCs]

# …

[]

  • Specifying the mesh geometry

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  • Defining the physics of the problem
    • Fields to solve for
    • Governing equations
    • Boundary conditions
    • Initial conditions

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  • Passing data between OpenMC and MOOSE

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  • Specifying the solver options

Demonstration of multiphysics simulation with a ‘single source of truth’ geometry representation

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Cardinal Coreform Cubit Demo

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Thank you for joining!

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  • We want to get this software into your hands! Engage with us to bring advanced simulation to industry.
    • Patrick Shriwise, Argonne National Laboratory: pshriwise@anl.gov
    • April Novak, University of Illinois: ajnovak2@illinois.edu

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  • Today’s webinar model is available online – try it out and let us know how it goes!

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