PhD Thesis

UQ of Monte Carlo XS Generation for HTRs

Ann Arbor, MI

Advised by Prof. Thomas Downar

Aug 2023

  • Thesis title: Quantification and Minimization the Uncertainty Propagation of Monte Carlo Cross Section Generation for HTR Applications
  • Developed an analytic UQ methods based on perturbation theory for UQ of MC generated XS, implemented in AGREE
  • Developed a stochastic UQ methods based on randomly sampling for UQ of MC generated XS, implemented with Dakota, coupled with AGREE and SAM
  • Monte Carlo-Deterministic hybrid methods for HTR neutronics analysis, SAM system code for thermal-hydraulics simulation
  • Methods were demonstrated on HTR-10 steady-state benchmark and gFHR steady-state / transient simulations
  • UQ
  • MC XS
  • Hybrid method
  • HTR

Experience

University of Michigan

Ann Arbor, MI

Postdoctoral Research Assistant

Sept 2023 - Current

  • Developed a gFHR multi-physics system model to train a Digital Twin surrogate using the VARMAX data-driven stochastic regression model
  • Over 4000x sppedup for the reactor simulation using data-driven machine learning algorithms
  • Decreasing the O&M cost and improving the economic efficiency of the advanced reactors
  • Developed visualization apps for user interaction and display over 40 Digital Twin predicted state variables
  • Python
  • C++
  • MatLab

Argonne National Laboratory Summer Intern

Lemont, IL

Graduate Research Aid

May 2022 - Aug 2022

  • SAM code development using C++ and MOOSE framework, implemented a control rod module with spacial effect
  • Implemented a numerical ODE solver to solve xenon/iodine Bateman equations
  • Created demo cases and unit tests for the newly implemented module/solver
  • gFHR neutronics/thermo-fluids modeling and simulation
  • C++
  • MatLab
  • Python

Research

RSOR - Linear Solver Preconditioner

  • Implemented RSOR (Reduced Successive Over Relaxation) preconditioner for banded matrices, improving run time by ~25%
  • The method was applied in the numerical library Futility to improve the performance of linear solvers
  • C++
  • Fortran

lpCMFD

  • Implemented a linear prolongation approach to accelerate the convergence of CMFD (Coarse Mesh Finite Difference) solver by ~30% iterations, the stability was also improved
  • The algorithm was applied in reactor simulation code MPACT
  • Fortran

Projects

gFHR Modeling and Simulations

  • Fluoride-cooled High-temperature Reactor (FHR), pebble-bed based design
  • Monte Carlo - Deterministic Hybrid Method with Serpent 2 code and AGREE code
  • Coupled neutronics / thermo-fluids simulation of the core and primary/secondary loops using system analysis code SAM
  • Model development for the Digital Twin (DT) training

MSRE

  • Molten Salt Reactor Experiment modeling and simulation
  • Neutronics simulation using hybrid method with Serpent/Shift and PARCS

SPERT

  • Development of the transient capability for the NEAMS neutronics code PROTEUS
  • Modeling and Simulation of the SPERT experimental benchmark

Publications

References

Thomas Downar (PhD Advisor) Professor at University of Michigan
  • +1 (765) 427-9239
  • [email protected]
  • Brendan Kochunas (PhD Committee Member) Assistant Professor at University of Michigan
  • +1 (734) 763-3867
  • [email protected]
  • Dan O'Grady (Internship Supervisor) Research Assistant at Argonne National Laboratory
  • +1 (630) 252-4870
  • [email protected]
  • Jin Li

    Profile

    PhD grad (Aug 2023) major in nuclear engineering. Interested in advanced nuclear reactor design, multi-physics coupled analysis, reactor physics code development, applying AI/ML on nuclear engineering. Seeking positions for nuclear engineering research.

    Diplomas

      • Doctor of Philosophy (2023)
      • Nuclear Engineering and Radiological Sciences
      • GPA = 3.926
      • University of Michigan, Ann Arbor
        Bachelor of Engineering (2018)
      • Engineering Physics
      • Tsinghua University, China

    Skills

      • Reactor Simulation Code
      • Serpent
      • MCNP
      • VERA
      • PARCS
      • OpenMC
      • SAM
      • AGREE
      • MPACT
      • SCALE
      • MOOSE Framework
        Programming
      • C++
      • Python
      • MATLAB
      • Fortran
      • C
      • Bash/Zsh
        Developer Tools
      • Linux system
      • Git
      • Docker
      • Conda
      • CMake/XMake
        Misc
      • LaTeX
      • Markdown
      • Microsoft Office
      • Adobe Tools

    Interests

    • Tennis
    • Ski
    • Cooking
    • Building website