Reactor modeling is largely limited by the computational time required to perform accurate full core calculations. There are many different methods and techniques employed in different reactor simulation codes, but properly modeling all of the physics that takes place in the system requires extensive computational effort. The Coarse Mesh Finite...
We present a deterministic spectral method to predict equilibrium temperature distributions, heat flux, and thermal conductivity in homogeneous and heterogeneous media. We solve the Boltzmann transport equation in a second order spatial, self-adjoint angular flux formulation. We implemented this method into the radiation transport code Rattlesnake, built using the MOOSE...
There exists a variety of methods to solve the radiation transport equation in stochastic materials, including the Levermore-Pomraning method and the atomic mix method, each of which is designed to replicate the results given by benchmarks with materials rearranged in a randomized fashion. While the atomic mix method is very...
Detection systems used to monitor reactor operations are of significant interest as tools for verification of operator declarations. Current reactor site safeguards are limited to visual inspections and intrusive monitoring systems. The recent development of antineutrino detectors may soon allow real-time monitoring from an unobtrusive location. Antineutrinos are produced through...
Ion therapy has long been investigated as a potential modality to improve cancer treatments beyond what is currently feasible with photon irradiations. Ions offer both a physical and biological advantage over photons. The physical advantages are well understood, ions deposit their maximum dose at defined penetration depths, allowing for minimal...
The implementation of advanced hybrid (Monte Carlo/Deterministic) transport methods for realistic test problems has been a challenge due to the overhead efforts associated with interfacing a solution generated by a deterministic solver with a Monte Carlo based radiation transport code. In this work, with the help of Transpire, Inc., a...
Detection of reactor antineutrinos for non-proliferation applications has been researched extensively across the globe and is considered as a potential technology to remotely monitor reactor operations without any intrusions to reactor components. Reactor antineutrino detection experiments have been conducted in the past and have proven successful in detecting the changes...
We spatially discretize the Sn transport equation using the high-order (HO) discontinuous finite element method (DFEM) on HO meshes. Previous work provided a proof-of-concept for this spatial discretization method in X-Y geometry. Included in the present work, we derive a spatial discretization for the Sn transport equation in both X-Y...
The objective of this thesis was to investigate the use of the Jacobian Free Newton Krylov Method (JFNK) with physics based preconditioning for solving coupled radiative transport and material energy balance. Modeling of these physics is important in inertial confinement fusion and other high energy density systems. In this thesis,...
During the past few decades, the U.S. Department of Energy (DOE) has made significant investments to improve nuclear data libraries, as the quality of this data impacts nearly all analyses of nuclear systems. Nuclear fission product yields are one component of these libraries, and are important for the analysis of...
The implicit Monte Carlo (IMC) method [16] for radiative transfer, developed in 1971, provides numerical solutions to the tightly-coupled, highly-nonlinear radiative heat transfer equations in many physical situations. Despite its popularity, there are instances of overheating in the solution for particular choices of time steps and spatial grid sizes. To...
Interest in increased fuel supply stability has driven an investigation into possible alternate fuel for use in the WWR-SM research reactor at the Institute of Nuclear Physics in Uzbekistan. The WWR-SM is a high-power, pool-type research reactor currently utilizing IRT-4M fuel made by a single Russian supplier. A candidate for...
This is the investigation into The generation of high-fidelity multigroup multiband cross sections from Monte Carlo neutron transport simulations. Previous methods for generating multigroup multiband (MGMB) cross sections, and multigroup cross sections, assume an approximate shape for the scalar flux. This approximate flux shape is the product of an energy-dependent...
The high-order finite element S[subscript N] transport equations are solved on several test problems to investigate the behavior of the discretization method on meshes with curved edges in X-Y geometry. Simpler problems ensured the correct implementation of MFEM, the general fi nite element library employed. A convergence study using the...
A Level 1 probabilistic risk assessment (PRA) is applied to a plutonium button-making process, but in regards to the risk of diversion (or theft) of special nuclear material (SNM) rather than the risk of mechanical failure. The main objective of the project was to identify the relative vulnerability of areas...
A lead slowing-down spectrometer (LSDS) was modeled in the hopes of beginning a nuclear data development campaign at Oregon State University. An LSDS can be used for neutron interrogation techniques, such as determining isotopic inventory of a sample of unknown components or determining the cross section of a sample of...
Radiation therapy is a sophisticated complex process. Systematic methods are needed to quantitatively evaluate the quality of a complex process and hence radiation therapy treatments. An ideal result for a complex process must be established to determine if the complex process is completed acceptably. For radiation therapy, this can be...
This thesis presents methods for treating annihilation photon pairs in deterministic pulse height distribution (PHD) simulations. The methods are applied in PHD simulations for monoenergtic sources of 1.6 and 2.6 MeV photons incident on 5 and 10 cm 1-D slabs of germanium, sodium iodide, and lead and the results are...
Adjoint-derived weight windowing is a hybrid deterministic/Monte Carlo method to simulate radiation transport. In adjoint-derived weight windowing, a deterministic adjoint solution is used to create weight windows for a Monte Carlo simulation. The intent of this work is to identify factors that reduce the Figure of Merit (FOM) of Monte...
Since the 1990s, researchers around the world have been creating antineutrino detectors for monitoring power reactors. These detectors have been deployed at light water reactors and are able to determine power levels and burn up throughout a fuel cycle. This technology could allow the IAEA to monitor LWRs remotely and...
In this dissertation, we attempt to overcome the "curse of dimensionality" inherent to radiation diffusion kinetics problems by employing a novel reduced order modeling technique known as proper generalized decomposition (PGD). After verifying a proposed PGD algorithm and associated solvers through various tests, we explore its performance for computing reduced-order...
With the advent of next generation reactor systems and new fuel designs, the U.S. Department of Energy (DOE) has identified the need for the resumption of transient testing of nuclear fuels. The DOE has decided that the Transient Reactor Test Facility (TREAT) at Idaho National Laboratory (INL) is best suited...
For over 30 years, the Implicit Monte Carlo (IMC) method has been used to
solve challenging problems in thermal radiative transfer. These problems are typically optically thick and di ffusive, as a consequence of the high degree of "pseudo-scattering" introduced to model the absorption and reemission of photons from a...