Our research was focused mainly on the field of plasma physics and the creation of plasmas in a laboratory environment. We first began our project with the goal to develop a tabletop Tokamak, a doughnut shaped device that magnetically confines plasmas at pressures greater than one atmosphere. After researching this...
Spent nuclear fuel (SNF) resultant from the generation of nuclear power is a chemically and radiologically diverse system which is advantageous to chemically process prior to geologic disposal. Hydrometallurgy is the primary technology for chemical processing for light water reactor spent fuels, where spent fuel is dissolved in an acid...
Advancements in power electronics to higher power levels and faster switching times allow new machine and systems designs, but also create higher stresses on electric machinery insulation. High performance, pulse-width modulated (PWM) inverters are now available for medium voltage drive systems, and are being considered by the U.S. Navy as...
The International Handbook of Evaluated Reactor Physics Benchmark Experiments contains detailed descriptions of many different reactor facilities. A large portion of these experiments have not been fully modeled due to the unavailability of computational power at the time of the experiment’s execution. With the advent of renewed interest in Sodium...
In this dissertation, we derive and implement a new transport-diffusion hybrid algorithm for solving thermal radiative transfer (TRT) problems. Using the method of nonlinear elimination (NLEM), the TRT system of equations can be written in terms of a transport equation with the absence of scattering and a diffusion equation. The...
This thesis assessed the passive, natural circulation, design for a Bi-Ca-CaH2 cooled microreactor based on initial figures of merit. The values for the figures of merit selected for this thesis were: the maximum temperature in the core should not be more than 150 K above the average core outlet temperature,...
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) prohibits the testing of nuclear weapons on the face of the earth. The detection of atmospheric radioxenon (131mXe, 133m/133Xe, and 135Xe) plays an important role in the identification of sub-surface clandestine nuclear weapon explosions. Since the radioxenon identified above decay via two radiation in coincidence,...
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...
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...
Instead of expensive and destructive chemical analysis, nondestructive assay (NDA) through radiography and tomography can be a faster, easier, and more appropriate method of analyzing spent nuclear fuel (SNF). As a preliminary study for the future design of a submersible SNF imaging system, this thesis demonstrates the ability of NDA...
Current research on the topic of advanced reactor fuel types include the use of ultrahigh density Uranium-Molybdenum fuels, towards their use in high-performance research reactors. These reactors operate with high power densities, and the increased cooling requirements therefore place high relevance on the fluid-structure interaction with these fuel elements; therefore...
Many devices and methods for radiological searches are currently being developed, including scanning using simple detectors, mapping using large-volume detectors, and Compton imaging using 3-D position sensitive detectors. However, these devices are typically expensive and the methods used require long periods of time to generate a direction or location. The...
Mechanical vibrations compromise the integrity of key components of thermal power plants. Without careful design, strong resonances during steady state operation can wear these components to the point of failure, leading to an unsafe situation that may force a plant to shut down. The purpose of this research is to...
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...
Advancements in digital detector technology over the past decade have facilitated the transition of mammography image acquisition from film screen to full field digital applications. Nearly 90% of the mammography performed in the United States utilizes digital imaging technologies. The ability to capture the image information in an electronic format...
The Code of Federal Regulations (10CFR20.1201) mandates occupational dose limits to the shallow, lens and deep tissue layers. The NRC-accepted procedure of estimating dose to these layers from contamination events is laborious. The current work aims to further the development of a portable phoswich-style skin dosimeter that will operate in...
In 2008, the Oregon State TRIGA® Reactor (OSTR) was converted from highly-enriched uranium (HEU) fuel lifetime improvement plan (FLIP) fuel to low-enriched uranium (LEU) fuel. This effort was driven and supported by the Department of Energy's (DoE's) Reduced Enrichment for Research and Test Reactors (RERTR) program. The basis behind the...
DSA (Diffusion Synthetic Acceleration) has been developed to accelerate the SN transport iteration. We have developed solution techniques for the diffusion equations of FLBLD (Fully Lumped Bilinear Discontinuous), SCB (Simple Corner Balance) and UCB (Upstream Corner Balance) modified 4-step DSA in x-y geometry. Our first multi-level method includes a block...
The Self-indicating Instant Radiation Alert Dosimeter, SIRAD™,
manufactured by JP Labs*, is a dosimeter that can be used by emergency response
persoimel. It is a user-friendly, inexpensive, and disposable radiation dosimeter. It
monitors high doses, 5-200 rads, of ionizing radiation. The card resembles the size of a
credit card and...
This thesis presents an approach to develop innovative methods for decontamination and surface protection applicable to naval nuclear ships and potentially, personnel, replacing antiquated techniques. To accomplish this goal, two products manufactured by CBI Polymers, LLC., DeconGel™ 1101 (1101) and a shampoo, DeconGel™ "prototype" (prototype), were tested.
The prototype was...
International recommendations provided by the International Commission on Radiation Protection (ICRP), as well as national regulations, set by the U.S. Nuclear Regulatory Commission (NRC), state that the exposure of skin to highly concentrated radioactive sources should be monitored at specified depths in skin and kept below specific dose equivalence levels....
Characteristic methods are widely known to be very accurate approaches to the
solution of numerical transport problems. These methods are most often used for
neutron transport applications (i.e. lattice physics calculations) where spatial cells
are of intermediate optical thickness (O(1) - O(100) mean free paths, depending on
the energy group)...
Fission product yields (FPYs) are used for a wide range of applications including nuclear fission theory, nuclear reactor design, reactor antineutrino anomaly, stellar nucleosynthesis, and nuclear forensics. These applications rely on FPYs that were last evaluated in 1993, which included measurements from all over the world up until 1993. In...
Mathematical modeling plays a pivotal role in understanding the mechanism of radiation-induced cellular effects, and also in quantifying the radiation risk to the cell. However, there are still compelling challenges facing the conventional modeling in radiobiology, such as lacking a generalized theory structure of quantifying target effect and non-target effect...
Characterization of uranium isotope compositions is of great interest in many nuclear sub-areas for safeguards purposes. Reprocessing facilities utilizing pyroprocessing raised an issue of uranium isotope monitoring due to the difficulty to apply traditional approaches under extreme environments. An rapid and remote method to characterize uranium isotope compositions for such...
Effective separation of lanthanides (Ln) from the minor actinides (MA) is a crucial technical challenge to closing the nuclear fuel cycle. This separation is a necessary prerequisite to transmute long-lived isotopes of Am and Cm, which will allow a reduction of the repository volume, thermal load, and radiological toxicity of...
There is renewed interest in the reliability and safety of nuclear power plants following the Fukushima Daiichi nuclear accident followed by 8.9 magnitude earthquake and Tsunami with the height of 15 m on March 11, 2011. Small Modular Reactors (SMRs) have been developed to improve safety systems by utilizing passive...
'Hot particle' skin dosimetry calculations are commonly performed using homogeneous dose-point kernels (DPK) in conjunction with scaling and backscatter models to account for non-homogeneous geometries. A new scaling model for determining the actual DPK for beta-particles transmitted by a high-Z source material has been developed. The model is based on...
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...
Total electronic energies are calculated numerically for
free and singly-ionized He, Li, C, and Ne atoms using density
functional theory. Immersion energies are calculated for a single
C impurity atom embedded or absorbed into a charge-neutral system
composed of a free-electron gas with uniform positive background,
also called 'jellium'. Nonspherical...
This study sought to ascertain the degree to which the night sky of Corvallis is affected by light pollution by determining the limiting visual magnitude. Defined as the brightness of the dimmest star that can be seen with the averted naked eye, the limiting visual magnitude establishes a quantitative standard...
The large population of 2r>100m near earth objects (NEOs) presents a certain hazard to life on earth. It has been proposed that a nuclear device may be used to alter the course of such objects, thereby averting a catastrophic collision with the earth. The asteroid interdiction problem includes a number...
The Advanced Test Reactor (ATR), under the Reduced Enrichment for Research and Test Reactors (RERTR) Program and the Global Threat Reduction Initiative (GTRI), is conducting feasibility studies for the conversion of its fuel from a highly enriched uranium (HEU) composition to a low enriched uranium (LEU) composition. These studies have...
There is a significant role in emergency response and personal radiation safety that can be played by a compact radiation detector that is capable of identifying radionuclides. Herein is described the design, construction, and characterization of a small, low-cost, low-power gamma ray spectrometer prototype intended to fill this role, conducted...
In 2008, the Department of Energy (DOE) and Nuclear Regulatory Commission (NCR) decided that the Next Generation Nuclear Plant (NGNP) would be the Very High Temperature Reactor (VHTR). In support of the licensing and validation effort of the VHTR, Oregon State University was tasked with designing, building, and operating a...
Oregon State University has hosted an International Atomic Energy Agency (IAEA) International Collaborative Standard Problem (ICSP) through testing conducted on the Multi-Application Small Light Water (MASLWR) facility. The MASLWR facility features a full-time natural circulation loop in the primary vessel and a unique pressure suppression device for accident scenarios. Automatic...
In intra-arterial radioembolization, nano- and micro-scaled carriers are used in patients with liver tumors that cannot be removed by surgery to deliver various radioisotopes with the aim of improving the outcome of tumor radiotherapy, of minimizing dose to healthy tissue, and of improving the quality of the diagnosis and imaging....
Radiation therapy is used in approximately half of all cancer treatments. The rapid advances in radiation therapy have led to techniques that are much more complex and therefore must be more carefully assessed for safety and efficacy. Accurate quality assurance methods must be implemented to provide patient safety and confidence...
The intent of this work is to extend Implicit Monte Carlo Diffusion (IMD)[Gen.
2001] to account for frequency dependence and to incorporate the difference formulation[Szo. 2005] as a source manipulation variance reduction technique. This
work shows the derivation of the probabilities and the associated proofs which
govern the frequency dependent...
Quick and accurate measurements of nanoparticles have important applications in biology, environmental and non-proliferation areas. Calculation of isotopic ratios, particularly in special nuclear materials, has relied on integration of nanoparticle counts and limited the capability of counting minor isotopes. Rapid transient detection method of nanoparticles has demonstrated the effectiveness of...
The primary goal of this dissertation is to improve the quality of nuclear data available to the nuclear science community. We propose to accomplish this by applying machine learning algorithms to the large number of available benchmark experiments and simulations, with the goal of determining which nuclear data have strong...
Cherenkov detectors have been developed and used in several fields since the discovery of Cherenkov radiation. They do have several advantages compared with other detector types, such as low noise due to the low-energy threshold of Cherenkov radiation, and short decay constant (on the order of picoseconds). However, the light...
The atmospheric detection of four radioxenon isotopes (131mXe, 133mXe, 133Xe, and 135Xe) released during a nuclear detonation is a key tool utilized by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) to identify clandestine nuclear weapon testing activity. These radioxenon isotopes all decay via the near-simultaneous release of an electron and a...
The evaluated nuclear data widely used in computational tools suffer from inaccuracies and large relative uncertainties, particularly with respect to short-lived and low-yield fission products. The existing data are often based on nuclear models, and limited experimental measurements of these fission product yields have been performed. This work seeks to...
Vortex shedding is a phenomenon relevant to any industry dealing with fluid flow. The shed vortices often produce oscillatory forces, which have been suspect in the catastrophic failure of airplanes and bridges alike. To prevent further engineering failures a better understanding of the underlying physics is needed. It has been...
Characterizing special nuclear material (SNM) is critical for nuclear security and non-proliferation. Temporal spectroscopy is a novel and efficient method for characterizing relative material content of special nuclear material. Fission products produced by SNM after being irradiated by a thermal neutron beam can have different half-lives, but can contribute to...
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) bans all nuclear explosion tests for military or civilian purposes. The International Monitoring System (IMS) was established to verify compliance with the treaty. It consists of several monitoring stations that detect: seismic activities, hydrocoustic activities, infrasound waves, and radionuclide particles and noble gases. Radioxenon detection...
Detection of xenon radioisotopes (radioxenons) has proven to be an important method for detecting nuclear explosions and is particularly well suited for detecting undeclared underground testing. The radioxenon isotopes ¹³¹mXe (t₁/₂ = 11.934 d), ¹³³mXe (t₁/₂ = 2.19 d), ¹³³Xe (t₁/₂ = 5.243 d) and ¹³⁵Xe (t₁/₂ = 9.14 h)...
The most widely used and versatile medical radioisotope today is technetium-99m. Roughly 30 million people depend on this radioisotope for diagnostic procedures each year, and this demand is expected to grow. Although there are numerous ways of procuring this isotope, the most common and most practical, for reasons to be...
A new method for delayed gamma-ray spectrometry to quantify the relative content of fissile material is developed and demonstrated to support international efforts in bolstering non-destructive assay capabilities. Previous traditional delayed gamma-ray spectrometry techniques rely upon nuclear data that often carry very high uncertainty. The new method removes the requirement...
). ...................................................................49
Figure 4-9: Ideal nuclear potential well for 238U and two 119Pd fragments
(Krane K. S