Material testing experiments are needed to enable the next generation of nuclear fission reactors. Concluding in 2009, the Boosted Fast Flux Loop (BFFL) project was devised as a way to test fast reactor materials and fuels in the Advanced Test Reactor (ATR), however the experiment location it used is now...
In this thesis, we expand the scope of a previously introduced Artificial Neural Network (ANN) method to solve the slab-geometry discrete ordinates (S$_N$) neutron transport equations. Specifically, we extend the method to energy-dependent (multi-group) fixed source problems involving heterogeneous media and more general boundary conditions - vacuum and incident flux...
The Direct Reactor Auxiliary Cooling System (DRACS) is a passive safety system capable of removing decay heat directly from the reactor core. Its modularity makes it scalable for use in reactors with various power levels. Work has previously been completed to support inclusion of the DRACS in liquid metal reactors...
This paper analyzes the decision-making process utilized in temperate environments for building nuclear facilities and whether it was going to be applicable to nuclear facilities built in arid environments. To answer this question, the total dose to individuals from arid and temperate environments were compared using RESRAD-OFFSITE and changing the...
Nanoscale Instrumented Indentation Testing (IIT) is a material characterization technique that is used to determine mechanical properties. The size effects present at this scale make it difficult to expand findings to a bulk scale. Modeling can be used to bridge this gap and better understand nanoscale IIT and the size...
Faithful modeling of the expected gamma signals inside an electrochemical facility at various key measurement points is important for understanding what detection limits are available for the next generation of safeguards technologies. Gamma Detector Response and Analysis Software (GADRAS) and the Separation Safeguards Performance Model (SSPM) were used to build...
Silicon photomultipliers (SiPM) have become increasingly popular in radiation detection design due to smaller profiles, lower operating voltage, and magnetic insensitivity. However, there are nonlinear effects that make modeling SiPM challenging. This study looks at using a Monte Carlo approach to modeling the output of an SiPM and front end...
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...
Since the International Commission on Radiation Protection (ICRP) recommended a revision to the eye lens dose limits in ICRP Publication 118 (Stewart, 2012) the radiation protection community has conducted many new studies related to eye dosimetry. The recommended reduction of eye lens dose limits may result in the reduction of...
When the ICRP updated their recommended limits for eye dose, they ignited a renewed interest in eye dosimetry. Especially, how the updated eye dose estimates affect current regulations and what that would mean to a radiation worker. Radiation workers are commonly required to wear leaded eyeglasses to reduce their dose...
The metastable isotope of technetium-99 (Tc-99m) is an important diagnostic tool used in the field of nuclear medicine due to the isotope's 6.0 hour half-life, 140.5 keV γ-decay mechanism, and multiple oxidation states [1,2]. Approximately 70% of the world’s nuclear medicine procedures involve the use of Tc-99m [3]. The conventional...
High purity niobium metal is used in the construction of superconducting radio frequency (SRF) cavities in superconducting particle accelerators, such as the Large Hadron Collider (LHC) at CERN or the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. The usual method for characterizing the impurities in this niobium, the...
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...
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...
Fortuitous dosimeters are radiosensitive objects carried by an individual who was exposed to radiation. These objects can be analyzed some time after exposure and the results can be used to aid in calculating radiation fields and doses received by individuals. Items that make good fortuitous dosimeters are those that are...
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...
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...
CR-39 foils were irradiated as part of nuclear accident dosimetry experiments using the Godiva reactor at the Nevada National Security Site and the Caliban and Prospero reactors at the Valduc Centre for Nuclear Studies in France. The irradiated foils were chemically etched using the standard Lawrence Livermore National Laboratory process...
'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...
The HENRI system was developed to narrow the pulse width of TREAT from 89 ms to below 60 ms with the goal of improving the test reactor's ability to simulate RIAs in LWRs by rapidly injecting helium-3, a strong neutron poison, into the core. A coupled model using the CFD...
This thesis describes calculations done to determine the radiation hazard of the current Prompt Gamma Neutron Activation Analysis (PGNAA) scattering chamber at the Oregon State TRIGA Reactor (OSTR) and compare it to the amount that would be given off by a new thin-walled chamber design. These calculations were completed with...
Recent advances in robotics have led to interest in exploring soft robotic technologies as an engineering control for reducing the risk of radiation exposure for workers in the nuclear industry. These emerging “soft” technologies offer many advantages over traditional rigid robotic systems and can perform a wide range of tasks...
Nonmelanoma skin cancer (NMSC) is the most common malignancy in Caucasian populations. One existing treatment modality for NMSCs is external radiotherapy delivered to the skin cancer tumor by a beta-emitter-containing radioactive skin patch. Alpha emitters, with their higher linear energy transfer than beta particles and shorter range in tissue, make...
Current neutron dosimetry methods rely on the assumption that charged particle equilibrium (CPE) is established within the tissue medium. This maintains that the kinetic energy transferred to the medium (KERMA) is equivalent to absorbed dose. However, this assumption is only valid for large volumes such as the whole body. For...
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...
Since Ranked Set Sampling (RSS) was proposed in 1952 by G.A. McIntyre, it has been the subject of many statistical investigations and a large number of field studies. Throughout these studies RSS has been proven to provide a better estimate of population the mean and variance than Simple Random Sampling...
The Oregon State University (OSU), Hydro Mechanical Fuel test Facility (HMFTF) is designed to hydro-mechanically test prototypical plate type fuel. OSU's fuel test program is a part of the Global Threat Reduction Initiative (GTRI), formerly known as the Reduced Enrichment for Research and Test Reactor program. One of the GTRI's...
Oregon State University is home to a TRIGA® Mark II reactor. In October of 2008, the reactor began operating on low enriched uranium fuel. A model of the facility exists in MCNP, a Monte Carlo code that can be used for criticality calculations. Until now, a bias in the calculation...
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....
The use of medical diagnostic imaging involving ionizing radiation has drastically increased in recent years causing concern about possible long term consequences such as the induction of cancer. Recognizing this recent trend, the
Institutional Review Board (IRB) at the Nebraska Medical Center commissioned this study in order to determine effective...
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 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...
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...
High-energy delayed γ-rays from photofission were demonstrated to be signatures for detection and identification of special nuclear materials. Such γ-rays were measured in between linac pulses using independent data acquisition systems. A list-mode system was developed to measure low-energy delayed γ-rays after irradiation. Photofission product yields of ²³⁸U and ²³⁹Pu...
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...
The use of Ionization Chambers and Thermo-luminescent dosimeters (TLD's) in the medical field has established a need to determine if the skin depth dose response is comparable between the two detectors. This research will determine if the dose response from an Ionization chamber is comparable to a Thermo-luminescent dosimeter system...
In this work a prompt gamma neutron activation analysis (PGNAA) facility has been designed, built, and characterized at the Oregon State University TRIGA® reactor. PGNAA is a technique used to determine the presence and quantity of trace elements such as boron, hydrogen and carbon which are more difficult to detect...
Power planning efforts in Oregon require accurate information
about hydroelectric potential. Potential uses for Geographic Information
Systems (GISs) are being investigated by three Oregon planning agencies.
This paper presents a method in which a 616 is used to help identify and
reduce uncertainty in previous hydroelectric inventories. Uncertainty with
respect...
Resident and migratory avifauna in the Willamette Valley, Oregon are heavily influenced by winter conditions and habitat characteristics, especially those of wetlands. As such, it is important to monitor avian communities and environmental factors at wetland sites within the Willamette Valley during winter. Using data from standardized avian point-count surveys,...
Partitioning of trivalent actinides (in particular, americium and curium) from the
fission produced light lanthanides is a major concern of used nuclear fuel reprocessing for
the purposes of waste disposal. Several solvent extraction processes have been developed
to address these chemically difficult separations. The historically employed TALSPEAK
Process utilizes di-2-ethylhexyl...
The Mahakam Delta which was once among the largest mangrove forests in Indonesia, has been subjected to dramatic changes in structure and function due to massive shifts from mangrove forest to shrimp ponds and oil and gas development. To understand the impacts of mangrove loss to the greenhouse gas (GHG)...
Purple nutsedge [Cyperus rotundas L.) has been recognized as one of the
most troublesome perennial weeds of agricultural lands in tropical and some
temperate regions. This research sought to determine the effects of timing of
herbicides, shading, and soil moisture on plant population growth and tuber
production of purple nutsedge...
There is considerable evidence to support the
hypothesis that seafood, poultry and meat are close
substitutes in consumer demand. Thus the relationships
among prices are important in determining consumption
patterns among these protein sources. In addition, there
are at least two kinds of outlets in which seafood, poultry
and meat...
Society uses massive quantities of wood fiber in production of paper, and demand for fiber is projected to increase further as production of biofuels from fermentation of plant cellulosic materials increases. Because these end uses generally require the costly step of removing of lignin, wood with reduced or more easily...
Most of the presently grown cultivars of rice (Oryza sativa L.) have poor
competitive ability against weeds if compared with traditional cultivars. Therefore,
effective weed control is an important but often costly and difficult management
practice in rice crop production. If weed competitive ability of rice cultivars could be
improved...
In order to effectively use foodgrain prices as tools of government policy, it is necessary to know the possible effects of price incentives on different economic variables. The present study
attempts to measure the effects of foodgrain prices, upon various economic variables, including production, consumption, both at the farm and...