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...