A model of the Oregon State TRIGA reactor was developed in Serpent 2 by translating a previously accepted MCNP model. Both models were verified and validated via comparison of each model and data gathered from the core start-up. Reactivity bias in each code was determined. Using the rod drop method,...
The Neutron radiography facility (NRF) at Oregon State University (OSU) has been modified to begin working on the non-destructive evaluation of concrete materials to study the early stages of shrinkage, cracking, and water transport of concrete during the curing process.
The objective of this work is to investigate the efficiency...
The objective of this work was to determine and optimize the resolution of a neutron sensitive Multi-Channel Plate (MCP) detector in order to determine its capabilities in radiography and tomography. The Oregon State University, Neutron Radiography Facility added an MCP Detector in 2012 in order to analyze these capabilities. The...
This thesis evaluates dose rates from the TRIGA® reactor by comparing ion chamber measured exposure rates to exposure rates calculated from MCNP5 model data. The first step evaluates the energy distribution required to match ion chamber exposure rates from measurements taken at 1 foot increments above the reactor core. Next,...
Breast cancer is the leading cancer in women with an estimated 13% of women in the United States developing a form of invasive breast cancer in her lifetime. The survival rate is estimated to be 85%, but the American Cancer Society estimates that early detection of breast cancer in the...
The neutron flux-energy spectral characterization of a Thermo Fisher MP320 deuterium-tritium neutron generator was performed for two shielding configurations, one with substantial moderator between the source and the sample and one without such moderator. The STAYSL PNNL spectral adjustment code was utilized in conjunction with MCNP modelled reference spectra and...
Neutron radiography has been used to study cementitious materials. This thesis studies the impact of heavy water on both the rate of hydration and neutron radiography. The neutron attenuation coefficients of light and heavy water were measured. Cement pastes were made with both heavy and light water. The attenuation coefficients...
Radiological emergency plans ensure that protective actions can and will be taken in the event of an accident. Principle protective actions for the early phase of an emergency are evacuation and sheltering-in-place. While evacuations are generally safe, there are deterministic, long-term health consequences from prolonged displacement that outweigh the stochastic...
Breast cancer is the most common cancer among women as it accounts for about 25% of all female cancer cases. Studies have shown that early detection of breast cancer increases the chances of a positive prognosis amongst patients therefore it is crucial to provide accurate diagnosis tools in routine exams....
Natural uranium samples were irradiated in-core for 7 seconds using the pneumatic rabbit system within the TRIGA Mark II Reactor at Oregon State University, and then used to generate a gamma-ray spectrum with a high purity germanium (HPGe) detector. The irradiated sample was simulated in Monte Carlo N-Particle (MCNP), a...
Thin foil samples of special nuclear materials (SNMs) were irradiated for 60s using a Mark TRIGA II reactor, and their associated gamma emissions were recorded with a count time of 60s following irradiation. A rapid pneumatic transfer system was used to irradiate the samples in front of beam port #4....
Following thermal neutron induced fission, supervised machine learning and temporal gamma-ray spectroscopy methods were used to identify differences in the delayed gamma-ray spectra of Pu-239 and U-235. The temporal gamma-ray spectroscopy method takes advantage of the time-dependent decay of fission products. Employing Spearman's rank-order correlation coefficient and without prior knowledge...
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...
Control rod calibration experiment results for the Oregon State TRIGA® Reactor (OSTR) immediately following LEU conversion in 2008, and MCNP® 5 predicted rod worths from the 2008 LEU Conversion Safety Analysis Report (CSAR) are discussed. The reactivity worth of the four OSTR control rods are measured using the rod-pull method....
In radiation therapy it is very important to accurately measure the amount of radiation delivered. The effectiveness of the treatment depends on delivering the dose with an accuracy of 5% or better. The dosimetry in different clinics must also be consistent. For these reasons national and international calibration protocols have...