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...
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...
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...
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...
Because of the growth of the nuclear power industry in the United States and the policy to ban reprocessing of commercial spent nuclear fuel, the spent fuel inventory at commercial reactor sites has been increasing. With the Yucca Mountain project on hold, more spent fuel is expected to be stored...
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...
Nanostructured material has been projected to be the next generation material for the detection of ionizing radiation due to the uniquely superior physical processes associated with charge creation and by virtue of their optoelectronic tunablility. Semiconducting Nanocrystal (NC) detectors, by nature of their low band gap material, low fabrication costs,...
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...
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HaoriYang
High-energy delayed γ-rays from photofission were demonstrated to be
In a radiological emergency scenario, the capability to rapidly visualize radiation emitted from debris, contamination, or absorbed in biological samples, while visualizing the non-radioactive (or “conventional” image) features within a field of view, will provide critical information to support optimization of further analysis, sample collection, and decision making. This research...
Nuclear material monitoring systems have long been established at ports of entry. However, there are no standard systems for monitoring points of interest within the country. Therefore, the use of a network of radiation sensors deployed throughout an area of interest is being investigated within this thesis. Before full scale...