Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 39 for “"Nuclear data"”.
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Quantification and propagation of nuclear data uncertainties
… first-order, linear Kalman filter is used as a nuclear data evaluation and uncertainty quantification tool combining available PFNS experimental data and a modified version of the Los Alamos (LA) model. The experimental covariance matrices, not generally given in the EXFOR database, are computed …
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Impact of nuclear data libraries for criticality calculation of HTGR
This work examines how variations among evaluated nuclear data libraries affect criticality calculation for High-Temperature Gas-cooled Reactors (HTGR). Accurate nuclear data is essential for reactor safety analysis. However, previous studies have reported significant differences in calculated keff …
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Algorithms for nuclear data analysis applied to safety and materials
… The availability of large amounts of digitized data gives rise to the necessity of processing digital signals efficiently. We have developed a general-purpose pulse post- processing program based on the ROOT framework to process the digital signals acquired with fast digitizers. We have …
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Accelerating Monte Carlo neutron transport with variable fidelity nuclear data
… can be performed with several types of nuclear data representations; the most common ones are continuous energy (CE) and multi-group (MG) data. CE is the highest fidelity option, since it allows each cross section resonance to be represented precisely. However, due to the need to perform …
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Computational methods for efficient nuclear data management in Monte Carlo neutron transport simulations
… methods for efficiently accessing and utilizing nuclear data in Monte Carlo neutron transport code simulations. Using the OpenMC code, profiling studies are conducted in order to determine the types of nuclear data that are used in realistic reactor physics simulations, as well as the frequencies …
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A Monte Carlo framework for nuclear data uncertainty propagation via the windowed multipole formalism
… arise due to uncertainties in the underlying nuclear data. This framework relies on first order uncertainty analysis using sensitivity methods. The major innovation in the proposed framework is the use of the windowed multipole formalism for calculating the sensitivities. The use of the …
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BAYESIAN INFERENCE ON NUCLEAR DATA AND NEUTRON STAR OBSERVATIONS FOR THE NUCLEAR EQUATION OF STATE
Nuclear matter is defined as a uniform infinite system composed of neutrons and protons at zero temperature interacting only through the nuclear force. Although an idealisation, it is achieved, to a good extent, in the interior of nuclei, where the density is roughly constant and the interaction is …
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On-the-fly nuclear data processing methods for Monte Carlo simulations of intermediate and fast spectrum systems
… for on-the-fly representation and processing of nuclear data within Monte Carlo neutron transport simulations of intermediate and fast spectrum systems are developed and implemented in a continuous-energy Monte Carlo code. First, a capability to compute temperature-dependent unresolved resonance …
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Nuclear Computations under Uncertainty New methods to infer and propagate nuclear data uncertainty across Monte Carlo simulations
… new methods to efficiently infer and propagate nuclear data uncertainty across Monte Carlo simulations of nuclear technologies. The main contributions come in two areas: 1. novel statistical methods and machine learning algorithms (Embedded Monte Carlo); 2. new mathematical parametrizations of …
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Using Nuclear data and Monte-Carlo techniques to study areal density and mix in D² inertial confinement fusion implosions
… values of [rho]Rhot,p and pRhot,n. From these data sets, we conclude that accurate inference of [rho]Rhot requires comprehensive measurements in combination with detailed modeling.
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The Automated Nuclear Spectroscopy of 194Pb.
… in this thesis, programs for the analysis of nuclear data now function on both the Physics Department’s PRIME computer and the University of Alabama in Birmingham’s SIGMA VII computer located in the Ziegler Research Building. These programs are: SAMPO—a program for peak analysis, …
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Development of sensitivity analysis with the use of TSUNAMI-3D sensitivity coefficients for benchmark uncertainty analysis
… code. TSUNAMI-3D produces sensitivities to the nuclear data, while the direct uncertainty analysis required sensitivities to the material, and physical properties. The goal of this work was to implement the sensitivities in the nuclear data with the first order derivative equations to offer a …
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Predictive analytics for maintenance activities in nuclear power plants: a feasibility study
Nuclear power plants are known for their use of legacy systems and processes. As plants age, the amount of maintenance increases while resources remain finite, leading to unwanted delays, affecting the health of assets and increasing costs. To aid in the modernization and digitization of nuclear …
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Phylogeographic structure in the CFR genus Pauridia revealed by inter-simple sequence repeat amplification
… the haploid chloroplast genome. Here the diploid nuclear genome is investigated using inter-simple sequence repeat amplification. Eleven populations were sampled from DNA collected for a previous study. Analysis of molecular variance was done. Ordination based on similarity and covariance was done …
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Evaluation of human error probabilities for post-initiating events
The United States Nuclear Regulatory Commission is responsible for the safe operation of the United States nuclear power plant fleet, and human reliability analysis forms an important portion of the probabilistic risk assessment that demonstrates the safety of sites. Treatment of post-initiating …
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Increased genome sampling reveals novel insights into vertebrate molecular evolution
… genomics with protein-protein interaction data to assess the dynamic relationship between gene duplicability and network structure in primates. Deciphering the timing of the Ursidae (bear) phylogeny speciation events has proven to be a challenging task. A valuable node to calibrate in such …
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Measurement and analysis of the resolved resonance cross sections of the natural hafnium isotopes
… process. The NEA High Priority Request List for nuclear data presents a need for improved characterisation of the hafnium cross section in the resolved resonance region. This thesis presents new resonance cross section parameters for the six natural hafnium isotopes. Cross section measurements, …
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Applications of machine learning in nuclear imaging and radiation detection
… of this work is to use machine learning and data mining techniques to address some challenging problems that arise from nuclear data. Specifically, two problem areas are discussed: nuclear imaging and radiation detection. The techniques to approach these problems are primarily based on a …
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Data-Driven Methods for Low-Energy Nuclear Theory
<p>The term data-driven describes computational methods for numerical problem solvingwhich have been developed by the field of data science; these are at the intersection of computer science,mathematics, and statistics. When applied to a domain science like nuclear physics, especially with the …
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The interaction of fast neutrons with shielding and fusion blanket materials
… with 14.1 MeV neutrons were measured to test nuclear data and calculational methods for D - T fusion reactor neutronics. The neutron spectra measured were performed by an organic scintillator using a pulse shape discrimination technique based on a charge comparison method to reject the gamma …
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