Nuclear Engineering Commons^™

Robust Multichannel Functional-Data-Analysis Methods For Data Recovery In Complex Systems, Jian Sun

Doctoral Dissertations

In recent years, Condition Monitoring (CM), which can be performed via several sensor channels, has been recognized as an effective paradigm for failure prevention of operational equipment or processes. However, the complexity caused by asynchronous data collection with different and/or time-varying sampling/transmission rates has long been a hindrance in the effective use of multichannel data in constructing empirical models. The problem becomes more challenging when sensor readings are incomplete. Traditional sensor data recovery techniques are often prohibited in asynchronous CM environments, not to mention sparse datasets. The proposed Functional Principal Component Analysis (FPCA) methodologies, e.g., nonparametric FPC model and semi-parametric …

Thermocouple Temperature Measurements For Twin Jet Thermal Mixing, Spero Michael Peters

Masters Theses

Thermocouples are commonly used devices for temperature measurement. This study concerns the implementation of thermocouples to collect thermal mixing data in an environment in which two parallel water jets are mixing. The measurements are taken with the purpose of modeling the jet mixing region so that Computational Fluid Dynamics (CFD) models can be validated against the test data. This thesis covers the design, construction, implementation and evaluation of a thermocouple system for immersion in a water environment to measure the thermal mixing of twin jets.

The measurement system being used is a thermocouple rake whose design and fabrication is covered. …

Spatially-Dependent Reactor Kinetics And Supporting Physics Validation Studies At The High Flux Isotope Reactor, David Chandler

Doctoral Dissertations

The computational ability to accurately predict the dynamic behavior of a nuclear reactor core in response to reactivity-induced perturbations is an important subject in the field of reactor physics. Space-time and point kinetics methodologies were developed for the purpose of studying the transient-induced behavior of the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor’s (HFIR) compact core. The space-time simulations employed the three-group neutron diffusion equations, which were solved via the COMSOL partial differential equation coefficient application mode. The point kinetics equations were solved with the PARET code and the COMSOL ordinary differential equation application mode. The basic nuclear …

Discovery And Development Of Rare Earth Activated Binary Metal Halide Scintillators For Next Generation Radiation Detectors, Kan Yang

Doctoral Dissertations

This work focuses on discovery and development of novel binary halide scintillation materials for radiation detection applications. A complete laboratory for raw materials handling, ampoule preparation, material rapid synthesis screening, single crystal growth, sample cutting, polishing and packaging of hygroscopic halide scintillation materials has been established. Ce³⁺ and Eu²⁺ activated scintillators in three binary systems: Alkali Halide – Rare Earth Halide (AX–REX₃), Alkali Halide – Alkaline Earth Halide (AX–AEX₂) and Alkalin Earth Halide – Rare Earth Halide (AEX₂–REX₃) were systematically studied. Candidates for new scintillation materials in the three systems …

Development Of A Safeguards Monitoring System For Special Nuclear Facilities, James Joseph Henkel

Doctoral Dissertations

Two important issues related to nuclear materials safeguards are the continuous monitoring of nuclear processing facilities to verify that undeclared uranium is not processed or enriched and to verify that declared uranium is accounted for. The International Atomic Energy Agency (IAEA) is tasked with ensuring special nuclear facilities are operating as declared and that proper material safeguards have been followed. Traditional safeguards measures have relied on IAEA personnel inspecting each facility and verifying material with authenticated instrumentation.

In newer facilities most plant instrumentation data are collected electronically and stored in a central computer. Facilities collect this information for a variety …

Development Of A Prognostic Method For The Production Of Undeclared Enriched Uranium, David Alan Hooper

Doctoral Dissertations

As global demand for nuclear energy and threats to nuclear security increase, the need for verification of the peaceful application of nuclear materials and technology also rises. In accordance with the Nuclear Nonproliferation Treaty, the International Atomic Energy Agency is tasked with verification of the declared enrichment activities of member states. Due to the increased cost of inspection and verification of a globally growing nuclear energy industry, remote process monitoring has been proposed as part of a next-generation, information-driven safeguards program. To further enhance this safeguards approach, it is proposed that process monitoring data may be used to not only …

A New Method For Coupling 2d And 3d Deterministic And Stochastic Radiation Transport Calculations, Joel Aaron Kulesza

Masters Theses

The objective of this body of work was to produce a code system capable of processing boundary angular flux data from discrete ordinates calculations in 2D and 3D Cartesian and cylindrical geometries into cumulative probability density functions that can be used with a Monte Carlo radiation transport code to define neutron and photon initial positions, directions, and energies. In order to accomplish this goal, the DISCO (DetermInistic-Stochastic Coupling Operation) code was created to interface between the DORT and TORT deterministic radiation transport codes and the MCNP stochastic radiation transport code. DISCO introduces new methods to use the boundary angular flux …

Positron Emission Tomography (Pet) For Flow Measurement, Bi Yao Zhang

Masters Theses

Positron Emission Tomography (PET) is frequently used for medical imaging. Maturity and flexibility of PET as an imaging technique has expanded its utility beyond the medical domain. It can be used as a tool for fluid flow studies in opaque fluids and for flow within complex geometry where conventional optical flow measurement approaches fail. This study explores the capabilities of PET as flow measurement tool suited to validation of computational fluid dynamic (CFD) predictions.

The MicroPET P4 scanner was used to image the diffusion process in flow around a rod bundle geometry similar to that found in a nuclear reactor …

Dynamic Modeling, Sensor Placement Design, And Fault Diagnosis Of Nuclear Desalination Systems, Fan Li

Doctoral Dissertations

Fault diagnosis of sensors, devices, and equipment is an important topic in the nuclear industry for effective and continuous operation of nuclear power plants. All the fault diagnostic approaches depend critically on the sensors that measure important process variables. Whenever a process encounters a fault, the effect of the fault is propagated to some or all the process variables. The ability of the sensor network to detect and isolate failure modes and anomalous conditions is crucial for the effectiveness of a fault detection and isolation (FDI) system. However, the emphasis of most fault diagnostic approaches found in the literature is …

Resonance Testing For Fault Detection Of Steam Generator Heat Transfer Tubing Walls, Michael C. Shannon, John Howington, Jesus Sanchez, Colin Sandidge, Jeremy Townsend, Keith Welsh

Chancellor’s Honors Program Projects

No abstract provided.

Vibration Fault Detection For Steam Generator Tubing, Brad Black, Laura Simmons, John Chapman, Jared Jennings, Jacob Johnson, Brian Paul, Kyle Woods

Faculty Publications and Other Works -- Nuclear Engineering

The detection of flaws within steam generator tubing is an important part of safety in a nuclear plant as it could potentially lead to release of radioactive material if unchecked. The current test method for testing these tubes is expensive and time consuming; however, as sound has been used to detect flaws successfully in other applications, an alternative method for using acoustics and accelerometers to detect flaws is what has been explored in this project. Preliminary results of testing with a simple hollow steel tube have given promising results of detecting a hole as small as 7.66% of the tube …

Estimates Of Linear Energy Transfer From Solar Energetic Particles In Earth's Upper Atmosphere To Human Tissue In Aluminium Aircraft, Michael Ian Hall

Masters Theses

Radiation from extraterrestrial sources is a concern for the safety of passengers and crew in high altitude aircraft. Cosmic radiation and solar particles constantly bombard the atmosphere with energy. Radiation levels from these sources can vary considerably depending on solar activity cycles and energetic particle events such as solar flares. In order to predict the effects of such events the nature of the radiation spectrum must be characterized, and the individual effects of each radiation type understood. The background radiation spectrum is known to good accuracy and prediction of radiation levels due to specific solar events is currently under investigation. …

Vibration Fault Detection For Steam Generator Tubing, Brad Patrick Black, Laura Simmons, John Chapman, Jared Jennings, Jacob Johnson, Brian Paul, Kyle Woods

Chancellor’s Honors Program Projects

No abstract provided.