Nuclear Engineering Commons^™

Theoretical And Experimental Study Of Degradation Monitoring Of Steam Generators And Heat Exchangers, Xuedong Huang

Masters Theses

The objective of this research is focused on the modeling, analysis, and experimental study of steam generator and heat exchanger degradation monitoring and fault diagnosis. Experimental and analytical studies of tube fouling are performed and the system-level degradations are monitored using data-driven modeling of heat exchanger measurements. Initially, a comprehensive literature study was made on the steam generator and heat exchanger degradation types and mechanisms, including fouling and corrosion.

Based on the mass balance, energy balance, and momentum balance and the moving-boundary method, a multi-node SIMULINK model of a U-tube steam generator (UTSG) has been developed so as to simulate …

Burnable Poison Design For The International Reactor, Innovative And Secure (Iris), Allan Benton Wollaber

Masters Theses

The purpose of this research was to create computer models to expedite the core design of the International Reactor, Innovative and Secure (IRIS), specifically, so that it may employ burnable absorbers to achieve a longer cycle length and enhanced safety while minimizing the use of soluble boron. The IRIS is a next-generation, integral pressurized water reactor (PWR) being designed by an international consortium led by Westinghouse Electric. Two series of comparison benchmarks, defined by Westinghouse, were completed to validate computer models of representative pin cell, assembly, and whole core geometries. The models were created using the collision probability code HELIOS …

Development Of A Data Driven Multiple Observer And Causal Graph Approach For Fault Diagnosis Of Nuclear Power Plant Sensors And Field Devices, Ke Zhao

Masters Theses

Data driven multiple observer and causal graph approach to fault detection and isolation is developed for nuclear power plant sensors and actuators. It can be integrated into the advanced instrumentation and control system for the next generation nuclear power plants.

The developed approach is based on analytical redundancy principle of fault diagnosis. Some analytical models are built to generate the residuals between measured values and expected values. Any significant residuals are used for fault detection and the residual patterns are analyzed for fault isolation.

Advanced data driven modeling methods such as Principal Component Analysis and Adaptive Network Fuzzy Inference System …

Optical Model Methods Of Predicting Nuclide Fragment Production For Space And Radiation Therapy Applications, Chester R. Ramsey

Masters Theses

Reliable methods of accurately and quickly estimating heavy fragment production cross sections are needed for a variety of applications including the production of beams of radioactive ions, studies of the relative abundance of the nuclei in galactic cosmic rays, space radiation protection, and in radiation therapy for treatment of cancers. Quantum mechanical optical model methods for calculating isotope production cross sections for nucleus-nucleus and nucleus-proton interaction are developed from a modified abrasion-ablation collision formalism. The abrasion step is treated quantum-mechanically as a knockout process which leave the residual prefragment nucleus in an excited state. In ablation the prefragment deexcites to …

Determination Of The Dose Rate From Naturally Occurring Radionuclides In Soil, Daniel James Chase

Masters Theses

This thesis addresses the problem of determining the dose rate that an artifact is exposed to while buried in soil. The determination of this dose rate is critical to obtaining an accurate age estimate for an artifact using the Thermoluminescent (TL) Dating technique. Determining the dose rate requires a two step process involving the measurement of the soil activity, and then calculation of the dose rate from this measured activity. For this paper soil samples taken from the Wickliffe Mound site located in Western Kentucky.

The activity of the soil is measured using a High Purity Germanium (HPGe) gamma spectrometry …

Radiological Characterization Of A Uranium Processing Facility, C. A. England

Masters Theses

This document describes the plan that was developed and is being carried out at the Oak Ridge Y-12 Plant to provide data needed for radiological characterization of the site in anticipation of new posting regulations provided in Title 10, Code of Federal Regulations, Part 835, as codified from Volume 58, Number 238 of the Federal Register. The characterization plan addresses the entire site in terms of three categories: 1) Outdoor paved surfaces, 2) buildings, and 3) outdoor non-paved surfaces. Instruments chosen for use in this project are described, as well as survey techniques and the data management scheme. A quantitative …

Monitoring And Prognosis Of Plant Components, Jeffrey Banks

Masters Theses

Many predictive maintenance approaches focus primarily on fault monitoring and diagnosis of rotating machinery. Today's industrial "reliability-based" maintenance programs implement vibrational analysis techniques as a sound foundation in minimizing unnecessary machine downtime. These approaches, based upon on-line data acquisitions and analysis may be used to increase component availability and ultimately forecast remaining life. Depending upon the specific type of machinery under consideration, measurements such as temperature, voltage, current, rotational speed, power, and torque may be analyzed to enhance machinery diagnostics capability.

The purpose of the proposed research is to formulate and implement a methodology to estimate the remaining useful life …

Effects Of Specimen Size Reduction On The Transition Curve Of The Charpy V-Notch Impact Test, Lonnie Eugene Schubert

Masters Theses

"This study was undertaken to correlate the impact properties of ASTM standard full size Charpy V-notch impact specimens to the impact properties of subsize specimens. An ASTM A533-B quenched and tempered plate steel was examined. The fine grained martensitic material had a coarse prior austenite grain size, which resulted in a low upper shelf energy for this material. Three sizes of specimens were included. Specimens were irradiated in the TRIGA Reactor Facility operated by the U. S. Geological Survey in Denver, Colorado, to 1 x 10¹⁹ n/cm² (E > 1 MeV) at 150°C (302°F). Unirradiated and irradiated specimens were …

A Pc-Based Signal Validation System For Nuclear Power Plants, Ali Seyfettin Erbay

Masters Theses

The safe operation and efficient control of a nuclear power plant requires reliable information about the state of the process. Therefore the validity of sensors which measure the process variables is of great importance. Signal validation is the detection, isolation and characterization of faulty signals. Properly validated process signals are also beneficial from the standpoint of increased plant availability and reliability of operator actions.

In recent years, several methods have been developed for signal validation (SV). Some of these methods include generalized consistency checking (GCC) , process empirical modeling (PEM) for prediction, multi-dimensional process hypercube (PHC), univariate and multivariate autoregression …

Analysis Of A Hypothetical Criticality Accident Involving Damp Low-Enriched Uo2 Powder, Benan Basoglu

Masters Theses

In this work, we report on the development of a computer model for predicting the excursion characteristics of a postulated criticality accident involving a homogeneous mixture of low-enriched UO₂ powder and water contained in a cylindrical blender. The model uses point neutronics coupled with simple lumped-parameter thermal feedback. The reactivity feedback coefficients, reactivity driving force function, and the mean generation time are computed a priori using Criticality Safety Analysis Sequences No.1(CSASlX) and No.2(CSAS25) in the SCALE-IV system. The temperature of the system is calculated using a simple time-dependent energy balance where two extreme conditions for the thermal behavior of …

Dose Rate Determination Of The Highly-Enriched Uranium Fuel At The University Of Missouri-Rolla Reactor In Preparation For Transportation, Alice Ann Netzer

Masters Theses

"An analytical model was developed in order to accurately estimate the dose rates in air of the highly-enriched uranium (HEU) fuel at the University of Missouri - Rolla Reactor. Based upon these results, a method is proposed to remove the fuel from the reactor.

First thermoluminescent dosimeters (TLDs) were exposed under water to each of the fuel elements in the reactor pool, except for the four control rodded elements. A model was developed to use the in-water TLD readings to calculate the dose rate of the fuel elements in air at 1 foot and 3 feet. The fuel was modeled …

Dynamic Modeling Of A Pressurized Water Reactor Plant For Diagnostics And Control, Masoud Naghedolfeizi

Masters Theses

A nonlinear model, based on lumped parameter approach, has been developed for computer simulation of a typical Westinghouse Pressurized Water Reactor (PWR) system. The model predicts dynamic behavior of system variables under steady-state and transient conditions. Nonlinear simulation has been applied to study the control systems of the PWR plant. This includes the design of proper actuator and control systems for reactor, steam generator, pressurizer, and turbine models. This model has also been used to identify the responses of plant variables to anomalies in the PWR subsystems at 85% power.

Linear models of the PWR primary loop components have been …

Mechanical And Neutronic Properties Of Neutron Absorbing Materials, Donald James Buth

Masters Theses

“The primary neutron absorbing material examined in this project was Boraflex™, which consists of a silicone polymer with boron carbide acting as the neutron absorber. Two aluminum based neutron absorbers, Boral™ and Al-B-Ten, were also examined. Both X-ray and neutron radiography were used to examine the Boraflex™. The neutron radiography gave better resolution in detecting fluctuations in the boron carbide distribution; however, X-ray radiography did perform better in detecting flaws in the base material. Tensile tests were performed to determine the uniformity of Boraflex™'s tensile properties. The average tensile strength was calculated to be 303 ± 15 psi. A small …

Fuel Loading For A Low-Leakage Core In A Pressurized Water Reactor, Omar Ivan Aguilar

Masters Theses

"A study of low-leakage core fuel loading as a means to reduce fast neutron flux incident upon the pressure vessel is presented. The specific case under study is Cycle 5 of Arkansas Nuclear One - Unit Two (ANO-2), a Combustion Engineering Pressurized Water Reactor. Neutron transport calculations were performed using the DOT two-dimensional transport code. The results from DOT provide the angular distribution of the fast neutron flux at the surface of the pressure vessel.

Seven different fuel loading schemes were studied and compared to the Reference Case. The angular distribution of the fast neutron flux for all cases studied …

Analyzing And Predicting Natural Circulation In A Snupps's Pwr Using "Retran-01", Roger Lee Boyer

Masters Theses

"The purpose of this project is to predict the natural circulation start-up test for the Standardized Nuclear Unit Power Plant System (SNUPPS). In order to make this prediction, a best-estimate, thermal-hydraulic computer code called RETRAN-01 is used.

The start-up test procedures require the simultaneous tripping of all four reactor coolant pumps (RCPs). Natural circulation is confirmed when the three test acceptance criteria have been met. Since this transient is symmetrical, a one-loop approximation of the Nuclear Steam Supply System (NSSS) is normally considered adequate in the nuclear industry. However, there is a concern over how to model the four actual …

A Theoretical And Experimental Investigation Of Single Phase Flow Through A Small Centrifugal Pump In Three Quadrants Of Operation, Lee Charles Cadwallader

Masters Theses

"The operating characteristics of a conventional centrifugal pump have been investigated, both theoretically and experimentally, in three modes of operation with single phase liquid water at atmospheric pressure and room temperature.

Simple one-dimensional theory has been used to evaluate the theoretical pump performance, and these evaluations are compared to actual experimental data. The actual data shows the degradation effects of flow friction and shock losses that the theory does not take into account. The comparison of the curves illustrates these differences.

The data obtained compares well to and reinforces data from experiments found in the literature review.

Based on the …

The Development, Implementation, And Evaluation Of Depletion Perturbation Theory In A Light Water Reactor Nodal Code, Stephen M. Bowman

Masters Theses

A generalized depletion perturbation (DPT) theory formulation for light water reactor (LWR) depletion problems is developed and implemented into the three-dimensional LWR nodal code SIMULATE. This development applies the principles of the original derivation by M. L. Williams to the nodal equations solved by SIMULATE. The present formulation is first described in detail, and the nodal coupling methodology in SIMULATE is used to determine partial derivatives of the coupling coefficients. The modifications to the original code and the new DPT options available to the user are discussed. Finally, the accuracy and the applicability of the new DPT capability to LWR …

An Investigation Of High Order And Low Order Dynamic Modeling Of A Complete Pressurized Water Reactor Nuclear Power Plant, James Downing Freels

Masters Theses

A reference high order PWR system model was developed resulting in a 57th order, lumped parameter, state variable dynamic model. Included in the model are representations of the reactor core, pressurizer, U-tube recirculation type steam generator, connecting piping, and turbine-feedwater heaters. Also included are the models of three-element feedwater flow control, nonlinear reactor control, pressurizer pressure control, and megawatt-frequency turbine control systems.

A low order PWR system model was developed by reducing the 57th order model to a 25th order model by physical methods.

A further reduction on the low order model was demonstrated by a numerical method called the …

Utilization Of Waste Heat From The University Of Missouri Research Reactor., Anek Punyakumleard

Masters Theses

"An analysis has been conducted to determine the economic as well as technical feasibility of using waste heat from the University of Missouri Research Reactor (MURR) to heat the reactor containment building and the associated laboratory building.

Several methods of waste heat utilization were reviewed, including open field agriculture, animal shelter heating, aquaculture, waste water treatment, and space heating. Based on this review, it was concluded that several of these waste heat utilization methods are feasible for the MURR. However, the most practical means of utilizing the MURR waste heat appears to be for space heating in the reactor containment …

A Fluid Control System For The University Of Missouri--Rolla Nuclear Reactor, Billy Roger Mcpherson

Masters Theses

"Solid control rods and their movement through a reactor core present problems inherent in any moving machinery. The problems of binding, wear, and noise have to be dealt with in the usage of a solid control rod system. Therefore, an alternate system that eliminates or minimizes these problems would lower maintenance costs, extend the lifetime of the control system, and produce safer operating conditions.

This thesis presents a control system that has no moving parts inside the reactor core. The system is based upon a neutron-absorbing fluid containe􀁠d in hollow tubes in the reactor core. The fluid level is operated …

Correlation Of Theory And Experiment For The Dynamics Of A Pressurized Water Reactor, J. G. Thakkar

Masters Theses

Dynamic tests were performed on the Carolina Power and Light Company's H. B. Robinson Unit 2 to determine the frequency response of the PWR steam supply system. Step inputs and multi-frequency binary signals of various sequence lengths and bit durations were used. The signals were introduced manually by the operator both for reactivity perturbation and steam flow perturbation tests. The experimental results were analyzed on and IBM 360/65 computer. The test results were compared with theoretical results predicted by a mathematical model of the system.

A mathematical model for the H. B. Robinson system was formulated. In most cases, the …

Experimental Study Of Electron Density And Confinement Time In An Electrostatically-Plugged Cusp Device Using A Microwave Interferometer, Robert Louis Hayward

Masters Theses

"The average electron density and electron confinement time in an electrostatically plugged magnetic spindle cusp device are studied using a 20 GHz microwave interferometer. The results are compared with the predictions from approximate theoretical equations. With a magnetic induction in the point cusp of 5000 Gauss, a plasma is produced by injecting a 5 mA, 500 eV electron beam into hydrogen gas at 10^-5 Torr. The measured electron density is 2 x 10^-10 cm^-3 and the measured confinement time is 80 ysec, which agree to within a factor of two with values predicted by theory"--Abstract, page ii.

The Effects Of Washout In Polydispersed Metalic Aerosols, Jerry N. Burford

Masters Theses

"Experimental Collection Efficiencies are presented for drops of approximately 0.1cm radius falling through aluminium, magnesium and molybdenum oxide polydispersed aerosols. The experimentation was conducted in two identical cylindrical chambers, one being used for aerosol washout, and the other for allowing the aerosol to decay normally. The Collection Efficiency data were thus determined by comparing the aerosol concentration changes in the two chambers. The rather strong effects that induced micro-turbulence and relative humidity have on aerosol collection and aerosol decay were observed and are discussed"--Abstract, page ii.

Reliability Analysis Of The University Of Missouri--Rolla Reactor, Jimmy Dale Schottel

Masters Theses

"The reliability of Nuclear Installations is becoming an important area of research. In this report an approach to reliability analysis was made. The actual failure data was utilized to predict theoretical failure distributions. These distributions were then used to determine future reliability of components, subsystems and system"--Abstract, p. ii

Calculation Of The Neutron Flux In The Side Regions Of The Prestressed Concrete Reactor Vessel Of A High Temperature Gas Cooled Reactor, Richard Robert Kent Jr.

Masters Theses

"Neutron flux in the side regions of the High Temperature Gas Cooled Reactor's (HTGR) Prestressed Concrete Reactor Vessel (PCRV) was determined using the Monte Carlo method. One quarter of the PCRV was modeled, with all major structures inside it, e.g. steam generator, auxiliary cooling loop, etc. imaged at their exact position and size. Initial neutron energies range from .001 eV to 3 MeV. Three neutron interactions were considered: absorbtion, elastic scattering, and inelastic scattering.

The flux was calculated for two different PCRV temperatures, 155° F and 647° F. The thermal flux showed a minor increase at the higher temperature. In …

Waste Heat Utilization From A Direct Cycle High Temperature Gas Cooled Nuclear Reactor For District Heating And Air Conditioning, John Joseph Blase

Masters Theses

"An analysis was conducted to determine the economic as well as technical feasibility of waste heat utilization from the proposed direct cycle high temperature gas cooled nuclear reactor, as designed by the General Atomic Company.

The rejected heat from this system is at considerably higher temperatures than those normally encountered in conventional steam-electric Rankine cycles. By taking advantage of these higher rejection temperatures, heat was translated into energy available to a district heating and air conditioning service. The transportation of this energy was considered to be in the form of heated and chilled water.

A refrigeration capacity on the order …

Possible Damage Mechanism In Dresden 2 Class Boiling Water Reactor Fuel, Donald Lee Moffett

Masters Theses

"A thermal hydraulic analysis of a typical hot channel of a Dresden 2 class boiling water reactor is studied for possible severe local overheating. The COBRA-II thermal hydraulic analysis code is modified to include critical heat flux calculations for each subchannel. The effects of flow distribution, inlet mass velocity variations, dimensional tolerances, enrichment variations, and input parameters are examined in detail. Bulk channel results are in good agreement with the published data, but the assembly wall side of the corner fuel rod has a minimum critical heat flux ratio of less than unity for a number of the situations examined. …

Post Irradiation Changes Of The Elastic Modulus Of Aluminum, Dale A. Powers

Masters Theses

"Aluminum samples of 99.99% and 99.999% purity were irradiated to neutron fluences of 3·8·10¹⁸ nvt and 1.4·10¹⁹ nvt (E greater than 0.1 Mev) at one-third of the melting temperature. The change in Young's modulus of elasticity after isothermal annealing in the temperature range of 110⁰C to 130⁰C was measured. After 2.5 hours of annealing, the modulus reached a steady state value which was decreased by 0.25% ± 0.17% from the unannealed value. Electron microscopy suggests the hardening mechanisms were dispersion hardening by silicon precipitates and void hardening"--Abstract, page ii.

Break-Even Criteria For A Pulsed D-T Reactor, Kenneth Franklin Keller

Masters Theses

"To those who keep track of such things and are in a position to make predictions, it appears that the use of controlled thermonuclear reactions to economically produce electric power is well within a lifetime from now. Indeed, experiments presently being conducted are putting us closer and closer to the development and construction of demonstration fusion reactors. Understandably, the people working on such products and processes are optimistic about their results. This is as it should be if our nation is to avoid major energy shortages in the future.

Unfortunately, the tenor of this paper is pessimistic. This is not …

Use Of Radioactive Iodine Evolved Into Reactor Cooling Water To Locate Defective Fuel Elements, Carl Mozel Stroud

Masters Theses

"The relative amount of radioactive iodine evolved in reactor cooling water by each fuel element provides an excellent indication of defective cladding on fuel elements. The radioactive iodine evolved into the reactor cooling water from a defective fuel element should be higher than the average radioactive iodine evolved by other fuel elements into the cooling water by an order of magnitude or more.

Radioactive iodine with non-radioactive iodine carrier is adsorbed on DOWEX SBR resin in the iodide form. The iodide is eluted from the resin with sodium hypochlorite and extracted into carbon tetrachloride. The iodine is reduced to iodide …