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Publications (109)
This paper provides an overview of the current MSR design space and lists unique features of the various designs under consideration. Some general considerations for source terms calculation for Molten Salt Reactors (MSRs) are explained. Applicability and limitations of terminology currently defined for legacy light water reactor (LWR) systems are...
The origins of naturally occurring and man-made radioactive sources are described, and their contributions to exposure to radiation are identified. Naturally occurring radioactive materials that become sufficiently concentrated by processing and handling to require regulatory attention are identified and discussed. Radioisotopes of concern for expo...
The 2011 Fukushima Daiichi nuclear accident in Japan resulted in the release of radioactive materials into the atmosphere, the nearby sea, and the surrounding land. Based on the International Atomic Energy Agency (IAEA) Convention on Early Notification of a nuclear accident, several radiological data were collected on the accident. Among the radioa...
Four sample groups were prepared by adding different concentrations of naphthalene (NP) or of 2,6-diisopropylnaphthalene (DIN) as a secondary solvent ( S2) in carborane-loaded toluene (TL)- and pseudocumene (PC)-based scintillators. The pulse-height spectra of the samples in response to 137Cs γ-rays and to thermal neutrons were collected to study t...
The scintillation efficiency in response to thermal neutrons was studied by loading different concentrations of carborane (0-8.5 wt%) and naphthalene (0 and 100 g/L) in five liquid organic scintillators. The sample was characterized in Pb and Cd shields under the irradiation of the thermal neutrons from a 252Cf source. A method was developed to ext...
Abstract—Thin polymeric films are evaluated in this research as a potential replacement technology for radiation portal monitors where specific attention is given to the physical basis for neutron-photon discrimination. It is shown that the difference in the energy deposition mechanics from charged particle reaction products and from the Compton sc...
Thin polymeric films are evaluated in this research as a potential replacement technology for radiation portal monitors where specific attention is given to the physical basis for neutron-photon discrimination. It is shown that the difference in the energy deposition mechanics from charged particle reaction products and from the Compton scattered e...
Biaxially stretched composite polyethylene naphthalate (PEN) films (BSCPF) embedded with submicron lithium fluoride (6LiF) particles and luminescent molecules were fabricated to make large area scintillation films (≈1 m × 1 m) for thermal neutron detection. BSCPF had 20.2% higher neutron light yield as compared to unstretched composite film (UCPF),...
Thin film polystyrene composite scintillators containing and organic fluors have been fabricated and tested as thermal neutron detectors. Varying fluorescence emission intensities for different compositions are interpreted in terms of the Beer-Lambert law and indicate that the sensitivity of fluorescent sensors can be improved by incorporating tran...
The Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) survey approach is comprised of systematic random sampling coupled with radiation scanning to assess acceptability of potential hot spots. Hot spot identification for some radionuclides may not be possible due to the very weak gamma or x-ray radiation they emit—these hard-to-...
Novel $^{6}{rm Li}$-loaded polyester scintillation films have been designed and fabricated to detect thermal neutrons. Lithium fluoride crystals containing enriched $^{6}{rm Li}$ were synthesized and integrated into polyethylene naphthalate polyester matrix containing appropriate luminescent molecules. Thermal neutron capture by $^{6}{rm Li}$ ions...
A methodology for simulating a neutron detector's pulse-height spectra (PHS) utilizing semiempirical equations for the light yield nonproportionality of organic scintillators is described. Using these simulations, suitable material synthesis techniques are established for optimizing the performance of neutron scintillators. A MATLAB program suite w...
In this work, we report on optical and scintillation properties of a new scintillation material CsGd2Cl7:Ce. Crystals were grown in vacuum sealed ampoules, and the response to gamma rays and thermal neutrons was characterized. The scintillation light yield was ∼38,000 ph/MeV, and the primary decay time was 60 ns under γ-ray excitation. A thermal ne...
A series of novel <sup>6</sup>Li-loaded plastic scintillation films have been designed and fabricated to detect thermal neutrons. Organolithium salts containing enriched <sup>6</sup>Li were synthesized and interspersed in a series of matrices comprising a polymer doped with an antenna fluor. Thermal neutron capture by <sup>6</sup>Li produces charge...
The Department of Nuclear Engineering at the University of Tennessee (UT) has undertaken an effort to develop a robust program in nuclear security education and research within the nuclear engineering curriculum. Multiple new faculty positions have been staffed over the last few years, and new coursework and certification programs have been develop...
Boron neutron capture therapy has now been used for several malignancies. Most clinical trials have addressed its use for the treatment of glioblastoma multiforme. A few trials have focused on the treatment of malignant melanoma with brain metastases. Trial results for the treatment of glioblastoma multiforme have been encouraging, but have not ach...
The field of nuclear engineering is being revitalized after several decades of decreased activity. This new development has resulted in nearly a factor of three increase in enrollment in nuclear engineering programs throughout the Unites States. It is important that this new group of engineers has an opportunity to acquire fundamental reactor opera...
A method is proposed for redesigning an existing pressurized water reactor simulator with modern control and data acquisition electronics along with a custom designed GUI. This system will be used in providing instruction to undergraduate and graduate Nuclear Engineers on the operation of a Pressurized Water Reactor and for simulation of nuclear cr...
Approximately 15 billion dollars has been paid into the Nuclear Waste Fund, about 55,000 metric tons of spent fuel resides at reactor and storage sites, and the time when Yucca Mountain will be available for disposal of spent fuel is at best uncertain. Results from a substantial number of studies show that space requirements for geologic disposal o...
Boron neutron capture therapy is a brachyradiotherapy utilizing the 10B(n,α)7Li reaction that has been used to treat glioblastoma multiforme (GBM), melanoma and colon carcinoma liver metastases. GBM
clinical trials resulted in modestly improved life expectancies compared with conventional therapies. Early results trials
focused on malignant melanom...
Pulse-shape discrimination (PSD) has been utilised for about 40 years as a method to obtain estimates for dose in mixed neutron and photon fields. Digitizers that operate close to GHz are currently available at a reasonable cost, and they can be used to directly sample signals from photomultiplier tubes. This permits one to perform digital PSD rath...
Monte Carlo calculations for megavoltage radiotherapy beams represent the next generation of dose calculation in the clinical environment. In this paper, calculations obtained by the MCNP code based on CT data from a human pelvis are compared against those obtained by a commercial radiotherapy treatment system (CMS XiO). The MCNP calculations are a...
Deep penetration radiation transport calculations have been performed to determine the dose rates at a positron emission tomography (PET) facility in China. The radiation source is a cyclotron that is used for the production of the PET isotopes, with a labyrinthine concrete wall arrangement to minimize dose to operation personnel. Since directional...
Composite neutron scintillators consisting of neutron-insensitive fluorescent dopant particles (e.g. ZnS:Ag) embedded in a
matrix material containing isotopes with high neutron cross sections that emit energetic charged particles (e.g. 6Li) are a popular method for neutron detection in a variety of applications. The size and volume doping fraction...
Solid tumours are often treated with external beams of photons generated by Bremsstrahlung radiation. These beams are shaped
and filtered to optimise the dose to specific regions defined by the treatment plans, which may involve irradiations from
multiple angles. It is important that doses to healthy tissue do not exceed tolerance doses and that th...
Two reactions deliver the majority of local dose in boron neutron capture therapy. The ionised particles (protons, alpha particles and lithium nuclei) produced in the two reactions, 10B(n,alpha,gamma)7Li and 14N(n,p)14O, have short ranges that are less than -14 microm (which is on the order of the diameter of a typical human cell). The ionised part...
The Micromegas is a type of ionising radiation detector that consists of a gas chamber sandwiched between two parallel plate
electrodes, with the gas chamber divided by a Frisch grid into drift and amplification gaps. Investigators have applied it
to a number of different applications, such as charged particle, X-ray and neutron detection. A Microm...
Monte Carlo and discrete ordinate calculations have been performed to determine the doses at several locations in a positron
emission tomography (PET) facility in China, where the radiation source is a cyclotron that is used for the production of
the isotopes necessary for PET scans. The energy-dependent neutron source term is obtained by calculati...
Quantification of uncertainties in doses from intakes of radionuclides is important in risk assessments and epidemiologic studies of individuals exposed to radiation. In this study, the uncertainties in the doses per unit intake (i.e., dose coefficients) for ingestion of 131I, 137Cs, and 90Sr by healthy individuals have been determined. Age-depende...
This paper describes a Micromegas neutron detector Monte Carlo simulation that has been developed, and compares its simulated neutron response with published experimental data. The theoretical and experimental results show good agreement, suggesting that the simulation is a reasonable indicator of what may be expected in practice. Modeling of chang...
Centers in Japan and the United States are extending boron neutron capture therapy ( BNCT) to the treatment of malignant melanoma ( MM). Positron emission tomography ( PET) has been used to image glioblastoma multiforme with F-18- boronophenylalanine ( F-18- BPA) for the purpose of generating B-10 distribution maps. These distribution maps can be u...
Centers in Japan and the United States are extending boron neutron capture therapy (BNCT) to the treatment of malignant melanoma (MM). Positron emission tomography (PET) has been used to image glioblastoma multiforme with 18F-boronophenylalanine (18F-BPA) for the purpose of generating 10B distribution maps. These distribution maps can be used to im...
The purpose of this research project is to develop compact (100 to 400 MWe) Generation IV nuclear power plant design and layout concepts that maximize the benefits of factory-based fabrication and optimal packaging, transportation and siting. The reactor concepts selected were compact designs under development in the 2000 to 2001 period. This inter...
Boron neutron capture therapy (BNCT) is a cancer brachytherapy based upon the thermal neutron reaction: 10B(n,alpha)7Li. The efficacy of the treatment depends primarily upon two conditions being met: (a) the preferential concentration of a boronated compound in the neoplasm and (b) an adequate fluence of thermal neutrons delivered to the neoplasm....
OAK B188 The objectives of this project are to develop and evaluate nuclear power plant designs and layout concepts to maximize the benefits of compact modular Generation IV reactor concepts including factory fabrication and packaging for optimal transportation and siting. This report covers the second year of the project during which the three rea...
This paper describes the evaluation of two 300 MWe modular Pb-Bi cooled reactor system concepts that can be field assembled from components shipped on standard rail cars or on trucks. Thus, the largest components must be smaller than 12' x 12' x 80' (3.66 m x 3.66 m x 24.4 m) and should weigh no more than 80 tons. One of these systems utilizes a cy...
A neutron detector technology is demonstrated based on 6Li/10B doped sol–gel glass. The detector is a sol–gel glass film coated silicon surface barrier detector (SBD). The ionized charged particles from (n, α) reactions in the sol–gel film enter the SBD and are counted. Data showing that gamma-ray pulse amplitudes interfere with identifying charged...
A micromechanical sensor for charged-particle flux detection utilizing the extreme force sensitivity of microcantilevers is demonstrated with alpha particles. The latter create a charge buildup on an electrically isolated collection plate, a metallic sphere. The cantilever detector measures the electric field emanating from the charge collection sp...
The objectives of this project are to develop and evaluate nuclear power plant designs and layout concepts to maximize the benefits of compact modular Generation IV reactor concepts including factory fabrication and packaging for optimal transportation and siting. Three nuclear power plant concepts are being studied representing water, helium and l...
OAK B188 The objectives of this project are to develop and evaluate nuclear power plant designs and layout concepts to maximize the benefits of compact modular Generation IV reactor concepts including factory fabrication and packaging for optimal transportation and siting. This report covers the eighth quarter of the project during which the three...
The production of F-18 from a 10.5 MeV proton beam on oxygen-18 results in significant yields of neutrons and photons. In order to optimize personnel shielding that satisfies regulatory requirements, it is essential that both the intensity of both neutrons and of photons be determined as a function of energy and angle, which was accomplished by com...
A system for testing potential BNCT pharmaceuticals in cell cultures has been developed with the cooperation of Oak Ridge National Laboratory (ORNL), the University of Tennessee Chemistry Department and the University of Tennessee Nuclear Engineering Department. A BNCT test model has been established with the use of the human lung cancer cell line...
The addition of dopants in the wet chemistry formation of glass in sol-gel technology is used for many purposes. Among the uses are the fabrication of films sensitive to pH, temperature, the presence of dissolved chemicals in solutions and many others. This paper describes the use of sol-gel technology for the doping of B-10, Li-6 and U-235 into gl...
The purpose of this work is to estimate off-site radiation doses and health risks (with uncertainties) associated with the release of radionuclides from the X-10 site. Following an initial screening analysis, the exposure pathways of interest included fish ingestion, drinking water ingestion, the ingestion of milk and meat, and external exposure fr...
Performance assessments that include uncertainty analyses and risk assessments are typically not obtained for time-dependent releases of radioactive contaminants to the geosphere when a series of sequentially coupled transport models is required for determining results. This is due, in part, to the geophysical complexity of the site, and to the num...
The Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory commenced operation in 1964 and was shut down in 1969. It was fueled with ²³³UFâ in a carrier salt of LiF-BeFâ-ZrFâ, and it operated at 1,200 F. After it was shut down, the fuel was heated annually to 200 C to recombine fluorine (with the fuel) released due to radiation-i...
In order to accurately determine dose equivalent in radiation fields that include both neutrons and photons, it is necessary to measure the relative number of neutrons to photons and to characterize the energy dependence of the neutrons. The relationship between dose and dose equivalent begins to increase rapidly at about 100 keV; thus, it is neces...
Two statistical models that include transit time spread and electronic noise effects are studied for evaluation of scintillation materials and for comparison of pulse shape discrimination (PSD) methods. The intrinsic PSD low-energy limitations for three scintillators are estimated by using these models, which can be used for PSD parameter optimizat...
The Californium User Facility for Neutron Science has been established at Oak Ridge National Laboratory (ORNL). The Californium User Facility (CUF) is a part of the larger Californium Facility, which fabricates and stores compact ²âµÂ²Cf neutron sources for worldwide distribution. The CUF can provide a cost-effective option for research with ²â...
This paper describes the steps taken to assess the potential of a solvent extraction process for separating plutonium from neptunium. The plutonium, namely ²³â¸Pu, is of importance because it is the isotope used in making radioisotope thermoelectric generators and radioisotope heaters and is obtained by irradiating ²³â·Np targets in a high ne...
It is beyond the current nondestructive analysis (NDA) state of the art to accurately measure important alpha- and beta-emitting radionuclides in the presence of typically occurring background levels of neutron and photon radiation associated with remotely handled (RH) transuranic (TRU) waste; in addition, it is not economically feasible to perform...
Functional analysis methods are applied to estimate upper bounds to changes in the eigenvalue and in the flux from multigroup diffusion theory results due to changes in the equation`s operator. Error estimates using functional analysis have been previously applied for studies involving absorption cross section. However, we evaluated this approach t...
The placement of criticality alarms at the Paducah plant has been studied. Four detectors placed in the halls of the first floor will provide double coverage of the first floor and single coverage of the basement, attic, and counting laboratory. Results from MCNP calculations also show that a detector placed in the hall adjacent to room 27 will cov...
Neutrons and photons often comprise radiation fields found in working environments, and the fluence-to-dose equivalent conversion factor for neutrons varies by about a factor of 3 between {approximately}60 and 500 keV. Thus, it is necessary to characterize the neutron energy spectrum and to discriminate between neutrons and photons to accurately de...
Laboratory experiments that use neutron time-of-flight (TOF) methods offer students the opportunity to learn a wide range of experimental concepts. Some of these include details associated with the interaction of the radiation with detectors, pulse shape and timing of outputs from the dynode and the anode of scintillators, pulse processing for gene...
Pulse Shape Discrimination (PSD) is an established technique for separating photon and neutron signals from some detectors. The motivation for this effort is to develop an instrument to measure neutron and photon dose equivalent in a mixed field. This requires that photon and neutron pulses be separated for neutrons with energies as low as 50 keV,...
Uncertainty analyses were performed in conjunction with radiological assessments of the Formerly Utilized Site Remedial Action Program (FUSRAP) St. Louis Downtown Site (SLDS), the Airport Site (SLAPS), and the Ball Field Site (SLBFS). Contaminants of concern at each location are natural uranium, radium, ²³²Th, and ²³°Th. The SLDS was used for...
The combination personal neutron dosemeter utilises two bubble detectors and a four element albedo thermoluminescence dosemeter to acquire a simple four interval neutron spectrum. Appropriate conversion factors may be applied to the measured fluence values to determine pertinent dosimetric quantities. The spectrometric and dosimetric accuracy of th...
The objective of this research was to advance the state-of-the-art of applying artificial intelligence technology (both expert systems and neural networks) to enhancing the performance (safety, efficiency, control and management) of nuclear power plants. A second, but equally important objective, was to build a broadly based critical mass of expert...
This paper reports the feasibility of using expert systems in combination with neural networks and neutronics calculations to improve the efficiency for obtaining optimal candidate reload core designs. The general objectives of this research are as follows: (1) generate a suitable data base and ancillary software for training neural networks that d...
Two applications of a noise diagnostic methodology were performed with ex-core neutron detector data from a pressurized-water reactor (PWR). A feedback dynamics model of the neutron power spectral denisty was derived from a low-order whole-plant physical model made stochastic with the Langevin technique. From a functional fit to plant data, the res...
The goal of the Heavy-Section Steel Irradiation (HSSI) Program Sixth Irradiation Series is to determine the effect of irradiation on the shape and shift of the crack-arrest toughness versus temperature curve. Two capsules which contained crack-arrest and Charpy V-notch test specimens have been irradiated at the Oak Ridge Research Reactor located at...
Artificial neural networks (ANNs) are an adaptive nonalgorithmic approach to information processing that provides an almost instantaneous capability for finding solutions to very complex problems. Although work in this area was deemphasized more than a decade ago following several critical reviews, there has been a resurgence of ANN-related researc...
The Loop Current Step Response (LCSR) method has been developed for in situ response time testing of thermocouples and resistance thermometers. A means for measuring the sensor response for actual operating conditions and installation details is provided. This technology is ready to be assembled into an instrument for use in aerospace, nuclear, che...
The Heavy-Section Steel Technology (HSST) Program, supported by the US Nuclear Regulatory Commission, has completed the Series 5 (HSST5) irradiation experiments. Twelve capsules which contain metallurgical test specimens have been irradiated at the Oak Ridge Research Reactor located at the Oak Ridge National Laboratory. These capsules have been dis...
A team evaluated several methods for remote measurement of the response time and detection of degradation (blockage or air in lines) of pressure sensor/sensing line systems typical of nuclear power plants. A method was developed for obtaining the response time of force-balance pressure transmitters by briefly interrupting the power supply to the tr...
Major components and primary functions of the process control system for the K/sub 1C/-HSST irradiation experiments at the Oak Ridge Research (ORR) are described. Information relative to methodology for integrating unique features of the Digital Equipment Corporation's RSX-11M Operating System with analog-to-digital and digital-to-analog hardware i...
The output feedback stabilization problem is reformulated into one of functional minimization which implicitly allows some control over eigenvalue placement. A numerical minimization algorithm that employs standard methods of optimization is used for solving four examples.
The report provides final results of Research Project 503-3, concerned with in-situ resistance temperature detector time response verification. The report covers the theoretical bases, laboratory experimentation, and in-plant testing of three prospective methods. Sensors employed in this project are representative of those employed in safety-relate...
The problem of designing a constrained feedback control system for a nuclear reactor is investigated. The constraint imposed is that system stability must be retained under possible loss of any arbitrary feedback signal due to failure of the signal sensor. In addition, the control law is synthesized using only partial state availability, and the no...
Through the use of a symbolic computer language, a set of multivariable polynomial inequalities are generated using the Lienard-Chipart criterion. These inequalities represent the output feedback stabilization problem. If a solution exists, it is a member of an open set. Utilizing this fact, a method for solving these inequalities that has a global...
The structure of the liquid alkali metals is obtained by an optimized iterative solution of the Percus-Yevick theory and by using recent pseudopotential models and screening functions for these metals. This solution involves an optimized expression for the correction function to g(r), knowing one guess and one calculated result for g(r). This is ob...
The Nuclear Engineering Department at the University of Tennessee offers three graduate programs that are available to distance students: the M.S. degree in Nuclear Engineering, a Graduate Certificate program in Nuclear Criticality Safety, and a Graduate Certificate program in Maintenance and Reliability Engineering. Most of the courses in the thre...
Documentation relative to the computer system hardware and supporting real-time application support software is included in this report. Data flow for intertask cummunication is described in relation to major computer system components. A complete listing of command files and codes for all tasks is provided in order to facilitate making changes for...
Self regulated power oscillation experiments with a variety of initial conditions have been performed with the ORNL Health Physics Research Reactor (HPRR) by undergraduate nuclear engineering students from The University of Tennessee for several years. These experiments demonstrate the coupling between reactor kinetics and heat transfer and show ho...
A comprehensive review of accident neutron dosimetry using blood and hair analysis was performed and is summarized in this report. Experiments and calculations were conducted at Oak Ridge National Laboratory (ORNL) and the University of Tennessee (UT) to develop measurement techniques for the activity of ²â´Na in blood and ³²P in hair for nucle...
2;
Project Summary: The Multi-University Southeast INIE Consortium (MUSIC) was;
established in response to the US Department of Energys (DOE);
Innovations in Nuclear Infrastructure and Education (INIE) program.;
MUSIC was established as a consortium composed of academic;
members and national laboratory partners. The members of MUSIC are;
the nuclea...
A neutronics library suitable for low-enrichment uranium (LEU) and high-enrichment uranium (HEU) fueled cores for both the Oak Ridge Research Reactor (ORR) and the Bulk Shielding Reactor (BSR) is documented herein. The library is obtained from version V of the Evaluated Nuclear Data File (ENDF/B-V) and contains 223 nuclides weighted over a variety...
This report is the second volume in a two-volume set which describes the development of a standardized computational methodology for analyzing the neutron environment in the Oak Ridge Research Reactor (ORR) and the Bulk Shielding Reactor (BSR). The first volume describes the development of a standard seven-group cross-section library based on ENDF/...
In the summer of 1988, the Department of Nuclear Engineering (NE) at the University of Tennessee (UT) in Knoxville was selected to carry out a research program in ``Enhancing the Operation of Nuclear Power plants through the use of Artificial Intelligence, This program is sponsored by the Department of Energy`s Office of Energy Research under 10CFR...
A procedure is outlined for formulating an accurate neutronics computational model of the ORNL-BSR. Results to data are presented and discussed.
A neutronics model for the Oak Ridge National Laboratory Bulk Shielding Reactor (ORNL-SAR) was developed and verified by experimental measurements. A cross-section library was generated from the 218 group Master Library using the AMPX Block Code system. A series of one-, two-, and three-dimensional neutronics calculations were performed utilizing b...
The objectives of this activity are to introduce students to liquid scintillation counting and to calibrate the counter using the sample channel ratio technique. This is accomplished by using quenched standards set for ¹â´C and tritium (³H) to generate a quench correction curve for the scintillation solution. It is a good method for students to...
Activation products from sodium in blood (²â´Na) and from sulfur in hair (³²P) are good nature dosimeters for determining neutron dose from criticality accidents. Both can be detected after moderate exposures to neutron fields, and their response characteristics to fast and thermal neutrons provide some information on the energy distribution of...
