UNT Libraries Government Documents Department - 254,172 Matching Results

Search Results

Acute Toxicity and Bioaccumulation of Chloroform to Four Species of Freshwater Fish

Description: Acute toxicity of chloroform to four species of freshwater fish was studied in flow-through 96-hr toxicity tests. Chloroform is toxic to fish in the tens of parts per million, a concentration well above that which would be expected to be produced under normal power plant chlorination conditions. Investigations of acute toxicity of chloroform and the bioaccumulation of chlorinated compounds in tissues of fish revealed differences in tolerance levels and tissue accumulations. Mean 96-hr LC{sub 50}s for chloroform were 18 ppm for rainbow trout and bluegill, 51 ppm for largemouth bass and 75 ppm for channel catfish. Mortalities of bluegill and largemouth bass occurred during the first 4 hr of exposure while rainbow trout and channel catfish showed initial tolerance and mortalities occurred during the latter half of the 96-hr exposure. Rainbow trout had the highest level of chloroform tissue accumulation, 7 {micro}g/g tissue, catfish the second highest, 4 {micro}g/g tissue, followed by bluegill and largemouth bass which each accumulated about 3 {micro}g/g tissue. Accumulation of chloroform was less than one order of magnitude above water concentrations for all species.
Date: August 1, 1980
Creator: ,

Chronic Effects of Chlorination By-Products on Rainbow Trout, Salmo gairdneri

Description: Rainbow trout were exposed to by-products of low-level water chlorination for several months in two separate experiments. In each test 2400 juvenile rainbow trout (Salmo gairdneri) were reared under chlorination conditions designed to simulate those of a power plant. Objectives were to determine effects of long term exposure to provide samples for tissue analysis of chlorination byroducts. No significant difference in fish condition factors was found between the test groups and controls, neither was there an apparent effect on mortality. Background levels of chloroform were found in all fish, but there was no evidence of an increased amount of chloroform or other chlorination by-products resulting from chronic low level exposure to chlorination by-products.
Date: November 1, 1980
Creator: ,

Estimated Incremental Costs for NRC Licensees to Implement the US/IAEA Safeguards Agreement

Description: At the request of the U.S. Nuclear Regulatory Commission (NRC), the Pacific Northwest Laboratory (PNL), operated by Battelle Memorial Institute for the Department of Energy, conducted a brief study to identify the incremental cost for implementing the US/IAEA safeguards treaty agreement. The purpose of the study was to develop an estimate of the cost impact to eligible NRC licensees for complying with the proposed Part 75 of Title 10, Code of Federal Regulations (10 CFR 75), the rule which will implement the treaty. The study was conducted using cost estimates from several eligible licensees who will be affected by the agreement and from cost analyses by PNL staff. A survey instrument was developed and sent to 25 NRC licensees, some of whom had more than one licensed facility. Their responses were obtained primarily by telephone after they had reviewed the survey insttument and a list of assumptions. The primary information received from the licensees was the incremental cost to their particular facility in the form of manpower, dollars or both. In summary, the one-time cost to all eligible NRC licensees to implement 10 CFR 75 is estimated by PNL to range from $1.9 to $7.2 millions. The annual cost to the industry for the required accounting and reporting activities is estimated by PNL at $0.5 to $1.4 millions. Annual inspection costs to the industry for the limited IAEA inspection being assumed is $80,000 to $160,000.
Date: July 19, 1979
Creator: ,

Mathematical Simulation of Sediment and Radionuclide Transport in Surface Waters

Description: The study objective of "The Mathematical Simulation of Sediment and Radionuclide Transport in Surface Waters" is to synthesize and test radionuclide transport models capable of realistically assessing radionuclide transport in various types of surface water bodies by including the sediment-radionuclide interactions. These interactions include radionuclide adsorption by sediment; desorption from sediment into water; and transport, deposition, and resuspension of sorbed radionuclides controlled by the sediment movements. During FY-1979, the modification of sediment and contaminant (radionuclide) transport model, FETRA, was completed to make it applicable to coastal waters. The model is an unsteady, two-dimensional (longitudinal and lateral) model that consists of three submodels (for sediment, dissolved-contaminant, and particulate-contaminant transport), coupled to include the sediment-contaminant interactions. In estuaries, flow phenomena and consequent sediment and radionuclide migration are often three-dimensional in nature mainly because of nonuniform channel cross-sections, salinity intrusion, and lateral-flow circulation. Thus, an unsteady, three-dimensional radionuclide transport model for estuaries is also being synthesized by combining and modifying a PNL unsteady hydrothermal model and FETRA. These two radionuclide transport models for coastal waters and estuaries will be applied to actual sites to examine the validity of the codes.
Date: April 1, 1981
Creator: ,

A Measurement Control Program for Nuclear Material Accounting

Description: A measurement control program for nuclear material accounting monitors and controls the quality of the measurements of special nuclear material that are involved in material balances. The quality is monitored by collecting data from which the current precision and accuracy of measurements can be evaluated. The quality is controlled by evaluations, reviews, and other administrative measures for control of selection or design of facilities. equipment and measurement methods and the training and qualification of personnel who perform SNM measurements. This report describes the most important elements of a program by which management can monitor and control measurement quality.
Date: June 1, 1980
Creator: ,

MODIFIED FINITE ELEMENT TRANSPORT MODEL, FETRA, FOR SEDIMENT AND RAOIONUCLIDE MIGRATION IN OPEN COASTAL WATERS

Description: The finite element model, FETRA, simulates transport of sediment and radionuclides (and other contaminants, such as heavy metals, pesticides, and other toxic substances) in surface water bodies. The model is an unsteady, two-dimensional (longitudinal and lateral} model which consists of the following three submodels coupled to include sediment-contaminant interactions: 1) sediment transport submodel, 2} dissolved contaminant transport submodel, and 3) particulate contaminant (contaminant adsorbed by sediment) transport submodel. Under the current phase of the study, FETRA was modified to include sediment-wave interaction in order to extend the applicability of the model to coastal zones and large lakes (e.g., the Great Lakes) where wave actions can be one of the dominant mechanisms to transport sediment and toxic contaminant. FETRA was further modified to handle both linear and quadratic approximations to velocity and depth distributions in order to be compatible with various finite element hydrodynamic models (e.g., RMA II and CAFE) which supply hydrodynamic input data to FETRA. The next step is to apply FETRA to coastal zones to simulate transport of sediment and radionuclides with their interactions in order to test and verify the model under marine and large lacustrine environments.
Date: August 1, 1979
Creator: ,

Monitoring the Random Errors of Nuclear Material Measurements

Description: Monitoring and controlling random errors is an important function of a measurement control program. This report describes the principal sources of random error in the common nuclear material measurement processes and the most important elements of a program for monitoring, evaluating and controlling the random error standard deviations of these processes.
Date: June 1, 1980
Creator: ,

Preliminary Results from an Investigation into Nanostructured Nuclear Radiation Detectors for Non-Proliferation Applications

Description: In recent years, the concept of embedding composite scintillators consisting of nanosized inorganic crystals in an organic matrix has been actively pursued. Nanocomposite detectors have the potential to meet many of the homeland security, non-proliferation, and border and cargo-screening needs of the nation and, by virtue of their superior nuclear identification capability over plastic, at roughly the same cost as plastic, have the potential to replace all plastic detectors. Nanocomposites clearly have the potential of being a gamma ray detection material that would be sensitive yet less expensive and easier to produce on a large scale than growing large, whole crystals of similar sensitivity. These detectors would have a broad energy range and a sufficient energy resolution to perform isotopic identification. The material can also be fabricated on an industrial scale, further reducing cost. This investigation focused on designing and fabricating prototype core/shell and quantum dot (QD) detectors. Fourteen core/shell and four QD detectors, all with the basic consistency of a mixture of nanoparticles in a polymer matrix with different densities of nanoparticles, were prepared. Nanoparticles with sizes <10 nm were fabricated, embedded in a polystyrene matrix, and the resultant scintillators’ radiation detector properties were characterized. This work also attempted to extend the gamma energy response on both low- and high-energy regimes by demonstrating the ability to detect low-energy and high-energy gamma rays. Preliminary results of this investigation are consistent with a significant response of these materials to nuclear radiation.
Date: October 1, 2012
Creator: ,

A Procedure for the Qualitative Interpretation of Fuel Centerline Thermocouple Response to Step-Power Decreases

Description: This report reviews the present calculational techniques that may be used to interpret the transient response of fuel centerline thermocouples to step decreases in rod power. A new technique developed herein involves plotting the natural logarithm of the normalized thermocouple data versus time, plotting various calculations in the same way, and observing the curvature of the resulting lines. Also described is the small computer code, MWRAM, which facilitates testing various models against transient data. Transient data from IFA-513 is presented. This test assembly in the Halden Reactor, Norway, is jointly sponsored by the Nuclear Regulatory Commission and the Halden Project. A comparison of MWRAM calculations with this data has shown that fuel cracking appears to greatly influence the heat transfer modes in the fuel rod. A method of estimating the effective fuel-cladding gap size from this transient data is also discussed in this report .
Date: October 1, 1979
Creator: ,

RCRA Permit for a Hazardous Waste Management Facility Permit Number NEV HW0101 Annual Summary/Waste Minimization Report Calendar Year 2012, Nevada National Security Site, Nevada

Description: This report summarizes the U.S. Environmental Protection Agency (EPA) identification number of each generator from which the Permittee received a waste stream, a description and quantity of each waste stream in tons and cubic feet received at the facility, the method of treatment, storage, and/or disposal for each waste stream, a description of the waste minimization efforts undertaken, a description of the changes in volume and toxicity of waste actually received, any unusual occurrences, and the results of tank integrity assessments. This Annual Summary/Waste Minimization Report is prepared in accordance with Section 2.13.3 of Permit Number NEV HW0101, issued 10/17/10.
Date: February 21, 2013
Creator: ,

Saturation and Dynamic Range of Microchannel Plate-Based X-Ray Imagers

Description: This paper describes recent advances in Monte Carlo simulations of microchannel plate (MCP)–based x-ray detectors, a continuation of ongoing work in this area. A Monte Carlo simulation model has been developed over the past several years by National Security Technologies, LLC (NSTec). The model simulates the secondary electron emission process in an MCP pore and includes the effects of gain saturation. In this work we focus on MCP gain saturation and dynamic range. We have performed modeling and experimental characterizations of L/D = 46, 10-micron diameter, MCP-based detectors. The detectors are typically operated by applying a subnanosecond voltage pulse, which gates the detector on. Agreement between the simulations and experiment is very good for a variety of voltage pulse waveforms ranging in width from 150 to 300 ps. The results indicate that such an MCP begins to show nonlinear gain around 5 × 10^4 electrons per pore and hard saturation around 105 electrons per pore. The simulations show a difference in MCP sensitivity vs voltage for high flux of photons producing large numbers of photoelectrons on a subpicosecond timescale. Simulations and experiments both indicate an MCP dynamic range of 1 to 10,000, and the dynamic range depends on how the voltage is applied.
Date: May 4, 2012
Creator: ,

Site-Directed Research and Development FY 2012 Annual Report

Description: The reports included in this report are for project activities that occurred from October 2011 through September 2012. These reports describe in detail the discoveries, achievements, and challenges encountered by our talented and enthusiastic principal investigators (PIs). Many of the reports describe R&D efforts that were “successful” in their pursuits and resulted in a positive outcome or technology realization. As we’ve stated before, and continue to stress, in some cases the result is a “negative” finding, for instance a technology is currently impractical or out of reach. This can often be viewed erroneously as a “failure,” but is actually a valid outcome in the pursuit of high-risk research, which often leads to unforeseen new paths of discovery. Either result advances our knowledge and increases our ability to identify solutions and/or likewise avoid costly paths not appropriate for the challenges presented. The SDRD program continues to provide an unfettered mechanism for innovation and development that returns multifold to the NNSS mission. Overall the program is a strong R&D innovation engine, benefited by an enhanced mission, committed resources, and sound competitiveness to yield maximum benefit. The 23 projects described exemplify the creativity and ability of a diverse scientific and engineering talent base. The efforts also showcase an impressive capability and resource that can be brought to find solutions to a broad array of technology needs and applications relevant to the NNSS mission and national security.
Date: April 1, 2013
Creator: ,

STATISTICAL METHODS FOR EVALUATING SEQUENTIAL MATERIAL BALANCE DATA

Description: Present material balance accounting methods focus primarily upon the "material unaccounted for" (MUF) statistic, which utilizes the data from only one material balance period as an indicator of a possible loss of nuclear material. Typically a cumulative MUF (CUMUF) statistic, which utilizes all the available flow data, is also calculated; but there is no statutory requirement that it be reported or evaluated. Previous work has shown that cumulative MUF has greater power than MUF to detect small constant losses. Techniques which emphasize the sequential nature of MUF (that is, MUF as a sequence of values related over time) are also expected to be more sensitive for detecting losses. The recursive estimation algorithm known as the Kalman filter has been proposed as a possible solution which uses the above idea. The purpose of this study was to evaluate the application of the Kalman filter to the MUF problem, to propose other approaches to the problem, and to re-examine the traditional MUF and cumulative MUF statistics in more general settings. The report considers the material balance model where the only modeled variability is that due to the measurements of the net throughput (inputs minus outputs) and the inventories. The problem discussed is how to extract more information from all the available data. Material balance models which assume no loss, and the constant loss and all-at-once loss situations are considered. Emphasis was placed on explaining state variable models and Kalman filtering in relation to the general linear statistical model to which least squares is applied yielding a minimum variance unbiased estimator. All errors affecting material balances were assumed to be random.
Date: April 1, 1979
Creator: ,

A Visual Aesthetic Prediction Method for Use in Benefit-Cost Analysis

Description: This report discusses the development of a method to predict landscape visual aesthetic changes caused by the siting of nuclear power plants. The methodology uses public perceptions as a measure of visual aesthetics. Individuals scored landscape photographs on a 0 to 50 visual aesthetic scale. The visual aesthetic scores were explained statistically by landscape characteristics, percent of the scene in clear, still water, and characteristics of the individuals scoring the photographs. Three visual aesthetic relationships were empirically estimated. The first is the relationship among group mean visual aesthetic scores and landscape characteristics. The second is the relationship among individual visual aesthetic scores, landscape characteristics, and the characteristics of the individuals who ranked the landscapes. These relationships were estimated using data from two regions in the U.S. and a diverse set of landscape photographs. The third relationship is among group mean visual aesthetic scores for landscapes with a visible nuclear power plant, landscape characteristics, and mean individual characteristics of the groups who scored the landscapes. This relationship was estimated using data from six regions in the U.S. and landscapes showing nuclear plants with a closed cycle cooling system. The statistical results are highly significant. Prediction validity test results indicate that the estimated relationships can predict visual aesthetic scores for groups of individuals outside the samples used to estimate the visual aesthetic relationships. This prediction method is not intended to determine social welfare impact. The social welfare impact of visible change is a measure of how consumers value changes in visual aesthetics relative to all other goods and services. The prediction methodology only provides an estimate of the impact of visible change on the perceived aesthetics associated with that landscape relative to other landscapes. It does not provide a measure relative to all other goods and services consumed.
Date: August 1, 1980
Creator: ,