This research was initiated to investigate the application of mobile robotics to hazardous waste site characterization, with the specific emphasis of employing the laser-based positioning measurement system developed by Spatial Positioning Systems, inc. (SPSi) for tracking a mobile robot and geographically tagging collected environmental data. The two specific objectives of this work were to design and construct a remotely piloted robotic system which could enter a simulated hazardous waste site and perform some aspect of initial characterization sampling, and to perform a feasibility study on the use of the SPSi system for outdoor mobile robot tracking. A Honda all-terrain vehicle was converted to a robotic test platform incorporating the SPSi system for positioning and a magnetometer for environmental sensing. The digitally-sampled magnetometer output was geographically tagged with sensor position, and transmitted to a remote computer for display and storage. Although the mechanics of integrating the SPSi system and an environmental sensor on a mobile robot were demonstrated, survey attempts with the mobile robot were unsuccessful because the SPSi system was unable to track the robot's movements outdoors on the simulated hazardous waste site. Tracking capability up to a limiting velocity of approximately 0.35 mls (0.8 mph) was demonstrated with the SPSi system. This restrictive limiting velocity as well as various errors later discovered in SPSi's tracking algorithm prevented a successful implementation of the positioning system on the robot. / Master of Science

This dissertation proposes a new type of modular, long-reach, truss-type manipulator. Variable Geometry Trusses (VGT’s) are used to construct a reconfigurable manipulator system in which all primary members are loaded in pure tension or compression. Each module of the manipulator system is either a static truss link or one of several possible VGT actuators. This results in an extremely stiff and strong manipulator system with minimal overall weight. While many potential applications exist for this technology, the present work was largely motivated by the need for a robotic waste remediation system for underground radioactive waste storage tanks. This new manipulator system provides several advantages when used for this application. The reconfigurable nature of the proposed system allows the manipulator to be adapted on site to unforeseen conditions. Additionally, the kinematic redundancy of the manipulator ensures that solutions can be accomplished even in a highly obstructed workspace. The parallel structure of the truss modules enables the manipulator to be withdrawn in the event of a structural failure. Finally, of particular importance to this task, the open framework of the modules provide a passageway for waste conveyance or additionally, could act as a shielded conduit for control and power cabling. Kinematic analysis algorithms tailored to address the peculiarities of this new manipulator system have also been developed. In this work, the kinematic redundancy of the system is exploited to provide alternative solutions, to avoid numerical difficulties at singularities, or to avoid workspace obstacles. These issues are addressed through a combination of null space optimization procedures and order reduction methods. The null space optimization procedures are accomplished by extracting information from a full singular value decomposition of the Jacobian matrix. This method is shown to converge quickly, even for systems with thirty or more degrees of freedom. This represents a significant increase over most of the current literature which typically addresses systems of eight or fewer degrees of freedom. This dissertation presents the first application of null space optimization techniques for the positional control of a high degree-of-freedom parallel manipulators. This work also formalizes the concept of a canonical input specification set. The application of this concept results in greatly simplified analyses of many parallel manipulators. Although the manipulator system discussed was specifically developed for robotic handling of radioactive waste, the final resulting methodology is suited to a much broader class of problems, namely, under-constrained, redundant manipulator systems in general. / Ph. D.

Graduation date: 1995

The detonation of a radiological dispersion device (RDD) may result in a situation where many individuals are exposed to contamination due to the inhalation of radioactive materials. Assessments of contamination may need to be performed by emergency response personnel in order to triage the potentially exposed public. The feasibility of using readily available standard 2x2-inch sodium-iodide detectors to determine the committed effective dose to a patient following the inhalation of a radionuclide has been investigated. The 2x2-NaI(Tl) detector was modeled using the Monte Carlo simulation code, MCNP-5, and was validated via a series of experimental benchmark measurements using a polymethyl methacrylate (PMMA) slab phantom. Such validation was essential in reproducing an accurate detector response. Upon verification of the detector model, six anthropomorphic phantoms, based on the MIRD-V phantoms, were modeled with nuclides distributed to simulate inhaled contamination. The nuclides assessed included Am-241, Co-60, Cs-137, I-131, and Ir-192. Detectors were placed at four positions on the phantoms: anterior right torso, posterior right torso, anterior neck, and lateral left thigh. The detected count-rate varied with respect to detector position, and the optimal detector location was determined on the body. The triage threshold for contamination was set at an action level of 250-mSv of intake. Time dependent biokinetic modeling was employed to determine the source distribution and activity in the body as a function of post-inhalation time. The detector response was determined as a function of count-rate per becquerel of activity at initial intake. This was converted to count-rate per 250-mSv intake for triage use by first responders operating the detector to facilitate triage decisions of contamination level. A set of procedure sheets for use by first responders was compiled for each of the phantoms and nuclides investigated.

In the event of a radioactive dispersal device (RDD), the assessment of the internal contamination level of victims is necessary to determine if immediate medical follow-up is necessary. Thermo Scientific's TPM-903B Portal Monitor was investigated to determine if it is a suitable first cut screening tool for internal contamination assessment of victims. A portal monitor was chosen for this study because they are readily accessible, transportable, easy to assemble, and provide whole body count rates due to the detector size. The TPM-903B was modeled in Monte Carlo N-Particles Transport Code Version 5 (MCNP). This computational model was validated against the portal monitor's response to a series of measurements made with four point sources in a polymethyl methacrylate (PMMA) slab box. Using the validated MCNP5 model and models of the MIRD male and female anthropomorphic phantoms, the response of the portal monitor was simulated for the inhalation and ingestion radionuclides from an RDD. Six representative phantoms were considered: Reference Male, Reference Female, Adipose Male, Adipose Female, Post-Menopausal Adipose Female, and 10-Year-Old Child. The biokinetics via Dose and Risk Calculation Software (DCAL) was implemented using both the inhalation and ingestion pathways to determine the radionuclide concentrations in the organs of the body which were then used to determine the count rate of the portal monitor as a function of time. Dose coefficients were employed to determine the count rate of the detector associated with specific dose limits. These count rates were then compiled into procedure sheets to be used by first responders during the triaging of victims following an RDD.

Conversion, the process by which natural uranium ore (yellowcake) is purified and converted through a series of chemical processes into uranium hexafluoride gas (UF6), has historically been excluded from the nuclear safeguards requirements of the 235U-based nuclear fuel cycle. With each step in the conversion process from yellowcake to feedstock for UF6, intermediary uranium oxide and uranium fluoride compounds become progressively attractive products for diversion toward activities noncompliant with international treaties. The diversion of this product material could potentially provide feedstock for a clandestine or undeclared enrichment for weapons development for state or non-state entities. With the realization of this potential, the International Atomic Energy Agency (IAEA) has only recently reinterpreted its policies to emphasize safeguarding this feedstock in response to such diversion pathways. This project employs a combination of simulation models and experimental measurements to develop and validate concepts of nondestructive assay monitoring systems in a natural uranium conversion plant (NUCP). In particular, uranyl nitrate (UN) solution exiting solvent extraction was identified as a key measurement point (KMP), where gamma-ray spectroscopy was selected as the process-monitoring tool. The Uranyl Nitrate Calibration Loop Equipment (UNCLE) facility at Oak Ridge National Laboratory was employed to simulate the full-scale operating conditions of a purified uranium-bearing aqueous stream exiting the solvent extraction process in an NUCP. This work investigates gamma-ray signatures UN circulating in the UNCLE facility and evaluates various gamma-ray detector (HPGe, LaBr3 and NaI) sensitivities to UN.

Stream transport is an important process in the dispersion of radioactive material that has been released by man into his environment. Some portion of the radionuclides that enter the stream system may remain in solution. However, a significant amount will become associated with aquatic organisms and sediments in the stream. The relative distribution will depend upon the particular radionuclide and the environmental factors of the stream system. Contemporary sediment samples from preselected locations in the Guadalupe River drainage basin were analyzed for their mineral composition, ion exchange capacity, and radionuclide sorption. The clay minerals were the most significant agents in the radionuclide sorption processes. X-ray diffraction patterns of the clay-sized particles show the presence of a heterogeneous mixed-layered clay mineral complex of poor crystallinity. The degraded nature of these crystallites is suggested by the low intensities and the broad and diffuse diffraction maxima. Ion exchange capacity measurements gave values of 10 to 47 meq/100 grams and projected values of 20 to 73 meq/100 grams of clay material. Radionuclide sorption studies using cesium-137 and strontium-89 were made on the naturally occurring sediments and sediments from which the organic fraction had been removed. Sorption values were compared with mineralogy and ion exchange capacity to obtain points of correlation. Rates of radionuclide sorption and release were highest during the first few moments of contact, but totals slowly continued to increase throughout the seven-day duration of the experiments. Sediments containing the naturally occurring organic fraction had the highest sorption values both for strontium-89 and cesium-137. The organic fraction contributes to the over-all sorption capacity of the sediments, even though some of the organic molecules may block exchange sites on the clay minerals against exchange with the radionuclide. These laboratory experiments indicated that radionuclide sorption in the dynamic fluvial environment was temporary. When the contaminated sediments were placed in conditions simulating a marine environment, 43 percent of the cesium-137 and 42 percent of the strontium-89 were released because of competition for the exchange sites from the more abundant ions in sea water. Even though fluvial releases are considered an acceptable means of radionuclide disposal, it should be emphasized that all stream systems are dynamic, and this disposal is at best temporary. The brief respite gained today may be overshadowed by the ultimate contamination of tomorrow. / text

The ability to map industrial discharges through remote sensing provides a powerful tool in environmental monitoring. Radionuclide effluents have been discharged, under authorization, into the Irish Sea from BNFL (British Nuclear Fuels Plc.) sites at Sellafield and Springfields since 1952. The quantitative mapping of this anthropogenic radioactivity in estuarine intertidal zones is crucial for absolute interpretations of radionuclide transport. The spatial resolutions of traditional approaches e.g. point sampling and airborne gamma surveys are insufficient to support geomorphic interpretations of the fate of radionuclides in estuaries. The research presented in this thesis develops the use of airborne remote sensing to derive high-resolution synoptic data on the distribution of anthropogenic radionuclides in the intertidal areas of the Ribble Estuary, Lancashire, UK. From multidate surface sediment samples a significant relationship was identified between the Sellafieldderived 137Cs & 241Am and clay content (r2=0.93 & 0.84 respectively). Detailed in situ, and laboratory, reflectance (0.4-2.5mn) experiments demonstrated that significant relationships exist between Airborne Thematic Mapper (ATM) simulated reflectance and intertidal sediment grain-size. The spectral influence of moisture on the reflectance characteristics of the intertidal area is also evident. This had substantial implications for the timing of airborne image acquisition. Low-tide Daedalus ATM imagery (Natural Environmental Research Council) was collected of the Ribble Estuary on May 30th 1997. Preprocessing and linear unmixing of the imagery allowed accurate sub-pixel determinations of sediment clay content distributions (r2=0.8 1). Subsequently, the established relationships between 137Cs & 241Am and sediment grain-size enabled the radionuclide activity distributions across the entire intertidal area (92km2) to be mapped at a geomorphic scale (1.75m). The accuracy of these maps was assessed by comparison with in situ samples and the results of previous radiological studies within the estuary. Finally, detailed conclusions are made regarding radionuclide sinks and sources, and surface activity redistribution within the Ribble Estuary environment.

The thesis deals with the knowledge of the population about the nuclear disaster at Fukushima in the Vysočina Region. The goal is to determine the level of knowledge of population about the accident and then compare the knowledge of people aged 18-44 years and older than 45 years. In the thesis were set two hypotheses, H1: the knowledge of the population in the nuclear accident will be close to normal distribution and H2: people under 45 years will have statisticly higher knowledge than older people. To achieve the setted goals and to test the hypotheses, a questionnaire was compiled and a survey was made. The results of the survey were evaluated by methods of descriptive and mathematical statistics. The questionnaire consisted of 11 questions. The survey consisted of 100 people aged 18-44 years and 100 people aged over 45 years. The results of the survey show that the overall percentage of correctly answered questions was 63,3 %, which can be considered slightly above average. 66,1 % of people aged 18-44 years answered the questions correctly and residents over the age of 45 years 60,6 % correctly. The set goals were achieved and both hypotheses were confirmed. The benefit of this thesis is to obtain a picture of knowledge of public in the nuclear disaster at Fukushima in the Vysočina Region. The results can also be used for crisis management authorities within the preparation and preventive educational activities focused on the issue of nuclear energy and radiation protection.

Made available in DSpace on 2014-10-09T12:42:16Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:15Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP