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11	Estimation par méthodes inverses des profils d’émission des machines à bois électroportatives / Emission profiles characterization by inverse method for hand-held wood working machines Chata, Florent 27 November 2015 (has links) Cette thèse est dédiée à l'estimation de l'intensité d'une source de polluant de type particulaire par inversion de signaux de concentration mesurés avec un nombre fini de capteurs placés loin de la source. Cette méthode d'estimation inclut deux étapes distinctes. La première étape consiste à déterminer les paramètres du modèle d'inversion en utilisant une source d'aérosol connue et les mesures de concentration en particules correspondantes. Dans une seconde étape, une source d'aérosol inconnue est reconstruite à partir de l'inversion du modèle et des mesures de la concentration. Ce manuscrit traite dans un premier temps du cas stationnaire. L'approche théorique exposée permet de proposer un placement optimal des capteurs en plus de la méthode d'estimation de la source. Dans un second temps, on considère le cas où la source inconnue d'aérosol est instationnaire. La méthode d'estimation repose sur une approche convolutive du système, en introduisant la notion d'impédance source/capteur. Après une présentation de la technique d'inversion propre à la méthode d'estimation, elle est appliquée expérimentalement au cas des machines à bois éléctroportatives, dans le but de les discriminer en fonction de leur caractère émissif / This thesis is dedicated to the determination of unknown aerosol sources emission profiles from aerosol concentration measurements in the far-field. This procedure includes two distinct steps. The first step consists in determining the model linking the aerosol source and the concentration measurements using a known source of aerosols and the corresponding dust measurements. In a second step, the unknown source of aerosols is reconstructed by inverting the model for the measured aerosol concentrations. This manuscript deals in a first time with the stationary case. The exposed theoretical approach allows to suggest an optimal sensors placement in addition to the source estimation method. In a second time, we consider the case where the unknown aerosol source is unsteady. The estimation method is then based on a convolutive system approach, introducing the concept of source/sensor impedance. After a presentation of the numerical inversion technique, the method is applied experimentally to the real case of hand-held wood working machines so as to classify the machines with respect to their emission rate Estimation de source Problème inverse Aérosol CFD Simulation numérique Suivi de particules Outils de régularisation Bilan de matière Poussières de bois Source estimation Inverse problem Aerosol transport CFD Numerical simulation Regularisation tools Material balance Wood dust 628.530 151
12	Safeguards for Uranium Extraction (UREX) +1a Process Feener, Jessica S. 2010 May 1900 (has links) As nuclear energy grows in the United States and around the world, the expansion of the nuclear fuel cycle is inevitable. All currently deployed commercial reprocessing plants are based on the Plutonium - Uranium Extraction (PUREX) process. However, this process is not implemented in the U.S. for a variety of reasons, one being that it is considered by some as a proliferation risk. The 2001 Nuclear Energy Policy report recommended that the U.S. "develop reprocessing and treatment technologies that are cleaner, more efficient, less waste-intensive, and more proliferation-resistant." The Uranium Extraction (UREX+) reprocessing technique has been developed to reach these goals. However, in order for UREX+ to be considered for commercial implementation, a safeguards approach is needed to show that a commercially sized UREX+ facility can be safeguarded to current international standards. A detailed safeguards approach for a UREX+1a reprocessing facility has been developed. The approach includes the use of nuclear material accountancy (MA), containment and surveillance (C/S) and solution monitoring (SM). Facility information was developed for a hypothesized UREX+1a plant with a throughput of 1000 Metric Tons Heavy Metal (MTHM) per year. Safeguard goals and safeguard measures to be implemented were established. Diversion and acquisition pathways were considered; however, the analysis focuses mainly on diversion paths. The detection systems used in the design have the ability to provide near real-time measurement of special fissionable material in feed, process and product streams. Advanced front-end techniques for the quantification of fissile material in spent nuclear fuel were also considered. The economic and operator costs of these systems were not considered. The analysis shows that the implementation of these techniques result in significant improvements in the ability of the safeguards system to achieve the objective of timely detection of the diversion of a significant quantity of nuclear material from the UREX+1a reprocessing facility and to provide deterrence against such diversion by early detection. nuclear material safeguards UREX UREX+1a Uranium Extraction proliferation resistant proliferation resistance reprocessing PUREX Plutonium Uranium IAEA TMFD Tension Metastable Fluid Detector detection probability nondetection probability non-detection probability nuclear material accountancy containment and surveillance solution monitoring process monitoring false alarm probability real-time measurement material balance area material balance period key measurement point significant quantity timely detection defense in depth detector non-destructive assay NDA front-end measurement material unaccounted for CCD-PEG TRUEX TALSPEAK

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Estimation par méthodes inverses des profils d’émission des machines à bois électroportatives / Emission profiles characterization by inverse method for hand-held wood working machines

Safeguards for Uranium Extraction (UREX) +1a Process