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Sample records for sur le plutonium

  1. Le Point sur... Astronomie IV

    NASA Astrophysics Data System (ADS)

    Pecker, J.-C.

    Cet ouvrage regroupe des articles de mise au point sollicités par le rédacteur en chef de la rubrique Astronomie des Comptes rendus de l'Académie des sciences. Les textes se proposent de faire découvrir aux lecteurs, dans les principales disciplines de l'astronomie, les résultats les plus remarquables des dernières années.Leurs auteurs sont des spécialistes participant activement à l'accroissement des connaissances dans des domaines faisant l'objet de recherches intensives. Ces mises au point sur des questions particulièrement importantes de l'astronomie sont rédigées soit en français, soit en anglais et accompagnées d'une bibliographie détaillée.

  2. Le point sur les amas de galaxies

    NASA Astrophysics Data System (ADS)

    Pierre, M.

    galaxies jouent donc un rôle de premier plan dans toute étude cosmologique et par conséquent, sont indispensables à notre compréhension globale de l'univers. Dans l'introduction générale, nous détaillons cet aspect fondamental en montrant comment l'étude des amas peut contribuer à contraindre les scénarios cosmologiques. Une fois le contexte scientifique délimité, les chapitres suivants s'attachent à présenter les diverses propriétés des amas et leur évolution cosmique observée dans diverses longueurs d'onde principalement dans les domaines visible (galaxies), X (gaz) et radio (gaz et particules). Nous verrons que l'étude détaillée d'un amas implique celle de l'interaction entre ses différentes composantes et est un passage obligé pour remonter au paramètre ultime (ou premier) qu'est sa masse. Loin d'être un détour ennuyeux, ceci sera l'occasion d'aborder des phénomènes physiques extrêmement variés tel l'aspect multi-phases du milieu intra-amas, les sursauts de formation d'étoiles et l'évolution morphologique des galaxies capturées par les amas, ou bien encore, l'interaction entre le plasma intra-amas et les particules relativistes accélérées lors de la fusion entre deux amas. Bien sûr, pour chaque longueur d'onde, nous ne manquerons pas de décrire simplement les techniques d'observation et d'analyse mises en oeuvre ; celles-ci sont particulièrement intéressantes dans le cas de l'instrumentation spatiale. Nous terminerons en présentant des projets d'observatoires pour l'horizon 2010 et leur impact prévu sur l'étude des amas de galaxies.

  3. Plutonium

    NASA Astrophysics Data System (ADS)

    Clark, David L.; Hecker, Siegfried S.; Jarvinen, Gordon D.; Neu, Mary P.

    The element plutonium occupies a unique place in the history of chemistry, physics, technology, and international relations. After the initial discovery based on submicrogram amounts, it is now generated by transmutation of uranium in nuclear reactors on a large scale, and has been separated in ton quantities in large industrial facilities. The intense interest in plutonium resulted fromthe dual-use scenario of domestic power production and nuclear weapons - drawing energy from an atomic nucleus that can produce a factor of millions in energy output relative to chemical energy sources. Indeed, within 5 years of its original synthesis, the primary use of plutonium was for the release of nuclear energy in weapons of unprecedented power, and it seemed that the new element might lead the human race to the brink of self-annihilation. Instead, it has forced the human race to govern itself without resorting to nuclear war over the past 60 years. Plutonium evokes the entire gamut of human emotions, from good to evil, from hope to despair, from the salvation of humanity to its utter destruction. There is no other element in the periodic table that has had such a profound impact on the consciousness of mankind.

  4. Évolution des lignes directrices sur le traitement de la dyslipidémie

    PubMed Central

    John Bosomworth, N.

    2014-01-01

    Résumé Objectif Comprendre comment les nouvelles lignes directrices sur la prise en charge du risque cardiovasculaire publiées par l’American Heart Association et l’American College of Cardiology (AHA-ACC) peuvent être interprétées et utilisées dans le contexte canadien. Sources des données Les lignes directrices de l’AHA-ACC ont été examinées, de même que toutes les références. Des recherches indépendantes dans PubMed ont été effectuées pour inclure l’ajout aux statines d’autres antihyperlipidémiants et l’emploi de calculatrices médicales visant à aider le patient à comprendre. Message principal Les nouvelles lignes directrices de l’AHA-ACC s’appuient sur les meilleures données probantes disponibles actuellement en matière de traitement de la dyslipidémie. Cela inclut le risque cardiovasculaire (CV) sur 10 ans comme seuil thérapeutique au lieu du taux de cholestérol des lipoprotéines de faible densité, de même que l’abandon des cibles thérapeutiques de lipoprotéines de faible densité. On met de plus en plus l’accent sur les interventions alimentaires et l’exercice, avec l’amorce d’un effort pour quantifier l’effet de ces interventions. Les statines constituent la principale intervention pharmacologique, et l’ajout d’autres médicaments pour accentuer la baisse lipidique n’est plus recommandé. En ce qui concerne l’application au Canada, les tables de risque de Framingham sont plus appropriées pour évaluer le risque que les équations de cohortes regroupées utilisées aux États-Unis. Les calculatrices du risque de maladie cardiovasculaire (MCV) devraient contenir de l’information sur l’âge cardiovasculaire et devraient pouvoir illustrer le risque et les interventions de rechange afin d’aider le patient à comprendre et de favoriser la prise de décision éclairée. Conclusion L’attention sur les meilleures données probantes concernant le risque CV peut simplifier le traitement de la

  5. Reflections on "Petit Battement sur le Cou de Pied": Is It Still Relevant?

    ERIC Educational Resources Information Center

    Paskevska, Anna

    2007-01-01

    This article presents multiple perspectives of "petit battement sur le cou de pied". These perspectives include historical, biomechanical, and pedagogic points of view. The article offers useful information for ballet specialists and applied research studies aimed at ballet pedagogy. (Contains 2 tables and 5 figures.)

  6. Reflections on "Petit Battement sur le Cou de Pied": Is It Still Relevant?

    ERIC Educational Resources Information Center

    Paskevska, Anna

    2007-01-01

    This article presents multiple perspectives of "petit battement sur le cou de pied". These perspectives include historical, biomechanical, and pedagogic points of view. The article offers useful information for ballet specialists and applied research studies aimed at ballet pedagogy. (Contains 2 tables and 5 figures.)

  7. Sur la reponse en frequence du tissu nerveux dans le cortex

    NASA Astrophysics Data System (ADS)

    Bedard, Claude

    Dans cette These de Physique, nous avons etudie la dependance en frequence du champ electrique du tissu nerveux dans le cortex. Ce champ est aussi designe par "Local field Potential" LFP dans la litterature scientifique. Cette etude est fondee sur la theorie du champ electromagnetisme de Maxwell et sur de l'information tiree de la donne experimentale. Le resultat essentiel de cette These est que la grandeur enorme du temps de relaxation de Maxwell des membranes cellulaires semble etre la cause principale de la dependance en frequence des LFPs. Cette dependance en frequence causee par chaque membrane cellulaire est l'analogue d'un circuit RC ou la resistance R est la resistivite parallele d'une membrane cellulaire, et ou la capacite C est la permittivite electrique de la membrane. L'effet resultant d'un tres grand nombre de cellules donne un spectre de Fourier dont l'enveloppe est tres pres d'un signal en 1/f. Le modele physique propose dans cette These permet de lier les mesures prises a l'interieur d'une dendrite des variations de potentiel electrique a celles prises dans le liquide extracellulaire. De plus, cette These semble ouvrir la possibilite de mesurer le temps de relaxation de Maxwell des membranes cellulaires a l'aide de la mesure de la reponse en frequence du potentiel electrique extracellulaire (LFP). Enfin, cette These permet de lever le voile sur un sujet peu etudie, principalement en raison de la difficulte que represente l'etude des phenomenes electriques dans des milieux complexes comme les tissus vivants. En particulier, le probleme du filtrage frequentiel du potentiel electrique extracellulaire est une propriete fondamentale du tissu nerveux et son origine n'est pas connue.

  8. Sur le chaos Lagrangien dans une cuve elliptique

    NASA Astrophysics Data System (ADS)

    Saatdjian, E.; Chassaing, M. I.; Midoux, N.; André, J. C.

    1995-02-01

    A viscous fluid is introduced into the annular space between two concentric, confocal ellipses. The inner and outer walls can be displaced along their circumference. A small quantity of fluorescent dye is introduced into the fluid and deformation and mixing are studied for the case of periodic boundary movement. An analytical solution in elliptical coordinates has been previously derived for creeping flow conditions. Poincaré sections for a given set of parameters indicate that counter-rotation leads to a more chaotic behaviour than co-rotation, this result is confirmed experimentally. This geometry can also be used as a heat exchanger. By a suitable choice of the parameters, the heat transfer for steady boundary motion can be increased by more than 50% with respect to the concentric cylinder system. If the inner and outer walls are displaced time-periodically, the heat transfer rate obtained can be more than double the rate obtained between concentric cylinders. Un fluide visqueux est introduit dans une cuve de géométrie elliptique, les parois interne et externe de cette cuve tournent suivant le périmètre de l'ellipse. Une petite quantité de traceur fluorescent est introduite dans le fluide et la déformation de l'élément marqué, lorsque le mouvement des deux parois est périodique, est étudiée. Pour cet écoulement où le nombre de Reynolds est très inférieur à 1 (régime de Stokes) et à partir d'une solution analytique récemmnent obtenue pour le cas stationnaire, des sections de Poincaré ont été tracées pour le cas d'une contra-rotation et d'une co-rotation. Les résultats expérimentaux montrent que, pour un protocole de mélange discontinu approprié, cette géométrie mène vers un mélange chaotique après un petit nombre de périodes. Par ailleurs, il est préférable de faire tourner les ellipses en contra-rotation. Ce résultat, en contradiction avec ceux déjà obtenus dans l'espace annulaire entre cylindres excentrés tournants, est

  9. A Recommended Methodology for Quantifying NDE/NDI Based on Aircraft Engine Experience (Le Projet de Methodologie Pour l’Evaluation du Controle Non- Destructif Fonde sur l’Experience Acquise sur les moteurs d’Avions)

    DTIC Science & Technology

    1993-04-01

    A Recommended Methodology for Quantifying NDE/NDI Based on Aircraft Engine Experience--Translation(Le Projet de Methodologie Pour l’Evaluation du Controle Non-Destructif Fonde sur l’Experience Acquise sur les moteurs d’Avions)

  10. Developpement d'un compresseur d'hydrogene base sur le cyclage thermique des hydrures metalliques

    NASA Astrophysics Data System (ADS)

    Laurencelle, Francois

    La compression de l'hydrogene est une etape incontournable de son utilisation dans l'industrie actuelle et dans les nouvelles applications energetiques de l'hydrogene (stockage stationnaire et transport). Les compresseurs mecaniques traditionnellement utilises posent plusieurs problemes d'ingenierie, de securite et de maintenance qui pourraient etre contournes en developpant de nouvelles technologies mieux adaptees a l'hydrogene. Dans cette these, notre objectif est de developper d'un compresseur d'hydrogene base sur les hydrures metalliques pouvant etre connecte a la sortie d'un electrolyseur fonctionnant a basse pression et d'ainsi repondre au besoin de productioncompression d'hydrogene decentralisee. La methodologie du projet comprend plusieurs etapes. Premierement, nous faisons la revue bibliographique des projets impliquant des compresseurs a hydrures metalliques. Deuxiemement, a travers des travaux experimentaux, nous recherchons des hydrures permettant une compression efficace entre 20 et 80°C. Les materiaux sont synthetises par fusion a arc electrique et caracterises sur bancs d'essais d'hydrogenation. La structure de certains materiaux est aussi investiguee par rayons X, methode de B.E.T. et microscopie electronique. Troisiemement, un reacteur d'hydrures est concu de maniere a promouvoir des echanges de chaleur rapides et efficaces. Quatriemement, le prototype et son interface de controle sont construits. Cinquiemement, le compresseur est caracterise pour en evaluer les performances en termes de debit et de capacite. Les resultats obtenus sont presentes dans trois articles publies et dans le chapitre 5 de cette these. Le compresseur (article I) est base sur trois hydrures (LaNi 4.8Sn0.2, LaNi5 et MMNi4.7Al0.3 ). Celui-ci permet d'atteindre un debit de compression de 10 a 20 L d'hydrogene par heure et son efficacite est, estimee a ˜5% par rapport a un compresseur adiabatique ideal. Il a ete demontre que l'efficacite pourrait etre augmentee en utilisant un

  11. Le Point sur la Pharmacologie des Agents Anesthesiques Chez le Brule Grave

    PubMed Central

    Siah, S.; Ababou, K.; Benziane, H.; El Jaoudi; Bensghir, M.; Bakali, H.; El Wali, A.; Ihrai, I.; Drissi, N.K.

    2008-01-01

    Summary La pharmacologie des agents anesthésiques chez le brûlé est variable et imprévisible. Dans les premières 48 h, il y a une hypovolémie avec chute du débit cardiaque et des fuites plasmatiques. Après 48 h, il y a une hypervolémie avec augmentation du débit cardiaque, hypermétabolisme et la clearance des médicaments est augmentée. Parmi les facteurs de déséquilibre, on retrouve les variations des protéines plasmatiques. Deux protéines sont importantes chez le brûlé grave : l'albumine et l'alpha 1- glycoprotéine. Leur taux varie beaucoup au cours de l'évolution de la brûlure. Les agents anesthésiques dont la liaison avec ces deux protéines est prédominante verront leur pharmacocinétique modifiée. L'anesthésiste-réanimateur du service des brûlés va maîtriser ces notions pharmacologiques pour utiliser à bon escient les agents anesthésiques. PMID:21991108

  12. Lignes directrices pour le suivi des cardiostimulateurs au canada : consensus du groupe de travail canadien sur la cardiostimulation

    PubMed

    D Fraser JD; M Gillis AM; Irwin; Nishimura; Tyers; Philippon

    2000-03-01

    Un sondage sur les pratiques de cardiostimulation au Canada effectue en 1997 a revele un profond desir pour des lignes directrices nationales sur le suivi des cardiostimulateurs. Ces lignes directrices sur le suivi des cardiostimulateurs representent une declaration de consensus du Groupe de travail canadien sur la cardiostimulation. Le suivi des patients en personne plutot que par moyens transtelephoniques est preferable. Les patients devraient etre examines au minimum dans les 72 heures suivant l'implantation, 2 a 12 semaines et 6 mois apres l'implantation, et annuellement par la suite. Des examens plus frequents peuvent etre requis pour certains patients. Ceci dependra des problemes cardiovasculaires associes et des appareils en particulier. Une visite de suivi typique devrait comprendre un examen cardiovasculaire oriente, l'interrogation du systeme de cardiostimulation et une revue des donnees de telemetrie, un examen du rythme sous-jacent, un examen des seuils de stimulation et de detection et une reprogrammation adequate des parametres pour optimaliser le fonctionnement et la longevite de l'appareil.

  13. Le cancer en Mauritanie : résultats sur 10 ans du registre hospitalier de Nouakchott

    PubMed Central

    Baba, Nacer Dine Ould Mohamed; Sauvaget, Catherine

    2013-01-01

    Le fardeau du cancer reste mal connu en Mauritanie. Il n'est basé que sur des extrapolations de l'incidence des cancers des pays avoisinants. Les données du registre de l'hôpital national permettent de décrire les cas avec un diagnostic histologique. Tous les cas de cancers enregistrés par le service d'anatomo-pathologie de l'hôpital national de Nouakchott de 2000 à 2009 ont été analysés. En 10 ans, 3305 prélèvements histologiques ont été analysés (hommes:42%, femmes:58%). Chez l'homme, le cancer le plus fréquemment analysé était le cancer de la peau (218 cas au total, 189 cas en excluant mélanome), suivi de la prostate (203), des cancers digestifs (179, colorectal et ‘sophage), et des lymphomes (151). Chez la femme, un quart des biopsies était des cancers du sein (485), suivi du col utérin (344), de la sphère gynécologique (218, ovaire et corps utérin), et de la peau (114). Les cancers du foie, du poumon ou de la vessie étaient peu fréquents. Ces résultats ne reflètent pas l'incidence ni l'actuel fardeau du cancer en Mauritanie puisque de nombreux patients diagnostiqués avec un cancer ne reçoivent pas d'examen anatomopathologique. Si, comme dans les pays avoisinants du Maroc et du Mali, les cancers du col et du sein sont les pathologies les plus fréquentes chez la femme, la distribution des cancers chez l'homme dans ce registre hospitalier diffère des résultats des registres de population du Maroc et du Mali où les cancers du poumon, du foie, de la prostate et de la vessie dominent. PMID:23785554

  14. 2010 Coalition Battle Management Language Workshop (Atelier 2010 sur le langage de gestion du champ de bataille pour les operations en coalition)

    DTIC Science & Technology

    2010-02-01

    Feb 2010 2010 Coalition Battle Management Language Workshop (Atelier 2010 sur le langage de gestion du champ de bataille pour les opérations en... bataille pour les opérations en coalition) Papers presented at the NATO Modeling and Simulation Group (NMSG) Workshop held in Farnborough, United Kingdom...RTO-MP-MSG-079 ES - 3 Atelier 2010 sur le langage de gestion du champ de bataille pour les opérations en coalition (RTO-MP-MSG-079

  15. When Marcel Mauss's Essai sur le Don becomes The Gift: variations on the theme of solidarity.

    PubMed

    Bateman, Simone

    2016-12-01

    Since the early 1970s, Marcel Mauss's Essai sur le Don (1923), translated into English as The Gift in 1954, has been a standard reference in the social science and bioethical literature on the use of human body parts and substances for medical and research purposes. At that time, three social scientists-political scientist Richard Titmuss in the United Kingdom and sociologist Renée C. Fox working with historian Judith Swazey in the United States-had the idea of using this concept to highlight the fundamental structure of the biomedical practices they were studying, respectively, blood donation, and hemodialysis and organ transplantation. The fact that these first applications of Mauss's essay should emerge in English- rather than in French-speaking countries raises the question of what the translation of the essay, and notably of the word don as gift, may have to do with this fact. Reading Mauss in translation undoubtedly inspired a seminal approach to interpreting medical and research practices based on bodily giving. This article posits that something may have also been lost: a much broader concept of giving with unquestionable links to the Durkheimian concept of solidarity, which Mauss conceptualizes not only as an obligation but also as a liberty to give.

  16. Considérations nosographiques sur le délire d'infestation parasitaire à travers trois observations cliniques

    PubMed Central

    Berhili, Nabil; Bout, Amine; Hlal, Hayat; Aarab, Chadya; Aalouane, Rachid; Rammouz, Ismail

    2016-01-01

    Le syndrome d'Ekbom, ou délire d'infestation parasitaire, est une pathologie rare, caractérisée par la conviction inébranlable d'avoir une peau infestée d'insectes ou de parasites. Il s'agit d'un délire monothématique à mécanisme hallucinatoire qui touche typiquement les femmes d’âge avancé. Nous rapportons les cas de trois patients qui présentent un délire d'infestation parasitaire dans des contextes cliniques différents. Le premier patient souffre d'un délire d'infestation isolé correspondant à la forme décrite par Karl Ekbom. Le deuxième cas présente un délire d'infestation secondaire, s'inscrivant dans le cadre d'une leuco-encéphalopathie de type CADASIL. Enfin, le troisième patient se présente dans un tableau évocateur d'un épisode dépressif avec une caractéristique psychotique qui intègre le délire d'infestation. Ces trois vignettes cliniques illustrent parfaitement le caractère trans-nosographique de ce syndrome ainsi que les difficultés de prise en charge de ces patients, tant au niveau de l'alliance thérapeutique que sur le plan des choix en matière de traitement pharmacologiques. PMID:27642468

  17. Mise à jour sur le nouveau vaccin 9-valent pour la prévention du virus du papillome humain

    PubMed Central

    Yang, David Yi; Bracken, Keyna

    2016-01-01

    Résumé Objectif Informer les médecins de famille quant à l’efficacité, à l’innocuité, aux effets sur la santé publique et à la rentabilité du vaccin 9-valent contre le virus du papillome humain (VPH). Qualité des données Des articles pertinents publiés dans PubMed jusqu’en mai 2015 ont été examinés et analysés. La plupart des données citées sont de niveau I (essais randomisés et contrôlés et méta-analyses) ou de niveau II (études transversales, cas-témoins et épidémiologiques). Des rapports et recommandations du gouvernement sont aussi cités en référence. Message principal Le vaccin 9-valent contre le VPH, qui offre une protection contre les types 6, 11, 16, 18, 31, 33, 45, 52 et 58 du VPH, est sûr et efficace et réduira encore plus l’incidence des infections à VPH, de même que les cas de cancer lié au VPH. Il peut également protéger indirectement les personnes non immunisées par l’entremise du phénomène d’immunité collective. Un programme d’immunisation efficace peut prévenir la plupart des cancers du col de l’utérus. Les analyses montrent que la rentabilité du vaccin 9-valent chez les femmes est comparable à celle du vaccin quadrivalent original contre le VPH (qui protège contre les types 6, 11, 16 et 18 du VPH) en usage à l’heure actuelle. Toutefois, il faut investiguer plus en profondeur l’utilité d’immuniser les garçons avec le vaccin 9-valent contre le VPH. Conclusion en plus d’être sûr, le vaccin 9-valent protège mieux contre le VPH que le vaccin quadrivalent. Une analyse coûtefficacité en favorise l’emploi, du moins chez les adolescentes. Ainsi, les médecins devraient recommander le vaccin 9-valent à leurs patients plutôt que le vaccin quadrivalent contre le VPH.

  18. Quatrième conférence consensuelle sur le diagnostic et le traitement de la démence

    PubMed Central

    Moore, Ainsley; Patterson, Christopher; Lee, Linda; Vedel, Isabelle; Bergman, Howard

    2014-01-01

    Résumé Objectif Revoir les stratégies diagnostiques de la maladie d’Alzheimer, actualiser les recommandations concernant le traitement des symptômes de démence et proposer une approche thérapeutique à la démence d’apparition précoce et d’évolution rapide. Composition du comité Des spécialistes et des délégués de diverses régions du Canada et représentant diverses disciplines pertinentes ont discuté et se sont mis d’accord sur les révisions à apporter aux lignes directrices de 2006. Méthodologie On a eu recours au système GRADE (grading of recommendations, assessment, development, and evaluation) pour évaluer le consensus concernant les recommandations, lequel était défini comme suit : lorsque 80 % ou plus des participants ont voté en faveur de la recommandation. La cote des données probantes est rapportée lorsque cela est possible. Rapport important pour les médecins de famille, malgré les progrès effectués dans les domaines des biomarqueurs liquidiens et de la neuro-imagerie, le diagnostic de démence au Canada demeure fondamentalement clinique. De nouveaux critères cliniques essentiels de diagnostic de la maladie d’Alzheimer en reconnaissent dorénavant les formes moins fréquentes et non amnestiques. La démence précoce, une affection rare, mais importante, devrait inciter les médecins à aiguiller les patients vers un spécialiste ayant accès à des conseillers en génétique. La démence d’évolution rapide, mal définie dans la littérature, faciliterait le dépistage de cette affection rare, mais importante. Les inhibiteurs de la cholinestérase sont maintenant indiqués pour le traitement d’affections autres que la maladie d’Alzheimer. Des lignes directrices concernant l’arrêt du traitement, lesquelles n’existaient pas auparavant, sont également apparues. De nouvelles données probantes sur le recours à la mémantine, aux antidépresseurs et à d’autres agents psychotropes dans le traitement de la

  19. Effet de l'etat de la surface de l'acier au carbone 300W sur l'entartrage par la gibbsite dans le procede Bayer

    NASA Astrophysics Data System (ADS)

    Gavril, Liliana

    Une etude a ete effectuee sur l'entartrage des surfaces en acier au carbone par la gibbsite dans le procede Bayer. Trois methodes ont ete utilisees afin de determiner le mecanisme de formation du tartre: mesure de la vitesse d'entartrage, etude electrochimique et protection cathodique. Cette etude demontre que le tartre de gibbsite est un tartre de cristallisation et que l'etat physico-chimique de la surface metallique a une influence marquee sur l'entartrage. Ainsi, l'oxyde en surface a ete identifie comme un facteur determinant pour l'entartrage. Les essais electrochimiques ont montre que la couche d'oxyde formee dans les solutions Bayer est un oxyde mixte de fer et d'aluminium. Les essais de protection cathodique a courant constant valident le role determinant joue par l'oxyde sur l'entartrage, puisqu'en empechant l'oxyde de se former, l'entartrage est pratiquement elimine. Le mecanisme d'adherence du tartre a l'acier implique trois etapes, soit l'oxydation du metal, la formation de la goethite/goethite alumineuse sur l'oxyde et finalement, la germination de la gibbsite sur la goethite/goethite alumineuse.

  20. Effet de l'interaction coulombienne sur la localisation d'Anderson dans le gaz bidimensionnel d'électrons

    NASA Astrophysics Data System (ADS)

    Fleury, G.

    2010-09-01

    Nous étudions l’effet des interactions coulombiennes sur la localisation d’Anderson dans le gaz bidimensionnel d’électrons désordonné. L’objectif est de statuer sur la question de l’existence de métaux à deux dimensions. En l’absence d’interaction, la théorie d’échelle de la localisation prédit qu’un désordre infinitésimal suffit à localiser la fonction d’onde électronique et donc à rendre le système isolant à température nulle (Abrahams et al., 1979). Dans certaines limites extrêmes, les interactions peuvent être prises en compte et l’on aboutit également à un état isolant. Cependant, aucune théorie analytique ne permet de traiter le régime quantique non-perturbatif où désordre et interaction sont intermédiaires. Expérimentalement, il est possible de l’explorer dans des échantillons de haute mobilité et basse densité. Depuis 1994, des comportements métalliques inexpliqués y ont été observés (Kravchenko et al., 1994). Nous avons mis au point une méthode numérique permettant d’étudier le problème couplé de la localisation d’Anderson en présence d’interaction. Cette méthode mêle Monte Carlo quantique à température nulle et théorie d’échelle pour la conductance de Thouless. Nous trouvons que la théorie d’échelle de la localisation est préservée en présence d’interaction et donc que le gaz bidimensionnel, même corrélé, est isolant à température nulle. Nos résultats montrent de plus que les interactions délocalisent le gaz bidimensionnel et que cet effet de délocalisation est accru en présence de dégénérescence de vallées. Ils nous permettent de proposer un mécanisme simple rendant compte des principales caractéristiques des comportements métalliques observés expérimentalement.

  1. LeČOns Sur Les Ondes De Gravité Des Fluides Incompressibles

    NASA Astrophysics Data System (ADS)

    van den Dungen, F. H.

    Le 3 Janvier 1814 au moment où les Alliés franchissant le Rhin allaient entamer la campagne de France, la classe des Sciences de l'Institut de France proposait comme sujet du grand prix de mathématique à décerner en Janvier 1816 la question suivante: "La théorie de la propagation des ondes à la surface d'un fluide pesant d'une profondeur infinie".

  2. Profil bactériologique du pied diabétique et son impact sur le choix des antibiotiques

    PubMed Central

    Zemmouri, Adil; Tarchouli, Mohamed; Benbouha, Abdellatif; Lamkinsi, Tarik; Bensghir, Mustapha; Elouennass, Mostafa; Haimeur, Cherqui

    2015-01-01

    Introduction Analyse du profil bactériologique des pieds diabétiques pris en charge à l'hôpital militaire de Rabat et son influence sur l'antibiothérapie de première intention. Méthodes Etude prospective non randomisée étalée sur 18 mois, ayant concerné 105 patients. Après recueil des données et en attente des résultats bactériologiques nos patients ont été divisés en deux groupes: un groupe a été mis sous Amoxicilline + Acide clavulanique + Gentamycine (59 patients) et un groupe sous Ertapénème±Gentamycine (46 patients). Résultats L’étude a regroupé 85 hommes et 20 femmes (sexe ratio = 4.26). L’âge moyen est de 64.4 ans. La gangrène a été observée chez 79% des malades; elle était humide-donc surinfectée en principe- dans 43% des cas. Par ailleurs, 67% des malades ont un chiffre de globules blancs 12000 définissant une infection sévère. L'ostéolyse a été mise en évidence chez 27% de nos patients. Parmi les différentes techniques de prélèvements: 81% ont été profonds dont 21% de biopsie osseuse per opératoire et 14% de prélèvements combinés. 42% de ces prélèvements sont poly microbiens et 21% sont stériles. Les résultats bactériologiques viennent confirmer la prédominance des bactéries aérobies à Gram positif. Le taux de remplacement de l'Ertapénème est de 22% contre un taux de 50% pour l'Amoxiclav. Conclusion L'antibiothérapie ne doit être instaurée qu'en cas d'infection du pied diabétique diagnostiquée sur les critères cliniques établis par les consensus internationaux récents. Le respect des mesures de lutte contre la diffusion de la résistance bactérienne s'avère primordiale. PMID:27386024

  3. Renaud Paulian et le programme du CNRS sur les hautes montagnes à Madagascar: étage vs domaine

    PubMed Central

    Guillaumet, Jean-Louis; Betsch, Jean-Marie; Callmander, Martin W.

    2011-01-01

    Résumé Le programme intitulé « Étude des écosystémes montagnards dans la région malgache» (RCP 225/CNRS; responsable: Recteur Renaud Paulian) avait pour ambition de dégager leurs caractères généraux, l'origine des éléments constitutifs et de tester la validité d'un Domaine malgache des Hautes Montagnes proposé par Humbert dès 1951. De 1970 à 1973, trois campagnes (Andringitra; Chaînes anosyennes et Ankaratra; Itremo, Ibity et Marojejy) ont permis une caractérisation écologique des milieux particuliers ainsi que des analyses de systématique sur certains taxa connus pour leur intérêt biogéographique. La succession altitudinale des formations végétales, définies par des critères physionomiques et structuraux, est précisée par massif. Le dernier étage caractérisé par le fourré éricoïde et ses groupements associés ne correspond pas à l'Étage des Hautes Montagnes de l'Est africain. Des groupes de la faune (invertébrés hexapodes: Collemboles et Dermaptères) indiquent une disjonction entre les massifs du Nord (Tsaratanana, Marojejy), ceux du Centre et du Sud; des éléments de la flore (Pandanaceae, Araliaceae, Asteraceae) sont en cours d'analyse dans le même sens. Le Domaine des Hautes montagnes à Madagascar est une réalité écologique mais ne peut être défini floristiquement; chaque massif montagneux est une entité phytogéographique d'étages de végétation interdépendants inclus dans les différents Sous-Domaines du Centre. Les groupes peu mobiles de la faune indiquent globalement une dépendance trophique et bioclimatique (effet tampon du climat intraforestier) vis-à-vis des étages de végétation, mais peuvent réagir à des microclimats locaux par des décalages à leurs limites. PMID:21731422

  4. Developpement et validation d'un outil base sur l'acoustique geometrique pour le diagnostic du bruit de nacelle

    NASA Astrophysics Data System (ADS)

    Minard, Benoit

    De nos jours, la problématique du bruit généré par les avions est devenue un point de développement important dans le domaine de l'aéronautique. C'est ainsi que de nombreuses études sont faites dans le domaine et une première approche consiste à modéliser de façon numérique ce bruit de manière à réduire de façon conséquente les coûts lors de la conception. C'est dans ce contexte qu'un motoriste a demandé à l'université de Sherbrooke, et plus particulièrement au groupe d'acoustique de l'Université de Sherbrooke (GAUS), de développer un outil de calcul de la propagation des ondes acoustiques dans les nacelles mais aussi pour l'étude des effets d'installation. Cet outil de prédiction leur permet de réaliser des études afin d'optimiser les traitements acoustiques (« liners »), la géométrie de ces nacelles pour des études portant sur l'intérieur de la nacelle et des études de positionnement des moteurs et de design pour les effets d'installation. L'objectif de ce projet de maîtrise était donc de poursuivre le travail réalisé par [gousset, 2011] sur l'utilisation d'une méthode de lancer de rayons pour l'étude des effets d'installation des moteurs d'avion. L'amélioration du code, sa rapidité, sa fiabilité et sa généralité étaient les objectifs principaux. Le code peut être utilisé avec des traitements acoustiques de surfaces («liners») et peut prendre en compte le phénomène de la diffraction par les arêtes et enfin peut être utilisé pour réaliser des études dans des environnements complexes tels que les nacelles d'avion. Le code développé fonctionne en 3D et procéde en 3 étapes : (1) Calcul des faisceaux initiaux (division d'une sphère, demi-sphère, maillage des surfaces de la géométrie) (2) Propagation des faisceaux dans l'environnement d'étude : calcul de toutes les caractéristiques des rayons convergents (amplitude, phase, nombre de réflexions, ...) (3) Reconstruction du champ de pression en un ou

  5. Technique distribuee de gestion de la charge sur le reseau electrique et ring-tree: Un nouveau systeme de communication P2P

    NASA Astrophysics Data System (ADS)

    Ayoub, Simon

    Le reseau de distribution et de transport de l'electricite se modernise dans plusieurs pays dont le Canada. La nouvelle generation de ce reseau que l'on appelle smart grid, permet entre autre l'automatisation de la production, de la distribution et de la gestion de la charge chez les clients. D'un autre cote, des appareils domestiques intelligents munis d'une interface de communication pour des applications du smart grid commencent a apparaitre sur le marche. Ces appareils intelligents pourraient creer une communaute virtuelle pour optimiser leurs consommations d'une facon distribuee. La gestion distribuee de ces charges intelligentes necessite la communication entre un grand nombre d'equipements electriques. Ceci represente un defi important a relever surtout si on ne veut pas augmenter le cout de l'infrastructure et de la maintenance. Lors de cette these deux systemes distincts ont ete concus : un systeme de communication peer-to-peer, appele Ring-Tree, permettant la communication entre un nombre important de noeuds (jusqu'a de l'ordre de grandeur du million) tel que des appareils electriques communicants et une technique distribuee de gestion de la charge sur le reseau electrique. Le systeme de communication Ring-Tree inclut une nouvelle topologie reseau qui n'a jamais ete definie ou exploitee auparavant. Il inclut egalement des algorithmes pour la creation, l'exploitation et la maintenance de ce reseau. Il est suffisamment simple pour etre mis en oeuvre sur des controleurs associes aux dispositifs tels que des chauffe-eaux, chauffage a accumulation, bornes de recharges electriques, etc. Il n'utilise pas un serveur centralise (ou tres peu, seulement lorsqu'un noeud veut rejoindre le reseau). Il offre une solution distribuee qui peut etre mise en oeuvre sans deploiement d'une infrastructure autre que les controleurs sur les dispositifs vises. Finalement, un temps de reponse de quelques secondes pour atteindre 1'ensemble du reseau peut etre obtenu, ce qui est

  6. Effets du stress familial lié au diabète sur le contrôle glycémique chez les jeunes diabétiques de type 1

    PubMed Central

    Tsiouli, Elina; Alexopoulos, Evangelos C.; Stefanaki, Charikleia; Darviri, Christina; Chrousos, George P.

    2013-01-01

    Objectif Examiner la façon dont le stress familial influence le contrôle glycémique chez les patients diabétiques de moins de 18 ans. Sources des données Une recherche des études pertinentes publiées depuis 1990 a été réalisée dans PubMed et Scopus à l'aide des mots-clés suivants en anglais: diabetes type 1, glycemic control, family stress, family conflict et family function. Sélection des études La recension initiale a permis de cerner un total de 1 478 articles. La synthèse finale portrait sur 6 études de cohortes, 3 études transversales et 1 étude qualitative dans lesquelles le stress familial était évalué à l'aide d'instruments de mesure des conflits spécifiquement reliés au diabète et le contrôle glycémique était mesuré en fonction de l'hémoglobine glycosylée. Synthèse Dans la plupart des études, il existait une corrélation négative entre le stress familial et le contrôle glycémique des patients. Le bon fonctionnement familial était fortement relié à un bon contrôle glycémique des patients, tandis que les conflits familiaux étaient associés à un mauvais contrôle glycémique. Les familles dont la situation socioéconomique était défavorisée, celles ayant des adolescents atteints de diabète et les familles monoparentales étaient plus enclines à vivre un stress relié au diabète et étaient, par conséquent, plus susceptibles de connaître un moins bon contrôle glycémique. Conclusion Les interventions psychologiques thérapeutiques et les programmes éducatifs peuvent aider à atténuer le stress familial relié au diabète et amélioreront probablement le contrôle glycémique.

  7. Un essai contrôlé randomisé: effet du port de chaussures à talons hauts sur le squelette appendiculaire inferieur

    PubMed Central

    Koussihouèdé, Fifamè Eudia Nadège; Falola, Jean-Marie; Fousseni, El-Mansour Barres

    2015-01-01

    Introduction Véritable attribut de la féminité, le port de chaussures à talons est devenu une exigence professionnelle dans certaines structures des pays en développement comme le Bénin. L'objectif de ce travail est de déterminer les effets spécifiques du port de chaussures à talons hauts sur le squelette appendiculaire inférieur. Méthodes Des examens radiographiques de face et de profil de la cheville et du genou ont été effectués sur 122 femmes volontaires, âgées en moyenne de 25,09 ± 1,34 ans et ayant les genu varum qui ont participé à cette étude. Résultats Les résultats ont indiqué une augmentation significative de l’écart inter malléolaire, de l’écart inter condylien, de l'angle antérieur du pied et de l'angle fémoro-patellaire. Une diminution significative de l'angle postérieur du pied a été constatée. Conclusion Le port de chaussures à talons hauts est l'une des causes de la gonarthrose, des troubles des articulations de la cheville et du pied. PMID:26113922

  8. Le défi de la recherche sur les médicaments et du traitement des enfants au Canada

    PubMed Central

    Rieder, Michael J

    2011-01-01

    RÉSUMÉ Les enfants ont toujours été des « orphelins thérapeutiques ». De nombreux médicaments n’ont pas fait l’objet d’études auprès des enfants et des adolescents ou leur utilisation n’est pas autorisée officiellement auprès d’eux, ce qui crée un défi constant en matière d’élaboration et de définition de pharmacothérapies à la sécurité et l’efficacité optimales au sein du groupe d’âge pédiatrique. Depuis dix ans, des réseaux ont germé aux États-Unis et en Europe afin d’accroître la recherche sur les médicaments dans ce groupe, mais aucune évolution comparable ne s’observe au Canada. Le présent document de principes expose le contexte de la situation canadienne et contient des recommandations qui tiennent compte de deux besoins pressants : plus de recherches sur les médicaments axées sur les enfants et les adolescents canadiens, y compris un financement dédié à de telles recherches, et plus d’effectifs pour mener des études ciblées. Ces initiatives devraient être entreprises en collaboration, sur les scènes nationale et internationale, et inclure des démarches stratégiques et novatrices afin de régler les problèmes et enjeux éthiques uniques que présente la recherche sur les médicaments au sein de cette population.

  9. Evaluation du niveau de connaissance des patients sur la gestion du traitement par les antis vitamines K dans le service de cardiologie de Ouagadougou

    PubMed Central

    Samadoulougou, André; Temoua Naibe, Dangwé; Mandi, Germain; Yameogo, Relwendé Aristide; Kabore, Elisé; Millogo, Georges; Yameogo, Nobila Valentin; Kologo, Jonas Koudougou; Thiam/Tall, Anna; Toguyeni, Boubacar Jean Yves; Zabsonre, Patrice

    2014-01-01

    Introduction Les antivitamines K (AVK), traitement anticoagulant oral le plus largement prescrit, posent un réel problème de santé publique du fait de leur risque iatrogène. L'objectif de cette étude était de préciser le niveau de connaissance des patients sur la gestion de leur traitement par les AVK. Méthodes Il s'est agi d'une enquête transversale descriptive réalisée au CHU-Yalgado Ouédraogo, sur une période de 03 mois : du 1er mars au 31 mai 2012. Un questionnaire a été administré aux patients bénéficiant d'un traitement AVK depuis au moins un mois. Résultats Soixante-dix patients ont été inclus dans l'étude dont 30 hommes. L'âge moyen était de 49 ans ± 16 ans. Les cardiopathies et la maladie thromboembolique veineuse justifiant l'institution du traitement AVK étaient retrouvées respectivement dans 58,6% et 41,4% des cas. Le nom de l'AVK et la raison exacte du traitement étaient connus respectivement dans 91,4% et 67,1% des cas. Plus de la moitié des patients (68,6%) savaient que les AVK rendaient le sang plus fluide. Quarante-six patients (65,7%) citaient l'INR comme examen biologique de surveillance du traitement et seulement 28 patients (40%) connaissaient les valeurs cibles. La majorité des patients ne connaissait pas les risques encourus en cas de surdosage (72,8%) et de sous-dosage (71,4%). Une automédication par anti-inflammatoire non stéroïdien était signalée par 18 patients (25,7%). Les choux (74,3%) et la laitue (62,9%), aliments à consommer avec modération, étaient les plus cités. Conclusion Les connaissances des patients sur la gestion des AVK étaient fragmentaires et insuffisantes pour assurer la sécurité et l'efficacité du traitement. La création d'un programme d'éducation thérapeutique sur les AVK s'avère alors nécessaire. PMID:25870741

  10. Plutonium controversy

    SciTech Connect

    Richmond, C.R.

    1980-01-01

    The toxicity of plutonium is discussed, particularly in relation to controversies surrounding the setting of radiation protection standards. The sources, amounts of, and exposure pathways of plutonium are given and the public risk estimated. (ACR)

  11. Une étude rétrospective sur le cancer de l'ovaire avec un recul médian de 42 mois

    PubMed Central

    Raherinantenaina, Fanomezantsoa; Rakotomena, Solonirina Davidà; Hasiniatsy, Nomeharisoa Rodrigue Emile; Rakototiana, Felantsoa Auberlin; Rafaramino, Florine; Ratsimba, Hery Nirina Rakoto

    2015-01-01

    Le cancer de l'ovaire est relativement fréquent mais grave et de mauvais pronostic. Le but de cette étude était de mettre en évidence les aspects épidémiologique, diagnostique, thérapeutique et évolutif de cette pathologie maligne prise en charge dans un pays en développement. Il s'agit d'une étude rétrospective et descriptive de 10 ans (2000- 2009) effectuée dans un CHU de chirurgie générale et d'Oncologie sur 62 patientes ayant développé un cancer de l'ovaire et opérées à visée curative. L’âge moyen des patientes était de 43 ans dont 53,23% avaient plus de 45 ans. Le dosage sanguin du CA-125 était positif chez 10 patientes sur 12. Les tumeurs étaient découvertes à l’échographie dans 87,10% des cas et à la laparotomie dans 12,90%. L'hystérectomie totale avec annexectomie bilatérale était l'intervention la plus pratiquée (64,52%). Les suites opératoires précoces étaient simples. Dix patientes étaient opérées de second regard (16,13%) pour des récidives locorégionales. Les tumeurs épithéliales étaient le type histologique le plus fréquent (93,55%) dont 79% au stade avancé (Ic-IV) et 21% au stade précoce (Ia-Ib). La chimiothérapie adjuvante était administrée chez 22,60% des patientes. Avec un recul médian de 42 mois, 29 patientes étaient perdues de vue. L’évolution était favorable dans 27,42% et dans 25,81% les décès se sont survenus en postopératoire tardif. Le cancer de l'ovaire n’était pas fréquent mais grave compte tenu des stades avancés et du taux élevé des décès postopératoires tardifs qui étaient largement observés chez les patientes privées d'une chimiothérapie adéquate. PMID:26113942

  12. L’érysipèle sur cicatrice post opératoire en traumatologie: à propos d'un cas et revue de la littérature

    PubMed Central

    Abid, Hatim; El Idrissi, Mohamed; Shimi, Mohamed; El Ibrahimi, Abdelhalim; El Mrini, Abdelmajid; Amraoui, Nissrine; Mernissi, Fatima Zohra

    2015-01-01

    L’érysipèle sur cicatrice post opératoire est une entité rare, décrite principalement chez des patients présentant les facteurs de risque classiques de la maladie au niveau des sites de veinectomie pour pontage coronarien. En traumatologie orthopédie, nous n'avons que les 3 cas rapportés dans le travail de Dhrif survenus au décours d'une implantation prothétique chez des malades à risque. Nous présentons à travers cet article, le cas d'un érysipèle post opératoire sur une cicatrice d'ostéosynthèse d'une fracture fermée du pilon tibial, ayant la particularité du terrain et des circonstances de survenues, pour enfin conclure aux principes de la prévention primaire à adopter. PMID:26401204

  13. Effets potentiels d’un modèle rationnel de prescription sur les dépenses nationales en santé

    PubMed Central

    Littman, Jordan; Halil, Roland

    2016-01-01

    Résumé Objectif Estimer les économies que pourrait engendrer la mise en œuvre d’un modèle rationnel de prescription pour des classes de médicaments équivalents sur les plans de l’efficacité, de la toxicité et de la commodité. Conception L’Institut canadien d’information sur la santé a fourni des renseignements sur les 10 principales classes de médicaments en fonction des dépenses annuelles qui leur sont attribuables. Ces classes ont été examinées en vue de leur inclusion potentielle dans l’étude selon qu’il était possible de comparer les médicaments à l’intérieur d’une même classe. Lorsqu’à la suite d’une recherche documentaire, une équivalence a été établie en fonction de l’efficacité, de la toxicité et de la commodité des médicaments, les données annuelles sur les prescriptions ont été recueillies à partir de la base de données du Système national d’information sur l’utilisation des médicaments prescrits. Les économies potentielles de coûts ont ensuite été calculées en comparant les parts de marché actuelles avec les parts potentielles futures de ce marché. Contexte Le Canada. Principaux paramètres à l’étude Les différences estimées dans les dépenses que produirait un modèle rationnel de prescription. Résultats Une équivalence a été établie sur les plans de l’efficacité, de la toxicité et de la commodité dans les classes de statines, d’inhibiteurs de la pompe à protons, d’inhibiteurs de l’enzyme de conversion de l’angiotensine et d’inhibiteurs sélectifs du recaptage de l’angiotensine. Les dépenses annuelles totales dans ces classes se situent à 856 millions $ dans les programmes publics de médicaments et à 1,97 milliard $ environ à l’échelle nationale. Grâce à des prescriptions rationnelles, on estime que les économies annuelles pourraient atteindre 222 millions $ pour les programmes publics et 521 millions $ à l’échelle nationale. Conclusion La

  14. Influence du traitement ionisant par rayonnement γ sur le pouvoir antioxydant de fractions polyphénoliques issues de substances d'origine végétale

    NASA Astrophysics Data System (ADS)

    Stuyck, S.; Connaulte, J.; Lesgards, G.; Prost, M.; Raffi, J.

    1998-04-01

    Ionizing radiation of vegetables is a cleaning up and preservation physical treatment which consists in submitting them to γ radiation, X radiation or electrons beam. This study deals with the influence of γ radiation on antioxidative effect of vegetables polyphenolic parts. In that purpose, we use a simple biological test based on erythrocytes haemolysis. Le traitement ionisant des produits végétaux est un procédé physique d'assainissement et de conservation qui consiste à les soumettre à l'action de rayonnements γ, de rayons X ou de faisceaux d'électrons. Ce travail porte sur l'étude de l'influence des rayonnements γ sur le pouvoir antioxydant de fractions polyphénoliques issues de substances d'origine végétale. Pour cela, un test biologique basé sur l'hémolyse d'érythrocytes est utilisé.

  15. Effets de la taille finie du milieu non-linéaire sur le bruit quantique spatial généré par un oscillateur paramétrique optique confocal

    NASA Astrophysics Data System (ADS)

    Lopez, L.; Gatti, A.; Maitre, A.; Treps, N.; Gigan, S.; Fabre, C.

    2004-11-01

    Nous nous intéressons au comportement spatial des fluctuations quantiques à la sortie d'un oscillateur paramétrique optique dégénéré en modes transverses, sous le seuil. En vue de futures expériences, nous étudions les effets de la diffraction dans le milieu paramétrique sur le bruit quantique spatial. Nous montrons que l'on voit apparaître une aire de cohérence de taille finie pour les effets quantiques transverses.

  16. NATO Guide for Judgment-Based Operational Analysis in Defence Decision Making (Guide OTAN pour l’analyse operationnelle basee sur le jugement dans la prise de decision de defense). Client-Oriented Volume

    DTIC Science & Technology

    2012-06-01

    Mitigation by Analytical Approach Formal Mitigation Identification of Issues Exploratory front-end (scoping) analysis for problem definition in the...RESEARCH AND TECHNOLOGY ORGANISATION RTO PUBLICATION SAS-087 NATO Guide for Judgement- Based Operational Analysis in Defence Decision...NATO Guide for Judgement- Based Operational Analysis in Defence Decision Making (Guide OTAN pour l’analyse opérationnelle basée sur le

  17. Impact du traitement antirétroviral sur le profil biologique des enfants VIH positifs suivis au Centre Hospitalier et Universitaire de Yaoundé au Cameroun

    PubMed Central

    Kalla, Ginette Claude Mireille; Assoumou, Marie-Claire Okomo; Kamgaing, Nelly; Monebenimp, Francisca; Mbopi-Keou, Francois-Xavier

    2015-01-01

    Introduction L'objectif de ce travail était d’évaluer l'impact du traitement antirétroviral sur le profil biologique des enfants VIH positifs suivis au Centre Hospitalier et Universitaire de Yaoundé au Cameroun. Méthodes Il s'agissait d'une étude rétrospective réalisée de Mai 2003 à Décembre 2012 au CHU de Yaoundé au Cameroun. Pour cette étude, nous avons obtenu une clairance éthique. Résultats L’âge moyen était de 54.02±46.34 mois. The sexe ratio était de 0.96 en faveur des garçons. Le diagnostic s’était fait tardivement (74.2%) ainsi que la mise sous traitement (83.3%). Seuls 36 des 116 enfants (31%) avait pu avoir un bilan biologique à l'initiation du traitement antirétroviral et six mois après l'initiation du traitement antirétroviral. Après six mois de traitement, nous avons enregistrés une augmentation significative des paramètres biologiques suivants: taux de glycémie de 0.09g/L (0.75-0.84; p= 0.007), pourcentage de CD4 chez les enfants de moins de 5 ans de 4.62% (20.12-24.75; p = 0.022), valeur absolue de CD4 chez les enfants de plus de 5 ans de 294 cellules/mm3 (151.18-445.18; p = 0.011), le rapport CD4/CD8 de 0.35 (0.55-0.90; p = 0.000). Enfin, après six mois de traitement, on enregistrait une baisse significative de la charge virale du VIH de 3.90 log (5.85-1.95; p = 0.006). Conclusion Il ressort de cette étude que la restauration immunitaire et la suppression virologique peuvent être obtenus après six mois de traitement antirétroviral. Cependant, des efforts doivent encore être faits en ce qui concerne la prise en charge du suivi biologique, gage d'un bon suivi thérapeutique au Cameroun. PMID:26113902

  18. CONCLUSIONS ET RECOMMANDATIONS À L’ISSUE DE LA CONSULTATION DE L’OMS SUR LA LUTTE CONTRE LA CARENCE MARTIALE CHEZ LE NOURRISSON ET LE JEUNE ENFANT DANS LES PAYS D’ENDÉMIE PALUSTRE

    PubMed Central

    Allen, L.; Black, R.E.; Brandes, N.; Brittenham, G.; Chazot, G.; Chunming, C.; Crawley, J.; de Benoist, B.; Dalmiya, N.; Darnton-Hill, I.; Dewey, K.; El-Arifeen, S.; Fontaine, O.; Geissler, C.; Haberle, H.; Harvey, P.; Hasler, J.; Hershko, C.; Hurrell, R.; Juma, M.A.; Lönnerdal, B.; Lozoff, B.; Lynch, S.; Salgado, H. Martines; McLean, E.; Metz, J.; Oppenheimer, S.; Premji, Z.; Prentice, A.; Ramsan, M.; Ratledge, C.; Stoltzfus, R.; Tielsch, J.; Winachagoon, P.

    2011-01-01

    Cet article présentent les résultats d'une Consultation d'Experts dont l'objectif était d'évaluer l'efficacité et l'innocuité des suppléments de fer administrés aux nourrissons et aux jeunes enfants dans les zones d’endémie palustre, ainsi que les conséquences d’une telle mesure pour la santé publique. Les participants à cette Consultation, qui s’est déroulée à Lyon (France) les 12–14 juin 2006, se sont entendus sur plusieurs questions importantes concernant l’administration d’une supplémentation martiale aux nourrissons et aux jeunes enfants dans les zones d’endémie palustre. Les conclusions du présent rapport s’appliquent plus particulièrement aux pays où le paludisme est endémique. PMID:18630054

  19. CONVERSION OF PLUTONIUM TRIFLUORIDE TO PLUTONIUM TETRAFLUORIDE

    DOEpatents

    Fried, S.; Davidson, N.R.

    1957-09-10

    A large proportion of the trifluoride of plutonium can be converted, in the absence of hydrogen fluoride, to the tetrafiuoride of plutonium. This is done by heating plutonium trifluoride with oxygen at temperatures between 250 and 900 deg C. The trifiuoride of plutonium reacts with oxygen to form plutonium tetrafluoride and plutonium oxide, in a ratio of about 3 to 1. In the presence of moisture, plutonium tetrafluoride tends to hydrolyze at elevated temperatures and therefore it is desirable to have the process take place under anhydrous conditions.

  20. Mise à jour sur la prévention et le dépistage selon l’âge à l’intention des médecins de soins primaires canadiens

    PubMed Central

    Shimizu, Tawnya; Bouchard, Manon; Mavriplis, Cleo

    2016-01-01

    Résumé Objectif Faire la synthèse des meilleures lignes directrices fondées sur des données probantes concernant la prévention et le dépistage chez les adultes canadiens selon l’âge. Qualité des données Les recommandations du Groupe d’étude canadien sur les soins de santé préventifs représentent la source principale des renseignements et sont complétées par les recommandations pertinentes du Preventive Services Task Force des États-Unis lorsque celles du Groupe d’étude canadien étaient inaccessibles ou désuètes. Les guides de pratique des principales organisations nationales axées spécifiquement sur une maladie ou une spécialité ont aussi fait l’objet d’une révision pour prendre en compte les données factuelles les plus récentes. Message principal Les interventions de dépistage recommandées selon l’âge et le sexe sont présentées dans un tableau de synthèse où est mise en évidence la qualité des données à l’appui de ces recommandations. Un exemple de modèle à suivre dans les dossiers médicaux électroniques ou sur papier est aussi proposé. Conclusion Qu’il s’agisse d’une visite consacrée à la prévention ou d’une occasion saisie autrement de faire du counseling et du dépistage de prévention chez leurs patients, les médecins de soins primaires peuvent se servir de cette synthèse des recommandations fondées sur des données probantes pour maximiser leur efficience et prévenir d’importantes omissions ou des dépistages inutiles.

  1. Radionuclide Basics: Plutonium

    EPA Pesticide Factsheets

    Plutonium (chemical symbol Pu) is a radioactive metal. Plutonium is considered a man-made element. Plutonium-239 is used to make nuclear weapons. Pu-239 and Pu-240 are byproducts of nuclear reactor operations and nuclear bomb explosions.

  2. Plutonium story

    SciTech Connect

    Seaborg, G T

    1981-09-01

    The first nuclear synthesis and identification (i.e., the discovery) of the synthetic transuranium element plutonium (isotope /sup 238/Pu) and the demonstration of its fissionability with slow neutrons (isotope /sup 239/Pu) took place at the University of California, Berkeley, through the use of the 60-inch and 37-inch cyclotrons, in late 1940 and early 1941. This led to the development of industrial scale methods in secret work centered at the University of Chicago's Metallurgical Laboratory and the application of these methods to industrial scale production, at manufacturing plants in Tennessee and Washington, during the World War II years 1942 to 1945. The chemical properties of plutonium, needed to devise the procedures for its industrial scale production, were studied by tracer and ultramicrochemical methods during this period on an extraordinarily urgent basis. This work, and subsequent investigations on a worldwide basis, have made the properties of plutonium very well known. Its well studied electronic structure and chemical properties give it a very interesting position in the actinide series of inner transition elements.

  3. Plutonium Story

    DOE R&D Accomplishments Database

    Seaborg, G. T.

    1981-09-01

    The first nuclear synthesis and identification (i.e., the discovery) of the synthetic transuranium element plutonium (isotope /sup 238/Pu) and the demonstration of its fissionability with slow neutrons (isotope /sup 239/Pu) took place at the University of California, Berkeley, through the use of the 60-inch and 37-inch cyclotrons, in late 1940 and early 1941. This led to the development of industrial scale methods in secret work centered at the University of Chicago's Metallurgical Laboratory and the application of these methods to industrial scale production, at manufacturing plants in Tennessee and Washington, during the World War II years 1942 to 1945. The chemical properties of plutonium, needed to devise the procedures for its industrial scale production, were studied by tracer and ultramicrochemical methods during this period on an extraordinarily urgent basis. This work, and subsequent investigations on a worldwide basis, have made the properties of plutonium very well known. Its well studied electronic structure and chemical properties give it a very interesting position in the actinide series of inner transition elements.

  4. PLUTONIUM ALLOYS

    DOEpatents

    Chynoweth, W.

    1959-06-16

    The preparation of low-melting-point plutonium alloys is described. In a MgO crucible Pu is placed on top of the lighter alloying metal (Fe, Co, or Ni) and the temperature raised to 1000 or 1200 deg C. Upon cooling, the alloy slug is broke out of the crucible. With 14 at. % Ni the m.p. is 465 deg C; with 9.5 at. % Fe the m.p. is 410 deg C; and with 12.0 at. % Co the m.p. is 405 deg C. (T.R.H.) l6262 l6263 ((((((((Abstract unscannable))))))))

  5. PRODUCTION OF PLUTONIUM METAL

    DOEpatents

    Lyon, W.L.; Moore, R.H.

    1961-01-17

    A process is given for producing plutonium metal by the reduction of plutonium chloride, dissolved in alkali metal chloride plus or minus aluminum chloride, with magnesium or a magnesium-aluminum alloy at between 700 and 800 deg C and separating the plutonium or plutonium-aluminum alloy formed from the salt.

  6. SEPARATION OF PLUTONIUM

    DOEpatents

    Maddock, A.G.; Smith, F.

    1959-08-25

    A method is described for separating plutonium from uranium and fission products by treating a nitrate solution of fission products, uranium, and hexavalent plutonium with a relatively water-insoluble fluoride to adsorb fission products on the fluoride, treating the residual solution with a reducing agent for plutonium to reduce its valence to four and less, treating the reduced plutonium solution with a relatively insoluble fluoride to adsorb the plutonium on the fluoride, removing the solution, and subsequently treating the fluoride with its adsorbed plutonium with a concentrated aqueous solution of at least one of a group consisting of aluminum nitrate, ferric nitrate, and manganous nitrate to remove the plutonium from the fluoride.

  7. STRIPPING PROCESS FOR PLUTONIUM

    DOEpatents

    Kolodney, M.

    1959-10-01

    A method for removing silver, nickel, cadmium, zinc, and indium coatings from plutonium objects while simultaneously rendering the plutonium object passive is described. The coated plutonium object is immersed as the anode in an electrolyte in which the plutonium is passive and the coating metal is not passive, using as a cathode a metal which does not dissolve rapidly in the electrolyte. and passing an electrical current through the electrolyte until the coating metal is removed from the plutonium body.

  8. Influence des macles sur le courant critique de transport selon c et sur la ligne d'irréversibilité dans les plans ab étudiée dans des échantillons monodomaines texturés d'YBaCuO

    NASA Astrophysics Data System (ADS)

    Sanfilippo, S.; Sulpice, A.; Bourgault, D.; Villard, C.; Gautier-Picard, P.; Chaud, X.; Beaugnon, E.; Tournier, R.

    1998-02-01

    Direct transport measurements at 77 K of the critical current density along the c-axis (J_c) and magnetic measurements are performed on the same bulk textured single domain YBaCuO samples with the longest dimension along the c-axis. A strong influence of the Twin Planes (TP) on J_c and on the ab-plane irreversibility line B(T^*) is reported when the field is rotated in the ab-planes perpendicularly to the c-axis. The different unusual behaviors observed for J_c and the B(T^*), depending on the range of temperature and field are explained by the strong influence of these extended correlated defects on the pinning of the flux lines. La densité de courant critique selon l'axe c (J_c) est mesurée à 77 K en transport et par des mesures magnétiques sur les mêmes échantillons texturés monodomaines d'YBaCuO. L'influence des plans de macles (TP) sur J_c et sur la ligne d'irréversibilité B(T^*) est étudiée en faisant tourner le champ dans les plans ab, perpendiculairement à l'axe c. Les résultats montrent que dans ces composés, J_c et B(T^*) sont fortement influencés par le piégeage par les TP. Divers comportements des lignes de flux résultant de l'influence de ces défauts corrélés sont proposés selon les gammes de température et de champ étudiées.

  9. Une étude rétrospective sur l'incidence de l'insuffisance rénale chronique dans le service de Médecine Interne et Néphrologie du Centre Hospitalier Universitaire d'Antananarivo

    PubMed Central

    Ramilitiana, Benja; Ranivoharisoa, Eliane Mikkelsen; Dodo, Mihary; Razafimandimby, Evanirina; Randriamarotia, Willy Franck

    2016-01-01

    L'insuffisance rénale chronique est un problème de santé publique au niveau mondial. Dans les pays développés, cette affection survient essentiellement chez les sujets âgés, mais en Afrique, elle s'installe plutôt chez les sujets jeunes actifs. C'est une affection de lourde prise en charge dans un pays à faible revenu à cause de ses coûts. Notre but est de décrire les aspects épidémiologiques des nouveaux cas d'insuffisance rénale chronique à Madagascar. Il s'agit d'une étude rétrospective descriptive de 3 ans partant du 1er janvier 2007 au 31 décembre 2009 dans le service de Médecine Interne et Néphrologie du Centre Hospitalier Universitaire d'Antananarivo portant sur 239 patients diagnostiqués comme une insuffisance rénale chronique. L'incidence était de 8,51% parmi les patients hospitalisés dans le service. L’âge moyen des patients était de 45,4 ans avec des extrêmes de 16 et 82 ans et un sex-ratio de 1,46. Le principal antécédent était l'hypertension artérielle (59,8%). L'insuffisance rénale chronique était terminale dans 75,31% des cas (n=180). Les causes de l'insuffisance rénale chronique étaient dominées par la glomérulonéphrite chronique (40,1%), la néphroangiosclérose (35,5%). L'hémodialyse était réalisée chez 3 patients (1,26%), aucun patient n’était pas programmé pour une greffe rénale. Le taux de mortalité dans le service était de 28,87%. L'insuffisance rénale chronique est une maladie de pronostic redoutable et handicapante qui affecte les sujets jeunes à Madagascar. Son traitement reste inaccessible dans la majorité des patients. L'accent doit donc être mis principalement sur la prévention notamment une bonne prise en charge précoce des infections, de l'hypertension artérielle et du diabète pour réduire ses impacts négatifs sur la santé communautaire et publique. Le projet de la transplantation rénale - donneur vivant, traitement efficace et moins coûteux par rapport à l

  10. Low risk of nevirapine resistance mutations in the prevention of mother-to-child transmission of HIV-1: Agence Nationale de Recherches sur le SIDA Ditrame Plus, Abidjan, Cote d'Ivoire.

    PubMed

    Chaix, Marie-Laure; Ekouevi, Didier Koumavi; Rouet, Francois; Tonwe-Gold, Besigin; Viho, Ida; Bequet, Laurence; Peytavin, Gilles; Toure, Hassane; Menan, Herve; Leroy, Valeriane; Dabis, Francois; Rouzioux, Christine

    2006-02-15

    The frequency of resistance mutations was estimated in the cohort of Agence Nationale de Recherches sur le SIDA Ditrame Plus, a study that evaluated the combination of short-course zidovudine (ZDV) plus lamivudine (3TC) and single-dose nevirapine (SD-NVP) followed by 3 days of postpartum ZDV plus 3TC for the prevention of mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1). The frequency with which resistance mutations were detected in mothers at week 4 postpartum was 1.14% (95% confidence interval [CI], 0.03%-6.17%) for NVP and 8.33% (95% CI, 3.66%-15.76%) for 3TC. In multivariate analysis, 3TC resistance was associated with a longer duration of ZDV plus 3TC prepartum prophylaxis (P=.009). This regimen, which is feasible in resource-limited settings, prevents most peripartum HIV-1 transmission and minimizes the development of NVP resistance.

  11. METHOD OF SEPARATING PLUTONIUM

    DOEpatents

    Brown, H.S.; Hill, O.F.

    1958-02-01

    Plutonium hexafluoride is a satisfactory fluorinating agent and may be reacted with various materials capable of forming fluorides, such as copper, iron, zinc, etc., with consequent formation of the metal fluoride and reduction of the plutonium to the form of a lower fluoride. In accordance with the present invention, it has been found that the reactivity of plutonium hexafluoride with other fluoridizable materials is so great that the process may be used as a method of separating plutonium from mixures containing plutonium hexafluoride and other vaporized fluorides even though the plutonium is present in but minute quantities. This process may be carried out by treating a mixture of fluoride vapors comprising plutonium hexafluoride and fluoride of uranium to selectively reduce the plutonium hexafluoride and convert it to a less volatile fluoride, and then recovering said less volatile fluoride from the vapor by condensation.

  12. Plutonium Training Opportunities

    SciTech Connect

    Balatsky, Galya Ivanovna; Wolkov, Benjamin

    2015-03-26

    This report was created to examine the current state of plutonium training in the United States and to discover ways in which to ensure that the next generation of plutonium workers are fully qualified.

  13. PREPARATION OF PLUTONIUM TRIFLUORIDE

    DOEpatents

    Burger, L.L.; Roake, W.E.

    1961-07-11

    A process of producing plutonium trifluoride by reacting dry plutonium(IV) oxalate with chlorofluorinated methane or ethane at 400 to 450 deg C and cooling the product in the absence of oxygen is described.

  14. PROCESS FOR PURIFYING PLUTONIUM

    DOEpatents

    Mastick, D.F.; Wigner, E.P.

    1958-05-01

    A method is described of separating plutonium from small amounts of uranium and other contaminants. An acidic aqueous solution of higher valent plutonium and hexavalent uranium is treated with a soluble iodide to obtain the plutonium in the plus three oxidation state while leaving the uranium in the hexavalent state, adding a soluble oxalate such as oxalic acid, and then separating the insoluble plus the plutonium trioxalate from the solution.

  15. Technical Programme 1993 (Le Programme Technique, 1993)

    DTIC Science & Technology

    1992-09-01

    Symposium sur "Les Effets de la Propagation Atmospherique a travers des Obscurcissants Naturels et Artificiels sur le Rayonnement des Ondes Millimetriques...for Small Gas Turbines" Reunion du Panel et Symposium sur "Les Technologies pour les Petites Turbines a Gaz " 4-8 CANADA TIP Panel Meeting/Specialists

  16. PLUTONIUM CLEANING PROCESS

    DOEpatents

    Kolodney, M.

    1959-12-01

    A method is described for rapidly removing iron, nickel, and zinc coatings from plutonium objects while simultaneously rendering the plutonium object passive. The method consists of immersing the coated plutonium object in an aqueous acid solution containing a substantial concentration of nitrate ions, such as fuming nitric acid.

  17. PLUTONIUM-THORIUM ALLOYS

    DOEpatents

    Schonfeld, F.W.

    1959-09-15

    New plutonium-base binary alloys useful as liquid reactor fuel are described. The alloys consist of 50 to 98 at.% thorium with the remainder plutonium. The stated advantages of these alloys over unalloyed plutonium for reactor fuel use are easy fabrication, phase stability, and the accompanying advantuge of providing a means for converting Th/sup 232/ into U/sup 233/.

  18. Connaissances et attitudes des relais communautaires sur les fièvres hémorragiques à virus Lassa et Ebola dans le département de la Donga (Nord Bénin)

    PubMed Central

    Attinsounon, Cossi Angelo; Hounnankan, Cossi Athanase; Dovonou, Comlan Albert; Alassani, Cossi Adébayo; Salifou, Sourakatou

    2017-01-01

    Introduction L’objectif de cette étude était d’évaluer les connaissances et attitudes des relais communautaires vis-à-vis des fièvres hémorragiques à virus Ebola et Lassa et leur implication dans la mise œuvre des activités de prévention de ces maladies. Méthodes Une enquête transversale descriptive a été menée auprès des relais communautaires recrutés par tirage au sort dans 40 villages du département de la Donga. Ces relais faisaient la prise en charge à domicile des maladies respiratoires, diarrhéiques et du paludisme chez les enfants de moins de cinq ans. Un questionnaire anonyme a été administré par interview directe. Les données ont été analysées à l’aide du logiciel Epi-info 3.5.1. Résultats Au total 58 relais communautaires (RC) ont participé à cette enquête sur les 60 attendus. L’âge moyen était de 38,7±10,6 ans avec un sex-ratio de 3,5. Il y avait majoritairement trente cinq cultivateurs (60,3%) et treize revendeuses (22,4%). Quarante huit enquêtés (82,8%) reconnaissaient les deux maladies comme étant graves, mortelles et transmissibles. Les trois principales voies de transmission citées étaient le contact ou la consommation de gibiers (87,9%), le contact direct avec les personnes infectées (74,1%) ou leurs cadavres (46,6%). Les principaux moyens préventifs énumérés étaient en lien avec les voies de transmission. La fièvre (81,0%), les vomissements (81,0%) et la diarrhée (60,3%) venaient en tête des symptômes cités. Seulement vingt-deux RC (37,9%) disposaient de gants mais les utilisaient rarement pour examiner les enfants malades. Quant à la conduite à tenir devant un cas suspect de fièvre hémorragique virale Lassa ou Ebola, quarante-et-un relais communautaires (70,7%) feraient recours aux agents de santé sans toucher au malade, neuf (15,5%) feraient appel à l’ambulance et huit (13,8%) transporteraient le cas sur leur propre moto ou sur un taxi-moto vers le centre de santé le plus proche

  19. Comparaison des effets de la xylazine et de la romifidine administrées en période péri-opératoire sur le réveil de chevaux anesthésiés

    PubMed Central

    Bauquier, Sébastien H.; Kona-Boun, Jean-Jacques

    2011-01-01

    Cette étude prospective compare les effets de la xylazine et de la romifidine sur la qualité du réveil de chevaux anesthésiés. Vingt-huit chevaux sains présentés pour des arthroscopies étaient aléatoirement distribués entre 2 groupes. Le protocole anesthésique intraveineux du groupe xylazine comprenait : butorphanol (0,02 mg/kg) et xylazine (0,5–0,7 mg/kg) en prémédication, diazépam (0,1 mg/kg), kétamine (2,2 mg/kg) et isoflurane comme agents anesthésiques, et xylazine (0,1 mg/kg) comme sédatif au réveil. La xylazine était remplacée par la romifidine 0,05–0,08 mg/kg (prémédication) et 0,01 mg/kg (réveil) dans le groupe romifidine. La qualité du réveil était évaluée à l’aveugle au moyen d’une grille d’évaluation. Le test de la somme des rangs de Wilcoxon (P < 0,05) a été utilisé pour l’analyse statistique. Les notes de la qualité du réveil n’étaient pas statiquement différentes entre les deux groupes. Dans cette étude, la romifidine et la xylazine influençaient de façon similaire la qualité du réveil. PMID:22379199

  20. Le Phénomène Wolf-Rayet au Sein des Etoiles chaudes de Populations I et II: Histoire des Vents stellaires et Impact sur la Structure nébulaire circumstellaire

    NASA Astrophysics Data System (ADS)

    Grosdidier, Yves

    2000-12-01

    Les spectres des étoiles Wolf-Rayet pop. I (WR) présentent de larges raies en émission dues à des vents stellaires chauds en expansion rapide (vitesse terminale de l'ordre de 1000 km/s). Le modèle standard des étoiles WR reproduit qualitativement le profil général et l'intensité des raies observées. Mais la spectroscopie intensive à moyenne résolution de ces étoiles révèle l'existence de variations stochastiques dans les raies (sous-pics mobiles en accélération échelles de temps: environ 10-100 min.). Ces variations ne sont pas comprises dans le cadre du modèle standard et suggèrent une fragmentation intrinsèque des vents. Cette thèse de doctorat présente une étude de la variabilité des raies spectrales en émission des étoiles WR pop. II; la question de l'impact d'un vent WR fragmenté sur le milieu circumstellaire est aussi étudiée: 1) à partir du suivi spectroscopique intensif des raies CIIIl5696 et CIVl5801/12, nous analysons quantitativement (via le calcul des Spectres de Variance Temporelle) les vents issus de 5 étoiles centrales de nébuleuses planétaires (NP) galactiques présentant le phénomène WR; 2) nous étudions l'impact de la fragmentation des vents issus de deux étoiles WR pop. I sur le milieu circumstellaire via: i) l'imagerie IR (NICMOS2/HST) de WR 137, et ii) l'imagerie H-alpha (WFPC2/HST) et l'interférométrie Fabry-Perot H-alpha (SIS-CFHT) de la nébuleuse M 1-67 (étoile centrale: WR 124). Les principaux résultats sont les suivants: VENTS WR POP. II: (1) Nous démontrons la variabilité spectroscopique intrinsèque des vents issus des noyaux de NP HD 826 ([WC 8]), BD +30 3639 ([WC 9]) et LSS 3169 ([WC 9]), observés durant respectivement 22, 15 et 1 nuits, et rapportons des indications de variabilité pour les noyaux [WC 9] HD 167362 et He 2-142. Les variabilités de HD 826 et BD +30 3639 apparaissent parfois plus soutenues (``bursts'' qui se maintiennent durant plusieurs nuits); (2) La cinématique des sous

  1. Les torsions sur testicules cryptorchides

    PubMed Central

    Gharbi, Mohamed; Amri, Najmeddine; Chambeh, Wahib; Braiek, Salem; Kamel, Rafik El

    2010-01-01

    Résumé But : La cryptorchidie est une pathologie assez fréquente en urologie. Elle est associée à un risque élevé d’infertilité et de dégénérescence. Elle semble aussi être associée à un risque important de torsion. Cette entité est très peu abordée dans la littérature. Nous rapportons tous les cas de torsion sur testicule cryptorchide observés à notre service dans le but de mieux caractériser cette pathologie et de réduire ainsi le taux d’orchidectomies. Méthodologie : Il s’agit d’une étude rétrospective portant sur tous les cas de torsion sur testicule cryptorchide opérés dans notre service d’urologie entre 1999 et 2007. Les patients ont fait l’objet d’une description basée sur le résumé de leurs observations. Résultats : Les patients étaient âgés de 7 mois à 39 ans. La torsion touchait le testicule droit dans 53 % des cas. Le tableau clinique comportait une douleur au niveau de la région inguinale d’apparition soudaine avec une masse sous-cutanée inflammatoire et douloureuse à ce niveau et surtout un hémiscrotum homolatéral vide. Dans 60 % des cas, le diagnostic était tardif et une orchidectomie a été réalisée. Dans les autre cas, un abaissement du testicule a été réalisé avec orchidopexie controlatéral dans le même temps opératoire. Conclusion : Bien qu’il s’agisse d’une pathologie peu courante, la torsion sur testicule cryptorchide doit être étudiée davantage. Le diagnostic précoce permettra de sauver et d’abaisser le testicule et faciliter ainsi le dépistage d’une éventuelle dégénérescence. PMID:21191497

  2. Effet paradoxal du type d’excision sur la prise et le délai de cicatrisation des greffes expansées pour le traitement des brûlures aiguës: a propos de 1129 cas

    PubMed Central

    Guibert, M.; Chaouat, M.; Boccara, D.; Marco, O.; Lavocat, R.; Alameri, O.; Deslandes, E.; Montlahuc, C.; Mimoun, M.

    2016-01-01

    Summary La greffe de peau mince expansée est très employée dans le traitement des brûlures aiguës. Nous avons étudié l’influence de la préparation du sous-sol sur le taux de prise et le délai de cicatrisation des greffes expansées. Nous avons analysé rétrospectivement les 1 129 greffes expansées réalisées dans notre service entre 1995 et 2005 pour le traitement des brûlures aiguës. Leur taux de prise a été significativement meilleur après une préparation du sous-sol par avulsion (82%) par rapport à une préparation du sous-sol par excision tangentielle (75%). Ce taux était meilleur lorsque l’avulsion était pratiquée dans les 7 jours suivant la brûlure (83% vs 73%). Pour une prise en charge entre 7 et 21 jours, ce taux a semblé être meilleur après excision tangentielle, mais de façon non significative. La durée d’évolution jusqu’à cicatrisation était significativement raccourcie pour une préparation du sous-sol par excision tangentielle par rapport à une préparation du sous-sol par avulsion. Ces résultats montrent, paradoxalement, qu’une préparation du sous-sol par avulsion favorise la prise des greffes expansées mais rallonge leur délai de cicatrisation au contraire de l’excision tangentielle. PMID:28149235

  3. METHOD OF SEPARATING PLUTONIUM

    DOEpatents

    Heal, H.G.

    1960-02-16

    BS>A method of separating plutonium from aqueous nitrate solutions of plutonium, uranium. and high beta activity fission products is given. The pH of the aqueous solution is adjusted between 3.0 to 6.0 with ammonium acetate, ferric nitrate is added, and the solution is heated to 80 to 100 deg C to selectively form a basic ferric plutonium-carrying precipitate.

  4. PREPARATION OF PLUTONIUM HALIDES

    DOEpatents

    Davidson, N.R.; Katz, J.J.

    1958-11-01

    A process ls presented for the preparation of plutonium trihalides. Plutonium oxide or a compound which may be readily converted to plutonlum oxide, for example, a plutonium hydroxide or plutonlum oxalate is contacted with a suitable halogenating agent. Speciflc agents mentioned are carbon tetrachloride, carbon tetrabromide, sulfur dioxide, and phosphorus pentachloride. The reaction is carried out under superatmospberic pressure at about 300 icient laborato C.

  5. PLUTONIUM-ZIRCONIUM ALLOYS

    DOEpatents

    Schonfeld, F.W.; Waber, J.T.

    1960-08-30

    A series of nuclear reactor fuel alloys consisting of from about 5 to about 50 at.% zirconium (or higher zirconium alloys such as Zircaloy), balance plutonium, and having the structural composition of a plutonium are described. Zirconium is a satisfactory diluent because it alloys readily with plutonium and has desirable nuclear properties. Additional advantages are corrosion resistance, excellent fabrication propenties, an isotropie structure, and initial softness.

  6. PREPARATION OF PLUTONIUM

    DOEpatents

    Kolodney, M.

    1959-07-01

    Methods are presented for the electro-deposition of plutonium from fused mixtures of plutonium halides and halides of the alkali metals and alkaline earth metals. Th salts, preferably chlorides and with the plutonium prefer ably in the trivalent state, are placed in a refractory crucible such as tantalum or molybdenam and heated in a non-oxidizing atmosphere to 600 to 850 deg C, the higher temperatatures being used to obtain massive plutonium and the lower for the powder form. Electrodes of graphite or non reactive refractory metals are used, the crucible serving the cathode in one apparatus described in the patent.

  7. Continuous plutonium dissolution apparatus

    DOEpatents

    Meyer, F.G.; Tesitor, C.N.

    1974-02-26

    This invention is concerned with continuous dissolution of metals such as plutonium. A high normality acid mixture is fed into a boiler vessel, vaporized, and subsequently condensed as a low normality acid mixture. The mixture is then conveyed to a dissolution vessel and contacted with the plutonium metal to dissolve the plutonium in the dissolution vessel, reacting therewith forming plutonium nitrate. The reaction products are then conveyed to the mixing vessel and maintained soluble by the high normality acid, with separation and removal of the desired constituent. (Official Gazette)

  8. North Korean plutonium production

    SciTech Connect

    Albright, D.

    1994-12-01

    In 1992, as part of its obligations under the Nuclear Non-Proliferation Treaty, North Korea declared that it had earlier separated about 100 grams of plutonium from damaged fuel rods removed from a 25 megawatt-thermal (MW{sub t}) gas-graphite reactor at Yongbyon. The plutonium was separated at the nearby {open_quotes}Radiochemical Laboratory.{close_quotes} Separated plutonium is the raw ingredient for making nuclear weapons, but 100 grams is too little to make a crude bomb. Based on intelligence reports and IAEA inspections, North Korea may have separated enough plutonium for a nuclear weapon. Regardless of whether this is true, there is no doubt that North Korea has enough weapons-grade plutonium in spent fuel to make four or five nuclear weapons. But it cannot turn this plutonium into nuclear weapons unless it separates the plutonium from the spent fuel. Preventing the North from separating any more plutonium must remain a global priority. The IAEA must also be able to verify North Korea`s past nuclear activities and determine the amount of plutonium North Korea may have diverted in the past.

  9. Quand le malheur frappe les bénéficiaires de la sécurité du revenu. Sur qui peuvent-ils s’appuyer ?

    PubMed Central

    Tousignant, Michel; Caron, Jean

    2013-01-01

    Cette étude analyse les conditions de réalisation du soutien social dans les quartiers de Saint-Henri et de la Pointe Saint-Charles, en comparant un groupe de 61 prestataires de la sécurité du revenu avec un échantillon de 21 personnes de la population vivant au-dessus du seuil de la pauvreté, et en fonction du degré de détresse dans chaque groupe. Elle vise également à décrire comment une adversité vécue par les prestataires avec ou sans détresse vient briser ou modifier le réseau de soutien. Les résultats indiquent que le réseau social est moins fiable en présence de détresse qu’en son absence, que les personnes en détresse se sont vues plus fréquemment refuser du soutien ou être abandonnées et qu’elles ont davantage de personnes nuisibles dans leur entourage. De plus, les événements vécus comportent souvent une atteinte à leur réputation, des menaces, des trahisons et des refus à un droit légitime. Les personnes en détresse sont aussi davantage isolées. PMID:16505926

  10. Sur le système Uo 2-CeO 2; étude cristallographique à haute température

    NASA Astrophysics Data System (ADS)

    Lorenzelli, R.; Touzelin, B.

    1980-12-01

    L'étude du système UO 2-CeO 2, par rayons X à haute température, et en atmosphère contrôlée a permis de tracer le diagramme ternaire U-Ce-O entre l'ambiante et 1000°C. La réduction des oxydes conduit pour Ce/U + Ce >/ 20 at%, à la coexistence de deux phases cfc à la température ambiante. La température de disparition de ce domaine biphasé croît avec le rapport Ce/U + Ce. Pour 70% at de Ce, elle a lieu à T= 260°C. L'existence d'un large domaine monophasé au-dessus de cette température permet d'envisager la structure de défauts dans ce système (essentiellement des lacunes d'oxygène). La limite expérimentale de réduction qui tend vers la composition O/Ce = 1.714 est très inférieure à celle observée par Markin et al. [2]. Pour les teneurs en Ce/U + Ce > 0.50, l'existence d'une phase type M 2O 3 est observée en équilibre avec la phase type MO 2-x.

  11. L'influence d'un stage d'enseignement dans un musee de sciences naturelles sur le sentiment d'autoefficacite en sciences de futurs enseignants

    NASA Astrophysics Data System (ADS)

    Deblois, Annick

    Cette etude qualitative multicas est ancree dans l'approche sociale-cognitive de la theorie de l'autoefficacite de Bandura (1977). Elle s'interesse a quatre stages a l'enseignement qui se sont deroules au Musee canadien de la nature a Ottawa, Canada, en 2009. L'utilisation de donnees secondaires issues du questionnaire STEBI-B traduit et modifie (Dionne et Couture, 2010) ainsi que des entrevues semi-dirigees ont permis une analyse du changement du sentiment d'autoefficacite en sciences chez les stagiaires. Les elements les plus interessants de cette recherche sont l'apprentissage vicariant et la possibilite de repetition qui favorise une meilleure connaissance de soi et une pratique reflexive. Les resultats, dans l'ensemble positifs, illustrent bien le potentiel d'un tel stage afin de rehausser le sentiment d'autoefficacite en sciences chez des stagiaires en enseignement, particulierement chez ceux qui se destinent a enseigner a l'elementaire puisque ceux-ci ont souvent une formation academique dans un domaine autre que les sciences.

  12. NATO Guide for Judgement-Based Operational Analysis in Defence Decision Making (Guide OTAN pour l’analyse operationnelle basee sur le jugement dans la prise de decision de defense). Analyst-Oriented Volume: Code of Best Practice for Soft Operational Analysis

    DTIC Science & Technology

    2012-06-01

    Strategic Assumptions Surfacing and Testing (SAST) B-5 B.11 SWOT (Strengths, Weaknesses, Opportunities, Threats) Analysis B-6 B.12 PESTLEM Analysis ...method is particularly useful in developing plans from a high-level strategy. B.11 SWOT (STRENGTHS, WEAKNESSES, OPPORTUNITIES, THREATS) ANALYSIS ...SAS-087 NATO Guide for Judgement-Based Operational Analysis in Defence Decision Making (Guide OTAN pour l’analyse opérationnelle basée sur le

  13. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2002-12-01

    XMM à la recherche de la matière exotique; Ancienne étoile; Le Trou noir volant; Magnétar; Stardust et Annefrank; Le centre de la galaxie; Deux trous noirs dans la même galaxie; Eruption géante sur Io; Le Soleil;

  14. Prévision de l'effet hygrothermique sur le comportement mécanique d'un composite stratifié équilibré carbone HR/époxyde

    NASA Astrophysics Data System (ADS)

    Mili, F.; Lekrine, A.; Necib, B.; Bradai, C.

    2005-05-01

    La prévision de l'effet de l'environnement, humidité et température, sur le comportement mécanique des structures en matériaux composites constitue l'axe principal de cette étude. Nous nous intéressons à la résistance ultime en traction du matériau composite à renforcement unidirectionnel carbone HR/époxyde travaillant dans des milieux hygrothermiques différents. Ce problème fait donc apparaître des déformations d'échelle macroscopique liées au changement de la séquence d'empilement du stratifié et la variation du degré d'anisotropie du matériau. L'utilisation de critères de résistance permet de prévoir la rupture du pli composant le moins résistant, de déterminer les différents modes de rupture et zones d'endommagement des stratifiés équilibrés [ +θ/-θ]4S et de caractériser le tenseur de déformation des plaques [ +45/-45]4S, [0/90]4S et [0/+45]4S. Les résultats ainsi obtenus montrent que la variation de la température d'utilisation et de l'humidité relative en fonction de l'orientation des fibres confère au matériau des caractéristiques mécaniques spéciales. De plus, ils fournissent des ressources objectives aux calculs visant à optimiser les performances de la structure sollicitée grâce à une connaissance de l'évolution des paramètres de résistance et des mécanismes d'endommagement du composite.

  15. DELTA PHASE PLUTONIUM ALLOYS

    DOEpatents

    Cramer, E.M.; Ellinger, F.H.; Land. C.C.

    1960-03-22

    Delta-phase plutonium alloys were developed suitable for use as reactor fuels. The alloys consist of from 1 to 4 at.% zinc and the balance plutonium. The alloys have good neutronic, corrosion, and fabrication characteristics snd possess good dimensional characteristics throughout an operating temperature range from 300 to 490 deg C.

  16. PLUTONIUM-CERIUM ALLOY

    DOEpatents

    Coffinberry, A.S.

    1959-01-01

    An alloy is presented for use as a reactor fuel. The binary alloy consists essentially of from about 5 to 90 atomic per cent cerium and the balance being plutonium. A complete phase diagram for the cerium--plutonium system is given.

  17. ELECTRODEPOSITION OF PLUTONIUM

    DOEpatents

    Wolter, F.J.

    1957-09-10

    A process of electrolytically recovering plutonium from dilute aqueous solutions containing plutonium ions comprises electrolyzing the solution at a current density of about 0.44 ampere per square centimeter in the presence of an acetate-sulfate buffer while maintaining the pH of the solution at substantially 5 and using a stirred mercury cathode.

  18. 31. VIEW OF A WORKER HOLDING A PLUTONIUM 'BUTTON.' PLUTONIUM, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. VIEW OF A WORKER HOLDING A PLUTONIUM 'BUTTON.' PLUTONIUM, A MAN-MADE SUBSTANCE, WAS RARE. SCRAPS RESULTING FROM PRODUCTION AND PLUTONIUM RECOVERED FROM RETIRED NUCLEAR WEAPONS WERE REPROCESSED INTO VALUABLE PURE-PLUTONIUM METAL (9/19/73). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO

  19. PLUTONIUM-CERIUM-COBALT AND PLUTONIUM-CERIUM-NICKEL ALLOYS

    DOEpatents

    Coffinberry, A.S.

    1959-08-25

    >New plutonium-base teroary alloys useful as liquid reactor fuels are described. The alloys consist of 10 to 20 atomic percent cobalt with the remainder plutonium and cerium in any desired proportion, with the plutonium not in excess of 88 atomic percent; or, of from 10 to 25 atomic percent nickel (or mixture of nickel and cobalt) with the remainder plutonium and cerium in any desired proportion, with the plutonium not in excess of 86 atomic percent. The stated advantages of these alloys over unalloyed plutonium for reactor fuel use are a lower melting point and a wide range of permissible plutonium dilution.

  20. Plutonium storage criteria

    SciTech Connect

    Chung, D.; Ascanio, X.

    1996-05-01

    The Department of Energy has issued a technical standard for long-term (>50 years) storage and will soon issue a criteria document for interim (<20 years) storage of plutonium materials. The long-term technical standard, {open_quotes}Criteria for Safe Storage of Plutonium Metals and Oxides,{close_quotes} addresses the requirements for storing metals and oxides with greater than 50 wt % plutonium. It calls for a standardized package that meets both off-site transportation requirements, as well as remote handling requirements from future storage facilities. The interim criteria document, {open_quotes}Criteria for Interim Safe Storage of Plutonium-Bearing Solid Materials{close_quotes}, addresses requirements for storing materials with less than 50 wt% plutonium. The interim criteria document assumes the materials will be stored on existing sites, and existing facilities and equipment will be used for repackaging to improve the margin of safety.

  1. Plutonium bioaccumulation in seabirds.

    PubMed

    Strumińska-Parulska, Dagmara I; Skwarzec, Bogdan; Fabisiak, Jacek

    2011-12-01

    The aim of the paper was plutonium (²³⁸Pu and ²³⁹⁺²⁴⁰Pu) determination in seabirds, permanently or temporarily living in northern Poland at the Baltic Sea coast. Together 11 marine birds species were examined: 3 species permanently residing in the southern Baltic, 4 species of wintering birds and 3 species of migrating birds. The obtained results indicated plutonium is non-uniformly distributed in organs and tissues of analyzed seabirds. The highest plutonium content was found in the digestion organs and feathers, the smallest in skin and muscles. The plutonium concentration was lower in analyzed species which feed on fish and much higher in herbivorous species. The main source of plutonium in analyzed marine birds was global atmospheric fallout.

  2. Plutonium Immobilization Canister Loading

    SciTech Connect

    Hamilton, E.L.

    1999-01-26

    This disposition of excess plutonium is determined by the Surplus Plutonium Disposition Environmental Impact Statement (SPD-EIS) being prepared by the Department of Energy. The disposition method (Known as ''can in canister'') combines cans of immobilized plutonium-ceramic disks (pucks) with vitrified high-level waste produced at the SRS Defense Waste Processing Facility (DWPF). This is intended to deter proliferation by making the plutonium unattractive for recovery or theft. The envisioned process remotely installs cans containing plutonium-ceramic pucks into storage magazines. Magazines are then remotely loaded into the DWPF canister through the canister neck with a robotic arm and locked into a storage rack inside the canister, which holds seven magazines. Finally, the canister is processed through DWPF and filled with high-level waste glass, thereby surrounding the product cans. This paper covers magazine and rack development and canister loading concepts.

  3. L'effet de la superoxyde dismutase sur le système nerveux central irradié à propos d'études pilotes expérimentales chez le rat

    NASA Astrophysics Data System (ADS)

    Baillet, F.; Lamproglou, I.; Boisserie, G.

    1998-04-01

    It has been observed that bovine superoxide dismutase (SOD) can reduce some chronic complications due to radiotherapy. For this reason this enzyme has been used in the rat to treat radiation induced encaphalitis, studied by the two-way avoidance test. SOD has allowed significant regression of troubles in two studies with chronic encephalitis and two studies with acute encephalitis. Moreover, another study has shown that SOD prevented cognitival troubles brought on by strong painful stimulus. Thus SOD has been shown able to improve cerebral performances after a specific aggression (after radiotherapy) or after a non specific one (after very painful stimulus). This observation leads to interesting prospects for therapy. Il a été constaté que la superoxyde dismutase bovine (SOD) pouvait faire régresser certaines complications chroniques de la radiothérapie. Pour cette raison cette enzyme a été utilisée chez le rat pour traiter des encéphalites radiques étudiées par le test de l'évitement actif bilatéral. La SOD a permis une régression significative des troubles dans deux études d'encéphalite chronique et deux études d'encéphalite aiguë. Par ailleurs une autre étude a montré que la SOD prévenait les troubles cognitifs engendrés par un stimulus douloureux important. Ainsi la SOD s'est révélée capable d'améliorer les performances cérébrales après une agression spécifique (radiothérapie) ou non spécifique (stimulus douloureux important). Cette constatation ouvre des perspectives intéressantes pour la thérapeutique.

  4. Method for dissolving plutonium dioxide

    DOEpatents

    Tallent, Othar K.

    1978-01-01

    The fluoride-catalyzed, non-oxidative dissolution of plutonium dioxide in HNO.sub.3 is significantly enhanced in rate by oxidizing dissolved plutonium ions. It is believed that the oxidation of dissolved plutonium releases fluoride ions from a soluble plutonium-fluoride complex for further catalytic action.

  5. Plutonium Vulnerability Management Plan

    SciTech Connect

    1995-03-01

    This Plutonium Vulnerability Management Plan describes the Department of Energy`s response to the vulnerabilities identified in the Plutonium Working Group Report which are a result of the cessation of nuclear weapons production. The responses contained in this document are only part of an overall, coordinated approach designed to enable the Department to accelerate conversion of all nuclear materials, including plutonium, to forms suitable for safe, interim storage. The overall actions being taken are discussed in detail in the Department`s Implementation Plan in response to the Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 94-1. This is included as Attachment B.

  6. Progress on plutonium stabilization

    SciTech Connect

    Hurt, D.

    1996-05-01

    The Defense Nuclear Facilities Safety Board has safety oversight responsibility for most of the facilities where unstable forms of plutonium are being processed and packaged for interim storage. The Board has issued recommendations on plutonium stabilization and has has a considerable influence on DOE`s stabilization schedules and priorities. The Board has not made any recommendations on long-term plutonium disposition, although it may get more involved in the future if DOE develops plans to use defense nuclear facilities for disposition activities.

  7. PLUTONIUM SEPARATION METHOD

    DOEpatents

    Beaufait, L.J. Jr.; Stevenson, F.R.; Rollefson, G.K.

    1958-11-18

    The recovery of plutonium ions from neutron irradiated uranium can be accomplished by bufferlng an aqueous solutlon of the irradiated materials containing tetravalent plutonium to a pH of 4 to 7, adding sufficient acetate to the solution to complex the uranyl present, adding ferric nitrate to form a colloid of ferric hydroxide, plutonlum, and associated fission products, removing and dissolving the colloid in aqueous nitric acid, oxldizlng the plutonium to the hexavalent state by adding permanganate or dichromate, treating the resultant solution with ferric nitrate to form a colloid of ferric hydroxide and associated fission products, and separating the colloid from the plutonlum left in solution.

  8. PLUTONIUM ELECTROREFINING CELLS

    DOEpatents

    Mullins, L.J. Jr.; Leary, J.A.; Bjorklund, C.W.; Maraman, W.J.

    1963-07-16

    Electrorefining cells for obtaining 99.98% plutonium are described. The cells consist of an impure liquid plutonium anode, a molten PuCl/sub 3/-- alkali or alkaline earth metal chloanode, a molten PuCl/sub 3/-alkali or alkaline earth metal chloride electrolyte, and a nonreactive cathode, all being contained in nonreactive ceramic containers which separate anode from cathode by a short distance and define a gap for the collection of the purified liquid plutonium deposited on the cathode. Important features of these cells are the addition of stirrer blades on the anode lead and a large cathode surface to insure a low current density. (AEC)

  9. Plutonium radiation surrogate

    DOEpatents

    Frank, Michael I [Dublin, CA

    2010-02-02

    A self-contained source of gamma-ray and neutron radiation suitable for use as a radiation surrogate for weapons-grade plutonium is described. The source generates a radiation spectrum similar to that of weapons-grade plutonium at 5% energy resolution between 59 and 2614 keV, but contains no special nuclear material and emits little .alpha.-particle radiation. The weapons-grade plutonium radiation surrogate also emits neutrons having fluxes commensurate with the gamma-radiation intensities employed.

  10. Psychiatric and substance use disorders in HIV/hepatitis C virus (HCV)-coinfected patients: does HCV clearance matter? [Agence Nationale de Recherche sur le SIDA et les Hépatites Virales (ANRS) HEPAVIH CO13 cohort].

    PubMed

    Michel, L; Lions, C; Winnock, M; Lang, J-P; Loko, M-A; Rosenthal, E; Marchou, B; Valantin, M-A; Morlat, P; Roux, P; Sogni, P; Spire, B; Poizot-Martin, I; Lacombe, K; Lascoux-Combe, C; Duvivier, C; Neau, D; Dabis, F; Salmon-Ceron, D; Carrieri, M P

    2016-11-01

    The objective of this nested study was to assess the prevalence of psychiatric disorders in a sample of HIV/hepatitis C virus (HCV)-coinfected patients according to their HCV status. The nested cross-sectional study, untitled HEPAVIH-Psy survey, was performed in a subset of HIV/HCV-coinfected patients enrolled in the French Agence Nationale de Recherche sur le SIDA et les Hépatites Virales (ANRS) CO13 HEPAVIH cohort. Psychiatric disorders were screened for using the Mini International Neuropsychiatric Interview (MINI 5.0.0). Among the 286 patients enrolled in the study, 68 (24%) had never received HCV treatment, 87 (30%) were treatment nonresponders, 44 (15%) were currently being treated and 87 (30%) had a sustained virological response (SVR). Of the 286 patients enrolled, 121 patients (42%) screened positive for a psychiatric disorder other than suicidality and alcohol/drug abuse/dependence, 40 (14%) screened positive for alcohol abuse/dependence, 50 (18%) screened positive for drug abuse/dependence, 50 (17.5%) were receiving an antidepressant treatment and 69 (24%) were receiving an anxiolytic. Patients with an SVR did not significantly differ from the other groups in terms of psychiatric disorders. Patients receiving HCV treatment screened positive less often for an anxiety disorder. The highest rate of drug dependence/abuse was among HCV treatment-naïve patients. Psychiatric disorders were frequent in HIV/HCV-coinfected patients and their rates were comparable between groups, even for patients achieving an SVR. Our results emphasize the need for continuous assessment and care of coinfected patients, even after HCV clearance. Drug addiction remains an obstacle to access to HCV treatment. Despite the recent advent and continued development of directly acting antiviral agents (DAAs), it is still crucial to offer screening and comprehensive care for psychiatric and addictive disorders. © 2016 British HIV Association.

  11. Plutonium dissolution process

    DOEpatents

    Vest, Michael A.; Fink, Samuel D.; Karraker, David G.; Moore, Edwin N.; Holcomb, H. Perry

    1996-01-01

    A two-step process for dissolving plutonium metal, which two steps can be carried out sequentially or simultaneously. Plutonium metal is exposed to a first mixture containing approximately 1.0M-1.67M sulfamic acid and 0.0025M-0.1M fluoride, the mixture having been heated to a temperature between 45.degree. C. and 70.degree. C. The mixture will dissolve a first portion of the plutonium metal but leave a portion of the plutonium in an oxide residue. Then, a mineral acid and additional fluoride are added to dissolve the residue. Alteratively, nitric acid in a concentration between approximately 0.05M and 0.067M is added to the first mixture to dissolve the residue as it is produced. Hydrogen released during the dissolution process is diluted with nitrogen.

  12. Plutonium: Requiem or reprieve

    SciTech Connect

    Pillay, K.K.S.

    1996-01-01

    Many scientific discoveries have had profound effects on humanity and its future. However, the discovery of fissionable characteristics of a man-made element, plutonium, discovered in 1941 by Glenn Seaborg and associates, has probably had the greatest impact on world affairs. Although about 20 new elements have been synthesized since 1940, element 94 unarguably had the most dramatic impact when it was introduced to the world as the core of the nuclear bomb dropped on Nagasaki. Ever since, large quantities of this element have been produced, and it has had a major role in maintaining peace during the past 50 years. in addition, the rapid spread of nuclear power technology worldwide contributed to major growth in the production of plutonium as a by-product. This article discusses the following issues related to plutonium: plutonium from Nuclear Power Generation; environmental safety and health issues; health effects; safeguards issues; extended storage; disposal options.

  13. Effets de l'interaction avec l'oxygène sur le comportement de couches semi-conductrices de ZnO, SnO{2} et CdSe

    NASA Astrophysics Data System (ADS)

    Ain-Souya, A.; Ghers, M.; Haddad, A.; Tebib, W.; Rehamnia, R.; Messsalhi, A.; Bounouala, M.; Djouama, M. C.

    2005-05-01

    Les propriétés superficielles des matériaux solides diffèrent de celles du volume. A la surface, des défauts de différentes natures peuvent être présents. Ils permettent à la surface d'être interactive avec le milieu ambiant. Les multiples interactions entre les états de surface et des éléments du milieu extérieur peuvent modifier les propriétés superficielles. Ce travail étudie la régénération de couches semi-conductrices après adsorption isotherme d'oxygène à différentes températures effectuées entre 20 ° C et 300 ° C. Les matériaux qui ont servi à l'étude sont des couches de ZnO, SnO{2} et CdSe. Celles de CdSe ont été obtenues par co-évaporation, sous vide, de cadmium et de sélénium. Les échantillons de ZnO et SnO{2} ont été élaborés par oxydation, à des températures respectives de 450 ° C et 200 ° , de Zn et Sn déposés par électrolyse et par évaporation sous vide. Les matériaux évaporés ont été déposés sur des plaquettes en verre, les autres ont été électrodéposés sur des substrats métalliques. Les variations des propriétés électriques des couches ont été suivies par mesure de leur résistance électrique superficielle R. Les courbes LogR = f (103 /T (K)), relevées sous vide à différentes températures, sont caractéristiques d'un comportement de semi-conducteur. Des essais d'adsorption d'O{2} à différentes températures montrent des variations considérables de R. En effet, la chimisorption forte d'un gaz par une surface semi-conductrice est telle que l'échange électronique entre adsorbant et adsorbat provoque la formation d'une zone de charge d'espace modifiant la conduction superficielle. Les résultats mettent en évidence des domaines de température de plus haute sensibilité à l'oxygène. Pour le CdSe, certaines désorptions isothermes ont été suffisantes pour une régénération totale des échantillons. Les couches de ZnO ont souvent nécessité des désorptions programm

  14. Target and Clutter Scattering and their Effects on Military Radar Performance: Electromagnetic Wave Propagation Panel Specialists Meeting Held in Ottawa, Canada on 6-9 May 1991 (Diffraction par les Cibles et le Fouillis et ses Effets sur les Performances des Radars Militaires)

    DTIC Science & Technology

    1991-09-01

    source ponctuelle: presentks plus loin. n ~2W 84 = 8 22.5* si x 2.2) FOUILLIS AMBIANT avec x distance de teat antenne/cible, D’un point de vue economique ...l’histogramme et la loi de Rayleigh (biais croissant avec l𔃾cart type). Le coefficient ac ainsi calcul6 correspond aux valeurs calcul~es sur l’image...vectour pseoudo-propre 11 qui lul oat X.pt msooc:i4, un clamsement do cam maxima par oa’dre a donc 6t6 d6tormWn A partir des 0-0) 6tapes croissant set

  15. METHOD OF MAKING PLUTONIUM DIOXIDE

    DOEpatents

    Garner, C.S.

    1959-01-13

    A process is presented For converting both trivalent and tetravalent plutonium oxalate to substantially pure plutonium dioxide. The plutonium oxalate is carefully dried in the temperature range of 130 to300DEC by raising the temperature gnadually throughout this range. The temperature is then raised to 600 C in the period of about 0.3 of an hour and held at this level for about the same length of time to obtain the plutonium dioxide.

  16. METHOD OF PRODUCING PLUTONIUM TETRAFLUORIDE

    DOEpatents

    Tolley, W.B.; Smith, R.C.

    1959-12-15

    A process is presented for preparing plutonium tetrafluoride from plutonium(IV) oxalate. The oxalate is dried and decomposed at about 300 deg C to the dioxide, mixed with ammonium bifluoride, and the mixture is heated to between 50 and 150 deg C whereby ammonium plutonium fluoride is formed. The ammonium plutonium fluoride is then heated to about 300 deg C for volatilization of ammonium fluoride. Both heating steps are preferably carried out in an inert atmosphere.

  17. Plutonium Disposition Now!

    SciTech Connect

    Buckner, M.R.

    1995-05-24

    A means for use of existing processing facilities and reactors for plutonium disposition is described which requires a minimum capital investment and allows rapid implementation. The scenario includes interim storage and processing under IAEA control, and fabrication into MOX fuel in existing or planned facilities in Europe for use in operating reactors in the two home countries. Conceptual studies indicate that existing Westinghouse four-loop designs can safety dispose of 0.94 MT of plutonium per calendar year. Thus, it would be possible to consume the expected US excess stockpile of about 50 MT in two to three units of this type, and it is highly likely that a comparable amount of the FSU excess plutonium could be deposed of in a few VVER-1000`s. The only major capital project for this mode of plutonium disposition would be the weapons-grade plutonium processing which could be done in a dedicated international facility or using existing facilities in the US and FSU under IAEA control. This option offers the potential for quick implementation at a very low cost to the governments of the two countries.

  18. Aqueous Solution Chemistry of Plutonium

    SciTech Connect

    Clark, David L.

    2014-01-28

    Things I have learned working with plutonium: Chemistry of plutonium is complex; Redox equilibria make Pu solution chemistry particularly challenging in the absence of complexing ligands; Understanding this behavior is key to successful Pu chemistry experiments; There is no suitable chemical analog for plutonium.

  19. Impact of HIV-1 genetic diversity on plasma HIV-1 RNA Quantification: usefulness of the Agence Nationale de Recherches sur le SIDA second-generation long terminal repeat-based real-time reverse transcriptase polymerase chain reaction test.

    PubMed

    Rouet, François; Chaix, Marie-Laure; Nerrienet, Eric; Ngo-Giang-Huong, Nicole; Plantier, Jean-Christophe; Burgard, Marianne; Peeters, Martine; Damond, Florence; Ekouevi, Didier Koumavi; Msellati, Philippe; Ferradini, Laurent; Rukobo, Sandra; Maréchal, Valérie; Schvachsa, Nilda; Wakrim, Lahcen; Rafalimanana, Christian; Rakotoambinina, Benjamin; Viard, Jean-Paul; Seigneurin, Jean-Marie; Rouzioux, Christine

    2007-08-01

    The high genetic diversity of HIV-1 has a major impact on the quantification of plasma HIV-1 RNA, representing an increasingly difficult challenge. A total of 898 plasma specimens positive for HIV-1 RNA by commercial assays (Amplicor v1.5; Roche Diagnostic Systems, Alameda, CA or Versant v3.0; Bayer Diagnostics, Emeryville, CA) were tested using the Agence Nationale de Recherches sur le SIDA second-generation (G2) real-time reverse transcriptase polymerase chain reaction (RT-PCR) test: 518 samples containing HIV-1 of known subtype, including 88 from 2 subtype panels and 430 harboring B (n = 266) and non-B (n = 164) group M HIV-1 subtypes from patients followed up in 2002 through 2005 at Necker Hospital (Paris, France), and 380 samples from 10 different countries (Argentina, Cambodia, Cameroon, Central African Republic, France, Ivory Coast, Madagascar, Morocco, Thailand, and Zimbabwe). HIV-1 RNA values obtained by G2 real-time PCR were highly correlated with those obtained by the Amplicor v1.5 for B and non-B subtypes (R = 0.892 and 0.892, respectively) and for samples from diverse countries (R = 0.867 and 0.893 for real-time PCR vs. Amplicor v1.5 and real-time PCR vs. Versant v3.0, respectively). Approximately 30% of specimens harboring non-B subtypes were underquantified by at least -0.51 log10 in Amplicor v1.5 versus 5% underquantified in G2 real-time PCR. Discrepant results were also obtained with subtype B samples (14% underquantified by Amplicor v1.5 vs. 7% by G2 real-time PCR). Similar percentages were observed when comparing results obtained with the G2 real-time PCR assay with those obtained using the Versant assay. Addressing HIV-1 diversity, continual monitoring of HIV-1 RNA assays, together with molecular epidemiology studies, is required to improve the accuracy of all HIV RNA assays.

  20. Role of uncontrolled HIV RNA level and immunodeficiency in the occurrence of malignancy in HIV-infected patients during the combination antiretroviral therapy era: Agence Nationale de Recherche sur le Sida (ANRS) CO3 Aquitaine Cohort.

    PubMed

    Bruyand, Mathias; Thiébaut, Rodolphe; Lawson-Ayayi, Sylvie; Joly, Pierre; Sasco, Annie Jeanne; Mercié, Patrick; Pellegrin, Jean Luc; Neau, Didier; Dabis, François; Morlat, Philippe; Chêne, Geneviève; Bonnet, Fabrice

    2009-10-01

    Human immunodeficiency virus (HIV)-infected patients are at higher risk of malignancies. In addition to traditional determinants, a specific deleterious effect of HIV and immunodeficiency is speculated. We aimed at studying the association between immunological and virological characteristics of HIV-infected patients in care and the risk of acquired immunodeficiency syndrome (AIDS)-defining and non-AIDS-defining malignancies. Patients consecutively enrolled in the hospital-based Agence Nationale de Recherche sur le Sida (ANRS) CO3 Aquitaine Cohort were included if the duration of follow-up was >3 months during the period 1998-2006. Multivariate modeling used an extended Cox proportional hazards model for time-dependent covariates and delayed entry. The 4194 patients included in the study developed 251 first malignancies during 22,389 person-years. A higher incidence of AIDS-defining malignancies (107 cases) was independently associated with (1) both longer and current exposures to a plasma HIV RNA level >500 copies/mL (hazard ratio [HR], 1.27 per year [P<.001] and 3.30 [P<.001], respectively) and (2) both longer and current exposure to a CD4(+) cell count <200 cells/mm(3) (HR, 1.36 per year [P<.001] and 6.33 [P<.001], respectively). A higher incidence of non-AIDS-defining malignancies (144 cases) was independently associated with longer and current exposure to a CD4(+) cell count <500 cells/mm(3) (HR, 1.13 per year [P=.01] and 2.07 [P<.001], respectively) and male sex (HR, 1.69; P=.02) but not with plasma HIV RNA level (P=.49 and P=.10 for cumulative and current exposures, respectively). Uncontrolled plasma HIV RNA level was independently associated with a higher likelihood of developing AIDS-defining malignancies, whereas immunosuppression was associated with a higher risk of developing any type of malignancies. Antiretroviral treatment should aim at reaching and maintaining a CD4(+) count >500 cells/mm(3) to prevent the occurrence of malignancy, this should be

  1. Lithium metal reduction of plutonium oxide to produce plutonium metal

    DOEpatents

    Coops, Melvin S.

    1992-01-01

    A method is described for the chemical reduction of plutonium oxides to plutonium metal by the use of pure lithium metal. Lithium metal is used to reduce plutonium oxide to alpha plutonium metal (alpha-Pu). The lithium oxide by-product is reclaimed by sublimation and converted to the chloride salt, and after electrolysis, is removed as lithium metal. Zinc may be used as a solvent metal to improve thermodynamics of the reduction reaction at lower temperatures. Lithium metal reduction enables plutonium oxide reduction without the production of huge quantities of CaO--CaCl.sub.2 residues normally produced in conventional direct oxide reduction processes.

  2. Plutonium 239 Equivalency Calculations

    SciTech Connect

    Wen, J

    2011-05-31

    This document provides the basis for converting actual weapons grade plutonium mass to a plutonium equivalency (PuE) mass of Plutonium 239. The conversion can be accomplished by performing calculations utilizing either: (1) Isotopic conversions factors (CF{sub isotope}), or (2) 30-year-old weapons grade conversion factor (CF{sub 30 yr}) Both of these methods are provided in this document. Material mass and isotopic data are needed to calculate PuE using the isotopic conversion factors, which will provide the actual PuE value at the time of calculation. PuE is the summation of the isotopic masses times their associated isotopic conversion factors for plutonium 239. Isotopic conversion factors are calculated by a normalized equation, relative to Plutonium 239, of specific activity (SA) and cumulated dose inhalation affects based on 50-yr committed effective dose equivalent (CEDE). The isotopic conversion factors for converting weapons grade plutonium to PuE are provided in Table-1. The unit for specific activity (SA) is curies per gram (Ci/g) and the isotopic SA values come from reference [1]. The cumulated dose inhalation effect values in units of rem/Ci are based on 50-yr committed effective dose equivalent (CEDE). A person irradiated by gamma radiation outside the body will receive a dose only during the period of irradiation. However, following an intake by inhalation, some radionuclides persist in the body and irradiate the various tissues for many years. There are three groups CEDE data representing lengths of time of 0.5 (D), 50 (W) and 500 (Y) days, which are in reference [2]. The CEDE values in the (W) group demonstrates the highest dose equivalent value; therefore they are used for the calculation.

  3. Le bégaiement

    PubMed Central

    Perez, Hector R.; Stoeckle, James H.

    2016-01-01

    Résumé Objectif Fournir une mise à jour sur l’épidémiologie, l’hérédité, la physiopathologie, le diagnostic et le traitement du bégaiement développemental. Qualité des données Une recherche d’études récentes ou non portant sur l’épidémiologie, l’hérédité, la physiopathologie, le diagnostic et le traitement du bégaiement développemental a été effectuée dans les bases de données MEDLINE et Cochrane. La plupart des recommandations s’appuient sur des études de petite envergure, des données probantes de qualité limitée ou des consensus. Message principal Le bégaiement est un trouble d’élocution fréquent chez les personnes de tous âges, il altère la fluidité verbale normale et l’enchaînement du discours. Le bégaiement a été lié à des différences de l’anatomie, du fonctionnement et de la régulation dopaminergique du cerveau qui seraient de source génétique. Il importe de poser le diagnostic avec attention et de faire les recommandations qui conviennent chez les enfants, car de plus en plus, le consensus veut que l’intervention précoce par un traitement d’orthophonie soit cruciale chez les enfants bègues. Chez les adultes, le bégaiement est lié à une morbidité psychosociale substantielle, dont l’anxiété sociale et une piètre qualité de vie. Les traitements pharmacologiques ont soulevé l’intérêt depuis quelques années, mais les données cliniques sont limitées. Le traitement des enfants et des adultes repose sur l’orthophonie. Conclusion De plus en plus de recherches ont tenté de lever le voile sur la physiopathologie du bégaiement. La meilleure solution pour les enfants et les adultes bègues demeure la recommandation à un traitement d’orthophonie.

  4. SULFIDE METHOD PLUTONIUM SEPARATION

    DOEpatents

    Duffield, R.B.

    1958-08-12

    A process is described for the recovery of plutonium from neutron irradiated uranium solutions. Such a solution is first treated with a soluble sullide, causing precipitation of the plutoniunn and uraniunn values present, along with those impurities which form insoluble sulfides. The precipitate is then treated with a solution of carbonate ions, which will dissolve the uranium and plutonium present while the fission product sulfides remain unaffected. After separation from the residue, this solution may then be treated by any of the usual methods, such as formation of a lanthanum fluoride precipitate, to effect separation of plutoniunn from uranium.

  5. Superconductivity in plutonium compounds

    NASA Astrophysics Data System (ADS)

    Sarrao, J. L.; Bauer, E. D.; Mitchell, J. N.; Tobash, P. H.; Thompson, J. D.

    2015-07-01

    Although the family of plutonium-based superconductors is relatively small, consisting of four compounds all of which crystallize in the tetragonal HoCoGa5 structure, these materials serve as an important bridge between the known Ce- and U-based heavy fermion superconductors and the high-temperature cuprate superconductors. Further, the partial localization of 5f electrons that characterizes the novel electronic properties of elemental plutonium appears to be central to the relatively high superconducting transition temperatures that are observed in PuCoGa5, PuRhGa5, PuCoIn5, and PuRhIn5.

  6. Plutonium in Concentrated Solutions

    SciTech Connect

    Clark, Sue B.; Delegard, Calvin H.

    2002-08-01

    Complex, high ionic strength media are used throughout the plutonium cycle, from its processing and purification in nitric acid, to waste storage and processing in alkaline solutions of concentrated electrolytes, to geologic disposal in brines. Plutonium oxidation/reduction, stability, radiolysis, solution and solid phase chemistry have been studied in such systems. In some cases, predictive models for describing Pu chemistry under such non-ideal conditions have been developed, which are usually based on empirical databases describing specific ion interactions. In Chapter 11, Non-Ideal Systems, studies on the behavior of Pu in various complex media and available model descriptions are reviewed.

  7. Management of plutonium contaminated waste

    SciTech Connect

    Grover, J.R.

    1982-01-01

    This study surveys the current management schemes for plutonium contaminated wastes arising from a reference mixed oxide fuel fabrication plant, and identifies possible areas of future research. It also outlines strategies for the future management of plutonium contaminated wastes. Topics of discussion include: the quantities and characteristics of various plutonium contaminated wastes produced by a plant; the current waste management practices for both solid and liquid plutonium contaminated wastes, considering measurement methods, transportation, storage and disposal; current practice for the problems of decommissioning and decontamination, and possible methods for the recovery of plutonium contaminated wastes.

  8. Plutonium Disposition by Immobilization

    SciTech Connect

    Gould, T.; DiSabatino, A.; Mitchell, M.

    2000-03-07

    The ultimate goal of the Department of Energy (DOE) Immobilization Project is to develop, construct, and operate facilities that will immobilize between 17 to 50 tonnes (MT) of U.S. surplus weapons-usable plutonium materials in waste forms that meet the ''spent fuel'' standard and are acceptable for disposal in a geologic repository. Using the ceramic can-in-canister technology selected for immobilization, surplus plutonium materials will be chemically combined into ceramic forms which will be encapsulated within large canisters of high level waste (HLW) glass. Deployment of the immobilization capability should occur by 2008 and be completed within 10 years. In support of this goal, the DOE Office of Fissile Materials Disposition (MD) is conducting development and testing (D&T) activities at four DOE laboratories under the technical leadership of Lawrence Livermore National Laboratory (LLNL). The Savannah River Site has been selected as the site for the planned Plutonium Immobilization Plant (PIP). The D&T effort, now in its third year, will establish the technical bases for the design, construction, and operation of the U. S. capability to immobilize surplus plutonium in a suitable and cost-effective manner. Based on the D&T effort and on the development of a conceptual design of the PIP, automation is expected to play a key role in the design and operation of the Immobilization Plant. Automation and remote handling are needed to achieve required dose reduction and to enhance operational efficiency.

  9. Plutonium: An introduction

    SciTech Connect

    Condit, R.H.

    1993-10-01

    This report is a summary of the history and properties of plutonium. It presents information on the atoms, comparing chemical and nuclear properties. It looks at the history of the atom, including its discovery and production methods. It summarizes the metallurgy and chemistry of the element. It also describes means of detecting and measuring the presence and quantity of the element.

  10. Atomic spectrum of plutonium

    SciTech Connect

    Blaise, J.; Fred, M.; Gutmacher, R.G.

    1984-08-01

    This report contains plutonium wavelengths, energy level classifications, and other spectroscopic data accumulated over the past twenty years at Laboratoire Aime Cotton (LAC) Argonne National Laboratory (ANL), and Lawrence Livermore National Laboratory (LLNL). The primary purpose was term analysis: deriving the energy levels in terms of quantum numbers and electron configurations, and evaluating the Slater-Condon and other parameters from the levels.

  11. Plutonium Finishing Plant. Interim plutonium stabilization engineering study

    SciTech Connect

    Sevigny, G.J.; Gallucci, R.H.; Garrett, S.M.K.; Geeting, J.G.H.; Goheen, R.S.; Molton, P.M.; Templeton, K.J.; Villegas, A.J.; Nass, R.

    1995-08-01

    This report provides the results of an engineering study that evaluated the available technologies for stabilizing the plutonium stored at the Plutonium Finishing Plant located at the hanford Site in southeastern Washington. Further processing of the plutonium may be required to prepare the plutonium for interim (<50 years) storage. Specifically this document provides the current plutonium inventory and characterization, the initial screening process, and the process descriptions and flowsheets of the technologies that passed the initial screening. The conclusions and recommendations also are provided. The information contained in this report will be used to assist in the preparation of the environmental impact statement and to help decision makers determine which is the preferred technology to process the plutonium for interim storage.

  12. 4. VIEW OF PLUTONIUM CANISTER ON CHAINVEYOR. SCRAP PLUTONIUM WAS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF PLUTONIUM CANISTER ON CHAINVEYOR. SCRAP PLUTONIUM WAS COLLECTED INTO CANS AT INDIVIDUAL WORKSTATIONS. THE CANS WERE TRANSFERRED VIA THE CHAIN CONVEYOR TO A WORKSTATION IN MODULE C WHERE THE MATERIAL WAS COMPRESSED INTO BRIQUETTES FOR LATER USE. (6/20/93) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

  13. Mise au point sur le comportement énergétique et cristallographique des n-alcanes. II. Série de C{22}H{46} à C{27}H{56}

    NASA Astrophysics Data System (ADS)

    Roblès, L.; Mondieig, D.; Haget, Y.; Cuevas-Diarte, M. A.

    1998-01-01

    A review on the energetic and crystallographic behaviour of the series of n alkanes from C{22}H{46} to C{27}H{56} is proposed. The polymormism is very rich (characterization of 12 transitions, 10 solid phases). The molecules are always parallel, their end methyl groups forming parallel layers. At low temperature ordered crystalline forms are observed. Their nature depends on the parity of n the number of carbon atoms. In the odd subfamily the molecules are perpendicular or nearly perpendicular to the layer; three different forms have been identified: orthorhombic O, O' and monoclinic M^*. In the even subfamily, the molecules are no more perpendicular to the layer and crystallize either in the triclinic T or monoclinic M lattice. On the contrary, the nature of the phases before melting are not dependent on the parity of n. Theses phases are orientationally disordered. Five rotators phases may be successively encountered RV, RI, RII, RIII, RIV with increasing temperature. None of the n-alkanes shows more than 3 of these rotator phases. Despite the high degree of disorder the crystalline cohesion remains important, the enthalpy of melting being higher than 158 J/g. Une mise au point sur le polymorphisme très riche des n-alcanes CnH2n+2, n allant de 22 à 27 est proposée au travers d'une étude énergétique et cristallographique de chacun des composés (caractérisation de 10 phases solides et de 12 transitions). Dans toutes ces phases, les molécules sont parallèles entre elles et disposées en chevrons, les têtes méthyle forment des couches. À basse température, les alcanes présentent des phases ordonnées dont la nature dépend de la parité du nombre de carbones dans la chaîne. Lorsque n est impair, les molécules sont droites (formes orthorhombiques O et O') ou quasi-droites (forme monoclinique M*). Lorsque n est pair, les molécules sont inclinées (forme triclinique T et forme monoclinique M).Au contraire, la nature des phases précédant la fusion est

  14. Plutonium age dating reloaded

    NASA Astrophysics Data System (ADS)

    Sturm, Monika; Richter, Stephan; Aregbe, Yetunde; Wellum, Roger; Mayer, Klaus; Prohaska, Thomas

    2014-05-01

    Although the age determination of plutonium is and has been a pillar of nuclear forensic investigations for many years, additional research in the field of plutonium age dating is still needed and leads to new insights as the present work shows: Plutonium is commonly dated with the help of the 241Pu/241Am chronometer using gamma spectrometry; in fewer cases the 240Pu/236U chronometer has been used. The age dating results of the 239Pu/235U chronometer and the 238Pu/234U chronometer are scarcely applied in addition to the 240Pu/236U chronometer, although their results can be obtained simultaneously from the same mass spectrometric experiments as the age dating result of latter. The reliability of the result can be tested when the results of different chronometers are compared. The 242Pu/238U chronometer is normally not evaluated at all due to its sensitivity to contamination with natural uranium. This apparent 'weakness' that renders the age dating results of the 242Pu/238U chronometer almost useless for nuclear forensic investigations, however turns out to be an advantage looked at from another perspective: the 242Pu/238U chronometer can be utilized as an indicator for uranium contamination of plutonium samples and even help to identify the nature of this contamination. To illustrate this the age dating results of all four Pu/U clocks mentioned above are discussed for one plutonium sample (NBS 946) that shows no signs of uranium contamination and for three additional plutonium samples. In case the 242Pu/238U chronometer results in an older 'age' than the other Pu/U chronometers, contamination with either a small amount of enriched or with natural or depleted uranium is for example possible. If the age dating result of the 239Pu/235U chronometer is also influenced the nature of the contamination can be identified; enriched uranium is in this latter case a likely cause for the missmatch of the age dating results of the Pu/U chronometers.

  15. Surprising Coordination for Plutonium in the First Plutonium (III) Borate

    SciTech Connect

    Wang, Shuao; Alekseev, Evgeny V.; Depmeier, Wulf; Albrecht-Schmitt, Thomas E.

    2011-02-22

    The first plutonium(III) borate, Pu2[B12O18(OH)4Br2(H2O)3]·0.5H2O, has been prepared by reacting plutonium(III) with molten boric acid under strictly anaerobic conditions. This compound contains a three-dimensional polyborate network with triangular holes that house the plutonium(III) sites. The plutonium sites in this compound are 9- and 10-coordinate and display atypical geometries.

  16. Gamma radiation characteristics of plutonium dioxide fuel

    NASA Technical Reports Server (NTRS)

    Gingo, P. J.

    1969-01-01

    Investigation of plutonium dioxide as an isotopic fuel for Radioisotope Thermoelectric Generators yielded the isotopic composition of production-grade plutonium dioxide fuel, sources of gamma radiation produced by plutonium isotopes, and the gamma flux at the surface.

  17. Plutonium process monitoring (PPM) system

    NASA Astrophysics Data System (ADS)

    Wong, A. S.; Ricketts, T. E.; Pansoy-Hejlvik, M. E.; Ramsey, K. B.; Hansel, K. M.; Romero, M. K.

    2000-07-01

    In mid-1980, Marsh and Pope developed an online gamma system to monitor americium, uranium and plutonium gamma rays during anion-exchange process for plutonium aqueous recovery operations. It has been shown that the real-time elution profiles of actinide impurities are important for plutonium loss via break-through, waste minimization, and process monitoring. However, the current monitoring equipment and data acquisition software are obsolete and are frequently problematic. In 1999, we redesigned the on-line gamma monitoring system in collaboration with Perkin-Elmer ORTEC (Oak Ridge, TN) to enhance and upgrade the current system. This paper describes the new integrated plutonium process monitoring (PPM) system for the aqueous plutonium recovery and anion-exchange processes at the Los Alamos Plutonium Facility.

  18. Plutonium recovery from organic materials

    DOEpatents

    Deaton, R.L.; Silver, G.L.

    1973-12-11

    A method is described for removing plutonium or the like from organic material wherein the organic material is leached with a solution containing a strong reducing agent such as titanium (III) (Ti/sup +3None)/, chromium (II) (Cr/ sup +2/), vanadium (II) (V/sup +2/) ions, or ferrous ethylenediaminetetraacetate (EDTA), the leaching yielding a plutonium-containing solution that is further processed to recover plutonium. The leach solution may also contain citrate or tartrate ion. (Official Gazette)

  19. PROCESS OF PRODUCING SHAPED PLUTONIUM

    DOEpatents

    Anicetti, R.J.

    1959-08-11

    A process is presented for producing and casting high purity plutonium metal in one step from plutonium tetrafluoride. The process comprises heating a mixture of the plutonium tetrafluoride with calcium while the mixture is in contact with and defined as to shape by a material obtained by firing a mixture consisting of calcium oxide and from 2 to 10% by its weight of calcium fluoride at from 1260 to 1370 deg C.

  20. Manufacturing of Plutonium Tensile Specimens

    SciTech Connect

    Knapp, Cameron M

    2012-08-01

    Details workflow conducted to manufacture high density alpha Plutonium tensile specimens to support Los Alamos National Laboratory's science campaigns. Introduces topics including the metallurgical challenge of Plutonium and the use of high performance super-computing to drive design. Addresses the utilization of Abaqus finite element analysis, programmable computer numerical controlled (CNC) machining, as well as glove box ergonomics and safety in order to design a process that will yield high quality Plutonium tensile specimens.

  1. Le ciment brûle toujours

    PubMed Central

    Lebreton, T.; Fontaine, M.; Le Floch, R.

    2017-01-01

    Summary Les brûlures chimiques par ciment représentent une cause fréquente de corrosion cutanée en France. Elles nécessitent fréquemment un traitement chirurgical. Notre étude rétrospective concerne tous les patients admis pour une brûlure par ciment dans le service entre 2004 et 2016. Quarante-neuf patients âgés de 21 à 71 ans ont été pris en charge dans le centre des brûlés du Centre Hospitalier Saint Joseph Saint Luc à Lyon entre 2004 et 2016. La population concernée était majoritairement masculine, relativement jeune (44 ans en moyenne) et professionnellement active. Les brûlures survenaient principalement dans le cadre d’accidents domestiques (78%). Elles étaient profondes et atteignaient majoritairement les membres inférieurs, de façon bilatérale. La surface brûlée représentait 3% de la surface cutanée totale. Presque tous les patients (98%) ont nécessité une prise en charge chirurgicale pour excision et autogreffe de peau mince. Un seul patient a bénéficié d’une cicatrisation dirigée. Le délai moyen entre la brûlure et la chirurgie était de 13 jours et la durée moyenne d’hospitalisation de 8 jours. Sept patients ont nécessité une prise en charge en centre de rééducation à leur sortie du service. Cette étude confirme la sévérité des brûlures chimiques par ciment. Elle met également en avant l’impact que peut avoir ce type de brûlure en terme de retentissement socio-économique dans une population de patients majoritairement jeune et active. Elle insiste sur le fait que des mesures doivent être prises afin d’informer cette population rarement professionnelle sur les risques encourus lors du mésusage du ciment. La réglementation actuelle, classant le ciment comme irritant, ne prend pas en compte son caractère corrosif et devrait être amendée. PMID:28592929

  2. PLUTONIUM-URANIUM ALLOY

    DOEpatents

    Coffinberry, A.S.; Schonfeld, F.W.

    1959-09-01

    Pu-U-Fe and Pu-U-Co alloys suitable for use as fuel elements tn fast breeder reactors are described. The advantages of these alloys are ease of fabrication without microcracks, good corrosion restatance, and good resistance to radiation damage. These advantages are secured by limitation of the zeta phase of plutonium in favor of a tetragonal crystal structure of the U/sub 6/Mn type.

  3. MOLDS FOR CASTING PLUTONIUM

    DOEpatents

    Anderson, J.W.; Miley, F.; Pritchard, W.C.

    1962-02-27

    A coated mold for casting plutonium comprises a mold base portion of a material which remains solid and stable at temperatures as high as the pouring temperature of the metal to be cast and having a thin coating of the order of 0.005 inch thick on the interior thereof. The coating is composed of finely divided calcium fluoride having a particle size of about 149 microns. (AEC)

  4. Welding Plutonium Storage Containers

    SciTech Connect

    HUDLOW, SL

    2004-04-20

    The outer can welder (OCW) in the FB-Line Facility at the Savannah River Site (SRS) is a Gas Tungsten Arc Weld (GTAW) system used to create outer canisters compliant with the Department of Energy 3013 Standard, DOE-STD-3013-2000, Stabilization, Packaging, and Storage of Plutonium-Bearing Materials. The key welding parameters controlled and monitored on the outer can welder Data Acquisition System (DAS) are weld amperage, weld voltage, and weld rotational speed. Inner 3013 canisters from the Bagless Transfer System that contain plutonium metal or plutonium oxide are placed inside an outer 3013 canister. The canister is back-filled with helium and welded using the outer can welder. The completed weld is screened to determine if it is satisfactory by reviewing the OCW DAS key welding parameters, performing a helium leak check, performing a visual examination by a qualified weld inspector, and performing digital radiography of the completed weld. Canisters with unsatisfactory welds are cut open and repackaged. Canisters with satisfactory welds are deemed compliant with the 3013 standard for long-term storage.

  5. Factors Affecting Attraction, Recruitment, and Retention of NATO Military Medical Professionals (Facteurs d’influence sur l’attraction, le recrutement et la fidelisation des professionnels de sante militaires de l’otan)

    DTIC Science & Technology

    2012-12-01

    de la RTO (Organisation OTAN pour la Recherche et la Technologie) a créé un Groupe de travail (HFM-213) concernant les Facteurs d’influence sur...Meeting in Cologne, 15-16 June 2011; • Meeting in Brussels, 19-21 October 2011; and • Final meeting in Prague, 27 February – 1 March 2012. The

  6. Plutonium worker dosimetry.

    PubMed

    Birchall, Alan; Puncher, M; Harrison, J; Riddell, A; Bailey, M R; Khokryakov, V; Romanov, S

    2010-05-01

    Epidemiological studies of the relationship between risk and internal exposure to plutonium are clearly reliant on the dose estimates used. The International Commission on Radiological Protection (ICRP) is currently reviewing the latest scientific information available on biokinetic models and dosimetry, and it is likely that a number of changes to the existing models will be recommended. The effect of certain changes, particularly to the ICRP model of the respiratory tract, has been investigated for inhaled forms of (239)Pu and uncertainties have also been assessed. Notable effects of possible changes to respiratory tract model assumptions are (1) a reduction in the absorbed dose to target cells in the airways, if changes under consideration are made to the slow clearing fraction and (2) a doubling of absorbed dose to the alveolar region for insoluble forms, if evidence of longer retention times is taken into account. An important factor influencing doses for moderately soluble forms of (239)Pu is the extent of binding of dissolved plutonium to lung tissues and assumptions regarding the extent of binding in the airways. Uncertainty analyses have been performed with prior distributions chosen for application in epidemiological studies. The resulting distributions for dose per unit intake were lognormal with geometric standard deviations of 2.3 and 2.6 for nitrates and oxides, respectively. The wide ranges were due largely to consideration of results for a range of experimental data for the solubility of different forms of nitrate and oxides. The medians of these distributions were a factor of three times higher than calculated using current default ICRP parameter values. For nitrates, this was due to the assumption of a bound fraction, and for oxides due mainly to the assumption of slower alveolar clearance. This study highlights areas where more research is needed to reduce biokinetic uncertainties, including more accurate determination of particle transport rates

  7. METHOD FOR OBTAINING PLUTONIUM METAL AND ALLOYS OF PLUTONIUM FROM PLUTONIUM TRICHLORIDE

    DOEpatents

    Reavis, J.G.; Leary, J.A.; Maraman, W.J.

    1962-11-13

    A process is given for both reducing plutonium trichloride to plutonium metal using cerium as the reductant and simultaneously alloying such plutonium metal with an excess of cerium or cerium and cobalt sufficient to yield the desired nuclear reactor fuel composition. The process is conducted at a temperature from about 550 to 775 deg C, at atmospheric pressure, without the use of booster reactants, and a substantial decontamination is effected in the product alloy of any rare earths which may be associated with the source of the plutonium. (AEC)

  8. Etude des effets du martelage repetitif sur les contraintes residuelles

    NASA Astrophysics Data System (ADS)

    Hacini, Lyes

    L'assemblage par soudage peut engendrer des contraintes residuelles. Ces contraintes provoquent des fissurations prematurees et un raccourcissement de la duree de vie des composants. Dans ce contexte, le martelage robotise est utilise pour relaxer ces contraintes residuelles. Trois volets sont presentes: le premier est l'evaluation des effets des impacts unitaires repetes sur le champ de contraintes developpe dans des plaques d'acier inoxydable austenitique 304L vierges ou contenant des contraintes residuelles initiales. Dans la deuxieme partie de ce projet, le martelage est applique grace au robot SCOMPI. Les contraintes residuelles induites et relaxees par martelage sont ensuite mesurees par la methode des contours, qui a ete adaptee a cet effet. Dans la troisieme partie, le martelage est modelise par la methode des elements finis. Un modele axisymetrique developpe grace au logiciel ANSYS permet de simuler des impacts repetes d'un marteau elastique sur une plaque ayant un comportement elastoplastique.

  9. PREPARATION OF HALIDES OF PLUTONIUM

    DOEpatents

    Garner, C.S.; Johns, I.B.

    1958-09-01

    A dry chemical method is described for preparing plutonium halides, which consists in contacting plutonyl nitrate with dry gaseous HCl or HF at an elevated temperature. The addition to the reaction gas of a small quantity of an oxidizing gas or a reducing gas will cause formation of the tetra- or tri-halide of plutonium as desired.

  10. Photochemical preparation of plutonium pentafluoride

    DOEpatents

    Rabideau, Sherman W.; Campbell, George M.

    1987-01-01

    The novel compound plutonium pentafluoride may be prepared by the photodissociation of gaseous plutonium hexafluoride. It is a white solid of low vapor pressure, which consists predominantly of a face-centered cubic structure with a.sub.o =4.2709.+-.0.0005 .ANG..

  11. PLUTONIUM-URANIUM-TITANIUM ALLOYS

    DOEpatents

    Coffinberry, A.S.

    1959-07-28

    A plutonium-uranium alloy suitable for use as the fuel element in a fast breeder reactor is described. The alloy contains from 15 to 60 at.% titanium with the remainder uranium and plutonium in a specific ratio, thereby limiting the undesirable zeta phase and rendering the alloy relatively resistant to corrosion and giving it the essential characteristic of good mechanical workability.

  12. METHOD OF REDUCING PLUTONIUM COMPOUNDS

    DOEpatents

    Johns, I.B.

    1958-06-01

    A method is described for reducing plutonium compounds in aqueous solution from a higher to a lower valence state. This reduction of valence is achieved by treating the aqueous solution of higher valence plutonium compounds with hydrogen in contact with an activated platinum catalyst.

  13. SEPARATION OF PLUTONIUM FROM URANIUM

    DOEpatents

    Feder, H.M.; Nuttall, R.L.

    1959-12-15

    A process is described for extracting plutonium from powdered neutron- irradiated urarium metal by contacting the latter, while maintaining it in the solid form, with molten magnesium which takes up the plutonium and separating the molten magnesium from the solid uranium.

  14. SOLVENT EXTRACTION PROCESS FOR PLUTONIUM

    DOEpatents

    Anderson, H.H.; Asprey, L.B.

    1960-02-01

    A process of separating plutonium in at least the tetravalent state from fission products contained in an aqueous acidic solution by extraction with alkyl phosphate is reported. The plutonium can then be back-extracted from the organic phase by contact with an aqueous solution of sulfuric, phosphoric, or oxalic acid as a complexing agent.

  15. PLUTONIUM-CERIUM-COPPER ALLOYS

    DOEpatents

    Coffinberry, A.S.

    1959-05-12

    A low melting point plutonium alloy useful as fuel is a homogeneous liquid metal fueled nuclear reactor is described. Vessels of tungsten or tantalum are useful to contain the alloy which consists essentially of from 10 to 30 atomic per cent copper and the balance plutonium and cerium. with the plutontum not in excess of 50 atomic per cent.

  16. Plutonium Multiple Recycling In PWRs

    SciTech Connect

    Nigon, Jean-Louis; Lenain, Richard; Zaetta, Alain

    2002-07-01

    Reprocessing and recycling open the road to a sustainable management of nuclear materials and an environment friendly management of nuclear waste. However, long or very long term recycling implies fast neutron reactors. High burn-ups of irradiated standard UO{sub 2} fuel as well as recycling of plutonium fuel in thermal reactors lead to a 'degradation' of plutonium that means a low fissile content, which is hardly compatible with recycling in LWRs. Thus the question of plutonium management has been raised; although there are some limitations, a truly large variety of options do exist; no one of the presently selected ways of plutonium management is a dead end road. Among these various options, some are fully compatible with the existing reactors and may be considered for the mid term future; they offer a competitive management of plutonium during the transition from thermal to fast reactors. (authors)

  17. Probing Phonons in Plutonium

    NASA Astrophysics Data System (ADS)

    Wong, Joe

    2004-03-01

    The phonon spectra of plutonium and its alloys have been sought after in the past few decades following the discovery of this actinide element in 1941, but with no success. This was due to a combination of the high neutron absorption cross section of 239Pu, the common isotope, and non-availability of large single crystals of any Pu-bearing materials. We have recent designed a high resolution inelastic x-ray scattering experiment using a bright synchrotron x-ray beam at the European Sychrotron Radiation Facility (ESRF), Grenoble and mapped the full phonon dispersion curves of an fcc delta-phase polycrystalline Pu-Ga alloy (1). Several unusual features including, a large elastic anisotropy, a small shear elastic modulus C', a Kohn-like anomaly in the T1[011] branch, and a pronounced softening of the [111] transverse modes are found. These features can be related to the phase transitions of plutonium and to strong coupling between the lattice structure and the 5f valence instabilities. Our results also provide a critical test for theoretical treatments of highly correlated 5f electron systems as exemplified by recent dynamical mean field theory (DMFT) calculations for d-plutonium.(2) This work was performed in collaboration with Dr. M. Krisch (ESRF)) and Prof. T.-C. Chiang (UIU), and under the auspices of the U. S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48. 1. Joe Wong et al. Science, vol.301, 1078 (2003) 2. X. Dai et al. Science, vol.300, 953 (2003)

  18. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2005-06-01

    Rosetta, Deep Impact, Titan Cratère sur Titan, Point chaud sur Titan, Phoebé, Treize nouvelles lunes pour Saturne, Épiméthée, Le mystère d'Amalthée, L'anomalie Pioneer, 2M1207, Oui, c'est une planète, Mini cratères martiens, On a retrouvé le Mars Polar Lander, Au Soleil toute l'année, Amplification cosmique, Hubble a quinze ans, Collision de vents dans WR 140, Création d'un trou noir, Un anneau d'Einstein presque parfait, Super flares, Mira en X

  19. PLUTONIUM-HYDROGEN REACTION PRODUCT, METHOD OF PREPARING SAME AND PLUTONIUM POWDER THEREFROM

    DOEpatents

    Fried, S.; Baumbach, H.L.

    1959-12-01

    A process is described for forming plutonlum hydride powder by reacting hydrogen with massive plutonium metal at room temperature and the product obtained. The plutonium hydride powder can be converted to plutonium powder by heating to above 200 deg C.

  20. Low temperature oxidation of plutonium

    SciTech Connect

    Nelson, Art J.; Roussel, Paul

    2013-05-15

    The initial oxidation of gallium stabilized {delta}-plutonium metal at 193 K has been followed using x-ray photoelectron spectroscopy. On exposure to Langmuir quantities of oxygen, plutonium rapidly forms a trivalent oxide followed by a tetravalent plutonium oxide. The growth modes of both oxides have been determined. Warming the sample in vacuum, the tetravalent oxide reduces to the trivalent oxide. The kinetics of this reduction reaction have followed and the activation energy has been determined to be 38.8 kJ mol{sup -1}.

  1. SOLVENT EXTRACTION PROCESS FOR PLUTONIUM

    DOEpatents

    Seaborg, G.T.

    1959-04-14

    The separation of plutonium from aqueous inorganic acid solutions by the use of a water immiscible organic extractant liquid is described. The plutonium must be in the oxidized state, and the solvents covered by the patent include nitromethane, nitroethane, nitropropane, and nitrobenzene. The use of a salting out agents such as ammonium nitrate in the case of an aqueous nitric acid solution is advantageous. After contacting the aqueous solution with the organic extractant, the resulting extract and raffinate phases are separated. The plutonium may be recovered by any suitable method.

  2. Probing phonons in plutonium

    SciTech Connect

    Wong, Joe; Krisch, M.; Farber, D.; Occelli, F.; Schwartz, A.; Chiang, T.C.; Wall, M.; Boro, C.; Xu, Ruqing

    2010-11-16

    Plutonium (Pu) is well known to have complex and unique physico-chemical properties. Notably, the pure metal exhibits six solid-state phase transformations with large volume expansions and contractions along the way to the liquid state: {alpha} {yields} {beta} {yields} {gamma} {yields} {delta} {yields} {delta}{prime} {yields} {var_epsilon} {yields} liquid. Unalloyed Pu melts at a relatively low temperature {approx}640 C to yield a higher density liquid than that of the solid from which it melts, (Figure 1). Detailed understanding of the properties of plutonium and plutonium-based alloys is critical for the safe handling, utilization, and long-term storage of these important, but highly toxic materials. However, both technical and and safety issues have made experimental observations extremely difficult. Phonon dispersion curves (PDCs) are key experimenta l data to the understanding of the basic properties of Pu materials such as: force constants, sound velocities, elastic constants, thermodynamics, phase stability, electron-phonon coupling, structural relaxation, etc. However, phonon dispersion curves (PDCs) in plutonium (Pu) and its alloys have defied measurement for the past few decades since the discovery of this element in 1941. This is due to a combination of the high thermal-neutron absorption cross section of plutonium and the inability to grow the large single crystals (with dimensions of a few millimeters) necessary for inelastic neutron scattering. Theoretical simulations of the Pu PDC continue to be hampered by the lack of suitable inter -atomic potentials. Thus, until recently the PDCs for Pu and its alloys have remained unknown experimentally and theoretically. The experimental limitations have recently been overcome by using a tightly focused undulator x-ray micro-beam scattered from single -grain domains in polycrystalline specimens. This experimental approach has been applied successfully to map the complete PDCs of an fcc d-Pu-Ga alloy using the

  3. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2006-06-01

    Deep Impact; Comète 73P/Schwassmann-Wachmann 3; L'anneau bleu d'Uranus; Triplet de neptunes; Triton; Dunes de Titan; Aréologie; Tache Rouge Junior; Obliquité des grosses planètes; Le jour de Saturne; Xéna; Un compagnon pour le Soleil; Galaxies satellites; Séisme sur une étoile à neutrons; Trou noir double; Hydrogène lointain

  4. Comprendre l'influence des facteurs contextuels sur la participation communautaire à la santé : une étude de cas dans le district sanitaire de Tenkodogo, au Burkina Faso.

    PubMed

    Sombié, Issa; Ilboudo, David O S; Soubeiga, André Kamba; Samuelsen, Helle

    2015-08-07

    Le Burkina Faso met en œuvre depuis plusieurs années la stratégie de la participation communautaire. Des comités de gestion (CoGes) ont été mis en place dans les centres de santé de la première ligne et doivent participer aux prises de décisions. L'objectif principal de cette stratégie est de favoriser l'utilisation des services de santé et une adhésion massive des communautés aux activités de promotion de la santé. Seulement, on constate que les résultats escomptés par les autorités sanitaires tardent à se réaliser. Le présent article convoque les facteurs liés au contexte socioculturel du district sanitaire, pour analyser le phénomène de la participation communautaire.L'étude s'est déroulée dans le district sanitaire de Tenkodogo, situé dans la région administrative du Centre-est, à environ 190 km de la capitale. Cette étude exclusivement qualitative, a utilisé deux méthodes de collecte : les entretiens individuels et les focus groups. Les participants à l'étude sont les chefs de ménage (n = 48), les membres des CoGes (n = 10), les agents de santé (n = 8) et les agents de santé communautaire (n = 24). La méthode de l'analyse de contenu a été utilisée pour l'analyse des données.Les résultats de l'étude montrent que plusieurs facteurs socioculturels influencent la dynamique de la participation communautaire dans le district. Ce sont les conditions économiques, la perception négative des services de santé, les inégalités sociales de sexe et d'âge, le faible ancrage social des organisations communautaires, les rivalités inter-villages et les conflits coutumiers. L'étude relève également que les communautés ne perçoivent pas leur implication dans le processus décisionnel des services de santé comme une priorité. Leurs principales attentes s'orientent vers la disponibilité de soins de qualité et à coût réduit.

  5. Modelisations des effets de surface sur les jets horizontaux subsoniques d'hydrogene et de methane

    NASA Astrophysics Data System (ADS)

    Gomez, Luis Fernando

    Le developpement des codes et de normes bases sur une methodologie scientifique requiert la capacite de predire l'etendue inflammable de deversements gazeux d'hydrogene sous differentes conditions. Des etudes anterieures ont deja etabli des modeles bases sur les lois de conservation de la mecanique des fluides basees sur des correlations experimentales qui permettent de predire la decroissance de la concentration et de la vitesse d'un gaz le long de l'axe d'un jet libre vertical. Cette etude s'interesse aux effets de proximite a une surface horizontale parallele sur un jet turbulent. Nous nous interessons a son impact sur l'etendue du champ de la concentration et sur l'enveloppe inflammable en particulier. Cette etude est comparative : l'hydrogene est compare au methane. Ceci permet de degager l'influence des effets de difference de la densite sur le comportement du jet, et de comparer le comportement de l'hydrogene aux correlations experimentales, qui ont ete essentiellement etablies pour le methane. Un modele decrivant l'evolution spatio-temporelle du champ de concentration du gaz dilue est propose, base sur la mecanique des fluides computationnelle. Cette approche permet de varier systematiquement les conditions aux frontieres (proximite du jet a la surface, par exemple) et de connaitre en detail les proprietes de l'ecoulement. Le modele est implemente dans le code de simulations par volumes finis de FLUENT. Les resultats des simulations sont compares avec les lois de similitudes decoulant de la theorie des jets d'ecoulements turbulents libres ainsi qu'avec les resultats experimentaux disponibles. L'effet de la difference des masses molaires des constituantes du jet et des constituantes du milieu de dispersion est egalement etudie dans le contexte du comportement d'echelle de la region developpee du jet.

  6. TERNARY ALLOY-CONTAINING PLUTONIUM

    DOEpatents

    Waber, J.T.

    1960-02-23

    Ternary alloys of uranium and plutonium containing as the third element either molybdenum or zirconium are reported. Such alloys are particularly useful as reactor fuels in fast breeder reactors. The alloy contains from 2 to 25 at.% of molybdenum or zirconium, the balance being a combination of uranium and plutonium in the ratio of from 1 to 9 atoms of uranlum for each atom of plutonium. These alloys are prepared by melting the constituent elements, treating them at an elevated temperature for homogenization, and cooling them to room temperature, the rate of cooling varying with the oomposition and the desired phase structure. The preferred embodiment contains 12 to 25 at.% of molybdenum and is treated by quenching to obtain a body centered cubic crystal structure. The most important advantage of these alloys over prior binary alloys of both plutonium and uranium is the lack of cracking during casting and their ready machinability.

  7. METHOD OF PREPARING PLUTONIUM TETRAFLUORIDE

    DOEpatents

    Beede, R.L.; Hopkins, H.H. Jr.

    1959-11-17

    C rystalline plutonium tetrafluoride is precipitated from aqueous up to 1.6 N mineral acid solutions of a plutorium (IV) salt with fluosilicic acid anions, preferably at room temperature. Hydrogen fluoride naay be added after precipitation to convert any plutonium fluosilicate to the tetrafluoride and any silica to fluosilicic acid. This process results in a purer product, especially as to iron and aluminum, than does the precipitation by the addition of hydrogen fluoride.

  8. IODATE METHOD FOR PURIFYING PLUTONIUM

    DOEpatents

    Stoughton, R.W.; Duffield, R.B.

    1958-10-14

    A method is presented for removing radioactive fission products from aqueous solutions containing such fission products together with plutonium. This is accomplished by incorporating into such solutions a metal iodate precipitate to remove fission products which form insoluble iodates. Suitable metal iodates are those of thorium and cerium. The plutonium must be in the hexavalent state and the pH of the solution must be manintained at less than 2.

  9. Particularités de la cardiomyopathie du péripartum en Afrique: le cas du Togo sur une étude prospective de 41 cas au Centre Hospitalier et Universitaire Sylvanus Olympio de Lomé

    PubMed Central

    Pio, Machihude; Afassinou, Yaovi; Baragou, Soodougoua; Akue, Edem Goeh; Péssinaba, Souleymane; Atta, Borgatia; Ehlan, Koffi; Alate, Amouzou; Damorou, Findibe

    2014-01-01

    Introduction La cardiomyopathie du péripartum (CMPP) est une défaillance cardiaque dont l’étiologie demeure encore méconnue. Méthodes Il s'agit d'une étude prospective descriptive réalisée dans le service de cardiologie du CHU Sylvanus olympio de Lomé du 1er janvier 2010 au 30 avril 2012. Elle a concerné 41 patientes ayant présenté une insuffisance cardiaque entre le 8eme mois de la grossesse et les 5 premiers mois du post-partum. Résultats L’âge moyen des patientes était de 31,47 ans (extrêmes 21 et 44ans). L'incidence de la CMPP était de 1/362 grossesses. La parité moyenne était de 3,07 (extrêmes 1 et 6). Les symptômes étaient apparus dans le post-partum dans 90,24% des cas. Un retard important de diagnostic était observé. L'insuffisance cardiaque globale était le mode de décompensation dans 65,85%. Les signes électrocardiographiques étaient essentiellement la tachycardie sinusale (97,56%) et l'hypertrophie ventriculaire gauche (97,56%). L’échographie cardiaque a montré dans tous les cas une cardiomyopathie dilatée. Quatre cas de thrombus intraventriculaire gauche étaient notés. La FEVG était sévèrement altérée. L'HTAP était importante dans 56,09%. Conclusion La cardiomyopathie du péripartum est une complication cardiaque grave de la grossesse de cause inconnue, fréquente dans la population africaine. PMID:25309645

  10. Analyseur de spectre RF présentant une bande passante de 10 GHz ainsi qu'une résolution sub-MHz basé sur le creusement spectral dans des cristaux Tm3+:YAG

    NASA Astrophysics Data System (ADS)

    Gorju, G.; Chauve, A.; Crozatier, V.; Lorgeré, I.; Le Gouët, J.-L.; Bretenaker, F.

    2006-10-01

    Nos travaux s'inscrivent dans le cadre des expériences de traitement optique des signaux hyperfréquence utilisant des ions de terres rares en matrice cristalline excités par des sources lasers agiles en fréquence. Nous présentons la réalisation d'un analyseur de spectre avec une bande passante de 10 GHz et une résolution ultime en dessous du MHz.

  11. Implémentation de la Méthode des Eléments de Frontière pour les problèmes de magnétostatique 3D sur architecture parallèle à mémoire distribuée

    NASA Astrophysics Data System (ADS)

    Lobry, Jacques; Daoudi, El Mostafa

    1992-11-01

    Linear and homogeneous problems of the 3D Magnetostatics are of a Poisson or Laplace type. In this case, the Boundary Element Method is a technique which often offers, among others, important advantages over “domain” types solutions, such as finite elements since it provides a great economy in computing time and memory amount. However, when the geometry is complex, a dense mesh is required, leading to a large linear system, of which the forming and solving times should be reduced. The Parallel Computing techniques offer new efficient tools in this respect. Our study is devoted to the presentation and the comparison of different parallel implementations of the Boundary Element Method for the 3D Poisson problems on multiprocessor computers with distributed memory. Experimental results are obtained on a Meiko Computing Surface with 32 T800 transputers. Les problèmes linéaires tridimensionnels de type Poisson ou Laplace que l'on rencontre en Magnétostatique se traitent souvent avec une grande économie de calcul et d'espace mémoire notamment par la Méthode des Eléments de Frontière en comparaison avec la Méthode des Eléments Finis. Cependant, quand la géométrie des domaines est complexe, un maillage de frontière dense devient nécessaire et il importe alors de minimiser les temps de construction et de résolution du système d'équations linéaires associé. Les techniques de calcul parallèle qui se développent actuellement offrent une solution très intéressante face aux limitations imposées par la modélisation numérique elle-même et la vitesse de traitement des ordinateurs classiques. L'objet du présent papier est d'étudier diverses stratégies d'implémentation parallèle de la Méthode des Eléments de Frontière appliquée au problème de Poisson 3D sur architecture multiprocesseurs à mémoire distribuée. Des résultats expérimentaux sont obtenus sur une surface de calcul Meiko composée de 32 transputers T800 et d'une station SUN qui

  12. Influence du comportement des accompagnants sur le vécu des patients admis pour hémorragies digestives hautes au CHU campus de Lomé (Togo)

    PubMed Central

    Bagny, Aklesso; Dusabe, Angelique; Bouglouga, Oumboma; Lawson-ananisoh, Mawuli Late; Kaaga, Yeba Laconi; Djibril, Mohaman Awalou; Soedje, Kokou Mensah; Dassa, Simliwa Kolou; Redah, Datouda

    2014-01-01

    Introduction L'hémorragie digestive haute est une urgence, qui constitue souvent pour les patients un danger mortel suscitant inquiétude et agitation. Dans cet état, le patient dépend de ses accompagnants pour ses soins et pour honorer le traitement; mais souvent, il a été observé une discordance entre l'urgence et les comportements des accompagnants. Le but de cette étude était de décrire les facteurs socioéconomiques et psychologiques pouvant influencer les comportements des accompagnants des patients admis pour HDH, estimer l'indice de relation entre ces comportements et les facteurs associés d'une part et le vécu des patients admis pour HDH d'autre part. Méthodes Il s'agit d'une étude prospective menée de Septembre 2010 à Juin 2011 (soit 10 mois). Nous avions utilisé l'entretien semi-dirigé et l'observation directe pour collecter nos données, ces dernières avaient été traitées par les méthodes statistiques et d'analyse de contenu. Résultats Dans la présente étude, les comportements des accompagnants des patients admis pour HDH sont en majorité marqués par l'abandon (84%) et le manque de sollicitude (80,2%). Ces comportements sont souvent stimulés par les facteurs socioéconomiques tels que les difficultés économiques (83,2%), des conflits intrafamiliaux (85,1%) et des représentations (maladie incurable ou envoûtement) de la maladie par les accompagnants (73,3%) des cas. Quant aux patients, ils vivent ces comportements comme étant des menaces de mort ou des rejets (77,20%) et comme étant une dévalorisation ou une humiliation de la part de leurs accompagnants (70,30%). Les résultats confirment l'existence de lien significatif entre les comportements des accompagnants et les facteurs socio économiques, entre les comportements des accompagnants et des facteurs psychologiques, et entre le vécu des patients admis pour l'HDH et les comportements des accompagnants. Conclusion Des études ultérieures devraient aborder les points

  13. Recent plutonium science and technology at ORNL

    SciTech Connect

    Bell, J.T.

    1985-01-01

    Plutonium research and development (R and D) at ORNL has generally followed development of the nuclear fuel cycle. Basic plutonium chemistry studies have diminished since the mid-1970s; however, significant efforts have been made recently to determine fundamental characteristics of the aqueous plutonium polymer and to develop thermodynamic representations of plutonium oxides. Some studies have also been made on plutonium phosphates related to waste isolation and on definition of the oxidation states of environmental plutonium. The remaining work has been supported by the Consolidated Fuel Reprocessing Program (CFRP) and includes: (1) establishment of boundary limits for polymer formation in Purex systems; (2) preparation of mixed uranium-plutonium oxide microspheres by internal gelation sol-gel techniques; (3) direct thermal denitration of aqueous systems; and (4) plutonium/uranium extraction from spent fast reactor fuels.

  14. Plutonium and americium separation from salts

    DOEpatents

    Hagan, Paul G.; Miner, Frend J.

    1976-01-01

    Salts or materials containing plutonium and americium are dissolved in hydrochloric acid, heated, and contacted with an alkali metal carbonate solution to precipitate plutonium and americium carbonates which are thereafter readily separable from the solution.

  15. Plutonium focus area

    SciTech Connect

    1996-08-01

    To ensure research and development programs focus on the most pressing environmental restoration and waste management problems at the U.S. Department of Energy (DOE), the Assistant Secretary for the Office of Environmental Management (EM) established a working group in August 1993 to implement a new approach to research and technology development. As part of this new approach, EM developed a management structure and principles that led to the creation of specific Focus Areas. These organizations were designed to focus the scientific and technical talent throughout DOE and the national scientific community on the major environmental restoration and waste management problems facing DOE. The Focus Area approach provides the framework for intersite cooperation and leveraging of resources on common problems. After the original establishment of five major Focus Areas within the Office of Technology Development (EM-50, now called the Office of Science and Technology), the Nuclear Materials Stabilization Task Group (EM-66) followed the structure already in place in EM-50 and chartered the Plutonium Focus Area (PFA). The following information outlines the scope and mission of the EM, EM-60, and EM-66 organizations as related to the PFA organizational structure.

  16. Plutonium solution analyzer

    SciTech Connect

    Burns, D.A.

    1994-09-01

    A fully automated analyzer has been developed for plutonium solutions. It was assembled from several commercially available modules, is based upon segmented flow analysis, and exhibits precision about an order of magnitude better than commercial units (0.5%-O.05% RSD). The system was designed to accept unmeasured, untreated liquid samples in the concentration range 40-240 g/L and produce a report with sample identification, sample concentrations, and an abundance of statistics. Optional hydraulics can accommodate samples in the concentration range 0.4-4.0 g/L. Operating at a typical rate of 30 to 40 samples per hour, it consumes only 0.074 mL of each sample and standard, and generates waste at the rate of about 1.5 mL per minute. No radioactive material passes through its multichannel peristaltic pump (which remains outside the glovebox, uncontaminated) but rather is handled by a 6-port, 2-position chromatography-type loop valve. An accompanying computer is programmed in QuickBASIC 4.5 to provide both instrument control and data reduction. The program is truly user-friendly and communication between operator and instrument is via computer screen displays and keyboard. Two important issues which have been addressed are waste minimization and operator safety (the analyzer can run in the absence of an operator, once its autosampler has been loaded).

  17. PROCESS OF SEPARATING PLUTONIUM FROM URANIUM

    DOEpatents

    Brown, H.S.; Hill, O.F.

    1958-09-01

    A process is presented for recovering plutonium values from aqueous solutions. It comprises forming a uranous hydroxide precipitate in such a plutonium bearing solution, at a pH of at least 5. The plutonium values are precipitated with and carried by the uranium hydroxide. The carrier precipitate is then redissolved in acid solution and the pH is adjusted to about 2.5, causing precipitation of the uranous hydroxide but leaving the still soluble plutonium values in solution.

  18. Plutonium Proliferation: The Achilles Heel of Disarmament

    SciTech Connect

    Leventhal, Paul

    2001-02-07

    Plutonium is a byproduct of nuclear fission, and it is produced at the rate of about 70 metric tons a year in the world's nuclear power reactors. Concerns about civilian plutonium ran high in the 1970s and prompted enactment of the Nuclear Non-Proliferation Act of 1978 to give the United States a veto over separating plutonium from U.S.-supplied uranium fuel. Over the years, however, so-called reactor-grade plutonium has become the orphan issue of nuclear non-proliferation, largely as a consequence of pressures from plutonium-separating countries. The demise of the fast breeder reactor and the reluctance of utilities to introduce plutonium fuel in light-water reactors have resulted in large surpluses of civilian, weapons-usable plutonium, which now approach in size the 250 tons of military plutonium in the world. Yet reprocessing of spent fuel for recovery and use of plutonium proceeds apace outside the United States and threatens to overwhelm safeguards and security measures for keeping this material out of the hands of nations and terrorists for weapons. A number of historical and current developments are reviewed to demonstrate that plutonium commerce is undercutting efforts both to stop the spread of nuclear weapons and to work toward eliminating existing nuclear arsenals. These developments include the breakdown of U.S. anti-plutonium policy, the production of nuclear weapons by India with Atoms-for-Peace plutonium, the U.S.-Russian plan to introduce excess military plutonium as fuel in civilian power reactors, the failure to include civilian plutonium and bomb-grade uranium in the proposed Fissile Material Cutoff Treaty, and the perception of emerging proliferation threats as the rationale for development of a ballistic missile defense system. Finally, immobilization of separated plutonium in high-level waste is explored as a proliferation-resistant and disarmament-friendly solution for eliminating excess stocks of civilian and military plutonium.

  19. Selecting a plutonium vitrification process

    SciTech Connect

    Jouan, A.

    1996-05-01

    Vitrification of plutonium is one means of mitigating its potential danger. This option is technically feasible, even if it is not the solution advocated in France. Two situations are possible, depending on whether or not the glass matrix also contains fission products; concentrations of up to 15% should be achievable for plutonium alone, whereas the upper limit is 3% in the presence of fission products. The French continuous vitrification process appears to be particularly suitable for plutonium vitrification: its capacity is compatible with the required throughout, and the compact dimensions of the process equipment prevent a criticality hazard. Preprocessing of plutonium metal, to convert it to PuO{sub 2} or to a nitric acid solution, may prove advantageous or even necessary depending on whether a dry or wet process is adopted. The process may involve a single step (vitrification of Pu or PuO{sub 2} mixed with glass frit) or may include a prior calcination step - notably if the plutonium is to be incorporated into a fission product glass. It is important to weigh the advantages and drawbacks of all the possible options in terms of feasibility, safety and cost-effectiveness.

  20. 49 CFR 175.704 - Plutonium shipments.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Plutonium shipments. 175.704 Section 175.704... Regulations Applicable According to Classification of Material § 175.704 Plutonium shipments. Shipments of plutonium which are subject to 10 CFR 71.88(a)(4) must comply with the following: (a) Each...

  1. 49 CFR 175.704 - Plutonium shipments.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Plutonium shipments. 175.704 Section 175.704... Regulations Applicable According to Classification of Material § 175.704 Plutonium shipments. Shipments of plutonium which are subject to 10 CFR 71.88(a)(4) must comply with the following: (a) Each...

  2. 49 CFR 175.704 - Plutonium shipments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Plutonium shipments. 175.704 Section 175.704... Regulations Applicable According to Classification of Material § 175.704 Plutonium shipments. Shipments of plutonium which are subject to 10 CFR 71.88(a)(4) must comply with the following: (a) Each...

  3. 49 CFR 175.704 - Plutonium shipments.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Plutonium shipments. 175.704 Section 175.704... Regulations Applicable According to Classification of Material § 175.704 Plutonium shipments. Shipments of plutonium which are subject to 10 CFR 71.88(a)(4) must comply with the following: (a) Each...

  4. Rapid Radiochemical Method for Plutonium-238 and ...

    EPA Pesticide Factsheets

    Technical Fact Sheet Technique: Alpha spectrometry Method Developed for: Plutonium-238 and plutonium-239 in building materials Method Selected for: SAM lists this method for qualitative analysis of plutonium-238 and -239 in concrete or brick building materials. Summary of subject analytical method which will be posted to the SAM website to allow access to the method.

  5. 49 CFR 175.704 - Plutonium shipments.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Plutonium shipments. 175.704 Section 175.704... Regulations Applicable According to Classification of Material § 175.704 Plutonium shipments. Shipments of plutonium which are subject to 10 CFR 71.88(a)(4) must comply with the following: (a) Each...

  6. Plutonium Oxide Process Capability Work Plan

    SciTech Connect

    Meier, David E.; Tingey, Joel M.

    2014-02-28

    Pacific Northwest National Laboratory (PNNL) has been tasked to develop a Pilot-scale Plutonium-oxide Processing Unit (P3U) providing a flexible capability to produce 200g (Pu basis) samples of plutonium oxide using different chemical processes for use in identifying and validating nuclear forensics signatures associated with plutonium production. Materials produced can also be used as exercise and reference materials.

  7. Plutonium stabilization and packaging system

    SciTech Connect

    1996-05-01

    This document describes the functional design of the Plutonium Stabilization and Packaging System (Pu SPS). The objective of this system is to stabilize and package plutonium metals and oxides of greater than 50% wt, as well as other selected isotopes, in accordance with the requirements of the DOE standard for safe storage of these materials for 50 years. This system will support completion of stabilization and packaging campaigns of the inventory at a number of affected sites before the year 2002. The package will be standard for all sites and will provide a minimum of two uncontaminated, organics free confinement barriers for the packaged material.

  8. PROCESS FOR SEPARATING PLUTONIUM FROM IMPURITIES

    DOEpatents

    Wahl, A.C.

    1957-11-12

    A method is described for separating plutonium from aqueous solutions containing uranium. It has been found that if the plutonium is reduced to its 3+ valence state, and the uranium present is left in its higher valence state, then the differences in solubility between certain salts (e.g., oxalates) of the trivalent plutonium and the hexavalent uranium can be used to separate the metals. This selective reduction of plutonium is accomplished by adding iodide ion to the solution, since iodide possesses an oxidation potential sufficient to reduce plutonium but not sufficient to reduce uranium.

  9. PLUTONIUM COMPOUNDS AND PROCESS FOR THEIR PREPARATION

    DOEpatents

    Wolter, F.J.; Diehl, H.C. Jr.

    1958-01-01

    This patent relates to certain new compounds of plutonium, and to the utilization of these compounds to effect purification or separation of the plutonium. The compounds are organic chelate compounds consisting of tetravalent plutonium together with a di(salicylal) alkylenediimine. These chelates are soluble in various organic solvents, but not in water. Use is made of this property in extracting the plutonium by contacting an aqueous solution thereof with an organic solution of the diimine. The plutonium is chelated, extracted and effectively separated from any impurities accompaying it in the aqueous phase.

  10. Plutonium inventory characterization technical evaluation report

    SciTech Connect

    Wittman, G.R., Westinghouse Hanford

    1996-07-10

    This is a technical report on the data, gathered to date, under WHC- SD-CP-TP-086, Rev. 1, on the integrity of the food pack cans currently being used to store plutonium or plutonium compounds at the Plutonium Finishing Plant. Workplan PFP-96-VO-009, `Inspection of Special Nuclear Material Using X-ray`, was used to gather data on material and containment conditions using real time radiography. Some of those images are included herein. A matrix found in the `Plutonium Inventory Characterization Implementation Plan` was used to categorize different plutonium items based upon the type of material being stored and the life expectancy of the containers.

  11. Method of separating thorium from plutonium

    DOEpatents

    Clifton, D.G.; Blum, T.W.

    A method of chemically separating plutonium from thorium is claimed. Plutonium and thorium to be separated are dissolved in an aqueous feed solution, preferably as the nitrate salts. The feed solution is acidified and sodium nitrite is added to the solution to adjust the valence of the plutonium to the +4 state. A chloride salt, preferably sodium chloride, is then added to the solution to induce formation of an anionic plutonium chloride complex. The anionic plutonium chloride complex and the thorium in solution are then separated by ion exchange on a strong base anion exchange column.

  12. Plutonium immobilization feed batching system concept report

    SciTech Connect

    Erickson, S.

    2000-07-19

    The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with high level waste glass for permanent storage. Feed batching is one of the first process steps involved with first stage plutonium immobilization. It will blend plutonium oxide powder before it is combined with other materials to make pucks. This report discusses the Plutonium Immobilization feed batching process preliminary concept, batch splitting concepts, and includes a process block diagram, concept descriptions, a preliminary equipment list, and feed batching development areas.

  13. Method of separating thorium from plutonium

    DOEpatents

    Clifton, D.G.; Blum, T.W.

    1984-07-10

    A method is described for chemically separating plutonium from thorium. Plutonium and thorium to be separated are dissolved in an aqueous feed solution, preferably as the nitrate salts. The feed solution is acidified and sodium nitrite is added to the solution to adjust the valence of the plutonium to the +4 state. A chloride salt, preferably sodium chloride, is then added to the solution to induce formation of an anionic plutonium chloride complex. The anionic plutonium chloride complex and the thorium in solution are then separated by ion exchange on a strong base anion exchange column.

  14. Method of separating thorium from plutonium

    DOEpatents

    Clifton, David G.; Blum, Thomas W.

    1984-01-01

    A method of chemically separating plutonium from thorium. Plutonium and thorium to be separated are dissolved in an aqueous feed solution, preferably as the nitrate salts. The feed solution is acidified and sodium nitrite is added to the solution to adjust the valence of the plutonium to the +4 state. A chloride salt, preferably sodium chloride, is then added to the solution to induce formation of an anionic plutonium chloride complex. The anionic plutonium chloride complex and the thorium in solution are then separated by ion exchange on a strong base anion exchange column.

  15. Plutonium inventories for stabilization and stabilized materials

    SciTech Connect

    Williams, A.K.

    1996-05-01

    The objective of the breakout session was to identify characteristics of materials containing plutonium, the need to stabilize these materials for storage, and plans to accomplish the stabilization activities. All current stabilization activities are driven by the Defense Nuclear Facilities Safety Board Recommendation 94-1 (May 26, 1994) and by the recently completed Plutonium ES&H Vulnerability Assessment (DOE-EH-0415). The Implementation Plan for accomplishing stabilization of plutonium-bearing residues in response to the Recommendation and the Assessment was published by DOE on February 28, 1995. This Implementation Plan (IP) commits to stabilizing problem materials within 3 years, and stabilizing all other materials within 8 years. The IP identifies approximately 20 metric tons of plutonium requiring stabilization and/or repackaging. A further breakdown shows this material to consist of 8.5 metric tons of plutonium metal and alloys, 5.5 metric tons of plutonium as oxide, and 6 metric tons of plutonium as residues. Stabilization of the metal and oxide categories containing greater than 50 weight percent plutonium is covered by DOE Standard {open_quotes}Criteria for Safe Storage of Plutonium Metals and Oxides{close_quotes} December, 1994 (DOE-STD-3013-94). This standard establishes criteria for safe storage of stabilized plutonium metals and oxides for up to 50 years. Each of the DOE sites and contractors with large plutonium inventories has either started or is preparing to start stabilization activities to meet these criteria.

  16. Prendre le virage des partenariats.

    PubMed

    Sebestyen, Norma; Sulatycky, Ron; Rondos, Spyro; Davis, Sheila

    2015-11-01

    Deux projets démontrent que la mise en œuvre de données colligées sur le terrain peut contribuer à régler des problèmes dans le milieu de la santé pour favoriser de meilleurs résultats et de plus grandes efficiences. Dans le premier exemple, une vaste coalition de partenaires publics et privés de l'Alberta recourt aux techniques de mesures améliorées et à la méthodologie du Triple objectif pour améliorer les résultats cliniques de populations de cas complexes et lourds du quartier Eastwood d'Edmonton. On espère que les conclusions novatrices qui en sont tirées seront adaptées à d'autres régions de la province. Dans le deuxième exemple, la Childhood Obesity Foundation s'associe à Merck au Canada et à Ayogo (une société de thérapies numériques située à Vancouver) et utilise le concept novateur de la « ludification » pour mobiliser les jeunes de plus en plus sédentaires du Canada et modifier leurs comportements. © 2015 Collège canadien des leaders en santé

  17. Le LHC, un tunnel cosmique

    ScienceCinema

    None

    2016-07-12

    Et si la lumière au bout du tunnel du LHC était cosmique ? En d’autres termes, qu’est-ce que le LHC peut nous apporter dans la connaissance de l’Univers ? Car la montée en énergie des accélérateurs de particules nous permet de mieux appréhender l’univers primordial, chaud et dense. Mais dans quel sens dit-on que le LHC reproduit des conditions proches du Big bang ? Quelles informations nous apporte-t-il sur le contenu de l’Univers ? La matière noire est-elle détectable au LHC ? L’énergie noire ? Pourquoi l’antimatière accumulée au CERN est-elle si rare dans l’Univers ? Et si le CERN a bâti sa réputation sur l’exploration des forces faibles et fortes qui opèrent au sein des atomes et de leurs noyaux, est-ce que le LHC peut nous apporter des informations sur la force gravitationnelle qui gouverne l’évolution cosmique ? Depuis une trentaine d’années, notre compréhension de l’univers dans ses plus grandes dimensions et l’appréhension de son comportement aux plus petites distances sont intimement liées : en quoi le LHC va-t-il tester expérimentalement cette vision unifiée ? Tout public, entrée libre / Réservations au +41 (0)22 767 76 76

  18. The First Weighing of Plutonium

    DOE R&D Accomplishments Database

    Seaborg, Glenn T.

    1967-09-10

    Recollections and reminiscences at the 25th Anniversary of the First Weighing of Plutonium, Chicago, IL, September 10, 1967, tell an important part of the story of this fascinating new element that is destined to play an increasingly significant role in the future of man.

  19. Plutonium disposition and storage model

    SciTech Connect

    Krupa, J.F.

    2000-03-01

    An EXTEND/SDI-Industry model of DOE plutonium disposition and storage has been created which can easily accommodate changes in scenarios by changing input parameters. It matches well with hand-crafted spreadsheet analyses, and has the advantage that it shows system logic and can be documented easily.

  20. Plutonium disposition and storage model

    SciTech Connect

    Krupa, J.F.

    1999-12-06

    An EXTEND/SDI-Industry model of DOE plutonium disposition and storage has been created which can easily accommodate changes in scenarios by changing input parameters. It matches well with hand-crafted spreadsheet analyses, and has the advantage that it shows system logic and can be documented easily.

  1. Plutonium Recycle: The Fateful Step

    ERIC Educational Resources Information Center

    Speth, J. Gustave; And Others

    1974-01-01

    Calls attention to the fact that if the Atomic Energy Commission proceeds with its plans to authorize the nuclear power industry to use plutonium as a fuel in commercial nuclear reactors around the country, this will result in a dramatic escalation in the risks posed by nuclear power. (PEB)

  2. Plutonium Recycle: The Fateful Step

    ERIC Educational Resources Information Center

    Speth, J. Gustave; And Others

    1974-01-01

    Calls attention to the fact that if the Atomic Energy Commission proceeds with its plans to authorize the nuclear power industry to use plutonium as a fuel in commercial nuclear reactors around the country, this will result in a dramatic escalation in the risks posed by nuclear power. (PEB)

  3. Plutonium waste incineration using pyrohydrolysis

    SciTech Connect

    Meyer, M.L.

    1991-12-31

    Waste generated by Savannah River Site (SRS) plutonium operations includes a contaminated organic waste stream. A conventional method for disposing of the organic waste stream and recovering the nuclear material is by incineration. When the organic material is burned, the plutonium remains in the incinerator ash. Plutonium recovery from incinerator ash is highly dependent on the maximum temperature to which the oxide is exposed. Recovery via acid leaching is reduced for a high fired ash (>800{degree}C), while plutonium oxides fired at lower decomposition temperatures (400--800{degrees}C) are more soluble at any given acid concentration. To determine the feasibility of using a lower temperature process, tests were conducted using an electrically heated, controlled-air incinerator. Nine nonradioactive, solid, waste materials were batch-fed and processed in a top-heated cylindrical furnace. Waste material processing was completed using a 19-liter batch over a nominal 8-hour cycle. A processing cycle consisted of 1 hour for heating, 4 hours for reacting, and 3 hours for chamber cooling. The water gas shift reaction was used to hydrolyze waste materials in an atmosphere of 336% steam and 4.4% oxygen. Throughput ranged from 0.14 to 0.27 kg/hr depending on the variability in the waste material composition and density.

  4. Plutonium waste incineration using pyrohydrolysis

    SciTech Connect

    Meyer, M.L.

    1991-01-01

    Waste generated by Savannah River Site (SRS) plutonium operations includes a contaminated organic waste stream. A conventional method for disposing of the organic waste stream and recovering the nuclear material is by incineration. When the organic material is burned, the plutonium remains in the incinerator ash. Plutonium recovery from incinerator ash is highly dependent on the maximum temperature to which the oxide is exposed. Recovery via acid leaching is reduced for a high fired ash (>800{degree}C), while plutonium oxides fired at lower decomposition temperatures (400--800{degrees}C) are more soluble at any given acid concentration. To determine the feasibility of using a lower temperature process, tests were conducted using an electrically heated, controlled-air incinerator. Nine nonradioactive, solid, waste materials were batch-fed and processed in a top-heated cylindrical furnace. Waste material processing was completed using a 19-liter batch over a nominal 8-hour cycle. A processing cycle consisted of 1 hour for heating, 4 hours for reacting, and 3 hours for chamber cooling. The water gas shift reaction was used to hydrolyze waste materials in an atmosphere of 336% steam and 4.4% oxygen. Throughput ranged from 0.14 to 0.27 kg/hr depending on the variability in the waste material composition and density.

  5. étude du transport lors de l'électropolissage de l'alliage 600 dans le mélange acide nitrique-acide hydroxyacétique-eau : mesures sur électrode à disque tournant

    NASA Astrophysics Data System (ADS)

    Saas, J. N.; Frualdo, J. C.; Gauchon, J. P.; Dalard, F.

    1998-01-01

    Electropolishing of Alloy 600 can be achieved in nitric acid-hydroxyacetic acid mixture. The analysis of the diffusive mass transport in the viscous layer during the electropolishing of Alloy 600 was made thanks to rotating disk electrode measurements. We studied the influence of electrolyte temperature, its composition and additives (Ni2+ and NO3- ions). The polishing phenomenon results from water concentration depletion. We give no conclusion about film formation resulting from saturation phenomenon. L'électropolissage de l'Alliage 600 peut être réalisé dans un mélange d'acide nitrique et d'acide hydroxyacétique. Nous avons analysé les phénomènes de transport dans la couche de diffusion pour l'électropolissage de l'Alliage 600 dans cet électrolyte en utilisant une électrode à disque tournant. Nous avons successivement étudié l'influence de la température, de la composition de l'électrolyte et l'ajout d'ions Ni2+ et NO3^-. Le polissage serait dû à l'appauvrissement en eau à la surface. Nous n'avons pas pu conclure quant à la formation d'un film à la surface du métal résultant d'un phénomène de saturation.

  6. Le gingembre contre la nausée et les vomissements de la grossesse

    PubMed Central

    Lindblad, Adrienne J.; Koppula, Sudha

    2016-01-01

    Question clinique Le gingembre peut-il traiter la nausée et les vomissements de la grossesse? Résultats Durant le premier trimestre, le gingembre soulagerait la nausée et les vomissements de quelque 4 points sur une échelle de 40 points, ou éliminerait les vomissements chez 1 femme sur 3 au jour 6. L’étude la plus vaste ne laisse croire à aucune hausse des malformations congénitales ou de la mortinatalité, mais les études de moins grande envergure laissent croire le contraire.

  7. Le pompage optique naturel dans le milieu astrophysique

    NASA Astrophysics Data System (ADS)

    Pecker, J.-C.

    The title of this lecture abstracts only a part of it : the importance in astrophysics of the study of non-LTE situations has become considerable, as well in the stellar atmospheres as, still more, in the study of fortuitous coincidences as a mechanism of formation of emission line nebular spectra, or of molecular interstellar « masers ». Another part of this talk underlines the role of Kastler in his time, and describes his warm personality through his public reactions in front of the nuclear armement, of the Viet-Nam and Algerian wars, of the problems of political refugees... Kastler was a great scientist ; he was also a courageous humanist. 1976 : Les accords nucléaires du Brésil : allocution d'ouverture (19 mars). Colloque sur le sujet ci-dessus. 1976 : La promotion de la culture dans le nouvel ordre économique international, allocution à l'occasion d'une table ronde sur ce thème par l'UNESCO (23-27 juin 1976) ; « Sciences et Techniques », octobre 1976. 1979 : La bête immonde (avec J.-C. Pecker), « Le Matin », 20 mars. 1979 : Appel à nos ministres (avec J.-C. Pecker), « Le Monde », 13 décembre. 1979 : Le flou, le ténébreux, l'irrationnel (avec J.-C. Pecker), « Le Monde », 14 septembre. 1980 : Education à la paix, Préface, in : Publ. UNESCO. 1981 : Le vrai danger, « Le Monde », 6 août 1981. 1982 : Nucléaire civil et militaire, « Le Monde », 1er juin 1982. 1982 : Les scientifiques face à la perspective d'holocauste nucléaire (texte inédit). Le titre de cette communication en résume seulement une partie : l'importance prise en astrophysique par l'analyse des situations hors ETL est devenue considérable, qu'il s'agisse des atmosphères stellaires, ou plus encore, des coïncidences fortuites de la formation des spectres d'émission nébulaires, ou des « masers » moléculaires interstellaires. Une autre partie de cet exposé souligne lele de Kastler dans son époque, et décrit sa personnalité généreuse à travers ses r

  8. Lithiase géante sur enterocystoplastie

    PubMed Central

    Elmortaji, Khalid; Elomri, Ghassane; Bennani, Saad; Rabii, Redouane; Aboutaib, Rachid; Meziane, Fethi

    2014-01-01

    La formation des lithiases est une complication fréquente des entérocystoplasties après cystectomie radicale pour tumeur de vessie infiltrante. Le délai d'apparition dépend des facteurs de risque favorisants notamment les infections urinaires. Néanmoins la survenue de lithiase géante sur néovessie reste exceptionnelle, seulement 5 cas ont été rapportés dans la littérature. Nous rapportons dans ce travail, le cas d'une lithiase géante compliquant une entérocystoplastie chez un malade suivi pour tumeur de vessie infiltrante. PMID:25932070

  9. PRECIPITATION METHOD FOR THE SEPARATION OF PLUTONIUM AND RARE EARTHS

    DOEpatents

    Thompson, S.G.

    1960-04-26

    A method of purifying plutonium is given. Tetravalent plutonium is precipitated with thorium pyrophosphate, the plutonium is oxidized to the tetravalent state, and then impurities are precipitated with thorium pyrophosphate.

  10. Surprising coordination for plutonium in the first plutonium(III) borate.

    PubMed

    Wang, Shuao; Alekseev, Evgeny V; Depmeier, Wulf; Albrecht-Schmitt, Thomas E

    2011-03-21

    The first plutonium(III) borate, Pu(2)[B(12)O(18)(OH)(4)Br(2)(H(2)O)(3)]·0.5H(2)O, has been prepared by reacting plutonium(III) with molten boric acid under strictly anaerobic conditions. This compound contains a three-dimensional polyborate network with triangular holes that house the plutonium(III) sites. The plutonium sites in this compound are 9- and 10-coordinate and display atypical geometries.

  11. Air transport of plutonium metal: content expansion initiative for the plutonium air transportable (PAT01) packaging

    SciTech Connect

    Caviness, Michael L; Mann, Paul T

    2010-01-01

    The National Nuclear Security Administration (NNSA) has submitted an application to the Nuclear Regulatory Commission (NRC) for the air shipment of plutonium metal within the Plutonium Air Transportable (PAT-1) packaging. The PAT-1 packaging is currently authorized for the air transport of plutonium oxide in solid form only. The INMM presentation will provide a limited overview of the scope of the plutonium metal initiative and provide a status of the NNSA application to the NRC.

  12. The production process of "Étude sur le Rein des Urinaires", doctoral thesis of Joaquin María Albarrán at the Faculty of Medicine in Paris.

    PubMed

    Fernández-Arias, M; Otero, I; Pérez-Albacete, M; Fariña, L A; Angulo, J C

    2014-01-01

    The manuscript of the Doctoral Thesis of Joaquín Albarrán in the Faculty of Medicine in Paris "Étudesur le Rein des Urinaires" has been donated to Asociación Española de Urología. Direct comparison of the original and printed material gives information of the production process of this master work. Direct comparison between the original hand-written work, a single hard bound volume covered with loin cloth and water paper composed of 145 numbered pages plus 206 newly numbered pages of clinico-pathological (37 subjects) and experimental (19 assays in 20 rabbits) data, and the printed work edited by Georges Steinheil in 1889. Prints included 4 plates with 14 figures, 9 temperature charts and 5 tables describing urine examinations. Figures were trichromic and charts and tables black & white. Chromolithographs were produced by Mr. Leuba in the printing owned by Lemercier et Cie, Paris. The original work was completed in 1887 without any correction or deletion. Differences are noticeable between the text in the master and printed works: rearrangement of data and inclusion of a new clinical observation, 5 new experiments, summary and dedications. Changes in iconography are noticeable. The masterwork included 24 plates (numbered from 1 to 22, 13bis, 16bis) with 46 figures (44 colored) integrated within the text and 26 double-page temperature registries that accompany clinical observations. Anatomical, histological and microbiological illustrations, including culture media, microbiological stains and histobacteriological preparations were depicted as watercolors (44%), watercolors mixed with pencil or ink (52%) or pencil drawings (4%). Four (9%) were signed by the author, 5 (11%) had numerical annotations and only 14 (30%) were definitely printed with loss of the black component and redrawn of 4/14 (29%) images. The largest images were not printed. Joaquín Albarrán described and beautifully illustrated himself the role "pyogenic bacillus" (E. coli) played in renal

  13. SEPARATION OF PLUTONIUM HYDROXIDE FROM BISMUTH HYDROXIDE

    DOEpatents

    Watt, G.W.

    1958-08-19

    An tmproved method is described for separating plutonium hydroxide from bismuth hydroxide. The end product of the bismuth phosphate processes for the separation amd concentration of plutonium is a inixture of bismuth hydroxide amd plutonium hydroxide. It has been found that these compounds can be advantageously separated by treatment with a reducing agent having a potential sufficient to reduce bismuth hydroxide to metalltc bisinuth but not sufficient to reduce the plutonium present. The resulting mixture of metallic bismuth and plutonium hydroxide can then be separated by treatment with a material which will dissolve plutonium hydroxide but not metallic bismuth. Sodiunn stannite is mentioned as a preferred reducing agent, and dilute nitric acid may be used as the separatory solvent.

  14. Multi-generational stewardship of plutonium

    SciTech Connect

    Pillay, K.K.S.

    1997-10-01

    The post-cold war era has greatly enhanced the interest in the long-term stewardship of plutonium. The management of excess plutonium from proposed nuclear weapons dismantlement has been the subject of numerous intellectual discussions during the past several years. In this context, issues relevant to long-term management of all plutonium as a valuable energy resource are also being examined. While there are differing views about the future role of plutonium in the economy, there is a recognition of the environmental and health related problems and proliferation potentials of weapons-grade plutonium. The long-term management of plutonium as an energy resource will require a new strategy to maintain stewardship for many generations to come.

  15. Biokinetics of Plutonium in Nonhuman Primates.

    PubMed

    Poudel, Deepesh; Guilmette, Raymond A; Gesell, Thomas F; Harris, Jason T; Brey, Richard R

    2016-10-01

    A major source of data on metabolism, excretion and retention of plutonium comes from experimental animal studies. Although old world monkeys are one of the closest living relatives to humans, certain physiological differences do exist between these nonhuman primates and humans. The objective of this paper was to describe the metabolism of plutonium in nonhuman primates using the bioassay and retention data obtained from macaque monkeys injected with plutonium citrate. A biokinetic model for nonhuman primates was developed by adapting the basic model structure and adapting the transfer rates described for metabolism of plutonium in adult humans. Significant changes to the parameters were necessary to explain the shorter retention of plutonium in liver and skeleton of the nonhuman primates, differences in liver to bone partitioning ratio, and significantly higher excretion of plutonium in feces compared to that in humans.

  16. PROCESS FOR THE RECOVERY OF PLUTONIUM

    DOEpatents

    Potratz, H.A.

    1958-12-16

    A process for the separation of plutonium from uranlum and other associated radioactlve fission products ls descrlbed conslstlng of contacting an acid solution containing plutonium in the tetravalent state and uranium in the hexavalent state with enough ammonium carbonate to form an alkaline solution, adding cupferron to selectlvely form plutonlum cupferrlde, then recoverlng the plutonium cupferride by extraction with a water lmmiscible organic solvent such as chloroform.

  17. PROCESS OF SEPARATING PLUTONIUM VALUES BY ELECTRODEPOSITION

    DOEpatents

    Whal, A.C.

    1958-04-15

    A process is described of separating plutonium values from an aqueous solution by electrodeposition. The process consists of subjecting an aqueous 0.1 to 1.0 N nitric acid solution containing plutonium ions to electrolysis between inert metallic electrodes. A current density of one milliampere io one ampere per square centimeter of cathode surface and a temperature between 10 and 60 d C are maintained. Plutonium is electrodeposited on the cathode surface and recovered.

  18. WET METHOD OF PREPARING PLUTONIUM TRIBROMIDE

    DOEpatents

    Davidson, N.R.; Hyde, E.K.

    1958-11-11

    S> The preparation of anhydrous plutonium tribromide from an aqueous acid solution of plutonium tetrabromide is described, consisting of adding a water-soluble volatile bromide to the tetrabromide to provide additional bromide ions sufficient to furnish an oxidation-reduction potential substantially more positive than --0.966 volt, evaporating the resultant plutonium tribromides to dryness in the presence of HBr, and dehydrating at an elevated temperature also in the presence of HBr.

  19. PLUTONIUM METAL: OXIDATION CONSIDERATIONS AND APPROACH

    SciTech Connect

    Estochen, E.

    2013-03-20

    Plutonium is arguably the most unique of all metals when considered in the combined context of metallurgical, chemical, and nuclear behavior. Much of the research in understanding behavior and characteristics of plutonium materials has its genesis in work associated with nuclear weapons systems. However, with the advent of applications in fuel materials, the focus in plutonium science has been more towards nuclear fuel applications, as well as long term storage and disposition. The focus of discussion included herein is related to preparing plutonium materials to meet goals consistent with non-proliferation. More specifically, the emphasis is on the treatment of legacy plutonium, in primarily metallic form, and safe handling, packaging, and transport to meet non-proliferation goals of safe/secure storage. Elevated temperature oxidation of plutonium metal is the treatment of choice, due to extensive experiential data related to the method, as the oxide form of plutonium is one of only a few compounds that is relatively simple to produce, and stable over a large temperature range. Despite the simplicity of the steps required to oxidize plutonium metal, it is important to understand the behavior of plutonium to ensure that oxidation is conducted in a safe and effective manner. It is important to understand the effect of changes in environmental variables on the oxidation characteristics of plutonium. The primary purpose of this report is to present a brief summary of information related to plutonium metal attributes, behavior, methods for conversion to oxide, and the ancillary considerations related to processing and facility safety. The information provided is based on data available in the public domain and from experience in oxidation of such materials at various facilities in the United States. The report is provided as a general reference for implementation of a simple and safe plutonium metal oxidation technique.

  20. PLUTONIUM-CUPFERRON COMPLEX AND METHOD OF REMOVING PLUTONIUM FROM SOLUTION

    DOEpatents

    Potratz, H.A.

    1959-01-13

    A method is presented for separating plutonium from fission products present in solutions of neutronirradiated uranium. The process consists in treating such acidic solutions with cupferron so that the cupferron reacts with the plutonium present to form an insoluble complex. This plutonium cupferride precipitates and may then be separated from the solution.

  1. Disposition options for separated plutonium

    SciTech Connect

    Hippel, F. von; Feiveson, H. )

    1993-01-01

    Russia and the United States expect to dismantle [approximately]50,000 nuclear warheads containing [approximately]150 tonnes of plutonium as a result of the drastic reductions in tactical nuclear weapons announced by Presidents Bush and Gorbachev during the fall of 1991 and the reductions in strategic weapons agreed to in the START I and START II Treaties. In addition, if current plans for reprocessing spent light water reactor (LWR) fuel are carried out (mainly in Britain and France) [approximately]200 tonnes of civilian plutonium will be separated during the 1990s. This paper addresses the public-policy issues in the U.S. and abroad regarding disposition options as well as some technical aspects for options.

  2. Plutonium Immobilization Can Loading Concepts

    SciTech Connect

    Kriikku, E.; Ward, C.; Stokes, M.; Randall, B.; Steed, J.; Jones, R.; Hamilton, L.; Rogers, L.; Fiscus, J.; Dyches, G.

    1998-05-01

    The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report discusses five can loading conceptual designs and the lists the advantages and disadvantages for each concept. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas. The can loading welder and cutter are very similar to the existing Savannah River Site (SRS) FB-Line bagless transfer welder and cutter and thus they are a low priority development item.

  3. Plutonium Immobilization Project Baseline Formulation

    SciTech Connect

    Ebbinghaus, B.

    1999-02-01

    A key milestone for the Immobilization Project (AOP Milestone 3.2a) in Fiscal Year 1998 (FY98) is the definition of the baseline composition or formulation for the plutonium ceramic form. The baseline formulation for the plutonium ceramic product must be finalized before the repository- and plant-related process specifications can be determined. The baseline formulation that is currently specified is given in Table 1.1. In addition to the baseline formulation specification, this report provides specifications for two alternative formulations, related compositional specifications (e.g., precursor compositions and mixing recipes), and other preliminary form and process specifications that are linked to the baseline formulation. The preliminary specifications, when finalized, are not expected to vary tremendously from the preliminary values given.

  4. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2014-06-01

    Future lune ? - L'âge de la Lune - Des volcans actifs sur Vénus - Un lac dans le cratère Gusev ? - Météorites et atmosphère martiennes - L’hexagone de Saturne - Pluton - Exo-Terre - Bêta Pictoris b - Cérès et Vesta depuis Mars - Naine froide - Parallaxes par Hubble - L2 Puppis et le sort du Soleil - Supernova et lentille gravitationnelle - Champ magnétique galactique - L’objet de Sakurai - Fermi et la matière noire - Lentille naine

  5. Regard sur les lazarets en terre canadienne

    PubMed Central

    Milot, Jean

    2008-01-01

    Puisant dans les nombreuses références qu’offrent les publications médicales canadiennes du milieu du XIXe siècle à nos jours, l’auteur fait découvrir l’existence de lazarets en terre canadienne, décrit l’impact de la maladie sur les conditions vie des lépreux qui y étaient confinés et en souligne les contrecoups tant sur le plan physique et psychologique que social. Il présente un bref aperçu de la maladie, ses symptômes, ses signes ainsi que ses complications oculaires et rappelle les premiers moyens thérapeutiques à base d’huile de chaulmoogra introduits dans la colonie de Tracadie vers 1901. Il illustre son propos en évoquant la vie dans les lazarets de l’île de Sheldrake (1844–1848) et de Tracadie (1848–1965) au Nouveau-Brunswick, puis dans ceux des îles D’Arcy (1891–1924) et de Bentinck (1924–1957) en Colombie-Britannique. PMID:19352451

  6. Plutonium transmutation in thorium fuel cycle

    SciTech Connect

    Necas, Vladimir; Breza, Juraj |; Darilek, Petr

    2007-07-01

    The HELIOS spectral code was used to study the application of the thorium fuel cycle with plutonium as a supporting fissile material in a once-through scenario of the light water reactors PWR and VVER-440 (Russian design). Our analysis was focused on the plutonium transmutation potential and the plutonium radiotoxicity course of hypothetical thorium-based cycles for current nuclear power reactors. The paper shows a possibility to transmute about 50% of plutonium in analysed reactors. Positive influence on radiotoxicity after 300 years and later was pointed out. (authors)

  7. NON-AQUEOUS DISSOLUTION OF MASSIVE PLUTONIUM

    DOEpatents

    Reavis, J.G.; Leary, J.A.; Walsh, K.A.

    1959-05-12

    A method is presented for obtaining non-aqueous solutions or plutonium from massive forms of the metal. In the present invention massive plutonium is added to a salt melt consisting of 10 to 40 weight per cent of sodium chloride and the balance zinc chloride. The plutonium reacts at about 800 deg C with the zinc chloride to form a salt bath of plutonium trichloride, sodium chloride, and metallic zinc. The zinc is separated from the salt melt by forcing the molten mixture through a Pyrex filter.

  8. METHOD OF REDUCING PLUTONIUM WITH FERROUS IONS

    DOEpatents

    Dreher, J.L.; Koshland, D.E.; Thompson, S.G.; Willard, J.E.

    1959-10-01

    A process is presented for separating hexavalent plutonium from fission product values. To a nitric acid solution containing the values, ferrous ions are added and the solution is heated and held at elevated temperature to convert the plutonium to the tetravalent state via the trivalent state and the plutonium is then selectively precipitated on a BiPO/sub 4/ or LaF/sub 3/ carrier. The tetravalent plutonium formed is optionally complexed with fluoride, oxalate, or phosphate anion prior to carrier precipitation.

  9. OXIDATIVE METHOD OF SEPARATING PLUTONIUM FROM NEPTUNIUM

    DOEpatents

    Beaufait, L.J. Jr.

    1958-06-10

    A method is described of separating neptunium from plutonium in an aqueous solution containing neptunium and plutonium in valence states not greater than +4. This may be accomplished by contacting the solution with dichromate ions, thus oxidizing the neptunium to a valence state greater than +4 without oxidizing any substantial amount of plutonium, and then forming a carrier precipitate which carries the plutonium from solution, leaving the neptunium behind. A preferred embodiment of this invention covers the use of lanthanum fluoride as the carrier precipitate.

  10. ION EXCHANGE ADSORPTION PROCESS FOR PLUTONIUM SEPARATION

    DOEpatents

    Boyd, G.E.; Russell, E.R.; Taylor, M.D.

    1961-07-11

    Ion exchange processes for the separation of plutonium from fission products are described. In accordance with these processes an aqueous solution containing plutonium and fission products is contacted with a cation exchange resin under conditions favoring adsorption of plutonium and fission products on the resin. A portion of the fission product is then eluted with a solution containing 0.05 to 1% by weight of a carboxylic acid. Plutonium is next eluted with a solution containing 2 to 8 per cent by weight of the same carboxylic acid, and the remaining fission products on the resin are eluted with an aqueous solution containing over 10 per cent by weight of sodium bisulfate.

  11. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2002-06-01

    Loi tchèque sur la pollution lumineuse; XTE J0929-314; Futurs amas de galaxies; Palomar 5; La météo des naines brunes; Trous noirs et galaxies elliptiques; Europe; 2MASS; Mars; Io; Matière sombre; Un objet très froid; Les oscillations stellaires; Un système lanétaire en formation; Binaire serrée; Satellites de Jupiter; Mars sous la loupe; Le Hubble nouveau

  12. Lignes directrices simplifiées sur les lipides

    PubMed Central

    Allan, G. Michael; Lindblad, Adrienne J.; Comeau, Ann; Coppola, John; Hudson, Brianne; Mannarino, Marco; McMinis, Cindy; Padwal, Raj; Schelstraete, Christine; Zarnke, Kelly; Garrison, Scott; Cotton, Candra; Korownyk, Christina; McCormack, James; Nickel, Sharon; Kolber, Michael R.

    2015-01-01

    Résumé Objectif Produire un guide de pratique clinique comportant une approche simplifiée à la prévention primaire des maladies cardiovasculaires (MCV), en insistant sur l’estimation du risque de MCV et la prise en charge des profils lipidiques à l’intention des cliniciens de soins primaires et leurs équipes; nous avons recherché la contribution de professionnels des soins primaires qui n’avaient que peu ou pas de conflits d’intérêts et nous nous sommes concentrés sur les données probantes de la plus haute qualité accessibles. Méthodes Neuf professionnels de la santé (4 médecins de famille, 2 internistes, 1 infirmière praticienne, 1 infirmière autorisée et 1 pharmacienne) et 1 membre non votant (pharmacienne gestionnaire de projet) formaient le comité principal appelé le Lipid Pathway Committee (le comité). La sélection des membres s’est fondée sur la profession, le milieu de pratique et son emplacement. Les membres ont divulgué tous leurs conflits d’intérêts potentiels ou réels. Le processus d’élaboration des lignes directrices était itératif et s’appuyait sur des affichages en ligne, une révision détaillée des données probantes, des réunions par téléphone et en ligne. Le comité a cerné 12 questions prioritaires à répondre. Le groupe de révision des données probantes a répondu à ces questions. À la suite d’un examen des réponses, les principales recommandations ont été formulées par consensus du comité. Nous avons produit une ébauche des lignes directrices qui a ensuite été peaufinée, distribuée à un groupe de cliniciens (médecins de famille, autres spécialistes, pharmaciens, infirmières et infirmières praticiennes) et à des patients pour obtenir de la rétroaction, la réviser en conséquence et le comité l’a ensuite finalisée. Recommandations Des recommandations sont présentées concernant le dépistage et les analyses, les évaluations du risque, le suivi, de même que lele

  13. Pyrochemical process for extracting plutonium from an electrolyte salt

    DOEpatents

    Mullins, Lawrence J.; Christensen, Dana C.

    1984-01-01

    A pyrochemical process for extracting plutonium from a plutonium-bearing salt is disclosed. The process is particularly useful in the recovery of plutonium from electrolyte salts which are left over from the electrorefining of plutonium. In accordance with the process, the plutonium-bearing salt is melted and mixed with metallic calcium. The calcium reduces ionized plutonium in the salt to plutonium metal, and also causes metallic plutonium in the salt, which is typically present as finely dispersed metallic shot, to coalesce. The reduced and coalesced plutonium separates out on the bottom of the reaction vessel as a separate metallic phase which is readily separable from the overlying salt upon cooling of the mixture. Yields of plutonium are typically on the order of 95%. The stripped salt is virtually free of plutonium and may be discarded to low-level waste storage.

  14. Pyrochemical process for extracting plutonium from an electrolyte salt

    DOEpatents

    Mullins, L.J.; Christensen, D.C.

    1982-09-20

    A pyrochemical process for extracting plutonium from a plutonium-bearing salt is disclosed. The process is particularly useful in the recovery of plutonium for electrolyte salts which are left over from the electrorefining of plutonium. In accordance with the process, the plutonium-bearing salt is melted and mixed with metallic calcium. The calcium reduces ionized plutonium in the salt to plutonium metal, and also causes metallic plutonium in the salt, which is typically present as finely dispersed metallic shot, to coalesce. The reduced and coalesced plutonium separates out on the bottom of the reaction vessel as a separate metallic phase which is readily separable from the overlying salt upon cooling of the mixture. Yields of plutonium are typically on the order of 95%. The stripped salt is virtually free of plutonium and may be discarded to low-level waste storage.

  15. Plutonium oxalate precipitation for trace elemental determination in plutonium materials

    SciTech Connect

    Xu, Ning; Gallimore, David; Lujan, Elmer; Garduno, Katherine; Walker, Laurie; Taylor, Fiona; Thompson, Pam; Tandon, Lav

    2015-05-26

    In this study, an analytical chemistry method has been developed that removes the plutonium (Pu) matrix from the dissolved Pu metal or oxide solution prior to the determination of trace impurities that are present in the metal or oxide. In this study, a Pu oxalate approach was employed to separate Pu from trace impurities. After Pu(III) was precipitated with oxalic acid and separated by centrifugation, trace elemental constituents in the supernatant were analyzed by inductively coupled plasma-optical emission spectroscopy with minimized spectral interferences from the sample matrix.

  16. Plutonium oxalate precipitation for trace elemental determination in plutonium materials

    DOE PAGES

    Xu, Ning; Gallimore, David; Lujan, Elmer; ...

    2015-05-26

    In this study, an analytical chemistry method has been developed that removes the plutonium (Pu) matrix from the dissolved Pu metal or oxide solution prior to the determination of trace impurities that are present in the metal or oxide. In this study, a Pu oxalate approach was employed to separate Pu from trace impurities. After Pu(III) was precipitated with oxalic acid and separated by centrifugation, trace elemental constituents in the supernatant were analyzed by inductively coupled plasma-optical emission spectroscopy with minimized spectral interferences from the sample matrix.

  17. Proceedings from the DRG Seminar on Robotics in the Battlefield (31st) Held on 6-8 March 1991 in Paris, France. Volume A (Actes du 31ieme Seminaire sur la Robotique du Champ de Bataille, Groupe sur la Recherche pour la Defense).

    DTIC Science & Technology

    1992-06-01

    3 1ime Seminaire sur la robotique du champ de Bataille Groupe sur la Recherche pour la Defense S92-25111 92 9 14 00O ;-" SANS CLASSIFICATION...Avanc~es (ENSTA), du 6 au 8 Mars 1991, sur le theme de la Robotique du Champ de Bataille . En juillet 1985, s𔄀tait tenu, dans les mimes lietix, tin...s dens le domaine de la Robotique dui Champ de Bataille et de mesurer les progr~s accomplis pendant cette p~riode. Le S~minaire a regroup6 prds de 230

  18. RECOVERY OF PLUTONIUM BY CARRIER PRECIPITATION

    DOEpatents

    Goeckermann, R.H.

    1961-04-01

    A process is given for recovering plutonium from an aqueous nitric acid zirconium-containing solution of an acidity between 0.2 and 1 N by adding fluoride anions (1.5 to 5 mg/l) and precipitating the plutonium with an excess of hydrogen peroxide at from 53 to 65 deg C.

  19. URANOUS IODATE AS A CARRIER FOR PLUTONIUM

    DOEpatents

    Miller, D.R.; Seaborg, G.T.; Thompson, S.G.

    1959-12-15

    A process is described for precipitating plutonium on a uranous iodate carrier from an aqueous acid solution conA plutonium solution more concentrated than the original solution can then be obtained by oxidizing the uranium to the hexavalent state and dissolving the precipitate, after separating the latter from the original solution, by means of warm nitric acid.

  20. Surplus Plutonium Disposition Final Environmental Impact Statement

    SciTech Connect

    N /A

    1999-11-19

    In December 1996, the U.S. Department of Energy (DOE) published the ''Storage and Disposition of Weapons-Usable Fissile Materials Final Programmatic Environmental Impact Statement (Storage and Disposition PEIS)'' (DOE 1996a). That PEIS analyzes the potential environmental consequences of alternative strategies for the long-term storage of weapons-usable plutonium and highly enriched uranium (HEU) and the disposition of weapons-usable plutonium that has been or may be declared surplus to national security needs. The Record of Decision (ROD) for the ''Storage and Disposition PEIS'', issued on January 14, 1997 (DOE 1997a), outlines DOE's decision to pursue an approach to plutonium disposition that would make surplus weapons-usable plutonium inaccessible and unattractive for weapons use. DOE's disposition strategy, consistent with the Preferred Alternative analyzed in the ''Storage and Disposition PEIS'', allows for both the immobilization of some (and potentially all) of the surplus plutonium and use of some of the surplus plutonium as mixed oxide (MOX) fuel in existing domestic, commercial reactors. The disposition of surplus plutonium would also involve disposal of both the immobilized plutonium and the MOX fuel (as spent nuclear fuel) in a potential geologic repository.

  1. MOLTEN PLUTONIUM FUELED FAST BREEDER REACTOR

    DOEpatents

    Kiehn, R.M.; King, L.D.P.; Peterson, R.E.; Swickard, E.O. Jr.

    1962-06-26

    A description is given of a nuclear fast reactor fueled with molten plutonium containing about 20 kg of plutonium in a tantalum container, cooled by circulating liquid sodium at about 600 to 650 deg C, having a large negative temperature coefficient of reactivity, and control rods and movable reflector for criticality control. (AEC)

  2. Uses for plutonium: Weapons, reactors, and other

    SciTech Connect

    Condit, R.H.

    1994-05-01

    This document begins with a introduction on criticality and supercriticality. Then, types and components, design and engineering, yields, and disassembly of nuclear weapons are discussed. Plutonium is evaluated as a reactor fuel, including neutronics and chemistry considerations. Finally, other uses of plutonium are analyzed.

  3. Source Book on Plutonium and Its Decontamination

    DTIC Science & Technology

    1973-09-24

    Data Entered) UNCLASIFIED 20. ABSTRACT (Continued) |development of the coupled differential equations, based on the 1965 and the proposed 1973...61 XV Some Foreign Plutonium Decontamination Standards . . ...... 63 XVI Variability of Sol Sampling Data .... ..... .... 64 XVII Criteria for...Scheduling Feces Samples . . .......... 66 XVIII Types of Data which may be Coliected for Plutonium Inhalation Incidents . 66 XIX Percent Efficiencies for

  4. Nondestructive assay methods for solids containing plutonium

    SciTech Connect

    Macmurdo, K.W.; Gray, L.W.; Gibbs, A.

    1984-06-01

    Specific nondestructive assay (NDA) methods, e.g. calorimetry, coincidence neutron counting, singles neutron counting, and gamma ray spectrometry, were studied to provide the Savannah River Plant with an NDA method to measure the plutonium content of solid scrap (slag and crucible) generated in the JB-Line plutonium metal production process. Results indicate that calorimetry can be used to measure the plutonium content to within about 3% in 4 to 6 hours by using computerized equilibrium sample power predictive models. Calorimetry results confirm that a bias exists in the present indirect measurement method used to estimate the plutonium content of slag and crucible. Singles neutron counting of slag and crucible can measure plutonium to only +-30%, but coincidence neutron counting methods improve measurement precision to better than +-10% in less than ten minutes. Only four portions of a single slag and crucible sample were assayed, and further study is recommended.

  5. Application of PGNAA to plutonium surveillance

    SciTech Connect

    Prettyman, T.H.; Foster, L.A.; Staples, P.

    1997-12-01

    Prompt gamma-ray neutron activation analysis (PGNAA) is a well-established tool for nondestructive elemental analysis of bulk samples. At Los Alamos National Laboratory we are investigating the use of PGNAA as a diagnostic tool for a number of applications, particularly matrix characterization for nondestructive assay and plutonium surveillance. Surveillance is an essential feature of most plutonium facility operations, including routine material processing and research, short-term storage, and processing operations prior to disposal or long-term storage. The ability to identify and assay specific elements from gamma-ray-produced active neutron interrogation (e.g., by neutron capture, nonelastic scattering, and the decay of activation products) makes PGNAA an ideal tool for surveillance. For example, PGNAA can help confirm item descriptions (for example, plutonium chloride versus plutonium oxide). This feature is particularly important in operations involving poorly characterized legacy materials where the material form could adversely impact plutonium-processing operations.

  6. PROCESS FOR THE RECOVERY OF PLUTONIUM

    DOEpatents

    Ritter, D.M.

    1959-01-13

    An improvement is presented in the process for recovery and decontamination of plutonium. The carrier precipitate containing plutonium is dissolved and treated with an oxidizing agent to place the plutonium in a hexavalent oxidation state. A lanthanum fluoride precipitate is then formed in and removed from the solution to carry undesired fission products. The fluoride ions in the reniaining solution are complexed by addition of a borate sueh as boric acid, sodium metaborate or the like. The plutonium is then reduced and carried from the solution by the formation of a bismuth phosphate precipitate. This process effects a better separation from unwanted flssion products along with conccntration of the plutonium by using a smaller amount of carrier.

  7. New Fecal Method for Plutonium and Americium

    SciTech Connect

    Maxwell, S.L. III

    2000-06-27

    A new fecal analysis method that dissolves plutonium oxide was developed at the Westinghouse Savannah River Site. Diphonix Resin (Eichrom Industries), is used to pre-concentrate the actinides from digested fecal samples. A rapid microwave digestion technique is used to remove the actinides from the Diphonix Resin, which effectively extracts plutonium and americium from acidic solutions containing hydrofluoric acid. After resin digestion, the plutonium and americium are recovered in a small volume of nitric acid that is loaded onto small extraction chromatography columns, TEVA Resin and TRU Resin (Eichrom Industries). The method enables complete dissolution of plutonium oxide and provides high recovery of plutonium and americium with good removal of thorium isotopes such as thorium-228.

  8. MOISTURE AND SURFACE AREA MEASUREMENTS OF PLUTONIUM-BEARING OXIDES

    SciTech Connect

    Crowder, M.; Duffey, J.; Livingston, R.; Scogin, J.; Kessinger, G.; Almond, P.

    2009-09-28

    To ensure safe storage, plutonium-bearing oxides are stabilized at 950 C for at least two hours in an oxidizing atmosphere. Stabilization conditions are expected to decompose organic impurities, convert metals to oxides, and result in moisture content below 0.5 wt%. During stabilization, the specific surface area is reduced, which minimizes readsorption of water onto the oxide surface. Plutonium oxides stabilized according to these criteria were sampled and analyzed to determine moisture content and surface area. In addition, samples were leached in water to identify water-soluble chloride impurity content. Results of these analyses for seven samples showed that the stabilization process produced low moisture materials (< 0.2 wt %) with low surface area ({le} 1 m{sup 2}/g). For relatively pure materials, the amount of water per unit surface area corresponded to 1.5 to 3.5 molecular layers of water. For materials with chloride content > 360 ppm, the calculated amount of water per unit surface area increased with chloride content, indicating hydration of hygroscopic salts present in the impure PuO{sub 2}-containing materials. The low moisture, low surface area materials in this study did not generate detectable hydrogen during storage of four or more years.

  9. The Plutonium Transition from Nuclear Weapons to Crypt

    SciTech Connect

    Gray, L.W.

    2000-03-14

    With the end of the ''Cold War'' thousands of nuclear warheads are being dismantled. The National Academy of Sciences termed this growing stockpile of plutonium and highly enriched uranium ''a clear and present danger'' to international security. DOE/MD selected a duel approach to plutonium disposition--burning MOX fuel in existing reactors and immobilization in a ceramic matrix surrounded by HLW glass. MOX material will be pits and clean metal. The challenges come with materials that will be transferred to Immobilization--these range from engineered materials to residues containing < 30% Pu. Impurity knowledge range from guesses to actual data. During packaging, sites will flag ''out of the ordinary'' containers for characterized. If the process history is lost, characterization cost will escalate rapidly. After two step blending and ceramic precursor addition, cold press and sintering will form 0.5-kg ceramic pucks containing {le}50 g Pu. Pucks will be sealed in cans, placed into magazines, then into HLW canisters; these canisters will be filled with HLW glass prior to being transported to the HLW repository. The Immobilization Program must interface with DP, EM, RW, and NN. Overlaid on top of these interfaces are the negotiations with the Russians.

  10. REMOVAL OF LEGACY PLUTONIUM MATERIALS FROM SWEDEN

    SciTech Connect

    Dunn, Kerry A.; Bellamy, J. Steve; Chandler, Greg T.; Iyer, Natraj C.; Koenig, Rich E.; Leduc, D.; Hackney, B.; Leduc, Dan R.; McClard, J. W.

    2013-08-18

    U.S. Department of Energy’s National Nuclear Security Administration (NNSA) Office of Global Threat Reduction (GTRI) recently removed legacy plutonium materials from Sweden in collaboration with AB SVAFO, Sweden. This paper details the activities undertaken through the U.S. receiving site (Savannah River Site (SRS)) to support the characterization, stabilization, packaging and removal of legacy plutonium materials from Sweden in 2012. This effort was undertaken as part of GTRI’s Gap Materials Program and culminated with the successful removal of plutonium from Sweden as announced at the 2012 Nuclear Security Summit. The removal and shipment of plutonium materials to the United States was the first of its kind under NNSA’s Global Threat Reduction Initiative. The Environmental Assessment for the U.S. receipt of gap plutonium material was approved in May 2010. Since then, the multi-year process yielded many first time accomplishments associated with plutonium packaging and transport activities including the application of the of DOE-STD-3013 stabilization requirements to treat plutonium materials outside the U.S., the development of an acceptance criteria for receipt of plutonium from a foreign country, the development and application of a versatile process flow sheet for the packaging of legacy plutonium materials, the identification of a plutonium container configuration, the first international certificate validation of the 9975 shipping package and the first intercontinental shipment using the 9975 shipping package. This paper will detail the technical considerations in developing the packaging process flow sheet, defining the key elements of the flow sheet and its implementation, determining the criteria used in the selection of the transport package, developing the technical basis for the package certificate amendment and the reviews with multiple licensing authorities and most importantly integrating the technical activities with the Swedish partners.

  11. ADSORPTION-BISMUTH PHOSPHATE METHOD FOR SEPARATING PLUTONIUM

    DOEpatents

    Russell, E.R.; Adamson, A.W.; Boyd, G.E.

    1960-06-28

    A process is given for separating plutonium from uranium and fission products. Plutonium and uranium are adsorbed by a cation exchange resin, plutonium is eluted from the adsorbent, and then, after oxidation to the hexavalent state, the plutonium is contacted with a bismuth phosphate carrier precipitate.

  12. Plutonium Uptake and Distribution in Mammalian Cells: Molecular vs Polymeric Plutonium

    PubMed Central

    ARYAL, BAIKUNTHA P.; GORMAN-LEWIS, DREW; PAUNESKU, TATJANA; WILSON, RICHARD E.; LAI, BARRY; VOGT, STEFAN; WOLOSCHAK, GAYLE E.; JENSEN, MARK P.

    2013-01-01

    Purpose To study the cellular responses to molecular and polymeric forms of plutonium using PC12 cells derived from rat adrenal glands. Materials and methods Serum starved PC12 cells were exposed to polymeric and molecular forms of plutonium for three hours. Cells were washed with 10 mM EGTA, 100 mM NaCl at pH 7.4 to remove surface sorbed plutonium. Localization of plutonium in individual cell was quantitatively analyzed by synchrotron X-ray fluorescence (XRF) microscopy. Results Molecular plutonium complexes introduced to cell growth media in the form of NTA, citrate, or transferrin complexes were taken up by PC12 cells, and mostly co-localized with iron within the cells. Polymeric plutonium prepared separately was not internalized by PC12 cells but it was always found on the cell surface as big agglomerates; however polymeric plutonium formed in situ was mostly found within the cells as agglomerates. Conclusions PC12 cells can differentiate molecular and polymeric forms of plutonium. Molecular plutonium is taken up by PC12 cells and mostly co-localized with iron but aged polymeric plutonium is not internalized by the cells. PMID:21770702

  13. Plutonium uptake and distribution in mammalian cells: molecular vs. polymeric plutonium.

    PubMed

    Aryal, Baikuntha P; Gorman-Lewis, Drew; Paunesku, Tatjana; Wilson, Richard E; Lai, Barry; Vogt, Stefan; Woloschak, Gayle E; Jensen, Mark P

    2011-10-01

    To study the cellular responses to molecular and polymeric forms of plutonium using PC12 cells derived from a rat pheochromocytoma. Serum starved PC12 cells were exposed to polymeric and molecular forms of plutonium for 3 h. Cells were washed with 10 mM ethylene glycol tetraacetic acid (EGTA), 100 mM NaCl at pH 7.4 to remove surface sorbed plutonium. Localization of plutonium in individual cell was quantitatively analyzed by synchrotron X-ray fluorescence (XRF) microscopy. Molecular plutonium complexes introduced to cell growth media in the form of nitrilotriacetic acid (NTA), citrate, or transferrin complexes were taken up by PC12 cells, and mostly colocalized with iron within the cells. Aged polymeric plutonium prepared separately was not internalized by PC12 cells but it was always found on the cell surface as big agglomerates; however, polymeric plutonium formed in situ was mostly found within the cells as agglomerates. PC12 cells can differentiate molecular and polymeric forms of plutonium. Molecular plutonium is taken up by PC12 cells and mostly co-localizes with iron but aged polymeric plutonium is not internalized by the cells.

  14. Potentiometric determination of plutonium by sodium bismuthate oxidation.

    PubMed

    Charyulu, M M; Rao, V K; Natarajan, P R

    1984-12-01

    A potentiometric method for the determination of plutonium is described, in which the plutonium is quantitatively oxidized to plutonium(VI) with sodium bismuthate in nitric acid medium, the excess of oxidant is destroyed chemically and plutonium(VI) is reduced to plutonium(IV) with a measured excess of iron(II), the surplus of which is back-titrated with dichromate. For 3-5 mg of plutonium the error is less than 0.2%. For submilligram quantities of plutonium in presence of macro-amounts of uranium the error is below 2.0%.

  15. Speech Processing in Realistic Battlefield Environments (Le Traitement de la Parole en Environnement de Combat Realiste)

    DTIC Science & Technology

    2009-04-01

    parole et du langage multilingue commence à être reconnue comme un enjeu important par les organisations internationales civiles et militaires. Par...sur le développement et l’évaluation des applications multilingues de la parole et du langage . Pour stimuler la recherche et l’évaluation, le Groupe...Opérationnel de Recherche sur la Parole et le Langage (IST-031/TG-013) de l’OTAN a collationné des données vocales en environnement de combat. Ces

  16. Laboratory-scale evaluations of alternative plutonium precipitation methods

    SciTech Connect

    Martella, L.L.; Saba, M.T.; Campbell, G.K.

    1984-02-08

    Plutonium(III), (IV), and (VI) carbonate; plutonium(III) fluoride; plutonium(III) and (IV) oxalate; and plutonium(IV) and (VI) hydroxide precipitation methods were evaluated for conversion of plutonium nitrate anion-exchange eluate to a solid, and compared with the current plutonium peroxide precipitation method used at Rocky Flats. Plutonium(III) and (IV) oxalate, plutonium(III) fluoride, and plutonium(IV) hydroxide precipitations were the most effective of the alternative conversion methods tested because of the larger particle-size formation, faster filtration rates, and the low plutonium loss to the filtrate. These were found to be as efficient as, and in some cases more efficient than, the peroxide method. 18 references, 14 figures, 3 tables.

  17. Ceramification: A plutonium immobilization process

    SciTech Connect

    Rask, W.C.; Phillips, A.G.

    1996-05-01

    This paper describes a low temperature technique for stabilizing and immobilizing actinide compounds using a combination process/storage vessel of stainless steel, in which measured amounts of actinide nitrate solutions and actinide oxides (and/or residues) are systematically treated to yield a solid article. The chemical ceramic process is based on a coating technology that produces rare earth oxide coatings for defense applications involving plutonium. The final product of this application is a solid, coherent actinide oxide with process-generated encapsulation that has long-term environmental stability. Actinide compounds can be stabilized as pure materials for ease of re-use or as intimate mixtures with additives such as rare earth oxides to increase their degree of proliferation resistance. Starting materials for the process can include nitrate solutions, powders, aggregates, sludges, incinerator ashes, and others. Agents such as cerium oxide or zirconium oxide may be added as powders or precursors to enhance the properties of the resulting solid product. Additives may be included to produce a final product suitable for use in nuclear fuel pellet production. The process is simple and reduces the time and expense for stabilizing plutonium compounds. It requires a very low equipment expenditure and can be readily implemented into existing gloveboxes. The process is easily conducted with less associated risk than proposed alternative technologies.

  18. Plutonium focus area. Technology summary

    SciTech Connect

    1997-09-01

    The Assistant Secretary for the Office of Environmental Management (EM) at the U.S. Department of Energy (DOE) chartered the Plutonium Focus Area (PFA) in October 1995. The PFA {open_quotes}...provides for peer and technical reviews of research and development in plutonium stabilization activities...{close_quotes} In addition, the PFA identifies and develops relevant research and technology. The purpose of this document is to focus attention on the requirements used to develop research and technology for stabilization, storage, and preparation for disposition of nuclear materials. The PFA Technology Summary presents the approach the PFA uses to identify, recommend, and review research. It lists research requirements, research being conducted, and gaps where research is needed. It also summarizes research performed by the PFA in the traditional research summary format. This document encourages researchers and commercial enterprises to do business with PFA by submitting research proposals or {open_quotes}white papers.{close_quotes} In addition, it suggests ways to increase the likelihood that PFA will recommend proposed research to the Nuclear Materials Stabilization Task Group (NMSTG) of DOE.

  19. 10 CFR 140.108 - Appendix H-Form of indemnity agreement with licensees possessing plutonium for use in plutonium...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of... Appendixes to Part 140 § 140.108 Appendix H—Form of indemnity agreement with licensees possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of...

  20. 10 CFR 140.108 - Appendix H-Form of indemnity agreement with licensees possessing plutonium for use in plutonium...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of... Appendixes to Part 140 § 140.108 Appendix H—Form of indemnity agreement with licensees possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of...

  1. 10 CFR 140.108 - Appendix H-Form of indemnity agreement with licensees possessing plutonium for use in plutonium...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of... Appendixes to Part 140 § 140.108 Appendix H—Form of indemnity agreement with licensees possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of...

  2. 10 CFR 140.108 - Appendix H-Form of indemnity agreement with licensees possessing plutonium for use in plutonium...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of... Appendixes to Part 140 § 140.108 Appendix H—Form of indemnity agreement with licensees possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of...

  3. Volatile fluoride process for separating plutonium from other materials

    DOEpatents

    Spedding, F. H.; Newton, A. S.

    1959-04-14

    The separation of plutonium from uranium and/or fission products by formation of the higher fluorides off uranium and/or plutonium is described. Neutronirradiated uranium metal is first converted to the hydride. This hydrided product is then treated with fluorine at about 315 deg C to form and volatilize UF/sub 6/ leaving plutonium behind. Thc plutonium may then be separated by reacting the residue with fluorine at about 5004DEC and collecting the volatile plutonium fluoride thus formed.

  4. VOLATILE FLUORIDE PROCESS FOR SEPARATING PLUTONIUM FROM OTHER MATERIALS

    DOEpatents

    Spedding, F.H.; Newton, A.S.

    1959-04-14

    The separation of plutonium from uranium and/or tission products by formation of the higher fluorides of uranium and/or plutonium is discussed. Neutronirradiated uranium metal is first convcrted to the hydride. This hydrided product is then treatced with fluorine at about 315 deg C to form and volatilize UF/sup 6/ leaving plutonium behind. The plutonium may then be separated by reacting the residue with fluorine at about 500 deg C and collecting the volatile plutonium fluoride thus formed.

  5. Plutonium in the atmosphere: A global perspective.

    PubMed

    Thakur, P; Khaing, H; Salminen-Paatero, S

    2017-09-01

    A number of potential source terms have contributed plutonium isotopes to the atmosphere. The atmospheric nuclear weapon tests conducted between 1945 and 1980 and the re-entry of the burned SNAP-9A satellite in 1964, respectively. It is generally believed that current levels of plutonium in the stratosphere are negligible and compared with the levels generally found at surface-level air. In this study, the time trend analysis and long-term behavior of plutonium isotopes ((239+240)Pu and (238)Pu) in the atmosphere were assessed using historical data collected by various national and international monitoring networks since 1960s. An analysis of historical data indicates that (239+240)Pu concentration post-1984 is still frequently detectable, whereas (238)Pu is detected infrequently. Furthermore, the seasonal and time-trend variation of plutonium concentration in surface air followed the stratospheric trends until the early 1980s. After the last Chinese test of 1980, the plutonium concentrations in surface air dropped to the current levels, suggesting that the observed concentrations post-1984 have not been under stratospheric control, but rather reflect the environmental processes such as resuspension. Recent plutonium atmospheric air concentrations data show that besides resuspension, other environmental processes such as global dust storms and biomass burning/wildfire also play an important role in redistributing plutonium in the atmosphere. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. How much plutonium does North Korea have?

    SciTech Connect

    Albright, D.

    1994-09-01

    U.S. intelligence discovered in the 1980s that North Korea was building a small nuclear reactor. The reactor was described as a gas-cooled, graphite-moderated model similar to those Britian and France used to produce electric power as well as plutonium for nuclear weapons. When Western nations expressed concern about the reactor Russia pressed North Korea to sign the Non-Proliferation Treaty (NPT) which it did on December 12, 1985. However, North Korea stalled on signing the required safeguards agreement that allows the International Atomic Energy Agency (IAEA) to inspect nuclear facilities until January 1992. Inspections by the IAEA revealed discrepancies with the amounts of plutonium separated as declared by the North Koreans. The IAEA also received reports that two North Korean waste sites were hidden. By February 1993 the IAEA and the North Koreans has reached an impasse: North Koreas initial declarations of plutonium inventory could not be confirmed and North Korea refused to cooperate. At the least, North Korea admits to having separated 100 grams of plutonium. At the most, worst case estimate, they could have a total of 6 - 13 kilograms of separated plutonium. A first nuclear weapon can require up to 10 kilograms of weapon-grade plutonium. Any settlement needs to include a way to insure that the IAEA can verify North Korea`s past nuclear activities and determine the amount of plutonium that may have been separated in the past. 2 refs.

  7. Cristallinité de l'illite.Le POINT SUR...

    NASA Astrophysics Data System (ADS)

    Kübler, Bernard; Jaboyedoff, Michel

    2000-07-01

    The illite-crystallinity (IC) method was developed during the early 1960s, first in Texas and later in France. It was applied in petroleum exploration to detect diagenetic stages, but essentially to characterize the ultimate evolution stages before metamorphism. This empirical approach had no precise theoretical support for clay mineralogists or crystallographic scientists. With the development of computerised XRD treatments, the application field of the IC method has essentially been for the anchizonal and its immediate limits, for which the method is most accurate. It corresponds to an indirect measurement of the mean consecutive illite layers contained in coherent scattering domains of mixed-layer illite-smectite. Its application field went beyond petroleum exploration to be applied to regional geology in studies of low-metamorphic orogenic belts.

  8. Remarques sur le Passif (suite) (Remarks on the Passive, Continued)

    ERIC Educational Resources Information Center

    Pinchon, Jacqueline

    1977-01-01

    The continuation of articles on the passive voice appearing in the "Grammaire vivante" section of the periodical. The production of the passive sentence is considered under two headings: the simple verb and the complex verbal group. (Text is in French.) (AMH)

  9. AIDS Resource Directory and Repertoire de ressources sur le SIDA.

    ERIC Educational Resources Information Center

    Department of National Health and Welfare, Ottawa (Ontario).

    This set of documents presents directories of resources on the topic of Acquired Immune Deficiency Syndrome (AIDS) available in Canada in English and in French. The first section in each directory contains a list of names, addresses, and telephone numbers of organizations from which readers may obtain the listed resources. Resources are then…

  10. AIDS Resource Directory and Repertoire de ressources sur le SIDA.

    ERIC Educational Resources Information Center

    Department of National Health and Welfare, Ottawa (Ontario).

    This set of documents presents directories of resources on the topic of Acquired Immune Deficiency Syndrome (AIDS) available in Canada in English and in French. The first section in each directory contains a list of names, addresses, and telephone numbers of organizations from which readers may obtain the listed resources. Resources are then…

  11. Excess Weapons Plutonium Immobilization in Russia

    SciTech Connect

    Jardine, L.; Borisov, G.B.

    2000-04-15

    The joint goal of the Russian work is to establish a full-scale plutonium immobilization facility at a Russian industrial site by 2005. To achieve this requires that the necessary engineering and technical basis be developed in these Russian projects and the needed Russian approvals be obtained to conduct industrial-scale immobilization of plutonium-containing materials at a Russian industrial site by the 2005 date. This meeting and future work will provide the basis for joint decisions. Supporting R&D projects are being carried out at Russian Institutes that directly support the technical needs of Russian industrial sites to immobilize plutonium-containing materials. Special R&D on plutonium materials is also being carried out to support excess weapons disposition in Russia and the US, including nonproliferation studies of plutonium recovery from immobilization forms and accelerated radiation damage studies of the US-specified plutonium ceramic for immobilizing plutonium. This intriguing and extraordinary cooperation on certain aspects of the weapons plutonium problem is now progressing well and much work with plutonium has been completed in the past two years. Because much excellent and unique scientific and engineering technical work has now been completed in Russia in many aspects of plutonium immobilization, this meeting in St. Petersburg was both timely and necessary to summarize, review, and discuss these efforts among those who performed the actual work. The results of this meeting will help the US and Russia jointly define the future direction of the Russian plutonium immobilization program, and make it an even stronger and more integrated Russian program. The two objectives for the meeting were to: (1) Bring together the Russian organizations, experts, and managers performing the work into one place for four days to review and discuss their work with each other; and (2) Publish a meeting summary and a proceedings to compile reports of all the excellent

  12. RECOVERY OF PLUTONIUM FROM AQUEOUS SOLUTIONS

    DOEpatents

    Reber, E.J.

    1959-09-01

    A process is described for recovering plutonium values from aqueous solutions by precipitation on bismuth phosphate. The plutonium is secured in its tetravalent state. bismuth salt is added to the solution, and ant excess of phosphoric acid anions is added to the solution in two approximately equal installments. The rate of addition of the first installment is about two to three times as high as the rate of addition of the second installment, whereby a precipitate of bismuth phosphate forms, the precipitate carrying the plutonium values. The precipitate is separated from the solution.

  13. SEPARATION OF URANIUM, PLUTONIUM AND FISSION PRODUCTS

    DOEpatents

    Nicholls, C.M.; Wells, I.; Spence, R.

    1959-10-13

    The separation of uranium and plutonium from neutronirradiated uranium is described. The neutron-irradiated uranium is dissolved in nitric acid to provide an aqueous solution 3N in nitric acid. The fission products of the solution are extruded by treating the solution with dibutyl carbitol substantially 1.8N in nitric acid. The organic solvent phase is separated and neutralized with ammonium hydroxide and the plutonium reduced with hydroxylamine base to the trivalent state. Treatment of the mixture with saturated ammonium nitrate extracts the reduced plutonium and leaves the uranium in the organic solvent.

  14. Immobilization of excess weapons plutonium in Russia

    SciTech Connect

    Borisov, G B; Jardine, L J; Mansourov, O A

    1999-01-25

    In this paper, we examine the logic and framework for the development of a capability to immobilize excess Russian weapons plutonium by the year 2004. The initial activities underway in Russia, summarized here, include engineering feasibility studies of the immobilization of plutonium-containing materials at the Krasnoyarsk and Mayak industrial sites. In addition, research and development (R&D) studies are underway at Russian institutes to develop glass and ceramic forms suitable for the immobilization of plutonium-containing materials, residues, and wastes and for their geologic disposal.

  15. Removal of plutonium from hepatic tissue

    DOEpatents

    Lindenbaum, Arthur; Rosenthal, Marcia W.

    1979-01-01

    A method is provided for removing plutonium from hepatic tissues by introducing into the body and blood stream a solution of the complexing agent DTPA and an adjunct thereto. The adjunct material induces aberrations in the hepatic tissue cells and removes intracellularly deposited plutonium which is normally unavailable for complexation with the DTPA. Once the intracellularly deposited plutonium has been removed from the cell by action of the adjunct material, it can be complexed with the DTPA present in the blood stream and subsequently removed from the body by normal excretory processes.

  16. HENC performance evaluation and plutonium calibration

    SciTech Connect

    Menlove, H.O.; Baca, J.; Pecos, J.M.; Davidson, D.R.; McElroy, R.D.; Brochu, D.B.

    1997-10-01

    The authors have designed a high-efficiency neutron counter (HENC) to increase the plutonium content in 200-L waste drums. The counter uses totals neutron counting, coincidence counting, and multiplicity counting to determine the plutonium mass. The HENC was developed as part of a Cooperative Research and Development Agreement between the Department of Energy and Canberra Industries. This report presents the results of the detector modifications, the performance tests, the add-a-source calibration, and the plutonium calibration at Los Alamos National Laboratory (TA-35) in 1996.

  17. Plutonium Immobilization Can Loading Conceptual Design

    SciTech Connect

    Kriikku, E.

    1999-05-13

    'The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report discusses the Plutonium Immobilization can loading conceptual design and includes a process block diagram, process description, preliminary equipment specifications, and several can loading issues. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas.'

  18. NON-CORROSIVE PLUTONIUM FUEL SYSTEMS

    DOEpatents

    Coffinberry, A.S.; Waber, J.T.

    1962-10-23

    An improved plutonium reactor liquid fuel is described for utilization in a nuclear reactor having a tantalum fuel containment vessel. The fuel consists of plutonium and a diluent such as iron, cobalt, nickel, cerium, cerium-- iron, cerium--cobalt, cerium--nickel, and cerium--copper, and an additive of carbon and silicon. The carbon and silicon react with the tantalum container surface to form a coating that is self-healing and prevents the corrosive action of liquid plutonium on the said tantalum container. (AEC)

  19. Weapons-grade plutonium dispositioning. Volume 4. Plutonium dispositioning in light water reactors

    SciTech Connect

    Sterbentz, J.W.; Olsen, C.S.; Sinha, U.P.

    1993-06-01

    This study is in response to a request by the Reactor Panel Subcommittee of the National Academy of Sciences (NAS) Committee on International Security and Arms Control (CISAC) to evaluate the feasibility of using plutonium fuels (without uranium) for disposal in existing conventional or advanced light water reactor (LWR) designs and in low temperature/pressure LWR designs that might be developed for plutonium disposal. Three plutonium-based fuel forms (oxides, aluminum metallics, and carbides) are evaluated for neutronic performance, fabrication technology, and material and compatibility issues. For the carbides, only the fabrication technologies are addressed. Viable plutonium oxide fuels for conventional or advanced LWRs include plutonium-zirconium-calcium oxide (PuO{sub 2}-ZrO{sub 2}-CaO) with the addition of thorium oxide (ThO{sub 2}) or a burnable poison such as erbium oxide (Er{sub 2}O{sub 3}) or europium oxide (Eu{sub 2}O{sub 3}) to achieve acceptable neutronic performance. Thorium will breed fissile uranium that may be unacceptable from a proliferation standpoint. Fabrication of uranium and mixed uranium-plutonium oxide fuels is well established; however, fabrication of plutonium-based oxide fuels will require further development. Viable aluminum-plutonium metallic fuels for a low temperature/pressure LWR include plutonium aluminide in an aluminum matrix (PuAl{sub 4}-Al) with the addition of a burnable poison such as erbium (Er) or europium (Eu). Fabrication of low-enriched plutonium in aluminum-plutonium metallic fuel rods was initially established 30 years ago and will require development to recapture and adapt the technology to meet current environmental and safety regulations. Fabrication of high-enriched uranium plate fuel by the picture-frame process is a well established process, but the use of plutonium would require the process to be upgraded in the United States to conform with current regulations and minimize the waste streams.

  20. Spectrophotometric determination of plutonium-239 based on the spectrum of plutonium(III) chloride

    SciTech Connect

    Temer, D.J.; Walker, L.F.

    1994-07-01

    This report describes a spectrophotometric method for determining plutonium-239 (Pu-239) based on the spectrum of Pu(III) chloride. The authors used the sealed-reflux technique for the dissolution of plutonium oxide with hydrochloric acid (HCl) and small amounts of nitric and hydrofluoric acids. To complex the fluoride, they added zirconium, and to reduce plutonium to Pu(III), they added ascorbic acid. They then adjusted the solution to a concentration of 2 M HCl and measured the absorbances at five wavelengths of the Pu(III) chloride spectrum. This spectrophotometric determination can also be applied to samples of plutonium metal dissolved in HCl.

  1. PRODUCTION OF PLUTONIUM FLUORIDE FROM BISMUTH PHOSPHATE PRECIPITATE CONTAINING PLUTONIUM VALUES

    DOEpatents

    Brown, H.S.; Bohlmann, E.G.

    1961-05-01

    A process is given for separating plutonium from fission products present on a bismuth phosphate carrier. The dried carrier is first treated with hydrogen fluoride at between 500 and 600 deg C whereby some fission product fluorides volatilize away from plutonium tetrafluoride, and nonvolatile fission product fluorides are formed then with anhydrous fluorine at between 400 and 500 deg C. Bismuth and plutonium distill in the form of volatile fluorides away from the nonvolatile fission product fluorides. The bismuth and plutonium fluorides are condensed at below 290 deg C.

  2. Opportunities in Plutonium Metallurgical Research

    SciTech Connect

    Schwartz, A J

    2006-12-19

    This is an exciting time to be involved in plutonium metallurgical research. Over the past few years, there have been significant advances in our understanding of the fundamental materials science of this unusual metal, particularly in the areas of self-irradiation induced aging of Pu, the equilibrium phase diagram, the homogenization of {delta}-phase alloys, the crystallography and morphology of the {alpha}{prime}-phase resulting from the isothermal martensitic phase transformation, and the phonon dispersion curves, among many others. In addition, tremendous progress has been made, both experimentally and theoretically, in our understanding of the condensed matter physics and chemistry of the actinides, particularly in the area of electronic structure. Although these communities have made substantial progress, many challenges still remain. This brief overview will address a number of important challenges that we face in fully comprehending the metallurgy of Pu with a specific focus on aging and phase transformations.

  3. PLUTONIUM METALLOGRAPHY AT LOS ALAMOS

    SciTech Connect

    PEREYRA, RAMIRO A.; LOVATO, DARRYL

    2007-01-08

    From early days of the Manhattan program to today, scientists and engineers have continued to investigate the metallurgical properties of plutonium (Pu). Although issues like aging was not a concern to the early pioneers, today the reliability of our aging stockpile is of major focus. And as the country moves toward a new generation of weapons similar problems that the early pioneers faced such as compatibility, homogeneity and malleability have come to the forefront. And metallography will continue to be a principle tool for the resolution of old and new issues. Standard metallographic techniques are used for the preparation of plutonium samples. The samples are first cut with a slow speed idamond saw. After mounting in Epon 815 epoxy resin, the samples are ground through 600 grit silicon carbide paper. PF 5070 (a Freon substitute) is used as a coolant, lubricant, and solvent for most operations. Rough mechanical polished is done with 9-{mu} diamond using a nap less cloth, for example nylon or cotton. Final polish is done with 1-{mu} diamond on a nappy cloth such as sylvet. Ethyl alcohol is then used ultrasonically to clean the samples before electro polishing. The sample is then electro-polished and etched in an electrolyte containing 10% nitric acid, and 90% dimethyleneformalmide. Ethyl alcohol is used as a final cleaning agent. Although standard metallographic preparation techniques are used, there are several reasons why metallography of Pu is difficult and challenging. Firstly, because of the health hazards associated with its radioactive properties, sample preparation is conducted in glove boxes. Figure 1 shows the metallography line, in an R and D facility. Since they are designed to be negative in pressure to the laboratory, cross-contamination of abrasives is a major problem. In addition, because of safety concerns and waste issues, there is a limit to the amount of solvent that can be used. Secondly, Pu will readily hydride or oxidize when in contact

  4. Adolescence et pornographie sur la toile

    PubMed Central

    Haza, Marion

    2012-01-01

    Dans cet article, nous abordons la question de l’accès à la pornographie sur Internet par les adolescents. Nous déclinons plusieurs facettes de ces rencontres: la rencontre «fortuite», quand les adolescents sont confrontés à des images intempestives, des publicités ou spams avec des contenus pornographiques; la rencontre «spectatrice», quand les adolescents cherchent activement des vidéos ou photos mettant en scène la sexualité; et enfin la rencontre «actrice», quand les adolescents se mettent en scène eux-mêmes, seuls ou à plusieurs, de façon pornographique sur le Net. A partir d’exemple, nous réfléchissons aux enjeux de ces rencontres virtuelles précoces de la sexualité adulte par rapport au développement adolescent et à la représentation de leur propre sexualité en construction. PMID:22876261

  5. A Plutonium Storage Container Pressure Measurement Technique

    SciTech Connect

    Grim, T.J.

    2002-05-10

    Plutonium oxide and metal awaiting final disposition are currently stored at the Savannah River Site in crimp sealed food pack cans. Surveillances to ensure continued safe storage of the cans include periodic lid deflection measurements using a mechanical device.

  6. SEPARATION OF URANIUM, PLUTONIUM, AND FISSION PRODUCTS

    DOEpatents

    Spence, R.; Lister, M.W.

    1958-12-16

    Uranium and plutonium can be separated from neutron-lrradiated uranium by a process consisting of dissolvlng the lrradiated material in nitric acid, saturating the solution with a nitrate salt such as ammonium nitrate, rendering the solution substantially neutral with a base such as ammonia, adding a reducing agent such as hydroxylamine to change plutonium to the trivalent state, treating the solution with a substantially water immiscible organic solvent such as dibutoxy diethylether to selectively extract the uranium, maklng the residual aqueous solutlon acid with nitric acid, adding an oxidizing agent such as ammonlum bromate to oxidize the plutonium to the hexavalent state, and selectlvely extracting the plutonium by means of an immlscible solvent, such as dibutoxy dlethyletber.

  7. IMPROVED PROCESS OF PLUTONIUM CARRIER PRECIPITATION

    DOEpatents

    Faris, B.F.

    1959-06-30

    This patent relates to an improvement in the bismuth phosphate process for separating and recovering plutonium from neutron irradiated uranium, resulting in improved decontamination even without the use of scavenging precipitates in the by-product precipitation step and subsequently more complete recovery of the plutonium in the product precipitation step. This improvement is achieved by addition of fluomolybdic acid, or a water soluble fluomolybdate, such as the ammonium, sodium, or potassium salt thereof, to the aqueous nitric acid solution containing tetravalent plutonium ions and contaminating fission products, so as to establish a fluomolybdate ion concentration of about 0.05 M. The solution is then treated to form the bismuth phosphate plutonium carrying precipitate.

  8. Recent plutonium metal production experience at Hanford

    SciTech Connect

    Gibson, M.W.; Nyman, D.H. )

    1989-11-01

    Plutonium metal is produced at the Hanford site in the remote mechanical C (RMC) line. The line is housed in the plutonium finishing plant (PFP). The PFP is operated by the Westinghouse Hanford Company for the U.S. Department of Energy. The RMC line was built in the early 1960s and operated until 1973 when it was shut down. The line was restarted in 1985 and has operated on a campaign basis since that time. The RMC line converts plutonium nitrate solution to plutonium metal in the classic precipitation/calcination/fluorination/reduction process. The operations are contained in glove boxes with a dry air atmosphere. Most of the process is remotely controlled from a central control room. Numerous process improvements were made in the line before initiating operations in 1985 and in 1988. These changes, in conjunction with improved conduct of operations, have resulted in improved yields.

  9. Pulmonary carcinogenesis from plutonium-containing particles

    SciTech Connect

    Thomas, R.G.; Smith, D.M.; Anderson, E.C.

    1980-01-01

    Plutonium administered as an alpha radiation source to the respiratory tracts of Syrian hamsters has resulted in various incidences of neoplasia. Adenomas are the primary lung tumor observed, but adenocarcinomas are also prevalent.

  10. Design and evaluation of plutonium electrorefining cells

    SciTech Connect

    Not Available

    1987-01-01

    A plutonium electrorefining cell was designed for stationary furnace operation. This cell and the LANL electrorefining cell were evaluated. Results of this evaluation and comparison to existing production electrorefining at Rocky Flats are presented.

  11. Plutonium finishing plant dangerous waste training plan

    SciTech Connect

    ENTROP, G.E.

    1999-05-24

    This training plan describes general requirements, worker categories, and provides course descriptions for operation of the Plutonium Finish Plant (PFP) waste generation facilities, permitted treatment, storage and disposal (TSD) units, and the 90-Day Accumulation Areas.

  12. Leaching behavior of particulate plutonium oxide

    SciTech Connect

    Kosiewicz, S.T.; Heaton, R.C.

    1985-08-01

    Different size cuts of /sup 238/PuO/sub 2/ particles were mixed with deionized water at two temperatures in a shaker bath. The gross plutonium concentration in the water was measured, as well as that portion of the plutonium retained on a 0.1-..mu..m pore filter. The concentration of the plutonium released was primarily a function of the surface area of the particles. The release rate of plutonium into the water for the size cut with particles having diameters between 30 and 20 ..mu..m was 3 ng/m/sup 2//s; this rate is within the range observed in past experiments involving aquatic environments. The amount of material retained by the 0.1-..mu..m filters decreased with increasing time, suggesting that size reduction or removal processes occurred. 6 refs., 3 figs., 9 tabs.

  13. Plutonium focus area: Technology summary

    SciTech Connect

    1996-03-01

    To ensure research and development programs focus on the most pressing environmental restoration and waste management problems at the U.S. Department of Energy (DOE), the Assistant Secretary for the Office of Environmental Management (EM) established a working group in August 1993 to implement a new approach to research and technology development. As part of this approach, EM developed a management structure and principles that led to creation of specific focus areas. These organizations were designed to focus scientific and technical talent throughout DOE and the national scientific community on major environmental restoration and waste management problems facing DOE. The focus area approach provides the framework for inter-site cooperation and leveraging of resources on common problems. After the original establishment of five major focus areas within the Office of Technology Development (EM-50), the Nuclear Materials Stabilization Task Group (NMSTG, EM-66) followed EM-50`s structure and chartered the Plutonium Focus Area (PFA). NMSTG`s charter to the PFA, described in detail later in this book, plays a major role in meeting the EM-66 commitments to the Defense Nuclear Facilities Safety Board (DNFSB). The PFA is a new program for FY96 and as such, the primary focus of revision 0 of this Technology Summary is an introduction to the Focus Area; its history, development, and management structure, including summaries of selected technologies being developed. Revision 1 to the Plutonium Focus Area Technology Summary is slated to include details on all technologies being developed, and is currently planned for release in August 1996. The following report outlines the scope and mission of the Office of Environmental Management, EM-60, and EM-66 organizations as related to the PFA organizational structure.

  14. PLUTONIUM CARRIER METATHESIS WITH ORGANIC REAGENT

    DOEpatents

    Thompson, S.G.

    1958-07-01

    A method is described for converting a plutonium containing bismuth phosphate carrier precipitate Into a compositton more readily soluble in acid. The method consists of dissolving the bismuth phosphate precipitate in an aqueous solution of alkali metal hydroxide, and adding one of a certaia group of organic compounds, e.g., polyhydric alcohols or a-hydrorycarboxylic acids. The mixture is then heated causiing formation of a bismuth hydroxide precipitate containing plutonium which may be readily dissolved in nitric acid for further processing.

  15. Plutonium: The first 50 years. United States plutonium production, acquisition, and utilization from 1944 through 1994

    SciTech Connect

    1996-02-01

    The report contains important newly declassified information regarding the US production, acquisition, and removals of plutonium. This new information, when combined with previously declassified data, has allowed the DOE to issue, for the first time, a truly comprehensive report on the total DOE plutonium inventory. At the December 7, 1993, Openness Press Conference, the DOE declassified the plutonium inventories at eight locations totaling 33.5 metric tons (MT). This report declassifies the remainder of the DOE plutonium inventory. Newly declassified in this report is the quantity of plutonium at the Pantex Site, near Amarillo, Texas, and in the US nuclear weapons stockpile of 66.1 MT, which, when added to the previously released inventory of 33.5 MT, yields a total plutonium inventory of 99.5 MT. This report will document the sources which built up the plutonium inventory as well as the transactions which have removed plutonium from that inventory. This report identifies four sources that add plutonium to the DOE/DoD inventory, and seven types of transactions which remove plutonium from the DOE/DoD inventory. This report also discusses the nuclear material control and accountability system which records all nuclear material transactions, compares records with inventory and calculates material balances, and analyzes differences to verify that nuclear materials are in quantities as reported. The DOE believes that this report will aid in discussions in plutonium storage, safety, and security with stakeholders as well as encourage other nations to declassify and release similar data. These data will also be available for formulating policies with respect to disposition of excess nuclear materials. The information in this report is based on the evaluation of available records. The information contained in this report may be updated or revised in the future should additional or more detailed data become available.

  16. A DGT technique for plutonium bioavailability measurements.

    PubMed

    Cusnir, Ruslan; Steinmann, Philipp; Bochud, François; Froidevaux, Pascal

    2014-09-16

    The toxicity of heavy metals in natural waters is strongly dependent on the local chemical environment. Assessing the bioavailability of radionuclides predicts the toxic effects to aquatic biota. The technique of diffusive gradients in thin films (DGT) is largely exploited for bioavailability measurements of trace metals in waters. However, it has not been applied for plutonium speciation measurements yet. This study investigates the use of DGT technique for plutonium bioavailability measurements in chemically different environments. We used a diffusion cell to determine the diffusion coefficients (D) of plutonium in polyacrylamide (PAM) gel and found D in the range of 2.06-2.29 × 10(-6) cm(2) s(-1). It ranged between 1.10 and 2.03 × 10(-6) cm(2) s(-1) in the presence of fulvic acid and in natural waters with low DOM. In the presence of 20 ppm of humic acid of an organic-rich soil, plutonium diffusion was hindered by a factor of 5, with a diffusion coefficient of 0.50 × 10(-6) cm(2) s(-1). We also tested commercially available DGT devices with Chelex resin for plutonium bioavailability measurements in laboratory conditions and the diffusion coefficients agreed with those from the diffusion cell experiments. These findings show that the DGT methodology can be used to investigate the bioaccumulation of the labile plutonium fraction in aquatic biota.

  17. Disposal of Surplus Weapons Grade Plutonium

    SciTech Connect

    H. Alsaed; P. Gottlieb

    2000-09-12

    The Office of Fissile Materials Disposition is responsible for disposing of inventories of surplus US weapons-usable plutonium and highly enriched uranium as well as providing, technical support for, and ultimate implementation of, efforts to obtain reciprocal disposition of surplus Russian plutonium. On January 4, 2000, the Department of Energy issued a Record of Decision to dispose of up to 50 metric tons of surplus weapons-grade plutonium using two methods. Up to 17 metric tons of surplus plutonium will be immobilized in a ceramic form, placed in cans and embedded in large canisters containing high-level vitrified waste for ultimate disposal in a geologic repository. Approximately 33 metric tons of surplus plutonium will be used to fabricate MOX fuel (mixed oxide fuel, having less than 5% plutonium-239 as the primary fissile material in a uranium-235 carrier matrix). The MOX fuel will be used to produce electricity in existing domestic commercial nuclear reactors. This paper reports the major waste-package-related, long-term disposal impacts of the two waste forms that would be used to accomplish this mission. Particular emphasis is placed on the possibility of criticality. These results are taken from a summary report published earlier this year.

  18. Plutonium Finishing Plant safety evaluation report

    SciTech Connect

    Not Available

    1995-01-01

    The Plutonium Finishing Plant (PFP) previously known as the Plutonium Process and Storage Facility, or Z-Plant, was built and put into operation in 1949. Since 1949 PFP has been used for various processing missions, including plutonium purification, oxide production, metal production, parts fabrication, plutonium recovery, and the recovery of americium (Am-241). The PFP has also been used for receipt and large scale storage of plutonium scrap and product materials. The PFP Final Safety Analysis Report (FSAR) was prepared by WHC to document the hazards associated with the facility, present safety analyses of potential accident scenarios, and demonstrate the adequacy of safety class structures, systems, and components (SSCs) and operational safety requirements (OSRs) necessary to eliminate, control, or mitigate the identified hazards. Documented in this Safety Evaluation Report (SER) is DOE`s independent review and evaluation of the PFP FSAR and the basis for approval of the PFP FSAR. The evaluation is presented in a format that parallels the format of the PFP FSAR. As an aid to the reactor, a list of acronyms has been included at the beginning of this report. The DOE review concluded that the risks associated with conducting plutonium handling, processing, and storage operations within PFP facilities, as described in the PFP FSAR, are acceptable, since the accident safety analyses associated with these activities meet the WHC risk acceptance guidelines and DOE safety goals in SEN-35-91.

  19. Complementary technologies for verification of excess plutonium

    SciTech Connect

    Langner, , D.G.; Nicholas, N.J.; Ensslin, N.; Fearey, B.L.; Mitchell, D.J.; Marlow, K.W.; Luke, S.J.; Gosnell, T.B.

    1998-12-31

    Three complementary measurement technologies have been identified as candidates for use in the verification of excess plutonium of weapons origin. These technologies: high-resolution gamma-ray spectroscopy, neutron multiplicity counting, and low-resolution gamma-ray spectroscopy, are mature, robust technologies. The high-resolution gamma-ray system, Pu-600, uses the 630--670 keV region of the emitted gamma-ray spectrum to determine the ratio of {sup 240}Pu to {sup 239}Pu. It is useful in verifying the presence of plutonium and the presence of weapons-grade plutonium. Neutron multiplicity counting is well suited for verifying that the plutonium is of a safeguardable quantity and is weapons-quality material, as opposed to residue or waste. In addition, multiplicity counting can independently verify the presence of plutonium by virtue of a measured neutron self-multiplication and can detect the presence of non-plutonium neutron sources. The low-resolution gamma-ray spectroscopic technique is a template method that can provide continuity of knowledge that an item that enters the a verification regime remains under the regime. In the initial verification of an item, multiple regions of the measured low-resolution spectrum form a unique, gamma-radiation-based template for the item that can be used for comparison in subsequent verifications. In this paper the authors discuss these technologies as they relate to the different attributes that could be used in a verification regime.

  20. Recovery of plutonium from nitric acid waste

    SciTech Connect

    Muscatello, A.C.; Saba, M.T.; Navratil, J.D.

    1986-12-21

    Seven candidate materials, each contained in a static-bed column, have been evaluated for removing plutonium from nitric acid waste. Three materials have insufficient capacity for plutonium: TBP (tri-n-butylphosphate) sorbed on Amberlite XAD-4 resin, O phi D(IB)CMPO (octylphenyl-N, N-diisobutylcarbamoylmethylphosphine oxide) sorbed on XAD-4, and Amberlite IRA-938 anion exchange resin. The remaining four materials reduced 10/sup -3/ g/l plutonium in 7.2M HNO/sub 3/ to low 10/sup -5/ g/l for 80 bed volumes (BV). The 10% breakthrough capacities for 3 x 10/sup -2/ g/l plutonium are: TOPO (tri-n-octylphosphine oxide) on XAD-4 - 1800 BV, DHDECMP (dihexyl-N, N-diethylcarbamoylmethylphosphonate) on XAD-4 - 960 BV, Dowex 1 x 4 - 840 BV, and DHDECMP + TBP - 640 BV. Based on these results and generally poor elution of all materials, TOPO on XAD-4 is recommended as the best candidate for recovery of plutonium followed by acid digestion or combustion of the TOPO to recover the concentrated plutonium.

  1. PROCESS OF FORMING PLUOTONIUM SALTS FROM PLUTONIUM EXALATES

    DOEpatents

    Garner, C.S.

    1959-02-24

    A process is presented for converting plutonium oxalate to other plutonium compounds by a dry conversion method. According to the process, lower valence plutonium oxalate is heated in the presence of a vapor of a volatile non- oxygenated monobasic acid, such as HCl or HF. For example, in order to produce plutonium chloride, the pure plutonium oxalate is heated to about 700 deg C in a slow stream of hydrogen plus HCl. By the proper selection of an oxidizing or reducing atmosphere, the plutonium halide product can be obtained in either the plus 3 or plus 4 valence state.

  2. SEPARATION OF PLUTONIUM FROM URANIUM AND FISSION PRODUCTS

    DOEpatents

    Boyd, G.E.; Adamson, A.W.; Schubert, J.; Russell, E.R.

    1958-10-01

    A chromatographic adsorption process is presented for the separation of plutonium from other fission products formed by the irradiation of uranium. The plutonium and the lighter element fission products are adsorbed on a sulfonated phenol-formaldehyde resin bed from a nitric acid solution containing the dissolved uranium. Successive washes of sulfuric, phosphoric, and nitric acids remove the bulk of the fission products, then an eluate of dilute phosphoric and nitric acids removes the remaining plutonium and fission products. The plutonium is selectively removed by passing this solution through zirconium phosphate, from which the plutonium is dissolved with nitric acid. This process provides a convenient and efficient means for isolating plutonium.

  3. Purification of aqueous plutonium chloride solutions via precipitation and washing.

    SciTech Connect

    Stroud, M. A.; Salazar, R. R.; Abney, Kent David; Bluhm, E. A.; Danis, J. A.

    2003-01-01

    Pyrochemical operations at Los Alamos Plutonium Facility (TA-55) use high temperature melt s of calcium chloride for the reduction of plutonium oxide to plutonium metal and hi gh temperature combined melts of sodium chloride and potassium chloride mixtures for the electrorefining purification of plutonium metal . The remaining plutonium and americium are recovered from thes e salts by dissolution in concentrated hydrochloric acid followed by either solvent extraction or io n exchange for isolation and ultimately converted to oxide after precipitation with oxalic acid . Figur e 1 illustrates the current aqueous chloride flow sheet used for plutonium processing at TA-55 .

  4. Human Factors Issues for Controlling Uninhabited Aerial Vehicles: Preliminary Findings in Support of the Canadian Forces Joint Unmanned Aerial Vehicle Surveillance Target Acquisition System Project (Incidence des Facteurs Humains sur le Pilotage des Vehicules Aeriens Telepilotes: Constatations Preliminaires a L’Appui du Projet de Systeme Interarmees D’Acquisition D’Objectif au Moyen de Vehicules Aeriens Telepilotes de Surveillance des Forces Canadiennes)

    DTIC Science & Technology

    2010-11-01

    DRDC Toronto TR 2009-043 21 ulcers (Costa, 1999). Chronic fatigue can also lead to hypertension, and ischemic heart diseases . Finally...accidents d’UAV. (2) L’opérateur qui contrôle l’UAV doit rester vigilant. (3) En raison de l’augmentation de l’utilisation d’UAV à grande autonomie , un...et grande autonomie (MALE). En conclusion, le présent rapport propose plusieurs recommandations, pour le court terme et le long terme, visant à

  5. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2006-11-01

    Glace et éclairs; Astéroïdes; Pluton; Avatars et avanie d'une petite planète (Xena, Eris); Nuage d'éthane sur Titan; Lacs de Titan; La NASA scrute Mars; Les express Mars et Venus; Cydonia, le visage sur Mars; Transit d'Ariel; Lune; Gonflée, la planète; Terres, terres!; Une planète extrasolaire aurait abrité de l'eau liquide; Des planètes au centre de la Voie Lactée; Anatomie d'un disque protoplanétaire; CHRX73 et pseudo-planète; Systèmes étranges; Premières galaxies; Voie Lactée; Neutrinos; RCW 86

  6. Grossesse sur cicatrice de césarienne: à propos d'un cas et revue de la literature

    PubMed Central

    Lachiri, Boutaina; Zazi, Abdelgheni; Benkerroum, Zineb; Hafidi, Moulay Rachid; Kouach, Jaouad; Rahali, Driss Moussaoui; Dehayni, Mohamed

    2015-01-01

    La grossesse sur cicatrice de césarienne est une forme rare de grossesse ectopique qui engage le pronostic vital et fonctionnel utérin par hémorragie ou par rupture utérine précoce. Nous rapportons le cas d'une grossesse ectopique sur cicatrice de césarienne diagnostiquée à 11 semaines d'aménorrhée suite à une aspiration blanche pour grossesse arrêtée chez une patiente de 43 ans porteuse d'un utérus bi-cicatriciel. A travers cette observation ainsi qu'une revue de la littérature les auteurs vont essayer de mettre le point sur les méthodes diagnostiques et thérapeutiques de cette entité rare afin d'améliorer la prise en charge. PMID:26213603

  7. Lignes directrices canadiennes sur la rhinosinusite chronique

    PubMed Central

    Kaplan, Alan

    2013-01-01

    Résumé Objectif Présenter un résumé clinique des lignes directrices canadiennes sur la rhinosinusite chronique (RSC) qui comporte des recommandations pertinentes aux médecins de famille. Qualité des données Les auteurs des lignes directrices ont effectué une recherche documentaire systématique dans la littérature médicale et ont rédigé une ébauche de recommandations. Une cote a été donnée à la fois en fonction de la fiabilité des données probantes et de la solidité des recommandations. On a sollicité les commentaires d’experts en contenu de l’extérieur, ainsi que l’aval des sociétés médicales (Association pour la microbiologie médicale et l’infectiologie Canada, Société canadienne d’allergie et d’immunologie clinique, Canadian Society of Otolaryngology—Head and Neck Surgery, Association canadienne des médecins d’urgence et Regroupement canadien des médecins de famille en santé respiratoire). Message principal Le diagnostic d’une RSC se fonde sur le type et la durée des symptômes et une constatation objective d’une inflammation de la muqueuse nasale ou des sinus paranasaux. La rhinosinusite chronique est catégorisée en fonction de la présence ou de l’absence de polypes nasaux et cette distinction entraîne des différences dans le traitement. On traite la rhinosinusite chronique avec polypes nasaux au moyen de corticostéroïdes par voie intranasale. Des antibiotiques sont recommandés quand les symptômes indiquent une infection (douleur ou purulence). Pour une RSC sans polypes nasaux, on recommande des corticostéroïdes par voie intranasale et des antibiotiques de deuxième ligne (par ex. combinaisons amoxicilline–acide clavulanique ou fluoroquinolones à activité accrue contre Gram positif). Une irrigation avec une solution saline, des stéroïdes par voie orale et des tests d’allergies pourraient être appropriées. Si le patient ne répond pas au traitement, il faudrait envisager d

  8. Influence des inclusions sur la rupture d'un acier faiblement allié

    NASA Astrophysics Data System (ADS)

    Hausild, P.; Berdin, C.; Bompard, P.; Prioul, C.

    2003-03-01

    L'étude de la rupture d'un acier faiblement allié dans le domaine de la transition ductile fragile a permis de mettre en évidence la présence croissante, avec la température de sollicitation, d'amas d'inclusions de seconde phase sur les surfaces de rupture. On montre, à l'aide de modélisations par éléments finis, que ces amas jouent néanmoins un rôle mineur dans le déclenchement du clivage. En revanche, leur influence sur la propagation de la rupture ductile est importante. On peut alors expliquer l'anisotropie de la résilience en prenant en compte la géométrie des inclusions et leur répartition spatiale.

  9. 16. VIEW OF GLOVE BOX WORKSTATIONS WITHIN THE PLUTONIUM BUTTON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. VIEW OF GLOVE BOX WORKSTATIONS WITHIN THE PLUTONIUM BUTTON BREAKOUT ROOM. (9/82) - Rocky Flats Plant, Plutonium Recovery Facility, Northwest portion of Rocky Flats Plant, Golden, Jefferson County, CO

  10. 69. INTERIOR, BUILDING 272 (PLUTONIUM STORAGE BUILDING) LOOKING SOUTHWEST THROUGH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    69. INTERIOR, BUILDING 272 (PLUTONIUM STORAGE BUILDING) LOOKING SOUTHWEST THROUGH DOOR-WAY INTO PLUTONIUM STORAGE AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  11. 71. INTERIOR, BUILDING 272 (PLUTONIUM STORAGE BUILDING) LOOKING NORTHEAST INTO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    71. INTERIOR, BUILDING 272 (PLUTONIUM STORAGE BUILDING) LOOKING NORTHEAST INTO PLUTONIUM STORAGE ROOM SHOWING CUBICLES FOR STORAGE. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  12. 17. VIEW OF THE FIRST PLUTONIUM BUTTON PRODUCED FROM THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. VIEW OF THE FIRST PLUTONIUM BUTTON PRODUCED FROM THE BUILDING 371 AQUEOUS RECOVERY OPERATION. (9/30/83) - Rocky Flats Plant, Plutonium Recovery Facility, Northwest portion of Rocky Flats Plant, Golden, Jefferson County, CO

  13. Magnetic excitations in plutonium monoantimonide

    SciTech Connect

    Lander, G.H.; Stirling, W.G.; Mignod, J.R.; Spirlet, J.C.; Rebezant, J.; Vogt, O.

    1985-01-01

    Neutron inelastic scattering studies of uranium compounds have illustrated the complexity of the interactions in this part of periodic table. Recently, large crystals of plutonium compounds have been grown at the Transuranium Institute, and we report here the first neutron inelastic scattering on PuSb. A monodomain sample of ferromagnetic PuSb was prepared by cooling in a field with H vector parallel to (001). We observe an almost dispersionless magnetic transition, assigned to arise within the GAMMA/sub 8/ ground state, with an energy of 4.3 THz. Surprisingly, the lowest frequency (3.5 THz) excitation occurs at the zone boundary, with a polarization along the wavevector. Theoretical predictions give the spin-wave gap and GAMMA/sub 8/-GAMMA/sub 7/ crystal field splitting (> 12 THz experimentally), but are presently unable to explain the lifting of the degeneracy of the longitudinal and transverse modes and the minimum of the former at the zone boundary. 7 refs., 3 figs.

  14. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2014-04-01

    Cartographie d’une naine brune; 2006DP14; Anatomie d’un astéroïde; L’astéroïde P/2013 R3; Formation des planètes; Planètes Kepler; Bêta Pictoris; Cratère Mojave; Les astéroïdes de la ceinture principale; Planète X; Mercure et la gravitation; Gloire sur Vénus; Galaxies elliptiques massives; Cas A; SN 2014J et les supernovae Ia; Le Grand Nuage de Magellan; Nébuleuse d’Andromède; ESO 137-001

  15. Preserving Plutonium-244 as a National Asset

    SciTech Connect

    Patton, Bradley D; Alexander, Charles W; Benker, Dennis; Collins, Emory D; Romano, Catherine E; Wham, Robert M

    2011-01-01

    Plutonium-244 (244 Pu) is an extremely rare and long-lived isotope of plutonium with a half-life of 80 million years. Measureable amounts of 244 Pu are found in neither reactor-grade nor weapons-grade plutonium. Production of this isotope requires a very high thermal flux to permit the two successive neutron captures that convert 242 Pu to 243 Pu to 244 Pu, particularly given the short (about 5 hour) half-life of 243 Pu. Such conditions simply do not exist in plutonium production processes. Therefore, 244 Pu is ideal for precise radiochemical analyses measuring plutonium material properties and isotopic concentrations in items containing plutonium. Isotope dilution mass spectrometry is about ten times more sensitive when using 244 Pu rather than 242 Pu for determining plutonium isotopic content. The isotope can also be irradiated in small quantities to produce superheavy elements. The majority of the existing global inventory of 244 Pu is contained in the outer housing of Mark-18A targets at the Savannah River Site (SRS). The total inventory is about 20 grams of 244 Pu in about 400 grams of plutonium distributed among the 65 targets. Currently, there are no specific plans to preserve these targets. Although the cost of separating and preserving this material would be considerable, it is trivial in comparison to new production costs. For all practical purposes, the material is irreplaceable, because new production would cost billions of dollars and require a series of irradiation and chemical separation cycles spanning up to 50 years. This paper will discuss a set of options for overcoming the significant challenges to preserve the 244 Pu as a National Asset: (1) the need to relocate the material from SRS in a timely manner, (2) the need to reduce the volume of material to the extent possible for storage, and (3) the need to establish an operational capability to enrich the 244 Pu in significant quantities. This paper suggests that if all the Mark-18A plutonium is

  16. PROCESS OF ELIMINATING HYDROGEN PEROXIDE IN SOLUTIONS CONTAINING PLUTONIUM VALUES

    DOEpatents

    Barrick, J.G.; Fries, B.A.

    1960-09-27

    A procedure is given for peroxide precipitation processes for separating and recovering plutonium values contained in an aqueous solution. When plutonium peroxide is precipitated from an aqueous solution, the supernatant contains appreciable quantities of plutonium and peroxide. It is desirable to process this solution further to recover plutonium contained therein, but the presence of the peroxide introduces difficulties; residual hydrogen peroxide contained in the supernatant solution is eliminated by adding a nitrite or a sulfite to this solution.

  17. COLUMBIC OXIDE ADSORPTION PROCESS FOR SEPARATING URANIUM AND PLUTONIUM IONS

    DOEpatents

    Beaton, R.H.

    1959-07-14

    A process is described for separating plutonium ions from a solution of neutron irradiated uranium in which columbic oxide is used as an adsorbert. According to the invention the plutonium ion is selectively adsorbed by Passing a solution containing the plutonium in a valence state not higher than 4 through a porous bed or column of granules of hydrated columbic oxide. The adsorbed plutonium is then desorbed by elution with 3 N nitric acid.

  18. Dispersion of plutonium from contaminated pond sediments

    USGS Publications Warehouse

    Rees, T.F.; Cleveland, J.M.; Carl, Gottschall W.

    1978-01-01

    Sediment-water distributions of plutonium as a function of pH and contact time are investigated in a holding pond at the Rocky Flats plant of the Department of Energy. Although plutonium has been shown to sorb from natural waters onto sediments, the results of this study indicate that under the proper conditions it can be redispersed at pH 9 and above. Concentrations greater than 900 pCi Pu/L result after 34 h contact at pH 11 or 12 and the distribution coefficient, defined as the ratio of concentration in the sediment to that in the liquid, decreases from 1.1 ?? 105 at pH 7 to 1.2 ?? 103 at pH 11. The plutonium is probably dispersed as discrete colloids or as hydrolytic species adsorbed onto colloidal sediment particles whose average size decreases with increasing pH above pH 9. About 5% of the total plutonium is dispersed at pH 12, and the dispersion seems to readsorb on the sediment with time. Consequently, migration of plutonium from the pond should be slow, and it would be difficult to remove this element completely from pond sediment by leaching with high pH solutions. ?? 1978 American Chemical Society.

  19. Plutonium Chemistry in the UREX+ Separation Processes

    SciTech Connect

    ALena Paulenova; George F. Vandegrift, III; Kenneth R. Czerwinski

    2009-10-01

    The project "Plutonium Chemistry in the UREX+ Separation Processes” is led by Dr. Alena Paulenova of Oregon State University under collaboration with Dr. George Vandegrift of ANL and Dr. Ken Czerwinski of the University of Nevada at Las Vegas. The objective of the project is to examine the chemical speciation of plutonium in UREX+ (uranium/tributylphosphate) extraction processes for advanced fuel technology. Researchers will analyze the change in speciation using existing thermodynamics and kinetic computer codes to examine the speciation of plutonium in aqueous and organic phases. They will examine the different oxidation states of plutonium to find the relative distribution between the aqueous and organic phases under various conditions such as different concentrations of nitric acid, total nitrates, or actinide ions. They will also utilize techniques such as X-ray absorbance spectroscopy and small-angle neutron scattering for determining plutonium and uranium speciation in all separation stages. The project started in April 2005 and is scheduled for completion in March 2008.

  20. 15. VIEW OF THE SAFE GEOMETRY PLUTONIUM METAL STORAGE PALLETS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. VIEW OF THE SAFE GEOMETRY PLUTONIUM METAL STORAGE PALLETS FROM THE INSIDE OF AN INPUT-OUTPUT STATION. INDIVIDUAL CONTAINERS OF PLUTONIUM ARE STORED IN THE WATER-FILLED, DOUBLE-WALLED STAINLESS STEEL TUBES THAT ARE WELDED ONTO THE PALLETS. (12/3/88) - Rocky Flats Plant, Plutonium Recovery Facility, Northwest portion of Rocky Flats Plant, Golden, Jefferson County, CO

  1. 10 CFR 71.88 - Air transport of plutonium.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any... citation of 49 CFR chapter I, as may be applicable, the licensee shall assure that plutonium in any...

  2. 10 CFR 71.63 - Special requirement for plutonium shipments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Special requirement for plutonium shipments. 71.63 Section... MATERIAL Package Approval Standards § 71.63 Special requirement for plutonium shipments. Shipments containing plutonium must be made with the contents in solid form, if the contents contain greater than...

  3. VIEW OF THE INTERIOR OF THE PLUTONIUM LABORATORY IN BUILDING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF THE INTERIOR OF THE PLUTONIUM LABORATORY IN BUILDING 559. THE LABORATORY WAS USED TO ANALYZE THE PURITY OF PLUTONIUM. PLUTONIUM SAMPLES WERE CONTAINED WITHIN GLOVE BOXES - Rocky Flats Plant, Chemical Analytical Laboratory, North-central section of Plant, Golden, Jefferson County, CO

  4. 10 CFR 71.63 - Special requirement for plutonium shipments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Special requirement for plutonium shipments. 71.63 Section... MATERIAL Package Approval Standards § 71.63 Special requirement for plutonium shipments. Shipments containing plutonium must be made with the contents in solid form, if the contents contain greater than...

  5. 10 CFR 71.63 - Special requirement for plutonium shipments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Special requirement for plutonium shipments. 71.63 Section... MATERIAL Package Approval Standards § 71.63 Special requirement for plutonium shipments. Shipments containing plutonium must be made with the contents in solid form, if the contents contain greater than...

  6. 10 CFR 71.63 - Special requirement for plutonium shipments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Special requirement for plutonium shipments. 71.63 Section... MATERIAL Package Approval Standards § 71.63 Special requirement for plutonium shipments. Shipments containing plutonium must be made with the contents in solid form, if the contents contain greater than...

  7. 10 CFR 71.63 - Special requirement for plutonium shipments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Special requirement for plutonium shipments. 71.63 Section... MATERIAL Package Approval Standards § 71.63 Special requirement for plutonium shipments. Shipments containing plutonium must be made with the contents in solid form, if the contents contain greater than...

  8. 10 CFR 71.88 - Air transport of plutonium.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any... citation of 49 CFR chapter I, as may be applicable, the licensee shall assure that plutonium in any...

  9. Aqueous Chloride Operations Overview: Plutonium and Americium Purification/Recovery

    SciTech Connect

    Kimball, David Bryan; Skidmore, Bradley Evan

    2016-06-22

    Acqueous Chloride mission is to recover plutonium and americium from pyrochemical residues (undesirable form for utilization and storage) and generate plutonium oxide and americium oxide. Plutonium oxide is recycled into Pu metal production flowsheet. It is suitable for storage. Americium oxide is a valuable product, sold through the DOE-OS isotope sales program.

  10. A particulate isotopic standard of plutonium in an aluminosilicate matrix

    SciTech Connect

    Stoffels, J.J.; Cannon, W.C.; Robertson, D.M. )

    1991-01-01

    Plutonium isotopic microstandard particles have been produced for mass spectrometer calibration. The particles may also be useful as an elemental standard for calibration of electron and ion microprobe instruments. The standard consists of spherical, micrometer-size aluminosilicate particles loaded with plutonium of known isotopic distribution. The morphology, elemental composition, and plutonium isotopic composition of the particles have been characterized.

  11. Electrochemical investigation into the mechanism of plutonium reduction in electrorefining

    SciTech Connect

    McCurry, L.E.; Moy, G.M.M.

    1987-01-01

    Currently impure plutonium metal is purified at Los Alamos National Laboratory by a molten salt electrorefining process. Electrorefining is an effective method for producing high-purity plutonium metal (> 99.95%). In general this process involves the oxidation of impure plutonium metal from a molten plutonium anode or a solvent metal/plutonium anode, transport of plutonium ions through a molten salt electrolyte, and reduction of the plutonium ions at a tungsten cathode to pure plutonium metal. Purification of the plutonium metal from impurities is based on the difference in free energies of formation between the various metallic impurities associated with plutonium. To obtain a better understanding of the overall electrorefining process and its inefficiencies, an electrochemical investigation into the mechanism for plutonium reduction in a typical electrorefining environment was undertaken. Cyclic voltammetry was selected as the method for determining the electrode mechanism for plutonium reduction at tungsten electrodes. In addition to the standard electrorefining melt (equimolar NaCl-KCl), additional melts that were being investigated in our solvent anode work were also investigated. With insight gained from this investigation, it was hoped that a better selection of electrorefining operating parameters could be obtained.

  12. OVERVIEW OF CALORIMETRIC ASSAY OF PLUTONIUM IN THE UNITED STATES

    SciTech Connect

    Rudy, C. R.

    2001-01-01

    Calorimetry is a primary measurement technique for assay of quantities of plutonium in the United States. It is the most accurate NDA technique for many forms of plutonium-bearing materials. This paper provides an overview of the use of calorimetry in combination with high-resolution gamma-ray spectroscopy for accurate plutonium mass determinations.

  13. Treatment of accidental intakes of plutonium and americium: guidance notes.

    PubMed

    Ménétrier, F; Grappin, L; Raynaud, P; Courtay, C; Wood, R; Joussineau, S; List, V; Stradling, G N; Taylor, D M; Bérard, Ph; Morcillo, M A; Rencova, J

    2005-06-01

    The scientific basis for the treatment of the contamination of the human body by plutonium, americium and other actinides is reviewed. Guidance Notes are presented for the assistance of physicians and others who may be called upon to treat workers or members of the public who may become contaminated internally with inhaled plutonium nitrate, plutonium tributyl phosphate, americium nitrate or americium oxide.

  14. Le syndrome d'embolie graisseuse post traumatique

    PubMed Central

    Berdai, Adnane Mohamed; Shimi, Abdelkarim; Khatouf, Mohammed

    2014-01-01

    Le syndrome d'embolie graisseuse est une complication grave des fractures des os longs, il est la conséquence de la dissémination des particules graisseuses dans la microcirculation. L'objectif de ce travail est de déterminer le profil épidémiologique, la présentation clinique et paraclinique de ce syndrome et sa prise en charge thérapeutique. Notre étude porte sur 11 cas de syndrome d'embolie graisseuse colligés au service de réanimation A1 au centre hospitalier universitaire Hassan II de Fès, de Janvier 2009 à Juin 2012. Le diagnostic positif est basé sur les critères de Gurd. Les cas collectés se caractérisent par la prédominance du sexe masculin, d'un âge inférieur à 40 ans, présentant une fracture fémorale. Ce syndrome survient souvent dans les 72 heures après le traumatisme. La présentation clinique est dominée par l'hypoxémie et les troubles de conscience. Sur le plan biologique: l'anémie et la thrombopénie sont les manifestations les plus fréquentes. La prise en charge est symptomatique, 63% des patients ont nécessité l'intubation et la ventilation. L’évolution n'est pas toujours bénigne. Nos résultats confirme le polymorphisme de la présentation clinique et paraclinique du syndrome d'embolie graisseuse. Le diagnostic de ce syndrome se base sur des critères cliniques, mais reste essentiellement un diagnostic d’élimination. La prise en charge est symptomatique. La prévention de ce syndrome est essentielle et se base sur une fixation précoce des fractures des os longs. PMID:25452829

  15. Effets des electrons secondaires sur l'ADN

    NASA Astrophysics Data System (ADS)

    Boudaiffa, Badia

    Les interactions des electrons de basse energie (EBE) representent un element important en sciences des radiations, particulierement, les sequences se produisant immediatement apres l'interaction de la radiation ionisante avec le milieu biologique. Il est bien connu que lorsque ces radiations deposent leur energie dans la cellule, elles produisent un grand nombre d'electrons secondaires (4 x 104/MeV), qui sont crees le long de la trace avec des energies cinetiques initiales bien inferieures a 20 eV. Cependant, il n'y a jamais eu de mesures directes demontrant l'interaction de ces electrons de tres basse energie avec l'ADN, du principalement aux difficultes experimentales imposees par la complexite du milieu biologique. Dans notre laboratoire, les dernieres annees ont ete consacrees a l'etude des phenomenes fondamentaux induits par impact des EBE sur differentes molecules simples (e.g., N2, CO, O2, H2O, NO, C2H 4, C6H6, C2H12) et quelques molecules complexes dans leur phase solide. D'autres travaux effectues recemment sur des bases de l'ADN et des oligonucleotides ont montre que les EBE produisent des bris moleculaires sur les biomolecules. Ces travaux nous ont permis d'elaborer des techniques pour mettre en evidence et comprendre les interactions fondamentales des EBE avec des molecules d'interet biologique, afin d'atteindre notre objectif majeur d'etudier l'effet direct de ces particules sur la molecule d'ADN. Les techniques de sciences des surfaces developpees et utilisees dans les etudes precitees peuvent etre etendues et combinees avec des methodes classiques de biologie pour etudier les dommages de l'ADN induits par l'impact des EBE. Nos experiences ont montre l'efficacite des electrons de 3--20 eV a induire des coupures simple et double brins dans l'ADN. Pour des energies inferieures a 15 eV, ces coupures sont induites par la localisation temporaire d'un electron sur une unite moleculaire de l'ADN, ce qui engendre la formation d'un ion negatif transitoire

  16. Le facteur XII de la coagulation: bien plus qu’un stabilisant de la fibrine

    PubMed Central

    Messaoudi, N.; Lamaalmi, F.; Chakour, M.; Belmekki, A.; Naji, M.

    2011-01-01

    Summary Les Auteurs considèrent lele du facteur XIII de la coagulation dans la cicatrisation. Identifié depuis 1923, lele du facteur XIII ou le facteur stabilisant de la fibrine dans la coagulation a été bien élucidé. Son rôle dans la cicatrisation suggéré dès 1960 est méconnu par les hématologistes et les médecins prenant en charge les brûlés. Les Auteurs se proposent de mettre la lumière sur ce rôle, qui reste encore mystérieux et mérite d’être élucidé. PMID:21991236

  17. ESTIMATING IMPURITIES IN SURPLUS PLUTONIUM FOR DISPOSITION

    SciTech Connect

    Allender, J.; Moore, E.

    2013-07-17

    The United States holds at least 61.5 metric tons (MT) of plutonium that is permanently excess to use in nuclear weapons programs, including 47.2 MT of weapons-grade plutonium. Surplus inventories will be stored safely by the Department of Energy (DOE) and then transferred to facilities that will prepare the plutonium for permanent disposition. The Savannah River National Laboratory (SRNL) operates a Feed Characterization program for the Office of Fissile Materials Disposition of the National Nuclear Security Administration and the DOE Office of Environmental Management. Many of the items that require disposition are only partially characterized, and SRNL uses a variety of techniques to predict the isotopic and chemical properties that are important for processing through the Mixed Oxide Fuel Fabrication Facility and alternative disposition paths. Recent advances in laboratory tools, including Prompt Gamma Analysis and Peroxide Fusion treatment, provide data on the existing inventories that will enable disposition without additional, costly sampling and destructive analysis.

  18. Characterization of Delta Phase Plutonium Metal

    SciTech Connect

    Rudisill, T.S.

    2000-09-21

    The FB-Line facility has developed the capability to recast plutonium metal using an M-18 reduction furnace with a new casting chamber. Plutonium metal is recast by charging a standard FB-Line magnesia crucible and placing the charge in the casting chamber. The loaded casting chamber is raised into the M-18 reduction furnace and sealed against the furnace head using a copper gasket following the same procedure used for a bomb reduction run. The interior volume of the chamber is evacuated and backfilled with argon gas. The M-18 motor-generator set is used to heat the surface of the casting chamber to nominally 750 Degrees C. Within about 2 hr, the plutonium metal reaches its melting temperature of approximately 640 Degrees C.

  19. Excess plutonium disposition using ALWR technology

    SciTech Connect

    Phillips, A.; Buckner, M.R.; Radder, J.A.; Angelos, J.G.; Inhaber, H.

    1993-02-01

    The Office of Nuclear Energy of the Department of Energy chartered the Plutonium Disposition Task Force in August 1992. The Task Force was created to assess the range of practicable means of disposition of excess weapons-grade plutonium. Within the Task Force, working groups were formed to consider: (1) storage, (2) disposal,and(3) fission options for this disposition,and a separate group to evaluate nonproliferation concerns of each of the alternatives. As a member of the Fission Working Group, the Savannah River Technology Center acted as a sponsor for light water reactor (LWR) technology. The information contained in this report details the submittal that was made to the Fission Working Group of the technical assessment of LWR technology for plutonium disposition. The following aspects were considered: (1) proliferation issues, (2) technical feasibility, (3) technical availability, (4) economics, (5) regulatory issues, and (6) political acceptance.

  20. Method for dissolving delta-phase plutonium

    DOEpatents

    Karraker, David G.

    1992-01-01

    A process for dissolving plutonium, and in particular, delta-phase plutonium. The process includes heating a mixture of nitric acid, hydroxylammonium nitrate (HAN) and potassium fluoride to a temperature between 40.degree. and 70.degree. C., then immersing the metal in the mixture. Preferably, the nitric acid has a concentration of not more than 2M, the HAN approximately 0.66M, and the potassium fluoride 0.1M. Additionally, a small amount of sulfamic acid, such as 0.1M can be added to assure stability of the HAN in the presence of nitric acid. The oxide layer that forms on plutonium metal may be removed with a non-oxidizing acid as a pre-treatment step.

  1. The United States Plutonium Balance, 1944 - 2009

    SciTech Connect

    2012-06-01

    This report updates the report -Plutonium: The first 50 years- which was released by the U.S.Department of Energy (DOE) in 1996. The topic of both reports is plutonium, sometimes referred to as Pu-239, which is capable of sustaining a nuclear chain reaction and is used in nuclear weapons and for nuclear power production. This report updates 1994 data through 2009. The four most significant changes since 1994 include: (a) the completion of cleanup activities at the Rocky Flats Plant in 2005; (b) material consolidation and disposition activities, especially shipments from Hanford to the Savannah River Site; (c) the 2007 declaration of an additional 9.0 MT of weapons grade plutonium to be surplus to defense needs in the coming decades; and (d) the opening of the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico in 1999.

  2. Excess plutonium disposition using ALWR technology

    SciTech Connect

    Phillips, A.; Buckner, M.R.; Radder, J.A.; Angelos, J.G.; Inhaber, H.

    1993-02-01

    The Office of Nuclear Energy of the Department of Energy chartered the Plutonium Disposition Task Force in August 1992. The Task Force was created to assess the range of practicable means of disposition of excess weapons-grade plutonium. Within the Task Force, working groups were formed to consider: (1) storage, (2) disposal,and(3) fission options for this disposition,and a separate group to evaluate nonproliferation concerns of each of the alternatives. As a member of the Fission Working Group, the Savannah River Technology Center acted as a sponsor for light water reactor (LWR) technology. The information contained in this report details the submittal that was made to the Fission Working Group of the technical assessment of LWR technology for plutonium disposition. The following aspects were considered: (1) proliferation issues, (2) technical feasibility, (3) technical availability, (4) economics, (5) regulatory issues, and (6) political acceptance.

  3. Excess plutonium disposition: The deep borehole option

    SciTech Connect

    Ferguson, K.L.

    1994-08-09

    This report reviews the current status of technologies required for the disposition of plutonium in Very Deep Holes (VDH). It is in response to a recent National Academy of Sciences (NAS) report which addressed the management of excess weapons plutonium and recommended three approaches to the ultimate disposition of excess plutonium: (1) fabrication and use as a fuel in existing or modified reactors in a once-through cycle, (2) vitrification with high-level radioactive waste for repository disposition, (3) burial in deep boreholes. As indicated in the NAS report, substantial effort would be required to address the broad range of issues related to deep bore-hole emplacement. Subjects reviewed in this report include geology and hydrology, design and engineering, safety and licensing, policy decisions that can impact the viability of the concept, and applicable international programs. Key technical areas that would require attention should decisions be made to further develop the borehole emplacement option are identified.

  4. Interaction of divalent plutonium and curium

    SciTech Connect

    Mikheev, N.B.; Kazakevich, M.Z.; Rumer, I.A.

    1988-11-01

    It has been established that at plutonium concentrations ranging from 10/sup -5/ to 10/sup -4/ mole % the oxidation potentials of the Pu/sup 3 +//Pu/sup 2 +/ and Cm/sup 3 +//Cm/sup 2 +/ pairs increased by 0.15-0.2 V due to the dimerization of Pu/sup 2 +/ and the formation of mixed dimers of plutonium and curium. Promethium(2+) does not have a similar ability to form mixed dimers owing to the fact that Pm/sup 2 +/ does not have a free d electron. The oxidation potential of the Pm/sup 3 +//Pm/sup 2 +/ pair does not vary in the presence of massive quantities of plutonium

  5. Disposition of plutonium in deep boreholes

    SciTech Connect

    Halsey, W.G.; Jardine, L.J.; Walter, C.E.

    1995-05-01

    Substantial inventories of excess plutonium are expected to result from dismantlement of U.S. and Russian nuclear weapons. Disposition of this material should be a high priority in both countries. A variety of disposition options are under consideration. One option is to place the plutonium either directly or in an immobilized form at the bottom of a deep borehole that is then sealed. Deep-borehole disposition involves placing plutonium several kilometers deep into old, stable, rock formations that have negligible free water present. Containment assurance is based on the presence of ancient groundwater indicating lack of migration and communication with the biosphere. Recovery would be extremely difficult (costly) and impossible to accomplish clandestinely.

  6. PLUTONIUM ALLOYS CONTAINING CONTROLLED AMOUNTS OF PLUTONIUM ALLOTROPES OBTAINED BY APPLICATION OF HIGH PRESSURES

    DOEpatents

    Elliott, R.O.; Gschneidner, K.A. Jr.

    1962-07-10

    A method of making stabilized plutonium alloys which are free of voids and cracks and have a controlled amount of plutonium allotropes is described. The steps include adding at least 4.5 at.% of hafnium, indium, or erbium to the melted plutonium metal, homogenizing the resulting alloy at a temperature of 450 deg C, cooling to room temperature, and subjecting the alloy to a pressure which produces a rapid increase in density with a negligible increase in pressure. The pressure required to cause this rapid change in density or transformation ranges from about 800 to 2400 atmospheres, and is dependent on the alloying element. (AEC)

  7. Study of the formation, prevention, and recovery of plutonium from plutonium esters in the Purex process

    SciTech Connect

    Gray, L. W.; Burney, G. A.

    1981-01-01

    The Savannah River Plant uses the basic Purex process to separate /sup 239/Pu from /sup 238/U and fission products. Dark-brown, dense solids containing up to 30% Pu have previously occurred in rotameters in the plutonium finishing operations. The kinetics of formation of this mixture of DBP- and MBP-Pu esters suggest two methods to prevent the formation of the solids. A selective dissolution method using NaOH metathesis has been developed to separate the phosphate ester from the plutonium before dissolution of the residual plutonium hydroxide in a HNO/sub 3/-HF medium.

  8. Alternating layers of plutonium and lead or indium as surrogate for plutonium

    SciTech Connect

    Rudin, Sven Peter

    2009-01-01

    Elemental plutonium (Pu) assumes more crystal structures than other elements, plausibly due to bonding f electrons becoming non-bonding. Complex geometries hamper understanding of the transition in Pu, but calculations predict this transition in a system with simpler geometry: alternating layers either of plutonium and lead or of plutonium and indium. Here the transition occurs via a pairing-up of atoms within Pu layers. Calculations stepping through this pairing-up reveal valuable details of the transition, for example that the transition from bonding to non-bonding proceeds smoothly.

  9. Plutonium Speciation, Solubilization, and Migration in soils

    SciTech Connect

    Neu, Mary; Haire, Richard G.

    1999-06-01

    The DOE is currently conducting cleanup activities at its nuclear weapons development sites, many of which have accumulated plutonium in soils for 50 years. To properly control Pu migration in soils within Federal sites and onto public lands, better evaluate the public risk, and design effective remediation strategies, a fundamental understanding of Pu speciation and environmental transport, and release mechanisms is needed. The key scientific goals of this project are: to determine Pu concentrations and speciation at a contaminated DOE site; to study the formation, stability, and structural and spectroscopic features of environmentally relevant Pu species; to determine the mechanism(s) of interaction between Pu and Mn/Fe minerals and the potential release of Pu via redox cycling; and to model the environmental behavior of plutonium. Our long-term goal is to use characterization, thermodynamic, mineral interaction, and mobility data to develop better models of radionuclide transport and risk assessment, and to enable the development of science-based decontamination strategies. This research will fill important gaps between basic actinide science and the problems impeding site clean-up, plutonium disposition, and accurate risk assessment. Information gained will allow for the development of technologies and clean-up approaches targeting particular plutonium contaminants and improved assessment of risks associated with actinide migration, site remediation, and decontamination. By combining very specific study of plutonium at the Rocky Flats Environmental Test Site (RFETS), a well characterized contaminated site, with laboratory studies on the most important plutonium and mineral component systems, we will provide essential knowledge of contaminant characteristics and distinguish critical geochemical processes and mechanisms.

  10. CHARACTERIZATION OF SURPLUS PLUTONIUM FOR DISPOSITION OPTIONS

    SciTech Connect

    Allender, J; Edwin Moore, E; Scott Davies, S

    2008-07-15

    The United States (U.S.) has identified 61.5 metric tons (MT) of plutonium that is permanently excess to use in nuclear weapons programs, including 47.2 MT of weapons-grade plutonium. Except for materials that remain in use for programs outside of national defense, including programs for nuclear-energy development, the surplus inventories will be stored safely by the Department of Energy (DOE) and then transferred to facilities that will prepare the plutonium for permanent disposition. Some items will be disposed as transuranic waste, low-level waste, or spent fuel. The remaining surplus plutonium will be managed through: (1) the Mixed Oxide (MOX) Fuel Fabrication Facility (FFF), to be constructed at the Savannah River Site (SRS), where the plutonium will be converted to fuel that will be irradiated in civilian power reactors and later disposed to a high-level waste (HLW) repository as spent fuel; (2) the SRS H-Area facilities, by dissolving and transfer to HLW systems, also for disposal to the repository; or (3) alternative immobilization techniques that would provide durable and secure disposal. From the beginning of the U.S. program for surplus plutonium disposition, DOE has sponsored research to characterize the surplus materials and to judge their suitability for planned disposition options. Because many of the items are stored without extensive analyses of their current chemical content, the characterization involves three interacting components: laboratory sample analysis, if available; non-destructive assay data; and rigorous evaluation of records for the processing history for items and inventory groups. This information is collected from subject-matter experts at inventory sites and from materials stabilization and surveillance programs, in cooperation with the design agencies for the disposition facilities. This report describes the operation and status of the characterization program.

  11. Etude de la transition tribologique entre le fretting et le meso-fretting pour des materiaux de contact electrique

    NASA Astrophysics Data System (ADS)

    Gagnon, Daniel

    Dans les installations electriques, les contacts sont toujours soumis a des contraintes alternees ou a des micro-deplacements. Il en resulte une corrosion par fretting, phenomene defini comme un type de deterioration de la surface qui se produit lorsque deux materiaux en contact sont soumis a des mouvements microscopiques d'oscillations de tres faible amplitude (0 a 100 mum). Ceci a pour effet de provoquer une degradation de la resistance de contact et une interruption du passage du courant. Ce phenomene a des repercussions considerables sur le plan pratique puisque les micro-deplacements de pieces en contact peuvent etre causes par la dilatation thermique differentielle des metaux, par des vibrations mecaniques, par la relaxation des contraintes ou par l'echauffement des contacts lorsqu'on interrompt et retablit le courant. Nous avons donc dans le cadre de cette these etudie plusieurs aspects du fretting (0--100 mum) et du meso-fretting (100 a 1000 mum) pour differents materiaux de contact electrique. Des travaux experimentaux ont ete realises a partir de deux montages reproduisant divers aspects de la degradation par le fretting. Un premier montage de fretting de type bille-plaque a ete entierement developpe a l'ETS et un second montage, de type fil-plaque a ete utilise en collaboration avec Hydro Quebec IREQ a Varennes. Plusieurs techniques de mesures et d'analyse relevant tant du domaine de la mecanique du contact que de la metallurgie ont ete utilisees pour traiter les resultats. L'influence du courant sur le taux d'usure et la force de friction a ete examinee pour divers materiaux de contacts. Des essais de fatigue thermique et electrique ont ete realises sur divers materiaux et lubrifiants de contact. Il a ete demontre que pour le domaine entre 100 mum et 1000 mum, le taux d'usure n'est pas le meme de 0 a 100 mum et au dela de 1000 mum. La plupart des materiaux evalues montrent un stade de comportement intermediaire dont le debut se situe entre 100 mum et

  12. Modeling of Diffusion of Plutonium in Other Metals and of Gaseous Species in Plutonium-Based Systems

    SciTech Connect

    Bernard R. Cooper; Gayanath W. Fernando; S. Beiden; A. Setty; E.H. Sevilla

    2004-07-02

    Establish standards for temperature conditions under which plutonium, uranium, or neptunium from nuclear wastes permeates steel, with which it is in contact, by diffusion processes. The primary focus is on plutonium because of the greater difficulties created by the peculiarities of face-centered-cubic-stabilized (delta) plutonium (the form used in the technology generating the waste).

  13. REVIEW OF PLUTONIUM OXIDATION LITERATURE

    SciTech Connect

    Korinko, P.

    2009-11-12

    A brief review of plutonium oxidation literature was conducted. The purpose of the review was to ascertain the effect of oxidation conditions on oxide morphology to support the design and operation of the PDCF direct metal oxidation (DMO) furnace. The interest in the review was due to a new furnace design that resulted in oxide characteristics that are different than those of the original furnace. Very little of the published literature is directly relevant to the DMO furnace operation, which makes assimilation of the literature data with operating conditions and data a convoluted task. The oxidation behavior can be distilled into three regimes, a low temperature regime (RT to 350 C) with a relatively slow oxidation rate that is influenced by moisture, a moderate temperature regime (350-450 C) that is temperature dependent and relies on more or less conventional oxidation growth of a partially protective oxide scale, and high temperature oxidation (> 500 C) where the metal autocatalytically combusts and oxidizes. The particle sizes obtained from these three regimes vary with the finest being from the lowest temperature. It is surmised that the slow growth rate permits significant stress levels to be achieved that help break up the oxides. The intermediate temperatures result in a fairly compact scale that is partially protective and that grows to critical thickness prior to fracturing. The growth rate in this regime may be parabolic or paralinear, depending on the oxidation time and consequently the oxide thickness. The high temperature oxidation is invariant in quiescent or nearly quiescent conditions due to gas blanketing while it accelerates with temperature under flowing conditions. The oxide morphology will generally consist of fine particles (<15 {micro}m), moderately sized particles (15 < x < 250 {micro}m) and large particles (> 250 {micro}m). The particle size ratio is expected to be < 5%, 25%, and 70% for fine, medium and large particles, respectively, for

  14. Le concept de banque d'items et ses implications sur le contenu didactique

    NASA Astrophysics Data System (ADS)

    Tistaert, G.; Mwene, Magabe

    1985-12-01

    The development of the concept of an item bank comes as a reply to the didactic situations which for reasons of efficiency require the storing of a number of susceptible items to be used at any time. Access to the computer makes possible an improvement and rationalization of the management of the item bank. At the same time the extension of the concept has followed two main directions. On the one hand, particular care relates to the adequacy of stored items with the content of learning and it brings about the emergence of a technology of item-editing. On the other hand, psychometric considerations have caused the invariance of essential characteristics of the items. This demands that the items respond to the presupposed models with latent traits. On the basis of theoretical arguments supported by some research findings the final part of the article calls attention to the deep discord among researchers concerning the reliability of the presuppositions of these models in the didactic field. The compromise will probably lead to it that the multidimensionality of items which have a didactic character are admitted.

  15. Impacts potentiels d'un changement climatique sur le pergelisol dans le nord canadien

    NASA Astrophysics Data System (ADS)

    Obretin, Calin

    This thesis explores the potential impacts of a climate change due to the greenhouse gases on the state and the evolution of the permafrost in the Canadian North. The permafrost represents the half of the Canadian national territory and a change of its current state will echo in all spheres of activity, on the biosphere and on the environment generally. In spite of the evident importance of the subject, there is no precise idea as to how the permafrost will react to the climate change and to what extent the frozen layer will be disrupted. This thesis investigates this problem by using a methodological approach inspired by the Canadian model on the evolution of permafrost (TTOP) coupled with a theoretical approach based on the theory of the complex neuronal systems. The general objective of this thesis is to improve the Canadian model of evolution of permafrost (TTOP-Temperature one the Top Of Permafrost) created by Smith and Riseborough in 1996, its structure of computation, spatial resolution and to determine the state of the permafrost in the study area between 2010 and 2100. The study zone is situated in the Mackenzie Basin (N-W.T) on a north-south transect of 1440 by 720 km. The first objective of the research is to derive maps of the annual values of temperature on the top of the permafrost from 2010 to 2100 by using an improved dynamic model of the evolution of permafrost (TTOP-A). Thereafter, these values are compared with those obtained by Smith and Riseborough (1996). The values of the evolution of air temperature for this period are supplied by the climatic scenarios CGCM32 SRES A1B, CGCM3 SRES A2 and CGCM3 SRES B1. Secondly, this thesis has as an objective the production of the maps of the thickness of permafrost for 2100 with a spatial resolution of 25 km. More exactly, we determine the evolution of the values of thickness of permafrost for the three climatic scenarios mentioned above. Furthermore, the study proposes: i) a new method for downscaling of climate data by using a Determined Stochastic Model, ii) the integration of soil type, iii) the integration of the soil humidity, iv) the integration of the values of thickness of the snow layer and v) the integration of remote sensing data (SSM/I). As a rule, the results obtained by the TTOP-A model reveal that the mean values of temperature at the surface of the permafrost follow closely the values of air temperature and that they are similar to those found by Smith and Riseborough (1996) and Heginbottom and coll. (1995). Also, the differences of the values of temperature on the surface of permafrost between 2010 and 2100 are similar to the values published by the Intergovernmental Panel on Climate Change (IPCC). Concerning the second objective of this thesis, the spatio-temporal dynamics of the permafrost until 2100 demonstrates that, in the study zone, the surface perturbed by global warming will be 37 %, 60 % and 29 % according to the scenarios CGCM3 SRES A1B, CGCM3 SRES A2 and CGCM3 SRES B1 respectively. The permafrost layer inside this zone will disappear by 20 %, 32 % and 18 % according to the scenarios mentioned before. These results lead us to believe that the estimations made by Smith and Riseborough were overvalued in the context of two of three current climates scenarios compared to that of the 1996. Finally, this study demonstrates that the method of downscaling of climate data using the neuronal network within a Determined Stochastic Model gives good results and it represents a reliable option which lends itself to large-scale generalizations. Keywords: permafrost, downscaling, snow, soil humidity, climate scenarios, neuronal network, Determined Stochastic Model, climate change, CGCM3, TTOP. 2The third generation Coupled Global Climate Model [CCCma, 2010].

  16. Technology for Evolutionary Software Development (Technologies pour le developpement de logiciels evolutifs)

    DTIC Science & Technology

    2003-06-01

    performs its mission with the support of an extensive network of national experts. It also ensures effective coordination with other NATO bodies involved in...intégré unique pour le matériel, le logiciel et la logistique . La session sur les stratégies et les approches, qui était axée sur un système...development process.3 • Requirements Engineering – Quality, Performance and Cost requirements quantified. Evolutionary development can be viewed as a

  17. Dehydration of plutonium or neptunium trichloride hydrate

    DOEpatents

    Foropoulos, J. Jr.; Avens, L.R.; Trujillo, E.A.

    1992-03-24

    A process is described for preparing anhydrous actinide metal trichlorides of plutonium or neptunium by reacting an aqueous solution of an actinide metal trichloride selected from the group consisting of plutonium trichloride or neptunium trichloride with a reducing agent capable of converting the actinide metal from an oxidation state of +4 to +3 in a resultant solution, evaporating essentially all the solvent from the resultant solution to yield an actinide trichloride hydrate material, dehydrating the actinide trichloride hydrate material by heating the material in admixture with excess thionyl chloride, and recovering anhydrous actinide trichloride.

  18. Dehydration of plutonium or neptunium trichloride hydrate

    DOEpatents

    Foropoulos, Jr., Jerry; Avens, Larry R.; Trujillo, Eddie A.

    1992-01-01

    A process of preparing anhydrous actinide metal trichlorides of plutonium or neptunium by reacting an aqueous solution of an actinide metal trichloride selected from the group consisting of plutonium trichloride or neptunium trichloride with a reducing agent capable of converting the actinide metal from an oxidation state of +4 to +3 in a resultant solution, evaporating essentially all the solvent from the resultant solution to yield an actinide trichloride hydrate material, dehydrating the actinide trichloride hydrate material by heating the material in admixture with excess thionyl chloride, and recovering anhydrous actinide trichloride is provided.

  19. Waste measurements at a plutonium facility

    SciTech Connect

    Wachter, J.R.

    1992-01-01

    Solid plutonium contaminated wastes are often highly heterogeneous, span a wide range of chemical compositions and matrix types, and are packaged in a variety of container sizes. NDA analysis of this waste depends on operator knowledge of these parameters so that proper segregation, instrument selection, quality assurance, and uncertainty estimation can take place. This report describes current waste measurement practices and uncertainty estimates at a US plutonium scrap recovery facility and presents a program for determining reproducibility and bias in NDA measurements. Following this, an operator's perspective on desirable NDA upgrades is offered.

  20. Measurement of Plutonium Isotopic Composition - MGA

    SciTech Connect

    Vo, Duc Ta

    2015-08-21

    In this module, we will use the Canberra InSpector-2000 Multichannel Analyzer with a high-purity germanium detector (HPGe) and the MGA isotopic anlysis software to assay a variety of plutonium samples. The module provides an understanding of the MGA method, its attributes and limitations. You will assess the system performance by measuring a range of materials similar to those you may assay in your work. During the final verification exercise, the results from MGA will be combined with the 240Pueff results from neutron coincidence or multiplicity counters so that measurements of the plutonium mass can be compared with the operator-declared (certified) values.

  1. Commande a saturation pour le controle de la position d'un robot volant de type quadrotor =

    NASA Astrophysics Data System (ADS)

    Boudguiga, Oussama

    Le quadrotor est un robot volant faisant partie de la famille des multirotors. Il possede plusieurs caracteristiques (une structure de taille reduite, faible poids, agilite, decollage et atterrissage vertical) qui lui offrent plusieurs avantages par rapport a d'autres types de robots volants. Mais malgre tous ses avantages, le quadrotor possede une dynamique fortement non lineaire et pleinement couplee, d'ou la necessite d'une commande robuste et stable. Ce memoire porte donc sur la modelisation et la commande de robot volant de type quadrotor. L'objectif principal dans ce memoire est de concevoir une commande a saturation pour le controle de la position d'un robot volant de type quadrotor. Pour atteindre cet objectif, un modele dynamique du quadrotor selon Euler Lagrange a ete developpe. Ensuite, une approche de commande basee sur une commande a saturation pour le controle de la position et une commande backstepping adaptative pour le controle de l'orientation a ete developpee a partir du modele dynamique. Sa stabilite a ete analysee par la suite en se basant sur le theoreme de Lyapunov et le lemme de Barbalat. L'approche de commande proposee a ete testee avec succes en simulation a l'aide du modele dynamique sur deux scenarios de vol differents, ensuite en ajoutant un bruit blanc dans les donnees de capteurs des positions.

  2. SEPARATION OF PLUTONIUM FROM LANTHANUM BY CHELATION-EXTRACTION

    DOEpatents

    James, R.A.; Thompson, S.G.

    1958-12-01

    Plutonium can be separated from a mixture of plutonlum and lanthanum in which the lanthanum to plutonium molal ratio ls at least five by adding the ammonium salt of N-nitrosoarylhydroxylamine to an aqueous solution having a pH between about 3 and 0.2 and containing the plutonium in a valence state of at least +3, to form a plutonium chelate compound of N-nitrosoarylhydroxylamine. The plutonium chelate compound may be recovered from the solution by extracting with an immiscible organic solvent such as chloroform.

  3. Plutonium dispersal in fires: Summary of what is known

    SciTech Connect

    Condit, R.H.

    1993-07-01

    In view of the great public apprehension about plutonium and nuclear weapons we should explore ways to prevent, limit, or mitigate possible plutonium dispersals. This review is primarily a tutorial on what is known about plutonium dispersal in fires. It concludes that in most types of fires involving plutonium the amount released will not be an immediate danger to life. Indeed, in many cases very few personnel will receive more than the lung burden allowed by current regulations for plutonium workers. However, the dangers may be significant in special situations, unusual terrains, certain meteorological conditions, and very high burn temperatures.

  4. Using magnetization measurements to detect small amounts of plutonium hydride formation in plutonium metal

    SciTech Connect

    Kim, Jae Wook; Mielke, Charles H.; Zapf, Vivien; Baiardo, Joseph P.; Mitchell, Jeremy N.; Richmond, Scott; Schwartz, Daniel S.; Mun, Eun D.; Smith, Alice Iulia

    2014-10-20

    We report the formation of plutonium hydride in 2 at % Ga-stabilized δ-Pu, with 1 atomic % H charging. We show that magnetization measurements are a sensitive, quantitative measure of ferromagnetic plutonium hydride against the nonmagnetic background of plutonium. It was previously shown that at low hydrogen concentrations, hydrogen forms super-abundant vacancy complexes with plutonium, resulting in a bulk lattice contraction. Here we use magnetization, X-ray and neutron diffraction measurements to show that in addition to forming vacancy complexes, at least 30% of the H atoms bond with Pu to precipitate PuHx, largely on the surface of the sample with x ~ 1.9. We observe magnetic hysteresis loops below 40 K with magnetic remanence, consistent with precipitates of ferromagnetic PuH1.9.

  5. Excess Weapons Plutonium Disposition: Plutonium Packaging, Storage and Transportation and Waste Treatment, Storage and Disposal Activities

    SciTech Connect

    Jardine, L J; Borisov, G B

    2004-07-21

    A fifth annual Excess Weapons Plutonium Disposition meeting organized by Lawrence Livermore National Laboratory (LLNL) was held February 16-18, 2004, at the State Education Center (SEC), 4 Aerodromnya Drive, St. Petersburg, Russia. The meeting discussed Excess Weapons Plutonium Disposition topics for which LLNL has the US Technical Lead Organization responsibilities. The technical areas discussed included Radioactive Waste Treatment, Storage, and Disposal, Plutonium Oxide and Plutonium Metal Packaging, Storage and Transportation and Spent Fuel Packaging, Storage and Transportation. The meeting was conducted with a conference format using technical presentations of papers with simultaneous translation into English and Russian. There were 46 Russian attendees from 14 different Russian organizations and six non-Russian attendees, four from the US and two from France. Forty technical presentations were made. The meeting agenda is given in Appendix B and the attendance list is in Appendix C.

  6. Quantitative ion-exchange separation of plutonium from impurities

    SciTech Connect

    Pietri, C.E.; Freeman, B.P.; Weiss, J.R.

    1981-09-01

    The methods used at the New Brunswick Laboratory for the quantitative ion exchange separation of plutonium from impurities prior to plutonium assay are described. Other ion exchange separation procedures for impurity determination and for isotopic abundance measurements are given. The primary technique used consists of sorption of plutonium(IV) in 8N HNO/sub 3/ on Dowex-1 anion exchange resin and elution of the purified plutonium with 0.3N HCl-0.01N HF. Other methods consist of the anion exchange separation of plutonium(IV) in 12N HCl and the cation exchange separation of plutonium(III) in 0.2 N HNO/sub 3/. The application of these procedures to the subsequent assay of plutonium, isotopic analysis, and impurity determination is described.

  7. Weapons-grade plutonium dispositioning. Volume 2: Comparison of plutonium disposition options

    SciTech Connect

    Brownson, D.A.; Hanson, D.J.; Blackman, H.S.

    1993-06-01

    The Secretary of Energy requested the National Academy of Sciences (NAS) Committee on International Security and Arms Control to evaluate disposition options for weapons-grade plutonium. The Idaho National Engineering Laboratory (INEL) offered to assist the NAS in this evaluation by investigating the technical aspects of the disposition options and their capability for achieving plutonium annihilation levels greater than 90%. This report was prepared for the NAS to document the gathered information and results from the requested option evaluations. Evaluations were performed for 12 plutonium disposition options involving five reactor and one accelerator-based systems. Each option was evaluated in four technical areas: (1) fuel status, (2) reactor or accelerator-based system status, (3) waste-processing status, and (4) waste disposal status. Based on these evaluations, each concept was rated on its operational capability and time to deployment. A third rating category of option costs could not be performed because of the unavailability of adequate information from the concept sponsors. The four options achieving the highest rating, in alphabetical order, are the Advanced Light Water Reactor with plutonium-based ternary fuel, the Advanced Liquid Metal Reactor with plutonium-based fuel, the Advanced Liquid Metal Reactor with uranium-plutonium-based fuel, and the Modular High Temperature Gas-Cooled Reactor with plutonium-based fuel. Of these four options, the Advanced Light Water Reactor and the Modular High Temperature Gas-Cooled Reactor do not propose reprocessing of their irradiated fuel. Time constraints and lack of detailed information did not allow for any further ratings among these four options. The INEL recommends these four options be investigated further to determine the optimum reactor design for plutonium disposition.

  8. Influence du traitement thermique sur l'usinabilite du laiton monophase

    NASA Astrophysics Data System (ADS)

    Cholley, Airy

    La connaissance des proprietes et du comportement d'un materiau en usinage est primordiale pour optimiser son utilisation et obtenir une usinabilite maximale. Dans ce but, l'etude de la modification de la ductilite par traitement thermiques sur plusieurs criteres d'usinabilite tels que les efforts de coupe, la rugosite, les bavures et la formation du copeau a ete menee sur le laiton monophase. A cette fin, l'influence du traitement thermique sur la microstructure du laiton a d'abord ete etudiee. La taille des grains et la durete ont permis de determiner les proprietes mecaniques des etats metallurgiques. Des essais de percage ont ensuite ete effectues sur les etats metallurgiques H01 (99HV), OS100 (88HV) et OS250 (47HV) pour regarder l'influence du traitement thermique sur l'usinabilite. Cette etude experimentale a permis de comprendre l'influence du taux de laminage et de la temperature de recuit sur les proprietes mecaniques. Les essais d'usinabilite ont ensuite permis de prouver que les efforts de coupe sont dependants des conditions de coupe mais pas de la ductilite dans les etats metallurgiques testes. La taille des bavures augmente avec la ductilite et la vitesse de coupe, et diminue avec l'avance. La rugosite de la surface des trous apres l'usinage a egalement ete etudiee. Il a aussi ete prouve par une etude sur les copeaux que la temperature croit avec la vitesse de coupe. L'analyse de la segmentation des copeaux n'a en revanche pas permis de trouver une correlation significative avec les traitements thermiques testes. Enfin, le revetement de l'outil a montre une grande importance sur l'usinabilite du materiau. Il a ete conclu que l'usinabilite du laiton C26000 (CuZn30) est meilleure lorsqu'on travaille dans un etat metallurgique dur. Ces conclusions sont valables pour le laiton monophase etudie, il serait interessant d'examiner aussi le cas des laitons biphases.

  9. Adsorption of plutonium oxide nanoparticles.

    PubMed

    Schmidt, Moritz; Wilson, Richard E; Lee, Sang Soo; Soderholm, L; Fenter, P

    2012-02-07

    Adsorption of monodisperse cubic plutonium oxide nanoparticles ("Pu-NP", [Pu(38)O(56)Cl(x)(H(2)O)(y)]((40-x)+), with a fluorite-related lattice, approximately 1 nm in edge size) to the muscovite (001) basal plane from aqueous solutions was observed in situ (in 100 mM NaCl background electrolyte at pH 2.6). Uptake capacity of the surface quantified by α-spectrometry was 0.92 μg Pu/cm(2), corresponding to 10.8 Pu per unit cell area (A(UC)). This amount is significantly larger than that of Pu(4+) needed for satisfying the negative surface charge (0.25 Pu(4+) for 1 e(-)/A(UC)). The adsorbed Pu-NPs cover 17% of the surface area, determined by X-ray reflectivity (XR). This correlates to one Pu-NP for every 14 unit cells of muscovite, suggesting that each particle compensates the charge of the unit cells onto which it adsorbs as well as those in its direct proximity. Structural investigation by resonant anomalous X-ray reflectivity distinguished two different sorption states of Pu-NPs on the surface at two different regimes of distance from the surface. A fraction of Pu is distributed within 11 Å from the surface. The distribution width matches the Pu-NP size, indicating that this species represents Pu-NPs adsorbed directly on the surface. Beyond the first layer, an additional fraction of sorbed Pu was observed to extend more broadly up to more than 100 Å from the surface. This distribution is interpreted as resulting from "stacking" or aggregation of the nanoparticles driven by sorption and accumulation of Pu-NPs at the interface although these Pu-NPs do not aggregate in the solution. These results are the first in situ observation of the interaction of nanoparticles with a charged mineral-water interface yielding information important to understanding the environmental transport of Pu and other nanophase inorganic species.

  10. Design-Only Conceptual Design Report: Plutonium Immobilization Plant

    SciTech Connect

    DiSabatino, A.; Loftus, D.

    1999-01-01

    This design-only conceptual design report was prepared to support a funding request by the Department of Energy Office of Fissile Materials Disposition for engineering and design of the Plutonium Immobilization Plant, which will be used to immobilize up to 50 tonnes of surplus plutonium. The siting for the Plutonium Immobilization Plant will be determined pursuant to the site-specific Surplus Plutonium Disposition Environmental Impact Statement in a Plutonium Deposition Record of Decision in early 1999. This document reflects a new facility using the preferred technology (ceramic immobilization using the can-in-canister approach) and the preferred site (at Savannah River). The Plutonium Immobilization Plant accepts plutonium from pit conversion and from non-pit sources and, through a ceramic immobilization process, converts the plutonium into mineral-like forms that are subsequently encapsulated within a large canister of high-level waste glass. The final immobilized product must make the plutonium as inherently unattractive and inaccessible for use in nuclear weapons as the plutonium in spent fuel from commercial reactors and must be suitable for geologic disposal. Plutonium immobilization at the Savannah River Site uses: (1) A new building, the Plutonium Immobilization Plant, which will convert non-pit surplus plutonium to an oxide form suitable for the immobilization process, immobilize plutonium in a titanate-based ceramic form, place cans of the plutonium-ceramic forms into magazines, and load the magazines into a canister; (2) The existing Defense Waste Processing Facility for the pouring of high-level waste glass into the canisters; and (3) The Actinide Packaging and Storage Facility to receive and store feed materials. The Plutonium Immobilization Plant uses existing Savannah River Site infra-structure for analytical laboratory services, waste handling, fire protection, training, and other support utilities and services. The Plutonium Immobilization Plant

  11. Plutonium Immobilization Can Loading Equipment Review

    SciTech Connect

    Kriikku, E.; Ward, C.; Stokes, M.; Randall, B.; Steed, J.; Jones, R.; Hamilton, L.

    1998-05-01

    This report lists the operations required to complete the Can Loading steps on the Pu Immobilization Plant Flow Sheets and evaluates the equipment options to complete each operation. This report recommends the most appropriate equipment to support Plutonium Immobilization Can Loading operations.

  12. Overview of surplus weapons plutonium disposition

    SciTech Connect

    Rudy, G.

    1996-05-01

    The safe disposition of surplus weapons useable plutonium is a very important and urgent task. While the functions of long term storage and disposition directly relate to the Department`s weapons program and the environmental management program, the focus of this effort is particularly national security and nonproliferation.

  13. Recovery of Plutonium by Carrier Precipitation

    DOEpatents

    Goeckermann, R. H.

    1961-04-01

    The recovery of plutonium from an aqueous nitric acid Zr-containing solution of 0.2 to 1N acidity is accomplished by adding fluoride anions (1.5 to 5 mg/l), and precipitating the Pu with an excess of H/sub 2/0/sub 2/ at 53 to 65 deg C. (AEC)

  14. Plutonium isotope ratio variations in North America

    SciTech Connect

    Steiner, Robert E; La Mont, Stephen P; Eisele, William F; Fresquez, Philip R; Mc Naughton, Michael; Whicker, Jeffrey J

    2010-12-14

    Historically, approximately 12,000 TBq of plutonium was distributed throughout the global biosphere by thermo nuclear weapons testing. The resultant global plutonium fallout is a complex mixture whose {sup 240}Pu/{sup 239}Pu atom ratio is a function of the design and yield of the devices tested. The average {sup 240}Pu/{sup 239}Pu atom ratio in global fallout is 0.176 + 014. However, the {sup 240}Pu/{sup 239}Pu atom ratio at any location may differ significantly from 0.176. Plutonium has also been released by discharges and accidents associated with the commercial and weapons related nuclear industries. At many locations contributions from this plutonium significantly alters the {sup 240}Pu/{sup 239}Pu atom ratios from those observed in global fallout. We have measured the {sup 240}Pu/{sup 239}Pu atom ratios in environmental samples collected from many locations in North America. This presentation will summarize the analytical results from these measurements. Special emphasis will be placed on interpretation of the significance of the {sup 240}Pu/{sup 239}Pu atom ratios measured in environmental samples collected in the Arctic and in the western portions of the United States.

  15. NNSS Soils Monitoring: Plutonium Valley (CAU366)

    SciTech Connect

    Miller, Julianne J.; Mizell, Steve A.; Nikolich, George; Campbell, Scott

    2012-02-01

    The U.S. Department of Energy (DOE) National Nuclear Security Administration (NNSA), Nevada Site Office (NSO), Environmental Restoration Soils Activity has authorized the Desert Research Institute (DRI) to conduct field assessments of potential sediment transport of contaminated soil from Corrective Action Unit (CAU) 366, Area 11 Plutonium Valley Dispersion Sites Contamination Area (CA) during precipitation runoff events.

  16. 233-S plutonium concentration facility hazards assessment

    SciTech Connect

    Broz, R.E.

    1994-12-19

    This document establishes the technical basis in support of Emergency Planning activities for the 233-S Plutonium Concentration Facility on the Hanford Site. The document represents an acceptable interpretation of the implementing guidance document for DOE ORDER 5500.3A. Through this document, the technical basis for the development of facility specific Emergency Action Levels and the Emergency Planning Zone is demonstrated.

  17. Method for calibration of plutonium NDA

    SciTech Connect

    Lemming, J.F.; Campbell, A.R.; Rodenburg, W.W.

    1980-01-01

    Calibration materials characterized by calorimetric assay can be a practical alternative to synthetic standards for the calibration of plutonium nondestructive assay. Calorimetric assay is an effective measurement system for the characterization because: it can give an absolute assay from first principles when the isotopic composition is known, it is insensitive to most matrix effects, and its traceability to international measurement systems has been demonstrated.

  18. Heterogeneity Effects in Plutonium Contaminated Soil

    DTIC Science & Technology

    2009-03-01

    masses up to one kilogram once the ratio of Americium -241 (Am-241) and plutonium concentrations was established (Rademacher, 2001). Alpha...with a sample number and tared weight with a non-smearing marker. A standard control was then set using a point source of Americium -241 on an aluminum

  19. Regulatory issues for deep borehole plutonium disposition

    SciTech Connect

    Halsey, W.G.

    1995-03-01

    As a result of recent changes throughout the world, a substantial inventory of excess separated plutonium is expected to result from dismantlement of US nuclear weapons. The safe and secure management and eventual disposition of this plutonium, and of a similar inventory in Russia, is a high priority. A variety of options (both interim and permanent) are under consideration to manage this material. The permanent solutions can be categorized into two broad groups: direct disposal and utilization. The deep borehole disposition concept involves placing excess plutonium deep into old stable rock formations with little free water present. Issues of concern include the regulatory, statutory and policy status of such a facility, the availability of sites with desirable characteristics and the technologies required for drilling deep holes, characterizing them, emplacing excess plutonium and sealing the holes. This white paper discusses the regulatory issues. Regulatory issues concerning construction, operation and decommissioning of the surface facility do not appear to be controversial, with existing regulations providing adequate coverage. It is in the areas of siting, licensing and long term environmental protection that current regulations may be inappropriate. This is because many current regulations are by intent or by default specific to waste forms, facilities or missions significantly different from deep borehole disposition of excess weapons usable fissile material. It is expected that custom regulations can be evolved in the context of this mission.

  20. Electrochemically Modulated Separation for Plutonium Safeguards

    SciTech Connect

    Pratt, Sandra H.; Breshears, Andrew T.; Arrigo, Leah M.; Schwantes, Jon M.; Duckworth, Douglas C.

    2013-12-31

    Accurate and timely analysis of plutonium in spent nuclear fuel is critical in nuclear safeguards for detection of both protracted and rapid plutonium diversions. Gamma spectroscopy is a viable method for accurate and timely measurements of plutonium provided that the plutonium is well separated from the interfering fission and activation products present in spent nuclear fuel. Electrochemically modulated separation (EMS) is a method that has been used successfully to isolate picogram amounts of Pu from nitric acid matrices. With EMS, Pu adsorption may be turned "on" and "off" depending on the applied voltage, allowing for collection and stripping of Pu without the addition of chemical reagents. In this work, we have scaled up the EMS process to isolate microgram quantities of Pu from matrices encountered in spent nuclear fuel during reprocessing. Several challenges have been addressed including surface area limitations, radiolysis effects, electrochemical cell performance stability, and chemical interferences. After these challenges were resolved, 6 µg Pu was deposited in the electrochemical cell with approximately an 800-fold reduction of fission and activation product levels from a spent nuclear fuel sample. Modeling showed that these levels of Pu collection and interference reduction may not be sufficient for Pu detection by gamma spectroscopy. The main remaining challenges are to achieve a more complete Pu isolation and to deposit larger quantities of Pu for successful gamma analysis of Pu. If gamma analyses of Pu are successful, EMS will allow for accurate and timely on-site analysis for enhanced Pu safeguards.

  1. Plutonium Immobilization Can Loading Preliminary Specifications

    SciTech Connect

    Kriikku, E.

    1998-11-25

    This report discusses the Plutonium Immobilization can loading preliminary equipment specifications and includes a process block diagram, process description, equipment list, preliminary equipment specifications, plan and elevation sketches, and some commercial catalogs. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas.

  2. PLUTONIUM PURIFICATION PROCESS EMPLOYING THORIUM PYROPHOSPHATE CARRIER

    DOEpatents

    King, E.L.

    1959-04-28

    The separation and purification of plutonium from the radioactive elements of lower atomic weight is described. The process of this invention comprises forming a 0.5 to 2 M aqueous acidffc solution containing plutonium fons in the tetravalent state and elements with which it is normally contaminated in neutron irradiated uranium, treating the solution with a double thorium compound and a soluble pyrophosphate compound (Na/sub 4/P/sub 2/O/sub 7/) whereby a carrier precipitate of thorium A method is presented of reducing neptunium and - trite is advantageous since it destroys any hydrazine f so that they can be removed from solutions in which they are contained is described. In the carrier precipitation process for the separation of plutonium from uranium and fission products including zirconium and columbium, the precipitated blsmuth phosphate carries some zirconium, columbium, and uranium impurities. According to the invention such impurities can be complexed and removed by dissolving the contaminated carrier precipitate in 10M nitric acid, followed by addition of fluosilicic acid to about 1M, diluting the solution to about 1M in nitric acid, and then adding phosphoric acid to re-precipitate bismuth phosphate carrying plutonium.

  3. In search of plutonium: A nonproliferation journey

    NASA Astrophysics Data System (ADS)

    Hecker, Siegfried

    2010-02-01

    In February 1992, I landed in the formerly secret city of Sarov, the Russian Los Alamos, followed a few days later by a visit to Snezhinsk, their Livermore. The briefings we received of the Russian nuclear weapons program and tours of their plutonium, reactor, explosives, and laser facilities were mind boggling considering the Soviet Union was dissolved only two months earlier. This visit began a 17-year, 41 journey relationship with the Russian nuclear complex dedicated to working with them in partnership to protect and safeguard their weapons and fissile materials, while addressing the plight of their scientists and engineers. In the process, we solved a forty-year disagreement about the plutonium-gallium phase diagram and began a series of fundamental plutonium science workshops that are now in their tenth year. At the Yonbyon reprocessing facility in January 2004, my North Korean hosts had hoped to convince me that they have a nuclear deterrent. When I expressed skepticism, they asked if I wanted to see their ``product.'' I asked if they meant the plutonium; they replied, ``Well, yes.'' Thus, I wound up holding 200 grams of North Korean plutonium (in a sealed glass jar) to make sure it was heavy and warm. So began the first of my six journeys to North Korea to provide technical input to the continuing North Korean nuclear puzzle. In Trombay and Kalpakkam a few years later I visited the Indian nuclear research centers to try to understand how India's ambitious plans for nuclear power expansion can be accomplished safely and securely. I will describe these and other attempts to deal with the nonproliferation legacy of the cold war and the new challenges ahead. )

  4. PLUTONIUM CONTAMINATION VALENCE STATE DETERMINATION USING X-RAY ABSORPTION FINE STRUCTURE PERMITS CONCRETE RECYCLE

    SciTech Connect

    Ervin, P. F.; Conradson, S. D.

    2002-02-25

    This paper describes the determination of the speciation of plutonium contamination present on concrete surfaces at the Rocky Flats Environmental Technology Site (RFETS). At RFETS, the plutonium processing facilities have been contaminated during multiple events over their 50 year operating history. Contamination has resulted from plutonium fire smoke, plutonium fire fighting water, milling and lathe operation aerosols, furnace operations vapors and plutonium ''dust'' diffusion.

  5. Le genre Tunga Jarocki, 1838 (Siphonaptera : Tungidae). I – Taxonomie, phylogénie, écologie, rôle pathogène

    PubMed Central

    Beaucournu, J.-C.; Degeilh, B.; Mergey, T.; Muñoz-Leal, S.; González-Acuña, D.

    2012-01-01

    Pour la première fois, les 12 espèces actuellement décrites dans le genre Tunga sont étudiées sur le plan de la taxonomie et de la répartition. Divers aspects de leur biologie et leur rôle pathogène sont également envisagés, et en particulier leur phylogénie, leur chorologie, leur phénologie, leur sexe-ratio et leurs dermecos. PMID:23193514

  6. A Note on the Reaction of Hydrogen and Plutonium

    SciTech Connect

    Noone, Bailey C

    2012-08-15

    Plutonium hydride has many practical and experimental purposes. The reaction of plutonium and hydrogen has interesting characteristics, which will be explored in the following analysis. Plutonium is a radioactive actinide metal that emits alpha particles. When plutonium metal is exposed to air, the plutonium oxides and hydrides, and the volume increases. PuH{sub 2} and Pu{sub 2}O{sub 3} are the products. Hydrogen is a catalyst for plutonium's corrosion in air. The reaction can take place at room temperature because it is fairly insensitive to temperature. Plutonium hydride, or PuH{sub 2}, is black and metallic. After PuH{sub 2} is formed, it quickly flakes off and burns. The reaction of hydrogen and plutonium is described as pyrophoric because the product will spontaneously ignite when oxygen is present. This tendency must be considered in the storage of metal plutonium. The reaction is characterized as reversible and nonstoichiometric. The reaction goes as such: Pu + H{sub 2} {yields} PuH{sub 2}. When PuH{sub 2} is formed, the hydrogen/plutonium ratio is between 2 and 2.75 (approximately). As more hydrogen is added to the system, the ratio increases. When the ratio exceeds 2.75, PuH{sub 3} begins to form along with PuH{sub 2}. Once the ratio surpasses 2.9, only PuH{sub 3} remains. The volume of the plutonium sample increases because of the added hydrogen and the change in crystal structure which the sample undergoes. As more hydrogen is added to a system of metal plutonium, the crystal structure evolves. Plutonium has a crystal structure classified as monoclinic. A monoclinic crystal structure appears to be a rectangular prism. When plutonium reacts with hydrogen, the product PuH{sub 2}, becomes a fluorite structure. It can also be described as a face centered cubic structure. PuH{sub 3} forms a hexagonal crystal structure. As plutonium evolves from metal plutonium to plutonium hydride to plutonium trihydride, the crystal structure evolves from monoclinic to

  7. Impact de la preparation des anodes crues et des conditions de cuisson sur la fissuration dans des anodes denses

    NASA Astrophysics Data System (ADS)

    Amrani, Salah

    La fabrication de l'aluminium est realisee dans une cellule d'electrolyse, et cette operation utilise des anodes en carbone. L'evaluation de la qualite de ces anodes reste indispensable avant leur utilisation. La presence des fissures dans les anodes provoque une perturbation du procede l'electrolyse et une diminution de sa performance. Ce projet a ete entrepris pour determiner l'impact des differents parametres de procedes de fabrication des anodes sur la fissuration des anodes denses. Ces parametres incluent ceux de la fabrication des anodes crues, des proprietes des matieres premieres et de la cuisson. Une recherche bibliographique a ete effectuee sur tous les aspects de la fissuration des anodes en carbone pour compiler les travaux anterieurs. Une methodologie detaillee a ete mise au point pour faciliter le deroulement des travaux et atteindre les objectifs vises. La majorite de ce document est reservee pour la discussion des resultats obtenus au laboratoire de l'UQAC et au niveau industriel. Concernant les etudes realisees a l'UQAC, une partie des travaux experimentaux est reservee a la recherche des differents mecanismes de fissuration dans les anodes denses utilisees dans l'industrie d'aluminium. L'approche etait d'abord basee sur la caracterisation qualitative du mecanisme de la fissuration en surface et en profondeur. Puis, une caracterisation quantitative a ete realisee pour la determination de la distribution de la largeur de la fissure sur toute sa longueur, ainsi que le pourcentage de sa surface par rapport a la surface totale de l'echantillon. Cette etude a ete realisee par le biais de la technique d'analyse d'image utilisee pour caracteriser la fissuration d'un echantillon d'anode cuite. L'analyse surfacique et en profondeur de cet echantillon a permis de voir clairement la formation des fissures sur une grande partie de la surface analysee. L'autre partie des travaux est basee sur la caracterisation des defauts dans des echantillons d'anodes crues

  8. Simulation de l'accretion de glace sur un obstacle bidimensionnel par la methode des bissectrices et par la modelisation des ruisselets et des gouttes de surface

    NASA Astrophysics Data System (ADS)

    Fortin, Guy

    Le LIMA (Laboratoire International des Materiaux Antigivre) en collaboration avec le CIRA (Italian Aerospace Research Centre) a developpe un logiciel simulant l'accretion de la glace en regimes sec et humide sur un objet bidimensionnel fixe. L'approche utilisee s'appuie sur les travaux de Lozowski pour les bilans energetiques, sur une etude du comportement du film d'eau, des ruisselets et des gouttes de surface pour le calcul des rugosites et des masses d'eau residuelle, ainsi que sur une methode de bissectrice pour l'evolution de la surface de glace. La contribution du CIRA a ete de fournir le logiciel pour le calcul des ecoulements et de la captation. Le bilan energetique base sur la conservation de l'energie est la sommation de la chaleur latente de fusion, d'evaporation et de sublimation, du rechauffement adiabatique et cinetique, et des pertes de chaleur par convection et conduction, ainsi que de l'evolution thermodynamique de l'eau de son etat initial a son etat final. La densite de la glace, qui a un impact important sur la simulation, est calculee a partir d'une correlation empirique developpee avec les cylindres tournants. En se basant sur les travaux de Al-Khalil et Hansman, le comportement des gouttes en regimes sec et humide a ete decrit analytiquement, ce qui a mene a determiner la hauteur maximale que peuvent atteindre les gouttes avant mouvement. Cette hauteur, appelee hauteur de mouvement, permet de determiner l'etat de l'eau sur la surface (film, ruisselets ou gouttes), ainsi que la hauteur des rugosites lorsque l'eau existe sous forme de gouttes ou de ruisselets. La hauteur de mouvement est determinee par l'equilibre entre les forces de cisaillement, induites par les effets aerodynamiques et gravitationnels evalues pour une goutte non deformee, et la force de cisaillement, induite par la tension de surface et la deformation de la goutte. Elle a ete validee en laboratoire et la precision obtenue pour la partie aerodynamique et gravitationnelle est

  9. Lambeau Expanse du Cuir Chevelu dans la Couverture des Alopecies Cicatricielles sur Sequelles de Brulures. A Propos d'une Observation

    PubMed Central

    El Mazouz, S.; Hafidi, J.; Fejjal, N.; Mejjati, H.; Cherkab, L.; Gharib, N.; Abbassi, A.

    2010-01-01

    Summary Les séquelles esthétiques des alopécies cicatricielles sur séquelles de brûlures sont responsables de préjudices empêchant parfois la réinsertion sociale du patient, surtout chez les sujets de sexe féminin. Le cuir chevelu permet la réalisation de lambeaux permettant de couvrir ces alopécies. Les Auteurs décrivent le cas d'une jeune patiente victime d'une alopécie cicatricielle sur séquelles de brûlures chez qui ils ont réalisé un lambeau expansé du cuir chevelu et mettent le point sur la prise en charge de ces lésions à travers ce cas clinique et une revue de littérature. PMID:21991195

  10. Le continu contre l'espace

    NASA Astrophysics Data System (ADS)

    Salanskis, Jean-Michel

    Disons pour conclure que, en tout état de cause, la façon de concevoir philosophiquement le conflit du continu et de l'espace que nous avons trouvée chez Hegel n'est pas homogène avec le style et les modalités de la pensée mathématique: 1) d'une part, le lien classique, le lien de référence entre continu et espace en mathématiques n'est pas que l'espace serait premier et privé de pensée, et le continu second, venant dissoudre l'espace en apportant la qualité, l'infini et la pensée, mais tout au contraire, il consiste en ce que l'espace est fondé sur l'abîme infinitaire du continu ; 2) d'autre part, l'éventuel divorce entre l'espace et le continu dans l'aire mathématique n'est pas celui d'une réflexivité purement conceptuelle du continu avec un positivisme géométrique, n'équivaut pas à une rupture disciplinaire ; il est plutôt le symptôme de la dérive d'une herméneutique à l'égard d'une autre, au sein d'un continent juridique commun définissant la discipline (la mathématique ensembliste), cette dérive pouvant, à la limite, induire une refonte de ce sol juridique, sans que jamais il soit question pour autant de nier l'unité des mathématiques, à comprendre ici comme l'unité ultime de responsabilité de la communauté mathématique à l'égard des trois questions Qu'est-ce que l'espace?”, “Qu'est-ce que le continu?” et “Qu'est-ce que l'infini?”.

  11. METHOD FOR RECOVERING PLUTONIUM VALUES FROM SOLUTION USING A BISMUTH HYDROXIDE CARRIER PRECIPITATE

    DOEpatents

    Faris, B.F.

    1961-04-25

    Carrier precipitation processes for separating plutonium values from aqueous solutions are described. In accordance with the invention a bismuth hydroxide precipitate is formed in the plutonium-containing solution, thereby carrying plutonium values from the solution.

  12. Anthropogenic plutonium-244 in the environment: Insights into plutonium's longest-lived isotope.

    PubMed

    Armstrong, Christopher R; Brant, Heather A; Nuessle, Patterson R; Hall, Gregory; Cadieux, James R

    2016-02-22

    Owing to the rich history of heavy element production in the unique high flux reactors that operated at the Savannah River Site, USA (SRS) decades ago, trace quantities of plutonium with highly unique isotopic characteristics still persist today in the SRS terrestrial environment. Development of an effective sampling, processing, and analysis strategy enables detailed monitoring of the SRS environment, revealing plutonium isotopic compositions, e.g., (244)Pu, that reflect the unique legacy of plutonium production at SRS. This work describes the first long-term investigation of anthropogenic (244)Pu occurrence in the environment. Environmental samples, consisting of collected foot borne debris, were taken at SRS over an eleven year period, from 2003 to 2014. Separation and purification of trace plutonium was carried out followed by three stage thermal ionization mass spectrometry (3STIMS) measurements for plutonium isotopic content and isotopic ratios. Significant (244)Pu was measured in all of the years sampled with the highest amount observed in 2003. The (244)Pu content, in femtograms (fg = 10(-15) g) per gram, ranged from 0.31 fg/g to 44 fg/g in years 2006 and 2003 respectively. In all years, the (244)Pu/(239)Pu atom ratios were significantly higher than global fallout, ranging from 0.003 to 0.698 in years 2014 and 2003 respectively.

  13. Process modeling of plutonium conversion and MOX fabrication for plutonium disposition

    SciTech Connect

    Schwartz, K. L.

    1998-10-01

    Two processes are currently under consideration for the disposition of 35 MT of surplus plutonium through its conversion into fuel for power production. These processes are the ARIES process, by which plutonium metal is converted into a powdered oxide form, and MOX fuel fabrication, where the oxide powder is combined with uranium oxide powder to form ceramic fuel. This study was undertaken to determine the optimal size for both facilities, whereby the 35 MT of plutonium metal will be converted into fuel and burned for power. The bounding conditions used were a plutonium concentration of 3-7%, a burnup of 20,000-40,000 MWd/MTHM, a core fraction of 0.1 to 0.4, and the number of reactors ranging from 2-6. Using these boundary conditions, the optimal cost was found with a plutonium concentration of 7%. This resulted in an optimal throughput ranging from 2,000 to 5,000 kg Pu/year. The data showed minimal costs, resulting from throughputs in this range, at 3,840, 2,779, and 3,497 kg Pu/year, which results in a facility lifetime of 9.1, 12.6, and 10.0 years, respectively.

  14. Plutonium disposition via immobilization in ceramic or glass

    SciTech Connect

    Gray, L.W.; Kan, T.; Shaw, H.F.; Armantrout, A.

    1997-03-05

    The management of surplus weapons plutonium is an important and urgent task with profound environmental, national, and international security implications. In the aftermath of the Cold War, Presidential Policy Directive 13, and various analyses by renown scientific, technical, and international policy organizations have brought about a focused effort within the Department of Energy to identify and implement paths for the long term disposition of surplus weapons- usable plutonium. The central goal of this effort is to render surplus weapons plutonium as inaccessible and unattractive for reuse in nuclear weapons as the much larger and growing stock of plutonium contained in spent fuel from civilian reactors. One disposition option being considered for surplus plutonium is immobilization, in which the plutonium would be incorporated into a glass or ceramic material that would ultimately be entombed permanently in a geologic repository for high-level waste.

  15. Erratum dans le numéro de mai-juin 1988

    NASA Astrophysics Data System (ADS)

    Erratum dans le numéro de mai-juin 1988: Dans l'article sur les étoiles à baryum: p. 74, 2e colonne (après la première formule), il faut lire «A est la masse atomique» au lieu de «nombre atomique»

  16. Plutonium speciation in water from Mono Lake, California

    USGS Publications Warehouse

    Cleveland, J.M.; Rees, T.F.; Nash, K.L.

    1983-01-01

    The solubility of plutonium in Mono Lake water is enhanced by the presence of large concentrations of indigenous carbonate ions and moderate concentrations of fluoride ions. In spite of the complex chemical composition of this water, only a few ions govern the behavior of plutonium, as demonstrated by the fact that it was possible to duplicate plutonium speciation in a synthetic water containing only the principal components of Mono Lake water.

  17. 14. END VIEW OF THE PLUTONIUM STORAGE VAULT FROM THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. END VIEW OF THE PLUTONIUM STORAGE VAULT FROM THE REMOTE CONTROL STATION. THE STACKER-RETRIEVER, A REMOTELY-OPERATED, MECHANIZED TRANSPORT SYSTEM, RETRIEVES CONTAINERS OF PLUTONIUM FROM SAFE GEOMETRY PALLETS STORED ALONG THE LENGTH OF THE VAULT. THE STACKER-RETRIEVER RUNS ALONG THE AISLE BETWEEN THE PALLETS OF THE STORAGE CHAMBER. (3/2/86) - Rocky Flats Plant, Plutonium Recovery Facility, Northwest portion of Rocky Flats Plant, Golden, Jefferson County, CO

  18. SEPARATION OF PLUTONIUM FROM AQUEOUS SOLUTIONS BY ION-EXCHANGE

    DOEpatents

    Schubert, J.

    1958-06-01

    A process is described for the separation of plutonium from an aqueous solution of a plutonium salt, which comprises adding to the solution an acid of the group consisting of sulfuric acid, phosphoric acid, and oxalic acid, and mixtures thereof to provide an acid concentration between 0.0001 and 1 M, contacting the resultant solution with a synthetic organic anion exchange resin, and separating the aqueous phase and the resin which contains the plutonium.

  19. Spectrophotometers for plutonium monitoring in HB-line

    SciTech Connect

    Lascola, R. J.; O'Rourke, P. E.; Kyser, E. A.; Immel, D. M.; Plummer, J. R.; Evans, E. V.

    2016-02-12

    This report describes the equipment, control software, calibrations for total plutonium and plutonium oxidation state, and qualification studies for the instrument. It also provides a detailed description of the uncertainty analysis, which includes source terms associated with plutonium calibration standards, instrument drift, and inter-instrument variability. Also included are work instructions for instrument, flow cell, and optical fiber setup, work instructions for routine maintenance, and drawings and schematic diagrams.

  20. Plutonium speciation in water from Mono Lake, California

    SciTech Connect

    Cleveland, J.M.; Rees, T.F.; Nash, K.L.

    1983-12-23

    The solubility of plutonium in Mono Lake water is enhanced by the presence of large concentrations of indigenous carbonate ions and moderate concentrations of fluoride ions. In spite of the complex chemical composition of this water, only a few ions govern the behavior of plutonium, as demonstrated by the fact that it was possible to duplicate plutonium speciation in a synthetic water containing only the principal components of Mono Lake water.

  1. Investigations of plutonium immobilization into the vitreous compositions

    SciTech Connect

    Matyunin, Y.I.,

    1998-04-15

    Development and characterizations of phosphate and borosilicate glasses for vitrifying high level waste (HLW) solutions in Russia has been extensive. The technical data generated were for low concentrations (less than 0.05% Pu) of plutonium. Limited studies have been performed with plutonium concentrations one to two orders of magnitude larger. The results of these studies are being used to plan and implement an expanded experimental program to establish the limitations and characteristics of plutonium in similar glass compositions.

  2. Pyrochemical investigations into recovering plutonium from americium extraction salt residues

    SciTech Connect

    Fife, K.W.; West, M.H.

    1987-05-01

    Progress into developing a pyrochemical technique for separating and recovering plutonium from spent americium extraction waste salts has concentrated on selective chemical reduction with lanthanum metal and calcium metal and on the solvent extraction of americium with calcium metal. Both techniques are effective for recovering plutonium from the waste salt, although neither appears suitable as a separation technique for recycling a plutonium stream back to mainline purification processes. 17 refs., 13 figs., 2 tabs.

  3. Plutonium stabilization and handling (PuSH)

    SciTech Connect

    Weiss, E.V.

    1997-01-23

    This Functional Design Criteria (FDC) addresses construction of a Stabilization and Packaging System (SPS) to oxidize and package for long term storage remaining plutonium-bearing special nuclear materials currently in inventory at the Plutonium Finishing Plant (PFP), and modification of vault equipment to allow storage of resulting packages of stabilized SNM for up to fifty years. The major sections of the project are: site preparation; SPS Procurement, Installation, and Testing; storage vault modification; and characterization equipment additions. The SPS will be procured as part of a Department of Energy nationwide common procurement. Specific design crit1460eria for the SPS have been extracted from that contract and are contained in an appendix to this document.

  4. Concentration and purification of plutonium or thorium

    DOEpatents

    Hayden, John A.; Plock, Carl E.

    1976-01-01

    In this invention a first solution obtained from such as a plutonium/thorium purification process or the like, containing plutonium (Pu) and/or thorium (Th) in such as a low nitric acid (HNO.sub.3) concentration may have the Pu and/or Th separated and concentrated by passing an electrical current from a first solution having disposed therein an anode to a second solution having disposed therein a cathode and separated from the first solution by a cation permeable membrane, the Pu or Th cation permeating the cation membrane and forming an anionic complex within the second solution, and electrical current passage affecting the complex formed to permeate an anion membrane separating the second solution from an adjoining third solution containing disposed therein an anode, thereby effecting separation and concentration of the Pu and/or Th in the third solution.

  5. Recent plutonium metal production experience at Hanford

    SciTech Connect

    Gibson, M.W.; Nyman, D.H.

    1989-10-01

    Plutonium metal is produced at the Hanford Site in the Remote Mechanical C (RMC) line. The line is housed in the Plutonium Finishing Plant (PFP). The RMC line was built in the early 1960s and operated until 1973 when it was shut down. The line was restarted in 1985 and has operated on a campaign basis since that time. The fiscal years (FY) 1988/89 RMC line campaigns have shown improved yields and plant safety performance when compared to previous years. This is attributed to numerous process improvements that have been made in the line and to an enhanced standard of disciplined operations. This report discusses the improvements made to the RMC line.

  6. Plutonium Speciation, Solubilization and Migration in Soils

    SciTech Connect

    Neu, Mary P.; Haire, Richard G.

    2002-06-01

    The DOE is currently conducting cleanup activities at its nuclear weapons development sites, many of which have accumulated plutonium in soils for 50 years. To properly control Pu migration in soils within Federal sites and onto public lands, better evaluate the public risk, and design effective remediation strategies, a fundamental understanding of Pu speciation and environmental transport is needed. The key scientific goals of this project are: to determine Pu concentrations and speciation at contaminated DOE sites; to study the formation, stability, and structural and spectroscopic features of environmentally relevant Pu species; to determine the mechanism(s) of interaction between Pu and Mn/Fe minerals and the potential release of Pu via redox cycling; and to model the environmental behavior of plutonium. Our goal is to use characterization, thermodynamic, mineral interaction, and mobility data to develop better models of radionuclide transport and risk assessment, and to enable the development of science-based decontamination strategies.

  7. Plutonium fractionation in southern Baltic Sea sediments.

    PubMed

    Strumińska-Parulska, Dagmara I; Skwarzec, Bogdan; Pawlukowska, Magdalena

    2012-01-01

    In this study, different chemical plutonium fractions (dissolved in water, connected to carbonates, connected to oxides, complexed with organic matter, mineral acids soluble and the rest) in sediments from the Vistula River estuary, the Gdańsk Basin and the Bornholm Deep were determined. The distribution of (239+240)Pu in analysed sediments samples was not uniform but dependent on its chemical form, depth and the sediment geomorphology. The highest amount of plutonium exists in middle parts of sediments and comes from the global atmospheric fallout from nuclear tests in 1958-1961. According to all analysed fractions, the biggest amount of (239+240)Pu was in the mobile form, connected to carbonate fractions from the Vistula River estuary, the Gulf of Gdańsk and the Bornholm Deep sediments.

  8. CRITICALITY CURVES FOR PLUTONIUM HYDRAULIC FLUID MIXTURES

    SciTech Connect

    WITTEKIND WD

    2007-10-03

    This Calculation Note performs and documents MCNP criticality calculations for plutonium (100% {sup 239}Pu) hydraulic fluid mixtures. Spherical geometry was used for these generalized criticality safety calculations and three geometries of neutron reflection are: {sm_bullet}bare, {sm_bullet}1 inch of hydraulic fluid, or {sm_bullet}12 inches of hydraulic fluid. This document shows the critical volume and critical mass for various concentrations of plutonium in hydraulic fluid. Between 1 and 2 gallons of hydraulic fluid were discovered in the bottom of HA-23S. This HA-23S hydraulic fluid was reported by engineering to be Fyrquel 220. The hydraulic fluid in GLovebox HA-23S is Fyrquel 220 which contains phosphorus. Critical spherical geometry in air is calculated with 0 in., 1 in., or 12 inches hydraulic fluid reflection.

  9. MEANS FOR PRODUCING PLUTONIUM CHAIN REACTIONS

    DOEpatents

    Wigner, E.P.; Weinberg, A.M.

    1961-01-24

    A neutronic reactor is described with an active portion capable of operating at an energy level of 0.5 to 1000 ev comprising discrete bodies of Pu/ sup 239/ disposed in a body of water which contains not more than 5 molecules of water to one atom of plutonium, the total amount of Pu/sup 239/ being sufficient to sustain a chain reaction. (auth)

  10. Dose estimates of alternative plutonium pyrochemical processes.

    SciTech Connect

    Kornreich, D. E.; Jackson, J. W.; Boerigter, S. T.; Averill, W. A.; Fasel, J. H.

    2002-01-01

    We have coupled our dose calculation tool Pandemonium with a discrete-event, object-oriented, process-modeling system ProMosO to analyze a set of alternatives for plutonium purification operations. The results follow expected trends and indicate, from a dose perspective, that an experimental flowsheet may warrant further research to see if it can be scaled to industrial levels. Flowsheets that include fluoride processes resulted in the largest doses.

  11. Surplus Plutonium Disposition (SPD) Environmental Data Summary

    SciTech Connect

    Fledderman, P.D.

    2000-08-24

    This document provides an overview of existing environmental and ecological information at areas identified as potential locations of the Savannah River Site's (SRS) Surplus Plutonium Disposition (SPD) facilities. This information is required to document existing environmental and baseline conditions from which SPD construction and operation impacts can be defined. It will be used in developing the required preoperational monitoring plan to be used at specific SPD facilities construction sites.

  12. Derivation of plutonium-239 materials disposition categories

    SciTech Connect

    Brough, W.G.

    1995-04-27

    At this time, the Office of Fissile Materials Disposition within the DOE, is assessing alternatives for the disposition of excess fissile materials. To facilitate the assessment, the Plutonium-Bearing Materials Feed Report for the DOE Fissile Materials Disposition Program Alternatives report was written. The development of the material categories and the derivation of the inventory quantities associated with those categories is documented in this report.

  13. Plutonium utilisation in future UK PWRs

    SciTech Connect

    Thomas, G. M.; Worrall, A.

    2006-07-01

    Plutonium recycling in the form of Mixed Oxide (MOX) fuels is already a reality in over 30 reactors in Europe (in Belgium, Switzerland, Germany and France). Japan also plans to use MOX in approximately 30% of its reactors in the near future[1]. This paper describes potential near to mid-term disposition strategies for the United Kingdom's stockpile of plutonium. In order to be confident that MOX fuel can be utilised effectively in Pressurised Water Reactors (PWRs) in the UK, details are given of studies carried out recently at Nexia Solutions on PWR cores loaded with MOX containing typical UK plutonium isotopic compositions. Three dimensional steady state neutronic models of a standard Westinghouse four loop PWR design are constructed using state of the art tools (Studsvik of America's Core Management System[2, 3, 4]). Initially, a standard 18-month equilibrium UO{sub 2} fuel cycle is generated, followed by safety analyses and fuel performance calculations to demonstrate its feasibility. This equilibrium UO{sub 2} core is then gradually transitioned through loading patterns containing increasing MOX core loading fractions. Finally, an equilibrium MOX core loading pattern is determined. Technical safety analyses are also carried out on the transition cores and the final equilibrium scenario to ensure that all of the MOX cores are robust from a technical and safety viewpoint. Once these studies are completed the annual fuel throughputs for each scenario can be determined and used to produce options for managing the UK's plutonium stockpile. This work is part of a wider exercise currently being carried out by Nexia Solutions to explore the options for the safe disposition of the UK civil stockpile of separated PUO{sub 2}. (authors)

  14. Carcinome papillaire sur kyste du tractus thyréoglosse: à propos de deux cas

    PubMed Central

    Dbab, Lamia; Nouri, Hassan; Iguelouane, Nassim; Rochdi, Youssef; Aderdour, Lahcen; Raji, Abdelaziz

    2015-01-01

    L'objectif de ce travail est de présenté deux cas de carcinomes papillaire sur kystes du tractus thyréoglosse (KTT) et d'exposer notre attitude thérapeutique. Il s'agit de deux patientes, une âgée de 30 ans et l'autre de 45 ans, qui ont été opéré dans notre centre. Le diagnostic du carcinome papillaire sur KTT a été retenu après étude anatomopathologique du kyste après exérèse selon la technique de Sistrunk. Une thyroïdectomie totale suivie d'une irathérapie et d'une hormonothérapie freinatrice a été réalisé chez l'une des patientes, pour l'autre une thyroïdectomie totale associée à une hormonothérapie freinatrice a été préconisé. L'évolution été favorable après un recule de 4 ans pour la première patiente et de 2 ans pour la deuxième. La thyroïdectomie totale après exérèse complète du KTT est le traitement recommandé pour le carcinome papillaire sur KTT. Il a été démontré qu'un cancer latent de la thyroïde peut être développé même après des années après l'exérèse du KTT. Le traitement du carcinome papillaire sur KTT est bien codifié, permettant un excellent pronostic. PMID:26848352

  15. PLUTONIUM RECOVERY FROM NEUTRON-BOMBARDED URANIUM FUEL

    DOEpatents

    Moore, R.H.

    1962-04-10

    A process of recovering plutonium from neutronbombarded uranium fuel by dissolving the fuel in equimolar aluminum chloride-potassium chloride; heating the mass to above 700 deg C for decomposition of plutonium tetrachloride to the trichloride; extracting the plutonium trichloride into a molten salt containing from 40 to 60 mole % of lithium chloride, from 15 to 40 mole % of sodium chloride, and from 0 to 40 mole % of potassium chloride or calcium chloride; and separating the layer of equimolar chlorides containing the uranium from the layer formed of the plutonium-containing salt is described. (AEC)

  16. Magnetic separation as a plutonium residue enrichment process

    SciTech Connect

    Avens, L.R.; McFarlan, J.T.; Gallegos, U.F.

    1989-01-01

    We have subjected several plutonium contaminated residues to Open Gradient Magnetic Separation (OGMS) on an experimental scale. Separation of graphite, bomb reduction sand, and bomb reduction sand, and bomb reduction sand, slag, and crucible, resulted in a plutonium rich fraction and a plutonium lean fraction. The lean fraction varied between about 20% to 85% of the feed bulk. The plutonium content of the lean fraction can be reduced from about 2% in the feed to the 0.1% to 0.5% range dependent on the portion of the feed rejected to this lean fraction. These values are low enough in plutonium to meet economic discard limits and be considered for direct discard. Magnetic separation of direct oxide reduction and electrorefining pyrochemical salts gave less favorable results. While a fraction very rich in plutonium could be obtained, the plutonium content of the lean fraction was to high for direct discard. This may still have chemical processing applications. OGMS experiments at low magnetic field strength on incinerator ash did give two fractions but the plutonium content of each fraction was essentially identical. Thus, no chemical processing advantage was identified for magnetic separation of this residue. The detailed results of these experiments and the implications for OGMS use in recycle plutonium processing are discussed. 4 refs., 3 figs., 9 tabs.

  17. Technical considerations and policy requirements for plutonium management

    SciTech Connect

    Christensen, D.C.; Dinehart, S.M.; Yarbro, S.L.

    1995-12-31

    The goals for plutonium management have changed dramatically over the past few years. Today, the challenge is focused on isolating plutonium from the environment and preparing it for permanent disposition. In parallel, the requirements for managing plutonium are rapidly changing. For example, there is a significant increase in public awareness on how facilities operate, increased attention to environmental safety and health (ES and H) concerns, greater interest in minimizing waste, more emphasis on protecting material from theft, providing materials for international inspection, and a resurgence of interest in using plutonium as an energy source. Of highest concern, in the immediate future, is protecting plutonium from theft or diversion, while the national policy on disposition is debated. These expanded requirements are causing a broadening of responsibilities within the Department of Energy (DOE) to include at least seven organizations. An unavoidable consequence is the divergence in approach and short-term goals for managing similar materials within each organization. The technology base does exist, properly, safely, and cost effectively to extract plutonium from excess weapons, residues, waste, and contaminated equipment and facilities, and to properly stabilize it. Extracting the plutonium enables it to be easily inventoried, packaged, and managed to minimize the risk of theft and diversion. Discarding excess plutonium does not sufficiently reduce the risk of diversion, and as a result, long-term containment of plutonium from the environment may not be able to be proven to the satisfaction of the public.

  18. Geomorphology of plutonium in the Northern Rio Grande

    SciTech Connect

    Graf, W.L.

    1993-03-01

    Nearly all of the plutonium in the natural environment of the Northern Rio Grande is associated with soils and sediment, and river processes account for most of the mobility of these materials. A composite regional budget for plutonium based on multi-decadal averages for sediment and plutonium movement shows that 90 percent of the plutonium moving into the system is from atmospheric fallout. The remaining 10 percent is from releases at Los Alamos. Annual variation in plutonium flux and storage exceeds 100 percent. The contribution to the plutonium budget from Los Alamos is associated with relatively coarse sediment which often behaves as bedload in the Rio Grande. Infusion of these materials into the main stream were largest in 1951, 1952, 1957, and 1968. Because of the schedule of delivery of plutonium to Los Alamos for experimentation and weapons manufacturing, the latter two years are probably the most important. Although the Los Alamos contribution to the entire plutonium budget was relatively small, in these four critical years it constituted 71--86 percent of the plutonium in bedload immediately downstream from Otowi.

  19. 30. VIEW OF A GLOVEBOX LINE USED IN PLUTONIUM OPERATIONS. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. VIEW OF A GLOVEBOX LINE USED IN PLUTONIUM OPERATIONS. SAFETY AND HEALTH CONCERNS WERE OF MAJOR IMPORTANCE AT THE PLANT, BECAUSE OF THE RADIOACTIVE NATURE OF THE MATERIALS USED. PLUTONIUM GIVES OFF ALPHA AND BETA PARTICLES, GAMMA PROTONS, NEUTRONS, AND IS ALSO PYROPHORIC. AS A RESULT, PLUTONIUM OPERATIONS ARE PERFORMED UNDER CONTROLLED CONDITIONS THAT INCLUDE CONTAINMENT, FILTERING, SHIELDING, AND CREATING AN INERT ATMOSPHERE. PLUTONIUM WAS HANDLED WITHIN GLOVEBOXES THAT WERE INTERCONNECTED AND RAN SEVERAL HUNDRED FEET IN LENGTH (5/5/70). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO

  20. Design of the improved plutonium canister assay system (IPCAS)

    SciTech Connect

    Abhold, M. E.; Baker, M. C.; Bourret, S. C.; Polk, P. J.; Vo, Duc T.

    2001-01-01

    The improved Plutonium Canister Assay System (iPCAS) is designed to detect gross and partial defects in the declared plutonium content of plutonium and MOX storage canisters during transfer to storage and process areas of the MOX fuel fabrication facility in Kokkasho, Japan. In addition, an associated Gamma Isotopics System (GIS) will be used to confirm facility-declared plutonium isotopics with accuracy sufficient to reduce the amount of destructive isotopic analysis needed. The design of the iPCAS instrument and its associated GIS is described and the expected performance of the instrument is discussed.

  1. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2003-01-01

    Premier plongeon d'Integral dans l'univers du rayonnement gamma; Collisions et cannibalisme galactique; Proplydes dans la Carène; Quasar record; Eta Carinae étoile double; Géantes rouges; La vitesse de la gravité; Sursaut gamma; Une planète lointaine; Un Troyen neptunien; L'univers lointain; Bébé galaxie; Le centre de notre Galaxie version X; Un HERO astronomique; Disque X géant; Electrons mystérieux dans RCW 38; Environnement martien; Interférométrie infrarouge; Méthane titanien; Micro-organismes atmosphériques; Réchauffement planétaire; La meilleure observation infrarouge de l'univers; Planètes en grand nombre?; Pôle sud et Big Bang; SS 433; Volcans et astéroïdes; Amalthée; De l'eau sur Mars; DEM L 106; Gliese 876; La taille des étoiles; Le danger des supernovas; Vieux cailloux

  2. A Plutonium-Contaminated Wound, 1985, USA

    SciTech Connect

    Doran M. Christensen, DO, REAC /TS Associate Director and Staff Physician Eugene H. Carbaugh, CHP, Staff Scientist, Internal Dosimetry Manager, Pacific Northwest National Laboratory, Richland, Washington

    2012-02-02

    A hand injury occurred at a U.S. facility in 1985 involving a pointed shaft (similar to a meat thermometer) that a worker was using to remove scrap solid plutonium from a plastic bottle. The worker punctured his right index finger on the palm side at the metacarpal-phalangeal joint. The wound was not through-and- through, although it was deep. The puncture wound resulted in deposition of ~48 kBq of alpha activity from the weapons-grade plutonium mixture with a nominal 12 to 1 Pu-alpha to {sup 241}Am-alpha ratio. This case clearly showed that DTPA was very effective for decorporation of plutonium and americium. The case is a model for management of wounds contaminated with transuranics: (1) a team approach for dealing with all of the issues surrounding the incident, including the psychological, (2) early surgical intervention for foreign-body removal, (3) wound irrigation with DTPA solution, and (4) early and prolonged DTPA administration based upon bioassay and in vivo dosimetry.

  3. Plutonium immobilization in glass and ceramics

    SciTech Connect

    Knecht, D.A.; Murphy, W.M.

    1996-05-01

    The Materials Research Society Nineteenth Annual Symposium on the Scientific Basis for Nuclear Waste Management was held in Boston on November 27 to December 1, 1995. Over 150 papers were presented at the Symposium dealing with all aspects of nuclear waste management and disposal. Fourteen oral sessions and on poster session included a Plenary session on surplus plutonium dispositioning and waste forms. The proceedings, to be published in April, 1996, will provide a highly respected, referred compilation of the state of scientific development in the field of nuclear waste management. This paper provides a brief overview of the selected Symposium papers that are applicable to plutonium immobilization and plutonium waste form performance. Waste forms that were described at the Symposium cover most of the candidate Pu immobilization options under consideration, including borosilicate glass with a melting temperature of 1150 {degrees}C, a higher temperature (1450 {degrees}C) lanthanide glass, single phase ceramics, multi-phase ceramics, and multi-phase crystal-glass composites (glass-ceramics or slags). These Symposium papers selected for this overview provide the current status of the technology in these areas and give references to the relevant literature.

  4. Proposed Modification to the Plutonium Systemic Model.

    PubMed

    Konzen, Kevin; Miller, Scott; Brey, Richard

    2015-10-01

    The currently accepted biokinetic model for plutonium distribution within the human body was recommended by the International Commission on Radiological Protection in publication 67. This model was developed from human and animal studies and behavioral knowledge acquired from other known bone-seeking radionuclides. The biokinetic model provides a mathematical means of predicting the distribution, retention, and clearance of plutonium within the human body that may be used in deriving organ, tissue, and whole body dose. This work proposed a modification to the ICRP 67 systemic model for plutonium that incorporated the latest knowledge acquired from recent human injection studies with physiologically based improvements. In summary, the changes included a separation of the liver compartments, removed the intermediate soft tissue-to-bladder pathway, and added pathways from the blood compartment to both the cortical and trabecular bone volumes. The proposed model provided improved predictions for several bioassay indicators compared to the ICRP 67 model while also maintaining its basic structure. Additionally, the proposed model incorporated physiologically based improvements for the liver and skeleton and continued to ensure efficient coupling with intake biokinetic models.

  5. Atomistic modeling of thermodynamic equilibrium of plutonium

    NASA Astrophysics Data System (ADS)

    Lee, Tongsik; Valone, Steve; Baskes, Mike; Chen, Shao-Ping; Lawson, Andrew

    2012-02-01

    Plutonium metal has complex thermodynamic properties. Among its six allotropes at ambient pressure, the fcc delta-phase exhibits a wide range of anomalous behavior: extraordinarily high elastic anisotropy, largest atomic volume despite the close-packed structure, negative thermal expansion, strong elastic softening at elevated temperature, and extreme sensitivity to dilute alloying. An accurate description of these thermodynamic properties goes far beyond the current capability of first-principle calculations. An elaborate modeling strategy at the atomic level is hence an urgent need. We propose a novel atomistic scheme to model elemental plutonium, in particular, to reproduce the anomalous characteristics of the delta-phase. A modified embedded atom method potential is fitted to two energy-volume curves that represent the distinct electronic states of plutonium in order to embody the mechanism of the two-state model of Weiss, in line with the insight originally proposed by Lawson et al. [Philos. Mag. 86, 2713 (2006)]. By the use of various techniques in Monte Carlo simulations, we are able to provide a unified perspective of diverse phenomenological aspects among thermal expansion, elasticity, and phase stability.

  6. Characterizing Surplus US Plutonium for Disposition - 13199

    SciTech Connect

    Allender, Jeffrey S.; Moore, Edwin N.

    2013-07-01

    The United States (US) has identified 61.5 metric tons (MT) of plutonium that is permanently excess to use in nuclear weapons programs, including 47.2 MT of weapons-grade plutonium. Surplus inventories will be stored safely by the Department of Energy (DOE) and then transferred to facilities that will prepare the plutonium for permanent disposition. The Savannah River National Laboratory (SRNL) operates a Feed Characterization program for the Office of Fissile Materials Disposition (OFMD) of the National Nuclear Security Administration (NNSA) and the DOE Office of Environmental Management (DOE-EM). SRNL manages a broad program of item tracking through process history, laboratory analysis, and non-destructive assay. A combination of analytical techniques allows SRNL to predict the isotopic and chemical properties that qualify materials for disposition through the Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF). The research also defines properties that are important for other disposition paths, including disposal to the Waste Isolation Pilot Plant (WIPP) as transuranic waste (TRUW) or to high-level waste (HLW) systems. (authors)

  7. The carbonate complexation of plutonium(IV)

    SciTech Connect

    Hobart, D E; Palmer, P D; Newton, T W

    1985-01-01

    Plutonium(IV) carbonate complexes are expected to be of particular importance in typical groundwaters at the Yucca Mountain site of the candidate nuclear waste repository being studied by the Nevada Nuclear Waste Storage Investigations Project. The chemistry of these complexes is also important in the areas of nuclear fuel reprocessing and purification, actinide separations, and environmental studies. This report describes initial experiments performed to determine the identity and equilibrium quotients of plutonium(IV) carbonate complexes. These experiments were performed at pH values between 7.2 and 9.6 using a spectrophotometric method. In addition, a brief review of the published literature on Pu(IV) carbonate complexes is presented. Since Pu(IV) exhibits low solubility in the near-neutral pH range, a complex-competition reaction where citrate ligands compete with carbonate ions for the plutonium will be employed. This will permit us to study the pure carbonate system; study the mixed carbonate/citrate system, and confirm and extend the literature work on the pure citrate system. The current experiments have demonstrated the existence of at least three distinct species in the pH region studied. This work will continue in the extended study of the pure citrate system, followed by the investigation of the citrate/carbonate complex/competition reaction. 9 refs., 4 figs., 2 tabs.

  8. Pyrochemical processing of plutonium. Technology review report

    SciTech Connect

    Coops, M.S.; Knighton, J.B.; Mullins, L.J.

    1982-09-08

    Non-aqueous processes are now in routine use for direct conversion of plutonium oxide to metal, molten salt extraction of americium, and purification of impure metals by electrorefining. These processes are carried out at elevated temperatures in either refractory metal crucibles or magnesium-oxide ceramics in batch-mode operation. Direct oxide reduction is performed in units up to 700 gram PuO/sub 2/ batch size with molten calcium metal as the reductant and calcium chloride as the reaction flux. Americium metal is removed from plutonium metal by salt extraction with molten magnesium chloride. Electrorefining is used to isolate impurities from molten plutonium by molten salt ion transport in a controlled potential oxidation-reduction cell. Such cells can purify five or more kilograms of impure metal per 5-day electrorefining cycle. The product metal obtained is typically > 99.9% pure, starting from impure feeds. Metal scrap and crucible skulls are recovered by hydriding of the metallic residues and recovered either as impure metal or oxide feeds.

  9. Characterizing surplus US plutonium for disposition

    SciTech Connect

    Allender, Jeffrey S.; Moore, Edwin N.

    2013-02-26

    The United States (US) has identified 61.5 metric tons (MT) of plutonium that is permanently excess to use in nuclear weapons programs, including 47.2 MT of weapons-grade plutonium. Surplus inventories will be stored safely by the Department of Energy (DOE) and then transferred to facilities that will prepare the plutonium for permanent disposition. The Savannah River National Laboratory (SRNL) operates a Feed Characterization program for the Office of Fissile Materials Disposition (OFMD) of the National Nuclear Security Administration (NNSA) and the DOE Office of Environmental Management (DOE-EM). SRNL manages a broad program of item tracking through process history, laboratory analysis, and non-destructive assay. A combination of analytical techniques allows SRNL to predict the isotopic and chemical properties that qualify materials for disposition through the Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF). The research also defines properties that are important for other disposition paths, including disposal to the Waste Isolation Pilot Plant (WIPP) as transuranic waste (TRUW) or to high-level waste (HLW) systems.

  10. PLUTONIUM METALLIC FUELS FOR FAST REACTORS

    SciTech Connect

    STAN, MARIUS; HECKER, SIEGFRIED S.

    2007-02-07

    Early interest in metallic plutonium fuels for fast reactors led to much research on plutonium alloy systems including binary solid solutions with the addition of aluminum, gallium, or zirconium and low-melting eutectic alloys with iron and nickel or cobalt. There was also interest in ternaries of these elements with plutonium and cerium. The solid solution and eutectic alloys have most unusual properties, including negative thermal expansion in some solid-solution alloys and the highest viscosity known for liquid metals in the Pu-Fe system. Although metallic fuels have many potential advantages over ceramic fuels, the early attempts were unsuccessful because these fuels suffered from high swelling rates during burn up and high smearing densities. The liquid metal fuels experienced excessive corrosion. Subsequent work on higher-melting U-PuZr metallic fuels was much more promising. In light of the recent rebirth of interest in fast reactors, we review some of the key properties of the early fuels and discuss the challenges presented by the ternary alloys.

  11. TRACKING SURPLUS PLUTONIUM FROM WEAPONS TO DISPOSITION

    SciTech Connect

    Allender, J.; Beams, J.; Sanders, K.; Myers, L.

    2013-07-16

    Supporting nuclear nonproliferation and global security principles, beginning in 1994 the United States has withdrawn more than 50 metric tons (MT) of government-controlled plutonium from potential use in nuclear weapons. The Department of Energy (DOE), including the National Nuclear Security Administration, established protocols for the tracking of this "excess" and "surplus" plutonium, and for reconciling the current storage and utilization of the plutonium to show that its management is consistent with the withdrawal policies. Programs are underway to ensure the safe and secure disposition of the materials that formed a major part of the weapons stockpile during the Cold War, and growing quantities have been disposed as waste, after which they are not included in traditional nuclear material control and accountability (NMC&A) data systems. A combination of resources is used to perform the reconciliations that form the basis for annual reporting to DOE, to U.S. Department of State, and to international partners including the International Atomic Energy Agency.

  12. Microdosimetry of plutonium in beagle dog lung

    SciTech Connect

    Fisher, D.R.; Roesch, W.C.

    1980-08-01

    A better understanding of the microdosimetry of internally-deposited radionuclides should provide new clues to the complex relationships between organ dose distribution and early or late biological effects. Our current interest is the microdosimetry of plutonium and other alpha emitters in the lung. Since the lung is an inhomogeneous tissue, it was necessary to characterize the microscopic distributions of alveolar tissue, air space, and epithelial cell nuclei to define source-target parameters. A statistical representation of the microstructure of beagle dog lung was developed from automated image analysis of specimens from three healthy adult male dogs. The statistical distributions obtained constituted a data base from which it was possible to calculate both the energy dissipation of an alpha particle as it traversed a straight line path through pulmonary tissue, and the probability of intersecting a potentially sensitive biological site in the cell. Computer methods were modified to accomodate tissues with air space regions such as one finds in lung tissue. With the lung model description, these methods were used to determine probability density curves in specific energy for inhaled plutonium aerosols. It was assumed that the activity was randomly distributed on alveolar walls. Calculated examples are given for various activities of inhaled plutonium point sources deposited in lung tissue.

  13. Plutonium Immobilization Project -- Robotic canister loading

    SciTech Connect

    Hamilton, R.L.

    2000-01-04

    The Plutonium Immobilization Program (PIP) is a joint venture between the Savannah River Site (SRS), Lawrence Livermore National Laboratory (LLNL), Argonne National Laboratory (ANL), and Pacific Northwest National Laboratory (PNNL). When operational in 2008, the PIP will fulfill the nation's nonproliferation commitment by placing surplus weapons-grade plutonium in a permanently stable ceramic form and making it unattractive for reuse. Since there are significant radiation and security concerns, the program team is developing novel and unique technology to remotely perform plutonium immobilization tasks. The remote task covered in this paper employs a jointed arm robot to load seven 3.5 inch diameter, 135-pound cylinders (magazines) through the 4 inch diameter neck of a stainless steel canister. Working through the narrow canister neck, the robot secures the magazines into a specially designed rack pre-installed in the canister. To provide the deterrent effect, the canisters are filled with a mixture of high-level waste and glass at the Defense Waste Processing Facility (DWPF).

  14. Real-time monitoring of plutonium content in uranium-plutonium alloys

    DOEpatents

    Li, Shelly Xiaowei; Westphal, Brian Robert; Herrmann, Steven Douglas

    2015-09-01

    A method and device for the real-time, in-situ monitoring of Plutonium content in U--Pu Alloys comprising providing a crucible. The crucible has an interior non-reactive to a metallic U--Pu alloy within said interior of said crucible. The U--Pu alloy comprises metallic uranium and plutonium. The U--Pu alloy is heated to a liquid in an inert or reducing atmosphere. The heated U--Pu alloy is then cooled to a solid in an inert or reducing atmosphere. As the U--Pu alloy is cooled, the temperature of the U--Pu alloy is monitored. A solidification temperature signature is determined from the monitored temperature of the U--Pu alloy during the step of cooling. The amount of Uranium and the amount of Plutonium in the U--Pu alloy is then determined from the determined solidification temperature signature.

  15. Plutonium release from pressed plutonium oxide fuel pellets in aquatic environments

    SciTech Connect

    Patterson, J.H.; Steinkruger, F.J.; Matlack, G.M.; Heaton, R.C.; Coffelt, K.P.; Herrera, B.

    1983-12-01

    Plutonium oxide pellets (80% /sup 238/Pu, 40 g each) were exposed to fresh water and sea water at two temperatures for 3 y in enclosed glass chambers. The concentrations of plutonium observed in the waters increased linearly with time throughout the experiment. However, the observed release rates were inversely dependent on temperature and salinity, ranging from 160 ..mu..Ci/day for cold fresh water to 1.4 ..mu..Ci/day for warm sea water. The total releases, including the chamber residues, showed similar dependencies. A major portion (typically greater than 50%) of the released plutonium passed through a 0.1-..mu..m filter, with even larger fractions (greater than 80%) for the fresh water systems.

  16. New nuclear safe plutonium ceramic compositions with neutron poisons for plutonium storage

    NASA Astrophysics Data System (ADS)

    Nadykto, B. A.; Timofeeva, L. F.

    2000-07-01

    A complex of works is conducted to study the possibility of reprocessing surplus weapon-grade plutonium to a critical-mass-free composition with neutron poison. Nuclear safe ceramic compositions of PuO2 with four most efficient neutron poisons, Hf, Gd, Li, and B, are fabricated in the laboratory. Various methods for fabrication of the compositions with PuO2 depending on neutron poison element are used and studied: a — by sintering initial component powders; b — by impregnation of a porous skeleton made of neutron poison oxide with plutonium sol-gel; c — by sintering microspheres made of plutonium oxide with neutron poison (B4C), with the microspheres having a coating completely absorbing alpha particles.

  17. Le naevus bleu cellulaire atypique du poignet: à propos d'un cas et revue de la literature

    PubMed Central

    Boussakri, Hassan; Roux, Jean Luc; Durand, Luc; Elibrahimi, Abdelhalim; Elmrini, Abdelmajid

    2014-01-01

    Le naevus bleu cellulaire atypique est une entité pathologique rare et sa localisation au niveau du poignet est exceptionnelle. Il est Considéré comme une Variante à des caractéristiques intermédiaires entre le naevus bleu cellulaire typique et le naevus bleu malin, dont l’évolution est incertaine. Le but de notre travail est d'attirer l'attention sur cette variété lésionnelle rare et de discuter les diagnostiques différentiels, ainsi que décrire les aspects histologique et les options thérapeutiques possibles. PMID:25426206

  18. SEPARATION OF PLUTONIUM IONS FROM SOLUTION BY ADSORPTION ON ZIRCONIUM PYROPHOSPHATE

    DOEpatents

    Stoughton, R.W.

    1961-01-31

    A method is given for separating plutonium in its reduced, phosphate- insoluble state from other substances. It involves contacting a solution containing the plutonium with granular zirconium pyrophosphate.

  19. Le syndrome d’alcoolisme foetal

    PubMed Central

    2002-01-01

    L’alcool est un tératogène physique et comportemental. Le syndrome d’alcoolisme foetal (SAF) est un trouble courant mais encore sous-diagnostiqué découlant de la consommation d’alcool par la mère pendant la grossesse. Bien qu’il puisse être prévenu, le SAF est également invalidant. Même si le SAF est présent dans tous les groupes socioéconomiques du Canada, sa prévalence est élevée dans certaines communautés inuites et des Premières nations du Canada. Le présent énoncé porte sur la prévention, le diagnostic, le dépistage précoce et la prise en charge du SAF par les professionnels de la santé. La prévention du SAF doit s’effectuer à deux échelons. La prévention primaire consiste à éliminer le SAF par une formation en classe ou dans la collectivité et à inciter les femmes à éviter de consommer de l’alcool avant la conception et pendant la grossesse. La prévention secondaire consiste à repérer les femmes qui boivent pendant leur grossesse et à réduire leur consommation. Le présent énoncé décrit plusieurs stratégies de dépistage, dont la stratégie T-ACE (tolérance-agacement, réduction, éveil). Les dispensateurs de soins devraient recommander l’abstinence dès la première visite prénatale. Un envoi rapide en consultation en vue de traiter l’alcoolisme est recommandé pour les femmes enceintes incapables d’arrêter de boire. Le présent énoncé décrit le diagnostic de SAF, de SAF partiel ou atypique, d’anomalies congénitales et de troubles neurodéveloppementaux reliés à l’alcool. En cas d’exposition à l’alcool in utero, un diagnostic de SAF devrait être envisagé en présence d’un retard de croissance courant ou antérieur, de certaines anomalies faciales touchant la lèvre supérieure et les yeux et d’anomalies neurodéveloppementales. Ces caractéristiques sont mieux quantifiées au moyen d’une méthode diagnostique à quatre chiffres. Des stratégies de dépistage précoce des

  20. Kyste hydatique du foie rompu dans la paroi abdominale et dans le muscle psoas : à propos d'une rare observation

    PubMed Central

    En-Nafaa, Issam; Moujahid, Mountassir; Alahyane, Abdelouahabe; Amil, Touria; Hanine, Ahmed; Ziadi, Tarik

    2011-01-01

    Le kyste hydatique du foie est une parasitose qui sévit à l′état endémique au maroc. La rupture dans la paroi abdominale et dans le psoas est une complication exceptionnelle. Nous rapportons un cas de kyste hydatique du foie rompu dans la paroi et dans le muscle psoas. Le diagnostic a été établi sur les données de l′échographie et surtout de la tomodensitométrie. Le patient a été opéré avec des suites simples. PMID:22187585

  1. Plutonium and Cesium Colloid Mediated Transport

    NASA Astrophysics Data System (ADS)

    Boukhalfa, H.; Dittrich, T.; Reimus, P. W.; Ware, D.; Erdmann, B.; Wasserman, N. L.; Abdel-Fattah, A. I.

    2013-12-01

    Plutonium and cesium have been released to the environment at many different locations worldwide and are present in spent fuel at significant levels. Accurate understanding of the mechanisms that control their fate and transport in the environment is important for the management of contaminated sites, for forensic applications, and for the development of robust repositories for the disposal of spent nuclear fuel and nuclear waste. Plutonium, which can be present in the environment in multiple oxidations states and various chemical forms including amorphous oxy(hydr)oxide phases, adsorbs/adheres very strongly to geological materials and is usually immobile in all its chemical forms. However, when associated with natural colloids, it has the potential to migrate significant distances from its point of release. Like plutonium, cesium is not very mobile and tends to remain adhered to geological materials near its release point, although its transport can be enhanced by natural colloids. However, the reactivity of plutonium and cesium are very different, so their colloid-mediated transport might be significantly different in subsurface environments. In this study, we performed controlled experiments in two identically-prepared columns; one dedicated to Pu and natural colloid transport experiments, and the other to Cs and colloid experiments. Multiple flow-through experiments were conducted in each column, with the effluent solutions being collected and re-injected into the same column two times to examine the persistence and scaling behavior of the natural colloids, Pu and Cs. The data show that that a significant fraction of colloids were retained in the first elution through each column, but the eluted colloids collected from the first run transported almost conservatively in subsequent runs. Plutonium transport tracked natural colloids in the first run but deviated from the transport of natural colloids in the second and third runs. Cesium transport tracked natural

  2. Chemical Disposition of Plutonium in Hanford Site Tank Wastes

    SciTech Connect

    Delegard, Calvin H.; Jones, Susan A.

    2015-05-07

    This report examines the chemical disposition of plutonium (Pu) in Hanford Site tank wastes, by itself and in its observed and potential interactions with the neutron absorbers aluminum (Al), cadmium (Cd), chromium (Cr), iron (Fe), manganese (Mn), nickel (Ni), and sodium (Na). Consideration also is given to the interactions of plutonium with uranium (U). No consideration of the disposition of uranium itself as an element with fissile isotopes is considered except tangentially with respect to its interaction as an absorber for plutonium. The report begins with a brief review of Hanford Site plutonium processes, examining the various means used to recover plutonium from irradiated fuel and from scrap, and also examines the intermediate processing of plutonium to prepare useful chemical forms. The paper provides an overview of Hanford tank defined-waste–type compositions and some calculations of the ratios of plutonium to absorber elements in these waste types and in individual waste analyses. These assessments are based on Hanford tank waste inventory data derived from separately published, expert assessments of tank disposal records, process flowsheets, and chemical/radiochemical analyses. This work also investigates the distribution and expected speciation of plutonium in tank waste solution and solid phases. For the solid phases, both pure plutonium compounds and plutonium interactions with absorber elements are considered. These assessments of plutonium chemistry are based largely on analyses of idealized or simulated tank waste or strongly alkaline systems. The very limited information available on plutonium behavior, disposition, and speciation in genuine tank waste also is discussed. The assessments show that plutonium coprecipitates strongly with chromium, iron, manganese and uranium absorbers. Plutonium’s chemical interactions with aluminum, nickel, and sodium are minimal to non-existent. Credit for neutronic interaction of plutonium with these absorbers

  3. Le Soleil et ses relations avec la Terre

    NASA Astrophysics Data System (ADS)

    Lang, Kenneth; Heidmann, M.

    C'est le 2e livre de K. Lang publié en français, considéré comme texte complementaire au célèbre Vagabonds de l'Espace qui avait gagné en 1994 le prix du livre d'astronomie en France. Maintenant l'auteur se concentre sur le système le plus élémentaire: l'étoile et son planète, et choisit celui qui est le plus intéressant pour nous: le Soleil et la Terre. Il a accumulé les observations terrestres et les plus récentes effectuées par des observatoires spatiales, et ceux des météorologues et géophysiciens, et nous présente un panorama fascinant du Soleil et ses relations avec la Terre. C'est la physique qui a les conséquences les plus fondamentales aux événements qui influencent notre environment, notre vie et même la condition humaine y inclu les arts et la litérature.

  4. Chemical species of plutonium in Hanford radioactive tank waste

    SciTech Connect

    Barney, G.S.

    1997-10-22

    Large quantities of radioactive wastes have been generated at the Hanford Site over its operating life. The wastes with the highest activities are stored underground in 177 large (mostly one million gallon volume) concrete tanks with steel liners. The wastes contain processing chemicals, cladding chemicals, fission products, and actinides that were neutralized to a basic pH before addition to the tanks to prevent corrosion of the steel liners. Because the mission of the Hanford Site was to provide plutonium for defense purposes, the amount of plutonium lost to the wastes was relatively small. The best estimate of the amount of plutonium lost to all the waste tanks is about 500 kg. Given uncertainties in the measurements, some estimates are as high as 1,000 kg (Roetman et al. 1994). The wastes generally consist of (1) a sludge layer generated by precipitation of dissolved metals from aqueous wastes solutions during neutralization with sodium hydroxide, (2) a salt cake layer formed by crystallization of salts after evaporation of the supernate solution, and (3) an aqueous supernate solution that exists as a separate layer or as liquid contained in cavities between sludge or salt cake particles. The identity of chemical species of plutonium in these wastes will allow a better understanding of the behavior of the plutonium during storage in tanks, retrieval of the wastes, and processing of the wastes. Plutonium chemistry in the wastes is important to criticality and environmental concerns, and in processing the wastes for final disposal. Plutonium has been found to exist mainly in the sludge layers of the tanks along with other precipitated metal hydrous oxides. This is expected due to its low solubility in basic aqueous solutions. Tank supernate solutions do not contain high concentrations of plutonium even though some tanks contain high concentrations of complexing agents. The solutions also contain significant concentrations of hydroxide which competes with other

  5. Le matérialisme scientifique

    NASA Astrophysics Data System (ADS)

    Meunier, Jean-François

    2004-03-01

    De nos jours, il arrive quotidiennement aux grands hommes d'avoir à fréquenter d'ignorants mortels épris d'une conviction maladive que la science est la grande responsable de tous les maux du monde. Évidemment sans physique atomique, il n'y aurait pas eu d'Hiroshima et sans révolution industrielle, pas de pollution et etc. Cependant, ces accusations envers le progrès technique sont tout à fait injustes, irréfléchies et, j'irai même jusqu'à dire, irresponsables, puisque le calcul, i.e. la planification, même la plus élémentaire, est ce qui caractérise le mieux, pragmatiquement, la société humaine. À mon avis, les problèmes sociaux tireraient plutôt leur origine de sciences sociales irréalistes, qui, concrètment, inspireraient ou serviraient d'alibis à ceux qui détiennent véritablement le pouvoir. Dans cet article, je tenterai donc de démontrer la meilleure véracité et efficacité du matérialisme scientifique. Cette doctrine, dont Mario Bunge est le plus illustre représentant, s'appuy sur les résultats théoriques et expérimentaux des sciences factuelles ainsi que sur l'exactitude logique des mathématiques, utilisées ici comme langage universel de l'expression des idées. Cette conception philosophique qui s'inspire principalement du modèle des théories physiques, stipule que les réalités sociales sont, comme tout autre réalité, matérielles, mathématisables et représentables comme des systèmes en interaction. En fait, le modèle des physiciens ayant historiquement fait ses preuves en matière de testabilité et de cohérence interne est proposé d'être appliquer aux sciences sociales, aujourd'hui scindées des sciences dites pures sous l'inspiration des pseudo penseurs néo-kantiens, phénoménologiques et post-moderne. Cette nouvelle approche permettrait ainsi d'évoluer plus exactement vers une compréhension des bases sociales et biologiques du comportement humain afin de développer une éthique sans cesse plus r

  6. Endocardite infectieuse sur communication interventriculaire: intérêt de l’échocardiographie? de l’antibioprophylaxie?

    PubMed Central

    Boussir, Hanane; Ghalem, Amine; Ismaili, Nabila; El Ouafi, Noha

    2016-01-01

    L’endocardite infectieuse peut survenir sur un cœur sain ou pathologique. Parmi les cardiopathies à risque, on trouve les cardiopathies congénitales dont la CIV est la plus fréquente. Nous rapportons le cas d’une endocardite infectieuse à streptocoque oral, survenue sur une CIV non connue jusqu’à maintenant, chez un patient de 17 ans, se présentant sous forme de fièvre prolongée associée à une éruption cutanée. L’examen de la sphère ORL révéla par ailleurs des angines pseudomembraneuses avec un mauvais état buccodentaire. Les EI sur CIV sont les plus fréquentes des EI sur cardiopathie congénitale. Leur présentation clinique peut être atypique d’où lele primordial de l’échocardiographie. La prévention dans ces cas passe par une hygiène bucco-dentaire et cutanée optimale et non par une antibioprophylaxie. PMID:28292116

  7. Fifty years of plutonium exposure to the Manhattan Project plutonium workers: an update.

    PubMed

    Voelz, G L; Lawrence, J N; Johnson, E R

    1997-10-01

    Twenty-six white male workers who did the original plutonium research and development work at Los Alamos have been examined periodically over the past 50 y to identify possible health effects from internal plutonium depositions. Their effective doses range from 0.1 to 7.2 Sv with a median value of 1.25 Sv. As of the end of 1994, 7 individuals have died compared with an expected 16 deaths based on mortality rates of U.S. white males in the general population. The standardized mortality ratio (SMR) is 0.43. When compared with 876 unexposed Los Alamos workers of the same period, the plutonium worker's mortality rate was also not elevated (SMR = 0.77). The 19 living persons have diseases and physical changes characteristic of a male population with a median age of 72 y (range = 69 to 86 y). Eight of the twenty-six workers have been diagnosed as having one or more cancers, which is within the expected range. The underlying cause of death in three of the seven deceased persons was from cancer, namely cancer of prostate, lung, and bone. Mortality from all cancers was not statistically elevated. The effective doses from plutonium to these individuals are compared with current radiation protection guidelines.

  8. Fifty years of plutonium exposure to the Mahattan Project plutonium workers: An update

    SciTech Connect

    Voelz, G.L.; Lawrence, J.N.P.; Johnson, E.R.

    1997-10-01

    Twenty-six white male workers who did the original plutonium research and development work at Los Alamos have been examined periodically over the past 50 y to identify possible health effects from internal plutonium depositions. Their effective doses range from 0.1 to 7.2 Sv with a median value of 1.25 Sv. As of the end of 1994, 7 individuals have died compared with an expected 16 deaths based on mortality rates of U.S. white males in the general population. The standardized mortality ratio (SMR) is 0.43. When compared with 876 unexposed Los Alamos workers of the same period, the plutonium worker`s mortality rate was also not elevated (SMR = 0.77). The 19 living persons have diseases and physical changes characteristic of a male population with a median age of 72 y (range = 69 to 86 y). Eight of the twenty-six workers have been diagnosed as having one or more cancers, which is within the expected range. The underlying cause of death in three of the seven deceased persons was from cancer, namely cancer of prostate, lung, and bone. Mortality from all cancers was not statistically elevated. The effective doses from plutonium to these individuals are compared with current radiation protection guidelines. 28 refs., 5 tabs.

  9. Ultra-small plutonium oxide nanocrystals: an innovative material in plutonium science.

    PubMed

    Hudry, Damien; Apostolidis, Christos; Walter, Olaf; Janssen, Arne; Manara, Dario; Griveau, Jean-Christophe; Colineau, Eric; Vitova, Tonya; Prüssmann, Tim; Wang, Di; Kübel, Christian; Meyer, Daniel

    2014-08-11

    Apart from its technological importance, plutonium (Pu) is also one of the most intriguing elements because of its non-conventional physical properties and fascinating chemistry. Those fundamental aspects are particularly interesting when dealing with the challenging study of plutonium-based nanomaterials. Here we show that ultra-small (3.2±0.9 nm) and highly crystalline plutonium oxide (PuO2 ) nanocrystals (NCs) can be synthesized by the thermal decomposition of plutonyl nitrate ([PuO2 (NO3 )2 ]⋅3 H2 O) in a highly coordinating organic medium. This is the first example reporting on the preparation of significant quantities (several tens of milligrams) of PuO2 NCs, in a controllable and reproducible manner. The structure and magnetic properties of PuO2 NCs have been characterized by a wide variety of techniques (powder X-ray diffraction (PXRD), X-ray absorption fine structure (XAFS), X-ray absorption near edge structure (XANES), TEM, IR, Raman, UV/Vis spectroscopies, and superconducting quantum interference device (SQUID) magnetometry). The current PuO2 NCs constitute an innovative material for the study of challenging problems as diverse as the transport behavior of plutonium in the environment or size and shape effects on the physics of transuranium elements. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Recommended plutonium release fractions from postulated fires. Final report

    SciTech Connect

    Kogan, V.; Schumacher, P.M.

    1993-12-01

    This report was written at the request of EG&G Rocky Flats, Inc. in support of joint emergency planning for the Rocky Flats Plant (RFP) by EG&G and the State of Colorado. The intent of the report is to provide the State of Colorado with an independent assessment of any respirable plutonium releases that might occur in the event of a severe fire at the plant. Fire releases of plutonium are of interest because they have been used by EG&G to determine the RFP emergency planning zones. These zones are based on the maximum credible accident (MCA) described in the RFP Final Environmental Impact Statement (FEIS) of 1980, that MCA is assumed to be a large airplane crashing into a RFP plutonium building.The objective of this report was first, to perform a worldwide literature review of relevant release experiments from 1960 to the present and to summarize those findings, and second, to provide recommendations for application of the experimental data to fire release analyses at Rocky Flats. The latter step requires translation between experimental and expected RFP accident parameters, or ``scaling.`` The parameters of particular concern are: quantities of material, environmental parameters such as the intensity of a fire, and the physico-chemical forms of the plutonium. The latter include plutonium metal, bulk plutonium oxide powder, combustible and noncombustible wastes contaminated with plutonium oxide powder, and residues from plutonium extraction processes.

  11. 10. VIEW OF THE INSTALLATION OF PLUTONIUM FABRICATION ROLLING MILL. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. VIEW OF THE INSTALLATION OF PLUTONIUM FABRICATION ROLLING MILL. THE MILL ROLLED INGOTS INTO SHEETS THAT WERE THEN CUT INTO CIRCLE BLANKS TO BE PASSED THROUGH THE CENTER LINE FOR PRESSING. (2/19/63) - Rocky Flats Plant, Plutonium Fabrication, Central section of Plant, Golden, Jefferson County, CO

  12. 26. Plutonium Recovery From Contaminated Materials, Architectural Elevations, Sections & ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. Plutonium Recovery From Contaminated Materials, Architectural Elevations, Sections & Dets., Building 232-Z, U.S. Atomic Energy Commission, Hanford Atomic Products Operation, General Electric Company, Dwg. No. H-2-23106, 1959. - Plutonium Finishing Plant, Waste Incinerator Facility, 200 West Area, Richland, Benton County, WA

  13. 25. Plutonium Recovery From Contaminated Materials, Architectural Plans & Details, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. Plutonium Recovery From Contaminated Materials, Architectural Plans & Details, Building 232-Z, U.S. Atomic Energy Commission, Hanford Atomic Products Operation, General Electric Company, Dwg. No. H-2-23105, 1959. - Plutonium Finishing Plant, Waste Incinerator Facility, 200 West Area, Richland, Benton County, WA

  14. Processing of Non-PFP Plutonium Oxide in Hanford Plants

    SciTech Connect

    Jones, Susan A.; Delegard, Calvin H.

    2011-03-10

    Processing of non-irradiated plutonium oxide, PuO2, scrap for recovery of plutonium values occurred routinely at Hanford’s Plutonium Finishing Plant (PFP) in glovebox line operations. Plutonium oxide is difficult to dissolve, particularly if it has been high-fired; i.e., calcined to temperatures above about 400°C and much of it was. Dissolution of the PuO2 in the scrap typically was performed in PFP’s Miscellaneous Treatment line using nitric acid (HNO3) containing some source of fluoride ion, F-, such as hydrofluoric acid (HF), sodium fluoride (NaF), or calcium fluoride (CaF2). The HNO3 concentration generally was 6 M or higher whereas the fluoride concentration was ~0.5 M or lower. At higher fluoride concentrations, plutonium fluoride (PuF4) would precipitate, thus limiting the plutonium dissolution. Some plutonium-bearing scrap also contained PuF4 and thus required no added fluoride. Once the plutonium scrap was dissolved, the excess fluoride was complexed with aluminum ion, Al3+, added as aluminum nitrate, Al(NO3)3•9H2O, to limit collateral damage to the process equipment by the corrosive fluoride. Aluminum nitrate also was added in low quantities in processing PuF4.

  15. A plutonium-based single-molecule magnet.

    PubMed

    Magnani, N; Colineau, E; Griveau, J-C; Apostolidis, C; Walter, O; Caciuffo, R

    2014-08-04

    The magnetic properties of the 5f(5) [tris-(tri-1-pyrazolylborato)-plutonium(III)] complex have been investigated by ac susceptibility measurements, showing it to be the first plutonium single-molecule magnet; its magnetic relaxation slows down with decreasing temperature through a thermally activated mechanism followed by a quantum tunnelling regime below 5 K.

  16. SEPARATION OF PLUTONIUM FROM URANIUM AND FISSION PRODUCTS BY ADSORPTION

    DOEpatents

    Seaborg, G.T.; Willard, J.E.

    1958-01-01

    A method is presented for the separation of plutonium from solutions containing that element in a valence state not higher than 41 together with uranium ions and fission products. This separation is accomplished by contacting the solutions with diatomaceous earth which preferentially adsorbs the plutonium present. Also mentioned as effective for this adsorbtive separation are silica gel, filler's earth and alumina.

  17. METHOD OF SEPARATION OF PLUTONIUM FROM CARRIER PRECIPITATES

    DOEpatents

    Dawson, I.R.

    1959-09-22

    The recovery of plutonium from fluoride carrier precipitates is described. The precipitate is dissolved in zirconyl nitrate, ferric nitrate, aluminum nitrate, or a mixture of these complexing agents, and the plutonium is then extracted from the aqueous solution formed with a water-immiscible organic solvent.

  18. Fuel bundle design for enhanced usage of plutonium fuel

    DOEpatents

    Reese, Anthony P.; Stachowski, Russell E.

    1995-01-01

    A nuclear fuel bundle includes a square array of fuel rods each having a concentration of enriched uranium and plutonium. Each rod of an interior array of the rods also has a concentration of gadolinium. The interior array of rods is surrounded by an exterior array of rods void of gadolinium. By this design, usage of plutonium in the nuclear reactor is enhanced.

  19. Procedure for plutonium determination using Pu(VI) spectra

    SciTech Connect

    Walker, L.F.; Temer, D.J.; Jackson, D.D.

    1996-09-01

    This document describes a simple spectrophotometric method for determining total plutonium in nitric acid solutions based on the spectrum of Pu(VI). Plutonium samples in nitric acid are oxidized to Pu(VI) with Ce(IV) and the net absorbance at the 830 nm peak is measured.

  20. COMPLEX FLUORIDES OF PLUTONIUM AND AN ALKALI METAL

    DOEpatents

    Seaborg, G.T.

    1960-08-01

    A method is given for precipitating alkali metal plutonium fluorides. such as KPuF/sub 5/, KPu/sub 2/F/sub 9/, NaPuF/sub 5/, and RbPuF/sub 5/, from an aqueous plutonium(IV) solution by adding hydrogen fluoride and alkali-metal- fluoride.

  1. 10 CFR 71.88 - Air transport of plutonium.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any..., whether for import, export, or domestic shipment, is not transported by air or delivered to a carrier...

  2. 10 CFR 71.88 - Air transport of plutonium.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any..., whether for import, export, or domestic shipment, is not transported by air or delivered to a carrier...

  3. 10 CFR 71.88 - Air transport of plutonium.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any..., whether for import, export, or domestic shipment, is not transported by air or delivered to a carrier...

  4. Plutonium and Cs-137 in autopsy tissues in Great Britain.

    PubMed

    Popplewell, D S; Ham, G J; Dodd, N J; Shuttler, S D

    1988-03-01

    Tissues removed at autopsy from members of the general public contain significantly higher concentrations of plutonium and 137Cs in west Cumbrians than in people from three other regions of Great Britain. Several autopsy cases from Cumbria showed unusually high values of plutonium. Subsequently it was found that the subjects had been former employees of British Nuclear Fuels.

  5. METHOD FOR OBTAINING PLUTONIUM METAL FROM ITS TRICHLORIDE

    DOEpatents

    Reavis, J.G.; Leary, J.A.; Maraman, W.J.

    1962-08-14

    A method was developed for obtaining plutonium metal by direct reduction of plutonium chloride, without the use of a booster, using calcium and lanthamum as a reductant, the said reduction being carried out at temperature in the range of 700 to 850 deg C and at about atmospheric pressure. (AEC)

  6. PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINATING ELEMENTS

    DOEpatents

    Duffield, R.B.

    1959-02-24

    S>A method is described for separating plutonium, in a valence state of less than five, from an aqueous solution in which it is dissolved. The niethod consists in adding potassium and sulfate ions to such a solution while maintaining the solution at a pH of less than 7.1, and isolating the precipitate of potassium plutonium sulfate thus formed.

  7. Removal of plutonium and americium from alkaline waste solutions

    DOEpatents

    Schulz, Wallace W.

    1979-01-01

    High salt content, alkaline waste solutions containing plutonium and americium are contacted with a sodium titanate compound to effect removal of the plutonium and americium from the alkaline waste solution onto the sodium titanate and provide an effluent having a radiation level of less than 10 nCi per gram alpha emitters.

  8. Density of Plutonium Turnings Generated from Machining Activities

    SciTech Connect

    Gonzales, John Robert; Vigil, Duane M.; Jachimowski, Thomas A.; Archuleta, Alonso; Arellano, Gerald Joseph; Melton, Vince Lee

    2016-10-20

    The purpose of this project was to determine the density of plutonium (Pu) turnings generated from the range of machining activities, using both surrogate material and machined Pu turnings. Verify that 500 grams (g) of plutonium will fit in a one quart container using a surrogate equivalent volume and that 100 grams of Pu will fit in a one quart Savy container.

  9. Plutonium finishing plant safety systems and equipment list

    SciTech Connect

    Bergquist, G.G.

    1995-01-06

    The Safety Equipment List (SEL) supports Analysis Report (FSAR), WHC-SD-CP-SAR-021 and the Plutonium Finishing Plant Operational Safety Requirements (OSRs), WHC-SD-CP-OSR-010. The SEL is a breakdown and classification of all Safety Class 1, 2, and 3 equipment, components, or system at the Plutonium Finishing Plant complex.

  10. Inhomogeneites dans le Vent des Etoiles Wolf-Rayet

    NASA Astrophysics Data System (ADS)

    Robert, Carmelle

    1992-01-01

    Des mesures spectroscopiques effectuees avec un haut rapport signal sur bruit et une bonne resolution ont demontre l'existence de regions perturbees en mouvement dans le vent d'etoiles Wolf-Rayet (WR). L'echantillon d'objets etudies ici comprend 9 etoiles WR couvrant differents sous-types WN et WC. De nombreuses petites structures variables superposees au profil des raies d'emission formees dans le vent stellaire signalent la presence des perturbations. L'etude des variations globales des raies et l'examen des micro-structures individuelles ont permis de decrire plusieurs caracteristiques des perturbations. Entre autres, on observe des correlations significatives entre le niveau de variabilite des raies et certains parametres des etoiles qui confirment que le phenomene de variabilite est intrinseque au vent stellaire. En comparant les changements des vitesses radiales et des largeurs equivalentes des differentes raies d'une meme etoile, on conclut que les regions perturbees ont une etendue finie par rapport a l'enveloppe des etoiles. On peut facilement suivre les structures individuelles sur une periode de temps couvrant ~eq8 heures (et peut etre meme 24 heures) avant qu'elles ne disparaissent. Durant ce temps les structures se deplacent en s'eloignant du centre de la raie. A partir des differents comportements notes lors de l'analyse des variations globales et lors de l'examen des structures individuelles, on propose de representer les perturbations par un modele d'inhomogeneites discretes en expansion dans le vent. On suppose simplement que les inhomogeneites emettent comme le vent global (et absorbent aussi si le vent global montre un profil P Cyg). La superposition du graphique de l'acceleration radiale moyenne des inhomogeneites de WR140 en fonction de leur vitesse radiale et du modele theorique d'inhomogeneites qui suivent la loi generale de vitesse donne un taux d'acceleration lent, avec beta >= 3 pour les inhomogeneites de cette etoile. On obtient, entre

  11. Transitions de phase dans le oxyde de yttrium vanadium

    NASA Astrophysics Data System (ADS)

    Roberge, Benoit

    Dans le mémoire qui suit, les ordres structural, magnétiques et orbital dans le YVO3 sont étudiés avec l'aide de la diffraction des rayons X,de la spectroscopie Raman et de la technique de la cavité résonnante hyperfréquence. L'objectif premier consiste à observer l'évolution de ces ordres en fonction de la température. Le mémoire met ensuite en évidence le couplage entre les différents ordres cohabitants dans le YVO3 . Les mesures effectuées par la diffraction des rayons X permettent de mesurer le caractère polycrystallin des échantillons du YVO 3. Une comparaison de nos mesures avec des mesures de diffraction des rayons X faites sur la poudre de YVO3 indique la faible présence de maclage. Les mesures effectuées avec la technique de résonnance hyperfréquence permettent de suivre l'évolution de la constante diélectrique en fonction de la température. Les changements impliquant l'ordre orbital se manifestent de manière évidente dans la constante diélectrique à 200 K et à 77 K. La transition diélectrique détectée à 77 K est une transition de premier ordre. Un couplage entre les propriétés diélectriques et magnétiques est observable à la température de Néel à 114 K. L'effet d'un champ magnétique fixe sur la température de transition de l'ordre orbital survenant à 77 K est également remarquable. Cela indique un couplage magnétodiélectrique démontrant ainsi le caractère multiferroïque du YVO 3. Finalement, l'observation d'un mécanisme de relaxation pouvant être modélisé par le modèle d'Havriliak-Negami est observé en dessous de 77 K. En utilisant le modèle d'Arrhénius et le modèle d'Havriliak-Negami, on peut caractériser le mécanisme avec son énergie d'activation et son temps de relaxation. Les mesures effectuées en spectroscopie Raman permettent de suivre l'évolution de la structure du YVO3 en fonction de la température. Les deux changements structuraux survenant à 200 K et 77 K sont observés. Le

  12. SEPARATION OF PLUTONIUM VALUES FROM URANIUM AND FISSION PRODUCT VALUES

    DOEpatents

    Maddock, A.G.; Booth, A.H.

    1960-09-13

    Separation of plutonium present in small amounts from neutron irradiated uranium by making use of the phenomenon of chemisorption is described. Plutonium in the tetravalent state is chemically absorbed on a fluoride in solid form. The steps for the separation comprise dissolving the irradiated uranium in nitric acid, oxidizing the plutonium in the resulting solution to the hexavalent state, adding to the solution a soluble calcium salt which by the common ion effect inhibits dissolution of the fluoride by the solution, passing the solution through a bed or column of subdivided calcium fluoride which has been sintered to about 8OO deg C to remove the chemisorbable fission products, reducing the plutonium in the solution thus obtained to the tetravalent state, and again passing the solution through a similar bed or column of calcium fluoride to selectively absorb the plutonium, which may then be recovered by treating the calcium fluoride with a solution of ammonium oxalate.

  13. BASIC PEROXIDE PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINANTS

    DOEpatents

    Seaborg, G.T.; Perlman, I.

    1959-02-10

    A process is described for the separation from each other of uranyl values, tetravalent plutonium values and fission products contained in an aqueous acidic solution. First the pH of the solution is adjusted to between 2.5 and 8 and hydrogen peroxide is then added to the solution causing precipitation of uranium peroxide which carries any plutonium values present, while the fission products remain in solution. Separation of the uranium and plutonium values is then effected by dissolving the peroxide precipitate in an acidic solution and incorporating a second carrier precipitate, selective for plutonium. The plutonium values are thus carried from the solution while the uranium remains flissolved. The second carrier precipitate may be selected from among the group consisting of rare earth fluorides, and oxalates, zirconium phosphate, and bismuth lihosphate.

  14. 23. AERIAL VIEW LOOKING SOUTHEAST AT THE PLUTONIUM OPERATION BUILDINGS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. AERIAL VIEW LOOKING SOUTHEAST AT THE PLUTONIUM OPERATION BUILDINGS 771, 776/777, AND 707. BUILDING 771, IN THE FOREGROUND, WAS BUILT IN 1952 TO HOUSE ALL PLUTONIUM OPERATIONS. BY 1956, BUILDING 771 WAS NO LONGER ADEQUATE FOR PRODUCTION DEMANDS. BUILDING 776/777, TO THE SOUTH OF BUILDING 771, WAS CONSTRUCTED TO HOUSE PLUTONIUM FABRICATION AND FOUNDRY OPERATIONS. PLUTONIUM RECOVERY REMAINED IN BUILDING 771. BY 1967, CONSTRUCTION ON BUILDING 707, TO THE SOUTH OF BUILDING 776/777, BEGAN AS PRODUCTION LEVELS CONTINUED TO EXPAND NECESSITATING THE NEED FOR ADDITIONAL PLUTONIUM FABRICATION SPACE (7/1/69). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO

  15. PROCESS FOR PRODUCTION OF PLUTONIUM FROM ITS OXIDES

    DOEpatents

    Weissman, S.I.; Perlman, M.L.; Lipkin, D.

    1959-10-13

    A method is described for obtaining a carbide of plutonium and two methods for obtaining plutonium metal from its oxides. One of the latter involves heating the oxide, in particular PuO/sub 2/, to a temperature of 1200 to 1500 deg C with the stoichiometrical amount of carbon to fornn CO in a hard vacuum (3 to 10 microns Hg), the reduced and vaporized plutonium being collected on a condensing surface above the reaction crucible. When an excess of carbon is used with the PuO/sub 2/, a carbide of plutonium is formed at a crucible temperature of 1400 to 1500 deg C. The process may be halted and the carbide removed, or the reaction temperature can be increased to 1900 to 2100 deg C at the same low pressure to dissociate the carbide, in which case the plutonium is distilled out and collected on the same condensing surface.

  16. Pyrochemical recovery of plutonium from calcium fluoride reduction slag

    DOEpatents

    Christensen, D.C.

    A pyrochemical method of recovering finely dispersed plutonium metal from calcium fluoride reduction slag is claimed. The plutonium-bearing slag is crushed and melted in the presence of at least an equimolar amount of calcium chloride and a few percent metallic calcium. The calcium chloride reduces the melting point and thereby decreases the viscosity of the molten mixture. The calcium reduces any oxidized plutonium in the mixture and also causes the dispersed plutonium metal to coalesce and settle out as a separate metallic phase at the bottom of the reaction vessel. Upon cooling the mixture to room temperature, the solid plutonium can be cleanly separated from the overlying solid slag, with an average recovery yield on the order of 96 percent.

  17. Preparation of Pure Plutonium Metal Standards for Nondestructive Assay

    SciTech Connect

    S. -T. Hsue; J. E. Stewart; M. S. Krick

    2000-11-01

    To calibrate neutron coincidence and neutron multiplicity counters for passive assay of plutonium, certain detector parameters must be determined. When one is using small plutonium metal samples, biases can be introduced from non-zero multiplication and impurities. This paper describes preparing small, pure plutonium metal standards with well-known geometries to enable accurate multiplication corrections and with acceptably low levels of impurities. To minimize multiplication, these standards are designed as 2-cm-diameter foils with varying thicknesses and masses of 1.4, 3.6, and 7.2 g plutonium. These standards will significantly improve characterization and calibration of neutron coincidence and multiplicity counters. They can also be equally useful for gamma-ray spectrometry and calorimetry. Five sets will be made: four for other US Department of Energy plutonium facilities, and one set to remain at Los Alamos. We will also describe other nondestructive assay standards that are planned for the next few years.

  18. Plutonium immobilization ceramic feed batching component test report

    SciTech Connect

    Erickson, S.A.

    1999-10-04

    The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with high level waste glass for permanent storage. Ceramic feed batching (CFB) is one of the first process steps involved with first stage plutonium immobilization. The CFB step will blend plutonium oxide powder before it is combined with other materials to make pucks. This report discusses the Plutonium Immobilization CFB process preliminary concept (including a process block diagram), batch splitting component test results, CFB development areas, and FY 1999 and 2000 CFB program milestones.

  19. Modelling the distribution of plutonium in the Pacific Ocean.

    PubMed

    Nakano, Masanao; Povinec, Pavel P

    2003-01-01

    An Oceanic General Circulation Model (OGCM) including a plutonium scavenging model as well as an advection-diffusion model has been developed for modelling the distribution of plutonium in the Pacific Ocean. Calculated 239, 240Pu water profile concentrations and 239, 240Pu inventories in water and sediment of the Pacific Ocean have showed a reasonable agreement with the experimental results. The presence of local fallout plutonium in central North Pacific waters has been confirmed. The observed 240Pu/239Pu mass ratios confirm that plutonium originating from local fallout from nuclear weapons tests carried out at Bikini and Enewetak Atolls is more rapidly removed from surface waters to deeper waters than plutonium originating from global fallout. The developed OGCM can be used for modelling the dispersion of other non-conservative tracers in the ocean as well.

  20. Uncertainties on lung doses from inhaled plutonium.

    PubMed

    Puncher, Matthew; Birchall, Alan; Bull, Richard K

    2011-10-01

    In a recent epidemiological study, Bayesian uncertainties on lung doses have been calculated to determine lung cancer risk from occupational exposures to plutonium. These calculations used a revised version of the Human Respiratory Tract Model (HRTM) published by the ICRP. In addition to the Bayesian analyses, which give probability distributions of doses, point estimates of doses (single estimates without uncertainty) were also provided for that study using the existing HRTM as it is described in ICRP Publication 66; these are to be used in a preliminary analysis of risk. To infer the differences between the point estimates and Bayesian uncertainty analyses, this paper applies the methodology to former workers of the United Kingdom Atomic Energy Authority (UKAEA), who constituted a subset of the study cohort. The resulting probability distributions of lung doses are compared with the point estimates obtained for each worker. It is shown that mean posterior lung doses are around two- to fourfold higher than point estimates and that uncertainties on doses vary over a wide range, greater than two orders of magnitude for some lung tissues. In addition, we demonstrate that uncertainties on the parameter values, rather than the model structure, are largely responsible for these effects. Of these it appears to be the parameters describing absorption from the lungs to blood that have the greatest impact on estimates of lung doses from urine bioassay. Therefore, accurate determination of the chemical form of inhaled plutonium and the absorption parameter values for these materials is important for obtaining reliable estimates of lung doses and hence risk from occupational exposures to plutonium.

  1. Development of characterization of plutonium storage containers

    SciTech Connect

    James, D.; Stevkovski, S.

    1999-02-01

    As a result of the end of the Cold War, at least 11,000 (possibly 20,000 or more) plutonium pits are projected to be stored at Pantex for up to fifty years. The current pit container, the ALR8 was not designed for this length of storage duration. As a result, Pantex officials have searched for alternative container options. The objective of this research is to develop and validate a model to predict the temperature distribution within the stored components and the internal structure of the proposed ALR8(SI) container, and to consider and analyze the safety features of the ALR8(SI) container as seen from the thermal performance view. Due to the time scale involved with the current simulations, the radioactive decay of the plutonium may be assumed to provide a uniform rate of heat generation. This heat is conducted to the surroundings through the solid structures of the assembly. In addition to conduction, the inert gas that fills the volume within the steel container convects a fraction of the generated heat from the plutonium to the colder steel surfaces. Radiation must also be accounted for as natural convection and limited conduction paths are present within the container. The research efforts in this project have been directed into two paths, numerical and experimental. First, the temperature distribution within the stored components are being determined experimentally as a function of fill gases, energy generation rate, and boundary conditions. Second, a finite element model of the ALR8 container has been developed so that the temperature distribution can be predicted as a function of the same experimental parameters. This paper presents the experimental method and data that have been obtained thus far, as well as the finite element model created using SDRC I-DEAS.

  2. Massive subcritical compact arrays of plutonium metal

    SciTech Connect

    Rothe, R.E.

    1998-04-01

    Two experimental critical-approach programs are reported. Both were performed at the Rocky Flats Plant near Denver, Colorado; and both date back to the late 1960s. Both involve very large arrays of massive plutonium ingots. These ingots had been cast in the foundry at the Rocky Flats Plant as part of their routine production operations; they were not specially prepared for either study. Consequently, considerable variation in ingot mass is encountered. This mass varied between approximately 7 kg and a little more than 10 kg. One program, performed in the spring of 1969, involved stacked arrays of ingots contained within cylindrical, disk-shaped, thin, steel cans. This program studied four arrays defined by the pattern of steel cans in a single layer. The four were: 1 x N, 3 x N, 2 x 2 x N, and 3 x 3 x N. The second was a tightly-packed, triangular-pitched patterns; the last two were square-pitched patterns. The other program, performed about a year earlier, involved similar ingots also contained in similar steel cans, but these canned plutonium ingots were placed in commercial steel drums. This study pertained to one-, two-, and three-layered horizontal arrays of drums. All cases proved to be well subcritical. Most would have remained subcritical had the parameters of the array under study been continued infinitely beyond the reciprocal multiplication safety limit. In one case for the drum arrays, an uncertain extrapolation of the data of the earlier program suggests that criticality might have eventually been attained had several thousand additional kilograms of plutonium been available for use.

  3. Volvulus du grêle sur paquet d’ascaris: à propos d’un cas

    PubMed Central

    Diouf, Cheikh; Kane, Ahmed; Ndoye, Ndeye Aby; Ndour, Oumar; Faye-Fall, Aimé Lakh; Fall, Mbaye; Alumeti, Désiré Munyali; Ngom, Gabriel

    2016-01-01

    Nous rapportons un cas exceptionnel de volvulus nécrosé de l'intestin grêle dû à des ascaris adultes chez un enfant de 7 ans. A l'admission, l'enfant présentait le tableau d'occlusion intestinale qui évoluait depuis deux jours avec altération de l'état général. La radiographie de l'abdomen sans préparation retrouvait des niveaux hydroaériques de type grêlique et un aspect tigré évoquant le diagnostic d'une occlusion intestinale haute sur masse abdominale. Après la réanimation, le traitement chirurgical consistait en une laparotomie qui avait retrouvé un volvulus nécrosé de l'iléon terminale contenant des ascaris adultes. Une résection du grêle sur environ un mètre emportant le segment nécrosé suivie d'une iléostomie était réalisée. L'évolution a été favorable, l'anastomose iléo-colique fut réalisée quatre semaines plus tard. Au recul de deux ans l'enfant est indemne de tout symptôme. PMID:27795803

  4. Thermal Stability Studies of Candidate Decontamination Agents for Hanford’s Plutonium Finishing Plant Plutonium-Contaminated Gloveboxes

    SciTech Connect

    Scheele, Randall D.; Cooper, Thurman D.; Jones, Susan A.; Ewalt, John R.; Compton, James A.; Trent, Donald S.; Edwards, Matthew K.; Kozelisky, Anne E.; Scott, Paul A.; Minette, Michael J.

    2005-09-29

    This report provides the results of PNNL's and Fluor's studies of the thermal stabilities of potential wastes arising from decontamination of Hanford's Plutonium Finishing Plant's plutonium contaminated gloveboxes. The candidate wastes arising from the decontamination technologies ceric nitrate/nitric acid, RadPro, Glygel, and Aspigel.

  5. Plutonium Hexaboride is a Correlated Topological Insulator

    NASA Astrophysics Data System (ADS)

    Deng, Xiaoyu; Haule, Kristjan; Kotliar, Gabriel

    2013-10-01

    We predict that plutonium hexaboride (PuB6) is a strongly correlated topological insulator, with Pu in an intermediate valence state of Pu2.7+. Within the combination of dynamical mean field theory and density functional theory, we show that PuB6 is an insulator in the bulk, with nontrivial Z2 topological invariants. Its metallic surface states have a large Fermi pocket at the X¯ point and the Dirac cones inside the bulk derived electronic states, causing a large surface thermal conductivity. PuB6 has also a very high melting temperature; therefore, it has ideal solid state properties for a nuclear fuel material.

  6. Modeling thermal properties of plutonium mononitride

    NASA Astrophysics Data System (ADS)

    Yu, H. L.; Huang, H.; Li, G.; Li, H. B.; Meng, D. Q.

    2015-06-01

    The thermal properties of plutonium mononitride (PuN) were investigated by molecular dynamics method. The interatomic potentials of PuN were fitted by using Chen-Möbius multiple lattice inversion technique. Based on these interatomic potentials, the lattice constant, bulk modulus, compressibility, cohesive energy and heat capacity of PuN were obtained and the results are well consistent with experimental data and previous reports. It indicates that the potentials we build in this study are effective for studying thermal properties of PuN.

  7. Plutonium hexaboride is a correlated topological insulator.

    PubMed

    Deng, Xiaoyu; Haule, Kristjan; Kotliar, Gabriel

    2013-10-25

    We predict that plutonium hexaboride (PuB(6)) is a strongly correlated topological insulator, with Pu in an intermediate valence state of Pu(2.7+). Within the combination of dynamical mean field theory and density functional theory, we show that PuB(6) is an insulator in the bulk, with nontrivial Z(2) topological invariants. Its metallic surface states have a large Fermi pocket at the X[over ¯] point and the Dirac cones inside the bulk derived electronic states, causing a large surface thermal conductivity. PuB(6) has also a very high melting temperature; therefore, it has ideal solid state properties for a nuclear fuel material.

  8. Plutonium hexaboride is a correlated topological insulator

    NASA Astrophysics Data System (ADS)

    Deng, Xiaoyu; Haule, Kristjan; Kotliar, Gabriel; Department of Physics and Astronomy, Rutgers University Team

    2014-03-01

    We predict that plutonium hexaboride (PuB6) is a strongly correlated topological insulator, with Pu in an intermediate valence state of Pu2 . 7 +. Within the combination of dynamical mean field theory and density functional theory, we show that PuB6 is an insulator in the bulk, with non-trivial Z2 topological invariants. Its metallic surface states have large Fermi pocket at X point and the Dirac cones inside the bulk derived electronic states causing a large surface thermal conductivity. PB6 has also a very high melting temperature therefore it has ideal solid state properties for a nuclear fuel material.

  9. PLUTONIUM-238 PRODUCTION TARGET DESIGN STUDIES

    SciTech Connect

    Hurt, Christopher J; Wham, Robert M; Hobbs, Randall W; Owens, R Steven; Chandler, David; Freels, James D; Maldonado, G Ivan

    2014-01-01

    A new supply chain is planned for plutonium-238 using existing reactors at the Oak Ridge National Laboratory (ORNL) and Idaho National Laboratory (INL) and existing chemical recovery facilities at ORNL. Validation and testing activities for new irradiation target designs have been conducted in three phases over a 2 year period to provide data for scale-up to production. Target design, qualification, target fabrication, and irradiation of fully-loaded targets have been accomplished. Data from post-irradiation examination (PIE) supports safety analysis and irradiation of future target designs.

  10. Multiple quantum phase transitions of plutonium compounds

    SciTech Connect

    Matsumoto, Munehisa; Yin, Quan; Otsuki, Junya; Savrasov, Sergey Y.

    2011-07-22

    We show by quantum Monte Carlo simulations of realistic Kondo lattice models derived from electronicstructure calculations that multiple quantum critical points can be realized in plutonium-based materials. We place representative systems, including PuCoGa5, on a realistic Doniach phase diagram and identify the regions where the magnetically mediated superconductivity could occur. The solution of an inverse problem to restore the quasiparticle renormalization factor for f electrons is shown to be sufficiently good to predict the trends among Sommerfeld coefficients and magnetism. A suggestion on the possible experimental verification for this scenario is given for PuAs.

  11. Influence des interactions du couple ciment/adjuvant dispersant sur les proprietes des betons: Importance du mode d'introduction des adjuvants

    NASA Astrophysics Data System (ADS)

    Baalbaki, Moussa

    1998-12-01

    Les travaux de recherche de cette these de doctorat ont porte sur les phenomenes d'incompatibilite (ou de compatibilite) ciment/adjuvant dispersant en mettant l'accent sur l'influence du mode d'introduction des adjuvants sur les proprietes des betons frais et durcis. Les aspects physiques et chimiques de l'interaction ciment/adjuvant a ete relies aux proprietes des betons en tenant compte du rapport E/C, de la teneur en C3A du ciment ainsi que du type d'adjuvant dispersant. Le programme experimental propose debute par une etude rheologique et mecanique sur pate et sur beton. Le comportement du superplastifiant a base de polynaphtalene (PNS) depend surtout de son interaction avec les premiers produits d'hydratation du ciment. Cette interaction du superplastifiant PNS avec le ciment est remarquablement differente dans le cas ou l'ajout du PNS est differe de quelques minutes. Lorsque le superplastifiant PNS est introduit directement avec l'eau de gachage, on remarque la formation d'un gel blanc compose d'ettringite, de CaCO 3 et de polynaphtalene et ce compose organo-mineral est presque inexistant lorsque le superplastifiant PNS est ajoute en mode differe. Ce gel organo-mineral se forme a partir de la solution entre les aluminates de calcium hydrates, les sulfates et le PNS, et est responsable de la perte d'affaissement du beton. Les analyses au microscope electronique a balayage montrent que l'introduction du superplastifiant PNS en mode S1 (ajout direct) engendre la precipitation d'une plus grande quantite d'ettringite et de produit organo-mineral. Cette ettringite finement cristallisee, abondante et enchevetree aura pour consequence de diminuer les proprietes rheologiques des betons et des pates. Ce phenomene ne s'observe pas lorsque le superplastifiant PNS est introduit en mode differe. Le mode d'introduction du superplastifiant a base de polyacrylate (PAE) n'affecte nullement le comportement rheologique du beton. Par ailleurs, le gel organo-mineral n'apparait pas

  12. Standardissimo. Les limitations théoriques du Modèle Standard. Quelles réponses y apporter?

    NASA Astrophysics Data System (ADS)

    Renard, F. M.

    Nous présentons I 'état du Modèle Standard des interactions fortes, faibles et électromagnétiques. Après une description rapide de ses 3 secteurs, secteur de jauge (radiation), secteur fermionique (matière) et secteur scalaire (génération des masses), nous insistons sur le grand nombre de paramètres libres et sur les choix arbitraires qu'il a fallu faire dans l'élaboration du modèle. Nous faisons ressortir les problèmes techniques non résolus et nous dressons la liste des questions fondamentales restées sans réponses. Nous passons ensuite en revue les idées et méthodes proposées pour répondre à ces questions. Elles utilisent essentiellement 3 voies différentes. La première consiste à requérir plus de symétrie (extension du modèle, symétrie Gauche-Droite, Grandes Unifications, Supersymétrie,...). La seconde contient les diverses alternatives au Modèle Standard impliquant des modifications dans certains secteurs (par exemple le secteur scalaire avec le modèle de la Technicouleur) ou de façon plus violente l'hypothèse d'une sous-structure des leptons, des quarks et des bosons W et Z eux-mêmes. Une dernière voie cherche à justifier les particularités du Modèle Standard et relier ses paramètres libres en se basant sur des principes de cohérence interne du modèle. Les conséquences observables de ces diverses approches sont dans chaque cas mentionnées.

  13. Plutonium contamination in the environment. September 1977-November 1989 (A Bibliography from the Selected Water Resources Abstracts data base). Report for September 1977-November 1989

    SciTech Connect

    Not Available

    1990-05-01

    This bibliography contains citations concerning the ecological impact of plutonium contamination in the environment. Topics include plutonium contamination in freshwater and marine sediments, plutonium bioaccumulation, plutonium transport in the food chain, plutonium contamination bioindicators, methods of analysis, plutonium genotoxicity, plutonium contamination in soil and groundwater, and plutonium contamination from nuclear fallout and nuclear facilities. Plutonium distribution changes due to stratification in oxic and anoxic environments are described. (Contains 83 citations fully indexed and including a title list.)

  14. Solvent extraction system for plutonium colloids and other oxide nano-particles

    DOEpatents

    Soderholm, Lynda; Wilson, Richard E; Chiarizia, Renato; Skanthakumar, Suntharalingam

    2014-06-03

    The invention provides a method for extracting plutonium from spent nuclear fuel, the method comprising supplying plutonium in a first aqueous phase; contacting the plutonium aqueous phase with a mixture of a dielectric and a moiety having a first acidity so as to allow the plutonium to substantially extract into the mixture; and contacting the extracted plutonium with second a aqueous phase, wherein the second aqueous phase has a second acidity higher than the first acidity, so as to allow the extracted plutonium to extract into the second aqueous phase. The invented method facilitates isolation of plutonium polymer without the formation of crud or unwanted emulsions.

  15. Direct reduction of actinide oxide and carbide to metal: Application to the preparation of plutonium metal

    NASA Astrophysics Data System (ADS)

    Spirlet, J. C.; Müller, W.; Van Audenhove, J.

    1985-06-01

    Three different conversion and refining methods for the preparation of high purity plutonium metal are described: the calciothermic reduction of plutonium oxide followed by electrorefining; the thoriothermic reduction of plutonium oxide followed by selective evaporation; the tantalothermic reduction of plutonium carbide followed by selective evaporation. The calciothermic reduction of plutonium oxide followed by electrorefining is used for the semi-industrial or large scale production of high purity plutonium metal. The rate and yield of preparation and refining is high. With high purity reactants the reduction of the oxide with thorium is well adapted to obtain high purity plutonium metal on the laboratory scale. The tantalothermic reduction of plutonium carbide gives high purity plutonium metal even with impure plutonium starting material (recovered from waste). This results from the high selectivity at the different steps of the process.

  16. Le tetanos chez le grand enfant dans un hôpital pédiatrique à Yaoundé, Cameroun

    PubMed Central

    Ntoto Njiki Kinkela, Mina; Nguefack, Félicitée; Mbassi Awa, Hubert; Chelo, David; Enyama, Dominique; Mbollo Kobela, Marie; Koki Ndombo, Paul Olivier

    2012-01-01

    Le tétanos est évitable par la vaccination, mais peut survenir en cas d'une immunisation incomplète. Nous avons mené une étude sur les dossiers médicaux des enfants admis pour tétanos entre 2008-2009 au Centre Mère et Enfant de la Fondation Chantal BIYA à Yaoundé. Le but était d'analyser les circonstances de survenue et les manifestations cliniques du tétanos chez le grand enfant, afin de proposer des stratégies de prévention adaptées au contexte camerounais. Le statut vaccinal était inconnu chez un patient, les autres (80%) n'avaient pas reçu de rappel vaccinal. Les portes d'entrée étaient les plaies aux membres, l'une était secondaire à une injection médicamenteuse. Tous ont présenté le tétanos généralisé. Le décès était survenu chez un patient. Le tétanos n'est pas rare chez le grand enfant au Cameroun. Il se dégage ainsi la problématique des rappels vaccinaux. PMID:22514771

  17. Etude sur les tendons en materiaux composites et leur application aux ancrages postcontraints

    NASA Astrophysics Data System (ADS)

    Chennouf, Adil

    L'objectif general de la presente these est d'evaluer le comportement a l'arrachement et au fluage d'ancrages injectes constitues de tendons en materiaux composites afin d'etablir des recommandations plus appropriees et realistes pour le dimensionnement et la conception. Quatre types de tendons en materiaux composites, deux a base de fibres d'aramide et deux a base de fibres de carbone, ont ete utilises dans l'etude. Les travaux de recherche de cette these ont porte notamment sur: (I) Une caracterisation physique et mecanique des tendons en materiaux composites utilises dans l'etude. (II) Une etude en laboratoire sur les coulis de scellement. La premiere etape de cette etude a concerne le developpement d'un coulis de scellement performant adapte aux tendons en materiaux composites et a differentes situations d'injection. La seconde etape a traite des essais de caracterisations physique et mecanique du coulis de scellement developpe comparativement a trois coulis de scellement usuels d'un meme rapport E/L de 0,4. (III) Une etude sur des modeles reduits d'ancrages injectes. (IV) Une etude sur des modeles d'ancrages a grande echelle. La synthese de ces etudes a permis d'enoncer les principales conclusions suivantes: (1) Les valeurs moyennes des charges de rupture des tendons en materiaux composites ont ete de 1% a 29% superieures a celles specifiees par les manufacturiers. (2) L'etude sur les coulis de scellement a permis le developpement de coulis de ciment repondant aux criteres fixes, soient une grande stabilite, une bonne fluidite, une legere expansion et de bonnes caracteristiques mecaniques. (3) Les tendons en materiaux composites ont montre des contraintes d'adherence maximum superieures a celles des tendons en acier. (4) Le type de fibre, la configuration et le fini de surface des tendons en materiaux composites gouvernent leur resistance a l'adherence. (5) L'introduction de sable et d'autres ajouts comme les fines de silice et la poudre d'aluminium au coulis

  18. Tags to Track Illicit Uranium and Plutonium

    SciTech Connect

    Haire, M. Jonathan; Forsberg, Charles W.

    2007-07-01

    With the expansion of nuclear power, it is essential to avoid nuclear materials from falling into the hands of rogue nations, terrorists, and other opportunists. This paper examines the idea of detection and attribution tags for nuclear materials. For a detection tag, it is proposed to add small amounts [about one part per billion (ppb)] of {sup 232}U to enriched uranium to brighten its radioactive signature. Enriched uranium would then be as detectable as plutonium and thus increase the likelihood of intercepting illicit enriched uranium. The use of rare earth oxide elements is proposed as a new type of 'attribution' tag for uranium and thorium from mills, uranium and plutonium fuels, and other nuclear materials. Rare earth oxides are chosen because they are chemically compatible with the fuel cycle, can survive high-temperature processing operations in fuel fabrication, and can be chosen to have minimal neutronic impact within the nuclear reactor core. The mixture of rare earths and/or rare earth isotopes provides a unique 'bar code' for each tag. If illicit nuclear materials are recovered, the attribution tag can identify the source and lot of nuclear material, and thus help police reduce the possible number of suspects in the diversion of nuclear materials based on who had access. (authors)

  19. Plutonium Detection with Straw Neutron Detectors

    SciTech Connect

    Mukhopadhyay, Sanjoy; Maurer, Richard; Guss, Paul

    2014-03-27

    A kilogram of weapons grade plutonium gives off about 56,000 neutrons per second of which 55,000 neutrons come from spontaneous fission of 240Pu (~6% by weight of the total plutonium). Actually, all even numbered isotopes (238Pu, 240Pu, and 242Pu) produce copious spontaneous fission neutrons. These neutrons induce fission in the surrounding fissile 239Pu with an approximate multiplication of a factor of ~1.9. This multiplication depends on the shape of the fissile materials and the surrounding material. These neutrons (typically of energy 2 MeV and air scattering mean free path >100 meters) can be detected 100 meters away from the source by vehicle-portable neutron detectors. [1] In our current studies on neutron detection techniques, without using 3He gas proportional counters, we designed and developed a portable high-efficiency neutron multiplicity counter using 10B-coated thin tubes called straws. The detector was designed to perform like commercially available fission meters (manufactured by Ortec Corp.) except instead of using 3He gas as a neutron conversion material, we used a thin coating of 10B.

  20. Expected radiation effects in plutonium immobilization ceramic

    SciTech Connect

    Van Konynenburg, R.A., LLNL

    1997-09-01

    The current formulation of the candidate ceramic for plutonium immobilization consists primarily of pyrochlore, with smaller amounts of hafnium-zirconolite, rutile, and brannerite or perovskite. At a plutonium loading of 10.5 weight %, this ceramic would be made metamict (amorphous) by radiation damage resulting from alpha decay in a time much less than 10,000 years, the actual time depending on the repository temperature as a function of time. Based on previous experimental radiation damage work by others, it seems clear that this process would also result in a bulk volume increase (swelling) of about 6% for ceramic that was mechanically unconfined. For the candidate ceramic, which is made by cold pressing and sintering and has porosity amounting to somewhat more than this amount, it seems likely that this swelling would be accommodated by filling in the porosity, if the material were tightly confined mechanically by the waste package. Some ceramics have been observed to undergo microcracking as a result of radiation-induced anisotropic or differential swelling. It is unlikely that the candidate ceramic will microcrack extensively, for three reasons: (1) its phase composition is dominated by a single matrix mineral phase, pyrochlore, which has a cubic crystal structure and is thus not subject to anisotropic swelling; (2) the proportion of minor phases is small, minimizing potential cracking due to differential swelling; and (3) there is some flexibility in sintering process parameters that will allow limitation of the grain size, which can further limit stresses resulting from either cause.

  1. Management of disused plutonium sealed sources

    SciTech Connect

    Whitworth, Julia Rose; Pearson, Michael W; Abeyta, Cristy

    2010-01-01

    The Global Threat Reduction Initiative's (GTRI) Offsite Source Recovery Project (OSRP) has been recovering excess and unwanted radioactive sealed sources since 1999, including more than 2,400 Plutonium (Pu)-238 sealed sources and 653 Pu-239-bearing sources that represent more than 10% of the total sources recovered by GTRI/OSRP to date. These sources have been recovered from hundreds of sites within the United States (US) and around the world. OSRP grew out of early efforts at the Los Alamos National Laboratory (LANL) to recover and disposition excess Plutonium-239 (Pu-239) sealed sources that were distributed in the 1960s and 1970s under the Atoms for Peace Program, a loan-lease program that serviced 31 countries, as well as domestic users. In the conduct of these recovery operations, GTRI/OSRP has been required to solve problems related to knowledge-of-inventory, packaging and transportation of fissile and heat-source materials, transfer of ownership, storage of special nuclear material (SNM) both at US Department of Energy (DOE) facilities and commercially, and disposal. Unique issues associated with repatriation from foreign countries, including end user agreements required by some European countries and denials of shipment, will also be discussed.

  2. AMS of the Minor Plutonium Isotopes

    PubMed Central

    Steier, P.; Hrnecek, E.; Priller, A.; Quinto, F.; Srncik, M.; Wallner, A.; Wallner, G.; Winkler, S.

    2013-01-01

    VERA, the Vienna Environmental Research Accelerator, is especially equipped for the measurement of actinides, and performs a growing number of measurements on environmental samples. While AMS is not the optimum method for each particular plutonium isotope, the possibility to measure 239Pu, 240Pu, 241Pu, 242Pu and 244Pu on the same AMS sputter target is a great simplification. We have obtained a first result on the global fallout value of 244Pu/239Pu = (5.7 ± 1.0) × 10−5 based on soil samples from Salzburg prefecture, Austria. Furthermore, we suggest using the 242Pu/240Pu ratio as an estimate of the initial 241Pu/239Pu ratio, which allows dating of the time of irradiation based solely on Pu isotopes. We have checked the validity of this estimate using literature data, simulations, and environmental samples from soil from the Salzburg prefecture (Austria), from the shut down Garigliano Nuclear Power Plant (Sessa Aurunca, Italy) and from the Irish Sea near the Sellafield nuclear facility. The maximum deviation of the estimated dates from the expected ages is 6 years, while relative dating of material from the same source seems to be possible with a precision of less than 2 years. Additional information carried by the minor plutonium isotopes may allow further improvements of the precision of the method. PMID:23565016

  3. Avoided valence transition in a plutonium superconductor.

    PubMed

    Ramshaw, B J; Shekhter, Arkady; McDonald, Ross D; Betts, Jon B; Mitchell, J N; Tobash, P H; Mielke, C H; Bauer, E D; Migliori, Albert

    2015-03-17

    The d and f electrons in correlated metals are often neither fully localized around their host nuclei nor fully itinerant. This localized/itinerant duality underlies the correlated electronic states of the high-Tc cuprate superconductors and the heavy-fermion intermetallics and is nowhere more apparent than in the 5f valence electrons of plutonium. Here, we report the full set of symmetry-resolved elastic moduli of PuCoGa5--the highest Tc superconductor of the heavy fermions (Tc = 18.5 K)--and find that the bulk modulus softens anomalously over a wide range in temperature above Tc. The elastic symmetry channel in which this softening occurs is characteristic of a valence instability--therefore, we identify the elastic softening with fluctuations of the plutonium 5f mixed-valence state. These valence fluctuations disappear when the superconducting gap opens at Tc, suggesting that electrons near the Fermi surface play an essential role in the mixed-valence physics of this system and that PuCoGa5 avoids a valence transition by entering the superconducting state. The lack of magnetism in PuCoGa5 has made it difficult to reconcile with most other heavy-fermion superconductors, where superconductivity is generally believed to be mediated by magnetic fluctuations. Our observations suggest that valence fluctuations play a critical role in the unusually high Tc of PuCoGa5.

  4. AMS of the Minor Plutonium Isotopes.

    PubMed

    Steier, P; Hrnecek, E; Priller, A; Quinto, F; Srncik, M; Wallner, A; Wallner, G; Winkler, S

    2013-01-01

    VERA, the Vienna Environmental Research Accelerator, is especially equipped for the measurement of actinides, and performs a growing number of measurements on environmental samples. While AMS is not the optimum method for each particular plutonium isotope, the possibility to measure (239)Pu, (240)Pu, (241)Pu, (242)Pu and (244)Pu on the same AMS sputter target is a great simplification. We have obtained a first result on the global fallout value of (244)Pu/(239)Pu = (5.7 ± 1.0) × 10(-5) based on soil samples from Salzburg prefecture, Austria. Furthermore, we suggest using the (242)Pu/(240)Pu ratio as an estimate of the initial (241)Pu/(239)Pu ratio, which allows dating of the time of irradiation based solely on Pu isotopes. We have checked the validity of this estimate using literature data, simulations, and environmental samples from soil from the Salzburg prefecture (Austria), from the shut down Garigliano Nuclear Power Plant (Sessa Aurunca, Italy) and from the Irish Sea near the Sellafield nuclear facility. The maximum deviation of the estimated dates from the expected ages is 6 years, while relative dating of material from the same source seems to be possible with a precision of less than 2 years. Additional information carried by the minor plutonium isotopes may allow further improvements of the precision of the method.

  5. Collector for recovering gallium from weapons plutonium

    SciTech Connect

    Philip, C.V.; Anthony, R.G.; Chokkaram, S.

    1998-09-01

    Currently, the separation of gallium from weapons plutonium involves the use of aqueous processing using either solvent extraction of ion exchange. However, this process generates significant quantities of liquid radioactive wastes. A Thermally Induced Gallium Removal process, or TIGR, developed by researchers at Los Alamos National Laboratories, is a simpler alternative to aqueous processing. This research examined this process, and the behavior of gallium suboxide, a vapor that is swept away by passing hydrogen/argon over gallium trioxide/plutonium oxide heated at 1100 C during the TIGR process. Through experimental procedures, efforts were made to prevent the deposition of corrosive gallium onto furnace and vent surfaces. Experimental procedures included three options for gallium removal and collection: (1) collection of gallium suboxide through use of a cold finger; (2) collection by in situ air oxidation; and (3) collection of gallium on copper. Results conclude all three collection mechanisms are feasible. In addition, gallium trioxide exists in three crystalline forms, and each form was encountered during each experiment, and that each form will have a different reactivity.

  6. Co-Design: Fabrication of Unalloyed Plutonium

    SciTech Connect

    Korzekwa, Deniece R.; Knapp, Cameron M.; Korzekwa, David A.; Gibbs, John W

    2012-07-25

    The successful induction casting of plutonium is a challenge which requires technical expertise in areas including physical metallurgy, surface and corrosion chemistry, materials science, electromagnetic engineering and a host of other technologies all which must be applied in concert. Here at LANL, we are employing a combined experimental and computational approach to design molds and develop process parameters needed to produce desired temperature profiles and improved castings. Computer simulations are performed using the commercial code FLOW-3D and the LANL ASC computer code TRUCHAS to reproduce the entire casting process starting with electromagnetic or radiative heating of the mold and metal and continuing through pouring with coupled fluid flow, heat transfer and non-isothermal solidification. This approach greatly reduces the time required to develop a new casting designs and also increases our understanding of the casting process, leading to a more homogeneous, consistent product and better process control. We will discuss recent casting development results in support of unalloyed plutonium rods for mechanical testing.

  7. Avoided valence transition in a plutonium superconductor

    PubMed Central

    Ramshaw, B. J.; Shekhter, Arkady; McDonald, Ross D.; Betts, Jon B.; Mitchell, J. N.; Tobash, P. H.; Mielke, C. H.; Bauer, E. D.; Migliori, Albert

    2015-01-01

    The d and f electrons in correlated metals are often neither fully localized around their host nuclei nor fully itinerant. This localized/itinerant duality underlies the correlated electronic states of the high-Tc cuprate superconductors and the heavy-fermion intermetallics and is nowhere more apparent than in the 5f valence electrons of plutonium. Here, we report the full set of symmetry-resolved elastic moduli of PuCoGa5—the highest Tc superconductor of the heavy fermions (Tc = 18.5 K)—and find that the bulk modulus softens anomalously over a wide range in temperature above Tc. The elastic symmetry channel in which this softening occurs is characteristic of a valence instability—therefore, we identify the elastic softening with fluctuations of the plutonium 5f mixed-valence state. These valence fluctuations disappear when the superconducting gap opens at Tc, suggesting that electrons near the Fermi surface play an essential role in the mixed-valence physics of this system and that PuCoGa5 avoids a valence transition by entering the superconducting state. The lack of magnetism in PuCoGa5 has made it difficult to reconcile with most other heavy-fermion superconductors, where superconductivity is generally believed to be mediated by magnetic fluctuations. Our observations suggest that valence fluctuations play a critical role in the unusually high Tc of PuCoGa5. PMID:25737548

  8. Measurements of plutonium residues from recovery processes

    SciTech Connect

    Hsue, S.-T.; Langner, D.G.; Longmire, V.L.; Menlove, H.O.; Russo, P.A.; Sprinkle, J.K. Jr.

    1989-01-01

    Conventional methods of nondestructive assay (NDA) have accurately assayed the plutonium content of many forms of relatively pure and homogeneous bulk items. However, physical and chemical heterogeneities and the high and variable impurity levels of many categories of processing scrap bias the conventional NDA results. The materials also present a significant challenge to the assignment of reference values to process materials for purposes of evaluating the NDA methods. A recent study using impure, heterogeneous, pyrochemical residues from americium molten salt extraction (MSE) has been aimed at evaluating NDA assay methods based on conventional gamma-ray and neutron measurement techniques and enhanced with analyses designed to address the problems of heterogeneities and impurities. The study included a significant effort to obtain reference values for the MSE spent salts used in the study. Two of the improved NDA techniques, suitable for in-line assay of plutonium in bulk, show promise for timely in-process assays for one of the most difficult pyrochemical residues generated as well as for other impure heterogeneous scrap categories. 12 refs., 4 figs., 5 tabs.

  9. Etude du Photochromisme et de la Photorefractivite dans le Poly

    NASA Astrophysics Data System (ADS)

    Ghailane, Fatima

    1995-11-01

    Nous avons etudie la possibilite d'utiliser un materiau organique, le poly(vinylcarbazole) comme milieu de stockage optique de masse en temps reel. Ce materiau dope aux photochromes presente un potentiel non negligeable pour l'holographie de volume en temps reel. Plusiers cycles, Ecriture-Lecture-Effacement, ont ete enregistres dans cette matrice polymerique avec une resolution assez elevee. Une etude a ete menee afin d'obtenir la valeur des parametres comme l'epaisseur du film et l'intensite d'ecriture pour un angle d'enregistrement theta_{ acute ecriture} donne qui permettent d'obtenir les meilleures efficacites diffractionelles tout en preservant ce milieu de tout effet de fatigue ou de degradation. Ce polymere devient photorefractif une fois melange avec un bon accepteur de charge, le trinitrofluorenone et un bon chromophore non-lineaire, le disperse orange 25. Nous avons etudie experimentalement la conductivite en obscurite et la photoconductivite de ce materiau. Des simulations numeriques ont ete realisees en se basant sur le modele de Poole-Frenkel. Nous avons aussi etudie l'implantation de faisceaux d'ions d'oxygene d'energie 200 keV pour inscrire dans le PVCz un guide d'onde plan a profil d'indice. Une etude ESCA complete cette partie afin de savoir les modifications induites par implementation ionique a l'interieur du film polymerique.

  10. Volvulus du mesentere sur lipome mesenterique: à propos d’un cas

    PubMed Central

    Dème, Hamidou; Badji, Nfally; Akpo, Léra Géraud; Touré, Mouhamed Hamine; Draha, Ronald; Niang, Fallou Gallas; Diop, Abdoulaye Dione; Niang, El Hadj

    2016-01-01

    Nous rapportons le cas d'une patiente de 7 ans qui a consulté pour une douleur abdominale aigue paroxystique siégeant au niveau de l'épigastre associée à des vomissements sans arrêt des matières et des gaz. L'examen clinique ainsi que le bilan biologique étaient sans particularité. L'échographie abdominale demandée en première intention a montré une masse du flanc et de la fosse iliaque droite échogène, homogène à contours réguliers sans signal vasculaire au Doppler associée à un signe du tourbillon des vaisseaux mésentériques. A la tomodensitométrie cette masse correspondait à une formation lipomateuse, bien limitée, exerçant un effet de masse sur le cœcum avec volvulus du mésentère au contact. La disposition des vaisseaux mésentériques à leur origine était normale. Le diagnostic de volvulus du mésentère sur lipome a été retenu. La prise en charge chirurgicale et l'analyse anatomopathologique de la pièce opératoire a confirmé le diagnostic. Nous allons à travers ce cas clinique revoir l'apport de l'échographie et du scanner dans le diagnostic de volvulus du mésentère. PMID:28250879

  11. Le consentement libre et éclairé aux soins en psychiatrie

    PubMed Central

    Neilson, Grainne; Chaimowitz, Gary

    2015-01-01

    Résumé Le patient a le droit d’être informé sur les soins de santé qui lui sont proposés et de participer activement à la prise de décisions relativement à ces soins. Le respect de la dignité et de l’autonomie de la personne passe par le respect de son droit de prendre des décisions à propos de ses soins psychiatriques, notamment de refuser un traitement, pour autant qu’elle soit apte à prendre des décisions. Il importe que le psychiatre connaisse les fondements éthiques du consentement libre et éclairé et les exigences prévues par le droit en cette matière, y compris la jurisprudence. Le consentement n’est pas immuable, pouvant changer avec le temps, au fil de l’évolution des conditions et des circonstances. Par conséquent, le consentement doit être un processus continu.

  12. Plutonium immobilization plant using glass in existing facilities at the Savannah River Site

    SciTech Connect

    DiSabatino, A., LLNL

    1998-06-01

    The Plutonium Immobilization Plant (PIP) accepts plutonium (Pu) from pit conversion and from non-pit sources and, through a glass immobilization process, converts the plutonium into an immobilized form that can be disposed of in a high level waste (HLW) repository. The objective is to make an immobilized form, suitable for geologic disposal, in which the plutonium is as inherently unattractive and inaccessible as the plutonium in spent fuel from commercial reactors.

  13. Determination of plutonium oxidation states in dilute nitric acid by complementary tristimulus colorimetry.

    PubMed

    Silver, G L

    1967-06-01

    The preparation of reference standards for use in complementary tristimulus colorimetry for plutonium is described. Plutonium(III) and (VI) are prepared by hydrazine reduction and silver(II) oxidation, respectively, of plutonium(IV). Plutonium(V) is prepared by reduction of plutonium(VI) with ascorbic or sulphurous acid. A method for computerizing tristimulus colorimetry is presented, and the technique is extended to three dimensions ("quadristimulus colorimetry").

  14. Si vous pensez que c'est juste un mal de jambe… détrompez-vous: ce que les leaders en santé doivent savoir sur la maladie artérielle périphérique.

    PubMed

    Papia, Giuseppe; Mayer, Perry; Kelton, David; Queen, Douglas; Elliott, James A; Kuhnke, Janet L

    2015-11-01

    Environ 800 000 Canadiens ont une maladie artérielle périphérique (MAP), une cause majeure d'amputation. Pourtant, le public et les cliniciens connaissent très peu cette maladie. Le présent article traite de la campagne de sensibilisation Si vous pensez que c'est juste un mal de jambe… détrompez-vous que l'Association canadienne du soin des plaies a lancée pour contrer cette tendance. Il porte également sur les facteurs de risque et le dépistage de la MAP, son lien avec le diabète, son traitement et ses soins, ses innovations en matière de soins de la MAP et la nécessité de faire preuve de leadership sur le plan des politiques. © 2015 Collège canadien des leaders en santé

  15. How much plutonium does North Korea really have?

    SciTech Connect

    Dreicer, J.S.

    1997-11-01

    In a previous study, as part of the Global Nuclear Material Control Model effort, the author estimated the maximum quantity of plutonium that could be produced in thermal research reactors in the potential nuclear weapon states (including North Korea), based on their declared power level. D. Albright has estimated the amount of plutonium the North Koreans may have produced since 1986 in the 5-megawatt-electric power reactor at Yongbon. Albright provided an upper-bound estimate of 53 kilograms of weapon-grade plutonium produced cumulatively if the gas-graphite (magnox) reactor had achieved a load factor of 0.80. This cumulative estimate of 53 kilograms ignores the potential plutonium production in the 8-megawatt-thermal research reactor, IRT-DPRK. To better quantify the cumulative North Korean production, the author conducted a study to estimate the amount of plutonium that could have been produced in the IRT-DPRK research reactor operating at the declared power level during the entire period it has operated, including a period it was not safeguarded. The author estimates that, at most, an additional 6 to 33 kilograms of plutonium could have been produced cumulatively in the research reactor operating at the declared power level during the entire period it has operated, including a 12-year period it was not safeguarded, resulting in a total of 13 to 47 kilograms of plutonium possibly produced in both the research and power reactors.

  16. Colloid-Facilitated Plutonium Transport in Fractured Tuffaceous Rock.

    PubMed

    Wolfsberg, Andrew; Dai, Zhenxue; Zhu, Lin; Reimus, Paul; Xiao, Ting; Ware, Doug

    2017-05-16

    Colloids have the potential to enhance the mobility of strongly sorbing radionuclide contaminants in groundwater at underground nuclear test sites. This study presents an experimental and numerical investigation of colloid-facilitated plutonium transport in fractured porous media to identify plutonium reactive transport processes. The transport parameters for dispersion, diffusion, sorption, and filtration are estimated with inverse modeling by minimizing the least-squares objective function of multicomponent concentration data from multiple transport experiments with the shuffled complex evolution metropolis algorithm. Capitalizing on an unplanned experimental artifact that led to colloid formation, we adopt a stepwise strategy to first interpret the data from each experiment separately and then to incorporate multiple experiments simultaneously to identify a suite of plutonium-colloid transport processes. Nonequilibrium or kinetic attachment and detachment of plutonium-colloid in fractures were clearly demonstrated and captured in the inverted modeling parameters along with estimates of the source plutonium fraction that formed plutonium-colloids. The results from this study provide valuable insights for understanding the transport mechanisms and environmental impacts of plutonium in groundwater aquifers.

  17. Plutonium recovery from spent reactor fuel by uranium displacement

    DOEpatents

    Ackerman, J.P.

    1992-03-17

    A process is described for separating uranium values and transuranic values from fission products containing rare earth values when the values are contained together in a molten chloride salt electrolyte. A molten chloride salt electrolyte with a first ratio of plutonium chloride to uranium chloride is contacted with both a solid cathode and an anode having values of uranium and fission products including plutonium. A voltage is applied across the anode and cathode electrolytically to transfer uranium and plutonium from the anode to the electrolyte while uranium values in the electrolyte electrolytically deposit as uranium metal on the solid cathode in an amount equal to the uranium and plutonium transferred from the anode causing the electrolyte to have a second ratio of plutonium chloride to uranium chloride. Then the solid cathode with the uranium metal deposited thereon is removed and molten cadmium having uranium dissolved therein is brought into contact with the electrolyte resulting in chemical transfer of plutonium values from the electrolyte to the molten cadmium and transfer of uranium values from the molten cadmium to the electrolyte until the first ratio of plutonium chloride to uranium chloride is reestablished.

  18. Plutonium recovery from spent reactor fuel by uranium displacement

    DOEpatents

    Ackerman, John P.

    1992-01-01

    A process for separating uranium values and transuranic values from fission products containing rare earth values when the values are contained together in a molten chloride salt electrolyte. A molten chloride salt electrolyte with a first ratio of plutonium chloride to uranium chloride is contacted with both a solid cathode and an anode having values of uranium and fission products including plutonium. A voltage is applied across the anode and cathode electrolytically to transfer uranium and plutonium from the anode to the electrolyte while uranium values in the electrolyte electrolytically deposit as uranium metal on the solid cathode in an amount equal to the uranium and plutonium transferred from the anode causing the electrolyte to have a second ratio of plutonium chloride to uranium chloride. Then the solid cathode with the uranium metal deposited thereon is removed and molten cadmium having uranium dissolved therein is brought into contact with the electrolyte resulting in chemical transfer of plutonium values from the electrolyte to the molten cadmium and transfer of uranium values from the molten cadmium to the electrolyte until the first ratio of plutonium chloride to uranium chloride is reestablished.

  19. Mesures experimentales de l'impact des revetements hydrophobeset superhydrophobes sur la trainee et la portance d'un profil aerodynamique propre et glace

    NASA Astrophysics Data System (ADS)

    Villeneuve, Eric

    Ce projet, realise a la demande du Laboratoire International des Materiaux Antigivre, a pour but de mesurer et definir experimentalement l'impact de revetements hydrophobes sur les coefficients de trainee et de portance d'un profil NACA 0012. Pour ce faire, la balance aerodynamique du LIMA devait tout d'abord etre amelioree afin d'offrir une sensibilite suffisante pour realiser le projet. Plusieurs ameliorations ont ete faites, comme le changement des cellules de charge, la diminution du nombre de cellules de charge, le changement du cadre de la balance, etc. Une fois ces ameliorations terminees, la reproductibilite, l'exactitude et la sensibilite ont ete valides afin de s'assurer de la fiabilite des resultats offerts par la balance. Pour les angles d'attaque etudies avec les revetements, soient -6° et 0°, la balance a une reproductibilite de +/-2,06% a 360 000 de nombre de Reynolds. Pour valider la sensibilite, des essais a -6° et 0° d'angle d'attaque et des nombres de Reynolds de 360 000 et 500 000 ont ete faits avec des papiers sables. Les resultats de ces essais ont permis de, tracer des courbes de tendances du coefficient de trainee du NACA 0012 en fonction de la rugosite de surface et d'etablir la valeur de la sensibilite de la balance a +/-8 mu m. Cinq revetements populaires ont ete choisis pour l'experimentation, soient le Wearlon, le Staclean, le Hirec, le Phasebreak ainsi que le Nusil. Les revetements sont soumis aux memes conditions experimentales que les papiers sables, et une rugosite equivalente est trouvee par extrapolation des resultats. Cependant, les rugosites equivalentes de surfaces different entre -6° et 0°. Les essais avec le Staclean et le Hirec donnent des coefficients de trainee equivalent a ceux avec l'aluminium, alors que le Wearlon, le Nusil et le Phasebreak donnent une augmentation du coefficient de trainee de 13%, 17% et 25% respectivement par rapport a l'aluminium. Pour les coefficients de portance, la balance ne detecte pas l

  20. Plutonium and tritium produced in the Hanford Site production reactors

    SciTech Connect

    Roblyer, S.P.

    1994-09-28

    In a news release on December 7, 1993, the Secretary of Energy announced declassification action that included totals for plutonium and tritium production in the Hanford Site production reactors. This information was reported as being preliminary because it was not fully supported by documentation. Subsequently, production data were made available from the US Department of Energy-Headquarters (DOE-HQ) records that indicated an increase of about one and one-half metric tons in total plutonium production. The Westinghouse Hanford Company was tasked by the US Department of Energy-Richland Operations Office to substantiate production figures and DOE-HQ data and to provide a defensible report of weapons- (6 wt% {sup 240}Pu) and nonweapons- (fuels-)grade (nominally 9 wt% or higher {sup 240}Pu) plutonium and tritium production in the Hanford Site production reactors. The task was divided into three parts. The first part was to determine plutonium and tritium production based on available reported accountability records. The second part was to determine plutonium production independently by calculational checks based on reactor thermal power generation and plutonium conversion factors representing the various reactor fuels. The third part was to resolve differences, if they occurred, in the reported and calculational results. In summary, the DOE-HQ-reported accountability records of plutonium and tritium production were determined to be the most defensible record of Hanford Site reactor production. The DOE-HQ records were consistently supported by the independent calculational checks and the records of operational data. Total production quantities are 67.4 MT total plutonium, which includes 12.9 MT of nonweapons-grade plutonium. The total tritium production was 10.6 kg.