Jules Horowitz reactor (RJH): its design

International Nuclear Information System (INIS)

Dupuy, J.P.

2002-01-01

This article presents the design of the new irradiation facility (Jules Horowitz reactor) that is planned to be built on the Cadarache site of Cea. 2 principles have been followed. The first one is based on a physical separation between the systems and activities related to the reactor and the experiments from one hand and the other systems and means dedicated to the treatment of the experimental devices before and after irradiation on the other hand. This first principle implies to build 2 buildings: the reactor building and the nuclear auxiliaries building. Inside the reactor building activities from the reactor itself are separated from those dedicated to experimentation. In order to maximize the efficiency of such a reactor, an important number of simultaneous experiments is expected, which will generate an endless flux of incoming and out-going experiments and as a consequence an important handling work between the different work posts. The second principle aims at easing any handling work without breaking the rules of confinement. The different storing pools, the water pits that lead to the 5 hot cells and the reactor tank will communicate through a water-filled canal that will link the 2 buildings. (A.C.)

Methodological developments and qualification of calculation schemes for the modelling of photonic heating in the experimental devices of the future Jules Horowitz material testing reactor (RJH); Developpements methodologiques et qualification de schemas de calcul pour la modelisation des echauffements photoniques dans les dispositifs experimentaux du futur reacteur d'irradiation technologiques Jules Horowitz (RJH)

Energy Technology Data Exchange (ETDEWEB)

Blanchet, D

2006-07-01

The objective of this work is to develop the modelling of the nuclear heating of the experimental devices of the future Jules Horowitz material testing reactor (RJH). The strong specific nuclear power produced (460 kW/l), induces so intense photonic fluxes which cause heating and large temperature gradients that it is necessary to control it by an adequate design. However, calculations of heating are penalized by the very large uncertainties estimated at a value of about 30% (2*{sigma}) coming from the gaps and uncertainties of the data of gamma emission present in the libraries of basic nuclear data. The experimental program ADAPh aims at reducing these uncertainties. Measurements by thermoluminescent detectors (TLD) and ionisation chambers are carried out in the critical assemblies EOLE (Mox) and Minerve (UO{sub 2}). The rigorous interpretation of these measurements requires specific developments based on Monte-Carlo simulations of coupled neutron-gamma and gamma-electron transport. The developments carried out are made different in particular by the modelling of cavities phenomena and delayed gamma emissions by the decay of fission products. The comparisons calculation-measurement made it possible to identify a systematic bias confirming a tendency of calculations to underestimate measurements. A Bayesian method of adjustment was developed in order to re-estimate the principal components of the gamma heating and to transpose the results obtained to the devices of the RJH, under conditions clearly and definitely representative. This work made possible to reduce significantly the uncertainties on the determination of the gamma heating from 30 to 15 per cent. (author)

Considerations concerning the reliability of reactor safety equipment; Considerations sur la fiabilite des ensembles de securite de reacteurs

Energy Technology Data Exchange (ETDEWEB)

Furet, J; Guyot, Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

A review is made of the circumstances which favor a good collection of maintenance data at the C.E.A. The large amount of data to be treated has made necessary the use of a computer for analyzing automatically the results collected. Here, only particular aspects of the reliability from the point of view of the electronics used for nuclear reactor control will be dealt with: sale and unsafe failures; probability of survival (in the case of reactor safety); availability. The general diagrams of the safety assemblies which have been drawn up for two types of reactor (power reactor and low power experimental reactor) are given. Results are presented of reliability analysis which could be applied to the use of functional modular elements, developed industrially in France. Improvement of this reliability appears to be fairly limited by an increase in the redundancy; on the other hand it is shown how it may be very markedly improved by the use of automatic tests with different frequencies for detecting unsafe failures rates of measurements for the sub-assemblies and for the logic sub-assemblies. Finally examples are given to show the incidence of the complexity and of the use of different technologies in reactor safety equipment on the reliability. (authors) [French] On rappelle les circonstances qui favorisent au C.E.A. la collecte d'une information valable des resultats de la maintenance. L'importance des donnees a traiter a rendu necessaire l'utilisation d'une calculatrice poux l'analyse automatique des resultats recueillis. On se limitera ici aux aspects particuliers de la fiabilite du point de vue de l'electronique pour le controle et la commande de reacteurs nucleaires: pannes sures et pannes non sures; probabilite de survie dans le cas de la securite des reacteurs; facteur de disponibilite. Les schemas de principe des ensembles de securite definis pour deux types de reacteurs (reacteur de puissance et reacteur experimental de faible puissance) sont indiques. On

Study of isotopic exchange reactors (1961); Etude des reacteurs d'echange isotopique (1961)

Energy Technology Data Exchange (ETDEWEB)

Grandcollot, P; Dirian, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

A study is made of the general case of the theory of first-order isotopic chemical exchange between a gaseous and a liquid phase in a reactor, starting from fundamental reaction kinetics data, and without making any limiting hypothesis concerning the value of the separation factor. The cases of counter-current reactors and of co-current reactors are considered successively. The general deuterium conservation equation requires the definition of the quotient of the reactor; the performances of this reactor are characterised by its overall efficiency. The idea of the ratio is introduced because it represents a convenient intermediary in the calculations. The search for an additive value for reactors in series leads logically to the defining of an exchange capacity, and a total efficiency, or number of theoretical reactors. This method of expressing the performances of a reactor is more general than the efficiency due to Murphee which only has a physical significance in the particular case of homogeneous liquid reactors. The relationships between these various quantities are established, and the representation due to Mc Cabe and Thiele is generalized. The reactor performances are linked to the first - order reaction kinetics by the transfer number. The relationships are given for a certain number of concrete cases. Finally the application of these calculations is given, together with the approximations necessary in the case where, because of the presence of several components in each phase, the exchange reaction no longer obeys a single kinetic law. (authors) [French] On examine dans le cas general la theorie d'un reacteur quelconque pour l'echange chimique isotopique du premier ordre entre une phase gazeuse et une phase liquide, a partir des donnees fondamentales sur la cinetique de la reaction, sans faire aucune hypothese limitative sur le cas des reacteurs a contre ourant, puis celui des reacteurs a co-courant. L'equation generale de conservation du deuterium

Would Jule Charney Have Cracked the Madden-Julian Oscillation?

Science.gov (United States)

Emanuel, K.

2017-12-01

Jule Charney's approach to science often involved looking at old problems in new ways. One example was his theory of baroclinic instability, which followed on the heels of long-standing efforts to explain well-observed cyclones and anticyclones. He mastered the art of boiling a physical phenomenon down to its essence, throwing away many things that others had considered important while expressing that which he retained in the simplest possible way. To help honor Charney's legacy, I will review the history of another well-observed phenomenon - the Madden Julian Oscillation (MJO) - together with the many largely unsuccessful efforts to explain it, culminating finally in a satisfying explanation that Jule would have loved.

Technique of nuclear reactors controls; Technique des controles des reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Weill, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1953-12-15

This report deal about 'Techniques of control of the nuclear reactors' in the goal to achieve the control of natural uranium reactors and especially the one of Saclay. This work is mainly about the measurement into nuclear parameters and go further in the measurement of thermodynamic variables,etc... putting in relief the new features required on behalf of the detectors because of their use in the thermal neutrons flux. In the domain of nuclear measurement, we indicate the realizations and the results obtained with thermal neutron detectors and for the measurement of ionizations currents. We also treat the technical problem of the start-up of a reactor and of the reactivity measurement. We give the necessary details for the comprehension of all essential diagrams and plans put on, in particular, for the reactor of Saclay. (author) [French] Nous avons aborde le probleme de la ''Technique du Controle des reacteurs nucleaires'' dans le but de realiser le controle du reacteur de Saclay. C'est ainsi que nous avons ete amene a etudier le probleme dans son ensemble, tel qu'il se pose pour tout reacteur a uranium naturel. Ce travail traite principalement du domaine des mesures a caractere nucleaire et s'etend dans le domaine des mesures thermodynamque de niveaux, etc... mettant en relief les caracteristiques nouvelles exigees de la part des detecteurs du fait de leur utilisation dans le flux de neutrons thermiques. Dans le domaine de mesures nucleaires, nous indiquons principalement les realisations et les resultats obtenus pour les detecteurs de neutrons thermiques et pour la mesure de courants d'ionisations. Nous traitons egalement du probleme technique du demarrage d'un reacteur et du probleme de la mesure de la reactivite. Nous donnons les details necessaires a la comrehension de tous les schemas et plans de cablages essentiels mis au point, en particulier, pour le reacteur de Saclay. (auteur)

Methodological developments and qualification of calculation schemes for the modelling of photonic heating in the experimental devices of the future Jules Horowitz material testing reactor (RJH); Developpements methodologiques et qualification de schemas de calcul pour la modelisation des echauffements photoniques dans les dispositifs experimentaux du futur reacteur d'irradiation technologiques Jules Horowitz (RJH)

Energy Technology Data Exchange (ETDEWEB)

Blanchet, D

2006-07-01

The objective of this work is to develop the modelling of the nuclear heating of the experimental devices of the future Jules Horowitz material testing reactor (RJH). The strong specific nuclear power produced (460 kW/l), induces so intense photonic fluxes which cause heating and large temperature gradients that it is necessary to control it by an adequate design. However, calculations of heating are penalized by the very large uncertainties estimated at a value of about 30% (2*{sigma}) coming from the gaps and uncertainties of the data of gamma emission present in the libraries of basic nuclear data. The experimental program ADAPh aims at reducing these uncertainties. Measurements by thermoluminescent detectors (TLD) and ionisation chambers are carried out in the critical assemblies EOLE (Mox) and Minerve (UO{sub 2}). The rigorous interpretation of these measurements requires specific developments based on Monte-Carlo simulations of coupled neutron-gamma and gamma-electron transport. The developments carried out are made different in particular by the modelling of cavities phenomena and delayed gamma emissions by the decay of fission products. The comparisons calculation-measurement made it possible to identify a systematic bias confirming a tendency of calculations to underestimate measurements. A Bayesian method of adjustment was developed in order to re-estimate the principal components of the gamma heating and to transpose the results obtained to the devices of the RJH, under conditions clearly and definitely representative. This work made possible to reduce significantly the uncertainties on the determination of the gamma heating from 30 to 15 per cent. (author)

Developpement d'une methode de Monte Carlo dependante du temps et application au reacteur de type CANDU-6

Science.gov (United States)

Mahjoub, Mehdi

La resolution de l'equation de Boltzmann demeure une etape importante dans la prediction du comportement d'un reacteur nucleaire. Malheureusement, la resolution de cette equation presente toujours un defi pour une geometrie complexe (reacteur) tout comme pour une geometrie simple (cellule). Ainsi, pour predire le comportement d'un reacteur nucleaire,un schema de calcul a deux etapes est necessaire. La premiere etape consiste a obtenir les parametres nucleaires d'une cellule du reacteur apres une etape d'homogeneisation et condensation. La deuxieme etape consiste en un calcul de diffusion pour tout le reacteur en utilisant les resultats de la premiere etape tout en simplifiant la geometrie du reacteur a un ensemble de cellules homogenes le tout entoure de reflecteur. Lors des transitoires (accident), ces deux etapes sont insuffisantes pour pouvoir predire le comportement du reacteur. Comme la resolution de l'equation de Boltzmann dans sa forme dependante du temps presente toujours un defi de taille pour tous types de geometries,un autre schema de calcul est necessaire. Afin de contourner cette difficulte, l'hypothese adiabatique est utilisee. Elle se concretise en un schema de calcul a quatre etapes. La premiere et deuxieme etapes demeurent les memes pour des conditions nominales du reacteur. La troisieme etape se resume a obtenir les nouvelles proprietes nucleaires de la cellule a la suite de la perturbation pour les utiliser, au niveau de la quatrieme etape, dans un nouveau calcul de reacteur et obtenir l'effet de la perturbation sur le reacteur. Ce projet vise a verifier cette hypothese. Ainsi, un nouveau schema de calcul a ete defini. La premiere etape de ce projet a ete de creer un nouveau logiciel capable de resoudre l'equation de Boltzmann dependante du temps par la methode stochastique Monte Carlo dans le but d'obtenir des sections efficaces qui evoluent dans le temps. Ce code a ete utilise pour simuler un accident LOCA dans un reacteur nucleaire de type

Jules Verne's Metaphor of the Iron Cage

NARCIS (Netherlands)

Ossewaarde, Marinus R.R.

2010-01-01

Max Weber's concept of the iron cage has become a byword in the scholarly world since the publication in 1930 of Talcott Parsons’ translation of The Protestant Ethic and the Spirit of Capitalism. What is less well-known is that Jules Verne had earlier used the iron cage metaphor in Twenty Thousand

JULES-crop: a parametrisation of crops in the Joint UK Land Environment Simulator

Science.gov (United States)

Osborne, T.; Gornall, J.; Hooker, J.; Williams, K.; Wiltshire, A.; Betts, R.; Wheeler, T.

2014-10-01

Studies of climate change impacts on the terrestrial biosphere have been completed without recognition of the integrated nature of the biosphere. Improved assessment of the impacts of climate change on food and water security requires the development and use of models not only representing each component but also their interactions. To meet this requirement the Joint UK Land Environment Simulator (JULES) land surface model has been modified to include a generic parametrisation of annual crops. The new model, JULES-crop, is described and evaluation at global and site levels for the four globally important crops; wheat, soy bean, maize and rice is presented. JULES-crop demonstrates skill in simulating the inter-annual variations of yield for maize and soy bean at the global level, and for wheat for major spring wheat producing countries. The impact of the new parametrisation, compared to the standard configuration, on the simulation of surface heat fluxes is largely an alteration of the partitioning between latent and sensible heat fluxes during the later part of the growing season. Further evaluation at the site level shows the model captures the seasonality of leaf area index and canopy height better than in standard JULES. However, this does not lead to an improvement in the simulation of sensible and latent heat fluxes. The performance of JULES-crop from both an earth system and crop yield model perspective is encouraging however, more effort is needed to develop the parameterisation of the model for specific applications. Key future model developments identified include the specification of the yield gap to enable better representation of the spatial variability in yield.

Jules Cotard (1840-1889): his life and the unique syndrome which bears his name.

Science.gov (United States)

Pearn, J; Gardner-Thorpe, C

2002-05-14

Dr. Jules Cotard (1840-1889) was a Parisian neurologist who first described the délire des négations. Cotard's syndrome or Cotard's delusion comprises any one of a series of delusions ranging from the fixed and unshakable belief that one has lost organs, blood, or body parts to believing that one has lost one's soul or is dead. In its most profound form, the delusion takes the form of a professed belief that one does not exist. Encountered primarily in psychoses such as schizophrenia and bipolar disorder, Cotard's syndrome has also been described in organic lesions of the nondominant temporoparietal cortex as well as in migraine. Cotard's delusion is the only self-certifiable syndrome of delusional psychosis. Jules Cotard, a Parisian neurologist and psychiatrist and former military surgeon, was one of the first to induce cerebral atrophy by the experimental embolization of cerebral arteries in animals and a pioneer in studies of the clinicopathologic correlates of cerebral atrophy secondary to perinatal and postnatal pathologic changes. He was the first to record that unilateral cerebral atrophy in infancy does not necessarily lead to aphasia and was also the pioneer of studies of altered conscious states in diabetic hyperglycemia.

Multi-site evaluation of the JULES land surface model using global and local data

Directory of Open Access Journals (Sweden)

D. Slevin

2015-02-01

Full Text Available This study evaluates the ability of the JULES land surface model (LSM to simulate photosynthesis using local and global data sets at 12 FLUXNET sites. Model parameters include site-specific (local values for each flux tower site and the default parameters used in the Hadley Centre Global Environmental Model (HadGEM climate model. Firstly, gross primary productivity (GPP estimates from driving JULES with data derived from local site measurements were compared to observations from the FLUXNET network. When using local data, the model is biased with total annual GPP underestimated by 16% across all sites compared to observations. Secondly, GPP estimates from driving JULES with data derived from global parameter and atmospheric reanalysis (on scales of 100 km or so were compared to FLUXNET observations. It was found that model performance decreases further, with total annual GPP underestimated by 30% across all sites compared to observations. When JULES was driven using local parameters and global meteorological data, it was shown that global data could be used in place of FLUXNET data with a 7% reduction in total annual simulated GPP. Thirdly, the global meteorological data sets, WFDEI and PRINCETON, were compared to local data to find that the WFDEI data set more closely matches the local meteorological measurements (FLUXNET. Finally, the JULES phenology model was tested by comparing results from simulations using the default phenology model to those forced with the remote sensing product MODIS leaf area index (LAI. Forcing the model with daily satellite LAI results in only small improvements in predicted GPP at a small number of sites, compared to using the default phenology model.

Impacts of revised PFTs on JULES simulated carbon and moisture fluxes

Science.gov (United States)

Harper, Anna; Cox, Peter; Sitch, Stephen; Mercado, Lina; Luke, Catherine; Jupp, Tim; Wiltshire, Andy; Jones, Chris; Friedlingstein, Pierre

2013-04-01

JULES is the land surface model in the Hadley Centre GCM, which is used for investigations of climate and climate change. We analyze the impacts on the simulated carbon and moisture fluxes of extending the PFTs in a manner consistent with observed leaf traits. The model currently represents global vegetation with five PFTs (needleleaf and broadleaf trees, C3 and C4 grasses, and shrubs). We add three new PFTs to delineate between deciduous and evergreen trees and shrubs. Since the inception of JULES in the late 90's, a tremendous amount of new data linking leaf traits and potential photosynthesis is available. We use data from the TRY plant trait data base to revise the relationships between leaf area, leaf lifespan, leaf nitrogen content, and Vcmax. In addition, JULES now includes a canopy radiation scheme based on fractions of sunlit and shaded leaves at 10 levels in the canopy. This results in a vertical distribution of nitrogren and Vcmax through the canopy and enables multilayer scaling from leaf to canopy level photosynthesis. The scheme is more physically realistic than previous canopy radiation schemes, but remains to be evaluated outside of the Tropics. Within the constraints of observed values, we optimize new parameter values related to the canopy radiation and photosynthesis, using optimization software developed at the University of Exeter. Impacts on simulated GPP, respiration, and latent heat flux are examined. In particular, we are interested in a better understanding of carbon cycle dynamics in tropical forests. Using data from TRY, carbon fluxes are improved across all PFTs compared to observations from Fluxnet tower sites. We adopt a regional analysis to compare JULES fluxes in certain regions (e.g. tropical forests, and boreal and tropical shrub-dominated landscapes).

Geometrical modification transfer between specific meshes of each coupled physical codes. Application to the Jules Horowitz research reactor experimental devices

International Nuclear Information System (INIS)

Duplex, B.

2011-01-01

The CEA develops and uses scientific software, called physical codes, in various physical disciplines to optimize installation and experimentation costs. During a study, several physical phenomena interact, so a code coupling and some data exchanges between different physical codes are required. Each physical code computes on a particular geometry, usually represented by a mesh composed of thousands to millions of elements. This PhD Thesis focuses on the geometrical modification transfer between specific meshes of each coupled physical code. First, it presents a physical code coupling method where deformations are computed by one of these codes. Next, it discusses the establishment of a model, common to different physical codes, grouping all the shared data. Finally, it covers the deformation transfers between meshes of the same geometry or adjacent geometries. Geometrical modifications are discrete data because they are based on a mesh. In order to permit every code to access deformations and to transfer them, a continuous representation is computed. Two functions are developed, one with a global support, and the other with a local support. Both functions combine a simplification method and a radial basis function network. A whole use case is dedicated to the Jules Horowitz reactor. The effect of differential dilatations on experimental device cooling is studied. (author) [fr

Neutron noise in nuclear reactors; Le bruit neutronique des reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Blaquiere, A. [Institut National des Sciences et Techniques Nucleaires (France); Pachowska, R. [Universite Technique de Varsovie (Poland)

1961-06-15

The power of a nuclear reactor, in the operating conditions, presents fluctuations due to various causes. This random behaviour can be included in the study of 'noises'. Among other sources of noise, we analyse hereafter the fluctuations due: a) to the discontinuous emissions of neutrons from an independent source; b) to the multiplication of neutrons inside the reactor. The method which we present makes use of the analogies between the rules governing a nuclear reactor in operation and a number of radio-electrical systems, in particular the feed-back loops. The reactor can be characterized by its 'passing band' and is described as a system submitted to a sequence of random pulses. In non linear operating condition, the effect of neutron noise is defined by means of a non-linear functional, this theory is thus related to previous works the references of which are given at the end of the present report. This leads us in particular in the case of nuclear reactors to some results given by A. Blaquiere in the case of radio-electrical loops. (author) [French] La puissance d'un reacteur nucleaire, dans les conditions du regime, est affectee de fluctuations dont les causes sont tres diverses. Ce comportement aleatoire rentre dans le cadre general de l'etude des 'bruits'. Entre autres sources ce bruit, nous analysons ici les fluctuations dues: a) a l'emission discontinue des neutrons provenant d'une source autonome; b) a la multiplication des neutrons au sein du reacteur. La methode que nous introduisons exploite les analogies entre les lois qui regissent un reacteur nucleaire au regime et certains systemes radioelectriques, en particulier les circuits a boucle de reaction. Le reacteur est caracterise par sa 'bande passante' et est decrit comme un systeme soumis a une succession d'impulsions aleatoires. Dans les conditions de fonctionnement non lineaires, l'effet du bruit neutronique est precise en utilisant une fonctionnelle non lineaire, ce qui relie cette theorie a

Speech by Prime Minister Francois Fillon. Visit of the Jules Horowitz experimental reactor works on the Commissariat a l'Energie et aux Energies Alternatives site. Cadarache, May 3, 2010

International Nuclear Information System (INIS)

2010-01-01

In this speech, the French Prime Minister evokes the present context, the importance of strategic technologies, and the challenge of investing in these technologies within a context of reduction of public expenses. He comments the decision of his government to finance research and education activities in different domains, and more specifically in the energy sector with this fourth generation Jules Horowitz experimental reactor. He recalls that the nuclear sector has always been very important to the eyes of the successive French governments, and outlines how this reactor will contribute to reactor operational optimization, lifetime extension and safety, nuclear fuel development, etc.

Alfred Jules Aver's induction and Marxian historical evolution: It's ...

African Journals Online (AJOL)

Alfred Jules Aver's induction and Marxian historical evolution: It's lessons for the current economic global crisis. ... Economic liberalism, political manipulation and gross capitalism have been given as the major causes of the present situation in the world economy. It is on this touchstone that we tried to examine the Marxian ...

Main technical options of the Jules Horowitz reactor project to achieve high flux performances and high safety level

International Nuclear Information System (INIS)

Ballagny, A.; Bergamaschi, Y.; Bouilloux, Y.; Bravo, X.; Guigon, B.; Rommens, M.; Tremodeux, P.

2003-01-01

Since the shutdown of the SILOE reactor in 1997, the OSIRIS reactor has ensured the needs regarding technological irradiation at CEA including those of its industrial partners and customers. The Jules Horowitz Reactor will replace it and will offer a quite larger experimental field. It has the ambition to provide the necessary nuclear data and to maintain a fission research capability in Europe after 2010. The Jules Horowitz Reactor will represent a significant step in terms of performances and experimental capabilities. This paper will present the main design option resulting from the preliminary studies. The choice of the specific power around 600 kW/I for the reference core configuration is a key decision to ensure the required flux level. Consequently many choices have to be made regarding the materials used in the core and the fuel element design. These involve many specific qualifications including codes validation. The main safety options are based on: - A safety approach based upon the defence-in-depth principle. - A strategy of generic approaches to assess experimental risks in the facility. - Internal events analysis taking into account risks linked to reactor and experiments (e.g., radioactive source-term). - Systematic consideration of external hazards (e.g., earthquake, airplane crash) and internal hazards. - Design of containment to manage and mitigate a severe reactor accident (consideration of 'BORAX' accident, according to french safety practice for MTRs, beyond design basis reactivity insertion accident, involving core melting and core destruction phenomena). (authors)

Main technical options of the Jules Horowitz Reactor project to achieve high flux performances and high safety level

International Nuclear Information System (INIS)

Ballagny, A.; Bergamaschi, Y.; Bouilloux, Y.; Bravo, X.; Guigon, B.; Rommens, M.; Tremodeux, P.

2003-01-01

Since the shutdown of the SILOE reactor in 1997, the OSIRIS reactor has ensured the needs regarding technological irradiation at CEA including those of its industrial partners and customers. The Jules Horowitz Reactor will replace it and will offer a quite larger experimental field. It has the ambition to provide the necessary nuclear data and to maintain a fission research capability in Europe after 2010. The Jules Horowitz Reactor will represent a significant step in terms of performances and experimental capabilities. This paper will present the main design option resulting from the preliminary studies. The choice of the specific power around 600 KW/l for the reference core configuration is a key decision to ensure the required flux level. Consequently many choices have to be made regarding the materials used in the core and the fuel element design. These involve many specific qualifications including codes validation. The main safety options are based on: 1) A safety approach based upon the defence-in-depth principle. 2) A strategy of generic approaches to assess experimental risks in the facility. 3) Internal events analysis taking into account risks linked to reactor and experiments (eg., radioactive source-term). 4) Systematic consideration of external hazards (eg., earthquake, airplane crash) and internal hazards. 5) Design of containment to manage and mitigate a severe reactor accident (consideration of 'BORAX' accident, according to french safety practice for MTRs, beyond design basis reactivity insertion accident, involving core melting and core destruction phenomena). (author)

Reactor. Mind picture of the future Jules-Horowitz Reactor (RHJ)

International Nuclear Information System (INIS)

Eustache, S.

1999-01-01

This paper gives information about the future research reactor, named Reactor Jules-Horowitz (RJH). This irradiation reactor will be placed at industrialists disposal, for research concerning the competitiveness and the safety french electro-nuclear park. Principles and innovations are detailed. This reactor will respect the ALARA principle (as low as reasonably achievable). (A.L.B.)

De Jules et Jim au Vel’ d’Hiv

Directory of Open Access Journals (Sweden)

Annie Oliver

2012-12-01

Full Text Available Dans son roman intitulé On ne peut plus dormir tranquille quand on a une fois ouvert les yeux, Robert Bober s’inspire de sa propre histoire et relate bon nombre de faits qui ont réellement eu lieu, à commencer par le tournage en 1961 du film de François Truffaut Jules et Jim. C’est à partir de ce film – et de nombreuses autres références cinématographiques, de Max Ophuls aux Marx Brothers – que le narrateur, d’origine juive polonaise, va retrouver l’histoire de sa famille mais aussi celle d’une ville, Paris, de la Commune de 1871 à la rafle du Vélodrome d’Hiver en 1942.In his novel On ne peut plus dormir tranquille quand on a une fois ouvert les yeux Robert Bober draws his inspiration from his own life and tells a good number of events which have really taken place. Starting with the shooting, in 1961, of François Truffaut Jules et Jim. From this movie, as well as from many other film references – from Max Ophuls to the Marx Brothers – the narrator of Jewish-Polish origin rediscovers the history of his own family together with that of Paris, from the 1971 Commune to the 1942 round-up of Jews in the Vélodrome d’Hiver.

Heavy water reactors physics; Physique des reacteurs a eau lourde

Energy Technology Data Exchange (ETDEWEB)

Girard, Y; Lourme, P; Naudet, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

An important research programme on heavy water reactor physics has been carried out in France for quite a few years. The decision to build the EL 4 prototype and so to choose the heavy water gas cooled type has renewed the interest in this programme and at the same time given to it a more specific orientation A summary of the results gained in this field is presented in this paper. In the first part are described the experimental investigations, most of them were carried out in the criticality facility AQUILON II. The experiments are grouped in four parts - Systematic studies of lattices Buckling measurements. - Specific studies of gas-cooled lattices. - Fine structure, spectral indices measurements etc... - Measurements on lattices or samples containing Uranium of various enrichment or Plutonium. The second part is devoted to a summary of the theoretical studies. The whole results have allowed an improvement of the calculation methods, have led to a better understanding of the neutron balance in lattices, and have permitted the establishment of a set of formula to predict not only the clean fuel conditions but also the evolution of the nuclear properties with irradiation. Some specific studies on power reactor are quoted. (authors) [French] Un important programme d'etudes sur la physique des reacteurs a eau lourde est mene en France depuis assez longtemps. La decision de construire le prototype EL 4 et de s'engager ainsi dans la filiere des reacteurs a eau lourde refroidis par gaz a redonne un nouvel interet a ce programme et l'a en meme temps oriente dans une direction plus particuliere. La presente communication, rassemble les resultats des etudes faites dans ce domaine depuis la derniere conference de Geneve. Dans la premiere partie on decrit les etudes experimentales dont la plupart ont ete effectuees dans la pile d'experiences critiques Aquilon II. Les experiences sont groupees en quatre ensembles: etude systematique de reseaux (mesures de laplaciens) etudes

Study of the uniform corrosion of an aluminium alloy used for the fuel cladding of the Jules Horowitz experimental reactor

International Nuclear Information System (INIS)

Wintergerst, M.

2008-01-01

For the Jules Horowitz new material testing reactor, an aluminium base alloy, AlFeNi, will be used for the cladding of the fuel plates. Taking into account the thermal properties of the alloy and of its oxide, the corrosion of the fuel cans presents many problems. The aim of this thesis is to provide a growing kinetic of the oxide layer at the surface of the AlFeNi fuel can in order to predict the life time of fuel element. Thus the mechanism of degradation of the cladding will be describe in order to integrate the different parameters of the operating reactor. (A.L.B.)

G2 and G3 reactors design; Description des reacteurs G2 et G3

Energy Technology Data Exchange (ETDEWEB)

Herreng,; Ertaud,; Pasquet, [Societe Alsacienne de Constructions Mecaniques (France)

1958-07-01

operating power levels of reactor. The regulating system has brought about difficult problems; experimental examination, while operating, will solve them. Special meetings will be held concerning the burst slug system and fuel elements. (author) [French] La construction des reacteurs G2 et G3, dans le cadre du premier plan quinquennal francais, a ete confiee par le C.E.A. au groupement d'industriels FRANCE-ATOME. Bien que ces reacteurs restent essentiellement plutonigenes, on a accole a chacun d'eux une centrale electrique devant fournir 40 MW, dont la responsabilite a ete assumee par l'E.D.F. Le coeur du reacteur adopte la plupart des solutions du reacteur G1 (excepte la fente centrale): canaux horizontaux, empilement de briques parallelepipediques de graphite, protection thermique en acier. Le refroidissement est assure par du gaz carbonique sous 15 atmospheres. Cette pression est tenue par un caisson en beton precontraint, ayant la forme d'un cylindre horizontal. Des cables d'acier sous tension entourent le cylindre de beton, dont ils sont isoles par des patins. Les fonds du cylindre ont pose des problemes particuliers qui ont conduit a la forme hemispherique adoptee. L'etancheite du caisson est assuree par une tole de 30 mm liee a la face interne du beton. Un des aspects les plus originaux de ces reacteurs est la possibilite de charger et decharger en marche. Cote chargement, des sas a barillets, pesant chacun 50 tonnes; permettent de faire passer les cartouches neuves sous la pression de 15 atmospheres. Ces cartouches progressent de facon quasi continue dans le canal pour tomber finalement par des goulottes inclinees et des toboggans helicoidaux dans un nouveau sas. La circulation du gaz carbonique est assuree par trois turbo-soufflantes, actionnees elles-memes par la vapeur moyenne pression obtenue dans echangeurs, chaque reacteur alimente quatre echangeurs ayant pose de difficiles problemes de construction et de mise en place. Le cycle secondaire est un cycle

Transient regimes in a heavy water reactor; Regimes transitoires dans un reacteur a eau lourde

Energy Technology Data Exchange (ETDEWEB)

Raievski, V [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1953-07-01

We studied the variations of power and reactivity of a reactor when we raise in a continuous way the starting plates. During the subcritical regime (negative reactivity), the power is determined by reactivity and by the intensity of the sources of photo neutrons, produced during the previous work of the reactor. When, during the rise of the plates, the reactor, pass by the critical regime (zero reactivity), one notes that the reached power is independent of the initial reactivity. During the sur-critical regime (positive reactivity), the elevation of temperature of the uranium bars slows down the growth of reactivity due to the movements of the plates. The power stretches then toward a value that depends only on the regime of cooling of the reactor and the excess of the available reactivity. This survey permits to choose such a rise speed, that reactivity remains constantly lower to a value beyond which the piloting of the reactor becomes difficult. This result is not more valid, if the intensity of the sources is insufficient, what takes place during the first divergences and after a stop of long length. (author) [French] On etudie les variations de puissance et de reactivite d'un reacteur quand on leve d'une facon continue les plaques de demarrage. Pendant le regime subcritique (reactivite negative), la puissance est determinee par la reactivite et par l'intensite des sources de photoneutrons, produites pendant la marche anterieure du reacteur. Quand, au cours de la montee des plaques, le reacteur passe par le regime critique (reactivite nulle), on constate que la puissance atteinte est independante de la reactivite initiale. Pendant le regime surcritique (reactivite positive), l'elevation de temperature des barres d'uranium ralentit l'accroissement de reactivite due aux mouvements des plaques. La puissance tend alors vers une valeur qui ne depend plus que du regime de refroidissement du reacteur et de l'exces de la reactivite disponible. Cette etude permet de

The fast breeder reactor Rapsodie (1962); Le reacteur rapide surregenerateur rapsodie (1962)

Energy Technology Data Exchange (ETDEWEB)

Vautrey, L; Zaleski, C P [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

1962-07-01

In this report, the authors describe the Rapsodie project, the French fast breeder reactor, as it stands at construction actual start-up. The paper provides informations about: the principal neutronic and thermal characteristics, the reactor and its cooling circuits, the main handling devices of radioactive or contaminated assemblies, the principles and means governing reactor operation, the purposes and locations of miscellaneous buildings. Rapsodie is expected to be critical by 1964. (authors) [French] Dans ce rapport, les auteurs font le point du projet RAPSODIE (reacteur francais surregenerateur a neutrons rapides), au moment du debut effectif de sa construction. On y trouvera decrits: les principales caracteristiques neutroniques et thermiques, le bloc pile et les circuits de refroidissement, les principaux moyens de manutention des ensembles actifs ou contamines, les principes et les moyens qui regissent la conduite du reacteur, les fonctions et l'implantation des divers batiments. La divergence de RAPSODIE est prevue pour 1964. (auteurs)

Constraining the JULES land-surface model for different land-use types using citizen-science generated hydrological data

Science.gov (United States)

Chou, H. K.; Ochoa-Tocachi, B. F.; Buytaert, W.

2017-12-01

Community land surface models such as JULES are increasingly used for hydrological assessment because of their state-of-the-art representation of land-surface processes. However, a major weakness of JULES and other land surface models is the limited number of land surface parameterizations that is available. Therefore, this study explores the use of data from a network of catchments under homogeneous land-use to generate parameter "libraries" to extent the land surface parameterizations of JULES. The network (called iMHEA) is part of a grassroots initiative to characterise the hydrological response of different Andean ecosystems, and collects data on streamflow, precipitation, and several weather variables at a high temporal resolution. The tropical Andes are a useful case study because of the complexity of meteorological and geographical conditions combined with extremely heterogeneous land-use that result in a wide range of hydrological responses. We then calibrated JULES for each land-use represented in the iMHEA dataset. For the individual land-use types, the results show improved simulations of streamflow when using the calibrated parameters with respect to default values. In particular, the partitioning between surface and subsurface flows can be improved. But also, on a regional scale, hydrological modelling was greatly benefitted from constraining parameters using such distributed citizen-science generated streamflow data. This study demonstrates the modelling and prediction on regional hydrology by integrating citizen science and land surface model. In the context of hydrological study, the limitation of data scarcity could be solved indeed by using this framework. Improved predictions of such impacts could be leveraged by catchment managers to guide watershed interventions, to evaluate their effectiveness, and to minimize risks.

Preliminary studies of the kinetics of a reactor by the probability method; Etude preliminaire de la cinetique d'un reacteur par la methode des probabilites

Energy Technology Data Exchange (ETDEWEB)

Bruna, J G; Brunet, J P; Clouet D' Orval, Ch; Caizergues, R; Verriere, Ph [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The {alpha} decay constant of prompt neutrons has been studied in the homogeneous plutonium-fueled, light-water-moderated reactor Alecto, by the probability method. In this method, the probability to count one, two,.... neutrons during a given time is measured. The value of {alpha} can be deduced from this measurement, for various subcritical states of the reactor. The experimental results were then compared with values obtained, for the same reactivities, by the pulsed neutron technique. (authors) [French] On a etudie sur Alecto, reacteur homogene au plutonium, modere a l'eau legere, la constante de decroissance {alpha} des neutrons prompts par la methode des probabilites. Celle-ci consiste a mesurer la probabilite de compter un, deux, etc..., neutrons pendant un intervalle de temps donne. On a pu en deduire la valeur de {alpha}, dans divers etats sous-critiques du reacteur. On a compare les resultats experimentaux a d'autres valeurs obtenues, aux memes reactivites, par la methode des neutrons pulses. (auteurs)

Dynamic problems of power reactors and analogic devices; Les problemes dynamiques du reacteur de puissance et les machines analogiques

Energy Technology Data Exchange (ETDEWEB)

Braffort, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

The raise of the nuclear physics came with heavy mathematical developments. The analogical installations became especially useful for precise calculations of parameters which depend the running of a reactor. They permit between other to study of kinetic problems and especially ''cybernetics'' of nuclear reactors. It doesn't make a doubt that their use will become widespread, not only in the calculations laboratories, in services for servo-mechanisms study, but also in the control panels of the reactors themselves. (M.B.) [French] L'essor de la physique nucleaire s'est accompagne de lourds developpements mathematiques. Les montages analogiques sont devenus particulierement utiles pour les calculs precis des parametres dont depend le fonctionnement d'un reacteur. Elles permettent entre autre l'etude des problemes cinetiques et surtout ''cybernetiques'' des reacteurs nucleaires. Il ne fait pas de doute que leur usage se generalisera, non seulement dans les laboratoires de calculs, les services d'etudes de servomecanismes, mais aussi pres des tableaux de commande des reacteurs eux-memes. (M.B.)

Operational experience of the Marcoule reactors; Experience d'exploitation des reacteurs de Marcoule

Energy Technology Data Exchange (ETDEWEB)

Conte, F [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1963-07-01

The results obtaining from three years operation of the reactors G-2, G-3 have made it possible to accumulate a considerable amount of operational experience of these reactors. The main original points: - the pre-stressed concrete casing - the possibility of loading while under power - automatic temperature control have been perfectly justified by the results of operation. The author confirms the importance of these original solutions and draws conclusions concerning the study of future nuclear power stations. (author) [French] Les resultats atteints apres trois ans de fonctionnement des reacteurs G-2/G-3 permettent une accumulation considerable de l'experience d'exploitation de ces reacteurs. Les principales originalites: - caisson en beton precontraint - chargement en marche - surveillance automatique des temperatures sont largement justifiees par l'exploitation actuelle. L'auteur confirme l'interet de ces solutions d'avant-garde et en tire des conclusions pour les etudes de futures centrales nucleaires. (auteur)

The research reactors their contribution to the reactors physics; Les reacteurs de recherche leur apport sur la physique des reacteurs

Energy Technology Data Exchange (ETDEWEB)

Barral, J C [Electricite de France (EDF), 75 - Paris (France); Zaetta, A [CEA/Cadarache, Direction des Reacteurs Nucleaires, DRN, 13 - Saint-Paul-lez-Durance (France); Johner, J [CEA/Cadarache, Dept. de Recherches sur la Fusion Controlee (DRFC), 13 - Saint Paul lez Durance (France); Mathoniere, G [CEA/Saclay, DEN, 91 - Gif sur Yvette (France); and others

2000-07-01

The 19 october 2000, the french society of nuclear energy organized a day on the research reactors. This associated report of the technical session, reactors physics, is presented in two parts. The first part deals with the annual meeting and groups general papers on the pressurized water reactors, the fast neutrons reactors and the fusion reactors industry. The second part presents more technical papers about the research programs, critical models, irradiation reactors (OSIRIS and Jules Horowitz) and computing tools. (A.L.B.)

A critical assessment of the JULES land surface model hydrology for humid tropical environments

Science.gov (United States)

Zulkafli, Z.; Buytaert, W.; Onof, C.; Lavado, W.; Guyot, J. L.

2013-03-01

Global land surface models (LSMs) such as the Joint UK Land Environment Simulator (JULES) are originally developed to provide surface boundary conditions for climate models. They are increasingly used for hydrological simulation, for instance to simulate the impacts of land use changes and other perturbations on the water cycle. This study investigates how well such models represent the major hydrological fluxes at the relevant spatial and temporal scales - an important question for reliable model applications in poorly understood, data-scarce environments. The JULES-LSM is implemented in a 360 000 km2 humid tropical mountain basin of the Peruvian Andes-Amazon at 12-km grid resolution, forced with daily satellite and climate reanalysis data. The simulations are evaluated using conventional discharge-based evaluation methods, and by further comparing the magnitude and internal variability of the basin surface fluxes such as evapotranspiration, throughfall, and surface and subsurface runoff of the model with those observed in similar environments elsewhere. We find reasonably positive model efficiencies and high correlations between the simulated and observed streamflows, but high root-mean-square errors affecting the performance in smaller, upper sub-basins. We attribute this to errors in the water balance and JULES-LSM's inability to model baseflow. We also found a tendency to under-represent the high evapotranspiration rates of the region. We conclude that strategies to improve the representation of tropical systems to be (1) addressing errors in the forcing and (2) incorporating local wetland and regional floodplain in the subsurface representation.

SHARP, a first step towards a full sized Jules Verne Launcher

Energy Technology Data Exchange (ETDEWEB)

Bertolini, L.R.; Hunter, J.W. [Lawrence Livermore National Lab., CA (United States); Powell, J.R. [Brookhaven National Lab., Upton, NY (United States); Tidman, D.A. [GT-Devices, Inc., Alexandria, VA (United States)

1993-05-01

A vital element for space exploration and utilization is the ability to affordably place large quantities of consumables and building material into low earth orbit. Calculations and supportive data indicate this can be done with a large hydrogen gas gun referred to as the Jules Verne Launcher (JVL). We present a design for the JVL based upon the concept of side injecting preheated hydrogen along a long barrel. This dramatically reduces the peak pressures in the launcher as well as the pressures and g-loads at the vehicle. The JVL has the promise of reducing payload delivery costs to Low Earth Orbit (LEO) to below $500/kg. The Super High Altitude Research Project (SHARP) is a conventional two-stage hydrogen gas gun which is configured to launch 5 kg packages on suborbital trajectories. It is the first step towards the much larger Jules Verne system and will demonstrate several important features of the larger system. SHARP is currently in the middle of a series of tests aimed at its first milestone. This is to launch 5 kg at 4 km/sec horizontally. In its inclined configuration SHARP should launch vehicles to apogees in excess of 400 km and ranges in excess of 700 km.

Prosa, poesía y sentimientos en la obra de Jules Supervielle

OpenAIRE

Gil-Cepeda Pérez, María de los Ángeles

1996-01-01

El artículo hace un repaso de la vida y obra de Jules Supervielle destacando la relación entre la poesía y la prosa, sus cuentos y la temática más significativa de su obra como son la muerte, la vida, las relaciones terrestres, el tiempo y el espacio, el más allá y la metamorfosis.

Testing the Joint UK Land Environment Simulator (JULES) for flood forecasting

Science.gov (United States)

Batelis, Stamatios-Christos; Rosolem, Rafael; Han, Dawei; Rahman, Mostaquimur

2017-04-01

Land Surface Models (LSM) are based on physics principles and simulate the exchanges of energy, water and biogeochemical cycles between the land surface and lower atmosphere. Such models are typically applied for climate studies or effects of land use changes but as the resolution of LSMs and supporting observations are continuously increasing, its representation of hydrological processes need to be addressed adequately. For example, changes in climate and land use can alter the hydrology of a region, for instance, by altering its flooding regime. LSMs can be a powerful tool because of their ability to spatially represent a region with much finer resolution. However, despite such advantages, its performance has not been extensively assessed for flood forecasting simply because its representation of typical hydrological processes, such as overland flow and river routing, are still either ignored or roughly represented. In this study, we initially test the Joint UK Land Environment Simulator (JULES) as a flood forecast tool focusing on its river routing scheme. In particular, JULES river routing parameterization is based on the Rapid Flow Model (RFM) which relies on six prescribed parameters (two surface and two subsurface wave celerities, and two return flow fractions). Although this routing scheme is simple, the prescription of its six default parameters is still too generalized. Our aim is to understand the importance of each RFM parameter in a series of JULES simulations at a number of catchments in the UK for the 2006-2015 period. This is carried out, for instance, by making a number of assumptions of parameter behaviour (e.g., spatially uniform versus varying and/or temporally constant or time-varying parameters within each catchment). Hourly rainfall radar in combination with the CHESS (Climate, Hydrological and Ecological research Support System) meteorological daily data both at 1 km2 resolution are used. The evaluation of the model is based on hourly runoff

Contribution to the determination of the neutronic parameters uncertainties of a compact heterogeneous core: the material testing Jules Horowitz reactor

International Nuclear Information System (INIS)

Di Salvo, J.

2002-01-01

The design studies of the future Material Testing Reactor Jules Horowitz require the development of an adapted neutronic calculation route. To guarantee good accuracy and save time cost, some approximations with deterministic modelling (APOLLO2 / CRONOS2) are needed. As no relevant integral experiments are yet available to ensure the accuracy of the calculation, the results need to be validated by a rigorous methodical approach, which is based on comparison against numerical benchmarks (Monte Carlo TRIPOLI4 code). In order to complete the validation results, sensitivity coefficients of main neutronic parameters to nuclear data are very useful to get an estimate of the final uncertainty on the calculation. Unfortunately, most of covariance information is missing in the recent evaluated files such as JEF-2.2. To generate missing covariance matrices, a method based on the comparison of different independent evaluations is used in this study. Special attention is paid to the determination of sensitivity coefficients, using perturbation methods and direct calculations. This study points out the importance of the non-diagonal elements of the covariance matrices as well as the neutron capture cross section uncertainty of the 27Al in the thermal range. In complement to uncertainty studies, it will be still necessary to obtain integral experimental validation of the Jules Horowitz Reactor neutronic parameters calculations. (author)

Contribution to the study of the stability of water-cooled reactors; Contribution a l'etude de la stabilite des reacteurs refroidis par de l'eau

Energy Technology Data Exchange (ETDEWEB)

Coudert, C [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

1969-06-01

This work is devoted to the study of the stability of reactors cooled by water subjected only to natural convection. It is made up of two parts, a theoretical study and experimental work, each of these parts being devoted to a consideration of linear and non-linear conditions: - calculation of the transfer function of the reactor using neutronic and hydrodynamic linear equations with the determination of the instability threshold; - demonstration of the existence of the limiting oscillation cycle in the case of a linear feedback using MALKIN'S method; - measurement and interpretation of the reactor's transfer functions and of the hydrodynamic transfer functions; and - analysis of the noise due to boiling. (author) [French] Dans ce travail on etudie la stabilite des piles refroidies par de l'eau circulant en convection naturelle. Cette etude se divise en deux parties: un travail theorique et un travail experimental, chacune de ces parties comportant une etude lineaire et une etude non-lineaire: - calcul de la fonction de transfert du reacteur a partir des equations lineaires de la neutronique et de l'hydrodynamique avec determination du seuil d'instabilite; - demonstration de l'existence du cycle limite des oscillations dans le cas d'une retroaction lineaire en utilisant la methode de MALKIN; - mesure et interpretation de la fonction de transfert du reacteur et des fonctions de transfert hydrodynamiques; et - analyse du bruit d'ebullition. (auteur)

The launching of the construction of the Jules Horowitz Reactor

International Nuclear Information System (INIS)

Anon.

2007-01-01

In March 2007 the French deputy minister of industry has officially launched the construction of the new research reactor called Jules Horowitz (RJH) on the Cea site of Cadarache. RJH, that is due to operate in 2014, will be used to study the aging process of irradiated materials in any type of reactors, the behaviour of new nuclear fuels irradiated in different configurations and scenarios, and to produce radionuclides for nuclear medicine and high-quality doped silicon for the electronics industry. The investment that reaches 500 million euros is dispatched between Cea (50%), EDF (20%), Areva (10%) and foreign contributors (20%). (A.C.)

Jules Verne : un processus d’écriture sous contraintes

OpenAIRE

Scheinhardt, Philippe

2013-01-01

Devenu célèbre, Jules Verne reçoit souvent la visite de journalistes qui l’interrogent aussi bien sur sa vie que sur son œuvre. De ces entretiens, il ressort que l’écrivain respecte comme tant d’autres des rites de création : habitudes de documentation, méthode de genèse littéraire. Ces rites, en écho à la contrainte externe du programme encyclopédique des Voyages extraordinaires, remplissent la fonction de contraintes internes au service de l’acte créateur. Ils renseignent sur les diverses p...

Natural uranium-graphite system. Critial experiments on the G1 reactor; Systeme uranium naturel-graphite. Experiences critiques sur le reacteur G1

Energy Technology Data Exchange (ETDEWEB)

Schmitt, A P; Tanguy, P; Teste du Bailler, A; Zaleski, C P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

A number of experiments have been performed during the start up period of the G1 (1956) and G2 (1958) reactors in Marcoule, both on their lattices and on different lattices (hollow rods, clusters, under moderated lattices). The first chapter gives a thorough description of the two reactors. The second chapter deals with buckling measurements, both absolute (flux plots) and relative by the method of progressive substitution. The experimental results are summarised in Table VI. The third chapter contains a number of other measurements performed on G1. (author)Fren. [French] Le demarrage des reacteurs G1 (1956) et G2 (1958) de Marcoule nous a permis d'effectuer une serie d'experiences tant sur les reseaux de ces piles que sur des reseaux differents (elements tubulaires ou divises, reseaux sous-moderes, etc...). Dans une premiere partie, nous donnons une description detaillee des deux reacteurs. Dans la deuxieme partie, relative aux mesures de laplaciens, nous decrivons d'abord les mesures absolues de laplaciens (cartes de flux), puis les mesures relatives effectuees par la methode originale de remplacement progressif. Les resultats experimentaux sont rassembles dans le tableau VI. Dans la troisieme partie, nous rappelons un certain nombre d'autres mesures effectuees sur G1. (auteur)

Study relating to the physico-chemical behaviour of heavy water in nuclear reactors; Etudes relatives au comportement physico-chimique de l'eau lourde dans les reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Chenouard, J; Dirian, G; Roth, E; Vignet, P; Platzer, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1959-07-01

Chemical and isotope pollution, and radiolytic decomposition are the two most important ways in which heavy water becomes degraded in nuclear reactors. Chemical pollution has led to the creation of ion exchange purification loops specially designed for reactors: the report contains a description in detail of the application of this purification method in CEA research reactors, including the analysis required, results obtained, and their interpretation. The intelligence obtained on radiolytic decomposition with the same facilities is also discussed, as well as the recombination apparatus and control equipment utilized. Finally, investigation to date in the CEA on recombination circuits for power reactors is also discussed. (author) [French] Parmi les degradations subies par l'eau lourde dans les reacteurs nucleaires, les deux plus importantes sont la pollution chimique et isotopique et la decomposition radiolytique. La pollution chimique a conduit a mettre au point pour le cas particulier des reacteurs, des circuits d'epuration par echange d'ions. On decrit ici en detail la mise en oeuvre de cette methode dans les reacteurs de recherche du CEA; les controles qu'elle necessite, les resultats obtenus et leur interpretation. En ce qui concerne la dissociation radiolytique de l'eau, les renseignements obtenus sur ces memes reacteurs sont communiques, ainsi que les details des dispositifs de recombinaison et des moyens de controle. Enfin, on fait le point des etudes poursuivies au CEA sur ces memes problemes de recombinaison dans le cas des reacteurs de puissance. (auteur)

Power Reactor Design at Zero Power; Etudes de Reacteurs de Puissance, au Moyen de Machines de Puissance Zero; Konstruktsiya ehnergeticheskogo reaktora nulevoj moshchnosti; Diseno de Reactores Generadores con Ayuda de Reactores de Potencia Nula

Energy Technology Data Exchange (ETDEWEB)

Redman, W. C.; Plumlee, K. E.; Baird, Q. L. [Argonne National Laboratory, Argonne, IL (United States)

1964-02-15

reliance placed in the past on exponential and critical systems for fulfilling Argonne's responsibilities in reactor development. An indication of their future role is provided by a brief summary of the current and planned programmes for the existing members of, and anticipated additions to, Argonne's family of operating zero-power reactors. (author) [French] Avec le reacteur de puissance zero du Laboratoire national d'Argonne, on a procede a des etudes de reacteurs tres divers; reacteurs de recherche, generatrices nucleaires, reacteurs pour la propulsion, pour la production de radioisotopes et reacteurs experimentaux; les ensembles associes - exponentiels et critiques non empoisonnes - ont fourni les donnees debase. Afin de rendre compte d'experiences recentes et de montrer quelle masse de renseignements sur la physique des reacteurs on peut obtenir avec des systemes a bas flux, les auteurs exposent les programmes experimentaux ci-apres: 1. Etude des proprietes des elements combustibles en oxydes d'uranium et de thorium, immerges dans l'eau lourde, en s'attachant particulierement aux donnees necessaires pour l'etude d'un deuxieme coeur pour le reacteur experimental a eau bouillante du Laboratoire d'Argonne; 2. Maquette d'un reacteur de recherche a haut flux, qui permettra de verifier les calculs faits au cours de l'etude, de determiner la geometrie optimale et d'estimer l'effet du taux de combustion; 3. Determination des repartitions energetiques et de l'effet de l'immersion des cartouches sur la reactivite pour un reacteur experimental a ebullition et a surchauffe combinees; 4. Etude d'un coeur de reacteur surgenerateur plutonigene a neutrons rapides, alimente en U{sup 235} et refroidi au sodium qui constituerait la charge initiale du Deuxieme reacteur surgenerateur experimental d'Argonne; 5. Etude des caracteristiques d'un reacteur a deux regions, l'une thermique et l'autre rapide, en interaction. Dans l'expose de ces programmes, les auteurs expliquent pourquoi on a

Prospects for the Use of Plutonium in Reactors; Prospective d'Utilisation du Plutonium dans les Reacteurs

Energy Technology Data Exchange (ETDEWEB)

Fossoul, E.; Haubert, P. [BELGONUCLEAIRE (Belgium); Hirschberg, D.; Morlet, E. [International Business Machines of Belgium, Bruxelles (Belgium)

1967-09-15

The introduction, at an increasing rate, of power reactors using slightly enriched uranium will inevitably lead to the production of considerable quantities of plutonium over the next decade. Fast reactors will not be capable of absorbing this material before 1980. The question thus arises of whether one should store the plutonium far future use in fast reactors, recycle it in existing thermal reactors, or try to sell it. The problem has been studied for an electric power generating system that does not foresee selling the plutonium produced by its reactors and does not buy plutonium outside, which enables a good approximation to be made and eliminates the major unknown quantity represented by the future market price of plutonium. Assuming within this system a programme that provides for the construction of power reactors of a given type and capacity at specific dates, the utilization of the plutonium produced can be optimized by linear programming techniques so as to minimize the discounted total cost of the power generated over a given period. A later stage consists in optimizing, by various techniques, not only the utilization but also the production of plutonium by appropriate selection of the power reactor types to be constructed. (author) [French] L'implantation, a un rythme croissant, de centrales nucleaires a uranium legerement enrichi entrainera la production ineluctable d'une quantite importante de plutonium au cours de la prochaine decennie. Les reacteurs a neutrons rapides ne seront capables d'absorber cette production qu'apres 1980. La question se pose donc de savoir s'il est preferable de stocker le plutonium en vue de son utilisation ulterieure dans les reacteurs a neutrons rapides plutot que de le recycler dans les reacteurs actuels a neutrons thermiques ou d'essayer de le vendre. Ce probleme a ete etudie dans le cadre d'un systeme de production d'energie electrique qui ne prevoirait pas la vente du plutonium produit par ses reacteurs nucleaires ni

Jules Horowitz Reactor: Organisation for the Preparation of the Commissioning Phase and Normal Operation

Energy Technology Data Exchange (ETDEWEB)

Estrade, J.; Fabre, J. L.; Marcille, O. [French Alternative Energies end Atomic Energy Commission, Provence (France)

2013-07-01

The Jules Horowitz Reactor (JHR) is a new modern Material Testing Reactor (MTR) currently under construction at CEA Cadarache research centre in the south of France. It will be a major research facility in support to the development and the qualification of materials and fuels under irradiation with sizes and environment conditions relevant for nuclear power plants in order to optimise and demonstrate safe operations of existing power reactors as well as to support future reactors design. It will represent also an important research infrastructure for scientific studies dealing with material and fuel behaviour under irradiation. The JHR will contribute also to secure the production of radioisotope for medical application. This is a key public health stake. The construction of JHR which started in 2007 is going-on with target of commissioning by the end of 2017. The design of the reactor provides modern experimental capacity in support to R and D programs for the nuclear energy for the next 60 years. In parallel to the facility construction, the preparation of the future staff and of the organisation to operate the reactor safely, reliably and efficiently is an important issue. In this framework, many actions are in progress to elaborate: Ο the staffing and the organisational structure for the commissioning test phases and also for normal operation, Ο the documentation in support to the reactor operation (safety analysis report, general operating rules, procedures, instructions, ···), Ο the maintenance, in service and periodic test programs, Ο staff training programs by using dedicated facilities (simulator, ···) Ο commissioning test programs for ensuring that the layout of systems and subcomponents is completed in accordance with the design requirements, the specification performances and the safety criteria. These commissioning tests will also be helpful for transferring the knowledge on the installed systems to the operating group. This paper gives the

Storage of plugs and experimental devices from reactors; Stockage des bouchons et dispositifs experimentaux en provenance des reacteurs (1961)

Energy Technology Data Exchange (ETDEWEB)

Cerre, P; Mestre, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

- Within the general programme of storage and treatment of radioactive waste produced by the various operations carried out in an atomic center, it is useful to consider separately the problem of certain waste from reactors, which, because of its size and physical nature, has to be stored with a view to being later treated and finally evacuated. The solution which we propose for this storage problem is presented in this paper. (authors) [French] - Dans le cadre du stockage et du conditionnement des dechets radioactifs provenant des diverses manipulations effectuees dans un centre atomique, il y a lieu de considerer a part certains dechets des reacteurs qui, par leur dimension et leur nature physique doivent etre stockes en vue de leur reprise ulterieure pour un conditionnement et une evacuation definitifs. La solution que nous avons apportee a ce stockage fait l'objet de l'expose qui suit. (auteurs)

Study relating to the physico-chemical behaviour of heavy water in nuclear reactors; Etudes relatives au comportement physico-chimique de l'eau lourde dans les reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Chenouard, J.; Dirian, G.; Roth, E.; Vignet, P.; Platzer, R. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1959-07-01

Chemical and isotope pollution, and radiolytic decomposition are the two most important ways in which heavy water becomes degraded in nuclear reactors. Chemical pollution has led to the creation of ion exchange purification loops specially designed for reactors: the report contains a description in detail of the application of this purification method in CEA research reactors, including the analysis required, results obtained, and their interpretation. The intelligence obtained on radiolytic decomposition with the same facilities is also discussed, as well as the recombination apparatus and control equipment utilized. Finally, investigation to date in the CEA on recombination circuits for power reactors is also discussed. (author) [French] Parmi les degradations subies par l'eau lourde dans les reacteurs nucleaires, les deux plus importantes sont la pollution chimique et isotopique et la decomposition radiolytique. La pollution chimique a conduit a mettre au point pour le cas particulier des reacteurs, des circuits d'epuration par echange d'ions. On decrit ici en detail la mise en oeuvre de cette methode dans les reacteurs de recherche du CEA; les controles qu'elle necessite, les resultats obtenus et leur interpretation. En ce qui concerne la dissociation radiolytique de l'eau, les renseignements obtenus sur ces memes reacteurs sont communiques, ainsi que les details des dispositifs de recombinaison et des moyens de controle. Enfin, on fait le point des etudes poursuivies au CEA sur ces memes problemes de recombinaison dans le cas des reacteurs de puissance. (auteur)

New modelling method for fast reactor neutronic behaviours analysis; Nouvelles methodes de modelisation neutronique des reacteurs rapides de quatrieme Generation

Energy Technology Data Exchange (ETDEWEB)

Jacquet, P.

2011-05-23

Due to safety rules running on fourth generation reactors' core development, neutronics simulation tools have to be as accurate as never before. First part of this report enumerates every step of fast reactor's neutronics simulation implemented in current reference code: ECCO. Considering the field of fast reactors that meet criteria of fourth generation, ability of models to describe self-shielding phenomenon, to simulate neutrons leakage in a lattice of fuel assemblies and to produce representative macroscopic sections is evaluated. The second part of this thesis is dedicated to the simulation of fast reactors' core with steel reflector. These require the development of advanced methods of condensation and homogenization. Several methods are proposed and compared on a typical case: the ZONA2B core of MASURCA reactor. (author) [French] Les criteres de surete qui regissent le developpement de coeurs de reacteurs de quatrieme generation implique l'usage d'outils de calcul neutronique performants. Une premiere partie de la these reprend toutes les etapes de modelisation neutronique des reacteurs rapides actuellement d'usage dans le code de reference ECCO. La capacite des modeles a decrire le phenomene d'autoprotection, a representer les fuites neutroniques au niveau d'un reseau d'assemblages combustibles et a generer des sections macroscopiques representatives est appreciee sur le domaine des reacteurs rapides innovants respectant les criteres de quatrieme generation. La deuxieme partie de ce memoire se consacre a la modelisation des coeurs rapides avec reflecteur acier. Ces derniers necessitent le developpement de methodes avancees de condensation et d'homogenisation. Plusieurs methodes sont proposees et confrontees sur un probleme de modelisation typique: le coeur ZONA2B du reacteur maquette MASURCA

Methods and experimental coefficients used in the computation of reactor shielding; Methodes et coefficients experimentaux pour le calcul des protections de reacteurs

Energy Technology Data Exchange (ETDEWEB)

Bourgeois, J; Lafore, P; Millot, J P; Rastoin, J; Vathaire, F de [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

1) The concept of an effective removal cross section has been developed in order more easily to compute reactor shielding thicknesses. We have built an experimental facility for the purpose of measuring effective removal cross sections, the value of which had not been published at that time. The first part of this paper describes the device or facility used, the computation method applied, and the results obtained. 2) Starting from this concept, we endeavoured to define a removal cross section as a function of energy. This enabled us to use the method for computations bearing on the attenuation of fast neutrons of any spectrum. An experimental verification was carried out for the case of fission neutrons filtered by a substantial thickness of graphite. 3) Finally, we outline a computation method enabling us to determine the sources of captured gamma rays by the age theory and we give an example of the application in a composite shield. (author) [French] 1) La notion de section efficace effective de deplacement a ete introduite pour calculer commodement les epaisseurs de protection des reacteurs. Nous avons construit un dispositif experimental destine a mesurer les sections efficaces effectives de deplacement dont la valeur n'avait pas ete publiee a cette epoque. La premiere partie de cette communication decrit le dispositif utilise, la methode de calcul employee et les resultats obtenus. 2) A partir de cette notion, nous avons essaye de definir une section efficace de deplacement fonction de l'energie. Ceci permet d'utiliser la methode du deplacement pour des calculs d'attenuation de neutrons rapides dont le spectre est quelconque. Une verification experimentale a ete faite dans le cas de neutrons de fission filtres par une epaisseur notable de graphite. 3) Enfin une methode de calcul permettant de determiner les sources de gamma de capture par la theorie de l'age est exposee et un exemple d'application donne dans une protection composite. (auteur)

Methods and experimental coefficients used in the computation of reactor shielding; Methodes et coefficients experimentaux pour le calcul des protections de reacteurs

Energy Technology Data Exchange (ETDEWEB)

Bourgeois, J; Lafore, P; Millot, J P; Rastoin, J; Vathaire, F de [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

1. The concept of an effective removal cross section has been developed in order more easily to compute reactor shielding thicknesses. We have built an experimental facility for the purpose of measuring effective removal cross sections, the value of which had not been published at that time. The first part of this paper describes the device or facility used, the computation method applied, and the results obtained. 2. Starting from this concept, we endeavored to define a removal cross section as a function of energy. This enabled us to use the method for computations bearing on the attenuation of fast neutrons of any spectrum. An experimental verification was carried out for the case of fission neutrons filtered by a substantial thickness of graphite. 3. Finally, we outline a computation method enabling us to determine the sources of captured gamma rays by the age theory and we give an example of the application in a composite shield. (author)Fren. [French] 1. La notion de section efficace effective de deplacement a ete introduite pour calculer commodement les epaisseurs de protection des reacteurs. Nous avons construit un dispositif experimental destine a mesurer les sections efficaces effectives de deplacement dont la valeur n'avait pas ete publiee a cette epoque. La premiere partie de cette communication decrit le dispositif utilise, la methode de calcul employee et les resultats obtenus. 2. A partir de cette notion, nous avons essaye de definir une section efficace de deplacement fonction de l'energie. Ceci permet d'utiliser la methode du deplacement pour des calculs d'attenuation de neutrons rapides dont le spectre est quelconque. Une verification experimentale a ete faite dans le cas de neutrons de fission filtres par une epaisseur notable de graphite. 3. Enfin une mde de calcul permettant de determiner les sources de gamma de capture par la theorie de l'age est exposee et un exemple d'application donne dans une protection composite. (auteur)

Methodological developments and qualification of calculation schemes for the modelling of photonic heating in the experimental devices of the future Jules Horowitz material testing reactor (RJH)

International Nuclear Information System (INIS)

Blanchet, D.

2006-01-01

The objective of this work is to develop the modelling of the nuclear heating of the experimental devices of the future Jules Horowitz material testing reactor (RJH). The strong specific nuclear power produced (460 kW/l), induces so intense photonic fluxes which cause heating and large temperature gradients that it is necessary to control it by an adequate design. However, calculations of heating are penalized by the very large uncertainties estimated at a value of about 30% (2*σ) coming from the gaps and uncertainties of the data of gamma emission present in the libraries of basic nuclear data. The experimental program ADAPh aims at reducing these uncertainties. Measurements by thermoluminescent detectors (TLD) and ionisation chambers are carried out in the critical assemblies EOLE (Mox) and Minerve (UO 2 ). The rigorous interpretation of these measurements requires specific developments based on Monte-Carlo simulations of coupled neutron-gamma and gamma-electron transport. The developments carried out are made different in particular by the modelling of cavities phenomena and delayed gamma emissions by the decay of fission products. The comparisons calculation-measurement made it possible to identify a systematic bias confirming a tendency of calculations to underestimate measurements. A Bayesian method of adjustment was developed in order to re-estimate the principal components of the gamma heating and to transpose the results obtained to the devices of the RJH, under conditions clearly and definitely representative. This work made possible to reduce significantly the uncertainties on the determination of the gamma heating from 30 to 15 per cent. (author)

In Jules Verne's Footsteps: Seismology in the source

Science.gov (United States)

Ellsworth, Bill; Ito, Hisao; Malin, Peter; Abercrombie, Rachel

When Professor Otto Lidenbrock led his little band to the center of the Earth in Jules Verne's 1864 classic novel, the intrepid adventurers needed little more than practical 19th century clothes to provide them with comfort and protection. How different the science of earthquakes would be if conditions in the Earth were really so friendly to the would-be observer. Even the operation of seismic sensors at the relatively modest depth of 2-3 km, roughly the depth of the shallowest crustal earthquakes, requires careful precautions against the effects of unstable materials, temperature, pressure, and water for successful long-term observations to be made. Indeed, the handful of successful deep borehole experiments that have been conducted to date have depended on simple sensors with limited bandwidth and dynamic range, and have yielded data that were not ideally suited to investigating the details of the earthquake source.

[Professor Jules Gavarret (1809-1890) and the application of mathematics and physics to medicine].

Science.gov (United States)

Beyneix, A

2001-01-01

Professor Jules Gavarret has undertaken pretigious offices, has accumulated various titles and honours and has left an abundant bibliography about physics and chemistry of life phenomenon. To recount the career of one of the academics who were benefited the traditional medicine of the progress achieved in physical and mathematical sciences give us the opportunity of recalling one of the great Parisian personalities of 19th Century who had not been appreciated for too long.

Jules Verne: de la odisea a la ciencia ficción

OpenAIRE

Javier Rodriguez Pequeño

2018-01-01

El artículo pretende recordar el importante papel que jugó Jules Verne en la moderna literatura fantástica. Sus Viajes extraordinarios modernizan la odisea clásica y, gracias a la incorporación de la ciencia y a la importancia que concede a la verosimilitud dentro de lo fantástico, crea la ciencia ficción, al tiempo que crea una literatura fantástica basada no el terror, como era común en su época, sino en la fascinación. La utopía es un género muy antiguo pero no le sucede lo mismo a la dist...

Concept of transfer functions for a nuclear reactor; Notion de fonction de transfert pour un reacteur nucleaire

Energy Technology Data Exchange (ETDEWEB)

Dalfes, Abdi [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Departement d' Electronique Generale, Service d' Electronique des Reacteurs

1966-07-01

The solution to the correlation equations are expressed in terms of the eigenvalues and Eigen-matrices of the transport operator, for a subcritical zero power reactor. This allows to define, for each point of the reactor and for detectors detecting neutrons of given velocities, correlation and transfer functions driven by the same white-noise source. A precise meaning is also given to the importance operator, which is the adjoin of the transport operator. (author) [French] La solution des equations regissant les matrices de correlation est exprimee en fonction des valeurs et matrices propres de l'operateur de transport pour un reacteur sous-critique et de puissance nulle. Ceci permet de definir, en chaque point du reacteur et pour des detecteurs repondant a des neutrons de vitesse definie, des fonctions de correlation et de transfert dont les entrees sont attaquees par une meme source de bruit blanc. Le role joue par l'operateur importance, adjoint de l'operateur de transport, est aussi precise. (auteur)

The Jules Horowitz nuclear complex a plat-form for research and development on nuclear fuel and materials for the 21st century

International Nuclear Information System (INIS)

Ballagny, A.; Bouilloux, Y.; Chantoin, P.; Iracane, D.

2001-01-01

The CEA intends to build a material test reactor at Cadarache (South of France). This reactor would be the central piece of a wider complex which would include experimental fuel fabrication, destructive and non destructive examinations, in-reactor on line measurement advanced methods and modelling. For 50 years this platform would provide the necessary knowledge to the nuclear industry, the safety authority and to the national decision makers. This material test reactor called Jules Horowitz reactor (JHR) could be a key facility for industry and the central component of the European research area on nuclear fission from 2010. In this paper an overview of the research complex is given and a first approach of the development effort undertaken to meet the requirements in term of : ''time to result, experimental cost, experiment quality and international co-operation. Finally are given several ways of technical development undertaken to meet the above requirements. (orig.)

The future Jules Horowitz material testing reactor: An opportunity for developing international collaborations on a major European irradiation infrastructure

International Nuclear Information System (INIS)

Parrat, D.; Bignan, G.; Maugard, B.; Gonnier, C.; Blandin, C.

2015-01-01

Development process of a fuel product or a nuclear material before using at an industrial scale in a power reactor ranges from characterization of the material itself under neutronic flux up to its qualification in accidental conditions. Irradiations in Material Testing Reactors (MTRs) are in practice the basis of the whole process, in complement of prediction capabilities gained by modelling. Dedicated experimental reactors play also an important complementary role for some specific integral tests (e.g. RIA tests). Irradiations of precursors in power reactors are often limited to products which present a slight design evolution compare to the standard product or are implemented for further tests when a statistical approach is useful for defining a safety criterion. However European MTR park status is characterized by ageing infrastructures, which could cause operational issues in coming years, either on technological or on safety point of views. Moreover some specific supplies related to the public demand could be strongly affected (e.g. radiopharmaceutical targets). To avoid a lack in irradiation capacity offer at European level, CEA launched the Jules Horowitz Material Testing Reactor (JHR) international program, in the frame of a Consortium gathering also EDF (FR), AREVA (FR), European Commission (EU), SCK.CEN (BE), VTT (FI), CIEMAT (SP), STUDSVIK (SE), UJV (CZ), NNL (UK), IAEC (IL), DAE (IN) and as associated partnership: JAEA (JP). Some institutions in this list are themselves the flagship of a national Consortium. Discussions for enlarging participation are on-going with other countries, as JHR Consortium is open to new member entrance until JHR completion. The Jules Horowitz Material Testing Reactor (JHR MTR) is under construction at CEA Cadarache in southern France and will be an important international User Facility for R&D in support to the nuclear industry, research centres, regulatory bodies and TSO, and academic institutions. It represents a unique

The Jules Horowitz Reactor (JHR), a European Material Testing Reactor (MTR), with extended experimental capabilities

International Nuclear Information System (INIS)

Ballagny, A.; Bergamaschi, Y.; Bouilloux, Y.; Bravo, X.; Guigon, B.; Rommens, M.; Tremodeux, P.

2003-01-01

The Jules Horowitz Reactor (JHR) is the European MTR (Material Testing Reactor) designed to provide, after 2010, the necessary knowledge for keeping the existing power plants in operation and to design innovative reactors types with new objectives such as: minimizing the radioactive waste production, taking into account additional safety requirements, preventing risks of nuclear proliferation. To achieve such an ambitious objective. The JHR is designed with a high flexibility in order to satisfy the current demand from European industry, research and to be able to accommodate future requirements. The JHR will offer a wide range of performances and services in gathering, in a single site at Cadarache, all the necessary functionalities and facilities for an effective production of results: e.g. fuel fabrication laboratories, preparation of the instrumented devices, interpretation of the experiments, modelling. The JHR must rely on a top level scientific environment based on experts teams from CEA and EC and local universities. With a thermal flux of 7,4.10 14 ncm -2 s -1 and a fast flux of 6,4.10 14 ncm -2 s -1 , it is possible to carry out irradiation experiments on materials and fuels whatever the reactor type considered. It will also be possible to carry out locally, fast neutron irradiation to achieve damage effect up to 25 dpa/year. (dpa = deplacement per atom). The study of the fuels behavior under accidental conditions, from analytical experiments, on a limited amount of irradiated fuel, is a major objective of the project. These oriented safety tests are possible by taking into account specific requirements in the design of the facility such as the tightness level of the containment building, the addition of an alpha hot cell and a laboratory for on line fission products measurement. (author)

Jules Verne, la géogenèse des diamants et la revue Nature

OpenAIRE

Bollinger , Jean-Claude

2015-01-01

International audience; Browsing through recent issues of the respected scientific journal Nature, the author has found a number of explicit references to Jules Verne’s famous novel "Journey to the Center of the Earth". For example, in a paper about the analysis of a solid inclusion within a diamond, diamond formation from a solution is mentioned. But this is in fact a main topic within another and lesser known novel, "The Southern Star". Then a discussion concerning diamond formation is pres...

Analysis of Media Stereotypes of the Russian Image in Media Studies in the Student Audience (example: the screen versions of Jules Verne's Novel “Michael Strogoff”

Directory of Open Access Journals (Sweden)

Alexander Fedorov

2014-09-01

Full Text Available As a result of the analysis students come to the conclusion that the screen adaptations of Jules Verne's novel ''Michael Strogoff'' create, though an oversimplified and adapted to western stereotypes of perception, but a positive image of Russia – as a stronghold of European values at the Asian frontiers, a country with a severe climate, boundless Siberian spacious areas, manly and patriotic warriors, a wise monarchy. At the same time, both Jules Verne's novel and its screen adaptations contain clear-cut western pragmatism – the confidence that if a man has a proper will he can rule his destiny.

The nuclear heating calculation scheme for material testing in the future Jules Horowitz Reactor

International Nuclear Information System (INIS)

Huot, N.; Aggery, A.; Blanchet, D.; Courcelle, A.; Czernecki, S.; Di-Salvo, J.; Doederlein, C.; Serviere, H.; Willermoz, G.

2004-01-01

An innovative nuclear heating calculation scheme for materials testing carried out in in the future Jules Horowitz reactor (JHR) is described. A heterogeneous gamma source calculation is first performed at assembly level using the deterministic code APOLLO2. This is followed by a Monte Carlo gamma transport calculation in the whole core using the TRIPOLI4 code. The calculated gamma sources at the assembly level are applied in the whole core simulation using a weighting based on power distribution obtained from the neutronic core calculation. (authors)

Sharp and the Jules Verne Launcher

Science.gov (United States)

Hunter, John; Cartland, Harry

1996-03-01

Lawrence Livermore National Laboratory (LLNL) has built the worlds largest hydrogen gas gun called SHARP, (Super High Altitude Research Project). Originally designed to launch 5 kg to a 450 km altitude, SHARP is configured horizontally at Site 300 in Tracy, California. SHARP is successfully delivering 5 kg scramjets at Mach 9 in aerophysics tests. Some of the results of the scramjet tests are enlightening and are presented insofar as they are relevant to future launches into space. Using a light gas gun to launch payloads into orbit has been analyzed. We look at LEO (Low Earth Orbit), GEO (Geosynchronous Earth Orbit), and LO (Lunar Orbit). We present a conceptual design for a large light gas gun called the Jules Verne Launcher (JVL). The JVL can deliver 3.3 metric tons to a 500 km low earth orbit. We anticipate one launch per day. We present the history of light gas guns, the SHARP design and performance, and the JVL design. Another section is devoted to the vehicle environment and resultant design. Lastly, we present a cost analysis. Our results indicated that the JVL will be able to deliver 1000 metric tons of payload to LEO yearly. The cost will be 5% of the best US rocket delivery cost. This technology will enable the next phase of man's exploration of space.

Neutron flux determinations in the reactors G2 and G3 during operation; Releves du flux neutronique dans les reacteurs G2 et G3 en puissance

Energy Technology Data Exchange (ETDEWEB)

Boulinier, C; Faurot, P; Sagot, M; Teste du Bailler, A [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1961-07-01

After demonstrating the sensitivity of the distribution of power in a production reactor to a deformation caused by dissymmetries of reactivity in the reactor, the authors describe the method of neutron flux determination devised for the reactors G2 and G3 under working conditions; the detector used is a tungsten or nickel wire, the {gamma} activity of which is measured with an ionisation chamber. Several flux determinations are given as examples to illustrate the sensitivity of the method. (author) [French] Apres avoir mis en evidence la sensibilite de la repartition de la puissance dans un reacteur de production a une deformation provoquee par de faibles dissymetries de reactivite dans le reacteur, les auteurs decrivent la methode de releve du flux neutronique mise au point pour les reacteurs G2 et G3 en puissance; le detecteur utilise est un fil de tungstene ou de nickel dont l'activite {gamma} est mesuree a l'aide d'une chambre d'ionisation. Quelques releves de flux illustrant la sensibilite de la methode sont donnes a titre d'exemple. (auteur)

Uncertainty and sensitivity analysis for the simulation of a station blackout scenario in the Jules Horowitz Reactor

International Nuclear Information System (INIS)

Ghione, Alberto; Noel, Brigitte; Vinai, Paolo; Demazière, Christophe

2017-01-01

Highlights: • A station blackout scenario in the Jules Horowitz Reactor is analyzed using CATHARE. • Input and model uncertainties relevant to the transient, are considered. • A statistical methodology for the propagation of the uncertainties is applied. • No safety criteria are exceeded and sufficiently large safety margins are estimated. • The most influential uncertainties are determined with a sensitivity analysis. - Abstract: An uncertainty and sensitivity analysis for the simulation of a station blackout scenario in the Jules Horowitz Reactor (JHR) is presented. The JHR is a new material testing reactor under construction at CEA on the Cadarache site, France. The thermal-hydraulic system code CATHARE is applied to investigate the response of the reactor system to the scenario. The uncertainty and sensitivity study was based on a statistical methodology for code uncertainty propagation, and the ‘Uncertainty and Sensitivity’ platform URANIE was used. Accordingly, the input uncertainties relevant to the transient, were identified, quantified, and propagated to the code output. The results show that the safety criteria are not exceeded and sufficiently large safety margins exist. In addition, the most influential input uncertainties on the safety parameters were found by making use of a sensitivity analysis.

Economic Effect on the Plutonium Cycle of Employing {sup 235}U in Fast Reactor Start-Up; Incidence Economique du Demarrage des Reacteurs Rapides a l'Aide d'Uranium-235 sur le Cycle du Plutonium

Energy Technology Data Exchange (ETDEWEB)

Van Dievoet, J.; Egleme, M.; Hermans, L. [BELGONUCLEAIRE, Bruxelles (Belgium)

1967-09-15

factors, inventory factors) from one cycle to another, with a comparative study of the use of {sup 235}U in thermal and fast reactors, variations in the discounted fuel cycle costs from one cycle to another, and weight and characteristics of the recycled fuel, of the additional fuel required and of excess fuel. (author) [French] Le memoire presente les premiers resultats d'une etude entreprise dans le cadre d'un contrat d'association Euratom-Belgique et destinee a evaluer l'interet de l'alimentation de reacteurs rapides en uranium-235. Plusieurs possibilites se presentent pour le demarrage d'un reacteur rapide a l'aide d'uranium-235. 1. Le reacteur peut etre alimente en permanence avec de l'uranium enrichi, le plutonium produit servant a demarrer et a alimenter d'autres reacteurs; dans ce cas, l'uranium est recycle dans le reacteur en y ajoutant de l'uranium enrichi. 2. Le plutonium produit dans le reacteur peut etre partiellement recycle dans celui-ci, ainsi que l'uranium; dans ce cas, le reacteur se transforme progressivement en un reacteur au plutonium. Ces deux cas peuvent etre combines pour un reacteur a plusieurs zones d'enrichissement, ou l'on peut appliquer simultanement les deux politiques a des zones differentes, c'est-a-dire: alimenter, par exemple, la zone interne en uranium enrichi et recycler le plutonium dans la zone externe. Le mode de traitement du combustible irradie rend egalement le probleme complexe, selon que l'on traite ensemble ou separement le coeur et les couvertures axiales; de meme, pour un reacteur a plusieurs zones d'enrichissement, celles-ci peuvent etre traitees ensemble ou separement. Les calculs sont effectues a l'aide d'un code de calcul utilisant, pour lavpartie relative aux caracteristiques des reacteurs successifs, les coefficients d'equivalence definis par Baker and Ross et, pour la partie economique, la methode du cout actualise du cycle du combustible. Dans la premiere phase des travaux, une analyse approcheedu phenomene a ete

Notes on a homogeneous reactor project; Idees sur un projet de reacteur homogene

Energy Technology Data Exchange (ETDEWEB)

Benveniste, J; Bernot, J; Eidelman, D; Grenon, M; Portes, L; Raspaud, G; Tachon, J; Vendryes, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Berthod, L; Cohen de Lara, G; Delachanal, M; Fontanet, P; Halbronn, G [Societe Grenobloise d' Etudes et d' Applications Hydrauliques, 38 (France)

1958-07-01

An attempt has been made to develop certain ideas concerning homogeneous reactors. The project under consideration is based on the simultaneous use of a suspension of uranium dispersed in heavy or light water and of boiling in the reactor for heat extraction. However, the studies of suspensions and of boiling are relatively independent and can also be developed for reactors of different types using one or the other. Our aim is a minimum investment in fissile material; for this we propose to extract the steam directly from the core and to make use of a cyclone to accelerate this extraction; a cyclone-type circulation creating a field of increasing tangential velocities of the fluid towards the axis causes the droplets of vapour to accelerate towards the axial vortex in which they are collected; the steam output is then evacuated to the external heat utilisation system, for example an exchanger of the condenser-boiler type. The input speed of water into the reactor being one of the important parameters in the running of the pile, a spiral supply input chamber is used, allowing this speed to be regulated in amount and direction. (author)Fren. [French] Nous nous sommes attaches a developper certaines idees relatives aux piles homogenes. Le projet que nous etudions est base sur l'emploi simultane d'une suspension contenant de l'uranium disperse dans l'eau legere ou lourde et de l'ebullition dans le reacteur pour l'extraction de chaleur. Neanmoins, les etudes de suspensions et d'ebullition sont relativement independantes et peuvent egalement etre developpees pour des reacteurs de type different utilisant l'une ou l'autre. Le but que nous cherchons a atteindre est un investissement minimum en matiere fissile; pour cela, nous proposons d'extraire directement la vapeur dans le coeur et de recourir a un dispositif cyclone pour accelerer cette extraction; une circulation type cyclone creant un champ de vitesses tangentielles du fluide croissantes veraxe a pour effet d

The dangers of irradiate uranium in nuclear reactors; Les dangers de l'uranium irradie dans les reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Jammet, H; Joffre, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

The danger of the uranium cans sur-activated by the use in the nuclear reactors is triple: - Irradiation from afar, during manipulations of the cans. - Contamination of air when decladding. - Contamination of air by fire of uranium in a reactor in function The first two dangers are usual and can be treated thanks to the rules of security in use in the atomic industry. The third has an accidental character and claimed for the use of special and exceptional rules, overflowing the industrial setting, to reach the surrounding populations. (authors) [French] Le danger des cartouches d'uranium suractive par utilisation dans les reacteurs nucleaires est triple: - Irradiation a distance, lors des manipulations des cartouches. - Contamination de l'air au moment de leur degainage. - Contamination de l'air par incendie d'uranium dans un reacteur en fonctionnement. Les deux premiers dangers sont habituels et peuvent etre traites grace aux regles de securite en usage dans l'industrie atomique. Le troisieme revet un caractere accidentel et reclame l'emploi de regles speciales et exceptionnelles, debordant le cadre industriel, pour atteindre celui des populations environnantes. (auteurs)

Measurements of reactivity of reactor G1; Mesures de reactivite sur reacteur G1

Energy Technology Data Exchange (ETDEWEB)

Bernot, J; Koechlin, J C; Portes, L; Teste du Bailler, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-07-01

The various methods used during the physical study of the reactor G1 to determine the variations of the effective multiplication factor consecutive to a given change in the geometry of the multiplying medium, are presented and discussed. The comparison of the results obtained by these various methods has allowed their validity to be tested and precise conditions of use to be given. In the first part are presented the principles used and their ranges of validity. In the second part the experimental results are given, together with some indications on their comparison with theoretical estimations. (author) [French] Nous exposons et discutons diverses methodes utilisees, lors de l'etude physique du reacteur G1, pour determiner les variations du facteur de multiplication effectif consecutives a un changement donne dans la geometrie du milieu multiplicateur. La comparaison des resultats obtenus par diverses methodes nous a permis de tester leur validite et d'en preciser les conditions d'emploi. Dans une premiere partie, nous exposons les principes utilises et leurs domaines de validite. Dans une seconde partie nous donnons les resultats experimentaux obtenus avec quelques indications sur leur comparaison avec les estimations theoriques. (auteur)

Incorporating JULES into NASA's Land Information System (LIS) and Investigations of Land-Atmosphere Coupling

Science.gov (United States)

Santanello, Joseph

2011-01-01

NASA's Land Information System (LIS; lis.gsfc.nasa.gov) is a flexible land surface modeling and data assimilation framework developed over the past decade with the goal of integrating satellite- and ground-based observational data products and advanced land surface modeling techniques to produce optimal fields of land surface states and fluxes. LIS features a high performance and flexible design, and operates on an ensemble of land surface models for extension over user-specified regional or global domains. The extensible interfaces of LIS allow the incorporation of new domains, land surface models (LSMs), land surface parameters, meteorological inputs, data assimilation and optimization algorithms. In addition, LIS has also been demonstrated for parameter estimation and uncertainty estimation, and has been coupled to the Weather Research and Forecasting (WRF) mesoscale model. A visiting fellowship is currently underway to implement JULES into LIS and to undertake some fundamental science on the feedbacks between the land surface and the atmosphere. An overview of the LIS system, features, and sample results will be presented in an effort to engage the community in the potential advantages of LIS-JULES for a range of applications. Ongoing efforts to develop a framework for diagnosing land-atmosphere coupling will also be presented using the suite of LSM and PBL schemes available in LIS and WRF along with observations from the U. S .. Southern Great Plains. This methodology provides a potential pathway to study factors controlling local land-atmosphere coupling (LoCo) using the LIS-WRF system, which will serve as a testbed for future experiments to evaluate coupling diagnostics within the community.

William Butcher, Jules Verne inédit, les manuscrits déchiffrés

OpenAIRE

Merello, Ida

2016-01-01

Les textes de Jules Verne sont des palimpsestes. Ils le sont au sens figuré, nous le savions déjà. Mais ils le sont également au sens propre, comme le montre le bel ouvrage de William Butcher. Ce dernier s’est donné pour objectif d’analyser les manuscrits de Verne parvenus jusqu’à nous. La ressource semble inépuisable : des milliers et des milliers de pages autographes à déchiffrer, à défricher. William Butcher s’est plongé dans ce labeur avec enthousiasme et il en tire de nombreuses informat...

Catálogo de los puentes proyectados por Jules Sagebien en la provincia de Matanzas.

OpenAIRE

Luis R. González Arestuche; C. J. Rolo Pico; Rubén A. Delgado Rodríguez

2014-01-01

Esta investigación recopila en documento único, el mejor quehacer de uno de los principales forjadores de Matanzas como ciudad y del desarrollo industrial inicial, alcanzado en el siglo XIX, para la demarcación. El respeto hacia la conservación y el rescate del patrimonio construido en la actual provincia homónima, por sus altísimos valores: histórico, cultural y tecnológico, considera la necesidad del conocimiento ciudadano sobre la actividad del francés Jules Sagebien Tavernier. Desde el añ...

Irradiation of fuels and materials in the Jules Horowitz reactor: The 6th European Union JHR co-ordination action (JHR-CA)

International Nuclear Information System (INIS)

Iracane, Daniel; Parrat, Daniel

2005-01-01

The Fermine thematic network in the 5th FP pointed out the need for a new MTR facility in Europe to answer the continuous need of irradiation capabilities for fission power reactors and fusion facilities and to face the ageing of present MTRs. The Jules Horowitz Reactor (JHR) Project in Cadarache copes with this context, as an international service-oriented user-facility. In the field of nuclear fuels and materials irradiation experiments, a 6th FP co-ordination action, called JHR-CA, has started at the beginning of 2004 for 2 years. The main objective is to network existing expertise on development of a new generation of experimental devices, through definition of conceptual designs, instrumentation and related in-reactor services. This paper presents the outline of the JHR project, the organization of the JHR-CA programme, and a choice of irradiation device conceptual design results. (author)

[Scientific contributions of Jules Hirsch regarding the physiopathogenesis of obesity].

Science.gov (United States)

Zárate, Arturo; Manuel, Leticia

2016-01-01

Jules Hirsch was born in New York City and died at age 88 after a long illness. He was considered notorious leader in the study of human metabolism mainly in the area of lipids and obesity. His research at The Rockefeller University helps establish the mechanism of obesity and lipids metabolism. Hirsch joined Rockefeller´s faculty in 1954 and remained there for the rest of his career. Hirsch´s research helped to support the idea of dynamic interactions among diet, physical activity, general metabolism and obesity. At that time most scientific considered adipose tissue to be biologically inert such as a passive insulator in which the body reserved energy in the form of triglycerides. Hirsch had a natural characteristic of showing a nice smile and greeting for everyone he worked with at the university. Another important contribution was there relationship between diet and cardiovascular ailments as well as metabolism disturbance.

Neutronics experimental validation of the Jules Horowitz reactor fuel by interpretation of the VALMONT experimental program-transposition of the uncertainties on the reactivity of JHR with JEF2.2 and JEFF3.1.1

International Nuclear Information System (INIS)

Leray, O.; Hudelot, J.P.; Doederlein, C.; Vaglio-Gaudard, C.; Antony, M.; Santamarina, A.; Bernard, D.

2012-01-01

The new European material testing Jules Horowitz Reactor (JHR), currently under construction in Cadarache center (CEA France), will use LEU (20% enrichment in 235 U) fuels (U 3 Si 2 for the start up and UMoAl in the future) which are quite different from the industrial oxide fuel, for which an extensive neutronics experimental validation database has been established. The HORUS3D/N neutronics calculation scheme, used for the design and safety studies of the JHR, is being developed within the framework of a rigorous verification-numerical validation-experimental validation methodology. In this framework, the experimental VALMONT (Validation of Aluminium Molybdenum uranium fuel for Neutronics) program has been performed in the MINERVE facility of CEA Cadarache (France), in order to qualify the capability of HORUS3D/N to accurately calculate the reactivity of the JHR reactor. The MINERVE facility using the oscillation technique provides accurate measurements of reactivity effect of samples. The VALMONT program includes oscillations of samples of UAl ∞ /Al and UMo/Al with enrichments ranging from 0.2% to 20% and Uranium densities from 2.2 to 8 g/cm 3 . The geometry of the samples and the pitch of the experimental lattice ensure maximum representativeness with the neutron spectrum expected for JHR. By comparing the effect of the sample with the one of a known fuel specimen, the reactivity effect can be measured in absolute terms and be compared to computational results. Special attention was paid to the rigorous determination and reduction of the experimental uncertainties. The calculational analysis of the VALMONT results was performed with the French deterministic code APOLLO2. A comparison of the impact of the different calculation methods, data libraries and energy meshes that were tested is presented. The interpretation of the VALMONT experimental program allowed the experimental validation of JHR fuel UMoAl8 (with an enrichment of 19.75% 235 U) by the Minerve

POSITIVISM, INDUSTRIAL REVOLUTION AND URBANISM - UTOPIA AND REALITY IN THE JULES VERNE'S NOVEL "THE BEGUM'S FORTUNE"

Directory of Open Access Journals (Sweden)

Daniel H. Valsecchi

2009-01-01

Full Text Available The aim of this article is to analyze negative consequences (social, political, psychological and so forth of utopian projects, which crippled society and people by negation of reality and at the same time oblige them to accept these plans. In order to do this we analyze characteristics of two constructions which are thoroughly depicted by Jules Verne: an Arms Fabric (Stahlstadt and a city which was mathematically built (France Ville. Furthermore there are reflections about positivism - i.e. the ground of these projects.

The physics design of EBR-II; Physique du reacteur EBR-II; Fizicheskij raschet ehksperimental'nogo reaktora - razmnozhitelya EVR-II; Aspectos fisicos del reactor EBR-II

Energy Technology Data Exchange (ETDEWEB)

Loewenstein, W. B. [Argonne National Laboratory, Argonne, IL (United States)

1962-03-15

notamment l'introduction de taux de reactivite normaux et anormaux, les consequences des effets supposes de reactivite, a partir du comportement physique de l'alliage combustible et de la structure du reacteur, ainsi que par extrapolation des experiences faites sur TREAT au systeme EBR-II. Il examine le probleme de la fusion du coeur de EBR-II. (author) [Spanish] La memoria informa sobre los calculos del comportamiento estatico, dinamico y a largo plazo de la reactividad del reactor reproductor experimental EBR-II, asi como sobre los resultados y analisis de los experimentos criticos en seco del EBR-II y de los experimentos simulados en el reactor de potencia cero ZPR-III. Insiste particularmente en los problemas de fisica del reactor que, en la elaboracion del proyecto, siguen a la eleccion del modelo, pero preceden a la construccion y puesta en marcha del reactor. Presenta diversos analisis del reactor desde el punto de vista de la seguridad y formula consideraciones sobre la evaluacion de los riesgos y su influencia sobre el diseno del reactor. El trabajo explica tambien la manera de emplear los datos obtenidos en los experimentos arriba citados. Estos experimentos, su analisis y sus predicciones teoricas constituyen la base para determinar el comportamiento fisico del reactor. La memoria estudia detalladamente las limitaciones inherentes a la aplicacion de los datos experimentales al funcionamiento del reactor de potencia. Ello incluye datos precisos sobre as dimensiones del cuerpo, el enriquecimiento de la aleacion combustible, o de ambos factores; el establecimiento de una reactividad adecuada para el reactor funcionando o detenido, la determinacion de la variacion de los coeficientes de reactividad en funcion de la temperatura de funcionamiento y de la potencia generadora y detalles de la distribucion de la potencia y del flujo en diversos puntos de la estructura del reactor. La memoria expone tambien el problema general que supone transferir a la verdadera geometria

The Application of Non-Metallic Core Materials in a High-Temperature Reactor Experiment; Utilisation de materes non metalliques dans le coeur d'un reacteur experimental a haute temperature; Ispol'zovanie nemetallicheskikh materialov dlya aktivnoj zony vysokotemperaturnogo opytnogo reaktora; Empleo de materiales no metalicos en el nucleo de un reactor experimental de alta temperatura

Energy Technology Data Exchange (ETDEWEB)

Huddle, R. A.U.; Shepherd, L. R. [Organization for Economic Co-Operation and Development, Dragon Project, Atomic Energy Establishment, Winfrith, Dorset (United Kingdom)

1963-11-15

refroidis par un gaz, construire et exploiter, dans le cadre de ce projet, un reacteur experimental de 20 MWth. Le reacteur - dont la construction touche a sa fin - est refroidi a l'helium; la temperature de sortie du coeur est de 750{sup o}C; il emploie de l'uranium-235 comme combustible et du thorium comme matiere fertile. Il est caracterise par l'absence de tout metal dans le coeur du reacteur. En raison'des hautes temperatures, qui peuvent atteindre 1050{sup o}C a la surface des elements combustibles et s'elever au dessus de 1500{sup o}C dans les regions les plus chaudes du combustible, on emploie des materiaux refractaires non metalliques. Le fait que tous les constituants du coeur sont reunis dans l'element combustible permet d'obtenir un rapport eleve entre la surface de transfert de la chaleur et le volume du coeur, d'ou une puissance specifique moyenne elevee pour un ensemble de dimension relativement faible. Chaque element combustible est constitue par un faisceau de tubes de graphite contenant les matieres fissiles et fertiles sous forme de carbure incorpore a des pastilles de graphite. Un courant refroidisseur d'helium traverse le centre de chaque barreau de combustible d'ou il ressort par la base pour etre conduit dans une installation de purification dans laquelle il est debarrasse des produits de fission et autres impuretes avant d'etre achemine de nouveau vers le reacteur. Cette methode permet de reduire la fuite des produits de fission qui, s'echappant du combustible ceramique porte a tres haute temperature, entrent dans le circuit de refroidissement primaire. Les auteurs exposent les problemes lies a la mise au point et a la fabrication du graphite et des elements combustibles ceramiques destines a ce reacteur ainsi que le comportement de ces materiaux dans les conditions de fonctionnement. Ils indiquent les resultats de recherches en pile et dans des boucles d'irradiation. Dans ce programme, tout l'effort se concentre sur la mise au point de reacteurs a

Test devices in Jules Horowitz Reactor dedicated to the material studies in support to the current and future nuclear power plants

International Nuclear Information System (INIS)

Colin, C.; Pierre, J.; Blandin, C.; Gonnier, G.; Auclair, M.; Rozenblum, F.

2015-01-01

The Jules Horowitz Reactor (JHR) is a tank pool Material Testing Reactor with a maximum thermal power designed at 100 MW. JHR is being built in the CEA Cadarache site and will take over the Osiris reactor whose decommissioning is planned. JHR's design allows a large experimental capability (around 20 experiments at the same time) inside the reactor core, close to the fuel with high fast neutron flux or outside the reactor core, in the reflector with higher thermal neutron flux. A special attention has been put on the improvement of the thermal stability and gradients of the interest zones in samples despite strong gamma heating and on an improvement of the instrumentation devoted to the experiments. This paper presents the JHR and its main experimental devices that include the MICA (Material Irradiation Capsule) device, the CALIPSO (in-Core Advanced Loop for Irradiation in Potassium and Sodium) loop, the OCCITANE (Out-of-Core Capsule for Irradiation Testing of Ageing by Neutrons) rig, and the CLOE (Corrosion Loop Experiment) loop. JHR will play an important role for Gen IV reactors: CEA studies the feasibility of transmutation capsules, of metal liquid irradiation loops for JHR

Detection and location of can rupture in reactors cooled by a flow of water; Detection et localisation des ruptures de gaines sur les reacteurs refroidis par circulation d'eau

Energy Technology Data Exchange (ETDEWEB)

Le Meur, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1968-07-01

This report brings together the principal methods of fission-product detection used for water reactors. The position, type and method of adjustment is given for each detector. The methods for localizing the defective elements are explained, in particular those using water sampling or decreases in the flux. A few installations are briefly described. They correspond to particular types of reactors using boiling, pressurized or cold water. Amongst the many methods used, it can be noted that when the fuel is resistant, the installations are fairly compact. In nuclear super-heated reactors on the other hand, the study of fuel behaviour calls for larger installations. An identification of defective elements exists when the reactor structure allows it. If this is not possible, a localization in a group of elements is obtained by a flux depression. (author) [French] Ce rapport rassemble les principales methodes de detection de produits de fission utilisees pour des reacteurs a eau. On indique pour les detecteurs leurs emplacements, leurs types, leurs reglages. On explique quelles sont les methodes de localisation des elements defectueux, en particulier celles utilisant des prelevements d'eau ou des depressions de flux. Quelques installations sont decrites sommairement. Elles correspondent a des types particuliers de reacteurs a eau bouillante, pressurisee ou froide. Parmi les nombreuses methodes utilisees, on constate que les installations sont peu importantes, lorsque le combustible est resistant. Par contre dans les reacteurs a surchauffe nucleaire l'etude du comportement du combustible necessite des installations plus importantes. Une identification d'elements defectueux existe lorsque la structure du reacteur le permet. A defaut une localisation dans un groupe d'elements est obtenue par depression de flux. (auteur)

Physical measurements in Marcoule reactors (1962); Mesures physiques sur les reacteurs de Marcoule (1962)

Energy Technology Data Exchange (ETDEWEB)

Teste du Bailler, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

A brief description of the physical measurements in Marcoule reactors is given here. During commissioning and subsequent years of operation, various experiments ha been carried out to check design data, and improve the operating conditions and also test theoretical models for kinetic studies. (author) [French] On presente une rapide description des mesures physiques effectuees sur les reacteurs de Marcoule. Au cours du demarrage et pendant les premieres annees de fonctionnement de G-2 - G-3, de nombreuses experiences ont ete effectuees pour verifier les donnees du projet, ameliorer les conditions de fonctionnement et eprouver des modeles theoriques de calculs de cinetique. (auteur)

HORUS3D/TH: thermal-hydraulic modelling of the Jules Horowitz reactor core with FLICA4

International Nuclear Information System (INIS)

Royer, E.; Gregoire, O.; Magnaud, J.P.; Roux, L.; Masson, X.

2007-01-01

Cea is planning to build a new pool type reactor as irradiation facility in Cadarache, France: the Jules Horowitz Reactor (JHR). For this purpose, a simulation program is carried out at Cea: HORUS3D, aimed at modeling neutronics, radio-protection and thermal-hydraulics. Advanced features of the thermal-hydraulics component of this simulation program (HORUS3D/TH) are presented in the paper. HORUS3D/TH is based on the FLICA4 thermalhydraulic code. Numerically the main features of HORUS3D/TH are unstructured mesh grids and non-conform mappings. From a phenomenological point of view, flows under study range from high velocity forced convection to natural convection regimes. Steady and transient regimes have been simulated. The validation of physical models used is an important part of HORUS3D project. For thermohydraulics, this validation relies on the SULTAN-RJH experimental facility and fine scale CFD simulations. We have shown in this paper that it is possible to calibrate the macroscopic heat exchange correlation in the forced convection regime and under very high heat fluxes thanks to low Reynolds fine scale calculations. We particularly underline how to cope with the difficulties due to the complex geometry (cylindrical fuel assemblies, made of curved plates) and very high pressure drops and heat fluxes

The Jules Horowitz reactor, a new high performance European material testing reactor open to international users: present status and objectives

International Nuclear Information System (INIS)

Iracane, D.; Bignan, G.

2010-01-01

The development of nuclear power as a sustainable and competitive energy source will continue to require research and development of fuel and material behaviour under irradiation. This necessitates a high performance material testing reactor (MTR). Facing the obsolescence of most of the existing MTR in Europe, France decided a few years ago the construction of the RJH (Jules Horowitz reactor). RJH is designed, built and will be operated as an international user facility. A first set of experimental hosting devices is being designed. For instance, there are the in-core CALIPSO Nak integrated loop for material studies and other loops for fuel studies under nominal or off-normal or accidental conditions. The RJH international program will focus on the following subjects: -) fuel reliability, assessed through power ramps tests and post-irradiation examination; -) Loss of coolant tests done out-of-pile in a first phase and in-pile in a possible second phase; and -) source term tests addressing fission products release. The paper reports also the point of view of VATTENFALL (a Swedish power utility), as a potential European RJH user. (A.C.)

Description of the french graphite reactor and of the experiments performed in 1956; Presentation du premier reacteur a graphite francais et des experiences effectuees en 1956

Energy Technology Data Exchange (ETDEWEB)

Bussac, J; Leduc, C; Zaleski, C P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-07-01

This paper is an introduction to the experiments performed on the G1 reactor, experiments fully described in the papers following (670 'B to P'). The main results are given together with some comments. The neutronic parameters of the core, a description of the most important structures, and a few words of the tests leading to normal operation of the reactor under load complete our survey. (author) [French] Ce rapport presente les experiences qui furent faites sur le reacteur G1 et dont la description en detail fait l'objet des rapports suivants (670 'B a P'). Les principaux resultats sont fournis ici et commentes. On trouvera en outre les caracteristiques neutroniques du coeur actif de la pile, une description des principales installations et une mention des essais qui ont conduit au fonctionnement normal du reacteur en puissance. (auteur)

Experience gained in two years operation of G1; Experience acquise au cours de deux ans de fonctionnement du reacteur G1

Energy Technology Data Exchange (ETDEWEB)

de, Rouville; Pascal, [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Scalliet, [Electricite de France (EDF), 75 - Paris (France)

1958-07-01

Technical specifications in respect of the first plutonium generating graphite reactor, the G1 at Marcoule, were stated in a paper read at the first Geneva Conference in 1955. We shall not therefore deal further with the technical characteristics of G1 in the present note, but rather propose to define - in the characteristic fields we think will be of major interest to foreign specialists - the results obtained in two and a half years operation since G1 first became critical on january 7, 1956. (author)Fren. [French] Les caracteristiques techniques du premier reacteur plutonigene, au graphite, de Marcoule, G1, ont ete donnees dans une communication presentee a la premiere conference de Geneve, en 1955. Nous n'y reviendrons donc pas dans la presente note qui a pour objet de faire le point, dans quelques domaines caracteristiques, qui nous ont paru les plus susceptibles d'interesser les specialistes etrangers, des resultats obtenus et des experiences faites au cours des deux annees et demi de fonctionnement du reacteur qui ont suivi sa divergence, le 7 janvier 1956. (auteur)

“Letter to the King” By Jules Destry: from Separatism to Unitarism in Belgium

Directory of Open Access Journals (Sweden)

Ella V. Ermakova

2016-01-01

Full Text Available Contradictions between the regions of Belgium - Wallonia and Flanders - have a long history associated with uneven political, economic and cultural development of the territories, which in 1830 became parts of an independent state, the Kingdom of Belgium. The "Letter to the King", written by eminent Belgian politician and writer, socialist Jules Destree (1863 - 1936 gg., is one of the most interesting sources on the history of Belgium of this period, It became a kind of manifesto of balance between the ideas of separatism and unitarianism. This article includes excerpts from the "Letter to the King", which were given for the first time in the author's Russian translation and conducted historical criticism of the source. The study is based on a set of scientific methods and approaches, including the principle of scientific objectivity and systematic approach, used in historical research. The main methods are problematic and historical-comparative analysis, classification and comparison of political and historical concepts. An external source of criticism included information about the place and the time of the creation of document, the biography of the author studies; internal critic source recreates the idea of the letter and the background of historical events. Prominent Belgian politician and writer, socialist Jules Destree (1863 - 1936, highly appreciated the personal qualities of King Albert I, appealed to his experience and political vision, describing all the problems Walloons faced in their opposition to the Flemish. Destree in his letter opposed the unequal development of the regions of Belgium and the protectionist policies of the central government in respect to the detriment of Flanders Wallonia. He summarized and formulated the factors that, in his opinion, interfere with the full development of his country. Destree pays great attention to linguistic differences, which were at the heart of conflicts between Walloons and Flemings, and

Measurements of combined neutron and photon fluxes for the accurate characterization of the future Jules Horowitz irradiation reactor experimental conditions

International Nuclear Information System (INIS)

Fourmentel, D.

2013-01-01

A new Material Testing Reactor (MTR), the Jules Horowitz Reactor (JHR), is under construction at the CEA Cadarache (French Alternatives Energies and Atomic Energy Commission). From 2016 this new MTR will be a new facility for the nuclear research on materials and fuels. The quality of the experiments to be conducted in this reactor is largely linked to the good knowledge of the irradiation conditions. Since 2009, a new research program called IN-CORE1 'Instrumentation for Nuclear radiations and Calorimetry Online in Reactor' is under progress between CEA and Aix-Marseille University in the framework of a joint laboratory LIMMEX2. This program aims to improve knowledge of the neutron and photon fluxes in the RJH core, with one hand, an innovative instrumentation performing mapping of experimental locations, and on the other hand by coupling neutron flux, photon flux and thermal measurements. Neutron flux expected in the JHR core is about 10 15 n.cm -2 .s -1 and nuclear heating up to 20 W.g -1 for a nominal power of 100 MWth. One of the challenges is to identify sensors able to measure such fluxes in JHR experimental conditions and to determine how to analyse the signals delivered by these sensors with the most appropriate methods. The thesis is part of this ambitious program and aims to study the potential and the interest of the combination of radiation measurements in the prospect of a better assessment of the levels of neutron flux, gamma radiation and nuclear heating in the JHR experimental locations. The first step of IN-CORE program is to develop and operate an instrumented device called CARMEN-1 adapted to the mapping of the OSIRIS reactor, then to develop a second version called CARMEN-2 dedicated to experiments in the JHR core, especially for its start-up. This experiment was the opportunity to test all the radiation sensors which could meet the needs of JHR, including recently developed sensors. Reference neutron measurements are performed by activation

Progress report of the French program, and basic design of the Jules Horowitz reactor

International Nuclear Information System (INIS)

Ballagny, A.

1998-01-01

Since the SILOE reactor was shutdown on December 23, 1997, France has been entirely depending on the OSIRIS reactor to conduct the material and fuel irradiation programmes necessary to the evolution of its nuclear power plants and to prepare the future by analysing further reactor designs which might originate in other strategies, namely in the fuel cycle field. The Jules Horowitz reactor, which operation scheduled to start in 2006, will last 50 years, must cover all irradiation needs including, as far as possible, those related to fast breeder reactor studies, more particularly since the SUPERPHENIX reactor shutdown was announced. RJH reactor studies therefore focus on the increase of flux levels and the search for the limit performance of U 3 Si 2 based MTR fuels. (author)

Preliminary studies leading to a conceptual design of a 1000 MWe fast neutron reactor; Etudes preliminaires conduisant a un concept de reacteur a neutrons rapides de 1000 MWe

Energy Technology Data Exchange (ETDEWEB)

Vendryes, G.; Zaleski, C.P. [Association Euratom-CEA Cadarache (France). Centre d' Etudes Nucleaires

1964-07-01

This report presents the results of studies which seemed important to undertake in connexion with the development of fast neutron reactors. - It points out the advantage of high internal breeding ratios ({approx}1, 1) which are necessary in order to get a small change in time both in power distribution and reactivity (less: than 0.005 {delta}k/k in 18 months). - It shows how to achieve this goal, when simultaneously power distribution flattening is obtained. These results in a higher mean specific power (which is an economic gain) and therefore in a smaller doubling time (about 10 years). - It attempts to find criteria concerning the specific power that should be used in future reactor designs -It presents a conceptional design of a 1000 MWe fast neutron reactor, for the realisation of which no technological impossibility appears. - It shows that the dynamic behaviour seems satisfactory despite a positive total isothermal sodium coefficient. - It tries to predict the development of fast reactors within the future total nuclear program. It does not appear that fissile materials supply problems should in France slow down the development of fast neutron reactors, which will be essentially tied up to its economical ability to produce cheap electric power. (authors) [French] Ce rapport presente les etudes qu'il nous a paru important d'aborder dans le cadre du developpement des reacteurs a neutrons rapides. - Il met en evidence l'interet des taux de regeneration internes eleves ({approx}1, 1) pour obtenir une bonne evolution dans le temps de la distribution de puissance et de la reactivite (moins de 0,005 {delta}k/k pour 18 mois). - Il montre la possibilite d'y parvenir tout en applatissant la distribution des fissions, ce qui se traduit par une puissance specifique moyenne plus elevee (gain economique), et donc un temps de doublement plus faible de l'ordte de 10 ans - Il tente de definir un optimum de la puissance specifique valable pour les

Preliminary studies leading to a conceptual design of a 1000 MWe fast neutron reactor; Etudes preliminaires conduisant a un concept de reacteur a neutrons rapides de 1000 MWe

Energy Technology Data Exchange (ETDEWEB)

Vendryes, G; Zaleski, C P [Association Euratom-CEA Cadarache (France). Centre d' Etudes Nucleaires

1964-07-01

This report presents the results of studies which seemed important to undertake in connexion with the development of fast neutron reactors. - It points out the advantage of high internal breeding ratios ({approx}1, 1) which are necessary in order to get a small change in time both in power distribution and reactivity (less: than 0.005 {delta}k/k in 18 months). - It shows how to achieve this goal, when simultaneously power distribution flattening is obtained. These results in a higher mean specific power (which is an economic gain) and therefore in a smaller doubling time (about 10 years). - It attempts to find criteria concerning the specific power that should be used in future reactor designs -It presents a conceptional design of a 1000 MWe fast neutron reactor, for the realisation of which no technological impossibility appears. - It shows that the dynamic behaviour seems satisfactory despite a positive total isothermal sodium coefficient. - It tries to predict the development of fast reactors within the future total nuclear program. It does not appear that fissile materials supply problems should in France slow down the development of fast neutron reactors, which will be essentially tied up to its economical ability to produce cheap electric power. (authors) [French] Ce rapport presente les etudes qu'il nous a paru important d'aborder dans le cadre du developpement des reacteurs a neutrons rapides. - Il met en evidence l'interet des taux de regeneration internes eleves ({approx}1, 1) pour obtenir une bonne evolution dans le temps de la distribution de puissance et de la reactivite (moins de 0,005 {delta}k/k pour 18 mois). - Il montre la possibilite d'y parvenir tout en applatissant la distribution des fissions, ce qui se traduit par une puissance specifique moyenne plus elevee (gain economique), et donc un temps de doublement plus faible de l'ordte de 10 ans - Il tente de definir un optimum de la puissance specifique valable pour les projets de reacteurs futurs

Major accident analyses for experimental zero-power fast reactor assemblies; Analyse des accidents graves pouvant survenir dans les reacteurs experimentaux a neutrons rapides de puissance zero; Analiz krupnoj avarii dlya ehksperimental'ny kh reaktornykh ustanovok nulevoj moshchnosti na bystrykh nejtronakh; Analisis de los accidentes graves que pueden producirse en los reactores experimentales rapidos de potencia cero

Energy Technology Data Exchange (ETDEWEB)

Fischer, G.; Barts, E. W.; Kapil, S.; Tomabechi, K. [Argonne National Laboratory, Argonne, IL (United States)

1962-03-15

rapidement que les plaques en uranium appauvri, la possibilite d'un effet Doppler positif net est beaucoup plus grande dans le cas d'un reacteur experimental que dans celui du reacteur surgenerateur de puissance equivalent. Ce danger a ete etudie pour un certain nombre de montages possibles. Les calculs montrent que, pour un reacteur de puissance zero, le coefficient de Doppler n'atteint une valeur dangereuse que lorsqu'il s'agit de reacteurs ayant les spectres d'energie neutronique tres mous qui caracterisent les grands reacteurs surgenerateur de puissance a oxyde. (author) [Spanish] Los autores han estudiado la posibilidad, el mecanismo y las consecuencias que produciria la fusion u otros accidentes nucleares graves en el caso de los reactores experimentales rapidos de potencia cero del tipo ZPR-III de cuerpo dividido. Este estudio se completo con una evaluacion de la importancia del efecto Doppler en un gran numero de reactores de ese tipo. Los autores demuestran que es muy improbable que se produzca una fusion del reactor debido a que en la practica dificilmente pueden concurrir las circunstancias necesarias. Despues de discutir el mecanismo del fallo, presentan los resultados de calculos neutronicos e hidrodinamicos combinados relativos a dos conjuntos de potencia cero. Se ha escogido para este estudio un cuerpo de 1200 litros, porque corresponde a un reactor relativamente grande con un cuerpo de composicion corriente. Tambien, se estudio el caso de un cuerpo mas pequeno con una elevada fraccion de vacio, que puede presentar un peligro mayor. Se comprobo que el comportamiento en funcion del tiempo es muy distinto para cada sistema. Al producirse un accidente subito en un conjunto critico de potencia cero, los atomos de {sup 235}U, separados en forma de placas de uranio enriquecido, se calientan muy rapidamente, en tanto que el resto del cuerpo permanece relativamente frio, de manera que se formaran vapores de {sup 235}U cuya presion provocara la ruptura del sistema. Los

Combined analysis of neutron and photon flux measurements for the Jules Horowitz reactor core mapping

Energy Technology Data Exchange (ETDEWEB)

Fourmentel, D.; Villard, J. F.; Lyoussi, A. [DEN Reactor Studies Dept., French Nuclear Energy and Alternative Energies Commission, CEA Cadarache, 13108 Saint Paul-Lez-Durance (France); Reynard-Carette, C. [Laboratoire Chimie Provence LCP UMR 6264, Univ. of Provence, Centre St. Jerome, 13397 Marseille Cedex 20 (France); Bignan, G.; Chauvin, J. P.; Gonnier, C.; Guimbal, P.; Malo, J. Y. [DEN Reactor Studies Dept., French Nuclear Energy and Alternative Energies Commission, CEA Cadarache, 13108 Saint Paul-Lez-Durance (France); Carette, M.; Janulyte, A.; Merroun, O.; Brun, J.; Zerega, Y.; Andre, J. [Laboratoire Chimie Provence LCP UMR 6264, Univ. of Provence, Centre St. Jerome, 13397 Marseille Cedex 20 (France)

2011-07-01

We study the combined analysis of nuclear measurements to improve the knowledge of the irradiation conditions in the experimental locations of the future Jules Horowitz Reactor (JHR). The goal of the present work is to measure more accurately neutron flux, photon flux and nuclear heating in the reactor. In a Material Testing Reactor (MTR), nuclear heating is a crucial parameter to design the experimental devices to be irradiated in harsh nuclear conditions. This parameter drives the temperature of the devices and of the samples. The numerical codes can predict this parameter but in-situ measurements are necessary to reach the expected accuracy. For this reason, one objective of the IN-CORE program [1] is to study the combined measurements of neutron and photon flux and their cross advanced interpretation. It should be reminded that both neutron and photon sensors are not totally selective as their signals are due to neutron and photon interactions. We intend to measure the neutron flux by three different kinds of sensors (Uranium Fission chamber, Plutonium Fission chamber and Self Powered Neutron Detector), the photon flux by two different sensors (Ionization chamber and Self Powered Gamma Detector) and the nuclear heating by two different ones (Differential calorimeter and Gamma Thermometer). For the same parameter, we expect that the use of different kinds of sensors will allow a better estimation of the aimed parameter by mixing different spectrum responses and different neutron and gamma contributions. An experimental test called CARMEN-1 is scheduled in OSIRIS reactor (CEA Saclay - France) at the end of 2011, with the goal to map irradiation locations in the reactor reflector to get a first validation of the analysis model. This article focuses on the sensor selection for CARMEN-1 experiment and to the way to link neutron and photon flux measurements in view to reduce their uncertainties but also to better assess the neutron and photon contributions to nuclear

Combined analysis of neutron and photon flux measurements for the Jules Horowitz reactor core mapping

International Nuclear Information System (INIS)

Fourmentel, D.; Villard, J. F.; Lyoussi, A.; Reynard-Carette, C.; Bignan, G.; Chauvin, J. P.; Gonnier, C.; Guimbal, P.; Malo, J. Y.; Carette, M.; Janulyte, A.; Merroun, O.; Brun, J.; Zerega, Y.; Andre, J.

2011-01-01

We study the combined analysis of nuclear measurements to improve the knowledge of the irradiation conditions in the experimental locations of the future Jules Horowitz Reactor (JHR). The goal of the present work is to measure more accurately neutron flux, photon flux and nuclear heating in the reactor. In a Material Testing Reactor (MTR), nuclear heating is a crucial parameter to design the experimental devices to be irradiated in harsh nuclear conditions. This parameter drives the temperature of the devices and of the samples. The numerical codes can predict this parameter but in-situ measurements are necessary to reach the expected accuracy. For this reason, one objective of the IN-CORE program [1] is to study the combined measurements of neutron and photon flux and their cross advanced interpretation. It should be reminded that both neutron and photon sensors are not totally selective as their signals are due to neutron and photon interactions. We intend to measure the neutron flux by three different kinds of sensors (Uranium Fission chamber, Plutonium Fission chamber and Self Powered Neutron Detector), the photon flux by two different sensors (Ionization chamber and Self Powered Gamma Detector) and the nuclear heating by two different ones (Differential calorimeter and Gamma Thermometer). For the same parameter, we expect that the use of different kinds of sensors will allow a better estimation of the aimed parameter by mixing different spectrum responses and different neutron and gamma contributions. An experimental test called CARMEN-1 is scheduled in OSIRIS reactor (CEA Saclay - France) at the end of 2011, with the goal to map irradiation locations in the reactor reflector to get a first validation of the analysis model. This article focuses on the sensor selection for CARMEN-1 experiment and to the way to link neutron and photon flux measurements in view to reduce their uncertainties but also to better assess the neutron and photon contributions to nuclear

Preliminary handling studies in large size fast piles; Etudes preliminaires de manutention dans les reacteurs a neutrons rapides de grande taille

Energy Technology Data Exchange (ETDEWEB)

Leduc, J.; Marmonier, P. [Association Euratom-CEA Cadarache (France). Centre d' Etudes Nucleaires

1964-07-01

This report examines the various fuel handling systems which presently seem feasible for a fast power reactor. It tries to point out the advantages and / or the the disadvantages and the fabrication problems for each solution involved and makes, a tentative to evaluate the time required for a fuel loading and / or unloading operation. One has investigated the influence of the maximum allowable irradiation, the number of of shut-downs, the power distribution shape within the core on the storage capacity needed, the load factor expected and the average irradiation obtained. (authors) [French] On a examine dans ce rapport les differents systemes de manutention, qui semblent actuellement realisables pour un reacteur a neutrons rapides de puissance, en essayant de faire ressortir les avantages, les inconvenients et les difficultes de realisation de chaque systeme, et de chiffer les temps de manutention auxquels ils conduisent. On a aussi regarde l'influence des variations du taux d'irradiation maximal,de la cadence des arrets ou de la forme du flux dans le coeur du reacteur, sur la capacite du stockage, le taux de disponibilite et le taux d'irradiation moyen. (auteurs)

Preliminary handling studies in large size fast piles; Etudes preliminaires de manutention dans les reacteurs a neutrons rapides de grande taille

Energy Technology Data Exchange (ETDEWEB)

Leduc, J; Marmonier, P [Association Euratom-CEA Cadarache (France). Centre d' Etudes Nucleaires

1964-07-01

This report examines the various fuel handling systems which presently seem feasible for a fast power reactor. It tries to point out the advantages and / or the the disadvantages and the fabrication problems for each solution involved and makes, a tentative to evaluate the time required for a fuel loading and / or unloading operation. One has investigated the influence of the maximum allowable irradiation, the number of of shut-downs, the power distribution shape within the core on the storage capacity needed, the load factor expected and the average irradiation obtained. (authors) [French] On a examine dans ce rapport les differents systemes de manutention, qui semblent actuellement realisables pour un reacteur a neutrons rapides de puissance, en essayant de faire ressortir les avantages, les inconvenients et les difficultes de realisation de chaque systeme, et de chiffer les temps de manutention auxquels ils conduisent. On a aussi regarde l'influence des variations du taux d'irradiation maximal,de la cadence des arrets ou de la forme du flux dans le coeur du reacteur, sur la capacite du stockage, le taux de disponibilite et le taux d'irradiation moyen. (auteurs)

Presence of Tritium in the Cooling Circuits of the Reactors G2 and G3; Presence de tritium dans les circuits de refroidissement des reacteurs G2 et G3

Energy Technology Data Exchange (ETDEWEB)

Estournel, R [Commissariat a l' Energie Atomique. Centre de Production de Plutonium de Marcoule, 30 - Chusclan (France)

1962-07-01

In a reactor of the G 2-G 3 type, tritium can be formed by the neutronic bombardment of many elements present in the core. Tritium was found to be present in the cooling circuits of the reactors G 2 and G 3 in the water coming from the regeneration of the CO{sub 2} dehydrating columns. (author) [French] Dans un reacteur du type G 2 - G 3, le tritium peut etre forme par le bombardement. neutronique de nombreux elements existant dans le c r. La presence de tritium dans les circuits de refroidissement des reacteurs G 2 - G 3 a ete mis en evidence dans l'eau provenant de la regeneration des colonnes de deshydratation du CO{sub 2}. (auteur)

[Present conceptions of the C.E.A. concerning] the development of fast neutron reactors in France; [Les conceptions actuelles du C.E.A. concernant] la filiere des reacteurs a neutrons rapides en France

Energy Technology Data Exchange (ETDEWEB)

Vendryes, G; Gaussens, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Pasquer, R [Electricite de France (EDF), 75 - Paris (France)

1964-07-01

. (authors) [French] 1 - Situation des reacteurs a neutrons rapides dans le programme d'energie nucleaire francais. En developpant un programme base sur l'uranium naturel, la France se trouvera dotee d'un stock important de plutonium riche on isotopes superieurs. L'existence de ce plutonium et de l'uranium appauvri provenant des memes reacteurs a pour consequence logique leur emploi dans des reacteurs a neutrons rapides. Justifiee par cet interet a court terme, la mise au point de reacteurs a neutrons rapides repond par ailleurs a une necessite pour l'avenir. 2 - Enonce des caracteristiques d'une centrale a neutrons rapides de 1000 MW el. Nous indiquons les caracteristiques d'une future centrale a neutrons rapides chargee au plutonium et refroidie au sodium. Si incertaines qu'elles soient, elles constituent un guide necessaire a l'orientation de nos travaux. 3 - Etudes effectuees a ce jour: Nous donnons un apercu des etudes souvent tres preliminaires qui ont permis de retenir les caracteristiques citees plus haut. Les principaux domaines techniques abordes sont les suivants: - Neutronique (masses critiques, taux de regeneration, enrichissements, aplatissement du flux de neutrons, coefficients de reactivite, evolution de la reactivite en fonction de l'irradiation), - Dynamique, controle et surete, - Combustible, - Technologie (conception du bloc-pile, des circuits de sodium, des dispositifs pour la manutention des assemblages). Ces etudes techniques se completent de considerations economiques. Le choix de caracteristiques optimales est lie a l'existence de programmes de production d'electricite et, dans ces programmes, a celle des reacteurs a neutrons thermiques producteurs de plutonium. On montre comment il y a lieu de tenir compte de l'existence du plutonium dans ce contexte, et quels sont les mecanismes qui rattachent l'economie de ce plutonium au choix des parametres essentiels des reacteurs surgenerateurs. 4 - Reacteur prototype: On justifie l'interet d'une etape

Jules Verne's Captain Nemo and French Revolutionary Gustave Flourens:A Hidden Character Model?

Directory of Open Access Journals (Sweden)

Leonidas Kallivretakis

2005-01-01

Full Text Available This article treats the recent assumption made by Vernian specialist William Butcher that Jules Verne's most famous character, Captain Nemo, is based on the French revolutionary intellectual Gustave Flourens (1838-1871, son of the eminent physiologist J. P. M. Flourens. Gustave Flourens fought in the Cretan insurrection of 1866-1868, later participated in the republican opposition against Napoleon III's imperial regime, eventually became a friend of Karl Marx and was finally killed as a general of the Paris Commune. By comparing step-by-step Verne's inspiration and writing procedures with Flourens' unfolding activities and fame, it is concluded that there is little basis for such an assumption. The article includes also a brief account of the Cretan question in the nineteenth century and of the deep discord between Marx's and Flourens' respective analyses of the Eastern Question.

Burst slug detection system in french power reactors (1961); La detection des ruptures de gaines dans les reacteurs de puissance francais (1961)

Energy Technology Data Exchange (ETDEWEB)

Megy, J; Roguin, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

Gas samples are taken from the channels of the reactor and the short lived fission products are electrostatically collected to be analysed by a phosphor and photomultiplier system. The electrostatic collection and rotating electrode detector is described and its main uses exposed. Experience has shown the interest of measuring the evolution of fission products activities and not their absolute value only. In this way, data processing equipment have been designed and adapted to the detection apparatus. The system developed and realized for the G-l - G-2 - G-3 - EDF-1 - EDF-2 reactors are compared. (authors) [French] Un prelevement de gaz est effectue dans les canaux du reacteur et les produits de fission a vie courte sont collectes electrostatiquement pour etre analyses par un ensemble scintillateur-photomultiplicateur. Le detecteur a collection electrostatique et electrode tournante est decrit et ses applications principales sont exposees. L'experience a montre l'interet de mesurer l'evolution des activites en produits de fission et non seulement leur valeur absolue. D'ou le developpement d'ensembles de traitement des informations associes aux chaines de detection. Comparaison des realisations sur les reacteurs G-l - G-2 - G-3 - EDF-1 et EDF-2. (auteurs)

[Project for] a high-flux extracted neutron beam reactor [for physicists]; Un [projet de] reacteur a haut flux et faisceaux sortis [pour physiciens

Energy Technology Data Exchange (ETDEWEB)

Ageron, P [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-07-01

tubes and the experimental equipment which can support doses much higher than the ones which are biologically permissible. The final part of the communication describes the studies carried out on the realization of a liquid hydrogen cold sink, one of the most important experimental devices envisaged. (authors) [French] Les besoins francais en canaux pour sortie de neutrons de differentes energies sont brievement indiques. L'interet bien connu des neutrons froids (plus de 4 Angstroem) est souligne. Les grandes lignes d'un reacteur permettant de satisfaire les physiciens sont esquissees. Ce sont les suivantes: 1 - Flux dans l'eau lourde du reflecteur de l'ordre de 7. 10{sup 14} thermiques. 2 - Souplesse d'emploi maximum obtenue par: - separation physique du coeur et du reflecteur, - independance des experiences entre elles, - possibilite de modification, sans interruption notable du fonctionnement de la pile, des experiences physiques jusqu'a - et y compris - la nature du reflecteur utilise, - reduction au minimum des protections fixes; emploi largement generalise des protections liquides (eau) et fluidisees (sables). 3 - Continuite technologique aussi grande que possible avec les reacteurs de recherche francais existant ou en construction (SILOE, PEGASE, OSIRIS). 4 - Surete de fonctionnement recherche par la simplicite de conception. 5 - Minimisation des frais de construction. La reduction des frais d'exploitation est recherchee plutot indirectement par la simplicite des solutions et la reduction du personnel d'exploitation, que directement par la minimisation des consommations d'elements combustibles et d'energie. La solution preconisee peut etre decrite comme un reacteur de type piscine a coeur clos, non pressurise, tres sous modere par l'eau legere de refroidissement. Entourant le reacteur, se trouvent un certain nombre de 'canaux boucles' comprenant chacun: - une portion du reflecteur (eau lourde dans l'exemple decrit), - une portion de canal d'extraction de neutrons

William Butcher, Jules Verne inédit : les manuscrits déchiffrés, Lyon, ENS Éditions, coll. « Métamorphoses du livre », 2015, 490 p.

OpenAIRE

Scheinhardt, Philippe

2016-01-01

C’est un travail de recherche conséquent sur le fonds manuscrit de Jules Verne que propose William Butcher. Ce chercheur anglophone s’intéresse depuis longtemps à la diffusion de cette œuvre qu’il a éditée et traduite. Le goût de la recherche, de la découverte s’affiche dans le titre Jules Verne inédit, avec une désignation de l’objet d’étude, qui ne concerne pas tant le manuscrit que son exégèse, puisqu’on nous invite avec le sous-titre Les manuscrits déchiffrés à l’interprétation des traces...

New developments in resonant mixture self-shielding treatment with Apollo code and application to Jules Horowitz reactor core calculation

International Nuclear Information System (INIS)

Coste-Delclaux, M.; Aggery, A.; Huot, N.

2005-01-01

APOLLO2 is a modular multigroup transport code developed by Cea in Saclay. Until last year, the self-shielding module could only treat one resonant isotope mixed with moderator isotopes. Consequently, the resonant mixture self-shielding treatment was an iterative one. Each resonant isotope of the mixture was treated separately, the other resonant isotopes of the mixture being then considered as moderator isotopes, that is to say non-resonant isotopes. This treatment could be iterated. Last year, we have developed a new method that consists in treating the resonant mixture as a unique entity. A main feature of APOLLO2 self-shielding module is that some implemented models are very general and therefore very powerful and versatile. We can give, as examples, the use of probability tables in order to describe the microscopic cross-section fluctuations or the TR slowing-down model that can deal with any resonance shape. The self-shielding treatment of a resonant mixture was developed essentially thanks to these two models. The calculations of a simplified Jules Horowitz reactor using a Monte-Carlo code (TRIPOLI4) as a reference and APOLLO2 in its standard and improved versions, show that, as far as the effective multiplication factor is concerned, the mixture treatment does not bring an improvement, because the new treatment suppresses compensation between the reaction rate discrepancies. The discrepancy of 300 pcm that appears with the reference calculation is in accordance with the technical specifications of the Jules Horowitz reactor

Integral physics data for fast-reactor design; Donnees de physique integrale intervenant dans les etudes de reacteur a neutrons rapides; Integral'nye fizicheskie dannye dlya raschetov reaktorov na bystrykh nejtronakh; Datos fisicos integrales para el diseno de reactores rapidos

Energy Technology Data Exchange (ETDEWEB)

Loewenstein, W B; Meneghetti, D [Argonne National Laboratory, Argonne, IL (United States)

1962-03-15

Integral physics data for fast-reactor design. The recent compilation of the section on fast-reactor physics for the forthcoming second edition of 'Reactor Physics Constants' has necessitated a survey of the available experimental integral data. The choice of fast-reactor-physics integral data to be included in the compilation was based upon two criteria besides availability: (a) the data arise from relatively simple systems which lend themselves to simple theoretical analyses; and (b) complicated systems representing prototypes or mock-ups having general interest in terms of fast-power reactors. The first criterion was decided upon so as to list integral data for those systems of most general utility for the verification of cross-section parameters and calculational procedures. The second criterion is based upon presentation of current data on actual fast power breeder reactor systems. These are too complicated for simple theoretical analysis. They demonstrate the complexity of the actual reactor versus the more idealized and easily analysed critical experiment. Integral physics data for reactor design refer to measurements on reactor systems, critical or otherwise, of the various reactor physics quantities of practical and/or theoretical importance. These characterize and lead to an understanding of the system. The measurements are represented by critical mass, core shape factor, detector ratios, neutron spectra, material replacement experiments, reflector savings, neutron lifetime, Rossi-{alpha}, and similar quantities. These data are reviewed and the range of applicability is described. Limitations of experimental and analytical results are shown to exist in certain spectral and criticality analyses. Experimental and analytical investigations are suggested for future work. These will tend to narrow the gap between theory and experiment on 'known' systems. They also include investigations to 'firm up' the physics of large conceptual, fast power-breeder reactor

The Jules Horowitz Reactor project, a driver for revival of the research reactor community

International Nuclear Information System (INIS)

Pere, P.; Cavailler, C.; Pascal, C.

2010-01-01

The first concrete of the nuclear island for the Jules Horowitz Reactor (JHR) was poured at the end of July 2009 and construction is ongoing. The JHR is the largest new platform for irradiation experiments supporting Generation II and III reactors, Generation IV technologies, and radioisotope production. This facility, composed of a unique grouping of workshops, hot cells and hot laboratories together with a first-rate MTR research reactor, will ensure that the process, from preparations for irradiation experiments through post-irradiation non-destructive examination, is completed expediently, efficiently and, of course, safely. In addition to the performance requirements to be met in terms of neutron fluxes on the samples (5x10 14 n.cm -2 /sec -1 E>1 MeV in core and 3,6x10 14 n.cm -2 /sec -1 E<0.625 eV in the reflector) and the JHR's considerable irradiation capabilities (more than 20 experiments and one-tenth of irradiation area for simultaneous radioisotope production), the JHR is the first MTR to be built since the end of the 1960s, making this an especially challenging project. The presentation will provide an overview of the reactor, hot cells and laboratories and an outline of the key milestones in the project schedule, including initial criticality in early 2014 and radioisotope production in 2015. This will be followed by a description of the project organization set up by the CEA as owner and future operator and AREVA TA as prime contractor and supplier of critical systems, and a discussion of project challenges, especially those dealing with the following items:accommodation of a broad experimental domain; involvement by international partners making in-kind contributions to the project; ? development of components critical to safety and performance; the revival of engineering of research reactors and experimental devices involving France's historical players in the field of research reactors, and; tools to carry out the project, including computer codes

Development of the electron beam welding of the aluminium alloy 6061-T6 for the Jules Horowitz reactor

International Nuclear Information System (INIS)

Leblanc, Y.

2013-01-01

The aluminium alloy 6061-T6 has been selected for the construction of the Jules Horowitz's reactor vessel. This reactor vessel is pressurized and will be made through butt welding of ∼ 2 cm thick aluminium slabs. The electron beam welding process has been tested and qualified. It appears that this welding process allows: -) welding without pre-heating, -) vacuum welding, -) welding of 100% of the thickness in one passage, -) very low deforming welding process, -) very low density and very low volume of blow holes, -) weak ZAT (Thermal Affected Zones), and -) high reproducibility that permits automation. (A.C.)

THE WITCH: A VETO-EUROPEAN MEMORY THROUGH HISTORIAN JULES MICHELET

Directory of Open Access Journals (Sweden)

Mónica Elivier Sánchez-González

2017-01-01

Full Text Available Reflections about the witch are presented as a challenge that goes through different dimensions. The first is the inaccessibility to a figure that modern societies closed down. However, the Witch encouraged the everyday life of pre-modern societies and peripherical spaces to the central modernity, but the witch still in these spaces. This paradox framing the following discussion. How could pose a witch access to medieval times, without transgressing its rapporteur and impose conditions on it current possibility? The proposal here arises is to work the text of nineteenth-century French historian Jules Michelet as a semantic, where resources of a pre- modern memory, which, to the extent that defines the witch, defines the society in which it is played are played. This paper is not concerned if the witch was real or not, whether or not it was true. Here he retraces his attributes as practices realized veteroeurpea otherness of society, in this case, the exclusion rested with women, the devil, evil. This work is not conclusive, its function is to present a way of looking at the witch, wondering from a specific theoretical corpus: the analysis of memory from systems theory Niklas Luhmann can be formulated.

G2 - G3 inventive properties, the first french nuclear plants; Caracteristiques generales et aspects originaux des reacteurs G2 et G3

Energy Technology Data Exchange (ETDEWEB)

Pascal,; Horowitz,; Bussac,; Joatton,; de Meux, De Lagge; Martin, [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

This paper points out the inventive properties of the frenchctors G2 and G3. These are dual purpose reactors, i.e. designed for the production of both plutonium and energy (30 electrical MW); in this respect, they can be considered as the start point of the french electrical energy produced from nuclear fuel. The following points are specially discussed in this paper: the choice of the prestressed concrete pressure vessel, the horizontal arrangement of the channels, the interest of neutron flux flattening, the advantages of the charging and discharging device working during pile operation. (author)Fren. [French] Les caracteres originaux des reacteurs fran is G2 et G3 sont decrits dans ce rapport. Ce sont des reacteurs a double fin, plutonigenes et aussi producteurs d'energie (30 MW electriques); ils constituent a ce titre le point de depart de la production fran ise d'electricite d'origine nucleaire. Sont discutes, en particulier, dans ce rapport: le choix du caisson en beton precontraint pour tenir la pression, la disposition horizontale des canaux, l'interet de l'aplatissement du flux neutronique, les avantages de l'appareil permettant le chargement et le dechargement du combustible sans arreter la pile. (auteur)

Radiation Transport Calculation of the UGXR Collimators for the Jules Horowitz Reactor (JHR)

Science.gov (United States)

Chento, Yelko; Hueso, César; Zamora, Imanol; Fabbri, Marco; Fuente, Cristina De La; Larringan, Asier

2017-09-01

Jules Horowitz Reactor (JHR), a major infrastructure of European interest in the fission domain, will be built and operated in the framework of an international cooperation, including the development and qualification of materials and nuclear fuel used in nuclear industry. For this purpose UGXR Collimators, two multi slit gamma and X-ray collimation mechatronic systems, will be installed at the JHR pool and at the Irradiated Components Storage pool. Expected amounts of radiation produced by the spent fuel and X-ray accelerator implies diverse aspects need to be verified to ensure adequate radiological zoning and personnel radiation protection. A computational methodology was devised to validate the Collimators design by means of coupling different engineering codes. In summary, several assessments were performed by means of MCNP5v1.60 to fulfil all the radiological requirements in Nominal scenario (TEDE < 25µSv/h) and in Maintenance scenario (TEDE < 2mSv/h) among others, detailing the methodology, hypotheses and assumptions employed.

Containment for Heavy-Water Gas-Cooled Reactors; Le Confinement des Reacteurs a Eau Lourde Refroidis par Gaz

Energy Technology Data Exchange (ETDEWEB)

Verstraete, P.; Lehmann, D.; Lafitte, R. [Bonard et Gardel, Ingenieurs-Conseils, Lausanne (Switzerland)

1967-09-15

The safety principles applicable to heavy-water, gas-cooled reactors are outlined, with a view to establishing containment specifications adapted to the sites available in Switzerland for the construction of nuclear plants. These specifications are derived from dose rates considered acceptable, in the event of a serious reactor accident, for persons living near the plant, and are based on-meteorological and demographic conditions representative of the majority of the country's sites. The authors consider various designs for the containment shell, taking into account the conditions which would exist in the shell after the maximum credible accident. The following types of shell are studied: pre-stressed concrete; pre-stressed concrete with steel dome; pre-stressed concrete with inner, leakproof steel lining; steel with concrete side shield to protect against radiation; double shell. The degree of leak proofing of the shells studied is regarded as a feature of the particular design and not as a fixed constructional specification. The authors assess the leak proofing properties of each type of shell and establish building costs for each of them on the basis of precise plans, with the collaboration of various specialized firms. They estimate the effectiveness of the various shells from a safety standpoint, in relation to different emergency procedures, in particular release into the atmosphere through appropriate filters and decontamination of the air within the shell by recycling through batteries of filters. The paper contains a very detailed comparison of about 10 cases corresponding to various combinations of design and emergency procedure; the comparison was made using a computer programme specially established for the purpose. The results are compared with those for a reactor of the same type and power, but assembled together with the heat exchangers in a pre-stressed concrete shell. (author) [French] Les principes de securite des reacteurs a eau lourde refroidis

Contribution to the study on the flow rate adjustment for gas cooled power reactors (1964); Contributiom a l'etude de reglage du debit pour les reacteurs industriels refroidis par gaz (1964)

Energy Technology Data Exchange (ETDEWEB)

Milliot, B [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1961-06-15

1. This original study firstly defines the problem of the adjustment of the coolant flow rate in a reactor channel as a function of the corresponding heat transfer equations and of the local and temporal neutron flux. The necessity of such an adjustment is pointed out and the modifying parameters are studied. An adjustment study using the envelope of the possible flux curves is developed. A short study on the technology and the economical advantage of this adjustment is presented. Some measurements, made on G-1 and G-2, show the precision one can obtain from adjustment apparatus itself as well as from the complete reactor adjustment system. 2. Evolution of nuclear properties of fuel in an heterogeneous thermal reactor. In the first port of this paper, the phenomena of fuel evolution have been mainly pointed out. Now a bibliographical study more qualitatively than quantitatively has been done. This survey specifies the present theories and relates to a real effective cross section and also yields to the bases of such a nuclear calculation. (author) [French] 1. Cette etude originale definit d'abord le probleme du reglage du debit de refrigerant dans un canal de reacteur en fonction de la formulation du calcul des performances thermodynamiques de ce canal et des variations du flux neutronique dans l'espace et le temps. La necessite du reglage est ensuite mise en evidence et les parametres le modifiant sont etudies. Une methode de reglage, basee sur l'emploi d 'une courbe enveloppe des courbes de flux possibles, est donnee. Une breve etude de la technologie et des incidences economiques du reglage est presentee. Des mesures effectuees sur les reacteurs G-1 et G-2 montrent la precision que l'on peut attendre des dispositifs de reglage comme du reglage d'ensemble du reacteur lui-meme. 2. Evolution des proprietes nucleaires du combustible dans un reacteur heterogene a neutrons thermiques. Les phenomenes d'evolution du combustible tiennent une place importante dans l

Measurement of the thermal utilisation factor of the reactor G1; Mesure du facteur d'utilisation thermique du reacteur G1

Energy Technology Data Exchange (ETDEWEB)

Roullier, F; Schmitt, A P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-07-01

The thermal utilisation factor of the lattice of the reactor G1 has been measured by applying the autoradiographic technique to thin detectors irradiated in the cell. The experimental apparatus is described, and the results compared with those obtained by calculation based on various formulae. The results of the study of the thermal flux distribution in a cell containing a thorium rod of the same diameter as the uranium rods in the lattice are also given. The precision of the measurements is discussed. Value found: f diameter 26 = 0.8949 {+-} 0,005. (author) [French] Le facteur d'utilisation thermique du reseau du reacteur G1 a ete mesure en appliquant la technique de l'autoradiographie a des detecteurs minces irradies dans la cellule. Les dispositifs experimentaux sont decrits et les resultats sont compares a ceux obtenus par le calcul a partir de diverses formules. Les resultats de l'etude de la distribution du flux thermique dans une cellule contenant une barre de thorium de meme diametre que les barres d'uranium du reseau sont egalement indiques. La precision des mesures est discutee. Valeur trouvee: f diametre 26 = 0,8949 {+-} 0,005. (author)

The Jules Horowitz reactor project, a driver for revival of the research reactor community

Energy Technology Data Exchange (ETDEWEB)

Pere, P.; Cavailler, C.; Pascal, C. [AREVA TA, CEA Cadarache - Etablissement d' AREVA TA - Chantier RJH - MOE - BV2 - BP no. 9 - 13115 Saint Paul lez Durance (France); CS 50497 - 1100, rue JR Gauthier de la Lauziere, 13593 Aix en Provence cedex 3 (France)

2010-07-01

The first concrete of the nuclear island for the Jules Horowitz Reactor (JHR) was poured at the end of July 2009 and construction is ongoing. The JHR is the largest new platform for irradiation experiments supporting Generation II and III reactors, Generation IV technologies, and radioisotope production. This facility, composed of a unique grouping of workshops, hot cells and hot laboratories together with a first -rate MTR research reactor, will ensure that the process, from preparations for irradiation experiments through post-irradiation non-destructive examination, is completed expediently, efficiently and, of course, safely. In addition to the performance requirements to be met in terms of neutron fluxes on the samples (5x10{sup 14} n.cm{sup -2}/sec{sup -1} E> 1 MeV in core and 3,6x10{sup 14} n.cm{sup -2}/sec{sup -1} E<0.625 eV in the reflector) and the JHR's considerable irradiation capabilities (more than 20 experiments and one-tenth of irradiation area for simultaneous radioisotope production), the JHR is the first MTR to be built since the end of the 1960's, making this an especially challenging project. The presentation will provide an overview of the reactor, hot cells and laboratories and an outline of the key milestones in the project schedule, including initial criticality in early 2014 and radioisotope production in 2015. This will be followed by a description of the project organization set up by the CEA as owner and future operator and AREVA TA as prime contractor and supplier of critical systems, and a discussion of project challenges, especially those dealing with the following items: - accommodation of a broad experimental domain, - involvement by international partners making in-kind contributions to the project, - development of components critical to safety and performance, - the revival of engineering of research reactors and experimental devices involving France's historical players in the field of research reactors, and

Problems related with the power regulation of reactors by physico-chemical methods, and the behaviour of water and heavy water in nuclear reactors; Comportement de l'eau et de l'eau lourde dans les reacteurs nucleaires et problemes de la regulation de puissance par voie physico-chimique

Energy Technology Data Exchange (ETDEWEB)

Dolle, L; Conan, D; Dirian, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

Experience of the CEA heavy water reactors and a systematic study of the radiolytic decomposition of water in the core of swimming-pool reactors are described. Setting up of reactivity control by physico-chemical methods. Reactivity control by homogeneous poisoning of the reactor A comparison of the evolution of xenon poisoning with the residual anti reactivity of the poison in solution during its nuclear consumption establishes the programme which must govern the variation in its concentration if the exact compensation is to be produced The behaviour of the poison towards the reactor materials under the particular operational conditions must be taken into account. Radiolytic decomposition of water in the reactors in the presence of soluble poisons: A study of the effect of certain chemically inert salts, present in small concentrations in the water, on its radiolytic decomposition rate, has led to some new results which are discussed. The choice of a soluble poison is justified on the basis of the above results. Reactivity control by the use of a gaseous absorbent The use of a gas control rod circuit for compensation purposes, in place of solid control rods is described. The use of soluble poisons in the moderator to compensate the xenon effect, and of a gaseous absorbent in a circuit known as a gas control rod form original aspects of the reactivity control in the reactor EL 4. (authors) [French] L'observation du comportement de l'eau et de l'eau lourde dans les reacteurs en exploitation, contribue au fonctionnement sur de ceux-ci et oriente certaines etudes relatives aux techniques de controle de la reactivite par mise en oeuvre de poisons solubles. L'utilisation de poisons nucleaires dissous dans l'eau du reacteur entraine une pollution chimique de celle-ci. Les conditions d'emploi permettant d'eviter les effets indesirables de cette pollution sont etudiees. Les problemes analytiques - bien qu'importants - ne sont pas abordes dans le cadre de la communication

Molten salts in nuclear reactors; Les sels fondus dans les reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Dirian, J; Saint-James, [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

Collection of references dealing with the physicochemical studies of fused salts, in particular the alkali and alkali earth halides. Numerous binary, ternary and quaternary systems of these halides with those of uranium and thorium are examined, and the physical properties, density, viscosity, vapour pressure etc... going from the halides to the mixtures are also considered. References relating to the corrosion of materials by these salts are included and the treatment of the salts with a view to recuperation after irradiation in a nuclear reactor is discussed. (author) [French] Bibliographie regroupant l'etude physico-chimique des sels fondus, en particulier des halogenures alcalins et alcalino-terreux. On etudie de nombreux systemes binaires, ternaires et quaternaires de ces halogenures avec des halogenures d'uranium, et de thorium. On etudie egalement les proprietes physiques des halogenures ou des melanges d'halogenures (densite, viscosite, tension de vapeur, etc...). On donne egalement des references quant a la corrosion des materiaux par ces sels, et le traitement de ceux-ci en vue de recuperation, apres irradiation dans un reacteur nucleaire. (auteur)

Testing of a reactimeter for a light water reactor in the range + 500 to - 5000 pcm; Essai d'un reactimetre pour reacteur a eau legere dans la gamme + 500, - 5000 pcm

Energy Technology Data Exchange (ETDEWEB)

Chauvet, G [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-07-01

This apparatus is designed to measure instantaneously the positive or negative reactivity of a uranium reactor moderated by light water, on condition that the point of departure is the critical state of the reactor, or an already known sub-critical state. Slight modifications only are required to adapt it to another type of reactor. It is an analogue computer which simply inverses the transfer function of the reactor; it is not therefore a model reactor of which the output voltage is connected by a servo-mechanism to the power of the reactor to give the reactivity; the principle of the calculation of the reactivity does not depend on a servomechanism. One of its disadvantages is that it cannot operate outside a power variation range of 2.5 decades. However the measurement of a negative reactivity value between 0 and 3000 pcm is immediate. It measures the reactivity without deducting it from the period; it therefore gives the reactivity very precisely both for divergence and convergence even through in this latter case the period does not in fact exist. The equipment makes it possible to calibrate very rapidly the control rods of a reactor (the rod-drop method), to measure the reactivity of an experiment in the core, and to measure certain temperature effects. It is also possible by introducing a control into the core at a measured rate, to deduce directly its efficiency curve. (author) [French] Cet appareil est destine a mesurer instantanement la reactivite positive ou negative d'un reacteur a uranium modere a l'eau legere, a condition de partir de l'etat critique du reacteur, ou eventuellement d'un etat sous-critique deja connu. De legeres modifications permettent de l'adapter a un autre type de moderateur. C'est un calculateur analogique, qui inverse purement et simplement la fonction de transfert du reacteur; ce n'est donc pas un simulateur de pile dont la tension de sortie est asservie a la puissance du reacteur pour elaborer la reactivite; le principe du

« Jules Crevaux, l’explorateur aux pieds nus ». Un mythe géographique amazonien

Directory of Open Access Journals (Sweden)

Emmanuel Lézy

2008-12-01

Full Text Available Le rejet par Claude Lévi Strauss du personnage de l’explorateur organise son exploration de l’Amazonie autant que sa quête de l’Indien. Le scientifique, entre les deux, est situé dans une position équidistante entre la clairvoyance et l’aveuglement. Le « voyage » frappé de la même opprobre est présenté, de façon similaire comme un travestissement du nomadisme indigène. L’exploration des régions du totémisme ou de l’animisme est décrite comme une activité cérébrale, intellectuelle, passant par  l’identification des structures fondamentales de mythes chargés d’organiser la connaissance du monde et ne devant pas grand chose au nécessaire mouvement des pieds. Pourtant, en observant attentivement la polarité doublement négative des pieds d’un explorateur de l’Amazonie, Jules Crevaux, on découvre des structures communes au territoire parcouru et au mythe moderne qui confirment de façon paradoxale la pertinence des analyses de l’anthropologue.The rejection by Lévi Strauss of the explorer organise his own exploration of Amazonia as much as his quest for the Indian. The scientist, between those two characters, holds a medium position between blindness and foresight. The « voyage », stuck by the same despise, is presented as a caricature of indigenous nomadism. The exploration of the countries of totemism and animism is described as a mental, intelectual activity based on the identification of the fundamental structures of the myths organising the knowledge of the world which has nothing to do with the necessary movement of the feet. Nevertheless, the carefull observation of the feet of an amazonian explorer, Jules Crevaux (1847-1882, reveals structures which are common to the covered territory and to a modern mythology. This structures give an unexpected confirmation of the efficiency of the anthropologist’s analyses.

Safety report concerning the reactor Pegase - volume 1 - Description of the installation - volume 2 - Safety of the installations; Rapport de surete du reacteur pegase - tome 1 - Description des installations - tome 2 - Surete des installations

Energy Technology Data Exchange (ETDEWEB)

Lacour, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Legoin, P. [S.E.M. Hispano-Suiza, 92 - Colombes (France)

1964-07-01

In the first volume: This report is a description of the reactor Pegase, given with a view to examine the safety of the installations. The Cadarache site at which they are situated is briefly described, in particular because of the consequences on the techniques employed for building Pegase. A description is also given of the original aspects of the reactor. The independent loops which are designed for full-scale testing of fuel elements used in natural uranium-gas-graphite reactor systems are described in this report, together with their operational and control equipment. In the second volume: In the present report are examined the accidents which could cause damage to the Pegase reactor installation. Among possible causes of accidents considered are the seismicity of the region, an excessive power excursion of the reactor and a fracture in the sealing of an independent loop. Although all possible precautions have been taken to offset the effects of such accidents, their ultimate consequences are considered here. The importance is stressed of the security action and regulations which, added to the precautions taken for the construction, ensure the safety of the installations. (authors) [French] Dans le volume 1: Ce rapport est une description du reacteur Pegase, afin d'examiner la surete des installations. Le site de CADARACHE ou elles sont situees, a ete sommairement decrit, en particulier, a cause des consequences sur les techniques mises en oeuvre pour la realisation de Pegase. Nous nous sommes egalement attache a decrire les aspects originaux du reacteur. Les boucles autonomes destinees a tester en vraie grandeur des elements combustibles de la filiere uranium naturel graphite-gaz, ainsi que leurs dispositifs de controle et d'exploitation, figurent egalement dans ce rapport. Dans le volume 2: Dans le present rapport, nous examinons des accidents pouvant endommager des installations du reacteur Pegase. Les origines d'accidents examines

Safety report concerning the reactor Pegase - volume 1 - Description of the installation - volume 2 - Safety of the installations; Rapport de surete du reacteur pegase - tome 1 - Description des installations - tome 2 - Surete des installations

Energy Technology Data Exchange (ETDEWEB)

Lacour, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Legoin, P [S.E.M. Hispano-Suiza, 92 - Colombes (France)

1964-07-01

In the first volume: This report is a description of the reactor Pegase, given with a view to examine the safety of the installations. The Cadarache site at which they are situated is briefly described, in particular because of the consequences on the techniques employed for building Pegase. A description is also given of the original aspects of the reactor. The independent loops which are designed for full-scale testing of fuel elements used in natural uranium-gas-graphite reactor systems are described in this report, together with their operational and control equipment. In the second volume: In the present report are examined the accidents which could cause damage to the Pegase reactor installation. Among possible causes of accidents considered are the seismicity of the region, an excessive power excursion of the reactor and a fracture in the sealing of an independent loop. Although all possible precautions have been taken to offset the effects of such accidents, their ultimate consequences are considered here. The importance is stressed of the security action and regulations which, added to the precautions taken for the construction, ensure the safety of the installations. (authors) [French] Dans le volume 1: Ce rapport est une description du reacteur Pegase, afin d'examiner la surete des installations. Le site de CADARACHE ou elles sont situees, a ete sommairement decrit, en particulier, a cause des consequences sur les techniques mises en oeuvre pour la realisation de Pegase. Nous nous sommes egalement attache a decrire les aspects originaux du reacteur. Les boucles autonomes destinees a tester en vraie grandeur des elements combustibles de la filiere uranium naturel graphite-gaz, ainsi que leurs dispositifs de controle et d'exploitation, figurent egalement dans ce rapport. Dans le volume 2: Dans le present rapport, nous examinons des accidents pouvant endommager des installations du reacteur Pegase. Les origines d'accidents examines comprennent la seismicite

Neutron detection in an atomic reactor core using semi-conductors; Detection des neutrons par semi-conducteur dans un coeur de reacteur atomique

Energy Technology Data Exchange (ETDEWEB)

Divoux, F [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1968-07-01

In this paper, the first part describes the principle of nuclear particle detection by means of semiconductor diodes and the general application of these. The second part describes fabrication of the device used to estimate thermic neutron fluxes in core of a swimming pool type reactor. The useful volume (2.9 mm thickness) is in the light water moderator, between combustible elements plates. The results, principally obtained in the core of Siloette reactor at the 'Centre d'Etudes Nucleaires de Grenoble' at low power, are mentioned in the third part. Flux maps have been set and comparison between converter's products: Bore 10, Lithium 6, Uranium 235 is made. (author) [French] Dans ce rapport, une premiere partie porte sur la description du principe de detection des particules nucleaires par diodes a semi-conducteur et sur l'application generale de celles-ci. Une deuxieme partie s'attache a decrire la fabrication du materiel utilise pour evaluer les flux de neutrons thermiques dans un coeur de reacteur type pile piscine. L'espace de mesure (2,9 mm d'epaisseur) se situe entre les plaques des elements combustibles, dans le moderateur eau legere. Les resultats, obtenus principalement dans le coeur du reacteur Siloette du Centre d'Etudes Nucleaires de Grenoble aux basses puissances de fonctionnement, sont rapportes dans la troisieme partie. Des cartes de flux ont ete dressees et une comparaison est faite entre les produits 'convertisseurs' suivants: Bore 10, Lithium 6, Uranium 235. (auteur)

The Role of Exponential and PCTR Experiments at Hanford in the Design of Large Power Reactors; Roles Respectifs des Experiences Exponentielles et du Reacteur d'Etude des Constantes Physiques de Hanford dans les Etudes de Grands Reacteurs de Puissance; Znachenie ehksponentsial'nykh opytov i opytov na reaktore PCTR pri proektirovanii bol'shikh ehnergeticheskikh reaktorov v khehnforde; Papel de los Experimentos Exponenciales y del Reactor PCTR de Hanford en el Proyecto de Grandes Reactores de Potencia

Energy Technology Data Exchange (ETDEWEB)

Heineman, R. E. [General Electric Company, Richland, WA (United States)

1964-02-15

Exponential pile measurements have been made at the Hanford Laboratories on graphite-uranium lattices for almost fifteen years. Although the results of these experiments were used to establish the bucklings of proposed production reactors they also served to advance the understanding of the reactor physics of these systems. It was recognized early that the utility of the exponential experiment was limited because of its large size and its lack of sensitivity to small, localized perturbations of the system. Thought was then given to the problem of devising an integral reactor experiment which would minimize the quantity of materials needed to provide meaningful data. This effort led to the construction of an advanced, several-region critical facility, the Physical Constants Testing Reactor (PCTR). The PCTR has been used to support the reactor physics design of several power reactors. In addition, the PCTR has served as a general-purpose facility for the measurement of reactor cross- sections and for the determination of both differential and integral reactor physics parameters for various types of multiplying media. The exponential piles were used after the PCTR was built, even though the advantages claimed for the PCTR were amply fulfilled. Typical data from these two facilities are reviewed. The use of these facilities for power reactor design, to support changes inoperation of existing reactors, as reactor physics tools, and as training devices are contrasted. Comparisons are made of the initial costs and the cost of subsequent operation. The development of new experimental techniques for use with these facilities and of the demand for a wider variety of experimental data are traced. Such contrasts and developments are necessary to predict more clearly the needs and the future trends in the specific use of such facilities for the support of the design of power reactors. A brief description of the high-temperature lattice test reactor is presented and its proposed

Reactor Physics Development for Advanced Gas-Cooled Reactors; Recherches en Physique des Reacteurs, pour des Reacteurs Perfectionnes Refroidis par un Gaz; Razrabotka metodov v oblasti reaktornoj fiziki dlya usovershenstvovannogo reaktora s gazovym okhlazhdeniem; Progresos de la Fisica de los Reactores de Tipo Avanzado Refrigerados por Gas

Energy Technology Data Exchange (ETDEWEB)

Moore, J. [United Kingdom Atomic Energy Authority (United Kingdom)

1964-04-15

effects in APEX, HERO and AGR and for determining fine structure data and power distribution in the complex fuel assemblies are of particular interest. Current and future theoretical work is concentrated primarily on development of an alternative method to hetrecontrol and FTD2 for dealing with reactor cores after considerable burn-up of the fuel. The experimental programme on HERO is designed to test these methods with complex cores including plutonium bearing fuel. Additional information on the effect of plutonium will be derived from operation of AGR and physics measurements on fuel after irradiation. (author) [French] Le memoire relate les recherches experimentales et theoriques auxquelles on a procede lois de l'etude, de la realisation et de la mise en service du reacteur perfectionne refroidi par un gaz (AGR) de Windscale et, d'une facon generale, pour la mise au point d'un filiere de ce type en vue de la production d'energie electrique industrielle. Il decrit l'important volume de travail qui a ete necessaire en vue d'elaborer les methodes theoriques voulues pour calculer: a) la repartition du flux et l'equilibre de la reactivite dans un coeur complexe; b) la repartition de la puissance dans des geometries de combustible complexes-, c) les effets de l'irradiation sur le cycle du combustible et la repartition de la puissance. A titre d'introduction, le memoire resume la documentation experimentale et les methodes theoriques qui sont le resultat des recherches sur la filiere a uranium gaine de magnox et decrit la documentation experimentale obtenue par le programme commun des industries britanniques (BICEP); toutes ces donnees ont servi de point de depart pour l'elaboration de methodes theoriques applicables a l'AGR. On s'est servi de l'ensemble critique APEX et du reacteur HERO de puissance zero avec des configurations de reseau regulieres et diverses combinaisons de perturbateurs (notamment des barres de commande) pour calculer les parametres de reseau de l'AGR et

Love stories can be unpredictable: Jules et Jim in the vortex of life.

Science.gov (United States)

Dercole, Fabio; Rinaldi, Sergio

2014-06-01

Love stories are dynamic processes that begin, develop, and often stay for a relatively long time in a stationary or fluctuating regime, before possibly fading. Although they are, undoubtedly, the most important dynamic process in our life, they have only recently been cast in the formal frame of dynamical systems theory. In particular, why it is so difficult to predict the evolution of sentimental relationships continues to be largely unexplained. A common reason for this is that love stories reflect the turbulence of the surrounding social environment. But we can also imagine that the interplay of the characters involved contributes to make the story unpredictable-that is, chaotic. In other words, we conjecture that sentimental chaos can have a relevant endogenous origin. To support this intriguing conjecture, we mimic a real and well-documented love story with a mathematical model in which the environment is kept constant, and show that the model is chaotic. The case we analyze is the triangle described in Jules et Jim, an autobiographic novel by Henri-Pierre Roché that became famous worldwide after the success of the homonymous film directed by François Truffaut.

Love stories can be unpredictable: Jules et Jim in the vortex of life

Science.gov (United States)

Dercole, Fabio; Rinaldi, Sergio

2014-06-01

Love stories are dynamic processes that begin, develop, and often stay for a relatively long time in a stationary or fluctuating regime, before possibly fading. Although they are, undoubtedly, the most important dynamic process in our life, they have only recently been cast in the formal frame of dynamical systems theory. In particular, why it is so difficult to predict the evolution of sentimental relationships continues to be largely unexplained. A common reason for this is that love stories reflect the turbulence of the surrounding social environment. But we can also imagine that the interplay of the characters involved contributes to make the story unpredictable—that is, chaotic. In other words, we conjecture that sentimental chaos can have a relevant endogenous origin. To support this intriguing conjecture, we mimic a real and well-documented love story with a mathematical model in which the environment is kept constant, and show that the model is chaotic. The case we analyze is the triangle described in Jules et Jim, an autobiographic novel by Henri-Pierre Roché that became famous worldwide after the success of the homonymous film directed by François Truffaut.

The Jules Horowitz Reactor - A new High Performance European Material Testing Reactor open to International Users Present Status and Objectives

International Nuclear Information System (INIS)

Iracane, Daniel; Bignan, Gilles; Lindbaeck, Jan-Erik; Blomgren, Jan

2010-01-01

The development of sustainable nuclear energy requires R and D on fuel and material behaviour under irradiation with a high level of performance in order to meet the needs and challenges for the benefit of industry, research and public bodies. These stakes require a sustainable and secured access to an up-to-date high performance Material Testing Reactor. Following a broad survey within the European Research Area, the international community agreed that the need for Material Test Reactors in support of nuclear power plant safety and operation will continue in the context of sustainable nuclear energy. The Jules Horowitz Reactor project (JHR) copes with this context. JHR is designed as a user facility addressing the needs of the international community. This means: - flexibility with irradiation loops able to reproduce a large variation in operation conditions of different power reactor technologies, - high flux capacity to address Generations II, III, and IV needs. JHR is designed, built and operated as an international user facility because: - Given the maturity and globalization of the industry, domestic tools have no more the required level of economic and technical efficiency. Meanwhile, countries with nuclear energy need an access to high performance irradiation experimental capabilities to support technical skill and guarantee the competitiveness and safety of nuclear energy. - Many research items related to safety or public policy (waste management, etc.) require international cooperation to share costs and benefits of resulting consensus. JHR design is optimised for offering high performance material and fuel irradiation capability for the coming decades. This project is driven and funded by an international consortium gathering vendors, utilities and public stakeholders. This consortium has been set up in March 2007 when the construction began. The construction is in progress and the start of operation is scheduled for 2014. The JHR is a research

Contribution to the study on the flow rate adjustment for gas cooled power reactors (1964); Contributiom a l'etude de reglage du debit pour les reacteurs industriels refroidis par gaz (1964)

Energy Technology Data Exchange (ETDEWEB)

Milliot, B. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1961-06-15

1. This original study firstly defines the problem of the adjustment of the coolant flow rate in a reactor channel as a function of the corresponding heat transfer equations and of the local and temporal neutron flux. The necessity of such an adjustment is pointed out and the modifying parameters are studied. An adjustment study using the envelope of the possible flux curves is developed. A short study on the technology and the economical advantage of this adjustment is presented. Some measurements, made on G-1 and G-2, show the precision one can obtain from adjustment apparatus itself as well as from the complete reactor adjustment system. 2. Evolution of nuclear properties of fuel in an heterogeneous thermal reactor. In the first port of this paper, the phenomena of fuel evolution have been mainly pointed out. Now a bibliographical study more qualitatively than quantitatively has been done. This survey specifies the present theories and relates to a real effective cross section and also yields to the bases of such a nuclear calculation. (author) [French] 1. Cette etude originale definit d'abord le probleme du reglage du debit de refrigerant dans un canal de reacteur en fonction de la formulation du calcul des performances thermodynamiques de ce canal et des variations du flux neutronique dans l'espace et le temps. La necessite du reglage est ensuite mise en evidence et les parametres le modifiant sont etudies. Une methode de reglage, basee sur l'emploi d 'une courbe enveloppe des courbes de flux possibles, est donnee. Une breve etude de la technologie et des incidences economiques du reglage est presentee. Des mesures effectuees sur les reacteurs G-1 et G-2 montrent la precision que l'on peut attendre des dispositifs de reglage comme du reglage d'ensemble du reacteur lui-meme. 2. Evolution des proprietes nucleaires du combustible dans un reacteur heterogene a neutrons thermiques. Les phenomenes d'evolution du combustible

An improved thermal-hydraulic modeling of the Jules Horowitz Reactor using the CATHARE2 system code

Energy Technology Data Exchange (ETDEWEB)

Pegonen, R., E-mail: pegonen@kth.se [KTH Royal Institute of Technology, Roslagstullsbacken 21, SE-10691 Stockholm (Sweden); Bourdon, S.; Gonnier, C. [CEA, DEN, DER, SRJH, CEA Cadarache, 13108 Saint-Paul-lez-Durance Cedex (France); Anglart, H. [KTH Royal Institute of Technology, Roslagstullsbacken 21, SE-10691 Stockholm (Sweden)

2017-01-15

Highlights: • An improved thermal-hydraulic modeling of the JHR reactor is described. • Thermal-hydraulics of the JHR is analyzed during loss of flow accident. • The heat exchanger approach gives more realistic and less conservative results. - Abstract: The newest European high performance material testing reactor, the Jules Horowitz Reactor, will support current and future nuclear reactor designs. The reactor is under construction at the CEA Cadarache research center in southern France and is expected to achieve first criticality at the end of this decade. This paper presents an improved thermal-hydraulic modeling of the reactor using solely CATHARE2 system code. Up to now, the CATHARE2 code was simulating the full reactor with a simplified approach for the core and the boundary conditions were transferred into the three-dimensional FLICA4 core simulation. A new more realistic methodology is utilized to analyze the thermal-hydraulic simulation of the reactor during a loss of flow accident.

Construction of the core of the 'heavy water-gas' reactor EL 4; Structures du coeur du reacteur 'eau- lourde-gaz EL 4'

Energy Technology Data Exchange (ETDEWEB)

Bernard, J L; Foulquier, H; Thome, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

problem of thermal insulation around a zirconium alloy liner tube. The neutron absorption equivalent is about 1, 1 mm of Al, and the mean loss around 2 p. 100 of the thermal power of the reactor. The methods proposed have proved practicable as a result of important research and developments on automatic remote control for all the operations which make up the sequences of mounting, demounting and repairing of the construction components. In particular the possibilities opened up by the new techniques of welding tubes from the inside have been extended to other problems connected with the assembling of a reactor. (authors) [French] Le coeur de ce reacteur est constitue par une cuve contenant l'eau lourde, cuve traversee d'une serie de tubes de force dans lesquels circule le gaz caloporteur sous pression de 60 at. Les specifications de depart qui ont joue un role important dans la conception de ces structures concernent des aspects de securite de fonctionnement (chargement du combustible par les deux faces du reacteur, remplacement des structures sur les deux faces du reacteur), des necessites neutroniques (absorption des structures minimum, pas du reseau, diametre des tubes de force) et des considerations thermiques (temperature de sortie 500 C). Ces specifications ont entraine une disposition horizontale des tubes de force et des problemes d'encombrement tres delicats qui ont elimine (pour les dimensions d'EL 4) toute possibilite de recourir a des compensateurs de dilatation sur les tubes de force. II s'ensuit un dessin de cuve semi-rigide dans lequel les tubes de force contribuent pour une part importante a la resistance mecanique de l'ensemble en jouant le role de tirant, d'ou des contraintes elevees sur les jonctions et tubes de force (et le choix des alliages de zirconium). Les structures comprennent le tube de force, les jonctions, l'isolement thermique et le tube de guidage. On expose brievement les moyens d'essais mis en oeuvre et les performances de ces diverses

Jules Verne’s Science fiction and the Physics teaching: an analysis of “Twenty Thousand Leagues Underwater”

Directory of Open Access Journals (Sweden)

Júlio César David Ferreira

2013-04-01

Full Text Available This article presents the results of a research on the literary work of Jules Verne in the context of the teaching of scientific concepts. In the book "Twenty Thousand Leagues Under the Sea", taking Bakhtin as reference for analysis, we find a systematic and deliberate teaching concepts by Verne. We note a similarity between the situations described by the author and the statements of physical phenomena typical of high school textbooks, with some differences: the richness and complexity of the Verne's narrative, with plots that make highly contextualized the scientific concepts and that expand the possibilities for the reader's understanding. Accordingly, the approach of different genres allows the emergence of interdiscourses that reading can produce, or, in the context of Physics Education, we find in the Verne's literature various points of support for the understanding of scientific knowledge in this school discourse.

La "Carta a los maestros" de Jules Ferry (1883 y el laicismo escolar de la IIIª República francesa

Directory of Open Access Journals (Sweden)

Juan Manuel FERNÁNDEZ SORIA

2010-03-01

Full Text Available RESUMEN: Partiendo del valor histórico —de lo que es una muestra su influencia en la política educativa de la Segunda República española— y de la proyección de su legado en nuestros días de la «Carta a los Maestros» (1883 del ministro francés de Instrucción Pública, Jules Ferry, este trabajo se acerca a la vida de su autor y a su política educativa para analizar luego con mayor profundidad los aspectos más sobresalientes del documento —que transcribimos en francés y castellano—, especialmente el laicismo escolar, como medio de establecer una escuela nacional y de fundación de la República, la defensa de la moral común y positiva, los modos y procedimientos —tanto directos como indirectos— de su enseñanza, así como el papel del maestro y del manual en la educación moral y cívica del futuro ciudadano. ABSTRACT: Starting with the historic value —of which it is an example its influence in the educational policy of the Second Republic— and with the influence that remains in our days, of the legate of the «Elementary Schoolteacher’s Letter», written by Jules Ferry, French minister of the Public Instruction, this piece of work approaches to its author’s life and to its educational policy in order to analyse later in greater detail the most relevant aspects of the document —which we reproduce in Spanish and French— specially the scholastic laicism as a way to establish a national school, and the foundation of the Republic, the defence of common and positive morality, the ways and procedures, both direct and indirect, of its teaching, and also the role of schoolteachers and the guide in the moral and civic education of the future citizens.

A pulsed fast reactor; Un reacteur pulse a neutrons rapides; Impul'snyj reaktor na bystrykh nejtronakh; Reactor rapido pulsado

Energy Technology Data Exchange (ETDEWEB)

Blokhin, G. E.; Blokhintsev, D. I.; Blyumkina, Yu. A.; Bondarenko, I. I.; Deryagin, B. N.; Zajmovskij, A. S.; Zinov' ev, V. P.; Kazachkovskij, O. D.; Krasnoyarov, N. V.; Lejpunskij, A. I.; Malykh, V. A.; Nazarov, P. M.; Nikolaev, S. K.; Stavisskij, Yu. Ya.; Ukraintsev, F. I.; Frank, I. M.; Shapiro, F. Ji.; Yazvitskij, Yu. S. [Akademiya Nauk, Moscow, SSSR (Russian Federation)

1962-03-15

A pulsed fast reactor (IBR) has been operating at rated capacity since December 1960 in the Joint Institute for Nuclear Research. This reactor is used as a pulsed neutron source for physical experiments carried out by the time-of-flight method. It is used for total cross-section and intermediate neutron capture cross- section measurements, for studying the interaction between slow neutrons and solids and liquids, and for measuring neutron spectra produced in various media. The paper describes the basic structural features of the reactor and the results of the experiments for which it has been used. The reactor's operating system is based on recurrent pulses. Power pulses are produced when the mobile part of the reactor core moves swiftly through the stationary part of the core. The mobile part of the core is fastened to a rotating disc and travels at a speed of 230 m/s. The frequency of power pulses can be altered by means of an auxiliary mobile zone which has a range of 2.3-88 pulses per second. The mean power of the reactor is 1 kW, and the half-width of the power pulse in 36 {mu}s. The reactor is provided with a control and safety system which ensures automatic maintenance of mean power and swift shutdown in the event of any operational irregularity. It is fitted with a system of evacuated-neutron-flight tubes used in time-of-flight experiments. The main tube is 1000 m in length. In the start-up process and during physical experiments carried out on the reactor, the influence on reactivity of displacing the controls and the mobile parts of the core was studied ; the length of the pulse was measured under various operating conditions, and power pulse amplitude fluctuations were studied. Further measurements were made to establish the lifetime of prompt neutrons, the effective fraction of delayed neutrons, and coefficients of reactivity. (author) [French] L'Institut unifie de recherches nucleaires dispose d'un reacteur puise a neutrons rapides (IBR), qui

Operating Experience with the VERA Zero-Energy Fast Reactor; Fonctionnement du Reacteur VERA a Neutrons Rapides, de Puissance Zero; Opyt ehkspluatatsii reaktora VERA na bystrykh nejtronakh nulevoj moshchnosti; Experiencia Adquirida con el Reactor Rapido VERA de Potencia Nula

Energy Technology Data Exchange (ETDEWEB)

Weale, J. W.; McTaggart, M. H.; Goodfellow, H.; Paterson, W. J. [Atomic Weapons Research Establishment, Aldermaston (United Kingdom)

1964-02-15

The design of a two-halves zero-energy fast reactor is briefly described, particular emphasis being placed on those features which determine the practicability and precision of reactor physics measurements. The advantages and disadvantages of the design are discussed with reference to the two years' operating experience of the reactor. The following topics are dealt with: the experimental convenience of the lay-out and of the two halves design; the size and precision of the fuel pieces and the accuracy of location of the fuel elements; the effects of edge irregularities and heterogeneity of structure on the accuracy with which the critical mass of an 'ideal' equivalent assembly is determined; reproducibility of the critical condition after dismantling the assembly, or separating the two halves; variation of reactivity with separation of the halves, including effects of asymmetric loading; sensitivity of various counters, neutron source strength, use of an accelerator neutron source; speed of response of safety circuits and consequent restrictions on rate of assembly of the two halves; additional precautions necessary in using plutonium fuel; and notes on the accuracy of measurement of reactivity and on the practical limitations affecting various other reactor physics measurements. (author) [French] Les auteurs decrivent brievement ce modele de reacteur a neutrons rapides et de puissance zero construit en deux moities, en insistant particulierment sur les caracteristiques qui determinent la possibilites de faire des mesures relatives a la physique des reacteurs et la precision de ces mesures. Ils exposent les avantages et les inconvenients de ce modele compte tenu de l'experience acquise au cours des deux annees de fonctionnement du reacteur. Ils traitent les sujets suivants: interet pratique, au point de vue experimental, du plan de ce reacteur et de sa constitution en deux moities; dimension et precision des pieces de combustible et exactitude de l'emplacement des

Automation of nonlinear calculations in the theory of fusion reactor; Automatisation des calculs non lineaires dans la theorie des reacteurs a fusion

Energy Technology Data Exchange (ETDEWEB)

Braffort, P; Chaigne, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

1) Introduction: The difficulties of the formulation of the equations of phenomena occurring during the operation of a fusion reactor are underlined. 2) The possibilities presented by analog computation of the solution of nonlinear differential equations are enumerated. The accuracy and limitations of this method are discussed. 3) The analog solution in the stationary problem of the measurement of the discharge confinement is given and comparison with experimental results. 4) The analog solution of the dynamic problem of the evolution of the discharge current in a simple case is given and it is compared with experimental data. 5) The analog solution of the motion of an isolated ion in the electromagnetic field is given. A spatial field simulator used for this problem (bidimensional problem) is described. 6) The analog solution of the preceding problem for a tridimensional case for particular geometrical configurations using simultaneously 2 field simulators is given. 7) A method of computation derived from Monte Carlo method for the study of dynamic of plasma is described. 8) Conclusion: the essential differences between the analog computation of fission reactors and fusion reactors are analysed. In particular the theory of control of a fusion reactor as described by SCHULTZ is discussed and the results of linearized formulations are compared with those of nonlinear simulation. (author)Fren. [French] 1) Introduction. On souligne les difficultes que presente la mise en equation des phenomenes mis en jeu lors du fonctionnement d'un reacteur a fusion. On selectionne un certain nombre d'equations generalement utilisees et on montre les impossibilites analytiques auxquelles on se heurte alors. 2) On rappelle les possibilites du calcul analogique pour la resolution des systemes differentiels non lineaires et on indique la precision de la methode ainsi que ses limitations. 3) On decrit esolution analogique du probleme statique de la mesure du confinement de la decharge

Further evaluation of wetland emission estimates from the JULES land surface model using SCIAMACHY and GOSAT atmospheric column methane measurements

Science.gov (United States)

Hayman, Garry; Comyn-Platt, Edward; McNorton, Joey; Chipperfield, Martyn; Gedney, Nicola

2016-04-01

The atmospheric concentration of methane began rising again in 2007 after a period of near-zero growth [1,2], with the largest increases observed over polar northern latitudes and the Southern Hemisphere in 2007 and in the tropics since then. The observed inter-annual variability in atmospheric methane concentrations and the associated changes in growth rates have variously been attributed to changes in different methane sources and sinks [2,3]. Wetlands are generally accepted as being the largest, but least well quantified, single natural source of CH4, with global emission estimates ranging from 142-284 Tg yr-1 [3]. The modelling of wetlands and their associated emissions of CH4 has become the subject of much current interest [4]. We have previously used the HadGEM2 chemistry-climate model to evaluate the wetland emission estimates derived using the UK community land surface model (JULES, the Joint UK Land Earth Simulator) against atmospheric observations of methane, including SCIAMACHY total methane columns [5] up to 2007. We have undertaken a series of new HadGEM2 runs using new JULES emission estimates extended in time to the end of 2012, thereby allowing comparison with both SCIAMACHY and GOSAT atmospheric column methane measurements. We will describe the results of these runs and the implications for methane wetland emissions. References [1] Rigby, M., et al.: Renewed growth of atmospheric methane. Geophys. Res. Lett., 35, L22805, 2008; [2] Nisbet, E.G., et al.: Methane on the Rise-Again, Science 343, 493, 2014; [3] Kirschke, S., et al.,: Three decades of global methane sources and sinks, Nature Geosciences, 6, 813-823, 2013; [4] Melton, J. R., et al.: Present state of global wetland extent and wetland methane modelling: conclusions from a model inter-comparison project (WETCHIMP), Biogeosciences, 10, 753-788, 2013; [5] Hayman, G.D., et al.: Comparison of the HadGEM2 climate-chemistry model against in situ and SCIAMACHY atmospheric methane data, Atmos. Chem

Handbook for the calculation of reactor protections; Formulaire sur le calcul de la protection des reacteurs

Energy Technology Data Exchange (ETDEWEB)

NONE

1963-07-01

This note constitutes the first edition of a Handbook for the calculation of reactor protections. This handbook makes it possible to calculate simply the different neutron and gamma fluxes and consequently, to fix the minimum quantities of materials necessary under general safety conditions both for the personnel and for the installations. It contains a certain amount of nuclear data, calculation methods, and constants corresponding to the present state of our knowledge. (authors) [French] Cette note constitue la premiere edition du 'Formulaire sur le calcul de la protection des reacteurs'. Ce formulaire permet de calculer de facon simple les difterents flux de neutrons et de gamma et, par suite, de fixer les quantites minima de materiaux a utiliser pour que les conditions generales de securite soient respectees, tant pour le personnel que pour les installations. Il contient un certain nombre de donnees nucleaires, de methodes de calcul et de constantes correspondant a l'etat actuel de nos connaissances. (auteurs)

The future Jules Horowitz material test reactor: A major European research infrastructure for sustaining the international irradiation capacity

International Nuclear Information System (INIS)

Parrat, D.; Bignan, G.; Chauvin, J.; Gonnier, C.

2011-01-01

Multipurpose experimental reactors are now key infrastructures, in complement of prediction capabilities gained thanks to progresses in the modelling, for supporting nuclear energy in terms of safety, ageing management, innovation capacity, economical performances and training. However the European situation in this field is characterized by ageing large infrastructures, which could face to operational issues in the coming years and could jeopardize the knowledge acquisition and the nuclear product qualification. Moreover some specific supplies related to the public demand could be strongly affected (e.g. radiopharmaceutical targets). To avoid a lack in the experimental capacity offer at the European level, the CEA has launched the Jules Horowitz material test reactor (JHR) international program, in the frame of a Consortium gathering EDF (FR), AREVA (FR), the European Commission (EU), SCK.CEN (BE), VTT (FI), CIEMAT (SP), VATTENFALL (SE), UJV (CZ), JAEA (JP) and the DAE (IN). The JHR will be a 100 MW tank pool reactor and will have several experimental locations either inside the reactor core or outside the reactor tank in a reflector constituted by beryllium blocks. Excavation works started mid-2007 on the CEA Cadarache site in the southeast of France. After the construction permit delivery gained in September 2007, building construction began at the beginning of 2009. Reactor start-up is scheduled in 2016. The JHR is designed to offer up-to-date irradiation experimental capabilities for studying nuclear material and fuel behaviour under irradiation in a modern safety frame, mainly due to: 1) High values of fast and thermal neutron fluxes in the core and high thermal neutron flux in the reflector (producing typically twice more material damages per year than available today in European MTRs); 2) A large variety of experimental devices capable to reproduce environment conditions of mainly light water reactors (LWRs) and sodium fast reactors; 3) Several equipment

Experimental study of the hydrodynamic instabilities occurring in boiling-water reactors; Etude experimentale des instabilites hydrodynamiques survenant dans les reacteurs nucleaires a ebullition

Energy Technology Data Exchange (ETDEWEB)

Fabreca, S [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-10-01

The subjects is an experimental out-of pile loop study of the hydrodynamic oscillations occurring in boiling-water reactors. The study was carried out at atmospheric pressure and at pressure of about 8 atmospheres, in channels heated electrically by a constant and uniform specified current. In the test at 8 atmospheres the channel was a round tube of approximately 6 mm interior diameter. At 1 atmosphere a ring-section channel was used, 10 * 20 mm in diameter, with an inner heating tube and an outer tube of pyrex. It was possible to operate with natural convection and also with forced convection with test-channel by-pass. The study consists of 3 parts: 1. Preliminary determination of the laws governing pressure-drop during boiling. 2. Determination of the fronts at which oscillation appears, within a wide range of the parameters involved. 3. A descriptive study of the oscillations and measurement of the periods. The report gives the oscillation fronts with natural and forced convection for various values of the singular pressure drop at the channel inlet and for various riser lengths. The results are presented in non-dimensional form, which is available, in first approximation, for all geometric scales and for all fluids. Besides the following points were observed: - the wall (nature and thickness) can be an important factor ; - oscillation can occur in a horizontal channel. (author) [French] II a ete effectue une etude experimentale, en boucle hors-pile, des oscillations hydrodynamiques survenant dans les reacteurs a ebullition. L'etude a ete effectuee a la pression atmospherique et a une pression voisine de 8 atmospheres dans des canaux chauffes electriquement a puissance imposee constante et uniforme. Dans les essais a 8 atmospheres le canal etait un tube circulaire de diametre interieur 6 mm environ. A 1 atmosphere le canal etait de section annulaire 10 * 20 mm avec un tube interieur chauffant et un tube exterieur en pyrex. Le fonctionnement etait possible en

Emission and transmission tomography systems to be developed for the future needs of Jules Horowitz material testing reactor

Energy Technology Data Exchange (ETDEWEB)

Kotiluoto, Petri [VTT Technical Research Centre of Finland, P.O.Box 1000, FI-02044 VTT (Finland)], E-mail: petri.kotiluoto@vtt.fi; Wasastjerna, Frej; Kekki, Tommi [VTT Technical Research Centre of Finland, P.O.Box 1000, FI-02044 VTT (Finland); Sipilae, Heikki; Banzuzi, Kukka [Oxford Instruments Analytical Oy, Nihtisillankuja 5, P.O.Box 85, FI-02631 Espoo (Finland); Kinnunen, Petri; Heikinheimo, Liisa [VTT Technical Research Centre of Finland, P.O.Box 1000, FI-02044 VTT (Finland)

2009-08-01

The new 100 MW Jules Horowitz material testing reactor will be built in Cadarache, France. It will support, for instance, research on new types of innovative nuclear fuel. As a Finnish in-kind contribution, 3D emission and transmission tomography equipment will be delivered for both the reactor and the active component storage pool. The image reconstruction of activities inside the used nuclear fuel will be based on gamma spectrometry measurements. A new type of underwater digital X-ray linear detector array is under development for transmission imaging, based on GaAs and direct conversion of X-rays into an electrical signal. A shared collimator will be used for both emission and transmission measurements. Some preliminary design has been performed. For the current design, the expected gamma spectrometric response of a typical high-purity germanium detector has been simulated with MCNP for minimum and maximum source activities (specified by CEA) to be measured in future.

A fly-wheel drive with controlled-torque clutch for a reactors cooling circuit pumps; Entrainement des pompes du circuit de refrigeration d'un reacteur par volant a embrayage sous couple controle

Energy Technology Data Exchange (ETDEWEB)

Riettini, A [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-10-15

After a theoretical study on the slowing down of a centrifugal pump, the motion equations have been checked by means of experimental tests. In order to have important slowing down times (which is the case of the cooling pumps of a research reactor) it is necessary to add a fly-wheel. To prevent troubles when starting, a block pump-fly-wheel with clutch under controlled torque was developed. It is so possible to start the fly-wheel progressively without increasing too much power of the driving motor. (author) [French] Apres une etude theorique sur le mouvement de ralentissement d'une pompe centrifuge, les equations du mouvement ont ete verifiees par des essais pratiques. Pour obtenir des temps de ralentissement importants (cas des pompes de refrigeration d'un reacteur de recherche) il est necessaire d'y adjoindre un volant d'inertie. Pour eviter les inconvenients au demarrage, on a etudie un ensemble pompe-volant avec embrayage sous couple controle. Cette solution permet de lancer progressivement le volant sans augmentation appreciable de la puissance du moteur d'entrainement. (auteur)

Chemical elimination of alumina in suspension in nuclear reactors heavy water; Elimination de l'alumine en suspension dans l'eau lourde des reacteurs nucleaires par voie chimique

Energy Technology Data Exchange (ETDEWEB)

Ledoux, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-02-01

Corrosion of aluminium in contact with moderating water in nuclear reactor leads to the formation of an alumina hydrosol which can have an adverse effect on the operation of the reactor. Several physical methods have been used in an attempt to counteract this effect. The method proposed here consists in the elimination of the aluminium by dissolution and subsequent fixation in the ionic form on mixed-bed ion-exchange resin. In order to do this, the parameters and the values of these parameters most favorable to the dissolution process have been determined. If the moderator is heavy water, the deuterated acid can be prepared by converting a solution in heavy water to a salt of the acid using a deuterated cationic resin. (author) [French] La corrosion de l'aluminium au contact de l'eau moderatrice des reacteurs nucleaires, donne lieu a la formation d'un hydrosol d'alumine nuisible au bon fonctionnement des reacteurs. Plusieurs methodes physiques ont ete mises en oeuvre pour pallier ces inconvenients. On propose ici d'eliminer l'alumine par solubilisation pour la fixer ensuite sous forme ionique par des resines echangeuses d'ions, en lit melange. A cette fin on determine les parametres et leurs grandeurs favorables a cette solubilisation. Si le moderateur est de l'eau lourde la preparation d'acide deutere peut etre effectuee par passage d'une solution en eau lourde a un sel de l'acide sur resine cationique deuteree.

Detection of burst cans in the reactors cooled by gaseous phase; Detection des ruptures de gaine dans les reacteurs refroidis par phase gazeuse

Energy Technology Data Exchange (ETDEWEB)

Labeyrie, J; Roguin, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

In a nuclear reactor including the bars or plates cooled by a gaseous fluid, burst risks to occur in the sheath assuring the tightness separation between the cooling gas and the fissile materials. It is necessary to be able to detect the formation of these cracks as possible in order to avoid all risk of fission products release or any reaction of uranium to the contact of the refrigerating gas. It is however the increase of the radioactivity in the cooling gas due to the scattering of the fission products that permits to signal the apparition of a crack or to follow its evolution. It is possible to detect cracks of the order of the square millimeter. In this report, we will detail the principle and the realization of a device used for the surveillance of a natural uranium reactor cooled by air circulation. (M.B.) [French] Dans un reacteur nucleaire comportant des barres ou des plaques refroidies par un fluide gazeux des fissures risquent de se produire dans les gaines assurant la separation etanche entre le gaz de refroidissement et les materiaux fissiles. II est necessaire de pouvoir detecter la formation de ces fissures des que possible afin d'eviter tout risque de liberation de produits de fission ou de reaction de l'uranium au contact du gaz refrigerant. C'est cependant l'augmentation de la radioactivite du gaz de refroidissement due a la dispersion des produits de fission qui permet de signaler l'apparition d'une fissure ou de suivre son evolution. On peut ainsi detecter des fissures de l'ordre du millimetre carre. Dans ce rapport, nous detaillerons le principe et la realisation d'un appareil utilise pour la surveillance d'un reacteur a uranium naturel refroidi par circulation d'air. (M.B.)

Determination of local boiling in light water reactors by correlation of the neutron noise; Determination de l'ebullition locale dans les reacteurs a eau legere par correlation du bruit neutronique

Energy Technology Data Exchange (ETDEWEB)

Zwingelstein, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1968-07-01

The power limit of swimming-pool type reactors depends on the phenomenon of the appearance of burn-out. In order to determine this limit we have attempted to detect the local boiling which usually occurs before the burn out. Local boiling has been simulated by an electrically heated plate placed in the core of the reactor Siloette. The study of local boiling, which is based on the properties of the correlation functions for the neutron noise of detectors placed in the core, shows that a privileged frequency occurs in the power spectrum of the noise. It is intended in the future to determine the influence of various parameters on this characteristic frequency. (author) [French] La limitation de la puissance des reacteurs nucleaires de type piscine est due au phenomene d'apparition de 'burn out'. Pour determiner cette limitation, nous nous sommes proposes dans ce rapport de detecter l'ebullition locale qui apparait generalement avant le 'burn out'. L'ebullition locale a ete simulee par une plaque chauffee electriquement et placee dans le coeur du reacteur SILOETTE. L'etude de l'ebullition locale, qui est basee sur les proprietes des fonctions de correlation du bruit neutronique de detecteurs places clans le coeur, fait apparaitre une frequence privilegiee dans le spectre de puissance du bruit. On envisage dans l'avenir, de determiner l'influence des divers parametres sur cette frequence caracteristique. (auteur)

General views about specimen irradiations in reactors; Considerations generales sur'les irradiations d'echantillons dans les reacteurs

Energy Technology Data Exchange (ETDEWEB)

Seguin, M [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1965-07-01

Specimen irradiation of fissile or non-fissile materials, carried out under circumstances becoming more and more severe and in reactor of increasing flux bas led to an evolution of irradiation rigs. A survey of the problems arising from irradiating under these various circumstances leads to conclude that it is possible to devise one capsule type suitable to every particular case, and that in a wide temperature range. Consequently, once the various irradiation-parameters known, a general method of calculation can be followed so as to determine the various sizes of the parts constituting the capsule. These theoretical calculations might sometimes be corrected through benefits gained from previous irradiations. Similarly, practical experimentation might allow to foresee more handy assembling of the capsule, specimen loading-and unloading being easier at the same time. (author) [French] L'irradiation d'echantillons, fissiles ou non fissiles, dans des conditions imposees de plus en plus strictes et dans des reacteurs a flux de plus en plus eleve, a eu pour consequence une evolution dans la conception des dispositifs d'irradiation. Lorsqu'on examine les problemes souleves par ces differentes irradiations, on en conclut qu'il est possible de concevoir un type de capsule capable de donner satisfaction dans chaque cas particulier, et ce, dans une tres large gamme de temperature. Par consequent, les differents parametres de l'irradiation etant connus, une methode generale de calcul peut etre suivie pour determiner les differentes cotes des pieces constitutives de la capsule. Ces calculs theoriques devront quelquefois etre corriges grace aux enseignements tires d'irradiations precedentes. De meme, l'experience acquise permettra d'envisager un montage plus aise de la capsule, tout en facilitant l'enfournement et le defournement des echantillons.

The control equipment of the Melusine II reactor; L'equipement de controle du reacteur Melusine II

Energy Technology Data Exchange (ETDEWEB)

Cordelle, M; Delcroix, V; Denis, P; Gariod, R

1963-07-01

Melusine II, low-power reactor, used for the study of Siloe core has diverged at the CEA Grenoble, the 23. May 1962; its monitoring board studied and carried out in this center is the first in France to be entirely transistorized. The first months of running have justified the hope put in the new electronics to improve the stability and the safety of running. The article describes the design of the control and gives the main characteristics of the measurement chains and of the actions on reactivity. (O.M.) [French] Melusine II, reacteur de faible puissance destine a l'etude du coeur de Siloe a diverge au Centre d'Etudes Nucleaires de Grenoble, le 23 mai 1962, son tableau de controle etudie et realise dans ce Centre est le premier en France a etre entierement transistorise. Les premiers mois de fonctionnement ont justifie l'espoir mis dans la nouvelle electronique pour ameliorer la stabilite et la surete de fonctionnement. L'article decrit la conception du controle et donne les principales caracteristiques des chaines de mesure et des actions sur la reactivite. (auteurs)

Experimental study of the hydrodynamic instabilities occurring in boiling-water reactors; Etude experimentale des instabilites hydrodynamiques survenant dans les reacteurs nucleaires a ebullition

Energy Technology Data Exchange (ETDEWEB)

Fabreca, S. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-10-01

The subjects is an experimental out-of pile loop study of the hydrodynamic oscillations occurring in boiling-water reactors. The study was carried out at atmospheric pressure and at pressure of about 8 atmospheres, in channels heated electrically by a constant and uniform specified current. In the test at 8 atmospheres the channel was a round tube of approximately 6 mm interior diameter. At 1 atmosphere a ring-section channel was used, 10 * 20 mm in diameter, with an inner heating tube and an outer tube of pyrex. It was possible to operate with natural convection and also with forced convection with test-channel by-pass. The study consists of 3 parts: 1. Preliminary determination of the laws governing pressure-drop during boiling. 2. Determination of the fronts at which oscillation appears, within a wide range of the parameters involved. 3. A descriptive study of the oscillations and measurement of the periods. The report gives the oscillation fronts with natural and forced convection for various values of the singular pressure drop at the channel inlet and for various riser lengths. The results are presented in non-dimensional form, which is available, in first approximation, for all geometric scales and for all fluids. Besides the following points were observed: - the wall (nature and thickness) can be an important factor ; - oscillation can occur in a horizontal channel. (author) [French] II a ete effectue une etude experimentale, en boucle hors-pile, des oscillations hydrodynamiques survenant dans les reacteurs a ebullition. L'etude a ete effectuee a la pression atmospherique et a une pression voisine de 8 atmospheres dans des canaux chauffes electriquement a puissance imposee constante et uniforme. Dans les essais a 8 atmospheres le canal etait un tube circulaire de diametre interieur 6 mm environ. A 1 atmosphere le canal etait de section annulaire 10 * 20 mm avec un tube interieur chauffant et un tube exterieur en pyrex. Le fonctionnement etait possible

Study of the consequences of the rupture of a pressure tube in the tank of a gas-cooled, heavy-water moderated reactor; Etude des consequences de la rupture d'un tube de force dans la cuve d'un reacteur modere a l'eau lourde et refroidi au gaz

Energy Technology Data Exchange (ETDEWEB)

Hareux, F; Roche, R; Vrillon, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

Bursting of a pressure tube in the tank of a heavy water moderated-gas cooled reactor is an accident which has been studied experimentally about EL-4. A first test (scale 1) having shown that the burst of a tube does not cause the rupture of adjacent tubes, tests on the tank resistance have been undertaken with a very reduced scale model (1 to 10). It has been found that the tank can endure many bursts of tube without any important deformation. Transient pressure in the tank is an oscillatory weakened wave, the maximum of which (pressure peak) has been the object of a particular experimental study. It appears that the most important parameters which affect the pressure peak are; the pressure of the gas included in the bursting pressure tube, the volume of this gas, the mass of air included in the tank and the nature of the gas. A general method to calculate the pressure peak value in reactor tanks has been elaborated by direct application of experimental data. (authors) [French] L'eclatement d'un tube de force dans la cuve d'un reacteur de puissance modere a l'eau lourde et refroidi par un gaz sous pression est un accident qui a ete etudie experimentalement a propos d'EL-4. Un premier essai a l'echelle 1 ayant montre que l'eclatement d'un tube ne provoque pas celui des tubes voisins, des essais relatifs a la tenue de la cuve ont ete effectues sur maquettes a echelle tres reduite (l/lO). Il a ete trouve que la cuve peut supporter plusieurs eclatements de tubes sans deformations notables. La pression transitoire dans la cuve a une allure oscillatoire amortie dont le maximum (pression de pic) a fait l'objet d'une etude experimentale detaillee. Il apparait que les parametres essentiels influant sur cette pression sont: la pression du gaz contenu dans le tube de force, le volume du gaz qui participe a l'eclatement, la flexibilite de la cuve, la masse d'air empoisonnee dans la cuve, la nature du gaz explosant. Une methode generale d'estimation des pics de pression dans

The CO{sub 2} cooling gas for the reactors G2/G3 (leaking, analysis, activity); Le CO{sub 2} de refroidissement des reacteurs G2/G3 (fuites, analyse, activite)

Energy Technology Data Exchange (ETDEWEB)

Meiffren, J; Dupay, F [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1965-07-01

The main objective of this study is to publicise the data obtained during five years operation of the reactor G2 and G3 at Marcoule as far as the cooling gas is concerned, from storage of reserves up to its slow escape into the atmosphere, and including all the stages of its practical use, its chemical examination, its nuclear behaviour and its possible physicochemical transformation. This work can not only yield information about the operations carried out at Marcoule but can also provide useful suggestions for improving the sealing and for decreasing the activity of the pressurized gas circuits in reactors similar to G2/G3. (authors) [French] Le but principal de cette etude est de diffuser les connaissances acquises au cours de cinq annees d'exploitation des reacteurs G2 et G3 de Marcoule en ce qui concerne le gaz de refroidissement, depuis son stockage d'appoint jusqu'a son echappement lent dans l'atmosphere, en passant par tous les stades de son utilisation pratique, de son etude chimique, de son comportement nucleaire, eventuellement de ses transformations physico-chimiques. Cette etude peut, non seulement renseigner sur les operations effectuees couramment a Marcoule, mais egalement donner des suggestions interessantes pour l'amelioration de l'etancheite et la diminution de l'activite des circuits de gaz en pression dans des reacteurs analogues a G2/G3. (auteurs)

The Jules Horowitz reactor: complementary safety evaluation in the light of the Fukushima 1 nuclear power station accident

International Nuclear Information System (INIS)

2011-01-01

This report proposes a complementary safety evaluation of the Jules Horowitz reactor in Cadarache (INB 172), one of the French basic nuclear installations (BNI, in French INB) in the light of the Fukushima accident. This evaluation takes the following risks into account: risks of flooding, earthquake, loss of power supply and loss of cooling, in addition to operational management of accident situations. It presents the main characteristics of the installation, identifies the risks of a cliff effect and the main structures and equipment, evaluates the seismic risk (installation sizing, installation conformity, margin evaluation), evaluates the flooding risk (installation sizing, installation conformity, margin evaluation), briefly examines other extreme natural phenomena (extreme meteorological conditions related to flooding, earthquake or flooding with a higher level than that for which the installation is designed). It analyzes the risk of a loss of power supply and of cooling (loss of external and internal electric sources, loss of the ultimate cooling system). It analyzes the management of severe accidents: crisis management organization, available intervention means, robustness of available means. It discusses the conditions of the use of subcontractors

Contribution to the study and use of ionisation chambers for nuclear reactor control (1965); Contribution a l'etude et a l'utilisation des chambres d'ionisation pour le controle des reacteurs nucleaires (1965)

Energy Technology Data Exchange (ETDEWEB)

Duchene, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-02-15

high-power reactors. (author) [French] Les chambres d'ionisation sont actuellement les detecteurs les mieux adaptes au controle des reacteurs nucleaires par des mesures neutroniques. Nous avons cru bon de rappeler quelques generalites concernant la dynamique des reacteurs, les differents procedes de detection des neutrons, le fonctionnement des chambres d'ionisation et les methodes de mesure utilisees. Notre contribution aux techniques de controle des reacteurs consiste d'une part en une tentative de synthese des facteurs intervenant dans le fonctionnement des chambres d'ionisation, l'etude de ces facteurs, et d'autre part l'elaboration de chambres d'ionisation a fission et a bore permettant de suivre la marche d'un reacteur du demarrage jusqu'a la puissance maximale. Dans le domaine des chambres a fission, nous avons en particulier ameliore les techniques de depot d'oxyde d'uranium sur l'aluminium et realise la mise au point de depots par electrolyse sur d'autres metaux: acier inoxydable, cuivre, molybdene, nickel, tantale, titane, kovar, tungstene et beryllium. Nous avons elabore plusieurs types de chambres a fission servant au demarrage des reacteurs: un type de performances moyennes actuellement utilise dans les piles francaises un type a haute sensibilite un type a haute temperature qui a fonctionne jusqu'a 600 deg. C. En ce qui concerne les chambres a bore, nous avons etudie les perturbations apportees dans les mesures par l'exposition des chambres a d'importants flux de neutrons et a un rayonnement {gamma} intense. Cette exposition produit une modification des proprietes des materiaux constitutifs et la production dans les chambres d'un bruit de fond qui peut gener considerablement les mesures neutroniques. Nous avons montre que la technique de compensation permettait de limiter l'importance de ce bruit de fond et d'augmenter ainsi la plage de fonctionnement des chambres d'ionisation classiques destinees aux mesures de puissance. Enfin, nous avons realise deux

A review of calculation methods for fast and intermediate reactors; Expose des methodes pour le calcul de reacteurs a neutrons rapides et intermediaires; Obzor metodov rascheta reaktorov na promezhutochnykh i bystrykh nejtronakh; Estudio panoramico de los metodos de calculo de los reactores rapidos e intermedios

Energy Technology Data Exchange (ETDEWEB)

Marchuk, G I [Akademiya Nauk, Moskva, Union of Soviet Socialist Republics (Russian Federation)

1962-03-15

This paper discusses the development of methods for calculating intermediate and fast reactors. It deals with various approaches to the problems of physical calculation. The calculation of resonance effects is discussed. Consideration is given to multi-group systems of fundamental and conjugate equations, various applications of perturbation theory to the problems of physical reactor calculation, and numerical methods of solving fundamental and conjugate reactor equations, which approximate the method of spherical harmonics. The paper describes an application of the response method to the solution of critical-mass problems, and methods of calculating reactors with hydrogeneous moderators. The fundamental features of an effective one-group reactor model are described. (author) [French] L'auteur examine la mise au point de methodes pour le calcul de reacteurs a neutrons rapides et intermediaires . Il decrit diverses manieres d'aborder les problemes des calculs sur la physique des reacteurs, notamment le calcul des effets de resonance. Il s'attache particulierement aux points suivants: systemes d'equations fondamentales et conjuguees a plusieurs groupes; diverses applications de la theorie des perturbations aux problemes de calculs sur la physique des reacteurs; methodes numeriques pour resoudre les equations fondamentales et conjuguees, voisines de la methode des harmoniques spheriques. L'auteur decrit ensuite une maniere d'appliquer la methode de la reponse aux problemes de la masse critique ainsi que des methodes pour le calcul de reacteurs ralentis a l'hydrogene. Il decrit les caracteristique s fondamentale s d'un modele de reacteur a un groupe effectif. (author) [Spanish] El autor analiza el desarrollo de los metodos de calculo de los reactores nucleares que trabajan con neutrones rapidos y con neutrones intermedios. Examina diversos planteos de los problemas del calculo fisico. Indica la forma de tomar en cuenta los efectos de resonancia y menciona los sistemas

Jules Horowitz reactor - Complementary safety assessment in the light of the Fukushima accident

International Nuclear Information System (INIS)

2011-01-01

This CSA (Complementary Safety Assessment) analyses the robustness of the Jules Horowitz reactor (RJH) to extreme situations such as those that led to the Fukushima accident and proposes a series of improvements. RJH is being built on the Cadarache CEA's site. Robustness is the ability for the facility to withstand events beyond the level for which the facility was designed. Robustness is linked to safety margins but also to the situations leading to a sudden deterioration of the accident sequence (cliff edge effect). Safety is not only a matter of design or of engineered systems, it is also a matter of organization. So issues like RJH's crisis organization, the organization of radiation protection, and work organization via subcontracting are also taken into consideration. This report is divided into 9 main chapters: 1) main features of the RJH facility, 2) identification of cliff edge risks and of equipment essential for safety, 3) earthquake risk, 4) flood risk, 5) risks due to other extreme natural disasters, 6) the loss of electrical power supplies and of cooling systems, 7) management of severe accidents, 8) subcontracting policy, 9) synthesis and list of improvements. This study shows a globally good robustness of the RJH for the considered risks. Nevertheless it can considered relevant to increase the robustness of the plant on a few points: -) to increase the seismic safety margins of some pieces of equipment, -) to increase the robustness of the internal electrical power supplies, -) to increase the fuel cooling capacity, and -) to improve the management of the post-accidental period. (A.C.)

Design of the fuel element 'snow-flake' in uranium oxide, canned with aluminium, for the experimental reactor EL 3 (1960); Etude d'un element combustible en oxyde d'uranium gaine d'aluminium, type ''cristal de neige'' pour la pile EL 3 (1960)

Energy Technology Data Exchange (ETDEWEB)

Gauthron, M; Guibert, B [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

This report sums up the main studies have been carried out on the fuel element 'Snowflake' (uranium oxide, canned with aluminium), designed to replace the present element of the experimental reactor EL3 in order to increase the reactivity without modifying the neutron flux/thermal power ratio. (author) [French] Ce rapport resume les principales etudes qui ont ete faites sur l'element combustible 'Cristal de Neige' (a oxyde d'uranium, gaine d'aluminium) destine a remnlacer l'element actuel du reacteur experimental EL3, afin d'en augmenter la reactivite sans modifier le rapport flux neutronique-puissance thermique. (auteur)

Study of a Slightly Enriched R Reactor Fuel by Means of a Pulsed Neutron Source; Etude d'un reacteur a combustible legerement enrichi (rubeole) a l'aide de sources pulsees de neutrons

Energy Technology Data Exchange (ETDEWEB)

Sagot, M; Tellier, H [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

1962-04-01

A Be O moderated reactor using slightly enriched uranium oxide as fuel was studied by the pulsed neutron source technique. The neutron lifetime was measured in two different cores without reflector, then attempts were made at the measurement of great negative reactivities introduced into the reactor under the following forms: decrease of the volume of the un reflected core, introduction of absorbing cadmium rods, removal of fuel at the periphery of the critical core while maintaining a constant height, and substitution of fuel elements by less reactive elements. In all cases, the results are compared with the data obtained by another type of experiment or by computation. (author) [French] Nous avons applique la methode des sources pulsees de neutrons a un reacteur utilisant de l'oxyde d'uranium legerement enrichi, modere a l'oxyde de beryllium et, apres avoir mesure le temps de vie des neutrons dans deux coeurs differents non reflechis, nous avons porte notre effort, sur la mesure de reactivites negatives importantes introduites dans le reacteur sous differentes formes: - diminution du volume du coeur non reflechi, - introduction de barres absorbantes en cadmium, - enlevement de combustible a la peripherie du coeur critique, tout en conservant une hauteur constante, - substitution d'elements de combustible par des elements moins reactifs. Dans tous les cas, les resultats sont compares aux valeurs obtenues par un autre type d'experience ou par le calcul. (auteur)

Study of new structures adapted to gas-graphite and gas-heavy water reactors; Etude de structures nouvelles adaptees aux reacteurs graphite-gaz et eau lourde-gaz

Energy Technology Data Exchange (ETDEWEB)

Martin, R; Roche, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The experience acquired as a result of the operation of the Marcoule reactors and of the construction and start-up of the E.D.F. reactors on the one hand, and the conclusions of research and tests carried out out-of-pile on the other hand, lead to a considerable change in the general design of reactors of the gas-graphite type. The main modifications envisaged are analysed in the paper. The adoption of an annular fuel element and of a down-current cooling will make it possible to increase considerably the specific power and the power output of each channel; as a result there will be a considerable reduction in the number of the channels and a corresponding increase in the size of the unit cell. The graphite stack will have to be adapted to there new conditions. For security reasons, the use of prestressed concrete for the construction of the reactor vessel is becoming more widespread; they could lead to the exchangers and the fuel-handling apparatus becoming integrated inside the vessel (the so-called 'attic' device). A full-size mode) of this attic has been built at Saclay with the participation of EURATOM; the operational results obtained are presented as well as a new original design for the control rods. As for as the gas-heavy-water system is concerned, the research is carried out on two points of design; the first, which retains the use of horizontal pressure tubes, takes into account the experience acquired during the construction of the EL 4 reactor of which it will constitute an extrapolation; the second, arising from the research carried out on the gas-graphite system, will use a pre-stressed concrete vessel for holding the pressure, the moderator being almost at the same pressure as the cooling fluid and the fuel being placed in vertical channels. The relative merits of these two variants are analysed in the present paper. (authors) [French] L'experience acquise par l'exploitation des reacteurs de MARCOULE, la construction et le demarrage des reacteurs d

A review of the current thermal-hydraulic modeling of the Jules Horowitz Reactor: A loss of flow accident analysis

International Nuclear Information System (INIS)

Pegonen, R.; Bourdon, S.; Gonnier, C.; Anglart, H.

2014-01-01

Highlights: • CEA methodology for thermal-hydraulic calculations in the JHR reactor is described. • Thermal-hydraulics of the JHR is analyzed during LOFA using CATHARE and FLICA4. • Safety criteria, important modeling parameters and correlations are presented. • Possible improvements of the current methodology are discussed and proposed. - Abstract: The newest European high performance material testing reactor, the Jules Horowitz Reactor, will support existing and future nuclear reactor designs. The reactor is under construction at CEA Cadarache research center in France and is expected to start operation at the end of this decade. R and D and analytical works have already been performed to set-up the methodology for thermal-hydraulic calculations of the reactor. This paper presents the off-line coupled thermal-hydraulic modeling of the reactor using the CATHARE system code and the FLICA4 core analysis code. The main objective of the present work is to analyze the thermal-hydraulic calculations of the reactor during the loss of flow accident using CEA methodology. Possible improvements of the current methodology are shortly discussed and suggested

Fluctuations in a system depending on several random parameters. Application to reactors (1962); Fluctuations d'un systeme dependant de plusieurs parametres aleatoires. Application aux reacteurs nucleaires (1962)

Energy Technology Data Exchange (ETDEWEB)

Blaquiere, A [Faculte des Sciences de Paris, 75 (France); Pachowska, R [Universite Technique de Varsovie (Poland)

1962-07-01

We have previously developed a method for studying neutronic fluctuations in nuclear reactors using the analogy between the behaviour of a reactor and that of certain common radioelectric circuits. The fluctuations may then be calculated by introducing into the circuit a suitable noise source. By this method we have been able to consider the overall fluctuations in a particularly simple form and we have provided a physical significance for certain results obtained more laboriously by other methods. The object of the present report is to generalise this method and in particular to extend it to the case of a reactor having a cellular structure and to apply it to fluctuations within a cell. It is thus shown that the fluctuations in a cell are the resultant of two terms: - a rapidly evolving Poissonian noise, not related to the overall fluctuations; - a slowly evolving noise, when the reactor is not too far from criticality, which is related to the overall fluctuations. The first term arises from a rapid 'ordering' of the system, during which time the cells come mutually into equilibrium. The second term is due to the coordinated evolution of all the cells, after the end of the first transitory phase. The conclusions reached show that it would be useful to complete the study with an analysis of non-linear phenomena which can considerably influence the transitory behaviour of the cells during the initial pre-equilibrium phase. This report also Stresses the relationship of the new method to the old methods. It tends also to place pile fluctuation theory in a more general framework, that of the fluctuations of a system depending on several random parameters; from this point of view, the method could easily be transposed and adapted to the study of other physical problems of this type. (authors) [French] Nous avons precedemment developpe une methode d'etude des fluctuations neutroniques des reacteurs nucleaires mettant a profit l'analogie entre le comportement d

The functioning of the reactors G2-G3 at Marcoule and E.D.F. 1; Experience de fonctionnement des reacteurs G2-G3 de Marcoule et enseignements des essais de demarrage du reacteur E.D.F. 1 de Chinon

Energy Technology Data Exchange (ETDEWEB)

Boussard, R; Conte, F [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires; Stolz, J M [Electricite de France (EDF), 75 - Paris (France)

1964-07-01

After resuming briefly the characteristics of the installations G2-G3 at Marcoule and EDF 1 at Chinon, the authors review the main aspects of the tests, the starting and the exploitation of these reactors. Among the various points examined, particular emphasis is given to the devices of original nature such as tubular fuel elements, flattening of the neutron flux by stuffing, behaviour of the reactor tanks and the cooling circuits, the blowers, unloading devices, regulation and functioning of the informations. This analysis deals equally with the performances obtained and the difficulties and the various incidents experienced during the initial starting period. Among the more interesting results, the progressive increase in the power of the Marcoule reactors is mentioned, obtained through a better knowledge of the parameters covering the functioning of the reactors such as the distribution of the flux and the temperatures etc... acquired during the course of the exploitation of the reactor. The conclusion reached by the authors is that the experience gained on these installations has shown: - that during an initial period, adjustments became necessary, all of which turned out to be possible, - that an analysis of their functioning has permitted the progressive movement towards a truly industrial exploitation. (authors) [French] Les auteurs, apres un bref rappel des caracteristiques des installations G2 - G3 de MARCOULE et E.D.F. 1 de CHINON, passent en revue les principaux aspects des essais, de la mise en service et de l'exploitation de ces centrales. Parmi les divers points examines, une attention speciale est accordee aux dispositifs presentant un caractere original tels que elements combustibles tubulaires, aplatissement du flux neutronique par gavage, comportement des caissons des reacteurs et des circuits de refroidissement, soufflantes, appareils de dechargement, regulation et fonctionnement des informations. L'analyse presentee porte tant sur les

Study of the strength of the internal can for internally and externally cooled fuel elements intended for gas graphite reactors; Etude de la tenue de la gaine interne pour-element combustible a refroidissement interne et externe d'un reacteur graphite-gaz

Energy Technology Data Exchange (ETDEWEB)

Boudouresque, B; Courcon, P; Lestiboubois, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The cartridge of an internally and externally cooled annular fuel element used in gas-graphite reactors is made up of an uranium fuel tube, an external can and an internal can made of magnesium alloy. For the thermal exchange between the internal can and the fuel to be satisfactory, it is necessary for the can to stay in contact with the uranium under all temperature conditions. This report, based on a theoretical study, shows how the internal can fuel gap varies during the processes of canning, charging into the reactor and thermal cycling. The following parameters are considered: tube diameter, pressure of the heat carrying gas, gas entry temperature, plasticity of the can alloy. It is shown that for all operating conditions the internal can of a 77 x 95 element, planned for a gas-graphite reactor with a 40 kg/cm{sup 2} gas pressure, should remain in contact with the fuel. (authors) [French] La cartouche d'un element combustible annulaire, a refroidissement interne et externe pour reacteur graphite-gaz, est composee d'un tube combustible en uranium, d'une gaine externe et d'une gaine interne en alliage de magnesium. Pour que l'echange thermique entre la gaine interne et le combustible soit bon, il faut que la gaine reste appliquee sur l'uranium quel que soit le regime de temperature. Cette note a pour but de montrer comment, d'apres une etude theorique, le jeu combustible-gaine interne varie au cours des operations de gainage, de chargement dans le reacteur, et des cyclages thermiques. Les parametres suivants sont etudies: diametres de tube, pression du gaz caloporteur, temperature d'entree du gaz, plasticite de l'alliage de gaine. Il est montre que, quel que soit le regime de fonctionnement, la gaine interne d'un element 77 x 95, en projet pour un reacteur graphite-gaz sous pression de 40 kg/cm{sup 2}, doit rester appliquee sur le combustible. (auteurs)

Insetos em presépios e as "formigas vestidas" de Jules Martin (1832-1906: uma curiosa manufatura paulistana do final do século XIX

Directory of Open Access Journals (Sweden)

Dante Martins Teixeira

2008-01-01

Full Text Available Present in Brazil since the beginning of Portuguese colonization, crèche nativity scenes were soon adapted to local reality, a propitious circumstance for the appearance of heterodox conceptions and the use of exotic elements of the fauna and flora peculiar to each region. As records about insects are very uncommon, it is noteworthy that females of leaf-cutting ants, Atta sp. (Hymenoptera, Formicidae, were used to compose crèche nativity scenes in São Paulo State. Having subsisted at least up to the decade of 1960, the "ant crèches" of cities such as Embu das Artes could be related to the then famous "dressed ants" created by Jules Martin, a curious manufacture of the city of São Paulo in the last quarter of the 19th century.

Development of Forest Drought Index and Forest Water Use Prediction in Gyeonggi Province, Korea Using High-Resolution Weather Research and Forecast Data and Localized JULES Land Surface Model

Science.gov (United States)

Lee, H.; Park, J.; Cho, S.; Lee, S. J.; Kim, H. S.

2017-12-01

Forest determines the amount of water available to low land ecosystems, which use the rest of water after evapotranspiration by forests. Substantial increase of drought, especially for seasonal drought, has occurred in Korea due to climate change, recently. To cope with this increasing crisis, it is necessary to predict the water use of forest. In our study, forest water use in the Gyeonggi Province in Korea was estimated using high-resolution (spatial and temporal) meteorological forecast data and localized Joint UK Land Environment Simulator (JULES) which is one of the widely used land surface models. The modeled estimation was used for developing forest drought index. The localization of the model was conducted by 1) refining the existing two tree plant functional types (coniferous and deciduous trees) into five (Quercus spp., other deciduous tree spp., Pinus spp., Larix spp., and other coniferous spp.), 2) correcting moderate resolution imaging spectroradiometer (MODIS) leaf area index (LAI) through data assimilation with in situ measured LAI, and 3) optimizing the unmeasured plant physiological parameters (e.g. leaf nitrogen contents, nitrogen distribution within canopy, light use efficiency) based on sensitivity analysis of model output values. The high-resolution (hourly and 810 × 810 m) National Center for AgroMeteorology-Land-Atmosphere Modeling Package (NCAM-LAMP) data were employed as meteorological input data in JULES. The plant functional types and soil texture of each grid cell in the same resolution with that of NCAM-LAMP was also used. The performance of the localized model in estimating forest water use was verified by comparison with the multi-year sapflow measurements and Eddy covariance data of Taehwa Mountain site. Our result can be used as referential information to estimate the forest water use change by the climate change. Moreover, the drought index can be used to foresee the drought condition and prepare to it.

Study of a Slightly Enriched R Reactor Fuel by Means of a Pulsed Neutron Source; Etude d'un reacteur a combustible legerement enrichi (rubeole) a l'aide de sources pulsees de neutrons

Energy Technology Data Exchange (ETDEWEB)

Sagot, M.; Tellier, H. [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

1962-04-01

A Be O moderated reactor using slightly enriched uranium oxide as fuel was studied by the pulsed neutron source technique. The neutron lifetime was measured in two different cores without reflector, then attempts were made at the measurement of great negative reactivities introduced into the reactor under the following forms: decrease of the volume of the un reflected core, introduction of absorbing cadmium rods, removal of fuel at the periphery of the critical core while maintaining a constant height, and substitution of fuel elements by less reactive elements. In all cases, the results are compared with the data obtained by another type of experiment or by computation. (author) [French] Nous avons applique la methode des sources pulsees de neutrons a un reacteur utilisant de l'oxyde d'uranium legerement enrichi, modere a l'oxyde de beryllium et, apres avoir mesure le temps de vie des neutrons dans deux coeurs differents non reflechis, nous avons porte notre effort, sur la mesure de reactivites negatives importantes introduites dans le reacteur sous differentes formes: - diminution du volume du coeur non reflechi, - introduction de barres absorbantes en cadmium, - enlevement de combustible a la peripherie du coeur critique, tout en conservant une hauteur constante, - substitution d'elements de combustible par des elements moins reactifs. Dans tous les cas, les resultats sont compares aux valeurs obtenues par un autre type d'experience ou par le calcul. (auteur)

Improvements in gas supply systems for heavy-water moderated reactors; Etudes de perfectionnements aux systemes d'alimentation en gaz d'un reacteur modere a l'eau lourde

Energy Technology Data Exchange (ETDEWEB)

Aubert, G; Hassig, J M; Laurent, N; Thomas, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

In a heavy-water moderated reactor cooled by pressurized gas, an important problem from the point of view, of the reactor block and its economics is the choice of the gas supply system. In the pressure tube solution, the whole of the reactor block structure is at a relatively low temperature, whereas the gas supply equipment is at that of the gas, which is much higher. These parts, through which passes the heat carrying fluid have to present as low a resistance as possible to it so as to avoid costly extra blowing power. Finally, they may only be placed in the reactor block after it has been built; the time required for putting them in position should therefore not be too long. The work reported here concerns the various problems arising in the case of each channel being supplied individually by a tube at the entry and the exit which is connected to a main circuit made up of large size collectors. This individual tubing is sufficiently flexible to absorb the differential expansion and the movement of its ends without stresses or prohibitive reactions being produced; the tubing is also of relatively short length so as to reduce the pressure head of the pressurized gas outside the channels; the small amount of space taken up by the tubing makes it possible to assemble it in a manner which is satisfactory from the point of view both of the time required and of the technical quality. (authors) [French] Dans un reacteur modere a l'eau lourde et refroidi au gaz sous pression, un probleme important du point de vue du trace du bloc pile et de son economie est le choix du systeme d'alimentation en gaz. Pour une solution a tubes de force, l'ensemble des structures du bloc reacteur est a temperature relativement faible, alors que les organes d'alimentation en gaz sont a celle, notablement plus elevee, du gaz. Ces organes, traverses par le debit du caloporteur, doivent lui opposer le minimum de resistance afin de ne pas necessiter un supplement onereux de puissance de

Design of the fuel element 'snow-flake' in uranium oxide, canned with aluminium, for the experimental reactor EL 3 (1960); Etude d'un element combustible en oxyde d'uranium gaine d'aluminium, type ''cristal de neige'' pour la pile EL 3 (1960)

Energy Technology Data Exchange (ETDEWEB)

Gauthron, M.; Guibert, B. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

This report sums up the main studies have been carried out on the fuel element 'Snowflake' (uranium oxide, canned with aluminium), designed to replace the present element of the experimental reactor EL3 in order to increase the reactivity without modifying the neutron flux/thermal power ratio. (author) [French] Ce rapport resume les principales etudes qui ont ete faites sur l'element combustible 'Cristal de Neige' (a oxyde d'uranium, gaine d'aluminium) destine a remnlacer l'element actuel du reacteur experimental EL3, afin d'en augmenter la reactivite sans modifier le rapport flux neutronique-puissance thermique. (auteur)

Two further years of operation of the reactor G1 (july 1958 - july 1960); Deux nouvelles annees de fonctionnement du reacteur G1. (juillet 1958 - Juillet 1960)

Energy Technology Data Exchange (ETDEWEB)

Mathot, P; Bauzit, J; Cante, R; Hebrard, L [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The aim of the present report is to present certain observations and to give the results obtained during the period from july the 1{sup st} 1958 to july the 1{sup st} 1960. The main operations carried out during this period were, chronologically: - From july the 5{sup th} to october the 18{sup th} 1958: preparation and execution of the first annealing of the graphite. - From dec. the 15{sup th} 1958 to july the 15{sup th} 1959: a discharging campaign which resulted in the complete renewal of the fuel elements. During the monthly stoppages of this campaign, it was possible to make certain observations concerning the packing of the graphite, while at the same time measurements of the temperature of the element cans were made at an increased number of points. - From september the 25{sup th} 1959 to december the 9{sup th} 1959: preparation and execution of the second annealing. At the end of the annealing, the thorium lattice was modified and extra thermocouples were installed for measuring the temperature of the body of the graphite. An apparatus was built for measuring the radial flux. - From december the 9{sup th} 1959 to july 1960: a continuous operation campaign, with a minimum of stoppages. The experimental results are re-assembled, independently of their chronological order, under three main headings which describe the reactors history: - continuous operation, - discharges, - annealing of the reactor. (author) [French] Le but du present rapport est d'exposer certaines observations faites et les resultats obtenus au cours de la periode du 1{sup er} juillet 1958 au 1{sup er} juillet 1960. Cette periode a ete marquee chronologiquement par les operations essentielles suivantes: - du 5 juillet au 18 octobre 1958: preparation et execution du premier recuit du graphite. - du 15 decembre 1958 au 15 juillet 1959: campagne de dechargement entrainant un renouvellement total des cartouches de combustibles. Au cours des arrets mensuels de cette campagne, certaines

Development and experimental qualification of a calculation scheme for the evaluation of gamma heating in experimental reactors. Application to MARIA and Jules Horowitz (JHR) MTR Reactors

Energy Technology Data Exchange (ETDEWEB)

Tarchalski, M.; Pytel, K.; Wroblewska, M.; Marcinkowska, Z.; Boettcher, A.; Prokopowicz, R. [NCBJ Institute, MARIA Reactor, ul.Andrzeja Soltana 7, 05-400 Swierk (Poland); Sireta, P.; Gonnier, C.; Bignan, G. [CEA, DEN, Reactor Studies Department, Cadarache, F-13108 St-Paul-Lez-Durance (France); Lyoussi, A.; Fourmentel, D.; Barbot, L.; Villard, J.F.; Destouches, C. [CEA, DEN, DER, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St-Paul-Lez-Durance (France); Reynard-Carette, C.; Brun, J. [Aix Marseille Universite, CNRS, Universite de Toulon, IM2NP UMR 7334, 13397, Marseille (France); Jagielski, J. [NCBJ Institute, MARIA Reactor, ul.Andrzeja Soltana 7, 05-400 Swierk (Poland); Institute of Electronic Materials Technolgy, Wolczynska 133, 01-919 Warszawa (Poland); Luks, A. [Institute of Heat Engineering, Nowowiejska 21/25, 00-665 Warsaw (Poland)

2015-07-01

Precise computational determination of nuclear heating which consists predominantly of gamma heating (more than 80 %) is one of the challenges in material testing reactor exploitation. Due to sophisticated construction and conditions of experimental programs planned in JHR it became essential to use most accurate and precise gamma heating model. Before the JHR starts to operate, gamma heating evaluation methods need to be developed and qualified in other experimental reactor facilities. This is done inter alia using OSIRIS, MINERVE or EOLE research reactors in France. Furthermore, MARIA - Polish material testing reactor - has been chosen to contribute to the qualification of gamma heating calculation schemes/tools. This reactor has some characteristics close to those of JHR (beryllium usage, fuel element geometry). To evaluate gamma heating in JHR and MARIA reactors, both simulation tools and experimental program have been developed and performed. For gamma heating simulation, new calculation scheme and gamma heating model of MARIA have been carried out using TRIPOLI4 and APOLLO2 codes. Calculation outcome has been verified by comparison to experimental measurements in MARIA reactor. To have more precise calculation results, model of MARIA in TRIPOLI4 has been made using the whole geometry of the core. This has been done for the first time in the history of MARIA reactor and was complex due to cut cone shape of all its elements. Material composition of burnt fuel elements has been implemented from APOLLO2 calculations. An experiment for nuclear heating measurements and calculation verification has been done in September 2014. This involved neutron, photon and nuclear heating measurements at selected locations in MARIA reactor using in particular Rh SPND, Ag SPND, Ionization Chamber (all three from CEA), KAROLINA calorimeter (NCBJ) and Gamma Thermometer (CEA/SCK CEN). Measurements were done in forty points using four channels. Maximal nuclear heating evaluated from

Description of methods for making activation detectors for use in nuclear reactors; Description des procedes de fabrication des detecteurs d'activation utilises dans les reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Barbalat, R; Le Coguie, R; Leger, P; Salon, L; Thierry, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1968-07-01

A brief description of methods currently used for making activation detectors, thin films and various deposits used in nuclear reactors. The thicknesses required vary from about a few tenths of a micron to a few tenths of a millimeter. Different techniques are used for fixing the large variety of elements: rolling, moulding, painting, electrolysis, vacuum deposition, thin films, wires, enamels, protective linings, etc. (authors) [French] Expose succinct des procedes actuellement mis en oeuvre pour la realisation des detecteurs d'activation, feuilles minces et depots divers utilises dans les reacteurs nucleaires. La gamme des epaisseurs necessaires s'etendant approximativement des dixiemes de micrometre aux dixiemes de millimetre. La diversite des elements a fixer justifiant les techniques differentes selon les cas: laminage, moulage, peinture, electrolyse, depot sous vide, couches minces, fils, emaux, revetements protecteurs, etc. (auteurs)

The Control of Fast Reactors: Current Methods and Future Prospects; Controle des Reacteurs a Neutrons Rapides. Methodes Actuelles et Perspectives d'Avenir; Upravlenie reaktorami na bystrykh nejtronakh. sushchestvuyushchie metody i dal'nejshie perspektivy; Control de Reactores Rapidos: Metodos Actuales y Perspectivas

Energy Technology Data Exchange (ETDEWEB)

Loewenstein, W. B. [Argonne National Laboratory, IL (United States)

1964-06-15

regarding the specification of this parameter. These considerations are discussed in terms of control reactivity in existing fast reactors as opposed to the amount that is really required for fast power-breeder reactor operation. Typical power- and temperature-dependent feedback parameters are cited for determination of their influence upon the control reactivity requirements. The methods used to predict the reactivity worth of control mechanisms have evolved from crude estimates to quite reliable calculations which can be confirmed by experimental data from critical assemblies. Experimental results and currently reliable analytical techniques are described. Critical experiments for the current generation of fast reactors included many investigations pertaining to the reactivity worth of their control mechanisms as well as peripheral experiments for larger-core-volume advanced systems. Exploratory analytical studies, which indicate that detailed experimental mockup investigations may not be required in the future, are cited. (author) [French] L'auteur examine dans ce memoire les aspects pratiques du probleme qui consiste a fournir une reactivite suffisante pour le controle des reacteurs a neutrons rapides; ce probleme differe dans une grande mesure de celui du controle des reacteurs a neutrons thenniques. Ces differences sont dues en premier lieu au fait que les sections efficaces d'absorption des neutrons rapides sont assez faibles. Il n'existe pas de poisons forts dans un reacteur a neutrons rapides. En consequence, les poisons forts que sont certains produits de fission dans un reacteur thermique (par exemple Xe et Sm) exigent un exces de reactivite beaucoup moins important que n'en exige la perte de reactivite due a la destruction de produit fissile par fission et capture. Comme les sections efficaces pour les neutrons rapides sont relativement petites comparees aux valeurs correspondantes pour les neutrons thermiques, la densite atomique du materiau joue un role

Space-time dependent impulse response of a subcritical cylindrical reactor; Reponse impulsionnelle spatio-temporelle d'un reacteur cylindrique en regime sous-critique

Energy Technology Data Exchange (ETDEWEB)

Cazemajou, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-07-01

In this paper, a new formulation of the spatial dependent impulse response of a subcritical reactor in a cylindrical geometry is proposed. An expression of the transfer function between a point source at the center of coordinates and the flux at a given point (r,z) is obtained by solving: by means of Laplace transform, the one group diffusion equation. In this transfer function, variables r and p (p being the Laplace variable) remain linked within a modified Bessel function. Taking the inverse Laplace transform is done by two different ways: - using the Mellin-Fourier method which separates variables r and t. This method makes it possible to establish that there is identity between the classical formulation and the new one. - using an inverse Laplace transform which keeps variables r and t linked. This method requires to approximate the inverse Laplace transform of the end factor. It is then possible to replace the radial harmonics modes series of the classical expression by a single function. This new formulation seems to be of particular interest when dealing with reactors of large size and lifetime. It is also interesting each time the harmonics play an important role. (author) [French] Dans le present rapport, on propose une nouvelle formulation de la reponse impulsionnelle spatio-temporelle d'un reacteur sous-critique, en geometrie cylindrique. Une expression de la fonction de transfert entre une source ponctuelle placee au centre des coordonnees et le flux au point courant (r,z) est obtenue en resolvant, par transformation de Laplace, l'equation de la diffusion a un seul groupe d'energie. Dans cette fonction de transfert, les variables r et p (variable de Laplace) demeurent groupees dans une fonction de Bessel modifiee. Le retour a l'original est effectue de deux manieres: - la methode de Mellin-Fourier qui separe les variables r et t, permet d'etablir l'identite entre la nouvelle formulation et la formulation classique. - un original conservant les variables

Economic aspects of electricity and industrial heat generating reactors; Aspect economique des reacteurs produisant de l'electricite et de la chaleur industrielle

Energy Technology Data Exchange (ETDEWEB)

Gaussens, J; Moulle, N; Dutheil, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Aldebert, J [Institut National des Sciences et Techniques Nucleaires (INSTN), CEA Saclay, 91 - Gif sur Yvette (France)

1964-07-01

The economic advantage of electricity-generating nuclear stations decreases when their size decreases. However, when a counter-pressure turbine is joined on to a reactor and the residual heat can be properly used, it can be shown that fairly low capacity nuclear equipment may compete with conventional equipment under certain realistic enough conditions. The aim of this paper is to define these special conditions under which nuclear energy can be profitable. They are connected with the location and the general economic environment of the station, the pattern of the electricity and heat demands it must meet, the level of fuel and specific capital costs, nuclear and conventional. These conditions entail certain technical and economic specifications for the reactors used in this way otherwise they are unlikely to be competitive. In addition, these results are referred to the potential steam and electricity market, which leads us to examine certain uses for the heat generated by double purpose power stations; for example, to supply combined industrial plants, various types of town heating and for removal of salt from sea water. (authors) [French] L'interet economique de centrales nucleaires productrices d'electricite decroit lorsque la puissance decroit. Cependant, lorsqu'on associe une turbine a contrepression a un reacteur et qu'il est possible d'utiliser dans de bonnes conditions la chaleur residuelle, on peut montrer que dans certaines conditions assez realistes, des equipements nucleaires d'une puissance unitaire peu elevee peuvent etre competitifs avec des equipements conventionnels. Cette communication a donc pour but de mettre en evidence quelles sont ces conditions particulieres de rentabilite de l'energie nucleaire. Elles sont liees a la localisation de la centrale et a son contexte economique general, a la structure de la demande d'energie electrique et thermique a laquelle elle doit satisfaire, au niveau des couts des combustibles et des investissements

Cats on the Couch: The Experimental Production of Animal Neurosis.

Science.gov (United States)

Winter, Alison

2016-03-01

Argument In the 1940s-50s, one of the most central questions in psychological research related to the nature of neurosis. In the final years of the Second World War and the following decade, neurosis became one of the most prominent psychiatric disorders, afflicting a high proportion of military casualties and veterans. The condition became central to the concerns of several psychological fields, from psychoanalysis to Pavlovian psychology. This paper reconstructs the efforts of Chicago psychiatrist Jules Masserman to study neurosis in the laboratory during the 1940s and 1950s. Masserman used Pavlovian techniques in a bid to subject this central psychoanalytic subject to disciplined scientific experimentation. More generally, his project was an effort to bolster the legitimacy of psychoanalysis as a human science by articulating a convergence of psychoanalytic categories across multiple species. Masserman sought to orchestrate a convergence of psychological knowledge between fields that were often taken to be irreconcilable. A central focus of this paper is the role of moving images in this project, not only as a means of recording experimental data but also as a rhetorical device. The paper argues that for Masserman film played an important role in enabling scientific observers (and then subsequent viewers) to see agency and emotion in the animals they observed.

The Role of Non-Destructive Testing in the Los Alamos Reactor Programme; Role des Essais Non Destructifs dans le Programme de Reacteurs de los Alamos; Rol' nedestruktivnykh ispytanij materialov v Los-Alamosskoj reaktornoj programme; Papel de los Metodos de Ensayo No Destructivo en el Programa de Reactores de Los Alamos

Energy Technology Data Exchange (ETDEWEB)

Tenney, G. H. [University of California, Los Alamos Scientific Laboratory, Los Alamos, NM (United States)

1965-10-15

the work on this subject has not been previously published. (author) [French] Le Laboratoire scientifique de Los Alamos, exploite par l'Universite de Californie pour la Commission de l'energie atomique des Etats-Unis, s'occupe depuis plus de vingt ans de l'etude, de la mise au point et de la construction de quatre types de reacteurs nucleaires: reacteurs de recherche, reacteurs de puissance, reacteurs pour la propulsion des fusees et assemblages critiques. Le Groupe des essais non destructifs collabore a presque tous les projets et travaux du Laboratoire. Le memoire decrit quelques-unes des methodes inedites d'essais non destructifs qui y ont ete mises au point et sont appliquees dans le cadre du programme de reacteurs. Le reacteur de puissance experimental LAMPRE est fonde sur l'utilisation d'une solution de phosphate d'uranium a haute temperature. Cette solution est tres corrosive et toutes les parties en contact avec elle ont un revetement en or. On a eu recours a des techniques radiographiques speciales pour controler l'or pendant le processus de laminage d'un lingot coule. On a procede de la meme maniere a l'inspection des soudures. Une methode d'inspection fondee sur les variations de potentiel aux electrodes a ete mise au point, pour la detection d'impuretes sur les surfaces d'or. Le reacteur experimental au plutonium fondu LAPRE est fonde sur l'utilisation de plutonium metallique, sous forme liquide plutot que sous forme solide, comme combustible. Le combustible est contenu dans des capsules en tantale. On a eu recours a des methodes non destructives pour verifier le bon etat du metal de base et des soudures pendant la fabrication des capsules, ainsi que pour controler les capsules remplies de plutonium avant, pendant et apres les essais de fusion et solidification. L'essai d'une pompe a plutonium fondu a ete suivi par des methodes radiographiques, en utilisant notamment un circuit ferme de television a rayons gamma. Pour le reacteur experimental a tres haute

Spatial flux instabilities, and their control in the graphite gas power reactors; Les instabilites spatiales du flux et leur controle dans les reacteurs de puissance graphite-gaz

Energy Technology Data Exchange (ETDEWEB)

Cailly, J L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

Radial-azimuthal and axial spatial flux instabilities in graphite-gas reactors are studied by means of an analytical approach. Results are checked with those which are given by two dimensional (r, z and r, {theta}) kinetic models programmed for an IBM 7094 computer. At least, conclusions on the control of instabilities obtained from these models are reported. (author) [French] Les instabilites spatiales du flux dans les reacteurs graphite-gaz, radiales et azimutales d'une part, axiales d'autre part, sont etudiees au moyen d'une formulation analytique. Les resultats sont confrontes avec ceux que fournissent des modeles cinetiques a deux dimensions (r, z et r, {theta}) programmes sur IBM 7094. On donne enfin les conclusions relatives au controle de ces instabilites que ces modeles ont permis de degager. (auteur)

Changements à la tête du CERN - Robert Aymar aux commandes pour 5 ans.

CERN Multimedia

2003-01-01

"Une nouvelle équipe prendra les rênes du CERN à partir du 1er janvier. Le Francais Robert Aymar, anciennement directeur du Projet de reacteur thermonucleaire experimental international (ITER), dirigera le centre de recherche pour la periode 2004-2008" (1 page).

A study of switch circuits for use as safety devices in nuclear reactors; Etude de circuits de commutation destines a la securite des reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Hantcherian, V [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1960-12-15

The author reviews briefly a few basic assemblies using electromagnetic relays for safety circuits in nuclear reactors; he then studies the use of static relays with a shorter time of response, based on impedance changes in a self-inductance consisting of a coil with a magnetic core having a rectangular hysteresis cycle. The author examines in particular the way in which it functions and the method of determining the parameters. (author) [French] L'auteur apres avoir examine sommairement en revue quelques montages de base des circuits de securite des reacteurs nucleaires utilisant des relais electromecaniques, etudie l'emploi des relais statiques a plus grande vitesse de reponse bases sur la variation d'impedance que presente une self-inductance realisee a l'aide d'une bobine enroulee autour d'un noyau magnetique a cycle d'hysteresis rectangulaire. En particulier, il en examine le mode de fonctionnement et la determination des parametres. (auteur)

Economic aspects of electricity and industrial heat generating reactors; Aspect economique des reacteurs produisant de l'electricite et de la chaleur industrielle

Energy Technology Data Exchange (ETDEWEB)

Gaussens, J.; Moulle, N.; Dutheil, F. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Aldebert, J. [Institut National des Sciences et Techniques Nucleaires (INSTN), CEA Saclay, 91 - Gif sur Yvette (France)

1964-07-01

The economic advantage of electricity-generating nuclear stations decreases when their size decreases. However, when a counter-pressure turbine is joined on to a reactor and the residual heat can be properly used, it can be shown that fairly low capacity nuclear equipment may compete with conventional equipment under certain realistic enough conditions. The aim of this paper is to define these special conditions under which nuclear energy can be profitable. They are connected with the location and the general economic environment of the station, the pattern of the electricity and heat demands it must meet, the level of fuel and specific capital costs, nuclear and conventional. These conditions entail certain technical and economic specifications for the reactors used in this way otherwise they are unlikely to be competitive. In addition, these results are referred to the potential steam and electricity market, which leads us to examine certain uses for the heat generated by double purpose power stations; for example, to supply combined industrial plants, various types of town heating and for removal of salt from sea water. (authors) [French] L'interet economique de centrales nucleaires productrices d'electricite decroit lorsque la puissance decroit. Cependant, lorsqu'on associe une turbine a contrepression a un reacteur et qu'il est possible d'utiliser dans de bonnes conditions la chaleur residuelle, on peut montrer que dans certaines conditions assez realistes, des equipements nucleaires d'une puissance unitaire peu elevee peuvent etre competitifs avec des equipements conventionnels. Cette communication a donc pour but de mettre en evidence quelles sont ces conditions particulieres de rentabilite de l'energie nucleaire. Elles sont liees a la localisation de la centrale et a son contexte economique general, a la structure de la demande d'energie electrique et thermique a laquelle elle doit satisfaire, au niveau des couts des

Measurement and regulation of the level of a homogeneous plutonium reactor; Mesure et regulation du niveau d'un reacteur homogene au plutonium

Energy Technology Data Exchange (ETDEWEB)

Berger, F; Bertrand, J

1958-12-01

Reactivity depends strongly on disturbances of the level of the plutonium solution In the homogeneous reactor. Proserpine has a small cylindrical core, 250 mm diameter, and 10 liters volume. With a view to reducing the dangers due to corrosion and contamination, the solution level in the core is raised by pneumatic pressure. The level is stabilized by means of a regulating system. During critical experiments the variations of the level are less than one hundredth part of a millimeter. (author) [French] Les variations du niveau de la solution de plutonium dans le reacteur homogene Proserpine ont une grosse influence sur la reactivite, car le coeur est petit (10 litres de solution dans un cylindre de diametre 250 mm). En vue de reduire les dangers dus a la corrosion et a la contamination, la commande du volume liquide est pneumatique. Nous avons realise la stabilite du niveau par une regulation qui, dans les essais en regime critique, limite les variations du plan liquide a une fraction de centieme de millimetre. (auteur)

Operating Experience with the BR-5 Reactor; Experience acquise aupres du reacteur BR-5; Opyt ehkspluatatsii reaktora BR-5; Experiencia practica con el reactor BR-5

Energy Technology Data Exchange (ETDEWEB)

Lejpunskij, A. I.; Kazachkovskij, O. D.; Pinkhasik, M. S.; Aristarkhov, N. N.; Karpov, A. V.; Larin, E. P.; Efimov, I. A.

1963-10-15

The paper discusses the carrying-out of repair and maintenance work on the radioactive liquid-metal circuit of the BR-5 fast neutron reactor. Attention is also given to problems of reactor operation after achievement of the planned 2% fuel burn-up with some disturbance of leak-tightness in individual fuel elements. An account is given of experience in discharging the active section, examining the condition and leak-tightness of the fuel elements, and decontaminating the equipment and piping of the first radioactive circuit after reaching 5% fuel burn-up. (author) [French] Dans ce memoire les auteurs decrivent l'execution des reparations et des travaux d'entretien dans le circuit radioactif liquide-metal du reacteur a neutrons rapides BR-5. Ils etudient egalement les problemes lies au fonctionnement du reacteur au taux de combustion de 2% prevu avec quelques defauts d'etancheite dans des elements combustibles particuliers. Ils decrivent le dechargementen zone active et examinent les conditions d'etancheite des elements combustibles. Ainsi que la decontamination de l'appareillage et des tuyauteries du premier circuit radioactif apres avoir atteint un taux de combustion de 5%. (author) [Spanish] En la memoria se examinan los problemas planteados por el mantenimiento del circuito radiactivo de metal liquido del reactor de neutrones rapidos BR-5. Se tratan cuestiones relacionadas con la explotacion del reactor una vez alcanzado el grado de combustion de 2%, previsto en el proyecto y luego de producirse ciertas alteraciones de la densidad de determinados elementos combustibles. Se describen la experiencia adquirida durante la descarga del cuerpo del reactor, las investigaciones del estado general y de la hermeticidad de los elementos combustibles y las operaciones de descontaminacion de la instalacion y de las tuberias del circuito radiactivo primario despues de alcanzado un grado de combustion de 5%. (author) [Russian] V doklade rassmatrivayutsya voprosy proizvodstva

Conversations avec Jules Hoüel regards sur la géométrie non euclidienne et l’analyse infinitésimale vers 1875

CERN Document Server

Nabonnand, Philippe

2017-01-01

Jules Hoüel (1823-1886) a occupé une place particulière dans les mathématiques en France durant la seconde partie du 19ème siècle. Par ses travaux de traduction et ses recensions, il a vivement contribué à la réception de la géométrie non euclidienne de Bolyai et Lobatchevski ainsi qu’aux débats sur les fondements de l’analyse. Il se situe au centre d’un vaste réseau international de correspondances en lien avec son rôle de rédacteur pour le Bulletin des sciences mathématiques et astronomiques. Cet ouvrage contient les correspondances actives et passives de Hoüel avec Joseph-Marie De Tilly, Gaston Darboux et Victor-Amédée Le Besgue ainsi qu’une introduction qui se focalise sur la découverte de l’impossibilité de démontrer le postulat des parallèles d’Euclide et l’apparition des premiers exemples de fonctions continues non dérivables.

Performance Characteristics of the Experimental Boiling Water Reactor from 0 to 100 MW(t); Performances de l'EBWR de 0 a 100 MW; Rabochaya kharakteristika ehksperimental'nogo kipyashchego reaktora EBWR pri moshchnosti 0 - 100 mgvt.; Rendimiento del reactor experimental de agua hirviente (EBWR) entre 0 y 100 MW

Energy Technology Data Exchange (ETDEWEB)

Iskenderian, A.; Lipinski, W. C.; Petrick, M.; Wimunc, E. A. [Argonne National Laboratory, Argonne, IL (United States)

1963-10-15

's performance characteristics changed radically. The steam disengaging velocity reached 1 ft/s and the steam dome height decreased to 3 ft. Under these conditions liquid carryover occurred and increased rapidly with increasing power. The reactor no longer behaved as a direct-cycle boiling-water reactor; in a sense it functioned as a natnral-circulation dual-cycle reactor. (author) [French] Le 25 mai 1962, le Laboratoire national d'Argonne a recu l'autorisation de la Commission de l'energie atomique des Etats-Unis (CEA-EU) d'exploiter le reacteur experimental a eau bouillante (EBWR) jusqu'a une puissance de 100 MW. Dans le cadre de l'administration du systeme de garanties, l'Agence internationale de l'energie atomique a autorise a aller de l'avant le 11 juillet 1962. Le 5 novembre 1962, on a atteint la puissance de 100 MW. Le programme experimental, realise avec le reacteur EBWR de 100 MW, a ete acheve le 6decembre 1962. L'un des principaux objectifs du projet etait de pourvoir le reacteur de tous les instruments de mesures necessaires pour obtenir des donnees et des renseignements sur les performances de cette filiere. C'est le premier programme de ce genre qui ait ete entrepris. On a mis au point plusieurs techniques d'instrumentation nouvelles pour obtenir les donnees voulues. Cet objectif a ete atteint avec le plus grand succes, et on a pu recueillir beaucoup de donnees nouvelles sur les performances d'un reacteur a eau bouillante a circulation naturelle. Ce programme a permis d'obtenir des indications sur les points suivants: debit de recirculation; limite de separation de la vapeur et du liquide (entrainement de vapeur dans le tube d'eau et de liquide par la vapeur); sous-refroidissement; localisation de l'interface vraie dans le reacteur et son influence sur le niveau de la colonne d'eau; taux de condensation de la vapeur dans le tube d'eau; coefficients cavitaires; antireactivite de l'acide borique; coefficients de temperature; emploi de bandes de bore a des fins de

French experience in design, operation and revamping of nuclear research reactors, in support of advanced reactors development

International Nuclear Information System (INIS)

Barre, B.; Bergeonneau, P.; Merchie, F.; Minguet, J.L.; Rousselle, P.

1996-01-01

The French nuclear program is strongly based on the R and D work performed in the CEA nuclear research centers and particularly on the various experimental programs carried out in its research reactors in the frame of cooperative actions between the Commissariat a l'Energie Atomique (CEA), Framatome and Electricite de France (EDF). Several types of research reactors have been built by Technicatome and CEA to carry out successfully this considerable R and D work on fuels and materials, among them the socalled Materials Testing Reactors (MTR) SILOE (35 MW) and OSIRIS (70 MW) which are indeed very well suited for technological irradiations. Their simple and flexible design and the large irradiation space available around the core, the SILOE and OSIRIS reactors can be shared by several types of applications such as fuel and material testings for nuclear power plants, radioisotopes production, silicon doping and fundamental research. It is worthwhile recalling that Technicatome and CEA have also built research reactors fully dedicated to safety experimental studies, such as the CABRI, SCARABEE and PHEBUS reactors at Cadarache, and others dedicated to fundamental research such as ORPHEE (14 MW) and the Reacteur a Haut Flux -High Flux Reactor- (RHF 57 MW). This paper will present some of the most significant conceptual and design features of all these reactors as well as the main improvements brought to most of them in the last years. Based on this wide experience, CEA and Technicatome have specially designed for export a new multipurpose research reactor named SIRIUS, with two versions depending on the utilization spectrum and the power range (5 MW to 30 MW). At last, CEA has recently launched the preliminary project study of a new MTR, the Jules Horowitz Reactor, to meet the future needs of fuels and materials irradiations in the next 4 or 5 decades, in support of the French long term nuclear power program. (J.P.N.)

Indium-Gallium Radiation Contour of the IRT Nuclear Reactor; Circuit d'activation d'indium-gallium dans le reacteur nucleaire IRT; Indij-gallievyj radiatsionnyj kontur yadernogo reaktora IRT; Circuito de radiaciones de indio-galio del reactor IRT

Energy Technology Data Exchange (ETDEWEB)

Breger, A K; Ryabukin, Y S; Tulkes, S G; Volkov, E N

1960-07-15

Following on theoretical work already published, an indium-gallium radiation contour of the IRT nuclear reactor has been prepared, and represents a powerful new source of gamma-radiation. The first contour of this type ''RK-1'' was prepared on the IRT reactor at the Physics Institute of the Academy of Sciences of the Georgian SSR. The paper gives the activation calculations for indium-gallium alloy; the structural components of RK-1 and their arrangement in the reactor tank and the hot cell; the devise for feeding liquid and gaseous substances into the irradiation zone; and the conveyor for solid substances to be irradiated. When the IRT reactor is at a power of 2000 kW, the radiation strength of the contour is equivalent to that of a gamma-emitter having an activity of 20,000 g. Ra equivalent. The prospects for the use of the indium-gallium radiation contour for research and semi-industrial purposes are discussed. (author) [French] A la suite de la publication d'un ouvrage theorique, on a etabli autour du reacteur nucleaire IRT un circuit d'activation d'indium-gallium qui represente une nouvelle source de rayonnements gamma de grande intensite. Le premier circuit de ce type ''RK-1'' a ete etabli sur le reacteur IRT a l'Institut de physique de l'Academie des sciences de la RSS de Georgie. Les auteurs donnent les calculs de l'activation pour l'alliage indium-gallium; ils indiquent les elements structurels du RK-1 et leur disposition dans le reservoir et dans la cellule de haute activite du reacteur; ils decrivent le dispositif permettant d'introduire des substances liquides et gazeuses dans la zone d'irradiation et le systeme qui transporte les substances solides a irradier. Lorsque le reacteur IRT fonctionne a 2 000 kW, la puissance de rayonnement du circuit equivaut a celle d'un emetteur gamma ayant une activite equivalente a 20 000 grammes de radium. Les auteurs examinent les perspectives d'emploi de ce processus pour la recherche et a des fins semi

Security report on Siloe - the descriptive part. (1963); Rapport de surete de Siloe - partie descriptive (1963)

Energy Technology Data Exchange (ETDEWEB)

Ageron, P; Chatoux, J; Denielou, G; Jacquemain, M; Mitault, G; Robien, E de; Rossillon, F [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1963-07-01

This report is a full description of the site, the reactor, the building and the experimental facilities. It gives the nuclear, thermodynamic and hydrodynamic characteristics of the core. (authors) [French] Ce rapport decrit completement le site, le reacteur, les batiments et les installations experimentales. Il donne les caracteristiques nucleaires, thermodynamiques et hydrodynamiques du coeur. (auteurs)

Water Will Be the Coal of the Future—The Untamed Dream of Jules Verne for a Solar Fuel

Directory of Open Access Journals (Sweden)

Vladimir K. Ryabchuk

2016-11-01

Full Text Available This article evokes the futuristic visions of two giants, one a writer, Jules Verne, who foresaw water as the coal of the future, and the other a scientist, Giacomo Ciamician, who foresaw the utilization of solar energy as an energy source with which to drive photochemical and photocatalytic reactions for the betterment of mankind. Specifically, we examine briefly the early work of the 1960s and 1970s on the photosplitting of free water and water adsorbed on solid supports, based mostly on metal oxides, from which both hydrogen and oxygen evolve in the expected stoichiometric ratio of 2 to 1. The two oil crises of the 1970s (1973 and 1979 spurred the interest of researchers from various disciplines (photochemistry, photo-catalysis and photoelectrochemistry in search of a Holy Grail photocatalyst, process, or strategy to achieve efficient water splitting so as to provide an energy source alternative to fossil fuels. Some approaches to the photosplitting of water adsorbed on solid insulators (high bandgap materials; Ebg ≥ 5 eV and semiconductor photocatalysts (metal oxides are described from which we deduce that metal oxides with bandgap energies around 5 eV (e.g., ZrO2 are more promising materials to achieve significant water splitting on the basis of quantum yields than narrower bandgap photocatalysts (e.g., TiO2; Ebg ≈ 3.0–3.2 eV, which tend to be relatively inactive by comparison. Although proof of concept of the photosplitting of water has been demonstrated repeatedly in the last four decades, much remains to be done to find the Holy Grail photocatalyst and/or strategy to achieve significant yields of hydrogen.

Study of the aqueous corrosion mechanisms and kinetics of the AlFeNi aluminium based alloy used for the fuel cladding in the Jules Horowitz research reactor; Etude des mecanismes et des cinetiques de corrosion aqueuse de l'alliage d'aluminium AlFeNi utilise comme gainage du combustible nucleaire de reacteurs experimentaux

Energy Technology Data Exchange (ETDEWEB)

Wintergerst, M.

2009-05-15

For the Jules Horowitz new material-testing reactor (JHR), an aluminium base alloy, called AlFeNi, will be used for the cladding of the fuel plates. This alloy (Al - 1% Fe - 1% Ni - 1 % Mg), which is already used as fuel cladding, was developed for its good corrosion resistance in water at high temperatures. However, few studies dealing with the alteration process in water and the relationships with irradiation effects have been performed on this alloy. The conception of the JHR fuel requires a better knowledge of the corrosion mechanisms. Corrosion tests were performed in autoclaves at 70 C, 165 C and 250 C on AlFeNi plates representative of the fuel cladding. Several techniques were used to characterize the corrosion scale: SEM, TEM, EPMA, XRD, Raman spectroscopy. Our observations show that the corrosion scale is made of two main layers: a dense amorphous scale close to the metal and a porous crystalline scale in contact with the water. More than the morphology, the chemical compositions of both layers are different. This duplex structure results from a mixed growth mechanism: an anionic growth to develop the inner oxide and a cationic diffusion followed by a dissolution-precipitation process to form the outer one. Dynamic experiments at 70 C and corrosion kinetics measurements have demonstrated that the oxide growth process is controlled by a diffusion step associated to a dissolution/precipitation process. A corrosion mechanism of the AlFeNi alloy in aqueous media has been proposed. Then post-irradiation exams performed on irradiated fuel plates were used to investigate the effects of the irradiation on the corrosion behaviour in the reactor core. (author)

Pre-design of MYRRHA, A Multipurpose Accelerator Driven System for Research and Development

International Nuclear Information System (INIS)

D'hondt, P.; Abderrahim, H. Aiet; Kupschus, P.; Malambu, E.; Aoust, Th.; Benoit, Ph.; Sobolev, V.; Tichelen, K. van; Arien, B.; Vermeersch, F.; Jongen, Y.; Ternier, S.; Vandeplassche, D.

2003-01-01

One of the main SCKCEN research facility, namely BR2, is nowadays arriving at an age of 40 years just like the major materials testing reactors (MTR) in the world and in Europe (i.e. BR2 (B-Mol), HFR (EU-Petten), OSIRIS (F-Saclay), R2 (S-Studsvik)). The MYRRHA facility in planning has been conceived as potentially replacing BR2 and to be a fast spectrum facility complementary to the thermal spectrum RJH (Reacteur Jules Horowitz) facility, in planning in France. This situation would give Europe a full research capability in terms of nuclear R and D. Furthermore, the disposal of radioactive wastes resulting from industrial nuclear energy production has still to find a fully satisfactory solution, especially in terms of environmental and social acceptability. Scientists are looking for ways to drastically reduce (by a factor of 100 or more) the radio-toxicity of the High Level Waste (HLW) to be stored in a deep geological repository. This can be achieved via burning of minor actinides (MA) and to a less extent of long-lived fission products (LLFP) in Accelerator Driven Systems. The MYRRHA project contribution will be in helping to demonstrate the ADS concept at reasonable power level and the demonstration of the technological feasibility of MA and LLFP transmutation under real conditions

Fabrication of the 4. set of fuel elements for the experimental pile EL2; Fabrication du 4. jeu de barreaux de la pile d'essai EL2

Energy Technology Data Exchange (ETDEWEB)

Ringot, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The reactor EL2 is the second atomic reactor built in France. It is a laboratory reactor using heavy water and natural uranium. Its cooling circuit operates with compressed CO{sub 2} gas at 8 kg/cm{sup 2} pressure. The subject of this lecture is the manufacturing of the fourth set of rods. The principle of uranium-can connection is exposed: that is the principle of a pre-pressed bound can. The EL2 reactor has been a prototype with respect to this aspect of the question, and a prototype which has been quite satisfactory. The main steps of the fabrication are exposed: the {gamma} phase extension of uranium, the machining, the three canning (die canning, hydraulic canning, compressed air treatment), the automatic argon arc welding of cups and the different manufacturing controls. (author) [French] Le reacteur EL2 est le deuxieme reacteur construit en France. C'est un reacteur de recherches qui utilise de l'eau lourde et de l'uranium naturel. Il est refroidi par du gaz carbonique sous 8 kg/cm{sup 2} de pression. On etudie dans cet expose la fabrication du quatrieme jeu d'elements combustibles. Le principe de la liaison uranium-gaine est expose: c'est celui d'une gaine precontrainte. La pile EL2 a constitue un prototype a ce point de vue, prototype qui a donne entiere satisfaction. Les principales etapes de la fabrication sont ensuite expliquees: le filage {gamma} de l'uranium, l'usinage des barreaux, les trois operations de gainages (gainage par filiere, gainage hydraulique, gainage a chaud), la soudure automatique des bouchons a l'argon-arc et les differents controles de fabrication. (auteur)

Determination of the Effectiveness of Control Rods in the VVER Reactor Fuel Assemblies; Determination de l'Efficacite des Barres de Reglage dans les Ensembles Combustibles du reacteur VVER; Opredelenie ehffektivnosti reguliruyushchikh sterzhnej v sborkakh reaktora VVEHR; Determinacion de la Eficacia de las Barras de Control en los Conjuntos de Elementos Combustibles del Reactor VVER

Energy Technology Data Exchange (ETDEWEB)

Semenov, V. N.; Lunin, G. L.; Komissarov, L. V.; Kamyshan, A. N.; Halizev, V. I.; Andrianov, G. Ja.; Voznesenskij, V. A.; Kuz' micheva, V. A.; Lebedev, V. I. [Ordena Lenina Institut Atomnoj Energii Im. I.V. Kurchatova, Moskva, SSSR (Russian Federation)

1964-06-15

The paper describes experiments done in homogeneous mock-ups of the fuel assemblies from the VVER Reactor (at one level of enrichment) to determine the effectiveness of absorbing systems comprising shim fuel assemblies or water cavities and of absorbing rods clad in jackets made of differing materials. The paper also gives data on some experiments that have been done in mock-ups of assemblies with differing levels of enrichment. These experiments make it possible to verify the methods used in calculation and to evaluate the prospects of using them for heterogeneous reactors. (author) [French] Le memoire decrit les experiences qui ont ete faites pour determiner l 'efficacite des absorbants contenus dans les barres de compensation, l'effet cavitaire et l 'efficacite des absorbants gaines de materiaux divers, au moyen d'assemblages homogenes de cartouches de combustible du reacteur VVER (reacteur de puissance ralenti et refroidi a l 'eau ayant le meme taux d'enrichissement. On y trouve en outre des donnees sur certaines experiences executees a l 'aide d'assemblages de cartouches de combustible taux d'enrichissement differents. Ces travaux permettent de verifier la methode de calcul et d'evaluer ses possibilites d'application aux reacteurs non homogenes. (author) [Spanish] Se describen en la memoria experimentos para determinar la eficacia de los materiales absorbentes contenidos en las barras de compensacion, el efecto de cavitacion y la eficacia de los materiales absorbentes revestidos de diversos materiales, realizados con ayuda de los conjuntos homogeneos de elementos combustibles del reactor VVER (reactor de potencia moderado y refrigerado por agua) con un solo grado de enriquecimiento. Ademas, se exponen datos sobre los experimentos efectuados con ayuda de conjuntos de grados de enriquecimientos; variados. Tales experimentos permiten verificar el metodo de calculo teorico, utilizad o y evaluar la posibilidad de aplicarlo a los reactores no homogeneos. (author

Rapsodie; Rapsodie

Energy Technology Data Exchange (ETDEWEB)

Vendryes, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; D' Ayguevives, Ch [Groupement Atomique Alsacienne Atlantique (France); Sahl, W [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France)

1964-07-01

interesting studies were carried out on the safety of Rapsodie, and in particular scale models (1/3 and 1/10) were used to estimate the damage caused by the theoretical maximum nuclear accident. The construction of the reactor was started in the autumn of 1961. The industrial architects are the Groupement Atomique Alsacienne Atlantique (G. AAA). A brief outline of the current situation in the construction will be given. (authors) [French] Rapsodie, le premier reacteur a neutrons rapides construit on France dans le cadre d'une Association entre Euratom et le CEA, repond a un triple but: - Il servira d'abord de reacteur experimental dont on etudiera en detail le comportement en regime statique et dynamique, - Les enseignements retires de sa construction et de son fonctionnement serviront a developper la technologie des futurs reacteurs industriels a neutrons rapides. - Son flux de neutrons rapides sera suffisant pour lui permettre de servir aux essais sous irradiation d'elements combustibles pour les reacteurs a neutrons rapides suivants. Rapsodie ayant deja fait l'objet de descriptions, on se contentera d'en faire ici une presentation tres breve en insistant sur les points particulierement significatifs et sur les recentes modifications du projet. Seront successivement evoques: - les principales caracteristiques neutroniques et thermiques, - les assemblages combustibles et fertiles, - le bloc pile et les circuits de refroidissement, - les principaux moyens de manutention des assemblages, - les principes et moyens qui regissent la conduite et la surete du reacteur. La construction du reacteur a ete precedee par la realisation de maquettes en vraie grandeur de ses parties essentielles comprenant notamment: - un circuit complet de sodium do 10 MW, prototype des deux circuits qui equiperont le reacteur, - une maquette du bloc pile (cuve, fermeture superieure, structures internes du coeur et de la couverture), munie d'un circuit de sodium special permettant d'effectuer des essais d

Improving the Fit of a Land-Surface Model to Data Using its Adjoint

Science.gov (United States)

Raoult, N.; Jupp, T. E.; Cox, P. M.; Luke, C.

2015-12-01

Land-surface models (LSMs) are of growing importance in the world of climate prediction. They are crucial components of larger Earth system models that are aimed at understanding the effects of land surface processes on the global carbon cycle. The Joint UK Land Environment Simulator (JULES) is the land-surface model used by the UK Met Office. It has been automatically differentiated using commercial software from FastOpt, resulting in an analytical gradient, or 'adjoint', of the model. Using this adjoint, the adJULES parameter estimation system has been developed, to search for locally optimum parameter sets by calibrating against observations. adJULES presents an opportunity to confront JULES with many different observations, and make improvements to the model parameterisation. In the newest version of adJULES, multiple sites can be used in the calibration, to giving a generic set of parameters that can be generalised over plant functional types. We present an introduction to the adJULES system and its applications to data from a variety of flux tower sites. We show that calculation of the 2nd derivative of JULES allows us to produce posterior probability density functions of the parameters and how knowledge of parameter values is constrained by observations.

General design and main problems of a gas-heavy-water power reactor contained in a pressure vessel; Conception generale et principaux problemes d'un reacteur de puissance eau lourde-gaz contenu dans un caisson resistant

Energy Technology Data Exchange (ETDEWEB)

Roche, R; Gaudez, J C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

In the framework of research carried out on a CO{sub 2}-cooled power reactor moderated by heavy water, the so-called 'pressure vessel' solution involves the total integration of the core, of the primary circuit (exchanges and blowers) and of the fuel handling machine inside a single, strong, sealed vessel made of pre-stressed concrete. A vertical design has been chosen: the handling 'attic' is placed above the core, the exchanges being underneath. This solution makes it possible to standardize the type of reactor which is moderated by heavy-water or graphite and cooled by a downward stream of carbon dioxide gas; it has certain advantages and disadvantages with respect to the pressure tube solution and these are considered in detail in this report. Extrapolation presents in particular.problems due specifically to the heavy water (for example its cooling,its purification, the balancing of the pressures of the heavy water and of the gas, the assembling of the internal structures, the height of the attic, etc. (authors) [French] Dans le cadre des etudes d'un reacteur de puissance modere a l'eau lourde et refroidi-au gaz carbonique, la solution dite 'en caisson' consiste en une integration totale du coeur, du circuit primaire (echangeurs et soufflantes) et du dispositif de manutention du combustible a l'interieur d'un meme caisson etanche et resistant en beton precontraint. La disposition envisagee est verticale; le grenier de manutention est dispose au-dessus du coeur, les echangeurs en dessous. Cette solution, qui permet d'uniformiser les types de reacteurs moderes a l'eau lourde ou au graphite et refroidis par une circulation descendante de gaz carbonique presente, par rapport a la solution a tube de force, des avantages et des inconvenients qui sont analyses dans cette etude. L'extrapolation pose, en particulier, des problemes specifiques a l'eau lourde (tels que son refroidissement, son epuration, l'equilibrage des pression entre l'eau lourde et le gaz, le montage

The Role of Non-Destructive Testing in Test-Reactor Operation at the National Reactor Testing Station; Role des Essais Non Destructifs dans l'Exploitation des Reacteurs d'Essai au Centre National d'Essais de Reacteurs; Rol' nedestruktivnykh ispytanij pri ehkspluatatsii ispytatel'nykh reaktorov na natsional'noj stantsii po ispytaniyam reaktorov; Papel de los Metodos No Destructivos en la Explotacion de los Reactores de la National Reactor Testing Station

Energy Technology Data Exchange (ETDEWEB)

Francis, W. C.; Brown, E. S.; Burdick, E. E.; Gibson, G. W.; Tingey, F. H. [Phillips Petroleum Company, Atomic Energy Division, Idaho Falls, Idaho (United States)

1965-10-15

surface cracks, thermal anneal tests for blistering, and gamma-scanning of irradiated plates. Hydraulic testing of statistical sampling of fuel elements is used to confirm structural integrity, particularly the fuel plate-side plate-joint strength. A continuous effort is made to improve existing techniques and to develop new non-destructive inspection procedures. (author) [French] Les investissements tres importants (plus de 100 millions de dollars) consacres aux reacteurs d'essai du Centre national d'essais de reacteurs et la necessite d'exploiter ces reacteurs en toute securite exigent un controle extremement strict de la qualite des reacteurs et de leurs parties constitutives, notamment des elements combustibles et du dispositif de commande. Les essais non destructifs ont donc joue un role essentiel dans le controle de la qualite de ces pieces avant leur utilisation dans les. reacteurs d'essai. Bien qu'un grand nombre de ces essais non destructifs soient executes selon des procedures bien etablies, on a mis au point de nombreuses methodes inedites et introduit de nouvelles utilisations du materiel classique. On applique depuis longtemps au Centre d'essais les methodes ultrasonores pour la detection des cavites, des defauts de liaison et des craquelures internes. Recemment, on a etendu ces methodes a l'exploration automatique des plaques courbes et a l'inspection des elements combustibles irradies dans les canaux de stockage. Des travaux tres interessants ont permis d'appliquer la methode des ultrasons a la detection des fractures qui peuvent se produire dans l'ame lors du faconnement. Une methode d'exploration par rayons gamma, pour determiner la teneur d'elements combustibles en {sup 23}5{sup U}, s'est revelee tellement fiable qu'elle a ete adoptee pour calculer les penalisations financieres pour les articles non conformes aux specifications. Les radiographies de plaques de combustible donnent les dimensions de l'ame et, associees aux explorations'a l'aide d

EURATOM's Programme of Participation in Power Reactor Construction; Le programme de participation d'Euratom aux reacteurs de puissance; Programma uchastiya v razrabotke ehnergeticheskikh reaktorov Evratoma; El programa de participacion de la Euratom en la construccion y explotacion de reactores de potencia

Energy Technology Data Exchange (ETDEWEB)

Ramadier, R. C.; Parker, E. [Communaute Europoenne de l' Energie Atomique, Bruxelles (Belgium)

1963-10-15

-years during which operating problems will become decisive for the development of atomic power. (author) [French] L'un des moyens mis en oeuvre par la Commission de l'Euratom en vue d'assurer le developpement d'une industrie nucleaire europeenne est un programme dit de ''participation communautaire''. Ce programme permet a la Commission de participer a concurrence de 32 millions d'u.c. AME a des realisations dans le domaine des reacteurs de puissance. La contrepartie est l'acquisition des informations relatives a la conception, la construction, le demarrage et le fonctionnement de ces reacteurs. Jusqu'a present des propositions emanant de trois societes ont donne lieu a la signature de contrats. Il s'agit de: a) la Societa Elettronucleare Nazionale (SENN) qui fait construire en Italie une centrale de 150 MW(e) nets equipee d'un reacteur a eau bouillante a double cycle; b) la Societa Italiana Meridionale Energia Atomica (SIMEA) qui a entrepris en Italie la construction d'une centrale de 200 MW(e) nets equipee d'un reacteur du type uranium naturel-graphite-gaz carbonique; c) la Societe d'Energie Nucleaire Franco-Belge des Ardennes (SENA) qui a entrepris a la frontiere franco-belge la construction d'une centrale equipee d'un reacteur a eau pressurisee d'une puissance qui pourra atteindre et probablement depasser 242 MW(e) nets. En outre, la Commission a e te saisie de demandes de participation a deux autres reacteurs de puissance presentees respectivement par le Groupement Rheinisch-Westfalisches Elektiizitatswerk-Bayernwerke (RWE-BW), et par la N.V. Samenwerkende Electriciteits-Productiebedrijve; la premiere pour un reacteur de 237 MW(e) a eau bouillante a double cycle, la seconde pour un reacteur de 50 MW(e) a eau bouillante a simple cyc le et circulation naturelle. La participation communautaire peut prendre des formes diverses. Elle peut en particulier prendre celle d'une participation au deficit eventuel de la production d'electricite des centrales pendant les premieres

Comparison of Calibration of Sensors Used for the Quantification of Nuclear Energy Rate Deposition

International Nuclear Information System (INIS)

Brun, J.; Reynard-Carette, C.; Tarchalski, M.; Pytel, K.; Lyoussi, A.; Fourmentel, D.; Villard, J.F.; Jagielski, J.

2015-01-01

This present work deals with a collaborative program called GAMMA-MAJOR 'Development and qualification of a deterministic scheme for the evaluation of GAMMA heating in MTR reactors with exploitation as example MARIA reactor and Jules Horowitz Reactor' between the National Centre for Nuclear Research of Poland, the French Atomic Energy and Alternative Energies Commission and Aix Marseille University. One of main objectives of this program is to optimize the nuclear heating quantification thanks to calculation validated from experimental measurements of radiation energy deposition carried out in irradiation reactors. The quantification of the nuclear heating is a key data especially for the thermal, mechanical design and sizing of irradiation experimental devices in specific irradiated conditions and locations. The determination of this data is usually performed by differential calorimeters and gamma thermometers such as used in the experimental multi-sensors device called CARMEN 'Calorimetric en Reacteur et Mesures des Emissions Nucleaires'. In the framework of the GAMMA-MAJOR program a new calorimeter was designed for the nuclear energy deposition quantification. It corresponds to a single-cell calorimeter and it is called KAROLINA. This calorimeter was recently tested during an irradiation campaign inside MARIA reactor in Poland. This new single-cell calorimeter differs from previous CALMOS or CARMEN type differential calorimeters according to three main points: its geometry, its preliminary out-of-pile calibration, and its in-pile measurement method. The differential calorimeter, which is made of two identical cells containing heaters, has a calibration method based on the use of steady thermal states reached by simulating the nuclear energy deposition into the calorimeter sample by Joule effect; whereas the single-cell calorimeter, which has no heater, is calibrated by using the transient thermal response of the sensor (heating and cooling

Comparison of Calibration of Sensors Used for the Quantification of Nuclear Energy Rate Deposition

Energy Technology Data Exchange (ETDEWEB)

Brun, J.; Reynard-Carette, C. [Aix Marseille Universite, CNRS, Universite de Toulon, IM2NP UMR 7334, 13397, Marseille (France); Tarchalski, M.; Pytel, K. [National Centre for Nuclear Research A. Soltana 7, 05-400 Swierk (Poland); Lyoussi, A.; Fourmentel, D.; Villard, J.F. [CEA, DEN, DER, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St-Paul-Lez-Durance (France); Jagielski, J. [National Centre for Nuclear Research A. Soltana 7, 05-400 Swierk (Poland); Institute of Electronic Materials Technolgy, Wolczynska 133, 01-919 Warszawa (Poland)

2015-07-01

This present work deals with a collaborative program called GAMMA-MAJOR 'Development and qualification of a deterministic scheme for the evaluation of GAMMA heating in MTR reactors with exploitation as example MARIA reactor and Jules Horowitz Reactor' between the National Centre for Nuclear Research of Poland, the French Atomic Energy and Alternative Energies Commission and Aix Marseille University. One of main objectives of this program is to optimize the nuclear heating quantification thanks to calculation validated from experimental measurements of radiation energy deposition carried out in irradiation reactors. The quantification of the nuclear heating is a key data especially for the thermal, mechanical design and sizing of irradiation experimental devices in specific irradiated conditions and locations. The determination of this data is usually performed by differential calorimeters and gamma thermometers such as used in the experimental multi-sensors device called CARMEN 'Calorimetric en Reacteur et Mesures des Emissions Nucleaires'. In the framework of the GAMMA-MAJOR program a new calorimeter was designed for the nuclear energy deposition quantification. It corresponds to a single-cell calorimeter and it is called KAROLINA. This calorimeter was recently tested during an irradiation campaign inside MARIA reactor in Poland. This new single-cell calorimeter differs from previous CALMOS or CARMEN type differential calorimeters according to three main points: its geometry, its preliminary out-of-pile calibration, and its in-pile measurement method. The differential calorimeter, which is made of two identical cells containing heaters, has a calibration method based on the use of steady thermal states reached by simulating the nuclear energy deposition into the calorimeter sample by Joule effect; whereas the single-cell calorimeter, which has no heater, is calibrated by using the transient thermal response of the sensor (heating and cooling

The Use of Prestressed Concrete Vessels in the French Power Reactor Programme; Les caissons en beton precontraint dans le programme francais des reacteurs de puissance; Korpusy iz predvaritel'no napryazhennogo betona vo frantsuzskoj programme ehnergeticheskikh reaktorov; Empleo de recipientes de presion de hormigon pretensado en el programa frances de reactores de potencia

Energy Technology Data Exchange (ETDEWEB)

Conte, F. [Centre d' Etudes Nucleaires de Marcoule (France); Dambrine, C. [Centre d' Etudes Nucleaires de Fontenay-aux-Roses (France); Gaussot, D. [Electricite de France, Clamart (France)

1963-10-15

This paper deals with the use of pre-stressed concrete for the G2 and G3 reactors at Marcoule and for the EDF3 reactor now under construction at Chinon. The first two reactors have been operating at power since 1959 and 1960 respectively. Messrs. Conte and Dambrine discuss the problems that arose during construction of the vessels for G2 and G3 and also deal with the experience gained in operation - experience which suggests that they are extremely safe- Work on the EDF3 vessel, begun at Chinon in the second half of 1961, is still under way and should be finished towards the end of 1963. Mr. Gaussot discusses the reasons for choosing this type of vessel, the results of calculations and mock-up tests, and the problems presented by the construction itself. A number of studies have been devoted to the future prospects of prestressed concrete structures for reactors. It would seem that working pressures could be increased, if desired, and, in any case, that dimensions could be considerably enlarged, thus offering the chance of integral-type solutions. (author) [French] La communication traite de l'application du beton precontraint aux reacteurs G2 et G3 de Marcoule et au reacteur EDF 3, en construction a Chinon. Les reacteurs sont en puissance depuis respectivement 1959 et I960; le CEA indique les problemes qui se sont poses pendant la construction du caisson du reacteur, et la lecon tiree des observations faites en service, qui tend a demontrer la tres grande securite de ces appareils. La construction du caisson de EDF3 a commence a Chinon dans la deuxieme partie de 1961; elle est en cours actuellement et sera terminee vers la fin de 1963. L'EDF presente les raisons du choix de ce caisson, les resultats des calculs et des essais sur maquette ainsi que les problemes poses par la construction. Diverses etudes ont ete faites sur les perspectives futures des ouvrages en beton precontraint pour reacteurs. Il semble que l 'on puisse realiser, si on le desire, une elevation

Purification by molecular sieve of helium used as inert cover gas in nuclear reactors; Epuration de l'helium de couverture des reacteurs nucleaires par adsorption sur tamis moleculaire

Energy Technology Data Exchange (ETDEWEB)

Rozenberg, J; Kahan, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

A method carried out at fairly low temperatures (between -50 and -80 deg. C) has been studied for the purification of the helium used as cover gas for heavy water in reactors. The use of the 5A molecular sieve has been adopted because of its superiority over other adsorbents in this temperature range. The particular problems connected with adsorption under dynamic conditions have been dealt with separately. The nitrogen adsorption isotherms have been plotted and the heat of adsorption calculated. (authors) [French] Une methode d'epuration, a temperature moderement basse (comprise entre -50 et -80 deg. C) de l'helium servant de couverture inerte a l'eau lourde des reacteurs a ete etudiee. L'emploi au tamis moleculaire 5A a ete retenu pour la superiorite de celui-ci sur d'autres adsorbants dans ce domaine de temperatures. Les problemes particuliers a l'adsorption en regime dynamique ont ete separement traites. Les isothermes d'adsorption d'azote ont ete tracees et la chaleur d'adsorp. tion calculee. (auteurs)

Effect of the plutonium isotopic composition on the performance of fast reactors; Effet de la composition isotopique du plutonium sur le rendement de reacteurs a neutrons rapides; Vliyanie izotopnogo sostava plutoniya na rabotu reaktorov na bystrykh nejtronakh; Efectos de la composicion isotopica del plutonio sobre el funcionamiento de los reactores rapidos

Energy Technology Data Exchange (ETDEWEB)

Yiftah, S [Israel Atomic Energy Commission (Israel)

1962-03-15

The isotopic composition of plutonium to be used as fuel for fast reactors will depend on the source of plutonium. In principle three different sources are possible: (a) production reactors; (6) thermal power reactors (using natural uranium or enriched uranium as fuel); (c) fast reactor blankets. In general, source (a) and to some extent source (c) will provide relatively 'clean' plutonium, that is mostly Pu{sup 239}, while plutonium from source (6) will be 'dirty' plutonium, that is plutonium rich in Pu{sup 240}, Pu{sup 241}, and Pu{sup 242}. The degree of 'dirtiness' will depend on the kind of reactor, amount of burn-up and in general on the irradiation history of the fuel. The question then arises, can one use as fuel for fast reactors any kind of plutonium? To investigate the effect of different isotopic composition of the plutonium fuel, in the metallic, oxide and carbide form, on the performance of fast reactors, a limited series of spherical geometry 16-group diffusion theory calculations were performed, using the 16-group cross-section set developed recently by Yiftah, Okrent and Moldauer and taking three different kinds of plutonium, starting with pure Pu{sup 239} and increasing the amount of higher isotopes. For the systems studied-800, 1500 and 2500-l core-volumes, which are typical for large fast power reactors-the result is, when one takes into account only the thermally fissionable isotopes Pu{sup 239} arid Pu{sup 241}, that the 'dirtier' the plutonium, the smaller the critical mass and the higher the breeding ratio. For the 1500-l reactor, taken as an example, it is further found that in the metallic, oxide and carbide plutonium fuels the reactivity change upon removal of 40% of the sodium initially present in the core is made more negative (or less positive) when the plutonium is richer in higher isotopes. (author) [French] La composition isotopique du plutonium qui doit etre utilise comme combustible dans des reacteurs a neutrons rapides depend de

Impact of land cover changes on the South African climate

International Nuclear Information System (INIS)

Ngwana, T I; Demory, M-E; Vidale, P L; Plant, R S; Mbedzi, M P

2010-01-01

The Joint UK Land Environmental Simulator (JULES) was run offline to investigate the sensitivity of land surface type changes over South Africa. Sensitivity tests were made in idealised experiments where the actual land surface cover is replaced by a single homogeneous surface type. The vegetation surface types on which some of the experiments were made are static. Experimental tests were evaluated against the control. The model results show among others that the change of the surface cover results in changes of other variables such as soil moisture, albedo, net radiation and etc. These changes are also visible in the spin up process. The model shows different surfaces spinning up at different cycles. Because JULES is the land surface model of Unified Model, the results could be more physically meaningful if it is coupled to the Unified Model.

French school and World War First: neurological consequences of a frightening time.

Science.gov (United States)

Gomes, Marleide da Mota

2015-05-01

Some aspects of a dark period in the history of the modern neurology, that of the World War I (WWI), are here remembered, mainly by the neurological French School participation . Some personalities and their works related to the WWI are presented such as Joseph Babinski, Jules Froment, Clovis Vincent, Jules Joseph Dejerine, Augusta Déjérine-Klumpke, Jules Tinel, Pierre Marie, Achille Alexandre Souques, Charles Foix, and Georges Guillain.

Fast flux measurements by means of threshold detectors on the reactor 'Melusine'; Mesures de flux rapides a l'aide de detecteurs a seuil sur le reacteur 'Melusine'

Energy Technology Data Exchange (ETDEWEB)

Leger, P; Sautiez, B [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

Using existing data on the (n,p) and (n,{alpha}) threshold reactions we have carried out fast flux measurements on the swimming pool type reactor 'Melusine'. Four common elements: P, S, Mg, Al were chosen because from the point of view of fast spectrum analysis they represent a fairly good energy range from 2.4 MeV to 8 MeV. The fission flux value found in the central element at a power of 1 MW is 1.4 x 10{sup 13} n/cm{sup 2}/s {+-} 0.14. (author) [French] A l'aide des donnees actuelles sur les reactions a seuil (n,p) et (n,{alpha}) nous avons realise des mesures de flux rapide dans le reacteur du type piscine 'Melusine'. Quatre corps courants: P, S, Mg, Al, ont ete choisis parce qu'ils constituent au point de vue de l'analyse du spectre rapide un assez bon etalement en energie de 2,4 MeV A 8 MeV. La valeur du flux de fission trouve dans l'element central a une puissance de 1 MW est de 1,4.10{sup 13} n/cm{sup 2}/s {+-} 0,14. (auteur)

French school and World War First: neurological consequences of a frightening time

Directory of Open Access Journals (Sweden)

Marleide da Mota Gomes

2015-05-01

Full Text Available Some aspects of a dark period in the history of the modern neurology, that of the World War I (WWI, are here remembered, mainly by the neurological French School participation . Some personalities and their works related to the WWI are presented such as Joseph Babinski, Jules Froment, Clovis Vincent, Jules Joseph Dejerine, Augusta Déjérine-Klumpke, Jules Tinel, Pierre Marie, Achille Alexandre Souques, Charles Foix, and Georges Guillain.

Neutronic evolution of SENA reactor during the first and second cycles. Comparison between the experimental power distributions obtained from the in-core instrumentation evaluation code CIRCE and the theoretical power values computed with the two-dimensional diffusion-evolution code EVOE

International Nuclear Information System (INIS)

Andrieux, Chantal

1976-03-01

The neutronic evolution of the reacteur Sena during the first and second cycles is presented. The experimental power distributions, obtained from the in-core instrumentation evaluation code CIRCE are compared with the theoretical powers calculated with the two-dimensional diffusion-evolution code EVOE. The CIRCE code allows: the study of the evolution of the principal parameters of the core, the comparison of the results of measured and theoretical estimates. Therefore this study has a great interest for the knowledge of the neutronic evolution of the core, as well as the validation of the refinement of theoretical estimation methods. The core calculation methods and requisite data for the evaluation of the measurements are presented after a brief description of the SENA core and its inner instrumentation. The principle of the in-core instrumentation evaluation code CIRCE, and calculation of the experimental power distributions and nuclear core parameters are then exposed. The results of the evaluation are discussed, with a comparison of the theoretical and experimental results. Taking account of the approximations used, these results, as far as the first and second cycles at SENA are concerned, are satisfactory, the deviations between theoretical and experimental power distributions being lower than 3% at the middle of the reactor and 9% at the periphery [fr

General design and main problems of a gas-heavy-water power reactor contained in a pressure vessel; Conception generale et principaux problemes d'un reacteur de puissance eau lourde-gaz contenu dans un caisson resistant

Energy Technology Data Exchange (ETDEWEB)

Roche, R.; Gaudez, J.C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

In the framework of research carried out on a CO{sub 2}-cooled power reactor moderated by heavy water, the so-called 'pressure vessel' solution involves the total integration of the core, of the primary circuit (exchanges and blowers) and of the fuel handling machine inside a single, strong, sealed vessel made of pre-stressed concrete. A vertical design has been chosen: the handling 'attic' is placed above the core, the exchanges being underneath. This solution makes it possible to standardize the type of reactor which is moderated by heavy-water or graphite and cooled by a downward stream of carbon dioxide gas; it has certain advantages and disadvantages with respect to the pressure tube solution and these are considered in detail in this report. Extrapolation presents in particular.problems due specifically to the heavy water (for example its cooling,its purification, the balancing of the pressures of the heavy water and of the gas, the assembling of the internal structures, the height of the attic, etc. (authors) [French] Dans le cadre des etudes d'un reacteur de puissance modere a l'eau lourde et refroidi-au gaz carbonique, la solution dite 'en caisson' consiste en une integration totale du coeur, du circuit primaire (echangeurs et soufflantes) et du dispositif de manutention du combustible a l'interieur d'un meme caisson etanche et resistant en beton precontraint. La disposition envisagee est verticale; le grenier de manutention est dispose au-dessus du coeur, les echangeurs en dessous. Cette solution, qui permet d'uniformiser les types de reacteurs moderes a l'eau lourde ou au graphite et refroidis par une circulation descendante de gaz carbonique presente, par rapport a la solution a tube de force, des avantages et des inconvenients qui sont analyses dans cette etude. L'extrapolation pose, en particulier, des problemes specifiques a l'eau lourde (tels que son refroidissement, son epuration

On stage at the Globe

CERN Document Server

2005-01-01

The Globe's first season this year is to be rounded off with two shows that are in perfect keeping with the centenary of the death of Jules Verne and Albert Einstein's theory of relativity. 'Signé Jules Verne' (Signed Jules Verne) The Miméscope company, which has already thrilled audiences at CERN with shows such as the 'Oracle of Delphi' and, more recently, 'Point de Suspension', returns with an interactive show entitled 'Signé Jules Verne'. Imagine a slightly crazy machine, which rolls along on wheels, floats, flies or moves in any other way you like, as long as it works on scientific principles. This is the task that Jules Verne sets his audience. Experiments, models, drawings, blueprints, he's interested in them all. In its typical style, Miméscope has created a world of enchantment that combines theatre, choreography, music and lighting effects in a show that evolves as a function of its audience. Performances at 3.00 p.m. on 4, 7, 10 and 11 December An interactive show for the general public...

Some physics aspects of cermet and ceramic fast systems; Quelques aspects de la physique des reacteurs a neutrons rapides utilisant des cermets et des ceramiques comme combustibles; Nekotorye fizicheskie aspekty kermetnykh i keramicheskikh sistem na bystrykh nejtronakh; Algunos aspectos fisicos de los sistemas rapidos a base de combustibles cermet y ceramicos

Energy Technology Data Exchange (ETDEWEB)

Codd, J; James, M F; Mann, J E [United Kingdom Atomic Energy Authority, Reactor Group (United Kingdom)

1962-03-15

The characteristics of a system using an iron-based oxide cermet as fuel material are discussed. A transport theory investigation to develop methods of predicting the effect of core heterogeneity on reactivity and flux distribution is described. Some preliminary calculations are also given of resonance self-shielding and Doppler temperature effects in a cermet system. (author) [French] Les auteurs etudient les caracteristique s d'un reacteur utilisant comme combustible un cermet d'oxydes a armature de fer. Ils exposent une application de la theorie du transport a la mise au point des methodes permettant de prevoir l'effet de l'heterogeneite du coeur sur la reactivite et sur la distribution du flux. Ils donnent egalement quelques calculs preliminaires d'effets d'autoprotection due a la resonance et d'effet Doppler du a la chaleur dans un reacteur utilisant un cermet. (author) [Spanish] La memoria discute las caracteristicas de un sistema que emplea como combustible un oxido tipo cermet a base de hierro. Describe una investigacion de la teoria de transporte con miras a desarrollar metodos para evaluar el efecto de la heterogeneidad del cuerpo sobre la reactividad y la distribucion de flujo. Tambien da algunos calculos preliminares de los efectos del autoblindaje por resonancia y de la temperatura de Doppler en un sistema de tipo cermet. (author) [Russian] Obsuzhdayutsya kharakteristiki sistemy, ispol'zuyushchej v kachestve toplivnogo materiala oksidnye kermety, razrabotannye na osnove zheleza. Opisyvaetsya issledovanie teorii perenosa, chtoby razvit' metody predskazaniya vliyaniya geterogennosti aktivnoj zony na reaktivnost' i raspredelenie potoka. Dayutsya takzhe nekotorye predvaritel'nye raschety ehffektov rezonansnoj samozashchity i temperaturnogo ehffekta Dopplera v kermetnoj sisteme. (author)

Operating Experience in Nuclear Power Plants with Boiling-Water Reactors; Experience acquise dans l'exploitation des reacteurs a eau bouillante; Opyt ehkspluatatsii kipyashchago reaktora; Experiencia adquirida con la explotacion de reactores de agua hirviente

Energy Technology Data Exchange (ETDEWEB)

Ascherl, R. J. [General Electric Company, San Jose, CA (United States)

1963-10-15

radioactivity exposure considerations. Recent full-scale inspection and overhaul of the Dresden turbine provided no maintenance problems, after over 12 000 h of operation on direct-cycle steam and after operation with known failed fuel elements in the reactor. (author) [French] On a maintenant acquis une experience appreciable dans l'exploitation des centrales equipees de reacteurs a eau bouillante. Vers la fin de 1962, on avait produit plus de 2,2.10{sup 9} kWh dans trois centrales nucleaires rattachees a des reseaux de distribution: la centrale de Dresden (Commonwealth Edison Company, Morris, Illinois), la centrale de Vallecitos (Pacific Gas and Electric Company and General Electric Company, Pleasanton, Californie) et la centrale de Kahl (Rheinish-Westfaiisches Elektrizitatswerk et Bayemwerk, a Kahl-sur-le-Main, Republique federale d'Allemagne). Le rendement de ces reacteurs a eau bouillante, exploites dans les conditions normales de production d'electricite, est excellent. On peut donc s'attendre que les centrales a eau bouillante continueront d'etre sures, etant donne le facteur de disponibilite et le facteur de puissance des reacteurs et des installations de ce type. Au cours de 1963, quatre nouvelles centrales equipees de reacteurs a eau bouillante entreront en service: la centrale de Big Rock Point (Consumers Power Company, Charlevoix, Michigan), la centrale de Humboldt Bay (Pacific Gas and Electric Company, Eureka, Californie), la centrale de Garigliano (Societa Elettronucleare Nazionale, Scauri, Italie) et la centrale de demonstration japonaise (Institut de recherches nucleaires du Japon, Tokai Mura, Japon). Les resultats obtenus lors du demarrage et pendant le fonctionnement initial de ces installations confirment les espoirs suscites par les centrales de Dresden, Kahl et Vallecitos. Les journaux de marche des centrales de Dresden, Kahl et Vallecitos mettent en evidence la stabilite et la securite des reacteurs a eau bouillante. De plus, les niveaux de rayonnements

Study of the formation and of the distribution of dissolved gases and hydrogen peroxide in water from a swimming-pool reactor (triton) (1961); Etude de la formation et de la repartition des gaz dissous et de l'eau oxygenee dans l'eau d'un reacteur piscine (triton) (1961)

Energy Technology Data Exchange (ETDEWEB)

Chenouard, J; Rozenberg, J; Dolle, L; Dirian, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

In order to determine experimentally the amount of radiolysis in the swimming-pool reactor Triton, direct measurements have been made of the quantity of radiolysis gas and hydrogen peroxide in the water, at the entry and exit of the core. The concentration distribution of these gases in the reactor was also determined. An explanation is given as to why no gases evolution is seen in the swimming-pool reactors of the C.E.A. The overall amount of radiolysis is zero, and a simple interpretation of this result is possible. The real amount of radiolysis occurring in the reactor core can be calculated. This is in satisfactory agreement with certain measurement mad elsewhere. (authors) [French] Pour determiner experimentalement le taux de radiolyse dans la pile piscine Triton, des mesures directes de la quantite de gaz de radiolyse et d'eau oxygenee dans l'eau a l'entree et a la sortie du coeur ont ete faites. La repartition de la concentration de ces gaz dans la piscine a egalement ete determinee. On explique pourquoi aucun degagement gazeux n'est observe dans les piles piscines du CE.A. Le taux de radiolyse global est nul, et une interpretation simple de ce resultat est possible. Un taux de radiolyse reel dans le coeur du reacteur peut etre calcule. Celui-ci est en accord satisfaisant avec certaines determinations faites ailleurs. (auteurs)

Partial combustion of a fuel cartridge in reactor G1; Combustion partielle d'une cartouche de combustible dans le reacteur G 1

Energy Technology Data Exchange (ETDEWEB)

De, Rouville; Leduc,; Segot, [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

-devices, some null regulating tension systems, annealing the background due to continuous pollution. This event has been fruitful. A grid trap has been set right ahead the reactor. Stricter instructions have been given for rising power operations and automatic burst slug sy (already improved as said above) has been duplicated by a human control. At last, the fault has pointed out that the reactors with gap had the disadvantage of facilitating the contamination of channels from one to another. On the other hand, graphite stores the radioactive dusts and hinders an easy decontamination. (author) [French] Le 26 octobre 1956, le reacteur G1 etait remis en marche apres un arret de quelques jours. L'installation de detection de rupture de gaines donna un premier signal de prealerte a 19h07 cote chargement, un second a 19h13 cote dechargement, puis d'autres. Le chef de quart ordonna a 19h15 une baisse rapide de la puissance mais voulant reperer le canal fautif avec precision la fit remonter ensuite a 2 puis a 5 MW. Bientot, par crainte de contamination exterieure, on dut arreter l'exploration et c'est par detection {gamma} a l'exterieur des tuyaux de detection de rupture de gaine qu'on identifia la cartouche endommagee dans le canal 19-13. Les enregistrements des stations de sante montrerent que les pointes observees etaient restees notablement inferieures aux limites maxima admissibles. L'examen methodique et le degagement du canal accidente occuperent trois semaines. On put apercevoir cote chargement les billettes d'uranium nues sur un lit de poudre de magnesie; cote dechargement, la gaine etait intacte mais l'extremite de la cartouche 'pendait' a l'interieur de la fente d'arrivee d'air. Repoussee cote chargement d'environ 30 cm, la cartouche se bloqua. Apres des essais divers, toujours sous injection d'argon, et avec des protections severes du personnel, on mit en oeuvre un tube fraise, analogue a ceux utilises pour les forages. On nettoya le canal par aspiration, sans toutefois

Group cross-sections for fast reactors; Sections efficaces de groupes pour les reacteurs a neutrons rapides; Gruppovye secheniya reaktorov na bystrykh nejtronakh; Secciones eficaces de grupos para reactores rapidos

Energy Technology Data Exchange (ETDEWEB)

Zweifel, P P [University of Michigan, Ann Arbor, MI (United States); Ball, G L [Atomic Power Development Associates, Inc., Detroit, MI (United States)

1962-03-15

groupes. Ils montrent notamment que la section efficace moyenne de transport peut, avec une certaine approximation, s'exprimer en termes de libre parcours moyen. Le calcul de cette quantite prend beaucoup de temps, car elle ne peut se reduire en moyennes elementaires; neanmoins, on a demontre certaines inegalites, qui simplifient la methode de calcul des moyennes qui doit etre utilisee. Les auteurs analysent trois autres aspects des sections efficaces de groupes, que l'on neglige souvent, mais qu'il peut etre important de connaitre pour les etudes de reacteurs. a) Il est injustifie d'utiliser pour tous les reacteurs a neutrons rapides le meme ensemble de sections efficaces dont la moyenne par groupe a ete calculee si les spectres des differents reacteurs sont dissemblables et si les sections efficaces varient rapidement a l'interieur du groupe, comme c'est le cas le plus souvent. Les auteurs decrivent une methode d'iteration qui permet d'obtenir les valeurs moyennes correctes; ils determinent ensuite, a l'aide de cette methode, dans quelle mesure les calculs de reacteurs sont influences par les effets de spectre. b) Dans les calculs de transport (la methode S{sub n}, par exemple), les moyennes doivent etre calculees en tenant compte a la fois de tous les angles et de toutes les energies. Etant donne qu'on ne peut dissocier dans le flux une partie angulaire et une partie energetique, la plus grande attention est necessaire pour eviter les erreurs. Les auteurs etudient l'equation obtenue par la methode S{sub n} sous la forme d'un modele simple, et en tirent un critere qui pourrait aider a determiner l'importance de la non-separabilite angulaire dans les calculs de reacteurs. c) A partir de raisonnements fondes sur la conservation du nombre de neutrons, il est possible d'obtenir une relation consistant entre les coefficients de diffusion de groupe, le pouvoir de ralentissement et les sections efficaces d'absorption. Les auteurs montrent qu'il n'est pas exact de definir

Report by the AERES on the unit: Reactor Study Department (DER) under the supervision of the establishments and bodies: Atomic Energy and Alternative Energies Commission (CEA); Rapport de l'AERES sur l'unite: Departement d'Etudes des Reacteurs (DER) sous tutelle des etablissements et organismes: CEA

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-02-15

This report is a kind of audit report on a research laboratory, the DER (Departement d'Etudes des Reacteurs, Reactor Study Department) whose activity if focused on four main themes: neutron transport simulation in reactor cores, thermal-hydraulic simulation of reactors, design and safety of innovative reactors, nuclear instrumentation for reactors. The authors discuss an assessment of the whole unit activities in terms of strengths and opportunities, aspects to be improved, risks and recommendations, productions and publications, scientific quality, influence and attractiveness (awards, recruitment capacity, capacity to obtain financing and to tender, participation to international programs), strategy and governance, and project. These same aspects are then discussed and commented for each theme

Adiabatic calorimeter with static vacuum for the measurement of the heating of in- pile materials; Calorimetre adiabatique a vide statique pour la mesure d'echauffements de materiaux en pile

Energy Technology Data Exchange (ETDEWEB)

Brun, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

After having reviewed the various interaction processes occurring between radiations present in nuclear reactors and matter, the author describes the different calorimetric methods which may be used for measuring the energy absorbed in the materials. He then gives a detailed description of the adiabatic calorimeter, the associated measurement device and the calibration methods which have been chosen. He finally gives values for the heating produced at various experimental positions in the reactors EL-2 and EL-3 for several materials currently used in reactor construction. (author) [French] Apres avoir passe en revue les differents processus d'interaction des rayonnements, existant dans les reacteurs nucleaires, avec la matiere, l'auteur decrit les differentes methodes calorimetriques qui peuvent etre utilisees pour mesurer l'energie absorbee dans les materiaux. II presente ensuite en detail le calorimetre adiabatique, le dispositif de mesure associe et les methodes d'etalonnage qui ont ete retenus. Enfin il donne des valeurs d'echauffement dans divers emplacements experimentaux des piles EL-2 et EL-3 pour differents materiaux d'utilisation courante dans les reacteurs. (auteur)

Methods of Containment Adopted for the EL4 Reactor and Projected Heavy-Water, Gas-Cooled Plants; Mode de Confinement Adopte pour le Reacteur EL4 et les Projets de Centrales Eau Lourde-Gaz

Energy Technology Data Exchange (ETDEWEB)

Schulhof, P.; Justin, F. [Commissariat a l' Energie Atomique, Paris (France)

1967-09-15

After a brief description of the plant, the paper explains the principles adopted for preventing the release of waste gas, from the EL4 reactor and refers to some of the difficulties associated with this type of containment. From the economic standpoint, the authors present the results of a comparative civil engineering study of pre-stressed concrete and steel shells for a projected 60 MW(e) power station, giving various values for accidental pressures. They demonstrate the influence of the stress values adopted. (author) [French] Les auteurs rappellent les principes adoptes dans le reacteur EL4 pour le confinement des rejets gazeux, apres une description sommaire des installations. Suivent quelques aspects des difficultes introduites par ce type de confinement. Dans le domaine economique, ils presentent le resultat d'une etude comparative de genie civil d'enceintes en beton precontraint et en acier pour un projet de centrale de 600 MW(e), avec diverses valeurs de pression accidentelle. Dans cette etude, ils font ressortir l'influence des valeurs admises pour le taux de travail des materiaux. (author)

Analysis of the AMMON experimental program in the EOLE facility supporting the qualification of the JHR neutron and photon tools

International Nuclear Information System (INIS)

Vaglio-Gaudard, C.; Colombier, A.C.; Hudelot, J.P.; Leray, O.; Lemaire, M.; Di-Salvo, J.; Gruel, A.; Sireta, P.

2013-06-01

The first divergence of the international Jules Horowitz Material Testing Reactor under construction at CEA Cadarache is foreseen in 2016. In order to perform all the design and safety studies, a specific neutron and photon calculation tool, HORUS3D/N and P, dedicated to the JHR simulation, was developed. This development follows the V and V-UQ process; in this frame, the validation and qualification steps aim at quantifying all the biases and associated uncertainties of HORUS3D/N and P calculations. These biases originate from both the nuclear data and the calculation scheme, for calculations at step zero (JHR BOL core) or during depletion (JHR core at equilibrium). This paper focusses on the quantification of the biases due to nuclear data and the associated uncertainties. A new experimental program, named AMMON, was performed between 2010 and 2013 to provide experimental data for this quantification. A large part of the measurements has been today analyzed with the Monte Carlo TRIPOLI-4 R code and the JEFF3.1.1 and EPDL97 data libraries relative to neutron/photon transport and photon emission. The C/E results were transposed from AMMON to JHR. The synthesis of the present analysis is very satisfactory. The calculation biases remains limited. In addition, thanks to a very good control to the experimental uncertainties during measurements, it is shown that the a priori uncertainties due to nuclear data for parameters at step zero was reduced up to a factor of 2. (authors)

The use and evolution of the CEA research reactors; Utilisation et evolution des reacteurs de recherche du C.E.A

Energy Technology Data Exchange (ETDEWEB)

Rossillon, F; Chauvez, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

organic liquids under irradiation. The equipments of Melusine are now being modernized. Siloe, another swimming-pool reactor, has been operating at 15 MW since the end of 1963. The performances achieved constitute a considerable progress in the field of swimming-pool reactors, since the fluxes obtained with Siloe are in the same order of magnitude than those which needed till now a tank type structure, whose numerous disadvantages in the fitting of experiments are well known. Siloe will be used mostly in the study of structural materials, graphites, refractory fissile materials, and for solid state physics. The reactor Pegase, in service in the Cadarache Nuclear Centre since 1963, is intended solely for testing full-scale fuel elements of EDF and EL 4 types. The current programme, for the eight loops of the reactor, covers the elements for the reactors EDF 2, EDF 3 and EL 4. New loops are in the course of being studied for the fuel elements of the EDF 4 and EDF 5 reactors. The general line of the CEA programmes has shown up the considerable need for fast neutron irradiations. The reactor Osiris which is in the course of being constructed will serve to complement the CEA's equipment in this field and at the same time fill the gap which will be left in the near future in the Centre de Saclay by the closing down of EL 2. Osiris is a light water reactor whose special structure will allow it to function at 50 MW without the disadvantages usually associated with the presence of a heavy waterproof tank. This reactor, which should be put into service in 1966, is mainly intended for the investigation of structural materials, graphite and refractory fuels; it will also serve to increase the production of high specific activity isotopes, and to develop activation analysis techniques. (authors) [French] Les auteurs examinent successivement les differents reacteurs de recherche en service dans les Centres du Commissariat a l'Energie Atomique. Ils retracent brievement l'histoire de ces

Qualification of an out-of-pile Thermohydraulic test Bench (BETHY) developed to calibrate calorimetric cells under specific JHR experimental conditions

International Nuclear Information System (INIS)

De Vita, C.; Brun, J.; Carette, M.; Reynard-Carette, C.; Lyoussi, A.; Fourmentel, D.; Villard, J.F.; Guimbal, P.; Malo, J.Y.

2013-06-01

Online in-pile measurement methods are crucial during irradiations in material testing reactors to better understand the behavior of materials under accelerated ageing conditions and of nuclear fuels under high irradiation levels. Thus, the construction of a new Material Testing Reactor such as the Jules Horowitz Reactor (JHR) leads to new research and development programs devoted to innovative instrumentation and measurement methods. The presented works are performed in the framework of the IN-CORE program, 'Instrumentation for Nuclear radiations and Calorimetry Online in Reactor', between CEA and Aix-Marseille University. The program aim is to develop experimental devices and test bench to quantify more precisely the nuclear heating parameter in the JHR experimental channels. This in-pile parameter is usually measured by means of calorimeter or gamma thermometer. This paper focuses on a new out-of-pile test bench called BETHY. This bench was developed to study the response of a differential calorimeter during its preliminary calibration step according to specific thermal and hydraulic conditions occurring inside one type of JHR core channel. The first section of this paper is dedicated to a detailed description of the bench. The second part presents the study of the thermal characteristics established in the bench for two main thermal running modes. The last one concerns the calibration curve of the reference cell of the differential calorimeter in the case of homogenous temperature. (authors)

Study and development of a pyrometric in-core measurement technique to follow the temperature of the fuel rod cladding; applied to the study of Loss of Coolant Accident (LOCA) during trial simulations in the Jules Horowitz Reactor (Material Testing Reactor)

International Nuclear Information System (INIS)

Ramiandrisoa, Liana

2014-01-01

In both research and industry, temperature is a key parameter for understanding and characterizing the behavior of materials. To study the thermomechanical behavior of a fuel rod, a test device is designed for the Jules Horowitz Material Testing Reactor (currently under construction in the CEA Cadarache). The device will be placed under accidental conditions (Loss Of Coolant Accident, LOCA) causing rapid overheating. The temperature tracking, between 700 and 1200 C, will be measured by a fiber optic sensor. The aim of the project is to optimize temperature measurement by comparing different pyrometry techniques. This study covers the management of the main difficulties inherent to the design of the sensor.The first challenge consists of predicting optical fiber behavior in such complex environments where irradiation and high temperature are combined. The fiber will be exposed to a neutron dose rate about 10 12 nfast/cm 2 /s and a dose rate of about 1 kGy/s. Moreover its extremity is heated to approximately 800 C. It is shown that under these conditions, light interferences, absorption bands and fluctuating attenuation are obstacles to overcome or to mitigate.The second challenge, concerning pyrometric measurement, comes from spectral variations expected for the rod emissivity. The material of study is chosen for its widespread use in France: Zircaloy-4. Under oxidizing conditions the spectral emissivity of this Zirconium alloy evolves. This thesis proves that between 700 and 800 C pyrometric measurement is possible from experimental point of view in laboratory without irradiation.In conclusion rod temperature tracking in JHR conditions may be possible providing that interferences are mastered and wavelengths are chosen. This work makes the use of optical pyrometry under civil nuclear extreme conditions more promising. (author) [fr

In-pile experimental device for Sirene thermionic converters; Dispositif d'experimentation en pile des convertisseurs thermoioniques sirene

Energy Technology Data Exchange (ETDEWEB)

Bliaux, J; Durand, J; Lazare-Chopard, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

The irradiation device described here, was built for in pile life tests of 100 We SIRENE converters. The nuclear converter is located in a sealed vacuum chamber, which is plugged at the lower end of a coaxial tubing acting as electrical leads. The output power is available on a variable resistive load on the bank of the reactor pool. Thermal, electrical and neutronic parameters of the converter are recorded. Since 1967, two permanent devices allowed five experiments in the swimming pool TRITON (CEN-FAR) and the results, obtained till now, are presented. (authors) [French] Le dispositif d'irradiation SIRENE decrit ici a ete concu en vue d'une etude statistique de performances de convertisseurs thermoioniques nucleaires de puissance unitaire 100 We. Le dispositif doit assurer la bonne marche du convertisseur en pile, permettre le changement de la position verticale du convertisseur dans le coeur, sortir du coeur la puissance electrique convertie sans degradation notable et enregistrer les differents parametres thermiques, electriques et neutroniques du convertisseur. Depuis 1967, deux dispositifs fonctionnent en permanence et ont permis de faire cinq experiences dans le reacteur piscine TRITON du CEN-FAR. Les resultats obtenus jusqu'a present, sont presentes. (auteurs)

General problems arising from the analogical resolution of the kinetic equations of nuclear reactors (1961); Problemes generaux poses par la resolution analogique des equations cinetiques des reacteurs nucleaires (1961)

Energy Technology Data Exchange (ETDEWEB)

Caillet, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

The author reviews precisely the analogical techniques used for the resolution of the kinetic equations of nuclear reactors. Prior to this, he recalls the reasons which oblige physicians and engineers, even today, to use electronic machines in this domain. The author then considers the technological problems posed by the range of values which the various nuclear parameters adopt. In each case, he shows that a compromise is possible allowing an optimum precision. He compares the results to those obtained by arithmetic calculation and uses the examples chosen in a critical analysis of the present possibilities of the two methods of calculation. (author) [French] L'auteur cherche a faire un point aussi exact que possible des techniques analogiques utilisees pour resoudre les equations cinetiques des reacteurs nucleaires. Il rappelle auparavant les raisons pour lesquelles physiciens et ingenieurs sont obliges, encore aujourd'hui, de faire appel aux machines electroniques dans ce domaine. Puis il etudie les problemes technologiques que souleve le champ des valeurs prises par les differents parametres nucleaires. Dans chacun des cas, il montre l'existence d'un compromis qui permet d'atteindre une precision optimum. Il compare les resultats obtenus a ceux provenant de calculateurs arithmetiques et profite des exemples choisis pour faire une analyse critique des possibilites actuelles offertes par les deux modes de calcul. (auteur)

Comparison of the HadGEM2 climate-chemistry model against in situ and SCIAMACHY atmospheric methane data

Directory of Open Access Journals (Sweden)

G. D. Hayman

2014-12-01

Full Text Available Wetlands are a major emission source of methane (CH4 globally. In this study, we evaluate wetland emission estimates derived using the UK community land surface model (JULES, the Joint UK Land Earth Simulator against atmospheric observations of methane, including, for the first time, total methane columns derived from the SCIAMACHY instrument on board the ENVISAT satellite. Two JULES wetland emission estimates are investigated: (a from an offline run driven with Climatic Research Unit–National Centers for Environmental Prediction (CRU-NCEP meteorological data and (b from the same offline run in which the modelled wetland fractions are replaced with those derived from the Global Inundation Extent from Multi-Satellites (GIEMS remote sensing product. The mean annual emission assumed for each inventory (181 Tg CH4 per annum over the period 1999–2007 is in line with other recently published estimates. There are regional differences as the unconstrained JULES inventory gives significantly higher emissions in the Amazon (by ~36 Tg CH4 yr−1 and lower emissions in other regions (by up to 10 Tg CH4 yr−1 compared to the JULES estimates constrained with the GIEMS product. Using the UK Hadley Centre's Earth System model with atmospheric chemistry (HadGEM2, we evaluate these JULES wetland emissions against atmospheric observations of methane. We obtain improved agreement with the surface concentration measurements, especially at high northern latitudes, compared to previous HadGEM2 runs using the wetland emission data set of Fung et al. (1991. Although the modelled monthly atmospheric methane columns reproduce the large-scale patterns in the SCIAMACHY observations, they are biased low by 50 part per billion by volume (ppb. Replacing the HadGEM2 modelled concentrations above 300 hPa with HALOE–ACE assimilated TOMCAT output results in a significantly better agreement with the SCIAMACHY observations. The use of the GIEMS product to constrain the JULES

A critical summary of microscopic fast-neutron interactions with reactor structural, fissile and fertile materials; Apercu critique des interactions microscopiques des neutrons rapides avec les materiaux de construction et les matieres fissiles et fertiles utilisees dans les reacteurs; Kriticheskij obzor mikroskopicheskog o vzaimodejstviya bystrykh nejtronov s konstruktsionnymi, rasshcheplyayushchimis ya i vosproizvodyashchim i reaktornymi materialami; Resumen critico de las interacciones microscopicas de los neutrones rapidos con los materiales estructurales fisionables y fertiles utilizados en los reactores

Energy Technology Data Exchange (ETDEWEB)

Smith, A B [Argonne National Laboratory, Argonne, IL (United States)

1962-03-15

Prevailing knowledge of fast-neutron-induced reactions utilized in the nuclear design of reactor systems is reviewed. Principal emphasis is placed upon microscopic experimental methods, results and precisions. Fast-neutron scattering is considered in detail, including the results of experimental determinations of scattering from oxygen, iron, zirconium, niobium, tungsten, thorium and uranium. Representative results of experimental studies of fast-neutron capture and fast-neutron-induced fission are given. The measurements discussed not only provide results of considerable applied usefulness but axe also examples of the application of advanced experimental nuclear techniques. Areas of limited, conflicting or non-existent experimental information are outlined. A prognosis of future knowledge of fast-neutron reactions is made, with emphasis on the fulfillment of reactor requirements for basic nuclear data. (author) [French] L'auteur fait le point des connaissances sur les reactions provoquees par les neutrons rapides sur lesquelles on tend a fonder les projets de reacteurs. Il met en relief les methodes, les resultats et la precision de mesures experimentales a l'echelle microscopique. Il etudie en detail la diffusion des neutrons rapides, et donne les resultats de mesures experimentales de diffusion dans l'oxygene, le fer, le zirconium, le niobium, le tungstene, le thorium et l'uranium. Il donne les resultats les plus significatifs d'etudes experimentales sur la capture des neutrons rapides et sur la fission provoquee par des neutrons rapides. Les mesures etudiees, non seulement fournissent des renseignements d'une utilite pratique considerable, mais aussi constituent des exemples de l'application de techniques experimentales nucleaires a la pointe du progres. L'auteur indique les domaines ou les donnees experimentales sont limitees, contradictoires ou inexistantes. Il se livre a des pronostics sur le developpement des connaissances experimentales en matiere de

Reactor Radiation Loops as Large Gamma Sources; Boucles d'irradiation des reacteurs nucleaires utilisees comme sources gamma intenses; Radiatsionnye kontury yadernykh reaktorov kak moshchnye gamma-istochniki; Empleo de circuitos de irradiacion de los reactores como fuentes gamma de gran intensidad

Energy Technology Data Exchange (ETDEWEB)

Ryabukhina, Yu. S.

1963-11-15

. On a etudie le comportement de deux alliages eutectiques de l'indium en presence de certains materiaux de construction; la premiere installation a ndium-gallium est entree en service au debut de 1960. Des travaux ulterieurs ont permis d'equiper le reacteur IRT de l'Academie des sciences de Georgie d'une boucle modele permettant d'obtenir dans le.canal d'irradiation une activite maximum equivalent a environ 100 g de radium, et d'installer une boucle d'essai a indium-gallium-etain dans le canal du reacteur IRT appartenant a l'Institut de l'energie atomique de l'Academie des sciences de l'URSS. Enfin, en 1962, une boucle a indium - gallium - etain a ete mise en service dans le reacteur IRT de l'Academie des sciences de Lituanie, en vue d'executer des irradiations a une echelle semi-industrielle. Son activite maximum atteignait, dans le dispositif d'irradiation, un niveau equivalent a 30 000 g de radium. Le memoire se compose des quatre parties suivantes: 1. ''Calcul des boucles d'irradiation''; les auteurs generalisent les resultats des travaux sur les methodes de calcul des boucles d'irradiation. 2. ''Modele d'une boucle d'irradiation a indium-gallium pour le reacteur IRT-2000 de Tbilisi''; les auteurs decrivent le fonctionnement de la boucle. 3. ''Boucle d'irradiation a indium-gallium-etain du reacteur nucleaire IRT de l'Academie des sciences de Lituanie''; les auteurs decrivent le fonctionnement de la boucle. 4.

CO{sub 2} direct cycles suitable for AGR type reactors; Cycles directs de gaz carbonique applicables aux reacteurs du genre AGR

Energy Technology Data Exchange (ETDEWEB)

Maillet, E [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

1967-10-01

The perspectives given by the gas turbines under pressure, to build simple nuclear power plants and acieving significantly high yield, are specified. The CO{sub 2} is characterised by by good efficiency under moderate temperature (500 to 750 Celsius degrees), compactness and the simpleness of machines and the safe exploitation (supply, storage, relief cooling, thermosyphon). The revision of thermal properties of the CO{sub 2} and loss elements show that several direct cycles would fit in particular to the AGR type reactors. Cycles that would diverge a little from classical models and able to lead to power and heat generation can lead by simple means to the best results. Several satisfying solutions present for the starting up, the power regulation and the stopping. The nuclear power plant components and the functioning safety are equally considered in the present report. The conclusions stimulate the studies and realizations of carbon dioxide gas turbines in when approprite. [French] Les perspectives offertes par la turbine a gaz sous pression, pour construire des centrales nucleaires simples et de rendement progressivement eleve, se precisent actuellement. le CO{sub 2} se distingue par sa bonne efficacite a temperature moderee (500 a 750 degres celsius), la compacite et la simplicite des machines, et la surete qu'il apporte a l'exploitation ( approvisionnement, stockage, refroidissement de secours, thermosiphon). La revision des proprietes thermophysiques du CO{sub 2} et des elements de pertes montre que divers cycles directs conviendraient en particulier aux reacteurs agr ou derives. Des cycles s'ecartant peu des modeles classiques, et se pretant ulterieurement a la production simultanee d'electricite et de chaleur, peuvent conduire par des moyens simples aux meilleurs resultats d'ensemble. Plusieurs solutions satisfaisantes se presentent pour le demarrage, le reglage de la puissance et l'arret. Les composants de la centrale et la surete de fonctionnement sont

General safety orientations of the Jules Horowitz Reactor Project (JHRP)

International Nuclear Information System (INIS)

Tremodeux, P.; Fiorini, G.L.

2000-01-01

After a brief reminder of the JHR purpose, the document outlines the General Safety related Orientations/Recommendations used for the design and the safety assessment of the facility. As far as the JHR design is new, the safety philosophy adopted for this reactor will be as consistent as possible with that recommended for future (power...) reactors. The general recommendations developed in the paper are: the general nuclear safety approach for the design, operation and analysis with, in particular, the adoption of the Defence In Depth principle; the general safety objectives in terms of radiological consequences; the use of Probabilistic Safety Studies; quality assurance. The 'Defence in Depth' concept using amongst others the 'Barrier' principle remains the basis of the JHR safety. 'Defence In Depth' is applied both to design and operation. Its adequacy is checked during the safety assessment and the paper gives the technical recommendations that should allow the designer to implement this concept into the final design. Built mainly for experimental irradiation the JHR facilities will be handled according to conventional or new operation rules which could put materials under stress and entail handling errors. Specific recommendations are defined to take into account the corresponding peculiarities; they are discussed in the paper. The safety design of the JHR takes into account the experience accumulated through the CEA experimental irradiation programmes, which represents several dozen reactor years; the consultation of CEA reactor facilities operators is ongoing. The corresponding feedback is shortly described. Recommendations related to maintenance and associated operation are indicated as well as those regarding the human factor. Details are given on the JHR safety practical implementation through the CEA/DRN Safety approach. Details of the corresponding Safety Objectives are also discussed. Finally the designer position on the role of probabilistic safety

Study of the aqueous corrosion mechanisms and kinetics of the AlFeNi aluminium based alloy used for the fuel cladding in the Jules Horowitz research reactor

International Nuclear Information System (INIS)

Wintergerst, M.

2009-05-01

For the Jules Horowitz new material-testing reactor (JHR), an aluminium base alloy, called AlFeNi, will be used for the cladding of the fuel plates. This alloy (Al - 1% Fe - 1% Ni - 1 % Mg), which is already used as fuel cladding, was developed for its good corrosion resistance in water at high temperatures. However, few studies dealing with the alteration process in water and the relationships with irradiation effects have been performed on this alloy. The conception of the JHR fuel requires a better knowledge of the corrosion mechanisms. Corrosion tests were performed in autoclaves at 70 C, 165 C and 250 C on AlFeNi plates representative of the fuel cladding. Several techniques were used to characterize the corrosion scale: SEM, TEM, EPMA, XRD, Raman spectroscopy. Our observations show that the corrosion scale is made of two main layers: a dense amorphous scale close to the metal and a porous crystalline scale in contact with the water. More than the morphology, the chemical compositions of both layers are different. This duplex structure results from a mixed growth mechanism: an anionic growth to develop the inner oxide and a cationic diffusion followed by a dissolution-precipitation process to form the outer one. Dynamic experiments at 70 C and corrosion kinetics measurements have demonstrated that the oxide growth process is controlled by a diffusion step associated to a dissolution/precipitation process. A corrosion mechanism of the AlFeNi alloy in aqueous media has been proposed. Then post-irradiation exams performed on irradiated fuel plates were used to investigate the effects of the irradiation on the corrosion behaviour in the reactor core. (author)

Some particular problems put by operating experimental reactors; Quelques problemes particuliers poses par le fonctionnement des piles laboratoires

Energy Technology Data Exchange (ETDEWEB)

Candiotti, C; Mabeix, R; Uguen, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

On basis of a six years experience in operating research reactors, the authors explain, first, the difference in their utilization between these piles and another similar ones and, after, in consequence, they set off corresponding servitudes. These servitudes put very particular problems in operating itself, maintenance, modifications or additions on these apparatus. (author) [French] Les redacteurs se basant sur six annees d'experience dans l'exploitation de reacteurs de recherche, exposent tout d'abord les differences d'utilisation entre ces engins et d'autres appareils fonctionnellement similaires et font ressortir, par voie de consequence, les servitudes correspondantes. Ces servitudes posent des problemes tres particuliers dans les domaines de l'exploitation proprement dite, de l'entretien, des modifications ou adjonctions apportees a l'ensemble. (auteur)

Recuperation of the energy released in the G-1, an air-cooled graphite reactor core; Recuperation de l'energie degagee dans G 1 pile a graphite refroidie a l'air

Energy Technology Data Exchange (ETDEWEB)

Chambadal, P [Electricite de France (EDF), 75 - Paris (France); Pascal, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

The CEA (in his five-year setting plan) has objective among others, the realization of the two first french reactors moderated with graphite. The construction of the G-1 reactor in Marcoule, first french plutonic core, is achieved so that it will diverge in the beginning of 1956 and reach its full power in the beginning of the second semester of the same year. In this report we will detail the specificities of the reactor and in particular its cooling and energy recuperation system. The G-1 reactor being essentially intended to allow the french technicians to study the behavior of an energy installation supply taking its heat in a nuclear source as early as possible. (M.B.) [French] Le Commissariat a l'Energie Atomique (dans le cadre du plan quinquennal) a entre autres objectifs, la realisation des deux premiers reacteurs francais moderes au graphite. La construction du reacteur G-1 a Marcoule, premiere pile plutonigene francaise, est realise afin qu'il puisse diverger au debut de 1956 et atteindre sa pleine puissance au debut du second semestre de la meme annee. Dans ce rapport nous detaillerons les specificites du reacteur et en particulier son systeme de refroidissement et de recuperation d'energie. Le reacteur G-1 etant essentielement destine a permettre aux techniciens francais d'etudier le plus tot possible le comportement d'une installation productrice d'energie empruntant sa chaleur a une source nucleaire. (M.B.)

Jules Horowitz reactor - presentation of the project and progress report

International Nuclear Information System (INIS)

Ballagny, A.; Frachet, S.; Rommens, M.; Guigon, B.; Minguet, J.L.; Dupuy, J.P.; Leydier, C.

2001-01-01

The RJH project was launched by CEA some years ago, with the objective to replace, after 2010, the material testing reactors of the previous generation. The objectives are also: to realise a significant step in term of performances, to ensure a high flexibility of the design, in order to host in the future new experiments, which are not completely defined at the project stage, to reach a high level of safety, according to the best current practice. After a summary of the main experimental objectives of the facility, the present paper deals with a detailed technical presentation of the project, resulting from preliminary design studies. The following topics are covered successively: the main functionalities, the resulting design options and technical solutions, the layout of the nuclear facility. (orig.)

Heat exchanges during the re-flooding of a water reactor core - within the framework of the 'reference accident'; Echanges thermiques lors du renoyage d'un coeur de reacteur a eau - dans le cadre de 'l'accident de reference'

Energy Technology Data Exchange (ETDEWEB)

Andreoni, Daniel

1975-11-28

After a brief presentation of reported studies made in different countries and regarding the so-called 'reference accident', this research thesis reports the study of reactor re-flooding when the reactor is completely dried and heating elements have reached a temperature between 300 and 900 C, with a constant water flow rate entering the test section, with a constant dissipated electrical power, and by using very simple geometries. After a first part addressing the experimental study, the author reports the development of conduction calculation codes used to compute the flow extracted by the two-phase flow, present the thermal-hydraulic code used to compute local values and to study the correlation of the upstream area exchange coefficient. The author finally reports an analysis of the different existing models and the study of a re-flooding model [French] La presente etude est consacree a l'un des aspects de la surete des reacteurs a eau sous pression, et plus precisement a l'accident tres important qui consiste en une perte de fluide caloporteur (Loss of Coolant Accident - 'LOCA'). Le but de l'etude est de fournir des renseignements necessaires a l'interpretation des experiences effectuees sur des grappes, de donner une correlation de coefficient d'echange dans la zone aval, et de donner aussi un modele de progression du front de trempe pour les analyses de surete. Une etude bibliographique preliminaire nous a permis de faire le point sur les experiences entreprises concernant le refroidissement de secours. Ensuite, les chapitres suivants seront decrits: 1) Le chapitre II, consacre a l'etude experimentale (boucle, sections d'essais, resultats globaux). 2) Le chapitre III ou seront presentes les codes de calcul de conduction, necessaires au calcul du flux extrait par le melange diphasique, le code de thermohydraulique necessaire au calcul des grandeurs locales et l'etude de la correlation du coefficient d'echange de la zone aval. 3) Enfin le chapitre IV ou, apres

Development of a power-period calculation unit for nuclear reactor Control; Etude et realisation d'un ensemble de calcul puissance periode pour le controle d'un reacteur nucleaire

Energy Technology Data Exchange (ETDEWEB)

Martin, J [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

1966-10-01

The apparatus studied is a digital calculating assembly which makes it possible to prepare and to present numerically the period and power of a nuclear reactor during operation, from start-up to nominal power. The pulses from a fission chamber are analyzed continuously, using real time. A small number of elements is required because of the systematic use of a calculation technique comprising the determination of a base 2 logarithm by a linear approximation. The accuracy obtained for the period is of the order of 14%; the response time of the order of the calculated period value. An approximate value of the power (30%) is given at each calculation cycle together with the power thresholds required for the control. (author) [French] L'appareil etudie est un ensemble de calcul digital permettant d'elaborer et d'afficher numeriquement la periode et la puissance, d'un reacteur nucleaire lors de son fonctionnement depuis le demarrage jusqu'a la puissance nominale. Il traite en temps reel, de facon continue, les impulsions en provenance d'une chambre de fission. Grace a l'utilisation systematique d'une technique de calcul, la determination d'un logarithme a base 2 par approximation lineaire, un nombre reduit d'elements est utilise. La precision obtenue sur la periode est de l'ordre de 14 pour cent, le temps de reponse de l'ordre de la valeur de la periode calculee. Un ordre de grandeur de la puissance (30 pour cent) est donne a chaque cycle de calcul ainsi que des seuils de puissance necessaires au controle. (auteur)

The cryogenic installations for irradiation in the reactors Melusine and Siloe; Les installations cryogeniques pour irradiations des reacteurs Melusine et Siloe

Energy Technology Data Exchange (ETDEWEB)

Bochirol, L; Le Calvez, J; Doulat, J; Verdier, J; Lacaze, A; Weil, L [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-07-01

vaporized in the atmosphere and without any pollution of the refrigerating circuit. Lastly, a few words are said about the liquid helium loop, a prototype of which has worked, and which is being rebuilt with an increased power. (authors) [French] L'etude des defauts crees par l'irradiation dans les solides est d'un interet theorique et pratique, considerable. L'irradiation a basse temperature permet d'obtenir les defauts dans leur etat le plus simple, leur etat 'primaire' sans que l'agitation thermique permette leur annihilation ou leur rearrangement. L'irradiation en pile a basse temperature pose un certain nombre de problemes techniques provenant de la puissance de refrigeration necessaire, qui est quelquefois considerable, des reactions chimiques possibles sous rayonnement et du manque d'espace dans un reacteur. Enfin, la necessite de faire toute l'irradiation et les mesures ulterieures sans rechauffer les; echantillons impose que le dispositif fonctionne en continu sans defaillance et qu'il soit equipe de facon a permettre la recuperation des echantillons froids, ou bien leur mesure et leur rechauffage controle 'in situ'. On decrit la facon dont ces problemes ont ete resolus a Grenoble, pour des dispositifs d'irradiation a 78 deg. K, 28 deg. K et 4 deg. K dans les deux piles piscines Melusine et Siloe. Quelques resultats d'exploitation sont donnes sur la boucle a azote liquide, dite type A, qui fonctionne depuis plusieurs annees dans Melusine. En particulier certaines observations sont faites sur les reactions chimiques qui peuvent se produire sous irradiation dans l'azote liquide impur. On decrit assez en detail la boucle a azote liquide, dite type A, qui vient d'etre installee dans le reacteur Siloe. Les traits essentiels de cet appareil sont: qu'il permet l'irradiation dans des flux plus eleves que le precedent et que son exploitation est grandement facilitee grace a un mode de realisation qui permet l'acces aux echantillons sans demontage ni deconnexion de l

Burnup determination of power reactor fuel elements by gamma spectrometry; Determination par spectrometrie {gamma} du taux d'irradiation des elements combustibles des reacteurs de puissance

Energy Technology Data Exchange (ETDEWEB)

Robin, M; Jastrzeb, M; Boisliveau, S; Boyer, R; Vidal, R [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

This report describes a method for determining by {gamma} spectrometry the burn up and the specific power of fuel elements irradiated in power reactors. The energy spectrum of {gamma} rays emitted by fission products is measured by means of a simple equipment using a sodium iodide detector and a multichannel analyzer. In order to extract from the spectrum a quantity proportional to the burn up, it is necessary to: - isolate an activity specific of one emitter,- give the same importance to fissions in uranium and plutonium - take into account the radioactive decay during and after irradiation. One hundred fuel elements were studied and burn up values obtained by {gamma} spectrometry are compared to results given by chemical analyses. Preliminary measurements show that the accuracy of the results is greatly increased by the use of a germanium detector, due to its good resolution. (authors) [French] Ce rapport expose une methode de determination par spectrometrie {gamma} du taux d'irradiation et de la puissance specifique des elements combustibles irradies dans les reacteurs de puissance. Une installation simple utilisant un detecteur d'iodure de sodium et un selecteur multicanaux mesure le spectre en energie du rayonnement {gamma} emis par les produits de fission. Afin d'extraire du spectre une quantite proportionnelle au taux de combustion, il faut: - isoler une activite specifique a un emetteur, - donner la meme importance aux fissions survenues dans l'uranium et le plutonium, - prendre en compte la decroissance radioactive pendant et apres l'irradiation. Les mesures ont porte sur une centaine d'elements combustibles et les taux de combustion obtenus par spectrometrie {gamma} sont compares aux resultats des analyses chimiques. Des mesures preliminaires montrent que l'utilisation d'un detecteur de germanium augmente considerablement la precision des resultats, en raison de son excellente resolution. (auteurs)

The first metallurgical tests on plutonium; Premiers essais metallurgiques sur le plutonium

Energy Technology Data Exchange (ETDEWEB)

Grison, E; Abramson, R; Anselin, F; Monti, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Metallic plutonium was first prepared in France in January 1956, as soon as we had access to quantities of the order of several grams of plutonium, which had been extracted from the rods of the pile EL2 at Saclay. Since up to the present this reactor, of thermal power 2 000 kW, has been our only source of plutonium, we have so far only worked on experimental quantities sufficient for the basic tests but not for tests on a scale of possible applications. It is this work, carried out during this phase of preliminary research, which is described below. With the starting up of the plutonium extraction plant at Marcoule, where the reactor G1 has been operating at power for more than a year, we shall go on next to a another order of magnitude which will allow the manufacture and experimentation of prototype fuel elements. (author) [French] La premiere elaboration de plutonium metallique en France fut faite en janvier 1956, des que nous pumes disposer de quantites de plutonium de l'ordre de quelques grammes, qui avaient ete retires des barreaux de la pile EL2 de Saclay. Ce reacteur, d'une puissance thermique de 2 000 kW, ayant ete jusqu'a present notre seule source de plutonium, nous n'avons encore travaille que sur des quantites experimentales suffisantes pour les essais de base, mais non pour des essais a l'echelle d'applications possibles. Ce sont les travaux effectues pendant cette phase de recherches preliminaires qui seront evoques ci-dessous. Avec la mise eu route de l'usine d'extraction de plutonium de Marcoule, ou le reacteur G1 fonctionne en puissance depuis plus d'un an, nous allons passer prochainement a un autre ordre de grandeur, qui nous permettra la fabrication et l'experimentation d'elements combustibles prototypes. (auteur)

Improving the representation of radiation interception and photosynthesis for climate model applications

International Nuclear Information System (INIS)

Mercado, Lina M.; Huntingford, Chris; Gash, John H.C.; Cox, Peter M.; Jogireddy, Venkata

2007-01-01

The Joint UK Land Environment Simulator (JULES) (which is based on Met Office Surface Exchange Scheme MOSES), the land surface scheme of the Hadley Centre General Circulation Models (GCM) has been improved to contain an explicit description of light interception for different canopy levels, which consequently leads to a multilayer approach to scaling from leaf to canopy level photosynthesis. We test the improved JULES model at a site in the Amazonian rainforest by comparing against measurements of vertical profiles of radiation through the canopy, eddy covariance measurements of carbon and energy fluxes, and also measurements of carbon isotopic fractionation from top canopy leaves. Overall, the new light interception formulation improves modelled photosynthetic carbon uptake compared to the standard big leaf approach used in the original JULES formulation. Additional model improvement was not significant when incorporating more realistic vertical variation of photosynthetic capacity. Even with the improved representation of radiation interception, JULES simulations of net carbon uptake underestimate eddy covariance measurements by 14%. This discrepancy can be removed by either increasing the photosynthetic capacity throughout the canopy or by explicitly including light inhibition of leaf respiration. Along with published evidence of such inhibition of leaf respiration, our study suggests this effect should be considered for inclusion in other GCMs

Micro manometer and pitot tube for measuring the velocity distribution in a natural convection water stream between two vertical parallel plates (1961); Micromano metre et tube de pitot destines a l'exploration du profil de vitesse dans un ecoulement d'eau de convection naturelle entre deux plaques verticales paralleles (1961)

Energy Technology Data Exchange (ETDEWEB)

Santon, L; Vernier, Ph [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1961-07-01

For heat transfer studies in certain cases of cooling in swimming-pool type nuclear reactors, a knowledge of the distribution of the velocities between two heating elements is of prime importance. A Pitot tube and a micro-manometer have been developed for making these measurements on an experimental model. (authors) [French] Pour l'etude du transfert de chaleur dans certains cas de refroidissement des reacteurs nucleaires du type piscine, la connaissance de la repartition des vitesses entre deux elements chauffants est primordiale. On a mis au point un tube de Pitot et un micromanometre pour effectuer ces mesures sur une maquette experimentale. (auteurs)

Turbulent precipitation of uranium oxalate in a vortex reactor - experimental study and modelling; Precipitation turbulente d'oxalate d'uranium en reacteur vortex - etude experimentale et modelisation

Energy Technology Data Exchange (ETDEWEB)

Sommer de Gelicourt, Y

2004-03-15

Industrial oxalic precipitation processed in an un-baffled magnetically stirred tank, the Vortex Reactor, has been studied with uranium simulating plutonium. Modelling precipitation requires a mixing model for the continuous liquid phase and the solution of population balance for the dispersed solid phase. Being chemical reaction influenced by the degree of mixing at molecular scale, that commercial CFD code does not resolve, a sub-grid scale model has been introduced: the finite mode probability density functions, and coupled with a model for the liquid energy spectrum. Evolution of the dispersed phase has been resolved by the quadrature method of moments, first used here with experimental nucleation and growth kinetics, and an aggregation kernel based on local shear rate. The promising abilities of this local approach, without any fitting constant, are strengthened by the similarity between experimental results and simulations. (author)

The influence of the (n, 2n) and (n, {alpha}) reactions of beryllium on the neutron balance in a BeO or Be moderated reactor and its consequences on the long term reactivity changes; Influence des reactions (n, 2n) et (n, {alpha}) du beryllium sur le bilan neutronique d'un reacteur modere a l'oxyde de beryllium ou au beryllium. Consequences sur l'evolution a long terme de la reactivite

Energy Technology Data Exchange (ETDEWEB)

Sahai, K; Benoist, P; Horowitz, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The reaction probabilities in an infinite and homogeneous medium of BeO or Be have been calculated from neutron cross-section curves, for a neutron produced with an energy distribution similar to a fission spectrum; the calculation shows that, after several elastic collisions, the neutron has yet an appreciable probability to undergo a reaction, in spite of the energy degradation in the spectrum due to each collision. This degradation has been calculated, taking into account of anisotropy of the collisions. The gain of the reactivity in a reactor has been obtained after correcting these probabilities for the attenuation of the flux of fission neutrons due to the inelastic scattering in the uranium. Finally, the calculation shows that in a power reactor, this gain of reactivity is in practice destroyed in a few years by the accumulation of poisonous nuclei such as Li{sup 6} and He{sup 3} following (n, {alpha}) reaction. (author) [French] Les probabilites de reaction en milieu infini et homogene de glucine (BeO) ou de beryllium ont ete calculees a partir des courbes de section efficace pour un neutron naissant suivant un spectre de fission; le calcul montre qu'apres plusieurs diffusions elastiques le neutron a encore une probabilite appreciable de subir une reaction, malgre la degradation du spectre a chaque diffusion; cette degradation a ete calculee en tenant compte de l'anisotropie du choc. Le gain de reactivite dans un reacteur a ensuite ete obtenu en corrigeant les probabilites en milieu homogene de l'effet l'attenuation du flux des neutrons de fission par les chocs inelastiques dans les barres d'uranium. Enfin, le calcul montre que, dans un reacteur de puissance, ce gain de reactivite est pratiquement detruit en peu d'annees par l'accumulation de noyaux poisons Li{sup 6} et He{sup 3} consecutive a la reaction (n, {alpha}). (auteur)

The noise-time of response compromise in d.c. period meters. A new type of circuit (1961); Le compromis bruit-temps de reponse dans les periodemetres a courant continu. un nouveau type de circuit (1961)

Energy Technology Data Exchange (ETDEWEB)

Friedling, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

The report compares the characteristics of three period meter circuits: - a linear circuit - a circuit which is non-linear according to the nuclear reactor period - a circuit which is non-linear according to the period and the power of the reactor. This last type of reactor has a fast time of response if the power is high or if the period is short, and it has a slow time of response when the power is low and the period long; this system makes it possible to maintain the noise at an acceptable level under all normal working conditions of the reactor. (author) [French] Le rapport compare les caracteristiques de trois circuits de periodemetres: - un circuit lineaire; - un circuit non lineaire selon la periode du reacteur nucleaire; - un circuit non lineaire selon la periode et la puissance du reacteur. Ce dernier type de circuit a un court temps de reponse si la puissance est faible et la periode grande; ce systeme permet de limiter le bruit a des niveaux acceptables dans toutes les conditions normales de fonctionnement du reacteur. (auteur)

Experimental studies of some of the physical features of beryllium-moderated intermediate reactors; Etude experimentale de quelques particularites physiques des reacteurs a neutrons intermediaires, ralentis au beryllium; Ehksperimental'ny e issledovaniya nekotorykh fizicheskikh osobennostej promezhutochnykh reaktorov s berillievym zamedlitelem; Estudios experimentales de algunas caracteristicas fisicas de los reactores intermedios moderados con berilio

Energy Technology Data Exchange (ETDEWEB)

Lejpunskij, A I; Kuznetsov, V A; Artyukhov, G Ya; Mogil' ner, A I; Prokhorov, Yu A; Steklovski, V M; Chernov, L A [Akademiya Nauk, Moskva, Union of Soviet Socialist Republics (Russian Federation)

1962-03-15

of neutrons absorbed by the uranium. The paper provides data, derived from the same assembly, on the efficiency of rods made of various absorbing materials. It gives the experimentally measured distribution of neutron density for neutrons of various energies in the neighbourhood of a boron-carbide rod, and the density of neutron captures by a 1/v detector within the rod. The paper also discusses methods used and the results obtained from experiments designed to assess the efficiency of recompensation, cylinders placed on the boundary between core and reflector. (author) [French] Le memoire analyse les resultats de plusieurs experiences effectuees sur l'ensemble critique PF-4, qui est destine a l'etude detaillee des particularites physiques des reacteurs a neutrons intermediaires. Les coeurs et les reflecteurs des differents esembles critiques etaient constitues par un assemblage compact de tubes en acier ou en aluminium dans lesquels etaient inseres des diques de diverses matieres. En combinant selon differentes proportions les disques d'uranium enrichi a 90% et les matieres de ralentissement et en introduisant dans le reflecteur des couches de ralentisseur de diverses epaisseurs, on a pu obtenir de grandes modifications du spectre des neutrons provoquant la fission. Le memoire decrit l'ensemble critique PF-4 et les differents assemblages qui le composent. Les auteurs analysent l'efficacite relative du ralentissement interieur et exterieur pour des reacteurs dans lesquels le rapport noyaux du ralentisseur noyaux d'uranium dans le coeur est tres peu eleve. Il ressort des experiences que, meme lorsqu'on emploie des reflecteurs tres epais, la faible dilution de l'uranium par le ralentisseur (le rap- port entre les noyaux du beryllium et de l'uranium-235 etant: {partial_derivative}Be/{partial_derivative}{sup 235}U{approx_equal}1) entraine un accroissement de la masse critique. Une partie importante du memoire est consacree a une analyse des effets hetero- genes produits

Some particular problems put by operating experimental reactors; Quelques problemes particuliers poses par le fonctionnement des piles laboratoires

Energy Technology Data Exchange (ETDEWEB)

Candiotti, C.; Mabeix, R.; Uguen, R. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

On basis of a six years experience in operating research reactors, the authors explain, first, the difference in their utilization between these piles and another similar ones and, after, in consequence, they set off corresponding servitudes. These servitudes put very particular problems in operating itself, maintenance, modifications or additions on these apparatus. (author) [French] Les redacteurs se basant sur six annees d'experience dans l'exploitation de reacteurs de recherche, exposent tout d'abord les differences d'utilisation entre ces engins et d'autres appareils fonctionnellement similaires et font ressortir, par voie de consequence, les servitudes correspondantes. Ces servitudes posent des problemes tres particuliers dans les domaines de l'exploitation proprement dite, de l'entretien, des modifications ou adjonctions apportees a l'ensemble. (auteur)

Experimental and numerical characterization of anisotropic damage evolution of forged Al6061-T6 alloy

International Nuclear Information System (INIS)

Shen, Y.; Garnier, J.; Allais, L.; Crepin, J.; Ancelet, O.; Hiver, J.M.

2011-01-01

Aluminum alloy 6061-T6 (Al-Mg-Si) has been selected as the material of the vessel for the construction of Jules-Horowitz material testing reactor. Fracture mechanism of this alloy has been investigated using mechanical testing of smooth and notched tensile specimens loaded in different directions. A strong anisotropic fracture behavior has been observed. Microstructural studies using tomography and image analysis have shown a presence of anisotropic distributed coarse precipitates which is the key microstructural feature affecting the damage evolution. These observations were complemented by investigations on fractured tensile samples. A damage scenario of anisotropic growth and coalescence of voids is proposed to explain the fracture behavior associated with the distribution of precipitates. A GTN (Gurson-Tvergaard-Needleman) damage model is used to simulate this scenario and to predict damage evolution. (authors)

Development and testing of the EDF-2 reactor fuel element; Essais et mise au point de l'element combustible pour le reacteur EDF-2

Energy Technology Data Exchange (ETDEWEB)

Delpeyroux, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Furhmann, R [Societe Industrielle de Combustible Nucleaire (France)

1964-07-01

rassemble les etudes qui ont ete necessaires pour mener a bien la definition de l'element combustible EdF 2. Apres un bref rappel des caracteristiques du reacteur EdF 2 et des options preliminaires ayant permis de fixer un avant-projet d'element combustible, on aborde les etudes proprement dites: - Etudes uranium: essais de passage d'une couronne interne du tube en phase {beta}, flechage du tube sous l'action d'une force concentree, soudage des pastilles d'extremites et verification de leur etancheite. La tenue du tube a l'ecrasement et la resistance des pastilles a l'enfoncement sous l'action de la pression externe sont etudiees en detail dans un autre rapport CEA - Etudes gaine: rappel des conditions de fabrication et verification de l'etancheite de la gaine, tenue des ailettes au fluage sous l'action du courant gazeux - Etudes d'extremites: fluage en compression et soudage des bouchons a la gaine. - Etudes cartouche: determination des caracteristiques des gorges d'ancrage gaine-combustible et des conditions de gainage, verification de la tenue au cyclage thermique de l'element combustible, determination de la chute de temperature au contact gaine-combustible traitee en detail dans un autre rapport CEA, - Etudes de l'ensemble: les etudes se rapportant a la chemise de graphite, au support et aux vibrations de la cartouche ont ete traitees par le service des Etudes Mecaniques et Thermiques (Section de Mecanique), Dans ce domaine, la Section d'Etude d'Elements Combustibles a etudie la tenue des centreurs sous l'action du courant gazeux. L'aboutissement des etudes est constitue par le dessin de l'element combustible, le schema de fabrication et les normes de fabrication. La validite de l'ensemble de ces essais hors pile sera confirmee par des assais en pile qui sont en cours et par l'irradiation des elements dans le reacteur EdF 2 lui-meme. En conclusion, on donne l'orientation des etudes pour l'amelioration de l'element combustible et la definition d'un element combustible

Alle ønsker sig en Lego-aktie til jul

DEFF Research Database (Denmark)

Iversen, Martin Jes

2014-01-01

Både små og store investorer får julelys i øjnene ved tanken om at eje et stykke af Lego. På sigt kunne en børsnotering gøre Danmark til et rigere land.......Både små og store investorer får julelys i øjnene ved tanken om at eje et stykke af Lego. På sigt kunne en børsnotering gøre Danmark til et rigere land....

For a Better Estimation of Gamma Heating in Experimental Reactors and Devices: Stakes and Work Plan from Calculation Methods to Nuclear Data

International Nuclear Information System (INIS)

Lemaire, Matthieu; Vaglio-Gaudard, Claire; Lyoussi, Abdallah; Reynard-Carette, Christelle

2013-06-01

The Jules Horowitz Reactor (JHR) is an international Material-Testing Reactor currently under construction at CEA Cadarache. The determination of gamma heating levels in this future commercial reactor is of crucial importance as gamma heating affects both safety and performance parameters of the JHR. Required accuracy (5% at one standard deviation) makes it necessary to calibrate bias and uncertainty associated with JHR gamma-heating calculations. Main steps of bias determination for gamma-heating calculations include, firstly, the development of a calculation methodology with controlled use of physical approximations; secondly, the interpretation of gamma-heating measurements so as to determine bias supposed to be only due to nuclear data. (authors)

Vision Restoration with a Collagen Cross-linked Boston Keratoprosthesis Unit

Science.gov (United States)

2017-09-01

Esen Akpek 4 W.K. Kellogg Eye Center Dr. Shahzad Mian 5 The Jules Stein Eye Institute Dr. Anthony Aldave 6 Illinois Eye and Ear Infirmary Dr. Jose...Principal Investigator 1 Mass Eye and Ear Infirmary Dr. Joseph Ciolino 3 The Willmer Eye Institute Dr. Esen Akpek 4 W.K. Kellogg Eye Center Dr...Dr. Esen Akpek 4 W.K. Kellogg Eye Center Dr. Shahzad Mian 5 The Jules Stein Eye Institute Dr. Anthony Aldave 7 Cincinnati Eye Institute Dr. Edward

Heavy water moderated gas-cooled reactors; Filiere eau lourde - gaz

Energy Technology Data Exchange (ETDEWEB)

Bailly du Bois, B; Bernard, J L; Naudet, R; Roche, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

France has based its main effort for the production of nuclear energy on natural Uranium Graphite-moderated gas-cooled reactors, and has a long term programme for fast reactors, but this country is also engaged in the development of heavy water moderated gas-cooled reactors which appear to present the best middle term prospects. The economy of these reactors, as in the case of Graphite, arises from the use of natural or very slightly enriched Uranium; heavy water can take the best advantages of this fuel cycle and moreover offers considerable development potential because of better reactor performances. A prototype plant EL 4 (70 MW) is under construction and is described in detail in another paper. The present one deals with the programme devoted to the development of this reactor type in France. Reasons for selecting this reactor type are given in the first part: advantages and difficulties are underlined. After reviewing the main technological problems and the Research and Development carried out, results already obtained and points still to be confirmed are reported. The construction of EL 4 is an important step of this programme: it will be a significant demonstration of reactor performances and will afford many experimentation opportunities. Now the design of large power reactors is to be considered. Extension and improvements of the mechanical structures used for EL 4 are under study, as well as alternative concepts. The paper gives some data for a large reactor in the present state of technology, as a result from optimization studies. Technical improvements, especially in the field of materials could lead to even more interesting performances. Some prospects are mentioned for the long run. Investment costs and fuel cycles are discussed in the last part. (authors) [French] La France, qui a base son effort principal pour la production d'energie nucleaire sur la filiere des reacteurs a uranium naturel et graphite refroidis par gaz, et qui a un programme a plus

Fast neutron flux in heavy water reactors; Flux de neutrons rapides dans les piles a eau lourde

Energy Technology Data Exchange (ETDEWEB)

Brisbois, J; Katz, S [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Fontenay-aux-Roses, 92 (France)

1966-07-01

The possibility of calculating the fast neutron flux in a natural uranium-heavy water lattice by superposition of the individual contributions of the different fuel elements was verified using a one-dimension Monte-Carlo code. The results obtained are in good agreement with experimental measurements done in the core and reflector of the reactor AQUILON. (author) [French] La possibilite de calculer le flux de neutrons rapides dans un reseau d'uranium naturel a eau lourde par superposition des apports des divers barreaux, a ete verifiee en utilisant un code Monte-Carlo monodimensionel. Les resultats obtenus concordent avec des mesures experimentales effectuees dans le coeur et reacteur de la pile Aquilon. (auteurs)

Calculation of the working capital invested in fuel cycles and its interest charges (1963); Calcul des immobilisations financieres des cycles de combustible (1963)

Energy Technology Data Exchange (ETDEWEB)

Gaussens, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

All the processes undergone by the nuclear material, including the various steps of fuel element manufacturing and of irradiated fuel reprocessing lead to working capital investments varying with the type of reactor, that must be taken into account in the kWh cost calculation. The author deals with a calculation method called: 'present worth method' and gives some examples concerning reactors the main fuel of which being either natural uranium or enriched uranium or plutonium. He especially points out the importance these investments may take in the case of fast breeder reactors. (author) [French] L'ensemble des etapes parcourues par la matiere fissile comprenant les divers stades d'elaboration des elements combustibles et de leur traitement apres irradiation, implique des immobilisations financieres tres differentes d'un type de reacteur a l'autre, dont il convient de tenir compte dans le calcul du cout du kWh. L'auteur expose une methode de calcul dite 'd'actualisation des couts' et donne quelques exemples relatifs aux reacteurs utilisant l'uranium naturel, l'uranium enrichi et le plutonium comme combustible principal. Il montre en particulier l'importance que peuvent avoir ces immobilisations dans le cas des reacteurs surregenerateurs. (auteur)

Activity report 1999; Rapport d'activites 1999

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

The aim of this report is to outline the main developments of the ''Departement des Reacteurs Experimentaux'', (DRE) during the year 1999. DRE is one of the Department of the ''Direction des Reacteurs Nucleaires'', itself depending of the CEA Institution. After a presentation of the year highlights, this report gathers the main research and development programs. The second part concerns the production of radioisotopes, the silicon doping, the neutron radiography, the Orphee experiments and the activation analysis. The installations management, the closed reactors improvement program and the effluents and wastes processing of Grenoble, are presented in the other parts. Data on staff, budget and safety are also provided. (A.L.B.)

Activity report 1998

International Nuclear Information System (INIS)

1998-01-01

The aim of this report is to outline the main developments of the ''Departement des Reacteurs Experimentaux'', (DRE) during the year 1998. DRE is one of the Department of the ''Direction des Reacteurs Nucleaires'', itself depending of the CEA Institution. After a presentation of the year highlights, this report gathers the main research and development programs. The second part concerns the production of radioisotopes, the silicon doping, the neutron radiography, the Orphee experiments and the activation analysis. The installations management, the closed reactors improvement program and the effluents and wastes processing of Grenoble, are presented in the other parts. Data on staff, budget and safety are also provided. (A.L.B.)

Activity report 1999

International Nuclear Information System (INIS)

1999-01-01

The aim of this report is to outline the main developments of the ''Departement des Reacteurs Experimentaux'', (DRE) during the year 1999. DRE is one of the Department of the ''Direction des Reacteurs Nucleaires'', itself depending of the CEA Institution. After a presentation of the year highlights, this report gathers the main research and development programs. The second part concerns the production of radioisotopes, the silicon doping, the neutron radiography, the Orphee experiments and the activation analysis. The installations management, the closed reactors improvement program and the effluents and wastes processing of Grenoble, are presented in the other parts. Data on staff, budget and safety are also provided. (A.L.B.)

Turbulent precipitation of uranium oxalate in a vortex reactor - experimental study and modelling; Precipitation turbulente d'oxalate d'uranium en reacteur vortex - etude experimentale et modelisation

Energy Technology Data Exchange (ETDEWEB)

Sommer de Gelicourt, Y

2004-03-15

Industrial oxalic precipitation processed in an un-baffled magnetically stirred tank, the Vortex Reactor, has been studied with uranium simulating plutonium. Modelling precipitation requires a mixing model for the continuous liquid phase and the solution of population balance for the dispersed solid phase. Being chemical reaction influenced by the degree of mixing at molecular scale, that commercial CFD code does not resolve, a sub-grid scale model has been introduced: the finite mode probability density functions, and coupled with a model for the liquid energy spectrum. Evolution of the dispersed phase has been resolved by the quadrature method of moments, first used here with experimental nucleation and growth kinetics, and an aggregation kernel based on local shear rate. The promising abilities of this local approach, without any fitting constant, are strengthened by the similarity between experimental results and simulations. (author)

Study of liquid hydrogen and liquid deuterium cold neutron sources; Etude de sources de neutrons froids a hydrogene et deuterium liquides

Energy Technology Data Exchange (ETDEWEB)

Harig, H D [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1967-12-01

In view of the plant of the cold neutron source for a high flux reactor (maximal thermal flux of about 10{sup 15} n/cm{sup 2}s) an experimental study of several cold sources of liquid hydrogen and liquid deuterium has been made in a low power reactor (100 kW, about 10{sup 12} n/cm{sup 2}s). We have investigated: -cold neutron sources of liquid hydrogen shaped as annular layers of different thickness. Normal liquid hydrogen was used as well as hydrogen with a high para-percentage. -Cold neutron sources of liquid deuterium in cylinders of 18 and 38 cm diameter. In this case the sources could be placed into different positions to the reactor core within the heavy water reflector. This report gives a general description of the experimental device and deals more detailed with the design of the cryogenic systems. Then, the measured results are communicated, interpreted and finally compared with those of a theoretical study about the same cold moderators which have been the matter of the experimental investigation. (authors) [French] En vue de l'installation d'une source a neutrons froids dans un reacteur a haut flux (flux thermique maximal environ 10{sup 15} n/cm{sup 2}s), nous avons fait une etude neutronique experimentale de differentes sources froides a hydrogene et a deuterium liquides aupres d'un reacteur a faible puissance (100 kW environ 10{sup 12} n/cm{sup 2}s). Nous avons etudie: des couches annulaires de differentes epaisseurs d'hydrogene liquide normal et d'hydrogene a grand pourcentage para, des cellules cylindriques de 18 et 38 cm de diametre, remplies de deuterium liquide et placees a differentes positions dans le reflecteur D{sub 2}O. Ce travail traite l'implantation de l'installation cryogenique et donne une description generale de l'experience. L'interpretation des resultats fait etat entre autres d'une comparaison entre l'experience et une etude theorique portant sur les memes moderateurs. (auteurs)

Activity report 1999; Rapport d'activites 1999

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

The aim of this report is to outline the main developments of the ''Departement des Reacteurs Experimentaux'', (DRE) during the year 1999. DRE is one of the Department of the ''Direction des Reacteurs Nucleaires'', itself depending of the CEA Institution. After a presentation of the year highlights, this report gathers the main research and development programs. The second part concerns the production of radioisotopes, the silicon doping, the neutron radiography, the Orphee experiments and the activation analysis. The installations management, the closed reactors improvement program and the effluents and wastes processing of Grenoble, are presented in the other parts. Data on staff, budget and safety are also provided. (A.L.B.)

Single Pellet String Reactor for Intensification of Catalyst Testing in Gas/Liquid/Solid Configuration Réacteur catalytique de type “filaire” pour l’intensification de tests catalytiques en configuration gaz/liquide/solide

Directory of Open Access Journals (Sweden)

Hipolito A.I.

2010-09-01

has been shown that the pressure drop is controlled by the liquid/solid friction surface and that the pressure drop is not a limiting parameter in the reactor’s operation (values always lower than 0.1 bar. So, from a hydrodynamic point of view, this new reactor exhibits characteristics suitable for its use in catalytic tests. Finally, this reactor was implemented under reaction conditions to study hydrogenation reactions with a real industrial catalyst. The selective hydrogenation of allene was studied. The string reactor was shown to run isothermal kinetic tests with a very small amount of industrial-sized catalyst particles (less than 2 cc and to explore kinetics of fast reaction at high space velocities impossible to achieve in standard fixed bed units with appropriate hydrodynamic conditions. For constant residence time, the allene conversion does not vary with pressure and feed flow rate, which confirms that the string reactor allows one to perform catalytic tests with such a fast reaction without external mass transfer resistance. L’optimisation du catalyseur est une etape cle pour l’optimisation d’un procede catalytique du point de vue des rendements, de l’efficacite energetique et de la selectivite des reactions. La strategie de developpement d’un catalyseur comprend des tests effectues sur des reacteurs pilotes avec des charges reelles ou modeles. Cette etape a fait l’objet de nombreuses etudes ces dernieres decennies portant sur le dimensionnement des reacteurs, l’amelioration des outils d’analyses et les procedures operatoires. La plupart des etudes ont pour but de determiner l’activite catalytique de catalyseur sous forme de grain dans des conditions isothermes de facon a pouvoir determiner les parametres cinetiques de la reaction. Avec l’optimisation des catalyseurs, les flux de transfert de matieres externes aux grains peuvent devenir l’etape limitante, dans les reacteurs de laboratoire standard, par rapport aux flux de reaction

Use of cadmium in solution in the EL 4 reactor moderator irreversible fixing of cadmium on the metallic surfaces; Utilisation du cadmium en solution dans le moderateur du reacteur EL 4 - fixation irreversible du cadmium sur les surfaces metalliques

Energy Technology Data Exchange (ETDEWEB)

Croix, O; Paoli, O; Lecomte, J; Dolle, L; Gallic, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

In the framework of research into the poisoning of the EL-4 reactor by cadmium sulphate, measurements have been made by two different methods of the residual amounts of cadmium liable to be fixed irreversibly on the surfaces in contact with the heavy water. A marked influence of the pH has been noticed. The mechanism of the irreversible fixing is compatible with the hypothesis of an ion-exchange in the surface oxide layer. In a sufficiently wide range of pH the cadmium thus fixed causes very little residual poisoning. The stability of the cadmium sulphate solutions is however rather low in the conditions of poisoning. (authors) [French] Dans le cadre des etudes sur l'empoisonnement du reacteur EL-4 par le sulfate de cadmium, les quantites residuelles de cadmium susceptibles de se fixer irreversiblement sur les parois que mouillerait l'eau lourde, ont ete mesurees experimentalement par deux methodes differentes. On observe une influence nette du pH. Le mecanisme de la fixation irreversible est compatible avec l'hypothese d'un echange d'ions dans la pellicule d'oxyde superficielle. Dans des limites suffisamment larges de pH, la cadmium ainsi fixe n'occasionne pas d'empoisonnement residuel important. La stabilite des solutions de sulfate de cadmium dans les conditions de l'empoisonnement est cependant mediocre. (auteurs)

Aspects of Reactor Physics Research at the Victoria University of Manchester; Quelques Aspects des Experiences de Physique des Reacteurs a l'Universite Victoria de Manchester; Aspekty ehksperimental'nykh issledovanij po fizike reaktorov v universitete viktorii v manchestere; Trabajos de Fisica Experimental con Reactores Efectuados en la Universidad Victoria de Manchester

Energy Technology Data Exchange (ETDEWEB)

Harris, M. J.; Walton, D. G. [Victoria University of Manchester (United Kingdom)

1964-02-15

The Nuclear Engineering Department at Manchester University was established in 1959. Since that time post-graduate reactor physics studies have gradually enlarged and developed, starting virtually from scratch; experimental studies have concentrated on light-water systems and centred on the accelerator-driven, natural-uranium, light-water exponential. The paper contains a survey of the work to date, discussion of the results obtained, outlines of proposed future work, and, as they arise in the text, descriptions of various low-cost, labour-saving experimental techniques which have been adopted. The various divisions of the work are described below. The authors have studied neutron diffusion in light water using both pulsed source and steady source methods. In the former method they have particularly stressed full harmonic analysis to the extent of actually studying the higher modes as opposed to most former work which has tried only to eliminate them. In the study of steady source methods they have concentrated on eliminating all effects from finite source and detector size, resonance activation, flux perturbation and so on. The results of both are discussed and compared. A very careful measurement of absorption cross-sections by the pulsed technique, taking care to eliminate harmonic and other effects likely to lead to error is also in progress and is described. Thermal neutron spectra in ''poisoned'' light water are being measured as a means of investigating and developing integral detector techniques. This discussion includes some interesting time- and cost-saving examples. Large foil activation and counting techniques for measuring spatially averaged neutron densities, and hence a number of reactor parameters, have been studied. Some interesting points have arisen, particularly with regard to spectrum measurement. The method makes possible many reactor physics investigations with limited resources. A low-cost natural uranium, light-water exponential has been

Alize 3 - first critical experiment for the franco-german high flux reactor - calculations; Alize 3 - premiere experience critique pour le reacteur a haut flux franco-allemand. Calculs

Energy Technology Data Exchange (ETDEWEB)

Scharmer, K [Commissariat a l' Energie Atomique, Dir. des Piles Atomiques, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

The results of experiments in the light water cooled D{sub 2}O reflected critical assembly ALIZE III have been compared to calculations. A diffusion model was used with 3 fast and epithermal groups and two overlapping thermal groups, which leads to good agreement of calculated and measured power maps, even in the case of strong variations of the neutron spectrum in the core. The difference of calculated and measured k{sub eff} was smaller than 0.5 per cent {delta}k/k. Calculations of void and structure material coefficients of the reactivity of 'black' rods in the reflector, of spectrum variations (Cd-ratio, Pu-U-ratio) and to the delayed photoneutron fraction in the D{sub 2}O reflector were made. Measurements of the influence of beam tubes on reactivity and flux distribution in the reflector were interpreted with regard to an optimum beam tube arrangement for the Franco- German High Flux Reactor. (author) [French] Les resultats des experiences faites dans la maquette critique ALIZE III, refrigeree a l'eau legere et reflechie par l'eau lourde, ont ete compares aux calculs. On a utilise un modele de la theorie de diffusion a trois groupes rapides et epithermiques et deux groupes thermiques qui se recouvrent. Ce modele a permis de calculer la distribution de puissance dans le coeur en bon accord avec les mesures, meme dans le cas d'une forte variation du spectre des neutrons dans le coeur. L'erreur entre k{sub eff} calcule et mesure etait inferieure a 0,5 pour cent {delta}k/k. Le coefficient de vide et des materiaux de structure, la reactivite des barres 'noires', les variations du spectre (rapport Cd, rapport Pu/U) et la fraction des photo-neutrons retardes sont egalement calcules. Les mesures de reactivite et de perturbation de flux dans le reflecteur, dues aux canaux, ont ete interpretees du point de vue d'un arrangement optimum des canaux pour le Reacteur a Haut Flux Franco-Allemand. (auteur)

Pegase: safety studies - experimental study of burn-out risks in transient operation; Pegase: etude de surete - etude experimentale des risques de burn out en regime transitoire

Energy Technology Data Exchange (ETDEWEB)

Vernier, P [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1968-07-01

An experiment out-of-pile experimental set up is proposed simulating the breakage of a pipe supplying the core of the reactor Pegase. The two fast phenomena, depressurization of the vessel and flow reversal, are reproduced. The aluminium heating channel has the same shape as that of the reactor channel but has twice the heat capacity. The starting conditions are V= 4.50 and 6 m/sec., T{sub E} = 50 and 60 degrees C and P{sub E} = 4 bars. The results show that the critical flux PHI{sub C} varies with the flow-rate from 45 to 60 W/cm{sup 2} in the case where there is no power reduction. For fluxes of 90 W/cm{sup 2} the results lead to the conclusion that the hot channel attains a state of burn-out after 0.1 sec. and that its temperature reaches 500 C in 0.8 sec. The hydrodynamic conditions in the channels after the accident involve periodic expulsion (0.2 to 0.5 sec.), characteristic of boiling at low pressure. A study of the steady state flow redistribution through a by-pass has given flux redistribution PHI{sub R} of 190 W/cm{sup 2} for a flow rate of 4.5 m/sec. at 50 and of 175 W/cm{sup 2} at 60 C. These values increase which has to be made between the critical flux PHI{sub C} during the periodic expulsion conditions and the flux redistribution PHI{sub R} during the steady state, has been shown. (author) [French] On propose un schema experimental hors pile d'une rupture du tuyau alimentant le coeur du reacteur PEGASE. On reproduit les phenomenes rapides de depressurisation du caisson et d'inversion du debit dans le coeur. Le canal chauffant en aluminium a la meme geometrie que le canal du reacteur, mais une capacite calorifique double. Les conditions initiales sont V= 4.5 et 6 m/s, T{sub E} = 50 et 60 C et P{sub E} = 4 bars. Les resultats montrent que le flux critique PHI{sub C} evolue avec la vitesse de 45 a 60 60 W/cm{sup 2} dans le cas ou il n'y a pas reduction de puissance. Pour des flux de 90 W/cm{sup 2} l'interpretation des resultats permet de conclure que le

CRN: 1986 progress report

International Nuclear Information System (INIS)

1987-01-01

Departments activities in high energy physics, nuclear physics, radiation physics and chemistry are reported. Collaboration with university led to creation of SRNU (Service du Reacteur Nucleaire). Vivitron studies are presented [fr

A new detector for the measurement of neutron flux in nuclear reactors; Nouvelle methode de mesure des flux de neutrons dans les reacteurs atomiques

Energy Technology Data Exchange (ETDEWEB)

Koch, L; Labeyrie, J; Tarassenko, S [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The detector described is designed for the instantaneous measurement of thermal neutron fluxes, in the presence of high {gamma} ray activity; this detector can withstand temperatures as high as 500 deg. C. It is based on the following principle: radioactive atoms resulting from heavy-nucleus fission are carried by a gas flow to a detector recording their {beta} and {gamma} disintegration. Thermal neutron fluxes as low as few neutrons per cm{sup 2} per second can be measured. This detector may be used to control a nuclear reactor, to plot the thermal flux distribution with an excellent definition (1 mm{sup 2}) for fluxes higher than 10{sup 8} n/cm{sup 2}/s. The time response of the system to a sharp variation of flux is limited, in case of large fluxes, to the transit time of the gas flow between the fission product emitter and the detector; of the order of one tenth of a sec per meter of piping. The detector may also be applied for spectroscopy of fission products eider than 0,1 s. (author)Fren. [French] On decrit un appareil permettant la mesure instantanee des flux de neutrons thermiques accompagnes de flux intenses de rayons {gamma} et situes dans des enceintes pouvant etre portees a des temperatures superieures a 500 deg. C. On utilise la radioactivite des atomes resultant de la fission des noyaux lourds; ces atomes sont entraines par un courant gazeux vers un detecteur de radioactivite qui enregistre leurs desintegrations {beta} et {gamma}. On peut mesurer des flux partir de quelques neutrons thermiques par cm{sup 2} et par seconde. L'appareil permet de suivre la puissance d'un reacteur atomique, de tracer des cartes de densite de neutrons avec une tres bonne definition (1 mm{sup 2}) dans le cas de flux superieurs a 10{sup 8} cm{sup 2}/s. Le temps de reponse du systeme a une variation du flux de neutrons est limite, poes flux importants, par le temps de transit du gaz entre l'emetteur de produits de fission et le detecteur: soit quelques dizaines de

Experimental Determination of the Neutron Characteristics of UO{sub 2}-PuO{sub 2}-H{sub 2}O Lattices; Determination Experimentale Des Caracteristiques Neutroniques De Reseaux UO{sub 2}-PuO{sub 2}-H{sub 2}O

Energy Technology Data Exchange (ETDEWEB)

Debrue, J.; Fabry, A.; Leenders, L.; Motte, F.; Van Den Broeck, H. [Centre d' Etude de l' Energie Nucleaire, Mol (Belgium)

1967-09-15

As part of the investigation, in the VENUS test facility, of the variably moderated core of the BR3/VULCAIN reactor, a fuel assembly consisting of 37 UO{sub 2}-PuO{sub 2} pins (94% natural UO{sub 2}, 6% PuO{sub 2} ) was substituted for one of the enriched (to 7% {sup 235}U) UO{sub 2} fuel assemblies constituting the reactor core. Experiments were carried out with the object of refining the mathematical models for calculating the performance of this special assembly; inter alia, the fission density distribution and the changing ratio of the effective cross-sections for fission in the {sup 233}Pu and {sup 235}U were measured. Using the same critical facility, the authors are carrying out a critical experiment related directly to the problems of plutonium recycling in pressurized light-water thermal reactors. Three types of fuel are being used: UO{sub 2}-PuO{sub 2} with 3% {sup 235}U and 1% fissile plutonium, UO{sub 2}-PuO{sub 2} with 2% {sup 235}U and 2% fissile plutonium, and UO{sub 2} with 4% {sup 235}U. The two UO{sub 2}-PuO{sub 2} mixtures have completely different isotopic contents of {sup 240}Pu: 7% and 17%. In the first part of the experimental programme, a study is being made of regular lattices in cores having two co-axial cylindrical zones: a UO{sub 2}-PuO{sub 2} zone and a UO{sub 2} zone. Particular attention is being paid to investigating the region on either side of the interface separating the two zones, where the neutron spectrum reflects the characteristic energy distributions in each of the two lattices. The experimental results are to be used in calibrating the computational methods. In the second part of the experimental programme, parts of the core of the SENA power reactor will be simulated with a view to studying the problems of reloading one third of the core with mixed UO{sub 2}-PuO{sub 2} fuel. Among the experimental techniques employed in these various experiments emphasis is given to those most specifically related to the presence of

G 2 reactor project; Projet de pile a double fin: G 2

Energy Technology Data Exchange (ETDEWEB)

Ailleret, [Electricite de France (EDF), Dir. General des Etudes de Recherches, 75 - Paris (France); Taranger, P; Yvon, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

The CEA actually constructs the G-2 reactor core working with natural uranium, which will use graphite as moderator, and gas under pressure as cooling fluid. This report presents the specificity of the new reactor: - the different elements of the reactor core, - the control and the security of the reactor, - the renewal of the fuel, - the biologic surrounding wall, - and the cooling circuit. (M.B.) [French] le Commissariat a l'Energie Atomique construit actuellement la pile G-2 a Uranium naturel, qui utilisera le graphite comme moderateur, et le gaz sous pression comme fluide de refroidissement. Ce rapport presente les specificite du nouveau reacteur: - les differents elements de la pile, - le controle et la securite du reacteur, - le renouvellement du combustible, - l'enceinte biologique, - et le circuit de refroidissement. (M.B.)

Sodium purification in Rapsodie; La purification du sodium a Rapsodie

Energy Technology Data Exchange (ETDEWEB)

Giraud, B [Commissariat a l' Energie Atomique, Dir. des Piles Atomiques, Cadarache (France). Centre d' Etudes Nucleaires

1968-07-01

This report is one of a series of publications presenting the main results of tests carried out during the start-up of the first french fast neutron reactor: Rapsodie. The article presents the sodium purification techniques used in the reactor cooling circuits both from the constructional point of view and with respect to results obtained during the first years working. (author) [French] Ce rapport fait partie d'une serie de publications presentant l'essentiel des resultats des essais effectues a l'occasion du demarrage du premier reacteur francais a neutrons rapides: RAPSODIE. Cet article expose les techniques de la purification du sodium utilise dans les circuits de refroidissement du reacteur tant au point de vue de leur realisation technologique, que des resultats obtenus pendant la premiere annee de fonctionnement. (auteur)

Handling and Separation of Short-Lived Radioisotopes from Research Reactors; Manipulation et Separation des Radioisotopes a Courte Periode Produits dans des Reacteurs de Recherche; ПОЛУЧЕНИЕ И ОТДЕЛЕНИЕ КОРОТКОЖИВУЩИХ ИЗОТОПОВ В ИССЛЕДОВАТЕЛЬСКИХ РЕАКТОРАХ; Manipulacion y Separacion de Radioisotopos de Periodo Corto Obtenidos en Reactores de Investigacion

Energy Technology Data Exchange (ETDEWEB)

Meinke, W. W. [University of Michigan, Ann Arbor, MI (United States)

1963-03-15

distillation, selective reduction, etc., also add to the variety of separation possibilities to be explored. The local research reactor, whether it is in a university in the United States, or in a developing country, thus opens a whole new era of tracer possibilities. (author) [French] L'emploi des radioisotopes a souvent ete limite aux radioisotopes dont la periode est superieure a un jour, etant donne l'eloignement du reacteur qui les produit. Ceci explique un certain manque d'interet a l'egard du traitement et de l'utilisation de ces radioisotopes, et par suite une certaine reticence de la part du consommateur a envisager meme les possibilites d'emploi de nombreux radioisotopes a courte periode. Comme il existe maintenant de nombreux reacteurs de recherche dans le monde, les laboratoires ne dependent plus de producteurs de radioisotopes eloignes; en outre, les radioisotopes a courte periode couvrent de nombreux champs d'experimentation nouveaux. Il importe, cependant, a cette fin de considerer la production des radioindicateurs sous un angle nouveau. Depuis pres de cinq annees, le programme execute au moyen du reacteur de recherche de l'Universite du Michigan comporte la manipulation, le traitement et la mesure de radioisotopes a courte periode. Les chercheurs de l'Universite emploient couramment des radioisotopes dont les periodes ne depassent pas plusieurs heures, voire quelques minutes. Les traveaux entrepris jusqu'a present avaient trait principalement a l'analyse par activation, mais le material, les methodes et les techniques utilises.peuvent s'appliquer a de nombreux autres domaines. Pour utiliser les radioisotopes a courte periode, il n'est pas necessaire de prevoir un roulement de trois equipes pour le reacteur; il n'est pas lion plus indispensable de disposer de stocks importants de radioisotopes, ni d'installations de traitement perfectionnees.En fait, de simples pinces, utilisees de la maniere courante, donnent generalement de meilleurs resultats que de

The behaviour of some polyatomic gases in nuclear reactors; Le comportement de quelques gaz polyatomiques dans les reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Dolle, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The chemical effect of ionizing radiations on a certain number of gaseous systems is described. Under the influence of radiations from a reactor, NH{sub 3}, is decomposed to nitrogen and hydrogen in stoichiometric proportions. Formation of N{sub 2}H{sub 3}, particularly could not be detected. Under a slow neutron flux the reaction {sup 14}N (n, p) {sup 14}C constitutes the main source of decomposition energy. Direct recombination of H, and N, has been brought about under the influence of radiation. The radiolysis of NH{sub 3}, occurs by a complex mechanism; and the kinetics follow a law of the order of about 2.5 which increases with the decomposition rate. The decomposition of hydrogen sulphide is appreciably faster than that of NH{sub 3}. Hydrogen is the only gaseous product of the reaction. The sulphur, which is deposited on the walls of the ampoules, is clearly visible to the naked eye. Up to the present decompositions up to 84 per cent have been obtained. The influence of the reaction {sup 32}S (n, p) {sup 32}P is considered. Radiochemical decomposition of nitrous oxide N{sub 2}O takes place with high yields. The reaction is complicated from the beginning by the formation of higher oxides of nitrogen which we identify and measure. Radiochemical decomposition of methane gives quantities of higher hydrocarbons. Certain of these gaseous systems could find applications in the measurement of high doses of radiation. This problem is discussed in the conclusion. (author)Fren. [French] L'effet chimique des rayonnements ionisants sur un certain nombre de systemes gazeux est decrit. Sous l'influence des rayonnements d'un reacteur, NH{sub 3} se decompose en azote et hydrogene en proportions stoechiometriques. En particulier aucune formation de N{sub 2}H{sub 4}, n'a pu etre detectee. Sous flux de neutrons lents, la reaction {sup 14}N (n, p){sup 14}C constitue la principale source d'energie de decomposition. La recombinaison directe de H{sub 2} et N{sub 2} a ete realisous l

Zigzag et « carré plastique » haïtiens en Amérique du nord à travers l’Autobiographie américaine de Dany Laferrière

OpenAIRE

Olivier-Messonnier, Laurence

2015-01-01

L’ « Autobiographie américaine » de Dany Laferrière et le « carré plastique » de Léonel Jules, artistes et amis haïtiens émigrés au Québec, déconstruisent la ville américaine par l’éclatement textuel et la plasticité picturale. Mythifient-ils pour autant le berceau natal ? L’écriture plastique et poétique efface les frontières. The « American Autobiography » by Dany Laferrière and the « Carré Plastique » by Léonel Jules, Haitian artists and friends who emigrated to Quebec, deconstruct the ...

RCC-MRx: Design and construction rules for mechanical components in high-temperature structures, experimental reactors and fusion reactors

International Nuclear Information System (INIS)

2015-01-01

The RCC-MRx code was developed for sodium-cooled fast reactors (SFR), research reactors (RR) and fusion reactors (FR-ITER). It provides the rules for designing and building mechanical components involved in areas subject to significant creep and/or significant irradiation. In particular, it incorporates an extensive range of materials (aluminum and zirconium alloys in response to the need for transparency to neutrons), sizing rules for thin shells and box structures, and new modern welding processes: electron beam, laser beam, diffusion and brazing. The RCC-MR code was used to design and build the prototype Fast Breeder Reactor (PFBR) developed by IGCAR in India and the ITER Vacuum Vessel. The RCC-Mx code is being used in the current construction of the RJH experimental reactor (Jules Horowitz reactor). The RCC-MRx code is serving as a reference for the design of the ASTRID project (Advanced Sodium Technological Reactor for Industrial Demonstration), for the design of the primary circuit in MYRRHA (Multi-purpose hybrid Research Reactor for High-tech Applications) and the design of the target station of the ESS project (European Spallation Source). Contents of the 2015 edition of the RCC-MRx code: Section I General provisions; Section II Additional requirements and special provisions; Section III Rules for nuclear installation mechanical components: Volume I: Design and construction rules: Volume A (RA): General provisions and entrance keys, Volume B (RB): Class 1 components and supports, Volume C (RC): Class 2 components and supports, Volume D (RD): Class 3 components and supports, Volume K (RK): Examination, handling or drive mechanisms, Volume L (RL): Irradiation devices, Volume Z (Ai): Technical appendices; Volume II: Materials; Volume III: Examinations methods; Volume IV: Welding; Volume V: Manufacturing operations; Volume VI: Probationary phase rules

the JHR Material Testing Reactor

International Nuclear Information System (INIS)

Roure, C.; Cornu, B.; Berthet, B.; Simon, E.; Estre, N.; Guimbal, P.; Kinnunen, P.; Kotiluoto, P.

2013-06-01

The Jules Horowitz Reactor (JHR) is a European experimental reactor under construction in CEA Cadarache. It will be dedicated to material and fuel irradiation tests, and to medical isotopes production. Non-Destructive nuclear Examinations systems (NDE) will be implemented in pools to analyse the irradiated fuel or tested material in their supporting experimental irradiation devices extracted from the core or its immediate periphery. The Nuclear Measurement Laboratory (NML) of CEA Cadarache is working in collaboration with VTT (Technical Research Centre in Finland) in designing and developing NDE systems implementing gamma-ray spectroscopy and high energy X-ray imaging of the sample and irradiation device. CEA is also designing a neutron radiography system for which NML is working on the detection system. Design studies are performed with Monte Carlo transport codes and specific simulation tools developed by the NML for Xray and neutron imaging. (authors)

"Gypsy" ehk killuke Ameerikat meie jaoks / Martin Gorris

Index Scriptorium Estoniae

Gorris, Martin

2001-01-01

2. dets. esietendus Vanemuises Ameerika vodevillistaari ja striptiisikuninganna Rose Louise Hovicki memuaaridel põhinev Jule Styne'i muusikal "Gypsy", lavastaja Mare Tommingas, osades Silvi Vrait ja Helena Merzin

Punane Veski ja plakatikunsti algus / Riina Robinson

Index Scriptorium Estoniae

Robinson, Riina

2007-01-01

Prantsuse plakatikunsti loojast Jules Cheret'st, ühest silmapaistvamast plakati- ja maalikunstnikust Henri Toulouse-Lautrecist, tema plakatite kangelannadest, kankaani tantsinud Louise Weberist ja Jane Avrilist ning Moulin Rouge'ist

Lennujaamast ja parunist puu otsas : [lugemiselamustest] / Ülar Ploom

Index Scriptorium Estoniae

Ploom, Ülar

2007-01-01

Maailmaklassikast: Mark Twaini "Huckelberry Finni seiklused", Jules Verne'i "Saladuslik saar", Gabriel García Márquezi "Sada aastat üksildust", Aleksandr Erteli "Gardeninid", Italo Calvino "Parun puu otsas"

Initial Operating Experience with the ''NPD'' Reactor; Experience recueillie pendant les premiers mois de fonctionnement du reacteur NPD; Pervyj opyt po ehkspluatatsii reaktora NPD; Experiencia inicial de funcionamiento del reactor NPD

Energy Technology Data Exchange (ETDEWEB)

McConnell, L. G. [Hydro-Electric Power Commission of Ontario, Toronto, Ontario (Canada)

1963-10-15

Canada's first nuclear power station, the Nuclear Power Demonstration station (NPD), is intended to serve as a means of proof-testing the performance of the Canadian type of station using natural uranium as fuel and heavy water as moderator and coolant. It reached full power on 28 June 1962. Although designed for base-load operation it will, during the early stages, be operated part of the time on high-capacity.runs and part of the time on improvement periods. Progress has been favourable so far; the first high-capacity run of six weeks'duration yielded a capacity factor of 70%. Improvements already made have increased safety, improved performance and demonstrated potential methods of capital-cost reduction for future stations. For example, shaft seals on primary coolant pumps have been modified for better performance, freezer-type vapour recovery equipment has been replaced in favour of absorption columns to reduce heavy-water vapour loss, and flow limiters are being installed in sample lines to reduce losses of heavy water in the event of joint failures. During December 1962 two simultaneous leaks from the on-power refuelling machine led to an unusual sequence of events in which a considerable amount of hot high-pressure heavy water was spilled into the reactor vault where it suffered a slight downgrading in isotopic purity. It was upgraded and the reactor returned to operation by the end of the month. All safety devices operated correctly during the incident as did the provisions for containment of heavy water. (author) [French] La premiere centrale nucleaire du Canada, NPD, est une centrale de demonstration, qui doit servir a verifier les performances des reacteurs fonctionnant a l'uranium naturel et utilisant de l'eau lourde comme ralentisseur et comme fluide de refroidissement. Elle a atteint sa pleine puissance le 28 juin 1962 bien que concue pour etre exploitee comme centrale de base, elle fonctionnera au debut comme centrale d'appoint, ce qui permettra d

Practical guide to dosimetry as applied in the research reactors of the Saclay and Grenoble nuclear research centers; Guide pratique de la dosimetrie mise en oeuvre dans les reacteurs de recherche du C.E.N./G et du C.E.N./S

Energy Technology Data Exchange (ETDEWEB)

NONE

1968-07-01

Since the problems concerning neutron and gamma flux measurements which arise during irradiation experiments in the reactors in the Grenoble and Saclay Centres are of the same type, and since the solutions found are very often adopted in common, we have attempted to describe the methods we use at the present time. A brief description is given of the production of the detectors, the electronic apparatus; the formulae usually used for the interpretation of the measurements are given. A series of technical data cards give the most commonly used detector characteristics. These cards give the physical characteristics of the detectors, their nuclear constants, if any, the most suitable counting methods and the field of application. (authors) [French] Les problemes de mesures de flux de neutrons et de flux gamma qui se posent pour les experiences irradiees dans les reacteurs des Centres de Grenoble et de Saclay etant du meme type et les solutions trouvees, tres souvent adoptees en commun, nous avons cherche a decrire les methodes que nous pratiquons actuellement. On decrit tres brievement la fabrication des detecteurs, l'appareillage electronique; on rappelle les formules usuelles qui servent dans l'interpretation des mesures. Une serie de fiches techniques rassemble les caracteristiques des detecteurs les plus couramment utilises. Ces fiches indiquent les caracteristiques physiques des detecteurs, leurs constantes nucleaires s'il y a lieu, les methodes de comptage les mieux adaptees et le domaine d'utilisation. (auteurs)

2342-IJBCS-Article-Ngueguim Jules Roger

African Journals Online (AJOL)

hp

4Institut de la Recherche Agricole pour le Développement (IRAD), Yokadouma, Cameroun. 5Departement ..... définition, le premier quartile, d'une série ordonnée ..... le site. Structure de population. Les structures de population présentent la répartition des arbres en fonction de leur taille dans un peuplement. Ces outils sont.

407-IJBCS-Article- Ngueguim Jules R

African Journals Online (AJOL)

Dr GATSING

2011 International Formulae Group. All rights ... principaux marchés de forêt dense humide du. Cameroun ... modes d'appropriation de l'arbre. Cela affecte particulièrement les familles rurales qui ont déjà du mal à .... rend leur accès facile.

2363-IJBCS-Article-Kouadio Nguessan Jules

African Journals Online (AJOL)

hp

Available online at http://ajol.info/index.php/ijbcs ... Evaluation de l'activité des feuilles de Mallotus oppositifolius (Geisel.) ... 3 Centre Suisse de Recherche Scientifique en Côte d'Ivoire, Côte d'Ivoire. ... hydro-méthanolique et aqueux des feuilles de cette plante sur des bactéries .... Le support bactérien était composé de.

2363-IJBCS-Article-Kouadio Nguessan Jules

African Journals Online (AJOL)

hp

de santé publique à cause de leur fréquence et de leur gravité. En effet, elles sont à l'origine de plus de 17 millions de décès par an dans le monde dont plus de la moitié provient du seul continent africain (OMS, 2006). Ainsi, la découverte des antibiotiques a été un véritable soulagement pour l'humanité car ces remèdes ...

2343-IJBCS-Article-Ngueguim Jules Roger

African Journals Online (AJOL)

hp

4University of Ngaoundéré, Faculty of Science, Department of Biological ... de Paris (MNHN) and the Service d'Action Culturelle of France Embassy in ..... management may allow plantations to ... JRN initiated the research project, did the data ...

General meeting. Technical reunion: the numerical and experimental simulation applied to the Reactor Physics; Assemblee generale. Reunion technique: la simulation numerique et experimentale appliquee a la physique des reacteurs

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-10-01

The SFEN (French Society on Nuclear Energy), organized the 18 october 2001 at Paris, a technical day on the numerical and experimental simulation, applied to the reactor Physics. Nine aspects were discussed, giving a state of the art in the domain:the french nuclear park; the future technology; the controlled thermonuclear fusion; the new organizations and their implications on the research and development programs; Framatome-ANP markets and industrial code packages; reactor core simulation at high temperature; software architecture; SALOME; DESCARTES. (A.L.B.)

Swimming Behavior of Individual Zooplankters During Night-Time Foraging

National Research Council Canada - National Science Library

McGehee, Duncan

1998-01-01

Amatzia Genin, Jules Jaffe, Duncan McGehee developed a method for automatically tracking individual plankters swimming through the imaging volume, and applied the method to track approximately 280,000 animals...

"Thais" muusika on fenomenaalne / Veronika Džiojeva ; intervjueerinud Silja Joon

Index Scriptorium Estoniae

Džiojeva, Veronika

2009-01-01

Küsimustele vastab 22. mail Pärnu Endla teatris esietenduva Jules Massenet' ooperi "Thais" nimiosatäitja, 2007. aastal toimunud Klaudia Taevi nim. rahvusvahelise ooperilauljate konkursi laureaat Veronika Džiojeva

Journey to the Center of Icy Moons

Data.gov (United States)

National Aeronautics and Space Administration — In Jules Verne's classic science fiction, Journey to the Center of the Earth, Professor Otto Lidenbrock and his company descend into an Icelandic volcano to explore...

Vegetative propagation of twelve fodder tree species indigenous to ...

African Journals Online (AJOL)

Vegetative propagation of twelve fodder tree species indigenous to the Sahel, West Africa. Catherine Ky-Dembele, Jules Bayala, Antoine Kalinganire, Fatoumata Tata Traoré, Bréhima Koné, Alain Olivier ...

First feedback with the AMMON integral experiment for the JHR calculations

Directory of Open Access Journals (Sweden)

Lemaire M.

2013-03-01

Full Text Available The innovative design of the next international Material Testing Reactor, the Jules Horowitz Reactor (JHR, induced the development of a new neutron and photon calculation formular HORUS3D/P&N, based on deterministic and stochastic codes and the European nuclear data library JEFF3.1.1. A new integral experiment, named the AMMON experiment, was designed in order to make the experimental validation of HORUS3D. The objectives of this experimental program are to calibrate the biases and uncertainties associated with the HORUS3D/N&P calculations for JHR safety and design calculations, but also the validation of some specific nuclear data (concerning mainly hafnium and beryllium isotopes. The experiment began in 2010 and is currently performed in the EOLE zero-power critical mock-up at CEA Cadarache. This paper deals with the first feedback of the AMMON experiments with 3D Monte Carlo TRIPOLI4©/JEFF3.1.1 calculations.

Change of I-V characteristics of SiC diodes upon reactor irradiation; Modification des caracteristiques I-V de jonctions p-n au SiC du fait d'une irradiation dans un reacteur; Izmeneniya kharakteristik I-V vyrashchennogo v SiC perekhoda tipa p-n posle oblucheniya ego v reaktore; Modificaciones que sufren por irradiacion en un reactor las caracteristicas I-V de uniones p-n en SiC

Energy Technology Data Exchange (ETDEWEB)

Heerschap, M; De Coninck, R [Solid State Physics Dept., SCK-CEN, Mol (Belgium)

1962-04-15

In search for semiconductors, which can be used in high-flux reactors in order to measure flux distributions, we irradiated SiC p-n junctions in the Belgium BR-1 reactor. Two types of SiC-diodes of different origin have been irradiated. These junctions are grown in the Lely-furnace. The change in forward and reverse characteristics have been measured during and after irradiation up to temperatures of 150{sup o}C, while measurements up to a temperature of 500{sup o}C are in progress. It has been found that one type resists BR-1 neutrons up to an integrated flux of 10{sup 15} n/cm{sup 2}, while the other resists irradiation up to a flux of 10{sup 17} n/cm{sup 2}. The changes in characteristics are given as well as the result of some annealing experiments. (author) [French] En recherchant des semi-conducteurs pouvant servir a mesurer les distributions de flux dans les reacteurs a haut flux de neutrons, les auteurs ont irradie des jonctions p-n au SiC dans le reacteur belge BR-1. Deux types de diodes a SiC d'origines differentes ont ete ainsi irradies. Les jonctions en question sont preparees par etirage dans le four Lely. Les auteurs ont mesure les modifications subies par les caracteristiques I-V apres et pendant l'irradiation a des temperatures allant jusqu'a 150{sup o}C; ils poursuivent leurs mesures dans la gamme des temperatures allant de 150{sup o}C a 500{sup o}C. Us ont constate que l'un des types de diode a SiC resiste aux neutrons du reacteur BR-1 jusqu'a 10{sup 15} n/cm{sup 2}, tandis que l'autre type resiste a l'irradiation jusqu'a 10{sup 17} n/cm{sup 2}. Les auteurs indiquent les modifications subies par les caracteristiques, ainsi que le resultat de certaines experiences de recuit. (author) [Spanish] Los autores estan tratando de encontrar semiconductores con los que sea posible medir distribuciones de flujo en reactores de flujo elevado, y con este fin irradiaron uniones p-n del SiC en el reactor BR-1 de Belgica. Irradiaron dos tipos de diodos de SiC de

Endlas etendub lugu mungast ja kurtisaanist / Silja Joon

Index Scriptorium Estoniae

Joon, Silja, 1966-

2008-01-01

Rahvusvahelise ooperimuusika festivali PromFest raames järgmise aasta 22. mail Pärnu teatris Endla esietenduvast Jules Massenet' ooperist "Thais" (peaosades eelmise Klaudia Taevi nimelise konkursi laureaadid Veronika Dzhiojeva ja Ilja Siltshukov)

Oklo: The fossil nuclear reactors. Physics study - Translation of chapters 6, 13 and conclusions

Energy Technology Data Exchange (ETDEWEB)

Naudet, R [CEA, Paris (France)

1996-09-01

Three parts of the 1991 book `Oklo: reacteurs nucleaires fossiles. Etude physique` have been translated in this report. The chapters bear the titles `Study of criticality`(45 p.), `Some problems with the overall functioning of the reactor zones`(45 p.) and `Conclusions` (15 p.), respectively.

Oklo: The fossil nuclear reactors. Physics study - Translation of chapters 6, 13 and conclusions

International Nuclear Information System (INIS)

Naudet, R.

1996-09-01

Three parts of the 1991 book 'Oklo: reacteurs nucleaires fossiles. Etude physique' have been translated in this report. The chapters bear the titles 'Study of criticality'(45 p.), 'Some problems with the overall functioning of the reactor zones'(45 p.) and 'Conclusions' (15 p.), respectively

Massenet "Thaisi" näeb otseülekandes kinolinal / Toomas Kuter

Index Scriptorium Estoniae

Kuter, Toomas, 1965-

2008-01-01

Forum Cinemas toob oktoobrist maini Tallinnas Coca-Cola Plazas ja Tartus Ekraanis publikuni New Yorgi Metropolitan Opera etenduste HD-otseülekanded, 20. dets. kantakse üle Jules Massenet' ooper "Thais", peaosas Renee Fleming

Theoretical, physical and experimental study of fissile aqueous media; Etudes theorique, physique et experimentale des milieux fissiles aqueux

Energy Technology Data Exchange (ETDEWEB)

Caizergues, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-04-01

This thesis consists of a set of theoretical and experimental studies. a) Theoretical calculation methods used for cross-sections and the critical parameters; b) Comparison of the theoretical and experimental results: it is shown that the agreement between these results cannot be improved above a certain limit because of the accuracy with which are known the composition and the dimensions of the media and the microscopic cross-sections; c) Determination of the ratios {eta}{sup 9}-bar / {eta}{sup 5}-bar, {eta}{sup 3}-bar / {eta}{sup 5}-bar for fissile aqueous media ({eta}-bar: number of neutrons emitted per neutron absorbed, averaged over the reactor neutron spectrum). Evaluation of the accuracy to which these ratios are known; d) Effect of {sup 240}Pu: the measurements are carried out on Pu with a {sup 240}Pu content of 1.5 per cent, 3.11 per cent and 9.95 per cent; Calculation of the resonance integral I240 using the experimental results gives values in reasonable agreement with the results obtained by other more conventional methods. e) Measurement of the spectrum indices for aqueous media containing Pu, U5 and U3. With these latter it is possible to obtain mean fission cross-section ratios {sigma}f239-bar / {sigma}f235-bar for these different spectra. A calculation-experiment comparison is carried out using various theoretical methods. (author) [French] Cette these groupe un ensemble d'etudes theoriques et experimentales. a) Methodes theoriques de calcul utilisees pour les sections efficaces et les parametres critiques; b) Comparaisons des resultats theoriques et experimentaux: on montre que l'accord entre ces resultats ne peut etre ameliore au-dela de certaines limites vu la precision avec laquelle sont connues la composition et les dimensions des milieux et les sections efficaces macroscopiques; c) Determination des rapports {eta}{sup 9}-bar / {eta}{sup 5}-bar, {eta}{sup 3}-bar / {eta}{sup 5}-bar pour les milieux fissiles aqueux ({eta}: nombre de

Theoretical, physical and experimental study of fissile aqueous media; Etudes theorique, physique et experimentale des milieux fissiles aqueux

Energy Technology Data Exchange (ETDEWEB)

Caizergues, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-04-01

This thesis consists of a set of theoretical and experimental studies. a) Theoretical calculation methods used for cross-sections and the critical parameters; b) Comparison of the theoretical and experimental results: it is shown that the agreement between these results cannot be improved above a certain limit because of the accuracy with which are known the composition and the dimensions of the media and the microscopic cross-sections; c) Determination of the ratios {eta}{sup 9}-bar / {eta}{sup 5}-bar, {eta}{sup 3}-bar / {eta}{sup 5}-bar for fissile aqueous media ({eta}-bar: number of neutrons emitted per neutron absorbed, averaged over the reactor neutron spectrum). Evaluation of the accuracy to which these ratios are known; d) Effect of {sup 240}Pu: the measurements are carried out on Pu with a {sup 240}Pu content of 1.5 per cent, 3.11 per cent and 9.95 per cent; Calculation of the resonance integral I240 using the experimental results gives values in reasonable agreement with the results obtained by other more conventional methods. e) Measurement of the spectrum indices for aqueous media containing Pu, U5 and U3. With these latter it is possible to obtain mean fission cross-section ratios {sigma}f239-bar / {sigma}f235-bar for these different spectra. A calculation-experiment comparison is carried out using various theoretical methods. (author) [French] Cette these groupe un ensemble d'etudes theoriques et experimentales. a) Methodes theoriques de calcul utilisees pour les sections efficaces et les parametres critiques; b) Comparaisons des resultats theoriques et experimentaux: on montre que l'accord entre ces resultats ne peut etre ameliore au-dela de certaines limites vu la precision avec laquelle sont connues la composition et les dimensions des milieux et les sections efficaces macroscopiques; c) Determination des rapports {eta}{sup 9}-bar / {eta}{sup 5}-bar, {eta}{sup 3}-bar / {eta}{sup 5}-bar pour les milieux fissiles aqueux ({eta}: nombre de neutrons emis

Scientific report 1999

International Nuclear Information System (INIS)

1999-01-01

The aim of this report is to outline the main developments of the 'Departement des Reacteurs Nucleaires' (DRN) during the year 1999. DRN is one of the CEA Institutions. This report is divided in three main parts: the DRN scientific programs, the scientific and technical publications (with abstracts in English) and economic data on staff, budget and communication. Main results of the Department for the year 1999 are presented giving information on the simulation of low mach number compressible flow, experimental irradiation of multi-materials, progress in the dry route conversion process of UF 6 to UO 2 , the neutronics, the CASCADE installation, the corium, the BWR type reactor cores technology, the reactor safety, the transmutation of americium and fuel cell flow studies, the crack propagation, the hybrid systems and the CEA sites improvement. (A.L.B.)

Detjam kapitana Granta privezli iz Ameriki bizonov i straussov / Margarita Golovanova

Index Scriptorium Estoniae

Golovanova, Margarita

2006-01-01

Kuidas "Mosfilmis" filmiti Jules Verne'i järgi mängufilmi "Kapten Granti lapsed" : režissöör Vladimir Vainshtok : helilooja Isaak Dunajevski : näitlejad Nikolai Tsherkassov, Jakov Segel : NSV Liit 1936

Alecto 1 - criticality experiment on a solution of plutonium and of uranium 235. Experimental results and calculations on tank number 2 ({phi} 300 mm); Alecto 1 - experience de criticite sur une solution de plutonium et d'uranium enrichi a 90 pour cent. Resultats experimentaux et calculs concernant la cuve no. 2 ({phi} = 300 mm)

Energy Technology Data Exchange (ETDEWEB)

Bruna, J G; Brunet, J P; Clouet D' Orval, Ch; Kremser, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

Experiments on plutonium and 90 pour cent enriched uranium solutions have been made in the Alecto reactor with a tank of external diameter 300 mm. Various geometries Lave been tested, for variable concentrations of fissionable salts. The critical mass was studied as a function of the concentration in various reflector conditions (water, concrete, wood) and the experimental values were compared with calculated values. The effects of cadmium as a reflector and of the stainless steel tank were also studied. Lastly were carried out measurements of {beta}/{tau}, ratio of the effective fraction of delayed neutrons to the average lifetime of the neutrons in the reactor. (authors) [French] Des experiences sur des solutions de plutonium et d'uranium enrichi a 90 pour cent ont ete effectuees dans le reacteur Alecto, avec une cuve de diametre exterieur 300 mm. Diverses configurations geometriques ont ete realisees, pour des concentrations variables du sel fissile. On a etudie la masse critique en fonction de la concentration, dans plusieurs conditions de reflexion (eau, beton, bois), et on a compare les resultats experimentaux aux valeurs donnees par le calcul. On a egalement etudie l'influence du cadmium comme reflecteur et celle de la cuve d'acier inoxydable. Enfin on a effectue des mesures de {beta}/{tau}, rapport de la proportion effective des neutrons retardes au temps de vie moyen des neutrons dans la pile. (auteurs)

Radioprotection problems resulting from the presence of experimental devices around an atomic reactor; Problemes de radioprotection poses par l'implantation de dispositifs experimentaux aupres d'une pile atomique

Energy Technology Data Exchange (ETDEWEB)

Fitoussi, L; Lebouleux, Ph; Bricard, Ph; Moreau, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-07-01

The setting up of experimental devices around a reactor produces dangers of irradiation and radioactive contamination which can become very great in the case of an accident, especially if the in-pile portion contains fissile matter. This may result in irradiation of personnel, prohibition of access to the experimental zones until the sources of irradiation and contamination have been eliminated, and a prolonged stoppage of the reactor. The plans for an in-pile experiment should take into account radioprotection factors; the aim of these is to reduce to a minimum the radioactive risks normally encountered during the experiment and to eliminate any risks of bad accidents and their consequences. In this report are classified the various types of experiments requiring installations outside the pile itself; for each of these experiments the particular radioprotection factors are given. In order to make possible a study of the radioactive dangers likely to arise during a projected experiment, the authors summarize the physical and technical data required by radioprotection specialists and give the rules and general advice concerning radioprotection which should be useful during the planning of an in-pile experiment and the setting-up of the equipment. (authors) [French] L'implantation de dispositifs experimentaux aupres des reacteurs cree des risques d'irradiation et de contamination radioactive qui peuvent devenir importants en cas d'accident, surtout si la partie en pile comprend des matieres fissiles. Il peut en resulter des irradiations de personne, l'interdiction des aires experimentales jusqu'a elimination des sources d'irradiation et de contamination, un arret prolonge de la pile. L'etude d'un projet d'experience en pile doit donc tenir compte des considerations de radioprotection dont le souci est de reduire aux niveaux tolerables les risques radioactifs inherents au fonctionnement normal de l'experience et d'eliminer les risques d'accidents graves et leurs

Kirjandus ja vabamüürlus / Paavo Matsin

Index Scriptorium Estoniae

Matsin, Paavo, 1970-

2009-01-01

Loetletakse vabamüürlastest kirjanikke (pikemalt Jules Verne'ist, Gustav Meyrinkist, Rudyard Kiplingist ja Mait Metsanurgast) ning vabamüürlikke tegelasi või motiive kasutanud kirjanikke (Lev Tolstoi, Fjodor Dostojevski, Mihhail Bulgakov, Edgar Allan Poe)

Data acquisition. GRAAL experiment. Hybrid reactor experiment. AMS experiment

International Nuclear Information System (INIS)

Barancourt, D.; Barbier, G.; Bosson, G.; Bouvier, J.; Gallin-Martel, L.; Meillon, B.; Stassi, P.; Tournier, M.

1997-01-01

The main activity of the data acquisition team has consisted in hardware and software developments for the GRAAL experiment with the trigger board, for the 'Reacteurs Hybrides' group with an acquisition board ADCVME8V and for the AMS experiment with the monitoring of the aerogel detector. (authors)

Calculation to experiment comparison of SPND signals in various nuclear reactor environments

Energy Technology Data Exchange (ETDEWEB)

Barbot, Loic; Radulovic, Vladimir; Fourmentel, Damien [CEA, DEN, DER, Instrumentation, Sensors and Dosimetry Laboratory, Cadarache, F-13108 St-Paul-Lez-Durance, (France); Snoj, Luka [Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, (Slovenia); Tarchalski, Mikolaj [National Centre for Nuclear Research, ulica Andrzeja Soltana 7, 05-400 Otwock (Swierk), (Poland); Dewynter-Marty, Veronique [CEA, DEN, DANS, DRSN, SIREN, LESCI, Saclay, F-91191 Gif sur Yvette, (France); Malouch, Fadhel [CEA, DEN, DANS, DM2S, SERMA, Saclay, F-91191 Gif sur Yvette, (France)

2015-07-01

In the perspective of irradiation experiments in the future Jules Horowitz Reactor (JHR), the Instrumentation Sensors and Dosimetry Laboratory of CEA Cadarache (France) is developing a numerical tool for SPND design, simulation and operation. In the frame of the SPND numerical tool qualification, dedicated experiments have been performed both in the Slovenian TRIGA Mark II reactor (JSI) and very recently in the French CEA Saclay OSIRIS reactor, as well as a test of two detectors in the core of the Polish MARIA reactor (NCBJ). A full description of experimental set-ups and neutron-gamma calculations schemes are provided in the first part of the paper. Calculation to experiment comparison of the various SPNDs in the different reactors is thoroughly described and discussed in the second part. Presented comparisons show promising final results. (authors)

An instrument for measuring doubling time; Un appareillage de mesure de temps de doublement

Energy Technology Data Exchange (ETDEWEB)

Ailloud, J; Chandanson, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1956-07-01

The instrument described here allows the direct and almost immediate measurement, with a precision of the order of 1 per cent, of the time taken by a reactor to double its power. The method of measurement consists of noting the instants when the power of the reactor passes the levels P{sub 1} and P{sub 2} such that P{sub 2} = 2 P{sub 1}, and of measuring the time lapse between these two instants. The instrument picks out, in the course of one rise in power, several levels, P{sub 1}, P{sub 2}, P{sub 3}... etc, chosen in such a manner as to give several successive measurements of the doubling time. It is also capable of making these same measurements when the reactor is working below the critical level. (author) [French] L'appareil decrit ici permet la mesure directe et quasi immediate du temps de doublement de la puissance d'un reacteur avec une precision de l'ordre de 1 pour cent. La methode de mesure consiste a reperer les instants de passage de la puissance du reacteur par des niveaux P{sub 1} et P{sub 2} tels que P{sub 2} = 2 P{sub 1}, et a mesurer le temps ecoule entre ces deux instants. L'appareil repere, au cours d'une meme montee en puissance, plusieurs niveaux, P{sub 1}, P{sub 2}, P{sub 3}... etc, choisis de maniere a donner plusieurs mesures successives du temps de doublement. Il est egalement utilisable pour effectuer ces memes mesures lorsque le reacteur est en regime sous-critique. (auteur)

Contribuições da psiquiatria clássica ao diagnóstico da melancolia: o delírio de negação e o delírio de indignidade

Directory of Open Access Journals (Sweden)

Maria de Fátima Ferreira

2008-09-01

Full Text Available Discute-se a respeito da importância que teve a pesquisa empreendida pelos psiquiatras franceses Jules Cotard e Jules Séglas nas primeiras elaborações freudianas acerca da melancolia. No esforço feito por Freud em distinguir as afecções psíquicas, ele leva em consideração os principais conceitos destacados pela psiquiatria clássica: a dor moral, condição para o delírio de indignidade, o mecanismo de auto-acusação e a hemorragia de libido. Busca-se uma articulação entre esses autores. Neste artigo essa retomada é importante para um aprimoramento no diagnóstico da melancolia. Constata-se que a melancolia na contemporaneidade nos remete não somente aos clássicos, mas sobretudo a Freud, em seus primeiros rascunhos.

Description of the Triton reactor; Pile Triton, rapport descriptif

Energy Technology Data Exchange (ETDEWEB)

NONE

1967-09-01

The Triton reactor is an enriched uranium pool type reactor. It began operation in 1959, after a divergence made on the June 30 the same year. Devoted to studies of radiation protection, its core can be displaced in the longitudinal direction. The pool can be separated in two unequal compartments by a wall. The Triton core is placed in a small compartment, the Nereide core in the big compartment. A third compartment without water is called Naiade II, is separated by a concrete wall in which is made a window closed by an aluminium plate (2.50 m x 2.70 m). The Naiade II hole is useful for protection experiments using the Nereide core. After a complete refitting, the power of the triton reactor that reached progressively from 1.2 MW to 2 MW, then 3 MW has reached in August 1965 6.5 MW. The reactor has been specialized in irradiations in fix position, the core become fix, the nereide core has been hung mobile. Since it has been used for structure materials irradiation, for radioelements fabrication and fundamental research. The following descriptions are valid for the period after August 1965. [French] Le reacteur Triton est un reacteur piscine, a uranium enrichi. Il est entre en fonctionnement en 1959, apres une divergence effectuee le 30 juin de cette meme annee. Destine a des etudes de protection contre les rayonnements, son coeur pouvait se deplacer dans le sens longitudinal. La piscine peut etre separee en deux compartiments inegaux par un batardeau. Le coeur triton est place dans le petit compartiment, le coeur Nereide dans le grand compartiment. Un troisieme compartiment sans eau, appele Naiade II, est separe par une paroi en beton dans laquelle est amenagee une fenetre obturee par une plaque d'aluminium (2,50 m x 2,70 m). La fosse Naiade II sert a des experiences de protection utilisant le coeur nereide. Apres une refonte complete, la puissance du reacteur triton qui etait passee progressivement de 1,2 MW a 2 MW, puis 3 MW, a atteint en aout 1965 6, 5 MW. Le

Slow Neutron Spectrometers at the Swedish Reactors; Spectrometres a Neutrons Lents des Reacteurs Suedois; 0421 041f 0415 041a 0422 0420 041e 041c 0415 0422 0420 042b 041c 0415 0414 041b 0415 041d 041d 042b 0425 041d 0415 0419 0422 0420 041e 041d 041e 0412 041d 0410 0428 0412 0415 0414 0421 041a 0418 0425 0420 0415 0410 041a 0422 041e 0420 0410 0425 ; Espectrometros para Neutrones Lentos en los Reactores de Suecia

Energy Technology Data Exchange (ETDEWEB)

Dahlborg, U.; Skoeld, K. [AB Atomenergi, Stockholm (Sweden); Larsson, K. -E. [Royal Institute of Technology, Stockholm (Sweden)

1965-06-15

is briefly discussed for illustrational purposes. A comparison between the light- and heavy-water moderated reactors for beam tube work shows the distinct advantages of the heavy-water type. (author) [French] Aux centres crees autour des deux, reacteurs de recherche suedois, Rl a Stockholm et R2 a Studsvik, on a maintenant la possibilite d'utiliser quatre spectrometres differents pour les experiences de diffusion inelastique des neutrons. A Stockholm, le reacteur Rl de 600 kW, ralenti a l'eau lourde, est equipe de deux spectrometres mecaniques a neutrons lents qui fonctionnent simultanement, Avec l'un, on utilise toujours un monochromateur a filtre en Be; avec l'autre, on peut employer soit le meme genre de monochromateur, soit un monochromateur a cristal. On a constate que pour les mesures de distribution angulaire, on obtient d'excellents resultats en combinant un monochromateur a cristal et un spectrometre mecanique, meme si l'intensite et le pouvoir de resolution sont relativement faibles. Recemment on a fait l'essai d'un selecteur de vitesse mecanique ayant un pouvoir de separation des longueurs d'onde de 4,2%. Cependant, cet instrument n'est pas encore utilise pour les experiences. Le spectrometre mecanique de Studsvik, avec lequel le reacteur R2 de 30 MW ralenti a l'eau legere est equipe, utilise pour la monochromatisation l'action combinee d'un monochromateur a filtre de Be et d'un hacheur a courbe de transmission etroite. Dans ce spectrometre, de meme que dans celui de Stockholm, le hacheur est place avant l'echantillon, ce qui permet l'enregistrement simultane de donnees pour des angles d'observation differents. Un spectrometre a cristal triaxial est aussi en service pres du reacteur R2. Les auteurs donnent certaines caracteristiques de ces instruments, notamment l'intensite, le pouvoir de resolution, et indiquent dans quelle mesure ils conviennent pour certaines operations. Ainsi, il ressort des donnees numeriques mentionnees qu'une amelioration assez

Measurements with a Pulsed and Modulated Source in a Reactor; Mesures au Moyen d'une Source Pulsee et Modulee dans un Reacteur; Izmereniya v reaktore s pomoshch'yu impul'snogo i moduliruemogo is tochnika; Mediciones Efectuadas en Reactor con una Fuente Pulsada y Modulada

Energy Technology Data Exchange (ETDEWEB)

Rotter, W. [Centre d' Etude de l' Energie Nucleaire, Mol (Belgium)

1965-10-15

a digital computer [French] Un generateur dont le debit neutronique est variable selon une fonction du temps quelconque a ete mis au point par les Laboratoires de recherches Philips. Son utilite pratique dans le domaine de la physique des reacteurs a ete demontree par une serie de mesures effectuees dans le reacteur BRO2 a fotat sous-critique. Sa bonne stabilite, la possibilite de faire varier brusquement l'intensite neutronique, de puiser le debit ou de le moduler sinusoldalement, rend ce generateur tres souple. Il permet de determiner la reactivite ({rho} = {Delta}k/{beta}) et le temps de vie des neutrons ( Script-Small-L /{beta}) d'apres differentes methodes independantes. Une comparaison exacte de ces methodes est possible puisqu'elles peuvent etre employees sans modifier les conditions de mesure. On a determine: a) {rho} sur la base des neutrons retardes, par une reduction instantanee du debit de neutrons; b) {rho} sur la base des neutrons instantanes par des bouffees de neutrons; c) Script-Small-L /{beta} par combinaison de a) et b) pour 0,5 $ < {rho} <2 $; d) Script-Small-L /{beta} sur la base de la fonction de transfert du reacteur pour une source modulee. Les fonctions de transfert pour un oscillateur de reactivite et pour une source modulee sinusoldalement sont discutees. Il est montre que la mesure de Script-Small-L /{beta} est possible pour 0,1 $ < {rho} < 10 $ en utilisant une source modulee. La meme methode fournit aussi la reactivite a l'aide du rapport des neutrons instantanes aux neutrons retardes pour une frequence optimale, pratiquement independamment des donnees relatives aux neutrons retardes et de la valeur de f Script-Small-L /{beta}. Par accumulation d'un grand nombre de cycles dans l'analyseur multicanal, la statistique peut etre amelioree pour chaque methode. Le debit du generateur etant bien sinusoiedal, la reponse du reacteur peut etre integree sur chaque quart d'une periode, etant donne que la chafhe de mesure est pilotee par le

RCC-MX (2008 edition)

International Nuclear Information System (INIS)

Bravo, X.; Drubay, B.

2008-10-01

The RCC-MX books is a compilation of design and construction rules for the mechanical materials of experimental reactors, for their auxiliaries and irradiation devices. This second edition includes the updates of references to NF, EN and ISO standards, the compliance with the regulations for nuclear pressure equipments, and the feedback since the 2005 edition. It comprises 9 books and a CD-Rom and includes a presentation document. The RCC-MX has been developed for the Jules Horowitz reactor but can be used for the design and construction of new projects of new experimental reactors or new equipments and devices for existing facilities. Content: - Book 1: general dispositions, materials for experimental reactors and their auxiliaries, for irradiation devices and for control or handling mechanisms, complementary requirements and particular dispositions; - Book 2: materials for the reactor and for its level 1 auxiliaries; - Book 3: materials for the reactor and for its level 2 and level 3 auxiliaries, control and handling mechanisms, materials for irradiation devices; - Book 4: technical appendixes - materials characteristics (steels and alloys); - Book 5: technical appendixes (design rules); - Book 6: technical specifications of materials; - Book 7: tests and control methods; - Book 8: welding; - Book 9: fabrication. (J.S.)

Defect-induced room temperature ferromagnetic properties of the Al-doped and undoped ZnO rod-like nanostructure

CSIR Research Space (South Africa)

Jule, L

2017-07-01

Full Text Available : 151-155 Defect-induced room temperature ferromagnetic properties of the Al-doped and undoped ZnO rod-like nanostructure Jule L Dejene F Ali AG Roro KT Mwakikunga BW ABSTRACT: In this work, electron paramagnetic resonance (EPR...

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Faculty of Humanities and Social Sciences, University of Rijeka, 51000 Rijeka, Croatia. Astronomical Observatory, Volgina 7, 11060 Belgrade, Serbia. LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universities, UPMC Univ. Paris 06, 5 Place Jules Janssen, 92195 Meudon Cedex, France.

1286-IJBCS-Article-André Jules Ibouda

African Journals Online (AJOL)

hp

La coagulation du lait par la présure est influencée par plusieurs facteurs parmi lesquels on cite la concentration en enzyme ..... 1987) Enfin certains microorganismes sont capables ... phases principales (Payen, 1976; Visser, 1981;. Green et ...

Chronophotography: engineer of life: Etienne-Jules Marey

Directory of Open Access Journals (Sweden)

Stojmenović Dragan

2016-01-01

Full Text Available The centre of the problem of understanding the process of movement control, incorporated in cognitive biomechanics, is theoretically determined by contemporary physiological and psychological studies, reflecting itself inevitably in cinematography. In this sense, hypothetical questions are imposed: What are the determinants of the relationship between the scientific study of the phenomenon of movement and film art? How to develop an analytical model of the body in motion diagram? What impact does a rapid movement in nature have on the development of cinematic expression? The analysis of locomotion, as a form of human biomechanical movement, leads to the construction of the necessary tool - the camera, implying the creation of scientific films, thereby raising the level of knowledge and observation of the phenomena of motion, transforming it into a contemporary aesthetical model of film art.

JHR Project: a future Material Testing Reactor working as an International user Facility: The key-role of instrumentation in support to the development of modern experimental capacity

Energy Technology Data Exchange (ETDEWEB)

Bignan, G. [CEA, DEN, DER, JHR user Facility Interface Manager' , Cadarache, F-13108 St-Paul-Lez-Durance (France); Gonnier, C. [CEA, DEN, DER, SRJH Jules Horowitz Reactor Service, Cadarache, F-13108 St-Paul-Lez-Durance (France); Lyoussi, A.; Villard, J.F.; Destouches, C. [CEA, DEN, DER, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St-Paul-Lez-Durance (France); Chauvin, J.P. [CEA,DEN, DER, SPEX, Experimental Physics Service, Cadarache, F-13108 St-Paul-Lez-Durance (France); Maugard, B. [CEA, DEN, DER, Reactor Department Studies, Cadarache, F-13108 St-Paul-Lez-Durance (France)

2015-07-01

Research and development on fuel and material behaviour under irradiation is a key issue for sustainable nuclear energy in order to meet specific needs by keeping the best level of safety. These needs mainly deal with a constant improvement of performances and safety in order to optimize the fuel cycle and hence to reach nuclear energy sustainable objectives. A sustainable nuclear energy requires a high level of performances in order to meet specific needs such as: - Pursuing improvement of the performances and safety of present and coming water cooled reactor technologies. This will require a continuous R and D support following a long-term trend driven by the plant life management, safety demonstration, flexibility and economics improvement. Experimental irradiations of structure materials are necessary to anticipate these material behaviours and will contribute to their optimisation. - Upgrading continuously nuclear fuel technology in present and future nuclear power plants to achieve better performances and to optimise the fuel cycle keeping the best level of safety. Fuel evolution for generation II, III and III+ is a key stake requiring developments, qualification tests and safety experiments to ensure the competitiveness and safety: experimental tests exploring the full range of fuel behaviour determine fuel stability limits and safety margins, as a major input for the fuel reliability analysis. To perform such accurate and innovative progress and developments, specific and ad hoc instrumentation, irradiation devices, measurement methods are necessary to be set up inside or beside the material testing reactor (MTR) core. These experiments require beforehand in situ and on line sophisticated measurements to accurately determine different key parameters such as thermal and fast neutron fluxes and nuclear heating in order to precisely monitor and control the conducted assays. The new Material Testing Reactor JHR (Jules Horowitz Reactor) currently under

Experimental study of heat transfer and pressures drops for cans with spiral herring-bone fins; Etude experimentale du transfert de chaleur et des pertes de charges des gaines a ailettes helicoidales en chevron

Energy Technology Data Exchange (ETDEWEB)

Pelce, J; Francois, S; Houseaux, O; Pierre, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

Cans fitted with herring-bone fins are used for cooling uranium in certain nuclear reactor. By herring-bone is meant a staggered arrangement of the fins which have a plane of symmetry parallel to the general direction of liquid flow. The main geometrical parameter are then: the number of fins, the number of herring-bones, the angle of inclination of the fins with respect to the can axis, the dimensions of the fins, the can diameter and the channel diameter. The research is essentially experimental. The test are of three types: full size tests, in conditions approaching those in the reactor (constant flux, CO{sub 2} under pressure); full size tests but with a constant wall temperature, much easier to set up, and intended to distinguish rapidly between the merits of the various types of can; large-scale tests with air at atmospheric pressure for studying the phenomena in more detail. For each can tried out there is a corresponding pressure drop coefficient, a mean thermal exchange coefficient Mo-bar and a minimum exchange coefficient Mo{sub min} and Mo-bar are related by the expression Mo{sub min} = Mo-bar * f{sub c} * f, where f{sub c} and f are respectively circumferential and longitudinal singularity factor determined from a statistical study of all the temperatures measured for each can. The results are presented in about thirty tables and figures the most noteworthy results being summarized in the conclusion. (authors) [French] Les gaines a ailettes en chevron sont utilisees pour le refroidissement de l'uranium dans certains reacteurs nucleaires. Par chevron, on entend une disposition alternee des ailettes ayant un plan de symetrie parallele a la direction generale de l'ecoulement fluide. Les principaux parametres geometriques sont alors: le nombre des ailettes, le nombre de chevrons, l'angle d'inclinaison des ailettes par rapport a l'axe de la gaine, les dimensions des ailettes, le diametre de la gaine et le diametre du canal. L'etude est essentiellement

Land-use change may exacerbate climate change impacts on water resources in the Ganges basin

Science.gov (United States)

Tsarouchi, Gina; Buytaert, Wouter

2018-02-01

Quantifying how land-use change and climate change affect water resources is a challenge in hydrological science. This work aims to quantify how future projections of land-use and climate change might affect the hydrological response of the Upper Ganges river basin in northern India, which experiences monsoon flooding almost every year. Three different sets of modelling experiments were run using the Joint UK Land Environment Simulator (JULES) land surface model (LSM) and covering the period 2000-2035: in the first set, only climate change is taken into account, and JULES was driven by the CMIP5 (Coupled Model Intercomparison Project Phase 5) outputs of 21 models, under two representative concentration pathways (RCP4.5 and RCP8.5), whilst land use was held fixed at the year 2010. In the second set, only land-use change is taken into account, and JULES was driven by a time series of 15 future land-use pathways, based on Landsat satellite imagery and the Markov chain simulation, whilst the meteorological boundary conditions were held fixed at years 2000-2005. In the third set, both climate change and land-use change were taken into consideration, as the CMIP5 model outputs were used in conjunction with the 15 future land-use pathways to force JULES. Variations in hydrological variables (stream flow, evapotranspiration and soil moisture) are calculated during the simulation period. Significant changes in the near-future (years 2030-2035) hydrologic fluxes arise under future land-cover and climate change scenarios pointing towards a severe increase in high extremes of flow: the multi-model mean of the 95th percentile of streamflow (Q5) is projected to increase by 63 % under the combined land-use and climate change high emissions scenario (RCP8.5). The changes in all examined hydrological components are greater in the combined land-use and climate change experiment. Results are further presented in a water resources context, aiming to address potential implications of

Temperature and Oxidative Stress as Triggers for Virulence Gene Expression in Pathogenic Leptospira spp.

Directory of Open Access Journals (Sweden)

Tricia Fraser

2017-05-01

Full Text Available Leptospirosis is a zooanthroponosis aetiologically caused by pathogenic bacteria belonging to the genus, Leptospira. Environmental signals such as increases in temperatures or oxidative stress can trigger response regulatory modes of virulence genes during infection. This study sought to determine the effect of temperature and oxidative stress on virulence associated genes in highly passaged Leptospira borgpeterseneii Jules and L. interrogans Portlandvere. Bacteria were grown in EMJH at 30°C, 37°C, or at 30°C before being transferred to 37°C. A total of 14 virulence-associated genes (fliY, invA, lenA, ligB, lipL32, lipL36, lipL41, lipL45, loa22, lsa21, mce, ompL1, sph2, and tlyC were assessed using endpoint PCR. Transcriptional analyses of lenA, lipL32, lipL41, loa22, sph2 were assessed by quantitative real-time RT-PCR at the temperature conditions. To assess oxidative stress, bacteria were exposed to H2O2 for 30 and 60 min with or without the temperature stress. All genes except ligB (for Portlandvere and ligB and mce (for Jules were detectable in the strains. Quantitatively, temperature stress resulted in significant changes in gene expression within species or between species. Temperature changes were more influential in gene expression for Jules, particularly at 30°C and upshift conditions; at 37°C, expression levels were higher for Portlandvere. However, compared to Jules, where temperature was influential in two of five genes, temperature was an essential element in four of five genes in Portlandvere exposed to oxidative stress. At both low and high oxidative stress levels, the interplay between genetic predisposition (larger genome size and temperature was biased towards Portlandvere particularly at 30°C and upshift conditions. While it is clear that expression of many virulence genes in highly passaged strains of Leptospira are attenuated or lost, genetic predisposition, changes in growth temperature and/or oxidative intensity and

Comparison of the Thermal Response of Two Calorimetric Cells Dedicated to Nuclear Heating Measurements during Calibration

International Nuclear Information System (INIS)

Brun, J.; Reynard, C.; De-Vita, C.; Carette, M.; Muraglia, M.; Lyoussi, A.; Fourmentel, D.; Guimbal, P.; Villard, J-F.

2013-06-01

Nuclear heating is a key parameter which contributes to the thermal design and the quality of in-pile experiments performed in Material Testing Reactors (MTRs) for the study of nuclear materials and fuels under irradiation. Nuclear heating is typically measured in MTRs by radiometric calorimeters. However this kind of sensor has to be suited and improved in perspective of the new experimental conditions inside the channels of Jules Horowitz Reactor (JHR). In this paper, we study the responses of two non adiabatic differential calorimeter cells having the same geometric design, but different dimensions. These experimental works are carried out during a preliminary out-of-pile calibration operating procedure of these sensors which consists in simulating the sample heating by Joule effect. The influence of the imposed electrical power and of the forced cooling flow is determined on the sensor calibration curves. A more sensitive sensor leads to a quadratic calibration curve. This behavior difference of the two calorimetric configurations is explained by means of temperature and heat flux measurements performed with a new instrumented jacket. (authors)

Problems presented by the filtration and sampling of aerosols in the atomic energy programme; Problemes poses par la filtration et le prelevement des aerosols dans le cadre de l'energie atomique

Energy Technology Data Exchange (ETDEWEB)

Cochinal, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

The maximum permissible limits for radioactive aerosols are much lower than those for aerosols encountered in the non-nuclear industries. These limits depend on numerous factors such as: nature of the radiation, half-life, etc. The radioactive aerosols can be prepared by various methods. The filtering of the air in high activity laboratories or in plutonium treatment factories necessitates an installation consisting of: - aspiration filters, - extraction filters of very high efficiency (those used for {alpha} emitter cells: designed to be replaced without incurring contamination risks; those used for {gamma} emitter cells: designed to be replaced by remote control). The filtering in nuclear reactors is also effectuated by filter papers: - the G1 reactor with open circuit: the air coolant is entirely filtered at the entry and on leaving; - the G2, G3 and EDF1 reactors with closed circuits: filtering under pressure of a small portion of the coolant gas. (author) [French] Les limites maxima permises des aerosols radioactifs sont beaucoup plus faibles que celles des aerosols rencontres dans l'industrie classique. Elles dependent de nombreux facteurs tel que: nature du rayonnement, periode radioactive, etc... La formation des aerosols radioactifs est de nature diverse. La filtration des laboratoires de haute activite, ou d'usines d'elaboration de plutonium conduit a des types d'installations comportant: - des filtres d'aspiration; - des filtres d'extraction a rendement extremement eleve (type pour cellules emettrices {alpha} concu pour etre change sans risque de contamination, type pour cellules emettrices {gamma}: concu pour etre change a distance) La filtration des reacteurs nucleaires sont egalement effectuee par des papiers filtres: - reacteur G1 a circuit ouvert: air de refroidissement totalement filtre a l'aspiration et a l'extraction; - reacteurs G2, G3, EDF1: a circuit ferme: filtration sous pression d'une faible partie du gaz de refroidissement. (auteur)

A Survey of the Fuel Cycles Operated in the United Kingdom; Etude d'ensemble sur les cycles de combustible au Royaume-Uni; Obzor toplivnykh tsiklov, ispol'zuemykh v soedinennom korolevstve; Estudio de los ciclos de combustible utilizados en el Reino Unido

Energy Technology Data Exchange (ETDEWEB)

Allday, C. [United Kingdom Atomic Energy Authority, Risley, Warrington, Lancs (United Kingdom)

1963-10-15

son programme d'energie d'origine nucleaire sur la filie re des reacteurs a l'uranium naturel et au graphite, refroidis par un gaz. Les reacteurs de Calder Hall et de Chapelcross fonctionnent depuis sept ans; ceux de Berkeley et de Bradwell, qui dependent du Central Electricity Generating Board (CEGB), sont maintenant en service et sept autres reacteurs sont en construction ou en projet. Le combustible destine a ces reacteurs est etudie et fabrique dans l'usine de l'Atomic Energy Authority (AEA) a Springfields, puis transporte jusqu'au reacteur. Apres irradiation et dechargement, le combustible est transporte a l'usine de l'AEA, situee a Windscale, ou l'uranium et le plutonium sont separes des produits de fission. L'auteur decrit l'experience britannique en matiere d'etude et de fabrication du combustible, d'exploitation du reacteur, de transport et de traitement chimique du combustible irradie. Il examine brievement le comportement du combustible dans le reacteur et les differents programmes possibles de chargement et de dechargement, ce sujet etant developpe dans un autre memoire. b) Reacteurs utilisant les combustibles enrichis. Le Royaume-Uni met au point un reacteur perfectionne refroidi par un gaz (Advanced Gas Cooled Reactor = AGR), dont le prototype a ete mis en service en 1963. Le combustible est fabrique a partir d'oxyde d'uranium enrichi gaine d' acier inoxydable; apres irradiation, il sera traite dans une novelle installation qui sera ajoutee a l'usine de separation de Windscale ou est actu ellement traite le combustible gaine de magnox. L'uranium enrichi destine a AGR est produit par l'usine de diffusion situee a Capenhurst. L'oxyde d'uranium naturel enrichi au plutonium peut remplacer, comme combustible, l'oxyde d'uranium enrichi. L'auteur decrit l'experience acquise dans la transformation de l'oxyde destine a AGR et dans le fonctionnement du reacteur et indique comment on envisage de traiter le combustible irradie. Il examine le cas de l'utilisation d

Fulltext PDF

Indian Academy of Sciences (India)

1Faculty of Humanities and Social Sciences, University of Rijeka, 51000 Rijeka, Croatia. 2Astronomical Observatory, Volgina 7, 11060 Belgrade, Serbia. 3LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universities,. UPMC Univ. Paris 06, 5 Place Jules Janssen, 92195 Meudon Cedex, France.

Speeches and Presentations on Day 1: Opening and Introductory ...

International Development Research Centre (IDRC) Digital Library (Canada)

4 nov. 2010 ... Pr. Dieudonné OUEDRAOGO, Director of ISSP Centre d'Excellence de l'UEMOA and Regional Coordinator of PARSEP;; M. Lauchlan MUNRO, Vice-president, Corporate Strategy and Regional Management, IDRC ;; M. Jules SAVARIA, Ambassador to the Embassy of Canada in Ouagadougou (Burkina ...

Fentes labiopalatines dans la province du Katanga en République ...

African Journals Online (AJOL)

Fentes labiopalatines dans la province du Katanga en République Démocratique du Congo: Aspects épidémiologiques, anatomocliniques et thérapeutiques. Cedrick Milindi Sangwa, Olivier Mukuku, Christian Tshisuz, Jules Mulefu Panda, Mireille Kakinga, Marius Feruzi Kitembo, Jean-Felix Mutomb, Bwana Fwamba ...

Amputation des quatre members | Feruzi | Pan African Medical Journal

African Journals Online (AJOL)

, Mireille Kakinga Zabibu, Jules Panda Mulefu, Francois Tshilombo Katombe. Abstract. Les auteurs présentent les cas d'amputation des quatre membres réalisée chez trois patients différents. Ce sont des amputations réalisées pour chaque ...

Critical sizes and flux distributions in the shut down pile; Tailles critiques et cartes de flux a froid

Energy Technology Data Exchange (ETDEWEB)

Banchereau, A; Berthier, P; Genthon, J P; Gourdon, C; Lattes, R; Martelly, J; Mazancourt, R de; Portes, L; Sagot, M; Schmitt, A P; Tanguy, P; Teste du Bailler, A; Veyssiere, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-07-01

An important part of the experiments carried out on the reactor G1 during a period of shut-down has consisted in determinations of critical sizes, and measurements of flux distribution by irradiations of detectors. This report deals with the following points: 1- Critical sizes of the flat pile, the long pile and the uranium-thorium pile. 2- Flux charts of the same piles, and study of an exponential experiment. 3- Determination of the slit effect. 4- Calculation of the anisotropy of the lattice. 5- Description of the experimental apparatus of the irradiation measurements. (author) [French] Une part importante des experiences a froid effectuees sur le reacteur G1 a consiste en des determinations de tailles critiques et des mesures de distributions de flux par irradiations de detecteurs. Le present rapport traite les points suivants: 1- Tailles critiques de la pile plate, de la pile longue, de la pile a uranium-thorium. 2 - Cartes de flux des memes piles et etude d'une experience exponentielle. 3 - Determination de l'effet de fente. 4 - Calcul de l'anisotropie du reseau. 5 - Description de l'appareillage experimental des mesures d'irradiations. (auteur)

Critical sizes and flux distributions in the shut down pile; Tailles critiques et cartes de flux a froid

Energy Technology Data Exchange (ETDEWEB)

Banchereau, A.; Berthier, P.; Genthon, J.P.; Gourdon, C.; Lattes, R.; Martelly, J.; Mazancourt, R. de; Portes, L.; Sagot, M.; Schmitt, A.P.; Tanguy, P.; Teste du Bailler, A.; Veyssiere, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-07-01

An important part of the experiments carried out on the reactor G1 during a period of shut-down has consisted in determinations of critical sizes, and measurements of flux distribution by irradiations of detectors. This report deals with the following points: 1- Critical sizes of the flat pile, the long pile and the uranium-thorium pile. 2- Flux charts of the same piles, and study of an exponential experiment. 3- Determination of the slit effect. 4- Calculation of the anisotropy of the lattice. 5- Description of the experimental apparatus of the irradiation measurements. (author) [French] Une part importante des experiences a froid effectuees sur le reacteur G1 a consiste en des determinations de tailles critiques et des mesures de distributions de flux par irradiations de detecteurs. Le present rapport traite les points suivants: 1- Tailles critiques de la pile plate, de la pile longue, de la pile a uranium-thorium. 2 - Cartes de flux des memes piles et etude d'une experience exponentielle. 3 - Determination de l'effet de fente. 4 - Calcul de l'anisotropie du reseau. 5 - Description de l'appareillage experimental des mesures d'irradiations. (auteur)

Carbon stocks and fluxes in the high latitudes: using site-levelbreak data to evaluate Earth system models

DEFF Research Database (Denmark)

Chadburn, S. E.; Krinner, G.; Porada, P.

2017-01-01

from northward expansion of vegetation under climate warming. Here we evaluate the simulation of tundra carbon stocks and fluxes in three land surface schemes that each form part of major Earth system models (JSBACH, Germany; JULES, UK; ORCHIDEE, France). We use a site-level approach in which...

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... Department of Physics and Astronomy, College of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia. LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, 5 Place Jules Janssen, 92195 Meudon Cedex, France.

"Sugar" jõuab lavale / Ülle Hallik

Index Scriptorium Estoniae

Hallik, Ülle, 1963-

2008-01-01

Vanemuises esietendub 5. juunil "Sugar", lavastaja Mare Tommingas. Muusikal põhineb Jule Styne muusikalil "Sugar ehk Dzhässis ainult tüdrukud". Muusikali libreto kirjutas Peter Stone Robert Thoereni jutustuse ning Billy Wilderi ja I. A. L. Dimanondi filmi "Some Like It Hot" põhjal

Possibilities and limitations of analogue methods for studying the dynamics of nuclear power stations; Possibilites et limitations du calcul analogique pour les etudes dynamiques de centrales nucleaires

Energy Technology Data Exchange (ETDEWEB)

Caillet, C; Deat, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

1. Introduction: the present paper is devoted to analog simulation of problems related to nuclear reactors other than the simulation of the kinetic equations which is well known. 2. Thermodynamic problems: various problems relative to temperature evolution in a reactor, in a pipe, in an exchanger, in a turbine, are studied, and simulation techniques used by earlier authors are critically reviewed. 3. Pipe simulators: it is shown that this problem can be solved by the use of specialized simulators which will be described and analysed. 4. Rotating machine simulators: the particular aspect of rotating machine calculations introducing frequent use of diagrams is emphasized. A simulator requiring both digital and analogue methods is described. 5. The study of a nuclear power station: as an example it is proposed to discuss problems a rising in connection with the preceding elements (a, b, c, d) when simulating the behaviour of large nuclear plants. The part played by ordinary computing elements for the simulation of the different servomechanism transfer functions is considered and process of regulation is outlined. 6. Conclusion: the necessity of the use of high quality simulators and computers is underlined and the accuracy of the solutions is discussed. (author)Fren. [French] 1. Cinetique des reacteurs: la simulation des equations cinetiques d'un reacteur nucleaire ne pose desormais plus de probleme. II est donc possible de faire le point des differentes applications de la technique analogique dans ce domaine. 2. Les problemes thermodynamiques: on discute les differents problemes poses par l'evolution des temperatures dans un reacteur, dans une tuyauterie, dans un echangeur, dans une turbine, et on passe en revue les techniques de simulation proposees jusqu'a ce jour. 3s simulateurs de tuyauteries: on montre comment les differents problemes poses ci-dessus peuvent etre resolus, pour une classe tres vaste de reacteurs par l'emploi de simulateurs speciaux que l

Description of the Triton reactor; Pile Triton, rapport descriptif

Energy Technology Data Exchange (ETDEWEB)

NONE

1967-09-01

The Triton reactor is an enriched uranium pool type reactor. It began operation in 1959, after a divergence made on the June 30 the same year. Devoted to studies of radiation protection, its core can be displaced in the longitudinal direction. The pool can be separated in two unequal compartments by a wall. The Triton core is placed in a small compartment, the Nereide core in the big compartment. A third compartment without water is called Naiade II, is separated by a concrete wall in which is made a window closed by an aluminium plate (2.50 m x 2.70 m). The Naiade II hole is useful for protection experiments using the Nereide core. After a complete refitting, the power of the triton reactor that reached progressively from 1.2 MW to 2 MW, then 3 MW has reached in August 1965 6.5 MW. The reactor has been specialized in irradiations in fix position, the core become fix, the nereide core has been hung mobile. Since it has been used for structure materials irradiation, for radioelements fabrication and fundamental research. The following descriptions are valid for the period after August 1965. [French] Le reacteur Triton est un reacteur piscine, a uranium enrichi. Il est entre en fonctionnement en 1959, apres une divergence effectuee le 30 juin de cette meme annee. Destine a des etudes de protection contre les rayonnements, son coeur pouvait se deplacer dans le sens longitudinal. La piscine peut etre separee en deux compartiments inegaux par un batardeau. Le coeur triton est place dans le petit compartiment, le coeur Nereide dans le grand compartiment. Un troisieme compartiment sans eau, appele Naiade II, est separe par une paroi en beton dans laquelle est amenagee une fenetre obturee par une plaque d'aluminium (2,50 m x 2,70 m). La fosse Naiade II sert a des experiences de protection utilisant le coeur nereide. Apres une refonte complete, la puissance du reacteur triton qui etait passee progressivement de 1,2 MW a 2 MW, puis 3 MW, a atteint en aout 1965 6, 5 MW

Combining Performance and Flexibility for RMS with a Hybrid Architecture

NARCIS (Netherlands)

Dennis Koole; Arjan Groenewegen; Daniël Telgen; Patrick Wit; Leo van Moergestel; Arjan van Zanten; John-Jules Meyer; Ing. Erik Puik; Dick van der Steen; Pascal Muller

2013-01-01

Author supplied Combining Performance and Flexibility for RMS with a Hybrid Architecture Dani¨el Telgen 12? , Leo van Moergestel 1 , Erik Puik 1 , Pascal Muller 1 , Arjan Groenewegen 1 , Dick van der Steen 1 , Dennis Koole 1 , Patrick de Wit 1 , Arjen van Zanten 1 , and John-Jules

Browse Title Index

African Journals Online (AJOL)

Items 101 - 150 of 3061 ... Maruis Kitembo Feruzi, Cédrick Sangwa Milindi, Mireille Kakinga Zabibu, Jules Panda Mulefu, Francois Tshilombo Katombe. Vol 24, No 1 (2016), Amyloïdosis, sarcoidosis and systemic lupus erythematosus, Abstract PDF. Amel Rezgui, Imene Ben Hassine, Monia Karmani, Fatma Ben Fredj, Chadia ...

RJH seminar

International Nuclear Information System (INIS)

2003-01-01

This document gathers the slides that have been presented at the Jules Horowitz reactor (RJH) seminar. RJH is the next experimental reactor to be built in France, it will be commissioned in 2013. Its main characteristics are: - power: 100 MW - coolant and moderator: water (input water temperature 25 C, exit water temperature 41 C), down to up flow inside the core - reflector: water and beryllium - maximal enrichment: 19,75 % - mass of 235 U: 21 kg - fast neutron flux (>0,907 MeV): 6,4.10 14 n.cm -2 .s -1 - thermal neutron flux ( 14 n.cm -2 .s -1 . The contributions can be classed into 6 topics: 1) presentation of RJH, 2) site studies, 3) its irradiation capacities, 4) calculation tools for its design (neutronic, photonic, fluid flow and heat transfer), 5) materials (aluminium alloys, mechanical resistance, welding, corrosion resistance), and 6) UMo nuclear fuel (fabrication, reprocessing). (A.C.)

Techniques d'inspection par ondes guidees ultrasonores d'assemblages brases dans des reacteurs aeronautiques =

Science.gov (United States)

Comot, Pierre

L'industrie aeronautique, cherche a etudier la possibilite d'utiliser de maniere structurelle des joints brases, dans une optique de reduction de poids et de cout. Le developpement d'une methode d'evaluation rapide, fiable et peu couteuse pour evaluer l'integrite structurelle des joints apparait donc indispensable. La resistance mecanique d'un joint brase dependant principalement de la quantite de phase fragile dans sa microstructure. Les ondes guidees ultrasonores permettent de detecter ce type de phase lorsqu'elles sont couplees a une mesure spatio-temporelle. De plus la nature de ce type d'ondes permet l'inspection de joints ayant des formes complexes. Ce memoire se concentre donc sur le developpement d'une technique basee sur l'utilisation d'ondes guidees ultrasonores pour l'inspection de joints brases a recouvrement d'Inconel 625 avec comme metal d'apport du BNi-2. Dans un premiers temps un modele elements finis du joint a ete utilise pour simuler la propagation des ultrasons et optimiser les parametres d'inspection, la simulation a permis egalement de demontrer la faisabilite de la technique pour la detection de la quantite de phase fragile dans ce type de joints. Les parametres optimises sont la forme de signal d'excitation, sa frequence centrale et la direction d'excitation. Les simulations ont montre que l'energie de l'onde ultrasonore transmise a travers le joint aussi bien que celle reflechie, toutes deux extraites des courbes de dispersion, etaient proportionnelles a la quantite de phase fragile presente dans le joint et donc cette methode permet d'identifier la presence ou non d'une phase fragile dans ce type de joint. Ensuite des experimentations ont ete menees sur trois echantillons typiques presentant differentes quantites de phase fragile dans le joint, pour obtenir ce type d'echantillons differents temps de brasage ont ete utilises (1, 60 et 180 min). Pour cela un banc d'essai automatise a ete developpe permettant d'effectuer une analyse similaire

59 forskellige kronikker, klummer mv. med hver deres titel i Berlingske, JP og Kristeligt Dagblad

DEFF Research Database (Denmark)

Sørensen, Lars Hovbakke

2017-01-01

og julemiddagen Den 16. december: Julens sange Den 17. december: Julebukken Den 18. december: ”Rudolf med den røde tud” Den 19. december: Kravlenisserne Den 20. december: Glöggen og juleøllet Den 21. december: Adventsstjernen Den 22. december: Julemarkedet Den 23. december: Walt Disneys juleshow Den...

Right of withdrawal - interoperability of directives

NARCIS (Netherlands)

Loos, M.B.M.; Terryn, E.; Straetmans, G.; Colaert, V.

2013-01-01

This paper is published in the liber amicorum for Jules Stuyck (Leuven). This liber amicorum consists of case notes to landmark cases of the CJEU. The Travel Vac case, which is relatively unknown, stands at the crossroads of unfair commercial practices and consumer contract law, just as the work of

Void Reactivity Effects in the Second Charge of the Halden Boiling Water Reactor; Effets Cavitaires dans la Deuxieme Charge du Reacteur a Eau Lourde Bouillante de Halden (HBWR); Ehffekty pustotnoj reaktivnosti vo vtoroj zag HBWR; Effectos de Cavitacion en la Segunda Carga del Reactor de Agua Pesada Hirviente de Halden (HBWR)

Energy Technology Data Exchange (ETDEWEB)

Lunde, J. E. [OECD Halden Reactor Project (Norway)

1964-02-15

The reactivity effect of voids caused by boiling inside the coolant channels in the second fuel charge of the Halden Boiling Heavy Water Reactor has been measured both in void-simulated zero-power experiments and under actual power conditions. The void-simulated experiments consisted of measuring the reactivity effect of introducing void columns inside thin-walled tubes to various depths. The tubes were placed at different positions between die stringers in a single 7-rod cluster element practically identical with the normal second-charge fuel elements. This experiment enables an investigation of the reactivity dependence upon void fraction, and also the reactivity dependence of steam-bubble position in the coolant channel. The experiment was carried out in the Norwegian zero-power facility NORA, with a core consisting of 36 second-charge elements and with a lattice geometry identical to the one in HBWR. The temperature dependence of the void effect was investigated in a zero-power experiment with the 100 fuel-element core of HBWR. In a single fuel element the water level inside the coolant channel was depressed to various depths, and the reactivity effect of this perturbation was measured at different temperatures in the temperature interval 50 Degree-Sign C-220 Degree-Sign C. The power void reactivity has been measured in HBWR as a function of nuclear power at different moderator temperatures between 150 Degree-Sign C and 230 Degree-Sign C at powers up to about 16 MW at the highest temperature. The power-void reactivity coefficient is an important quantity in determining the dynamic behaviour of a boiling- water reactor. The theoretical determination of this quantity is, however, complicated by the fact that knowledge about the void distribution in the core is required. The detailed power-void distribution is not easily amenable to experimental determination, and accordingly the void-simulated experiments represent a better case for testing the reactor physics

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

... University of Caen, 6 bd Ml Juin, 14050 Caen, France; Laboratoire de Physique des Systèmes Complexes, Université Picardie Jules Verne, 33 rue St Leu, 80039 Amiens Cedex, France; Centre Wallon de Recherche Agronomique, CRA-W, Bâtiment Maurice Henseval, Chaussée de Namur, 24, 50030 Gembloux, Belgium ...

In core instrumentation for online nuclear heating measurements of material testing reactor

International Nuclear Information System (INIS)

Reynard, C.; Andre, J.; Brun, J.; Carette, M.; Janulyte, A.; Merroun, O.; Zerega, Y.; Lyoussi, A.; Bignan, G.; Chauvin, J-P.; Fourmentel, D.; Glayse, W.; Gonnier, C.; Guimbal, P.; Iracane, D.; Villard, J.-F.

2010-01-01

The present work focuses on nuclear heating. This work belongs to a new advanced research program called IN-CORE which means 'Instrumentation for Nuclear radiations and Calorimetry Online in REactor' between the LCP (University of Provence-CNRS) and the CEA (French Atomic Energy Commission) - Jules Horowitz Reactor (JHR) program. This program started in September 2009 and is dedicated to the conception and the design of an innovative mobile experimental device coupling several sensors and ray detectors for on line measurements of relevant physical parameters (photonic heating, neutronic flux ...) and for an accurate parametric mapping of experimental channels in the JHR Core. The work presented below is the first step of this program and concerns a brief state of the art related to measurement methods of nuclear heating phenomena in research reactor in general and MTR in particular. A special care is given to gamma heating measurements. A first part deals with numerical codes and models. The second one presents instrumentation divided into various kinds of sensor such as calorimeter measurements and gamma ionization chamber measurements. Their basic principles, characteristics such as metrological parameters, operating mode, disadvantages/advantages, ... are discussed. (author)

Study of the thermal drop at the uranium-can interface for fuel elements in gas-graphite reactors; Etude de la chute thermique au contact uranium-gaine pour des elements combustibles de reacteur de la filiere graphite-gaz

Energy Technology Data Exchange (ETDEWEB)

Faussat, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Levenes, G; Michel, M [Societe Industrielle de Combustible Nucleaire (France)

1964-07-01

The report reviews the tests now under way at the CEA, for determining the thermal contact resistance at the uranium-can interface for fuel elements used in gas-graphite type reactors. These are laboratory tests carried out with equipment based on the principle of a heat flow across a stack of test pieces having planar contact surfaces. The following points emerge from this work: - for a metallic uranium element canned in magnesium, of the type G-2 or EDF-2, a value of 0.2 deg C/W/cm{sup 2} seems reasonable for can temperatures of 400 deg C and above. - this value is independent of the micro-geometric state of the uranium surface in a range of roughness which easily includes those observed on tubes and rods produced industrially. - for the internal cans of elements cooled internally and externally, the value of the contact resistance for temperatures of under 400 deg C as a function of the stresses in the can has not yet been measured exactly. (authors) [French] Le rapport fait le point des essais actuellement en cours au CEA pour determiner la resistance thermique de contact uranium-gaine pour des reacteurs de la filiere graphite-gaz. Ces essais sont effectues en laboratoire sur des appareils bases sur le principe d'une circulation de flux de chaleur a travers un empilement d'eprouvettes dont les faces en contact sont planes. De l'etude, il ressort essentiellement que: - pour un element a uranium metallique et gaine de magnesium type G-2 ou EdF-2, on peut admettre la valeur de 0,2 deg C/W/cm{sup 2} pour des temperatures de gaines de 400 deg C et plus. - cette valeur ne depend pas de l'etat de surface microgeometrique de l'uranium pour un domaine de rugosites couvrant largement celles que l'on observe sur des tubes et barreaux fabriques en serie. - pour les gaines internes d'elements a refroidissement interne et externe la valeur de la resistance de contact reste a preciser pour les temperatures inferieures a 400 deg C, en fonction des contraintes existant dans les

SUPPLEMENTARY INFORMATION REGULAR ARTICLE Synthesis ...

Indian Academy of Sciences (India)

wafa_info

e LCMT, ENSICAEN, UMR 6507 CNRS, University of Caen, 6 bd Ml Juin, 14050 Caen, France. f Laboratoire de Physique des Systèmes Complexes, Université Picardie Jules Verne, 33 rue St Leu, 80039 Amiens cedex, France. g Centre Wallon de Recherche Agronomique, CRA-W, Bâtiment Maurice Henseval, Chaussée ...

New Instruments and Principles for the Dimensional Measurement and Measurement of Spacing of Reactor Components; Nouveaux Instruments et Procedes de Mesure des Dimensions et de l'Espacement des Elements d'un Reacteur; Novye pribory i printsipy izmereniya razmerov i raspolozheniya komponentov reaktora; Nuevos Instrumentos y Principios para Medir las Dimensiones y la Separacion Entre Componentes de Reactor

Energy Technology Data Exchange (ETDEWEB)

Mueller, P. [Institut Dr. Foerster, Reutlingen, Federal Republic of Germany (Germany)

1965-09-15

instrument for reactor components are discussed. Special attention is given to the possibility of using a small and versatile pick-up by means of manipulators in the ''hot'' zones and on ''hot'' materials. The increase of surface roughness with increasing irradiation dose is discussed. (author) [French] Full text: L'auteur presente les problemes de mesure de l'epaisseur de feuilles et des parois de tubes et recipients en aciers austenitiques ou en metaux non ferreux. Deux methodes de mesure des epaisseurs sans contact sont discutees: la mesure, par courants de Foucault, de l'epaisseur de feuilles et des parois de recipients en metaux non ferreux ou en aciers austenitiques, au moyen de bobines se deplacant le long des pieces a examiner: la mesure, par courants de Foucault, de l'epaisseur des parois de tubes, au moyen de bobines dans lesquelles se deplacent les pieces a examiner. L'auteur decrit des instruments appropries et le mode d'utilisation. Il discute egalement la mesure de l'epaisseur des parois de parties constitutives de reacteurs, en metaux non ferreux, par la 'methode de la bille magnetique' et explique le principe de ce nouveau type de mesure et son domaine d'utilisation - notamment pour les mesures par points; il decrit un instrument approprie. L'auteur examine la mesure des revetements non magnetiques de materiaux magnetiques; il explique les principes de mesure (methodes fondees sur les champs magnetiques des courants continus et des courants alternatifs) et decrit des instruments de mesure de revetements non magnetiques dont l'epaisseur varie entre 3 {mu}m et 20 mm. Il expose le probleme special de la mesure des depots de stellite sur les parois en aciers ferritiques des cuves de reacteurs. La mesure des revetements non conducteurs de metaux non ferreux est etudiee. Le memoire explique le principe de mesure (courants de Foucault). Il decrit un instrument approprie et donne des exemples de mesures typiques. L'auteur examine egalement la mesure sans contact, en

Heat exchange and pressure drop of herring-bone fin surfaces. Experimental cell results at constant wall temperature; Echange de chaleur et perte de charge de surfaces a ailettes en chevrons. Resultats experimentaux en cellule a temperature de paroi constante

Energy Technology Data Exchange (ETDEWEB)

NONE

1968-07-01

The increase in the specific power of nuclear reactors of the gas-graphite type has necessitated the use of high performance exchange surfaces for canning the fuel (natural uranium). For this, experiments were carried out on cans fitted with herring-bone fins, at constant wall temperature; a flow of water at 100 deg. C passes inside the can which is cooled externally by a flow of CO{sub 2} at 15 bars pressure. This experimental set-up makes it possible to compare the aero-thermal performances of the different cans with an accuracy of 5 per cent. This report presents the results obtained in the form of a friction coefficient f{sub 0} and mean Margoulis number m{sub 0} as a function of the Reynolds number Re{sub 0}, this latter varying from 3 x 10{sup 5} to 9 x 10{sup 5}. (authors) [French] L'augmentation de la puissance specifique des reacteurs nucleaires de la filiere graphite-gaz a necessite l'utilisation de surfaces d'echange a hautes performances pour gainer le combustible (uranium naturel). Dans cette optique, des gaines munies d'ailettes disposees en chevron ont ete experimentees a temperature de paroi constante: un courant d'eau a 100 deg. C circule a l'interieur de la gaine qui est refroidie exterieurement par un ecoulement de CO{sub 2} sous une pression de 15 bars. Cette methode experimentale permet de situer les performances aerothermiques des gaines les unes par rapport aux autres a 5 pour cent pres. Ce rapport presente les resultats obtenus sous la forme d'un coefficient de frottement f{sub 0} et d'un nombre de Margoulis moyen m{sub 0} en fonction du nombre de Reynolds Re{sub 0}, ce dernier pouvant varier de 3. 10{sup 5} a 9. 10{sup 5}. (auteurs)

The life of some metallic uranium based fuel elements; Duree de vie de quelques combustibles a base d'uranium metal

Energy Technology Data Exchange (ETDEWEB)

Stohr, J A; Englander, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Description of some theoretical and experimental data concerning the design and most economic preparation of metallic uranium based fuel elements, which are intended to produce an energy of 3 kW days/g of uranium in a thermal reactor, at a sufficiently high mean temperature. Experimental results obtained by testing by analogy or by actually trying out fuel elements obtained by alloying uranium with other metals in proportions such that the resistance to deformation of the alloy produced is much higher than that of pure metallic uranium and that the thermal utilisation factor is only slightly different from that of the uranium. (author) [French] Description de quelques donnees theoriques et experimentales concernant la conception et la preparation la plus economique d'elements combustibles a base d'uranium metallique naturel, destines a degager dans un reacteur thermique une energie de l'ordre de 3 kWj/g d'uranium a une temperature moyenne suffisamment elevee. Resultats experimentaux acquis par tests analogiques ou reels sur combustibles obtenus par alliage de l'uranium avec des elements metalliques en proportions telles que la resistance a la deformation soit bien superieure a celle de l'uranium metal pur et que le facteur propre d'utilisation thermique n ne soit que peu affecte. (auteur)

Reach for the Stars: Visions for Literacy Coaching Programs

Science.gov (United States)

DeFord, Diane

2012-01-01

This brief by the Literacy Coaching Clearinghouse is about reaching for the stars--stories of vision and commitment from educators in small and large schools. Everyone knows of people who are held up as "visionaries" throughout history: Leonardo Da Vinci, Mahatma Gandhi, Jules Verne, Thomas Edison, Susan Anthony, or John Dewey, to name a few. The…

What Is Steampunk, and Do I Want It in My Library?

Science.gov (United States)

Rozmus, Emily

2011-01-01

What is steampunk? Most call it Victorian science fiction. Steampunk can claim such authors as H.G. Wells and Jules Verne as its earliest writers. These two Victorian/Edwardian era writers created steampunk settings in books such as "The Time Machine" and "Journey to the Center of the Earth". In the 1990s, writers such as William Gibson, Bruce…

Contribution to the study of can deformations in the fuel elements of gas-graphite reactors during thermal cycling; Contribution a l'etude des deformations des gaines des elements combustibles de reacteur graphite-gaz au cours du cyclage thermique

Energy Technology Data Exchange (ETDEWEB)

Gauthron, M; Boudouresques, B; Delpeyroux, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The cans of fuel cartridges used in reactors of the gas-graphite type have either longitudinal fins of variable thickness, short herring-bone fins, or else a mixture of the two. An important test of the strength of these cartridges is their behaviour during thermal cycling carried out in cells reproducing in-pile conditions. It has been observed during with rapid cooling that there occurs a shortening at the base of the fins which can be accompanied in particular by a compression effect at the fin type, which has a tendency to curl, and by a tractive force acting on the body of the can at the ends of the longitudinal fins; this last phenomenon can result in a fracturing of the welds at the extremities or of the ends of the cartridge. This report presents first of all the way in which the stress diagram can be drawn for a can touching the fuel, and then the effect of the ratchet along a fin fixed to a bar with or without grooves. Finally the importance is shown of the test cycling variables (temperature, heating and cooling rates). (authors) [French] Les gaines des cartouches combustibles des reacteurs de la filiere graphite-gaz comportent soit des ailettes longitudinales plus ou moins epaisses, soit de courtes ailettes a chevrons, soit un ensemble des deux. Un test important de la tenue des cartouches, est la tenue au cyclage thermique en cellule pour reproduire le comportement en pile. On a observe au cours des cyclages a refroidissement rapide, un raccourcissement a la base des ailettes qui peut s'accompagner notamment d'une mise en compression du sommet de l'ailette qui a tendance a friser, et d'une traction exercee sur le corps des gaines au bout des ailettes longitudinales; ce dernier phenomene peut se traduire par des ruptures de soudures d'extremites ou des parties terminales de la cartouche. Ce rapport presente d'abord la maniere dont peut etre trace le diagramme des contraintes dans une gaine liee au combustible, puis l'effet du rochet le long d

Aterosclerose experimental em coelhos Experimental atherosclerosis in rabbits

Directory of Open Access Journals (Sweden)

Waleska C. Dornas

2010-08-01

Full Text Available Numerosas pesquisas têm sido realizadas utilizando modelos experimentais para estudar o desenvolvimento da aterosclerose com dieta induzindo hiperlipidemia. Devido ao fato de que coelhos são muito sensíveis a dietas ricas em colesterol e acumulam grandes quantidades no plasma, a utilização destes animais como modelo experimental para avaliar o desenvolvimento de aterosclerose é de grande relevância, trazendo informação sobre fatores que contribuem para progressão e regressão aplicadas a situações humanas. Sendo assim, nessa revisão a função aterogênica do colesterol é mostrada em trabalhos que incluem o coelho como modelo experimental, uma vez que este animal tornou-se o mais popular modelo experimental de aterosclerose.Many researches have been conducted in experimental models in order to study the development of atherosclerosis from hyperlipidemia-inducing diets. Since rabbits are very sensitive to cholesterol-rich diets and accumulate large amounts of cholesterol in their plasma, their use as experimental models to evaluate the development of atherosclerosis is highly relevant and brings information on factors that contribute to the progression and regression of this condition that can be applied to humans. As such, this review includes studies on the atherogenic function of cholesterol based on rabbits as the experimental model, since they have become the most largely used experimental model of atherosclerosis.

Liquid distribution in trickle-bed reactor; Distribution du liquide en reacteur a lit ruisselant

Energy Technology Data Exchange (ETDEWEB)

Marcandelli, C.; Wild, G. [Centre National de la Recherche Scientifique (CNRS-ENSIC), Lab. des Sciences du Genie Chimique, 54 - Nancy (France); Lamine, A.S. [CNRS-Universite de Paris-Nord, Lab. d' Ingenierie des Materiaux et des Hautes Pressions, 93 - Villetaneuse (France); Bernard, J.R. [Elf Antar France, Centre de Recherche Elf de Solaize, 69 - Solaize (France)

2000-07-01

The aim of this study is to develop techniques to qualify the efficiency of liquid distribution in trickle-bed reactors, using cold mockups. The experimental setup consists mainly in a 0.3-m-ID packed-bed column with three different plates used to vary the quality of inlet liquid distribution. Liquid distribution has been qualified using several techniques: global pressure drop measurements, global RTD (Residence-Time Distribution) of the liquid, local heat transfer probes, capacitance tomography, collector at the bottom of the reactor with nine equal zones. The bed pressure drop and the overall external liquid saturation decrease when the maldistribution increases; quantitative information is however difficult to obtain this way. Global RTD of the liquid allows quantifying of the average liquid distribution in the bed. The local thermal sensors give an indication of local liquid velocity and indicate possible local maldistribution of the liquid (scale mm) even when global distribution is good. Concerning the results obtained with the collector, a maldistribution index is defined ranging from 0 (ideal distribution) to 1 (worst possible distribution), and the influence of the different operating parameters (gas and liquid velocities, particle shape) is discussed. (authors)

Experimental Engineering: Articulating and Valuing Design Experimentation

DEFF Research Database (Denmark)

Vallgårda, Anna; Grönvall, Erik; Fritsch, Jonas

2017-01-01

In this paper we propose Experimental Engineering as a way to articulate open- ended technological experiments as a legitimate design research practice. Experimental Engineering introduces a move away from an outcome or result driven design process towards an interest in existing technologies and...

Experimental thermodynamics experimental thermodynamics of non-reacting fluids

CERN Document Server

Neindre, B Le

2013-01-01

Experimental Thermodynamics, Volume II: Experimental Thermodynamics of Non-reacting Fluids focuses on experimental methods and procedures in the study of thermophysical properties of fluids. The selection first offers information on methods used in measuring thermodynamic properties and tests, including physical quantities and symbols for physical quantities, thermodynamic definitions, and definition of activities and related quantities. The text also describes reference materials for thermometric fixed points, temperature measurement under pressures, and pressure measurements. The publicatio

Minimally invasive devices for treating lower urinary tract symptoms in benign prostate hyperplasia: technology update

Directory of Open Access Journals (Sweden)

Aoun F

2015-08-01

Full Text Available Fouad Aoun1, Quentin Marcelis,1,2 Thierry Roumeguère,2 1Department of Urology, Jules Bordet Institute, 2Department of Urology, Erasme Hospital, University Clinics of Brussels, Université Libre de Bruxelles, Brussels, Belgium Abstract: Benign prostatic hyperplasia (BPH represents a spectrum of related lower urinary tract symptoms (LUTS. The cost of currently recommended medications and the discontinuation rate due to side effects are significant drawbacks limiting their long-term use in clinical practice. Interventional procedures, considered as the definitive treatment for BPH, carry a significant risk of treatment-related complications in frail patients. These issues have contributed to the emergence of new approaches as alternative options to standard therapies. This paper reviews the recent literature regarding the experimental treatments under investigation and presents the currently available experimental devices and techniques used under local anesthesia for the treatment of LUTS/BPH in the vast majority of cases. Devices for delivery of thermal treatment (microwaves, radiofrequency, high-intensity focused ultrasound, and the Rezum system, mechanical devices (prostatic stent and urethral lift, fractionation of prostatic tissue (histotripsy and aquablation, prostate artery embolization, and intraprostatic drugs are discussed. Evidence for the safety, tolerability, and efficacy of these “minimally invasive procedures” is analyzed. Keywords: lower urinary tract symptoms (LUTS, benign prostatic hyperplasia (BPH, minimally invasive therapies, new approaches, experimental therapy

Resolution of the multigroup scattering equation in a one-dimensional geometry and subsidiary calculations: the MUDE code; Resolution de l'equation multigroupe de la diffusion dans une geometrie a une dimension et calculs annexes: code MUDE

Energy Technology Data Exchange (ETDEWEB)

Bore, C; Dandeu, Y; Saint-Amand, Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-07-01

MUDE is a nuclear code written in FORTRAN II for IBM 7090-7094. It resolves a system of difference equations approximating to the one-dimensional multigroup neutron scattering problem. More precisely, this code makes it possible to: 1. Calculate the critical condition of a reactor (k{sub eff}, critical radius, critical composition) and the corresponding fluxes; 2. Calculate the associated fluxes and various subsidiary results; 3. Carry out perturbation calculations; 4. Study the propagation of fluxes at a distance; 5. Estimate the relative contributions of the cross sections (macroscopic or microscopic); 6. Study the changes with time of the composition of the reactor. (authors) [French] MUDE est un code nucleaire ecrit en FORTRAN II pour IBM 7090-7094. Il resout un systeme d'equations aux differences approchant le probleme de diffusion neutronique multigroupe a une dimension. Plus precisement ce code permet de: 1. Calculer la condition critique d'un reacteur (k{sub eff}, rayon critique, composition critique) et les flux correspondants; 2. Calculer les flux adjoints et divers resultats connexes; 3. Effectuer des calculs de perturbation; 4. Etudier la propagation des flux a longue distance; 5. Ponderer des sections efficaces (macroscopiques ou microscopiques); 6. Etudier l'evolution de la composition du reacteur au cours du temps. (auteurs)

Processing Th C{sub 2} - UC{sub 2} fuel extracted from high temperature reactors HTGCR; Etude du traitement des combustibles Th C{sub 2} - UC{sub 2} issus de reacteurs a haute temperature

Energy Technology Data Exchange (ETDEWEB)

Derrien, C; Lessart, P; Pianezza, E; Verry, C; Villain, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

The object of this investigation is solubilisation head-end (from crushing and grinding phase to non included first purification phase) of pulverulent ({sup 233}U/{sup 232}Th)C{sub 2} (200 - 500 microns diameter) contained in a graphite matrix extracted from a 4.10{sup 13} n.cm{sup -2}.s{sup -1} thermalized neutrons average flux with an irradiation of 80000 MWjT{sup -1} HTGCR reactor. After having succinctly described different bibliographic processes we have chosen the burn - leach of reactor fuel and graphite matrix containing it. The technology of burner is original in nuclear field and still more by utilizing ultra-sounds to intensify burning reaction and to minimize the weight of unburnables. The mixture of ThO{sub 2}, U{sub 3}O{sub 8}, and fission products oxides is solubilized by boiling HNO{sub 3} 13 M + HF 0.05 M. This process is profit-learning in a thorium recuperation and reprocessing point of view. In the contrary-case it would be interesting to consider a dry-process which would permit to separate solid ThF{sub 4} from gaseous UF{sub 6}. (authors) [French] Cette etude a pour objet le traitement initial de mise en solution ou 'head-end' (allant de la phase broyag-concassage a la phase de premiere purification exclue) d'un combustible ({sup 233}U/{sup 232}Th)C{sub 2} pulverulent (de 200 a 500 {mu} de diametre) contenu dans une matrice de graphite issu d'un reacteur HTGCR surgenerateur a neutrons thermiques de flux moyen 4. l0{sup 13} n.cm{sup -2}.s{sup -1} et taux d'irradiation 80000 MWjT{sup -1}. Apres exposition succincte des differents procedes bibliographiques decrits, nous avons finalement choisi le traitement par combustion-attaque ('Burn-Leach') du combustible et de la matrice etanche graphite qui le contient. La technologie du bruleur est originale dans le domaine nucleaire d'autant qu'elle utilise les ultra-sons pour ameliorer le rendement de la reaction de combustion et reduire au minimum le poids des imbrules. Le melange ThO{sub 2}, U{sub 3}O

Simulation of power excursions - Osiris reactor; Simulation des excursions de puissance - pile Osiris

Energy Technology Data Exchange (ETDEWEB)

Pascouet, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

Following the experimental work accomplished in the U.S.A. on Borax 1 and SPERT 1 and the accident of SL 1, the 'Commissariat a l'Energie Atomique' started a research program about the safety of its own swimming Pool reactors, with regard to power excursions. The first research work led to the design of programmed explosive charges, adapted to the simulation of a power excursion. This report describes the application of these methods to the investigation of Osiris safety. (author) [French] A la suite des essais effectues aux U.S.A. sur BORAX 1 et SPERT 1 et de l'accident survenu a SL 1, le Commissariat a l'Energie Atomique a lance un programme d'etudes sur la surete de ses reacteurs piscines vis-a-vis des excursions de puissance. Les premieres etudes ont abouti A la mise au point de charges programmees capables de simuler une excursion de puissance. On trouvera dans le present rapport l'application de ces methodes a l'etude de la surete d'OSIRIS. (auteur)

Some fundamental aspects of boiling in nuclear reactors; Quelques aspects fondamentaux de l'ebullition dans les reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Mondin, H; Lavigne, P; Semeria, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-07-01

oscillation, the conditions of burnout are compared with those obtained under steady conditions. The burn-out flux following uniform 'stopped' heating has been studied in a channel containing still water. The flux shows a maximum as a function of unsaturation. The influence of the geometry and the nature of the metal was investigated. 4 - Output Oscillations: Using a low pressure (8 atm) loop, the influence of various parameters on the periods of output oscillations in a boiling channel on the thresholds at which they appear, was studied. Some new aspects of this complex phenomena were observed and are reported. (authors) [French] On indique les principaux resultats obtenus a Grenoble depuis quatre ans dans le domaine des mecanismes de l'ebullition et des phenomenes connexes dans les reacteurs nucleaires. 1 - OBSERVATION DE L'EBULLITION: Par photographie et cinematographie ultrarapide (8000 images par seconde maximum) on a observe l'ebullition en vase ou en canal jusqu'a 140 kg/cm{sup 2}. On a denombre les populations de germes (sites) generateurs de bulles et obtenu une correlation donnant leur nombre par unite de surface en fonction du flux thermique et de la pression. Le diametre des bulles se detachant de la paroi a ete etudie jusqu'a 140 kg/cm{sup 2}. On a mis en evidence trois types de bulles: - Les bulles en equilibre dont le diametre suit la formule de Fritz et Ende, - Les bulles d'ebullition dont le diametre diminue rapidement avec la pression (1/100 mm a 140 kg/cm{sup 2}), - Les coalescences apparaissant en liquide sature au-dessus de 15 W/cm{sup 2} et dont la proportion est independante de la pression. Par visualisation en strioscopie on observe les mouvements du film thermique associes a l'amorcage des germes, au depart et a la condensation des bulles; les mecanismes responsables de l'excellent transfert de chaleur ont pu ainsi etre precises. 2 - PERTES DE PRESSION EN ECOULEMENT DIPHASE: On a etabli un modele de variation continue du taux de vide dans un canal

World Tour

CERN Multimedia

Tauxe,H

H.C.Tauxe est Dr.ès lettres de l'Université de Lausanne et a enseigné la philosophie jusqu'en 1962. Ensuite il s'est tourné vers le journalisme, et dans ce cadre il a fait le voyage, qui sera le thème de sa conférence, en suivant ce qui a écrit Jules Verne.

Research means to back the development of nuclear reactors; Les moyens de recherche en support a l'evolution des reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

After 50 year long feedback experience on nuclear reactor operations it is legitimate to wonder whether experimental facilities used to support nuclear power programs are still necessary. The various participants of this conference said yes for mainly 4 reasons: -) to validate the extension of the service life of a reactor without putting at risk its high safety standard, -) to give the reactor more flexibility to cope with the power demand, -) to confront the results given by computerized simulations with experimental data, and -) to qualify the nuclear systems of tomorrow. (A.C.)

Critical mass, rod values and reactivity coefficients for Rapsodie; Masse critique, valeur des barres et coefficients de reactivite de rapsodie

Energy Technology Data Exchange (ETDEWEB)

Stevens, L; Gourdon, J [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

1967-07-01

Besides a brief general description, the report contains a description and discussion of the aims, the methods used and the results of critical mass, rod worth and static reactivity coefficient measurements on the Rapsodie reactor. (authors) [French] Apres une breve description generale, le rapport decrit et discute le but, les methodes employees et les resultats des mesures de masse critique, de reactivite des barres et des coefficients de reactivite statiques du reacteur RAPSODIE. (auteurs)

The astronomer Jules Janssen a globetrotter of celestial physics

CERN Document Server

Launay, Françoise

2012-01-01

Every aspect of the personality of Janssen (1824—1907) – that D’Artagnan of science, this bard of the Sun, and this audacious master builder – is covered here by Françoise Launay, his attentive and equally erudite biographer. A physicist, inventor and builder, Janssen was guided by his energy and curiosity. His research followed two directions: on the one hand the atmospheres of the Earth and the Sun, and on the other, two techniques: spectroscopy and photography. Among his numerous voyages across the globe, he went to Japan in 1874 to follow the transit of Venus in front of the Sun, the same year in which he invented his famous photographic revolver, which was, in truth, a great technical success. To observe the Sun during total eclipses he traveled to the Indies in 1868, to Oran in 1870 (escaping from besieged Paris by balloon!), returned to India in 1871, left for Siam in 1875 and, in 1883, for an island in the Pacific. One can thus understand why Henriette often complained of the solitude in whic...

Evolution of mechanical behavior of 6XXX aluminium alloy due to the precipitation state during a thermo-mechanical process

International Nuclear Information System (INIS)

Bardel, Didier; Perez, Michel; Nelias, Daniel; Chaise, Thibaut; Garnier, Jerome; Bourlier, Florent

2014-01-01

The aim of this research is to link the microstructural state and the mechanical properties of an age hardening alloy during a fast heat treatment such as encountered during welding. A coupled model between precipitation state and mechanical properties is used to predict the yield strength and hardening behavior that can be observed experimentally. The method permits the identification of the kinematic and isotropic contributions in the hardening model. The methodology is applied to a 6061-T6 aluminium alloy which is used in the Jules Horowitz reactor vessel. The general idea of this methodology is to couple an efficient microstructural model to a mechanical one based on the dislocation theory and ad'hoc experiments. The theoretical background is based on the work of Kampmann and Wagner, known as the KWN model, to account for nucleation, growth/dissolution and coarsening of precipitates. This analysis requires transient thermo-mechanical experimental data. The efficiency of these models and their coupling are shown for a series 6XXX aluminium alloy which contains β'' and β' precipitates. Ultimately these models are coupled to a FEA model and allows to predict the distribution of precipitates within each element of the mesh, and subsequently its mechanical behavior. (authors)

Viis värvikat visiooni / Tanel Veenre

Index Scriptorium Estoniae

Veenre, Tanel, 1977-

2009-01-01

Eesti Kunstiakadeema lõputööde näitus "Tase'09" Rüütelkonna hoones Toompeal 21. juunini. Arhitekt Martin Voltri Tartu linnujaama projektist. Madis Nurmsi lavakujundusest ja -kostüümidest Jules Massenet' ooperile "Thais", mis esietendus 22. mail Pärnu Endlas. Klaasikunstnik Merle Bukoveci sisepurskkaevude seeriast "Voolujooned". Tootedisainer Pent Talveti magistritööst. Uku-Kristjan Küttise tehtud kirjatüübist

Codification of LMFBR rules and comparison of codes

International Nuclear Information System (INIS)

Faure, O.; Debaene, J.P.

1993-01-01

The first part of this report presents the basic RCC-MR (regles de conception et de construction des materiels mecaniques des ilots nucleaires, reacteurs a neutrons rapides) design rules and their purpose. The second part is a qualitative comparison between RCC-MR, Code case N47 (ASME) and ETSDG Guide (MONJU Guide), made on the following topics: negligible creep test, ratcheting, creep fatigue, buckling, piping rules. An outline is given on improvements to RCC-MR rules now in progress

In-core program for on line measurements of neutron, photon and nuclear heating parameters inside Jules Horowitz MTR reactor

International Nuclear Information System (INIS)

Lyoussi, A.; Reynard-Carette, C.

2014-01-01

Accurate on-line measurements of key parameters inside experimental channels of Material Testing Reactor are necessary to dimension the irradiation devices and consequently to conduct smart experiments on fuels and materials under suitable conditions. In particular the quantification of nuclear heating, a relevant parameter to reach adapted thermal conditions, has to be improved. These works focus on an important collaborative program between CEA and Aix-Marseille University called INCORE (Instrumentation for Nuclear radiations and Calorimetry On-line in Reactor) dedicated to the development of a new measurement methodology to quantify both nuclear heating and accurate radiation flux levels (neutrons and photons). The methodology, which is based on experiments carried out under irradiation conditions with a multi-sensor device (ionization chamber, fission chamber, gamma thermometer, calorimeter, SPND, SPGD) as well as works performed out-of nuclear/radiative environment on a reference sensor used to measure nuclear heating (calorimeter), is presented (authors)

Convenience experimentation.

Science.gov (United States)

Krohs, Ulrich

2012-03-01

Systems biology aims at explaining life processes by means of detailed models of molecular networks, mainly on the whole-cell scale. The whole cell perspective distinguishes the new field of systems biology from earlier approaches within molecular cell biology. The shift was made possible by the high throughput methods that were developed for gathering 'omic' (genomic, proteomic, etc.) data. These new techniques are made commercially available as semi-automatic analytic equipment, ready-made analytic kits and probe arrays. There is a whole industry of supplies for what may be called convenience experimentation. My paper inquires some epistemic consequences of strong reliance on convenience experimentation in systems biology. In times when experimentation was automated to a lesser degree, modeling and in part even experimentation could be understood fairly well as either being driven by hypotheses, and thus proceed by the testing of hypothesis, or as being performed in an exploratory mode, intended to sharpen concepts or initially vague phenomena. In systems biology, the situation is dramatically different. Data collection became so easy (though not cheap) that experimentation is, to a high degree, driven by convenience equipment, and model building is driven by the vast amount of data that is produced by convenience experimentation. This results in a shift in the mode of science. The paper shows that convenience driven science is not primarily hypothesis-testing, nor is it in an exploratory mode. It rather proceeds in a gathering mode. This shift demands another shift in the mode of evaluation, which now becomes an exploratory endeavor, in response to the superabundance of gathered data. Copyright © 2011 Elsevier Ltd. All rights reserved.

Proserpine - plutonium 239 - Proserpine - uranium 235 - comparison of experimental results; Proserpine - plutonium 239 - proserpine - uranium 235 - comparaison de resultats experimentaux

Energy Technology Data Exchange (ETDEWEB)

Brunet, J P; Caizergues, R; Clouet D' Orval, Ch; Kremser, J; Moret-Bailly, J; Verriere, Ph [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The Proserpine homogeneous reactor is constituted by a tank, 25 cm dia, 30 cm high, surrounded by a composite reflector made of beryllium oxide and graphite. In this tank can be made critical plutonium or 90 per cent enriched uranium solutions, the fissile substances being in the form of a dissolved salt. In varying the concentration of the solution, critical masses were studied as a function of the level of the liquid in the tank. The minimum critical mass is 256 {+-} 2 grs for plutonium and 409 {+-} 3 grs for uranium 235. In the range of the critical concentrations which were studied, the neutronic properties of fissionable solutions of plutonium and enriched uranium were compared for identical geometries. (authors) [French] Proserpine est un reacteur homogene comportant une cuve de diametre 25 cm, de hauteur 30 cm, entouree d'un reflecteur composite d'oxyde de beryllium et de graphite. On y a rendu critiques des solutions de plutonium ou d'uranium enrichi a 90 pour cent, le produit fissile se trouvant sous la forme d'un sel dissous. En faisant varier la concentration de la solution, on a etudie les masses critiques en fonction de la hauteur du liquide dans la cuve. La masse- critique minimum est, pour le plutonium de 256 {+-} 2 g, pour l'uranium 235 de 409 {+-} 3 g. Dans la gamme des concentrations critiques etudiees, on a compare, dans des conditions de geometrie identique, les proprietes neutroniques des solutions fissiles de plutonium et d'uranium enrichi. (auteurs)

Fast neutron dosimetry in research reactors; Dosimetrie en neutrons rapides dans les reacteurs de recherche

Energy Technology Data Exchange (ETDEWEB)

Eckert, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

This work chiefly concerns the measurement of fast neutron fluxes by means of threshold detectors. It is shown first that the cross sections to use for measurements by threshold detectors depend largely on the neutron spectrum, that is the position in which the measurement is performed. The spectrum is determined by calculation for several positions in the piles EL2 and EL3; from this can be deduced the cross-sections to be used for the measurements carried out in these positions. In the last part of the report, possible methods for the experimental determination of the spectrum are indicated. (author) [French] On etudie principalement la mesure des flux de neutrons rapides a l'aide de detecteurs a seuil. On montre d'abord que les sections efficaces a utiliser pour les mesures par detecteurs a seuil, dependent grandement du spectre des neutrons, c'est-a-dire de l'emplacement ou s'effectue la mesure. La determination du spectre est effectuee par le calcul pour plusieurs emplacements des piles EL2 et EL3; on en deduit les sections efficaces a utiliser pour les mesures effectuees a ces emplacements. Dans la derniere partie du rapport, on indique quelles methodes sont possibles pour la determination experimentale du spectre. (auteur)

Optimal experimental design with R

CERN Document Server

Rasch, Dieter; Verdooren, L R; Gebhardt, Albrecht

2011-01-01

Experimental design is often overlooked in the literature of applied and mathematical statistics: statistics is taught and understood as merely a collection of methods for analyzing data. Consequently, experimenters seldom think about optimal design, including prerequisites such as the necessary sample size needed for a precise answer for an experimental question. Providing a concise introduction to experimental design theory, Optimal Experimental Design with R: Introduces the philosophy of experimental design Provides an easy process for constructing experimental designs and calculating necessary sample size using R programs Teaches by example using a custom made R program package: OPDOE Consisting of detailed, data-rich examples, this book introduces experimenters to the philosophy of experimentation, experimental design, and data collection. It gives researchers and statisticians guidance in the construction of optimum experimental designs using R programs, including sample size calculations, hypothesis te...

Magnesium and aluminium-base products. For use as structural materials; Magnesium, aluminium et alliages. Emploi comme materiaux de structure

Energy Technology Data Exchange (ETDEWEB)

Bernard, J; Boudouresques, B; Alfille, L; Klersy, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

This paper deals with the ability of some Mg and Al-base products to be used as structural materials in thermal reactors. The results presented here are relating to investigations carried out for completing the design of french reactors. (author)Fren. [French] Les auteurs traitent de l'aptitude de quelques materiaux legers et ultra-legers a l'utilisation comme elements de structure des reacteurs thermiques. Les resultats presentes sont relatifs aux etudes effectuees pour l'etablissement des projets de piles fran ises. (auteur)

Perturbation method utilization in the analysis of the Convertible Spectral Shift Reactor (RCVS)

International Nuclear Information System (INIS)

Bruna, G.B; Legendre, J.F.; Porta, J.; Doriath, J.Y.

1988-01-01

In the framework of the preliminary faisability studies on a new core concept, techniques derived from perturbation theory show-up very useful in the calculation and physical analysis of project parameters. We show, in the present work, some applications of these methods to the RCVS (Reacteur Convertible a Variation de Spectre - Convertible Spectral Shift Reactor) Concept studies. Actually, we present here the search of a few group project type energy structure and the splitting of reactivity effects into individual components [fr

RJH seminar; Seminaire RJH du 7 mars 2003

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

This document gathers the slides that have been presented at the Jules Horowitz reactor (RJH) seminar. RJH is the next experimental reactor to be built in France, it will be commissioned in 2013. Its main characteristics are: - power: 100 MW - coolant and moderator: water (input water temperature 25 C, exit water temperature 41 C), down to up flow inside the core - reflector: water and beryllium - maximal enrichment: 19,75 % - mass of {sup 235}U: 21 kg - fast neutron flux (>0,907 MeV): 6,4.10{sup 14} n.cm{sup -2}.s{sup -1} - thermal neutron flux (<0,625 eV) inside the reflector on aluminium block: 7,3.10{sup 14} n.cm{sup -2}.s{sup -1}. The contributions can be classed into 6 topics: 1) presentation of RJH, 2) site studies, 3) its irradiation capacities, 4) calculation tools for its design (neutronic, photonic, fluid flow and heat transfer), 5) materials (aluminium alloys, mechanical resistance, welding, corrosion resistance), and 6) UMo nuclear fuel (fabrication, reprocessing). (A.C.)

BENSC. Experimental reports 1994

International Nuclear Information System (INIS)

Kirschbaum, Y.; Gast, H.; Michaelsen, R.

1995-05-01

This volume contains the guest groups' experimental reports describing experimental work carried out on the Berlin Scattering Center in 1994. These experimental reports are intended as interim summaries. (HP)

BENSC experimental reports 1993

International Nuclear Information System (INIS)

Kirschbaum, Y.; Michaelsen, R.

1994-05-01

This volume contains the guest groups' experimental reports describing experimental work carried out on the Berlin Scattering Center in 1993. These experimental reports are intended as interim summaries. (HP)

Characteristics and construction problems of EL 4; Caracteristiques et problemes de construction d'EL4

Energy Technology Data Exchange (ETDEWEB)

Carle, R; Schulhof, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires; Sevin, Ph [Electricite de France (EDF), 75 - Paris (France); Buttin, J [Societe INDATOM (France)

1964-07-01

detail and the connections to be employed were tested. The whole circuit is made in fairly classical materials (slightly alloyed steels) whose behaviour in the carbon dioxyde at 500 deg. C was proved. The CO{sub 2}, and heavy water circuits construction will begin in October 1964. Aerodynamic tests were carried out for the helico-centrifugal blowers (of unit power 9 MW). The choice of a pressure as high as 60 kg/cm{sup 2} does not seem to induce new problems in connection with leaks on the machine shafts. Finally, the choice of a type of CO{sub 2} - steam heat exchanger with forced circulation led Electricite de France to test the operation and stability of a prototype exchanger in its test plant The reactor will be equipped with a de-pressurizing and de-superheating system which will allow the reactor to operate at 20 p. 100 of its nominal power whether the turbo-alternator is available or not. (authors) [French] EL 4 est le prototype d'une filiere originale de reacteurs moderes a l'eau lourde et refroidis au gaz carbonique. Son etude a ete menee dans la double optique de: - realiser un reacteur suffisamment important et complet pour y tester l'ensemble des problemes de construction et d'exploitation de la filiere; - menager dans l'installation les possibilites de tenir compte des ameliorations (materiaux nouveaux, elements combustibles ameliores) qui sont etudiees par ailleurs. Le premier objectif n'etait envisageable que sous reserve d'un volume d'etudes preliminaires important. A ce titre, ont ete realises et essayes de 1962 a 1964 plusieurs canaux prototypes, hors pile, mais dans les conditions reelles de temperature et de pression. Ces essais ont montre la bonne tenue des materiaux aux difficiles conditions mecaniques et chimiques du projet. Ces installations seront d'ailleurs disponibles pour eprouver, avant mise en pile, les modifications ulterieures. D'importants essais touchant la securite du reacteur en cas d'explosion du circuit de CO{sub 2}, ont ete realises

Is animal experimentation fundamental?

Science.gov (United States)

d'Acampora, Armando José; Rossi, Lucas Félix; Ely, Jorge Bins; de Vasconcellos, Zulmar Acciolli

2009-01-01

The understanding about the utilization of experimental animals in scientific research and in teaching is many times a complex issue. Special attention needs to be paid to attain the understanding by the general public of the importance of animal experimentation in experimental research and in undergraduate medical teaching. Experimental teaching and research based on the availability of animals for experimentation is important and necessary for the personal and scientific development of the physician-to-be. The technological arsenal which intends to mimic experimentation animals and thus fully replace their use many times does not prove to be compatible with the reality of the living animal. The purpose of this paper is to discuss aspects concerning this topic, bringing up an issue which is complex and likely to arouse in-depth reflections.

Ethics in Animal Experimentation

Directory of Open Access Journals (Sweden)

Yusuf Ergun

2010-08-01

Full Text Available Experimental animals are frequently used to obtain information for primarily scientific reasons. In the present review, ethics in animal experimentation is examined. At first, the history of animal experimentation and animal rights is outlined. Thereafter, the terms in relation with the topic are defined. Finally, prominent aspects of 3Rs constituting scientific and ethical basis in animal experimentation are underlined. [Archives Medical Review Journal 2010; 19(4.000: 220-235

Description of a Reactivity Measuring Apparatus; Description d'un Type d'Appareil de Mesure de la Reactivite

Energy Technology Data Exchange (ETDEWEB)

Deiss, M.; Uberschlag, J. [Centre d' Etudes Nucleaires de Saclay (France)

1966-06-15

apparatuses have different dividers in the output unit, in the one case Potentiometric, and in the other electronic. The first apparatus is suitable in principle for most normal measurements. The second, by reason of its shorter response time, is suited both to measurements of higher reactivity values with the reactor level rising, and also with the reactor level falling, even over limited power ranges. (author) [French] La mesure de la periode ou du temps de doublement fournit en general au technicien du controle des reacteurs une information suffisante sur l'evolution du reacteur. Le physicien attache a la determination de parametres physiques ne peut se satisfaire de la mesure ordinaire de ces grandeurs, dont les concepts font abstraction de la nature du phenomene de la fission nucleaire. Habituellement le physicien doit donc convertir la mesure du temps de doublement, effectuee sur un temps suffisamment long, afin d'en eliminer les termes transitoires perturbateurs, et convertir, par intermediaire des courbes de Nordheim, cette mesure en valeur de reactivite. Cette procedure est longue et contraignante. Il a donc semble utile de concevoir un type d'appareil capable d'evaluer directement et instantanement le coefficient de multiplication excedentaire Greek-Small-Letter-Delta K a partir de l'evolution d'une grandeur physique N supposee proportionnelle au flux neutronique regnant dans le coeur du reacteur. Le coefficient Greek-Small-Letter-Delta K est pratiquement assimilable a la reactivite au voisinage de la criticalite. Un appareil de ce type peut en consequence resoudre la relation inverse a celle definie par le systeme des equations differentielles se rapportant au reacteur, en considerant le cas simplifie du reacteur point dans la theorie a un groupe. L'application des techniques du calcul analogique conduit a utiliser un reseau du type Pagels qui sera dispose, soit comme impedance d'entree, soit comme impedance de contre-reaction d'un amplificateur operationnel. Cette

Development and optimization of nuclear heating and gamma flux measurement techniques in experimental reactors: identification, mastery, treatment and reduction of uncertainties

International Nuclear Information System (INIS)

Amharrak, H.

2012-01-01

This thesis work focuses on the needs for qualification of neutron and photonics calculation schemes in the future Jules Horowitz technological Reactor (RJH) and Pressurized Water Reactors (PWR). It is necessary to establish reliable measurement results with well defined associated uncertainties, for qualification and/or validation. The objective of this thesis is to develop and to improve the nuclear heating measurement methods (especially gamma photons) in MINERVE and EOLE experimental reactors at CEA-Cadarache, using thermo-luminescent detectors (TLD), optically stimulated luminescence detectors (OSLD) and an ionization chamber. It is to identify, prioritize, treat and reduce the various sources of uncertainty and systematic bias associated with the measurement. In a previous study, where nuclear heating was estimated from an integrated radiation dose by TLD in MINERVE and EOLE reactors, it has been shown that dose calculation underestimated the experiment by 25% with a total uncertainty of 15% (2σ). This systematic bias observed has been largely attributed to a lack of nuclear data used to perform the calculations. Therefore, in this work a new series of experiments was set up in the MINERVE reactor to reduce the measurement uncertainties, and better understand the origins of the discrepancies with the modeling. These experiments were carried out in an aluminum or hafnium surrounding (in specifically designed boxes) using a new procedure and analysis methodology. In these experiments, the TLD are calibrated individually, the repeatability of the measurement is experimentally evaluated and the laws of TLD heat are optimized. These improvements are subsequently used for the measurement of nuclear heating in AMMON program (EOLE reactor), dedicated to the qualification of neutron and photonics calculation schemes in the RJH reactor. The measurements of the gamma emitted, with a delay (delayed gamma) after shutdown of the MINERVE reactor, were also carried out

The Use of Research Reactors and Short-Lived Isotopes in the Study of Nuclear-Reactor Fuel Materials; Emploi de Reacteurs de Recherche et de Radioisotopes de Courte Periode dans l'Etude des Combustibles pour Reacteurs Nucleaires; ИСПОЛЬЗОВАНИЕ ИССЛЕДОВАТЕЛЬСКИХ РЕАКТОРОВ И КОРОТКОЖИВУЩИХ ИЗОТОПОВ ПРИ ИЗУЧЕНИИ ТОПЛИВНЫХ МАТЕРИАЛОВ ДЛЯ ЯДЕРННХ РЕАКТОРОВ; Empleo de Reactores de Investigacion y de Isotopos de Periodo Corto en el Estudio de Combustibles Nucleares

Energy Technology Data Exchange (ETDEWEB)

Elleman, T. S.; Townley, C. W.; Sunderman, D. N. [Battelle Memorial Institute, Columbus, OH (United States)

1963-03-15

can often exhibit preferential release of particular elements, rapid fission- product release during temperature changes, and fission-gas release after reactor shutdown. The use of this technique allows fundamental information to be obtained on the performance of prototype fuel materials without the necessity for large testing reactors or high-level cave facilities for handling irradiated specimens. (author) [French] On peut employer avec profit un reacteur de recherche pour etudier la mobilite des produits de fission dans les prototypes de combustibles nucleaires en creant un milieu analogue a celui dans lequel le combustible est appele a fonctionner normalement, et en controlant rigoureusement les conditions de l'experience, tout en prevoyant une certaine souplesse dans le dispositif d'experimentation. Si l'on fait varier les conditions d'irradiation et que l'on procede a une analyse quantitative des produits de fission de courte periode liberes par l'echantillon, on pourra determiner les mecanismes de la liberation des produits de fission et leurs rapports avec les proprietes physiques et chimiques tant du combustible servant d'echantillon que des produits de fission eux-memes. On pourra en outre obtenir des donnees de technogenie utiles sur la valeur brute de la radioactivite liberee et la duree de vie probable du combustible. En regle generale, on irradie les echantillons dans des capsules a double paroi qu'on chauffe et introduit dans la piscine ou dans les canaux d'irradiation du reacteur, les produits de fission volatils liberes etant elimines de la capsule par un gaz de balayage. Etant donne .que le rapport entre la vitesse de degagement et la periode du radioisotope constitue un indice important du mecanisme, on recueille et analyse les gaz de fission- krypton et xenon - dont la periode va de 1,7 s jusqu'a 5,3 d. On determine les gaz rares de courte periode (krypton-89, krypton-91, krypton-92, xenon-137, xenon-138, xenon-139, xenon-140 et xenon-141) en

Calculation programme for transient thermo-pneumatic flows; Programme de calcul pour les ecoulements transitoires thermopneumatiques

Energy Technology Data Exchange (ETDEWEB)

Coste, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

With a view to determining the changes occurring in gas reactors after cooling accidents, a calculation programme is established for unidimensional gas flows with pressure drops, heat exchanges and in certain cases blowing, in a reticulated lattice. Any schematization can be taken into account by the use of a set of indices. This programme, of which the FORTRAN list is given, is applied to particular cases of sudden pressure drops in the circuits. The results obtained are in good agreement with those obtained both from the graphical method using the characteristics and from experimental recorded data. (author) [French] En vue de determiner les evolutions des reacteurs a gaz apres accident de refroidissement, on etablit un programme de calcul pour les ecoulements gazeux unidimensionnels avec pertes de charge, echanges thermiques et eventuellement soufflage, en reseau maille. Toute schematisation peut etre prise en compte grace a un jeu d'indices. Ce programme, dont la liste FORTRAN est presentee, est applique a des cas particuliers de degonflage brutal de circuits. Ses resultats sont en bon accord, d'une part avec ceux de la methode graphique des caracteristiques, d'autre part avec des enregistrements experimentaux. (auteur)

Fuel slugs considered for use in the high flux reactor EL3; Elements combustibles envisages pour la pile a haut flux EL 3

Energy Technology Data Exchange (ETDEWEB)

Stohr, J A; Caillat, R; Gauthron, M; Montagne, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

EL3 was designed essentially for the study, under irradiation conditions, of materials used in the construction of atomic reactors. The study schedule allocates considerable time and effort to new types of fuel slugs. The present report described the various types of slug being tested or scheduled for tests. After laboratory study, each slug is tested in an experimental cell in the pile. The best are retained and used to charge the reactor (the present charge is purely provisional to permit first criticality and power rise tests)ren. [French] La pile EL3 est essentiellement destinee a l'etude sous irradiation des materiaux utilises dans la construction des reacteurs atomiques. Dans ce programme, une tres large part est reservee a l'etude de nouveaux elements combustibles. Le present rapport decrit les differentes solutions de cartouches dont l'essai est envisage ou en cours. Apres etude en laboratoire, chacune de ces solutions est testee dans une cellule experimentale en pile. Les meilleures seront retenues pour constituer le chargement normal de la pile (le chargement actuel etant essentiellement une solution provisoire qui a permis la divergence de la pile et les premiers essais de montee en puissance). (auteur)

Calculation programme for transient thermo-pneumatic flows; Programme de calcul pour les ecoulements transitoires thermopneumatiques

Energy Technology Data Exchange (ETDEWEB)

Coste, D. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

With a view to determining the changes occurring in gas reactors after cooling accidents, a calculation programme is established for unidimensional gas flows with pressure drops, heat exchanges and in certain cases blowing, in a reticulated lattice. Any schematization can be taken into account by the use of a set of indices. This programme, of which the FORTRAN list is given, is applied to particular cases of sudden pressure drops in the circuits. The results obtained are in good agreement with those obtained both from the graphical method using the characteristics and from experimental recorded data. (author) [French] En vue de determiner les evolutions des reacteurs a gaz apres accident de refroidissement, on etablit un programme de calcul pour les ecoulements gazeux unidimensionnels avec pertes de charge, echanges thermiques et eventuellement soufflage, en reseau maille. Toute schematisation peut etre prise en compte grace a un jeu d'indices. Ce programme, dont la liste FORTRAN est presentee, est applique a des cas particuliers de degonflage brutal de circuits. Ses resultats sont en bon accord, d'une part avec ceux de la methode graphique des caracteristiques, d'autre part avec des enregistrements experimentaux. (auteur)

Magnesium and aluminium-base products. For use as structural materials; Magnesium, aluminium et alliages. Emploi comme materiaux de structure

Energy Technology Data Exchange (ETDEWEB)

Bernard, J.; Boudouresques, B.; Alfille, L.; Klersy, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

This paper deals with the ability of some Mg and Al-base products to be used as structural materials in thermal reactors. The results presented here are relating to investigations carried out for completing the design of french reactors. (author)Fren. [French] Les auteurs traitent de l'aptitude de quelques materiaux legers et ultra-legers a l'utilisation comme elements de structure des reacteurs thermiques. Les resultats presentes sont relatifs aux etudes effectuees pour l'etablissement des projets de piles fran ises. (auteur)

Some Aspects of Diffusion Theory

CERN Document Server

Pignedoli, A

2011-01-01

This title includes: V.C.A. Ferraro: Diffusion of ions in a plasma with applications to the ionosphere; P.C. Kendall: On the diffusion in the atmosphere and ionosphere; F. Henin: Kinetic equations and Brownian motion; T. Kahan: Theorie des reacteurs nucleaires: methodes de resolution perturbationnelles, interactives et variationnelles; C. Cattaneo: Sulla conduzione del calore; C. Agostinelli: Formule di Green per la diffusione del campo magnetico in un fluido elettricamente conduttore; A. Pignedoli: Transformational methods applied to some one-dimensional problems concerning the equations of t

Cotard’s Syndrome in a Patient with Schizophrenia: Case Report and Review of the Literature

OpenAIRE

Huarcaya-Victoria, Jeff; Ledesma-Gastañadui, Mario; Huete-Cordova, Maria

2016-01-01

Jules Cotard described, in 1880, the case of a patient characterized by delusions of negation, immortality, and guilt as well as melancholic anxiety among other clinical features. Later this constellation of symptoms was given the eponym Cotard's syndrome, going through a series of theoretical vicissitudes, considering itself currently as just the presence of nihilistic delusions. The presentation of the complete clinical features described by Cotard is a rare occurrence, especially in the co...

Experimental Object-Oriented Modelling

DEFF Research Database (Denmark)

Hansen, Klaus Marius

through, e.g., technical prototyping and active user involvement. We introduce and examine “experimental object-oriented modelling” as the intersection of these practices. The contributions of this thesis are expected to be within three perspectives on models and modelling in experimental system...... development: Grounding We develop an empirically based conceptualization of modelling and use of models in system development projects characterized by a high degree of uncertainty in requirements and point to implications for tools and techniques for modelling in such a setting. Techniques We introduce......This thesis examines object-oriented modelling in experimental system development. Object-oriented modelling aims at representing concepts and phenomena of a problem domain in terms of classes and objects. Experimental system development seeks active experimentation in a system development project...

Non-Destructive Testing in Reactor Pressure-Vessel Fabrication; Essais non Destructifs dans la Fabrication des Caissons Etanches de Reacteurs; Nedestruktivnoe ispytanie pri izgotovlenii reaktornykh bakov vysokogo davleniya; Ensayo no Destructivo Durante la Fabricacion de Recipientes de Presion para Reactores

Energy Technology Data Exchange (ETDEWEB)

McGonnagle, W. J. [Fluids Dynamics Research, Iit Research Institute, Chicago, IL (United States)

1965-09-15

of the pressure vessel are discussed. (author) [French] Le memoire a pour objet d'exposer les grandes lignes d'un programme de controle de la qualite dans la fabrication d'un caisson etanche de reacteur qui satisfera a toutes les specifications du point de vue nucleaire et de la securite, et de mettre en evidence le role et l'importance des essais non destructifs dans ce programme. Les defauts constates dans les materiaux, les elements et leur assemblage montrent que les methodes actuelles de fabrication ne permettent pas en elles-memes d'assurer le maintien de la qualite des elements critiques. 11 se produit des pailles et des heterogeneites memes lorsque l'on utilise les meilleurs procedes de fabrication et que l'on applique des methodes et techniques dument controlees. C'est pourquoi, afin d'obtenir la qualite requise pour un caisson de reacteur, il faut executer un programme approprie et coherent d'essais non destructifs. Les principales methodes d'essais non destructifs appliquees par les fabricants de caissons de reacteurs sont les suivantes: inspection visuelle, radiographie par les rayons X ou gamma, ultrasons, particules magnetiques et penetration de liquides. Le programme d'essais non destructifs comporte le controle des materiau', du forgeage, du moulage, du gainage et des soudures. L'auteur etudie les problemes particuliers que posent les essais non destructifs des caissons etanches. Il decrit et discute les techniques speciales propres aux essais non destructifs des caissons et de leurs elements. Le memoire donne un apercu des reglements et specifications applicables, notamment du reglement de fabrication des bouilleurs et caissons etanches publie par la Societe americaine des ingenieurs mecaniciens. L'auteur etudie la mesure dans laquelle les essais non destructifs peuvent contribuer a repondre aux specifications imposees par les institutions de normalisation, ainsi que la mesure dans laquelle les normes admises pour ces essais sont appropriees et

High pressure experimental water loop; Cellule experimentale a eau sous pression

Energy Technology Data Exchange (ETDEWEB)

Grenon, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Terny, M [Societe Grenobloise d' Etudes et d' Applications Hydrauliques, 38 (France)

1958-07-01

A high pressure experimental water loop has been made for studying the detection and evolution of cladding failure in a pressurized reactor. The loop has been designed for a maximum temperature of 360 deg. C, a maximum of 160 kg/cm{sup 2} and flow rates up to 5 m{sup 3}/h. The entire loop consists of several parts: a main circuit with a canned rotor circulation pump, steam pressurizer, heating tubes, two hydro-cyclones (one de-gasser and one decanter) and one tubular heat exchanger; a continuous purification loop, connected in parallel, comprising pressure reducing valves and resin pots which also allow studies of the stability of resins under pressure, temperature and radiation; following the gas separator is a gas loop for studying the recombination of the radiolytic gases in the steam phase. The preceding circuits, as well as others, return to a low pressure storage circuit. The cold water of the low pressure storage flask is continuously reintroduced into the high pressure main circuit by means of a return pump at a maximum head of 160 kg /cm{sup 2}, and adjusted to the pressurizer level. This loop is also a testing bench for the tight high pressure apparatus. The circulating pump and the connecting flanges (Oak Ridge type) are water-tight. The feed pump and the pressure reducing valves are not; the un-tight ones have a system of leak recovery. To permanently check the tightness the circuit has been fitted with a leak detection system (similar to the HRT one). (author)Fren. [French] Une cellule experimentale a eau sous pression a ete realisee pour l'etude de l'evolution et de la detection de ruptures de gaines dans le cas d'un reacteur pressurise. Les performances de ce circuit sont: 350 deg. C maximum pour la temperature et 160 kg/cm{sup 2} maximum pour la pression, le debit pouvant atteindre 5 m{sup 3}/h. Le circuit complet est constitue de plusieurs parties: un circuit principal avec pompe de circulation a rotor immerge, preiseur a vapeur, tubes chaudieres

Experimental atomic physics

International Nuclear Information System (INIS)

Anon.

1985-01-01

The experimental atomic physics program within the physics division is carried out by two groups, whose reports are given in this section. Work of the accelerator atomic physics group is centered around the 6.5-MV EN tandem accelerator; consequently, most of its research is concerned with atomic processes occurring to, or initiated by, few MeV/amu heavy ions. Other activities of this group include higher energy experiments at the Holifield Heavy Ion Research Facility (HHIRF), studies of electron and positron channeling radiation, and collaborative experiments at other institutions. The second experimental group concerns itself with lower energy atomic collision physics in support of the Fusion Energy Program. During the past year, the new Electron Cyclotron Resonance Source has been completed and some of the first data from this facility is presented. In addition to these two activities in experimental atomic physics, other chapters of this report describe progress in theoretical atomic physics, experimental plasma diagnostic development, and atomic data center compilation activities

Review of Development Status of Nuclear Superheat; Expose sur l'etat actuel des travaux concernant la surchauffe nucleaire; Obzor razrabotki voprosa o yadernykh peregrevatelyakh; Estudio de los progresos realizados en niateria de sobrecalentamiento nuclear

Energy Technology Data Exchange (ETDEWEB)

Imhoff, D. H.; Pennington, R. T. [General Electric Company, San Jose, CA (United States)

1963-10-15

fuel irradiation performance, in-pile and out-of-pile uniform and localized corrosion evaluations, results from thermal superheat critical experiments, results from experimental heat-transfer testing and a brief appraisal of the economic incentives of the separate superheat reactor, integral superheat reactor, and mixed-spectrum superheat reactor design studies. (b) A brief description is given of the USAEC-Sponsored ESADA-VESR nuclear superheat fuel development programme. The development tasks, the initial core superheat fuel-element design, the range of experimental variables, and the expected results for the three-year fuel development programme are discussed. (author [French] Depuis 1959, la Societe General Electric s'occupe activement de mettre au point la surchauffe nucleaire dans les reacteurs ralentis a l'eau ordinaire. A cette epoque, le ''Superheat Advance Demonstration Experiment'' (SADE), finance par la societe, a permis d'obtenir, pour la premiere fois aux Etats-Unis, de la vapeur surchauffee par un dispositif nucleaire. Les auteurs du memoire font le point de la situation actuelle concernant la surchauffe nucleaire. Ils decrivent, dans une premiere partie, les trois principales installations de surchauffe nucleaire utilisees par la General Electric et, dans la seconde, les deux principaux programmes de recherches sur la surchauffe ainsi que les resultats les plus importants obtenus jusqu'ici dans ce domaine. 1. Principales installations pour les experiences de surchauffe: a) Breve description du SADE utilise dans le reacteur a eau bouillante de Vallecitos (VBWR), avec tableaux des conditions dans lesquelles se deroulent les experiences, et des elements combustibles irradies pendant la periode comprise entre mai 1959 et juin 1962; puis examen critique des resultats les plus importants ainsi obtenus. b) Breve description de l' ''Expanded Superheat Advance Demonstration Experiment'' (E-SADE) installe dans le reacteur de Vallecitos, avec tableaux des

New reactor concepts; Nieuwe rectorconcepten - nouveaux reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Meskens, G.; Govaerts, P.; Baugnet, J.-M.; Delbrassine, A

1998-11-01

The document gives a summary of new nuclear reactor concepts from a technological point of view. Belgium supports the development of the European Pressurized-Water Reactor, which is an evolutionary concept based on the European experience in Pressurized-Water Reactors. A reorientation of the Belgian choice for this evolutionary concept may be required in case that a decision is taken to burn plutonium, when the need for flexible nuclear power plants arises or when new reactor concepts can demonstrate proved benefits in terms of safety and cost.

Production of artificial radioelements; Production des radioelements artificiels

Energy Technology Data Exchange (ETDEWEB)

Fisher, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The techniques used in the production of artificial radioelements are described, with special emphasis on the following points: - nuclear reactions and use of reactors; - chemical separation methods and methods for enriching the activity of preparations; - protection of personnel and handling methods. (author) [French] On decrit l'ensemble des techniques utilisees dans la fabrication des radioelements artificiels en insistant notamment sur les points suivants: - reactions nucleaires et utilisation des reacteurs; - methodes de separations chimiques et methodes d'enrichissement d'activite des preparations; - protection du personnel et methodes de manipulation. (auteur)

A modular simulation code applied to pressurized water nuclear power plants

International Nuclear Information System (INIS)

Agnoux, D.

1992-01-01

Analysis of the overall operation of an installation requires taking into account all couplings between the various components and integrating all the automatic actions initiated by control and instrumentation. The tool used for this analysis must be a high performing simulation model, flexible enough to be able to be quickly adapted to varying configurations. In order to study the behaviour of PWR nuclear power stations during normal or incidental operating transients, EDF-SEPTEN has developed the ERABLE code (Etudes Reacteurs a Base LEGO), based on the LEGO software package. (author)

Aerodynamic and thermal studies of cans of gas cooled fuel elements; Etudes aerodynamiques et thermiques de gaines d'elements combustibles refroidis par gaz

Energy Technology Data Exchange (ETDEWEB)

Gelin, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Milliat, J P [Electricite de France (EDF), 75 - Paris (France)

1964-07-01

Research on clusters was undertaken at the CEA in 1959, while studies on herring-bone cans were developed at the EDF Laboratory at Chatou and the CEA laboratory at Saclay at the end of 1959. In 1962, a general study on corrugations was begun at the Saclay Laboratory with a view to improving the clusters, and continued later in both laboratories relative to the internal cooling of annular fuel elements. As these studies progressed, trial facilities were extended while experimental methods have improved constantly. At the present time, both laboratories, working in complete collaboration, have powerful means at their disposal. Work on the clusters has been concerned chiefly with pressure losses due to the assembly parts, and with the temperature variations around the elements of the cluster. In this way, we have been able to determine satisfactorily the hot points of the can, the deformations of the rods and the conditions of stability of these deformations. In the case of the herring-bone cans, studies have been directed to the evolution of performances as a function of the geometric parameters on the one hand, and to the special aerodynamic and thermal features caused by the fins and by interruptions of cartridge on the other hand. These studies have led to a very thorough knowledge of the cartridges chosen for the reactors EDF 2 and EDF 3, and now open up very hopeful prospects for future reactors, particularly those fitted with annular elements; among the alternatives suitable for the inner surface of the annular element can, corrugations and longitudinal fins have been fairly extensively tested over a wide range of Reynolds number. (authors) [French] Les etudes de grappes ont ete entreprises au C.E.A. en 1959, tandis que les etudes de gaines a chevrons se sont developpees au Laboratoire de Chatou de l'EDF et au Laboratoire de Saclay du C.E.A. a la fin de l'annee 1959. En 1962, une etude generale sur les corrugations a ete commencee au Laboratoire de Saclay pour

Entfremdung als Strukturmoment von Unterricht? Eine Fallstudie zur Arbeit eines Schülers an der Tafel aus der Sicht der pädagogischen Unterrichtsforschung

OpenAIRE

Twardella, Johannes

2010-01-01

"In den 70er Jahren des 20. Jahrhunderts beobachtete Jules Henry im Rahmen seiner ethnographischen Schulforschungen die Arbeit eines Schülers an der Tafel und interpretierte sie aus einer sozialpsychologischen Perspektive heraus als einen Prozess, in dem ein Schüler lernt, was "Entfremdung" ist. Ausgehend von dieser Deutung wird in dem vorliegenden Aufsatz der Frage nachgegangen, ob der Begriff der Entfremdung auch heute noch für die Erforschung von Unterricht fruchtbar gemacht werden kann. D...

Advanced epithermal thorium reactor (AETR) physics; Physique d'un reacteur au thorium, a neutrons epithermiques, de type perfectionne (AETR); Fizika usovershenstvovannog o nadteplovogo torievogo reaktora; Fisica del reactor epitermico de tipo avanzado, alimentado con torio (AETR)

Energy Technology Data Exchange (ETDEWEB)

Campise, A. V. [Atomics International, Canoga Park, CA (United States)

1962-03-15

The AETR concept is reviewed in reference to existing theory, nuclear parameters, and potential neutron economy. The effect of thorium resonance capture in graphite-moderate d systems with median absorption energies in the range from 0.10 to 100 keV have been studied. Narrow-resonance (NR) and wide-resonance (NRIA) formulations are used to obtain the temperature-dependent effective resonance integral of thorium rods which are expressed as equivalent multi-group cross-sections. The need for nuclear data in the intermediate energy range led to design and con- struction of a critical assembly. Nuclear design of this assembly emphasizes the importance of cross-section data and the theoretical interpretation of these experimental results, both pertinent to the design of an AETR. The accuracy of the analytical techniques has been demonstrated in the analysis of ZPR-III experimental results. Three heat-transfer configurations are compared using doubling time as an optimizing parameter. The effect of Pa{sup 233} and uranium-isotope s production on relative neutron economy, potential breeding ratios, and burn-up characteristics are evaluated in regard to the uncertainties in the nuclear cross-sections. (author) [French] L'auteur analyse la conception de l'AETR du point de vue de la theorie actuelle, des parametres nucleaires et du bilan potentiel de neutrons. On a etudie l'effet de la capture par resonance dans le thorium, dans des systemes ralentis au graphite pour des energies d'absorption moyennes comprises entre 0,10 et 100 keV. On utilise des formules de resonance etroite et de resonance large pour obtenir l'integrale de resonance effective en fonction de la temperature, relative aux barres de thorium dont on tient compte dans ces calculs en les exprimant sous forme des sections efficaces multigroupes equivalentes. Pour obtenir les donnees nucleaires indispensables pour la gamme d'energies intermediaires, on a ete amene a etudier et a construire un ensemble critique. L

Experimental halls workshop summary

International Nuclear Information System (INIS)

Thorndike, A.

1976-01-01

At the experimental halls workshop, discussions were held on: (1) open areas as compared with enclosed halls; (2) the needs of ep, anti pp, and other options; (3) the hall for the lepton detector; and (4) the hall for the hadron spectrometer. The value of different possibilities for the future experimental program was explored. A number of suggestions emerged which will be used as the design of the experimental halls progresses

Experimental Volcanology: 2010 and 2020

Science.gov (United States)

Dingwell, D. B.

2010-12-01

The advent of an experimental approach to volcanology has its roots in decades-old laboratory based approaches to characterising the properties of magmas and analog materials, together with the attempts at simulating volcanic processes in the lab. A little over ten years ago many new thrusts of experimental advance led to a new dawn for experimental science applied to volcanic eruptions. Along with that, new expectations, new goals and new strategies emerged about ten years ago. Ten years later, in 2010, many fruits have been born of this labour, and new frontiers are being unfolded as we meet here. Here are some of the youngest captivating themes being explored in experimental programs today: 1) interfacing volcanic monitoring systems to experimentally generated eruptions. 2) elucidating the physicochemical behavior of experimentally generated volcanic ash as an agent in the earth system. 3) blending experimental rock deformation and magmatology studies to understand the strength and stability of volcanic materials and volcanic structures 4) exploiting the kinematics of experimentally-generated versus natural volcanic products to understand flow style and strain history. The past ten years of experimental developments in volcanology have prepared us for great advances in the future, most of which were not perceived as likely avenues of investigation as little as ten years ago! The situation is likely to repeat itself in 2020.

Preliminary studies of vanadium-base alloys intended for use in fabrication of cans for fast reactors; Etudes preliminaires sur les alliages a base de vanadium envisages pour la fabrication de gaines de reacteurs rapides

Energy Technology Data Exchange (ETDEWEB)

Conte, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1967-03-15

Preliminary research has been carried out on a series of vanadium-based alloys: V, 0.5 per cent Si; V, 5 per cent Ca; V, 5 per cent Mo; V, 5 per cent Nb; V, 2 per cent Zr; V, 20 per cent Ti; V, 10 per cent Al; V, 10 per cent Sn and v, 10 per cent Ti liable to be used as canning material in fast reactors. The transformation by forging at about 1000 deg. C and rolling between 200 deg. C and room temperature is satisfactory for all types of alloys except V with 10 per cent Sn and V with 10 per cent Al. The mechanical properties deduced from tensile strength tests carried out on alloy samples annealed 1 hour at 1050 deg. C in a vacuum show that, generally speaking, the addition elements lead to an improvement in these properties as compared to those of pure vanadium. After undergoing corrosion tests in a liquid sodium loop purified by a cold trap, the alloys become brittle at room temperature. Only the vanadium containing 20 per cent Ti keeps its plastic properties. These alloys are covered by a layer of vanadium carbide VC. After undergoing treatment in a liquid sodium loop purified by a hot trap, all the alloys keep their good mechanical characteristics. The surface layer with which they are covered is composed of two vanadium carbides VC and {sub {gamma}}VC, and a vanadium sub-oxide VO{sub 0.9}. (author) [French] Des etudes preliminaires ont ete faites sur une serie d'alliages a base de vanadium: V-0,5 pour cent Si, V-5 pour cent Ca, V-5 pour cent Mo, V-5 pour cent Nb, V-2 pour cent Zr, V-20 pour cent Ti, V-10 pour cent Al, V-10 pour cent Sn et V-10 pour cent Ti susceptibles d'etre utilises comme materiau de gainage pour les reacteurs rapides. La transformation par forgeage a 1000 deg. C environ et laminage entre 200 deg. C et la temperature ambiante est satisfaisante pour toutes les nuances d'alliage sauf le V-10 pour cent Sn et le V-10 pour cent Al. Les proprietes mecaniques deduites des essais de traction realises sur des eprouvettes d'alliages recuits 1 heure a

A Nitrogen-16 Power Channel in the Melusine Cooling Circuit; Chaine de puissance azote 16 sur le circuit de refrigeration de melusine

Energy Technology Data Exchange (ETDEWEB)

Tiberghien, R [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires, 38 - Grenoble (France)

1962-07-01

A power channel, which is to be used on Melusine, the 2 MW pool-type reactor built at Grenoble Nuclear Center, is described. It will be used for measuring of {sup 16}N activity of water after passage through the reactor core. The experimental system as well as the measuring instruments are described. Solutions to problems likely to arise are given. The experimental results show that this power measurement is free from neutron flux local deformations, from control rods position, and from experiments. The power indicated is to {+-}2% the same as the thermodynamic power. Since May 1962, this power channel is used as a reference for the operation of the reactor. It is also provided for on the Siloe 10 MW reactor. (author) [French] L'objet de ce rapport est la description d'une nouvelle chaine de puissance pour la pile piscine 'Melusine' de 2 MW du Centre d'etudes Nucleaires de Grenoble. Il s'agit de la mesure de l'activite en azote 16 de l'eau apres son passage dans le coeur du reacteur. Le dispositif experimental ainsi que les appareils de mesure y sont decrits. Les reponses aux differents problemes poses sont donnees. Les resultats experimentaux montrent que cette mesure de puissance est independante des deformations locales de flux de neutrons, de la position des barres de controle et des manipulations. La puissance indiquee par cette chaine est a 2 % pres identique a la puissance thermodynamique. Depuis mai 1962, elle est utilisee comme reference pour le pilotage de la pile. Elle est aussi prevue sur la pile 'Siloe' de 10 MW. (auteur)

Ansiedade experimental humana Human experimental anxiety

Directory of Open Access Journals (Sweden)

Frederico Guilherme Graeff

2007-01-01

Full Text Available CONTEXTO: A ansiedade experimental no ser humano constitui-se em ponte entre os modelos animais e os ensaios clínicos. OBJETIVO: Este artigo focaliza métodos químicos e psicológicos utilizados para provocar ansiedade experimental em seres humanos. MÉTODOS: Realizou-se revisão seletiva da literatura. RESULTADOS: Os desafios farmacológicos têm sido usados principalmente para induzir ataques de pânico em pacientes com transtorno de pânico, os quais são mais sensíveis a eles que indivíduos normais ou pacientes portadores de outros transtornos psiquiátricos. Uma das mais importantes contribuições deste método é a de ter mostrado que os agentes panicogênicos mais seletivos, como o lactato ou a inalação de CO2, não ativam o eixo hormonal do estresse. Entre os métodos psicológicos, destacam-se o condicionamento de respostas elétricas da condutância da pele, cujo perfil farmacológico se aproxima daquele do transtorno de ansiedade generalizada, e o teste da simulação do falar em público, cuja farmacologia é semelhante à do transtorno de pânico. CONCLUSÕES: Tais resultados salientam a diferença entre a neurobiologia da ansiedade e a do pânico.BACKGROUND: Human experimental anxiety methods bridge the gap between animal models and clinical assays. OBJECTIVE: This article is focused on chemical and psychological procedures used to generate experimental anxiety in human beings. METHODS: A selective review of the literature has been carried out. RESULTS: Pharmacological challenges have been mainly used to induce panic attacks in panic disorder patients, who are more susceptible than normal individuals or patients with other psychiatric disorders. One of the most important contributions of this method is to have shown that the most selective panicogenic agents, such as lactate or CO2 inhalation, do not activate the hormonal stress axis. Among the psychological methods stand the conditioning of the electrical skin conductance

The experimental watersheds in Slovenia

International Nuclear Information System (INIS)

Sraj, M; Rusjan, S; Petan, S; Vidmar, A; Mikos, M; Globevnik, L; Brilly, M

2008-01-01

Experimental watersheds are critical to the advancement of hydrological science. By setting up three experimental watersheds, Slovenia also obtained its grounds for further development of the science and discipline. In the Dragonja experimental watershed the studies are focused on the afforestation of the watershed in a mediterranean climate, on the Reka river the water balance in a partly karstic area is examined, and on the case of the Glinscica stream the implications of the urban environment are studied. We have obtained valuable experience and tested new measuring equipment on all three experimental watersheds. Measurements and analysis on the experimental watersheds improved the current understanding of hydrological processes. They resulted in several PhD Theses, Master Theses and scientific articles. At the same time the experimental watersheds provide support to the teaching and studying process.

Neutronics calculation of an heterogeneous compact and thermal core by means of deterministic and stochastic transport theory. Application to the experimental reactor of the University of Strasbourg; Modelisation neutronique d`un coeur thermique compact et heterogene en theorie du transport deterministe et probabiliste. Application au reacteur experimental de l`Universite de Strasbourg

Energy Technology Data Exchange (ETDEWEB)

Jammes, Ch

1997-11-28

The aim of this work is to create, validate theoretically and experimentally a calculation route for a thermal irradiation reactor. This is the research reactor of the University of Strasbourg, which presents all of characteristics of this reactor-type: compact and heterogeneous core, slab-type fuel with a high 235-uranium enrichment. This calculation route is based on the first use of the following two modern transport methods: the TDT method and the Monte Carlo method. The former, programmed within the APOLLO2 code, is a two dimensional collision probabilities method. The later, used by the TRIPOLI4 code, is a stochastic method. Both can be applied to complex geometries. After a few theoretical reminders about transport codes, a set of integral experiments is described which have been realized within the research reactor of the University of Strasbourg. One of them has been performed for this study. At the beginning of the theoretical part, significant errors are apparent due to the use of calculation route based on homogenization, condensation and the diffusion approximation. An extensive comparison between the discrete ordinates method and the TDT method carries out that the use of the TDT method is relevant for the studied reactor. The treatment of axial leakage with this method is the only disadvantage. Therefore, the use of the code TRIPOLI4 is recommended for a more accurate study of leakage within a reflector. By means of the experimental data, the ability of our calculation route is confirmed for essential neutronics questions such as the critical mass determination, the power distribution and the fuel management. (author)

Experimental heavy quarkonium physics

International Nuclear Information System (INIS)

Bugge, L.

1986-08-01

Following some brief arguments on why heavy quarkonium spectroscopy is an important field of particle physics, some points on experimental techniques are discussed. Parts of the basic quarkonium phenomenology, including discussions of various items related to potensial models, are then presented. An up-to-date presentation is given of the state-of-the-art of experimental charmonium and bottomonium spectroscopy below open flavour threshold, including the confrontation of experimental results to representative theoretical predictions

Experimentation with PEC channel prototype

International Nuclear Information System (INIS)

Caponetti, R.; Iacovelli, M.

1984-01-01

Experimentation on prototypes of PEC components is presently being carried out at Casaccia CRE. This report shows the results of the first cycle of experimentation of the central channel, concerning the aspects of sodium removal after experimentation

Experimental philosophy.

Science.gov (United States)

Knobe, Joshua; Buckwalter, Wesley; Nichols, Shaun; Robbins, Philip; Sarkissian, Hagop; Sommers, Tamler

2012-01-01

Experimental philosophy is a new interdisciplinary field that uses methods normally associated with psychology to investigate questions normally associated with philosophy. The present review focuses on research in experimental philosophy on four central questions. First, why is it that people's moral judgments appear to influence their intuitions about seemingly nonmoral questions? Second, do people think that moral questions have objective answers, or do they see morality as fundamentally relative? Third, do people believe in free will, and do they see free will as compatible with determinism? Fourth, how do people determine whether an entity is conscious?

Administrative Aspects of Human Experimentation.

Science.gov (United States)

Irvine, George W.

1992-01-01

The following administrative aspects of scientific experimentation with human subjects are discussed: the definition of human experimentation; the distinction between experimentation and treatment; investigator responsibility; documentation; the elements and principles of informed consent; and the administrator's role in establishing and…

Reconstruction of dynamic structures of experimental setups based on measurable experimental data only

Science.gov (United States)

Chen, Tian-Yu; Chen, Yang; Yang, Hu-Jiang; Xiao, Jing-Hua; Hu, Gang

2018-03-01

Nowadays, massive amounts of data have been accumulated in various and wide fields, it has become today one of the central issues in interdisciplinary fields to analyze existing data and extract as much useful information as possible from data. It is often that the output data of systems are measurable while dynamic structures producing these data are hidden, and thus studies to reveal system structures by analyzing available data, i.e., reconstructions of systems become one of the most important tasks of information extractions. In the past, most of the works in this respect were based on theoretical analyses and numerical verifications. Direct analyses of experimental data are very rare. In physical science, most of the analyses of experimental setups were based on the first principles of physics laws, i.e., so-called top-down analyses. In this paper, we conducted an experiment of “Boer resonant instrument for forced vibration” (BRIFV) and inferred the dynamic structure of the experimental set purely from the analysis of the measurable experimental data, i.e., by applying the bottom-up strategy. Dynamics of the experimental set is strongly nonlinear and chaotic, and itʼs subjects to inevitable noises. We proposed to use high-order correlation computations to treat nonlinear dynamics; use two-time correlations to treat noise effects. By applying these approaches, we have successfully reconstructed the structure of the experimental setup, and the dynamic system reconstructed with the measured data reproduces good experimental results in a wide range of parameters.

Experimental program at Fermilab

International Nuclear Information System (INIS)

Jovanovic, D.

1974-01-01

The experimental program at Fermilab is briefly surveyed: accelerators and experimental areas, current experiments such as elastic scattering of π +- , K +- , p +- , on proton and deuteron total cross sections, neutrino physics, high transverse momentum [fr

Experimental technique of neutron reflection

International Nuclear Information System (INIS)

Chen Bo; Huang Chaoqiang; Li Xinxi

2006-12-01

It is presented that the classifications, structures and components of neutron reflectometer (NR), as well s functions and parameters of each components, detailed characters of NR facility 'PRN-2M'. Based on the practical experiments, the basic experimental techniques, the measurement and the related experimental settings are described, including the choice of experimental conditions, adjustments of polarized neutron beam line, basic experimental technique and approach of measurement. The above can be an instruction for NR experiments and a reference for NR construction. (authors)

Animal experimentation.

Science.gov (United States)

Kolar, Roman

2006-01-01

Millions of animals are used every year in often times extremely painful and distressing scientific procedures. Legislation of animal experimentation in modern societies is based on the supposition that this is ethically acceptable when certain more or less defined formal (e.g. logistical, technical) demands and ethical principles are met. The main parameters in this context correspond to the "3Rs" concept as defined by Russel and Burch in 1959, i.e. that all efforts to replace, reduce and refine experiments must be undertaken. The licensing of animal experiments normally requires an ethical evaluation process, often times undertaken by ethics committees. The serious problems in putting this idea into practice include inter alia unclear conditions and standards for ethical decisions, insufficient management of experiments undertaken for specific (e.g. regulatory) purposes, and conflicts of interest of ethics committees' members. There is an ongoing societal debate about ethical issues of animal use in science. Existing EU legislation on animal experimentation for cosmetics testing is an example of both the public will for setting clear limits to animal experiments and the need to further critically examine other fields and aspects of animal experimentation.

Experimental approaches and applications

CERN Document Server

Crasemann, Bernd

1975-01-01

Atomic Inner-Shell Processes, Volume II: Experimental Approaches and Applications focuses on the physics of atomic inner shells, with emphasis on experimental aspects including the use of radioactive atoms for studies of atomic transition probabilities. Surveys of modern techniques of electron and photon spectrometry are also presented, and selected practical applications of inner-shell processes are outlined. Comprised of six chapters, this volume begins with an overview of the general principles underlying the experimental techniques that make use of radioactive isotopes for inner-sh

Ice condenser experimental plan

International Nuclear Information System (INIS)

Kannberg, L.D.; Piepel, G.F.; Owczarski, P.C.; Liebetrau, A.M.

1986-01-01

An experimental plan is being developed to validate the computer code ICEDF. The code was developed to estimate the extent of aerosol retention in the ice compartments of pressurized water reactor ice condenser containment systems during severe accidents. The development of the experimental plan began with review of available information on the conditions under which the code will be applied. Computer-generated estimates of thermohydraulic and aerosol conditions entering the ice condenser were evaluated and along with other information, used to generate design criteria. The design criteria have been used for preliminary test assembly design and for generation of statistical test designs. Consideration of the phenomena to be evaluated in the testing program, as well as equipment and measurement limitations, have led to changes in the design criteria and to subsequent changes in the test assembly design and statistical test design. The overall strategy in developing the experimental plan includes iterative generation and evaluation of candidate test designs using computer codes for statistical test design and ICEDF for estimation of experimental results. Estimates of experimental variability made prior to actual testing will be verified by replicate testing at preselected design points

4. Food and the Futurist ‘Revolution’. A Note

OpenAIRE

Roberto Ibba; Domenico Sanna

2016-01-01

The Italian futurist movement dealt with all branches traditionally tied to high culture, but, at the same time, it approached ‘humbler’ fields as fashion, sports and cookery. In his french period, Marinetti met the chef Jules Maincave and they opened together a ‘Futurist’ restaurant. In 1913 Maincave published the manifesto La cuisine futuriste. In 1930, Marinetti issued in Turin the Manifesto of Futurist Cooking. The publication was preceded by a celebration dinner which took place at the P...

50 Years of Army Computing From ENIAC to MSRC

Science.gov (United States)

2000-09-01

CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING...about 50 years ago. None of these capabilities that we take for granted now even existed. They hadn’t even been dreamt of by such visionaries as Jules...not work at Disneyland . We are not trying to make motion pictures for entertainment. We are trying to solve problems for scientifi c analysis, for

Graafikatriennaali grand prix Korea kunstnikule

Index Scriptorium Estoniae

1998-01-01

Tallinna XI graafikatriennaali rahvusvaheline žürii andis grand prix korea kunstnikule Chung¡Sang-Gonile, kolm võrdset preemiat - soome kunstnikele Anita Jensenile ja Tapani Mikkonenile ning jaapani kunstnikule Estuko Obatale. Eesti Kunstimuuseumi preemia - Wendy Swallow. Tallinna linna preemia ja Ivar Luki sponsoripreemia - Walter Jule. Sponsoripreemiad : Paletti Eesti AS preemia - Inga Heamägi; Rannila Profiili preemia - Mojca Zlokarnik; UNDP preemia - Andrea Juan. Rotermanni soolalao arhitektuuri- ja kunstikeskuse diplom - Lis Ingram, Heli Päivikki Kurunsaari, Randi Strand, Wendy Swallow

The research reactors their contribution to the reactors physics

International Nuclear Information System (INIS)

Barral, J.C.; Zaetta, A.; Johner, J.; Mathoniere, G.

2000-01-01

The 19 october 2000, the french society of nuclear energy organized a day on the research reactors. This associated report of the technical session, reactors physics, is presented in two parts. The first part deals with the annual meeting and groups general papers on the pressurized water reactors, the fast neutrons reactors and the fusion reactors industry. The second part presents more technical papers about the research programs, critical models, irradiation reactors (OSIRIS and Jules Horowitz) and computing tools. (A.L.B.)

Librarians are vicious monsters, but canalso recommend a good read : En analys av alternativa bibliotekarieframställningar iscience fiction-litteratur

OpenAIRE

Österman Solborg, Amanda

2014-01-01

Uppsatsens syfte är att studera framställningar av manliga bibliotekarier i science fiction-litteratur, analysera vad dessa framställningar förmedlar för föreställningar om bibliotek och biblioteksverksamhet, samt att analysera de manliga bibliotekariernas koppling till maskuliniteter. Titlarna som analyseras är fyra romaner; Audrey Niffeneggers Tidsresenärens hustru, Dmitrij Gluchovskijs Metro 2033, Jules Vernes Paris i tjugonde seklet, och Jasper Ffordes Uppslukad – En fängslande historia o...

Experimental semiotics: a review.

Science.gov (United States)

Galantucci, Bruno; Garrod, Simon

2011-01-01

In the last few years a new line of research has appeared in the literature. This line of research, which may be referred to as experimental semiotics (ES; Galantucci, 2009; Galantucci and Garrod, 2010), focuses on the experimental investigation of novel forms of human communication. In this review we will (a) situate ES in its conceptual context, (b) illustrate the main varieties of studies thus far conducted by experimental semioticians, (c) illustrate three main themes of investigation which have emerged within this line of research, and (d) consider implications of this work for cognitive neuroscience.

ECG-cryptography and authentication in body area networks.

Science.gov (United States)

Zhang, Zhaoyang; Wang, Honggang; Vasilakos, Athanasios V; Fang, Hua

2012-11-01

Wireless body area networks (BANs) have drawn much attention from research community and industry in recent years. Multimedia healthcare services provided by BANs can be available to anyone, anywhere, and anytime seamlessly. A critical issue in BANs is how to preserve the integrity and privacy of a person's medical data over wireless environments in a resource efficient manner. This paper presents a novel key agreement scheme that allows neighboring nodes in BANs to share a common key generated by electrocardiogram (ECG) signals. The improved Jules Sudan (IJS) algorithm is proposed to set up the key agreement for the message authentication. The proposed ECG-IJS key agreement can secure data communications over BANs in a plug-n-play manner without any key distribution overheads. Both the simulation and experimental results are presented, which demonstrate that the proposed ECG-IJS scheme can achieve better security performance in terms of serval performance metrics such as false acceptance rate (FAR) and false rejection rate (FRR) than other existing approaches. In addition, the power consumption analysis also shows that the proposed ECG-IJS scheme can achieve energy efficiency for BANs.

Theory-laden experimentation

DEFF Research Database (Denmark)

Schindler, Samuel

2013-01-01

light bending in 1919 by Eddington and others) to show that TDRs are used by scientists to resolve data conflicts. I argue that the rationality of the practices which employ TDRs can be saved if the independent support of the theories driving TDRs is construed in a particular way.......The thesis of theory-ladenness of observations, in its various guises, is widely considered as either ill-conceived or harmless to the rationality of science. The latter view rests partly on the work of the proponents of New Experimentalism who have argued, among other things, that experimental...... practices are efficient in guarding against any epistemological threat posed by theory-ladenness. In this paper I show that one can generate a thesis of theory-ladenness for experimental practices from an influential New Experimentalist account. The notion I introduce for this purpose is the concept...

The philosophy of scientific experimentation: a review

Science.gov (United States)

2009-01-01

Practicing and studying automated experimentation may benefit from philosophical reflection on experimental science in general. This paper reviews the relevant literature and discusses central issues in the philosophy of scientific experimentation. The first two sections present brief accounts of the rise of experimental science and of its philosophical study. The next sections discuss three central issues of scientific experimentation: the scientific and philosophical significance of intervention and production, the relationship between experimental science and technology, and the interactions between experimental and theoretical work. The concluding section identifies three issues for further research: the role of computing and, more specifically, automating, in experimental research, the nature of experimentation in the social and human sciences, and the significance of normative, including ethical, problems in experimental science. PMID:20098589

New experimental model for training in videosurgery Novo modelo experimental para treinamento em videocirurgia

Directory of Open Access Journals (Sweden)

Danilo Malta Batista

2012-10-01

Full Text Available PURPOSE: To develop a new experimental model of lower cost for training in videosurgery. METHODS: This project was performed at the Nucleus of Experimental Surgery of the Bahiana School of Medicine and Public Health, based on previous models described in the literature and under the supervision of the full professor of Operative Technique and Experimental Surgery II. It was made a model cube-shaped, made of wood, with holes distributed in various locations, rubber stoppers for the holes and lined externally with carpet, and internally with laminate. RESULTS: The new experimental model is of low cost and reproduces quite faithfully several videosurgical procedures. CONCLUSION: Medical schools interested in the subject may adopt the new model for training in videosurgery without the need of high costs for making and using these models.OBJETIVO: Desenvolver um novo modelo experimental de baixo custo para treinamento em videocirurgia MÉTODOS: Este projeto foi conduzido no Núcleo de Cirurgia Experimental da Escola Bahiana de Medicina e Saúde Pública, baseado em modelos prévios descritos na literatura e sob a supervisão do professor titular de Técnica Operatória e Cirurgia Experimental II. Foi feito um modelo em formato de cubo, de madeira, com furos distribuídos em vários locais, tampas de borracha para os orifícios e forrado externamente com carpete e internamente com laminado. RESULTADOS: O novo modelo experimental desenvolvido é de baixo custo e reproduz de forma bastante fiel diversos procedimentos videocirúrgicos. CONCLUSÃO: Faculdades médicas interessadas no tema poderão adotar o novo modelo para o treinamento em videocirurgia sem que sejam necessários gastos elevados para a confecção e o uso desses modelos.

Nuclear Test-Experimental Science

International Nuclear Information System (INIS)

Struble, G.L.; Donohue, M.L.; Bucciarelli, G.; Hymer, J.D.; Kirvel, R.D.; Middleton, C.; Prono, J.; Reid, S.; Strack, B.

1988-01-01

Fiscal year 1988 has been a significant, rewarding, and exciting period for Lawrence Livermore National Laboratory's nuclear testing program. It was significant in that the Laboratory's new director chose to focus strongly on the program's activities and to commit to a revitalized emphasis on testing and the experimental science that underlies it. It was rewarding in that revolutionary new measurement techniques were fielded on recent important and highly complicated underground nuclear tests with truly incredible results. And it was exciting in that the sophisticated and fundamental problems of weapons science that are now being addressed experimentally are yielding new challenges and understanding in ways that stimulate and reward the brightest and best of scientists. During FY88 the program was reorganized to emphasize our commitment to experimental science. The name of the program was changed to reflect this commitment, becoming the Nuclear Test-Experimental Science (NTES) Program

H.J. Andrews Experimental Forest.

Science.gov (United States)

Art McKee; Pamela. Druliner

1998-01-01

The H.J. Andrews Experimental Forest is a world renowned center for research and education about the ecology and management of forests and streams. Located about 50 miles (80 km) east of Eugene, Oregon, the Andrews Experimental Forest lies in the Blue River Ranger District of the Willamette National Forest. Established in 1948, the Experimental Forest is administered...

Experimental facility of innovative types as the laboratory analog of research reactor experimental device

International Nuclear Information System (INIS)

Androsenko, A.A.; Androsenko, P.A.; Zabud'ko, A.N.; Kremenetskij, A.K.; Nikolaev, A.N.; Trykov, L.A.

1991-01-01

The paper analyses capability of creating laboratory analogs of complex experimental facilities at research reactors utilizing power radionuclide neutron sources fabricated in industrial conditions. Some experimental and calculational investigations of neutron-physical characteristics are presented, which have been attained at the RIZ research reactor laboratory analog. Experimental results are supplemented by calculational investigations, fulfilled by means of the BRAND three-dimensional computational complex and the ROZ-6 one-dimensional program. 4 refs.; 3 figs

Study of transient states in thermo-ionic converters; Etude des regimes transitoires des convertisseurs thermoioniques

Energy Technology Data Exchange (ETDEWEB)

Landrot, J [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

1968-07-01

In order to control a thermo-ionic reactor, it is necessary to know the dynamic influence of four fundamental parameters: the injected thermal power, the electrical charge resistance, the temperature of the cesium and the thermal exchange coefficient of the collector cooling circuit. The principles of the thermo-ionic converter are briefly exposed. The over-riding influence of the first two parameters is shown with the help of experimental static readings. These two parameters are then made to vary in turn. The laws of variation as a function of the time, of the electrical power produced and of the temperature of the various parts of the converter are deduced. (author) [French] Pour envisager le controle et la regulation d'un reacteur thermoionique, il est necessaire de connaitre l'influence dynamique de quatre parametres fondamentaux: puissance thermique injectee, resistance electrique de charge, temperature de cesium et coefficient d'echange thermique du circuit de refroidissement du collecteur. On rappelle brievement les principes du convertisseur thermoionique. A l'aide de releves statiques experimentaux, on montre l'influence preponderante des deux premiers parametres. On fait ensuite varier successivement ces deux parametres. On met en evidence les lois de variation en fonction du temps de la puissance electrique produite et de la temperature des differents points du convertisseur. (auteur)

Experimental halls workshop summary

International Nuclear Information System (INIS)

Thorndike, A.

1976-01-01

On May 26 and 27, 1976, approximately 50 people met for an informal workshop on plans for experimental halls for ISABELLE. Plans as they exist in the May 1976 version of the ISABELLE proposal were presented. Discussions were held on the following four general topics by separate working groups: (1) pros and cons of open areas as compared with enclosed halls; (2) experimental hall needs of ep, anti pp, and other options; (3) hall for the lepton detector; and (4) hall for the hadron spectrometer. The planning for experimental halls at PEP, the hall for the lepton detector, the hadron spectrometer, and open areas are discussed

Generation of charged particles on the Sun on Jule 22, 1972

International Nuclear Information System (INIS)

Grigor'eva, V.P.; Kudryavtsev, M.V.; Kurt, V.G.

1974-01-01

The increase in the intensity of solar cosmic ray electrons and electromagnetic radiation bursts measured by means of Earth artificial satellites 'Prognoz-1' and 'Prognoz-2' on July 22, 1972 are examined. It is shown that the optical flare occured behind the west solar limb and that the shock wave generated by the flare caused an additional acceleration of charged particles in the region distant from the main flare location

The AFR. An approved network of research reactors

Energy Technology Data Exchange (ETDEWEB)

Hampel, Gabriele [Mainz Univ. (Germany). Arbeitsgemeinschaft fuer Betriebs- und Sicherheitsfragen an Forschungsreaktoren (AFR)

2012-10-15

AFR (Arbeitsgemeinschaft fuer Betriebs- und Sicherheitsfragen an Forschungsreaktoren) is the German acronym for 'Association for Research Reactor Operation and Safety Issues' which was founded in 1959. Reactor managers of European research reactors mainly from the German linguistic area meet regularly for their mutual benefit to exchange experience and knowledge in all areas of operating, managing and utilization of research reactors. In the last 2 years joint meetings were held together with the French association of research reactors CER (Club d'Exploitants des Reacteurs). In this contribution the AFR, its members, work and aims as well as the French partner CER are presented. (orig.)

Report of experimental hall subworking group

International Nuclear Information System (INIS)

Miyake, K.; Ohama, T.; Takahashi, K.

1982-01-01

The general plan of constructing the TRISTAN e + e - colliding beam experimental halls may be divided into two parts. The first step is to construct two test-experimental halls associated with the 6.5 GeV x 6.5 GeV e + e - accumulator ring, and the second step is to build four experimental halls at the 30 GeV x 30 GeV e + e - TRISTAN main ring. At this workshop, extensive discussions on the detailed design of the four main ring experimental halls have been made. Four experimental areas will be built at the main ring, and two test-experimental halls at the accumulating ring. Among the four areas at the main ring, two will be used for electron-proton possible as well as electron-positron colliding beam experiment. The other two will be used exclusively for e + e - colliding experiments. Only a preliminary design has been made for these four experimental areas. A tentative plan of a larger experimental hall includes a counting and data processing room, a utility room, and a radiation safety control room. Two smaller halls have simpler structure. The figures of the experimental halls are presented. The two test-experimental halls at the accumulator ring will be used to test the detectors for e + e - colliding experiments before the final installation. The utility rooms designed for the halls are used to supply coolant and electric power of superconducting magnets. At the workshop, various ideas concerning the preliminary plan are presented. (Kato, T.)

Children's Understanding of Experimental Contrast and Experimental Control: An Inventory for Primary School

Science.gov (United States)

Osterhaus, Christopher; Koerber, Susanne; Sodian, Beate

2015-01-01

Experimentation skills are a central component of scientific thinking, and many studies have investigated whether and when primary-school children develop adequate experimentation strategies. However, the answers to these questions vary substantially depending on the type of task that is used: while discovery tasks, which require children to…

[Psychology, psychiatry and oncology: recent and future findings].

Science.gov (United States)

Razavi, D

2006-01-01

There is an important development of research at the interface of psychology, psychiatry and oncology. There are now precise knowledges about assessment and type of difficulties experimented by patients and their significant others. The content of psychological interventions needed to optimize quality of care is starting to be better defined. All this has certainly allowed the development of "psycho-oncology" as a new discipline. Our experience at the Jules Bordet Institute, Cancer Center of the University of Brussels, will be reported in this paper.

Howard Hughes and the Cold War Aviation Film Jet Pilot (1957

Directory of Open Access Journals (Sweden)

Richard Andrew Voeltz

2016-10-01

War.  But sexual intimacy, conspicuous consumption, and aviation technology also inserted themselves into the perfect safetly of American domestic bliss. This paper will analyze how the eccentric Cold War romantic comedy Jet Pilot (1957 so associated with the compulsiveness of Howard Hughes, produced and written by Jules Furthman, directed ( partially by Josef von Sternburg and starring John Wayne and Janet Leigh, reflects all these themes making it the paradigmatic Cold Film that remains a camp classic from the American popular cultyre of the 1950s.

Contribution to the studies on the mineral content of plant material through radioactivation analysis; Contribution a l'etude de la composition minerale des matieres vegetales au moyen de l'analyse par radioactivation

Energy Technology Data Exchange (ETDEWEB)

Fourcy, A [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1968-03-15

Radioactivation analysis is by its great sensibility or its rapidity quite helpful in plant biology and agronomy. Specific composition of plants and results to obtain in biological experimentation have needed a practical research on analytical methods for plant materials, using for radioactivation swimming-pool reactor neutrons and 14 MeV neutrons from a generator. Dosage process for 25 elements is exposed, taking account of the interest of the analysis for each element, the average amount occurring in plants and the result obtained. Many applications are developed, concerning nutrition physiology, genetics, parasitology, toxicology, control of manufactured agricultural and pharmaceutical products industrial and pesticides residues, ecology, radioecology and biochemistry. (author) [French] L'analyse par radioactivation, par sa grande sensibilite ou sa rapidite, est susceptible de rendre de nombreux services en biologie vegetale et en agronomie. La composition particuliere des plantes et les buts recherches dans l'experimentation ont exige une etude concrete des methodes d'analyse propres a la matiere vegetale en utilisant, pour la radioactivation, soit un reacteur de type piscine a eau legere, soit un accelerateur generateur de neutrons de 14 MeV. Le mode de dosage de 25 elements est expose en tenant compte de l'interet de l'analyse de chaque element, des teneurs moyennes rencontrees dans les plantes, et du resultat atteint. De nombreuses applications sont developpees qui touchent a la physiologie de la nutrition, la genetique, la parasitologie, la toxicologie, le controle des fabrications, les pollutions industrielles, l'ecologie, la radioecologie et la biochimie. (auteur)

Contribution to the studies on the mineral content of plant material through radioactivation analysis; Contribution a l'etude de la composition minerale des matieres vegetales au moyen de l'analyse par radioactivation

Energy Technology Data Exchange (ETDEWEB)

Fourcy, A. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1968-03-15

Radioactivation analysis is by its great sensibility or its rapidity quite helpful in plant biology and agronomy. Specific composition of plants and results to obtain in biological experimentation have needed a practical research on analytical methods for plant materials, using for radioactivation swimming-pool reactor neutrons and 14 MeV neutrons from a generator. Dosage process for 25 elements is exposed, taking account of the interest of the analysis for each element, the average amount occurring in plants and the result obtained. Many applications are developed, concerning nutrition physiology, genetics, parasitology, toxicology, control of manufactured agricultural and pharmaceutical products industrial and pesticides residues, ecology, radioecology and biochemistry. (author) [French] L'analyse par radioactivation, par sa grande sensibilite ou sa rapidite, est susceptible de rendre de nombreux services en biologie vegetale et en agronomie. La composition particuliere des plantes et les buts recherches dans l'experimentation ont exige une etude concrete des methodes d'analyse propres a la matiere vegetale en utilisant, pour la radioactivation, soit un reacteur de type piscine a eau legere, soit un accelerateur generateur de neutrons de 14 MeV. Le mode de dosage de 25 elements est expose en tenant compte de l'interet de l'analyse de chaque element, des teneurs moyennes rencontrees dans les plantes, et du resultat atteint. De nombreuses applications sont developpees qui touchent a la physiologie de la nutrition, la genetique, la parasitologie, la toxicologie, le controle des fabrications, les pollutions industrielles, l'ecologie, la radioecologie et la biochimie. (auteur)

Computer system for Monte Carlo experimentation

International Nuclear Information System (INIS)

Grier, D.A.

1986-01-01

A new computer system for Monte Carlo Experimentation is presented. The new system speeds and simplifies the process of coding and preparing a Monte Carlo Experiment; it also encourages the proper design of Monte Carlo Experiments, and the careful analysis of the experimental results. A new functional language is the core of this system. Monte Carlo Experiments, and their experimental designs, are programmed in this new language; those programs are compiled into Fortran output. The Fortran output is then compiled and executed. The experimental results are analyzed with a standard statistics package such as Si, Isp, or Minitab or with a user-supplied program. Both the experimental results and the experimental design may be directly loaded into the workspace of those packages. The new functional language frees programmers from many of the details of programming an experiment. Experimental designs such as factorial, fractional factorial, or latin square are easily described by the control structures and expressions of the language. Specific mathematical modes are generated by the routines of the language

Experimenter gender and replicability in science.

Science.gov (United States)

Chapman, Colin D; Benedict, Christian; Schiöth, Helgi B

2018-01-01

There is a replication crisis spreading through the annals of scientific inquiry. Although some work has been carried out to uncover the roots of this issue, much remains unanswered. With this in mind, this paper investigates how the gender of the experimenter may affect experimental findings. Clinical trials are regularly carried out without any report of the experimenter's gender and with dubious knowledge of its influence. Consequently, significant biases caused by the experimenter's gender may lead researchers to conclude that therapeutics or other interventions are either overtreating or undertreating a variety of conditions. Bearing this in mind, this policy paper emphasizes the importance of reporting and controlling for experimenter gender in future research. As backdrop, it explores what we know about the role of experimenter gender in influencing laboratory results, suggests possible mechanisms, and suggests future areas of inquiry.

Strength of Experimental Grouts

DEFF Research Database (Denmark)

Sørensen, Eigil V.

 The present report describes tests carried out on 5 experimental grouts developed by BASF Construction Materials and designed for use in grouted connections of offshore windmill foundations....... The present report describes tests carried out on 5 experimental grouts developed by BASF Construction Materials and designed for use in grouted connections of offshore windmill foundations....

Introduction: Experimental Green Strategies

DEFF Research Database (Denmark)

Peters, Terri

2011-01-01

Defining new ways in which archietcts are responding to the challenge of creating sustainable architecture , Experimental Green Strategies present a state of the art in applied ecological architectural research.......Defining new ways in which archietcts are responding to the challenge of creating sustainable architecture , Experimental Green Strategies present a state of the art in applied ecological architectural research....

The '3Is' of animal experimentation.

Science.gov (United States)

2012-05-29

Animal experimentation in scientific research is a good thing: important, increasing and often irreplaceable. Careful experimental design and reporting are at least as important as attention to welfare in ensuring that the knowledge we gain justifies using live animals as experimental tools.

2016 International Symposium on Experimental Robotics

CERN Document Server

Nakamura, Yoshihiko; Khatib, Oussama; Venture, Gentiane

2017-01-01

Experimental Robotics XV is the collection of papers presented at the International Symposium on Experimental Robotics, Roppongi, Tokyo, Japan on October 3-6, 2016. 73 scientific papers were selected and presented after peer review. The papers span a broad range of sub-fields in robotics including aerial robots, mobile robots, actuation, grasping, manipulation, planning and control and human-robot interaction, but shared cutting-edge approaches and paradigms to experimental robotics. The readers will find a breadth of new directions of experimental robotics. The International Symposium on Experimental Robotics is a series of bi-annual symposia sponsored by the International Foundation of Robotics Research, whose goal is to provide a forum dedicated to experimental robotics research. Robotics has been widening its scientific scope, deepening its methodologies and expanding its applications. However, the significance of experiments remains and will remain at the center of the discipline. The ISER gatherings are...

Experimental Research in Marketing

Directory of Open Access Journals (Sweden)

Jose Mauro Hernandez

2014-05-01

Full Text Available Considering the growing number of scientific studies published in the marketing field and the development of unique theories of the area (Hunt, 2010, using experimental designs seems increasingly appropriate to investigate marketing phenomena. This article aims to discuss the main elements in conducting experimental studies and also to stimulate researchers to adopt this research method. Several international journals (e.g., JCR, JCP, JMR, JR, JBR have been publishing articles based on experiments that not only demonstrate a relationship between two events, but also elucidate how they occur by means of mediation and moderation analyses. This article intents to be a roadmap for novice researchers on how to conduct experiments and to offer new perspectives in experimental research for experienced researchers.  

Information perception, wishes, and satisfaction in ambulatory cancer patients under active treatment: patient-reported outcomes with QLQ-INFO25

Science.gov (United States)

Pinto, Ana Catarina; Ferreira-Santos, Fernando; Lago, Lissandra Dal; de Azambuja, Evandro; Pimentel, Francisco Luís; Piccart-Gebhart, Martine; Razavi, Darius

2014-01-01

Background Information is vital to cancer patients. Physician–patient communication in oncology presents specific challenges. The aim of this study was to evaluate self-reported information of cancer patients in ambulatory care at a comprehensive cancer centre and examine its possible association with patients’ demographic and clinical characteristics. Patients and methods This study included adult patients with solid tumours undergoing chemotherapy at the Institute Jules Bordet’s Day Hospital over a ten-day period. EORTC QLQ-C30 and QLQ-INFO25 questionnaires were administered. Demographic and clinical data were collected. Descriptive and inferential statistics were used. Results 101 (99%) fully completed the questionnaires. They were mostly Belgian (74.3%), female (78.2%), with a mean age of 56.9 ± 12.8 years. The most frequent tumour was breast cancer (58.4%). Patients were well-informed about the disease and treatments, but presented unmet information domains. The Jules Bordet patients desired more information on treatment side effects, long-term outcome, nutrition, and recurrence symptoms. Patients on clinical trials reported having received less information about their disease and less written information than patients outside clinical trials. Higher information levels were associated with higher quality of life (QoL) scores and higher patient satisfaction. Conclusion Patients were satisfied with the information they received and this correlated with higher QoL, but they still expressed unmet information wishes. Additional studies are required to investigate the quality of the information received by patients enrolled in clinical trials. PMID:24834120

Design and construction of a fast critical facility; Etude et construction d'un ensemble critique a neutrons rapides; Proektirovanie i sooruzhenie kriticheskoj sborki na bystrykh nejtronakh; Proyecto u construccion de un conjunto critico de neutrones rapidos

Energy Technology Data Exchange (ETDEWEB)

Kato, W Y; Dates, L R [Argonne National Laboratory, Argonne, IL (United States)

1962-03-15

criteres qui ont servi a mettre au point ses elements du point de vue de la physique des reacteurs. Ils presentent egalement des considerations sur le mode d'exploitation et de fonctionnement, sur les risques de manipulation, sur les methodes d'experiences qu'il convient d'utiliser et sur le cout de la construction. (author) [Spanish] Los conjuntos criticos constituyen auxiliares sumamente valiosos en los programas de perfeccionamiento de los reactores rapidos de potencia. Con ellos se pueden comprobar tecnicas de calculo y series de secciones eficaces neutronicas, y se obtienen los parametros fisicos necesarios para el proyecto de reactores de potencia. Como se trata primordialmente de un instrumento de fisica, el diseno del propio conjunto critico de neutrones rapidos implica la solucion de problemas que difieren radicalmente de los que se plantean en el diseno de los reactores de potencia. Ademas de las cuestiones habituales de emplazamiento, confinamiento, proyecto del cuerpo y del instrumental, se plantean problemas como el de alcanzar un elevado grado de flexibilidad en la aplicacion sin detrimento de la seguridad, hallar las dimensiones y el tipo de conjunto mas adecuado para satisfacer las necesidades de la fisica experimental, determinar el numero y la posicion de las barras de control y de seguridad para reducir a un minimo los efectos perturbadores y asegurar la reproducibilidad en el empleo de las barras de control y otros elementos moviles para lograr la precision requerida en la medicion de la reactividad. La memoria discute estos y otros problemas basandose en la experiencia adquirida en el Argonne National Laboratory, que en su centro de Lemont, Illinois, esta construyendo un conjunto critico de neutrones rapidos, el ZPR-VI, destinado a la realizacion de estudios sobre la fisica de los reactores rapidos. El ZPR-VI es del tipo de cuerpo dividido, como el ZPR-III. El volumen de su matriz es 2,5 veces superior al de la matriz del modelo anterior y servira para

Shielding in experimental areas

International Nuclear Information System (INIS)

Stevens, A.; Tarnopolsky, G.; Thorndike, A.; White, S.

1979-01-01

The amount of shielding necessary to protect experimental detectors from various sources of background radiation is discussed. As illustrated an experiment has line of sight to sources extending approx. 90 m upstream from the intersection point. Packing a significant fraction of this space with shielding blocks would in general be unacceptable because primary access to the ring tunnel is from the experimental halls. (1) From basic machine design considerations and the inherent necessity to protect superconducting magnets it is expected that experimental areas in general will be cleaner than at any existing accelerator. (2) Even so, it will likely be necessary to have some shielding blocks available to protect experimental apparatus, and it may well be necessary to have a large amount of shielding available in the WAH. (3) Scraping will likely have some influence on all halls, and retractable apparatus may sometimes be necessary. (4) If access to any tunnel is needed to replace a magnet, one has 96 h (4 days) available to move shielding away to permit access without additional downtime. This (the amount of shielding one can shuffle about in 96 h) is a reasonable upper limit to shielding necessary in a hall

The Experimental Art School

DEFF Research Database (Denmark)

Ørum, Tania

2014-01-01

The article describes the Experimental Art School from its early beginnings, its development from formal experiments to political action, the question of gender and politics, and the power of the self-organised......The article describes the Experimental Art School from its early beginnings, its development from formal experiments to political action, the question of gender and politics, and the power of the self-organised...

Experimental work on drift chambers

International Nuclear Information System (INIS)

Alcaraz, J.; Duran, I.; Gonzalez, E.; Martinez-Laso, L.; Olmos, P.

1989-01-01

An experimental work made on drift chambers is described in two chapters. In the firt chapter we present the description of the experimental installation used, as well as some details on the data adquisition systems and the characteristics on three ways used for calibration proposes (cosmic muons, β radiation and test beam using SPS at CERN facilities). The second chapter describes the defferent prototypes studied. The experimental set up and the analysis are given. Some results are discussed. The magnetic field effect is also studied. (Author)

Experimental plasma research project summaries

International Nuclear Information System (INIS)

1982-10-01

The experimental plasma Research Branch has responsibility for developing a broad range of experimental data and new experimental techniques that are required for operating and interpreting present large-scale confinement experiments, and for designing future deuterium-tritium burining facilities. The Branch pursued these objectives by supporting research in DOE laboratories, other Federal laboratories, other Federal laboratories, universities, and private industry. Initiation and renewal of research projects are primarily through submission of unsolicited proposals by these institutions to DOE. Summaries of these projects are given

Development and qualification of reference calculation schemes for absorbers in pressured water reactor; Elaboration et qualification de schemas de calcul de reference pour les absorbants dans les reacteurs a eau pressurisee

Energy Technology Data Exchange (ETDEWEB)

Blanc-Tranchant, P

2001-07-01

The general field in which this work takes place is the field of the accuracy improvement of neutronic calculations, required to operate Pressurized Water Reactors (PWR) with a better precision and a lower cost. More specifically, this thesis deals with the calculation of the absorber clusters used to control these reactors. The first aim of that work was to define and validate a reference calculation route of such an absorber cluster, based on the deterministic code APOLLO2. This calculation scheme was then to be checked against experimental data. This study of the complex situation of absorber clusters required several intermediate studies, of simpler problems, such as the study of fuel rods lattices and the study of single absorber rods (B4C, AIC, Hafnium) isolated in such lattices. Each one of these different studies led to a particular reference calculation route. All these calculation routes were developed against reference continuous energy Monte-Carlo calculations, carried out with the stochastic code TRIPOLI4. They were then checked against experimental data measured during French experimental programs, undertaken within the EOLE experimental reactor, at the Nuclear Research Center of Cadarache: the MISTRAL experiments for the study of isolated absorber rods and the EPICURE experiments for the study of absorber clusters. This work led to important improvements in the calculation of isolated absorbers and absorber clusters. The reactivity worth of these clusters in particular, can now be obtained with a great accuracy: the discrepancy observed between the calculated and the experimental values is less than 2.5 %, and then slightly lower than the experimental uncertainty. (author)

Modelization of physical phenomena in research reactors with the help of new developments in transport methods, and methodology validation with experimental data; Modelisation des phenomenes physiques dans les reacteurs de recherche a l'aide de developpements realises dans les methodes de transport et qualification

Energy Technology Data Exchange (ETDEWEB)

Rauck, St

2000-10-01

The aim of this work is to develop a scheme for experimental reactors, based on transport equations. This type of reactors is characterized by a small core, a complex, very heterogeneous geometry and a large leakage. The possible insertion of neutron beams in the reflector and the presence of absorbers in the core increase the difficulty of the 3D-geometrical description and the physical modeling of the component parameters of the reactor. The Orphee reactor has been chosen for our study. Physical models (homogenization, collapsing cross section in few groups, albedo multigroup condition) have been developed in the APOLLO2 and CRONOS2 codes to calculate flux and power maps in a 3D-geometry, with different burnup and through transport equations. Comparisons with experimental measurements have shown the interest of taking into account anisotropy, steep flux gradients by using Sn methods, and on the other hand using a 12-group cross section library. The modeling of neutron beams has been done outside the core modeling through Monte Carlo calculations and with the total geometry, including a large thickness of heavy water. Thanks to this calculations, one can evaluate the neutron beams anti-reactivity and determinate the core cycle. We assure these methods more accurate than usual transport-diffusion calculations will be used for the conception of new research reactors. (author)

RPV-1: a first virtual reactor to simulate irradiation effects in light water reactor pressure vessel steels; RPV-1: un premier reacteur virtuel pour simuler les effets d'irradiation dans les aciers de cuve des reacteurs a eau legere

Energy Technology Data Exchange (ETDEWEB)

Jumel, St

2005-01-15

The presented work was aimed at building a first VTR (virtual test reactor) to simulate irradiation effects in pressure vessel steels of nuclear reactor. It mainly consisted in: - modeling the formation of the irradiation induced damage in such steels, as well as their plasticity behavior - selecting codes and models to carry out the simulations of the involved mechanisms. Since the main focus was to build a first tool (rather than a perfect tool), it was decided to use, as much as possible, existing codes and models in spite of their imperfections. - developing and parameterizing two missing codes: INCAS and DUPAIR. - proposing an architecture to link the selected codes and models. - constructing and validating the tool. RPV-1 is made of five codes and two databases which are linked up so as to receive, treat and/or transmit data. A user friendly Python interface facilitates the running of the simulations and the visualization of the results. RPV-1 relies on many simplifications and approximations and has to be considered as a prototype aimed at clearing the way. According to the functionalities targeted for RPV-1, the main weakness is a bad Ni and Mn sensitivity. However, the tool can already be used for many applications (understanding of experimental results, assessment of effects of material and irradiation conditions,....). (O.M.)

Experimental intrauterine growth retardation.

Science.gov (United States)

van Marthens, E; Harel, S; Zamenshof, S

1975-01-01

The effects of experimental intrauterine growth retardation on subsequent fetal development, especially with respect to brain development, were studied in a new animal model. The rabbit was chosen since it has a perinatal pattern of brain development similar to that of the human. Experimental ischemia was induced during the last trimester by ligation of spiral arterioles and the differential effects on fetal development at term (30th gestational day) are reported. Specific brain regions were examined for wet weight, total cell number (DNA) and total protein content. Highly significant decreases in all these parameters were found in both the cortex and cerebellum following experimental intrauterine growth retardation; these two organs were differentially affected. The prospects and advantages of using this animal model for the study of the postnatal "catch-up growth" are discussed.

The State regains control of Areva

International Nuclear Information System (INIS)

Dupin, Ludovic

2014-01-01

This article first gives an overview of problems faced by Areva during the past years: financial losses, new delay for the Finnish EPR and for the French one in Flamanville, delay for the construction of the Jules Horowitz reactor, bad investments, high expenses in offshore wind energy and solar energy. The second part comments the decision taken by the government for a closer relationship between Areva and EDF, the perspectives for Areva associated with the extension of French reactor lifetime, new orientation of activities and definition of a new strategy for Areva

Theme Enrichment Analysis: A Statistical Test for Identifying Significantly Enriched Themes in a List of Stories with an Application to the Star Trek Television Franchise

OpenAIRE

Onsjö, Mikael; Sheridan, Paul

2017-01-01

In this paper, we describe how the hypergeometric test can be used to determine whether a given theme of interest occurs in a storyset at a frequency more than would be expected by chance. By a storyset we mean simply a list of stories defined according to a common attribute (e.g. author, movement, period). The test works roughly as follows: Given a background storyset (e.g. 19th century adventure novels), and a sub-storyset of interest (e.g. Jules Verne novels), the test determines whether a...

O realismo mágico - uma dimensão da literatura francesa do Século XX

OpenAIRE

Pereira, Maria Eugénia Tavares

2005-01-01

Pierre Mac Orlan, Jules Supervielle, Alain-Fournier, Jean Cocteau, Jean Giono, Marcel Aymé, André Dhôtel, Julien Green, Julien Gracq, Yves Bonnefoy, Michel Tournier foram os autores do século XX que elegemos, de entre muitos outros, para, através da releitura das suas obras – Le Quai des brumes, L’Enfant de la haute mer, Le Grand Meaulnes, Les Enfants terribles, Mort d’un personnage, Le Passe-muraille, Le Pays où l’on n’arrive jamais, Le Visionnaire, Au Château d’Argol, L’Ar...

Research and materials irradiation reactors

International Nuclear Information System (INIS)

Ballagny, A.; Guigon, B.

2004-01-01

Devoted to the fundamental and applied research on materials irradiation, research reactors are nuclear installations where high neutrons flux are maintained. After a general presentation of the research reactors in the world and more specifically in France, this document presents the heavy water cooled reactors and the water cooled reactors. The third part explains the technical characteristics, thermal power, neutron flux, operating and details the Osiris, the RHF (high flux reactor), the Orphee and the Jules Horowitz reactors. The last part deals with the possible utilizations. (A.L.B.)

Revisiting Cotard’s syndrome: illustration of two psychiatric clinical cases

OpenAIRE

Sousa, L; Oliveira, S; Bastos, L

2015-01-01

Introdução: A Síndrome de Cotard (SC) é uma Síndrome neuropsiquiátrica rara e grave, cuja característica central é a existência de delírios niilistas. Tem surgido controvérsia relativamente ao quadro clínico que Jules Cotard descreveu e recentemente têm sido feitas tentativas, não só para clarificar a terminologia utilizada, mas também para definir dife - rentes subtipos desta síndrome e explorar as suas bases biológicas. Objetivos: Rever sumariamente ...

Experimental design a chemometric approach

CERN Document Server

Deming, SN

1987-01-01

Now available in a paperback edition is a book which has been described as ``...an exceptionally lucid, easy-to-read presentation... would be an excellent addition to the collection of every analytical chemist. I recommend it with great enthusiasm.'' (Analytical Chemistry). Unlike most current textbooks, it approaches experimental design from the point of view of the experimenter, rather than that of the statistician. As the reviewer in `Analytical Chemistry' went on to say: ``Deming and Morgan should be given high praise for bringing the principles of experimental design to the level of the p

Summary of experimental insertions workshop

International Nuclear Information System (INIS)

Sandweiss, J.; Month, M.

1976-01-01

The last ISABELLE workshop of the summer 1976 series, which was held at Brookhaven, August 16-20, focused on the design and utilization of the experimental insertions. The goals of the workshop, which were somewhat more general than might be suggested by the title, are: (1) review the ISABELLE proposal from the point of view of experimental use; (2) contribute useful information on the ''open questions'' in the ISABELLE design; (3) develop data for experimental equipment and operating cost estimates; and (4) project a first approximation to ISABELLE operating modes

Experimental study of Coal Pyrolysis 1.: Review of the experimental information from the literature

International Nuclear Information System (INIS)

Hugony, F.; Migliavacca, G.

2007-01-01

A brief analysis of some of the main experimental works published in the past decades about coal pyrolysis is here reported. In particular the results of some series of experiments are cited and reported in details, coming from the activity of some important international research teams; they supply a survey wide and complete enough of the different operating and experimental conditions proposed in this field. With the aim of giving a comparison benchmark for the original experimental data published in the companion paper of this series and in order to grant a good support to the validation of the predictive models of coal devolatilization [it

Color and experimental physics

International Nuclear Information System (INIS)

Chanowitz, M.S.

1975-01-01

After a brief review of the color hypothesis and the motivations for its introduction, the experimental tests arare discussed. It is assumed that colored states have not been produced at present energies and only experimental tests which apply below the color threshold, when color is a ''hidden symmetry,'' are discussed. Some of these tests offer the possibility of distinguishing between quark models with fractional and integral quark charges. (auth)

Materials Control in the Fabrication of Enriched Uranium Fuels; Controle des Matieres au Cours de la Fabrication des Combustibles a Base d'Uranium Enrichi; Uchet materialov pri izgotovlenii topliva na obogashchennom urane; Control de Materiales en la Elaboracion de Combustibles de Uranio Enriquecido

Energy Technology Data Exchange (ETDEWEB)

Cardwell, Jr., R. G. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

1966-02-15

measurement were successfully used where alloy fuel content was critical. Scrap handling had an important effect on the materials balance, by which fuel content was confirmed and good accountability was assured. Records and handling procedures, including batching and physical marking methods, were formulated in a manner that assisted the fabricator in criticality control. (author) [French] Grace aux efforts intenses qui ont ete accomplis au cours des 15 dernieres annees dans le domaine de la technologie des elements de combustible par le Laboratoire national d'Oak Ridge, il a ete possible d'etablir des methodes rationnelles de fabrication et de controle des combustibles eraichis, qui trouvent une iaige application dans la fabrication industrielle des elements de combustible a l'heure actuelle. Des techniques eprouvees de manipulation du combustible enrichi en alliages, en dispersion et sous forme d'oxyde en vrac ont ete mises au point et appliquees a l'etude et a la' fabrication des prototypes d'elements combustibles utilises pour le demarrage du reacteur d'essai de materiaux, du reacteur a protection constituee par la masse du ra- lentisseur ou reacteur piscine, du reacteur de puissance transportable construit pat V, du reacteur protection en tour, du reacteur expose a la Conference de Geneve, du reacteur a haut flux pour la production de radioisotopes et du reacteur experimental refroidi par un gaz. L'experience acquise est la base du present memoire qui traite essentiellement des problemes de controle des matieres qui se posent au cours de la fabrication de differents types d'elements de combustible a base d'uranium enrichi et montre comment ils ont ete resolus. Les objectifs principaux d'un systeme rationnel de controle des matieres sont les suivants: 1. reduire le plus possible le nombre des postes matiere a controler; 2. etablir des releves distincts pour chacune des phases principales des operations et les coordonner de maniere a pouvoir relever les ecarts avec un

Surface physics : experimental

International Nuclear Information System (INIS)

Padalia, B.D.

1978-01-01

In this report, discussion is confined to some important ultra high vacuum surface techniques such as ultra-violet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and the low energy electron diffraction (LEED). An attempt is made to cover the basic principles and the experimental details of XPS and AES. Selected examples illustrating the potentialities of the above techniques to solve the important basic as well as applied problems relating to surfaces are presented. Salient features of the available commercial machines in which UPS, AES and LEED are combined to facilitate surface examination sequentially or simultaneously under identical experimental conditions are indicated. (auth.)

Threats to the Internal Validity of Experimental and Quasi-Experimental Research in Healthcare.

Science.gov (United States)

Flannelly, Kevin J; Flannelly, Laura T; Jankowski, Katherine R B

2018-01-24

The article defines, describes, and discusses the seven threats to the internal validity of experiments discussed by Donald T. Campbell in his classic 1957 article: history, maturation, testing, instrument decay, statistical regression, selection, and mortality. These concepts are said to be threats to the internal validity of experiments because they pose alternate explanations for the apparent causal relationship between the independent variable and dependent variable of an experiment if they are not adequately controlled. A series of simple diagrams illustrate three pre-experimental designs and three true experimental designs discussed by Campbell in 1957 and several quasi-experimental designs described in his book written with Julian C. Stanley in 1966. The current article explains why each design controls for or fails to control for these seven threats to internal validity.

Experimental Methods in Media Research

NARCIS (Netherlands)

C.W. Handke (Christian); C. Herzog (Christian)

2017-01-01

textabstractCausal effects are a prime concern in media policy research, and experimental research designs are widely regarded as the most effective way to identify and gauge causality. Nevertheless, explicit applications of experimental methods are rare in media policy research. This chapter

Online Experimentation in Education and Training

Directory of Open Access Journals (Sweden)

Maria Teresa Restivo

2014-03-01

Full Text Available The increasing use of emergent technologies in industry, medicine, research, training and education attests to the relevance of their integration in teaching/learning approaches. Online experimentation comprises remote and virtual experimentation also supported and complemented by other online tools that incorporate necessarily the use of emergent technologies. The present work synthesizes the final outcomes of a project aiming to develop, use and disseminate Online Experimentation, funded by the Calouste Gulbenkian Foundation. Some application examples are given to illustrate the use of online experimentation on different contexts, such as secondary and higher education (STEM, lifelong learning or industrial training.

Toward a Holistic Federated Future Internet Experimentation Environment: The Experience of NOVI Research and Experimentation

NARCIS (Netherlands)

Maglaris, V.; Papagianni, C.; Androulidakis, G.; Grammatikou, M.; Grosso, P.; van der Ham, J.; de Laat, C.; Pietrzak, B.; Belter, B.; Steger, J.; Laki, S.; Campanella, M.; Sallent, S.

This article presents the design and pilot implementation of a suite of intelligent methods, algorithms, and tools for federating heterogeneous experimental platforms (domains) toward a holistic Future Internet experimentation ecosystem. The proposed framework developed within the NOVI research and

Experimental Research in Marketing

OpenAIRE

Jose Mauro Hernandez; Kenny Basso; Marcelo Moll Brandão

2014-01-01

Considering the growing number of scientific studies published in the marketing field and the development of unique theories of the area (Hunt, 2010), using experimental designs seems increasingly appropriate to investigate marketing phenomena. This article aims to discuss the main elements in conducting experimental studies and also to stimulate researchers to adopt this research method. Several international journals (e.g., JCR, JCP, JMR, JR, JBR) have been publishing articles based on expe...

Experimental guidelines

International Nuclear Information System (INIS)

1997-01-01

The paper proposes a model experimental design to study the effects of pesticides on particular ecosystem. It takes maize as a model crop and an alternative crop while studying the adverse effects on untargeted arthropods, residues in the soil and other plants. 5 refs, 7 figs

Experimental approach to explosive nucleosynthesis

International Nuclear Information System (INIS)

Kubono, S.

1991-07-01

Recent development of experimental studies on explosive nucleosynthesis, especially the rapid proton process and the primordial nucleosynthesis were discussed with a stress on unstable nuclei. New development in the experimental methods for the nuclear astrophysics is also discussed which use unstable nuclear beams. (author)

Open source in Experimental Psychology

OpenAIRE

Dalmaijer, Edwin

2015-01-01

Talk on using open-source software in experimental psychology. Presented on 3 March 2015, at the Attention, Brain and Cognitive Development group (http://www.psy.ox.ac.uk/research/attention-brain-and-cognitive-development-group) at the University of Oxford's Department of Experimental Psychology.

Cameroon Journal of Experimental Biology

African Journals Online (AJOL)

The Cameroon Journal of Experimental Biology is the official journal of the Cameroon Forum for Biological Sciences (CAFOBIOS). It is an interdisciplinary journal for the publication of original research papers, short communications and review articles in all fields of experimental biology including biochemistry, physiology, ...

Contribution to the study of nuclear fuel materials with a metallic uranium base; Contribution a l'etude des materiaux combustibles nucleaires a base d'uranium metallique

Energy Technology Data Exchange (ETDEWEB)

Englander, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-11-15

In a power reactor destined to supply industrially recoverable thermal energy, the most economical source of heat still consists of natural metallic uranium. However, the nuclear fuel material, most often employed in the form of rods of 20 to 40 mm diameter, is subjected to a series of stresses which lead to irreversible distortions usually incompatible with the substructure of the reactor. As a result the fuel material must possess at the outset a certain number of qualities which must be determined. Investigations have therefore been carried out, first on the technological characters peculiar to each of the three allotropic phases of pure uranium metal, and on their interactions on the stabilisation of the material which consists of either cast uranium or uranium pile-treated in the {gamma} phase. (author) [French] Dans un reacteur de puissance destine a fournir de l'energie thermique industriellement recuperable, la source de chaleur la plus economique reste constituee par de l'uranium metallique naturel. Or, le materiau combustible nucleaire, employe le plus souvent sous forme de barreaux de 20 a 40 mm de diametre, se trouve soumis a un ensemble de contraintes qui provoque des deformations irreversibles, le plus souvent incompatibles avec l'infrastructure du reacteur. Par consequent, le materiau combustible doit presenter a l'origine un certain nombre de qualites qu'il est necessaire de determiner. Aussi a-t-on d'abord etudie les caracteres technologiques propres a chacune des trois phases allotropiques de l'uranium-metal pur et leurs interactions sur la stabilisation du materiau constitue soit par de l'uranium coule, soit par de l'uranium traite en pile en phase {gamma}. (auteur)

Problems of the experimental implementation of MTJ

International Nuclear Information System (INIS)

Mazaletskiy, L A; Rudy, A S; Trushin, O S; Naumov, V V; Mironenko, A A; Vasilev, S V

2015-01-01

The results of experimental studies of MRAM technology based on standard magnetic tunneling junctions are presented. Basic steps of experimental fabrication of MRAM cell are considered. Experimental samples of MTJ with variable lateral sizes are fabricated. Current-voltage characteristics of the tunnel barriers are investigated. Main parameters of the tunnel barriers are estimated from comparison of the experimental data with the theory. (paper)

Experimental tests of gauge theories

International Nuclear Information System (INIS)

Haidt, D.

1984-11-01

This series of five lectures is intended to provide the experimental basis to the theoretical courses on gauge symmetries delivered by C. Jarlskog and R. Petronzio. The framework is the standard model. The experimental material is taken mainly from lepton-hadron and e + e - -experiments. (orig./HSI)

A proposal for experimental homework

Science.gov (United States)

Rodríguez, Eduardo E.

1998-10-01

Homework in Physics courses usually deal with conceptual inquiries or numerical solution of theoretical problems. However, experimental homework is rather uncommon. I propose that certain physical situations properly simulated may be useful to encourage students to seek a solution behind the steps of the "experimental method."

Strongly correlated systems experimental techniques

CERN Document Server

Mancini, Ferdinando

2015-01-01

The continuous evolution and development of experimental techniques is at the basis of any fundamental achievement in modern physics. Strongly correlated systems (SCS), more than any other, need to be investigated through the greatest variety of experimental techniques in order to unveil and crosscheck the numerous and puzzling anomalous behaviors characterizing them. The study of SCS fostered the improvement of many old experimental techniques, but also the advent of many new ones just invented in order to analyze the complex behaviors of these systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and materials science, belong to this class of systems. The volume presents a representative collection of the modern experimental techniques specifically tailored for the analysis of strongly correlated systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognize...

Los Alamos Experimental Engineering Waste Burial Facility: design considerations and preliminary experimental plan

International Nuclear Information System (INIS)

DePoorter, G.L.

1981-01-01

The Experimental Engineered Waste Burial Facility is a field test site where generic experiments can be performed on several scales to get the basic information necessary to understand the processes occurring in low-level waste disposal facilities. The experiments include hydrological, chemical, mechanical, and biological factors. In order to separate these various factors in the experiments and to extrapolate the experimental results to actual facilities, experiments will be performed on several different scales

Experimental test of magnetic photons

International Nuclear Information System (INIS)

Lakes, R.S.

2004-01-01

A 'magnetic' photon hypothesis associated with magnetic monopoles is tested experimentally. These photons are predicted to easily penetrate metal. Experimentally the optical transmittance T of a metal foil was less than 2x10-17. The hypothesis is not supported since it predicts T=2x10-12

The effective lifetime and temperature coefficient in a coupled fast-thermal reactor; Temps de vie effectif et coefficient de temperature dans un reacteur a couplage neutrons rapides-neutrons thermiques; Ehffektivnyj srok zhizni i temperaturnyj koehffitsient nejtronov v dvoyakom reaktore na bystrykh i teplovykh nejtronakh; Vida efectiva y coeficiente de temperatura en un reactor con acoplamiento rapido-termico

Energy Technology Data Exchange (ETDEWEB)

Haefele, W. [Kernforschungszentrum, Karlsruhe (Germany)

1962-03-15

The theory of coupled systems was extensively developed by Avery and co-workers at the Argonne National Laboratory. One of the main points of interest in a coupled system is the larger effective lifetime of neutrons. The effect of the thermal component acts as a sort of neutron-delayer. As in the theory of delayed neutrons the delaying effect disappears if the reactivity worth is high enough to make the fast component critical by itself. In the study a coupled reactor is considered where the fast component suffers a sudden reactivity step {alpha}{sub 0}. Because of the increasing power-level the temperature rises and two temperature coefficients start to work: the temperature coefficient of the fast component and the temperature coefficient of the thermal component. The problem is considered with one group of delayed neutrons (in the ordinary meaning). A formalism is given to express the effective lifetime and temperature coefficient during the different stages of the excursion. Excursions for different {alpha}{sub 0} are given so that the limit of fast-reactor kinetics is reached. (author) [French] La theorie des systemes a couplage a ete mise au point par Avery et ses collaborateurs au Laboratoire national d'Argonne. L'une des caracteristique les plus interessantes d'un systeme a couplage est que le temps de vie effectif des neutrons est plus long. L'effet de la partie thermique contribue en quelque sorte a retarder les neutrons. Comme dans la theorie des neutrons retardes, l'effet de retardement disparait lorsque la reactivite a une valeur suffisamment elevee pour rendre la partie rapide critique par elle-meme. L'auteur du memoire considere un reacteur a couplage dont la partie rapide subit un saut instantane de reactivite, {alpha}{sub 0}. La temperature s'eleve a cause de l'augmentation de puissance et deux coefficients de temperature commencent a s'appliquer: le coefficient de temperature de la partie rapide et le coefficient de temperature de la partie

Preclinical electrogastrography in experimental pigs

Science.gov (United States)

Květina, Jaroslav; Varayil, Jithinraj Edakkanambeth; Ali, Shahzad Marghoob; Kuneš, Martin; Bureš, Jan; Tachecí, Ilja; Rejchrt, Stanislav; Kopáčová, Marcela

2010-01-01

Surface electrogastrography (EGG) is a non-invasive means of recording gastric myoelectric activity or slow waves from cutaneous leads placed over the stomach. This paper provides a comprehensive review of preclinical EGG. Our group recently set up and worked out the methods for EGG in experimental pigs. We gained our initial experience in the use of EGG in assessment of porcine gastric myoelectric activity after volume challenge and after intragastric administration of itopride and erythromycin. The mean dominant frequency in pigs is comparable with that found in humans. EGG in experimental pigs is feasible. Experimental EGG is an important basis for further preclinical projects in pharmacology and toxicology. PMID:21217873

Experimental Learning Enhancing Improvisation Skills

Science.gov (United States)

Pereira Christopoulos, Tania; Wilner, Adriana; Trindade Bestetti, Maria Luisa

2016-01-01

Purpose: This study aims to present improvisation training and experimentation as an alternative method to deal with unexpected events in which structured processes do not seem to work. Design/Methodology/Approach: Based on the literature of sensemaking and improvisation, the study designs a framework and process model of experimental learning…

BENSC. Experimental reports 1995

International Nuclear Information System (INIS)

Kirschbaum, Y.; Gast, H.; Michaelsen, R.

1996-06-01

The present volume contains a collection of BENSC Experimental Reports. The reports present an overview on the experimental work carried out on BENSC in 1995. About 70 percent of the beam time is available to external users. A qualitative step is the start of user operation of the new advanced Time-of-Flight Spectrometer V3 (NEAT). The increase of SANS project for the Double Crystal Diffractometer V12 is noticed. The current list of instruments and instrument responsibles is given. (DG)

An experimenter's history of neutral currents

International Nuclear Information System (INIS)

Sciulli, F.

1979-01-01

The history of the experimental study of neutral currents, defined as the class of weak interactions engaged in by lepton pairs of net zero charge, is traced under the headings; historical motivations, experimental searches, first positive indications, neutral currents corroborated, neutrino experiments on neutral currents and some general experimental comments. It is concluded that the neutral current does exist and predicted on the basis of gauge theory ideas, and though to connect the weak and electromagnetic interactions, its very general experimental properties are quite consistent with those ideas. Among these are flavor conserving complicated isospin structure, complicated V, A structure and a structure which depends on the type (or quantum numbers) of the target. 50 references. (UK)

Experimental studies

International Nuclear Information System (INIS)

Cowser, K.E.; Stansbury, P.S.; Poston, J.W.; Deus, S.F.; Chen, W.L.; Roswell, R.L.; Goans, R.E.; Cantrell, J.H. Jr.

1978-01-01

Spectral fluence measurements in an adult phantom are reported. A NaI(Tl) probe was used in various locations within the phantom and pulse-height spectra were obtained for seven beam configurations and three generating potentials. Some typical spectra results are presented. A comparison of calculated dose to experimental measurements is presented

Simultaneous estimation of experimental and material parameters

CSIR Research Space (South Africa)

Jansen van Rensburg, GJ

2012-07-01

Full Text Available to the experimental data. An inverse analysis is performed that determines material properties and boundary conditions simultaneously. This idea is investigated using virtual experimental data. The virtual experimental data is obtained by performing a finite element...