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Sample records for nuclear glass long-term

  1. Study of archaeological analogs for the validation of nuclear glass long-term behavior models

    International Nuclear Information System (INIS)

    Verney-Carron, A.

    2008-10-01

    Fractured archaeological glass blocks collected from a shipwreck discovered in the Mediterranean Sea near Embiez Island (Var) were investigated because of their morphological analogy with vitrified nuclear waste and of a known and stable environment. These glasses are fractured due to a fast cooling after they were melted (like nuclear glass) and have been altered for 1800 years in seawater. This work results in the development and the validation of a geochemical model able to simulate the alteration of a fractured archaeological glass block over 1800 years. The kinetics associated with the different mechanisms (interdiffusion and dissolution) and the thermodynamic parameters of the model were determined by leaching experiments. The model implemented in HYTEC software was used to simulate crack alteration over 1800 years. The consistency between simulated alteration thicknesses and measured data on glass blocks validate the capacity of the model to predict long-term alteration. This model is able to account for the results from the characterization of crack network and its state of alteration. The cracks in the border zone are the most altered due to a fast renewal of the leaching solution, whereas internal cracks are thin because of complex interactions between glass alteration and transport of elements in solution (influence of initial crack aperture and of the crack sealing). The lowest alteration thicknesses, as well as their variability, can be explained. The analog behavior of archaeological and nuclear glasses from leaching experiments makes possible the transposition of the model to nuclear glass in geological repository. (author)

  2. Physicochemical properties and long-term behavior of french R7T7 nuclear waste glass

    International Nuclear Information System (INIS)

    Vernaz, E.

    1990-01-01

    The French R7T7 nuclear glass composition was carefully selected to allow incorporation of some thirty different oxides found in fission product solutions. The resulting glass exhibits very low crystallization, and its physical and chemical properties are very similar to those of standard industrial glasses. Nuclear glasses have been shown to withstand α doses corresponding to several hundred thousand years under repository conditions. Predicting the long-term behavior of fission product glasses subjected to aqueous corrosion is no doubt the most difficult aspect of the problem. Predictions are necessarily based on mathematical models. A substantial research effort has been undertaken to identify all the basic corrosion mechanisms liable to control long-term alteration. These mechanisms are now relatively well understood, and provide the basis for developing the indispensable models. Realistic storage conditions exist under which glass alteration occurs at a very slow rate, and can fulfill its role as the first containment barrier for several tens of thousands of years

  3. Long-term behavior of nuclear glass: the r(t) operational model

    International Nuclear Information System (INIS)

    Ribet, I.; Gin, S.; Minet, Y.; Vernaz, E.; Chaix, P.; Do Quang, R.

    2001-01-01

    Predicting the long-term behavior of vitrified waste packages requires the development of models incorporating knowledge of the aqueous alteration mechanisms of nuclear glass. The r(t) model allows for the formation of a protective gel layer during leaching, and is thus able to account for the major drops in the glass alteration rate that are observed experimentally. This article describes the model hypotheses, the methodology implemented to determine its three internal parameters, and the results obtained from about fifty leaching experiments performed under various conditions. The orders of magnitude of the internal parameter values are indicated according to the alteration conditions. (author)

  4. Current Understanding and Remaining Challenges in Modeling Long-Term Degradation of Borosilicate Nuclear Waste Glasses

    International Nuclear Information System (INIS)

    Vienna, John D.; Ryan, Joseph V.; Gin, Stephane; Inagaki, Yaohiro

    2013-01-01

    Chemical durability is not a single material property that can be uniquely measured. Instead it is the response to a host of coupled material and environmental processes whose rates are estimated by a combination of theory, experiment, and modeling. High-level nuclear waste (HLW) glass is perhaps the most studied of any material yet there remain significant technical gaps regarding their chemical durability. The phenomena affecting the long-term performance of HLW glasses in their disposal environment include surface reactions, transport properties to and from the reacting glass surface, and ion exchange between the solid glass and the surrounding solution and alteration products. The rates of these processes are strongly influenced and are coupled through the solution chemistry, which is in turn influenced by the reacting glass and also by reaction with the near-field materials and precipitation of alteration products. Therefore, those processes must be understood sufficiently well to estimate or bound the performance of HLW glass in its disposal environment over geologic time-scales. This article summarizes the current state of understanding of surface reactions, transport properties, and ion exchange along with the near-field materials and alteration products influences on solution chemistry and glass reaction rates. Also summarized are the remaining technical gaps along with recommended approaches to fill those technical gaps

  5. Thermal stability of the French nuclear waste glass - long term behavior modeling

    International Nuclear Information System (INIS)

    Orlhac, X.

    2000-01-01

    The thermal stability of the French nuclear waste glass was investigated experimentally and by modeling to predict its long-term evolution at low temperature. The crystallization mechanisms were analyzed by studying devitrification in the supercooled liquid. Three main crystalline phases were characterized (CaMoO 4 , CeCO 2 , ZnCr 2 O 4 ). Their crystallisation was TO 4.24 wt%, due to the low concentration of the constituent elements. The nucleation and growth curves showed that platinoid elements catalysed nucleation but did not affect growth, which was governed by volume diffusion. The criteria of classic nucleation theory were applied to determine the thermodynamic and diffusional activation energies. Viscosity measurements illustrate the analogy between the activation energy of viscous flow and diffusion, indicating control of crystallization by viscous flow phenomena. The combined action of nucleation and growth was assessed by TTT plots, revealing a crystallization equilibrium line that enables the crystallized fractions to be predicted over the long term. The authors show that hetero-genetics catalyze the transformation without modifying the maximum crystallized fraction. A kinetic model was developed to describe devitrification in the glass based on the nucleation and growth curves alone. The authors show that the low-temperature growth exhibits scale behavior (between time and temperature) similar to thermo-rheological simplicity. The analogy between the resulting activation energy and that of the viscosity was used to model growth on the basis of viscosity. After validation with a simplified (BaO 2 SiO 2 ) glass, the model was applied to the containment glass. The result indicated that the glass remained completely vitreous after a cooling scenario with the one measured at the glass core. Under isothermal conditions, several million years would be required to reach the maximum theoretical crystallization fraction. (author)

  6. Materials interactions relating to long-term geologic disposal of nuclear waste glass

    International Nuclear Information System (INIS)

    Bibler, N.E.; Jantzen, C.M.

    1987-01-01

    In the geologic disposal of nuclear waste glass, the glass will eventually interact with groundwater in the repository system. Interactions can also occur between the glass and other waste package materials that are present. These include the steel canister that holds the glass, the metal overpack over the canister, backfill materials that may be used, and the repository host rock. This review paper systematizes the additional interactions that materials in the waste package will impose on the borosilicate glass waste form-groundwater interactions. The repository geologies reviewed are tuff, salt, basalt, and granite. The interactions emphasized are those appropriate to conditions expected after repository closure, e.g. oxic vs anoxic conditions. Whenever possible, the effect of radiation from the waste form on the interactions is examined. The interactions are evaluated based on their effect on the release and speciation of various elements including radionuclides from the glass. It is noted when further tests of repository interactions are needed before long-term predictions can be made. 63 references, 1 table

  7. Thermal and physicochemical properties important for the long term behavior of nuclear waste glasses

    International Nuclear Information System (INIS)

    Vernaz, E.; Matzke, H.J.

    1992-01-01

    High level nuclear waste from reprocessing of spent nuclear fuel has to be solidified in a stable matrix for safe long-time storage. Vitrification in borosilicate glasses is the technique accepted worldwide. A number of different glasses was developed in different national programs. The criteria and the reasons for selecting the final compositions are briefly described. Emphasis is placed on the French product R7T7 and on thermal and physicochemical properties though glasses developed in other national projects (e.g. the German product GP 98/12 etc.) are also treated. The basic physical and mechanical properties and the chemical durability of the glass in contact with water or other aqueous solutions are described. The basic mechanisms of aqueous corrosion are discussed and the evolving modelling of the leaching process is dealt with, as well as effects of container material, backfill, etc. The thermal behavior has also been studied and extensive data exist on diffusion of glass constituents (Na) and of interesting elements of the waste such as the alkalis Rb and Cs or the actinides U and Pu, as well as on crystallization processes in the glass during storage at elevated temperatures. Emphasis is placed on the radiation stability of the glasses, based on extensive studies using short-lived actinides (e.g. Cm-244) or ion-implantation to produce the damage expected during long storage at an accelerated rate. The radiation stability is shown to be very good, if realistic damage conditions are used. The knowledge accumulated in the past years is used to evaluate and predict the long-term evolution of the glass under storage conditions

  8. Remaining uncertainties in predicting long-term performance of nuclear waste glass from experiments

    International Nuclear Information System (INIS)

    Grambow, B.

    1994-01-01

    The current knowledge on the glass dissolution mechanism and the representation of glass dissolution concepts within overall repository performance assessment models are briefly summarized and uncertainties related to mechanism, radionuclide chemistry and parameters are discussed. Understanding of the major glass dissolution processes has been significantly increased in recent years. Long-term glass stability is related to the long-term maintenance of silica saturated conditions. The behavior of individual radionuclides in the presence of a dissolving glass has not been sufficiently and results do no yet allow meaningful predictions. Conserving long-term predictions of glass matrix dissolution as upper limit for radionuclide release can be made with sufficient confidence, however these estimations generally result in a situation where the barrier function of the glass is masked by the efficiency of the geologic barrier. Realistic long-term predictions may show that the borosilicate waste glass contributes to overall repository safety to a much larger extent than indicated by overconservatism. Today realistic predictions remain highly uncertain and much more research work is necessary. In particular, the long-term rate under silica saturated conditions needs to be understood and the behavior of individual radionuclides in the presence of a dissolving glass deserves more systematic investigations

  9. Thermal stability of the French nuclear waste glass - long term behavior modeling; Etude de la stabilite thermique du verre nucleaire. Modelisation de son evolution a long terme

    Energy Technology Data Exchange (ETDEWEB)

    Orlhac, X

    2000-07-01

    The thermal stability of the French nuclear waste glass was investigated experimentally and by modeling to predict its long-term evolution at low temperature. The crystallization mechanisms were analyzed by studying devitrification in the supercooled liquid. Three main crystalline phases were characterized (CaMoO{sub 4}, CeCO{sub 2}, ZnCr{sub 2}O{sub 4}). Their crystallisation was TO 4.24 wt%, due to the low concentration of the constituent elements. The nucleation and growth curves showed that platinoid elements catalysed nucleation but did not affect growth, which was governed by volume diffusion. The criteria of classic nucleation theory were applied to determine the thermodynamic and diffusional activation energies. Viscosity measurements illustrate the analogy between the activation energy of viscous flow and diffusion, indicating control of crystallization by viscous flow phenomena. The combined action of nucleation and growth was assessed by TTT plots, revealing a crystallization equilibrium line that enables the crystallized fractions to be predicted over the long term. The authors show that hetero-genetics catalyze the transformation without modifying the maximum crystallized fraction. A kinetic model was developed to describe devitrification in the glass based on the nucleation and growth curves alone. The authors show that the low-temperature growth exhibits scale behavior (between time and temperature) similar to thermo-rheological simplicity. The analogy between the resulting activation energy and that of the viscosity was used to model growth on the basis of viscosity. After validation with a simplified (BaO{sub 2}SiO{sub 2}) glass, the model was applied to the containment glass. The result indicated that the glass remained completely vitreous after a cooling scenario with the one measured at the glass core. Under isothermal conditions, several million years would be required to reach the maximum theoretical crystallization fraction. (author)

  10. Contributions of vitreous natural analogs to the investigation of long-term nuclear glass behavior

    International Nuclear Information System (INIS)

    Techer, I.

    1999-01-01

    This study assesses the extend of the analogy between the alteration behavior in water and in a moist clay environment of aluminosilicate volcanic glass and alumino-borosilicate nuclear containment glass. Basaltic glass alteration in water initially occurs by hydrolysis processes with an activation energy on the order of 73 kJ.mol -1 . As the reaction progresses, the alteration rate drops by over four orders of magnitude from the initial rate r 0 , The alteration kinetics are not governed by the alteration solution chemistry alone, the glass alteration film appears to have a major role as a diffusion barrier limiting the transfer of reaction species and products. All these aspects highlight the behavioral analogy between basaltic glass and nuclear borosilicate glass in aqueous media. Conversely, the alteration reaction of obsidian-type volcanic glass involves other mechanisms than those governing the dissolution of borosilicate glass. Basaltic glass alteration is also examined in the presence of a clay environmental material, in a study of the natural basaltic glass and argillaceous pelites system of the Salagou basin in southern France, in an approach combining mineralogical, chemical and isotopic data to assess the interactions between a basaltic glass and the argillaceous pelites. Laboratory leach test results with basaltic glass and measured data for the Salagou glass in its natural environment are modeled using a code implementing a kinetic law coupling diffusive transfer of dissolved silica with a reaction affinity law. (author)

  11. Material interactions relating to long-term geologic disposal of nuclear waste glass

    International Nuclear Information System (INIS)

    Bibler, N.E.; Jantzen, C.M.

    1986-01-01

    This review paper systematizes the additional interactions that materials in a geologic repository will impose on the borosilicate glass waste form-groundwater interactions. These materials are the steel canister that holds the glass, the steel overpack over the canister, backfill materials that may be used, and last, the repository host rock. The repository geologies reviewed are tuff, salt, basalt, and granite. The interactions emphasized are those appropriate to conditions expected after repository closure, e.g., oxic vs anoxic conditions. Whenever possible, the effect of radiation from the waste form on the interaction(s) is examined. The interactions are evaluated based on their effect on the release and speciation of various elements including radionuclides from the glass. Repository relevant interactions testing that requires further study before long-term predictions can be made are noted. 62 refs

  12. A statistical approach to determine the effects of nuclear glass components on the short and long term glass alteration

    International Nuclear Information System (INIS)

    Advocat, Th.; Tovena, I.; Vernaz, E.; Larche, F.; Phan Tan Luu, R.

    1997-01-01

    The experimentation plan methodology may be a powerful tool to design statistical models able to calculate quantitative leach rates as a function of glass compositions. The investigation discussed here implemented an experimentation plan methodology covering a wide range of glass composition variations with two major objectives: - identify the effects of the main component oxides of R7T7 glass (SiO 2 , B 2 O 3 , Al 2 O 3 , Na 2 O+Li 2 O, additive oxides, Fission Products oxides, actinide oxides) on the dissolution rates far and close to equilibrium; - and develop a statistical model relating the measured initial dissolution rate with the selected oxide compositions. A second-degree silica-based model was developed to express the initial dissolution rates at 100 deg C according to the oxide weight percentage of 6 major oxides or oxide groups. The model is qualified by comparison with independent experimental results. For the short term, far from saturation conditions (confined media), plotting the effects of the oxides clearly showed that SiO 2 , Al 2 O 3 and the additive oxides enhanced glass durability at 100 deg C, while B 2 O 3 and Na 2 O+Li 2 O diminished the initial corrosion resistance. For the long term, plotting the effects of the oxides showed that additive oxides, Al 2 O 3 and SiO 2 enhanced glass durability at 90 deg C, in that order, while Na 2 O+Li 2 O still diminished the corrosion resistance. The fission products and actinide oxides and ZrO 2 have apparently a slight beneficial effect on the glass durability, under saturation conditions (long term). (author)

  13. A statistical approach to determine the effects of nuclear glass components on the short and long term glass alteration

    Energy Technology Data Exchange (ETDEWEB)

    Advocat, Th; Tovena, I; Vernaz, E [CEA Valrho, Dir. de l' Energie Nucleaire, DEN, 30 - Marcoule (France); Larche, F [Montpellier-2 Univ., 34 (France); Phan Tan Luu, R [Faculte de St Jerome, 13 - Marseille (France)

    1997-07-01

    The experimentation plan methodology may be a powerful tool to design statistical models able to calculate quantitative leach rates as a function of glass compositions. The investigation discussed here implemented an experimentation plan methodology covering a wide range of glass composition variations with two major objectives: - identify the effects of the main component oxides of R7T7 glass (SiO{sub 2}, B{sub 2}O{sub 3}, Al{sub 2}O{sub 3}, Na{sub 2}O+Li{sub 2}O, additive oxides, Fission Products oxides, actinide oxides) on the dissolution rates far and close to equilibrium; - and develop a statistical model relating the measured initial dissolution rate with the selected oxide compositions. A second-degree silica-based model was developed to express the initial dissolution rates at 100 deg C according to the oxide weight percentage of 6 major oxides or oxide groups. The model is qualified by comparison with independent experimental results. For the short term, far from saturation conditions (confined media), plotting the effects of the oxides clearly showed that SiO{sub 2}, Al{sub 2}O{sub 3} and the additive oxides enhanced glass durability at 100 deg C, while B{sub 2}O{sub 3} and Na{sub 2}O+Li{sub 2}O diminished the initial corrosion resistance. For the long term, plotting the effects of the oxides showed that additive oxides, Al{sub 2}O{sub 3} and SiO{sub 2} enhanced glass durability at 90 deg C, in that order, while Na{sub 2}O+Li{sub 2}O still diminished the corrosion resistance. The fission products and actinide oxides and ZrO{sub 2} have apparently a slight beneficial effect on the glass durability, under saturation conditions (long term). (author)

  14. The role of natural glasses as analogues in projecting the long-term alteration of high-level nuclear waste glasses: Part 1

    International Nuclear Information System (INIS)

    Mazer, J.J.

    1993-01-01

    The common observation of glasses persisting in natural environments for long periods of time (up to tens of millions of years) provides compelling evidence that these materials can be kinetically stable in a variety of subsurface environments. This paper reviews how natural and historical synthesized glasses can be employed as natural analogues for understanding and projecting the long-term alteration of high-level nuclear waste glasses. The corrosion of basaltic glass results in many of the same alteration features found in laboratory testing of the corrosion of high-level radioactive waste glasses. Evidence has also been found indicating similarities in the rate controlling processes, such as the effects of silica concentration on corrosion in groundwater and in laboratory leachates. Naturally altered rhyolitic glasses and tektites provide additional evidence that can be used to constrain estimates of long-term waste glass alteration. When reacted under conditions where water is plentiful, the corrosion for these glasses is dominated by network hydrolysis, while the corrosion is dominated by molecular water diffusion and secondary mineral formation under conditions where water contact is intermittent or where water is relatively scarce. Synthesized glasses that have been naturally altered result in alkali-depleted alteration features that are similar to those found for natural glasses and for nuclear waste glasses. The characteristics of these alteration features appear to be dependent on the alteration conditions which affect the dominant reaction processes during weathering. In all cases, care must be taken to ensure that the information being provided by natural analogues is related to nuclear waste glass corrosion in a clear and meaningful way

  15. The dual effect of Mg on the long-term alteration rate of AVM nuclear waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Thien, Bruno M.J., E-mail: bruno.thien@psi.ch [Commissariat a l' Energie Atomique (CEA), Laboratoire d' Etude du Comportement a Long Terme des Materiaux, DTCD/DEN, Marcoule, 30207 Bagnols sur Ceze (France); Godon, Nicole; Ballestero, Anthony; Gin, Stephane [Commissariat a l' Energie Atomique (CEA), Laboratoire d' Etude du Comportement a Long Terme des Materiaux, DTCD/DEN, Marcoule, 30207 Bagnols sur Ceze (France); Ayral, Andre [Institut Europeen des Membranes, Universite de Montpellier, cc. 047, Place Eugene Bataillon, 34095 Montpellier (France)

    2012-08-15

    Inactive Mg-containing nuclear waste glasses simulating actual HLW glasses produced at the AVM facility since 1995 (Marcoule, France), were leached in aqueous solution in order to assess their long term behaviour. The focus was on the effect of Mg. Our findings show that the distribution of Mg between the gel and the secondary crystalline phases strongly influences the glass dissolution rate. The glasses were leached in initially pure water (T = 50 Degree-Sign C, surface/volume ratio (S/V) = 55 cm{sup -1}) with and without addition of Mg{sup 2+} in the solution. 'Mg-free' AVM glasses were also leached in initially pure water (50 Degree-Sign C, 200 cm{sup -1}) with and without addition of Mg{sup 2+} in the solution. Accurate identification of Mg-smectite secondary phases and gel composition calculations enable us to explain the different observed behaviours. Glass AVM 10 was the less altered glass in pure water. Its gel is more protective than the other probably because it is mainly balanced by Mg{sup 2+}. The addition of Mg{sup 2+} in the solution triggers the precipitation of smectite (not observed in pure water experiments), which consumes silicon from the gel, leading finally to a significant increase of the glass alteration. We also focused on the AVM 6 glass which was the most altered glass in pure water of available AVM glasses. Contrary to AVM 10, the gel of AVM 6 is mainly balanced by Na{sup +}. The addition of Mg{sup 2+} in the solution allows the replacement of Na by Mg within the gel. This reaction clearly improves the gel properties and allows the rate to decrease more rapidly, in spite of the precipitation of smectite (also observed in pure water experiments). Finally, the two glasses were altered in synthetic groundwater (SGW) with a high Mg-Ca content. As expected from the previous observations, AVM 10 was insensitive to the presence of alkaline earths in the leaching solution whereas AVM 6 glass exhibited a lower rate than in pure water

  16. Irradiations effects on the structure of boro-silicated glasses: long term behaviour of nuclear waste glassy matrices

    International Nuclear Information System (INIS)

    Bonfils, J. de

    2007-09-01

    This work deals with the long term behaviour of R7T7-type nuclear waste glasses and more particularly of non-active boro-silicated glasses made up of 3 or 5 oxides. Radioactivity of active glasses is simulated by multi energies ions implantations which reproduce the same defects. The damages due to the alpha particles are simulated by helium ions implantations and those corresponding to the recoil nucleus are obtained with gold ions ones. Minor actinides, stemming from the used fuel, is simulated by trivalent rare-earths (Eu 3+ and Nd 3+ ). In a first part, we have shown by macroscopic experiments (Vickers hardness - swelling) and optical spectroscopies (Raman - ATR-IR) that the structure of the glassy matrices is modified under implantations until a dose of 2,3.10 13 at.cm -2 , which corresponds to a R7T7 storage time estimated at 300 years. Beyond this dose, no additional modifications have been observed. The second part concerns the local environment of the rare-earth ions in glasses. Two different environments were found and identified as follows: one is a silicate rich one and the other is attributed to a borate rich one. (author)

  17. Geochemical modelling of the long-term dissolution behaviour of the French nuclear glass R7T7

    International Nuclear Information System (INIS)

    Michaux, L.; Mouche, E.; Petit, J.-C.; Fritz, B.

    1992-01-01

    The long-term dissolution behaviour of the French nuclear reference glass R7T7 was studied by means of the geochemical code DISSOL. New experimental data which support some of the assumptions of DISSOL are presented: namely, that the dissolution is congruent and that the altered layer can be considered as an assemblage of secondary phases. At 100 o C the main results of modelling are that the altered layer is essentially formed of a pure siliceous phase (amorphous silica or chalcedony) associated with smectites and zeolites. This sequence of secondary minerals is closely linked to the chemical composition of the glass. For high degrees of reaction, corresponding to high B concentration, the ionic strength reaches 1 and the pH varies from 9 to 10 depending on the CO 2 fugacity; B,Li and Na are essentially found in solution and their concentrations depend on the amount of dissolved glass. By contrast Fe,Al and Zn have low solution concentrations which are controlled by solubility products of secondary minerals. Silicon and Ca have an intermediate behaviour which depends on the choice of selected secondary minerals. The total volume of the secondary phases is always lower than that of the corresponding dissolved glass. The results of modelling compared to static leaching experimental results show only minor differences which can be explained by kinetic control or colloid formation. It is concluded that the altered layer is not a barrier to diffusion. The consequences of this work for actinide solubility are also discussed. (author)

  18. Nuclear Energy, Long Term Requirements

    International Nuclear Information System (INIS)

    Knapp, V.

    2006-01-01

    There are serious warnings about depletion of oil and gas and even more serious warnings about dangers of climate change caused by emission of carbon dioxide. Should developed countries be called to replace CO2 emitting energy sources as soon as possible, and the time available may not be longer then few decades, can nuclear energy answer the call and what are the requirements? Assuming optimistic contribution of renewable energy sources, can nuclear energy expand to several times present level in order to replace large part of fossil fuels use? Paper considers intermediate and long-term requirements. Future of nuclear power depends on satisfactory answers on several questions. First group of questions are those important for near and intermediate future. They deal with economics and safety of nuclear power stations in the first place. On the same time scale a generally accepted concept for radioactive waste disposal is also required. All these issues are in the focus of present research and development. Safer and more economical reactors are targets of international efforts in Generation IV and INPRO projects, but aiming further ahead these innovative projects are also addressing issues such as waste reduction and proliferation resistance. However, even assuming successful technical development of these projects, and there is no reason to doubt it, long term and large-scale nuclear power use is thereby not yet secured. If nuclear power is to play an essential role in the long-term future energy production and in reduction of CO2 emission, than several additional questions must be replied. These questions will deal with long-term nuclear fuel sufficiency, with necessary contribution of nuclear power in sectors of transport and industrial processes and with nuclear proliferation safety. This last issue is more political then technical, thus sometimes neglected by nuclear engineers, yet it will have essential role for the long-term prospects of nuclear power. The

  19. The use of natural and archaeological analogues for understanding the long-term behavior of nuclear glasses; L'utilisation des analogues naturels et archeologiques pour la comprehension de l'evolution a long terme des verres nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Libourel, G.; Verney-Carron, A.; Morlok, A. [CNRS UPR2300, centre de recherches petrographiques et geochimiques (CRPG), Nancy-universite, 15, rue Notre-Dame-des-Pauvres, BP 20, 54501 Vandoeuvre-les-Nancy (France); Libourel, G. [INPL, Ecole nationale superieure de geologie (ENSG), Nancy-universite, rue du Doyen-Marcel-Roubault, BP 20, 54501 Vandoeuvre-les-Nancy (France); Gin, St. [CEA Marcoule, DEN/SECM/LCLT, 30 (France); Sterpenich, J. [G2R, CNRS-UMR 7566, Nancy-universite, BP 70239, 54506 Vandoeuvre-les-Nancy cedex (France); Michelin, A.; Neff, D.; Dillmann, Ph. [Laboratoire archeomateriaux et prevision de l' alteration LAPA/SIS2 M, CEA and CNRS, Bat 637, CEA Saclay, 91191 Gif/Yvette cedex (France); Michelin, A.; Dillmann, Ph. [LMC IRAMAT UMR5060 CNRS (France)

    2011-02-15

    The knowledge of the long-term behavior of nuclear waste in anticipation of ultimate disposal in a deep geological formation is of prime importance in a waste management strategy. If phenomenological models have been developed to predict the long-term behavior of these materials, validating these models remains a challenge, when considering the time scale of radioactive decay of radionuclides of environmental concern, typically 10{sup 4}-10{sup 5} yrs. Here we show how natural or archaeological analogues provide critical constraints not only on the phenomenology of glass alteration and the mechanisms involved, but also on the ability of experimental short-term data to predict long-term alteration in complex environments. (authors)

  20. Contribution and limits of geochemical calculation codes to evaluate the long term behavior of nuclear waste glasses

    International Nuclear Information System (INIS)

    Fritz, B.; Crovisier, J.L.

    1997-01-01

    Geochemical models have been intensively developed by researchers since more than twenty five years in order to be able to better understand and/or predict the long term stability/instability of water-rock systems. These geochemical codes were ail built first on a thermodynamic approach deriving from the application of Mass Action Law. The resulting first generation of models allowed to detect or predict the possible mass transfers (thermodynamic models) between aqueous and mineral phases including irreversible dissolutions of primary minerals and/or precipitation near equilibrium of secondary mineral phases. The recent development of models based on combined thermodynamics and kinetics opens the field of Lime dependent reactions prediction. This is crucial if one thinks to combine geochemical and hydrological studies in the so-called coupled models for transport and reaction calculations. All these models are progressively applied to the prediction of long term behavior of mineral phases, and more specifically glasses. In order to succeed in chat specific extension of the models, but also the data bases, there is a great need for additional new data from experimental approaches and from natural analogues. The modelling approach appears than also very useful in order to interpret the results of experimental data and to relate them to long term data extracted from natural analogues. Specific functions for modelling solid solution phases mat' also be used for describing the products of glasses alterations. (authors)

  1. A mechanistic model for long-term nuclear waste glass dissolution integrating chemical affinity and interfacial diffusion barrier

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Teqi [Northwest Institute of Nuclear Technology, No.28 Pingyu Road, Baqiao District, Xi' an,Shaanxi, 710024 (China); Mechanics and Physics of Solids Research Group, Modelling and Simulation Centre, The University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom); Jivkov, Andrey P., E-mail: andrey.jivkov@manchester.ac.uk [Mechanics and Physics of Solids Research Group, Modelling and Simulation Centre, The University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom); Li, Weiping; Liang, Wei; Wang, Yu; Xu, Hui [Northwest Institute of Nuclear Technology, No.28 Pingyu Road, Baqiao District, Xi' an,Shaanxi, 710024 (China); Han, Xiaoyuan, E-mail: xyhan_nint@sina.cn [Northwest Institute of Nuclear Technology, No.28 Pingyu Road, Baqiao District, Xi' an,Shaanxi, 710024 (China)

    2017-04-01

    Understanding the alteration of nuclear waste glass in geological repository conditions is critical element of the analysis of repository retention function. Experimental observations of glass alterations provide a general agreement on the following regimes: inter-diffusion, hydrolysis process, rate drop, residual rate and, under very particular conditions, resumption of alteration. Of these, the mechanisms controlling the rate drop and the residual rate remain a subject of dispute. This paper offers a critical review of the two most competitive models related to these regimes: affinity–limited dissolution and diffusion barrier. The limitations of these models are highlighted by comparison of their predictions with available experimental evidence. Based on the comprehensive discussion of the existing models, a new mechanistic model is proposed as a combination of the chemical affinity and diffusion barrier concepts. It is demonstrated how the model can explain experimental phenomena and data, for which the existing models are shown to be not fully adequate.

  2. Natural analogue of nuclear waste glass in a geologic formation. Study on long-term behavior of volcanic glass shards collected from drill cores

    International Nuclear Information System (INIS)

    Yoshikawa, Hideki; Yui, Mikazu; Futakuchi, Katsuhito; Hiroki, Minenari

    2005-01-01

    Alteration of the volcanic glass in geologic formation was investigated as one of the natural analog for a glass of high-level nuclear waste in geological disposal. We analyzed some volcanic glasses included in the core sample of the bore hole and estimated the history of its burying and observed its alteration using the polarizing microscope. Some information at the piling up temperature and the piling up time was collected. (author)

  3. Influence of clay environment and of corroding canister on the long-term behaviour of nuclear glasses

    International Nuclear Information System (INIS)

    GIn, St.

    1997-01-01

    This article reviews the current state of knowledge of R77 glass alteration mechanisms in the presence of the clay materials under consideration for use in an engineered barrier, and in the presence of metal canister corrosion products. These issues are addressed by a phenomenological approach and by modeling. In most cases, the codes are unable to account for the glass alteration data obtained in clay media. The main reason for this discrepancy lies in the glass alteration kinetics (a first-order law based exclusively on silicon) that do not take into account other elements including aluminum, zirconium or the rare earths, which are strongly mobilized in clay media. (author)

  4. Study of rhyolitic glasses alteration in contact with natural brines (Bolivia). Application to the study of the long-term behaviour of the R7T7 nuclear glass

    International Nuclear Information System (INIS)

    Abdelouas, A.

    1996-01-01

    The purpose of this work is to complement an experimental program on the R7T7 nuclear waste glass alteration in brines at 190 deg C in Germany by the analysis of the structure and the chemical composition of the alteration layers, and to study the alteration of rhyolitic glasses in natural brines from Bolivia as analogue for nuclear waste glasses disposed in salt formations. Alteration experiments with the R7T7 and basaltic glasses and obsidian in MgCl 2 -CaCl 2 -saturated brine at 190 deg. C were also conducted in order to study the influence of the glass composition on the nature of the secondary phases. The experiments with the R7T7 glass in three salt brines, saturated respectively in MgCl 2 , MgCl 2 -CaCl 2 and NaCl, showed that the solubilities of most radionuclides are controlled by the secondary phases. Nd, La, and Pr are trapped in powellite, Ce in cerianite, U in coffinite, and Sr is partially immobilized in barite. These phases are stable for more than one year. There is a good similarity between the secondary phases formed experimentally on volcanic glasses and the R7T7 glass altered in MgCl 2 -CaCl 2 -saturated brine. The abundance of Mg in solution permits the formation of similar magnesian clays on the glass samples independently of the nature of the initial glasses. These results support the use of volcanic glasses alteration patterns in Mg-rich solutions to understand the long-term behavior of nuclear waste glasses and to evaluate the stability of the secondary phases. The study of the sediments of Uyuni (Bolivia) showed that the corrosion rate of the rhyolitic glass in brines at 10 deg. C is 12 to 30 time lower than those of rhyolitic glasses altered in high dilute conditions. The low alteration rate of rhyolitic glasses in brines and the formation of secondary phases such as smectite, barite and cerianite (also formed during the experimental alteration of the R7T7 glass), permit us to expect the low alteration of nuclear waste glasses at long-term

  5. Long-term behavior of glass-ceramic zirconolite

    International Nuclear Information System (INIS)

    Martin, Ch.

    2003-01-01

    This work is a part of the investigation of new containment matrices considered for specific conditioning of radionuclides after separation. The aim was to demonstrate the long-term aqueous corrosion resistance of the glass-ceramic zirconolite considered for the conditioning of plutonium and the minor actinides. This material is composed of crystals of zirconolite (CaZrTi 2 O 7 ) dispersed in a residual vitreous phase. It appears that glass-ceramic zirconolite presents a better kinetic behavior than the nuclear glass R 7T7. This is mainly due to a more important rate decrease that occurs more rapidly, that induces a quantity of glass altered at least 10 times as small as for R 7T7 glass. This high slowdown of the alteration rate is attributed to the formation of an alteration film that has been the subject of a specific study. We have demonstrated that the rate decrease was controlled as for the R7T7 glass by the amorphous phase of the alteration film forming a diffusion barrier for reactive species. It seems that the porosity is not the single parameter that explains the protective effect of the gel. The main differences compared with R7T7 glass are that silicon does not control the alteration of the material and that the gel is composed of two distinct phases. We have in particular identified a dense phase enriched in titanium and neodymium that probably influences deeply the kinetics. (author)

  6. Contributions of vitreous natural analogs to the investigation of long-term nuclear glass behavior; Apports des analogues naturels vitreux a la validation des codes de prediction du comportement a long terme des verres nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Techer, I

    1999-07-01

    This study assesses the extend of the analogy between the alteration behavior in water and in a moist clay environment of aluminosilicate volcanic glass and alumino-borosilicate nuclear containment glass. Basaltic glass alteration in water initially occurs by hydrolysis processes with an activation energy on the order of 73 kJ.mol{sup -1}. As the reaction progresses, the alteration rate drops by over four orders of magnitude from the initial rate r{sub 0}, The alteration kinetics are not governed by the alteration solution chemistry alone, the glass alteration film appears to have a major role as a diffusion barrier limiting the transfer of reaction species and products. All these aspects highlight the behavioral analogy between basaltic glass and nuclear borosilicate glass in aqueous media. Conversely, the alteration reaction of obsidian-type volcanic glass involves other mechanisms than those governing the dissolution of borosilicate glass. Basaltic glass alteration is also examined in the presence of a clay environmental material, in a study of the natural basaltic glass and argillaceous pelites system of the Salagou basin in southern France, in an approach combining mineralogical, chemical and isotopic data to assess the interactions between a basaltic glass and the argillaceous pelites. Laboratory leach test results with basaltic glass and measured data for the Salagou glass in its natural environment are modeled using a code implementing a kinetic law coupling diffusive transfer of dissolved silica with a reaction affinity law. (author)

  7. Contribution and limits of geochemical calculation codes to evaluate the long term behavior of nuclear waste glasses; Apports et limites des modeles geochimiques pour l'evaluation du comportement a long terme des verres de confinement des dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, B; Crovisier, J L [Universite Louis Pasteur, Centre de Geochimie de la Surface, CNRS ULP, Ecole et Observatoire des Sciences de la Terre, 67 - Strasbourg (France)

    1997-07-01

    Geochemical models have been intensively developed by researchers since more than twenty five years in order to be able to better understand and/or predict the long term stability/instability of water-rock systems. These geochemical codes were ail built first on a thermodynamic approach deriving from the application of Mass Action Law. The resulting first generation of models allowed to detect or predict the possible mass transfers (thermodynamic models) between aqueous and mineral phases including irreversible dissolutions of primary minerals and/or precipitation near equilibrium of secondary mineral phases. The recent development of models based on combined thermodynamics and kinetics opens the field of Lime dependent reactions prediction. This is crucial if one thinks to combine geochemical and hydrological studies in the so-called coupled models for transport and reaction calculations. All these models are progressively applied to the prediction of long term behavior of mineral phases, and more specifically glasses. In order to succeed in chat specific extension of the models, but also the data bases, there is a great need for additional new data from experimental approaches and from natural analogues. The modelling approach appears than also very useful in order to interpret the results of experimental data and to relate them to long term data extracted from natural analogues. Specific functions for modelling solid solution phases mat' also be used for describing the products of glasses alterations. (authors)

  8. Long term wet spent nuclear fuel storage

    International Nuclear Information System (INIS)

    1987-04-01

    The meeting showed that there is continuing confidence in the use of wet storage for spent nuclear fuel and that long-term wet storage of fuel clad in zirconium alloys can be readily achieved. The importance of maintaining good water chemistry has been identified. The long-term wet storage behaviour of sensitized stainless steel clad fuel involves, as yet, some uncertainties. However, great reliance will be placed on long-term wet storage of spent fuel into the future. The following topics were treated to some extent: Oxidation of the external surface of fuel clad, rod consolidation, radiation protection, optimum methods of treating spent fuel storage water, physical radiation effects, and the behaviour of spent fuel assemblies of long-term wet storage conditions. A number of papers on national experience are included

  9. Long-term characteristics of nuclear emulsion

    International Nuclear Information System (INIS)

    Naganawa, N; Kuwabara, K

    2010-01-01

    Long-term characteristics of the nuclear emulsion so called 'OPERA film' used in the neutrino oscillation experiment, OPERA, has been studied for 8 years since its production or refreshing after it. In the results, it turned out to be excellent in sensitivity, amount of random noise, and refreshing characteristics. The retention capacity of latent image of tracks was also studied. The result will open the way to the recycling of 7,000,000 emulsion films which will remain not developed after 5 years of OPERA's run, and other long-term experiments with emulsion.

  10. Long-term characteristics of nuclear emulsion

    Science.gov (United States)

    Naganawa, N.; Kuwabara, K.

    2010-02-01

    Long-term characteristics of the nuclear emulsion so called ``OPERA film'' used in the neutrino oscillation experiment, OPERA, has been studied for 8 years since its production or refreshing after it. In the results, it turned out to be excellent in sensitivity, amount of random noise, and refreshing characteristics. The retention capacity of latent image of tracks was also studied. The result will open the way to the recycling of 7,000,000 emulsion films which will remain not developed after 5 years of OPERA's run, and other long-term experiments with emulsion.

  11. Evaluation of long term leaching of borosilicate glasses

    International Nuclear Information System (INIS)

    Lanza, F.; Parnisari, E.

    1978-01-01

    For the evaluation of long term hazard of glass, data on long term glass leaching are needed. Moreover for long term leaching a model of homogeneous dissolution seems reasonable and ask for confirmation. Tests were performed at 30 0 , 80 0 , 100 0 , using an apparatus of the Soxhlet type, to 3.600 hours. Results were obtained as a weight loss and analysed following a relation with time composed by a parabolic and a linear part. Analysis of the surface layer using energy dispersion X ray spectrometry were performed. A critical analysis of the results and of the apparatus is presented

  12. The long-term nuclear explosives predicament

    International Nuclear Information System (INIS)

    Swahn, J.

    1992-01-01

    A scenario is described, where the production of new military fissile materials is halted and where civil nuclear power is phased out in a 'no-new orders' case. It is found that approximately 1100 tonnes of weapons-grade uranium, 233 tonnes of weapons-grade plutonium and 3795 tonnes of reactor-grade plutonium have to be finally disposed of as nuclear waste. This material could be used for the construction of over 1 million nuclear explosives. Reactor-grade plutonium is found to be easier to extract from spent nuclear fuel with time and some physical characteristics important for the construction of nuclear explosives are improved. Alternative methods for disposal of the fissile material that will avoid the long-term nuclear explosives predicament are examined. Among these methods are dilution, denaturing or transmutation of the fissile material and options for practicably irrecoverable disposal in deep boreholes, on the sea-bed, and in space. It is found that the deep boreholes method for disposal should be the primary alternative to be examined further. This method can be combined with an effort to 'forget' where the material was put. Included in the thesis is also an evaluation of the possibilities of controlling the limited civil nuclear activities in a post-nuclear world. Some surveillance technologies for a post-nuclear world are described, including satellite surveillance. In a review part of the thesis, methods for the production of fissile material for nuclear explosives are described, the technological basis for the construction of nuclear weapons is examined, including use of reactor-grade plutonium for such purposes; also plans for the disposal of spent fuel from civil nuclear power reactors and for the handling of the fissile material from dismantled warheads is described. The Swedish plan for the handling and disposal of spent nuclear fuel is described in detail. (490 refs., 66 figs., 27 tabs.)

  13. Dissolution rates of DWPF glasses from long-term PCT

    International Nuclear Information System (INIS)

    Ebert, W.L.; Tam, S.W.

    1996-01-01

    We have characterized the corrosion behavior of several Defense Waste Processing Facility (DWPF) reference waste glasses by conducting static dissolution tests with crushed glasses. Glass dissolution rates were calculated from measured B concentrations in tests conducted for up to five years. The dissolution rates of all glasses increased significantly after certain alteration phases precipitated. Calculation of the dissolution rates was complicated by the decrease in the available surface area as the glass dissolves. We took the loss of surface area into account by modeling the particles to be spheres, then extracting from the short-term test results the dissolution rate corresponding to a linear decrease in the radius of spherical particles. The measured extent of dissolution in tests conducted for longer times was less than predicted with this linear dissolution model. This indicates that advanced stages of corrosion are affected by another process besides dissolution, which we believe to be associated with a decrease in the precipitation rate of the alteration phases. These results show that the dissolution rate measured soon after the formation of certain alteration phases provides an upper limit for the long-term dissolution rate, and can be used to determine a bounding value for the source term for radionuclide release from waste glasses. The long-term dissolution rates measured in tests at 20,000 per m at 90 degrees C in tuff groundwater at pH values near 12 for the Environmental Assessment glass and glasses made with SRL 131 and SRL 202 frits, respectively

  14. The prediction of the long-term behaviour of glasses

    International Nuclear Information System (INIS)

    Courtois, Ch.; Regent, A.; Plas, F.

    1997-01-01

    Several experts draw a conclusion about the scientific content of this week-long seminar. All agree to highlight the variety and quality of the work done. It appears that there is a consensus about the phenomenology of the long-term behaviour of glasses. All the parameters that are likely to intervene in alteration processes have been identified, but some particular points require further studies: - the impact of alpha, beta and gamma irradiation, - the alteration of glass in no-saturated water, - the coupling effect with the materials surrounding glass (metal canister, over-container...), - the optimization of glass composition to deal with high burn-up spent fuels, - the relation between the formation free energy of glasses and their alteration kinetics, - the release of radionuclides trapped in glass, and - the use of mutual analogue. (A.C.)

  15. Irradiations effects on the structure of boro-silicated glasses: long term behaviour of nuclear waste glassy matrices; Effets d'irradiations sur la structure de verres borosilicates - comportement a long terme des matrices vitreuses de stockage des dechets nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Bonfils, J. de

    2007-09-15

    This work deals with the long term behaviour of R7T7-type nuclear waste glasses and more particularly of non-active boro-silicated glasses made up of 3 or 5 oxides. Radioactivity of active glasses is simulated by multi energies ions implantations which reproduce the same defects. The damages due to the alpha particles are simulated by helium ions implantations and those corresponding to the recoil nucleus are obtained with gold ions ones. Minor actinides, stemming from the used fuel, is simulated by trivalent rare-earths (Eu{sup 3+} and Nd{sup 3+}). In a first part, we have shown by macroscopic experiments (Vickers hardness - swelling) and optical spectroscopies (Raman - ATR-IR) that the structure of the glassy matrices is modified under implantations until a dose of 2,3.10{sup 13} at.cm{sup -2}, which corresponds to a R7T7 storage time estimated at 300 years. Beyond this dose, no additional modifications have been observed. The second part concerns the local environment of the rare-earth ions in glasses. Two different environments were found and identified as follows: one is a silicate rich one and the other is attributed to a borate rich one. (author)

  16. Effects of MgO on short and long term stabilities in water of R7T7 and M7 nuclear waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Advocat, T; Vernaz, E; Dussossoy, J [CEA Centre d` Etudes de la Vallee du Rhone, 30 - Marcoule (France). Dept. des Procedes de Retraitement; Crovisier, J L [Centre National de la Recherche Scientifique (CNRS), 67 - Strasbourg (France)

    1993-12-31

    Magnesium oxide was added to the standard R7T7 and M7 glass compositions developed for containment of fission product solutions. M7 differs from the R7T7 reference glass mainly by a larger proportion of network modifier elements and a correspondingly lower proportion of glass network forming elements. The percentage of fission products, simulated in this study by inactive elements, was the same in both cases. Increasing the MgO content of the glass compositions by 2 to 5 wt% resulted in significant variations in the aqueous leaching resistance at 90 and 100 deg C. Experimental findings demonstrated that the initial dissolution rate measured at 100 deg C in a Soxhlet apparatus was proportional to the MgO content and inversely proportional to the network former content (mainly SiO2). This was confirmed by a glass hydration model based on the thermodynamic stability of the glass matrix components. Aqueous corrosion tests were also conducted at 90 deg C under static conditions at various SA/V ratios to simulate the progress of the reaction. Under these conditions, the glass dissolution rate diminished more slowly in time when the initial magnesium content was high and the network former content was low. This may be due primarily to a variation in the glass silica solubility limit related to the glass composition; it may also be related to the formation of secondary silica and magnesia alteration products controlling the glass dissolution reaction affinity.

  17. Long-Term Nuclear Industry Outlook - 2004

    Energy Technology Data Exchange (ETDEWEB)

    Reichmuth, Barbara A.; Wood, Thomas W.; Johnson, Wayne L.

    2004-09-30

    The nuclear industry has become increasingly efficient and global in nature, but may now be poised at a crossroads between graceful decline and profound growth as a viable provider of electrical energy. Predicted population and energy-demand growth, an increased interest in global climate change, the desire to reduce the international dependence on oil as an energy source, the potential for hydrogen co-generation using nuclear power reactors, and the improved performance in the nuclear power industry have raised the prospect of a “nuclear renaissance” in which nuclear power would play an increasingly more important role in both domestic and international energy market. This report provides an assessment of the role nuclear-generated power will plan in the global energy future and explores the impact of that role on export controls.

  18. Long term panorama of the nuclear technology

    International Nuclear Information System (INIS)

    Velez, C.

    2009-01-01

    The concern for the security of the hydrocarbons supply, essentials for the transport and every time more important in the electricity production, it is one of the rebirth causes of interest for the nuclear energy. On the other hand, it is the increase of the hydrocarbons price. In some countries, included Mexico, the price of gas is subject to strong seasonal fluctuations, aggravating by the congestion of the ducts. It is certain that great part of the prices rise of petroleum that we are experiencing is due to speculation, for what it is necessary to look for objective elements that allow to venture in the difficult topic of the future price of crude. One finishes reason of the resurgence of interest for the nuclear energy, is the growing perception that with the gases emission of greenhouse effect we are exposing our planet to an uncontrollable experiment with consequences potentially catastrophic. This perception is translated in a pressure of the public opinion for to use renewable energy sources that do not contribute to the greenhouse effect. In this work a general panorama is exposed on the advances that exist at the present time, like nuclear reactors with the purpose of solving the current problem that the world is crossing. (Author)

  19. The long-term outlook for nuclear capacity in Ontario

    International Nuclear Information System (INIS)

    Archinoff, G.H.

    1979-04-01

    This report derives three estimates of long-term nuclear growth in Ontario for use in strategy studies of alternate nuclear fuel cycles. The low and high estimates encompass the full range of possible long-term nuclear growth rates. The middle, or base growth, estimate represents the nuclear growth pattern which seems at the present time most likely to occur. For the base growth estimate, nuclear capacity in Ontario reaches 31 GWe in 2000, grows to 175 GWe by 2060, and then remains constant. For the high growth estimate, the capacity in 2000 is 33 GWe, and climbs continuously to 833 GWe by the year 2100. (auth)

  20. The composition effect on the long-term corrosion of high-level waste glass

    Energy Technology Data Exchange (ETDEWEB)

    Hrma, P. [Pacific Northwest National Laboratory, Richland, Washington (United States)

    1997-07-01

    Waste glass can be optimized for long-term corrosion behavior if the key parameters that control the rate of corrosion are identified, measured, and modeled as functions of glass composition. Second-order polynomial models have been used to optimize glass with respect to a set of requirements on glass properties, such as viscosity and outcomes of standard corrosion tests. Extensive databases exist for the 7-day Product Consistency Test and the 28-day Materials Characterization Center tests, which have been used for nuclear waste glasses in the United States. Models based on these tests are reviewed and discussed to demonstrate the compositional effects on the extent of corrosion under specified conditions. However, modeling the rate of corrosion is potentially more useful for predicting long-term behavior than modeling the extent of corrosion measured by standard tests. Based on an experimental study of two glasses, it is shown that the rate of corrosion can be characterized by simple functions with physically meaningful coefficients. (author)

  1. Polymers in nuclear environment - long term behaviour

    International Nuclear Information System (INIS)

    Audouin, Laurent; Colin, Xavier; Fayolle, Bruno; Richaud, Emmanuel

    2012-01-01

    This bibliographical note presents a book which addresses original theoretical tools which are required for the prediction of polymer life time in a nuclear environment, and notably the kinetic modelling of low dose rate radiation-induced oxidation and the consequences of irradiation on thermo-mechanical properties. The authors discuss the anaerobic radiochemical ageing, the general aspects of radio-oxidation, the radio-thermo-oxidation, and the effects of radiochemical ageing on mechanical properties of industrial polymers. They identify research fields for the radiochemical ageing of polymers

  2. Results from the long-term interaction and modeling of SRL-131 glass with aqueous solutions

    International Nuclear Information System (INIS)

    Strachan, D.M.; Pederson, L.R.; Lokken, R.O.

    1985-11-01

    Leaching studies of SRL-131 simulated defense nuclear waste glass have been carried out to two years duration, in leachants that simulate groundwaters of different ionic strengths. The leachability of SRL-131 glass followed the trend: deionized water > silicate water > salt brine = simulated groundwater at 40 0 C and deionized water = simulated groundwater > silicate water > salt brine at 90 0 C. The results are in general agreement with calculations using the PHREEQE geochemical code and indicate a sometimes complex sequence temperature dependent of mineral precipitation and redissolution. The calculations done in this study have illustrated the complexity of the precipitation sequence of mineral phases as a function of reaction progress. Complex, temperature dependent, precipitation/dissolution sequences have also been observed in experiments using natural materials, such as sea water and basaltic glass. The results of this two-year study point to the need for further work in establishing the thermodynamics of the observed phases and the relationship of these phases to the thermodynamically favored suite of phases for any given waste form/host rock/groundwater system. In order to study these phases, very long-term experiments may be necessary so that the phases grow to sizes which can be studied. In addition, geochemical codes should be used to better understand the experiments, to design leach test matrices, and to help predict the long-term results of experiments. The combination of long-term experiments and geochemical codes should lead to an improved method for forecasting the long-term behavior of a nuclear waste repository. 15 refs., 3 figs., 4 tabs

  3. Long-term physical ageing in As-Se glasses with short chalcogen chains

    International Nuclear Information System (INIS)

    Golovchak, R; Shpotyuk, O; Kozdras, A; Vlcek, M; Bureau, B; Kovalskiy, A; Jain, H

    2008-01-01

    Long-term physical ageing of chalcogenide glasses, which occurs over tens of years, is much less understood than the short-term ageing. With Se-rich underconstrained As 30 Se 70 glass as a model composition (consisting of Se n chains with n≤3 on average), a microscopic model is developed for this phenomenon by combining information from differential scanning calorimetry, extended x-ray absorption fine structure, Raman, and 77 Se solid state nuclear magnetic resonance spectroscopies. The accompanying changes in the electronic structure of these glasses are investigated by x-ray photoelectron spectroscopy. The data suggest ageing from cooperative relaxation, presumably involving bond switching or reconfiguration of As-Se-Se-As fragments

  4. Long-term physical ageing in As-Se glasses with short chalcogen chains

    Energy Technology Data Exchange (ETDEWEB)

    Golovchak, R; Shpotyuk, O [Lviv Scientific Research Institute of Materials of SRC ' Carat' , 202, Stryjska street, Lviv, UA-79031 (Ukraine); Kozdras, A [Faculty of Physics of Opole University of Technology, 75, Ozimska street, Opole, 45370 (Poland); Vlcek, M [Department of General and Inorganic Chemistry, Faculty of Chemistry, University of Pardubice, 532 10 Pardubice (Czech Republic); Bureau, B [Verres et Ceramiques, UMR CNRS 6226 Sciences Chimiques de Rennes, University of Rennes, 1, Campus de Beaulieu, Rennes, 35042 (France); Kovalskiy, A; Jain, H [Department of Materials Science and Engineering, Lehigh University, 5, East Packer Avenue, Bethlehem, PA 18015-3195 (United States)

    2008-06-18

    Long-term physical ageing of chalcogenide glasses, which occurs over tens of years, is much less understood than the short-term ageing. With Se-rich underconstrained As{sub 30}Se{sub 70} glass as a model composition (consisting of Se{sub n} chains with n{<=}3 on average), a microscopic model is developed for this phenomenon by combining information from differential scanning calorimetry, extended x-ray absorption fine structure, Raman, and {sup 77}Se solid state nuclear magnetic resonance spectroscopies. The accompanying changes in the electronic structure of these glasses are investigated by x-ray photoelectron spectroscopy. The data suggest ageing from cooperative relaxation, presumably involving bond switching or reconfiguration of As-Se-Se-As fragments.

  5. Long-Term Problems of Nuclear Energy, December 1976

    International Nuclear Information System (INIS)

    Broda, E.

    1976-01-01

    The Text was written by Enelbert Broda in Oktober 1976. In this report, the physicist and chemist Engelbert Broda discusses various areas of peaceful uses of nuclear energy and concludes that the negative aspects outweigh the positive and that the use of nuclear energy has to be rejected in the long term. In 16 chapters the biggest and most dangerous problems are discussed. Include the unresolved question of disposal, problems of reprocessing and transport of fissile materials, the proliferation of nuclear weapons technology, risks of terrorism, dismantling and decontamination of old nuclear power plants, the toxicity of fissile material, as well as the general unprofitable use of nuclear power plants. As a long-term alternative the author suggests an intensification of the exploitation of solar energy, as well as a deliberate restriction of the rising demand for energy.(roessner)

  6. Long-Term Problems of Nuclear Energy, October 1976

    International Nuclear Information System (INIS)

    Broda, E.

    1976-01-01

    The Text was written by Enelbert Broda in Oktober 1976. In this report, the physicist and chemist Engelbert Broda discusses various areas of peaceful uses of nuclear energy and concludes that the negative aspects outweigh the positive and that the use of nuclear energy has to be rejected in the long term. In 16 chapters the biggest and most dangerous problems are discussed. Include the unresolved question of disposal, problems of reprocessing and transport of fissile materials, the proliferation of nuclear weapons technology, risks of terrorism, dismantling and decontamination of old nuclear power plants, the toxicity of fissile material, as well as the general unprofitable use of nuclear power plants. As a long-term alternative the author suggests an intensification of the exploitation of solar energy, as well as a deliberate restriction of the rising demand for energy.(roessner) [de

  7. Use of natural and archaeological analogs to validate long - term behaviour of HLW glass in geological disposal conditions

    International Nuclear Information System (INIS)

    Gin, S.; Verney-Carron, A.; Libourel, G.

    2008-01-01

    Some old basaltic and Roman glasses have been studied in order to validate the predictive models developed for assessing the long-term behaviour of nuclear glass in geological repository conditions. Leaching behaviour of basaltic glass altered in both laboratory and natural environment conditions allows to validate the key mechanisms that control glass dissolution kinetics and the order of magnitude of glass packages lifetime In a stable clayey formation (French reference concept for a geological disposal of high level waste). The study of Roman glass blocks (with the same geometry as nuclear glass package) altered during 1800 years in a marine environment gives new insight on the basic mechanisms involved in confined media (fractures and small cracks). Results show the importance of the coupling between transport of reactive species and chemical reactions. This study, still in progress, would allow to validate the modelling of such a complex system. (author)

  8. Long-term behavior of glass-ceramic zirconolite; Etude du comportement a long terme des vitrocristallins a base de zirconolite

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Ch

    2003-07-01

    This work is a part of the investigation of new containment matrices considered for specific conditioning of radionuclides after separation. The aim was to demonstrate the long-term aqueous corrosion resistance of the glass-ceramic zirconolite considered for the conditioning of plutonium and the minor actinides. This material is composed of crystals of zirconolite (CaZrTi{sub 2}O{sub 7}) dispersed in a residual vitreous phase. It appears that glass-ceramic zirconolite presents a better kinetic behavior than the nuclear glass R 7T7. This is mainly due to a more important rate decrease that occurs more rapidly, that induces a quantity of glass altered at least 10 times as small as for R 7T7 glass. This high slowdown of the alteration rate is attributed to the formation of an alteration film that has been the subject of a specific study. We have demonstrated that the rate decrease was controlled as for the R7T7 glass by the amorphous phase of the alteration film forming a diffusion barrier for reactive species. It seems that the porosity is not the single parameter that explains the protective effect of the gel. The main differences compared with R7T7 glass are that silicon does not control the alteration of the material and that the gel is composed of two distinct phases. We have in particular identified a dense phase enriched in titanium and neodymium that probably influences deeply the kinetics. (author)

  9. Long-term leach rates of glasses containing actual waste

    International Nuclear Information System (INIS)

    Wiley, J.R.; LeRoy, J.H.

    1979-01-01

    Leach rates of borosilicate glasses that contained actual Savannah River Plant waste were measured. Leaching was done by water and by buffer solutions of pH 4, 7, and 9. Leach rates were then determined from the amount of 137 Cs, 90 Sr, and Pu released into the leach solutions. The cumulative fractions leached were fit to a mathematical model that included leaching by diffusion and glass dissolution

  10. Long-term leach rates of glasses containing actual waste

    International Nuclear Information System (INIS)

    Wiley, J.R.; LeRoy, J.H.

    1979-01-01

    Leach rates of borosilicate glasses that contained actual Savannah River Plant waste were measured. Leaching was done by water and by buffer solutions of pH 4, 7, and 9. Leach rates were then determined from the amount of 137 Cs, 90 Sr, and plutonium released into the leach solutions. The cumulative fractions leached were fit to a mathematical model that included leaching by diffusion and glass dissolution. 5 figures, 3 tables

  11. Nuclear energy; real problems of the long term development

    International Nuclear Information System (INIS)

    Knapp, V.

    1996-01-01

    Whilst general public accepts the operation of western designed nuclear power stations as safe, waste management and decommission still figure as open problems, although such views are not in agreement with technical and economic status of these operations. A concern with imagined problems can have the effect of neglecting the real ones. In considering the long term development of nuclear energy the real problems can be associated with the wide use of plutonium and multiplication of national reprocessing and enrichment installations. Nuclear proliferation safety could be retained and developed through establishment of international nuclear fuel centres. Their operation would be particularly beneficial for small or medium nuclear countries. Several arguments are given why it is not premature to initiate a study which would identify and analyze the problems of establishing an international nuclear fuel centre. Central Europe could be a region which could be served by one of such nuclear fuel centres. (author)

  12. Long-term global nuclear energy and fuel cycle strategies

    International Nuclear Information System (INIS)

    Krakowski, R.A.

    1997-01-01

    The Global Nuclear Vision Project is examining, using scenario building techniques, a range of long-term nuclear energy futures. The exploration and assessment of optimal nuclear fuel-cycle and material strategies is an essential element of the study. To this end, an established global E 3 (energy/economics/environmental) model has been adopted and modified with a simplified, but comprehensive and multi-regional, nuclear energy module. Consistent nuclear energy scenarios are constructed using this multi-regional E 3 model, wherein future demands for nuclear power are projected in price competition with other energy sources under a wide range of long-term demographic (population, workforce size and productivity), economic (price-, population-, and income-determined demand for energy services, price- and population-modified GNP, resource depletion, world-market fossil energy prices), policy (taxes, tariffs, sanctions), and top-level technological (energy intensity and end-use efficiency improvements) drivers. Using the framework provided by the global E 3 model, the impacts of both external and internal drivers are investigated. The ability to connect external and internal drivers through this modeling framework allows the study of impacts and tradeoffs between fossil- versus nuclear-fuel burning, that includes interactions between cost, environmental, proliferation, resource, and policy issues

  13. Long-term global nuclear energy and fuel cycle strategies

    Energy Technology Data Exchange (ETDEWEB)

    Krakowski, R.A. [Los Alamos National Lab., NM (United States). Technology and Safety Assessment Div.

    1997-09-24

    The Global Nuclear Vision Project is examining, using scenario building techniques, a range of long-term nuclear energy futures. The exploration and assessment of optimal nuclear fuel-cycle and material strategies is an essential element of the study. To this end, an established global E{sup 3} (energy/economics/environmental) model has been adopted and modified with a simplified, but comprehensive and multi-regional, nuclear energy module. Consistent nuclear energy scenarios are constructed using this multi-regional E{sup 3} model, wherein future demands for nuclear power are projected in price competition with other energy sources under a wide range of long-term demographic (population, workforce size and productivity), economic (price-, population-, and income-determined demand for energy services, price- and population-modified GNP, resource depletion, world-market fossil energy prices), policy (taxes, tariffs, sanctions), and top-level technological (energy intensity and end-use efficiency improvements) drivers. Using the framework provided by the global E{sup 3} model, the impacts of both external and internal drivers are investigated. The ability to connect external and internal drivers through this modeling framework allows the study of impacts and tradeoffs between fossil- versus nuclear-fuel burning, that includes interactions between cost, environmental, proliferation, resource, and policy issues.

  14. Long-term storage of spent nuclear fuel

    International Nuclear Information System (INIS)

    Kempe, T.F.; Martin, A.; Thorne, M.C.

    1980-06-01

    This report presents the results of a study on the storage of spent nuclear fuel, with particular reference to the options which would be available for long-term storage. Two reference programmes of nuclear power generation in the UK are defined and these are used as a basis for the projection of arisings of spent fuel and the storage capacity which might be needed. The characteristics of spent fuel which are relevant to long-term storage include the dimensions, materials and physical construction of the elements, their radioactive inventory and the associated decay heating as a function of time after removal from the reactor. Information on the behaviour of spent fuel in storage ponds is reviewed with particular reference to the corrosion of the cladding. The review indicates that, for long-term storage, both Magnox and AGR fuel would need to be packaged because of the high rate of cladding corrosion and the resulting radiological problems. The position on PWR fuel is less certain. Experience of dry storage is less extensive but it appears that the rate of corrosion of cladding is much lower than in water. Unit costs are discussed. Consideration is given to the radiological impact of fuel storage. (author)

  15. Global prospects for nuclear power development in the long term

    International Nuclear Information System (INIS)

    Semenov, Boris A.

    1994-01-01

    Population growth, economic development and improvement of quality of life will lead to significant increase of electricity consumption worldwide with more rapid growth in developing and newly industrialised countries. At the same time, concerns for environmental protection and security of supply will call for the development of alternatives to fossil fuels for electricity generation. Sustain ability will be a major driving factor for the choice of electricity generation options and strategies. Costs, and macro-economic and social impacts, will also influence future strategies in the electricity sector. Since renewable sources require significant development efforts to reach competitiveness, nuclear power is the most likely non-fossil source to be deployed on a large scale for base load electricity generation. Nuclear power is already a proven technology providing a significant share of electricity supply worldwide. In several countries, including the Republic of Korea, nuclear generated electricity is a major contributor to secure and competitive electricity supply. Technological progress aiming towards enhancing safety as well as technical and economic performance of nuclear power plants will enlarge the potential market share of nuclear generated electricity. The purpose of the paper is to give an overview of the prospects for nuclear power development in the world in the medium and long term. For the short term, up to 2005, projections of nuclear power installed capacities are rather straightforward to establish. The Agency publishes such projections every years, based upon a review of nuclear programmes in Member States. For the medium term, up to 2015, two illustrative cases have been developed by the IAEA reflecting contrasted, but not extreme, assumptions on the different parameters influencing nuclear power deployment worldwide. The paper gives estimations of the installed nuclear capacity, and of the share of nuclear power in total electricity and energy

  16. Prediction of long-term behaviour for nuclear waste disposal

    International Nuclear Information System (INIS)

    Shoesmith, D.W.; Ikeda, B.M.; King, F.; Sunder, S.

    1996-09-01

    The modelling procedures developed for the long-term prediction of the corrosion of used fuel and of titanium and copper nuclear waste containers are described. The corrosion behaviour of these materials changes with time as the conditions within the conceptual disposal vault evolve from an early warm, oxidizing phase to an indefinite period of cool, anoxic conditions. For the two candidate container materials, this evolution of conditions means that the containers will be initially susceptible to localized corrosion but that in the long-term, corrosion should be more general in nature. The propagation of the pitting of Cu and of the crevice corrosion of Ti alloys is modelled using statistical models. General corrosion processes are modelled deterministically. For the fuel, deterministic electrochemical models have been developed to predict the long-term dissolution rate of U0 2 . The corrosion behaviour of materials in the disposal vault can be influenced by reengineering the vault environment. For instance, increasing the areal loading of containers will produce higher vault temperatures resulting in more extensive drying of the porous backfill materials. The initiation of crevice corrosion on Ti may then be delayed, leading to longer container lifetimes. For copper containers, minimizing the amount Of O 2 initially trapped in the pores of the backfill, or adding reducing agents to consume this O 2 faster, will limit the extent of corrosion, permitting a reduction of the container wall thickness necessary for containment. (author). 55 refs., 19 figs

  17. Corrosion of Spent Nuclear Fuel: The Long-Term Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rodney C. Ewing

    2004-10-07

    Spent nuclear fuel, essentially U{sub 2}, accounts for over 95% of the total radioactivity of all of the radioactive wastes in the United States that require disposal, disposition or remediation. The UO{sub 2} in SNF is not stable under oxiding conditions and may also be altered under reducing conditions. The alteration of SNF results in the formation of new uranium phases that can cause the release or retardation of actinide and fission product radionuclides. Over the long term, and depending on the extent to which the secondary uranium phases incorporate fission products and actinides, these alteration phases become the near-field source term.

  18. Corrosion of Spent Nuclear Fuel: The Long-Term Assessment

    International Nuclear Information System (INIS)

    Ewing, Rodney C.

    2004-01-01

    Spent nuclear fuel, essentially U 2 , accounts for over 95% of the total radioactivity of all of the radioactive wastes in the United States that require disposal, disposition or remediation. The UO 2 in SNF is not stable under oxiding conditions and may also be altered under reducing conditions. The alteration of SNF results in the formation of new uranium phases that can cause the release or retardation of actinide and fission product radionuclides. Over the long term, and depending on the extent to which the secondary uranium phases incorporate fission products and actinides, these alteration phases become the near-field source term

  19. Long-term cost targets for nuclear energy

    International Nuclear Information System (INIS)

    Rogner, H.H.; McDonald, A.

    2004-01-01

    In 2000 the International Atomic Energy Agency (IAEA) began the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO) to help guide nuclear R and D strategies targeted on anticipated mid-century energy system needs. One part of INPRO seeks to develop cost targets for new designs to be competitive in mid-century markets. The starting point was the 40 scenarios of the Special Report on Emissions Scenarios (SRES) of the Intergovernmental Panel on Climate Change. This paper summarizes four of the SRES scenarios, one from each of the four SRES scenario families. It discusses their implications for nuclear energy, including cost targets, and develops for each an 'aggressive nuclear' variant. The aggressive nuclear variants estimate the potential market for nuclear energy if, by improving faster than assumed by the SRES authors, nuclear energy can make inroads into vulnerable market shares projected for its competitors. In addition to projected demands for nuclear generated electricity, hydrogen and heat, the aggressive variants include prospective demand for nuclear desalination and use in upgrading fossil fuels. The paper then presents learning rates and implied cost targets consistent with the aggressive nuclear variants of the SRES scenarios. One provocative initial result is that many of the scenarios with substantial nuclear expansion do not seem to require big reductions in nuclear investment costs. One interpretation discussed at the end of the paper highlights the difference between cost reductions consistent with long-term energy system optimization based on perfect foresight, and cost reductions necessary to attract private investment in today's 'deregulating' and uncertain energy markets. (orig.)

  20. Corrosion of Spent Nuclear Fuel: The Long-Term Assessment

    International Nuclear Information System (INIS)

    Ewing, Rodney C.

    2003-01-01

    The successful disposal of spent nuclear fuel (SNF) is one of the most serious challenges to the successful completion of the nuclear fuel cycle and the future of nuclear power generation. In the United States, 21 percent of the electricity is generated by 107 commercial nuclear power plants (NPP), each of which generates 20 metric tons of spent nuclear fuel annually. In 1996, the total accumulation of spent nuclear fuel was 33,700 metric tons of heavy metal (MTHM) stored at 70 sites around the country. The end-of-life projection for current nuclear power plants (NPP) is approximately 86,000 MTHM. In the proposed nuclear waste repository at Yucca Mountain over 95% of the radioactivity originates from spent nuclear fuel. World-wide in 1998, approximately 130,000 MTHM of SNF have accumulated, most of it located at 236 NPP in 36 countries. Annual production of SNF is approximately 10,000 MTHM, containing about 100 tons of ''reactor grade'' plutonium. Any reasonable increase in the proportion of energy production by NPP, i.e., as a substitute for hydrocarbon-based sources of energy, will significantly increase spent nuclear fuel production. Spent nuclear fuel is essentially UO 2 with approximately 4-5 atomic percent actinides and fission product elements. A number of these elements have long half-lives hence, the long-term behavior of the UO 2 is an essential concern in the evaluation of the safety and risk of a repository for spent nuclear fuel. One of the unique and scientifically most difficult aspects of the successful disposal of spent nuclear fuel is the extrapolation of short-term laboratory data (hours to years) to the long time periods (10 3 to 10 5 years) as required by the performance objectives set in regulations, i.e. 10 CFR 60. The direct verification of these extrapolations or interpolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the public that there is a reasonable basis for

  1. Corrosion of Spent Nuclear Fuel: The Long-Term Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, Rodney C.

    2003-09-14

    The successful disposal of spent nuclear fuel (SNF) is one of the most serious challenges to the successful completion of the nuclear fuel cycle and the future of nuclear power generation. In the United States, 21 percent of the electricity is generated by 107 commercial nuclear power plants (NPP), each of which generates 20 metric tons of spent nuclear fuel annually. In 1996, the total accumulation of spent nuclear fuel was 33,700 metric tons of heavy metal (MTHM) stored at 70 sites around the country. The end-of-life projection for current nuclear power plants (NPP) is approximately 86,000 MTHM. In the proposed nuclear waste repository at Yucca Mountain over 95% of the radioactivity originates from spent nuclear fuel. World-wide in 1998, approximately 130,000 MTHM of SNF have accumulated, most of it located at 236 NPP in 36 countries. Annual production of SNF is approximately 10,000 MTHM, containing about 100 tons of ''reactor grade'' plutonium. Any reasonable increase in the proportion of energy production by NPP, i.e., as a substitute for hydrocarbon-based sources of energy, will significantly increase spent nuclear fuel production. Spent nuclear fuel is essentially UO{sub 2} with approximately 4-5 atomic percent actinides and fission product elements. A number of these elements have long half-lives hence, the long-term behavior of the UO{sub 2} is an essential concern in the evaluation of the safety and risk of a repository for spent nuclear fuel. One of the unique and scientifically most difficult aspects of the successful disposal of spent nuclear fuel is the extrapolation of short-term laboratory data (hours to years) to the long time periods (10{sup 3} to 10{sup 5} years) as required by the performance objectives set in regulations, i.e. 10 CFR 60. The direct verification of these extrapolations or interpolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the

  2. Corrosion of Spent Nuclear Fuel: The Long-Term Assessment

    International Nuclear Information System (INIS)

    Ewing, Rodney C.

    2003-01-01

    This research program is a broadly based effort to understand the long-term behavior of spent nuclear fuel (SNF) and its alteration products in a geologic repository. We have established by experiments and field studies that natural uraninite, UO2+x, and its alteration products are excellent ''natural analogues'' for the study of the corrosion of UO2 in SNF. This on-going research program has addressed the following major issues: (1) What are the long-term corrosion products of natural UO2+x, uraninite, under oxidizing and reducing conditions? (2) What is the paragenesis or the reaction path for the phases that form during alteration? (3) What is the radionuclide content in the corrosion products as compared with the original UO2+x? Do the trace element contents substantiate models developed to predict radionuclide incorporation into the secondary phases? Are the corrosion products accurately predicted from geochemical codes (e.g., EQ3/6 or Geochemist's Workbench) that are used in performance assessments? Can these codes be tested by studies of natural analogue sites (e.g., Oklo, Cigar Lake or Pena Blanca)

  3. Constraints on the affinity term for modeling long-term glass dissolution rates

    International Nuclear Information System (INIS)

    Bourcier, W.L.; Carroll, S.A.; Phillips, B.L.

    1993-11-01

    Predictions of long-term glass dissolution rates are highly dependent on the form of the affinity term in the rate expression. Analysis of the quantitative effect of saturation state on glass dissolution rate for CSG glass (a simple analog of SRL-165 glass), shows that a simple (1-Q/K) affinity term does not match experimental results. Our data at 100 degree C show that the data is better fit by an affinity term having the form (1 - (Q/K) 1 /σ) where σ = 10

  4. Maintenance Issues in Long Term Operation of Nuclear Power Plant

    International Nuclear Information System (INIS)

    Contri, P.; Bieth, M.; Rieg, C.

    2006-01-01

    Due to current social and economical framework, in last years many nuclear power plant owners started a program for the Long Term Operation (LTO)/PLEX (Plant Life Extension) of their older nuclear facilities. This process has many nuclear safety implications, other than strategic and political ones. The need for tailoring the available safety assessment tools to such applications has become urgent in recent years and triggered many research actions. The review of regular maintenance and ageing management programs are tools widely used in LTO/PLEX context in many Countries. However, most of these tools are rather general and in many cases they need reshaping in an LTO/PLEX framework before application, with focus to the safety implications of the LTO/PLEX. Many Countries and plants radically modified their maintenance rules towards a condition based approach as a precondition for the implementation of LTO/PLEX programs. In 2004 a network of European Organisations operating Nuclear Power Plants, SENUF, under the coordination of the JRC-IE, carried out an extensive questionnaire on maintenance practice in their facilities aiming at capturing the aspects of the maintenance programs where research is mostly needed. This paper uses some results of the questionnaire, which was not oriented to LTO/PLEX, to draw some conclusions on how the current maintenance programs could support a potential LTO/PLEX, among the other programs running at NPPs. In this sense, it is spin-off of the SENUF WG on maintenance. The paper aims at identifying the technical attributes of the maintenance programs more directly affecting the decision for a long-term safe operation of a nuclear facility, the issues related to their implementation and safety review. The paper includes an analysis of the questionnaire circulated among the SENUF participants and a discussion on the implications of optimised maintenance programs in existing plants. Some examples at WWER plants taken by sources other than

  5. Long-term release from high level waste glass. Part IV. The effect of leaching mechanism

    International Nuclear Information System (INIS)

    Freude, E.; Grambow, B.; Lutze, W.; Rabe, H.; Ewing, R.C.

    1984-01-01

    A linear time dependence for the corrosion under near saturation conditions is considered, and a rate equation in the QTERM code is used to model the long-term behavior of the German glass, C-31-3EC, JSS A, and SRL TDS 131. 22 refs., 4 figs., 1 tab

  6. Foresight of nuclear generation at long term in Mexico

    International Nuclear Information System (INIS)

    Guadarrama L, R.; Sanchez R, O. E.; Martin del Campo M, C.

    2009-10-01

    This paper presents an analysis of the nuclear generation expansion for the period 2008-2030. The main objective is to plan the expansion of electrical generation system at long term taking into account four decision criteria. These are, the total cost of generation, the risk associated whit changes in fuel prices, the diversity of the generation park and polluting emissions of global impact (greenhouse effect gases) and local effects (acid rain and suspended particles). The analyzed expansion plans were developed using a model of uni nodal planning called WASP-IV. The analysis methodology was based on four steps. The first consisted in developing, with model WASP-IV, different expansion plans of the electrical generation system that fulfill the energy demand and certain conditions of the study in which was optimized the additions program of generator units searching the minimal cost of electrical generation. The second step was to calculate the generation costs of each plan for two scenarios of fuel prices, also with model WASP-IV. Later was calculated the diversity index and the accumulated emissions during the expansion and the avoided emission of CO 2 when units of combined cycle that burn natural gas are replaced by nuclear power units. (Author)

  7. Long-term biological consequences of nuclear war

    International Nuclear Information System (INIS)

    Ehrlich, P.R.; Harte, J.; Harwell, M.A.

    1983-01-01

    Subfreezing temperatures, low light levels, and high doses of ionizing and ultraviolet radiation extending for many months after a large-scale nuclear war could destroy the biological support systems of civilization, at least in the Northern Hemisphere. Productivity in natural and agricultural ecosystems could be severely restricted for a year or more. Postwar survivors would face starvation as well as freezing conditions in the dark and be exposed to near-lethal doses of radiation. If, as now seems possible, the Southern Hemisphere were affected also, global disruption of the biosphere could ensue, In any event, there would be severe consequences, even in the areas not affected directly, because of the interdependence of the world economy. In either case the extinction of a large fraction of the Earth's animals, plants, and microorganisms seems possible. The population size of Homo sapiens conceivably could be reduced to prehistoric levels or below and extinction of the human species itself cannot be excluded. These conclusions are the concensus from the meeting on Long-Term Worldwide Biological Consequences of Nuclear War

  8. Glass and nuclear wastes

    International Nuclear Information System (INIS)

    Sombret, C.

    1982-10-01

    Glass shows interesting technical and economical properties for long term storage of solidified radioactive wastes by vitrification or embedding. Glass composition, vitrification processes, stability under irradiation, thermal stability and aqueous corrosion are studied [fr

  9. Long-term product consistency test of simulated 90-19/Nd HLW glass

    International Nuclear Information System (INIS)

    Gan, X.Y.; Zhang, Z.T.; Yuan, W.Y.; Wang, L.; Bai, Y.; Ma, H.

    2011-01-01

    Chemical durability of 90-19/Nd glass, a simulated high-level waste (HLW) glass in contact with the groundwater was investigated with a long-term product consistency test (PCT). Generally, it is difficult to observe the long term property of HLW glass due to the slow corrosion rate in a mild condition. In order to overcome this problem, increased contacting surface (S/V = 6000 m -1 ) and elevated temperature (150 o C) were employed to accelerate the glass corrosion evolution. The micro-morphological characteristics of the glass surface and the secondary minerals formed after the glass alteration were analyzed by SEM-EDS and XRD, and concentrations of elements in the leaching solution were determined by ICP-AES. In our experiments, two types of minerals, which have great impact on glass dissolution, were found to form on 90-19/Nd HLW glass surface when it was subjected to a long-term leaching in the groundwater. One is Mg-Fe-rich phyllosilicates with honeycomb structure; the other is aluminosilicates (zeolites). Mg and Fe in the leaching solution participated in the formation of phyllosilicates. The main components of phyllosilicates in alteration products of 90-19/Nd HLW glass are nontronite (Na 0.3 Fe 2 Si 4 O 10 (OH) 2 .4H 2 O) and montmorillonite (Ca 0.2 (Al,Mg) 2 Si 4 O 10 (OH) 2 .4H 2 O), and those of aluminosilicates are mordenite ((Na 2 ,K 2 ,Ca)Al 2 Si 10 O 24 .7H 2 O)) and clinoptilolite ((Na,K,Ca) 5 Al 6 Si 30 O 72 .18H 2 O). Minerals like Ca(Mg)SO 4 and CaCO 3 with low solubility limits are prone to form precipitant on the glass surface. Appearance of the phyllosilicates and aluminosilicates result in the dissolution rate of 90-19/Nd HLW glass resumed, which is increased by several times over the stable rate. As further dissolution of the glass, both B and Na in the glass were found to leach out in borax form.

  10. Analysis of long-term behaviour of nuclear reactor containment

    Energy Technology Data Exchange (ETDEWEB)

    Hora, Z. [Czech Technical University in Prague, Faculty of Civil Engineering, Department of Mechanics, Thakurova 7, 166 29 Prague 6 (Czech Republic)]. E-mail: Zbynek.Hora@fsv.cvut.cz; Patzak, B. [Czech Technical University in Prague, Faculty of Civil Engineering, Department of Mechanics, Thakurova 7, 166 29 Prague 6 (Czech Republic)

    2007-02-15

    For assessment of safety and durability of a nuclear power plant (NPP), knowledge of the containment behaviour under various service and extreme conditions is crucial. To perform reliable analysis of such a large-scale structure, a sufficiently realistic but still feasible numerical model must be used, in which the relevant physical phenomena are reflected. Therefore, a constitutive model for concrete including effects of moisture and heat transfer, cement hydration, creep, shrinkage and optionally microcracking of concrete should be chosen. The present paper focuses on the simulation of the service life of NPP containment, aiming to determine the material and model parameters to enable reliable prediction of structural behaviour under various conditions. The purpose of the work is to provide a numerical model calibrated using existing measurements to predict the long-term behaviour reliably. Extensive in situ measurements are used to calibrate the model and to check the validity of the model hypotheses. Moreover, the material model parameters are systematically re-calibrated based on the continuous monitoring of the structure. The structural integrity test is reanalysed numerically to show the model capability of predicting behaviour of the structure under given loading and climate conditions.

  11. Alteration of medieval stained-glasses. Contribution to the long-term behaviour of vitrified wastes

    International Nuclear Information System (INIS)

    Sterpenich, J.

    1998-01-01

    In this work, the behaviour of glasses during alteration have been studied in two different ways: 1)study of the alteration of medieval stained-glasses 2)experimental leaching of modelled glasses. Medieval stained-glasses have a silico-calcic and alkaline composition. It appears three different alteration modes for these glasses: 1)by condensation waters 2)by atmospheric agents 3)by porosity waters and humic acids. A chemical study of the altered areas has allowed to understand the alteration behaviour of a lot of elements: in particular transition elements, heavy metals and some rare earths. On the other hand, two vitrified wastes and a glass having the same composition of the potassic medieval stained-glasses have been leached in a static mode (pH=1 to 10, T=20 to 80 degrees Celsius, T=12 hours to 6 months). These experiments have revealed that the alteration mechanisms depend on the pH of the solution and on the chemical composition of the glass. An increasing durability of glasses in terms of the global polymerization degree has been revealed too. At last, the behaviours of glasses during alteration, observed with natural and experimental conditions, show that it is necessary to study natural analogous for predicting the long-term behaviour of vitrified wastes. (O.M.)

  12. Glass implanted 210Po as a method of determination of long term exposure to radon: First experiments in Israel

    International Nuclear Information System (INIS)

    Haquin, G.; Lang, B.; Even, O.; Asael, Y.; Shamai, Y.; Margaliot, M.; Shirav, M.

    2002-01-01

    Radon gas ( 222 Rn) is known to be the major contributor of the total exposure of the population to ionizing radiation. Retrospective assessment techniques have been developed to estimate long term exposures to ( 222 Rn and its progeny in epidemiological studies. Measurements of implanted 210 Po on glass panes surfaces characterize room radon concentration or habitant characterization.Various methods for retrospective radon measurement are described in the literature. The surface trap method is based on the 210 Po implanted on glass or other vitreous objects, measured using solid-state nuclear track detectors (SSNTD). The volume trap method is based on measurements of 210 Po in spongy, porous materials ( 210 Po volume traps). Other approach is in-vivo measurements of 210 Pb in the human skeleton. The present study uses the surface trap retrospective technique for the first time in Israel, coupled with an approach to estimate the 210 Po concentration in glasses exposed to 222 Rn using alpha spectrometry

  13. The long-term acceleration of waste glass corrosion: A preliminary review

    International Nuclear Information System (INIS)

    Kielpinski, A.L.

    1995-07-01

    Whereas a prior conception of glass dissolution assumed a relatively rapid initial dissolution which then slowed to a smaller, fairly constant longer-term rate, some recent work suggests that these two stages are followed by a third phase of dissolution, in which the dissolution rate is accelerated with respect to what had previously been thought of as the final long-term rate. The goals of the present study are to compile experimental data which may have a bearing on this phenomena, and to provide an initial assessment of these data. The Savannah River Technology Center (SRTC) is contracted to develop glass formulation models for vitrification of Hanford low-level waste (LLW), in support of the Hanford Tank Waste Remediation System Technology Development Program. The phenomenon of an increase in corrosion rate, following a period characterized by a low corrosion rate, has been observed by a number of researchers on a number of waste glass compositions. Despite inherent ambiguities arising from SA/V (glass surface area to solution volume ratio) and other effects, valid comparisons can be made in which accelerated corrosion was observed in one test, but not in another. Some glass compositions do not appear to attain a plateau region; it may be that the observation of continued, non-negligible corrosion in these glasses represents a passage from the initial rate to the accelerated rate. The long-term corrosion is a function of the interaction between the glass and its environment, including the leaching solution and the surrounding materials. Reaction path modeling and stability field considerations have been used with some success to predict the changes in corrosion rate over time, due to these interactions. The accelerated corrosion phenomenon highlights the need for such integrated corrosion modeling and the scenario-specific nature of a particular glass composition's durability

  14. Nuclear Winter: Uncertainties Surround the Long-Term Effects of Nuclear War. Report to the Congress.

    Science.gov (United States)

    General Accounting Office, Washington, DC.

    Nuclear winter, a term used to describe potential long-term climate and environmental effects of nuclear war, has been a subject of debate and controversy. This report examines and presents scientific and policy implications of nuclear winter. Contents include: (1) an executive summary (highlighting previous and current studies on the topic); (2)…

  15. Na, Mg, Ni and Cs distribution and speciation after long-term alteration of a simulated nuclear waste glass: A micro-XAS/XRF/XRD and wet chemical study

    Science.gov (United States)

    Curti, Enzo; Dähn, Rainer; Farges, François; Vespa, Marika

    2009-04-01

    Microscopic distribution and speciation of Na, Mg, Ni and Cs in a simulated (inactive) nuclear waste glass were studied using micro X-ray fluorescence (μ-XRF) and micro X-ray absorption spectroscopy (μ-XAS), after aqueous leaching during 12 years at 90 °C. Na and Mg are major constituents of the glass that can be used to determine the progress of the glass corrosion process and the nature of secondary alteration phases. Ni and Cs represent dose determining long-lived radionuclides ( 59Ni, 135Cs) in vitrified nuclear waste. The Na-Mg μ-XRF maps revealed that the core regions of the glass fragments are apparently unaltered and compositionally homogeneous, whereas rims and interstitial spaces are enriched with Mg-rich smectite formed during the leaching process. The micro X-ray absorption near edge structure (μ-XANES) spectra collected at the Mg K-edge in the altered zones show three sharp resonances typical for crystalline Mg-silicates. These resonances are distinctive of Mg occupying undistorted octahedral positions. In contrast, the μ-XANES spectra collected in the core zones of the glass fragments lack this resonance pattern and are identical to the spectra measured on the pristine (unleached) MW glass. Micro extended X-ray absorption fine structure (μ-EXAFS) and μ-XANES analyses at the Ni K-edge revealed three distinct Ni(II) species: (a) Ni uniformly distributed in the glass matrix, (b) micro-inclusions with high Ni concentrations and (c) Ni associated to the Mg-clay. The comparison with reference spectra of unleached MW and other Ni-bearing silicate glasses indicated that species (a) represents the original coordinative environment of Ni in the glass. The μ-EXAFS analyses revealed that species (b) is structural Ni in trevorite (NiFe 2O 4), which probably formed through unmixing processes during the cooling of the glass melt. The μ-EXAFS of species (c) could be successfully modeled assuming specific adsorption or incorporation of Ni into the lattice of

  16. The long-term Global LAnd Surface Satellite (GLASS) product suite and applications

    Science.gov (United States)

    Liang, S.

    2015-12-01

    Our Earth's environment is experiencing rapid changes due to natural variability and human activities. To monitor, understand and predict environment changes to meet the economic, social and environmental needs, use of long-term high-quality satellite data products is critical. The Global LAnd Surface Satellite (GLASS) product suite, generated at Beijing Normal University, currently includes 12 products, including leaf area index (LAI), broadband shortwave albedo, broadband longwave emissivity, downwelling shortwave radiation and photosynthetically active radiation, land surface skin temperature, longwave net radiation, daytime all-wave net radiation, fraction of absorbed photosynetically active radiation absorbed by green vegetation (FAPAR), fraction of green vegetation coverage, gross primary productivity (GPP), and evapotranspiration (ET). Most products span from 1981-2014. The algorithms for producing these products have been published in the top remote sensing related journals and books. More and more applications have being reported in the scientific literature. The GLASS products are freely available at the Center for Global Change Data Processing and Analysis of Beijing Normal University (http://www.bnu-datacenter.com/), and the University of Maryland Global Land Cover Facility (http://glcf.umd.edu). After briefly introducing the basic characteristics of GLASS products, we will present some applications on the long-term environmental changes detected from GLASS products at both global and local scales. Detailed analysis of regional hotspots, such as Greenland, Tibetan plateau, and northern China, will be emphasized, where environmental changes have been mainly associated with climate warming, drought, land-atmosphere interactions, and human activities.

  17. R7T7 glass alteration mechanism in an aqueous closed system: understanding and modelling the long term alteration kinetic

    International Nuclear Information System (INIS)

    Chave, T.

    2007-10-01

    The long term alteration rate of the French R7T7 nuclear glass has been investigated since many years because it will define the overall resistance of the radionuclide containment matrix. Recent studies have shown that the final rate remains constant or is slightly decreasing with time. It never reaches zero. Though this residual rate is very low, only 5 nm per year at 50 C, it would be the dominant alteration phenomenon in a geological repository. Two mechanisms are suggested for explaining such behaviour: diffusion in solution of elements from glass through an amorphous altered layer and precipitation of neo-formed phases. The diffusion processes are in agreement with a solid state diffusion mechanism and can lead to secondary phase precipitation due to solution concentration increases. Observed phases are mainly phyllosilicates and zeolites, in specific conditions. Phyllosilicates are expected to maintain the residual kinetic rate whereas alteration resumption could be observed in presence of zeolites at very high pH or temperature (10.5 at 90 C or temperature above 150 C). Both diffusion and neo-formed phase precipitation have been investigated in order to better understand their impact on the residual alteration rate and have then been modelled by a calculation code, coupling chemistry and transport, in order to be able to better anticipate the long term behaviour of the glass R7T7 in an aqueous closed system. (author)

  18. Long term alteration of glass/iron systems in anoxic conditions: contribution of archaeological analogues to the study of mechanisms

    International Nuclear Information System (INIS)

    Michelin, A.

    2011-01-01

    silicate phase, the latter having a great impact on short term alteration kinetics. All these data underlines the importance of this iron silicate phase that seems to have a significant effect on long term alteration kinetics. In the context of nuclear glass alteration, the precipitation of this phase must be taken into account to predict long term behaviour, as it can maintain high rate of dissolution for a long time. (author) [fr

  19. Necessity of long term nuclear data development for various applications needing nuclear data

    International Nuclear Information System (INIS)

    Fukahori, Tokio

    2001-01-01

    Necessity of long term nuclear data development for accelerator-driven system target design, high-energy radiation shielding, medical application, space and astrophysical applications, etc. is described in this paper. For each application field needing nuclear data, considered were importance of nuclear data in determining the success or failure of the application, important gaps remaining in the nuclear data and feasibility of filling the gaps with a modest research effort. It can be concluded much more international discussions are required. (author)

  20. The long-term effect of 1550 nm erbium:glass fractional laser in acne vulgaris.

    Science.gov (United States)

    Liu, Yale; Zeng, Weihui; Hu, Die; Jha, Smita; Ge, Qin; Geng, Songmei; Xiao, Shengxiang; Hu, Guanglei; Wang, Xiaoxiao

    2016-04-01

    We evaluated the short-term and long-term effects of the 1550 nm erbium:glass (Er:glass) fractional laser in the treatment of facial acne vulgaris. Forty-five (9 male and 36 female) acne patients were treated 4 times at 4-week intervals with the following parameters: 169 spot density and 15-30 mJ/cm(2) fluence. There was no control group. The laser spots were adjustable (maximum overlap: 20%) according to the treatment area, and delivered in rows in order to cover all the face. Clinical photographs were taken. The IGA scores and lesion counts were performed for each treatment. Their current state was obtained by phone call follow-up to determine the long-term effect and photographs were offered by themselves or taken in hospital. After four treatments, all patients had an obvious reduction of lesion counts and IGA score and the peak lesion counts decreased to 67.7% after the initial four treatment sessions. For long-term effect, 8 patients lost follow-up, hence 37 patients were followed-up. 8 patients were 2-year follow up, 27 at the 1-year follow-up, and all patients at the half-year follow-up. The mean percent reduction was 72% at the half-year follow-up, 79 at the 1-year follow-up and 75% at the 2-year follow-up. Side effects and complications were limited to transient erythema and edema, and few patients suffered from transient acne flare-ups and sensitivity. All patients responded that their skin was less prone to oiliness. In conclusion, acne can be successfully treated by 1550 nm Er:glass fractional laser, with few side effects and prolonged acne clearing.

  1. Glasses and nuclear waste vitrification

    International Nuclear Information System (INIS)

    Ojovan, Michael I.

    2012-01-01

    Glass is an amorphous solid material which behaves like an isotropic crystal. Atomic structure of glass lacks long-range order but possesses short and most probably medium range order. Compared to crystalline materials of the same composition glasses are metastable materials however crystallisation processes are kinetically impeded within times which typically exceed the age of universe. The physical and chemical durability of glasses combined with their high tolerance to compositional changes makes glasses irreplaceable when hazardous waste needs immobilisation for safe long-term storage, transportation and consequent disposal. Immobilisation of radioactive waste in glassy materials using vitrification has been used successfully for several decades. Nuclear waste vitrification is attractive because of its flexibility, the large number of elements which can be incorporated in the glass, its high corrosion durability and the reduced volume of the resulting wasteform. Vitrification involves melting of waste materials with glass-forming additives so that the final vitreous product incorporates the waste contaminants in its macro- and micro-structure. Hazardous waste constituents are immobilised either by direct incorporation into the glass structure or by encapsulation when the final glassy material can be in form of a glass composite material. Both borosilicate and phosphate glasses are currently used to immobilise nuclear wastes. In addition to relatively homogeneous glasses novel glass composite materials are used to immobilise problematic waste streams. (author)

  2. Severity Stages in Essential Tremor: A Long-Term Retrospective Study Using the Glass Scale

    Directory of Open Access Journals (Sweden)

    Alexandre Gironell

    2015-03-01

    Full Text Available Background:  Few prospective studies have attempted to estimate the rate of decline of essential tremor (ET and these were over a relatively short time period (less than 10 years.  We performed a long-term study of severity stages in ET using the Glass scale scoring system.Methods: Fifty consecutive patients with severe ET were included. We retrospectively obtained Glass Scale scores throughout the patient’s life. Common milestone events were used to help recall changes in tremor severity.Results:  According to the Glass Scale, the age distributions were as follows: score I, 40±17 years, score II, 55±12 years, score III, 64±9 years, and score IV, 69±7 years. A significant negative correlation between age at first symptom and rate of progression was found (r=−0.669, p<0.001. The rate of progression was significantly different (p<0.001 when the first symptom appeared at a younger age (under 40 years of age compared with older age (40 years or older.Discussion:  Our results support the progressive nature of ET. Age at onset was a prognostic factor. The Glass Scale may be a useful tool to determine severity stages during the course of ET in a manner similar to the Hoehn and Yahr Scale for Parkinson’s disease.

  3. Severity Stages in Essential Tremor: A Long-Term Retrospective Study Using the Glass Scale

    Science.gov (United States)

    Gironell, Alexandre; Ribosa-Nogué, Roser; Gich, Ignasi; Marin-Lahoz, Juan; Pascual-Sedano, Berta

    2015-01-01

    Background Few prospective studies have attempted to estimate the rate of decline of essential tremor (ET) and these were over a relatively short time period (less than 10 years). We performed a long-term study of severity stages in ET using the Glass Scale scoring system. Methods Fifty consecutive patients with severe ET were included. We retrospectively obtained Glass Scale scores throughout the patient's life. Common milestone events were used to help recall changes in tremor severity. Results According to the Glass Scale, the age distributions were as follows: score I, 40±17 years, score II, 55±12 years, score III, 64±9 years, and score IV, 69±7 years. A significant negative correlation between age at first symptom and rate of progression was found (r = −0.669, p<0.001). The rate of progression was significantly different (p<0.001) when the first symptom appeared at a younger age (under 40 years of age) compared with older age (40 years or older). Discussion Our results support the progressive nature of ET. Age at onset was a prognostic factor. The Glass Scale may be a useful tool to determine severity stages during the course of ET in a manner similar to the Hoehn and Yahr Scale for Parkinson's disease. PMID:25793146

  4. Nuclear power : world and Australia - a long-term view

    Energy Technology Data Exchange (ETDEWEB)

    Ford, G W.K.

    1989-01-01

    Developments in world and Australian activities relating to nuclear power and the nuclear fuel cycle are reviewed. Main issues addressed include environment, energy sources, uranium mining, enrichment, reactor design, fuel reprocessing and waste disposal. The benefits for Australia through its involvement in all stages of the nuclear fuel cycle are also discussed.

  5. The long-term management of nuclear emergencies: The principles

    International Nuclear Information System (INIS)

    Baverstock, K.; Cherp, A.; Gray, P.

    2004-01-01

    The long-term impact of the Chernobyl accident on the most affected populations in Belarus (Ukraine)) and the Russian Federation is still evident in terms of a continuing elevated level of thyroid cancer, prominent psychosocial effects, a depressed economy and a low level of well being. Some of these impacts are directly and primarily attributable to exposure to ionising radiation, while others have more complex origins and have evolved over the period since the accident. It is argued that although these latter impacts were largely unpredictable at the time of the accident, they could have been minimised had an appropriate management plan been in force. The principles underlying such a management plan for use in future accidents are enumerated. An essential component in further developing such a plan would be a thorough review of the experience of the Chernobyl accident in order to 'learn the lessons' that accident holds. (authors)

  6. Change of nuclear administrative system and long-term program for nuclear energy in Japan

    International Nuclear Information System (INIS)

    Yun, S. W.; Yang, M. H.; Jeong, H. S.

    2001-01-01

    Japanese new governmental adminstrative system was restructured and became in operation from January 1, 2001 including newly establishment of the Ministry of Cabinet. Accordingly, Japanese nuclear administrative system were also changed significantly, in order to reflect the changing policy environment and response to them more efficiently in the use and development of nuclear energy. Atomic Energy Commission, Nuclear Safety Commission administrated by Science and Technology Agency in the past, were moved to the Ministry of Cabinet, and Integrated Science and Technology Council was also newly established under the Ministry of Cabinet. And Ministry of Economy, Trade and Industry(METI) is in charge of nuclear energy policy and the Ministry of Education, Culture, Sports, Science and Technology(MEXT) is in charge of nuclear academic science consequently. At the same time, the revision work of 'Long-term Program for Research, Development and Utilization of Nuclear of Japan' established in 1994, has been carried out from 1999 in order to set up the long term based national nuclear policy towards the 21st century, and finally the results were open to the public in November 2000. Major changes of nuclear policy of Japan the will be good references in the establishing future national nuclear policy for the use and development of nuclear energy

  7. Natural analogues of nuclear waste glass corrosion

    International Nuclear Information System (INIS)

    Abrajano, T.A. Jr.; Ebert, W.L.; Luo, J.S.

    1999-01-01

    This report reviews and summarizes studies performed to characterize the products and processes involved in the corrosion of natural glasses. Studies are also reviewed and evaluated on how well the corrosion of natural glasses in natural environments serves as an analogue for the corrosion of high-level radioactive waste glasses in an engineered geologic disposal system. A wide range of natural and experimental corrosion studies has been performed on three major groups of natural glasses: tektite, obsidian, and basalt. Studies of the corrosion of natural glass attempt to characterize both the nature of alteration products and the reaction kinetics. Information available on natural glass was then compared to corresponding information on the corrosion of nuclear waste glasses, specifically to resolve two key questions: (1) whether one or more natural glasses behave similarly to nuclear waste glasses in laboratory tests, and (2) how these similarities can be used to support projections of the long-term corrosion of nuclear waste glasses. The corrosion behavior of basaltic glasses was most similar to that of nuclear waste glasses, but the corrosion of tektite and obsidian glasses involves certain processes that also occur during the corrosion of nuclear waste glasses. The reactions and processes that control basalt glass dissolution are similar to those that are important in nuclear waste glass dissolution. The key reaction of the overall corrosion mechanism is network hydrolysis, which eventually breaks down the glass network structure that remains after the initial ion-exchange and diffusion processes. This review also highlights some unresolved issues related to the application of an analogue approach to predicting long-term behavior of nuclear waste glass corrosion, such as discrepancies between experimental and field-based estimates of kinetic parameters for basaltic glasses

  8. Natural analogues of nuclear waste glass corrosion.

    Energy Technology Data Exchange (ETDEWEB)

    Abrajano, T.A. Jr.; Ebert, W.L.; Luo, J.S.

    1999-01-06

    This report reviews and summarizes studies performed to characterize the products and processes involved in the corrosion of natural glasses. Studies are also reviewed and evaluated on how well the corrosion of natural glasses in natural environments serves as an analogue for the corrosion of high-level radioactive waste glasses in an engineered geologic disposal system. A wide range of natural and experimental corrosion studies has been performed on three major groups of natural glasses: tektite, obsidian, and basalt. Studies of the corrosion of natural glass attempt to characterize both the nature of alteration products and the reaction kinetics. Information available on natural glass was then compared to corresponding information on the corrosion of nuclear waste glasses, specifically to resolve two key questions: (1) whether one or more natural glasses behave similarly to nuclear waste glasses in laboratory tests, and (2) how these similarities can be used to support projections of the long-term corrosion of nuclear waste glasses. The corrosion behavior of basaltic glasses was most similar to that of nuclear waste glasses, but the corrosion of tektite and obsidian glasses involves certain processes that also occur during the corrosion of nuclear waste glasses. The reactions and processes that control basalt glass dissolution are similar to those that are important in nuclear waste glass dissolution. The key reaction of the overall corrosion mechanism is network hydrolysis, which eventually breaks down the glass network structure that remains after the initial ion-exchange and diffusion processes. This review also highlights some unresolved issues related to the application of an analogue approach to predicting long-term behavior of nuclear waste glass corrosion, such as discrepancies between experimental and field-based estimates of kinetic parameters for basaltic glasses.

  9. Completely automated nuclear reactors for long-term operation

    International Nuclear Information System (INIS)

    Teller, E.; Ishikawa, M.; Wood, L.

    1996-01-01

    The authors discuss new types of nuclear fission reactors optimized for the generation of high-temperature heat for exceedingly safe, economic, and long-duration electricity production in large, long-lived central power stations. These reactors are quite different in design, implementation and operation from conventional light-water-cooled and -moderated reactors (LWRs) currently in widespread use, which were scaled-up from submarine nuclear propulsion reactors. They feature an inexpensive initial fuel loading which lasts the entire 30-year design life of the power-plant. The reactor contains a core comprised of a nuclear ignitor and a nuclear burn-wave propagating region comprised of natural thorium or uranium, a pressure shell for coolant transport purposes, and automatic emergency heat-dumping means to obviate concerns regarding loss-of-coolant accidents during the plant's operational and post-operational life. These reactors are proposed to be situated in suitable environments at ∼100 meter depths underground, and their operation is completely automatic, with no moving parts and no human access during or after its operational lifetime, in order to avoid both error and misuse. The power plant's heat engine and electrical generator subsystems are located above-ground

  10. Durability of feldspathic veneering ceramic on glass-infiltrated alumina ceramics after long-term thermocycling.

    Science.gov (United States)

    Mesquita, A M M; Ozcan, M; Souza, R O A; Kojima, A N; Nishioka, R S; Kimpara, E T; Bottino, M A

    2010-01-01

    This study compared the bond strength durability of a feldspathic veneering ceramic to glass-infiltrated reinforced ceramics in dry and aged conditions. Disc shaped (thickness: 4 mm, diameter: 4 mm) of glass-infiltrated alumina (In-Ceram Alumina) and glass-infiltrated alumina reinforced by zirconia (In-Ceram Zirconia) core ceramic specimens (N=48, N=12 per groups) were constructed according to the manufacturers' recommendations. Veneering ceramic (VITA VM7) was fired onto the core ceramics using a mold. The core-veneering ceramic assemblies were randomly divided into two conditions and tested either immediately after specimen preparation (Dry) or following 30000 thermocycling (5-55 ºC±1; dwell time: 30 seconds). Shear bond strength test was performed in a universal testing machine (cross-head speed: 1 mm/min). Failure modes were analyzed using optical microscope (x20). The bond strength data (MPa) were analyzed using ANOVA (α=0.05). Thermocycling did not decrease the bond strength results for both In-Ceram Alumina (30.6±8.2 MPa; P=0.2053) and In-Ceram zirconia (32.6±9 MPa; P=0.3987) core ceramic-feldspathic veneering ceramic combinations when compared to non-aged conditions (28.1±6.4 MPa, 29.7±7.3 MPa, respectively). There were also no significant differences between adhesion of the veneering ceramic to either In-Ceram Alumina or In-Ceram Zirconia ceramics (P=0.3289). Failure types were predominantly a mixture of adhesive failure between the veneering and the core ceramic together with cohesive fracture of the veneering ceramic. Long-term thermocycling aging conditions did not impair the adhesion of the veneering ceramic to the glass-infiltrated alumina core ceramics tested.

  11. Approach to long- term regalement of nuclear energy installation decommissioning

    International Nuclear Information System (INIS)

    Dryapachenko, Yi.P.; Rudenko, B. A.; Ozimaj, M.S.

    2001-01-01

    In this report we make an accent on because the rules of nuclear installation decommissioning should provide controllability with compounded operations not one generations of the performers. The strategy should take into account problems of the economic completion, environment and standards of health, script of decommissioning and its execution, and so on. These strategies are bound with the social conditions, with accent on work with the low level wastes

  12. Long-term alternatives for nuclear fuel cycles

    International Nuclear Information System (INIS)

    Vira, J.; Vieno, T.

    1981-07-01

    Several technical alternatives have been proposed to the nuclear spent fuel management but the practical experience on any of these is small or totally lacking. Since the management method is also connected with the composition of fresh fuel, the comparison of the alternatives must include the whole fuel cycle of a nuclear power plant. In the planning of the nuclear fuel cycle over a time range of several decades a consideration must be given, in addition, to the potential of the new reactor types with increased efficiency of uranium utilization. For analyses and mutual comparisons of the fuel cycle alternatives a number of computer models have been designed and implemented at the Technical Research Centre of Finland. Given the estimated boundary conditions the models can be used to study the impact of different goals and requirements on the fuel cycle decisions. Further, they facilitate cost predictions and display information on the role of the intrinsic uncertainties in the decision-making. The conclusions of the study are tied to the questions of price and availability of uranium. Hence, for instance, the benefits from the reprocessing of spent fuel might prove to be small when compared to the costs required, especially as the current reprocessing contracts do not allow the custemer to dismiss the duty of building the final disposal facilities for high level radioactive waste. For a few decades the final decisions can be postponed by extending the interim storage period. Farther in the future the decisions in the nuclear fuel cycle arrangements will more link to the introduction of the fast breeder reactors. (author)

  13. Long-term worldwide effects of multiple nuclear weapons detonations

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    The NAS report, issued in 1975 shocked the scientific community by suggesting that detonation of a fraction of the world's nuclear arsenal (10 4 megatons) could produce a major, 30-70%, reduction in stratospheric ozone, lasting a year or more. The consequences of such a reduction in the natural barrier to solar ultraviolet radiation include the potential extinction of mammalian life. The summary section of the 1975 report is reprinted here

  14. Nuclear power in long term energy strategies in Macedonia

    International Nuclear Information System (INIS)

    Volkanovski, A.

    2000-01-01

    The Macedonian Power System was an integral part of the European power transmission system. At the present time, it works isolated from the main portion of the UCPTE network, connected only with the neighboring power systems After independence, the electricity generation in Macedonia was on the level of its needs. The dominant contribution was by the thermal power plants with about 80%, and the hydro power plants with 20% in total electricity supply covering the peaking part of load curves. Nowadays, the electric power system in Macedonia has only 3 fossil fuel thermal power plants: Negotino, Oslomej and Bitola. Both the electricity production and the very high capacity factors for the lignite fired power plants, show that the maximum production possibilities of mines and power plants have already been achieved. In addition to that, at the beginning of the 21-st century, as a consequence of the depletion of lignite reserves, Macedonia must start with activities for substitution of the existing thermal power plants. The options that are at our disposal are the introduction of gas for electricity generation by utilizing the already built pipeline through Bulgaria, and the introduction of nuclear power. For the later, in the area of Mariovo at the confluence of the river Crna, there is an ideal location for construction of a hydro-nuclear complex. This complex, according to some sources, may include up to three nuclear plants, each one with 600 MW and two hydro-plants with pumped storage facility. (author)

  15. Helium behaviour in nuclear glasses

    International Nuclear Information System (INIS)

    Fares, T.

    2011-01-01

    with helium at high concentrations, doped with curium and irradiated in nuclear reactor showed a homogeneous microstructure free of helium bubbles, pores or cracking. The results of the present work were used to develop a long-term diffusion model of helium in an industrial R7T7 nuclear waste glass. The model considers the thermal history, the fracturing and the alpha activity of the glass. (author) [fr

  16. The long-term behavior of glasses for wastes containment purposes

    International Nuclear Information System (INIS)

    Gin, S.

    2010-01-01

    In the presence of water, nuclear glasses undergo reactions that may be attributed, in part, to the nature of the chemical bonds set up within the glass structure, and - as regards other reactions - owing to the properties of the solute species. The main reactions involved include ion exchanges, these chiefly involving alkali metals, weakly bonded as these are to the glass network, silicon hydrolysis-condensation reactions, resulting in the formation of a porous hydrated layer, gradually taking on a passivating role, along with the precipitation of crystallized secondary phases. At the temperatures of interest in the disposal context (25 - 90 C degrees), such secondary phases mainly involve clay minerals. Fundamental research studies, conducted to gain an understanding of the mechanisms involved, have highlighted the existence of a strong coupling, at the mesoscopic scale, between the aforementioned chemical reactions, and solute transport, the hydrated layer having the ability to take on a passivating role, as its porosity closes. A new model named GRAAL (for Glass Reactivity with Allowance for the Alteration Layer), includes an explicit description of the four chief alteration mechanisms acting on glass: formation of the passivating layer by glass hydration, diffusion of water across that layer, dissolution of that layer over its outside surface, and precipitation of crystallized secondary phases. The equations may either be solved analytically, for simple cases, or be integrated into a geochemical code, to cater for chemistry-transport couplings, and simulate complex systems

  17. Nuclear power from a long term global perspective

    International Nuclear Information System (INIS)

    Davis, D.A.

    1994-01-01

    The global problem with energy, now and into the longer term, is the same as the global problem with food. There is no absolute shortage of either and nor is there likely to be. But the pattern of availability is such that large numbers of people have inadequate supplies of one or the other, or of both. Thus, in considering global energy futures the problems are more about energy distribution than about its absolute availability: it is important that in arguing its case for expansion the nuclear industry bears that fact in mind. (Author)

  18. Long term operation of nuclear power plants - economic challenges

    International Nuclear Information System (INIS)

    David, J.; Devezeaux de Lavergne, J.G.; Duquesnoy, T.

    2014-01-01

    The lifetime extension of nuclear power plants is an open issue in a lot of countries. At the international scale, the costs of upgrading the plant equipment were assessed in 2012 to be between 500 and 1000 dollars per kWe. The post-Fukushima measures taken for increasing the safety standard of the plant reach around 15% of the bill. In almost all countries the lifetime extension strategy appears to be economical if the extension time is for 10 years at least. For France the lifetime extension strategy is also economical: a recent report of the 'French Court of Auditors' concludes that the complete cost of nuclear energy in 2013 is 59.8 euros/MWh and is estimated to reach 62 euros/MWh in the case of a lifetime extension to 50 years of operation which is still very competitive. Another advantage of the life extension strategy is to allow a smoothing of the investment needs and of the industrial loads: the replacement of reactors would take place on a broader period. (A.C.)

  19. Spent fuel, plutonium and nuclear waste: long-term management; Le combustible use et le plutonium en tant que dechets nucleaires: gestion a long terme

    Energy Technology Data Exchange (ETDEWEB)

    Collard, G

    1998-11-01

    Different options for the management of nuclear waste arising from the nuclear fuel cycle are discussed. Special emphasis is on reprocessing followed by geological disposal, geological disposal of reprocessing waste, direct geological disposal of spent nuclear fuel, long term storage. Particular emphasis is on the management of plutonium including recycling, immobilisation and disposal, partitioning and transmutation.

  20. Long-term problem for the nuclear industry

    International Nuclear Information System (INIS)

    Norman, C.

    1982-01-01

    Dismantling of the 24-year-old Shippingport atomic power station over the next two years will test whether the nuclear industry can safely dispose of high-level radioactive facilities. Recent findings that some components will remain radioactive longer than anticipated may require dismantling instead of the permanent entombment the industry was planning. The five-year dismantlement will cost $40 million and generate 11,700 cubic meters of radioactive waste. Larger reactors will be even more costly. Current regulations require utilities to choose between dismantlement, safe storage, or entombment of contaminated materials. Each has its problems, but the industry objects to an evolving policy for dismantling and an accompanying requirement for a segregated decommissioning fund that would be set aside before a reactor begins operating or during plant lifetime. The latter would require an adequate insurance mechanism to cover premature shutdown

  1. Long-term biological consequences of nuclear war.

    Science.gov (United States)

    Ehrlich, P R; Harte, J; Harwell, M A; Raven, P H; Sagan, C; Woodwell, G M; Berry, J; Ayensu, E S; Ehrlich, A H; Eisner, T

    1983-12-23

    Subfreezing temperatures, low light levels, and high doses of ionizing and ultraviolet radiation extending for many months after a large-scale nuclear war could destroy the biological support systems of civilization, at least in the Northern Hemisphere. Productivity in natural and agricultural ecosystems could be severely restricted for a year or more. Postwar survivors would face starvation as well as freezing conditions in the dark and be exposed to near-lethal doses of radiation. If, as now seems possible, the Southern Hemisphere were affected also, global disruption of the biosphere could ensue. In any event, there would be severe consequences, even in the areas not affected directly, because of the interdependence of the world economy. In either case the extinction of a large fraction of the Earth's animals, plants, and microorganisms seems possible. The population size of Homo sapiens conceivably could be reduced to prehistoric levels or below, and extinction of the human species itself cannot be excluded.

  2. Nuclear power in long term energy strategies in Macedonia

    International Nuclear Information System (INIS)

    Volkanovski, A.

    2001-01-01

    The Macedonian Power System (MPS) used to be a part of the former Yugoslav Power System, and it was connected to the European system by 400 kV transmission lines. at the present time, the MPS works isolated from the UCPTE, only connected to the Yugoslav and Greek power systems. The connections with the Bulgarian and Albanian power systems are on a lower voltage level. The reliability and stability of the MPS needs to be improved. Macedonia is located in the central area of the Balkan, where the transmission lines from other Balkan countries are crossing. In the near future, the Macedonian Power System needs to be linked to the European system. To prepare for the energy demand at the beginning of the 21-st century, when the local coal reserves get exhausted, Macedonia needs to start with activities for substitution of the existing coal-fired thermal power plants with nuclear plants. This paper discusses the activities for global development solutions in the area of power generation. (author)

  3. Present state and long term planning on nuclear power plants in principal countries in the world

    International Nuclear Information System (INIS)

    Nomura, Junichi

    1978-01-01

    The situation of nuclear power stations and the long term planning in each major country in the world were summarized, but the situation is changing from time to time, therefore it is difficult to make the long term prediction. The advanced countries in terms of nuclear power established the long term plans to adopt nuclear power generation largely owing to the oil crisis, but thereafter the revision was carried out again and again in respective countries. The developing countries already started the operation of nuclear power generation occupy only 2 to 3% of the total installed capacity in the world, but the countries constructing or planning nuclear power generation are many, and if the operation will be started as scheduled, their capacity will reach 30 million kW by 1985, and occupy about 10% of the total installed capacity of nuclear power generation in the world. As for the range of investigation of this report, the countries where the long term plans are unknown or the number of construction is small, Japan, Great Britain, USA and communist countries are excluded. As a rule, the light water reactors with power output of more than 200,000 kW are listed. The number of nuclear power plants in operation, under construction and in planning stage, national situation, long term plan, and others in each country are described. (Kako, I.)

  4. Analysis on long-term perspectives of sustainable nuclear energy towards global warming protection

    International Nuclear Information System (INIS)

    Yamazawa, M.; Ichimura, E.; Shibata, Y.; Kobayashi, K.; Wajima, T.

    1998-01-01

    Study of long-term perspectives of the nuclear power generation was made from the point of views of both CO 2 emission constraints and sustainability of nuclear energy. To this end, STREAM (Semi-empirical TRiple E Analysis Model) program, as a social model, has been developed by Tokyo Electric Power Co. and Hitachi, Ltd. Using this program, long-term world demands of primary and nuclear energy were deduced, in view of the protection against the global warming due to the CO 2 gas accumulation. The inevitable conclusion has been drawn that nuclear energy plays an indispensable role in the reduction of green house effect. Evaluations were then made on conditions that the nuclear power system would be the long-term major sustainable energy source. (author)

  5. Challenges in long-term operation of nuclear power plants - Implications for regulatory bodies

    International Nuclear Information System (INIS)

    Soda, Kunihisa; Van Wonterghem, Frederik; Khouaja, Hatem; Vilpas, Martti; Osouf, Nicolas; Harikumar, S.; Ishigaki, Hiroki; Osaki, Toru; Yamada, Tomoho; Carlsson, Lennart; Shepherd, David; Galloway, Melanie; Liszka, Ervin; Svab, Miroslav; Pereira, Ken; Huerta, Alejandro

    2012-01-01

    Nuclear power reactors have become a major source of electricity supply in many countries in the past half a century. Based on this experience, many operators have sought and have received authorisation for long-term operation, whereby plant operation continues beyond the period considered in the design of the plant. Acceptance of a nuclear power plant for extended service should be based on assurance of the fitness of the plant and the operator for safe and reliable operation over the entire period considered for long-term operation. This assurance may be obtained by establishment of appropriate regulatory requirements, specification of goals and safety levels and regulatory assessment and oversight of the operator's programme for long-term operation. The operators and regulators should ensure that operating experience continues to be evaluated during long-term operation to ensure that any relevant lessons are effectively applied. Other considerations for assurance of safe operation are effective management of ageing, possible need for safety improvements, application of lessons learnt from operating experience, evaluation of environmental impacts, adequate staff resources and performance, review of security at the plant, action in response to emerging issues, and openness and transparency in the transition to long-term operation. Even though most of these considerations are addressed under the regulatory framework that applies to the initial operating period, additional regulatory activities in these areas may be necessary for long-term operation. Although there can be significant differences in regulatory approaches used by different countries for evaluating acceptability of long-term operation, there is general agreement on the purposes and goals of the regulatory reviews. An authorisation of long-term operation could involve a licence renewal or a periodic safety review or an approach that melds elements of both. This report presents guidance that is intended

  6. Analytical electron microscopy examination of solid reaction products in long-term test of SRL 200 waste glasses

    International Nuclear Information System (INIS)

    Buck, E.C.; Fortner, J.A.; Bates, J.K.; Feng, X.; Dietz, N.L.; Bradley, C.R.; Tani, B.S.

    1993-01-01

    Alteration phases, found on the leached surfaces and present as colloids in the leachates of 200-based frit (fully active and simulated) nuclear waste glass, reacted under static test conditions, at a surface area to leachate volume ratio of 20,000 m -1 for 15 days to 728 days, have been examined by analytical electron microscopy. The compositions of the secondary phases were determined using x-ray energy dispersive spectroscopy and electron energy loss spectroscopy, and structural analysis was accomplished by electron diffraction. Long-term samples of simulated glass, which had undergone an acceleration of reaction after 182 days, possessed a number of silicate secondary phases, including; smectite (iron silicate and potassium iron alumina-silicate, weeksite (uranium silicate), zeolite (calcium potassium alumino-silicate), tobermorite (calcium silicate), and a pure silica phase. However, uranium silicates and smectite have also been observed in tests, which have not undergone the acceleration of reaction, in both the leachate and leached layer, suggesting that these phases are not responsible for the acceleration of reaction

  7. The understanding of the R7T7 glass blocks long term behavior: chemical and transport coupling in fractured media

    International Nuclear Information System (INIS)

    Chomat, L.

    2008-04-01

    The long term behavior of nuclear waste glass blocks depends highly on chemical reactions which occur at the surface in contact with water. Studies carried out on inactive fractured glass blocks show that fracture networks play a significant part in reactive surface area. Nevertheless, the complexity of results interpretation, due to a weak knowledge of fracture networks and local lixiviation conditions, does not allow us to comprehend the physical and chemical mechanisms involved. Model cracks are a key step to study chemical and transport coupling in fractured media. Crack lixiviation in aggressive conditions (pH≥11) show that the crack's position (horizontal or vertical) determines the dominant transport mechanism (respectively diffusion or convection induced by gravity). This gravity driven flow seems to be negligible in lower pH conditions. The convective velocity is estimated by a 1D model of reactive transport. Two other parameters are studied: the influence of thermal gradient and the influence of interconnected cracks on alteration. A strong retroactive effect of convection, due to thermal gradient, on the alteration kinetic is observed inside the crack. These works lead to a complete alteration experiment of a 163 crack network subject to a thermal gradient. The use of the geochemical software, HYTEC, within the framework of this study shows the potential of the software which is however limited by the kinetics law used. (author)

  8. Canada's plan for the long-term management of used nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Shaver, K. [Nuclear Waste Management Organization, Toronto, ON (Canada)

    2015-07-01

    Our mission is to develop and implement collaboratively with Canadians, a management approach for the long-term care of Canada's used nuclear fuel that is socially acceptable, technically sound, environmentally responsible, and economically feasible. The technical method is for Isolation of used nuclear fuel in deep geological repository with continuous monitoring and potential for retrievability.

  9. Neutron balance as indicator of long-term resource availability in growing nuclear energy system

    Energy Technology Data Exchange (ETDEWEB)

    Blandinskiy, Victor [National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation)

    2017-09-15

    The article describes neutron balance in nuclear energy system as necessary but not sufficient indicator of long-term sustainability. Three models are introduced to evaluate neutron balance based on nuclide chain evolution and reaction rates comparison. The indicator introduced is used to compare several nuclear energy systems consisting of thermal, fast and molten salt reactors.

  10. The use of natural analogues in the long-term extrapolation of glass corrosion processes

    International Nuclear Information System (INIS)

    Lutze, W.; Grambow, B.; Ewing, R.C.; Jercinovic, M.J.

    1987-01-01

    One of the most critical aspects of nuclear waste management is the extrapolation of materials and systems behavior from short term experiments, typically on the order of one year, over comparatively very long periods of time. Safety and risk analyses have to rely on extrapolations and the respective findings have to be evaluated in the frame of licensing procedures. In this unique situation, any source of information that can lend support to the credibility of predicted behavior, should be exploited and investigated with great care. There are natural systems, e.g. the Oklo reactor, which can provide evidence of radionuclide migration over very long periods of time and thus help to answer specific questions of interest. Natural glasses and minerals can serve as analogues for both glass and crystalline nuclear waste forms, and the alteration of the natural materials can be studied to infer information on the behavior of the man-made products in geologic environments. This paper reviews most of the work performed by the authors and their colleagues in this field together with information available from literature and discusses the extent to which natural glasses can be used to validate or verify predictions. (author)

  11. Nuclear Waste Disposal and Strategies for Predicting Long-Term Performance of Material

    International Nuclear Information System (INIS)

    Wicks, G.G.

    2001-01-01

    Ceramics have been an important part of the nuclear community for many years. On December 2, 1942, an historic event occurred under the West Stands of Stagg Field, at the University of Chicago. Man initiated his first self-sustaining nuclear chain reaction and controlled it. The impact of this event on civilization is considered by many as monumental and compared by some to other significant events in history, such as the invention of the steam engine and the manufacturing of the first automobile. Making this event possible and the successful operation of this first man-made nuclear reactor, was the use of forty tons of UO2. The use of natural or enriched UO2 is still used today as a nuclear fuel in many nuclear power plants operating world-wide. Other ceramic materials, such as 238Pu, are used for other important purposes, such as ceramic fuels for space exploration to provide electrical power to operate instruments on board spacecrafts. Radioisotopic Thermoelectric Generators (RTGs) are used to supply electrical power and consist of a nuclear heat source and converter to transform heat energy from radioactive decay into electrical power, thus providing reliable and relatively uniform power over the very long lifetime of a mission. These sources have been used in the Galileo spacecraft orbiting Jupiter and for scientific investigations of Saturn with the Cassini spacecraft. Still another very important series of applications using the unique properties of ceramics in the nuclear field, are as immobilization matrices for management of some of the most hazardous wastes known to man. For example, in long-term management of radioactive and hazardous wastes, glass matrices are currently in production immobilizing high-level radioactive materials, and cementious forms have also been produced to incorporate low level wastes. Also, as part of nuclear disarmament activities, assemblages of crystalline phases are being developed for immobilizing weapons grade plutonium, to

  12. Communication on energy: who pays for the long-term costs of nuclear power

    International Nuclear Information System (INIS)

    Jeffery, J.W.

    1987-01-01

    The question in the title arises in making a fair comparison between a coal-fired station, which has no long-term costs, and a nuclear station, whose large long-term costs are discounted into insignificance by the present method of calculation. This problem was raised by the present author in his evidence to the Sizewell Inquiry, and has recently been discussed by the House of Commons Select Committee on Energy, who expressed grave disquiet that 'the costs of decommissioning become almost irrelevant to the current economics of nuclear power'. The present article analyses the bizarre effects of long-term discounting, and suggests a method of making a fair and symmetrical comparison between coal-fired and nuclear stations. (author)

  13. Statement on safety requirements concerning the long-term operation of the Muehleberg nuclear power station

    International Nuclear Information System (INIS)

    2012-12-01

    This report published by the Swiss Federal Nuclear Safety Inspectorate ENSI investigates the safety requirements with respect to the long-term operation of the Muehleberg nuclear power station in Switzerland. Relevant international requirements and Swiss legal stipulations concerning the long-term operation of the power station are stated. The management of aging processes is looked at. The regular verification of the integrity of various plant components such as containments, piping, steam generation system, etc. is looked at in detail. The state-of-the-art concerning deterministic accident analyses and refitting technology are discussed, as are automated safety systems. The applicable laws, decrees and guidelines are listed in appendices

  14. Long term corrosion behavior of the WAK-HLW glass in salt solutions

    International Nuclear Information System (INIS)

    Luckscheiter, B.; Nesovic, M.

    1998-01-01

    The corrosion behavior of the HLW glass GP WAK1 containing simulated HLW oxides from the WAK reprocessing plant in Karlsruhe is investigated in long-term corrosion experiments at high S/V ratios in two reference brines at 110 and 190 C. In case of the MgCl 2 -rich solution the leachate becomes increasingly acid with reaction time up to a final pH of about 3.5 at 190 C. In the NaCl-rich solution the pH rises to about 8.5 after one year of reaction. The release of soluble elements in MgCl 2 solution, under Si-saturated conditions, is proportional to the surface area of the sample and the release increases at 190 C according to a t 1/2 rate law. This time dependence may be an indication of diffusion controlled matrix dissolution. However, at 110 C the release of the mobile elements cannot be described by a t 1/2 rate law as the time exponents are much lower than 0.5. This difference in corrosion behavior may be explained by the higher pH of about 5 at 110 C. In case of NaCl solution under alkaline conditions, the release of soluble elements is not proportional to the surface area of the sample and it increases with time exponents much lower than 0.5. After one year of reaction at 190 C a sharp increase of the release values of some elements was observed. This increase might be explained by the high pH of the solution attained after one year. The corrosion mechanism in NaCl solution, as well as in MgCl 2 solution at 110 C, has not yet been explained. By corrosion experiments in water at constant pH values between 2 and 10, it could be shown that the time exponents of the release of Li and B decrease with increasing pH of the solution. This result can explain qualitatively the differences found in the corrosion behavior of the glass under the various conditions

  15. Compartment model for long-term contamination prediction in deciduous fruit trees after a nuclear accident

    International Nuclear Information System (INIS)

    Antonopoulos-Domis, M.; Clouvas, A.; Gagianas, A.

    1990-01-01

    Radiocesium contamination from the Chernobyl accident of different parts (fruits, leaves, and shoots) of selected apricot trees in North Greece was systematically measured in 1987 and 1988. The results are presented and discussed in the framework of a simple compartment model describing the long-term contamination uptake mechanism of deciduous fruit trees after a nuclear accident

  16. Borosilicate nuclear waste glass alteration kinetics theoretical basis for the kinetic law of nuclear glass alteration

    International Nuclear Information System (INIS)

    Jegou, Ch.; Gin, St.; Advocat, Th.; Vernaz, E.

    1997-01-01

    Work carried out since the early 1980's to predict the long-term behavior of nuclear containment glasses has revealed the inadequacy of existing models, notably in accounting for the fundamental mechanisms involved in some complex systems (e.g. glass-water-clay), inciting us to examine and discuss the theoretical basis for the hypotheses generally assumed in our models. This paper discusses the theoretical basis for the Aagaard-Helgeson law and its application to nuclear glasses. The contribution of other types of kinetic laws is also considered to describe the alteration kinetics of nuclear glasses. (authors)

  17. Long term impacts of nuclear energy: On which purpose do we try to evaluate them?

    International Nuclear Information System (INIS)

    Beutler, Didier

    1998-01-01

    The indicators and the time limits for evaluation of the long term impacts of nuclear energy depend on the purpose: assessing the total cost of electricity generation; comparing different nuclear strategies; responding to public acceptance concerns; elaborating and selecting the most sustainable energy systems. Indicators that can be used are: consumption of non renewable resources; concentrations in the environment; individual exposures; collective dose; potential radiotoxicity. For all of them predicted or conditional values can be applied

  18. Report on the possibilities of long-term storage of irradiated nuclear fuels; Rapport sur les possibilites d'entreposage a long terme de combustibles nucleaires irradies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This report aims at giving a legislative aspect to the many rules that govern the activities of the back-end of the fuel cycle in France. These activities concern the unloading of spent nuclear fuels, their reprocessing, storage, recycling and definitive disposal. The following points are reviewed and commented: the management of non-immediately reprocessed fuels (historical reasons of the 'all wastes reprocessing' initial choice, evolution of the economic and political context, the future reprocessing or the definitive disposal of spent fuels in excess); the inevitable long-term storage of part of the spent fuels (quantities and required properties of long-term stored fuels, the eventuality of a definitive disposal of spent fuels); the criteria that long-term storage facilities must fulfill (confinement measures, reversibility, surveillance and control during the whole duration of the storage); storage concept to be retained (increase of storage pools capacity, long-term storage in pools of reprocessing plants, centralized storage in pools, surface dry-storage on power plant sites, reversible underground storage, subsurface storage and storage/disposal in galleries, surface dry-storage facilities); the preliminary studies for the creation of long-term storage facilities (public information, management by a public French organization, clarifying of the conditions of international circulation of spent fuels); problems linked with the presence of foreign spent fuels in France (downstream of the reprocessing cycle, foreign plutonium and wastes re-shipment); conclusions and recommendations. (J.S.)

  19. Report on the possibilities of long-term storage of irradiated nuclear fuels; Rapport sur les possibilites d'entreposage a long terme de combustibles nucleaires irradies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This report aims at giving a legislative aspect to the many rules that govern the activities of the back-end of the fuel cycle in France. These activities concern the unloading of spent nuclear fuels, their reprocessing, storage, recycling and definitive disposal. The following points are reviewed and commented: the management of non-immediately reprocessed fuels (historical reasons of the 'all wastes reprocessing' initial choice, evolution of the economic and political context, the future reprocessing or the definitive disposal of spent fuels in excess); the inevitable long-term storage of part of the spent fuels (quantities and required properties of long-term stored fuels, the eventuality of a definitive disposal of spent fuels); the criteria that long-term storage facilities must fulfill (confinement measures, reversibility, surveillance and control during the whole duration of the storage); storage concept to be retained (increase of storage pools capacity, long-term storage in pools of reprocessing plants, centralized storage in pools, surface dry-storage on power plant sites, reversible underground storage, subsurface storage and storage/disposal in galleries, surface dry-storage facilities); the preliminary studies for the creation of long-term storage facilities (public information, management by a public French organization, clarifying of the conditions of international circulation of spent fuels); problems linked with the presence of foreign spent fuels in France (downstream of the reprocessing cycle, foreign plutonium and wastes re-shipment); conclusions and recommendations. (J.S.)

  20. Long-term capital planning considering nuclear plant life-cycle management

    International Nuclear Information System (INIS)

    Negin, C.A.; Simpson, J.M.; Hostetler, D.R.

    1992-09-01

    The creation of a Life Cycle Management (LCM) group at utilities to evaluate the long term capital refurbishment needs is gaining favor. Among the functions of such groups can be the responsibility for recommending long term capital planning projects based on results of evaluations of systems, structures, and components that are not only essential to achieving the full current license term of operation, but also to extend the service life of the plant. Making such recommendations, in content and timing, requires the ability to view all recommendations in the context of an overall capital budget and long range outage impacts. This report illustrates an approach for creating a Long-Term Capital Plan with methods for deciding on, compiling, integrating, and presenting projects from the perspective of an LCM program for a nuclear power plant. It also addresses a rationale for capitalization of LCM program activities that would not be allowed under current accounting treatment

  1. The role and position of nuclear energy in the long-term energy supply of China

    International Nuclear Information System (INIS)

    Bao Yunqiao

    1992-03-01

    The history for development of world nuclear energy and policies in various countries are retrospected, and the development of world nuclear energy is reviewed. On the basis of analysis for the economy of nuclear power in abroad, it is verified that the cost of nuclear power is cheaper than that of coal-fired power. In the future, the nuclear power is still competitive in economy. The prospect for long-term energy supply in China is predicted on the present situation of energy industry. It is estimated that the gap between energy demands and supply will become larger and larger. The solution is to develop nuclear energy in south-east area. The long-term demands of electricity and electrical resources are estimated in China, and if nuclear energy is utilized, it will optimize the constitution of electricity. The economy of nuclear power is also evaluated. It is expected that the nuclear power will be cheaper than that of coal-fired power in China after equipment are made domestically and serially. From the analysis of the conditions of communication, transportation and pollution, the development of nuclear energy will reduce the tension of transportation and improve the environmental quality. Finally, the prospect of developing nuclear heating and the supply level of uranium resources in China are analyzed

  2. Report on the possibilities of long-term storage of irradiated nuclear fuels

    International Nuclear Information System (INIS)

    2001-01-01

    This report aims at giving a legislative aspect to the many rules that govern the activities of the back-end of the fuel cycle in France. These activities concern the unloading of spent nuclear fuels, their reprocessing, storage, recycling and definitive disposal. The following points are reviewed and commented: the management of non-immediately reprocessed fuels (historical reasons of the 'all wastes reprocessing' initial choice, evolution of the economic and political context, the future reprocessing or the definitive disposal of spent fuels in excess); the inevitable long-term storage of part of the spent fuels (quantities and required properties of long-term stored fuels, the eventuality of a definitive disposal of spent fuels); the criteria that long-term storage facilities must fulfill (confinement measures, reversibility, surveillance and control during the whole duration of the storage); storage concept to be retained (increase of storage pools capacity, long-term storage in pools of reprocessing plants, centralized storage in pools, surface dry-storage on power plant sites, reversible underground storage, subsurface storage and storage/disposal in galleries, surface dry-storage facilities); the preliminary studies for the creation of long-term storage facilities (public information, management by a public French organization, clarifying of the conditions of international circulation of spent fuels); problems linked with the presence of foreign spent fuels in France (downstream of the reprocessing cycle, foreign plutonium and wastes re-shipment); conclusions and recommendations. (J.S.)

  3. New long-term plan of nuclear development and perspectives of nuclear fuel cycle policy

    International Nuclear Information System (INIS)

    Uchiyama, Yohji

    2005-01-01

    Japan's nuclear fuel cycle policy, recently issued as an interim report of the Council to Formulate the New Long-Term Nuclear Program of the Atomic Energy Commission, is summarized and briefly explained together with the concluding remarks from the sub-committee for discussing technical and economical problems on the spent nuclear fuels with the present state of the Rokkasho reprocessing plant in mind. As for the nuclear fuel treatment, the panel considered four scenarios: (1) total reprocessing (the reprocessing for spent fuel after an appropriate period of storage); (2) partial reprocessing (spent fuel is reprocessed, with direct disposal of any spent fuel in excess of reprocessing capacity); (3) total direct disposal (direct disposal of all spent fuel); and (4) temporary storage (spent fuel is temporarily stored, and in about 2060 a choice will be made about whether to reprocess it or directly dispose of it). These four scenarios were studied from various perspectives, namely: (1) ensuring safety; (2) energy security; (3) environmental compatibility; (4) economic efficiency; (5) nuclear nonproliferation; (6) technical feasibility; (7) social acceptance; (8) securing choices; (9) issues concerning change in policy; and (10) overseas trends. Regarding economic efficiency, the council in particular conducted detailed studies and reassessment of nuclear fuel cycle costs. Scenario 1 (total reprocessing) is about 0.5-0.7 yen/kWh higher than scenario 3 (total direct disposal). However, looking at the situation from the perspectives of energy security, that is the stable supply and moderate use of resources, and environmental compatibility, scenario 1 (total reprocessing) can be evaluated as superior to the other scenarios. And more importantly, if the fast-breeder reactor cycle is commercialized, this superiority increases considerably. (S. Ohno)

  4. Workshop on IAEA Tools for Nuclear Energy System Assessment for Long-Term Planning and Development

    International Nuclear Information System (INIS)

    2009-01-01

    The purpose of the workshop is to present to Member States tools and methods that are available from the IAEA in support of long-term energy planning and nuclear energy system assessments, both focusing on the sustainable development of nuclear energy. This includes tools devoted to energy system planning, indicators for sustainable energy development, the INPRO methodology for Nuclear Energy System Assessment (NESA) and tools for analysing nuclear fuel cycle material balance. The workshop also intends to obtain feedback from Member States on applying the tools, share experiences and lessons learned, and identify needs for IAEA support

  5. Thermodynamic model of natural, medieval and nuclear waste glass durability

    International Nuclear Information System (INIS)

    Jantzen, C.M.; Plodinec, M.J.

    1983-01-01

    A thermodynamic model of glass durability based on hydration of structural units has been applied to natural glass, medieval window glasses, and glasses containing nuclear waste. The relative durability predicted from the calculated thermodynamics correlates directly with the experimentally observed release of structural silicon in the leaching solution in short-term laboratory tests. By choosing natural glasses and ancient glasses whose long-term performance is known, and which bracket the durability of waste glasses, the long-term stability of nuclear waste glasses can be interpolated among these materials. The current Savannah River defense waste glass formulation is as durable as natural basalt from the Hanford Reservation (10 6 years old). The thermodynamic hydration energy is shown to be related to the bond energetics of the glass. 69 references, 2 figures, 1 table

  6. Parameter values for the long-term nuclear waste management food chain model LIMCAL

    International Nuclear Information System (INIS)

    Zach, Reto.

    1982-09-01

    Eighteen parameters of LIMCAL, a comprehensive food chain model for predicting ICRP 26 50-year committed effective dose equivalents to man due to long-term nuclear waste management are reviewed. The parameters are: soil bulk density, plowlayer depth, soil surface layer depth, resusupension factor, atmospheric dust load, deposition velocity, plant interception fraction, plant environmental half-time, translocation factor, time of above-ground exposure, plant yield, holdup time, animals' feed consumption rate, animals' water consumption rate, man's water consumption rate, food type calorie conversion factors, man's total caloric intake rate and food type calorie fractions. LIMCAL has both traditional and unique parameters. The former occur in most of the currently used assessment models for nuclear installations, whereas the latter do not. For each of the parameters of LIMCAL, a suitable generic value for long-term nuclear waste management was determined. Thus, the general literature and the values currently used or recommended by various agencies were reviewed

  7. Synthesis on the long term behavior of spent nuclear fuel. Vol.1,2

    International Nuclear Information System (INIS)

    Poinssot, Ch.; Toulhoat, P.; Grouiller, J.P.; Pavageau, J.; Piron, J.P.; Pelletier, M.; Dehaudt, Ph.; Cappelaere, Ch.; Limon, R.; Desgranges, L.; Jegou, Ch.; Corbel, C.; Maillard, S.; Faure, M.H.; Cicariello, J.C.; Masson, M.

    2001-01-01

    The aim of this report is to present the major objectives, the key scientific issues, and the preliminary results of the research conducted in France in the framework of the third line of the 1991 Law, on the topic of the long term behavior of spent nuclear fuel in view of long term storage or geological disposal. Indeed, CEA launched in 1998 the Research Program on the Long Term Behavior of Spent Nuclear Fuel (abbreviated and referred to as PRECCI in French; Poinssot, 1998) the aim of which is to study and assess the ability of spent nuclear fuel packages to keep their initially allocated functions in interim storage and geological disposal: total containment and recovery functions for duration up to hundreds of years (long term or short-term interim storage and/or first reversible stages of geological disposal) and partial confinement function (controlled fluxes of RN) for thousands of years in geological disposal. This program has to allow to obtain relevant and reliable data concerning the long term behavior of the spent fuel packages so that feasibility of interim storage and/or geological disposal can be assessed and demonstrated as well as optimized. Within this framework, this report presents for every possible scenario of evolution (closed system, in Presence of water in presence of gases) what are estimated to be the most relevant evolution mechanism. For the most relevant scientific issues hence defined, a complete scientific review of the best state of knowledge is subsequently here given thus allowing to draw a clear guideline of the major R and D issues for the next years. (authors)

  8. Risk assessment in long-term storage of spent nuclear fuel

    International Nuclear Information System (INIS)

    Ahn, T.; Guttmann, J.; Mohseni, A.

    2013-01-01

    This paper presents probabilistic risk-informed approaches that the Nuclear Regulatory Commission (NRC) staff is planning to consider in preparing regulatory bases for long-term storage of spent nuclear fuel (SNF) for up to 300 years. Due to uncertainties associated with long-term SNF storage, the NRC is considering a probabilistic risk-informed approach as well as a deterministic design-based approach. The uncertainties considered here are primarily associated with materials aging of the canister and SNF in the cask system during long-term storage of SNF. This paper discusses some potential risk contributors involved in long-term SNF storage. Methods of performance evaluation are presented that assess the various types of risks involved. They include deterministic evaluation, probabilistic evaluation, and consequence assessment under normal conditions and the conditions of accidents and natural hazards. Some potentially important technical issues resulting from the consideration of a probabilistic risk-informed evaluation of the cask system performance are discussed for the canister and SNF integrity. These issues are also discussed in comparison with the deterministic approach for comparison purposes, as appropriate. Probabilistic risk-informed methods can provide insights that deterministic methods may not capture. Two specific examples include stress corrosion cracking of the canister and hydrogen-induced cladding failure. These examples are discussed in more detail, in terms of their effects on radionuclide release and nuclear subcriticality associated with the failure. The plan to consider the probabilistic risk-informed approaches is anticipated to provide helpful regulatory insights for long-term storage of SNF that provide reasonable assurance for public health and safety. (authors)

  9. Long-term consequences of and prospects for recovery from nuclear war: Two views. View II

    International Nuclear Information System (INIS)

    Anspaugh, L.R.

    1986-01-01

    The author comments on the information presented in this volume and speculates on the long-term consequences of nuclear war and the prospects for recovery. In order to do that, it might be useful to define long term. To him this means time frames of years to perhaps even hundreds of years in terms of the ultimate response and recovery of large-scale ecosystems. Such long time frames may seem excessive, but if some of the speculated efforts of nuclear war are actually realized, it may indeed take centuries before native ecosystems restabilize. Also, when referring to long-term effects of the magnitude required to have a major impact on entire ecosystems, it is clear that the driving force would not be the direct effects of nuclear war. Of potentially greater significance would be the secondary effects mediated by the intermediate-term impacts on global climate. Specifically, he refers to the speculative impacts of major decreases in the heat and light fluxes reaching the Earth's surface. Such changes are commonly referred to as ''nuclear winter.''

  10. Global economics/energy/environmental (E3) modeling of long-term nuclear energy futures

    International Nuclear Information System (INIS)

    Krakowski, R.A.; Davidson, J.W.; Bathke, C.G.; Arthur, E.D.; Wagner, R.L. Jr.

    1997-01-01

    A global energy, economics, environment (E 3 ) model has been adopted and modified with a simplified, but comprehensive and multi-regional, nuclear energy module. Using this model, consistent nuclear energy scenarios are constructed. A spectrum of future is examined at two levels in a hierarchy of scenario attributes in which drivers are either external or internal to nuclear energy. Impacts of a range of nuclear fuel-cycle scenarios are reflected back to the higher-level scenario attributes. An emphasis is placed on nuclear materials inventories (in magnitude, location, and form) and their contribution to the long-term sustainability of nuclear energy and the future competitiveness of both conventional and advanced nuclear reactors

  11. Long-term perspectives of the worldwide use of nuclear power

    International Nuclear Information System (INIS)

    Jaek, W.

    1981-01-01

    The world energy scenarios developed by WEC and IIASA, which contain analyses and estimates on the long-term development perspectives of regional development areas, show that the worldwide energy requirement can no longer be met without the large-scale expansion of nuclear power. This implies an expansion on nuclear power in the next forty or fifty years to more than the 38 countries at present known to use or wanting to use nuclear power. With respect to the aspects of supply and non-proliferation, the question of the geographic distribution of future nuclear power plants is becoming more and more important. If the more global statements in the different world energy scenarios can be translated into information about the potential use of nuclear power in specific countries in the fifty years, this will allow a picture of a possible nuclear future to be sketched, on the basis of which considerations of non-proliferation and nuclear transfer can be put on a firm basis. This is not meant to be another set of long-term forecasts of nuclear power, but a concrete implementation of world energy scenarios and the consequences with respect to non-proliferation and transfer potentially arising from them. (orig.) [de

  12. The long-term environmental and medical effects of nuclear war

    International Nuclear Information System (INIS)

    1986-03-01

    Part 1 describes the physical structure of the atmosphere and reviews recent studies which have considered the atmospheric perturbations which could follow a nuclear war according to various scenarios. Part 2 describes the biological consequences of predicted atmospheric and climatic changes, concentrating on the long term implications for health and human well- being. Part 3 outlines some policy implications arising out of these environmental consequences and includes the conclusions and a summary of the report. (author)

  13. Nuclear wastes: vitrification and long term behaviour. Information available on Internet sites

    International Nuclear Information System (INIS)

    Macias, R.M.

    2004-01-01

    This document reports an information search on the long-term behaviour of vitrified nuclear wastes. This search has been performed on the Internet and this report presents 21 forms corresponding to the 21 relevant Internet web sites. These forms contain the name of the organization, its country, its Internet address, its language, a brief description of the available information, the concerned public (general public, scholars and students, scientific community)

  14. The role of nuclear energy system for Korean long-term energy supply strategy

    International Nuclear Information System (INIS)

    Chae, K.N.; Lee, D.G.; Lim, C.Y.; Lee, B.W.

    1995-01-01

    The energy supply optimization model MESSAGE-III is improved to evaluate the role of nuclear energy system in Korean long-term energy supply strategy. Emphasis is placed on the potential contribution of nuclear energy in case of environmental constraints and energy resource limitation. The time horizon is 1993-2040. A program to forecast useful energy demand is developed, and optimization is performed from the overall energy system to the nuclear energy system. Reactor and fuel cycle strategy and the expanded utilization options for nuclear energy system are suggested. FBRs, HTGRs and thorium fuel cycle would play key roles in the long run. The most important factors for nuclear energy in Korean energy supply strategy would be the availability of fossil fuels, CO 2 reduction regulation, and the supply capability of nuclear energy. (author)

  15. Factors influencing chemical durability of nuclear waste glasses

    International Nuclear Information System (INIS)

    Feng, Xiangdong; Bates, J.K.

    1993-01-01

    A short summary is given of our studies on the major factors that affect the chemical durability of nuclear waste glasses. These factors include glass composition, solution composition, SA/V (ratio of glass surface area to the volume of solution), radiation, and colloidal formation. These investigations have enabled us to gain a better understanding of the chemical durability of nuclear waste glasses and to accumulate.a data base for modeling the long-term durability of waste glass, which will be used in the risk assessment of nuclear waste disposal. This knowledge gained also enhances our ability to formulate optimal waste glass compositions

  16. Long term testing and evaluation of PV modules with and without Sunarc antireflective coating of the cover glass

    DEFF Research Database (Denmark)

    Perers, Bengt; Furbo, Simon; Han, Jiangong

    2015-01-01

    Two Photovoltaic (PV) modules have been manufactured by Swemodule. One with Sunarc antireflective coated glass and one without glass surface treatment. The modules have been tested at DTU during 16 months under realistic outdoor conditions. Exactly the same polycrystalline cells were used...... in the modules. No cleaning of the glass has been made except for removal of bird droppings and leaves on single cells that could give a very wrong comparison. The PV modules were mounted due south at 45 degree tilt angle. They were connected to the electric grid with small 250W module inverters from Involar...... that also realized the MPP tracking to give the maximum output of each module. The electric power output was measured both on the AC and DC side and with different measurement equipment to be sure about the accuracy in improvement. The results indicate a potential long term improvement in a system from 3...

  17. Long-term tradeoffs between nuclear- and fossil-fuel burning

    International Nuclear Information System (INIS)

    Krakowski, R.A.

    1996-01-01

    A global energy/economics/environmental (E 3 ) model has been adapted with a nuclear energy/materials model to understand better open-quotes top-levelclose quotes, long-term trade offs between civilian nuclear power, nuclear-weapons proliferation, fossil-fuel burning, and global economic welfare. Using a open-quotes business-as-usualclose quotes (BAU) point-of-departure case, economic, resource, proliferation-risk implications of plutonium recycle in LAIRs, greenhouse-gas-mitigating carbon taxes, and a range of nuclear energy costs (capital and fuel) considerations have been examined. After describing the essential elements of the analysis approach being developed to support the Los Alamos Nuclear Vision Project, preliminary examples of parametric variations about the BAU base-case scenario are presented. The results described herein represent a sampling from more extensive results collected in a separate report. The primary motivation here is: (a) to compare the BAU basecase with results from other studies; (b) to model on a regionally resolved global basis long-term (to year ∼2100) evolution of plutonium accumulation in a variety of forms under a limited range of fuel-cycle scenarios; and (c) to illustrate a preliminary connectivity between risks associated with nuclear proliferation and fossil-fuel burning (e.g., greenhouse-gas accumulations)

  18. The economics of long-term operation of nuclear power plants

    International Nuclear Information System (INIS)

    Lokhov, Alexey; Huerta, Alejandro; Dufresne, Luc; Giraud, Anne; Osouf, Nicolas

    2012-01-01

    Refurbishment and long-term operation (LTO) of existing nuclear power plants (NPPs) today are crucial to the competitiveness of the nuclear industry in OECD countries as existing nuclear power plants produce base-load power at a reliable cost. A number of nuclear power plants, most notably 73 units in the United States (up to 2012), have been granted lifetime extensions of up to 60 years, a development that is being keenly watched in other OECD countries. In many of these (e.g. France, Switzerland), there is no legal end to the operating licence, but continued operation is based on the outcomes of periodic safety reviews. This study analyses technical and economic data on the upgrade and lifetime extension experience in OECD countries. A multi-criteria assessment methodology is used considering various factors and parameters reflecting current and future financial conditions of operation, political and regulatory risks, the state of the plants' equipment and the general role of nuclear power in the country's energy policy. The report shows that long-term operation of nuclear power plants has significant economic advantages for most utilities envisaging LTO programmes. In most cases, the continued operation of NPPs for at least ten more years is profitable even taking into account the additional costs of post-Fukushima modifications, and remains cost-effective compared to alternative replacement sources

  19. Long-term modeling of glass waste in portland cement- and clay-based matrices

    International Nuclear Information System (INIS)

    Stockman, H.W.; Nagy, K.L.; Morris, C.E.

    1995-12-01

    A set of ''templates'' was developed for modeling waste glass interactions with cement-based and clay-based matrices. The templates consist of a modified thermodynamic database, and input files for the EQ3/6 reaction path code, containing embedded rate models and compositions for waste glass, cement, and several pozzolanic materials. Significant modifications were made in the thermodynamic data for Th, Pb, Ra, Ba, cement phases, and aqueous silica species. It was found that the cement-containing matrices could increase glass corrosion rates by several orders of magnitude (over matrixless or clay matrix systems), but they also offered the lowest overall solubility for Pb, Ra, Th and U. Addition of pozzolans to cement decreased calculated glass corrosion rates by up to a factor of 30. It is shown that with current modeling capabilities, the ''affinity effect'' cannot be trusted to passivate glass if nuclei are available for precipitation of secondary phases that reduce silica activity

  20. Long-term reliability evaluation of nuclear containments with tendon force degradation

    International Nuclear Information System (INIS)

    Kim, Sang-Hyo; Choi, Moon-Seock; Joung, Jung-Yeun; Kim, Kun-Soo

    2013-01-01

    Highlights: • A probabilistic model on long-term degradation of tendon force is developed. • By using the model, we performed reliability evaluation of nuclear containment. • The analysis is also performed for the case with the strict maintenance programme. • We showed how to satisfy the target safety in the containments facing life extension. - Abstract: The long-term reliability of nuclear containment is important for operating nuclear power plants. In particular, long-term reliability should be clarified when the service life of nuclear containment is being extended. This study focuses not only on determining the reliability of nuclear containment but also presenting the reliability improvement by strengthening the containment itself or by running a strict maintenance programme. The degradation characteristics of tendon force are estimated from the data recorded during in-service inspection of containments. A reliability analysis is conducted for a limit state of through-wall cracking, which is conservative, but most crucial limit state. The results of this analysis indicate that reliability is the lowest at 3/4 height of the containment wall. Therefore, this location is the most vulnerable for the specific limit state considered in this analysis. Furthermore, changes in structural reliability owing to an increase in the number of inspecting tendons are analysed for verifying the effect of the maintenance program's intensity on expected containment reliability. In the last part of this study, an example of obtaining target reliability of nuclear containment by strengthening its structural resistance is presented. A case study is conducted for exemplifying the effect of strengthening work on containment reliability, especially during extended service life

  1. Do we soon run out of uranium? Long-term concepts of nuclear fuel supply

    International Nuclear Information System (INIS)

    Prasser, Horst-Michael

    2008-01-01

    The extension of the worldwide light water reactor fleet will cause the demand for uranium to grow. The static reach of identified resources might soon fall below the life time of new nuclear power plants which are usually designed for 60 years of operation, if the exploration of new uranium deposits will stop resulting in exploitable resources. The article discusses, if, as frequently claimed, the energy consumption in the uranium mines renders impossible to secure the nuclear fuel supply in the long term. (orig.)

  2. Recycling versus Long-Term Storage of Nuclear Fuel: Economic Factors

    Directory of Open Access Journals (Sweden)

    B. Yolanda Moratilla Soria

    2013-01-01

    Full Text Available The objective of the present study is to compare the associated costs of long-term storage of spent nuclear fuel—open cycle strategy—with the associated cost of reprocessing and recycling strategy of spent fuel—closed cycle strategy—based on the current international studies. The analysis presents cost trends for both strategies. Also, to point out the fact that the total cost of spent nuclear fuel management (open cycle is impossible to establish at present, while the related costs of the closed cycle are stable and known, averting uncertainties.

  3. Modeling long-term aspects of nuclear waste disposal: the AEGIS experience

    International Nuclear Information System (INIS)

    Dove, F.H.

    1983-01-01

    Modeling the long-term aspects of nuclear waste disposal has its roots in risk analysis of man-made systems like nuclear reactors. Analytical problems can be introduced into the performance assessment of a site-specific repository if an appreciation for the behavior of a natural earth system is not maintained. However, this should not preclude the application of historically useful analytical techniques like bounding strategies in favor of emerging, data-intensive techniques. The technical challenge is to apply existing technology and available data to a complex problem and produce a useful result

  4. Long term needs for nuclear data development. Summary report of the advisory group meeting

    International Nuclear Information System (INIS)

    Muir, D.W.; Herman, M.

    2001-05-01

    The Advisory Group Meeting on Long Term Needs for Nuclear Data Development, was held from 28 November - 1 December 2000 at IAEA Headquarters, Vienna, Austria. The goal of this meeting was to develop a vision of the work needed over the next decades (2000-2020) on the measurement, calculation and evaluation of improved nuclear data for emerging applications. Of particular interest were data improvement activities that could be coordinated by the IAEA. The following areas of nuclear data applications were selected for discussion during the Meeting: Medical Applications; Ion Beam Analysis and Related Techniques; Nuclear Astrophysics; Nuclear Safeguards and Related Applications; Critical Reactors, including Closed Fuel Cycles; Accelerator Driven Subcritical Reactors; ADS Target Design and High-Energy Radiation Shielding. (author)

  5. Studies on the long-term characteristics of HLW glass under ultimate storage conditions

    International Nuclear Information System (INIS)

    Roggendorf, H.; Conradt, R.; Ostertag, R.

    1987-01-01

    This interim report deals with first results of corrosion investigations of HLW simulation glass (COGEMA glass SON 68) in quinary salt solutions of different concentrations; the aim of these investigations was to find out about the corrosion mechanism at the surface of the glass and the quantitative registration of the corrosion products. It became obvious that the surface layers developed can be easily removed and that a determination of weight losses becomes possible thereby. The corrosion rates for a test period of 30 days were determined. (RB) [de

  6. Long-term damage to glass in Paris in a changing environment.

    Science.gov (United States)

    Ionescu, Anda; Lefèvre, Roger-Alexandre; Brimblecombe, Peter; Grossi, Carlota M

    2012-08-01

    Glass weathering depends mainly on its chemical composition: Si-Ca-K mediaeval glass is low durable, while Si-Ca-Na Roman as well as modern glass are very durable. Mediaeval glass is subject to the superficial leaching of K and Ca ions leading to the formation of a hydrated silica-gel layer. Both types of glass develop a superficial stratum of deposited atmospheric particles cemented by crystals of gypsum (and syngenite in the case of Si-Ca-K glass), leading to an impairment of the optical properties: decrease of transparency and increase of haze. Dose-response functions established for the two types of glass reveal that haze depends only on pollution parameters (PM, SO(2), NO(2)), while leaching depends both on pollution and climate parameters (RH, T, SO(2), NO(2)). Instrumental records are available for temperature in Paris from 1800. Air pollution in Paris was estimated from statistics of fuel use from 1875 to 1943, measurements that started in the 1950s and projections across the 21st century. The estimated annual rate of haze development indicates a gradual rise from the 16th century. The increasing importance of coal as a fuel through the 19th century and enhanced sulphur dioxide concentration make a rapid increase in haze formation, which reaches a peak about 1950. The likely damage to mediaeval glass follows a rather similar pattern. The period of damage from aggressive pollutants looks later and for a briefer time in Paris than in London. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Effects of beta/gamma radiation on nuclear waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Weber, W.J. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-07-01

    A key challenge in the disposal of high-level nuclear waste (HLW) in glass waste forms is the development of models of long-term performance based on sound scientific understanding of relevant phenomena. Beta decay of fission products is one source of radiation that can impact the performance of HLW glasses through the interactions of the emitted {beta}-particles and g-rays with the atoms in the glass by ionization processes. Fused silica, alkali silicate glasses, alkali borosilicate glasses, and nuclear waste glasses are all susceptible to radiation effects from ionization. In simple glasses, defects (e.g., non-bridging oxygen and interstitial molecular oxygen) are observed experimentally. In more complex glasses, including nuclear waste glasses, similar defects are expected, and changes in microstructure, such as the formation of bubbles, have been reported. The current state of knowledge regarding the effects of {beta}/{gamma} radiation on the properties and microstructure of nuclear waste glasses are reviewed. (author)

  8. Effects of beta/gamma radiation on nuclear waste glasses

    International Nuclear Information System (INIS)

    Weber, W.J.

    1997-01-01

    A key challenge in the disposal of high-level nuclear waste (HLW) in glass waste forms is the development of models of long-term performance based on sound scientific understanding of relevant phenomena. Beta decay of fission products is one source of radiation that can impact the performance of HLW glasses through the interactions of the emitted β-particles and g-rays with the atoms in the glass by ionization processes. Fused silica, alkali silicate glasses, alkali borosilicate glasses, and nuclear waste glasses are all susceptible to radiation effects from ionization. In simple glasses, defects (e.g., non-bridging oxygen and interstitial molecular oxygen) are observed experimentally. In more complex glasses, including nuclear waste glasses, similar defects are expected, and changes in microstructure, such as the formation of bubbles, have been reported. The current state of knowledge regarding the effects of β/γ radiation on the properties and microstructure of nuclear waste glasses are reviewed. (author)

  9. Long-term development of nuclear maintenance service provider in Slovenia

    International Nuclear Information System (INIS)

    Androjna, A.; Racic, Z.; Balazic, D.

    2004-01-01

    In recent years, most utilities have been facing a challenge of optimizing maintenance costs, while maintaining or improving equipment reliability. As the equipment ages and maintenance skills within the plant staff may decline due to a generation exchange, the challenge becomes even stronger. Consequently, many plants are looking for possible solutions through partnering with maintenance service providers. The fact that there is only one nuclear power plant in Slovenia hinders the development of local maintenance contractors to some extent. Additionally, they have to face everincreasing technical and organizational requirements while a longer fuel cycle and shorter outage durations result in a narrower annual scope of outage activities. In such circumstances, it may be very difficult for local maintenance service providers to retain and improve skills and qualifications in the long run. Even more so, since they also face the need to rejuvenate their staff and the interest of subcontractors to participate diminishes. The paper presents a case on long-term development issues as experienced by NUMIP, the leading Slovenian nuclear maintenance service provider. Above all, we would like to contribute to a better understanding of efficient local maintenance support. NUMIP's future strategic options are explored in light of possible partnering relationship with the nuclear power plant, based on trust, win-win attitude and continuous improvement. Long-term benefits of the proposed partnering are indicated for both parties, the nuclear power plant and the local maintenance service provider. (author)

  10. Life Limiting Issues for Long Term Operation of Nuclear Power Plants

    International Nuclear Information System (INIS)

    Esselman, Thomas; Gaertner, John

    2012-01-01

    This paper reports on a study which identified and characterized life limiting issues for consideration by nuclear plant owners in their decision to extend plant life or seek subsequent license renewal. As nuclear plants operate for longer periods, the risk that a condition in the plant or an event that occurs, at the plant or elsewhere, will cause a plant owner not to extend plant life increases. The Fukushima accident has made this concept concrete. This paper defines 'Life Limiting' concepts for nuclear plants. It identifies the highest risk conditions and events that may limit duration of continued operation in nuclear plants and employs a survey to prioritize these concerns. Methods for evaluating these risks and changing the capability of systems, structures, and components (SSC) to reduce and manage this risk in long term operation are presented. Integrated obsolescence -the existence of an accumulation of events or condition that can threaten long term operation- is discussed. Many of the life limiting conditions or events may be controllable by early identification, recognition, and mitigation of the potential threat. The recognition of conditions may allow measures to be taken to mitigate the condition. Recognition of the potential for events that may be life limiting may allow actions to be taken that will minimize the likelihood or consequences of the event. These actions may include enhanced research on the expected behavior of the SSC, risk assessment and management, and enhanced monitoring and aging management at the plant. (author)

  11. Long term bleaching of optical glasses darkened by Co60 ionizing radiation

    International Nuclear Information System (INIS)

    Wirtenson, G.R.; White, R.H.

    1997-01-01

    Typical camera designs include optical glass elements that may be affected by the ionizing radiation present in the natural space environment. Ordinary optical glasses darken at low (10(to the 3rd power) rad) dose levels when exposed to ionizing radiation. This darkening decreases the sensitivity of optical sensors. Optical glass flats of FK 51, LaK 0, PK 51A, and ZK Ny were exposed to a 10.6 krad dose of ionizing radiation. Spectrophotometer traces determined the transmittance of the samples as a function of wavelength in the range 350 to 850 nm before and at various time intervals after the irradiation. These measured values were then use to evaluate the rate of recovery or ''bleaching'' of the exposed samples. To prevent accelerated bleaching, the samples were kept at room temperature and away from light, except during measurement. Tables of the measured data and plots of the transmissivity vs. wavelength at various times after irradiation are presented

  12. Outlook for world nuclear power generation and long-term energy supply and demand situations

    International Nuclear Information System (INIS)

    Matsuo, Yuhji

    2012-01-01

    In this article, the author presents a long-term outlook for the world's nuclear generating capacity, taking into account the nuclear policy changes after Fukushima Daiichi nuclear power plant accident. World primary energy demand will grow from 11.2 billion tons of oil equivalent (toe) in 2009 to 17.3 billion toe in 2035. Along with this rapid increase in global energy consumption, the world's nuclear generating capacity will grow from 392 GW in 2010 to 484 GW in 2020 and 574 GW in 2035 in the 'Reference scenario'. Even in the 'Low nuclear scenario', where the maximum impact of Fukushima accident to the nuclear policies of each government is assumed, it will continue to grow in the future, exceeding 500 GW in 2035. In particular, Asian countries such as China and India will lead the growth both in the energy demand and in the nuclear power capacity. Therefore, it is essential to better ensure the safety of nuclear power generation. It is important for technologically developed countries, including Japan, to make active contributions to the establishment of a global nuclear safety control system. On the other hand, energy security and global warming will continue to be major issues, which will make it indispensable to make the best effort to save energy and expand renewable energy utilization. Japan is competitive in energy-saving and environmental conservation technologies, thus further development and utilization of there technologies should be a key option of Japan's growth growth strategy in the future. (author)

  13. Closing the gap between short- and long-term scenarios for nuclear energy

    International Nuclear Information System (INIS)

    Toth, F. L.; Rogner, H.-H.

    2005-01-01

    Many scenarios published in recent years explore the driving forces and assess plausible ranges of global energy use and the resources they draw on. Some scenarios (e.g., OECD IEA, Organization for Economic Co-operation and Development International Energy Agency, 2004) focus on the next decade or two and project the evolution of world energy demand, supply as well as the resources, technologies, and prices to match them. Other scenarios (e.g., the Special Report on Emissions Scenarios, SRES, prepared by the Intergovernmental Panel on Climate Change, IPCC, 2000) explore the long term with a view to resource availability and depletion, technological transformations, and environmental concerns, predominantly climate change. A persistent gap (see Figure 1) can be observed in the projections for nuclear energy: near-term scenarios typically project a flat or slightly declining contribution of nuclear energy to the world energy supply whereas medium- and long-term scenarios anticipate significant increases. The magnitude of the gap between the OECD IEA (2002) projections and the median of the 40 IPCC SRES scenarios for the year 2020 amounts to almost 300 GWe installed capacity. Reasons for the gap originate in the differences between the analytical frameworks (including projection techniques) adopted by the short- and long-term studies. Another, closely related reason is the difference in the underlying assumptions, particularly their relations to recent trends and the current situation. In addition, near-term projections are heavily influenced by the social context (perceived unpopularity or outright rejection of nuclear power after Chernobyl), political factors (government pronouncements and policies at the national level, diplomacy and balancing of national positions at international organizations), economic aspects (energy market deregulation and liberalization unveiling excess capacities; financial risks), technology matters (the role of learning, definition of

  14. Evaluation of long-term leaching of borosilicate glass in pure water

    International Nuclear Information System (INIS)

    Lanza, F.; Parnisari, E.

    1979-01-01

    In order to confirm the validity of the model of the dissolving sphere, a series of tests of leaching of borosilicate glasses has been performed. The leaching rate is followed by measurements of weight loss and analysis of the surface composition. An accumulation at the surface of the less soluble cations is observed

  15. The long-term corrosion of glass by ground-water

    International Nuclear Information System (INIS)

    Cox, G.A.; Ford, B.A.

    1993-01-01

    Specimens of corroded soda and potash glasses, which had been exposed to groundwater for periods of up to about 1650 years, have been physically and chemically analysed. The morphology and compositional profiles of their finely laminated weathering crusts were determined by scanning electron microscopy and electron-probe microanalysis. It is shown that the surface layers on all specimens are depleted, to varying extents, of their principal constituents, with the exception of Si, Al and Fe. X-ray and electron diffraction studies have revealed the (tentative) identities of complex, poorly crystalline silicates and aluminosilicates within the largely amorphous crusts on potash glasses. The mean thickness of the crusts was found to correlate well with the free energy of hydration, ΔG o , of the pristine glasses. The rate of layer formation on the most durable specimens (ΔG o ∼ -15 kJ mol -1 ) was about 4 x 10 -3 μm year -1 . Deposits of calcite, calcium phosphate and manganese rich minerals occurred within the crusts; they were largely of external origin. Thus, in addition to the composition of the glass, the geochemistry of the local groundwater plays a decisive role in determining the identity of the compounds present within the weathering crusts. (author)

  16. Natural analogue study of long-term leaching behavior of vitrification glass

    International Nuclear Information System (INIS)

    Arai, Takashi; Yusa, Yasuhisa; Kamei; Gento

    1990-01-01

    In the research on the formation disposal of high level radioactive wastes, the evaluation of the leaching behavior of vitrification glass over ultralong term is one of the important themes. Therefore, the research on the phenomena of quality change in natural environment of volcanic glass, of which the chemical composition resembles well, was carried out (natural analogue study). Among the pyroclastic fall deposit in Fuji and Izu Oshima Volcanoes, the examples of the weathering change of quality of basaltic glass over several hundreds-several thousands years were selected, and on the spot survey, the analysis of groundwater, SEM observation, EPMA and so on were carried out. As the results, the following facts were found. According to the review of the literatures on ancient climate, the atmospheric temperature and precipitation in the past 3000 years were regarded as nearly the same as now. The products from the quality change were similar to the case of laboratory leaching experiment on vitrification glass. The measured ion concentration in groundwater agreed with the calculated values. (K.I.)

  17. Long term behaviour of glass and steel in interaction with argillites in deep geological conditions

    International Nuclear Information System (INIS)

    Bildstein, O.; Lartigue, J.E.; Devallois, V.; Pointeau, V.; Trotignon, L.; Michau, N.; Cochepin, B.; Munier, I.

    2010-01-01

    Document available in extended abstract form only. The concept developed in France for the disposal of vitrified high level waste in deep geological repository includes the containment in steel canisters, designed to prevent contact between glass and water and to maintain mechanical stability, and the confinement at ca. 500 m into an argillaceous host rock. After canister disposal and repository closure, the site will progressively re-saturate in non-isothermal conditions and the alteration of the different materials will start: corrosion of the canisters, degradation of concrete plugs, and ultimately, the alteration of glass waste. These perturbations will affect the properties of the different materials present in the near field and the lifetime of the glass matrix. Several scenarios are investigated which all involve (1) the geochemical interactions between iron and clay-rich materials, and (2) the alteration of glass in the presence of corrosion products. The evolution of the near field system is complex since geochemical and transport processes are highly coupled. Steel corrosion and glass alteration produce an increase of pH which in turn affects the rate of glass dissolution. The concentration of dissolved silica is also one key to the rate of glass alteration and, along with the concentration of other elements such as iron and aluminum, it determines the nature of steel corrosion and clay alteration products. These interactions may also lead to partial dissolution of the initial clay minerals potentially affecting the overall confinement properties such as swelling and capacity to exchange cations. Coupled reaction-transport simulations with the Crunch code was used to assess the impact of steel corrosion and glass alteration phases in the presence of corrosion products (CP), looking at mass transfer for chemical elements, especially iron and silicon, pH, porosity change. A first set of calculations based on a reference case in isothermal conditions (90 deg

  18. Safety aspects in the dry storage of spent nuclear fuel in long term operation

    Energy Technology Data Exchange (ETDEWEB)

    Nodarim, Claudir J.; Silva, Viviane B. da; Fontes, Gladson S. [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil); Saldanha, Pedro L.C., E-mail: claudirnodari@gmail.com, E-mail: vivisborges@gmail.com, E-mail: gsfontes@hotmail.com, E-mail: Saldanha@cnen.gov.br [Comissão Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    The purpose of the present paper is to discuss the safety assessment of the Dry Storage Unit (DSU), taking into account the long term operation and the operational experience already evidenced in similar facilities. In this sense, the RIDM (Risk-Informed Decision-Making) concept will be adopted for the regulatory decision-making process. Potential technical issues associated with the aging of materials from the dry storage unit will be considered. The work will be done using the rules and requirements of 10 CFR Part 72 and the U.S. NRC (United States Nuclear Regulatory Commission) regulatory guides. (author)

  19. The role of nuclear techniques in the long-term prediction of radionuclide transport

    International Nuclear Information System (INIS)

    Airey, P.L.; Duerden, P.

    1985-01-01

    Problems associated with the long-term prediction of the migration of radionuclides, and the role of natural analogues in reducing the inherent uncertainties are discussed. Particular reference is made to the evaluation of uranium ore bodies in the Alligator Rivers region, Northern Territory, as analogues of high-level radioactive waste repositories. A range of nuclear techniques has been used to identify the role of colloids, of alpha recoil and of mineralogy in transport. Specific mention is made of a method being developed which enables models of the migration of solute through fractured rock to be assessed via a combination of alpha track, fission track and PIXE/PIGME techniques

  20. Radiolytic gas production during long-term storage of nuclear wastes

    International Nuclear Information System (INIS)

    Bibler, N.E.

    1976-01-01

    Gases produced by in situ radiolysis of sealed solidified nuclear wastes during long-term storage could conceivably breach containment. Therefore, candidate waste forms (matrices containing simulated nuclear wastes) were irradiated with 60 Co-γ and 244 Cm-α radiation. These forms were: cement containing simulated fission product sludges, vermiculite containing organic liquids, and cellulosics contaminated with α-emitting transuranic isotopes. For cement waste forms exposed to γ-radiolysis, an equilibrium hydrogen pressure was reached that was dose rate dependent. For α-radiolysis, equilibrium was not reached. With organic wastes (n-octane on vermiculite), H 2 and traces of CO 2 and CH 4 were produced, and O 2 was consumed with both radiations. Only energy absorbed by the organic material was effective in producing H 2 . At low dose rates with both α- and γ-irradiations, G(H 2 ) was 4.5 and G(-O 2 ) was 5.0. Also, equilibrium was not obtained. For cellulosic material, H 2 , CO 2 , and CO were produced in the ratio of 1.0:0.7:0.3, and O 2 was consumed. With α-radiolysis, G(gas) was dose dependent; measured values ranged from 2.2 to 0.6 as the dose increased. Implications of all these results on long-term storage of radioactive waste are discussed. Some data from an actual nuclear wasteform are also presented

  1. Nuclear energy contribution to restraining greenhouse gas emissions and long-term energy production

    International Nuclear Information System (INIS)

    Khoda-Bakhsh, R.

    2004-01-01

    An important source of greenhouse gases, in particular Co 2 , is fossil fuel combustion for energy applications. Since nuclear power is an energy source that does not produce Co 2 , nuclear energy is already making a contribution to restraining greenhouse gas emissions. Because it has been internationally decided to reduce carbon dioxide emission before the year 2005 in order to avoid the green house catastrophy of the earth's atmosphere, and since there is an urgent need of energy especially in the developing countries, there is now a strong demand for alternative energy sources. While the established low cost energy production by light water nuclear fission reactors could be a solution for a period of transition (limited by resources of the light Uranium isotope), fusion energy is of interest for long- term and large scale energy production to provide the increased energy demand

  2. Foundations of a long-term strategy for nuclear power development in Japan

    International Nuclear Information System (INIS)

    Murata, H.

    1975-01-01

    A long-term strategy for nuclear power developments in Japan is proposed. The situation in the world has greatly changed in the recent years due to the rise in oil prices as well as the considerable concern about the environmental problems caused by the nuclear power plants. Stress is being placed on the harmonization with the environmental protection rather than on the economical generation of the nuclear power. In order to meet the future requirements, five systems are given for the short, medium and long ranges beyond the year 2000. For the final stage a system is proposed that combines fusion-fission hybrid reactors with very high temperature gas cooled reactors to supply clean energy. (author)

  3. Long term operation of nuclear power plants in Spain: preparing for the future

    Energy Technology Data Exchange (ETDEWEB)

    Marcelles, I.; Frutos, E.; Jardi, X.; Cosgaya, F., E-mail: imarcelles@tecnatom.es [Tecnatom, S. A., Av. Montes de Oca 1, 28703 San Sebastian de los Reyes, Madrid (Spain)

    2017-09-15

    The Spanish nuclear industry is preparing for the Long Term Operation (LTO) of its complete fleet. Therefore, an important number of activities are being currently developed in order to achieve the safe and economical life extension of the operational life of the Spanish nuclear power plants. This paper describes the main activities that will be performed to meet the licensing requirements, in order to be granted and operating license for LTO, such as the development of Ageing Management Plans (Amp), Time Limited Ageing Analysis (TLAA) as well as databases and software tools to support LTO. In addition to this, this paper will describe the implementation of the NDE activities included in the AMPs and some of the research and development programs that the Spanish nuclear industry research is working on related to LTO (e.g. cable ageing, concrete degradation, etc.) (Author)

  4. Long term operation of nuclear power plants in Spain: preparing for the future

    International Nuclear Information System (INIS)

    Marcelles, I.; Frutos, E.; Jardi, X.; Cosgaya, F.

    2017-09-01

    The Spanish nuclear industry is preparing for the Long Term Operation (LTO) of its complete fleet. Therefore, an important number of activities are being currently developed in order to achieve the safe and economical life extension of the operational life of the Spanish nuclear power plants. This paper describes the main activities that will be performed to meet the licensing requirements, in order to be granted and operating license for LTO, such as the development of Ageing Management Plans (Amp), Time Limited Ageing Analysis (TLAA) as well as databases and software tools to support LTO. In addition to this, this paper will describe the implementation of the NDE activities included in the AMPs and some of the research and development programs that the Spanish nuclear industry research is working on related to LTO (e.g. cable ageing, concrete degradation, etc.) (Author)

  5. Long term effects of bioactive glass particulates on dental pulp stem cells in vitro

    Directory of Open Access Journals (Sweden)

    Gholami Sanaz

    2017-12-01

    Full Text Available Bioactive glasses (BG are known for their ability to induce bone formation by the action of their dissolution products. Glasses can deliver active ions at a sustained rate, determined by their composition and surface area. Nanoporous sol-gel derived BGs can biodegrade rapidly, which can lead to a detrimental burst release of ions and a pHrise. The addition of phosphate into the glass can buffer the pH during dissolution. Here, dissolution of BG with composition 60 mol% SiO2, 28 mol% CaO and 12 mol% P2O5 at 600 μg/ml were investigated. Initially, the dissolution and apatite formation of the BG particulates were examined in simulated body fluid using FTIR and XRD. BG particulates were indirectly exposed to dental pulp stem cells, and the effect of 14 days continuous ion release on human dental pulp stem cells (hDPSC viability and differentiation was evaluated. Alamar blue assay showed that cell proliferation was not inhibited by the continuous release of Ca, P and soluble silica. In fact, hDPSC in the presence of BG particulate displayed a higher density of mineralized nodules than untreated cells, as assessed by Alizarin red. The results will have a great contribution to the in vivo application of this particular BG.

  6. Long-term dimensional stability and longitudinal uniformity of line scales made of glass ceramics

    International Nuclear Information System (INIS)

    Takahashi, Akira

    2010-01-01

    Line scales are commonly used as a working standard of length for the calibration of optical measuring instruments such as profile projectors, measuring microscopes and video measuring systems. For high-precision calibration, line scales with low thermal expansion are commonly used. Glass ceramics have a very low coefficient of thermal expansion (CTE) and are widely used for precision line scales. From a previous study, it is known that glass ceramics decrease in length from the time of production or heat treatment. The line scale measurement method can evaluate more than one section of the line scale and is capable of the evaluation of the longitudinal uniformity of the secular change of glass ceramics. In this paper, an arithmetic model of the secular change of a line scale and its longitudinal uniformity is proposed. Six line scales made of Zerodur®, Clearceram® and synthetic quartz were manufactured at the same time. The dimensional changes of the six line scales were experimentally evaluated over 2 years using a line scale calibration system

  7. Long term operation of nuclear power plants in the U.S

    International Nuclear Information System (INIS)

    Young, G.G.

    2015-01-01

    This series of slides shows that safety, performance, cost, environmental and public opinion factors are favorable for long term operation of U.S. nuclear power plants. In the U.S. 1 reactor has an operating life ranging between 10 and 19 years, 37 reactors have an operating life ranging between 20 and 29 years, 42 reactors between 30 and 39 years and 20 reactors have an operating life over 40 years. The original license term is 40 years and it can be extended by 20 years for each renewal. The application for renewal must be at least 5 years before expiration of the current license. 3 main areas are reviewed by NRC to get the renewal: safety, environmental and adjudicatory. A slide describes the NRC license renewal process and another slide lists the regulatory and industry guidance documents based on lessons learned and operating experience. Research and development efforts around materials aging and safety margin characterization by EPRI, DOE, NRC and industry groups are essential to support and maintain the option of long term operation of nuclear reactors. (A.C.)

  8. Technology transfer on long-term radioactive waste management - a feasible option for small nuclear programmes?

    International Nuclear Information System (INIS)

    Mele, I.; Mathieson, J.

    2007-01-01

    The EU project CATT - Co-operation and technology transfer on long-term radioactive waste management for Member States with small nuclear programmes investigated the feasibility of countries with small nuclear programmes implementing long-term radioactive waste management solutions within their national borders, through collaboration on technology transfer with those countries with advanced disposal concepts. The main project objective was to analyse the existing capabilities of technology owning Member States and the corresponding requirements of potential technology acquiring Member States and, based on the findings, to develop a number of possible collaboration models and scenarios that could be used in a technology transfer scheme. The project CATT was performed as a specific support action under the EU sixth framework programme and it brought together waste management organisations from six EU Member States: UK, Bulgaria, Germany, Lithuania, Slovenia and Sweden. In addition, the EC Joint Research Centre from the Netherlands also participated as a full partner. The paper summarises the analyses performed and the results obtained within the project. (author)

  9. Viability for controlling long-term leaching of radionuclides from HLW glass by amorphous silica additives

    International Nuclear Information System (INIS)

    Inagaki, Y.; Uehara, S.

    2004-01-01

    Dissolution and deterioration experiments in coexistence system of amorphous silica and vitrified wastes have been executed in order to evaluating the effects of amorphous silica addition to high level radioactive vitrified waste (HLW glass) on suppression of nuclide leaching. Geo-chemical reaction mechanism among the vitrified waste, the amorphous silica and water was also evaluated. Dissolution of the silica network was suppressed by addition of the amorphous silica. However, the leaching of soluble nuclides like B proceeded depending on the hydration deterioration reaction. (A. Hishinuma)

  10. Long term needs for nuclear data development. Texts of papers presented at the advisory group meeting

    International Nuclear Information System (INIS)

    Herman, M.

    2001-08-01

    This report contains the texts of the invited presentations delivered at the Advisory Group Meeting on Long Term Needs for Nuclear Data Development. The meeting was organized by the International Atomic Energy Agency (IAEA) and held at IAEA Headquarters, Vienna, Austria, 28 November - 1 December 2000. The texts are reproduced here, directly from the author's manuscripts with little or no editing, in the order in which the presentations were made at the meeting. For the main conclusions refer to the Summary Report, published as INDC(NDS)-423. The contributed papers deal with cross section data needed for production of radionuclides; for internal radiation dosimetry; for ion beam analysis; neutron data needs in astrophysics; nuclear data for advanced fast reactors; lead cooled reactors; accelerator driven subcritical assemblies

  11. Status of long term operation of nuclear power plants in the US

    Energy Technology Data Exchange (ETDEWEB)

    Young, G., E-mail: gyoung4@entergy.com [Entergy Nuclear, License Renewal, New Orleans, LA (United States)

    2014-07-01

    As of early-2014, the U.S. Nuclear Regulatory Commission (NRC) has renewed the operating licenses for 73 of the 100 U.S. operating nuclear units, allowing for up to 60 years of safe operation. In addition, the NRC has license renewal applications under review for 18 more units and up to 8 additional units have announced plans to submit applications by 2018. This brings the total of renewed licenses and announced plans for renewal to 99% of the operating nuclear units in the U.S. In addition, by the end of 2014, there will be 38 nuclear plants that will have operated for more than 40 years and will be eligible to seek a subsequent license renewal to allow operation up to 80 years. Although some of the operating nuclear units are expected to shutdown due to economic issues, most of the remaining operating plant owners are keeping the option open for long term operation beyond 60 years. NRC and the U.S. nuclear industry have made significant progress in preparing the way for subsequent license renewal applications. This presentation covers the status of the U.S. license renewal process and issues being addressed for possible applications for subsequent renewals for up to 80 years of operation. (author)

  12. Evaluation of nuclear power development scenarios in romania envisaging the long-term national energy sustainability

    International Nuclear Information System (INIS)

    Margeanu, C.; Apostol, M.; Visan, I.; Prodea, I.

    2015-01-01

    The paper summarizes the results of RATEN ICN Pitesti experts' activities in the IAEA's Collaborative Project INPRO-SYNERGIES. Romanian study proposes to evaluate and analyze development of the nuclear capacity and increasing of its share in national energy sector, envisaging the long term national and regional energy sustainability by keeping options open for the future while bringing solutions to short/medium-term challenges. The study focused on the modelling of national NES (Nuclear Energy System) development on short and medium-term (time horizon 2050), considering the existing NFC (Nuclear Fuel Cycle) infrastructure and legislation, provisions of strategic documents in force and including also the possibility of regional collaboration regarding U/fresh fuel supply and SF (Spent Fuel) storage, as services provided at international market prices. The energy system modelling was realized by using the IAEA's MESSAGE program. The study results offer a clear image and also the possible answer to several key questions regarding: potential of nuclear energy to participate with an important share in national energy mix, in conditions of cost competitiveness, safety and security of supply; impact on national energy mix portfolio of capacities and electricity production; impact on Uranium domestic resources; economic projection/investments needed for new nuclear capacities addition; fresh fuel requirements for nuclear capacities; SF annually discharged and transferred to interim wet storage for cooling; SF volume in interim dry storage, etc. (authors)

  13. A study on the long-term nuclear policy direction responding the changes of international and domestic nuclear situation

    International Nuclear Information System (INIS)

    Kim, Hyun Jun; Yang, M. H.; Lee, B. O.; Ham, C. H.; Chung, W. S.; Lee, T. J.; Yun, S. W.; Ko, H. S.; Nha, K. H.

    1998-06-01

    The long-term nuclear policy directions are proposed with three aspects of nuclear technology development policy, nuclear regulatory policy, and tasks required for promoting pro-nuclear movement. Several nuclear technology areas, such as technology for the improvement of nuclear economics, safety enhancement technology, radwaste, treatment/disposal technology, fuel cycle technology, and proliferation-resistant nuclear technology, fuel recycle technology, and proliferation-resistant nuclear technology, appear very important in the future nuclear technology development policy. Nuclear regulation policy should be established with balancing between public safety and expansion of nuclear industry. Objective of nuclear regulation should be recognized not to collapse a nuclear industry, and the worth of nuclear regulatory regime may be also meaningful if nuclear industry can be well developed. It should be necessary to make a proper atmosphere that can resolve revealed or potential problems and issues against the harmonious implementation of nuclear policy. For the purpose, nuclear policy should contain certain policies to promote a nuclear development, such as social policy, international cooperation strategy, and national resource allocation policy. (author). 20 refs., 8 tabs., 5 figs

  14. Requirement for nuclear calcium signaling in Drosophila long-term memory.

    Science.gov (United States)

    Weislogel, Jan-Marek; Bengtson, C Peter; Müller, Michaela K; Hörtzsch, Jan N; Bujard, Martina; Schuster, Christoph M; Bading, Hilmar

    2013-05-07

    Calcium is used throughout evolution as an intracellular signal transducer. In the mammalian central nervous system, calcium mediates the dialogue between the synapse and the nucleus that is required for transcription-dependent persistent neuronal adaptations. A role for nuclear calcium signaling in similar processes in the invertebrate brain has yet to be investigated. Here, we show by in vivo calcium imaging of adult brain neurons of the fruit fly Drosophila melanogaster, that electrical foot shocks used in olfactory avoidance conditioning evoked transient increases in cytosolic and nuclear calcium concentrations in neurons. These calcium signals were detected in Kenyon cells of the flies' mushroom bodies, which are sites of learning and memory related to smell. Acute blockade of nuclear calcium signaling during conditioning selectively and reversibly abolished the formation of long-term olfactory avoidance memory, whereas short-term, middle-term, or anesthesia-resistant olfactory memory remained unaffected. Thus, nuclear calcium signaling is required in flies for the progression of memories from labile to transcription-dependent long-lasting forms. These results identify nuclear calcium as an evolutionarily conserved signal needed in both invertebrate and vertebrate brains for transcription-dependent memory consolidation.

  15. EU 2030 targets 'unachievable' without long-term nuclear operation

    Energy Technology Data Exchange (ETDEWEB)

    Mitev, Lubomir [NucNet, Brussels (Belgium)

    2015-01-15

    Nuclear energy will continue to support greenhouse gas emission reduction targets until 2020, but without decisions on long-term operation of ageing reactors, it will be difficult for the EU to meet its 2030 targets, International Energy Agency (IEA) executive director Maria van der Hoeven, tells NucNet in an interview. The IEA has quite a few remarks and questions related to the EU goals of competitiveness, security of supply and sustainability. It is good to have these targets, but up until now the EU is missing the direct connection between the three goals. What is mostly needed to achieve the goals is to finalise the EU's internal energy market. Secondly cost-effective climate and energy policies are needed because it is not only about climate and energy, but also about economic development and competitiveness. The ageing EU reactor fleet requires country-level and owner/operator-level decisions in the short term regarding plant safety regulations, plant upgrades, uprates, lifetime extensions and licence renewals. Upgrading and uprating existing nuclear plants is one of the cheapest ways of producing carbon-free electricity in the EU. Without long-term operation, the IEA expects nuclear capacity in the EU could fall by a factor of six by 2030 and that will make it more difficult to achieve the EU's 2030 climate targets. Public opinion is an important topic for the acceptance of all energy sources and it is different in all IEA member countries. Europe is very sensitive to almost all forms of energy, including wind turbines and solar panels. This is linked to a lack of information, so we need more and better transparency on information for people.

  16. Long term operation of nuclear power plants – IAEA SALTO peer review service and its results

    Energy Technology Data Exchange (ETDEWEB)

    Krivanek, Robert, E-mail: r.krivanek@iaea.org

    2014-12-15

    Highlights: • SALTO peer review service is designed for reviewing of ageing management and NPPs’ preparedness LTO. • It has been established as an effective tool to review the compliance with IAEA safety standards. • The important issues for safe LTO are being identified by SALTO missions. • Analysis of those issues is provided in the paper. • This peer review service is strongly recommended for NPPs prior to entering LTO period. - Abstract: This paper presents main IAEA activities for safe long term operation (LTO) which includes establishment of IAEA Safety Standards and other LTO related documents, fostering information exchange and establishing databases and provision of SALTO (Safety Aspects of Long Term Operation) peer review service. This paper provides insights into IAEA SALTO peer review service objectives, scope and methodology. The SALTO peer review service was designed to assist nuclear power plant (NPP) operators in adopting a proper approach to LTO of their plants and in implementing complete and appropriate activities to ensure that plant safety will be maintained during the LTO period. The SALTO peer review service can also support regulators in establishing or improving regulatory and licensing strategies for LTO of NPPs. Issues derived from 19 SALTO missions and 2 LTO modules of OSART (Operational Safety Review Team) missions conducted during the period of 2005 to March 2014 are also analyzed in this paper.

  17. Human factors and nuclear space technology in long-term exploration

    International Nuclear Information System (INIS)

    Brown-VanHoozer, S.A.; VanHoozer, W.R.

    2000-01-01

    Allocation of manual versus automated tasks for operation and maintenance of nuclear power systems in space will be crucial at the onset and at the return of a space flight. Such factors as space adaptation syndrome (SAS), a temporary space motion sickness that has affected 40 to 50% of crew members on past space flights, can result in lost effort ranging from a few hours to a full day. This could have a significant impact on manual performance where high levels of execution are likely to be required in the very early stages of the mission. Other considerations involving higher-level behavioral phenomena such as interpersonal and group processes, individual belief systems, social and motivational factors, and (subjective) cognitive function have received little attention; nevertheless these will be essential elements for success in long-term exploration. Understanding that long-term space flight missions may create groups that become unique societies distinct unto themselves will test current ethical, moral, and social belief systems, requiring one to examine the amalgamation as well as organizational structures for the safety and balance of the crew

  18. Spectroscopic studies of irradiated glasses: Application in nuclear dosimetry

    International Nuclear Information System (INIS)

    Farah, Khaled

    2010-01-01

    The present work aims to study the effects of ionizing radiation on silicate glasses in order to develop a new dosimetry system simple, precise, stable and inexpensive. Indeed, changes in mechanical properties, optical and paramagnetic glasses when subjected to ionizing radiation. The prediction of long-term behavior, physical aging under irradiation, the glass is paramount. many studies have brought many ways to avoid obscuring glass windows used in nuclear reactors or hot cells and optical devices. Recently, much work has concentrated on the application of the color induced by irradiation for developing a recyclable glass in the glass industry is of great interest economically and environmentally.

  19. Long-term issues associated with spent nuclear power fuel management options

    International Nuclear Information System (INIS)

    Jae-Sol, Lee; Kosaku, Fukuda; Burcl, R.; Bell, M.

    2003-01-01

    Spent fuel management is perceived as one of the crucial issues to be resolved for sustainable utilisation of nuclear power. In the last decades, spent fuel management policies have shown diverging tendencies among the nuclear power production countries - a group has adhered to reprocessing- recycle and another has turned to direct disposal, while the rest of the countries have not taken decision yet, often with ''wait and see'' position. Both the closed and open fuel cycle options for spent fuel management have been subject to a number of debates with pros and cons on various issues such as proliferation risk, environmental impact, etc. The anticipation for better technical solutions that would mitigate those issues has given rise to the renewal of interest in partitioning and transmutation of harmful nuclides to be disposed of, and in a broader context, the recent initiatives for development of innovative nuclear systems. The current trend toward globalization of market economy, which has already brought important impacts on nuclear industry, might have a stimulating effect on regional-international co-operations for cost-effective efforts to mitigate some of those long-term issues associated with spent fuel management. (author)

  20. Nuclear fuel cycle requirements and supply considerations, through the long-term

    International Nuclear Information System (INIS)

    1978-02-01

    The OECD Nuclear Energy Agency and the International Atomic Energy Agency have for many years published a joint report entitled ''Uranium Resources, Production and Demand'', and a revised edition of this work, dated December 1977, is now available. This report, on the other hand, is the result of a separate study of the supply and demand outlook for all fuel cycle services, as well as for uranium, through the long-term. The work was undertaken by the Nuclear Energy Agency's Working Party on Uranium Demand, whose members are listed in Appendix III. The intent here has been to contribute to the orderly development of nuclear power, by: 1. identifying potential problems in the supply of uranium and fuel cycle services, and possible areas for international co-operation in the resolution of such problems; 2. examining several long-range scenarios to determine the comparative needs of advanced reactors for uranium and for supporting services, thereby establishing the basis for the further development of uranium resources and specific reactor systems; and 3. assisting those having responsibilities in planning, forecasting, and programme management. This report is the work of a group of technical experts and does not necessarily reflect official policy or endorsement of the report's projections and conclusions by the Member Governments of the Nuclear Energy Agency

  1. Some aspects of nuclear power development in Russian and studies on its optimal long term structure

    International Nuclear Information System (INIS)

    Ermakov, N.I.; Poplavsky, V.M.; Troyanov, M.F.; Oussanov, V.I.; Chebeskov, A.N.; Malenkov, A.V.; Gordeev, B.K.

    1997-01-01

    The paper presents the authors' outlook for nuclear power development in Russia. The analysis is based on the documents published and other materials as well as on the experience of the authors who participated in working out the state fuel-power program Power Strategy of Russia. The crucial point of the Strategy is that moratorium on the nuclear power development in Russia is inadmissible and a part of electricity production in the country will be covered by NPPs with increased safety. The studies which have been carried out by the organizations of MINATOM and ROSENERGOATOM and by some authors have shown that a potential of the Russia nuclear power complex meets the requirements of the nuclear power development up to year 2010. From the standpoint of the authors of the paper the investment climate in the country is the most important and uncertain factor influencing the program realization. But nuclear power preserves competitive ability in any option of new electric capacities introduced in Russia. Application of the market-oriented IAEA's planning tools have confirmed the competitive ability of nuclear power in the central region of Russia. This study is to be continued for other Russian regions. The estimates of the long-term prospects of nuclear power development in Russia made by the authors are based on the assumptions of natural uranium resources conservation, plutonium stockpile minimization and reduction of the radiotoxical waste to the lowest possible level. These requirements may be answered in the plutonium balanced system of thermal and fast reactors with a very economical consumption of natural uranium and a very small quantity of radioactive waste (mainly consisting of fission products and losses in reprocessing operations). (author)

  2. Investigation on polyetheretherketone composite for long term storage of nuclear waste

    Science.gov (United States)

    Ajeesh, G.; Bhowmik, Shantanu; Sivakumar, Venugopal; Varshney, Lalit; Kumar, Virendra; Abraham, Mathew

    2015-12-01

    This investigation highlights the effect of radiation, chemical and thermal environments on mechanical and thermal properties of Polyetheretherketone (PEEK) composites, which could prove to be an alternative material for long term storage of nuclear wastes. The tests are conducted on specimens made from PEEK and PEEK reinforced with carbon short fiber. The specimens are subjected to radiation doses, equivalent to the cumulative dosage for 500 years followed by exposure under highly corrosive and thermal environments. Studies under optical microscopy reveal that the dispersion of carbon short fiber in the PEEK Composites is significantly uniform. Differential scanning calorimeter (DSC) and thermo gravimetric analysis (TGA) indicates that there are no significant changes in thermal properties of PEEK composite when exposed to aggressive environments. It is further observed that there are no significant changes in mechanical properties of the composite after exposure to radiation and thermo-chemical environment.

  3. Birth Outcomes after the Fukushima Daiichi Nuclear Power Plant Disaster: A Long-Term Retrospective Study.

    Science.gov (United States)

    Leppold, Claire; Nomura, Shuhei; Sawano, Toyoaki; Ozaki, Akihiko; Tsubokura, Masaharu; Hill, Sarah; Kanazawa, Yukio; Anbe, Hiroshi

    2017-05-19

    Changes in population birth outcomes, including increases in low birthweight or preterm births, have been documented after natural and manmade disasters. However, information is limited following the 2011 Fukushima Daiichi Nuclear Power Plant Disaster. In this study, we assessed whether there were long-term changes in birth outcomes post-disaster, compared to pre-disaster data, and whether residential area and food purchasing patterns, as proxy measurements of evacuation and radiation-related anxiety, were associated with post-disaster birth outcomes. Maternal and perinatal data were retrospectively collected for all live singleton births at a public hospital, located 23 km from the power plant, from 2008 to 2015. Proportions of low birthweight (effects on maternal and perinatal health.

  4. Investigation on polyetheretherketone composite for long term storage of nuclear waste

    International Nuclear Information System (INIS)

    Ajeesh, G.; Bhowmik, Shantanu; Sivakumar, Venugopal; Varshney, Lalit; Kumar, Virendra; Abraham, Mathew

    2015-01-01

    This investigation highlights the effect of radiation, chemical and thermal environments on mechanical and thermal properties of Polyetheretherketone (PEEK) composites, which could prove to be an alternative material for long term storage of nuclear wastes. The tests are conducted on specimens made from PEEK and PEEK reinforced with carbon short fiber. The specimens are subjected to radiation doses, equivalent to the cumulative dosage for 500 years followed by exposure under highly corrosive and thermal environments. Studies under optical microscopy reveal that the dispersion of carbon short fiber in the PEEK Composites is significantly uniform. Differential scanning calorimeter (DSC) and thermo gravimetric analysis (TGA) indicates that there are no significant changes in thermal properties of PEEK composite when exposed to aggressive environments. It is further observed that there are no significant changes in mechanical properties of the composite after exposure to radiation and thermo-chemical environment.

  5. Post-LOCA long term cooling performance in Korean standard nuclear power plants

    International Nuclear Information System (INIS)

    Bang, Young Seok; Jung, Jae Won; Seul, Kwang Won; Kim, Hho Jung

    1999-01-01

    The post-LOCA long term cooling (LTC) performance of the Korean Standard Nuclear Power Plant (KSNPP) is analyzed for both small break LOCA and large break LOCA. The RELAP5/MOD3.2.2 code is used to calculate the LTC sequences based on the LTC plan of the KSNPP. A standard input model is developed such that LOCA and the followed LTC sequence can be calculated in a single run for both small break LOCA and large break LOCA. A spectrum of small break LOCA ranging from 0.02 to 0.5 ft 2 of break area and a double-ended guillotine break are analyzed. Through the code calculations, the thermal-hydraulic behavior and the boron behavior are evaluated and the effect of the important manual action including the safety injection tank isolation in LTC procedure is investigated

  6. Inventory extension considerations for long-term storage at the nuclear materials storage facility

    International Nuclear Information System (INIS)

    Olinger, C.T.; Stanbro, W.D.; Longmire, V.; Argo, P.E.; Nielson, S.M.

    1996-01-01

    Los Alamos National Laboratory is in the process of modifying its nuclear materials storage facility to a long-term storage configuration. In support of this effort, we examined technical and administrative means to extend periods between physical inventories. Both the frequency and sample size during a physical inventory could significantly impact required sizing of the non-destructive assay (NDA) laboratory as well as material handling capabilities. Several options are being considered, including (1) treating each storage location as a separate vault, (2) minimizing the number of items returned for quantitative analysis by optimizing the use of in situ confirmatory measurements, and (3) utilizing advanced monitoring technologies. Careful consideration of these parameters should allow us to achieve and demonstrate safe and secure storage while minimizing the impact on facility operations and without having to increase the size of the NDA laboratory beyond that required for anticipated shipping and receiving activities

  7. Mineral-modeled ceramics for long-term storage of high-level nuclear wastes

    International Nuclear Information System (INIS)

    Vance, E.R.

    1980-01-01

    Over the past ten years, Penn State's Materials Research Laboratory has done extensive work on mineral-modeled ceramics for high-level nuclear waste storage. These ceramics are composed of several mineral analogues that form a monolithic polycrystalline aggregate. Mineral-modeling can be made in a similar fashion to nuclear waste glasses, and their naturally occurring analogues are known to last millions, and even billions, of years in hot, wet conditions. It is believed that such ceramics could reduce dispersal of radionuclides by leaching to a minimum

  8. Long-term conversion of 45S5 bioactive glass-ceramic microspheres in aqueous phosphate solution.

    Science.gov (United States)

    Fu, Hailuo; Rahaman, Mohamed N; Day, Delbert E; Huang, Wenhai

    2012-05-01

    The conversion of 45S5 glass and glass-ceramics to a hydroxyapatite (HA)-like material in vitro has been studied extensively, but only for short reaction times (typically glass-ceramic microspheres (designated 45S5c) in an aqueous phosphate solution. Microspheres of 45S5c (75-150 μm) were immersed for 10 years at room temperature (~25 °C) in K(2)HPO(4) solution with a concentration of 0.01 M or 1.0 M, and with a starting pH of 7.0 or 9.5. The reacted 45S5c microspheres and solutions were analyzed using structural and analytical techniques. Only 25-45 vol% of the 45S5c microspheres were converted to an HA-like material after the 10 year reaction. In solutions with a starting pH of 9.5, an increase in the K(2)HPO(4) concentration from 0.01 to 1.0 M resulted in a doubling of the volume of the microspheres converted to an HA-like material but had little effect on the composition of the HA-like product. In comparison, reaction of the 45S5c microspheres in the solution with a starting pH of 7.0 resulted in an HA-like product in the 0.01 M K(2)HPO(4) solution but a calcium pyrophosphate product, Ca(10)K(4)(P(2)O(7))(6).9H(2)O, in the 1.0 M solution. The consequences of these results for the long-term use of 45S5 glass-ceramics in biomedical applications are discussed.

  9. Nuclear protein phosphatase-1: an epigenetic regulator of fear memory and amygdala long-term potentiation.

    Science.gov (United States)

    Koshibu, K; Gräff, J; Mansuy, I M

    2011-01-26

    Complex brain diseases and neurological disorders in human generally result from the disturbance of multiple genes and signaling pathways. These disturbances may derive from mutations, deletions, translocations or rearrangements of specific gene(s). However, over the past years, it has become clear that such disturbances may also derive from alterations in the epigenome affecting several genes simultaneously. Our work recently demonstrated that epigenetic mechanisms in the adult brain are in part regulated by protein phosphatase 1 (PP1), a protein Ser/Thr phosphatase that negatively regulates hippocampus-dependent long-term memory (LTM) and synaptic plasticity. PP1 is abundant in brain structures involved in emotional processing like the amygdala, it may therefore be involved in the regulation of fear memory, a form of memory related to post-traumatic stress disorder (PTSD) in human. Here, we demonstrate that PP1 is a molecular suppressor of fear memory and synaptic plasticity in the amygdala that can control chromatin remodeling in neurons. We show that the selective inhibition of the nuclear pool of PP1 in amygdala neurons significantly alters posttranslational modifications (PTMs) of histones and the expression of several memory-associated genes. These alterations correlate with enhanced fear memory, and with an increase in long-term potentiation (LTP) that is transcription-dependent. Our results underscore the importance of nuclear PP1 in the amygdala as an epigenetic regulator of emotional memory, and the relevance of protein phosphatases as potential targets for therapeutic treatment of brain disorders like PTSD. © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  10. Long-term performance of structures comprising nuclear power plants PART 1: Deterioration assessment of nuclear power station buildings PART 2: Long-term stability and the leak-tightness of reactor containments

    International Nuclear Information System (INIS)

    Pocock, D.C.; Worthington, J.C.; Oberpichler, R.; Van Exel, H.; Beukelmann, D.; Huth, R.; Rose, B.

    1990-01-01

    The objective of this research was to study the long-term performance of structures comprising nuclear power plants. The time period of interest for this study is 140 years (this figure is based on maximum periods of 40 years for operation and 100 years of storage). It was divided in two parts: - the first based on four UK nuclear power plants examine the principle deterioration mechanism of reinforced structure which is chloride ingress and carbonation penetration - the second based on 2 German nuclear power plants examine the long term behaviour of reinforced and prestressed concrete and also the corrosion of steel containments with particular reference on plastic seals and potential risk areas

  11. An assessment method for long-term management of Canada's used nuclear fuel

    International Nuclear Information System (INIS)

    Leiss, W.

    2006-01-01

    The nine-member Assessment Team, assembled by the Nuclear Waste Management Organization in early 2004, reported the results of its work in the NWMO document, 'Assessing the Options: Future Management of Used Nuclear Fuel in Canada (June 2004). The team was responding to the challenge to develop a rigorous and credible evaluation of multiple options, and one which would also satisfy a complex set of objectives: a solution that would be 'socially acceptable, technically sound, environmentally responsible, and economically feasible.' This paper describes the special challenges faced by the Assessment Team in seeking to respond to this multifaceted assignment. I open by discussing the implications of the institutional and legal framework inherited by the NWMO from the Seaborn Panel (including the government's response to the Seaborn Panel report), which in effect set a new standard for the practice of risk management decision making in Canada. I then review the highlights of the Assessment Team's report, including its chosen method, namely, multi-objective utility analysis. I conclude with a discussion of the longer term implications of the assessment work done to date for the next stages in the process of finding a credible solution for the long-term management of used nuclear fuel in Canada. (author)

  12. On the pathway towards disposal. The need for long-term interim storage of high-level nuclear waste

    International Nuclear Information System (INIS)

    Budelmann, Harald; Koehnke, Dennis; Reichardt, Manuel

    2017-01-01

    The disposal of spent nuclear fuel is a still unsolved problem with social, ethical, economical, ecological and political dimensions. The stagnating decision process on the final repository concept in several countries has the consequence of the inclusion of long-term interim storage into the disposal concept. The contribution discusses several approaches. This opens the question whether the long-term interim storage is a matter of delaying tactic or a pragmatic solution on the way to a final repository.

  13. The role of pressure vessel embrittlement in the long term operation of nuclear power plants

    International Nuclear Information System (INIS)

    Ballesteros, A.; Ahlstrand, R.; Bruynooghe, C.; Estorff, U. von; Debarberis, L.

    2012-01-01

    Highlights: ► Relevant open scientific issues for the long term operation of RPVs are discussed (flux effect, late blooming phases, etc.). ► Several European and American research programmes dealing with these open issues are reviewed. ► A method for consolidation and preservation of knowledge in this field is presented. - Abstract: The lack of new build of plants over the last twenty years has resulted in a switch within the industry from design, construction and development of new systems to the strengthening of safety systems and to the life extension, or long term operation (LTO), of existing reactors. The most relevant component of any nuclear power plan (NPP) is the reactor pressure vessel (RPV). This is because currently the RPV is still considered irreplaceable or prohibitively expensive to replace. This means, that if it degrades sufficiently, it could be the operational life limiting feature of the NPP. A RPV operational life of 60 years is being considered frequently by many utilities in their plant life management programmes. Areas of improvement facing long term operation are the reduction of uncertainties in the embrittlement parameters of irradiated vessels, and the development of embrittlement trend curves at high fluence levels, where surveillance data are scarce. Different techniques can be used to upgrade the surveillance programmes, as the use of miniature or reconstituted specimens and the application of best estimate assessment tools (e.g. Master Curve). Several relevant international research projects are on-going or have been proposed to clarify the material condition of long operated vessels. Knowledge management is a complementary tool, but not for it less important. The general context for LTO of RPVs is presented in this paper. Starting with a review of relevant embrittlement issues still open, followed by presenting the different techniques and tools that can be used to support LTO, and summarising the scopes of relevant European

  14. Nuclear Materials Diversion Safety and the Long-term Future of Nuclear Energy

    International Nuclear Information System (INIS)

    Knapp, V.

    2002-01-01

    Primarily due to irresponsible cold war politics of nuclear weapon countries nuclear proliferation situation is little short of getting out of control. In addition to five nominal nuclear weapon countries there are at present at least three more nuclear weapon countries and several countries with nuclear weapon potential. Non-proliferation treaty (NPT), signed in 1970, has been recognized by most non-nuclear weapon countries as unjust and ineffective. After the initial, deliberate, nuclear weapon developments of five nominal nuclear weapon countries, subsequent paths to nuclear weapons have been preceded by nominal peaceful use of nuclear energy. Uranium enrichment installations as well as reprocessing installations in non-nuclear weapon countries are the weakest spots of fuel cycle for diversion of nuclear materials either by governments or by illicit groups. An energy scenario, which would, by the end of century, replace the large part of fossil fuels use through extension of present nuclear practices, would mean very large increase in a number of such installations, with corresponding increase of the probability of diversion of nuclear materials. Such future is not acceptable from the point of view of proliferation safety. Recent events make it clear, that it cannot be accepted from the requirements of nuclear terrorism safety either. Nuclear community should put it clearly to their respective governments that the time has come to put general interest before the supposed national interest, by placing all enrichment and reprocessing installations under full international control. Such internationalization has a chance to be accepted by non-nuclear weapon countries, only in case should it apply to nuclear weapon countries as well, without exception. Recent terrorist acts, however horrible they were, are child,s play compared with possible acts of nuclear terrorism. Nuclear energy can be made proliferation safe and diversion of nuclear materials safe, and provide

  15. China's current status and long-term outlook of nuclear power and radioactive waste disposal management

    International Nuclear Information System (INIS)

    Li, Zhidong

    2015-01-01

    This study identified the current status and long-term outlook of China's nuclear power development and radioactive waste disposal management after the 3.11 FUKUSHIMA accidents. China strengthened the actions for achieving nuclear power safety and cost efficiency as well as safety management of radioactive waste. It is a hard work to expand the capacity to 58 GW, the governmental target in 2020. The long-term development will strongly depend on the progress in safety management of nuclear power and radioactive waste and economic competitiveness. (author)

  16. Radiation characteristics of spent nuclear fuel at accumulation in long-term storage

    International Nuclear Information System (INIS)

    Bergelson, Boris R.; Gerasimov, Aleksander S.

    1999-01-01

    Time dependence of a decay heat power and radiotoxicity of a single spent nuclear fuel unloading of VVER-1000 reactors at its storage or the same characteristics in accumulation mode with annual addition of spent nuclear fuel in long-term storage are investigated. At calculations of decay heat power, the contributions of alpha-, beta-, and gamma- irradiations were taken into account, at calculations of a radiotoxicity - maximum permissible activity of nuclides in air and in water were taken into account. It is determined that at accumulation less than 100 years, the main contribution to decay heat power is given by fission products, at further storage the power is determined in greater degree by actinides. The radiotoxicity of actinides by air is rich greater than that of fission products - more than 50 times in beginning of a storage and by 2-3 orders of magnitude after 100 and more years. A radiotoxicity of fission products by water at accumulation less than 20 years is a little bit more than actinides, at further accumulation the contribution of fission products decreases. At time of accumulation 100 years, the fission products give the contribution in total radiotoxicity about 40%, at time 1000 years - about 7%. (author)

  17. Economic aspects of long term operation (LTO) of nuclear power plants

    International Nuclear Information System (INIS)

    Lokhov, A.

    2015-01-01

    In 2011, 289 reactors in the world were older than 25 years, and only 45 new units were connected to the grid in 2000-2011. Without life extensions, nuclear capacity would thus fall dramatically in the next decade. In this series of slides the author reviews the legal limits and possibilities for long term operations (LTO) of nuclear reactors in the world. It appears 2 basic regulatory approaches to LTO: the license renewal and the periodic safety review. The typical investment in LTO is in the range of 500-1100 US dollar per kWe. The additional costs of post-Fukushima modifications are about 10 to 20% of initially projected LTO investment. It appears that life extension of more than 10 years is profitable. There are several uncertainties that can influence LTO programmes such as public acceptance, changes in national policies, changes in the prices of other energies and technological issues. The specific investment in LTO is detailed for Belgium, Hungary, the USA and Russia. (A.C.)

  18. Transmutation technologies to solve the problem of long-term spent nuclear fuel storage

    International Nuclear Information System (INIS)

    Hosnedl, P.; Valenta, V.; Blahut, O.

    2000-01-01

    The paper gives a brief description of the transmutation process for actinides and long-lived fission products which are present in spent nuclear fuel. Transmutation technologies can solve the problem of long-term spent nuclear fuel storage and reduce the requirements for storage time and conditions. The basic data and requirements for the detailed design of the transmutor are summarized, and the views upon how to address the fuel purification and dry reprocessing issues are discussed. The results of activities of SKODA JS are highlighted; these include, for instance, the fluoride salt-resistant material MONICR, test loops, and electrowinners. The preliminary design of the transmutor is also outlined. Brief information regarding activities in the field of transmutation technologies in the Czech Republic and worldwide is also presented. The research and design activities to be developed for the whole design of the demonstration and basic units are summarized. It is emphasized that SKODA JS can join in international cooperation without constraints. The Attachment presents a simple assessment of how the radioactivity balance can be reduced, based on the actinide and long-lived fission product transmutation half-lives, is presented in the Attachment. (author)

  19. Evaluation of post-LOCA long term cooling performance in Korean standard nuclear power plants

    International Nuclear Information System (INIS)

    Bang, Young Seok; Jung, Jae Won; Seul, Kwang Won; Kim, Hho Jung

    2001-01-01

    The post-LOCA long term cooling (LTC) performance of the Korean Standard Nuclear Power Plant (KSNPP) is analyzed for both small break loss-of-coolant accidents (LOCA) and large break LOCA at cold leg. The RELAP5/MOD3.2.2 beta code is used to calculate the LTC sequences based on the LTC plan of the Korean Standard Nuclear Power Plants (KSNPP). A standard input model is developed such that LOCA and the followed LTC sequence can be calculated in a single run for both small break LOCA and large break LOCA. A spectrum of small break LOCA ranging from 0.02 to 0.5 ft 2 of break area and a double-ended guillotine break are analyzed. Through the code calculations, the thermal-hydraulic behavior and the boron behavior are evaluated and the effect of the important action including the safety injection tank (SIT) isolation and the simultaneous injection in LTC procedure is investigated. As a result, it is found that the sufficient margin is available in avoiding the boron precipitation in the core. It is also found that a further specific condition for the SIT isolation action need to be setup and it is recommended that the early initiation of the simultaneous injection be taken for larger break LTC sequences. (author)

  20. The value and need for long term conservation of information regarding nuclear waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Eng, T. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Jensen, M. [Swedish Radiation Protection Inst., Stockholm (Sweden)

    1993-12-31

    An important question in safety assessment of all repositories where toxic waste is disposed is how long should information be available to society about the repository and its content? Future societies right to knowledge must be considered and actions must already today be taken to ensure that proper information conservation, transfer and retrieval are provided. Collection of relevant information must be planned for at the research, construction and the operational phase of a repository. One of the main areas for information conservation and transfer is to mitigate future human intrusion. A system for best possible mitigation of human intrusion should with the present knowledge comprise the following parts: (a) development of planning procedures for long-term conservation of gathered information (present and future national and international archives, markers etc.); (b) continuous follow up of the state-of-the-art of information media; (c) preparations for national rules and regulations on nuclear waste information; (d) participation in international cooperation on issues concerning nuclear waste information keeping, transfer and retrieval.

  1. Long-term consequences of and prospects for recovery from nuclear war: Two views. View I

    International Nuclear Information System (INIS)

    Sagan, C.

    1986-01-01

    There is a kind of deadly embrace between the United States and the Soviet Union - their military establishments depend on each other - that goes back at least to 1945 and that has led to the construction of a kind of global doomsday machine, which has been almost entirely ignored until lately. The population of the plant has, by and large, been sleepwalking through the last 40 years. The consequences of nuclear war, even as they were known 20 or 30 years ago, did not permeate the public consciousness. And this is still the case, although less so, as a kind of race transpires between how fast and disquieting discoveries are made about the nature of nuclear war and and how fast these discoveries are absorbed, often with great reluctance, into the consciousness of the public and the government. In this summary, the author proceeds in rough serial order through some of the topics presented in this volume and gives a few impressions. On the nuclear winter issue itself, there now seems to be a fairly broad consensus after the original TTAPS study that is something worth worrying about, something probably very grave. Even the most conservative and carefully phrased reports on this subject make that apparent. The National Research Council's report states that nuclear winter is a ''clear possibility'' and that the probability that the severity winter would be worse than in the ''baseline case'' is roughly the same as the probability that it would be better. Despite uncertainties, ''the committee believes that long-term climatic effects with severe implications for the biosphere could occur.''

  2. Application of nuclear and physico-chemical analysis methods in the study of an after-implanting bioactive glass deposition on a titanium alloy, in view of optimizing the long-term bio-compatibility and operability; Application de methodes nucleaires et physico-chimiques d`analyse a l`etude, apres implantation, d`un depot de bioverre sur un alliage de titane, en vue d`une optimisation de la biocompatibilite et de la fonctionnalite a long terme

    Energy Technology Data Exchange (ETDEWEB)

    Brun, Vanessa [Lab. de Physique Corpusculaire, Clermont-Ferrand-2 Univ., 63 - Aubiere (France)

    1999-01-27

    To improve the anchorage of orthopedic prosthesis into surrounding bone, osteo-conductive biomaterials are usually used as coatings. Among usual coatings, we find bioactive glasses. The bioactive glass A9 is analyzed before and after implantation. It is plasma sprayed onto titanium alloy cylinders (Ti-6Al-4V). Neutron Activation Analysis and Coupled Plasma-Atomic Emission Spectrometry allow us to get the precise composition of A9 before implantation, and to observe a volatilization of some A9 oxides during plasma spraying. Scanning Electron Microscopy shows a coating constituted by pores and by A9 particles of different sizes, into a non compact and non homogeneous form of variable thickness. Wavelength Dispersive Spectroscopy is applied to the analysis of A9 major element composition, in surface and thickness: the composition of the coating is homogeneous in volume. Ti alloy cylinders coated with A9 are implanted in ovine femur epiphysis. At different times after implantation they are extracted to be analyzed. The formation of an in vivo gel in contact with the coated implant and neo-formed bone was found. Time variations in the concentration of the bioactive glass constituents were observed in the gel. Titanium is detected within gel and neo-formed bone, in a higher quantity than within an old bone. P.I.X.E. method enables us to get elemental mapping of several interesting areas and to trace elements (zinc, strontium) in the neo-formed bone. The percentages of bone surface in contact and of bone volume are calculated and the results show that at 12 months, the bone surface in contact is equivalent for coated and uncoated cylinders. However, the bone volume is higher for coated cylinders. This last point clearly stresses the interest of A9 bioactive glass shows its osteo-conductivity 63 refs., 74 figs., 12 tabs.

  3. Long term aging of selenide glasses: evidence of sub-Tg endotherms and pre-Tg exotherms

    Science.gov (United States)

    Chen, Ping; Boolchand, P.; Georgiev, D. G.

    2010-02-01

    Long term aging, extending from months to several years, is studied on several families of chalcogenide glasses including the Ge-Se, As-Se, and Ge-As-Se systems. Special attention is given to the As-Se binary, a system that displays a rich variety of aging behavior intimately tied to sample synthesis conditions and the ambient environment in which samples are aged. Calorimetric (modulated DSC) and Raman scattering experiments are undertaken. Our results show all samples display a sub-Tg endotherm typically 10-70 °C below Tg in glassy networks possessing a mean coordination number r in the 2.25 < r < 2.45 range. Two sets of AsxSe100-x samples aged for eight years were compared, set A consisted of slow cooled samples aged in the dark, and set B consisted of melt-quenched samples aged at laboratory environment. Samples of set B in the As concentration range, 35% < x < 60%, display a pre-Tg exotherm, but the feature is not observed in samples of set A. The aging behavior of set A presumably represents intrinsic aging in these glasses, while that of set B is extrinsic due to the presence of light. The reversibility window persists in both sets of samples, but is less well defined in set B. These findings contrast with a recent study by Golovchak et al (2008 Phys. Rev. B 78 014202), which finds the onset of the reversibility window moved up to the stoichiometric composition (x = 40%). Here we show that the up-shifted window is better understood as resulting due to demixing of As4Se4 and As4Se3 molecules from the backbone, i.e., nanoscale phase separation (NSPS). We attribute sub-Tg endotherms to compaction of the flexible part of the networks upon long term aging, while the pre-Tg exotherm is to NSPS. The narrowing and sharpening of the reversibility window upon aging is interpreted as the slow 'self-organizing' stress relaxation of the phases just outside the intermediate phase, which itself is stress free and displays little aging.

  4. Development of nuclear fuel cycle technologies - bases of long-term provision of fuel and environmental safety of nuclear power

    International Nuclear Information System (INIS)

    Solonin, M.I.; Polyakov, A.S.; Zakharkin, B.S.; Smelov, V.S.; Nenarokomov, E.A.; Mukhin, I.V.

    2000-01-01

    To-day nuclear power is one of the options, however, to-morrow it may become the main source of the energy, thus, providing for the stable economic development for the long time to come. The availability of the large-scale nuclear power in the foreseeable future is governed by not only the safe operation of nuclear power plants (NPP) but also by the environmentally safe management of spent nuclear fuel, radioactive waste conditioning and long-term storage. More emphasis is to be placed to the closing of the fuel cycle in view of substantial quantities of spent nuclear fuel arisings. The once-through fuel cycle that is cost effective at the moment cannot be considered to be environmentally safe even for the middle term since the substantial build-up of spent nuclear fuel containing thousands of tons Pu will require the resolution of the safe management problem in the nearest future and is absolutely unjustified in terms of moral ethics as a transfer of the responsibility to future generations. The minimization of radioactive waste arisings and its radioactivity is only feasible with the closed fuel cycle put into practice and some actinides and long-lived fission radionuclides burnt out. The key issues in providing the environmentally safe fuel cycle are efficient processes of producing fuel for NPP, radionuclide after-burning included, a long-term spent nuclear fuel storage and reprocessing as well as radioactive waste management. The paper deals with the problems inherent in producing fuel for NPP with a view for the closed fuel cycle. Also discussed are options of the fuel cycle, its effectiveness and environmental safety with improvements in technologies of spent nuclear fuel reprocessing and long-lived radionuclide partitioning. (authors)

  5. Development of nuclear fuel cycle technologies - bases of long-term provision of fuel and environmental safety of nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Solonin, M I; Polyakov, A S; Zakharkin, B S; Smelov, V S; Nenarokomov, E A; Mukhin, I V [SSC, RF, A.A. Bochvar ALL-Russia Research Institute of Inorganic Materials, Moscow (Russian Federation)

    2000-07-01

    To-day nuclear power is one of the options, however, to-morrow it may become the main source of the energy, thus, providing for the stable economic development for the long time to come. The availability of the large-scale nuclear power in the foreseeable future is governed by not only the safe operation of nuclear power plants (NPP) but also by the environmentally safe management of spent nuclear fuel, radioactive waste conditioning and long-term storage. More emphasis is to be placed to the closing of the fuel cycle in view of substantial quantities of spent nuclear fuel arisings. The once-through fuel cycle that is cost effective at the moment cannot be considered to be environmentally safe even for the middle term since the substantial build-up of spent nuclear fuel containing thousands of tons Pu will require the resolution of the safe management problem in the nearest future and is absolutely unjustified in terms of moral ethics as a transfer of the responsibility to future generations. The minimization of radioactive waste arisings and its radioactivity is only feasible with the closed fuel cycle put into practice and some actinides and long-lived fission radionuclides burnt out. The key issues in providing the environmentally safe fuel cycle are efficient processes of producing fuel for NPP, radionuclide after-burning included, a long-term spent nuclear fuel storage and reprocessing as well as radioactive waste management. The paper deals with the problems inherent in producing fuel for NPP with a view for the closed fuel cycle. Also discussed are options of the fuel cycle, its effectiveness and environmental safety with improvements in technologies of spent nuclear fuel reprocessing and long-lived radionuclide partitioning. (authors)

  6. Long-term prediction of corrosion damage in nuclear waste systems

    International Nuclear Information System (INIS)

    Hidekazu Asano; Feron, Damien; Gens, Robert; Padovani, Cristiano; Naoki Taniguchi

    2014-01-01

    Complete text of publication follows: The Fifth International Workshop on Long-Term Prediction of Corrosion Damage in Nuclear Waste Systems was held at the Taisetsu Crystal Hall in Asahikawa, Hokkaido, Japan from October 6 to 10, 2013, following the four previous successful workshops (Cadarache, France, 2001; Nice, France, 2004; Pennsylvania State University, USA, 2007 and Bruges, Belgium, 2010). It was organised by the Japan Society of Corrosion Engineering (JSCE) and supported by the European Federation of Corrosion (EFC): Nuclear Corrosion Working Party (WP4) as of EFC event No.360. Furthermore, it was supported by the Division of Nuclear Fuel Cycle and Environment (NUCE) of the Atomic Energy Society of Japan (AESJ) and The Japan Society of Mechanical Engineers (JSME). Twenty nine (29) oral presentations were distributed among eleven (11) sessions covering a broad range of subjects. Another twenty eight (28) studies were presented at a poster session. A total of sixty seven (67) participants from twelve (12) countries attended the event. The presentations and the following discussion provided contextual information about the state of some national programmes and covered in detail a range of experimental and modelling studies aimed at evaluating the corrosion behaviour of a range of candidate materials and designs for the storage and disposal of radioactive wastes considered across the globe. These included modelling studies aimed at evaluating the durability of container designs for high level waste (HLW), spent nuclear fuel (SNF) and intermediate level waste (ILW), experimental studies of the corrosion behaviour of copper, carbon steel, and stainless steel in conditions relevant to storage (atmospheric) or disposal (near neutral or alkaline), as well as studies of archaeological artifacts and natural analogues aimed at supporting long-term predictions. Specific sessions were dedicated to microbial induced corrosion (MIC) and to the corrosion properties of

  7. Long-term α-hazard of high activity waste from nuclear fuel reprocessing

    International Nuclear Information System (INIS)

    Girardi, F.; Bertozzi, G.

    1974-01-01

    The concentration and decay of α-emitters in high activity waste arising from spent nuclear fuel reprocessing was calculated under specified reference conditions. An attempt to evaluate the long-term hazard of such waste is being made by applying the ''barrier'' approach derived from reactor safety studies. Four barriers were identified, which could be evaluated in a probabilistic way by taking into account the great uncertainties present in each of them. The barriers are: 1) quality of the segregation afforded by deep geological formations, 2) stability of conditioned waste (chemical and physical), 3) retention by immediate surrounding, 4) distribution pattern of actinides in the environment. The analysis of a fictional accident showed that the uncertainties connected with the evaluation of the barriers' value are rather large. Additional studies particularly on the stability of conditioned waste and ecological properties of the environment towards actinides, would considerably improve our knowledge of the value of the barrier system. Chemical separation of actinides from high activity waste would be an additional option of undoubted value for the disposal of high activity waste. Its value for the overall safety of the entire waste inventory depends on many factors which need better evaluation, such as safety of the disposal of the separated actinides and the amount and quality of the additional waste generated by the separation process. An analysis of various levels of possible separations suggests that a reasonable target might be: Pu, Am and Cm, decontamination factor 10 3 ; Np, coextraction with U and Pu with a 90% yield

  8. Birth Outcomes after the Fukushima Daiichi Nuclear Power Plant Disaster: A Long-Term Retrospective Study

    Science.gov (United States)

    Leppold, Claire; Nomura, Shuhei; Sawano, Toyoaki; Ozaki, Akihiko; Tsubokura, Masaharu; Hill, Sarah; Kanazawa, Yukio; Anbe, Hiroshi

    2017-01-01

    Changes in population birth outcomes, including increases in low birthweight or preterm births, have been documented after natural and manmade disasters. However, information is limited following the 2011 Fukushima Daiichi Nuclear Power Plant Disaster. In this study, we assessed whether there were long-term changes in birth outcomes post-disaster, compared to pre-disaster data, and whether residential area and food purchasing patterns, as proxy measurements of evacuation and radiation-related anxiety, were associated with post-disaster birth outcomes. Maternal and perinatal data were retrospectively collected for all live singleton births at a public hospital, located 23 km from the power plant, from 2008 to 2015. Proportions of low birthweight (increased proportions of low birthweight or preterm births in any year after the disaster (merged post-disaster risk ratio of low birthweight birth: 0.98, 95% confidence interval (CI): 0.64–1.51; and preterm birth: 0.68, 95% CI: 0.38–1.21). No significant associations between birth outcomes and residential area or food purchasing patterns were identified, after adjustment for covariates. In conclusion, no changes in birth outcomes were found in this institution-based investigation after the Fukushima disaster. Further research is needed on the pathways that may exacerbate or reduce disaster effects on maternal and perinatal health. PMID:28534840

  9. Long-term measurement with calorimetric probes at unit 1 of V-1 nuclear power plant

    International Nuclear Information System (INIS)

    Erben, O.; Szasz, Z.; Jirousek, V.; Teren, S.

    1989-01-01

    Two calorimetric probes were tested at the first unit of the Bohunice V-1 nuclear power plant in long-term operation, i.e., during one whole reactor duty time. Each probe consisted of five fission calorimeters and one compensation calorimeter with a tungsten body. The actual calorimeters were provided with jacketed thermocouples 0.5 mm indiameter and 19 m in length. A detailed description is presented of the measuring chains and measurement techniques. Also described is the method of the disposal of the irradiated probes. The method is presented of the evaluation of measured data and the results are discussed of the analysis of these data. The measurements, including measurements during reactor shut-down and the results of the analysis of the measured data proved good viability and stability of the used calorimetres. The method of measuring the thermocouple signals is simple and the in-service evaluation of required data is quick. In order to increase measurement efficiency it would be appropriate to complete the measuring chain and to automate it. Reliability is a affected merely by protecting the thermocouples against mechanical damage during measurement probe handling and on the reactor. (Z.M.). 5 figs., 5 tabs., 5 refs

  10. Nuclear waste glass corrosion mechanisms

    International Nuclear Information System (INIS)

    Jantzen, C.M.

    1987-04-01

    Dissolution of nuclear waste glass occurs by corrosion mechanisms similar to those of other solids, e.g., metallurgical and mineralogic systems. Metallurgical phenomena such as active corrosion, passivation and immunity have been observed to be a function of the glass composition and the solution pH. Hydration thermodynamics was used to quantify the role of glass composition and its effect on the solution pH during dissolution. A wide compositional range of natural, lunar, medieval, and nuclear waste glasses, as well as some glass-ceramics were investigated. The factors observed to affect dissolution in deionized water are pertinent to the dissolution of glass in natural environments such as the groundwaters anticipated to interact with nuclear waste glass in a geologic repository. The effects of imposed pH and oxidation potential (Eh) conditions existing in natural environments on glass dissolution is described in the context of Pourbaix diagrams, pH potential diagrams, for glass

  11. Plant life management for long term operation of nuclear power plants

    International Nuclear Information System (INIS)

    2005-01-01

    The world's fleet of Nuclear Power Plants (NPPs) is approximately 20 years old on average, and most plants are believed to be able to operate for 60 years or more. The design life of a NPP is typically 30 to 40 years. This may be extended by 10 to 20 years, or more, provided that the plant can demonstrate by analysis, trending, equipment and system upgrades, increased vigilance, testing, ageing management, and other means that license renewal presents no threat to public health and safety. The basic goal of Plant Life Management (PLiM) is to satisfy requirements for safe long-term supplies of electricity in an economically competitive way. The basic goal of the operating company and the owners to operate as long as economically reasonable and possible from safety point of view. PLiM is a management tool for doing that. PLiM is a system of programmes and procedures to satisfy safety requirements for safe operation and for power production in a competitive way and for time which is rational from technical and economical point of view. PLiM is not only a technical system, it is also an attitude of the operational company to keep the plant in operation as long as possible from safety and business point of view. The common objectives of PLiM assessment is to help and review the pre-conditions for PLiM and long-term operation approaches. PLiM should not be associated with extension of operational life-time of the NPP only. It is an owner's attitude and rational approach of the operating company to run the business economically and safely. The effectiveness of PLiM Programme can be assessed by three complementary kinds of assessment: self-assessment, peer review and comprehensive programme review by the plant owner/ operator. IAEA will provide the assessment service for peer review of PLiM. Preparation for a PLiM Assessment service will be initiated only after the IAEA has been formally approached by a MS and funding (e.g. an existing Technical cooperation project) has

  12. Long term operation of nuclear power plants – IAEA SALTO missions observations and trends

    Energy Technology Data Exchange (ETDEWEB)

    Krivanek, Robert, E-mail: r.krivanek@iaea.org [Operational Safety Section, Department of Nuclear Safety and Security, International Atomic Energy Agency (IAEA), Vienna 1400 (Austria); Havel, Radim, E-mail: Radim.Havel@gmail.com [RESCO, Nitranska 894/8, 10100 Praha 10 (Czech Republic)

    2016-08-15

    Highlights: • During the period 2005–mid 2015, 22 SALTO peer review missions and 2 LTO modules of OSART missions were conducted. • Analysis of these mission results and main trends observed are gathered in this paper. • The main task of the assessment performed was to evaluate and give a weight to the evaluation. • Results of SALTO follow-up missions as well as OSART follow-up missions with LTO module are summarized. • The SALTO peer review service is strongly recommended for NPPs prior to entering LTO period. - Abstract: This paper builds on paper “Long term operation of nuclear power plants – IAEA SALTO peer review service and its results”, NED8070, presented in Nuclear Engineering and Design in September 2014. This paper presents the analysis of SALTO mission results and main trends observed so that all the most important results of SALTO missions are gathered in one paper. The paper also includes the results of LTO module reviews performed in the frame of OSART missions where applicable as well as follow-up missions. This paper is divided in three main Sections. Section 1 provides brief introduction to SALTO peer review service. Section 2 provides overview of performed SALTO missions and LTO modules of OSART missions performed between 2005 and mid-2015. Section 3 summarizes the most significant observations and trends resulting from the missions between 2005 and mid-2015. Section 4 summarizes the results of SALTO follow-up missions as well as OSART follow-up missions.

  13. Long term panorama of the nuclear technology; Panorama a largo plazo de la tecnologia nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Velez, C. [Electricite de France, Comite Cientifico Asesor, 22-30 avenue de Wagram, 75382 Paris (France)

    2009-07-01

    The concern for the security of the hydrocarbons supply, essentials for the transport and every time more important in the electricity production, it is one of the rebirth causes of interest for the nuclear energy. On the other hand, it is the increase of the hydrocarbons price. In some countries, included Mexico, the price of gas is subject to strong seasonal fluctuations, aggravating by the congestion of the ducts. It is certain that great part of the prices rise of petroleum that we are experiencing is due to speculation, for what it is necessary to look for objective elements that allow to venture in the difficult topic of the future price of crude. One finishes reason of the resurgence of interest for the nuclear energy, is the growing perception that with the gases emission of greenhouse effect we are exposing our planet to an uncontrollable experiment with consequences potentially catastrophic. This perception is translated in a pressure of the public opinion for to use renewable energy sources that do not contribute to the greenhouse effect. In this work a general panorama is exposed on the advances that exist at the present time, like nuclear reactors with the purpose of solving the current problem that the world is crossing. (Author)

  14. Birth Outcomes after the Fukushima Daiichi Nuclear Power Plant Disaster: A Long-Term Retrospective Study

    Directory of Open Access Journals (Sweden)

    Claire Leppold

    2017-05-01

    Full Text Available Changes in population birth outcomes, including increases in low birthweight or preterm births, have been documented after natural and manmade disasters. However, information is limited following the 2011 Fukushima Daiichi Nuclear Power Plant Disaster. In this study, we assessed whether there were long-term changes in birth outcomes post-disaster, compared to pre-disaster data, and whether residential area and food purchasing patterns, as proxy measurements of evacuation and radiation-related anxiety, were associated with post-disaster birth outcomes. Maternal and perinatal data were retrospectively collected for all live singleton births at a public hospital, located 23 km from the power plant, from 2008 to 2015. Proportions of low birthweight (<2500 g at birth and preterm births (<37 weeks gestation at birth were compared pre- and post-disaster, and regression models were conducted to assess for associations between these outcomes and evacuation and food avoidance. A total of 1101 live singleton births were included. There were no increased proportions of low birthweight or preterm births in any year after the disaster (merged post-disaster risk ratio of low birthweight birth: 0.98, 95% confidence interval (CI: 0.64–1.51; and preterm birth: 0.68, 95% CI: 0.38–1.21. No significant associations between birth outcomes and residential area or food purchasing patterns were identified, after adjustment for covariates. In conclusion, no changes in birth outcomes were found in this institution-based investigation after the Fukushima disaster. Further research is needed on the pathways that may exacerbate or reduce disaster effects on maternal and perinatal health.

  15. The role of nuclear energy for Korean long-term energy supply strategy : application of energy demand-supply model

    International Nuclear Information System (INIS)

    Chae, Kyu Nam

    1995-02-01

    An energy demand and supply analysis is carried out to establish the future nuclear energy system of Korea in the situation of environmental restriction and resource depletion. Based on the useful energy intensity concept, a long-term energy demand forecasting model FIN2USE is developed to integrate with a supply model. The energy supply optimization model MESSAGE is improved to evaluate the role of nuclear energy system in Korean long-term energy supply strategy. Long-term demand for useful energy used as an exogeneous input of the energy supply model is derived from the trend of useful energy intensity by sectors and energy carriers. Supply-side optimization is performed for the overall energy system linked with the reactor and nuclear fuel cycle strategy. The limitation of fossil fuel resources and the CO 2 emission constraints are reflected as determinants of the future energy system. As a result of optimization of energy system using linear programming with the objective of total discounted system cost, the optimal energy system is obtained with detailed results on the nuclear sector for various scenarios. It is shown that the relative importance of nuclear energy would increase especially in the cases of CO 2 emission constraint. It is concluded that nuclear reactor strategy and fuel cycle strategy should be incorporated with national energy strategy and be changed according to environmental restriction and energy demand scenarios. It is shown that this modelling approach is suitable for a decision support system of nuclear energy policy

  16. A Specific Long-Term Plan for Management of U.S. Nuclear Spent Fuel

    International Nuclear Information System (INIS)

    Levy, Salomon

    2006-01-01

    A specific plan consisting of six different steps is proposed to accelerate and improve the long-term management of U.S. Light Water Reactor (LWR) spent nuclear fuel. The first step is to construct additional, centralized, engineered (dry cask) spent fuel facilities to have a backup solution to Yucca Mountain (YM) delays or lack of capacity. The second step is to restart the development of the Integral Fast Reactor (IFR), in a burner mode, because of its inherent safety characteristics and its extensive past development in contrast to Acceleration Driven Systems (ADS). The IFR and an improved non-proliferation version of its pyro-processing technology can burn the plutonium (Pu) and minor actinides (MA) obtained by reprocessing LWR spent fuel. The remaining IFR and LWR fission products will be treated for storage at YM. The radiotoxicity of that high level waste (HLW) will fall below that of natural uranium in less than one thousand years. Due to anticipated increased capital, maintenance, and research costs for IFR, the third step is to reduce the required number of IFRs and their potential delays by implementing multiple recycles of Pu and Neptunium (Np) MA in LWR. That strategy is to use an advanced separation process, UREX+, and the MIX Pu option where the role and degradation of Pu is limited by uranium enrichment. UREX+ will decrease proliferation risks by avoiding Pu separation while the MIX fuel will lead to an equilibrium fuel recycle mode in LWR which will reduce U. S. Pu inventory and deliver much smaller volumes of less radioactive HLW to YM. In both steps two and three, Research and Development (R and D) is to emphasize the demonstration of multiple fuel reprocessing and fabrication, while improving HLW treatment, increasing proliferation resistance, and reducing losses of fissile material. The fourth step is to license and construct YM because it is needed for the disposal of defense wastes and the HLW to be generated under the proposed plan. The

  17. OECD/NEA study on the economics of the long-term operation of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Lokhov, A.; Cameron, R. [OECD Nuclear Energy Agency, 12, boulevard des Iles, 92130 Issy-les-Moulineaux (France)

    2012-07-01

    The OECD Nuclear Energy Agency (NEA) established the Ad hoc expert group on the Economics of Long-term Operation (LTO) of Nuclear Power Plants. The primary aim of this group is to collect and analyse technical and economic data on the upgrade and lifetime extension experience in OECD countries, and to assess the likely applications for future extensions. This paper describes the key elements of the methodology of economic assessment of LTO and initial findings for selected NEA member countries. (authors)

  18. Nuclear energy - Standard method for testing the long-term alpha irradiation stability of matrices for solidification of high-level radioactive waste. 2. ed.

    International Nuclear Information System (INIS)

    2004-01-01

    This International Standard specifies a method designed to check the long-term stability of a solid to alpha disintegration by detection of all modifications in the properties of an irradiated sample. The material favoured hitherto is a borosilicate glass, but possible alternatives include: ceramics or glass-ceramics, and other glass compositions

  19. Glass containing radioactive nuclear waste

    International Nuclear Information System (INIS)

    Boatner, L.A.; Sales, B.C.

    1985-01-01

    Lead-iron phosphate glasses containing a high level of Fe 2 O 3 for use as a storage medium for high-level-radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90 C, with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10 2 to 10 3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe 2 O 3 in forming the lead-iron phosphate glass is critical. Lead-iron phosphate nuclear waste glass can be prepared at temperatures as low as 800 C, since they exhibit very low melt viscosities in the 800 to 1050 C temperature range. These waste-loaded glasses do not readily devitrify at temperatures as high as 550 C and are not adversely affected by large doses of gamma radiation in H 2 O at 135 C. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear waste forms. (author)

  20. Long-term leaching behavior of simulated Savannah River Plant waste glass: Part 1, MCC-1 leachability results, four-year leaching data

    International Nuclear Information System (INIS)

    Wicks, G.G.; Stone, J.A.; Chandler, G.T.; Williams, S.

    1986-08-01

    Long-term leaching data were obtained on SRP 131/TDS waste glass using MCC-1 or slightly modified MCC-1 standard leaching tests. Experiments were conducted out to four years at 40 0 C and 3-1/2 years at 90 0 C. These experiments have produced the longest standardized leaching data currently available in the waste management community. Long-term leaching data provide important input to modeling of waste glass behavior and ultimate prediction of waste glass performance. In this study, the leaching behavior of SRP waste glass was found to be excellent; leachates based on a variety of elements were not only very low, but also improved with increasing time. In addition to these data, results are also reported from another independent Savannah River study. Leaching behavior at 40 0 C and 90 0 C was assessed not only for a similar SRP 131 waste glass composition, but also for extreme waste glass compositions involving high-iron and high-aluminum waste. In addition, these experiments were performed using not only a standard deionized water leachant, but also simplified brine and silicate groundwater simulations. These two large data bases will be summarized and correlated along with some of the more interesting results recently reported in another study, a two-year leaching program performed on a similar SRP waste glass composition at Battelle Pacific Northwest Laboratories

  1. Long-term management of Canada's spent nuclear fuel: the nuclear waste management organizations recommendation to government

    International Nuclear Information System (INIS)

    Shaver, K.

    2006-01-01

    Full text: Like many countries with nuclear power programs, Canada is in the process of addressing the long-term management of its spent fuel. The Nuclear Waste Management Organization (NWMO) was tasked through federal legislation to conduct a three-year study of approaches for the long-term management of spent fuel, and to recommend a preferred approach to the Government of Canada. Legislation required NWMO to compare at least three approaches -approaches based on deep geological disposal in the Canadian Shield, storage at nuclear reactor sites, and centralized storage either above or below ground. In assessing the options, NWMO sought a recommendation that would be socially acceptable, technically sound, environmentally responsible and economically feasible. The study drew on a vast base of social, technical, engineering, and financial research, and included an extensive engagement program with the public and Aboriginal peoples. The recommendation emerged from a collaborative dialogue with specialists and citizens, for an approach that is built on sound science and technology and responsive to citizen values. NWMO submitted its completed options study, with recommendation, to the Government in November 2005. NWMO has proposed an alternative approach, Adaptive Phased Management, which has as its key attributes: central containment and isolation of spent fuel in a deep repository, in an appropriate geological formation; contingency provision for central shallow storage; monitoring and retrievability; and a staged, adaptive process of concept implementation, reflecting the complex nature of the task and the desire of citizens to proceed through cautious, deliberate steps of technical demonstration and social acceptance. This paper will review: 1) the development of the assessment framework for comparing the technical options, which incorporated social and ethical considerations expressed by citizens; 2) findings of the assessment; and 3) features of the proposed

  2. Long Term Storage with Surveillance of Canadian Prototype Nuclear Power Reactors

    International Nuclear Information System (INIS)

    Janzen, Rick

    2008-01-01

    Atomic Energy of Canada (AECL) was originally formed by the government of Canada in 1952 to perform research in radiation and nuclear areas. In the mid 1950's Canada decided to limit itself to peaceful uses of nuclear energy and AECL embarked on several research and development programs, one of them being the development of nuclear power plants. This led to the development of the CANDU TM design of heavy water power reactors, of which there are now 29 operating around the world. This presentation discusses the present state of the first two CANDU TM prototype reactors and a prototype boiling light water reactor and lessons learnt after being in a long-term storage with surveillance state for more than 20 years. AECL facilities undergo decommissioning by either a prompt or a deferred removal approach. Both approaches are initiated after an operating facility has been declared redundant and gone through final operational shutdown. For the deferred approach, initial decommissioning activities are performed to put the facility into a sustainable, safe, shutdown state to minimize the hazards and costs of the ensuing extended storage with surveillance (SWS) or Safestor phase. At the appropriate time, the facility is dismantled and removed, or put into a suitable condition for re-use. AECL has a number of facilities that were built during its history, and some of these are now redundant or will become redundant in the near future. The deferred removal approach is part of AECL's decommissioning strategy for several reasons: 1. Reduction in radiation doses to workers during the final dismantling, 2. No facilities are available yet in Canada for the management of quantity of wastes arising from decommissioning, 3. Financial constraints presented by the number of facilities that will undergo decommissioning, compared to the availability of funds to carry out the work. This has led to the development of a comprehensive decommissioning plan that includes all of AECL's redundant

  3. Nuclear power: renaissance or relapse? Global climate change and long-term Three Mile Island activists' narratives.

    Science.gov (United States)

    Culley, Marci R; Angelique, Holly

    2010-06-01

    Community narratives are increasingly important as people move towards an ecologically sustainable society. Global climate change is a multi-faceted problem with multiple stakeholders. The voices of affected communities must be heard as we make decisions of global significance. We document the narratives of long-term anti-nuclear activists near the Three Mile Island (TMI) nuclear power plant who speak out in the dawn of a nuclear renaissance/relapse. While nuclear power is marketed as a "green" solution to global warming, their narratives reveal three areas for consideration; (1) significant problems with nuclear technology, (2) lessons "not" learned from the TMI disaster, and (3) hopes for a sustainable future. Nuclear waste, untrustworthy officials and economic issues were among the problems cited. Deceptive shaping of public opinion, nuclear illiteracy, and an aging anti-nuclear movement were reasons cited for the lessons not learned. However, many remain optimistic and envision increased participation to create an ecologically-balanced world.

  4. A Strategy for Maintenance of the Long-Term Performance Assessment of Immobilized Low-Activity Waste Glass

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, Joseph V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Freedman, Vicky L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-28

    Approximately 50 million gallons of high-level radioactive mixed waste has accumulated in 177 buried single- and double-shell tanks at the Hanford Site in southeastern Washington State as a result of the past production of nuclear materials, primarily for defense uses. The United States Department of Energy (DOE) is proceeding with plans to permanently dispose of this waste. Plans call for separating the tank waste into high-level waste (HLW) and low-activity waste (LAW) fractions, which will be vitrified at the Hanford Waste Treatment and Immobilization Plant (WTP). Principal radionuclides of concern in LAW are 99Tc, 129I, and U, while non-radioactive contaminants of concern are Cr and nitrate/nitrite. HLW glass will be sent off-site to an undetermined federal site for deep geological disposal while the much larger volume of immobilized low-activity waste will be placed in the on-site, near-surface Integrated Disposal Facility (IDF).

  5. Global economics/energy/environmental (E{sup 3}) modeling of long-term nuclear energy futures

    Energy Technology Data Exchange (ETDEWEB)

    Krakowski, R.A.; Davidson, J.W.; Bathke, C.G.; Arthur, E.D.; Wagner, R.L. Jr.

    1997-09-01

    A global energy, economics, environment (E{sup 3}) model has been adopted and modified with a simplified, but comprehensive and multi-regional, nuclear energy module. Using this model, consistent nuclear energy scenarios are constructed. A spectrum of future is examined at two levels in a hierarchy of scenario attributes in which drivers are either external or internal to nuclear energy. Impacts of a range of nuclear fuel-cycle scenarios are reflected back to the higher-level scenario attributes. An emphasis is placed on nuclear materials inventories (in magnitude, location, and form) and their contribution to the long-term sustainability of nuclear energy and the future competitiveness of both conventional and advanced nuclear reactors.

  6. Dungeness 'A' Nuclear Power Station. The findings of NII's assessment of Nuclear Electric's long term safety review

    International Nuclear Information System (INIS)

    1994-01-01

    The assessment is reported of Nuclear Electrics' Long Term Safety Reviews (LTSR) of the Dungeness A magnox reactors. The assessment was undertaken by the Health and Safety Executive's Nuclear Installations Inspectorate (NII) which is responsible for regulating the safety of nuclear installations in the United Kingdom. This was one of a programme of LTSRs for all the UK magnox reactors. The LTSR for each plant was proceeded by a Generic Issues programme. The results of both the LTSR and the Generic Issues programme have been used by NII in forming the conclusions of this assessment. Overall the safety case for Dungeness A is satisfactory for continued operation. A programme of additional modifications and inspections has been put in place which further enhances the safety justification. Reactor operations will continue to be monitored and regulated in accordance with the inspections required under the licensing arrangements. Provided these requirements and the agreed further analysis, improvements and inspections give satisfactory results it is expected that the station will be able to operate safely till each reactor is at least 30 years old. Beyond this point a further Periodic Safety Review will be required. (UK)

  7. Contribution to a proposition for a long term development of nuclear energy: the TASSE concept (Thorium based Accelerator driven System with Simplified fuel cycle for long term Energy Production); Contribution a une proposition d'un developpement a long terme de l'energie nucleaire: le concept TASSE (Thorium based Accelerator driven System with Simplified fuel cycle for long term Energy Production)

    Energy Technology Data Exchange (ETDEWEB)

    Berthou, V

    2000-10-30

    Nuclear industry creates waste which are in the middle of the discussion concerning the Nuclear Energy future. At this time, important decisions for the Energy production must be taken, so numerous researches are conducted within the framework of the Bataille law. The goal of these studies is to find a range of solutions concerning the waste management. An innovative system, called TASSE (Thorium based Accelerator driven System with Simplified fuel cycle for long term Energy production), is studied in this thesis. This reactor is included in a long term strategy, and is destined for the renewal of the reactor park. In the first part of this work, the main characteristics of TASSE have been defined. They are commensurate with some specific requirements such as: to insure a large time to the Nuclear Energy, to reduce the waste production in an important way, to eliminate waste already stocked in the present park, to insure the non proliferation, and to be economically competitive. Neutronics studies of TASSE have been done. A calculation procedure has been developed to reach the system equilibrium state. Several types of molten salts as well as a pebble-bed fuel have been studied. Thus, an optimal fuel has been brought out in regard to some parameters such as the burn up level, the spectrum, the waste toxicity, the cycle type. Eventually, various TASSE core layout have been envisaged. (author)

  8. Contribution to a proposition for a long term development of nuclear energy: the TASSE concept (Thorium based Accelerator driven System with Simplified fuel cycle for long term Energy Production); Contribution a une proposition d'un developpement a long terme de l'energie nucleaire: le concept TASSE (Thorium based Accelerator driven System with Simplified fuel cycle for long term Energy Production)

    Energy Technology Data Exchange (ETDEWEB)

    Berthou, V

    2000-10-30

    Nuclear industry creates waste which are in the middle of the discussion concerning the Nuclear Energy future. At this time, important decisions for the Energy production must be taken, so numerous researches are conducted within the framework of the Bataille law. The goal of these studies is to find a range of solutions concerning the waste management. An innovative system, called TASSE (Thorium based Accelerator driven System with Simplified fuel cycle for long term Energy production), is studied in this thesis. This reactor is included in a long term strategy, and is destined for the renewal of the reactor park. In the first part of this work, the main characteristics of TASSE have been defined. They are commensurate with some specific requirements such as: to insure a large time to the Nuclear Energy, to reduce the waste production in an important way, to eliminate waste already stocked in the present park, to insure the non proliferation, and to be economically competitive. Neutronics studies of TASSE have been done. A calculation procedure has been developed to reach the system equilibrium state. Several types of molten salts as well as a pebble-bed fuel have been studied. Thus, an optimal fuel has been brought out in regard to some parameters such as the burn up level, the spectrum, the waste toxicity, the cycle type. Eventually, various TASSE core layout have been envisaged. (author)

  9. Cold-crucible fabrication of nuclear glasses

    International Nuclear Information System (INIS)

    Boen, R.

    2010-01-01

    Vitrification has stood the nuclear industry in good stead, for many years now, as a safe long-term conditioning technology for high-level waste. Major advances are nonetheless still being made, with the development of the cold-crucible technology, affording as it does new possibilities, in terms of volume reduction, and of extending the range of waste products amenable to incorporation. Indeed, by allowing higher melting temperatures to be achieved (1200 - 1400 C degrees), this process opens the way to a considerable increase in glass production capacities, and the fabrication of novel matrices, involving higher incorporation rates than current glasses. In the cold-crucible technology, materials put into the crucible are heated directly through induction. The crucible made of metal is cooled by water circulation. Where the glass comes into contact with the cold wall, a thin layer of solidified glass forms, with a thickness of 5-10 mm preventing the metal forming the crucible from coming into contact with the molten glass. A full scale pilot of the cold crucible was constructed at the La Hague vitrification workshop

  10. The basis for confidence in the long-term safety of nuclear waste disposal

    International Nuclear Information System (INIS)

    Allen, C.J.; Whitaker, S.H.

    1993-07-01

    Confidence in the acceptability and the long-term safety of deep geological disposal draws strength from a number of sources: the technical approach, i.e., the use of multiple barriers for redundancy and defence in depth; the adoption of the observational approach to site characterization and to disposal vault design, construction, operation and, eventually, closure; the overall approach, which is based on ongoing review and incremental decision making; and, active and effective involvement of the public in this process

  11. High polymer composites for containers for the long-term storage of spent nuclear fuel and high level radioactive waste

    International Nuclear Information System (INIS)

    Bonin, H.W.; Vui, V.T.; Legault, J.-F.

    1997-01-01

    The feasibility of using polymeric composite materials as an alternative to metals in the design of a nuclear waste disposal container was examined. The disposal containers would be stored in deep underground vaults in plutonic rock formations within the Canadian Shield for several thousands of years. The conditions of disposal considered in the evaluation of the polymeric composite materials were based on the long-term disposal concept proposed by Atomic Energy of Canada Limited. Four different composites were considered for this work, all based on boron fibre as reinforcing material, imbedded in polymeric matrices made of polystyrene (PS), polymethyl methacrylate (PMMA), Devcon 10210 epoxy, and polyetheretherketone (PEEK). Both PS and PMMA were determined as unsuitable for use in the fabrication of the storage container because of thermal failure. This was determined following thermal analysis of the materials in which heat transfer calculations yielded the temperature of the container wall and of the surroundings resulting from the heat generated by the spent nuclear fuel stored inside the container. In the case of the PS, the temperature of the container, the buffer and the backfill would exceed the 100 degrees C imposed in the AECL's proposal as the maximum allowable. In the case of the PMMA, the 100 degrees temperature is too close to the glass transition temperature of this material (105 degrees C) and would cause structural degradation of the container wall. The other two materials present acceptable thermal characteristics for this application. An important concern for polymeric materials in such use is their resistance to radiations. The Devcon 10210 epoxy has been the object of research at the Royal Military College in the past years and fair, but limited, resistance to both neutrons and gamma radiation has been demonstrated, with the evidence of increased mechanical strength when subjected to moderate doses. Provided that the container wall could be

  12. Turning nuclear waste into glass

    Energy Technology Data Exchange (ETDEWEB)

    Pegg, Ian L.

    2015-02-15

    Vitrification has emerged as the treatment option of choice for the most dangerous radioactive waste. But dealing with the nuclear waste legacy of the Cold War will require state-of-the-art facilities and advanced glass formulations.

  13. Dormancy effects on the reliability of nuclear thermal propulsion systems for long-term manned space missions

    International Nuclear Information System (INIS)

    Shooman, M.L.; Sforza, P.M.

    1993-01-01

    This paper explores the effects of dormancy on the reliability of a Nuclear Thermal Propulsion (NTP) system for long-term manned space missions, such as Mars exploration. Dormancy refers to the portion of space systems operation where the power and stress levels are significantly reduced from nominal values and the authors have identified dormancy as a significant effect. Three approaches are used to evaluate the relative importance of failure rates during dormant operation: use of failure rate models involving dormancy, power cycling and fully energized operation; study of data bases which include both dormant and energized failure rates; predictions based on an Arrhenius rate process formulation. The results of these approaches suggest that for a long term manned mission the dormancy, cycle, and energized failure rates will all be important. Reliability in the energized state normally receives utmost attention and care during design, however, unless equal attention is directed to dormancy, the mission reliability may be severely compromised

  14. Nuclear energy - short-term and long-term aspects of its answerability and realization

    International Nuclear Information System (INIS)

    Birkhofer, A.

    1982-01-01

    The recommendations of the two phases 'nuclar energy I' and 'nuclear energy II' create the necessary technological conditions for nuclear energy utilization on one hand, on the other, they basically secure that it shall still be possible to waive nuclear energy in the future. Within this framework the lecture deals with the question of reactor safety, nuclear waste management and breeder reactor technology, especially of the SNR-300. (HSCH) [de

  15. Long term trend analysis of emergency power diesel generator reliability in german nuclear power plants

    International Nuclear Information System (INIS)

    Kotthoff, K.; Maqua, M.

    1990-01-01

    The paper deals with a long-term investigation on the availability of diesel generators. This investigation has been performed in two steps in 1980/81 and 1988/89. It is based on the operating experiences of a total of 110 diesel generators in 20 German NPP's. The overall probability of diesel failure during start and short-time operation amounts to about 5E-3/demand. Compared to the result of the first part of the investigation (8E-3/demand) there has been some further improvement of diesel generator performance in recent years. The upper limit calculated for the probability of common mode failures (about 6E-4/demand) is approximately one order of magnitude smaller. The influence of various parameters on the failure probability has been discussed. A statistically significant dependence could not be identified

  16. Glass dissolution at 20, 40, 70 and 90 C: Short-term effects of solution chemistry and long-term Na release

    International Nuclear Information System (INIS)

    Bakel, A.J.; Ebert, W.L.; Strachan, D.M.

    1996-01-01

    The corrosion behavior of a borosilicate glass containing 20 mass 5 Na 2 O was assessed using static dissolution tests. This glass (LD6-5412) is representative of high Na glasses that may be used to stabilize Hanford low-level radioactive waste. The normalized mass loss (NL) decreases as NL(Na) ∼ NL(B) > NL(Si) in 20 and 40 C for tests conducted at glass surface area to leachant volume (S/V) ratio of 10 m -1 , and decreases as NL(Na) > NL(B) ∼ NL(Si) in 90 C tests conducted at 10 m -1 and in all tests conducted at higher S/V. The difference in the corrosion behavior is probably caused by the influence of dissolved glass components in the leachates. The NL(Na) is greater than the NL(B) or NL(Si) in all the tests conducted. Results from long-term tests at 2,000 m -1 show that the preferential release of Na persists for longer than one year at all temperatures and indicate that Na is released from this glass by an ion exchange process

  17. Introduction of Thorium in the Nuclear Fuel Cycle. Short- to long-term considerations

    International Nuclear Information System (INIS)

    Allibert, M.; Merle-Lucotte, E.; Ghetta, V.; Ault, T.; Krahn, S.; Wymer, R.; Croff, A.; Baron, P.; Chauvin, N.; Eschbach, R.; Rimpault, G.; Serp, J.; Bergeron, A.; Bromley, B.; Floyd, M.; Hamilton, H.; Hyland, B.; Wojtaszek, D.; McDonald, M.; Collins, E.; Cornet, S.; Michel-Sendis, F.; ); Feinberg, O.; Ignatiev, V.; Hesketh, K.; Kelly, J.F.; Porsch, D.; Vidal, J.; Taiwo, T.; Uhlir, J.; Van Den Durpel, L.; Van Den Eynde, G.; Vitanza, C.; Butler, Gregg; Cornet, Stephanie; Dujardin, Thierry; Greneche, Dominique; Nordborg, Claes; Rimpault, Gerald; Van Den Durpel, Luc; Michel-Sendis, Franco

    2015-01-01

    Since the beginning of the nuclear era, significant scientific attention has been given to thorium's potential as a nuclear fuel. Although the thorium fuel cycle has never been fully developed, the opportunities and challenges that might arise from the use of thorium in the nuclear fuel cycle are still being studied in many countries and in the context of diverse international programmes around the world. This report provides a scientific assessment of thorium's potential role in nuclear energy both in the short to longer term, addressing diverse options, potential drivers and current impediments to be considered if thorium fuel cycles are to be pursued. (authors)

  18. Management of main generator condition during long term plant shut down at Higashidori Nuclear Power Station Unit 1

    International Nuclear Information System (INIS)

    Kato, Seiji

    2014-01-01

    Higashidori Nuclear Power Station Unit 1 shut down on February 6, 2011 to start 4th refuel outage. On March 11, 2011, we keep going refuel outage on this moment a large earthquake occurred and tsunami was generated following it which called 'Great East Japan Earthquake'. Refuel outage takes 3 ∼ 5 months normally but Higashidori NPS still keeping shut down over 3 years due to some issues. In this paper, we introduce about management of Main generator condition during long term plant shut down situation in addition to normal plant shut down situation to keep well. (author)

  19. The role of long-term geologic changes in the regulation of the Canadian nuclear fuel waste management program

    International Nuclear Information System (INIS)

    Flavelle, P.

    1996-01-01

    It is recognized that the geosphere is a dynamic system over the long time frames of nuclear fuel waste disposal. This paper describes how consideration of a dynamic geosphere has impacted upon the evolving regulatory environment in Canada, and how the approach taken to comply with the regulatory requirements can affect the evaluation of long-term geologic changes. AECB staff opinion is that if the maximum possible effect of geologic changes can be demonstrated to have negligible impact on the safety of a nuclear fuel waste repository, then further consideration of a dynamic geosphere is unnecessary for the current review of the Canadian Nuclear Fuel Waste Management Program. (authors). 7 refs., 4 figs

  20. Automated long-term surveillance of a commercial nuclear power plant

    International Nuclear Information System (INIS)

    Smith, C.M.; Gonzalez, R.C.

    1987-08-01

    This report presents and describes a pattern recognition system for monitoring nuclear reactor signals. The system is based on detecting deviations from baseline signatures identified during normal plant operation. The capabilities and limitations of this pattern recognition approach were investigated during a 2-1/2-year series of continuous online experiments at the Sequoyah-1 Nuclear Power Plant

  1. Long-term automated surveillance of a commercial nuclear power plant

    International Nuclear Information System (INIS)

    Smith, C.M.; Gonzalez, R.C.

    1984-01-01

    A pattern recognition system for monitoring nuclear reactor signals is presented. The system is based on detecting deviations from baseline signatures learned automatically during normal plant operation. The capabilities and limitations of the recognition approach were investigated during a 2-1/2-year continuous, on-line series of experiments at the Sequoyah-1 nuclear power plant

  2. The future of nuclear power in China: Long-term scenarios - 5129

    International Nuclear Information System (INIS)

    Paltsev, S.; Zhang, D.

    2015-01-01

    Nuclear power will play an important role in reaching China government's 2020 goal of raising the proportion of energy produced by non-fossil fuel to 15 percent and stabilizing carbon emissions by 2030. It will also contribute to lower air pollution emissions. In the medium scenario, nuclear power development is constrained by the available sites verified in preliminary explorations. The installed nuclear power capacity reaches 160 GW by 2050. Nuclear generation grows ten times relative to the current capacity, but a share of nuclear power is still only 10% of total electricity generation in China by 2050. In the high scenario, the installed nuclear power capacity reaches 400 GW by 2050, which provides about 30% of electricity by 2050. In the low scenario of no licensing for new sites, the installed nuclear power capacity reaches 95 GW by 2050. For environmental impacts, in 2050 high scenario leads to about 20% reduction in total China's CO 2 emissions and about 25% reduction in a major air pollutant SO 2 relative to medium scenario. Availability of relatively cheap natural gas for electricity mostly replaces coal-based generation while keeping similar profiles for nuclear generation as in the high cost natural gas scenarios. (authors)

  3. Synthesis on the long term behavior of spent nuclear fuel. Vol.1,2; Synthese sur l'evolution a long terme des colis de combustibles irradies. Tome 1,2

    Energy Technology Data Exchange (ETDEWEB)

    Poinssot, Ch.; Toulhoat, P.; Grouiller, J.P.; Pavageau, J.; Piron, J.P.; Pelletier, M.; Dehaudt, Ph.; Cappelaere, Ch.; Limon, R.; Desgranges, L.; Jegou, Ch.; Corbel, C.; Maillard, S.; Faure, M.H.; Cicariello, J.C.; Masson, M. [CEA Saclay, DEN/DDIN/DPRGD, 91 - Gif sur Yvette (France)

    2001-07-01

    The aim of this report is to present the major objectives, the key scientific issues, and the preliminary results of the research conducted in France in the framework of the third line of the 1991 Law, on the topic of the long term behavior of spent nuclear fuel in view of long term storage or geological disposal. Indeed, CEA launched in 1998 the Research Program on the Long Term Behavior of Spent Nuclear Fuel (abbreviated and referred to as PRECCI in French; Poinssot, 1998) the aim of which is to study and assess the ability of spent nuclear fuel packages to keep their initially allocated functions in interim storage and geological disposal: total containment and recovery functions for duration up to hundreds of years (long term or short-term interim storage and/or first reversible stages of geological disposal) and partial confinement function (controlled fluxes of RN) for thousands of years in geological disposal. This program has to allow to obtain relevant and reliable data concerning the long term behavior of the spent fuel packages so that feasibility of interim storage and/or geological disposal can be assessed and demonstrated as well as optimized. Within this framework, this report presents for every possible scenario of evolution (closed system, in Presence of water in presence of gases) what are estimated to be the most relevant evolution mechanism. For the most relevant scientific issues hence defined, a complete scientific review of the best state of knowledge is subsequently here given thus allowing to draw a clear guideline of the major R and D issues for the next years. (authors)

  4. Characterization of glass and glass ceramic nuclear waste forms

    International Nuclear Information System (INIS)

    Lutze, W.; Borchardt, J.; De, A.K.

    1979-01-01

    Characteristics of solidified nuclear waste forms, glass and glass ceramic compositions and the properties (composition, thermal stability, crystallization, phase behavior, chemical stability, mechanical stability, and radiation effects) of glasses and glass ceramics are discussed. The preparation of glass ceramics may be an optional step for proposed vitrification plants if tailored glasses are used. Glass ceramics exhibit some improved properties with respect to glasses. The overall leach resistance is similar to that of glasses. An increased leach resistance may become effective for single radionuclides being hosted in highly insoluble crystal phases mainly when higher melting temperatures are applicable in order to get more leach resistant residual glass phases. The development of glass ceramic is going on. The technological feasibility is still to be demonstrated. The potential gain of stability when using glass ceramics qualifies the material as an alternative nuclear waste form

  5. Long-term Monitoring Plan for the Shoal Underground Nuclear Test

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed Hassan

    2005-02-01

    The flow and transport model of Shoal is used to design a three-well monitoring network to be part of the long-term monitoring network for the site and achieve two objectives: (1) detect the presence of radionuclides in case they migrate to the monitoring well locations, and (2) provide field data to compare with model predictions as part of the model validation process. Using three different quantitative approaches and the numerical groundwater flow and transport model developed for Shoal, three new monitoring well locations were identified from 176 different networks. In addition to the quantitative analyses using the numerical model, the development of the monitoring network for Shoal will also be subject to qualitative hydrogeologic interpretation during implementation. information will only be available during the fieldwork, it will be incorporated in the monitoring well design at the time of well installation. Finally, it should be noted that the CADD-CAP for Shoal, including the compliance boundary, is not yet approved. Should the compliance boundary change from the 1,000-year MCL contaminant boundary, well locations may also need to change. However, the analysis reported here provides a number of alternatives with reasonable detection efficiency.

  6. Long-term Monitoring Plan for the Shoal Underground Nuclear Test

    International Nuclear Information System (INIS)

    Ahmed Hassan

    2005-01-01

    The flow and transport model of Shoal is used to design a three-well monitoring network to be part of the long-term monitoring network for the site and achieve two objectives: (1) detect the presence of radionuclides in case they migrate to the monitoring well locations, and (2) provide field data to compare with model predictions as part of the model validation process. Using three different quantitative approaches and the numerical groundwater flow and transport model developed for Shoal, three new monitoring well locations were identified from 176 different networks. In addition to the quantitative analyses using the numerical model, the development of the monitoring network for Shoal will also be subject to qualitative hydrogeologic interpretation during implementation. information will only be available during the fieldwork, it will be incorporated in the monitoring well design at the time of well installation. Finally, it should be noted that the CADD-CAP for Shoal, including the compliance boundary, is not yet approved. Should the compliance boundary change from the 1,000-year MCL contaminant boundary, well locations may also need to change. However, the analysis reported here provides a number of alternatives with reasonable detection efficiency

  7. Estimate of long-term dissolution rate of basaltic glass. A case study on Mt. Fuji area

    Energy Technology Data Exchange (ETDEWEB)

    Shikazono, Naotatsu; Takino, Akitsugu [Keio Univ., Environmental Geochemistry, Tokyo (Japan)

    2002-03-01

    Bulk compositional, mineralogical and physical properties of weathered basaltic ash soil ('Andisol') derived mainly from Mt. Fuji were studied. Mineralogical studies revealed that the dominant primary material and weathering products are volcanic glass, allophane and halloysite and the sequence of weathering is volcanic glass {yields} allophane {yields} 10A halloysite {yields} 7A halloysite. X-ray fluorescence analysis indicates that the relative elemental mobilities during the weathering is Na, Ca>K>Mg>P>Si>Ti, Fe>Al>Mn. The trends of soilwater chemistry (H{sub 4}SiO{sub 4} concentration) with depth were calculated based on dissolution - precipitation kinetics - fluid flow coupling model. In order to calculate the trends, the data on present-day annual rainfall, solubility of basalt glass, porosity and specific weight of soil, deposition rate of volcanic ash and grain size of volcanic glass were used. The calculated results were compared with analytical trends of soilwater chemistry. From this comparison the dissolution rate constant of basalt glass was estimated to be 10{sup -9.4} - 10{sup -9.2} (mole Si m{sup -2} s{sup -1}). This value is consistent with previous experimental dissolution rate constant of basalt glass reported in the literature. (author)

  8. Estimate of long-term dissolution rate of basaltic glass. A case study on Mt. Fuji area

    International Nuclear Information System (INIS)

    Shikazono, Naotatsu; Takino, Akitsugu

    2002-01-01

    Bulk compositional, mineralogical and physical properties of weathered basaltic ash soil ('Andisol') derived mainly from Mt. Fuji were studied. Mineralogical studies revealed that the dominant primary material and weathering products are volcanic glass, allophane and halloysite and the sequence of weathering is volcanic glass → allophane → 10A halloysite → 7A halloysite. X-ray fluorescence analysis indicates that the relative elemental mobilities during the weathering is Na, Ca>K>Mg>P>Si>Ti, Fe>Al>Mn. The trends of soilwater chemistry (H 4 SiO 4 concentration) with depth were calculated based on dissolution - precipitation kinetics - fluid flow coupling model. In order to calculate the trends, the data on present-day annual rainfall, solubility of basalt glass, porosity and specific weight of soil, deposition rate of volcanic ash and grain size of volcanic glass were used. The calculated results were compared with analytical trends of soilwater chemistry. From this comparison the dissolution rate constant of basalt glass was estimated to be 10 -9.4 - 10 -9.2 (mole Si m -2 s -1 ). This value is consistent with previous experimental dissolution rate constant of basalt glass reported in the literature. (author)

  9. Prospective opportunities for using the innovative nuclear reactors in Armenian energy sector long-term programme development

    International Nuclear Information System (INIS)

    Gevorgyan, A.

    2003-01-01

    Full text: In the base of the long-term planning for the Armenian energy sector development there have been laid the principles of energy independence and energy security, and not only those of least-cost criteria. The concept of energy security for Armenia under the existing conditions can be formulated in the following way - the country should have guaranteed ability for the reliable energy supply for all requirements of society both under the sustainable development and in extreme conditions. Ensuring the energy security is the main task and responsibility of all the state institutions without exceptions. In order to ensure the country's energy security, it is necessary to guarantee its energy independence. It means that the country's energy sector should be minimum dependent on the imported fuels, that is, it should be achieved the maximum utilization of the domestic energy sources. Taking the above-mentioned principles as a basis, we have modeled the Armenian electric-energy sector long-term development taking into account the future needs to cover the electricity demand forecasted. Two options were considered: the energy sector development including the nuclear energy scenario, and the option without the nuclear way of electricity generation, called combined cycle scenario. Summarizing the experience of energy crisis, lasted in Armenia during 1992-1996, we can assert that, upon having 40% energy independence, the normal functioning of practically all the life-support systems of Armenia in wide range of emergency situations can be assured. And only restarting Unit 2 of the ANPP made it possible to stop that crisis evolution and enable the country to move toward the further economic development. Besides, the environmental aspects are also among the most important components of the energy security. The ecological factors were included into the study when modeling scenarios of long-term energy development. As it is known, while nuclear power plants do not produce

  10. Nuclear non-proliferation and disarmament: A long-term perspective

    International Nuclear Information System (INIS)

    Haeckel, E.

    1990-01-01

    International nuclear policy has been determined for a long time by the exigencies of the status quo. The non-proliferation regime draws its legitimacy from the continuation of extant patterns of power in world politics. Such a static policy cannot succeed forever. Overcoming the threat of nuclear proliferation will require innovative strategy that reaches beyond the status quo. It calls for structural change in the international system to be accomodated instead of resisted. If the Non-Proliferation Treaty is to hold, nuclear weapon states will finally have to forgo their privileged status. This cannot, however, be accomplished simply through the abolition or renunciation of nuclear weapons since nuclear weapons themselves continue to be instrumental for war prevention and international stability. Rather, what is needed is a new approach to the management of the nuclear world system under international responsibility. Nonproliferation and disarmament objectives together call for a concept of global security in which multilateral institutions assume an increasingly important role of nuclear diplomacy. (orig.) [de

  11. Nuclear energy in medium and long term energy generation of Turkey

    International Nuclear Information System (INIS)

    Sarici, L. E.; Yilmaz, S.; Guray, B. S.

    2001-01-01

    In this study; objectives and activities of Nuclear Power Plants Department and Turkish Electricity Generation and Transmission Corporation is briefly mentioned. A brief history of electricity generation, development of Turkish electrical energy sector and development of the installed capacity of country is presented. The history and future perspectives of AKZuyu Nuclear Power Plant Project is sharply outlined. In the light of the current situation in electricity generation and demand projections, importance of nuclear power among the other future electricity generation alternatives of Turkey is underlined

  12. Nuclear energy and ensuring the long-term energy supply in the German Federal Republic

    International Nuclear Information System (INIS)

    Koenig, H.H.

    1975-01-01

    The author reports on the papers read at the Reactor Conference in 1975. He pays special attention to the development of energy supply from nuclear stations, investigates the motives behind the growing resistance of the public, and shows that the acceptance procedure ensures the construction and operation of safe nuclear power installations. He also discusses the possibilities of improved energy utilisation, the climatic changes in coming generations, the characteristics of supply with nuclear district heating and process heat, as well as the state of building projects with high-temperature reactors and fast breeders. (orig.) [de

  13. MAI: the institute is dedicated for long-term operating of nuclear power plants

    International Nuclear Information System (INIS)

    2016-01-01

    The MAI (Materials Ageing Institute) was founded in 2008 by the most important nuclear power plant operators in the world with the aim of sharing resources and expertise for proving that nuclear power plant service life can be extended without jeopardizing safety. Most of MAI's work has focused on the ageing of stainless steels, alloys, polymers and concretes that are used in light water cooled reactors. (A.C.)

  14. Data requirements for meaningful long-term epidemiology study of the commercial nuclear power industry

    International Nuclear Information System (INIS)

    Kniazewycz, B.G.; McArthur, W.C.

    1983-01-01

    The paper briefly reviews typical data collected at nuclear plants and questions whether more definitive information is required to ensure that the risk cancer from radiation exposure can be adequately addressed in the future. Activities by the National Research Council, National Institute of Health, Department of Energy, Nuclear Regulatory Commission, are briefly reviewed, as is the recent study, Federal Research on the Biological and Health Effects of Ionizing Radiation. A potential role for the Health Physics Society is identified

  15. Long term energy plan of Mongolian with nuclear power plant using Message code

    Energy Technology Data Exchange (ETDEWEB)

    Tsolmonbaatar, Batmunkh; Roh, Myung Sub [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2014-10-15

    In this paper, an overview of the current situation of Mongolia's energy sector and its role and contribution in the country's economy and environment, and a comprehensive assessment of the sector, are provided. Most importantly, the Model for Energy Supply Strategy Alternatives and their General Environmental Impacts (MESSAGE) model used to forecast the future energy supply and demand and to build and compare possible scenarios that could sustain economic development, environmental sustainability, and energy security in the country. In this paper, two scenarios for long-term energy development in Mongolia by 2040 were built using the MESSAGE model, and 2010 was set as the base year. The forecasting of the energy demand and supply was shown as a build the first model of Mongolia energy system to forecast the potentials of using NPP technology in the energy mix of Mongolia energy system. The industry and mining project sectors are expected to remain as the main energy consumers in the next decades. The demand of the sector will be three times of the total energy demand by 2040. The development of big mining projects and the increasing number of vehicles in Mongolia are the main factors that will contribute to the increased demand. Coal still accounts for the largest share in Mongolia's total primary energy demand. MESSAGE result shown in fig.2, which shows an exponential increase in coal resources demand in the future. It will be big issue to environmental impact (e.g., CO{sub 2} emission). The estimated CO{sub 2} emissions from fuel combustion are 13.0 million tones in Mongolia, this should be mitigated significantly, to meet the CO{sub 2} reduction target.

  16. Qualitative and quantitative assessment of the short- and long-term consequences of opting out of nuclear energy

    International Nuclear Information System (INIS)

    Briem, G.; Halstrick, M.; Heilemann, U.; Hillebrand, B.; Kiy, M.; Neuhaus, R.; Knieper, O.; Schmidt, H.W.; Weiss, T.

    1986-08-01

    A reference scenario establishes the prospective development of the energy and overall economy under status-quo conditions, i.e. assuming especially the continued use of nuclear energy, while two scenarios (alternative I: 'immediate opting out' and alternative II: 'opting out in the long term') try to assess the consequences of a shutdown of nuclear energy for the economic development of the Federal Republic of Germany. Especially, the study deals with the effects on the power industry, the ecological consequences, and the overall economic effects both in the short and long run. In all three scenarios, the development of the home consumption of electric power is first of all determined by a structure model of the entire economy. The capacity required to meet that demand and its use are calculated with the aid of a power plant model; short- and long-term cost-minimization programmes making allowance especially for fuel and capital costs from the elements from which these quantities are derived. Fuel and capital costs operate as variables in the structure model to determine the sectoral and overall economic development. The report in addition investigates separately, in partial models, the effects on the chemical industry and the branches of industry processing iron, steel, and non-ferrous metals, all of which are greatly in demand of electric power. (orig./UA) [de

  17. Meeting Czechoslovak demands for heat in long-term prospective, especially with regard to nuclear sources

    International Nuclear Information System (INIS)

    Klail, M.

    1988-01-01

    The development was studied of heat demand in the CSSR till the year 2030. The ratio of centralized and decentralized heat supply is currently 60 to 40; in the future a slight increase is expected in the decentralized type of heat supply, mainly as a result of more intensive use of natural gas. In 2030, 710 PU of centralized heat should be produced. A decisive element in meeting the demand will be a growing proportion of combined production of electric power and heat by nuclear power plants. The installed capacity of the nuclear power plants in 2030 should range between 23 and 41 thousand MW, the production of electric power in these plants should be 193 to 238 TWh/y. 109 territorial areas potentially suitable for use of heat from nuclear sources were selected. They were included in 19 regions of which 9 should in the year 2010 be linked to heat supply from nuclear power plants that will be in operation. It is expected that in the year 2030, nuclear sources will supply 250 PU of centralized heat. (Z.M.). 2 tabs., 14 refs

  18. Integrated scheme of long-term for spent fuel management of power nuclear reactors

    International Nuclear Information System (INIS)

    Ramirez S, J. R.; Palacios H, J. C.; Martinez C, E.

    2015-09-01

    After of irradiation of the nuclear fuel in the reactor core, is necessary to store it for their cooling in the fuel pools of the reactor. This is the first step in a processes series before the fuel can reach its final destination. Until now there are two options that are most commonly accepted for the end of the nuclear fuel cycle, one is the open nuclear fuel cycle, requiring a deep geological repository for the fuel final disposal. The other option is the fuel reprocessing to extract the plutonium and uranium as valuable materials that remaining in the spent fuel. In this study the alternatives for the final part of the fuel cycle, which involves the recycling of plutonium and the minor actinides in the same reactor that generated them are shown. The results shown that this is possible in a thermal reactor and that there are significant reductions in actinides if they are recycled into reactor fuel. (Author)

  19. Acceptance of nuclear power in Germany: A long-term perspective

    International Nuclear Information System (INIS)

    Schulz, R.

    2006-01-01

    20 years ago, in July 1986, a few months after the Chernobyl accident, the renowned nuclear physicist Heinz Maier-Leibnitz published his book 'Lernschock Tschernobyl', in which he attempted a rational assessment of the risk involved in the utilisation of nuclear energy. He conceded that decisions made by government and industry are never purely rational and thus cannot be justified purely on rational grounds. In a democracy, the will and emotions of the people must be taken into account as well. In the case of atomic power, Heinz Maier-Leibniz viewed these emotions as 'fear of unknown, invisible radiation and fear of serious if rare accidents'. (orig.)

  20. Basaltic glass alteration in confined media: analogy with nuclear glass in geological disposal conditions

    International Nuclear Information System (INIS)

    Parruzot, Benjamin

    2014-01-01

    This dissertation concerns basaltic glass alteration mechanisms and rates. Through a better understanding of the processes controlling the basaltic glass durability, this thesis attempts to establish a link between laboratory studies and volcanic glass alteration in natural environment. The methodology used here is similar to the one used for nuclear glasses. Thus, we measured for the first time the residual alteration rate of basaltic glasses. Protective effect of the alteration film is clearly established. Moreover, synthetic glass representativeness is evaluated through a study focused on the effect of iron oxidation degree on the glass structure and leaching properties. A minor effect of Fe II on the forward rate and a negligible effect on the residual rate are shown. The residual rate is extrapolated at 5 C and compared to the mean alteration rate of natural samples of ages ranging from 1900 to 10 7 years. Non-zeolitized natural glasses follow this linear tendency, suggesting a control of the long-term rate by clayey secondary phase precipitation. Natural environments are open environments: a parametric study was performed in order to quantify the water flow rate effect on chemical composition of the alteration layer. When applied to two natural samples, the obtained laws provide coherent results. It seems possible to unify the descriptive approach from the study of natural environments to the mechanistic approach developed at the laboratory. The next step will consist in developing a model to transpose these results to nuclear glasses. (author) [fr

  1. Long-term prospects of capital demands of nuclear power sources construction in Czechoslovakia

    International Nuclear Information System (INIS)

    Sladek, V.; Kysel, J.

    1988-01-01

    The capital demands are compared for four variants of nuclear power plant construction projects to be implemented in Czechoslovakia by the year 2030. By the year 2000, all variants are expected to achieve the total installed capacity of 11,280 MW. Construction in the following period then differs: by the year 2030 total installed nuclear capacity is to reach the following values: 1st variant - 30,000 MW; 2nd variant - 35,000 MW, 3rd variant - 36,500 MW and 4th variant - 27,760 MW. WWER-1000, WWER-1500 and WWER-500 reactors are expected to be installed in the variant projects which differ in speed of construction and life of the units. They are designed such as to provide for the smooth transfer of building workers from one site to the next. The comparison of capital demands shows that a suitable siting strategy and site preparation can save costs and preclude serious sociological problems. The possible extension of the life of nuclear power plants will provide for a better use of primary investments and improve the economic efficiency of nuclear power plants. (Z.M.). 2 figs., 4 tabs., 6 refs

  2. Flexible decision making in the wake of large scale nuclear emergencies: Long-term response

    NARCIS (Netherlands)

    D. Yumashev (Dmitry); Johnson, P. (Paul)

    2017-01-01

    textabstractWe develop a decision-making model that describes optimal protection and recovery strategies for a single economic location affected by radioactive release from the nearby Nuclear Power Plant. The initial period of release and deposition is characterised by high degrees of uncertainty,

  3. Glass and antimony electrodes for long-term pH monitoring: a dynamic in vitro comparison

    NARCIS (Netherlands)

    Geus, W. P.; Smout, A. J.; Kooiman, J. C.; Lamers, C. B.; Gues, J. W.

    1995-01-01

    OBJECTIVE: To compare the performance of combined glass microelectrodes with monocrystalline and polycrystalline antimony electrodes with external reference in a 24-h dynamic in vitro study. DESIGN AND METHODS: In an artificial stomach, the pH of the contents titrated from pH1-7 and back by NaOH and

  4. Long-Term Sustainability from the Perspective of Cullet Recycling in the Container Glass Industry: Evidence from Italy

    Directory of Open Access Journals (Sweden)

    Mario Testa

    2017-10-01

    Full Text Available Glass manufacturing is a high-volume process, during which large substance quantities are transformed into commercial products, and significant amounts of non-renewable resources and energy (i.e., thermal fuels and electrical power are consumed. The main purpose of this study is to give a critical explanation of the performance of the Italian container glass industry from the perspective of cullet being recycled, to outline the opportunities for transition towards circular business models that stimulate innovation in new sectors based on reverse-cycle activities for recycling. In 2015, disparate performances have been achieved as regards the container glass recycling rate in northern, central, and southern Italy, accounting for around 73%, 64%, and 55%, respectively. In fact, only northern Italy is in line with European targets, as by 2025 it will only need to increase its current performance by two percentage points, unlike central and southern Italy that will have to increase performance by, respectively, 11% and 20%. This shows a need to improve the efficiency of municipal waste collection systems in central and southern Italy, where undifferentiated waste still holds appreciable amounts of glass. Consequently, we propose several improvement channels, from the revision of waste legislation to the re-engineering of waste management supply chains.

  5. Main corrective measures in an early phase of nuclear power plants’ preparation for safe long term operation

    Energy Technology Data Exchange (ETDEWEB)

    Krivanek, Robert, E-mail: r.krivanek@iaea.org [International Atomic Energy Agency (IAEA), Department of Nuclear Safety and Security, Operational Safety Section, Vienna 1400 (Austria); Fiedler, Jan, E-mail: fiedler@fme.vutbr.cz [University of Technology Brno, Faculty of Mechanical Engineering, Energy Institute, Technická 2896/2, 616 69 Brno (Czech Republic)

    2017-05-15

    Highlights: • Results of SALTO missions provide the most important issues for safe long term operation (LTO) of nuclear power plants. • The most important technical corrective measures in an early phase of preparation for safe LTO are described. • Their satisfactory resolution creates a basis for further activities to demonstrate preparedness for safe LTO. - Abstract: This paper presents the analysis of main technical deficiencies of nuclear power plants (NPPs) in preparedness for safe long term operation (LTO) and the main corrective measures in an early phase of preparation for safe LTO of NPPs. It focuses on technical aspects connected with management of physical ageing of NPP structures, systems and components (SSCs). It uses as a basis results of IAEA SALTO missions performed between 2005 and 2016 (see also paper NED8805 in Nuclear Engineering and Design in May 2016) and the personal experiences of the authors with preparation of NPPs for safe LTO. This paper does not discuss other important aspects of safe LTO of NPPs, e.g. national nuclear energy policies, compliance of NPPs with the latest international requirements on design, obsolescence, environmental impact and economic aspects of LTO. Chapter 1 provides a brief introduction of the current status of the NPP’ fleet in connection with LTO. Chapter 2 provides an overview of SALTO peer review service results with a focus on deficiencies related to physical ageing of safety SSCs and a demonstration that SSCs will perform their safety function during the intended period of LTO. Chapter 3 discusses the main corrective measures which NPPs typically face during the preparation for demonstration of safe LTO. Chapter 4 summarizes the current status of the NPP’ fleet in connection with LTO and outlines further steps needed in preparation for safe LTO.

  6. Liabilities identification and long-term management decommissioning of nuclear installations in Slovak Republic

    International Nuclear Information System (INIS)

    Burclova, Jana; Konecny, Ladislav

    2003-01-01

    The decommissioning is defined as the safe removal of nuclear facilities from service and reduction of residual radioactivity and/or risk to a level enabling their use for the purpose of another nuclear facility or unrestricted use (site release) and termination of license. The Legal Basis for Decommissioning and Waste Management are described in 4 acts: - 1. Act 130/98 Coll. on peaceful use of nuclear energy (Atomic Act); - 2. The act No 127/1994 Coll. on environmental impact assessment (amended 2000); - 3. The act No 254/1994 Coll. on creation of state found for NPP decommissioning, spent fuel management and disposal investment (amended 2000, 2001); 4. The act No 272/1994 Coll. on protection of public health (amended 1996,2000). The licensing process for radioactive waste management installations as for all nuclear installations is running in following principal steps. The permits for siting, construction, operation including commissioning, individual steps of decommissioning and site release are issued by municipal environmental office on the basis of the Act No 50/1976 Coll. on territorial planning and construction rules and the decisions of the Nuclear regulatory Authority (UJD SR) based on the Atomic Act. The safety documentation shall be prepared by applicant and it is subject of the regulatory bodies approval, for nuclear safety is responsible UJD SR, for radiation protection Ministry of Health, for fire protection Ministry of Interior and for general safety Ministry of Labour, Social Policy and Family. UJD SR issues the permit for each decommissioning phase based on review and approval of safety documentation. Decommissioning Strategy of Slovak Republic was strongly influenced by the changes of Waste Management Strategy. During the last time UJD SR dedicated the great effort to principal improvement of legislation, to cooperation with Ministry of Economy with the aim to create rules for financial sources for decommissioning activities and to enforcement of

  7. Nuclear electric energy in Romania - present status and long term prospects

    International Nuclear Information System (INIS)

    Fulga, V.

    1996-01-01

    The paper presents an analysis of the option for nuclear power in view of the decreasing energy demand in Romania, following industrial restructuring and abandonment of highly consuming industrial capacities. The costs of Cernavoda NPP based on CANDU type reactors amounted up to USD 2.2 billions, 160 % higher than the real price. Even though this reactor type is positioned among the highest as the safety is concerned, it could be assumed that even small incidents (predictable as well as repairable) would result in a decay of the tourism on Romanian sea shore or Danube delta. The paper raises also five questions and asks for updating the data necessary for a renewal of governmental decision concerning the Romanian nuclear power program

  8. Climate Considerations in Long-Term Safety Assessments for Nuclear Waste Repositories

    Energy Technology Data Exchange (ETDEWEB)

    Naeslund, Jens-Ove; Brandefelt, Jenny; Claesson Liljedahl, Lillemor [Svensk Kaernbraenslehantering AB, Stockholm (Sweden)], E-mail: jens-ove.naslund@skb.se

    2013-05-15

    For a deep geological repository for spent nuclear fuel planned in Sweden, the safety assessment covers up to 1 million years. Climate scenarios range from high-end global warming for the coming 100 000 years, through deep permafrost, to large ice sheets during glacial conditions. In contrast, in an existing repository for short-lived waste the activity decays to low levels within a few tens of thousands of years. The shorter assessment period, 100 000 years, requires more focus on climate development over the coming tens of thousands of years, including the earliest possibility for permafrost growth and freezing of the engineered system. The handling of climate and climate change in safety assessments must be tailor-made for each repository concept and waste type. However, due to the uncertain future climate development on these vast time scales, all safety assessments for nuclear waste repositories require a range of possible climate scenarios.

  9. Climate considerations in long-term safety assessments for nuclear waste repositories.

    Science.gov (United States)

    Näslund, Jens-Ove; Brandefelt, Jenny; Liljedahl, Lillemor Claesson

    2013-05-01

    For a deep geological repository for spent nuclear fuel planned in Sweden, the safety assessment covers up to 1 million years. Climate scenarios range from high-end global warming for the coming 100 000 years, through deep permafrost, to large ice sheets during glacial conditions. In contrast, in an existing repository for short-lived waste the activity decays to low levels within a few tens of thousands of years. The shorter assessment period, 100 000 years, requires more focus on climate development over the coming tens of thousands of years, including the earliest possibility for permafrost growth and freezing of the engineered system. The handling of climate and climate change in safety assessments must be tailor-made for each repository concept and waste type. However, due to the uncertain future climate development on these vast time scales, all safety assessments for nuclear waste repositories require a range of possible climate scenarios.

  10. Long-term concepts for the peaceful uses of nuclear energy

    International Nuclear Information System (INIS)

    Kugeler, K.

    1996-01-01

    An even greater improvement in reactor safety is demanded for the future use of nuclear energy. It will be possible to build reactors whose cores can never melt down even in extreme accidents, this design being of interest for lower output reactors in dual-purpose generation, in small networks as well as on the heat market of the future. Confinement of the radioactive materials in the fuel elements is bound to compliance with four principles of stability: nuclear, thermal, chemical and mechanical stability and integrity must be warranted. Details of these principles as well as the underlying inherent characteristics of reactors are explained. Activities and measures for compliance with the principles are specified for a high-temperature reactor as an example. (orig.)

  11. The Role of Nuclear Energy for Long-term National Energy Planning

    International Nuclear Information System (INIS)

    Soetrisnanto, Arnold Y; Adiwardojo; Soentono, Soedyartomo

    2001-01-01

    Energy planning development is a part of the sustainable development that supports the attainment of national development goals. The objective of the study is to support the national planning and decision-making process in the energy and electric sector in Indonesia with nuclear option for period of 1997- 2027. This study performs the provision of detailed economic sector and regional energy demand projection by MAED simulation model based on the economic and population scenarios. Then continued with the optimization of the future energy supply such as electricity supply taking all known Indonesian energy sources and all relevant technologies into consideration by MARKAL Model. The result shows that Indonesia's need for final energy is forecasted to increase two times, from 4,028.4 PJ at the beginning of study become 8,145.6 PJ at the end of study. The more the use of fossil fuels are tightened and enforced because of its environmental impact, the earlier the nuclear power becomes part of the optimum generation mix. In the case IEA1001 (reduction of 1% CO 2 emission), nuclear energy is needed in Jawa-Bali region in the earliest possibility i.e. year 2018 corresponding to 0.37 GW and it will increase in the next years

  12. The strategy of the long-term back-end nuclear fuel cycle in the Czech Republic

    International Nuclear Information System (INIS)

    Palagyi, S.; Fajman, V.

    2002-01-01

    The present status of the strategy of the long-term back-end nuclear fuel cycle in the Czech Republic is briefly outlined in this paper. This strategy is based on the once-through option in the use of the nuclear fuel with subsequent interim storage of the spent fuel and its final disposal as a declared high level waste. However, other technologies for the management of the back-end of the nuclear fuel cycle are not excluded at all. Besides the first already existing and the second interim spent fuel storage facility being sited at Dukovany Nuclear Power Plant, an interim spent fuel storage facility at Temelin Nuclear Power Plant is also under the siting process. To cover the total storing needs a central spent nuclear fuel interim storage facility at Skalka in the Czech-Moravian Highlands is also under consideration. These facilities are or will be equipped with dry-storage containers of cask-type placed in the concrete building and cooled by natural air ventilation. Since 1993 there is a joint effort of several governmental organisations and institutions and private companies to study the scientific, technical and economical possibilities of the construction of the deep geological repository for spent nuclear fuel disposal. A horizontal repository facility with vertical access was selected and a reference project has been accepted. A time horizon for construction in about the year of 2035 was scheduled. The necessary legal and administrative basis of the spent fuel and radioactive waste management was laid down by the law No. 18/1997 (Atomic Act) passed in 1997. This basic law with its implementing regulations fully reflects the internationally accepted principles of the provision of nuclear safety and radiation protection in this respect and it also strongly supports the policy and strategy of the back-end of the nuclear fuel cycle. (author)

  13. The problem of the long-term management of nuclear wastes; Le probleme de la gestion a long terme des dechets nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The law from December 30, 1991, precisely defines 3 axes of researches for the management of high level and long-lived radioactive wastes: separation/transmutation, surface storage and underground disposal. A global evaluation report about these researches is to be supplied in 2006 by the French government to the Parliament. A first synthesis of the knowledge gained after 14 years of research has led the national commission of the public debate (CNDP) to organize a national debate about the general options of management of high-level and long-lived radioactive wastes before the 2006 date line. The debate comprises 4 public hearings (September 2005: Bar-le-Duc, Saint-Dizier, Pont-du-Gard, Cherbourg), 12 round-tables (October and November 2005: Paris, Joinville, Caen, Nancy, Marseille), a synthesis meeting (December 2005, Dunkerque) and a closing meeting (January 2006, Lyon). This document is the proceedings of the synthesis meeting of Dunkerque. It comprises an introduction which recalls the stakes and modalities of the debate, followed by a talk from the president of the national association of local commissions for nuclear activities information (ANCLI), and three synthesis talks from the particular commission of the public debate, the ministry of industry, and the committee of experts and counter-experts. These proceedings end with some questions and answers with the public. A slide presentation by B. Dessus about the progresses made in the debate on nuclear wastes management is attached to the document. (J.S.)

  14. From Streams to Lumps: Transforming Long-Term Incentives into Up-Front Financing for New Nuclear Construction

    International Nuclear Information System (INIS)

    George, Glenn R.

    2006-01-01

    The Energy Policy Act of 2005 is an important development in the financing of new nuclear capacity in the near- to mid-term in the U.S.A. Key features of the Act, including production tax credits, loan guarantees, funding support, and 'standby support', are intended to provide significant incentives for new nuclear development, construction, and operation. There is a mismatch, however, between the nature and extent of incentives being offered and what is needed to spur nuclear plant deployment in light of power market uncertainty, utility investor wariness, and the need to raise significant capital before a nuclear construction project can be launched. In this paper, the author addresses these issues through the lens of financial tools and techniques. The paper considers various ways in which long-term streams of subsidies can be transformed into up-front financing for new nuclear capacity. Securing and related financial structures are among the mechanisms considered for potentially bridging the temporal gap between flows of financial benefits conferred legislatively and lumps of capital required by developers and investors in advance of a construction program. (authors)

  15. Nuclear traces in glass

    International Nuclear Information System (INIS)

    Segovia A, M. de N.

    1978-01-01

    The charged particles produce, in dielectric materials, physical and chemical effects which make evident the damaged zone along the trajectory of the particle. This damaged zone is known as the latent trace. The latent traces can be enlarged by an etching of the detector material. This treatment attacks preferently the zones of the material where the charged particles have penetrated, producing concavities which can be observed through a low magnification optical microscope. These concavities are known as developed traces. In this work we describe the glass characteristics as a detector of the fission fragments traces. In the first chapter we present a summary of the existing basic theories to explain the formation of traces in solids. In the second chapter we describe the etching method used for the traces development. In the following chapters we determine some chatacteristics of the traces formed on the glass, such as: the development optimum time; the diameter variation of the traces and their density according to the temperature variation of the detector; the glass response to a radiation more penetrating than that of the fission fragments; the distribution of the developed traces and the existing relation between this ditribution and the fission fragments of 252 Cf energies. The method which has been used is simple and cheap and can be utilized in laboratories whose resources are limited. The commercial glass which has been employed allows the registration of the fission fragments and subsequently the realization of experiments which involve the counting of the traces as well as the identification of particles. (author)

  16. Lifetime Management Programs as a basis for the long term operation of nuclear installations

    Energy Technology Data Exchange (ETDEWEB)

    López González, Manuel; Lobato Galeote, Carlos, E-mail: mlopezg@idom.com, E-mail: carlos.lobato@idom.com [IDOM - Consulting, Engineering & Architecture SAU, Madrid (Spain)

    2017-07-01

    From the licensing standpoint there are several approaches worldwide to obtain an authorization to operate a NPP beyond its design life. According to the License Renewal Application (LRA) approach, followed in the United States of America and another countries, plants need to develop a Life Time Management Program (LTMP) with which manage the potential aging processes (corrosion, erosion, erosion-corrosion, radiation and thermally induced embrittlement, fatigue, corrosion fatigue, creep, binding and wear) associated to the Structures, Systems and Components. A LTMP is composed of several tasks which represents a technical challenge for a nuclear installation. (author)

  17. Corrosion issues in the long term storage of aluminum-clad spent nuclear fuels

    International Nuclear Information System (INIS)

    Louthan, M.R. Jr.; Peacock, H.B. Jr.; Sindelar, R.L.; Iyer, N.C.

    1996-01-01

    Approximately 8% of the spent nuclear fuel owned by the US Department of Energy is clad with aluminum alloys. The spent fuel must be either reprocessed or temporarily stored in wet or dry storage systems until a decision is made on final disposition in a repository. There are corrosion issues associated with the aluminum cladding regardless of the disposition pathway selected. This paper discusses those issues and provides data and analysis to demonstrate that control of corrosion induced degradation in aluminum clad spent fuels can be achieved through relatively simple engineering practices

  18. Ageing Management of the reactor internals in Belgian nuclear units in view of Long Term Operation

    International Nuclear Information System (INIS)

    Gerard, R.; Bertolis, D.; Vissers, S.

    2012-01-01

    The reactor internals support the reactor core, distribute the coolant flow through the core, and guide and protect the rod control cluster assemblies and in-core instrumentation. Their integrity must be guaranteed in all operating and accident conditions. They are exposed to specific degradation mechanisms linked to the intense neutron irradiation, like Irradiation Assisted Stress Corrosion Cracking (IASCC) or potentially void swelling, in addition to more classical mechanisms like fatigue, wear and stress corrosion cracking. A rigorous follow-up of in-service degradation and an effective ageing management is therefore of crucial importance and contributes to the safe and economical operation of nuclear PWR units. (author)

  19. Lifetime Management Programs as a basis for the long term operation of nuclear installations

    International Nuclear Information System (INIS)

    López González, Manuel; Lobato Galeote, Carlos

    2017-01-01

    From the licensing standpoint there are several approaches worldwide to obtain an authorization to operate a NPP beyond its design life. According to the License Renewal Application (LRA) approach, followed in the United States of America and another countries, plants need to develop a Life Time Management Program (LTMP) with which manage the potential aging processes (corrosion, erosion, erosion-corrosion, radiation and thermally induced embrittlement, fatigue, corrosion fatigue, creep, binding and wear) associated to the Structures, Systems and Components. A LTMP is composed of several tasks which represents a technical challenge for a nuclear installation. (author)

  20. Prediction of prestressing losses for long term operation of nuclear reactor buildings

    Directory of Open Access Journals (Sweden)

    Thillard G.

    2011-04-01

    Full Text Available Prestressed concrete is used in nuclear reactor buildings to guarantee containment and structural integrity in case of an accident. Monitoring and operating experience over 40 years has shown that prestressing losses can be much greater than the design estimation based on the usual standard laws. A method was developed to determine the realistic residual prestress level in structures, in particular for those where no embedded instrumentation was installed, taking into account in situ measurement results rather than design characteristics. The results can enable the owner to justify extending the lifespan while guaranteeing adequate safety and to define and plan adequate maintenance actions.

  1. The problem of the long-term management of nuclear wastes

    International Nuclear Information System (INIS)

    2005-01-01

    The law from December 30, 1991, precisely defines 3 axes of researches for the management of high level and long-lived radioactive wastes: separation/transmutation, surface storage and underground disposal. A global evaluation report about these researches is to be supplied in 2006 by the French government to the Parliament. A first synthesis of the knowledge gained after 14 years of research has led the national commission of the public debate (CNDP) to organize a national debate about the general options of management of high-level and long-lived radioactive wastes before the 2006 date line. The debate comprises 4 public hearings (September 2005: Bar-le-Duc, Saint-Dizier, Pont-du-Gard, Cherbourg), 12 round-tables (October and November 2005: Paris, Joinville, Caen, Nancy, Marseille), a synthesis meeting (December 2005, Dunkerque) and a closing meeting (January 2006, Lyon). This document is the proceedings of the synthesis meeting of Dunkerque. It comprises an introduction which recalls the stakes and modalities of the debate, followed by a talk from the president of the national association of local commissions for nuclear activities information (ANCLI), and three synthesis talks from the particular commission of the public debate, the ministry of industry, and the committee of experts and counter-experts. These proceedings end with some questions and answers with the public. A slide presentation by B. Dessus about the progresses made in the debate on nuclear wastes management is attached to the document. (J.S.)

  2. The long term operation of nuclear power plants in the US

    International Nuclear Information System (INIS)

    Young, G.G.

    2015-01-01

    The NRC has so far granted the renewal license for 73 nuclear reactors in the US but because of economic issues some power plants that got a renewal license are planned to be decommissioned earlier: for instance the Oyster Creek reactor will be stopped definitely in 2019 after a 50 year operating life, another example is the Kewaunee plant that closed mid 2013 while this reactor had been allowed to operate till 2033. The economy concern is the falling price of natural gas that make gas-burning power plants more competitive than nuclear stations. The reactors at risk are the oldest and the smallest ones but in the non-deregulated sector the economic benefit is important for the most powerful reactors to be allowed to operate over 40 and 60 years. A renewal request is composed of a safety assessment of the plant and the assessment of its environmental impact. The safety assessment relies on an Integrated Plant Assessment and on a Time-Limited Ageing Analyses. In order to prepare the second renewal campaign that will allow some reactors to operate up to 80 years, NRC, DOE and EPRI have begun first to identify potential concerns concerning material degradation and secondly to develop an adequate ageing management strategy. (A.C.)

  3. Overview of plant life management for long term operation in nuclear power plants

    International Nuclear Information System (INIS)

    Kang, K.S.; Vincze, P.; Bychkov, A.

    2014-01-01

    Many IAEA member states have given high priority to licensing their nuclear power plants to operate for terms longer than the time frame originally anticipated (generally 40 years). The task of managing plant ageing is assigned in most member states to an engineering specialty called 'plant life management' (PLiM) applying a systematic analysis methodology to System Structure Components (SSCs) ageing. In many countries, the safety performance of nuclear power plants is periodically assessed and characterized via the periodic safety review (PSR) process. Regulatory review and acceptance of PSRs constitutes for these countries the licensing requirement for continued operation of the plant to the following PSR cycle (usually 10 years). In the USA and in other countries operating US designed plants, instead of PSR process, a license renewal application (LRA) process is followed, which requires certain prerequisites such as ageing management programs, particularly for passive irreplaceable SSCs. Active components are normally addressed via the maintenance rule (MR) requirements and other established regulatory processes. A third group of member states have adopted a combined approach that incorporates elements of both the PSR process and selected LRA specific requirements, such as time limited ageing analysis. The article ends with some IAEA recommendations for the implementation of national PLiM programs

  4. Protection of people living in long-term contaminated areas after a nuclear accident: the guidance of ICRP Publication 111

    International Nuclear Information System (INIS)

    Lochard, Jacques

    2012-01-01

    The International Commission on Radiological Protection provides guidance for the protection of people living in long-term contaminated areas after nuclear accidents or radiological emergencies in ICRP Publication 111 (Ann. ICRP 2009, 39(3)). The prolonged exposures resulting from such events are defined as existing exposure situations and the driving principle for managing exposure situations is the optimization of protection. In conjunction with optimization, the Commission recommends the use of reference levels to restrict individual doses. To be effective, protection strategies to maintain and reduce exposure as low as reasonably achievable should include actions implemented by public authorities and private businesses, but also by the affected population itself. The process through which inhabitants living in a contaminated environment identify problems and apply their own protective actions has been named 'self-help protection' by the Commission. Such a process supposes that affected individuals are fully aware of the situation and are well informed. It is the responsibility of the authorities to establish programmes for continuous radiation monitoring, information and education of the population. The involvement of local professionals and inhabitants in the definition and implementation of protection strategies is a key factor for the sustainability of long-term rehabilitation programmes. (note)

  5. Engaging aboriginal peoples in Canada's plan for the long-term management of used nuclear fuel

    International Nuclear Information System (INIS)

    Patton, P.

    2011-01-01

    The interests and concerns of Aboriginal peoples are integral to development and implementation of Canada's plans for the long-term management of used nuclear fuel. The Nuclear Waste Management Organization (NWMO) has an ongoing statutory obligation and a commitment to active and meaningful participation with Aboriginal peoples. The organization has worked with Aboriginal organizations and individuals to develop long-term engagement and dialogue processes that respect traditional Aboriginal practices, culture, protocols and approaches to decision-making. Aboriginal peoples were significant participants in the 2003-2005 study that resulted in the recommendation for Adaptive Phased Management (APM). After the Canadian government agreed to proceed with APM, Aboriginal peoples provided valuable input into development of the process for selecting a site for a deep geological repository (DGR) for the long-term management of Canada's used nuclear fuel. The involvement of Aboriginal stakeholders continues to be important as Canada moves into the siting process. Engagement of Aboriginal peoples is guided by principles that respond to the unique interests, perspectives and culture of Aboriginal peoples. These principles recognize and honour the special relationship that Aboriginal peoples have with the natural environment, their unique stewardship responsibilities, and the fact that Aboriginal peoples are holders of Aboriginal Traditional Knowledge (ATK), which brings value to planning processes. The NWMO has been working with Aboriginal Elders and others to learn about ATK and to interweave this knowledge into its work. ATK includes important knowledge about the land, ecology and intergenerational decision-making. The NWMO and Aboriginal peoples have given life to engagement principles and the wisdom of ATK by collaboratively developing a number of programs including agreements with national, regional and local Aboriginal organizations. Additionally, the NWMO has

  6. Regional long-term co-operation in the field of nuclear and radiation emergency preparedness

    International Nuclear Information System (INIS)

    Sladek, V.; Metke, E.; Janko, K.; Hohenberg, J. K.; Hofer, P.

    2004-01-01

    Emergency preparedness is generally covered by methodical and coordinative activities of the International Atomic Energy Agency (IAEA) in Member States of the IAEA and by the European Commission (EC) in EU Member and EU Accession Countries. However, the regional harmonisation of emergency arrangements is an important trend of emergency preparedness. The present paper gives a couple of illustrative examples for a regional co-operation in the field of emergency preparedness in Central Europe and an overview on international exercises in this region. The penultimate section contains an outlook on future activities regarding regional co-operation in Central Europe. The following topics have been suggested inter alia: the harmonisation of intervention criteria and countermeasures, co-ordination in the field of information of the public, comprehensive bi lateral and multilateral exercises, exchange of experts between the national nuclear emergency centres and inter-comparison calculations of the computer codes. (authors)

  7. Long Term Operation for EDF Nuclear Power Plants : Towards 60 years

    International Nuclear Information System (INIS)

    Ternon-Morin, Francoise; Degrave, Claude

    2012-01-01

    The lifetime extension of the French nuclear fleet, significantly beyond 40 years (initial design basis) is presently one of the major objectives for EDF, in order to smooth the commissioning flow for the new build program. A lifetime extension up to 60 years should be reasonably achieved, owing to the compliance with additional safety and environmental requirements, an adequate LTO strategy including an exceptional maintenance program periodically updated, and a LTO support program (R and D) consisting of aging knowledge improvement and decision-making tools and methods. The LTO program is illustrated with some examples of replaceable components and a focus is placed on the complementary analysis in progress for RPV and containment safety assessment. (author)

  8. A comparative physics study of alternative long-term strategies for closure of the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Cometto, M.; Wydler, P.; Chawla, R.

    2004-01-01

    The appropriate management of radioactive waste arising from the nuclear fuel cycle is considered to be a key issue in the development of future, more sustainable nuclear energy systems. In this context, the partitioning and transmutation of actinides could play an important role through the achievement of very significant reductions in the actinide content and radiotoxicity of the high-level waste requiring geological disposal. The current paper reports on the results of a detailed physics study carried out to compare the pros and cons of alternative strategies for closure of the nuclear fuel cycle. Different long-term 'steady-state' scenarios have been considered, involving the deployment, to varying degrees, of light water reactors (LWRs) and advanced fast-spectrum systems. The same nuclear data and calculation methods have been used throughout, so that a consistent and reliable comparison of the relative performance of the three basic fuel cycle options (once-through, plutonium recycle, and recycling of all actinides) has been made possible. In addition, with transmutation having been considered employing both critical and accelerator-driven fast-spectrum systems, the study has provided an evaluation of the advantages and disadvantages of these two different advanced system types

  9. Analysis on Japan's long-term energy outlook considering massive deployment of variable renewable energy under nuclear energy scenario

    International Nuclear Information System (INIS)

    Komiyama, Ryoichi; Fujii, Yasumasa

    2012-01-01

    This paper investigates Japan's long-term energy outlook to 2050 considering massive deployment of solar photovoltaic (PV) system and wind power generation under nuclear energy scenario. The extensive introduction of PV system and wind power system are expected to play an important role in enhancing electricity supply security after Fukushima Nuclear Power Accident which has increased the uncertainty of future additional construction of nuclear power plant in Japan. On these backgrounds, we develop integrated energy assessment model comprised of both econometric energy demand and supply model and optimal power generation mix model. The latter model is able to explicitly analyze the impact of output fluctuation in variable renewable in detailed time resolution at 10 minutes on consecutive 365 days, incorporating the role of stationary battery technology. Simulation results reveal that intermittent fluctuation derived from high penetration level of those renewables is controlled by quick load following operation by natural gas combined cycle power plant, pumped-storage hydro power, stationary battery technology and the output suppression of PV and wind power. The results show as well that massive penetration of the renewables does not necessarily require the comparable scale of stationary battery capacity. Additionally, on the scenario which assumes the decommissioning of nuclear power plants which lifetime are over 40 years, required PV capacity in 2050 amounts to more than double of PV installment potential in both building and abandoned farmland area. (author)

  10. Super long-term scenario of world nuclear power generation and uranium supply and demand until 2030 and further 2100

    International Nuclear Information System (INIS)

    Komiyama, Ryoichi; Kakinoki, Tatsuro

    2007-01-01

    Based on latest nuclear policy and development trend in each country in the world, quantity of nuclear power generation and the uranium supply and demand until 2030 and further 2100 were predicted. As a result, the introduction of nuclear power stations spreads around Asia until 2030. The limitation on the uranium resources clearly does not exist until 2030, but a development period of around 10 years is necessary for exploitation of uranium resources. If timely development investment does not advance, it may invite shortage of uranium supply and promote a remarkable rise of uranium supply price. If the reinforcement of the anti-global warming measure and the diversification of the energy source advance at the super long-term time span called 2100, the world coal power largely decreases and the introduction of the nuclear power enlarges steadily. Introduction of the light water reactor (LWR) extends until 2080 since the fuel uses uranium resources of about 70 year ratio of reserves to production, but quantity of LWR power stations and power generation changes for the decrease due to the limitation of uranium resources after it. On the other hand, sustained expansion of the plutonium utilization by the fuel cycle technology and the introduction of the fast breeder reactor (FBR) advance after 2050. Then the sustained expansion of nuclear power is surely expected to occupy the first share of power generation in 2100. On this account it is necessary to push forward the plutonium use, backend technology and FBR development globally, and Japan is expected to carry a positive role to lead international nuclear energy technology development as a nuclear energy developed nation. (T. Tanaka)

  11. Long-term modelling of Carbon Capture and Storage, Nuclear Fusion, and large-scale District Heating

    DEFF Research Database (Denmark)

    Grohnheit, Poul Erik; Korsholm, Søren Bang; Lüthje, Mikael

    2011-01-01

    before 2050. The modelling tools developed by the International Energy Agency (IEA) Implementing Agreement ETSAP include both multi-regional global and long-term energy models till 2100, as well as national or regional models with shorter time horizons. Examples are the EFDA-TIMES model, focusing...... on nuclear fusion and the Pan European TIMES model, respectively. In the next decades CCS can be a driver for the development and expansion of large-scale district heating systems, which are currently widespread in Europe, Korea and China, and with large potentials in North America. If fusion will replace...... fossil fuel power plants with CCS in the second half of the century, the same infrastructure for heat distribution can be used which will support the penetration of both technologies. This paper will address the issue of infrastructure development and the use of CCS and fusion technologies using...

  12. Neural network analysis of nuclear waste glass composition vs durability

    International Nuclear Information System (INIS)

    Seibel, C.K.

    1994-01-01

    The relationship between the chemical composition of oxide glasses and their physical properties is poorly understood, but it is becoming more important as vitrification (transformation into glass) of high-level nuclear waste becomes the favored method for long-term storage. The vitrified waste will be stored deep in geologic repositories where it must remain intact for at least 10,000 years. A strong resistance to groundwater exposure; i.c. a slow rate of glass dissolution, is of great importance. This project deals specifically with glass samples developed and tested for the nuclear fuel reprocessing facility near West Valley, New York. This facility needs to dispose of approximately 2.2 million liters of high-level radioactive liquid waste currently stored in stainless steel tanks. A self-organizing, artificial neural network was used to analyze the trends in the glass dissolution data for the effects of composition and the resulting durability of borosilicate glasses in an aqueous environment. This durability data can be used to systematically optimize the properties of the complex nuclear glasses and slow the dissolution rate of radionuclides into the environment

  13. Development of a long term macro econometric model for strategic analysis and cost assessments in nuclear R and D fields

    International Nuclear Information System (INIS)

    Mankin, Shuichi; Yamazaki, Shigeki.

    1985-11-01

    A Long Term Macro Econometric Model (LTMEMO) has been developed for the purpose of generating economic scenarios for strategic analysis and for cost assessments of technologies in the field of nuclear research and development. The program system of the model is composed of such sub-programs as related social and economic statistic data base and its treatment program, identification and estimation programs of various econometric functions, simulation programs for future projections, and a reference econometric model program. The reference econometric model in the program system would be improved and modified easily by using data base and other sub-programs as the purpose of data retrieval, application of economic hypothesis, and scenario generation. The reference model belongs to a category of such standard types as macro-econometric, deterministic, and descriptive one, however, it was deviated based on the combination of Keynesian theories and Neo-classical theories and was modified by system engineering aspects. The model obtained good performances in such various econometric tests as statistical examinations in parameter estimation of each functions and so called partial tests, total tests, and final tests. Macro economic scenarios α and β, long term projections through 2030 of macro economy in our country were evaluated appropriately by this model. This report describes the process in the development of the model from needs of econometric model in nuclear fields to examples of economic scenarios generated by this model. Some consideration are taken into descriptions on the deviation of each functions and on the application of economic theories for practical use of this program system at the time of modification and improvements of the reference model. (author)

  14. Long-Term Nuclear Knowledge Management (NKM) on Nuclear Production of Hydrogen - A Case Study of the Japan Atomic Energy Research Institute (JAERI)

    International Nuclear Information System (INIS)

    Yanagisawa, Kazuaki

    2007-01-01

    In Japan, so-called a formal nuclear policy; The Framework for Nuclear Energy Policy is built up by Japan Atomic Energy Commission at every 5-year, in which not only a conventional light water reactor (LWR) but also a fast breeder reactor (FBR), HTGR and a fusion reactor (FR) is referred as a prominent candidate of long-term (<100 years) nuclear energy source. The policy makers might have multi-purpose scenarios for a future of innovated nuclear energy systems through results of various discussions at their level. According to long-term nuclear knowledge management, the author made ex ante evaluation of HTGR known as the intellectual assets of JAERI 1, from the viewpoint of hypothetical benefits under conditions of substantial uncertainty. Nuclear knowledge management (NKM) is an integrated, systematic approach to identifying, managing and sharing an organization's nuclear knowledge, and enabling persons to create new nuclear knowledge collectively and thereby helping achieve the objectives. NKM identifies, optimizes, and actively manages intellectual assets either in the form of explicit knowledge held in intangible products or tacit knowledge possessed by individuals or communities in the nuclear fields. In the present study the authors wish not only to show the validity of long-term NKM as a key factor of HTGR but also to assess their hypothetical benefits through the year 2050 under conditions of substantial uncertainty. It should be stressed that those factors are important intellectual assets of JAERI developed to date. Additionally, in the Framework for Nuclear Energy Policy constructed up by the Japan Atomic Energy Commission, a LWR, a fast breeder reactor (FBR), a HTGR, and a fusion reactor (FR) are all defined as eligible and prominent candidates for long-term nuclear energy sources. In this sense, we estimate here a direct market creation of (1) hydrogen energy production and (2) electricity generation, by commercialized HTGR through the year 2050 with

  15. Nuclear fuel cycle in France: today's situation and long term options

    International Nuclear Information System (INIS)

    Boullis, B.; Drevon, C.; Pays, M.

    2015-01-01

    In France plutonium and uranium are recycled as MOX fuel (used in 22 reactors) and URE (enriched uranium from spent fuel). Fission products and minor actinides, that composed ultimate wastes, are vitrified and cast in stainless steel containers. Fuel recycling has reached industrial maturity and about 30.000 tonnes of spent fuels have been processed. This strategy has allowed France to save about 17% of its annual consumption of uranium and to get a least volume of high-level radioactive wastes. This strategy can be pushed forwards by introducing a multi-recycling option in which plutonium and uranium from spent MOX fuels are recycled. Multi-recycling produces a nuclear fuel that is polluted with remainders of actinides and fission products and to compensate this deterioration of its neutronic properties a higher concentration of fissile materials is required. For safety reasons the concentration of plutonium in MOX fuels is limited to 12% so multi-recycling is not a strategy for a fleet of PWRs only. Fast neutron reactors use uranium and plutonium in a more efficiently way and can be a solution for multi-recycling. The study shows that for a constant output of 420 TWh a year a fleet of PWRs need 7600 tonnes of natural uranium. If mono-recycling is allowed this consumption decreases to 6300 tonnes a year and if multi-recycling is allowed by integrating fast reactors in the proportion of 40% of the fleet, this consumption drops to 2700 tonnes a year. The study also shows the changes in the production of wastes in relation with multi-recycling. (A.C.)

  16. Distribution, Diversity, and Long-Term Retention of Grass Short Interspersed Nuclear Elements (SINEs).

    Science.gov (United States)

    Mao, Hongliang; Wang, Hao

    2017-08-01

    Instances of highly conserved plant short interspersed nuclear element (SINE) families and their enrichment near genes have been well documented, but little is known about the general patterns of such conservation and enrichment and underlying mechanisms. Here, we perform a comprehensive investigation of the structure, distribution, and evolution of SINEs in the grass family by analyzing 14 grass and 5 other flowering plant genomes using comparative genomics methods. We identify 61 SINE families composed of 29,572 copies, in which 46 families are first described. We find that comparing with other grass TEs, grass SINEs show much higher level of conservation in terms of genomic retention: The origin of at least 26% families can be traced to early grass diversification and these families are among most abundant SINE families in 86% species. We find that these families show much higher level of enrichment near protein coding genes than families of relatively recent origin (51%:28%), and that 40% of all grass SINEs are near gene and the percentage is higher than other types of grass TEs. The pattern of enrichment suggests that differential removal of SINE copies in gene-poor regions plays an important role in shaping the genomic distribution of these elements. We also identify a sequence motif located at 3' SINE end which is shared in 17 families. In short, this study provides insights into structure and evolution of SINEs in the grass family. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  17. The share of nuclear energy in the long-term electricity generation development in Poland

    International Nuclear Information System (INIS)

    Lipko, Krzysztof; Kwiatkowski, Mieczyslaw

    1999-01-01

    Polish power sector is currently undergoing rapid restructuring changes and according to new energy legislation electricity begins to be recognized as other tradable goods. Simultaneously an awareness of interdependencies between power generation expansion and a protection of the environment increases. Presented paper shows these interdependencies against the background of current and future electricity demand satisfying plans determined in Development Office of Polish Power Grid Company in the time range up to the year 2020. Special consideration is given to constraints assumed for power generation sector, relating to emissions of air pollutants, and their influence on possible changes in the mix of fuels used for power generation. In the first part of the paper an applied methodology of drawing up demand satisfying plans consistent with the rules of integrated resource planning (IRP) is described. Accepted macroeconomic assumptions (including these concerning electricity demand forecast) and development constraints related to emissions of air pollutants consistent with national legislation as well as signed international agreements are presented. The set of new generation technologies considered in development studies is described. Two scenarios of the power generation expansion plants developed for a high electricity demand growth are presented. One of them takes into account CO 2 emission constraint while the other neglects it. In the paper it is proved that the above constraint has great influence on the future mix of power plants. In the case when this constraint is taken into account the expansion of electricity generation beyond the year 2010 is based on technologies which do not increase CO 2 emissions, as for example, nuclear power. (author)

  18. FFSM, Long-Term Nuclear Waste Repository Site Simulation by Monte-Carlo

    International Nuclear Information System (INIS)

    Hadlock, L.R.; Hellstrom, D.I.; Mikulis, M.J.B.; Little, A.D.; Golis, M.J.

    1988-01-01

    1 - Description of program or function: FFSM (Far Field State Model) predicts the approximate geologic and climatic state of a site for a nuclear waste repository over relatively long periods of time. The purpose of FFSM is to represent quantitatively certain events and processes that could alter the effectiveness of one or more natural barriers in a waste isolation system. The barriers treated by the model are primarily components of the geologic environment surrounding the repository, although biosphere components (e.g. climate parameters) that could affect the impact of radionuclide releases are also considered. These components are treated outside the realm of wastes or repository-induced effects, which is indicated by use of the term f ar field . The model treats both natural and man-induced changes in these barriers within a probabilistic framework, and it accounts for cumulative and interactive effects of multiple phenomena. 2 - Method of solution: Fifteen submodels are included in FFSM to account for phenomena that may be of importance individually or in combination in evaluating sites for repositories. These submodels include: undetected features, climate, worldwide glaciation, local glaciation, folding, salt dispersion, magmatic events, faulting, biosphere state, regional deformation, geomorphic processes, dissolution fronts, localized dissolution (breccia pipes), solution mining, and drilling. FFSM can be used in both a deterministic mode, to evaluate interactions or to calculate point values, and a probabilistic mode, to make statistical estimates of future changes. In the probabilistic mode, Monte Carlo simulation is used to generate output probabilities, based on user-supplied input, largely in the form of probability density functions for variable or uncertain parameters

  19. Long-term environmental monitoring at two US Department of Energy Nuclear Sites

    International Nuclear Information System (INIS)

    Gray, R.H.

    1996-01-01

    The U.S. Department of Energy's Hanford Site was established in southeastern Washington during the 1940s to produce plutonium during World War II. The Pantex Plant in the Texas Panhandle was originally used by the U.S. Army for loading conventional ammunition shells and bombs. The Plant was rehabilitated and enhanced in the 1950s to assemble nuclear weapons. Environmental monitoring has been ongoing at both locations for several decades. Monitoring objectives are to detect and assess potential impacts of facility operations on air, surface and ground waters, foodstuffs, fish, wildlife, soils, and vegetation. Currently, measured concentrations of airborne radionuclides around the perimeters of both sites are below applicable guidelines. The low levels of 137 Cs and 90 Sr in some onsite Hanford wildlife samples and concentrations of radionuclides in soils and vegetation from onsite and offsite at both locations are typical of those attributable to naturally occurring radioactivity and to worldwide fallout. Ironically, by virtue of its size (1,450 km 2 [560 mi 2 )], restricted public access, and conservative use of undeveloped land, the Hanford Site has provided a sanctuary for plant and animal populations that have been eliminated from, or greatly reduced on, surrounding agricultural and range lands. Ongoing studies will determine if this is also true at Pantex Plant. The Hanford Reach of the Columbia River and its islands and the Pantex Plant with its playas both serve as refuges for raptorial birds and migratory waterfowl. In addition, the Hanford Reach serves as a migration route for several species of salmon, and chinook salmon and steelhead trout spawn there. Bald eagles congregate along the Hanford Reach in the fall and winter to feed on the spawned-out carcasses of salmon and on wintering waterfowl

  20. Impact of long-term climate change on a deep geological repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Boulton, G.S.; Kautsky, U.; Moren, L.; Wallroth, T.

    2001-05-01

    The radioactivity of spent nuclear fuel will decay over a period of time (100,000 years or longer) in which we expect major environmental change. Climatically driven changes such as glaciation, permafrost and changes in sea level will affect the subsurface environment and must therefore be considered in performance and safety assessments. We regard the state of climate to be determined by the climate system, comprising the atmosphere, the biosphere, the oceans, the ice sheets and the surface of the lithosphere. Climate can change as a consequence of external forcing or as a consequence of the internal dynamics. The changes in the past show a complex cyclical pattern with repetitive periodicities and magnitudes of change. On the relatively long time scale which is of concern in this report climate changes are believed to be triggered by changes in insolation due to cyclical changes in the earth's orbit around the sun. This is referred to as the Milankovitch theory or the astronomical climate theory. A brief review of our knowledge of the climate system, proxy records and observations of past climate change is presented in the report. The most extreme departures from modern environmental conditions in Sweden have occurred during the cold, glacial cycles with ice sheets covering the whole of Sweden. As part of SKB's palaeohydrogeological research programme a time-dependent, thermo-mechanically coupled model of ice sheet behaviour has been developed in order to simulate past fluctuations of the Scandinavian ice sheet and forecast its future. The ice sheet model can calculate the temperature field and isostatic response of the underlying bedrock, subglacial and proglacial permafrost and the subglacial melt rates. By connecting the glaciation model with hydrogeological and rock mechanical models, the response of the subsurface to climate change can be investigated. In this report the climate-driven environmental changes are represented as a series of successive climate

  1. Impact of long-term climate change on a deep geological repository for spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Boulton, G.S. [Edinburgh Univ. (United Kingdom); Kautsky, U.; Moren, L. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Wallroth, T. [Bergab Consulting Geologists (Sweden)

    2001-05-01

    The radioactivity of spent nuclear fuel will decay over a period of time (100,000 years or longer) in which we expect major environmental change. Climatically driven changes such as glaciation, permafrost and changes in sea level will affect the subsurface environment and must therefore be considered in performance and safety assessments. We regard the state of climate to be determined by the climate system, comprising the atmosphere, the biosphere, the oceans, the ice sheets and the surface of the lithosphere. Climate can change as a consequence of external forcing or as a consequence of the internal dynamics. The changes in the past show a complex cyclical pattern with repetitive periodicities and magnitudes of change. On the relatively long time scale which is of concern in this report climate changes are believed to be triggered by changes in insolation due to cyclical changes in the earth's orbit around the sun. This is referred to as the Milankovitch theory or the astronomical climate theory. A brief review of our knowledge of the climate system, proxy records and observations of past climate change is presented in the report. The most extreme departures from modern environmental conditions in Sweden have occurred during the cold, glacial cycles with ice sheets covering the whole of Sweden. As part of SKB's palaeohydrogeological research programme a time-dependent, thermo-mechanically coupled model of ice sheet behaviour has been developed in order to simulate past fluctuations of the Scandinavian ice sheet and forecast its future. The ice sheet model can calculate the temperature field and isostatic response of the underlying bedrock, subglacial and proglacial permafrost and the subglacial melt rates. By connecting the glaciation model with hydrogeological and rock mechanical models, the response of the subsurface to climate change can be investigated. In this report the climate-driven environmental changes are represented as a series of successive

  2. Economic comparison of long-term nuclear fuel cycle management scenarios: The influence of the discount rate

    International Nuclear Information System (INIS)

    Le Dars, Aude; Loaec, Christine

    2007-01-01

    This article presents some main economic results obtained by the CEA in the DERECO project, which aimed to evaluate the global cost of contrasted and long-term nuclear fuel cycle scenarios. The scenarios have been studied for the period 2000-2150 in the French context. They all assume a sustainable nuclear development. These scenarios must not be considered as forecasts and do not reflect any industrial strategy. The article focuses on the comparison of five scenarios including the Generation IV fast reactors and their associated fuel cycles. Common trends as well as specific features can be identified. The article describes the scenarios with the replacement of the nuclear power and the associated fuel cycle. It details the main technical and economic assumptions common to all the scenarios, and exposes some main key results, concerning the flows and inventories as well as concerning economic evaluation. Economic results are given in a comparative manner due to the level of uncertainties at this time horizon. The key economic elements described in the article deal with the sensitivity of the results to the choice of the discount rate

  3. A Strategy to Conduct an Analysis of the Long-Term Performance of Low-Activity Waste Glass in a Shallow Subsurface Disposal System at Hanford

    Energy Technology Data Exchange (ETDEWEB)

    BP McGrail, WL Ebert, DH Bacon, DM Strachan

    1998-02-18

    Privatized services are being procured to vitrify low-activity tank wastes for eventual disposal in a shallow subsurface facility at the Hanford Site. Over 500,000 metric tons of low-activity waste glass will be generated, which is among the largest volumes of waste within the U.S. Department of Energy (DOE) complex and is one of the largest inventories of long-lived radionuclides planned for disposal in a low-level waste facility. Before immobilized waste can be disposed, DOE must approve a "performance assessment," which is a document that describes the impacts of the disposal facility on public health and environmental resources. Because the release rate of radionuclides from the glass waste form is a key factor determining these impacts, a sound scientific basis for determining their long-term release rates must be developed if this disposal action is to be accepted by regulatory agencies, stakeholders, and the public. In part, the scientific basis is determined from a sound testing strategy. The foundation of the proposed testing strategy is a well accepted mechanistic model that is being used to calculate the glass corrosion behavior over the geologic time scales required for performance assessment. This model requires that six parameters be determined, and the testing program is defined by an appropriate set of laboratory experiments to determine these parameters, and is combined with a set of field experiments to validate the model as a whole. Three general classes of laboratory tests are proposed in this strategy: 1) characterization, 2) accelerated, and 3) service condition. Characterization tests isolate and provide specific information about processes or parameters in theoretical models. Accelerated tests investigate corrosion behavior that will be important over the regulated service life of a disposal system within a laboratory time frame of a few years or less. Service condition tests verify that the techniques used in accelerated tests do not change

  4. Contribution to a proposition for a long term development of nuclear energy: the TASSE concept (Thorium based Accelerator driven System with Simplified fuel cycle for long term Energy Production)

    International Nuclear Information System (INIS)

    Berthou, V.

    2000-01-01

    Nuclear industry creates waste which are in the middle of the discussion concerning the Nuclear Energy future. At this time, important decisions for the Energy production must be taken, so numerous researches are conducted within the framework of the Bataille law. The goal of these studies is to find a range of solutions concerning the waste management. An innovative system, called TASSE (Thorium based Accelerator driven System with Simplified fuel cycle for long term Energy production), is studied in this thesis. This reactor is included in a long term strategy, and is destined for the renewal of the reactor park. In the first part of this work, the main characteristics of TASSE have been defined. They are commensurate with some specific requirements such as: to insure a large time to the Nuclear Energy, to reduce the waste production in an important way, to eliminate waste already stocked in the present park, to insure the non proliferation, and to be economically competitive. Neutronics studies of TASSE have been done. A calculation procedure has been developed to reach the system equilibrium state. Several types of molten salts as well as a pebble-bed fuel have been studied. Thus, an optimal fuel has been brought out in regard to some parameters such as the burn up level, the spectrum, the waste toxicity, the cycle type. Eventually, various TASSE core layout have been envisaged. (author)

  5. The understanding of the R7T7 glass blocks long term behavior: chemical and transport coupling in fractured media; Comprehension de l'alteration a long terme des colis de verre R7T7: etude du couplage chimie transport dans un milieu fissure

    Energy Technology Data Exchange (ETDEWEB)

    Chomat, L

    2008-04-15

    The long term behavior of nuclear waste glass blocks depends highly on chemical reactions which occur at the surface in contact with water. Studies carried out on inactive fractured glass blocks show that fracture networks play a significant part in reactive surface area. Nevertheless, the complexity of results interpretation, due to a weak knowledge of fracture networks and local lixiviation conditions, does not allow us to comprehend the physical and chemical mechanisms involved. Model cracks are a key step to study chemical and transport coupling in fractured media. Crack lixiviation in aggressive conditions (pH{>=}11) show that the crack's position (horizontal or vertical) determines the dominant transport mechanism (respectively diffusion or convection induced by gravity). This gravity driven flow seems to be negligible in lower pH conditions. The convective velocity is estimated by a 1D model of reactive transport. Two other parameters are studied: the influence of thermal gradient and the influence of interconnected cracks on alteration. A strong retroactive effect of convection, due to thermal gradient, on the alteration kinetic is observed inside the crack. These works lead to a complete alteration experiment of a 163 crack network subject to a thermal gradient. The use of the geochemical software, HYTEC, within the framework of this study shows the potential of the software which is however limited by the kinetics law used. (author)

  6. The understanding of the R7T7 glass blocks long term behavior: chemical and transport coupling in fractured media; Comprehension de l'alteration a long terme des colis de verre R7T7: etude du couplage chimie transport dans un milieu fissure

    Energy Technology Data Exchange (ETDEWEB)

    Chomat, L

    2008-04-15

    The long term behavior of nuclear waste glass blocks depends highly on chemical reactions which occur at the surface in contact with water. Studies carried out on inactive fractured glass blocks show that fracture networks play a significant part in reactive surface area. Nevertheless, the complexity of results interpretation, due to a weak knowledge of fracture networks and local lixiviation conditions, does not allow us to comprehend the physical and chemical mechanisms involved. Model cracks are a key step to study chemical and transport coupling in fractured media. Crack lixiviation in aggressive conditions (pH{>=}11) show that the crack's position (horizontal or vertical) determines the dominant transport mechanism (respectively diffusion or convection induced by gravity). This gravity driven flow seems to be negligible in lower pH conditions. The convective velocity is estimated by a 1D model of reactive transport. Two other parameters are studied: the influence of thermal gradient and the influence of interconnected cracks on alteration. A strong retroactive effect of convection, due to thermal gradient, on the alteration kinetic is observed inside the crack. These works lead to a complete alteration experiment of a 163 crack network subject to a thermal gradient. The use of the geochemical software, HYTEC, within the framework of this study shows the potential of the software which is however limited by the kinetics law used. (author)

  7. Cost tradeoffs in consequence management at nuclear power plants: A risk based approach to setting optimal long-term interdiction limits for regulatory analyses

    International Nuclear Information System (INIS)

    Mubayi, V.

    1995-05-01

    The consequences of severe accidents at nuclear power plants can be limited by various protective actions, including emergency responses and long-term measures, to reduce exposures of affected populations. Each of these protective actions involve costs to society. The costs of the long-term protective actions depend on the criterion adopted for the allowable level of long-term exposure. This criterion, called the ''long term interdiction limit,'' is expressed in terms of the projected dose to an individual over a certain time period from the long-term exposure pathways. The two measures of offsite consequences, latent cancers and costs, are inversely related and the choice of an interdiction limit is, in effect, a trade-off between these two measures. By monetizing the health effects (through ascribing a monetary value to life lost), the costs of the two consequence measures vary with the interdiction limit, the health effect costs increasing as the limit is relaxed and the protective action costs decreasing. The minimum of the total cost curve can be used to calculate an optimal long term interdiction limit. The calculation of such an optimal limit is presented for each of five US nuclear power plants which were analyzed for severe accident risk in the NUREG-1150 program by the Nuclear Regulatory Commission

  8. SALTO Peer Review Guidelines. Guidelines for Peer Review of Safety Aspects of Long Term Operation of Nuclear Power Plants

    International Nuclear Information System (INIS)

    2014-01-01

    International peer review is a useful tool for Member States to exchange experiences, learn from each other and apply good practices in the long term operation (LTO) of nuclear power plants (NPPs). The peer review is also an important mechanism through which the IAEA supports Member States in enhancing the safety of NPPs. The IAEA has conducted various types of safety review that indirectly address aspects of LTO, including safety reviews for design, engineering, operation and external hazards. Operational Safety Review Team (OSART) services include review of ageing management programmes. In addition, several Member States have requested Ageing Management Assessment Team (AMAT) missions. Through these experiences, it was recognized that a comprehensive peer review on LTO would be very useful to Member States. The Safety Aspects of Long Term Operation (SALTO) peer review addresses strategy and key elements for the safe LTO of NPPs, which includes AMAT objectives and complements OSART reviews. The SALTO peer review is designed to assist operating organizations in adopting a proper approach to LTP including implementing appropriate activities to ensure that plant safety will be maintained during the LTO period. The SALTO peer review can be tailored to focus on ageing management programmes (AMPs) or on other activities related to LTO to support the Member State in enhancing the safety of its NPPs. The SALTO peer review can also support regulators in establishing or improving regulatory and licensing strategies for the LTO of NPPs. The guidelines in this publication are primarily intended for members of a SALTO review team and provide a basic structure and common reference for peer reviews of LTO. Additionally, the guidelines also provide useful information to the operating organizations of NPPs (or technical support organizations) for carrying out their own self-assessments or comprehensive programme reviews. The guidelines are intended to be generic, as there are

  9. Foresight of nuclear generation at long term in Mexico;Prospectiva de la generacion nucleoelectrica en Mexico a largo plazo

    Energy Technology Data Exchange (ETDEWEB)

    Guadarrama L, R.; Sanchez R, O. E.; Martin del Campo M, C., E-mail: rodrigoguadarrama28@hotmail.co [UNAM, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2009-10-15

    This paper presents an analysis of the nuclear generation expansion for the period 2008-2030. The main objective is to plan the expansion of electrical generation system at long term taking into account four decision criteria. These are, the total cost of generation, the risk associated whit changes in fuel prices, the diversity of the generation park and polluting emissions of global impact (greenhouse effect gases) and local effects (acid rain and suspended particles). The analyzed expansion plans were developed using a model of uni nodal planning called WASP-IV. The analysis methodology was based on four steps. The first consisted in developing, with model WASP-IV, different expansion plans of the electrical generation system that fulfill the energy demand and certain conditions of the study in which was optimized the additions program of generator units searching the minimal cost of electrical generation. The second step was to calculate the generation costs of each plan for two scenarios of fuel prices, also with model WASP-IV. Later was calculated the diversity index and the accumulated emissions during the expansion and the avoided emission of CO{sub 2} when units of combined cycle that burn natural gas are replaced by nuclear power units. (Author)

  10. Assessment of nuclear energy cost competitiveness against alternative energy sources in Romania envisaging the long-term national energy sustainability

    International Nuclear Information System (INIS)

    Margeanu, C. A.

    2016-01-01

    The paper includes some of the results obtained by RATEN ICN Pitesti experts in the IAEA.s Collaborative Project INPRO-SYNERGIES. The case study proposed to evaluate and analyze the nuclear capacity development and increasing of its share in the national energy sector, envisaging the long term national and regional energy sustainability by keeping collaboration options open for the future while bringing solutions to short/medium-term challenges. The following technologies, considered as future competing technologies for electric energy generation in Romania, were selected: nuclear technology (represented by PHWR CANDU Units 3 and 4 - CANDU new, advanced HWR - Adv. HWR, and advanced PWR - Adv. PWR) and, as alternative energy sources, classical technology (represented by Coal-fired power plant using lignite fossil fuel, with carbon capture - Coal_new, and Gas-fired power plant operating on combined cycle, with carbon capture - Gas_new). The study included assessment of specific economic indicators, sensitivity analyses being performed on Levelised Unit Energy Cost (LUEC) variation due to different perturbations (e.g. discount rate, overnight costs, etc). Robustness indices (RI) of LUEC were also calculated by considering simultaneous variation of input parameters for the considered power plants. The economic analyses have been performed by using the IAEA.s NEST program. The study results confirmed that in Romania, under the national specific conditions defined, electricity produced by nuclear power plants is cost competitive against coal and gas fired power plants electricity. The highest impact of considered perturbations on LUEC has been observed for capital intensive technologies (nuclear technologies) comparatively with the classic power plants, especially for discount rate changes. (authors)

  11. Evolution of safety standards for the long-term management of nuclear waste, and their application in Ontario Power Generation

    International Nuclear Information System (INIS)

    Kempe, T.F.

    2006-01-01

    This paper examines the need to develop current radiation protection methodologies further in order to take account of the special features of long-term waste management. The need to expand the scope and nature of regulatory submissions is also addressed. It is concluded that an international consensus is emerging as to requirements for a safety case for long-term waste management, and on safety assessment approaches and criteria to be applied in the regulation of long-term waste management facilities. The application of some of this methodology in preliminary concept assessments carried out by OPG for long-term waste management facilities is described. (author)

  12. The French program on the spent nuclear fuel long term evolution: Major results, uncertainties and new requirements

    International Nuclear Information System (INIS)

    Ferry, Cecile; Poinssot, Christophe; Gras, Jean-Marie

    2006-01-01

    The 1991 Radioactive Waste Management Act established a framework in France for research activities on nuclear waste. Within this context, the Commissariat a l'Energie Atomique initiated a research program in 1999 to investigate the long-term behaviour of commercial spent nuclear fuel under the PRECCI project (from the French acronym for Research Project on Long-Term Evolution of Spent Fuel Packages), supported by the French electrical utility EDF and partially by FRAMATOME ANP. The scientific and technical studies performed within the project aim to address the operational issues of the spent fuel end-of-life. Within the context of the law which ends in 2006, the major part of the studies focused on the behaviour of the spent fuel (SF) in interim long-term dry storage and deep geological disposal. The operational questions initially identified concern (i) the retrievability of spent fuel assemblies at the end of the interim period of storage, (ii) the feasibility of treatment after the period of storage, (iii) the radionuclide source terms for SF in storage and geological disposal and (iv) the compatibility between storage and a subsequent geological disposal. Therefore the long-term evolution of the irradiated fuel is studied under the various boundary conditions encountered during storage and geological disposal: - in a closed system; this condition corresponds to the nominal scenario during storage and to the first confinement phase in disposal conditions (with a duration of 10,000 years in the reference scenario); - it consists in assessing the effects of the residual temperature and high radioactivity on the chemical and physical properties of the spent fuel pellets; - some of the studies are also dedicated to the mechanical behaviour of the cladding and structural materials of the assemblies; - in air, it refers to an incidental loss of confinement during storage or to a breaching of the canister before the site re-saturation in geological disposal

  13. Sandia National Laboratories performance assessment methodology for long-term environmental programs : the history of nuclear waste management.

    Energy Technology Data Exchange (ETDEWEB)

    Marietta, Melvin Gary; Anderson, D. Richard; Bonano, Evaristo J.; Meacham, Paul Gregory (Raytheon Ktech, Albuquerque, NM)

    2011-11-01

    Sandia National Laboratories (SNL) is the world leader in the development of the detailed science underpinning the application of a probabilistic risk assessment methodology, referred to in this report as performance assessment (PA), for (1) understanding and forecasting the long-term behavior of a radioactive waste disposal system, (2) estimating the ability of the disposal system and its various components to isolate the waste, (3) developing regulations, (4) implementing programs to estimate the safety that the system can afford to individuals and to the environment, and (5) demonstrating compliance with the attendant regulatory requirements. This report documents the evolution of the SNL PA methodology from inception in the mid-1970s, summarizing major SNL PA applications including: the Subseabed Disposal Project PAs for high-level radioactive waste; the Waste Isolation Pilot Plant PAs for disposal of defense transuranic waste; the Yucca Mountain Project total system PAs for deep geologic disposal of spent nuclear fuel and high-level radioactive waste; PAs for the Greater Confinement Borehole Disposal boreholes at the Nevada National Security Site; and PA evaluations for disposal of high-level wastes and Department of Energy spent nuclear fuels stored at Idaho National Laboratory. In addition, the report summarizes smaller PA programs for long-term cover systems implemented for the Monticello, Utah, mill-tailings repository; a PA for the SNL Mixed Waste Landfill in support of environmental restoration; PA support for radioactive waste management efforts in Egypt, Iraq, and Taiwan; and, most recently, PAs for analysis of alternative high-level radioactive waste disposal strategies including repositories deep borehole disposal and geologic repositories in shale and granite. Finally, this report summarizes the extension of the PA methodology for radioactive waste disposal toward development of an enhanced PA system for carbon sequestration and storage systems

  14. Overview of technical Issues Associated with the Long Term Storage of Light Water Reactor used Nuclear Fuel

    International Nuclear Information System (INIS)

    Sorenson, Ken B.

    2014-01-01

    The nuclear power technical community is developing the technical basis for demonstrating the safety of storing used nuclear fuel for extended periods of time. The combination of reactor operations that off-load spent fuel to interim storage, coupled with delays in repository construction, has resulted in the expectation that storage periods may be for longer periods of time than originally intended. As more fuel continues to be off-loaded from operating reactors, the need for expanded interim storage also increases. As repository programs are delayed, interim storage requirements will likely exceed licensing term limits. To address these operational realities, there has been a concerted international effort to identify and prioritize the technical issues that need to be addressed in order to demonstrate the safety of storing used nuclear fuel for extended periods of time. Since this is an international effort, different storage systems, regulations, and policies need to be considered. This results in differences in technical issues, as well as differences in priorities. However, this effort also identifies important commonalities in some technical areas that need to be addressed. A broad-based international evaluation of these technical issues provides a better understanding of technical concerns as they relate to individual storage systems and specific national regulatory frameworks. While there are several international activities underway that are focused on long term storage, this paper will discuss the activities of the Electric Power Research Institute (EPRI)/Extended Storage Collaboration Program (ESCP) International Subcommittee. A status report detailing the identification and prioritization of the technical issues was presented at the PSAM11 Conference in June 2012 (1). Since that conference, a final report has been completed by the EPRI/ESCP International Subcommittee (2). This paper will provide important results of the final report as well as

  15. The long-term impact of a man-made disaster: An examination of a small town in the aftermath of the Three Mile Island Nuclear Reactor Accident.

    Science.gov (United States)

    Goldsteen, R; Schorr, J K

    1982-03-01

    This paper explores the long-term effects of a nuclear accident on residents' perceptions of their physical and mental health, their trust of public officials, and their attitudes toward the future risks of nuclear power generation In their community. We find that in the period after the accident at Three Mile Island that there are constant or Increasing levels of distress reported by community residents. We conclude that the effects of a technological disaster may often be more enduring than those natural disaster and that greater research efforts should be made to Investigate the long-term consequences of man-made catastrophies of all types.

  16. Long-Term Stability of New Co-Amorphous Drug Binary Systems: Study of Glass Transitions as a Function of Composition and Shelf Time

    Directory of Open Access Journals (Sweden)

    Luz María Martínez

    2016-12-01

    Full Text Available The amorphous state is of particular interest in the pharmaceutical industry due to the higher solubility that amorphous active pharmaceutical ingredients show compared to their respective crystalline forms. Due to their thermodynamic instability, drugs in the amorphous state tend to recrystallize; in order to avoid crystallization, it has been a common strategy to add a second component to hinder the crystalline state and form a thermally stable co-amorphous system, that is to say, an amorphous binary system which retains its amorphous structure. The second component can be a small molecule excipient (such as a sugar or an aminoacid or a second drug, with the advantage that a second active pharmaceutical ingredient could be used for complementary or combined therapeutic purposes. In most cases, the compositions studied are limited to 1:1, 2:1 and 1:2 molar ratios, leaving a gap of information about phase transitions and stability on the amorphous state in a wider range of compositions. In the present work, a study of novel co–amorphous formulations in which the selection of the active pharmaceutical ingredients was made according to the therapeutic effect is presented. Resistance against crystallization and behavior of glass transition temperature ( T g were studied through calorimetric measurements as a function of composition and shelf time. It was found that binary formulations with T g temperatures higher than those of pure components presented long-term thermal stability. In addition, significant increments of T g values, of as much as 15 ∘ C, were detected as a result of glass relaxation at room temperature during storage time; this behavior of glass transition has not been previously reported for co-amorphous drugs. Based on these results, it can be concluded that monitoring behavior of T g and relaxation processes during the first weeks of storage leads to a more objective evaluation of the thermomechanical stability of an amorphous

  17. Decay heat power of spent nuclear fuel of power reactors with high burnup at long-term storage

    Science.gov (United States)

    Ternovykh, Mikhail; Tikhomirov, Georgy; Saldikov, Ivan; Gerasimov, Alexander

    2017-09-01

    Decay heat power of actinides and fission products from spent nuclear fuel of power VVER-1000 type reactors at long-term storage is calculated. Two modes of storage are considered: mode in which single portion of actinides or fission products is loaded in storage facility, and mode in which actinides or fission products from spent fuel of one VVER reactor are added every year in storage facility during 30 years and then accumulated nuclides are stored without addition new nuclides. Two values of fuel burnup 40 and 70 MW·d/kg are considered for the mode of storage of single fuel unloading. For the mode of accumulation of spent fuel with subsequent storage, one value of burnup of 70 MW·d/kg is considered. Very long time of storage 105 years accepted in calculations allows to simulate final geological disposal of radioactive wastes. Heat power of fission products decreases quickly after 50-100 years of storage. The power of actinides decreases very slow. In passing from 40 to 70 MW·d/kg, power of actinides increases due to accumulation of higher fraction of 244Cm. These data are important in the back end of fuel cycle when improved cooling system of the storage facility will be required along with stronger radiation protection during storage, transportation and processing.

  18. LIMCAL: a comprehensive food chain model for predicting radiation exposure to man in long-term nuclear waste management

    International Nuclear Information System (INIS)

    Zach, Reto.

    1982-08-01

    A food chain model, LIMCAL, has been designed to aid in the assessment of the effects of long-term nuclear waste management on man far into the future. LIMCAL is particularly suited to the evaluation of an underground vault. Energy budgets, a basic feature of food chains, have been introduced in LIMCAL to help overcome uncertainties imposed by long time spans. LIMCAL includes all the ingestion pathways leading to man, which comprise terrestrial, fresh-water and saltwater food types and man's and animals' drinking water. The terrestrial pathways include both root uptake and leaf deposition. The basic input terms for LIMCAL are annual average radionuclide concentrations in soil, fresh water and saltwater. Annual average air concentrations can be calculated from soil concentrations by using the resuspension factor or the mass-loading approach. Many of the equations in LIMCAL are similar to those in FOOD II and NEPTUN, existing food chain models for contemporary assessments. The basic output of LIMCAL consists of radionculide concentrations in various food types and drinking water, and the resulting ICRP 26 50-year committed effective dose equivalents for infant and adult man. Dose/ concentration ratios can also be calculated readily by LIMCAL. LIMCAL is best described as a deterministic generic quasi-equilibrium assessment model of the linear-chain type. The parameters of LIMCAL have been reviewed in detail in a separate document

  19. Decay heat power of spent nuclear fuel of power reactors with high burnup at long-term storage

    Directory of Open Access Journals (Sweden)

    Ternovykh Mikhail

    2017-01-01

    Full Text Available Decay heat power of actinides and fission products from spent nuclear fuel of power VVER-1000 type reactors at long-term storage is calculated. Two modes of storage are considered: mode in which single portion of actinides or fission products is loaded in storage facility, and mode in which actinides or fission products from spent fuel of one VVER reactor are added every year in storage facility during 30 years and then accumulated nuclides are stored without addition new nuclides. Two values of fuel burnup 40 and 70 MW·d/kg are considered for the mode of storage of single fuel unloading. For the mode of accumulation of spent fuel with subsequent storage, one value of burnup of 70 MW·d/kg is considered. Very long time of storage 105 years accepted in calculations allows to simulate final geological disposal of radioactive wastes. Heat power of fission products decreases quickly after 50-100 years of storage. The power of actinides decreases very slow. In passing from 40 to 70 MW·d/kg, power of actinides increases due to accumulation of higher fraction of 244Cm. These data are important in the back end of fuel cycle when improved cooling system of the storage facility will be required along with stronger radiation protection during storage, transportation and processing.

  20. Analysis of long-term geological and hydrogeological changes in the Swedish programme for final disposal of nuclear waste

    International Nuclear Information System (INIS)

    Ericsson, L.O.; Boulton, G.S.

    1996-01-01

    In assessing the safety of deep disposal of nuclear waste in crystalline rocks it is important establish whether recent or future changes in loading can lead to fracturing and block displacement which may change the hydrogeological setting of a repository. Furthermore, it is of vital importance to understand how future climate changes, especially future glaciations, will influence the groundwater flow around a deep repository. The Swedish programme comprises R and D activities which attempt to quantify probable impacts of earthquakes, glaciation and land uplift. The activities emphasize geodynamic processes in the Baltic Shield, post-glacial faulting and glacial impacts on hydrogeology and ground water chemistry. A time-dependent, thermo-mechanically coupled, three-dimensional model of the ice sheet behaviour in Scandinavia has been developed. The model is driven by changes in the elevation of the permanent snow line on its surface and by air temperature and predicts the behaviour of the ice sheet for an earth's surface of given form and mechanical properties. The ice sheet model reconstructs the ice sheet thickness, ice sheet temperature distribution, including basal temperature, basal meting pattern and velocity distribution. The model is coupled to a sub-glacial Dancian groundwater flow model which in turn provides boundary for evaluations of long-term hydrogeological evolution at specific sites. (authors). 22 refs., 3 figs

  1. The long-term strength and deformation properties of crystalline rock in a high level nuclear waste repository

    International Nuclear Information System (INIS)

    Tuokko, T.

    1990-12-01

    The time-dependent phenomena which can affect the strength and deformation properties of hard crystal line rock are clarified. Suitable measuring methods for field conditions are also summarized. The significance of time is evaluated around a shaft in a high level nuclear waste repository. According to the investigation it is generally held that creep and cyclic fatigue are the most important phenomena. They arise from subcritical crack growth which is most affected by stress intensity, chemical environment, temperature, and microstructure. There are many theoretical models, which can be used to analyse creep and cyclic fatigue, but they are defective in describing the triaxial stress condition and strength criteria. Additionally, the required parameters are often too difficult to determine with adequate accuracy. The joint creep rate depends on the affecting stress regime, on the water conditions, and on the properties of filling material. The acoustic emission method is suited to observe long-term microcrack development in field conditions. The computer program developed by Atomic Energy of Canada Limited (AECL) is used to evaluate the time-dependent de-formation around a main shaft. According to the model the enlargement of the shaft radius by 30 cm takes millions of years. The possible reduction of shaft radius by 3 mm will happen during 200 years. The model is very sensitive to changes in stress state, in the uniaxial compressive strength, and in the stress corrosion index

  2. Advanced Nuclear Fuel Cycle Effects on the Treatment of Uncertainty in the Long-Term Assessment of Geologic Disposal Systems - EBS Input

    International Nuclear Information System (INIS)

    Sutton, M.; Blink, J.A.; Greenberg, H.R.; Sharma, M.

    2012-01-01

    The Used Fuel Disposition (UFD) Campaign within the Department of Energy's Office of Nuclear Energy (DOE-NE) Fuel Cycle Technology (FCT) program has been tasked with investigating the disposal of the nation's spent nuclear fuel (SNF) and high-level nuclear waste (HLW) for a range of potential waste forms and geologic environments. The planning, construction, and operation of a nuclear disposal facility is a long-term process that involves engineered barriers that are tailored to both the geologic environment and the waste forms being emplaced. The UFD Campaign is considering a range of fuel cycles that in turn produce a range of waste forms. The UFD Campaign is also considering a range of geologic media. These ranges could be thought of as adding uncertainty to what the disposal facility design will ultimately be; however, it may be preferable to thinking about the ranges as adding flexibility to design of a disposal facility. For example, as the overall DOE-NE program and industrial actions result in the fuel cycles that will produce waste to be disposed, and the characteristics of those wastes become clear, the disposal program retains flexibility in both the choice of geologic environment and the specific repository design. Of course, other factors also play a major role, including local and State-level acceptance of the specific site that provides the geologic environment. In contrast, the Yucca Mountain Project (YMP) repository license application (LA) is based on waste forms from an open fuel cycle (PWR and BWR assemblies from an open fuel cycle). These waste forms were about 90% of the total waste, and they were the determining waste form in developing the engineered barrier system (EBS) design for the Yucca Mountain Repository design. About 10% of the repository capacity was reserved for waste from a full recycle fuel cycle in which some actinides were extracted for weapons use, and the remaining fission products and some minor actinides were encapsulated

  3. ADVANCED NUCLEAR FUEL CYCLE EFFECTS ON THE TREATMENT OF UNCERTAINTY IN THE LONG-TERM ASSESSMENT OF GEOLOGIC DISPOSAL SYSTEMS - EBS INPUT

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, M; Blink, J A; Greenberg, H R; Sharma, M

    2012-04-25

    The Used Fuel Disposition (UFD) Campaign within the Department of Energy's Office of Nuclear Energy (DOE-NE) Fuel Cycle Technology (FCT) program has been tasked with investigating the disposal of the nation's spent nuclear fuel (SNF) and high-level nuclear waste (HLW) for a range of potential waste forms and geologic environments. The planning, construction, and operation of a nuclear disposal facility is a long-term process that involves engineered barriers that are tailored to both the geologic environment and the waste forms being emplaced. The UFD Campaign is considering a range of fuel cycles that in turn produce a range of waste forms. The UFD Campaign is also considering a range of geologic media. These ranges could be thought of as adding uncertainty to what the disposal facility design will ultimately be; however, it may be preferable to thinking about the ranges as adding flexibility to design of a disposal facility. For example, as the overall DOE-NE program and industrial actions result in the fuel cycles that will produce waste to be disposed, and the characteristics of those wastes become clear, the disposal program retains flexibility in both the choice of geologic environment and the specific repository design. Of course, other factors also play a major role, including local and State-level acceptance of the specific site that provides the geologic environment. In contrast, the Yucca Mountain Project (YMP) repository license application (LA) is based on waste forms from an open fuel cycle (PWR and BWR assemblies from an open fuel cycle). These waste forms were about 90% of the total waste, and they were the determining waste form in developing the engineered barrier system (EBS) design for the Yucca Mountain Repository design. About 10% of the repository capacity was reserved for waste from a full recycle fuel cycle in which some actinides were extracted for weapons use, and the remaining fission products and some minor actinides were

  4. Guided wave technology for in-service inspection and online monitoring for long term operation of nuclear power plants

    International Nuclear Information System (INIS)

    Bertoncini, Francesco; Raugi, Marco; Cappelli, Mauro; Cordella, Francesco; Mazzini, Davide

    2015-01-01

    In-Service Inspection (ISI) and monitoring of all equipment (Systems, Structures and Components, SSCs) of a Nuclear Power Plant (NPP), are actions aimed at preventing failures both for economical and safety purposes. SSCs ageing due to stresses such as corrosion, load variations, flow conditions, temperature and neutron irradiation can be a potential limit for NPP life extension or operation beyond their license term (Long Term Operation. LTO). ISI has a main role on the actual possibility of LTO assuring the required safety. Guided Waves are structure-borne ultrasonic waves that propagate along the structure confined and guided by its geometric boundaries. Guided Wave Testing can find defect locations through long-range screening using low-frequency waves (from 5 to 250 kHz). The technology is regularly used for pipe testing in the oil and gas industry. In the nuclear industry, regulators are working to standardize monitoring and inspection procedures. To use the technology inside an active plant, operators must solve issues like high temperatures (up to more than 300degC inside a light-water reactor's primary piping), high wall thickness of components in the primary circuit and characteristic defect typologies. Magnetostrictive sensors are expected to overcome such issues due to their physical properties, namely robust constitution and simplicity. Recent experimental results have demonstrated magnetostrictive transducers can withstand temperatures close to 300degC. In this paper, new experimental tests conducted using such a methodology will be described and open issues related to high temperature guided wave applications (e.g. wave velocity or amplitude fluctuations during propagation in variable temperature components) will be discussed. (author)

  5. RADIATION SAFETY JUSTIFICATION FOR THE LONG-TERM STORAGE OF GAS CONDENSATE IN THE UNDERGROUND RESERVOURS FORMED BY THE NUCLEAR EXPLOSION TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    I. K. Romanovich

    2010-01-01

    Full Text Available The paper presents approaches to the safety justification of the gas condensate and brine long-term storage in the underground reservoirs formed by the nuclear explosion technology. Gas condensate and brine are the intermediate level liquid radioactive waste containing isotopes: 3Н, 137Cs and 90Sr, in traces - 239Pu, 235U, 241Am.Safety of the gas condensate and brine long-term storage in the underground reservoirs is assessed on the base of the multi-barrier principle implementation, used during radioactive waste disposal. It is shown that the gas condensate and brine long-term storage in the sealed underground reservoirs formed by nuclear explosion technologies in salt domes does not lead to the surface radioactive contamination and population exposure.

  6. Radionuclides containment in nuclear glasses. An overview

    Energy Technology Data Exchange (ETDEWEB)

    Gin, Stephane; Jollivet, Patrick; Tribet, Magaly; Peuget, Sylvain; Schuller, Sophie [CEA Marcoule, Bagnols-sur-Ceze (France). DE2D SEVT

    2017-07-01

    Radioactive waste vitrification has been carried out industrially in several countries for nearly 40 years. Research into the formulation and long term behavior of high and intermediate level waste glasses, mainly borosilicate compositions, is still continuing in order to (i) safely condition new types of wastes and (ii) design and demonstrate the safety of the disposal of these long-lived waste forms in a deep geological repository. This article presents a summary of current knowledge on the formulation, irradiation resistance and the chemical durability of these conditioning materials, with a special focus on the fate of radionuclides during glass processing and aging. It is shown that, apart from the situation for certain elements with very low incorporation rate in glass matrices, vitrification in borosilicate glass can enable waste loadings of up to ∝20 wt% while maintaining the glass homogeneity for geological time scales and guaranteeing a high stability level in spite of irradiation and water contact.

  7. Non steady-state model for dry oxidation of nuclear wastes metallic containers in long term interim storage conditions

    International Nuclear Information System (INIS)

    Bertrand, Nathalie; Desgranges, Clara; Poquillon, Dominique; Monceau, Daniel

    2006-01-01

    For high-level nuclear waste containers in long-term interim storage, dry oxidation will be the first and the main degradation mode. The reason is that, for this kind of waste, the temperature on the surface of the containers will be high enough to avoid any condensation phenomena for several years. Even if the scale growth kinetics is expected to be very slow since the temperature will be moderate at the beginning of the storage (around 300 deg. C) and will keep on decreasing, the metal thickness lost by dry oxidation over such a long period must be evaluated with a good reliability. To achieve this goal, modelling of the oxide scale growth is necessary and this is the aim of the dry oxidation studies, performed in the frame of the COCON programme. All existing oxidation models are based on the two main oxidation theories developed by Wagner between the 1930's and 1970's on the one hand, and by Cabrera and Mott in the 1960 and next by Fromhold on the other hand. These used to be associated with high temperature behaviour for Wagner's theory and with low temperature for the second one. Indeed it is certainly more relevant to consider their range of application in terms of the oxide scale thickness rather than in terms of temperature. The question is posed about which theory should an appropriate model rely on. It can be expected that the oxide scale could have a thickness ranging from a few tens of nanometers up to several tens of micrometers depending on temperature and class of alloys chosen. At the present time, low-alloyed steels or carbon steels are considered candidate materials for high-level nuclear waste containers in long term interim storage. For this type of alloys, the scale formed during the dry oxidation stage will be 'rapidly' thick enough to neglect the Mott field. Hence, in a first step, some basic models based on a parabolic rate assumption, that is to say Wagner's model, have been derived from experimental data on iron and on low-alloy steel

  8. THEREDA - a contribution to long-term safety of repositories of nuclear and non-nuclear wastes

    International Nuclear Information System (INIS)

    Altmaier, M.; Kienzler, B.; Marquardt, C.M.; Neck, V.; Voigt, W.; Wilhelm, S.

    2008-01-01

    Long-term safety analyses of German repositories of radioactive waste as well as underground repositories for chemical toxic waste and other uses (contaminated site remediation) urgently require a standardized, comprehensive thermodynamic reference database. The former 'Thermodynamic Standard Database Working Party' was set up to establish such a database. The activities of that group have been supported within the integrated 'THEREDA' (Thermodynamic Reference Database) project since July 2006 for an initial period of 3 years by the German Federal Ministries of Education and Research, of Economics, and by the Federal Office of Radiation Protection. THEREDA at present is composed of 5 partner institutions essentially representing the key German research institutions in the field of repository safety research. THEREDA is to improve the transparency and validity of safety analyses in Germany and, for the first time, provides consistent thermodynamic datasets for the repository options discussed in Germany. Quality levels are indicated for each thermodynamic quantity on the basis of unambiguously defined evaluation criteria, which allow users to either include or exclude data in accordance with the specific problems at hand. Missing thermodynamic data are substituted in THEREDA by well-founded estimates, thus permitting future model calculations for safety analysis to be carried out on a clearly broader basis of data. The data are managed centrally in a database and will be available to users free of charge on the Internet. Import formats allowing THEREDA to be transferred into the most common modeling codes (EQ3/6, PHREEQC, Geochemist's Workbench, CHEMAPP, etc.) are also made available free of charge. (orig.)

  9. Kinetic and thermodynamic studies of uranium minerals. Assessment of the long-term evolution of spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Casas, I; Bruno, J; Cera, E [MBT Tecnologia Ambiental, Cerdanyola (Spain); Finch, R J; Ewing, R C [Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM (United States)

    1994-10-01

    We have studied the dissolution behavior of uraninite, becquerelite, schoepite and uranophane. The information obtained under a variety of experimental conditions has been combined with extensive solid phase characterizations, performed in both leached and unleached samples. The overall objective is to construct a thermodynamic and kinetic model for the long-term oxidation alteration of UO{sub 2}(s), as an analogy of the spent nuclear fuel matrix. We have determined the solubility product for becquerelite (logK{sub s0} 32.7{+-}1.3) and uranophane (logK{sub s0} = 7.8{+-}0.8). In some experiments, the reaction progress has shown initial dissolution of uranophane followed by precipitation of a secondary solid phase, characterized as soddyite. The solubility production for this phase has been determined (logK{sub s0} = 3.0{+-}2.9). We have studied the kinetics of dissolution of uraninite, uranophane and schoepite under oxidizing conditions in synthetic granitic groundwater. BET measurements have been performed for uraninite and uranophane. For schoepite, the measurement has not been performed due to lack of sufficient amount of sample. The normalized rates of dissolution of uraninite and uranophane have been calculated referred to the uranium release, as 1.97x10{sup -8} moles h{sup -1} m{sup -2} and 4.0x 10{sup -9} moles h{sup -1} m{sup -2}, respectively. For schoepite, the dissolution process has shown two different rates, with a relatively fast initial dissolution rate of 1.97x10{sup -8} moles h{sup -1} followed, after approximately 1000 hours, by a slower one of 1.4x10{sup -9} moles h{sup -1}. No formation of secondary phases has been observed in those experiments, although final uranium concentrations have in all cases exceeded the solubility of uranophane, the thermodynamically more stable phase under the experimental conditions. 24 refs, 45 figs.

  10. Kinetic and thermodynamic studies of uranium minerals. Assessment of the long-term evolution of spent nuclear fuel

    International Nuclear Information System (INIS)

    Casas, I.; Bruno, J.; Cera, E.; Finch, R.J.; Ewing, R.C.

    1994-10-01

    We have studied the dissolution behavior of uraninite, becquerelite, schoepite and uranophane. The information obtained under a variety of experimental conditions has been combined with extensive solid phase characterizations, performed in both leached and unleached samples. The overall objective is to construct a thermodynamic and kinetic model for the long-term oxidation alteration of UO 2 (s), as an analogy of the spent nuclear fuel matrix. We have determined the solubility product for becquerelite (logK s0 32.7±1.3) and uranophane (logK s0 = 7.8±0.8). In some experiments, the reaction progress has shown initial dissolution of uranophane followed by precipitation of a secondary solid phase, characterized as soddyite. The solubility production for this phase has been determined (logK s0 = 3.0±2.9). We have studied the kinetics of dissolution of uraninite, uranophane and schoepite under oxidizing conditions in synthetic granitic groundwater. BET measurements have been performed for uraninite and uranophane. For schoepite, the measurement has not been performed due to lack of sufficient amount of sample. The normalized rates of dissolution of uraninite and uranophane have been calculated referred to the uranium release, as 1.97x10 -8 moles h -1 m -2 and 4.0x 10 -9 moles h -1 m -2 , respectively. For schoepite, the dissolution process has shown two different rates, with a relatively fast initial dissolution rate of 1.97x10 -8 moles h -1 followed, after approximately 1000 hours, by a slower one of 1.4x10 -9 moles h -1 . No formation of secondary phases has been observed in those experiments, although final uranium concentrations have in all cases exceeded the solubility of uranophane, the thermodynamically more stable phase under the experimental conditions. 24 refs, 45 figs

  11. The Role of the Government and the Public in the Planning of Long Term Management for Nuclear Fuel Wastes in Canada

    International Nuclear Information System (INIS)

    Diah Hidayanti; Yudi Pramono

    2007-01-01

    The generation of electricity from nuclear power has the consequence of producing some wastes that are radioactive, especially in the form of spent fuels which are classified as high level nuclear wastes. Nuclear fuel wastes must be managed properly in order to protect public and environment from its big potential hazard. One type of long term management for nuclear fuel wastes is the final disposal in a permanent storage. Because of the importance of safety aspects for final disposal, it needs the involvement of government and the public to determine the reliability and the acceptance of final disposal concept. Those involvements can be implemented in some aspects such as regulation aspect, review and assessment process, and the public feedback. The evaluation on the plan of long term management for nuclear fuel wastes in Canada provides Indonesia an overview of its long term management plans for all radioactive materials, including nuclear fuel wastes generated from the nuclear power plant which is planned to be in service by 2016. (author)

  12. The reaction of glass during gamma irradiation in a saturated tuff environment: Part 3, long-term experiments at 1 x 10{sup 4}rad/hour

    Energy Technology Data Exchange (ETDEWEB)

    Abrajano, T.A. Jr.; Bates, J.K.; Gerding, T.J.; Ebert, W.L.

    1988-02-01

    Savannah River Laboratory 165 type glass was leached with equilibrated J-13 groundwater at 90{degree}C for times up to 182 days. These experiments were performed as part of an effort by the Nevada Nuclear Waste Storage Investigations Project to assess the importance of radiation effects on repository performance and waste glass corrosion. The gamma radiation field used in this work was 1. 0 +- 0.2 x 10{sup 4} rad/h. Glass dissolution is notably incongruent throughout the entire experimental periods and normalized releases follow the sequence Li {ge} Na {ge} B {approx_equal} U {ge} Si. The normalized leach rates of these elements, as well as the measured growth rates of the reaction layers, decreased with time. The only significant variation observed in the abundance of anions is the systematic decrease in NO{sub 3}/sup {minus}//NO{sub 2}/sup {minus}/ ratio from the starting EJ-13 groundwater to the EJ-13 blank experiments to the tuff- and glass-containing experiments. A leaching model that is consistent with the observed solution data and depth profiles is presented. The applicability and limitation of the present results in predicting the actual interactions that may occur in the NNWSI repository are discussed. 35 refs., 30 figs., 12 tabs.

  13. Long-term management of radioactive waste - will the Price-Anderson system work for third party liability issues arising from the Nuclear Waste Policy Act of 1982

    International Nuclear Information System (INIS)

    Kuznick, S.K.

    1985-01-01

    Two pieces of legislation have been enacted in the United States to provide a framework for the management of radioactive waste and spent nuclear fuel: the Low-level Radioactive Waste Policy Act (1980) and the Nuclear Waste Policy Act of 1982. Neither of these statutes provide a means for resolving third party liability issues arising out of radioactive waste management. However, the Price Anderson Act (originally enacted in 1957) provides a system of financial protection that can be applied to waste management activities and that can resolve most issues pertaining to liability for nuclear damage that may result from long-term management of radioactive waste and spent nuclear fuel. (NEA) [fr

  14. SALTO guidelines. Guidelines for peer review of long term operation and ageing management of nuclear power plants

    International Nuclear Information System (INIS)

    2008-01-01

    The average age of nuclear power plants (NPPs) connected to the grid worldwide is increasing. About 20% of all the power reactors operating worldwide have been in operation for more than 30 years, and almost 50% have been in operation for 20 to 30 years, while a rather limited number of new NPPs are being put into operation. In view of this trend, many countries are giving a high priority to continuing the operation of NPPs beyond the time frame originally anticipated (e.g. 30 or 40 years). Long term operation (LTO) for NPPs is operation beyond the established time frame originally set forth by the license term, design limits, standards or regulations. LTO needs to be justified by a safety assessment considering life limiting processes and features for structures, systems and components. Proper and safe LTO is based on the experience and practices of various countries in areas such as plant license renewal, life extension, continued operation and life management. Other activities, including periodic safety review, ageing management and plant modification, are also relevant to LTO. Ageing management of an NPP is an important activity that must be considered before and in conjunction with the decision to enter LTO. Ageing management of NPPs deals with the physical ageing of structures, systems and components (SSCs) that can result in the degradation of their performance characteristics. Thus ageing management helps ensure that SSCs important to safety remain capable of performing their required safety functions. An effective ageing management programme (AMP) is a key element of the safe and reliable operation of NPPs during the originally planned time frame originally planned for their operation, as well as for the period of LTO. In order to assist Member States in managing ageing effectively, the IAEA is developing related safety standards and guidance publications. International peer review is a useful tool for Member States to exchange experience, learn from each

  15. Introduction: Long term prediction

    International Nuclear Information System (INIS)

    Beranger, G.

    2003-01-01

    Making a decision upon the right choice of a material appropriate to a given application should be based on taking into account several parameters as follows: cost, standards, regulations, safety, recycling, chemical properties, supplying, transformation, forming, assembly, mechanical and physical properties as well as the behaviour in practical conditions. Data taken from a private communication (J.H.Davidson) are reproduced presenting the life time range of materials from a couple of minutes to half a million hours corresponding to applications from missile technology up to high-temperature nuclear reactors or steam turbines. In the case of deep storage of nuclear waste the time required is completely different from these values since we have to ensure the integrity of the storage system for several thousand years. The vitrified nuclear wastes should be stored in metallic canisters made of iron and carbon steels, stainless steels, copper and copper alloys, nickel alloys or titanium alloys. Some of these materials are passivating metals, i.e. they develop a thin protective film, 2 or 3 nm thick - the so-called passive films. These films prevent general corrosion of the metal in a large range of chemical condition of the environment. In some specific condition, localized corrosion such as the phenomenon of pitting, occurs. Consequently, it is absolutely necessary to determine these chemical condition and their stability in time to understand the behavior of a given material. In other words the corrosion system is constituted by the complex material/surface/medium. For high level nuclear wastes the main features for resolving problem are concerned with: geological disposal; deep storage in clay; waste metallic canister; backfill mixture (clay-gypsum) or concrete; long term behavior; data needed for modelling and for predicting; choice of appropriate solution among several metallic candidates. The analysis of the complex material/surface/medium is of great importance

  16. Investigation regarding the long-term security developments in the Swedish nuclear power and the response to the accident at Fukushima

    International Nuclear Information System (INIS)

    Skaanberg, Lars

    2012-01-01

    Swedish nuclear plants need to continue to work on analysis and actions in the plants, partly to meet the demands of legislation and agreed action plans, and partly due to additional security requirements on account of experiences from the Fukushima Dai-ichi accident, stress tests, security investigations and investigations relating to physical protection. It is also essential to continue with safety improvements to gradually increase margins against unforeseen events in aging plants during long-term operation

  17. New maintenance strategy of Tokyo Electric Power Company and Fukushima Dai-ichi Nuclear Power Plant for effective ageing management and safe long-term operation

    International Nuclear Information System (INIS)

    Inagaki, Takeyuki; Yamashita, Norimichi

    2009-01-01

    Fukushima Dai-ichi Nuclear Power Plant is the oldest among three nuclear power plants owned and operated by Tokyo Electric Power Company, which consists of six boiling water reactor units. The commercial operation of Unit 1 was commenced in 1971 (37 years old) and Unit 6 in 1978 (29 years old). Currently ageing degradations of systems, structures and components are managed through maintenance programs, component replacement/refurbishment programs and long-term maintenance plans. The long-term maintenance plans are established through ageing management component replacement/refurbishment programs reviews performed before the 30th year of operation and they are for safe and reliable operation after 30 years (long-term operation). However the past maintenance actions and past component replacement/refurbishment programs were not always proactive and past operational experience and maintenance practices suggest that effective/proactive ageing management programs be introduced in earlier stage of the plant operation. In this circumstance, Tokyo Electric Power Company and Fukushima Dai-ichi Nuclear Power Plant are setting up a new maintenance strategy that includes 1) improving the normal maintenance programs by using ageing degradation data, 2) effective use of information on internal/external operational experience and maintenance practices related to ageing, and 3) proactive component/equipment refurbishment programs during a refreshment outage for safe and reliable long-term operation. To accomplish the goal of this strategy, strengthening engineering capability of plant staff members is a crucial required for the plant. The objective of this paper is to briefly explain main results ageing management reviews, past and current significant ageing issues and management programs against them, and the new maintenance strategy established by Tokyo Electric Power Company and Fukushima Dai-ichi Nuclear Power Plant. (author)

  18. Review of the seismic risk in the design of civil engineering of nuclear installations excepted the long term storage of radioactive wastes

    International Nuclear Information System (INIS)

    2006-01-01

    This guide aims to define, for the nuclear installations excepted the long term storage of radioactive wastes, from site data, the design specifications of earthquake resistant civil engineering and the possible methods for: the determination of the seismic response of the buildings, taking into account the interactions with the materials and the evaluation of the associated strains to size the installation; the determination of seismic displacements to be considered to size the materials. (A.L.B.)

  19. Radiologic Predictors for Clinical Stage IA Lung Adenocarcinoma with Ground Glass Components: A Multi-Center Study of Long-Term Outcomes.

    Directory of Open Access Journals (Sweden)

    Zhao Li

    Full Text Available This study was to define preoperative predictors from radiologic findings for the pathologic risk groups based on long-term surgical outcomes, in the aim to help guide individualized patient management.We retrospectively reviewed 321 consecutive patients with clinical stage IA lung adenocarcinoma with ground glass component on computed tomography (CT scanning. Pathologic diagnosis for resection specimens was based on the 2011 IASLC/ATS/ERS classification of lung adenocarcinoma. Patients were classified into different pathologic risk grading groups based on their lymph node status, local regional recurrence and overall survival. Radiologic characteristics of the pulmonary nodules were re-evaluated by reconstructed three-dimension CT (3D-CT. Univariate and multivariate analysis identifies independent radiologic predictors from tumor diameter, total volume (TV, average CT value (AVG, and solid-to-tumor (S/T ratio. Receiver operating characteristic curves (ROC studies were carried out to determine the cutoff value(s for the predictor(s. Univariate cox regression model was used to determine the clinical significance of the above findings.A total of 321 patients with clinical stage IA lung adenocarcinoma with ground glass components were included in our study. Patients were classified into two pathologic low- and high- risk groups based on their distinguished surgical outcomes. A total of 134 patients fell into the low-risk group. Univariate and multivariate analyses identified AVG (HR: 32.210, 95% CI: 3.020-79.689, P<0.001 and S/T ratio (HR: 12.212, 95% CI: 5.441-27.408, P<0.001 as independent predictors for pathologic risk grading. ROC curves studies suggested the optimal cut-off values for AVG and S/T ratio were-198 (area under the curve [AUC] 0.921, 2.9 (AUC 0.996 and 54% (AUC 0.907, respectively. The tumor diameter and TV were excluded for the low AUCs (0.778 and 0.767. Both the cutoff values of AVG and S/T ratio were correlated with pathologic

  20. Factors determining the long term back end nuclear fuel cycle strategy and future nuclear systems. Proceedings of a technical committee meeting

    International Nuclear Information System (INIS)

    2002-05-01

    The Technical Committee Meeting (TCM) was held in Vienna on 8-10 November 1999; it was organized by the International Atomic Energy Agency and attended by 26 participants from 16 Member States. The purpose of the meeting was to exchange information among experts on the back end fuel cycle strategies adopted by Member States; to identify key factors determining the long-term back end fuel cycle strategies; and to assess the applicability of these factors to future nuclear systems. Issues associated with the back end fuel cycle supporting a country's nuclear power programme are technical, economic, institutional and political. This TCM provided an opportunity to address these issues and their impacts to the back end fuel cycles, as well as to identify and assess factors affecting the back end fuel cycle strategies. The discussion was organized ib the following topical sessions: the nuclear fuel cycle; spent fuel management; waste management and repository; plutonium management. This document contains a summary of the meeting and 22 individual papers presented by participants. Each of the papers was indexed separately

  1. Factors determining the long term back end nuclear fuel cycle strategy and future nuclear systems. Proceedings of a technical committee meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-05-01

    The Technical Committee Meeting (TCM) was held in Vienna on 8-10 November 1999; it was organized by the International Atomic Energy Agency and attended by 26 participants from 16 Member States. The purpose of the meeting was to exchange information among experts on the back end fuel cycle strategies adopted by Member States; to identify key factors determining the long-term back end fuel cycle strategies; and to assess the applicability of these factors to future nuclear systems. Issues associated with the back end fuel cycle supporting a country's nuclear power programme are technical, economic, institutional and political. This TCM provided an opportunity to address these issues and their impacts to the back end fuel cycles, as well as to identify and assess factors affecting the back end fuel cycle strategies. The discussion was organized ib the following topical sessions: the nuclear fuel cycle; spent fuel management; waste management and repository; plutonium management. This document contains a summary of the meeting and 22 individual papers presented by participants. Each of the papers was indexed separately.

  2. Rhyolitic glasses as natural analogues of nuclear waste glasses: behaviour of an Icelandic glass upon natural aqueous corrosion

    International Nuclear Information System (INIS)

    Magonthier, M.-C.; Petit, J.-C.; Dran, J.-C.

    1992-01-01

    A detailed study of the altered rims present in narrow fissures of a 52 ka-old Icelandic obsidian reveals the behaviour of transition and heavy elements, as well as the mechanism and kinetics of alteration, during glass/solution interaction. These complex altered rims are alkali depleted and consist of alternating layers of Fe-rich aluminosilicate and aluminium thihydroxide. The elemental partitioning observed on this naturally corroded obsidian is supported by laboratory experiments performed on the same glass, the elemental accumulation being explained by the formation of a hydrosilicate. A good correlation exists between the thickness of the altered rims and that calculated from the amounts of Fe and Ti accumulated locally. Thus, immobile elements can be used reliably as indices of the extent of alteration because only near-equilibrium conditions occur. The good agreement between the experimental hydration rate of obsidians and the progress of natural corrosion, leads to the assumption that ion diffusion is the long-term controlling mechanism of corrosion. Such an assumption is supported by the particular distribution of the immobile elements which is due to ion diffusion and coprecipitation processes (self-organization genesis). These observations have implications for nuclear waste disposal topics and support the validity of obsidians as analogues of nuclear waste glasses with respect to some local environmental constraints induced by waste packaging and disposal. (author)

  3. Diffusion processes in nuclear waste glasses

    International Nuclear Information System (INIS)

    Serruys, Y.; Limoge, Y.; Brebec, G.

    1992-01-01

    Problems concerning the containment of nuclear wastes are presented. Different materials which have been considered for this purpose are briefly reviewed and we see why glass is one of the favorite candidates. It is focussed on what is known about diffusion in 'simple enough' glasses. After a recall concerning the structure and possible defects, the main results on diffusion in 'simple' glasses are given and it is shown what these results involve for the mechanisms of diffusion. The diffusion models are presented which can account for transport in random media: percolation and random walk models. Specific phenomena for the nuclear waste glasses are considered: the effect of irradiation on diffusion and leaching (i.e. corrosion by water). Finally diffusion data in nuclear waste glasses are presented. (author). 199 refs., 6 figs., 1 tab

  4. Corrosion of simulated nuclear waste glass

    International Nuclear Information System (INIS)

    Music, S.; Ristic, M.; Gotic, M.; Foric, J.

    1988-01-01

    In this study the preparation and characterization of borosilicate glasses of different chemical composition were investigated. Borosilicate glasses were doped with simulated nuclear waste oxides. The chemical corrosion in water of these glasses was followed by measuring the leach rates as a function of time. It was found that a simulated nuclear waste glass with the chemical composition (weight %), 15.61% Na 2 O, 10.39% B 2 O 3 , 45.31% SiO 2 , 13.42% ZnO, 6.61% TiO 2 and 8.66% waste oxides, is characterized by low melting temperature and with good corrosion resistance in water. Influence of passive layers on the leaching behaviour of nuclear waste glasses is discussed. (author) 20 refs.; 7 figs.; 4 tabs

  5. Systems approach to nuclear waste glass development

    International Nuclear Information System (INIS)

    Jantzen, C.M.

    1986-01-01

    Development of a host solid for the immobilization of nuclear waste has focused on various vitreous wasteforms. The systems approach requires that parameters affecting product performance and processing be considered simultaneously. Application of the systems approach indicates that borosilicate glasses are, overall, the most suitable glasses for the immobilization of nuclear waste. Phosphate glasses are highly durable; but the glass melts are highly corrosive and the glasses have poor thermal stability and low solubility for many waste components. High-silica glasses have good chemical durability, thermal stability, and mechanical stability, but the associated high melting temperatures increase volatilization of hazardous species in the waste. Borosilicate glasses are chemically durable and are stable both thermally and mechanically. The borosilicate melts are generally less corrosive than commercial glasses, and the melt temperature miimizes excessive volatility of hazardous species. Optimization of borosilicate waste glass formulations has led to their acceptance as the reference nuclear wasteform in the United States, United Kingdom, Belgium, Germany, France, Sweden, Switzerland, and Japan

  6. Mechanical properties of nuclear waste glasses

    International Nuclear Information System (INIS)

    Connelly, A.J.; Hand, R.J.; Bingham, P.A.; Hyatt, N.C.

    2011-01-01

    The mechanical properties of nuclear waste glasses are important as they will determine the degree of cracking that may occur either on cooling or following a handling accident. Recent interest in the vitrification of intermediate level radioactive waste (ILW) as well as high level radioactive waste (HLW) has led to the development of new waste glass compositions that have not previously been characterised. Therefore the mechanical properties, including Young's modulus, Poisson's ratio, hardness, indentation fracture toughness and brittleness of a series of glasses designed to safely incorporate wet ILW have been investigated. The results are presented and compared with the equivalent properties of an inactive simulant of the current UK HLW glass and other nuclear waste glasses from the literature. The higher density glasses tend to have slightly lower hardness and indentation fracture toughness values and slightly higher brittleness values, however, it is shown that the variations in mechanical properties between these different glasses are limited, are well within the range of published values for nuclear waste glasses, and that the surveyed data for all radioactive waste glasses fall within relatively narrow range.

  7. Improved method for P and T strategy selection by long-term risk evaluation of nuclear energy systems

    International Nuclear Information System (INIS)

    Csom, G.; Feher, S.; Szieberth, M.

    2001-01-01

    The paper presents a detailed introduction of the presently used indicators of long-term risk, namely various concepts of radiotoxicity, analyses their advantages and disadvantages, and proposes further indicators called residual hazard and residual hazard index. In order to illustrate them, the time behavior of the relative radiotoxicity and the residual hazard index is investigated for a few representative cases. In the first one, conventional thermal and fast reactors, while in the second one molten salt reactors are investigated from the viewpoint of transmutation. The results shown indicate the usefulness of the application of the now proposed quantities. (author)

  8. Risks of nuclear waste disposal in space. III - Long-term orbital evolution of small particle distribution

    Science.gov (United States)

    Friedlander, A. L.; Wells, W. C.

    1980-01-01

    A study of long term risks is presented that treats an additional pathway that could result in earth reentry, namely, small radioactive particles released in solar orbit due to payload fragmentation by accidental explosion or meteoroid impact. A characterization of such an event and of the initial mass size distribution of particles is given for two extremes of waste form strength. Attention is given to numerical results showing the mass-time distribution of material and the fraction of initial mass intercepted by earth. It is concluded that it appears that program planners need not be to concerned about the risks of this particular failure mechanism and return pathway.

  9. Qualitative and, as far as possible, quantitative assessment of the short-term and long-term effect of a nuclear phase-out

    International Nuclear Information System (INIS)

    Jaenicke, M.; Mez, L.; Spelthahn, S.; Springmann, F.; Theissen, A.; Ullrich, O.; Leuchtner, J.; Seifried, D.

    1986-08-01

    This survey starts from a series of scenarios or comments on the question of West Germany, leaving the field of nuclear power. These were submitted after the accident at Chernobyl and have gained particular importance in this context. The possibilities of leaving in the short, medium and long term were examined. In a further section, the connection between operation of powerstations and the resulting environmental effects is treated. Economic aspects of leaving the field of nuclear power are examined and the possibilities and potentials of rational energy use (potential saving of electricity, potential of combined heat and power plants and potential from regenerative sources of energy) are estimated. (orig./UA) [de

  10. A study on the establishment of the national mid and long-term R and D plan for the nuclear technology

    International Nuclear Information System (INIS)

    Lee, Kang il; Oh, K. B.; Kim, S. W.; Won, B. C.; Park, S. G.; Kim, S. K.; Cho, S. G.; Kim, M. Y.; Jung, Y. H.

    1993-01-01

    The main objective of this study is to establish practice plan of them and to propose main R and D projects achieving the National Nuclear R and D target - becoming one of an advanced nuclear countries in the early 2000s. With this point of view, this study especially carried out the analysis of the Japanese long-term plans for nuclear power utilization and development. And we tried to propose main R and D projects with Nuclear Power Technology Relevance Tree. Also, the budget essential to the R and D plan for nuclear technology is estimated and the method to finance the budget for the next 10 years (1992-2001) has been considered in this study so as to make the national R and D plan more realistic. (Author)

  11. A Strategy to Conduct an Analysis of the Long-Term Performance of Low-Activity Waste Glass in a Shallow Subsurface Disposal System at Hanford

    Energy Technology Data Exchange (ETDEWEB)

    Neeway, James J.; Pierce, Eric M.; Freedman, Vicky L.; Ryan, Joseph V.; Qafoku, Nikolla

    2014-08-04

    The federal facilities located on the Hanford Site in southeastern Washington State have been used extensively by the U.S. government to produce nuclear materials for the U.S. strategic defense arsenal. Currently, the Hanford Site is under the stewardship of the U.S. Department of Energy (DOE) Office of Environmental Management (EM). A large inventory of radioactive and mixed waste resulting from the production of nuclear materials has accumulated, mainly in 177 underground single- and double-shell tanks located in the central plateau of the Hanford Site (Mann et al., 2001). The DOE-EM Office of River Protection (ORP) is proceeding with plans to immobilize and permanently dispose of the low-activity waste (LAW) fraction onsite in a shallow subsurface disposal facility (the Integrated Disposal Facility [IDF]). Pacific Northwest National Laboratory (PNNL) was contracted to provide the technical basis for estimating radionuclide release from the engineered portion of the IDF (the source term) as part of an immobilized low-activity waste (ILAW) glass testing program to support future IDF performance assessments (PAs).

  12. Lead-iron phosphate glass: a stable storage medium for high-level nuclear waste

    International Nuclear Information System (INIS)

    Sales, B.C.; Boatner, L.A.

    1984-01-01

    Results are presented which show that lead-iron phosphate glasses are a promising new waste form for the safe immobilization of both high-level defense and high-level commercial radioactive waste. Relative to the borosilicate nuclear waste glasses that are currently the ''reference'' waste form for the long-term disposal of nuclear waste, lead-iron phosphate glasses have several distinct advantages: (1) an aqueous corrosion rate that is about 1000 times lower, (2) a processing temperature that is 100 0 to 250 0 C lower and, (3) a much lower melt viscosity in the temperature range from 800 0 to 1000 0 C. Most significantly, the lead-iron phosphate waste form can be processed using a technology similar to that developed for borosilicate nuclear waste glasses

  13. Nanoporous Glasses for Nuclear Waste Containment

    Directory of Open Access Journals (Sweden)

    Thierry Woignier

    2016-01-01

    Full Text Available Research is in progress to incorporate nuclear waste in new matrices with high structural stability, resistance to thermal shock, and high chemical durability. Interactions with water are important for materials used as a containment matrix for the radio nuclides. It is indispensable to improve their chemical durability to limit the possible release of radioactive chemical species, if the glass structure is attacked by corrosion. By associating high structural stability and high chemical durability, silica glass optimizes the properties of a suitable host matrix. According to an easy sintering stage, nanoporous glasses such as xerogels, aerogels, and composite gels are alternative ways to synthesize silica glass at relatively low temperatures (≈1,000–1,200°C. Nuclear wastes exist as aqueous salt solutions and we propose using the open pore structure of the nanoporous glass to enable migration of the solution throughout the solid volume. The loaded material is then sintered, thereby trapping the radioactive chemical species. The structure of the sintered materials (glass ceramics is that of nanocomposites: actinide phases (~100 nm embedded in a vitreous silica matrix. Our results showed a large improvement in the chemical durability of glass ceramic over conventional nuclear glass.

  14. High-level nuclear waste borosilicate glass: A compendium of characteristics

    International Nuclear Information System (INIS)

    Cunnane, J.C.; Bates, J.K.; Ebert, W.L.; Feng, X.; Mazer, J.J.; Wronkiewicz, D.J.; Sproull, J.; Bourcier, W.L.; McGrail, B.P.

    1992-01-01

    With the imminent startup, in the United States, of facilities for vitrification of high-level nuclear waste, a document has been prepared that compiles the scientific basis for understanding the alteration of the waste glass products under the range of service conditions to which they may be exposed during storage, transportation, and eventual geologic disposal. A summary of selected parts of the content of this document is provided. Waste glass alterations in a geologic repository may include corrosion of the glass network due to groundwater and/or water vapor contact. Experimental testing results are described and interpreted in terms of the underlying chemical reactions and physical processes involved. The status of mechanistic modeling, which can be used for long-term predictions, is described and the remaining uncertainties associated with long-term simulations are summarized

  15. AREVA's toolbox for long-term best performance and reliable operation of nuclear steam generators

    International Nuclear Information System (INIS)

    Drexler, Andreas; Weiss, Steffen; Caris, Neil; Stiepani, Christoph

    2015-01-01

    Long-term integrity and high performance of major plant systems and components are of uppermost importance for the successful operation of any power plant. AREVA's experience gathered with water-steam cycle chemistry treatments in more than 40 years yields the conclusion: Accumulation of corrosion products in SGs may result in local overheating and enrichment of impurities up to critical levels. This can lead to several degradation phenomena of the structural materials of the SGs. Therefore, minimization of corrosion product generation and prevention of deposit accumulation is required. The objective of AREVA's asset management program is to support operators by minimizing corrosion damage and performance losses of water-steam cycle systems and components and thereby to maximize the availability and economic performance of the plant. Such asset management program is in principle a closed cycle process. It is based on control, corrective and preventive measures. The objective of control measure is deriving a widespread assessment of the corrosion status of the steam-water cycle which yields to weak points and identifying the best suited corrective and/or preventive measures. In the subsequent steps appropriate measures which improve the current status or counteract on identified issues are identified and applied. Corrective measures, likes mechanical and/or chemical cleaning are targeting the minimization of negative influence on plant performance caused by corrosion in the steam-water cycle. Complementary to corrective measures are preventive ones, like optimization of pH strategy and AREVA's FFA technology could by applied. They are focusing on the origin of corrosion product generation. AREVA is offering a toolbox for long-term best performance and reliable operation of NPPs. (author)

  16. Production of an impermeable composite of irradiated graphite and glass by hot isostatic pressing as a long term leach resistant waste form

    Energy Technology Data Exchange (ETDEWEB)

    Fachinger, Johannes; Muller, Walter [FNAG ZU Hanau, Hanau (Germany); Marsat, Eric [FNAG SAS Le Pont de Claix (France); Grosse, Karl-Heinz; Seemann, Richard [ALD Hanau (Germany); Scales, Charlie; Easton, Michael Mark [NNL, Workington (United Kingdom); Anthony Banford [NNL, Warrington (United Kingdom); University of Manchester, Manchester (United Kingdom)

    2013-07-01

    Around 250,000 tons of irradiated graphite (i-graphite) exists worldwide and can be considered as a current waste or future waste stream. The largest national i-graphite inventory is located in UK (∼ 100,000 tons) with significant quantities also in Russia and France [5]. Most of the i-graphite remains in the cores of shutdown nuclear reactors including the MAGNOX type in UK and the UNGG in France. Whilst there are still operational power reactors with graphite cores, such as the Russian RBMKs and the AGRs in UK, all of them will reach their end of life during the next two decades. The most common reference waste management option of i-graphite is a wet or dry retrieval of the graphite blocks from the reactor core and the grouting of these blocks in a container without further conditioning. This produces large waste package volumes because the encapsulation capacity of the grout is limited and large cavities in the graphite blocks could reduce the packing densities. Packing densities from 0.5 to 1 tons per cubic meter have been assumed for grouting solutions. Furthermore the grout is permeable. This could over time allow the penetration of aqueous phases into the waste block and a potential dissolution and release of radionuclides. As a result particularly highly soluble radionuclides may not be retained by the grout. Vitrification could present an alternative, however a similar waste package volume increase may be expected since the encapsulation capacity of glass is potentially similar to or worse than that of grout. FNAG has developed a process for the production of a graphite-glass composite material called Impermeable Graphite Matrix (IGM) [3]. This process is also applicable to irradiated graphite which allows the manufacturing of an impermeable material without volume increase. Crushed i-graphite is mixed with 20 vol.% of glass and then pressed under vacuum at an elevated temperature in an axial hot vacuum press (HVP). The obtained product has zero or

  17. Production of an impermeable composite of irradiated graphite and glass by hot isostatic pressing as a long term leach resistant waste form

    International Nuclear Information System (INIS)

    Fachinger, Johannes; Muller, Walter; Marsat, Eric; Grosse, Karl-Heinz; Seemann, Richard; Scales, Charlie; Easton, Michael Mark; Anthony Banford

    2013-01-01

    Around 250,000 tons of irradiated graphite (i-graphite) exists worldwide and can be considered as a current waste or future waste stream. The largest national i-graphite inventory is located in UK (∼ 100,000 tons) with significant quantities also in Russia and France [5]. Most of the i-graphite remains in the cores of shutdown nuclear reactors including the MAGNOX type in UK and the UNGG in France. Whilst there are still operational power reactors with graphite cores, such as the Russian RBMKs and the AGRs in UK, all of them will reach their end of life during the next two decades. The most common reference waste management option of i-graphite is a wet or dry retrieval of the graphite blocks from the reactor core and the grouting of these blocks in a container without further conditioning. This produces large waste package volumes because the encapsulation capacity of the grout is limited and large cavities in the graphite blocks could reduce the packing densities. Packing densities from 0.5 to 1 tons per cubic meter have been assumed for grouting solutions. Furthermore the grout is permeable. This could over time allow the penetration of aqueous phases into the waste block and a potential dissolution and release of radionuclides. As a result particularly highly soluble radionuclides may not be retained by the grout. Vitrification could present an alternative, however a similar waste package volume increase may be expected since the encapsulation capacity of glass is potentially similar to or worse than that of grout. FNAG has developed a process for the production of a graphite-glass composite material called Impermeable Graphite Matrix (IGM) [3]. This process is also applicable to irradiated graphite which allows the manufacturing of an impermeable material without volume increase. Crushed i-graphite is mixed with 20 vol.% of glass and then pressed under vacuum at an elevated temperature in an axial hot vacuum press (HVP). The obtained product has zero or

  18. Studies on nuclear fusion energy potential based on a long-term world energy and environment model

    International Nuclear Information System (INIS)

    Tokimatsu, K.; Fujino, J.; Asaoka, Y.

    2001-01-01

    This study investigates introduction conditions and potential of nuclear fusion energy as energy supply and CO 2 mitigation technologies in the 21st century. Time horizon of the 21st century, 10 regionally allocated world energy/environment model (Linearized Dynamic New Earth 21) is used for this study. Following nuclear fusion technological data are taken into consideration: cost of electricity (COE) in nuclear fusion introduction year, annual COE reduction rates, regional introduction year, and maximum regional plant capacity constraints by maximum plant construction speed. We made simulation under a constraint of atmospheric CO 2 concentration of 550 parts per million by volume (ppmv) targeted at year 2100, assuming that sequestration technologies and unknown innovative technologies for CO 2 reduction are available. The results indicate that under the 550ppm scenario with nuclear fusion within maximum construction speed, 66mill/kWh is required for introducing nuclear fusion in 2050, 92 mill/kWh in 2060, and 106 mill/kWh in 2070. Therefore, tokamak type nuclear fusion reactors of present several reactor cost estimates are expected to be introduced between 2060 and 2070, and electricity generation fraction by nuclear fusion will go around 20% in 2100 if nuclear fusion energy growth is limited only by the maximum construction speed. CO 2 reduction by nuclear fusion introduced in 2050 from business-as-usual (BAU) scenario without nuclear fusion is about 20% of total reduction amount in 2100. In conclusion, nuclear fusion energy is revealed to be one of the candidates of energy supply technologies and CO 2 mitigation technologies. Cost competitiveness and removal of capacity constraint factors are desired for use of nuclear fusion energy in a large scale. (author)

  19. Nuclear waste immobilization in iron phosphate glasses

    International Nuclear Information System (INIS)

    Garcia, D.A.; Rodriguez, Diego A.; Menghini, Jorge E.; Bevilacqua, Arturo

    2007-01-01

    Iron-phosphate glasses have become important in the nuclear waste immobilization area because they have some advantages over silicate-based glasses, such as a lower processing temperature and a higher nuclear waste load without losing chemical and mechanical properties. Structure and chemical properties of iron-phosphate glasses are determined in terms of the main components, in this case, phosphate oxide along with the other oxides that are added to improve some of the characteristics of the glasses. For example, Iron oxide improves chemical durability, lead oxide lowers fusion temperature and sodium oxide reduces viscosity at high temperature. In this work a study based on the composition-property relations was made. We used different techniques to characterize a series of iron-lead-phosphate glasses with uranium and aluminium oxide as simulated nuclear waste. We used the Arquimedes method to determine the bulk density, differential temperature analysis (DTA) to determine both glass transition temperature and crystallization temperature, dilatometric analysis to calculate the linear thermal expansion coefficient, chemical durability (MCC-1 test) and X-ray diffraction (XRD). We also applied some theoretic models to calculate activation energies associated with the glass transition temperature and crystallization processes. (author)

  20. Evaluation of economical introduction of nuclear fusion based on a long-term world energy and environment model

    International Nuclear Information System (INIS)

    Tokimatsu, K.; Asaoka, Y.; Okano, K.; Konishi, S.; Ogawa, Y.; Yamaji, K.

    2003-01-01

    Debates about whether or not to invest heavily in nuclear fusion as a future innovative energy option have been made within the context of energy technology development strategies. The time frame by which nuclear fusion could become competitive in the energy market has not been adequately studied, nor has roles of the nuclear fusion in energy systems and the environment. The present study has two objectives. One is to reveal the conditions under which nuclear fusion could be introduced economically (hereafter, we refer to such introductory conditions as breakeven prices) in future energy systems. The other objective is to evaluate the future roles of nuclear fusion in energy systems and in the environment. Here we chose two roles that nuclear fusion will take on when breakeven prices are achieved: i) reduction of annual global total energy systems cost, and ii) mitigation of carbon tax (shadow price of carbon) under CO 2 constraints. Future uncertainties are key issues in evaluating nuclear fusion. Here we treated the following uncertainties: energy demand scenarios, introduction time frame for nuclear fusion, capacity projections of nuclear fusion, CO 2 target in 2100. From our investigations, we conclude that the presently designed nuclear fusion reactors may be ready for economical introduction into energy systems beginning around 2050-2060, and we can confirm that the favorable introduction of the reactors would reduce both the annual energy systems cost and the carbon tax (the shadow price of carbon) under a CO 2 concentration constraint; however, latter introduction of them decreases the cost and the tax less than five times. Earlier introduction of nuclear fusion reactors are desirable for energy systems and environment. (author)

  1. Long-term therapy for polymorphic mental disorders in liquidators of the consequences of the accident at the Chernobyl nuclear power plant

    Directory of Open Access Journals (Sweden)

    V. N. Krasnov

    2012-01-01

    Full Text Available The paper gives the results of a long-term comparative therapeutic study of a large cohort of more than 500 liquidators of the consequences of the accident at the Chernobyl nuclear power plant in 1986. The patients were followed up (and periodically treated at hospital 5 years or more, usually 10—15 years. The study confirmed mainly the cerebrovascular nature of disorders following the pattern seen in moderate psychoorganic syndrome. Therapy with cerebroprotective agents having vascular vegetotropic properties could yield certain therapeutic results and, to some extent, preserve social functioning capacity in these patients.

  2. The assessment of the long-term evolution of the spent nuclear fuel matrix by kinetic, thermodynamic and spectroscopic studies of uranium minerals

    International Nuclear Information System (INIS)

    Bruno, J.; Casas, I.; Cera, E.; Ewing, R.C.; Finch, R.J.

    1995-01-01

    The long term behavior of spent nuclear fuel is discussed in the light of recent thermodynamic and kinetic data on mineralogical analogues related to the key phases in the oxidative alteration of uraninite. The implications for the safety assessment of a repository of the established oxidative alteration sequence of the spent fuel matrix are illustrated with Pagoda calculations. The application to the kinetic and thermodynamic data to source term calculations indicates that the appearance and duration of the U(VI) oxyhydroxide transient is critical for the stability of the fuel matrix

  3. Long-term collections

    CERN Multimedia

    Collectes à long terme

    2007-01-01

    The Committee of the Long Term Collections (CLT) asks for your attention for the following message from a young Peruvian scientist, following the earthquake which devastated part of her country a month ago.

  4. Relevance of biotic pathways to the long-term regulation of nuclear waste disposal. Phase I. Final report. Vol. 4

    International Nuclear Information System (INIS)

    McKenzie, D.H.; Cadwell, L.L.; Eberhardt, L.E.; Kennedy, W.E. Jr.; Peloquin, R.A.; Simmons, M.A.

    1984-05-01

    Licensing and regulation of commercial low-level waste (CLLW) burial facilities require that anticipated risks associated with burial sites be evaluated for the life of the facility. This work reviewed the existing capability to evaluate dose to man resulting from the potential redistribution of buried radionuclides by plants and animals that we have termed biotic transport. Through biotic transport, radionuclides can be moved to locations where they can enter exposure pathways to man. We found that predictive models currently in use did not address the long-term risks resulting from the cumulative transport of radionuclides. Although reports in the literature confirm that biotic transport phenomena are common, assessments routinely ignore the associated risks or dismiss them as insignificant without quantitative evaluation. To determine the potential impacts of biotic transport, we made order-of-magnitude estimates of the dose to man for biotic transport processes at reference arid and humid CLLW disposal sites. Estimated doses to site residents after assumed loss of institutional control were comparable to dose estimates for the intruder-agricultural scenario defined in the DEIS for 10 CFR 61 (NRC). The reported lack of potential importance of biotic transport at low-level waste sites in earlier assessment studies is not confirmed by order of magnitude estimates presented in this study. 17 references, 10 figures, 8 tables

  5. Corrosion mechanisms and behaviour of actinides in the 'R7T7' nuclear glass

    International Nuclear Information System (INIS)

    Fillet, Sylvie

    1987-01-01

    This research thesis reports the study of aqueous corrosion of the R7T7 nuclear glass and of the identified corrosion mechanisms in conditions of static lixiviation which are close to that expected during long term storage in a geological environment. More specifically, this work aims at assessing the durability of this glass which has been selected for the vitrification of solutions from pressurized water reactors. The main glass alteration phenomena have been studied. The first part addresses the study of the alteration of the glassy matrix, and aims at identifying corrosion mechanisms in various lixiviation conditions (high temperature, saturation). The second part addresses the action of different materials present in the environment on the glassy matrix by simulating as well as possible a storage case. Based on the obtained results, a mathematical model is developed to predict the glass behaviour on the long term. Finally, the glass confinement power with respect to actinides is studied [fr

  6. Nuclear waste glass product consistency test (PCT), Version 5.0

    International Nuclear Information System (INIS)

    Jantzen, C.M.; Bibler, N.E.; Beam, D.C.; Ramsey, W.G.; Waters, B.J.

    1992-06-01

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Preliminary Specifications (WAPS), the durability of the glass needs to be measured during production to assure its long term stability and radionuclide release properties. A durability test, designated the Produce Consistency Test (PCT), was developed for DWPF glass in order to meet the WAPS requirements. The response of the PCT procedure was based on extensive testing with glasses of widely different compositions. The PCT was determined to be very reproducible, to yield reliable results rapidly, and to be easily performed in shielded cell facilities with radioactive samples. Version 5.0 of the PCT procedure is attached

  7. Alternative long term strategies for sustainable development: Rapidly increasing electricity consumption in Asian countries and future role of nuclear energy

    International Nuclear Information System (INIS)

    Sagawa, N.

    1997-01-01

    Many people in the world express the concern that global warming will become an increasingly serious problem. A rapid increase in population and demand for energy in the Asian region must be discussed in this context. Despite the forecast of an increase in demand for energy, the Asian region is short of oil and natural gas resources. In addition, only less energy can be supplied by renewable energy sources in the Asian region than in the other regions because of high population density. Nuclear energy is an important energy resource for fulfilling the future increasing energy demand in the Asian region and for contributing to the suppression of carbon dioxide emissions. In the Asian region alone, however, we cannot rely limitlessly on LWR which does not use plutonium. According to a scenario analysis, the total capacity of nuclear power plants in the Asian region would reach large scale and the cumulative amount of demand for natural uranium will increase to about 5 million tons in the Asian region alone. Just the nuclear power plants of this scale in Asia alone will rapidly consume the world's cheap natural uranium resources if we rely only on natural uranium. In the Asian region, few countries have embarked on nuclear power generation and the capacity of equipment is still small. Currently, however, many plans for nuclear power generation are being designed. Many Asian countries obviously consider nuclear power generation as a valid option. Many potential policies must be examined in the light of future uncertainty. In the future, both renewable energy and nuclear energy must be resorted to. When nuclear energy is utilized, the use of plutonium and FBR in the Asian region must be taken into account in order to attain continual growth and development. (author)

  8. Key Performance Criteria Affecting the Most the Safety of a Nuclear Waste Long Term Storage : A Case Study Commissioned by CEA

    International Nuclear Information System (INIS)

    Marvy, A.; Lioure, A; Heriard-Dubreuil, G.; Gadbois, S.; Schneider, T.; Schieber, C.

    2003-01-01

    As part of the work scope set in the French law on high level long lived waste R and D passed in 1991, CEA is conducting a research program to establish the scientific basis and assess the feasibility of long term storage as an option for the safe management of nuclear waste for periods as long as centuries. This goal is a significant departure from the current industrial practice where storage facilities are usually built to last only a few decades. From a technical viewpoint such an extension in time seems feasible provided care and maintenance is exercised. Considering such long periods of time, the risk for Society of loosing oversight and control of such a facility is real, which triggers the question of whether and how long term storage safety can be actually achieved. Therefore CEA commissioned a study (1) in which MUTADIS Consultants (2) and CEPN (3) were both involved. The case study looks into several past and actual human enterprises conducted over significant periods o f time, one of them dating back to the end of the 18th century, and all identified out of the nuclear field. Then-prevailing societal behavior and organizational structures are screened out to show how they were or are still able to cope with similar oversight and control goals. As a result, the study group formulated a set of performance criteria relating to issues like responsibility, securing funds, legal and legislative implications, economic sustainable development, all being areas which are not traditionally considered as far as technical studies are concerned. These criteria can be most useful from the design stage onward, first in an attempt to define the facility construction and operating guiding principles, and thereafter to substantiate the safety case for long term storage and get geared to the public dialogue on that undertaking should it become a reality

  9. Key Performance Criteria Affecting the Most the Safety of a Nuclear Waste Long Term Storage : A Case Study Commissioned by CEA

    Energy Technology Data Exchange (ETDEWEB)

    Marvy, A.; Lioure, A; Heriard-Dubreuil, G.; Gadbois, S.; Schneider, T.; Schieber, C.

    2003-02-24

    As part of the work scope set in the French law on high level long lived waste R&D passed in 1991, CEA is conducting a research program to establish the scientific basis and assess the feasibility of long term storage as an option for the safe management of nuclear waste for periods as long as centuries. This goal is a significant departure from the current industrial practice where storage facilities are usually built to last only a few decades. From a technical viewpoint such an extension in time seems feasible provided care and maintenance is exercised. Considering such long periods of time, the risk for Society of loosing oversight and control of such a facility is real, which triggers the question of whether and how long term storage safety can be actually achieved. Therefore CEA commissioned a study (1) in which MUTADIS Consultants (2) and CEPN (3) were both involved. The case study looks into several past and actual human enterprises conducted over significant periods o f time, one of them dating back to the end of the 18th century, and all identified out of the nuclear field. Then-prevailing societal behavior and organizational structures are screened out to show how they were or are still able to cope with similar oversight and control goals. As a result, the study group formulated a set of performance criteria relating to issues like responsibility, securing funds, legal and legislative implications, economic sustainable development, all being areas which are not traditionally considered as far as technical studies are concerned. These criteria can be most useful from the design stage onward, first in an attempt to define the facility construction and operating guiding principles, and thereafter to substantiate the safety case for long term storage and get geared to the public dialogue on that undertaking should it become a reality.

  10. Aiming at super long term application of nuclear energy. Scope and subjects on the water cooled breeder reactor, the 'reduced moderation water reactor'

    International Nuclear Information System (INIS)

    Sato, Osamu; Tatematsu, Kenji; Tanaka, Yoji

    2001-01-01

    In order to make possible on nuclear energy application for super long term, development of sodium cooling type fast breeder reactor (FBR) has been carried out before today. However, as it was found that its commercialization was technically and economically difficult beyond expectation, a number of nations withdrew from its development. And, as Japan has continued its development, scope of its actual application is not found yet. Now, a research and development on a water cooling type breeder reactor, the reduced moderation water reactor (RMWR)' using LWR technology has now been progressed under a center of JAERI. This RMWR is a reactor intending a jumping upgrade of conversion ratio by densely arranging fuel bars to shift neutron spectrum to faster region. The RMWR has a potential realizable on full-dress plutonium application at earlier timing through its high conversion ratio, high combustion degree, plutonium multi-recycling, and so on. And, it has also feasibility to solve uranium resource problem by realization of conversion ratio with more than 1.0, to contribute to super long term application of nuclear energy. Here was investigated on an effect of reactor core on RMWR, especially of its conversion ratio and plutonium loading on introduction effect as well as on how RMWR could be contributed to reduction of uranium resource consumption, by drawing some scenario on development of power generation reactor and fuel cycle in Japan under scope of super long term with more than 100 years in future. And, trial calculation on power generation cost of the RMWR was carried out to investigate some subjects at a viewpoint of upgrading on economy. (G.K.)

  11. A look at new key performance criteria that could most affect the safety of long term storage of nuclear waste. A case study commissioned by CEA

    International Nuclear Information System (INIS)

    Marvy, A.; Lioure, A.; Heriard-Dubreuil, G.; Gadbois, S.; Schneider, T.; Schieber, C

    2002-01-01

    As part of the work scope set in the French law on high level long lived waste R and D passed in 1991, CEA is conducting research work to establish the scientific basis and assess the feasibility of long term storage as an option for the safe management of nuclear waste for periods as long as a few centuries. This goal is a significant departure from current industrial practice where storage facilities are usually built to last only a few decades. From a technical viewpoint such an extension in time seems feasible provided care and maintenance is exercised. Considering such long periods of time risk for Society of loosing oversight and control of such a facility is real which triggers the question of whether and how long term storage safety can be actually achieved. Therefore CEA commissioned a study in which MUTADIS Consultants and CEPN were both involved. The case study looks into several past and actual human enterprises conducted over significant periods of time - one dating back to the end of the 18th century - and identified off the nuclear field. Then-prevailing societal behaviour and organizational structures are screened out to show how they were and are still able to cope with similar oversight and control goals. As a result the study group obtained a set of performance criteria relating to issues like responsibility, securing funds, legal and legislative implications, economic sustainable development, all being areas which are not traditionally considered when technical studies are conducted. These criteria can be most useful from the design stage onward, first in an attempt to define the facility construction and operating guiding principles, and thereafter to substantiate the safety case for long term storage and get geared to the public dialogue on that undertaking should it become a reality. (author)

  12. Organic tritium in freshwater ecosystems: long-term trends in the environment of French nuclear power plants

    International Nuclear Information System (INIS)

    Gontier, G.; Siclet, F.

    2011-01-01

    From 1977 to 2009, more than 600 measurements of organic tritium were performed on fish, aquatic plants and sediments upstream and downstream of the 15 French NPP located along rivers. Examination of the results shows that organic tritium activities have exponentially decreased over the last thirty years, in all components of aquatic ecosystems. Upstream of all NPP, OBT levels in sediments are higher than in plants and fish, themselves larger than HTO in surface water. The magnitude of these differences and the long-term trends depend on the river basin and can be explained by the varying nature of tritium sources. In river catchment, where atmospheric test fallout is the main source of tritium, the observed levels result from the exposure of aquatic organisms to two distinct tritium pools of different ages: atmospheric tritiated water (representing present fallout), and organic tritium from soils (formed over several decades) which supplies particulate matter to surface waters. In the Rhone and Rhine river basins, an additional source of organic tritium of very low bio-availability, probably originating from the luminescent paint industry, is responsible for the spiking of sediment organic matter up to 100 to 100 000 Bq.L -1 combustion water. The comparison of upstream and downstream NPP tritium levels shows that the influence of tritium discharges is detectable only in rivers, with low background OBT activities, i.e in basins other than the Rhone and Rhine. The observed increase in plant and fish OBT is lower than the added HTO activity in water due to discharge, which supports the absence of bioaccumulation for tritium originating from HTO and the absence of highly bio-available tritiated organic molecules in NPP discharges. (authors)

  13. Heterogeneities in nuclear waste glass

    International Nuclear Information System (INIS)

    Ladirat, Ch.

    1997-01-01

    The industrial vitrification of high level radioactive wastes is a 2 stage process. During the first stage, the concentrated solution is heated in a spinning resistance oven at the temperature of 400 Celsius degrees till evaporation and calcination. The second stage begins when the dry residue falls into a melting pot that is maintained at a temperature of 1100-1150 Celsius degrees. Glass fretting is added and the glass is elaborated through the fusion of the different elements present in the melting pot. Heterogeneities in the glass may be associated to: - the presence in the solution to vitrify of insoluble elements from the dissolution of the fuel (RuO 2 , Rh, Pd), - the presence of minuscule metal scraps (Zr) that have been produced during the cutting of the fuel element, - the failures to conform to the technical specifications of the vitrification process, for instance, temperatures or flow rates when introducing the different elements in the melting pot. (A.C.)

  14. Use of long-term stable CsPbBr3 perovskite quantum dots in phospho-silicate glass for highly efficient white LEDs.

    Science.gov (United States)

    Di, Xiaoxuan; Hu, Zemin; Jiang, Jutao; He, Meiling; Zhou, Lei; Xiang, Weidong; Liang, Xiaojuan

    2017-10-05

    We report the synthesis of CsPbBr 3 QDs with great stability and high quantum yield in phospho-silicate glass, which was fabricated by using a heat-treatment approach, for white light emitting devices. QD glasses exhibited excellent photo- and thermal stability, and significantly prolonged the lifetime of light emitters under ambient air conditions.

  15. R7T7 glass alteration mechanism in an aqueous closed system: understanding and modelling the long term alteration kinetic; Etude des mecanismes d'alteration par l'eau du verre R7T7 en milieu confine: comprehension et modelisation de la cinetique residuelle

    Energy Technology Data Exchange (ETDEWEB)

    Chave, T

    2007-10-15

    The long term alteration rate of the French R7T7 nuclear glass has been investigated since many years because it will define the overall resistance of the radionuclide containment matrix. Recent studies have shown that the final rate remains constant or is slightly decreasing with time. It never reaches zero. Though this residual rate is very low, only 5 nm per year at 50 C, it would be the dominant alteration phenomenon in a geological repository. Two mechanisms are suggested for explaining such behaviour: diffusion in solution of elements from glass through an amorphous altered layer and precipitation of neo-formed phases. The diffusion processes are in agreement with a solid state diffusion mechanism and can lead to secondary phase precipitation due to solution concentration increases. Observed phases are mainly phyllosilicates and zeolites, in specific conditions. Phyllosilicates are expected to maintain the residual kinetic rate whereas alteration resumption could be observed in presence of zeolites at very high pH or temperature (10.5 at 90 C or temperature above 150 C). Both diffusion and neo-formed phase precipitation have been investigated in order to better understand their impact on the residual alteration rate and have then been modelled by a calculation code, coupling chemistry and transport, in order to be able to better anticipate the long term behaviour of the glass R7T7 in an aqueous closed system. (author)

  16. SKI and SSI's recommendations to the government concerning long-term responsibility after closure of a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Paeivioe Jonsson, Josefin

    2008-01-01

    Many activities will cease at the closure of a repository, but not responsibilities. The candidate municipalities in Sweden expressed concern about who will take over after the implementer is released from responsibility for the facility. The government thus commissioned SKI (Swedish Nuclear Power Inspectorate) and SSI (Swedish Radiation Protection Authority) to review the legal obligations of institutional players as laid out today in legislation in Sweden. After closure of the repository in about 100 years there will be post-closure monitoring, possibly for a few hundred years. This will be a part of the conditions on SKB (Swedish Nuclear Fuel and Waste Management Company) which will be set out at the time. Some activities will end at the closure of the facility but monitoring and safeguards obligations may continue. The exact nature of this monitoring and safeguard work needs to be discussed and agreed upon. With the proposed approach most of the liabilities rest with the state in the long term, the waste producers only have liabilities in the short term but their decisions could have big impacts on long term liabilities

  17. Thermochemical modeling of nuclear waste glass

    International Nuclear Information System (INIS)

    Spear, K.E.; Besmann, T.M.; Beahm, E.C.

    1998-06-01

    The development of assessed and consistent phase equilibria and thermodynamic data for major glass constituents used to incorporate high-level nuclear waste is discussed in this paper. The initial research has included the binary Na 2 O-SiO 2 , Na 2 O-Al 2 O 3 , and SiO 2 -Al 2 O 3 systems. The nuclear waste glass is assumed to be a supercooled liquid containing the constituents in the glass at temperatures of interest for nuclear waste storage. Thermodynamic data for the liquid solutions were derived from mathematical comparisons of phase diagram information and the thermodynamic data available for crystalline solid phases. An associate model is used to describe the liquid solution phases. Utilizing phase diagram information provides very stringent limits on the relative thermodynamic stabilities of all phases which exist in a given system

  18. Analysis on long-term perspective of nuclear energy in the global energy system in terms of CO2 mitigation

    International Nuclear Information System (INIS)

    Sugiyama, T.; Uotani, M.

    2001-01-01

    The value of nuclear energy is analyzed for prevention of global warming and climate change by means of a global energy model, which finds the cost minimum energy system over the time range of 2000 - 2100. Six scenarios are examined in this analysis, considering two scenarios of economic growth rate, two scenarios of electrification rate, and FBR introduction or not. The results indicate that progress of electricity generation is the key to reduce the global CO 2 emission, and the role of FBRs with its nuclear fuel cycle is very robust against any economic conditions. (author)

  19. An Improved Methodology of Monetary Values of the Unit Collective Dose for Intervention Against Long-Term Exposure Following a Nuclear Accident

    International Nuclear Information System (INIS)

    Hwang, Won Tae; Kim, Eun Han; Suh, Kyung Suk; Choi, Young Gil; Han, Moon Hee

    2002-01-01

    A more practice approach for the determination of monetary values of the unit collective dose for intervention against long-term exposure following a nuclear accident was proposed. In addition, the monetary values of the unit collective dose estimated from the proposed approach were compared with those estimated from the previous model, which are derived from assumptions of routine exposure and the same values are applied in a nuclear accident without modification, using Korea economic data. The monetary values based on the proposed approach showed a distinct difference depending on inequity in the distribution of individual doses. The discounting rate was also an important factor in determination of monetary values of the unit collective dose

  20. An Improved Methodology of Monetary Values of the Unit Collective Dose for Intervention Against Long-Term Exposure Following a Nuclear Accident

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Won Tae; Kim, Eun Han; Suh, Kyung Suk; Choi, Young Gil; Han, Moon Hee [KAERI, Daejeon (Korea, Republic of)

    2002-06-15

    A more practice approach for the determination of monetary values of the unit collective dose for intervention against long-term exposure following a nuclear accident was proposed. In addition, the monetary values of the unit collective dose estimated from the proposed approach were compared with those estimated from the previous model, which are derived from assumptions of routine exposure and the same values are applied in a nuclear accident without modification, using Korea economic data. The monetary values based on the proposed approach showed a distinct difference depending on inequity in the distribution of individual doses. The discounting rate was also an important factor in determination of monetary values of the unit collective dose.

  1. Composition - structure - properties relationships of peraluminous glasses for nuclear waste containment

    International Nuclear Information System (INIS)

    Piovesan, Victor

    2016-01-01

    Part of the Research and Development program concerning high level nuclear waste conditioning aims to assess new glass formulations able to incorporate a high waste content with enhanced properties in terms of homogeneity, thermal stability, long term behavior and process ability. This study focuses on peraluminous glasses, defined by an excess of aluminum ions Al"3"+ in comparison with modifier elements such as Na"+, Li"+ or Ca"2"+. A Design of Experiment approach has been employed to determine relationships between composition of simplified peraluminous glasses (SiO_2 - B_2O_3 - Al_2O_3 - Na_2O - Li_2O - CaO - La_2O_3) and their physical properties such as viscosity, glass transition temperature and glass homogeneity. Moreover, some structural investigation (NMR) was performed in order to better understand the structural role of Na"+, Li"+ and Ca"2"+ and the structural organization of peraluminous glasses. Then, physical and chemical properties of fully simulated peraluminous glasses were characterized to evaluate transposition between simplified and fully simulated glasses and also to put forward the potential of peraluminous glasses for nuclear waste containment. (author) [fr

  2. Experimental verification of the reversibility window concept in binary As-Se glasses subjected to a long-term physical aging

    International Nuclear Information System (INIS)

    Golovchak, R.; Jain, H.; Shpotyuk, O.; Kozdras, A.; Saiter, A.; Saiter, J.-M.

    2008-01-01

    Physical aging effects caused by prolonged natural storage (∼22 years) in binary As x Se 100-x glasses are probed by temperature-modulated differential scanning calorimetry. It is shown that all aged samples with x 2 Se 3 glass; lack of aging within the so-called reversibility window, 28< x<38, is not found. High-resolution x-ray photoelectron spectroscopy fails to show any evidence of fourfold-coordinated As atoms, which is consistent with the aging ability of glasses with x<40

  3. Acceptance of nuclear power in Germany: A long-term perspective; Die Akzeptanz der Kernenergie in Deutschland in laengerfristiger Perspektive

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, R.

    2006-10-15

    20 years ago, in July 1986, a few months after the Chernobyl accident, the renowned nuclear physicist Heinz Maier-Leibnitz published his book 'Lernschock Tschernobyl', in which he attempted a rational assessment of the risk involved in the utilisation of nuclear energy. He conceded that decisions made by government and industry are never purely rational and thus cannot be justified purely on rational grounds. In a democracy, the will and emotions of the people must be taken into account as well. In the case of atomic power, Heinz Maier-Leibniz viewed these emotions as 'fear of unknown, invisible radiation and fear of serious if rare accidents'. (orig.)

  4. Guidelines for DOE Long Term Civilian Research and Development. Volume III. Basic Energy Sciences, High Energy and Nuclear Physics

    International Nuclear Information System (INIS)

    1985-12-01

    The Research Panel prepared two reports. This report reviews the Department of Energy's Basic Energy Sciences, High Energy Physics, and Nuclear Physics programs. The second report examines the Environment, Health and Safety programs in the Department. This summary addresses the general value and priority of basic research programs for the Department of Energy and the nation. In addition, it describes the key strategic issues and major recommendations for each program area

  5. The long term plan for the integration of nuclear power plants into the Turkish Electrical Power System

    International Nuclear Information System (INIS)

    Kutukcuoglu, A.

    1974-03-01

    The report covers in detail the study of the expansion of the Turkish Electric Power System for the period 1980-1987. Load forecast is done by sectors and regions and inter-regions power balances gave the basis for the high voltage network configurations. Expansion alternatives are defined giving priority to hydroelectric projects, to local resources and nuclear power plants concurrently with conventional plants (lignite and oil). Several reactor strategies are analysed with LWR, HWR, FBR and HTGR power plants. Present worth value method is used for comparison of alternatives and sensitivity analysis is done for those ranked in the first places. Load flow, transient stability and frequency deviation studies of the power system are studied carefully by means of A.C. calculator and digital computer codes in order to see the influence of the introduction of large-sized power plants (600-750MW(e)) and their location in the power system. A 600MW(e) nuclear plant in 1983 and a second one of 750MW(e) in 1987 should, it is found, be commissioned into the system. The economic optimization was done with two computer programmes developed by KFA (Juelich): IACO for fuelling nuclear plant and RESTRAPO for power system with high hydroelectric component. The report is bound in three volumes: Volume I: Summary and Conclusions; Volume II: System Planning; Volume III: Electrical Survey

  6. 3. International Conference on Nuclear Power Plant Life Management (PLiM) for Long Term Operations (LTO). Keynotes, papers, presentations, posters

    International Nuclear Information System (INIS)

    2012-01-01

    The world's fleet of nuclear power plants is, on average, more than 20 years old. Even though the design life of a nuclear power plant is typically 30-40 years, many plants will operate in excess of their design lives, provided that nuclear power plant engineers demonstrate by analysis, equipment and system upgrades, increased vigilance, testing and ageing management that the plant will operate safely. In the operation of nuclear power plants, safety should always be the prime consideration. Plant operators and regulators must always ensure that plant safety is maintained and, where possible, enhanced during its operating lifetime. Nuclear power plant life management (PLiM) has gained increased attention over the past decade, and effective ageing management of systems, structures and components (SSCs) is a key element in PLiM for the safe and reliable long term operation of nuclear power plants. A PLiM programme is an effective tool that allows an operator to safely and cost effectively manage ageing effects in SSCs for long term operation (LTO). A PLiM programme helps facilitate decisions concerning when and how to repair, replace or modify SSCs in an economically optimized way, while assuring that a high level of safety is maintained. The option for extended nuclear power plant operation has been recognized by operators and regulators alike, as evidenced in the number of licence renewal programmes that are being developed by Member States. After the severe accident at the Fukushima Daiichi nuclear power plant, the safe operation of nuclear power plants has become even more important; not only in terms of technical or ageing issues, but also in terms of management system and qualified workforce related issues. Application of an integrated management system and structured workforce planning are needed throughout the plant life in order to ensure effective plant organization and management. The IAEA organized the first and second International Conference on Nuclear

  7. Numerical modelling of the long term mechanical behaviour of a storage cell for high level nuclear wastes

    International Nuclear Information System (INIS)

    Bian, H.B.; Jia, Y.; Duveau, G.; Shao, J.F.; Poutrel, A.

    2010-01-01

    the various important processes in the storage structures, the coupling between the corrosion/strain processes and the Callovo-Oxfordian clay formation is death with in this study. The principal objective is to establish a numerical method capable to reproduce correctly the evolutionary interface between the metallic container and clay formation taking into account the decrease of mechanical resistance and the generated supplementary volume. Special attention is paid on the evolution of the interface of steel and rock, the amplitude of possible overpressure and stress and the evolution of the EDZ (Excavation Damaged Zone). In the numerical analyses, different materials are taken into account: limestone, argillite, steel and air. Firstly, a brief presentation of the constitutive models for the Callovo-Oxfordian clay is given. For the sake of simplicity, a poro-elastic model is used for limestone and an elasto-plasticity model using a Mises type criterion is applied to the steel. Then a series of parametric studies is performed in order to study the mechanical resistance of corroded steel.. Finally, a storage cell of High-Level Wastes is simulated. In the numerical model, the wastes cell is taken as a circular borehole. The loading path is composed of the following three steps: the excavation phase, the waiting phase for the installation of waste package, and the evolution phase after the backfilling of the storage cell. The proposed model is able to describe the main features of poro-mechanical behaviour for the clay formation: such as plastic deformation, material damage by microcracks, transition of volumetric compressibility/dilatancy and the viscoplastic strain. In spite of the simplifications used, the numerical results allow us to obtain some quantitative results describing the mechanical behaviour and the coupled thermo-hydro-mechanical processes for a short and long-term in the storage cell. (authors)

  8. An assessment of the potentials of nuclear power and carbon capture and storage in the long-term global warming mitigation options based on Asian Modeling Exercise scenarios

    International Nuclear Information System (INIS)

    Mori, Shunsuke

    2012-01-01

    This paper presents an evaluation of global warming mitigation options based on scenarios from the Asian Modeling Exercise. Using an extended version of the integrated assessment model MARIA-23 (Multiregional Approach for Resource and Industry Allocation), we analyze nuclear fuel recycling options, carbon capture and storage technologies (CCS), and biomass utilization. To assess the potential implications of decreased social acceptance of nuclear power in the wake of the Fukushima nuclear accident, additional scenarios including a nuclear power expansion limitation, are analyzed. We also evaluate MARIA-23 model simulation estimates of long-term contributions and interrelationships among nuclear power, biomass, and CCS. Finally, potential costs of nuclear limitation under carbon control policies are assessed. The simulation results in this paper suggest the following: (1) under the reference scenario, global GDP losses in climate limitation scenarios range from 1.3% per year to 3.9% per year in 2060, rising to between 3.5% per year and 4.5% per year in 2100; (2) the use of nuclear fuel reprocessing technologies increase rapidly in all carbon control policy scenarios; (3) under a scenario where the price of CO 2 is $30 and nuclear power expansion is strictly limited, GDP losses increase significantly—from 4.5% per year to 6.4% per year by 2100; (4) nuclear power and CCS are substitute mitigation technologies. With nuclear power technology available CCS deployment reaches approximately 15,000 Mt-CO 2 per year by 2010; without a nuclear power option, CCS deployment rises to more than 80,000 Mt-CO 2 per year; and (5) biomass utilization cannot fully compensate for limitations to nuclear power expansion in policy scenarios. In addition to examining the role of these three technologies on global scales, we report results for several major Asian regions, namely Japan, China, and India. China tends to deploy nuclear power (if available) in response to rapidly growing

  9. Study on behaviour in long term of vitrified materials

    International Nuclear Information System (INIS)

    Vernaz, E.

    1993-01-01

    In collaboration with EDF (Electricite de France), after testing fusion of Refiom (Residus d'Epuration des Fumees d'Incineration d'Ordures Menageres), residues from purification of incineration smokes of household rubbish, realised at Porcheville and at the Laboratory of Renardieres with experimental processing of vitrification by plasma, CEA (Centre d'Etudes Atomiques), atomic center of research, began study on resistance in long term of vitrified products. From about thirty five years, CEA carries out research to confine radioactive waste of high activity in stable materials. Glass was the first best one which allowed to incorporate about thirty different chemical elements found in fission products solutions into a stable die with a good chemical durability; three vitrification shops raised, one at Marcoule ('AVM', 1978) in the south of France, the two other ones at La Hague ('R7', 1989 and 'T7', 1992) in Normandy. To determine a possible impact of a deep radioactive waste disposal on human and environment, several studies began. In particular, studies on aqueous corrosion of glasses to determine behaviour in long term of glass package (first barrier of confinement) and to estimate kinetics of releasing confined toxical elements on periods of several thousands years. Principal results are exposed in this conference. Experience shows that safety analysis cannot be based on long term extrapolation of a simple lixiviation result. This analysis must include: a sufficient knowledge in basic mechanisms of alteration to predict the kinetic evolution in a long term. To take in account environment conditions with a normal or accidental scheme (acidity, clay, organic compounds,...). This knowledge broadly developed by CEA for nuclear glasses seems to be easily transposable to different wastes (industrial ones or from hospitals) and takes place in a contract of research CEA/EDF to valorize vitrified products. 9 figs. 4 refs

  10. An assessment of the long-term impact of chemically toxic contaminants from the disposal of nuclear fuel waste

    International Nuclear Information System (INIS)

    Goodwin, B.W.; Garisto, N.C.; Barnard, J.W.

    1987-01-01

    This paper presents a study on the potential for impact on man of chemically toxic contaminants associated with the Canadian concept for the disposal of nuclear fuel waste. The elements of concern are determined through a series of screening criteria such as elemental abundances and solubilities. A systems variability analysis approach is then used to predict the possible concentrations of these elements that may arise in the biosphere. These concentrations are compared with environmental guidelines such as permissible levels in drinking water. Conclusions are made regarding the potential for the chemically toxic contaminants to have an impact on man. 54 refs

  11. Short term and long term radiation protection aspects of a nuclear accident: a Cd-Rom for a better stake holders' involvement

    International Nuclear Information System (INIS)

    Oudiz, A.; Badie, M.; Brenot, J.

    2002-01-01

    Many players are involved in managing a nuclear accident apart from radiation protection and nuclear safety experts. In an emergency response situation, the decision making process involves many non-technical players who nonetheless have a major role to play: in France these may include the Prefet, the emergency and civil defence services, the health services, the police, the gendarmerie and local councillors, with advice from the safety and radiological protection authorities and expert evaluation organisations. Within the post-accident response, other players will be involved alongside those already described: professional bodies, particularly farming organisations, residents' associations, those responsible for environmental decontamination, agencies responsible for compensating victims, etc., etc. In both the short and the long-term phases of the crisis management process, it is essential to enable participants who may have very different backgrounds and professional experience to work together with co-operation and mutual understanding. If non-technical players are to contribute effectively, there needs to be a minimum level of mutual understanding between them and the technical players on what the nuclear risk really is and what is the rationale of the short and long term counter-measures aimed at protecting the public and restoring the contaminated environment. Local communities also need to share this basic understanding because their cooperation is required in order to implement the counter-measures properly. Conversely, if the experts are to advise the local authorities properly, they need to understand the criteria on which these local authorities and communities base their decisions: what psycho-sociological factors apply, what logistical support is needed, what are the concerns of the local communities?

  12. Long-Term Collections

    CERN Multimedia

    Comité des collectes à long terme

    2011-01-01

    It is the time of the year when our fireman colleagues go around the laboratory for their traditional calendars sale. A part of the money of the sales will be donated in favour of the long-term collections. We hope that you will welcome them warmly.

  13. Bentonite deposits as a natural analogue to long-term barriers in a final repository of nuclear waste

    International Nuclear Information System (INIS)

    Keto, P.

    2000-01-01

    The geology of bentonite occurrences in Almeria (Spain) and Wyoming (USA) were studied in order to find suitable natural analogue to the longterm mechanical behaviour of the bentonite barrier in the final nuclear waste disposal. The study is based on literature review over both occurrence areas and on fieldwork observations from Almeria, Spain. The deposit areas differ from each other by age, deposition environment, exchangeable cation chemistry, alteration condition, occurrence and deformational features. One of the most important deformational feature in Almeria bentonites was the existence of Tertiary (Middle and Upper Miocene, 6-15.5 Ma old) bentonite intrusion inside/over younger Quaternary (Pleistocene Superior, 0.01-0.72 Ma old) sediments. This was a result of the confining pressure of overlying volcanic rocks and sediments and the high plasticity behaviour of bentonites. According to this observation, the pressure effect in final nuclear waste repositories requires further investigations. The bentonites in Wyoming have survived weathering and shearing without losing their expandability or other properties typical of smectite-rich materials. (orig.)

  14. The coupling of coal and nuclear energy for the long-term supply of energy and raw materials

    International Nuclear Information System (INIS)

    Knizia, K.

    1986-10-01

    In view of the limited world reserves of fossil fuels and the increase in demand to be expected because of the continued growth of the world population, coal and nuclear energy will have to make an increasing contribution to the energy supply. Their contribution will range from electricity generation to the heat sector and to the raw materials market via various gases obtained from them. The further development towards this field of tasks will lead first via the gasification of coal. It will be carried out autothermally in the first stage of development. The gas produced is suitable for realising considerable improvements in efficiency as compared to coal-fired power stations of present-day design since it will permit the generation of electricity via combined gas turbine/steam turbine processes. Efforts are being made to take further the processes based on this technology by introducing a sodium circuit in addition to the coal gasification, which will make it possible to keep the plants required for coal gasification small. In later stages, this technology will also be suitable for producing a considerable improvement in the diversion of heat at high temperatures from high-temperature reactor nuclear power stations for several purposes. (author)

  15. Atmospheric Direct Uptake and Long-term Fate of Radiocesium in Trees after the Fukushima Nuclear Accident

    Science.gov (United States)

    Mahara, Yasunori; Ohta, Tomoko; Ogawa, Hideki; Kumata, Atsushi

    2014-11-01

    Large areas of forests were radioactively contaminated by the Fukushima nuclear accident of 2011, and forest decontamination is now an important problem in Japan. However, whether trees absorb radioactive fallout from soil via the roots or directly from the atmosphere through the bark and leaves is unclear. We measured the uptake of radiocesium by trees in forests heavily contaminated by the Fukushima nuclear accident. The radiocesium concentrations in sapwood of two tree species, the deciduous broadleaved konara (Quercus serrata) and the evergreen coniferous sugi (Cryptomeria japonica), were higher than that in heartwood. The concentration profiles showed anomalous directionality in konara and non-directionality in sugi, indicating that most radiocesium in the tree rings was directly absorbed from the atmosphere via bark and leaves rather than via roots. Numerical modelling shows that the maximum 137Cs concentration in the xylem of konara will be achieved 28 years after the accident. Conversely, the values for sugi will monotonously decrease because of the small transfer factor in this species. Overall, xylem 137Cs concentrations will not be affected by root uptake if active root systems occur 10 cm below the soil.

  16. Long-term evacuation after the nuclear accident in Fukushima. Different daily living under low-dose radioactive suffering

    International Nuclear Information System (INIS)

    Ishikawa, Kazunobu

    2013-01-01

    One year has passed since the Great East Japan Earthquake and the Fukushima No. 1 nuclear power plant accident. Even currently, more than 150,000 evacuees in Fukushima Prefecture are forced to leave their home and to move throughout Japan. Because of the limited space of temporary housing and the weakening of personal ties in local communities, many families need to move and have separate lives. As a consequence, Fukushima has a serious shortage of caregivers for the elderly. There have been more than 1,300 disaster-related deaths due to shock and stress after long-distance drifts from town to town. Most of the victims were the elderly, who collapsed, caught pneumonia, suffered stroke and heart attack. Concerns about the safety of low-dose radiation exposure deprived the elderly of important contact with playing outside with their grandchildren in Fukushima. Fear of invisible radioactive contamination inactivated outdoor activities such as farming, dairy, fishing, gardening, hiking and wild-vegetable/mushroom hunting, although most of these activities have been traditionally supported by the wisdom of the elderly. Several recent questionnaire investigations revealed that older evacuees wish to go home even if the environment has significant contamination. In contrast, more than half of younger generation with small children have a different attitude. Nuclear accident brought serious social pains although it did not acutely hurt our bodies. (author)

  17. Long-Term Waste Package Degradation Studies at the Yucca Mountain Potential High-Level Nuclear Waste Repository

    International Nuclear Information System (INIS)

    Mon, K. G.; Bullard, B. E.; Longsine, D. E.; Mehta, S.; Lee, J. H.; Monib, A. M.

    2002-01-01

    The Site Recommendation (SR) process for the potential repository for spent nuclear fuel (SNF) and high-level nuclear waste (HLW) at Yucca Mountain, Nevada is underway. Fulfillment of the requirements for substantially complete containment of the radioactive waste emplaced in the potential repository and subsequent slow release of radionuclides from the Engineered Barrier System (EBS) into the geosphere will rely on a robust waste container design, among other EBS components. Part of the SR process involves sensitivity studies aimed at elucidating which model parameters contribute most to the drip shield and waste package degradation characteristics. The model parameters identified included (a) general corrosion rate model parameters (temperature-dependence and uncertainty treatment), and (b) stress corrosion cracking (SCC) model parameters (uncertainty treatment of stress and stress intensity factor profiles in the Alloy 22 waste package outer barrier closure weld regions, the SCC initiation stress threshold, and the fraction of manufacturing flaws oriented favorably for through-wall penetration by SCC). These model parameters were reevaluated and new distributions were generated. Also, early waste package failures due to improper heat treatment were added to the waste package degradation model. The results of these investigations indicate that the waste package failure profiles are governed by the manufacturing flaw orientation model parameters and models used

  18. Cholangiocarcinomas associated with long-term inflammation express the activation-induced cytidine deaminase and germinal center-associated nuclear protein involved in immunoglobulin V-region diversification.

    Science.gov (United States)

    Chan-On, Waraporn; Kuwahara, Kazuhiko; Kobayashi, Naoya; Ohta, Kazutaka; Shimasaki, Tatsuya; Sripa, Banchob; Leelayuwat, Chanvit; Sakaguchi, Nobuo

    2009-08-01

    Cholangiocarcinoma (CCA) represents a model of tumor development after long-term inflammation which causes DNA damage or impairs DNA repair mechanism. AID and GANP, both appearing in antigen-driven B cells, are involved in affinity maturation of the immunoglobulin V-region with increased somatic mutation. A normal cholangiocyte line showed the induction of AID transcripts after stimulation with TNF-alpha, whereas ganp transcripts appeared constitutively in this cell line. Next, we examined the expression of AID and GANP in clinical CCA specimens to obtain information whether their expression levels are associated with the malignant grade of CCA. AID expression was similarly detected in the clinical cases of both well-differentiated and poorly-differentiated CCAs. On the contrary, GANP expression was detected in CCA cells at a higher level in the nucleus of poorly-differentiated CCAs with shorter survivals than in that of well-differentiated CCAs. The high and low cases of nuclear GANP expression showed no change in the frequency of the TP53 mutations, however, further investigation by in vitro experiment demonstrated that the high GANP expression caused the increased number of gammaH2AX foci after DNA damage by ionizing-irradiation. These results suggest that GANP is involved in regulation of DNA repair mechanism and the abnormal over-expression of GANP together with AID might be associated with rigorous DNA damage, potentially causing the malignant development of CCAs during long-term inflammation.

  19. Long-term assessment of airborne radiocesium after the Fukushima nuclear accident. Re-suspension from bare soil and forest ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Kajino, Mizuo [Japan Meteorological Agency (JMA), Ibaraki (Japan). Meteorological Research Inst. (MRI); RIKEN Advanced Institute for Computational Science (AICS), Hyogo (Japan); Ishizuka, Masahide [Kagawa Univ. (Japan). Faculty of Engineering; Igarashi, Yasuhito [Japan Meteorological Agency (JMA), Ibaraki (Japan). Meteorological Research Inst. (MRI); Kita, Kazuyuki [Ibaraki Univ. (Japan). Faculty of Science; Yoshikawa, Chisato [Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Kanagawa (Japan); Inatsu, Masaru [Hokkaido Univ., Sapporo (Japan). Faculty of Science

    2016-07-01

    The long-term effect of {sup 137}Cs re-suspension from contaminated soil and forests due to the Fukushima nuclear accident has been quantitatively assessed by numerical simulation, a field experiment on dust emission flux in a contaminated area (town of Namie, Fukushima prefecture), and air concentration measurements inside (Namie) and outside (city of Tsukuba, Ibaraki prefecture) the contaminated area. In order to assess the long-term effect, the full year of 2013 was selected to study just after the start of the field experiments. The {sup 137}Cs concentrations at Namie and Tsukuba were approximately 10{sup -1}-1 and 10{sup -2}-10{sup -1} mBq m{sup -3}, respectively. The observed monthly median concentration at Namie was 1 to 2 orders of magnitude larger than that at Tsukuba. This observed difference between the two sites was consistent with the simulated difference, indicating successful modeling of {sup 137}Cs re-suspension and atmospheric transport. The estimated re-suspension rate was approximately 10{sup -6} day{sup -1}, which was significantly lower than the decreasing rate of the ambient gamma dose rate in Fukushima prefecture (10{sup -4}-10{sup -3} day{sup -1}) as a result of radioactive decay, migration in the soil and biota, and decontamination. Consequently, re-suspension contributed negligibly in reducing ground radioactivity. The dust emission model could reproduce the air concentration of {sup 137}Cs in winter, whereas the summer air concentration was underestimated by 1 to 2 orders of magnitude. Re-suspension from forests at a constant rate of 10{sup -7} h{sup -1}, multiplied by the green area fraction, could explain the air concentration of {sup 137}Cs at Namie and its seasonal variation. The simulated contribution of dust re-suspension to the air concentration was 0.7-0.9 in the cold season and 0.2-0.4 in the warm season at both sites; the remainder of the contribution was re-suspension from forest. The re-suspension mechanisms, especially

  20. Long-term assessment of airborne radiocesium after the Fukushima nuclear accident: re-suspension from bare soil and forest ecosystems

    Science.gov (United States)

    Kajino, Mizuo; Ishizuka, Masahide; Igarashi, Yasuhito; Kita, Kazuyuki; Yoshikawa, Chisato; Inatsu, Masaru

    2016-10-01

    The long-term effect of 137Cs re-suspension from contaminated soil and forests due to the Fukushima nuclear accident has been quantitatively assessed by numerical simulation, a field experiment on dust emission flux in a contaminated area (town of Namie, Fukushima prefecture), and air concentration measurements inside (Namie) and outside (city of Tsukuba, Ibaraki prefecture) the contaminated area. In order to assess the long-term effect, the full year of 2013 was selected to study just after the start of the field experiments. The 137Cs concentrations at Namie and Tsukuba were approximately 10-1-1 and 10-2-10-1 mBq m-3, respectively. The observed monthly median concentration at Namie was 1 to 2 orders of magnitude larger than that at Tsukuba. This observed difference between the two sites was consistent with the simulated difference, indicating successful modeling of 137Cs re-suspension and atmospheric transport. The estimated re-suspension rate was approximately 10-6 day-1, which was significantly lower than the decreasing rate of the ambient gamma dose rate in Fukushima prefecture (10-4-10-3 day-1) as a result of radioactive decay, migration in the soil and biota, and decontamination. Consequently, re-suspension contributed negligibly in reducing ground radioactivity. The dust emission model could reproduce the air concentration of 137Cs in winter, whereas the summer air concentration was underestimated by 1 to 2 orders of magnitude. Re-suspension from forests at a constant rate of 10-7 h-1, multiplied by the green area fraction, could explain the air concentration of 137Cs at Namie and its seasonal variation. The simulated contribution of dust re-suspension to the air concentration was 0.7-0.9 in the cold season and 0.2-0.4 in the warm season at both sites; the remainder of the contribution was re-suspension from forest. The re-suspension mechanisms, especially through the forest ecosystems, remain unknown. This is the first study that provides a crude

  1. Long-term maintenance of reducing conditions in a spent nuclear fuel repository. A re-examination of critical factors

    Energy Technology Data Exchange (ETDEWEB)

    Gascoyne, M. [Gascoyne GeoProjects Inc, Pinawa, MB (Canada)

    1999-04-01

    Penetration of oxidising groundwaters to depths of 500 m in a permeable bedrock, over a glacial/interglacial cycle, may compromise the stability of a spent nuclear fuel repository and cause the release and migration towards the surface of actinides and associated fission products. This report examines the potential for the penetration of oxygen (O{sub 2}) to depths of 500 m in a fractured crystalline rock environment, typical of the Fennoscandian Shield. Previous studies performed for the Swedish program of nuclear waste disposal (principally the SITE-94 safety assessment) have indicated that O{sub 2} might reach repository depths during a deglaciation when melt-water from the base of an ice sheet could enter the bedrock, driven by strong hydraulic gradients. This report re-examines aspects of this scenario and finds that: 1. The capacity of flow-path minerals to scavenge O{sub 2} from recharging groundwater may be lower than expected due to a previously unrecognised depletion of Fe(II)-bearing minerals in the active flow-paths in a fractured crystalline rock. 2. Assumptions in the SITE-94 assessment, such as the use of a continental-scale flow model, the lack of structural controls on groundwater flow, a preferred horizontal permeability, and the use of permeabilities to depths of 10 km that are up to two orders of magnitude greater than comparable environments, are disproportionately simplistic and represent an extremely conservative case. 3. Assumptions of a thin, discontinuous permafrost, a warm-based ice sheet, and high-O{sub 2} content melt-water at the repository site are unrealistic and overly conservative. A more realistic scenario, which includes a greater influence of permafrost, a cold based ice sheet, lower bedrock permeabilities and a more-limited, regional-scale flow path, is recommended as being more appropriate for use in the safety assessment. Under this revised scenario, it is believed that O{sub 2} will not penetrate to repository depths over

  2. Long-term maintenance of reducing conditions in a spent nuclear fuel repository. A re-examination of critical factors

    International Nuclear Information System (INIS)

    Gascoyne, M.

    1999-04-01

    Penetration of oxidising groundwaters to depths of 500 m in a permeable bedrock, over a glacial/interglacial cycle, may compromise the stability of a spent nuclear fuel repository and cause the release and migration towards the surface of actinides and associated fission products. This report examines the potential for the penetration of oxygen (O 2 ) to depths of 500 m in a fractured crystalline rock environment, typical of the Fennoscandian Shield. Previous studies performed for the Swedish program of nuclear waste disposal (principally the SITE-94 safety assessment) have indicated that O 2 might reach repository depths during a deglaciation when melt-water from the base of an ice sheet could enter the bedrock, driven by strong hydraulic gradients. This report re-examines aspects of this scenario and finds that: 1. The capacity of flow-path minerals to scavenge O 2 from recharging groundwater may be lower than expected due to a previously unrecognised depletion of Fe(II)-bearing minerals in the active flow-paths in a fractured crystalline rock. 2. Assumptions in the SITE-94 assessment, such as the use of a continental-scale flow model, the lack of structural controls on groundwater flow, a preferred horizontal permeability, and the use of permeabilities to depths of 10 km that are up to two orders of magnitude greater than comparable environments, are disproportionately simplistic and represent an extremely conservative case. 3. Assumptions of a thin, discontinuous permafrost, a warm-based ice sheet, and high-O 2 content melt-water at the repository site are unrealistic and overly conservative. A more realistic scenario, which includes a greater influence of permafrost, a cold based ice sheet, lower bedrock permeabilities and a more-limited, regional-scale flow path, is recommended as being more appropriate for use in the safety assessment. Under this revised scenario, it is believed that O 2 will not penetrate to repository depths over the next 100,000 years

  3. Effects of long-term exposure of tuffs to high-level nuclear waste-repository conditions. Preliminary report

    International Nuclear Information System (INIS)

    Blacic, J.; Carter, J.; Halleck, P.; Johnson, P.; Shankland, T.; Andersen, R.; Spicochi, K.; Heller, A.

    1982-02-01

    Tests have been performed to explore the effects of extended exposure of tuffs from the southwestern portion of the Nevada Test Site to temperatures and pressures similar to those that will be encountered in a high-level nuclear waste repository. Tuff samples ranging from highly welded, nonzeolitized to unwelded, highly zeolitized varieties were subjected to temperatures of 80, 120, and 180 0 C; confining pressures of 9.7 and 19.7 MPa; and water-pore pressures of 0.5 to 19.7 MPa for durations of 2 to 6 months. The following basic properties were measured before and after exposure and compared: tensile strength, uniaxial compressive strength, grain density, porosity, mineralogy, permeability, thermal expansion, and thermal conductivity. Depending on rock type and exposure conditions, significant changes in ambient tensile strength, compressive strength, grain density, and porosity were measured. Mineralogic examination, permeability, and thermal property measurements remain to be completed

  4. A decision analysis framework to support long-term planning for nuclear fuel cycle technology research, development, demonstration and deployment

    International Nuclear Information System (INIS)

    Sowder, A.G.; Machiels, A.J.; Dykes, A.A.; Johnson, D.H.

    2013-01-01

    To address challenges and gaps in nuclear fuel cycle option assessment and to support research, develop and demonstration programs oriented toward commercial deployment, EPRI (Electric Power Research Institute) is seeking to develop and maintain an independent analysis and assessment capability by building a suite of assessment tools based on a platform of software, simplified relationships, and explicit decision-making and evaluation guidelines. As a demonstration of the decision-support framework, EPRI examines a relatively near-term fuel cycle option, i.e., use of reactor-grade mixed-oxide fuel (MOX) in U.S. light water reactors. The results appear as a list of significant concerns (like cooling of spent fuels, criticality risk...) that have to be taken into account for the final decision

  5. Long-term outlook for global natural uranium and uranium enrichment supply and demand situations after the impact of Fukushima Daiichi Nuclear Power Plant accident

    International Nuclear Information System (INIS)

    Matsuo, Yuhji; Murakami, Tomoko

    2012-01-01

    In this paper, the authors propose long-term projections of global nuclear power generation, uranium production, and uranium enrichment capacities by region, and estimate the trade flows of natural uranium and uranium enrichment activities in 2020 and 2035. In spite of the rapid nuclear power generation capacity growth expected especially in Asia, the natural uranium and uranium enrichment trade will not be tightened by 2020 due to the projected increase in both natural uranium production and uranium enrichment capacities, which may cause a drop in natural uranium and uranium enrichment prices. Thus, there is a great possibility that the current projects for capacity expansion will be delayed considerably. However, in the 'high-demand scenario', where nuclear expansion will be accelerated due to growing concerns about global warming and energy security issues, additional investments in uranium production and enrichment facilities will be needed by 2035. In Asia, the self-sufficiency ratio for both natural uranium supply and uranium enrichment activities will remain relatively low until 2035. However, the Herfindahl-Hirschman (HH) index of natural uranium and uranium enrichment activity trade to Asia will be lowered considerably up to 2035, indicating that nuclear capacity expansion can contribute to enhancing energy security in Asia. (author)

  6. Long-term research plan for human factors affecting safeguards at nuclear power plants. Volume 1. Summary and users' guide. Vol. 1

    International Nuclear Information System (INIS)

    O'Brien, J.N.; Fainberg, A.

    1984-04-01

    This report presents a long-term research plan for addressing human factors which can adversely affect safeguards at nuclear power plants. It was developed in order to prioritize and propose research for NRC in regulating power plant safeguards. Research efforts addressing human factors in safeguards were developed and prioritized according to the importance of human factors areas. Research was also grouped to take advantage of common research approaches and data sources where appropriate. Four main program elements emerged from the analysis, namely (1) Training and Performance Evaluation, (2) Organizational Factors, (3) Man-Machine Interface, and (4) Trustworthiness and Reliability. Within each program element, projects are proposed with results and information flowing between program elements where useful. An overall research plan was developed for a 4-year period and it would lead ultimately to regulatory activities including rulemaking, regulatory guides, and technical bases for regulatory action. The entire plan is summarized in Volume 1 of this report

  7. Potential impact of Andrassy bentonite microbial diversity in the long-term performance of a deep nuclear waste repository

    Science.gov (United States)

    Tadza, M. Y. Mohd; Tadza, M. A. Mohd; Bag, R.; Harith, N. S. H.

    2018-01-01

    Copper and steel canning and bentonite buffer are normally forseen as the primary containment component of a deep nuclear waste repository. Distribution of microbes in subsurface environments have been found to be extensive and directly or indirectly may exert influence on waste canister corrosion and the mobility of radionuclides. The understanding of clays and microbial interaction with radionuclides will be useful in predicting the microbial impacts on the performance of the waste repositories. The present work characterizes the culture-dependent microbial diversity of Andrassy bentonite recovered from Tawau clay deposits. The evaluation of microbial populations shows the presence of a number of cultivable microbes (e.g. Staphylococcus, Micrococcus, Achromobacter, Bacillus, Paecilomyces, Trichoderma, and Fusarium). Additionally, a pigmented yeast strain Rhodotorula mucilaginosa was also recovered from the formation. Both Bacillus and Rhodotorula mucilaginosa have high tolerance towards U radiation and toxicity. The presence of Rhodotorula mucilaginosa in Andrassy bentonite might be able to change the speciation of radionuclides (e.g. uranium) in a future deep repository. However, concern over the presence of Fe (III) reduction microbes such as Bacillus also found in the formation could lead to corrosion of copper steel canister and affect the overall performance of the containment system.

  8. Sustained safety and efficacy of extended-shelf-life {sup 90}Y glass microspheres: long-term follow-up in a 134-patient cohort

    Energy Technology Data Exchange (ETDEWEB)

    Lewandowski, Robert J.; Minocha, Jeet; Memon, Khairuddin; Riaz, Ahsun; Gates, Vanessa L.; Ryu, Robert K.; Sato, Kent T.; Omary, Reed; Salem, Riad [Northwestern University, Department of Radiology, Chicago, IL (United States)

    2014-03-15

    To validate our initial pilot study and confirm sustained safety and tumor response of extended-shelf-life {sup 90}Y glass microspheres. We hypothesized that for the same planned tissue dose, the increase in number of glass microspheres (decayed to the second week of their allowable shelf-life) administered for the same absorbed dose would result in better tumor distribution of the microspheres without causing additional adverse events. Between June 2007 and January 2010, 134 patients underwent radioembolization with extended-shelf-life {sup 90}Y glass microspheres; data from 84 new patients were combined with data from our 50-patient pilot study cohort. Baseline and follow-up imaging and laboratory data were obtained 1 and 3 months after therapy and every 3 months thereafter. Clinical and biochemical toxicities were prospectively captured and categorized according to the Common Terminology Criteria. Response in the index lesion was assessed using WHO and EASL guidelines. The mean delivered radiation dose was 123 Gy to the target liver tissue. The mean increase in number of microspheres with this approach compared to standard {sup 90}Y glass microsphere dosimetry was 103 %, corresponding to an increase from 3.84 to 7.78 million microspheres. Clinical toxicities included fatigue (89 patients, 66 %), abdominal pain (49 patients, 36.6 %), and nausea/vomiting (25 patients, 18.7 %). Grade 3/4 bilirubin toxicity was seen in three patients (2 %). Two (1 %) of the initial 50-patient cohort showed gastroduodenal ulcers; gastroduodenal ulcers were not seen in any of the subsequent 84 patients. According to WHO and EASL guidelines, response rates were 48 % and 57 %, respectively, and 21 % demonstrated a complete EASL response. This study showed sustained safety and efficacy of extended-shelf-life {sup 90}Y glass microspheres in a larger, 134-patient cohort. The increase in number of microspheres administered theoretically resulted in better tumor distribution of the

  9. Long-term consequences for Northern Norway of a hypothetical release from the Kola nuclear power plant

    International Nuclear Information System (INIS)

    Howard, B.J.; Wright, S.M.; Salbu, B.; Skuterud, K.L.; Hove, K.; Loe, R.

    2004-01-01

    The spatial and temporal variation in radiocaesium and 90 Sr doses to two population groups of the two Northernmost counties of Norway, Troms and Finnmark, following a hypothetical accident at the Kola nuclear power plant (KNPP) have been estimated using a model implemented within a geographical information system. The hypothetical accident assumes a severe loss of coolant accident at the KNPP coincident with meteorological conditions causing significant radionuclide deposition in the two counties. External doses are estimated from ground deposition and the behaviour of the different population groups, and internal doses from predicted food product activity concentrations and dietary consumption data. Doses are predicted for reindeer keepers and other Norwegian inhabitants, taking account of existing 137 Cs and 90 Sr deposition but not including the remedial effect of any countermeasures that might be used. The predicted doses, arising mainly from radiocaesium, confirm the Arctic Monitoring and Assessment Programme assessment that residents of the Arctic are particularly vulnerable to radiocaesium contamination, which could persist for many years. External doses are predicted to be negligible compared to ingestion doses. Ingestion doses for reindeer keepers are predicted to exceed 1 mSv y -1 for several decades primarily due to their high consumption of reindeer meat. Other Norwegians would also be potentially exposed to doses exceeding 1 mSv y -1 for several years, especially if they consume many local products. Whilst reindeer production is the most important exposure pathway, freshwater fish, lamb meat, dairy products, mushrooms and berries are also significant contributors to predicted ingestion doses. Radionuclide fluxes, defined as the total output of radioactivity in food from an area for a unit time, are dominated by reindeer meat. The results show the need for an effective emergency response, with appropriate countermeasures, should an accident of the

  10. Glass produced by underground nuclear explosions

    International Nuclear Information System (INIS)

    Schwartz, L.; Piwinskii, A.; Ryerson, F.; Tewes, H.; Beiriger, W.

    1983-01-01

    Detonation of an underground nuclear explosive produces a strong shock wave which propagates spherically outward, vaporizing the explosive and nearby rock and melting, the surrounding rock. The vaporized material expands adiabatically, forming a cavity. As the energy is dissipated during the cavity formation process, the explosive and rock debris condense and mix with the melted rock. The melt flows to the bottom of the cavity where it is quenched by fractured rock fragments falling from above as the cavity collapses. Measurements indicate that about 740 tonnes of rock and/or soil are melted for every kiloton (10 12 calories) of explosive energy, or about 25% of the explosive energy goes to melting rock. The resulting glass composition reflects the composition of the unaltered rock with explosive debris. The appearance ranges from white pumice to dense, dark lava. The bulk composition and color vary with the amount of explosive iron incorporated into the glass. The refractory explosion products are mixed with the solidified melt, although the degree of mixing is variable. Electron microprobe studies of glasses produced by Rainier in welded tuff have produced the following results: glasses are dehydrated relative to the host media, glasses are extremely heterogeneous on a 20 μm scale, a ubiquitous feature is the presence of dark marble-cake regions in the glass, which were locally enriched in iron and may be related to the debris, optically amorphous regions provide evidence of shock melting, only limited major element redistribution and homogenization occur within the cavity

  11. Long term simulation of {sup 137}Cs radioactivity in the regional ocean following the Fukushima Daiichi nuclear power plant accident

    Energy Technology Data Exchange (ETDEWEB)

    Tsumune, D.; Tsubono, T.; Misumi, K.; Yoshida, Y.; Hayami, H. [Central Research Institute of Electric Power Industry (Japan); Aoyama, M. [Meteorological Research Institute (Japan); Uematsu, M. [University of Tokyo (Japan); Maeda, Y. [CERES, Inc. (Japan)

    2014-07-01

    A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant following the earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways, direct release from the accident site and atmospheric deposition. A regional-scale simulation of {sup 137}Cs activity in the ocean offshore of Fukushima was carried out, the sources of radioactivity being direct release, atmospheric deposition, and the inflow of {sup 137}Cs deposited on the ocean by atmospheric deposition outside the domain of the model for more than two years. Direct releases of {sup 131}I, {sup 134}Cs, and {sup 137}Cs were estimated for 1 year after the accident by comparing simulated results and measured activities. The estimated total amounts of directly released {sup 131}I, {sup 134}Cs, and {sup 137}Cs were 11.1±2.2 PBq, 3.5±0.7 PBq, and 3.6±0.7 PBq, respectively. The contributions of each source were estimated by analysis of {sup 131}I/{sup 137}Cs and {sup 134}Cs/{sup 137}Cs activity ratios and comparisons between simulated results and measured activities of {sup 137}Cs. Simulated {sup 137}Cs activities attributable to direct release were in good agreement with measured activities close to the accident site, a result that implies that the estimated direct release rate was reasonable, while simulated {sup 137}Cs activities attributable to atmospheric deposition were low compared to measured activities. The rate of atmospheric deposition onto the ocean was underestimated because of a lack of measurements of deposition onto the ocean when atmospheric deposition rates were being estimated. Measured {sup 137}Cs activities attributable to atmospheric deposition helped to improve the accuracy of simulated atmospheric deposition rates. Simulated {sup 137}Cs activities attributable to the inflow of {sup 137}Cs deposited onto the ocean outside the domain of the model were in good agreement with measured activities in the open ocean within the

  12. Long term radioactive waste management

    International Nuclear Information System (INIS)

    Lavie, J.M.

    1984-01-01

    In France, waste management, a sensitive issue in term of public opinion, is developing quickly, and due to twenty years of experience, is now reaching maturity. With the launching of the French nuclear programme, the use of radioactive sources in radiotherapy and industry, waste management has become an industrial activity. Waste management is an integrated system dealing with the wastes from their production to the long term disposal, including their identification, sortage, treatment, packaging, collection and transport. This system aims at guaranteing the protection of present and future populations with an available technology. In regard to their long term management, and the design of disposals, radioactive wastes are divided in three categories. This classification takes into account the different radioisotopes contained, their half life and their total activity. Presently short-lived wastes are stored in the shallowland disposal of the ''Centre de la Manche''. Set up within the French Atomic Energy Commission (CEA), the National Agency for waste management (ANDRA) is responsible within the framework of legislative and regulatory provisions for long term waste management in France [fr

  13. Feeding the nuclear fuel cycle with a long term view; AREVA's front-end business units, uranium mining, UF6 conversion and isotopic enrichment

    International Nuclear Information System (INIS)

    Capus, G.A.P.; Autegert, R.

    2005-01-01

    As a leading provider of technological solutions for nuclear power generation and electricity transmission, the AREVA group has the unique capability of offering a fully integrated fuel supply, when requested by its customers. At the core of the AREVA group, COGEMA Front End Division is an essential part of the overall fuel supply chain. Composed of three Business Units and gathering several subsidiaries and joint 'ventures, this division enjoys several leading positions as shown by its market shares and historical production records. Current Uranium market evolutions put the natural uranium supply under focus. The uranium conversion segment also recently revealed some concerning evolutions. And no doubt, the market pressure will soon be directed also at the enrichment segment. Looking towards the long term, AREVA strongly believes that a nuclear power renewal is needed, especially to help limiting green house effect gas release. Therefore, to address future supplies needed to fuel the existing fleet of nuclear power plants, but also new ones, the AREVA group is planning very significant investments to build new facilities in all the three front-end market segments. As far as uranium mining is concerned, these new mines will be based upon uranium reserves of outstanding quality. As for uranium conversion and enrichment, two large projects will be based on the most advanced technologies. This paper is aimed at recalling COGEMA Front End Division experience, the current status of its plants and operating entities and will provide a detailed overview of its major projects. (authors)

  14. An optimized cask technology for conditioning, transportation and long term interim storage of 'End of Life' nuclear waste

    International Nuclear Information System (INIS)

    Lefort-Mary, Florence; Clement, Gilles; Lamouroux, Christine; Dumont, Bruno

    2016-01-01

    When preparing for the decommissioning of a nuclear facility, during its 'end of life' management and while performing the actual dismantling operations, one has to consider a large diversity of nuclear waste in term of types, volumes and activities. Customers are frequently faced with the obligation to undertake multiple and costly waste management operations including handling, reconditioning or re-transferring from one package to another, for example when moving from on-site storage to transportation. To address this issue, a new - highly flexible - cask system named TN R MW is being developed. This cask has a total weight of 10 T and is compliant with the 2012 IAEA regulations. It is developed on a flexible concept basis, adaptable to the various nuclear needs, including: from IP2 to B(U) / B(U)F; on-site/ international transportation; long term interim storage. Licensing and manufacturing of number of items of this TN R MW family is underway. (authors)

  15. On the pathway towards disposal. The need for long-term interim storage of high-level nuclear waste; Auf dem Weg in die Endlagerung. Die Notwendigkeit der langfristigen Zwischenlagerung hoch radioaktiver Abfaelle

    Energy Technology Data Exchange (ETDEWEB)

    Budelmann, Harald; Koehnke, Dennis; Reichardt, Manuel [Technische Univ. Braunschweig (Germany). Inst. fuer Baustoffe, Massivbau und Brandschutz; Di Nucci, Maria Rosaria; Isidoro Losada, Ana Maria [Freie Univ. Berlin (Germany). Forschungszentrum fuer Umweltpolitik (FFU)

    2017-09-01

    The disposal of spent nuclear fuel is a still unsolved problem with social, ethical, economical, ecological and political dimensions. The stagnating decision process on the final repository concept in several countries has the consequence of the inclusion of long-term interim storage into the disposal concept. The contribution discusses several approaches. This opens the question whether the long-term interim storage is a matter of delaying tactic or a pragmatic solution on the way to a final repository.

  16. Long-term stability of high-level waste forms

    International Nuclear Information System (INIS)

    Vernaz, E.; Loida, A.; Malow, G.; Marples, J.A.C.; Matzke, H.J.

    1990-01-01

    The long-term stability of HLW forms is reviewed with regard to temperature, irradiation and aqueous corrosion in a geological environment. The paper focuses on borosilicate glasses, but the radiation stability results are compared with some HLW ceramics. Thermal stability: most nuclear waste glass compositions have been adjusted to ensure a low final crystallized fraction. The crystallization of highly active Pamela glass samples was similar to that of nonradioactive glass. Radiation stability: No adverse effect of irradiation damage was found in glasses doped with short-lived actinides: volume changes were small, no significant change in the leach rate was observed, and the fracture toughness increased. For most ceramics investigated, volume changes of up to 9%, amorphization and higher leach rates were observed as a consequence of high α decay doses. For the KAB 78 ceramic, however, none of these effects were detected since the matrix was not subject to α recoil damage. Chemical stability: It has been demonstrated that alteration by water depends largely on the repository conditions. Most clay act as silica sinks, and increase the glass corrosion rate. It is possible, however, to specify realistic temperature, pressure and environmental conditions to ensure glass integrity for more than 10 000 years

  17. Long-term irradiation of a MSGC made of gold strips on electron conducting C85-1 glass under several gas mixtures and cleanliness conditions

    CERN Document Server

    Bouclier, Roger; Hoch, M; Million, G; Ropelewski, L; Sauli, F; Sharma, A; Shekhtman, L

    1996-01-01

    The present study aims to create reproducible and controlled polluted conditions in a clean gas system in order to be able to compare the behaviour of an MSGC plate operating with Ar-DME and Ne-DME gas mixtures. The achievement of such conditions seems to be more difficult than would be expected from the long term behaviour shown by MSGCs years ago in the same gas system. The pollutants present in the gas rack, possibly originating the dramatic losses reported then, are not present anymore in the gas system after four years of continuous operation with the Ar-DME mixture. The use of new and supposedly clean stainless steel gas pipes of smaller diameter might affect the chamber operation, although the lines are rapidly cleaned ( ~weeks) after being flushed with DME. The back-diffusion of pollutants due to the use of a Si-Oil bubbler affects dramatically the chamber operation, which behave s slightly better with argon than with neon; in view of the other variables, we do not consider this difference as signific...

  18. An autoimmune myositis-overlap syndrome associated with autoantibodies to nuclear pore complexes: description and long-term follow-up of the anti-Nup syndrome.

    Science.gov (United States)

    Senécal, Jean-Luc; Isabelle, Catherine; Fritzler, Marvin J; Targoff, Ira N; Goldstein, Rose; Gagné, Michel; Raynauld, Jean-Pierre; Joyal, France; Troyanov, Yves; Dabauvalle, Marie-Christine

    2014-11-01

    Autoimmune myositis encompasses various myositis-overlap syndromes, each being identified by the presence of serum marker autoantibodies. We describe a novel myositis-overlap syndrome in 4 patients characterized by the presence of a unique immunologic marker, autoantibodies to nuclear pore complexes. The clinical phenotype was characterized by prominent myositis in association with erosive, anti-CCP, and rheumatoid factor-positive arthritis, trigeminal neuralgia, mild interstitial lung disease, Raynaud phenomenon, and weight loss. The myositis was typically chronic, relapsing, and refractory to corticosteroids alone, but remitted with the addition of a second immunomodulating drug. There was no clinical or laboratory evidence for liver disease. The prognosis was good with 100% long-term survival (mean follow-up 19.5 yr).By indirect immunofluorescence on HEp-2 cells, sera from all 4 patients displayed a high titer of antinuclear autoantibodies (ANA) with a distinct punctate peripheral (rim) fluorescent pattern of the nuclear envelope characteristic of nuclear pore complexes. Reactivity with nuclear pore complexes was confirmed by immunoelectron microscopy. In a cohort of 100 French Canadian patients with autoimmune myositis, the nuclear pore complex fluorescent ANA pattern was restricted to these 4 patients (4%). It was not observed in sera from 393 adult patients with systemic sclerosis (n = 112), mixed connective tissue disease (n = 35), systemic lupus (n = 94), rheumatoid arthritis (n = 45), or other rheumatic diseases (n = 107), nor was it observed in 62 normal adults.Autoantibodies to nuclear pore complexes were predominantly of IgG isotype. No other IgG autoantibody markers for defined connective tissue diseases or overlap syndromes were present, indicating a selective and highly focused immune response. In 3 patients, anti-nuclear pore complex autoantibody titers varied in parallel with myositis activity, suggesting a pathogenic link to

  19. Overview of long-term observations of radioactivity in the area around Institute of nuclear physics of Uzbekistan Academy of Sciences

    International Nuclear Information System (INIS)

    Salikhbaev, U.S.; Yuldashev, B.S.; Radyuk, R.I.

    2006-01-01

    Full text: The radiation protection problem is mainly important with its relation with potential radioactivity threat to society and environment. Therefore, development of nuclear science in Uzbekistan since foundation of the Institute of Nuclear Physic (INP) is directly related to radiation protection of the personnel, population and environment. One of the major tasks highlighted in this report, importance of complex approach to the radiation protection and security, is worth of mentioning. Development of such an approach allows creation of a concept to predict the radiation situation and transition to radiation monitoring around the research nuclear centre. The aim of this complex approach to the solution of the radiation protection task is to find the methods for making predictions and managing the radiation situation around the nuclear centre. Complex approach to this research implies integration of theoretical and experimental activities. Theoretical studies involve primarily radiation prediction models. Experimental works are, on one hand, the data to approve the theoretical models, the obtained empirical parameters, and, on the other hand, information on the radiation situation for its forecasting. Lack of reliable information on the radioactivity level creates various rumours and is the major reason for radiophobia. The aim of this report is to present realistic information on the radioactivity level at the INP AS RU site and at the surrounding area, which is based on long-term measurements provided by the radiation protection department. In this work the following results of the research are presented: -total beta and gamma-activity of herbs and soil; - specific activity of waters (waste, underground, and surface); - activity of the air aerosols; - activity of the atmospheric precipitations; - background at the site of the INP, at the sanitary-protection area and observation area. What has been accomplished for these years? Firstly, the model for cobalt

  20. Overview of chemical modeling of nuclear waste glass dissolution

    International Nuclear Information System (INIS)

    Bourcier, W.L.

    1991-02-01

    Glass dissolution takes place through metal leaching and hydration of the glass surface accompanied by development of alternation layers of varying crystallinity. The reaction which controls the long-term glass dissolution rate appears to be surface layer dissolution. This reaction is reversible because the buildup of dissolved species in solution slows the dissolution rate due to a decreased dissolution affinity. Glass dissolution rates are therefore highly dependent on silica concentrations in solution because silica is the major component of the alteration layer. Chemical modeling of glass dissolution using reaction path computer codes has successfully been applied to short term experimental tests and used to predict long-term repository performance. Current problems and limitations of the models include a poorly defined long-term glass dissolution mechanism, the use of model parameters determined from the same experiments that the model is used to predict, and the lack of sufficient validation of key assumptions in the modeling approach. Work is in progress that addresses these issues. 41 refs., 7 figs., 2 tabs

  1. Effect of irradiation on the evolution of alteration layer formed during nuclear glass leaching

    International Nuclear Information System (INIS)

    Mougnaud, Sarah

    2016-01-01

    High-level radioactive waste (HLW) remaining after spent nuclear fuel reprocessing is immobilized within a glass matrix, eventually destined for geological disposal. Water intrusion into the repository is expected after several thousand years. The alteration of a non-radioactive surrogate for nuclear glass has been extensively studied and it has been determined that successive leaching mechanisms lead to the formation of a 'passivating' alteration layer and to the establishment of a residual rate regime in the long term. However, glass packages are submitted to the radioactivity of confined radioelements. This work focuses on the influence of irradiation on the alteration layer formed during the residual rate regime, in a structural and mechanistic point of view. Three focal areas have been selected. Non-radioactive simple glasses have been leached and externally irradiated in order to determine modifications induced by electronic effects (irradiations with electrons and alpha particles). The same type of glass samples have been previously irradiated with heavy ions and their leaching behavior have been studied in order to assess the impact of ballistic dose cumulated by the glass before water intrusion. Leaching behavior of a complex radioactive glass, doped with an alpha-emitter, has been studied to consider a more realistic situation. (author) [fr

  2. Molecular glasses for nuclear waste encapsulation

    International Nuclear Information System (INIS)

    Ropp, R.C.

    1982-01-01

    The use of a molecular glass based upon a polymerized phosphate of aluminum (PAP), indium or gallium overcomes all of the prior objections to use of glass as a high-level nuclear waste (HLW) encapsulation agent. This HLW glass product could not be made to devitrify, dissolved all of the oxides found in calcine, including the difficultly soluble ones, did not form microcrystallites in the melt or subsequent glass-casting, and possessed a hydrolytic etching rate to boiling water even lower than that of HLW-ZBS glass. A precursor compound, M(H 2 PO 4 ) 3 , is prepared, where M is a trivalent metal selected from the group consisting of aluminum, indium and gallium. The impurity level is carefully controlled so as not to exceed 300 ppm total. The precursor crystals may be washed to remove excess phosphoric acid as desired. HLW is added to the crystals and the mixture is then heated at a controlled heating rate to induce solid state polymerization and to form a melt at 1350 degrees C in which the HLW oxides dissolve rapidly

  3. Mineralogy and thermodynamic properties of magnesium phyllosilicates formed during the alteration of a simplified nuclear glass

    Energy Technology Data Exchange (ETDEWEB)

    Debure, Mathieu, E-mail: m.debure@brgm.fr [CEA, DEN, DTCD, SECM, F-30207 Bagnols-sur-Ceze (France); MINES-ParisTech, PSL Research University, Centre de Géosciences, 77305 Fontainebleau (France); De Windt, Laurent [MINES-ParisTech, PSL Research University, Centre de Géosciences, 77305 Fontainebleau (France); Frugier, Pierre; Gin, Stéphane [CEA, DEN, DTCD, SECM, F-30207 Bagnols-sur-Ceze (France); Vieillard, Philippe [IC2MP-CNRS-UMR 7285, 5 Ave. Albert Turpain TSA 51106, 86073 Poitiers Cedex 09 (France)

    2016-07-15

    The precipitation of crystallized magnesium phyllosilicates generally sustains the alteration rate of nuclear waste containment glass. However, glass alteration slows down to a residual rate as soon as Mg disappears from the solution. The identification of the phyllosilicates formed is therefore crucial for modeling the long-term behavior of nuclear glass. This study deals with batch alteration of the simplified nuclear glass ISG in presence of magnesium, and the characterization of the secondary phases. Morphological, chemical and structural analyses (MET, EDX, XRD) were performed to determine the nature and structure of the precipitated phases identified as trioctahedral smectites. Analyses conducted on the secondary phases proved the presence of Al, Na and Ca in the Mg-phyllosilicate phases. Such elements had been suspected but never quantitatively measured. The experimental results were then used to determine the thermodynamic solubility constants for each precipitated secondary phase at various temperatures. The calculated values were consistent with those available for sodium and magnesium saponites in the existing thermodynamic databases. - Highlights: • The international simple glass dissolution rate increases in presence of magnesium. • Mg added in solution combines with Si from glass to yield trioctahedral smectites. • Their calculated logK are close to smectite thermodynamic constants reported in databases. • It confirms assumptions on Mg-silicates phases made in previous geochemical modeling.

  4. Contribution to the study of diffusion as related to the leaching of glasses: application to the potential risk of long-term storage

    International Nuclear Information System (INIS)

    Imbert, J.C.; Pacaud, F.

    Leaching of glasses made from radioactive wastes of very high activity was studied. Leaching agents used were water for temperatures below 100 0 C; molten nitrates for temperatures higher than 100 0 C; solutions of various pH or charged with either sodium chloride or cesium; and dry or wet air. From the quantities of entrained radioactive elements, overall apparent diffusion coefficients were determined for fission products with long periods such as cerium, cesium, ruthenium, and strontium. Diffusion activation energies were also determined. These results are applied to the calculation of the potential risk of storage for vitrified fission products

  5. Nanoporous Glasses for Nuclear Waste Containment

    OpenAIRE

    Woignier, Thierry; Primera, Juan; Reynes, Jerôme

    2016-01-01

    Research is in progress to incorporate nuclear waste in new matrices with high structural stability, resistance to thermal shock, and high chemical durability. Interactions with water are important for materials used as a containment matrix for the radio nuclides. It is indispensable to improve their chemical durability to limit the possible release of radioactive chemical species, if the glass structure is attacked by corrosion. By associating high structural stability and high chemical dura...

  6. ICRP Publication 111 - Application of the Commission's recommendations to the protection of people living in long-term contaminated areas after a nuclear accident or a radiation emergency.

    Science.gov (United States)

    Lochard, J; Bogdevitch, I; Gallego, E; Hedemann-Jensen, P; McEwan, A; Nisbet, A; Oudiz, A; Oudiz, T; Strand, P; Janssens, A; Lazo, T; Carr, Z; Sugier, A; Burns, P; Carboneras, P; Cool, D; Cooper, J; Kai, M; Lecomte, J-F; Liu, H; Massera, G; McGarry, A; Mrabit, K; Mrabit, M; Sjöblom, K-L; Tsela, A; Weiss, W

    2009-06-01

    In this report, the Commission provides guidance for the protection of people living in long-term contaminated areas resulting from either a nuclear accident or a radiation emergency. The report considers the effects of such events on the affected population. This includes the pathways of human exposure, the types of exposed populations, and the characteristics of exposures. Although the focus is on radiation protection considerations, the report also recognises the complexity of post-accident situations, which cannot be managed without addressing all the affected domains of daily life, i.e. environmental, health, economic, social, psychological, cultural, ethical, political, etc. The report explains how the 2007 Recommendations apply to this type of existing exposure situation, including consideration of the justification and optimisation of protection strategies, and the introduction and application of a reference level to drive the optimisation process. The report also considers practical aspects of the implementation of protection strategies, both by authorities and the affected population. It emphasises the effectiveness of directly involving the affected population and local professionals in the management of the situation, and the responsibility of authorities at both national and local levels to create the conditions and provide the means favouring the involvement and empowerment of the population. The role of radiation monitoring, health surveillance, and the management of contaminated foodstuffs and other commodities is described in this perspective. The Annex summarises past experience of longterm contaminated areas resulting from radiation emergencies and nuclear accidents, including radiological criteria followed in carrying out remediation measures.

  7. Design analysis of various transportation package options for BN-350 SNF in terms of nuclear radiation safety in planning for long-terms dry storage

    International Nuclear Information System (INIS)

    Aisabekov, A.Z.; Mukenova, S.A.; Tur, E.S.; Tsyngaev, V.M.

    2004-01-01

    Full text: This effort is performed under the BN-350 reactor facility decommissioning project. One of the project tasks - spent nuclear fuel handling - includes the following: fuel packaging into sealed canisters, transportation of the canisters in multi-seat metallo-concrete containers and placement of the containers for a long-term dry storage. The goal of this effort is to computationally validate nuclear and radiation safety of the SNF containers placed for storage both under normal storage conditions and probable accident situations. The basic unit structure and design configurations are presented: assemblies, canisters, transportation containers. The major factors influencing nuclear and radiation safety are presented: fuel burn-up, enrichment, fabrication tolerance, types of fuel assemblies, configuration of assemblies in the canister and canisters in the container, background of assemblies placed in the reactor and cooling pool. Conditions under which the SNF containers will be stored are described and probable accident situations are listed. Proceeding from the conservatism principle, selection of the assemblies posing the greatest nuclear hazard is validated. A neutron effective multiplication factor is calculated for the SNF containers under the normal storage conditions and for the case of emergency. The effective multiplication factor is shown to be within a standard value of 0.95 in any situation. Based on the experimental data on assembly and canister dose rates, canisters posing the highest radiation threat are selected. Activities of sources and gamma-radiation spectral composition are calculated. Distribution of the dose rate outside the containers both under the normal storage conditions and accident situations are calculated. The results obtained are analyzed

  8. Long-term outcomes of patients evacuated from hospitals near the Fukushima Daiichi nuclear power plant after the Great East Japan Earthquake.

    Science.gov (United States)

    Igarashi, Yutaka; Tagami, Takashi; Hagiwara, Jun; Kanaya, Takahiro; Kido, Norihiro; Omura, Mariko; Tosa, Ryoichi; Yokota, Hiroyuki

    2018-01-01

    After the accident of the Fukushima Daiichi nuclear power plant due to the Great East Japan Earthquake in March 2011, the Japanese government issued a mandatory evacuation order for people living within a 20 km radius of the nuclear power plant. The aim of the current study was to investigate long-term outcomes of these patients and identify factors related to mortality. Patients who were evacuated from hospitals near the Fukushima Daiichi nuclear power plant to the Aizu Chuo Hospital from 15 to 26 March, 2011 were included in this study. The following data were collected from medical records: age, sex, activities of daily life, hospital they were admitted in at the time of earthquake, distance between the facility and the nuclear power plant, reasons of evacuation and number of transfers. The patient outcomes were collected from medical records and/or investigated on the telephone in January 2012. A total of 97 patients (28 men and 69 women) were transferred from 10 hospitals via ambulances or buses. No patients died or experienced exacerbation during transfer. Median age of the patients was 86 years. Of the total, 36 patients were not able to obey commands, 44 were bed-ridden and 61 were unable to sustain themselves via oral intake of food. Among 86 patients who were followed-up, 41 (48%) died at the end of 2011. Multiple-regression analysis showed that non-oral intake [Hazard Ratio (HR): 6.07, 95% Confidence interval (CI): 1.94-19.0] and male sex [HR: 8.35, 95% CI: 2.14-32.5] had significant impact on mortality. This study found that 48% of the evacuated patients died 9 months after the earthquake and they had significantly higher mortality rate than the nursing home residents. Non-oral intake and male sex had significant impact on mortality. These patients should be considered as especially vulnerable in case of hospital evacuation.

  9. Long-Term Collections

    CERN Multimedia

    Staff Association

    2016-01-01

    45 years helping in developing countries! CERN personnel have been helping the least fortunate people on the planet since 1971. How? With the Long-Term Collections! Dear Colleagues, The Staff Association’s Long-Term Collections (LTC) Committee is delighted to share this important milestone in the life of our Laboratory with you. Indeed, whilst the name of CERN is known worldwide for scientific discoveries, it also shines in the many humanitarian projects which have been supported by the LTC since 1971. Several schools and clinics, far and wide, carry its logo... Over the past 45 years, 74 projects have been supported (9 of which are still ongoing). This all came from a group of colleagues who wanted to share a little of what life offered them here at CERN, in this haven of mutual understanding, peace and security, with those who were less fortunate elsewhere. Thus, the LTC were born... Since then, we have worked as a team to maintain the dream of these visionaries, with the help of regular donat...

  10. Long-Term Collection

    CERN Multimedia

    Staff Association

    2016-01-01

    Dear Colleagues, As previously announced in Echo (No. 254), your delegates took action to draw attention to the projects of the Long-Term Collections (LTC), the humanitarian body of the CERN Staff Association. On Tuesday, 11 October, at noon, small Z-Cards were widely distributed at the entrances of CERN restaurants and we thank you all for your interest. We hope to have achieved an important part of our goal, which was to inform you, convince you and find new supporters among you. We will find out in the next few days! An exhibition of the LTC was also set up in the Main Building for the entire week. The Staff Association wants to celebrate the occasion of the Long-Term Collection’s 45th anniversary at CERN because, ever since 1971, CERN personnel have showed great support in helping the least fortunate people on the planet in a variety of ways according to their needs. On a regular basis, joint fundraising appeals are made with the Directorate to help the victims of natural disasters around th...

  11. Collectes à long terme

    CERN Multimedia

    Collectes à long terme

    2014-01-01

    En cette fin d’année 2014 qui approche à grands pas, le Comité des Collectes à Long Terme remercie chaleureusement ses fidèles donatrices et donateurs réguliers pour leurs contributions à nos actions en faveur des plus démunis de notre planète. C’est très important, pour notre Comité, de pouvoir compter sur l’appui assidu que vous nous apportez. Depuis plus de 40 ans maintenant, le modèle des CLT est basé principalement sur des actions à long terme (soit une aide pendant 4-5 ans par projet, mais plus parfois selon les circonstances), et sa planification demande une grande régularité de ses soutiens financiers. Grand MERCI à vous ! D’autres dons nous parviennent au cours de l’année, et ils sont aussi les bienvenus. En particulier, nous tenons à remercier...

  12. Fluorescent CdSe/ZnS nanocrystal-peptide conjugates for long-term, nontoxic imaging and nuclear targeting in living cells

    International Nuclear Information System (INIS)

    Chen, Fanqing; Gerion, Daniele

    2004-01-01

    One of the biggest challenges in cell biology is the imaging of living cells. For this purpose, the most commonly used visualization tool is fluorescent markers. However, conventional labels, such as organic fluorescent dyes or green fluorescent proteins (GFP), lack the photostability to allow the tracking of cellular events that happen over minutes to days. In addition, they are either toxic to cells (dyes), or difficult to construct and manipulate (GFP). We report here the use of a new class of fluorescent labels, silanized CdSe/ZnS nanocrystal-peptide conjugates, for imaging the nuclei of living cells. CdSe/ZnS nanocrystals, or so called quantum dots (qdots), are extremely photostable, and have been used extensively in cellular imaging of fixed cells. However, most of the studies about living cells so far have been concerned only with particle entry into the cytoplasm or the localization of receptors on the cell membrane. Specific targeting of qdots to the nucleus of living cells ha s not been reported in previous studies, due to the lack of a targeting mechanism and proper particle size. Here we demonstrate for the first time the construction of a CdSe/ZnS nanocrystal-peptide conjugate that carries the SV40 large T antigen nuclear localization signal (NLS), and the transfection of the complex into living cells. By a novel adaptation of commonly used cell transfection techniques for qdots, we were able to introduce and retain the NLS-qdots conjugate in living cells for up to a week without detectable negative cellular effects. Moreover, we can visualize the movement of the CdSe/ZnS nanocrystal-peptide conjugates from cytoplasm to the nucleus, and the accumulation of the complex in the cell nucleus, over a long observation time period. This report opens the door for using qdots to visualize long-term biological events that happen in the cell nucleus, and provides a new nontoxic, long-term imaging platform for cell nuclear processes

  13. Long-term nuclear knowledge management (NKM) of innovative nuclear energy systems (INES). A case study of the Japan Atomic Energy Research Institute (JAERI)

    International Nuclear Information System (INIS)

    Yanagisawa, Kazuaki; Bezdek, Roger H.; Sawada, Tetsuo

    2008-01-01

    Within JAERI, funds invested in a 45-year study of LWR totaled 4.2b$ for research and 3.4b$ (34,718 man years) for personnel. The benefits to taxpayers from this JAERI work were estimated to be about 6.3b$ , resulting in a favorable cost-benefit ratio of 1.5 (6.3/4.2). JAERI is a national research institute and this figure may be regarded as sufficiently high, and many high risk and complex tasks were completed successfully. Funds invested in the 32-year study of HTGR were 1.5b$ for R and D and 0.3b$ (2966 man years) for personnel. Commercialized HTGR will result in a cost reduction of electricity during power generation. Retail cost is 0.36b$/year and the share of JAERI (MCP) is 0.018b$/year. Funds invested in the 32-year study of FR were 5.4b$ for R and D and 0.6b$ (6331 man years) for personnel. Estimate is that after commercialization in 2050, a FR will generate revenue from electricity as high as 1687b$ during the period 2050-2100, or 34b$/year - which is greater than that of LWR. However, there is substantial uncertainty in these estimates. To achieve long-term INES, it is necessary to develop the sustainable scenarios and the long-term robust NKM, as shown in the present study. (author)

  14. Nuclear waste under glass, further discussion

    Science.gov (United States)

    O'Keefe, J. A.; Barkatt, A.; Glass, B. P.; Alterescu, S.

    J. J. Crovisier and J. Honnorez [1988] discuss an article by W. W. Maggs, “Mg May Protect Waste Under Glass” [Maggs, 1988] summarizing work by A. Barkatt (Catholic University, Washington, D.C.), B. P. Glass (University of Delaware, Newark), and S. Alterescu and J. A. O'Keefe (NASA/GSFC, Greenbelt, Md.). We found that seawater is orders of magnitude less corrosive t h an fresh water in attacking tektite glass; traced the protective effect to the presence of magnesium, at a level of about 1.3 g/L in seawater; and suggested that the effect might be useful in protecting nuclear waste glasses from corrosion.Crovisier and Honnorez first make the point that the rate of corrosion of glass is, in principle, a function of the ratio of surface area 5 to the effective volume V. This concept, which is usually discussed in American literature under the name of S/V effects, is discussed by Crovisier and Honnorez in terms of the “permeability of the environment.” These effects have been carefully considered throughout our work (see, for example, Barkatt et al. [19867rsqb;). It turns out that in the sea the effective S/V is so small that the effects referred to by Crovisier and Honnorez can be ignored.

  15. Review of the seismic risk in the design of civil engineering of nuclear installations excepted the long term storage of radioactive wastes; Prise en compte du risque sismique a la conception des ouvrages de genie civil d'installations nucleaires de base a l'exception des stockages a long terme des dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This guide aims to define, for the nuclear installations excepted the long term storage of radioactive wastes, from site data, the design specifications of earthquake resistant civil engineering and the possible methods for: the determination of the seismic response of the buildings, taking into account the interactions with the materials and the evaluation of the associated strains to size the installation; the determination of seismic displacements to be considered to size the materials. (A.L.B.)

  16. Loads imposed on dual purpose casks in German on-site-storage facilities for long term intermediate storage of spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, N.; Rabe, O. [TUeV NORD EnSys Hannover GmbH und Co. KG, Hanover (Germany)

    2004-07-01

    In accordance with recent changes of the atomic energy act and in order to secure reliable removal of spent fuel from the nuclear power plants' fuel storage ponds the German utilities filed license applications for a total of 12 onsite- storage facilities for spent fuel assemblies. By the end of 2003 the last of these storage facilities were licensed and are currently under construction. The first on-site-storage facility of that line became operational in late 2002. There are several design lines of storage facilities with different handling procedures or possible accident conditions. Short term interim storage facilities for a few casks are characterized by individual concrete hoods shielding the casks in horizontal position whereas long term intermediate storage facilities currently erected for large numbers of casks typically feature a condensed pattern of casks stored in upright position and massive structures of reinforced concrete. TUeV Hannover/Sachsen-Anhalt e. V. (now TUeV NORD EnSys Hannover GmbH and Co. KG) has been contracted as a body of independent experts for the assessment of all related safety requirements on behalf of the national licensing authority, the federal office for radiation protection (BfS).

  17. Long-term management of liquid high-level radioactive wastes stored at the Western New York Nuclear Service Center, West Valley. Final environmental impact statement

    International Nuclear Information System (INIS)

    1982-06-01

    The statement assesses and compares environmental implications of possible alternatives for long-term management of the liquid high-level radioactive wastes stored in underground tanks at the Western New York Nuclear Service Center in West Valley, New York. Four basic alternatives, as well as options within these alternatives, have been considered in the EIS: (1) onsite processing to a terminal waste form for shipment and disposal in a federal repository (the preferred alternative); (2) onsite conversion to a solid interim form for shipment to a federal waste facility for later processing to a terminal form and shipment and subsequent disposal in a federal repository; (3) mixing the liquid wastes with cement and other additives, pouring it back into the existing tanks, and leaving onsite; and (4) no action (continued storage of the wastes in liquid form in the underground tanks at West Valley). Mitigative measures for environmental impacts have been considered for all alternatives. No significant stresses on supplies or irreversible and irretrievable resources are anticipated, and no scarce resource would be required

  18. Loads imposed on dual purpose casks in German on-site-storage facilities for long term intermediate storage of spent nuclear fuel

    International Nuclear Information System (INIS)

    Wetzel, N.; Rabe, O.

    2004-01-01

    In accordance with recent changes of the atomic energy act and in order to secure reliable removal of spent fuel from the nuclear power plants' fuel storage ponds the German utilities filed license applications for a total of 12 onsite- storage facilities for spent fuel assemblies. By the end of 2003 the last of these storage facilities were licensed and are currently under construction. The first on-site-storage facility of that line became operational in late 2002. There are several design lines of storage facilities with different handling procedures or possible accident conditions. Short term interim storage facilities for a few casks are characterized by individual concrete hoods shielding the casks in horizontal position whereas long term intermediate storage facilities currently erected for large numbers of casks typically feature a condensed pattern of casks stored in upright position and massive structures of reinforced concrete. TUeV Hannover/Sachsen-Anhalt e. V. (now TUeV NORD EnSys Hannover GmbH and Co. KG) has been contracted as a body of independent experts for the assessment of all related safety requirements on behalf of the national licensing authority, the federal office for radiation protection (BfS)

  19. The Fukushima nuclear accident and the pale grass blue butterfly: evaluating biological effects of long-term low-dose exposures.

    Science.gov (United States)

    Hiyama, Atsuki; Nohara, Chiyo; Taira, Wataru; Kinjo, Seira; Iwata, Masaki; Otaki, Joji M

    2013-08-12

    On August 9th 2012, we published an original research article in Scientific Reports, concluding that artificial radionuclides released from the Fukushima Dai-ichi Nuclear Power Plant exerted genetically and physiologically adverse effects on the pale grass blue butterfly Zizeeria maha in the Fukushima area. Immediately following publication, many questions and comments were generated from all over the world. Here, we have clarified points made in the original paper and answered questions posed by the readers. The following points were clarified. (1) There are many advantages to using the pale grass blue butterfly as an indicator species. (2) The forewings of the individuals collected in Fukushima were significantly smaller than in the northern and southern localities. (3) We observed growth retardation in the butterflies from the Fukushima area. (4) The aberrant colour patterns in the butterflies obtained in the Fukushima area were different from the colour patterns induced by temperature and sibling crosses but similar to those induced by external and internal exposures to the artificial radionuclides and by a chemical mutagen, suggesting that genetic mutations caused the aberrations. (5) This species of butterfly has been plentiful in Fukushima area for at least half a century. We here present specimens collected from Fukushima Prefecture before the accident. (6) Mutation accumulation was detected by the increase in the abnormality rates from May 2011 to September 2011. (7) The abnormal traits were heritable. (8) Our sampling localities were not affected by the tsunami. (9) We used a high enough number of samples to obtain statistically significant results. (10) The standard rearing method was followed, producing normal adults in the control groups. (11) The exposure experiments successfully reproduced the results of the field work. This species of butterfly is vulnerable to long-term low-dose internal and external exposures; however, insect cells are known to be

  20. Long-term biodosimetry Redux

    International Nuclear Information System (INIS)

    Simon, Steven L.; Bouville, Andre

    2016-01-01

    This paper revisits and reiterates the needs, purposes and requirements of bio-dosimetric assays for long-term dose and health risk assessments. While the most crucial need for bio-dosimetric assays is to guide medical response for radiation accidents, the value of such techniques for improving our understanding of radiation health risk by supporting epidemiological (long-term health risk) studies is significant. As new cohorts of exposed persons are identified and new health risk studies are undertaken with the hopes that studying the exposed will result in a deeper understanding of radiation risk, the value of reliable dose reconstruction is underscored. The ultimate application of biodosimetry in long-term health risk studies would be to completely replace model-based dose reconstruction-a complex suite of methods for retrospectively estimating dose that is commonly fraught with large uncertainties due to the absence of important exposure-related information, as well as imperfect models. While biodosimetry could potentially supplant model-based doses, there are numerous limitations of presently available techniques that constrain their widespread application in health risk research, including limited ability to assess doses received far in the past, high cost, great inter-individual variability, invasiveness, higher than preferred detection limits and the inability to assess internal dose (for the most part). These limitations prevent the extensive application of biodosimetry to large cohorts and should be considered a challenge to researchers to develop new and more flexible techniques that meet the demands of long-term health risk research. Events in recent years, e.g. the Fukushima reactor accident and the increased threat of nuclear terrorism, underscore that any event that results in significant radiation exposures of a group of people will also produce a much larger population, exposed at lower levels, but that likewise needs (or demands) an exposure

  1. Long-Term Symbolic Learning

    National Research Council Canada - National Science Library

    Kennedy, William G; Trafton, J. G

    2007-01-01

    What are the characteristics of long-term learning? We investigated the characteristics of long-term, symbolic learning using the Soar and ACT-R cognitive architectures running cognitive models of two simple tasks...

  2. Introduction to the crystallization phenomenon in nuclear glass

    International Nuclear Information System (INIS)

    Jacquet Francillon, N.

    1997-01-01

    Crystallization is a subject for concern because of its potentially detrimental effects on the technological feasibility of high-temperature melting, and on the chemical durability of the material at intermediate and low temperatures during interim storage or after disposal. The tendency of glass to crystallize depends to a large extent on the composition of the frit and/or of the waste to be solidified. It depends too of the thermal history of the glass generally, the knowledge is mainly upon determination of the time-temperature-transition (TTT) curves, crystal identification and quantification techniques, and their effects on the durability of the glass matrix. French experience is presented. Only a few authors addressed the long-term development of crystalline phases, notably at temperatures below the vitreous transition temperature Tg. Some recommendations for glass crystallization studies are made but glass crystallization after disposal is acceptable provided some conditions are met. (author)

  3. Long term radiotoxicity

    International Nuclear Information System (INIS)

    Slessarev, I.

    2001-01-01

    A major issue to secure the development of nuclear energy in future is the radioactive waste minimization, both inside the fuel cycle and in a deep geological storage. The aim of this paper is to establish the physical principles which provide an inherent minimization of the radioactive wastes. A new concept is introduced to characterize the radiotoxicity associated to various nuclei families in equilibrium state. The analysis shows the potential of evolutionary nuclear systems, mostly based on known technologies and the potential of more futuristic systems, like accelerator-driven systems and Th-fuel cycle. Several groups of the toxicity sources are object of the studies: Actinides as a part of the nuclear fuel which is remaining unusable after irradiation in nuclear power plants; long-lived fission products as the inevitable result of nuclear energy production; Lanthanides as an important part of fission products which separation from Actinides is technologically difficult because of similar chemical properties

  4. LONG TERM COLLECTIONS

    CERN Multimedia

    STAFF ASSOCIATION

    2010-01-01

    ACKNOWLEDGMENTS The Long-Term Collections (CLT) committee would like to warmly thank its faithful donors who, year after year, support our actions all over the world. Without you, all this would not be possible. We would like to thank, in particular, the CERN Firemen’s Association who donated 5000 CHF in the spring thanks to the sale of their traditional calendar, and the generosity of the CERN community. A huge thank you to the firemen for their devotion to our cause. And thank you to all those who have opened their door, their heart, and their purses! Similarly, we warmly thank the CERN Yoga Club once again for its wonderful donation of 2000 CHF we recently received. We would also like to tell you that all our projects are running well. Just to remind you, we are currently supporting the activities of the «Réflexe-Partage» Association in Mali; the training centre of «Education et Développement» in Abomey, Benin; and the orphanage and ...

  5. Factors to be Considered in Long-Term Monitoring of a Former Nuclear Test Site in a Geophysically Active and Water-rich Environment

    Science.gov (United States)

    Eichelberger, J.; Hill, G.; Patrick, M.; Freymueller, J.; Barnes, D.; Kelley, J.; Layer, P.

    2001-12-01

    The US Department of Energy (USDOE) is currently undertaking an ambitious program of environmental remediation of the surface of Amchitka Island in the western Aleutians, where three underground nuclear tests were conducted during 1963-1971. Among these tests was Cannikin, at approximately 5 megatons the largest nuclear device ever exploded underground by the United States and equivalent in seismic energy release to a magnitude 7 earthquake. The blast caused about 1 m of uplift of the Bering Sea coastline in the 3-km-wide fault-bounded block within which it was detonated. The impending final transfer of stewardship of this area to the US Fish and Wildlife Service as part of the Alaska Maritime National Wildlife Refuge raises anew the question of the potential for transport of radionuclides from the shot cavity, located at 1791 m depth in mafic laharic breccias, into the accessible environment. In particular, there is concern about whether such contaminants could become concentrated in the marine food chain that is used for subsistence by Alaskan Natives (and by the broader international community through the North Pacific and Bering Fisheries). Both possible transport pathways in the form of faults and transport medium in the form of abundant water are present. Since the pre-plate tectonics paradigm days of active testing, the scientific community's understanding of the tectonic context of the Aleutian Islands has grown tremendously. Recently, the first direct measurements of motion within the arc have been made. How this new understanding should guide plans for long-term monitoring of the site is an important question. Convergence due to subduction of the North Pacific plate beneath North America ranges from near-normal at the Alaska Peninsula and eastern Aleutian islands to highly oblique in the west. Amchitka itself can be seen as a subaerial portion of a 200-km-long Rat Island arc crest segment. This fragment has torn from the Andreanof Islands to the east at

  6. Aqueous corrosion of silicate glasses. Analogy between volcanic glasses and the French nuclear waste glass R7T7

    International Nuclear Information System (INIS)

    Goldschmidt, F.

    1991-01-01

    The behaviour of borosilicate glasses upon aqueous corrosion is controlled for long periods of time (>10,000 years) by processes which are not directly accessible by means of laboratory experiments. The analogical approach consists here to compare leaching performances between the french nuclear waste glass R7T7 and natural volcanic glasses, basaltic and rhyolitic ones. The three glasses were leached in the same conditions; open system, 90 deg C, initial pH of 9.7. Basaltic and R7T7 glasses having the same kinetic of dissolution, the basaltic glass was chosen as the best analogue. (author). refs., figs., tabs

  7. Regulatory Practices on Ageing Management and Long Term Operation of Nuclear Power Plants in the Ibero-American Region. Results of the FORO/IAEA Programme on Nuclear and Radiation Safety in Ibero-America

    International Nuclear Information System (INIS)

    2014-09-01

    Although the operating lifetime of a nuclear power plant was originally anticipated to be in the range of 30-40 years, 200 of the 434 currently in operation are over 30 years old. In this context, Member States have assigned high priority to continuing the operation of nuclear power plants beyond the lifetime initially planned - while also maintaining the highest safety conditions possible. It is thus essential to encourage international cooperative efforts in the development of safety regulatory practices on ageing management and long term operation. Established in 1997, the Ibero-American Forum of Radiological and Nuclear Regulatory Agencies (FORO) aims to strengthen its members' radiological and nuclear safety regulatory organizations. Through a regional network of radiological and nuclear safety regulators, States in the Ibero-American region have worked together to strengthen radiation protection for patients, to improve safety at radiation installations, to tightten controls on radioactive sources used in medicine, agriculture and industry, and to improve safety and security at nuclear power plants. Since FORO's creation, it has cooperated with the IAEA in areas of mututal interest, and a technical programme administered by the IAEA was established in 2003 and formalized in Practical Arrangements signed in 2010. This publication presents the results of the 2009-2010 FORO/IAEA project on regulatory practices on ageing management and safety considerations for extending the operating lifetime of nuclear power plants. The purpose of the project was to provide nuclear regulators in the region with guidance on regulatory criteria, assessment, regulatory inspection and periodic safety reviews relating to ageing management and long term operation of nuclear power plants. The results are presented in a set of four reports, with guidelines for FORO members and a summary report of the project. These reports contain valuable information for the development of future

  8. Evaluating long term forecasts

    Energy Technology Data Exchange (ETDEWEB)

    Lady, George M. [Department of Economics, College of Liberal Arts, Temple University, Philadelphia, PA 19122 (United States)

    2010-03-15

    The U.S. Department of Energy's Energy Information Administration (EIA), and its predecessor organizations, has published projections of U.S. energy production, consumption, distribution and prices annually for over 30 years. A natural issue to raise in evaluating the projections is an assessment of their accuracy compared to eventual outcomes. A related issue is the determination of the sources of 'error' in the projections that are due to differences between the actual versus realized values of the associated assumptions. One way to do this would be to run the computer-based model from which the projections are derived at the time the projected values are realized, using actual rather than assumed values for model assumptions; and, compare these results to the original projections. For long term forecasts, this approach would require that the model's software and hardware configuration be archived and available for many years, possibly decades, into the future. Such archival creates many practical problems; and, in general, it is not being done. This paper reports on an alternative approach for evaluating the projections. In the alternative approach, the model is run many times for cases in which important assumptions are changed individually and in combinations. A database is assembled from the solutions and a regression analysis is conducted for each important projected variable with the associated assumptions chosen as exogenous variables. When actual data are eventually available, the regression results are then used to estimate the sources of the differences in the projections of the endogenous variables compared to their eventual outcomes. The results presented here are for residential and commercial sector natural gas and electricity consumption. (author)

  9. Phosphorus forms and chemistry in the soil profile under long-term conservation tillage: a phosphorus-31 nuclear magnetic resonance study.

    Science.gov (United States)

    Cade-Menun, Barbara J; Carter, Martin R; James, Dean C; Liu, Corey W

    2010-01-01

    In many regions, conservation tillage has replaced conventional tilling practices to reduce soil erosion, improve water conservation, and increase soil organic matter. However, tillage can have marked effects on soil properties, specifically nutrient redistribution or stratification in the soil profile. The objective of this research was to examine soil phosphorus (P) forms and concentrations in a long-term study comparing conservation tillage (direct drilling, "No Till") and conventional tillage (moldboard plowing to 20 cm depth, "Till") established on a fine sandy loam (Orthic Humo-Ferric Podzol) in Prince Edward Island, Canada. No significant differences in total carbon (C), total nitrogen (N), total P, or total organic P concentrations were detected between the tillage systems at any depth in the 0- to 60-cm depth range analyzed. However, analysis with phosphorus-31 nuclear magnetic resonance spectroscopy showed differences in P forms in the plow layer. In particular, the concentration of orthophosphate was significantly higher under No Till than Till at 5 to 10 cm, but the reverse was true at 10 to 20 cm. Mehlich 3-extractable P was also significantly higher in No Till at 5 to 10 cm and significantly higher in Till at 20 to 30 cm. This P stratification appears to be caused by a lack of mixing of applied fertilizer in No Till because the same trends were observed for pH and Mehlich 3-extractable Ca (significantly higher in the Till treatment at 20 to 30 cm), reflecting mixing of applied lime. The P saturation ratio was significantly higher under No Till at 0 to 5 cm and exceeded the recommended limits, suggesting that P stratification under No Till had increased the potential for P loss in runoff from these sites.

  10. Analysing the Air: Experiences and Results of Long Term Air Pollution Monitoring in the Asia-Pacific Region Using Nuclear Analysis Techniques

    International Nuclear Information System (INIS)

    Atanacio, Armand J.

    2015-01-01

    Particles present in the air we breathe are now recognized as a major cause of disease and premature death globally. In fact, a World Health Organization (WHO) report recently ranked ambient air pollution as one of the top 10 causes of death in the world, directly contributing annually to around 3.7 million premature deaths worldwide 65% of which occurred in the Asian region alone. Airborne particulate matter (PM) can be generated from natural sources such as windblown soil or coastal sea-spray; as well as anthropogenic sources such as power stations, industry, vehicles and domestic biomass burning. At low concentration these fine pollution particles are too small to be seen by eye, but penetrate deep into our lungs and even our blood stream as our nose and throat are inefficient at filtering them out. At large concentrations, they can also have wider regional effects including reduced visibility, acid rain and even climate variability. The International Atomic Energy Agency (IAEA) in 2000, recognizing air pollution as a significant local, national and global challenge, initiated a collaborative air pollution study involving 14 countries across the greater Asia-pacific region from 2000 to 2015. This has amassed a database containing more than 14,000 data lines of PM mass concentration and the concentration of up to 40 elements using nuclear analytical techniques. It represents the most comprehensive and long-term airborne PM data set compiled to date for the Asia-Pacific region and as will be discussed, can be used to statistically resolve individual source fingerprints and their contributions to total air pollution using Positive Matrix Factorization (PMF). This sort of data necessary for implementing or reviewing the effectiveness of policy level changes aimed at targeted air pollution reduction. (author)

  11. Assessment of the long-term risks of inadvertent human intrusion into a proposed Canadian nuclear fuel waste disposal vault in deep plutonic rock -revision 1

    International Nuclear Information System (INIS)

    Wuschke, D.M.

    1996-04-01

    Canada has conducted an extensive research program on a concept of safe disposal of nuclear fuel wastes deep In plutonic rock of the Canadian Shield. An essential goal of this program has been to develop and demonstrate a methodology to evaluate the performance of the facility against safety criteria established by Canada's regulatory agency, the Atomic Energy Control Board. These criteria are expressed in terms of risk, where risk is defined as the sum, over all significant scenarios, of the product of the probability of the scenario, the magnitude of the resultant dose, and the probability of a health effect per unit dose. This report describes the methodology developed to assess the long-term risk from inadvertent human intrusion into such a facility, and the results of its application to the proposed facility. Four intrusion scenarios were analysed, all initiated by a drilling operation. These scenarios are exposure of a member of the drilling crew, of a technologist conducting a core examination, of a construction worker and of a resident. The consequence of each scenario was estimated using standard computer codes for environmental pathways analysis and radiation dosimetry. For comparison with the risk criterion, an estimate of the probability of each scenario is also required. An event-tree methodology was used to estimate these probabilities. The estimated risks from these intrusion scenarios are several orders of magnitude below the established risk criterion. The event-tree methodology has the advantages of explicity displaying the assumptions made, of permitting easy testing of the sensitivity of the risk estimates to assumptions, and of combining technical and sociological information. (author). 53 refs., 8 tabs., 2 figs

  12. Assessment of the long-term risks of inadvertent human intrusion into a proposed Canadian nuclear fuel waste disposal vault in deep plutonic rock -revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Wuschke, D M

    1996-04-01

    Canada has conducted an extensive research program on a concept of safe disposal of nuclear fuel wastes deep In plutonic rock of the Canadian Shield. An essential goal of this program has been to develop and demonstrate a methodology to evaluate the performance of the facility against safety criteria established by Canada`s regulatory agency, the Atomic Energy Control Board. These criteria are expressed in terms of risk, where risk is defined as the sum, over all significant scenarios, of the product of the probability of the scenario, the magnitude of the resultant dose, and the probability of a health effect per unit dose. This report describes the methodology developed to assess the long-term risk from inadvertent human intrusion into such a facility, and the results of its application to the proposed facility. Four intrusion scenarios were analysed, all initiated by a drilling operation. These scenarios are exposure of a member of the drilling crew, of a technologist conducting a core examination, of a construction worker and of a resident. The consequence of each scenario was estimated using standard computer codes for environmental pathways analysis and radiation dosimetry. For comparison with the risk criterion, an estimate of the probability of each scenario is also required. An event-tree methodology was used to estimate these probabilities. The estimated risks from these intrusion scenarios are several orders of magnitude below the established risk criterion. The event-tree methodology has the advantages of explicity displaying the assumptions made, of permitting easy testing of the sensitivity of the risk estimates to assumptions, and of combining technical and sociological information. (author). 53 refs., 8 tabs., 2 figs.

  13. Compositional threshold for Nuclear Waste Glass Durability

    International Nuclear Information System (INIS)

    Kruger, Albert A.; Farooqi, Rahmatullah; Hrma, Pavel R.

    2013-01-01

    Within the composition space of glasses, a distinct threshold appears to exist that separates 'good' glasses, i.e., those which are sufficiently durable, from 'bad' glasses of a low durability. The objective of our research is to clarify the origin of this threshold by exploring the relationship between glass composition, glass structure and chemical durability around the threshold region

  14. Nuclear waste glass product consistency test (PCT): Version 7.0. Revision 3

    International Nuclear Information System (INIS)

    Jantzen, C.M.; Bibler, N.E.; Beam, D.C.; Ramsey, W.G.

    1994-06-01

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Product Specifications (WAPS), the durability of the glass needs to be measured during production to assure its long term stability and radionuclide release properties. A durability test, designated the Product Consistency Test (PCT), was developed for DWPF glass in order to meet the WAPS requirements. The response of the PCT procedure was based on extensive testing with glasses of widely different compositions. The PCT was determined to be very reproducible, to yield reliable results rapidly, and to be easily performed in shielded cell facilities with radioactive samples. Version 7.0 of the PCT procedure is attached. This draft version has been submitted to ASTM for full committee (C26, Nuclear Fuel Cycle) ballot after being balloted successfully through subcommittee C26.13 on Repository Waste Package Materials Testing

  15. Study of nuclear glasses alteration gel and synthesis of some model gels

    International Nuclear Information System (INIS)

    Ricol, S.

    1995-01-01

    This work deals with the general problem of alteration of the reference nuclear glass R7T7. Attention is paid particularly to the altered layer formed at the glass surface during alteration process. In opposition to previous works, related essentially to glass dissolution kinetics based on chemical analyses of lixiviated elements, this thesis deals with alteration problems through structural studies of the reference glass and derived gel. This approach allows the determination of mechanisms for the gel formation and a better understanding of the behaviour of glasses towards lixiviation. Both approaches appeared complementary. Based on several spectroscopic techniques, this work showed the particular role of cations such as calcium, zirconium and iron. Studies of silica-based synthetic gels showed the synergic effect of formers cation and of one highly coordinated cation. The variation of the wavenumber related to Si-O-Si asymmetric stretching vibration can be correlated to O/Si ratio for ternary systems Si/Na/Zr. On the contrary, the Si losses of the materials depend on the number of non-bridging oxygen atoms. In the perspective of long-term behaviour, the alteration gel presents better characteristics than initial glass. It is therefore a highly stable material in static conditions. In the same way, synthetic gels are materials with very low solubilities (much lower than the alteration gel) and could be used as confining matrices. (authors). refs., 71 figs., 37 tabs

  16. World's trend of national nuclear power policy and long-term perspective of nuclear power and supply and demand of uranium fuels

    International Nuclear Information System (INIS)

    Matsuo, Yuji; Nishida, Naoki; Yamaguchi, Yuji; Shimogoori, Kei; Murakami, Tomoko

    2013-01-01

    Based on perspective of nuclear power reflecting latest trend of national nuclear policy, supply and demand of uranium resources until 2035 was evaluated based on latest data. After the Fukushima nuclear accident, Germany and Italy dramatically changed nuclear power to phase out, while United States, Russia, France and Korea as well as China and India continued to promote nuclear power with no essential change of policy. Thus world's nuclear power capacity was foreseen to expand from 389 GW (2010) to 471 GW (2035, low growth case) and 760 GW (2035, high growth case). Following sharp increase of uranium cost after 2005, investment on natural uranium development became active and new operation start of uranium enrichment plants was anticipated in US and Europe, and then both supply and demand of natural uranium and uranium enrichment service would tend to relax until around 2020 and until 2035 extreme tightness of supply and demand might not occur even for high growth case. Uranium demand of Asian region including China and India would be largely expanded with natural uranium from Africa and Australia and uranium enrichment services from US, and Asian high overseas dependence would be continued. (T. Tanaka)

  17. Long-term stability of Sm2Co17-type magnets for control rod drive mechanism (CRDM) in a nuclear reactor

    International Nuclear Information System (INIS)

    Iida, H.; Imayoshi, S.; Morimoto, K.; Watanabe, M.; Komada, N.; Takeshita, T.

    1995-01-01

    Control rod drive mechanism (CRDM) is an apparatus that regulates vertical position of control rods in a nuclear reactor by using a driving motor of synchronous type. While CRDM is usually placed outside the reactor vessel to escape from the severe environment inside the vessel, built-in type CRDM, which is now being developed for advanced marine reactors, is placed inside the vessel for making the reactor compact. The driving motor must stand in high-temperature (573--603 K) and high-pressure (approximately 120 atm) water which contains a trace amount of hydrogen. Although the magnet rotor is sealed by corrosion-resistant alloy, the magnets still need to have excellent thermal and chemical stabilities in order to ensure the reliability of the system. For an application of Sm 2 Co 17 -type magnets for a driving motor of control rod drive mechanism (CRDM) placed inside a nuclear reactor vessel, long-term stabilities of Sm(Co 0.61 Fe 0.28 Cu 0.08 Ni 0.01 Zr 0.02 ) 7.3 magnets were evaluated under the severe conditions. Initial magnetic properties of the specimens at room temperature were: B r = 1.03 T, H cJ = 1,400 kA/m and (BH) max = 207 kJ/m 3 . Irreversible losses of open-circuit remanent flux of the specimens exposed for 19,000 hours in 1 atm Ar atmosphere were 5--10% at the temperature (573--603 K) and the operating point (permeance coefficient of 1.7--2.4) of the actual driving motor application. Large fraction of the irreversible loss is attributed to permanent flux loss due to oxidation of the specimen. Losses due to thermal fluctuation aftereffect of these specimens are estimated to be less than 5%. Multilayer coating of Ni, Cu, Ni and Au was found to be effective to protect the magnets from the oxidation. The coated specimens exhibited a small permanent loss value of 0.5% after the exposure to 120 atm water for 2,000 hours at 613 K

  18. ENSI's view on technical safety for the long term operation of reactors 1 and 2 in the Beznau nuclear power plant

    International Nuclear Information System (INIS)

    2010-11-01

    The reactors 1 and 2 of the Beznau nuclear power plant (KKB) are operated since about 40 years. For an operation beyond the design period of 40 years the Swiss Federal Nuclear Safety Inspectorate (ENSI) demands the evidence to be brought that the design limits of the safety relevant components will not be reached during the extended operation period. In 2008 the license holder of KKB delivered the requested documentation on material ageing on the basis of deterministic as well as probabilistic safety analyses and concluded that both reactors can be safely operated beyond 40 years. Thanks to continuous additional outfits, both reactors are in good condition from the point of view of technical safety. With a view to the extension of operation beyond 40 years, KKB already applied the necessary measures regarding technics, finances and personnel in order to keep the present technical level. Since 1991 KKB has analysed and checked components that are difficult to replace. From the evidence presented, ENSI concluded that both reactors are able to be operated up to 60 years long, however with two restrictions for reactor 1 because there the material used for the reactor pressure vessel (RPV) suffered more neutron brittleness than in reactor 2. In addition, reactor 1 is much more affected by ageing phenomena than reactor 2, but, according to neutron fluence calculations, the limiting criteria will not be reached even after 60 years of operation. Some corrosion damages were noted at the lower part of the RPV due to water containing boron acid; they are more pronounced in reactor 1 than in reactor 2. Even though the calculations done by KKB are very conservative, they show that also in the long term the operation limiting criteria about the mechanical resistance of the RPV are never reached. ENSI concludes that the safety design of both KKB reactors ensures safe control of the design basis accidents. Both reactors were continuously fitted with new equipment. With the planed

  19. Assessment of risk associated with long-term corrosion of alloy 22 and Ti-7 in the potential yucca mountain high-level nuclear waste repository

    International Nuclear Information System (INIS)

    Ahn, T.M.; Pensado, O.; Dunn, D.

    2004-01-01

    Full text of publication follows: The potential high-level nuclear waste (HLW) repository at Yucca Mountain (YM) may rely on the robustness of the outer container of the waste package (WP) as one of many barriers for waste isolation. The container is proposed to be constructed of Alloy 22, a Ni-Cr-Mo alloy known to be resistant to localized corrosion and stress corrosion cracking. Additionally, drip shields (DS) will be emplaced above the WP to minimize the groundwater contact, in the form of seepage, with the WP. The candidate alloy to construct the drip shields is a titanium based alloy (Ti-7) with some small amounts of Pd and is also known for resistance to localized corrosion. To enhance confidence of long-term WP and DS lifetimes, it is necessary to assess the conditions under which loss of passivity or localized degradation processes could occur. The accelerated degradation processes may include uniform passivity breakdown, localized corrosion, and stress corrosion cracking. This paper evaluates how such processes may occur under the long-term YM repository conditions. In the uniform passivity breakdown, three potential concerns are evaluated. The first is anodic sulphur segregation at the interface between the passive film and the bare metal. This paper models the cyclic behavior of free transient fast dissolution (induced by sulfur segregation) and re-passivation. The second is the potential accumulation of corrosion products on the WP surface, which may act as cathode of large surface area leading to fast corrosion. The effective ratio of the corrosion product area to the bare metal area is evaluated. The third is the ion selectivity in the corrosion products to alter the aqueous chemistry, which may accelerate or inhibit the corrosion. Thermodynamics of ionic sorption in the corrosion products is reviewed. In the localized corrosion, the groundwater chemistry on the WP surface is evaluated at the temperatures of the WP above 100 deg. C during the early

  20. Long Term Financing of Infrastructure

    OpenAIRE

    Sinha, Sidharth

    2014-01-01

    Infrastructure projects, given their long life, require long term financing. The main sources of long term financings are insurance and pension funds who seek long term investments with low credit risk. However, in India household financial savings are mainly invested in bank deposits. Insurance and pension funds account for only a small percentage of household financial savings. In addition most infrastructure projects do not qualify for investment by insurance and pension funds because of t...

  1. Basaltic glasses from Iceland and the deep sea: Natural analogues to borosilicate nuclear waste-form glass

    International Nuclear Information System (INIS)

    Jercinovic, M.J.; Ewing, R.C.

    1987-12-01

    The report provides a detailed analysis of the alteration process and products for natural basaltic glasses. Information of specific applicability to the JSS project include: * The identification of typical alteration products which should be expected during the long-term corrosion process of low-silica glasses. The leached layers contain a relatively high proportion of crystalline phases, mostly in the form of smectite-type clays. Channels through the layer provide immediate access of solutions to the fresh glass/alteration layer interface. Thus, glasses are not 'protected' from further corrosion by the surface layer. * Corrosion proceeds with two rates - an initial rate in silica-undersaturated environments and a long-term rate in silica-saturated environments. This demonstrates that there is no unexpected change in corrosion rate over long periods of time. The long-term corrosion rate is consistent with that of borosilicate glasses. * Precipitation of silica-containing phases can result in increased alteration of the glass as manifested by greater alteration layer thicknesses. This emphasizes the importance of being able to predict which phases form during the reaction sequence. * For natural basaltic glasses the flow rate of water and surface area of exposed glass are critical parameters in minimizing glass alteration over long periods of time. The long-term stability of basalt glasses is enhanced when silica concentrations in solution are increased. In summary, there is considerable agreement between corrosion phenomena observed for borosilicate glasses in the laboratory and those observed for natural basalt glasses of great age. (With 121 refs.) (authors)

  2. The 2013 Long-Term Budget Outlook

    Science.gov (United States)

    2013-09-01

    number of years, leading to substantial additional federal spending. For example, the nation could experience a massive earthquake, a nuclear meltdown...budget surpluses remaining after paying down publicly held debt available for redemption . a. For comparison with the current long-term projections, CBO

  3. Scoping study of salt domes, basalts and crystalline rock as related to long term risk modeling for deep geologic disposal of nuclear waste

    International Nuclear Information System (INIS)

    1978-11-01

    Purpose is to provide a preliminary geotechnical data base sufficient to initiate the development of Long-Term Risk Models for salt domes, basalt, and crystalline rock. Geology, hydrology, specific sites, and potential release pathways are considered for each type. A summary table of site suitability characteristics is presented

  4. Long term storage techniques for 85Kr

    International Nuclear Information System (INIS)

    Foster, B.A.; Pence, D.T.; Staples, B.A.

    1975-01-01

    As new nuclear fuel reprocessing plants go on stream, the collection of fission product 85 Kr will be required to avoid potential local release problems and long-term atmospheric buildup. Storage of the collected 85 Kr for a period of at least 100 years will be necessary to allow approximately 99.9 percent decay before it is released. A program designed to develop and evaluate proposed methods for long-term storage of 85 Kr is discussed, and the results of a preliminary evaluation of three methods, high pressure steel cylinders, zeolite encapsulation, and clathrate inclusion are presented. (U.S.)

  5. Long-term urethral catheterisation.

    Science.gov (United States)

    Turner, Bruce; Dickens, Nicola

    This article discusses long-term urethral catheterisation, focusing on the relevant anatomy and physiology, indications for the procedure, catheter selection and catheter care. It is important that nurses have a good working knowledge of long-term catheterisation as the need for this intervention will increase with the rise in chronic health conditions and the ageing population.

  6. Nuclear Waste Management Organization: moving forward together - program update: Canada's plan for the long-term management of used nuclear fuel

    International Nuclear Information System (INIS)

    Nash, K.

    2011-01-01

    In June 2007, the Government of Canada selected Adaptive Phased Management as Canada's plan for safeguarding the public and environment over the very long time in which used nuclear fuel must be managed. The plan requires that Canada's used nuclear fuel be safely and securely contained and isolated from people and the environment in a deep geological repository in a suitable rock formation. In May 2010, the NWMO published a process for identifying an informed and willing community to host the project and currently a number of communities in northwestern Ontario and Saskatchewan have expressed interest in learning about the project. The NWMO anticipates that it will take between seven and ten years to decide on where to locate the deep geological repository and associated facilities. By international standards, this is an ambitious timeline. Ultimately, there will have to be a compelling demonstration of willingness expressed by the citizens of any interested community after a long period of site assessment, and learning about the project, before it is selected to host the project. The presentation will cover the history leading to the 2007 government decision and the full range of activities being undertaken to i