WorldWideScience

Sample records for based radioactive decay

  1. Validation of Geant4-based Radioactive Decay Simulation

    OpenAIRE

    Hauf, Steffen; Kuster, Markus; Batič, Matej; Bell, Zane W.; Dieter H.H. Hoffmann; Lang, Philipp M.; Neff, Stephan; Pia, Maria Grazia; Weidenspointner, Georg; Zoglauer, Andreas

    2013-01-01

    Radioactive decays are of concern in a wide variety of applications using Monte-Carlo simulations. In order to properly estimate the quality of such simulations, knowledge of the accuracy of the decay simulation is required. We present a validation of the original Geant4 Radioactive Decay Module, which uses a per-decay sampling approach, and of an extended package for Geant4-based simulation of radioactive decays, which, in addition to being able to use a refactored per-decay sampling, is cap...

  2. Validation of Geant4-based Radioactive Decay Simulation

    CERN Document Server

    Hauf, Steffen; Batič, Matej; Bell, Zane W; Hoffmann, Dieter H H; Lang, Philipp M; Neff, Stephan; Pia, Maria Grazia; Weidenspointner, Georg; Zoglauer, Andreas

    2013-01-01

    Radioactive decays are of concern in a wide variety of applications using Monte-Carlo simulations. In order to properly estimate the quality of such simulations, knowledge of the accuracy of the decay simulation is required. We present a validation of the original Geant4 Radioactive Decay Module, which uses a per-decay sampling approach, and of an extended package for Geant4-based simulation of radioactive decays, which, in addition to being able to use a refactored per-decay sampling, is capable of using a statistical sampling approach. The validation is based on measurements of calibration isotope sources using a high purity Germanium (HPGe) detector; no calibration of the simulation is performed. For the considered validation experiment equivalent simulation accuracy can be achieved with per-decay and statistical sampling.

  3. Radioactive Decays in Geant4

    CERN Document Server

    Hauf, Steffen; Batič, Matej; Bell, Zane W; Hoffmann, Dieter H H; Lang, Philipp M; Neff, Stephan; Pia, Maria Grazia; Weidenspointner, Georg; Zoglauer, Andreas

    2013-01-01

    The simulation of radioactive decays is a common task in Monte-Carlo systems such as Geant4. Usually, a system either uses an approach focusing on the simulations of every individual decay or an approach which simulates a large number of decays with a focus on correct overall statistics. The radioactive decay package presented in this work permits, for the first time, the use of both methods within the same simulation framework - Geant4. The accuracy of the statistical approach in our new package, RDM-extended, and that of the existing Geant4 per-decay implementation (original RDM), which has also been refactored, are verified against the ENSDF database. The new verified package is beneficial for a wide range of experimental scenarios, as it enables researchers to choose the most appropriate approach for their Geant4-based application.

  4. Radioactive decay data tables

    International Nuclear Information System (INIS)

    The estimation of radiation dose to man from either external or internal exposure to radionuclides requires a knowledge of the energies and intensities of the atomic and nuclear radiations emitted during the radioactive decay process. The availability of evaluated decay data for the large number of radionuclides of interest is thus of fundamental importance for radiation dosimetry. This handbook contains a compilation of decay data for approximately 500 radionuclides. These data constitute an evaluated data file constructed for use in the radiological assessment activities of the Technology Assessments Section of the Health and Safety Research Division at Oak Ridge National Laboratory. The radionuclides selected for this handbook include those occurring naturally in the environment, those of potential importance in routine or accidental releases from the nuclear fuel cycle, those of current interest in nuclear medicine and fusion reactor technology, and some of those of interest to Committee 2 of the International Commission on Radiological Protection for the estimation of annual limits on intake via inhalation and ingestion for occupationally exposed individuals

  5. Natural decay and half-life: Two bases for the radioactive waste management policy

    International Nuclear Information System (INIS)

    How can environmental protection imperatives and technical requirements be reconciled in radioactive waste disposal? In France, two kind of facilities illustrate how radioactive waste disposal can merge scientific, regulatory and political concerns, based on the natural decay property of radioactive material. Andra's near-surface disposal facilities for short-lived waste are operated for one generation (30 years) and monitored for ten generations (300 years), with the radioactivity of the waste declining to naturally-occurring levels through the process of radioactive decay by the end of that time. The waste to be disposed of in such facilities contains nuclides with half-life below 30 years and is said time-degradable at human scale. The challenges are different for long-lived waste, which are also time-degradable, but not at human scale. Risk assessments for disposal of such waste, relatively straightforward for the first few thousand years, must also demonstrate that levels decline to naturally-occurring levels, even though this may occur in tens of thousands of years, when it is predicted that climatic change, new glacial activity, and a drop in sea level will occur, and when civilizations will no doubt have changed as well. This demonstration of very long-term safety is an express requirement for radioactive waste disposal. The paper briefly describes the criteria used in the French regulation to determine what waste can be accepted for near-surface disposal and the recent significant steps taken to resume field work for the siting of underground laboratories and possible, much later, a repository for waste non acceptable for near-surface disposal. The conclusion focuses in demonstrating how a consistent National or International Waste Management Program based on clear ethical, societal, scientific and technological choices has to be prepared and presented to the Authorities and to the Public, allowing the waste management Organization to gain the necessary

  6. Radioactive Decays in Geant4

    OpenAIRE

    Hauf, Steffen; Kuster, Markus; Batič, Matej; Bell, Zane W.; Dieter H.H. Hoffmann; Lang, Philipp M.; Neff, Stephan; Pia, Maria Grazia; Weidenspointner, Georg; Zoglauer, Andreas

    2013-01-01

    The simulation of radioactive decays is a common task in Monte-Carlo systems such as Geant4. Usually, a system either uses an approach focusing on the simulations of every individual decay or an approach which simulates a large number of decays with a focus on correct overall statistics. The radioactive decay package presented in this work permits, for the first time, the use of both methods within the same simulation framework - Geant4. The accuracy of the statistical approach in our new pac...

  7. Is Radioactive Decay Really Exponential?

    CERN Document Server

    Aston, Philip J

    2012-01-01

    Radioactive decay of an unstable isotope is widely believed to be exponential. This view is supported by experiments on rapidly decaying isotopes but is more difficult to verify for slowly decaying isotopes. The decay of 14C can be calibrated over a period of 12,550 years by comparing radiocarbon dates with dates obtained from dendrochronology. It is well known that this approach shows that radiocarbon dates of over 3,000 years are in error, which is generally attributed to past variation in atmospheric levels of 14C. We note that predicted atmospheric variation (assuming exponential decay) does not agree with results from modelling, and that theoretical quantum mechanics does not predict exact exponential decay. We give mathematical arguments that non-exponential decay should be expected for slowly decaying isotopes and explore the consequences of non-exponential decay. We propose an experimental test of this prediction of non-exponential decay for 14C. If confirmed, a foundation stone of current dating meth...

  8. Progress and Validation of Geant4 Based Radioactive Decay Simulation Using the Examples of Simbol-X and IXO

    CERN Document Server

    Hauf, S; Pia, M G; Bell, Z; Briel, U; Chipaux, R; Hoffmann, D H H; Kendziorra, E; Laurent, P; Strüder, L; Tenzer, C; Weidenspointer, G; Zoglauer, A

    2009-01-01

    The anticipated high sensitivity and the science goals of the next generation X-ray space missions, like the International X-ray Observatory or Simbol-X, rely on a low instrumental background, which in turn requires optimized shielding concepts. We present Geant4 based simulation results on the IXO Wide Field Imager cosmic ray proton induced background in comparison with previous results obtained for the Simbol-X LED and HED focal plane detectors. Our results show that an improvement in mean differential background flux compared to actually operating X-ray observatories may be feasible with detectors based on DEPFET technology. In addition we present preliminary results concerning the validation of Geant4 based radioactive decay simulation in space applications as a part of the Nano5 project.

  9. Optical potential obtained from relativistic-mean-field theory-based microscopic nucleon-nucleon interaction: applied to cluster radioactive decays

    Science.gov (United States)

    Singh, BirBikram; Bhuyan, M.; Patra, S. K.; Gupta, Raj K.

    2012-02-01

    A microscopic nucleon-nucleon (NN) interaction is derived from the popular relativistic-mean-field (RMF) theory Lagrangian and used to obtain the optical potential by folding it with the RMF densities of cluster and daughter nuclei. The NN-interaction is remarkably related to the inbuilt fundamental parameters of RMF theory, and the results of the application of the so obtained optical potential, made to exotic cluster radioactive decays and α+α scattering, are found comparable to that for the well-known, phenomenological M3Y effective NN-interaction. The RMF-based NN-interaction can also be used to calculate a number of other nuclear observables.

  10. R and D on the Geant4 radioactive decay physics

    Energy Technology Data Exchange (ETDEWEB)

    Hauf, Steffen; Kuster, Markus; Lang, Philipp M.; Hoffmann, Dieter H.H. [IKP, TU Darmstadt (Germany); Pia, Maria Grazia [CERN, Genf (Switzerland); INFN, Genua (Italy); Bell, Zane [Oak Ridge National Lab. (United States); Weidenspointner, Georg [MPI HLL, Muenchen (Germany); MPE, Garching (Germany); Zoglauer, Andreas [SSL, Berkeley (United States)

    2010-07-01

    The anticipated high sensitivity of the next generation X-ray space missions, like the International X-ray Observatory, rely on a low instrumental background, which in turn requires optimized shielding concepts for the instruments. Most state-of-the-art approaches estimate the prompt cosmic ray, solar proton and the cosmic X-ray induced background with simulations using the Geant4 Monte Carlo tool-kit whose electromagnetic and hadronic physics models have extensively been verified with space and ground based experiments. In contrast measurements to verify the radioactive decay implementation in Geant4 have been rare or have only been tested on a limited set of isotopes, which are not necessarily those used in satellite construction. We present first results of two experiments aimed to verify Geant4 activation and decay physics for materials significant for low background X-ray detectors in space.

  11. Radioactive decays at limits of nuclear stability

    DEFF Research Database (Denmark)

    Pfützner, M.; Karny, M.; Grigorenko, L. V.;

    2012-01-01

    , and their relative probabilities. When approaching limits of nuclear stability, new decay modes set in. First, beta decays are accompanied by emission of nucleons from highly excited states of daughter nuclei. Second, when the nucleon separation energy becomes negative, nucleons start being emitted from the ground...

  12. Investigations of the chemical consequences of radioactive decay of iodine 125 and tritium in labelled pyrimidine bases using the double labelling technique and ESR spectroscopy

    International Nuclear Information System (INIS)

    In the present work, the chemical secondary reactions of the radioactive decay (K capture) of I 125 in solutions of the synthetic DNA forerunner iodouracil were investigated with the aim to interpret the large radiotoxicity of DNA-bonded I 125 by procedures at molecular level. Furthermore, the radical formation as a result of the decay of tritium in 3H-labelled thymine and cytosine were also traced on a smaller scale. The chemical decay effects of molecular bonded iodine 125 was investigated using the double labelling technique (I 125 + C 14). After accumulation of the I 125 decays and hence the product molecules in aqueous solution at +20 or -1960C, the reaction products were radio-gas chromatographically separated or by means of high-pressure liquid chromatography and then analyzed. Radiolytic side effects were simultaneously determined by separate γ-irradiation experiments. The results show that due to the Auger effect as a result of the radioactive decay of 125I, a significantly greater destruction occurs in the immediate environment than can be achieved by external irradiation with γ-quanta. It could be shown for the first time, by detection of the volatile transmutation products CO and CO2, that drastic chemical consequences result for the molecule residue in the decay of molecular-bonded 125I even in the condensed phase. The β-autoradiolysis was also determined to be the main source of fragmentation in the case of tritium beta decay in thymine and cytosine. ESR investigations show distinct differences in the radical formation compared to external γ-radiolysis. (orig./RB)

  13. Comprehensive decay law for emission of charged particles and exotic cluster radioactivity

    Indian Academy of Sciences (India)

    Basudeb Sahu

    2014-04-01

    A general decay formula for the emission of charged particles from metastable nuclei is developed based on the basic phenomenon of resonances occurring in quantum scattering process under Coulomb-nuclear potential. It relates the half-lives of radioactive decays with the values of the outgoing elements with masses and charges of the nuclei involved in the decay. The relation is found to be a generalization of the Geiger–Nuttall law in radioactivity and explains well all the known emissions of charged particles including clusters, alpha and proton.

  14. Digital signal processing for radioactive decay studies

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D.; Madurga, M.; Paulauskas, S. V. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Ackermann, D.; Heinz, S.; Hessberger, F. P.; Hofmann, S. [GSI Helmholtzzentrum fuer Schwerionenforschung, D-64220, Darmstadt (Germany); Grzywacz, R. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Miernik, K.; Rykaczewski, K. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Tan, H. [XIA LLC, Hayward, CA 94544 (United States)

    2011-11-30

    The use of digital acquisition system has been instrumental in the investigation of proton and alpha emitting nuclei. Recent developments extend the sensitivity and breadth of the application. The digital signal processing capabilities, used predominately by UT/ORNL for decay studies, include digitizers with decreased dead time, increased sampling rates, and new innovative firmware. Digital techniques and these improvements are furthermore applicable to a range of detector systems. Improvements in experimental sensitivity for alpha and beta-delayed neutron emitters measurements as well as the next generation of superheavy experiments are discussed.

  15. Metastable Dark Energy with Radioactive-like Decay

    CERN Document Server

    Shafieloo, Arman; Sahni, Varun; Starobinsky, Alexei A

    2016-01-01

    We propose a new class of metastable dark energy (DE) models in which the DE decay rate does not depend on external parameters such as the scale factor or the curvature of the Universe. Instead, the DE decay rate is a function only of the intrinsic properties of DE and, in this sense, resembles the radioactive decay of particles and nuclei. As a consequence, the DE energy density becomes a function of the proper time elapsed since its formation, presumably in the very early Universe. Such a natural type of DE decay can profoundly affect the expansion history of the Universe and its age. Metastable DE can decay in three distinct ways: (i) exponentially, (ii) into dark matter, (iii) into dark radiation. Testing metastable DE models with observational data we find that the decay half-life must be larger than the age of the Universe. Models in which dark energy decays into dark matter lead to lower values of the Hubble parameter at large redshifts relative to $\\Lambda$CDM. Consequently these models provide a bett...

  16. Analysis of the radioactivity of air dust particles and simulation of radioactive decay

    International Nuclear Information System (INIS)

    This document presents the decay equations of 2 successive radionuclides Pb 214 and Bi 214 in the decay chain of radon. Both radionuclides are present in the air and a measurement of the radioactivity of dust particles collected on an air filter during regular intervals of time has been performed. The experimental data has been analysed through the Excel software and it appears that the values of the decay constants that fit best the experimental curve are 4.2 10-4 /s for lead 214 and 5.1 10-4 /s for bismuth 214 while theoretical values are respectively 4.3 10-4 /s and 5.6 10-4 /s. This experiment can be made in any college physics class. The second part of this document is dedicated to a simulation of radioactive decay that could be performed in school through the use of 200 dice parted into 10 groups of students. Each group tosses its 20 dice, sets aside the dice whose 1-face have showed up and writes down the number of remaining dice before tossing them again. The results of the 10 groups have to be gathered in a unique table, the processing of the results with the Excel software shows that the value of the constant decay that fits best the curve would be closer to 1/6 if the total number of dice was more important. (A.C.)

  17. An Accelerated Radioactive Decay (ARD) Model for Type Ia Supernovae

    Science.gov (United States)

    Rust, Bert W.; Leventhal, Marvin

    2016-01-01

    In 1975, Leventhal and McCall [Nature, 255, 690-692] presented a radioactive decay model 56N i --> 56Co --> 56Fe for the post-peak luminosity decay of Type I supernovae light curves, in which the two decay rates are both accelerated by a common factor. In 1976, Rust, Leventhal and McCall [Nature, 262, 118-120] used sums of exponentials fitting to confirm the acceleration hypothesis, but their result was nevertheless rejected by the astronomical community. Here, we model Type Ia light curves with a system of ODEs (describing the nuclear decays) forced by a Ni-deposition pulse modelled by a 3-parameter Weibull pdf, with all of this occuring in the center of a pre-existing, optically thick, spherical shell which thermalizes the emitted gamma rays. Fitting this model to observed light curves routinely gives fits which account for 99.9+% of the total variance in the observed record. The accelerated decay rates are so stable, for such a long time, that they must occur in an almost unchanging environment -- not it a turbulent expanding atmosphere. The amplitude of the Ni-deposition pulse indicates that its source is the fusion of hydrogen. Carbon and oxygen could not supply the large energy/nucleon that is observed. The secondary peak in the infrared light curve can be easily modelled as a light echo from dust in the back side of the pre-existing shell, and the separation between the peaks indicates a radius of ≈15 light days for the shell. The long-term stability of the acceleration suggests that it is a kinematic effect arising because the nuclear reactions occur either on the surface of a very rapidly rotating condensed object, or in a very tight orbit around such an object, like the fusion pulse in a tokomak reactor.

  18. Kinetics analysis and quantitative calculations for the successive radioactive decay process

    Science.gov (United States)

    Zhou, Zhiping; Yan, Deyue; Zhao, Yuliang; Chai, Zhifang

    2015-01-01

    The general radioactive decay kinetics equations with branching were developed and the analytical solutions were derived by Laplace transform method. The time dependence of all the nuclide concentrations can be easily obtained by applying the equations to any known radioactive decay series. Taking the example of thorium radioactive decay series, the concentration evolution over time of various nuclide members in the family has been given by the quantitative numerical calculations with a computer. The method can be applied to the quantitative prediction and analysis for the daughter nuclides in the successive decay with branching of the complicated radioactive processes, such as the natural radioactive decay series, nuclear reactor, nuclear waste disposal, nuclear spallation, synthesis and identification of superheavy nuclides, radioactive ion beam physics and chemistry, etc.

  19. Kinetics analysis and quantitative calculations for the successive radioactive decay process

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Zhiping, E-mail: zhouzp@ujs.edu.cn [School of Materials Science and Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013 (China); Yan, Deyue [School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Zhao, Yuliang; Chai, Zhifang [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2015-01-15

    The general radioactive decay kinetics equations with branching were developed and the analytical solutions were derived by Laplace transform method. The time dependence of all the nuclide concentrations can be easily obtained by applying the equations to any known radioactive decay series. Taking the example of thorium radioactive decay series, the concentration evolution over time of various nuclide members in the family has been given by the quantitative numerical calculations with a computer. The method can be applied to the quantitative prediction and analysis for the daughter nuclides in the successive decay with branching of the complicated radioactive processes, such as the natural radioactive decay series, nuclear reactor, nuclear waste disposal, nuclear spallation, synthesis and identification of superheavy nuclides, radioactive ion beam physics and chemistry, etc.

  20. Nuclear structure from radioactive decay: Annual progress report

    International Nuclear Information System (INIS)

    The primary focus this year has been the continuing studies of intruder states and shape coexistence in the neutron-deficient Z /approximately/ 82 region. Most notably, an extensive region of odd-mass nuclei is emerging within which low-lying low-energy electric monopole (EO) transitions occur. This is a completely new nuclear structure phenomenon. The empirical results are based on on-line decay scheme spectroscopy of mass-separated isotopes at UNISOR. In particular, many transition multipolarities are determined from conversion electron subshell ratios observed in γ-gated electron coincidence spectra. This is a completely new nuclear spectroscopic technique. To cite a specific example: our studies of the 185Au → 185Pt decay scheme reveal at least 11 transitions with EO components. This is unprecedented in nuclear structure. The role of EO transitions is being pursued in the larger framework of a signature of shape coexistence in nuclei

  1. A radioactive decay gamma-ray retrieval system

    International Nuclear Information System (INIS)

    This report describes the implementation of an Information Retrieval System which is used to help researchers identify the isotopes in a radioactive sample. The system was implemented in Prolog and uses data structure techniques to store the information and speed the retrieval. The main features of scientific systems are static data and a quantity of information well below that of commercial systems. Such features make Prolog the ideal language for programming these applications. This data base includes gamma energies by nuclide in the energy range from 1.6 keV to 9480.4 keV. Data can be retrieved either by energy, nuclide or element. (Author)

  2. The light curve in supernova modeled by a continuous radioactive decay of $^{56}$Ni

    CERN Document Server

    Zaninetti, L

    2014-01-01

    The UVOIR bolometric light curves are usually modeled by the radioactive decay. In order to model more precisely the absolute/apparent magnitude versus time relationship the continuous production of radioactive isotopes is introduced. A differential equation of the first order with separable variables is solved.

  3. Cluster emission in the radioactive decay of 223Ac

    CERN Document Server

    Steyn, G F; Faccio, D; Bonetti, R; Tretyakova, S P; Shishkin, S V; Ogloblin, A A; Pik-Pichak, G A; Vermeulen, C; van der Meulen, N P; van der Walt, T N; McGee, D

    2010-01-01

    The branching ratio of 223Ac decay by spontaneous 14C emission was measured and a search for 15N clusters was performed. After exposure of a hemispherical array of solid-state nuclear track detectors, 347 14C events were identified and no 15N events. B(14C) = λ(14C)/λ(α) = (3.2 ± 1.0) x 10-11 is consistent with a favoured ground state to ground state transition. As no nitrogen tracks were found, only an upper limit could be inferred for 15N emission, B(15N) = λ(15N)/λ(α) ≤ 2.2 x 10-13 (confidence limit 90%), consistent with an unfavoured transition. Intense 227Pa sources were produced for this study, using the reaction 232Th(p,6n)227Pa. This offered an opportunity to compare the measured source strength with predictions based on published excitation function data.

  4. The Determination of Components of Radioactive Decay Mixtures by Computer Analysis of Count-Rate Data

    International Nuclear Information System (INIS)

    The components of a mixture of n radioactive isotopes can be determined from the change in activity with time provided that the activity of at least n-1 components changes significantly during the period of observation, either by direct decay or by the growth of decay products. ft is possible to predict a set of possible components for each mixture encountered, based on considerations such as the origin and history of the mixture and the separation chemistry and counting technique(s) used. If such considerations are properly applied, the set of possible components will include all of the actual components in the mixture. The appropriate growth and/or decay equations can then be formulated and solved simultaneously to obtain each component, or the mixture can be resolved graphically by extrapolations of the linear portions of the total decay-growth curve. However, when the number of components is large and/or when complex decay schemes are involved, these two techniques either cannot be applied or the errors associated with the estimates cannot be assessed. Selection of decay components by a least-squares procedure provides better estimates than solution by simultaneous equations alone. Consequently, a least-squares Fortran computer programme (designated CORD) has been developed which solves the general problem: given the times and counts per unit time from a sample, the possible radioisotopic parents and decay schemes and all associated decay constants and detection efficiencies compute the amount of each parent actually present at a predetermined zero time. In addition, the programme yields the amounts of the parents and daughters present at all data times. Initially used with bioassay and environmental samples, the programme has been specifically designed for analysing count-rate data obtained by non-spectroscopic alpha- or beta-counting. However, it should be adaptable to total gamma and spectroscopic data, provided the energy ranges over which these

  5. Cold valleys in the radioactive decay of 248-254Cf isotopes

    Indian Academy of Sciences (India)

    R K Biju; Sabina Sahadevan; K P Santosh; Antony Joseph

    2008-04-01

    Based on the concept of cold valley in cold fission and fusion, we have investigated the cluster decay process in 248-254Cf isotopes. In addition to alpha particle minima, other deep minima occur for S, Ar and Ca clusters. It is found that inclusion of proximity potential does not change the position of minima but minima become deeper. Taking Coulomb and proximity potential as interacting barrier for post-scission region, we computed half-lives and other characteristics for various clusters from these parents. Our study reveals that these parents are stable against light clusters and unstable against heavy clusters. Computed half-lives for alpha decay agree with experimental values within two orders of magnitude. The most probable clusters from these parents are predicted to be 46Ar, 48,50Ca which indicate the role of doubly or near doubly magic clusters in cluster radioactivity. Odd A clusters are found to be favorable for emission from odd A parents. Cluster decay model is extended to symmetric region and it is found that symmetric fission is also probable which stresses the role of doubly or near doubly magic 132Sn nuclei. Geiger-Nuttal plots were studied for various clusters and are found to be linear with varying slopes and intercepts.

  6. Simulation software of radioactive decay, β and γ disintegration of cesium 137

    International Nuclear Information System (INIS)

    We present a software dedicated to radioactivity studies, in particular to radioactive decays. The software has been developed to model the C.R.A.B. (Alpha Beta radioactivity counter), a device constructed in the seventies for use as an educational support for radioactive studies in french schools. The evolution of safety rules prevents nowadays the use of such educational devices in schools. At the origin, the software was developed to train students before a tutorial session using a real radioactive source of Cesium 237 and now the software substitutes entirely the experiments. Indeed, the simulation reassures parents and students who are always afraid of radioactivity. Various studies are proposed: study of the exponential nuclear radioactive decay on a network of radioactive nuclei and roll of dices, Poisson and Gauss distributions, influence of the source-detector distance, radiation absorption by aluminum or by lead. This software is currently used either in the last year of high school or at the University for students in their first year. (author)

  7. Global Anisotropy of Space and experimental investigation of changes in $\\beta$-decay count rate of radioactive elements

    CERN Document Server

    Baurov, Yu A; Kushniruk, V F; Sobolev, Yu G; Baurov, Yu.A.; Sobolev, Yu.G.

    1998-01-01

    The results of experimental investigations of changes in beta-decay count rate of radioactive elements, are presented, and an explanation of those on the base of a new physical conception of forming the observed three-dimensional space from a finite set of one-dimensional discrete vectorial objects (byuons), containing the cosmological vectorial potential, a new fundamental vectorial constant, is given. In the theory, the vector direction corresponds with that of the axis of Universe rotation being discussed in literature.

  8. The use of a velocity filter in α-decay studies of microsecond radioactivities

    International Nuclear Information System (INIS)

    A new method of studying microsecond radioactivities of evaporation residues produced by heavy-ion reactions is described. Forward recoiling products were separated from the beam particles by using a velocity filter and implanted into a Si(Au) detector. Their subsequent α decays were then studied with the same detector. (orig.)

  9. Description of alpha decay and cluster radioactivity in the dinuclear system model

    Science.gov (United States)

    Kuklin, S. N.; Adamian, G. G.; Antonenko, N. V.

    2016-03-01

    A unified description of cluster radioactivity and α-decay of cold nuclei in the dinuclear system model is proposed. Quantum dynamical fluctuations along the charge (mass) asymmetry coordinate determine the spectroscopic factor, and tunneling along the relative distance coordinate determines the penetrability of the barrier of the nucleus-nucleus interaction potential. A new method for calculating the spectroscopic factor is proposed. The hindrance factors for the orbital angular momentum transfer are studied. A potential reason for the half-life to deviate from the Geiger-Nuttall law in α-decays of neutron-deficient nuclei 194, 196Rn is found. The fine structure of α-decays of U and Th isotopes is predicted and characterized. The model is used to describe α-decays from the rotational band of even-even nuclei. The known half-lives in the regions of "lead" and "tin" radioactivities are reproduced well, and the most probable cluster yields are predicted. The cluster decay of excited nuclei is discussed. The relation of cluster radioactivity to spontaneous fission and highly deformed nuclear states is analyzed.

  10. Radioactive decay products in neutron star merger ejecta: heating efficiency and $\\gamma$-ray emission

    CERN Document Server

    Hotokezaka, Kenta; Tanaka, Masaomi; Bamba, Aya; Terada, Yukikatsu; Piran, Tsvi

    2015-01-01

    The radioactive decay of the freshly synthesized $r$-process nuclei ejected in compact binary mergers power optical/infrared macronovae (kilonovae) that follow these events. The light curves depend critically on the energy partition among the different products of the radioactive decay and this plays an important role in estimates of the amount of ejected $r$-process elements from a given observed signal. We study the energy partition and $\\gamma$-ray emission of the radioactive decay. We show that $20$-$50\\%$ of the total radioactive energy is released in $\\gamma$-rays on timescales from hours to a month. The number of emitted $\\gamma$-rays per unit energy interval has roughly a flat spectrum between a few dozen keV and $1$ MeV so that most of this energy is carried by $\\sim 1$ MeV $\\gamma$-rays. However at the peak of macronova emission the optical depth of the $\\gamma$-rays is $\\sim 0.02$ and most of the $\\gamma$-rays escape. The loss of these $\\gamma$-rays reduces the heat deposition into the ejecta and h...

  11. Asymptotic Analysis of Time-Dependent Neutron Transport Coupled with Isotopic Depletion and Radioactive Decay

    Energy Technology Data Exchange (ETDEWEB)

    Brantley, P S

    2006-09-27

    We describe an asymptotic analysis of the coupled nonlinear system of equations describing time-dependent three-dimensional monoenergetic neutron transport and isotopic depletion and radioactive decay. The classic asymptotic diffusion scaling of Larsen and Keller [1], along with a consistent small scaling of the terms describing the radioactive decay of isotopes, is applied to this coupled nonlinear system of equations in a medium of specified initial isotopic composition. The analysis demonstrates that to leading order the neutron transport equation limits to the standard time-dependent neutron diffusion equation with macroscopic cross sections whose number densities are determined by the standard system of ordinary differential equations, the so-called Bateman equations, describing the temporal evolution of the nuclide number densities.

  12. Selection of nuclide decay chains for use in the assessment of the radiological impact of geological repositories for radioactive waste

    International Nuclear Information System (INIS)

    The criteria for selecting nuclide decay chains for use in the assessment of the radiological impact of geological repositories for radioactive waste are given. The reduced chains recommended for use with SYVAC are described. (author)

  13. Wait for it: Post-supernova winds driven by delayed radioactive decays

    CERN Document Server

    Shen, Ken J

    2016-01-01

    In most astrophysical situations, the radioactive decay of 56Ni to 56Co occurs via electron capture with a fixed half-life of 6.1 days. However, this decay rate is significantly slowed when the nuclei are fully ionized because K-shell electrons are unavailable for capture. In this paper, we explore the effect of these delayed decays on white dwarfs (WDs) that may survive Type Ia and Type Iax supernovae (SNe Ia and SNe Iax). The energy released by the delayed radioactive decays of 56Ni and 56Co drives a persistent wind from the surviving WD's surface that contributes to the late-time appearance of these SNe after emission from the bulk of the SN ejecta has faded. We use the stellar evolution code MESA to calculate the hydrodynamical evolution and resulting light curves of these winds. Our post-SN Ia models conflict with late-time observations of SN 2011fe, but uncertainties in our initial conditions prevent us from ruling out the existence of surviving WD donors. Much better agreement with observations is achi...

  14. Entrance channel effect with stable and radioactive beams using dynamical cluster decay model

    International Nuclear Information System (INIS)

    The decay of hot and rotating 172Yb*, formed in two entrance channels 124Sn + 48Ca and 132Sn + 40Ca, is studied using the dynamical cluster-decay model. The effect of entrance channel, deformations (up to β2), barrier modification and fusion enhancement are addressed. The decay pattern of compound system, formed in different channels at comparable energy around the barrier, shows change in magnitude with structure remains almost same. There is an increase in the fusion probability with decrease in barrier modification, which leads to fusion enhancement at low energies. The higher ℓ values are contributing for 132Sn + 40Ca channel at lower energies as compare to 124Sn + 48Ca. It is inferred that with the use of stable and radioactive beam, forming same compound nucleus, the entrance channel dependence changes with the excitation energy

  15. Entrance channel effect with stable and radioactive beams using dynamical cluster decay model

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Raj, E-mail: rajkumarfzr@gmail.com [Dipartimento di Fisica “Galileo Galilei” and INFN, University of Padova, Padova-35131 (Italy); Jain, Deepika [School of Physics and Material Science, Thapar University, Patiala-147004 (India)

    2014-09-15

    The decay of hot and rotating {sup 172}Yb*, formed in two entrance channels {sup 124}Sn + {sup 48}Ca and {sup 132}Sn + {sup 40}Ca, is studied using the dynamical cluster-decay model. The effect of entrance channel, deformations (up to β{sub 2}), barrier modification and fusion enhancement are addressed. The decay pattern of compound system, formed in different channels at comparable energy around the barrier, shows change in magnitude with structure remains almost same. There is an increase in the fusion probability with decrease in barrier modification, which leads to fusion enhancement at low energies. The higher ℓ values are contributing for {sup 132}Sn + {sup 40}Ca channel at lower energies as compare to {sup 124}Sn + {sup 48}Ca. It is inferred that with the use of stable and radioactive beam, forming same compound nucleus, the entrance channel dependence changes with the excitation energy.

  16. LEAF: a computer program to calculate fission product release from a reactor containment building for arbitrary radioactive decay chains

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.E.; Apperson, C.E. Jr.; Foley, J.E.

    1976-10-01

    The report describes an analytic containment building model that is used for calculating the leakage into the environment of each isotope of an arbitrary radioactive decay chain. The model accounts for the source, the buildup, the decay, the cleanup, and the leakage of isotopes that are gas-borne inside the containment building.

  17. LEAF: a computer program to calculate fission product release from a reactor containment building for arbitrary radioactive decay chains

    International Nuclear Information System (INIS)

    The report describes an analytic containment building model that is used for calculating the leakage into the environment of each isotope of an arbitrary radioactive decay chain. The model accounts for the source, the buildup, the decay, the cleanup, and the leakage of isotopes that are gas-borne inside the containment building

  18. Radioactivity and decay heat generation in precambrian magmatic rocks (with the South Pamirs as an example)

    International Nuclear Information System (INIS)

    The evaluation of the heat generation share in the results of the long-living radioactive elements (RAE) decay in the Earth surface layers is accomplished on the basis of the data on the uranium and thorium concentration in the precambrian magmatic rocks of the South Pamirs. It was supposed by the calculations, that the value of the heat flux, generated by the rocks, is determined mainly by the RAE content in the Earth upper layer crust itself of 10-15 km. It is shown that the radioheat generation share is within the range of 5-10% from the measured values of the geothermal flows

  19. Simulation of ambient dose equivalent from -rays from radioactive decays with FLUKA and DORIAN

    CERN Document Server

    Vujanovic, Milena

    2015-01-01

    During my stay (29. June- 25. September 2015.) as a participant of Summer Student Programme I was working in Radiation Protection group at CERN. The primary task of my project was to extend the functionality of the DORIAN (DOse Rate Inspector and ANalyzer) code that is used for prediction and analysis of residual dose rated due to accelerator radi- ation induced activation. This task consisted of writing and validating a dedicated FLUKA user routine to simulate the radiation coming from radioactive decays. The results of the FLUKA simulations using this user routine then had to be integrated into the DORIAN code.

  20. GETOUT, Radioactive Release and Decay Chain Calculation for Nuclear Waste Disposal

    International Nuclear Information System (INIS)

    1 - Description of problem or function: GETOUT is a set of four FORTRAN programs and associated subroutines developed as an aid to investigate the migration of radionuclide chains from an underground source. The model to be analyzed is an underground nuclear waste disposal site and a uniform one-dimensional soil column that connects the site with a surface water body. At an arbitrary time after the waste is deposited, the radioactive material is released to an underground aquifer which flows at constant velocity directly through the soil column into the surface body. The program takes into account the compilations introduced by the radioactive decay of first-order chains to produce other species which have different absorption characteristics and, in turn, decay at different rates. 2 - Method of solution: GETOUT's programs ONE, TWO, and THREE solve analytical expressions describing the migration of single nuclides, and 2- and 3-member chains, respectively. Program FOUR solves more complex chains described by empirical combinations of simpler chains. The equations used were developed by Lester, Burkholder, Jansen, and Cloninger. Solutions are computed for impulse release without dispersion,impulse release with dispersion, band release without dispersion, and band release with dispersion. Time/inventory profiles are calculated. 3 - Restrictions on the complexity of the problem: Maxima of: 88 discharge profiles, 51 single chains, 26 two-member chains, 11 three-member chains

  1. Alloy development for fast induced radioactivity decay for fusion reactor applications

    International Nuclear Information System (INIS)

    The Cr-Mo ferritic (martensitic) steels and austenitic stainless steels (primarily type 316 and variations on that composition) are the leading candidates for the structural components for future fusion reactors. However, irradiation of such steels in a fusion environment produces long-lived radioactive isotopes. These isotopes lead to difficult radioactive waste disposal problems once the structure is removed from service. Such problems could be reduced by developing steels that contain only elements that produce radioactive isotopes that decay to low levels in a reasonable time (tens of years instead of hundreds or thousands of years). This report discusses the development of such steels by making elemental substitutions in the steels now under consideration. Molybdenum must be replaced in the Cr-Mo steels; nickel and molybdenum both must be replaced in the austenitic stainless steels (the nitrogen concentration must be limited, and niobium, maintained to extremely low levels). Appropriate substitutions are tungsten for molybdenum in the Cr-Mo steels and manganese for nickel in the austenitic stainless steels. Indications are that suitable ferritic steels can be developed, but development of a nickel-free austenitic stainless steel with properties similar to the Cr-Ni stainless steels appears to be much more complex

  2. Transport of radioactive decay chains in finite and semi-infinite porous media

    International Nuclear Information System (INIS)

    This report presents analytic solutions, numerical implementation and numerical illustrations for the transport of radioactive decay chains of arbitary length in porous media of limited and unlimited extent. The analytic solutions for the problem of chains transport in finite and semi-infinite media are complicated. Sophisticated numerical methods were required in order to implement the solutions as computer programs. These steps are detailed in the report. The main part of this report are illustrations of the solutions with problems in nuclear waste disposal. We show the transport of two chains, uranium 234 to radium 226 and curium 245 to thorium, from concentration-limited boundary condition and Bateman-type boundary condition, in a porous region of limited extent such as a backfill and in a semi-infinite field. These illustrations are examples of the capabilities and usefulness of these solutions. 5 refs., 33 figs

  3. GAMCAT - a personal computer database on alpha particles and gamma rays from radioactive decay

    International Nuclear Information System (INIS)

    The GAMCAT database is a compilation of data describing the alpha particles and gamma rays that occur in the radioactive decay of all known nuclides, adapted for IBM Personal Computers and compatible systems. These compiled data have been previously published, and are now available as a compact database. Entries can be retrieved by defining the properties of the parent nuclei as well as alpha-particle and gamma-ray energies or any combination of these parameters. The system provides fast access to the data and has been completely written in C to run on an AT-compatible computer, with a hard disk and 640K of memory under DOS 2.11 or higher. GAMCAT is available from the Fachinformationszentrum Karlsruhe. (orig.)

  4. Characteristics of spent fuel, high-level waste, and other radioactive wastes which may require long-term isolation: Appendix 3A, ORIGEN2 decay tables for immobilized high-level waste, Appendix 3B, Interim high-level waste forms, Appendix 3C, User's guide to the high-level waste PC data base

    Energy Technology Data Exchange (ETDEWEB)

    1987-12-01

    The purpose of this report, and the information contained in the associated computerized data bases, is to establish the DOE/OCRWM reference characteristics of the radioactive waste materials that may be accepted by DOE for emplacement in he mined geologic disposal system. This report provides relevant technical data for use by DOE and its supporting contractors and is not intended to be a policy document. This document is backed up by five PC-compatible data bases, written in a user-oriented, menu-driven format, which were developed for this purpose. The data bases are the LWR Assemblies Data Base; the LWR Radiological Data Base; the LWR Quantities Data Base; the LWR NFA Hardware Data Base; and the High-Level Waste Data Base. The above data bases may be ordered using the included form. Volume 6 contains decay tables for immobilized high-level waste, information on interim high-level waste forms, and a user's guide to the high-level waste PC data base.

  5. Radioactive decay products in neutron star merger ejecta: heating efficiency and γ-ray emission

    Science.gov (United States)

    Hotokezaka, K.; Wanajo, S.; Tanaka, M.; Bamba, A.; Terada, Y.; Piran, T.

    2016-06-01

    The radioactive decay of the freshly synthesized r-process nuclei ejected in compact binary mergers powers optical/infrared macronovae (kilonovae) that follow these events. The light curves depend critically on the energy partition among the different decay products and it plays an important role in estimates of the amount of ejected r-process elements from a given observed signal. We show that 20-50 per cent of the total radioactive energy is released in γ-rays on time-scales from hours to a month. The number of emitted γ-rays per unit energy interval has roughly a flat spectrum between a few dozen keV and 1 MeV so that most of the energy is carried by ˜1 MeV γ-rays. However, at the peak of macronova emission the optical depth of the γ-rays is ˜0.02 and most of the γ-rays escape. The loss of these γ-rays reduces the heat deposition into the ejecta and hence reduces the expected macronova signals if those are lanthanides dominated. This implies that the ejected mass is larger by a factor of 2-3 than what was previously estimated. Spontaneous fission heats up the ejecta and the heating rate can increase if a sufficient amount of transuranic nuclei are synthesized. Direct measurements of these escaping γ-rays may provide the ultimate proof for the macronova mechanisms and an identification of the r-process nucleosynthesis sites. However, the chances to detect these signals are slim with current X-ray and γ-ray missions. New detectors, more sensitive by at least a factor of 10, are needed for a realistic detection rate.

  6. Suicide of EMT-6 tumor cells by decays from radioactively-labelled sensitizer adducts

    International Nuclear Information System (INIS)

    Nitroaromatic radiosensitizers become metabolically bound preferentially to hypoxic cells and at least 10/sup 9/ adducts/cell can be tolerated as non-toxic. EMT-6 tumor cells have been incubated in hypoxia in the presence of /sup 3/H-Misonidazole and /sup 125/I-Azomycin Riboside for various times and the amount of /sup 3/H or /sup 125/I bound/cell was determined. Cells were stored as monolayers at 250C for up to 96 hr to accumulate radioactive decays and transferred at various times to 370C for colony-forming assays. No radiation inactivation was measured in cells which had incorporated at least 10/sup 6/ /sup 3/H or 10/sup 5/ /sup 125/I atoms. Previous studies had shown that -- 1% of MISO adducts to EMT-6 cells was associated with cellular DNA. These data indicate that the radiation-induced damage produced by these quantities of bound /sup 3/H or /sup 125/I causes little or not cell inactivation. The results of current studies to measure the colony-forming ability of sensitizer-labelled cells which have been stored in liquid nitrogen to facilitate the accumulation of more decays will be reported. These data suggest that a ''sensitizer-adduct suicide technique'' as a hypoxic cell selective adjunct to other cancer therapies is not feasible. These data are also instructive for those who attempt to develop radiolabelled ''tumor specific'' antibodies for therapeutic purposes

  7. An Improved Method of Lifetime Measurement of Nuclei in Radioactive Decay Chain

    CERN Document Server

    Puzović, J M; Nađđerđ, L J

    2016-01-01

    We present an improved statistical method for calculation of mean lifetime of nuclei in a decay chain with uncertain relation between mother and daughter nuclei. The method is based on formation of time distribution of intervals between mother and daughter nuclei, without trying to set the exact mother-daughter nuclei relationship. If there is a coincidence of mother and daughter nuclei decays, sum of these distributions has flat term on which an exponential term is superimposed. Parameters of this exponential function allow lifetime of daughter nucleus to be extracted. The method is tested on Monte Carlo simulation data.

  8. EDISTR: a computer program to obtain a nuclear decay data base for radiation dosimetry

    International Nuclear Information System (INIS)

    This report provides documentation for the computer program EDISTR. EDISTR uses basic radioactive decay data from the Evaluated Nuclear Structure Data File developed and maintained by the Nuclear Data Project at the Oak Ridge National Laboratory as input, and calculates the mean energies and absolute intensities of all principal radiations associated with the radioactive decay of a nuclide. The program is intended to provide a physical data base for internal dosimetry calculations. The principal calculations performed by EDISTR are the determination of (1) the average energy of beta particles in a beta transition, (2) the beta spectrum as function of energy, (3) the energies and intensities of x-rays and Auger electrons generated by radioactive decay processes, (4) the bremsstrahlung spectra accompanying beta decay and monoenergetic Auger and internal conversion electrons, and (5) the radiations accompanying spontaneous fission. This report discusses the theoretical and empirical methods used in EDISTR and also practical aspects of the computer implementation of the theory. Detailed instructions for preparing input data for the computer program are included, along with examples and discussion of the output data generated by EDISTR

  9. LWR decay heat calculations using a GRS improved ENDF/B-6 based ORIGEN data library

    Energy Technology Data Exchange (ETDEWEB)

    Hesse, U.; Hummelsheim, K.I.; Kilger, R.; Moser, F.E.; Langenbuch, S. [Gesellschaft fur Anlagen- und Reaktorsicherheit (GRS) mbH, Forschungsinstitute, Garching (Germany)

    2008-07-01

    The known ORNL ORIGEN code is widely spread over the world for inventory, activity and decay heat tasks and is used stand-alone or implemented in activation, shielding or burn-up systems. More than 1000 isotopes with more than six coupled neutron capture and radioactive decay channels are handled simultaneously by the code. The characteristics of the calculated inventories, e.g., masses, activities, neutron and photon source terms or the decay heat during short or long decay time steps are achieved by summing over all isotopes, characterized in the ORIGEN libraries. An extended nuclear GRS-ORIGENX data library is now developed for practical appliance. The library was checked for activation tasks of structure material isotopes and for actinide and fission product burn-up calculations compared with experiments and standard methods. The paper is directed to the LWR decay heat calculation features of the new library and shows the differences of dynamical and time integrated results of Endf/B-6 based and older Endf/B-5 based libraries for decay heat tasks compared to fission burst experiments, ANS curves and some other published data. A multi-group time exponential evaluation is given for the fission burst power of {sup 235}U, {sup 238}U, {sup 239}Pu and {sup 241}Pu, to be used in quick LWR reactor accident decay heat calculation tools. (authors)

  10. Contribution of the radioactive decay to the study of the structure of N=Z nuclei of mass A>70

    International Nuclear Information System (INIS)

    Radioactive decay study gives an access to the interaction which rules the β decay process as well as the structure of the nuclear states involved. This work describes the observation of the decay of N = Z nuclei with mass A > 70. For the odd-odd N = Z nuclei 78Y, 82Nb and 86Tc, the decay has been established as superallowed Fermi type transitions. The results pave the way for more precise measurements and extend the mass range nowadays used to understand the behaviour of the weak interaction in the nuclear matter. The observation of the decay of the even-even N = Z 72Kr leads us to build the Gamow-Teller strength distribution from which some clues about the ground state deformation of this isotope can be obtained. More complete experimental observation and some developments of the calculations used to interpret the distribution of the Gamow-Teller strength are needed. Finally, this work describes the developments and tests of a prototype detector the aim of which to determine the contribution of β particles to energy distribution observed in germanium detector. The tests we have performed show that this prototype can identify and reject 80% of the β particles emitted by a source with a 2,3 MeV end-point. The very satisfactory performances of this prototype need now to be confirmed under experimental conditions. (author)

  11. Influence of the decay products of 222Rn on the background counting rate of a sensitive whole-body radioactive monitor

    International Nuclear Information System (INIS)

    The background counting rates of a sensitive whole-body radioactivity monitor and the decay products of 222Rn have been measured simultaneously. The background counting rate and the concentrations do not show a simple relationship because of the deposition of decay products on the surfaces in the shielded space of the monitor. 'Plate out' of decay products at concentrations of the order of 1 pCi/l has been clearly demonstrated. Contributions from airborne radioactivity and deposited radioactivity to the background counting rate are shown to be of the same order. Deposition of radioactivity due to the presence of electrostatic charges on the surface of polythene is shown to be reduced by covering it with a conducting foil. The increase in background counting rate when uncovered polythene phantoms are used in calibration work is demonstrated. It is recommended that the use of bare polythene phantoms must be discontinued in the light of this study. The advantage of high turnover rates of air into the shielded space to prevent accumulation of decay products of 222Rn is likely to be offset by the deposition of radioactivity on surfaces of synthetic materials used in the monitor. The small but variable contribution to the background counting rate from decay products of 222Rn is undesirable when scrupulous precautions are taken to reduce the traces of radioactive impurities in the materials used in fabricating the monitor. (Auth.)

  12. Data bases concerning the transportation of radioactive materials

    International Nuclear Information System (INIS)

    This paper will describe two data bases which provide supporting information on radioactive material transport experience in the United States. The Radioactive Material Incident Report (RMIR) documents accident/incident experience from 1971 to the present from data acquired from the US Department of Transportation (DOT) and the Nuclear Regulatory Commission (NRC). The Radioactive Material Postnotification (RAMPOST) data base documents the shipments that have taken place for Highway Route Controlled Quantities (HRCQ) of radioactive material. HRCQ shipments are post notified (that is, after the shipment) to the DOT

  13. On the possibility to search for 2β decay of initially unstable (α/β radioactive) nuclei

    International Nuclear Information System (INIS)

    An alternative method to search for 2β decay is discussed. Contrary to the 'conventional' approach (where only β stable 2β candidates are used), it is intended to study α/β unstable nuclei, whose 2β energy release, Qββ, is much higher in most of the cases than that of 'conventional' 2β candidates. As an example, the first experimental half-life limits on 2β decay of radioactive nuclides from U and Th families (contaminants of the CaWO4 and CdWO4 scintillators) were set by reanalyzing the data of low-background measurements in the Solotvina Underground Laboratory (1734 h with CaWO4 and 13316 h with CdWO4). (authors)

  14. Late-Time Photometry of Type Ia Supernova SN2012cg Reveals the Radioactive Decay of $^{57}$Co

    CERN Document Server

    Graur, Or; Shara, Michael M; Riess, Adam G

    2015-01-01

    Seitenzahl et al. (2009) have predicted that $\\sim 3$ years after its explosion, the light we receive from a Type Ia supernova will come mostly from reprocessing of electrons and X-rays emitted by the radioactive decay chain $^{57}{\\rm Co}~\\to~^{57}{\\rm Fe}$, instead of positrons from the decay chain $^{56}{\\rm Co}~\\to~^{56}{\\rm Fe}$ that dominates the supernova light at earlier times. Using the Hubble Space Telescope, we followed the light curve of the Type Ia supernova SN2012cg out to $1055$ days after maximum light. Our measurements are consistent with the light curves predicted by the contribution of energy from the reprocessing of electrons and X-rays emitted by the decay of $^{57}$Co. This provides conclusive evidence that $^{57}$Co is produced in Type Ia supernova explosions. The ratio of luminosities produced by the decays of $^{57}$Co and $^{56}$Co, a strong constraint on any Type Ia supernova explosion model, is in the range $(0.4$ - $8.5)\\times10^{-3}$.

  15. Decay data file based on the ENSDF file

    Energy Technology Data Exchange (ETDEWEB)

    Katakura, J. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    A decay data file with the JENDL (Japanese Evaluated Nuclear Data Library) format based on the ENSDF (Evaluated Nuclear Structure Data File) file was produced as a tentative one of special purpose files of JENDL. The problem using the ENSDF file as primary source data of the JENDL decay data file is presented. (author)

  16. An analytically based model for the simultaneous leaching-chain decay of radionuclides from contaminated ground surface soil layers.

    Science.gov (United States)

    Jarzemba, M S; Manteufel, R D

    1997-12-01

    This paper describes an analytically based method for modeling the time-dependent radionuclide areal densities of contaminated soil surface layers when the soil experiences simultaneous leaching, surface erosion and chain radioactive decay. The model is used to predict time-dependent radionuclide areal densities in a volcanic ash blanket contaminated with spent nuclear fuel particles for the purpose of assessing the risks of radiation exposure from an extrusive volcanic event near a proposed high-level waste repository at Yucca Mountain. The method uses general analytical solutions (an expansion of the Bateman equations) for calculating serial decay, including non-radioactive decay loss terms, in order to calculate time-dependent radionuclide areal densities in the ash blanket. In the presented example, 43 "key" radionuclides are tracked and their concentrations in the blanket are displayed for a 10,000-y time period following the volcanic event. Although the analysis presented herein is for modeling contaminated volcanic ash blankets, the model would work equally well for modeling time-dependent radionuclide contamination of land surfaces in, for example, site decommissioning. It is suggested that the general solutions for serial decay (with non-radioactive decay loss terms) can also be used to model the release of radionuclides from the waste packages under anticipated repository conditions. PMID:9373070

  17. Changes of decay rates of radioactive 111In and 32P induced by mechanic motion

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The changes of decay rates of radionuclide 111In(electron capture) and 32P(β decay) induced by exter-nal mechanic motion are studied. The results indicate that,in the external circular rotation in clockwise and anticlockwise centrifuge on Northern Hemisphere(radius 8 cm,2000 r/min) ,the half life of 111In compared with the referred(2.83 d) is decreased at 2.83% and increased at 1.77%,respectively;the half life of 32P compared with the referred(14.29 d) is decreased at 3.78% and increased at 1.75%,respec-tively. When the clockwise and anticlockwise rotations increase to 4000 r/min,the half life of 111In is decreased at 11.31% and increased at 6.36%,respectively;the half life of 32P is decreased at 10.08% and increased at 4.34%,respectively. When the circular rotation is removed,the decay rates of 111In and 32P return back to the referred,respectively. It is found that the external circular rotations in clockwise and anticlockwise centrifuge selectively increased and decreased the decay rates of 111In and 32P,respec-tively,and the effects are strongly dependent on the strength of circular rotation. It is suggested that these effects may be caused by the chiral interaction.

  18. Radioactive decay studies at TRISTAN. Progress report, January 1, 1983-September 30, 1984

    International Nuclear Information System (INIS)

    Our study of nuclear structure of neutron-rich fission products at the on-line mass separator TRISTAN has continued at a strong pace during the past year. The study of the odd-odd La nuclides, 142144146148La, has been concluded with the preparation of the 146La level scheme. The systematic drop in position of the lowest 1+ levels and the abrupt increase in the number of levels that are strongly fed in β decay in 146La can be used to pinpoint the onset of strong deformation in that nuclide. Or, that spread of β strength can be attributed to the presence of low-lying octupole structures. New data have been presented on the lower odd-odd N=83 nuclides which indicate that the Pi g/sub 7/2/nu f/sub 7/2/ parabola which is a large particle hole parabola in 140La is quenched in 138Cs and inverted in 136I. The first results of a major new study of 132Sb and 130Sb levels populated in the decay of 40-s 132Sn and 2-min and 4-min 130Sn, respectively, are reported. These data indicate a 4+ ground state for 130Sb and reveal many new negative parity levels. Angular correlation and decay scheme data are reported for decay of 139Xe to levels of 139Cs. The results support 5/2+ and 3/2+ assignments for the 218- and 289-keV levels, respectively, and reveal a close doublet at 393 keV. Except for an extra low-lying level, a nearly level-for-level correspondence is observed with isotonic 141La, which is also under study. An angular correlation study of the levels of the 2-particle-4-hole nuclide 116Cd fed in the decay of 2- and 5+ isomers of 116Ag has resolved the location of the two lowest excited 0+ levels and disclosed over 200 new γ rays. The possibility of intruder levels in 142Ba is also under study

  19. K concentration in seven rice varieties and two infusions (coffee and tea) determined by 40K-40Ar radioactive decay

    International Nuclear Information System (INIS)

    As a result of the event occurred in Mexico about 20 years ago, by which milk powder contaminated with 137CS was imported from an European country after the Chernobyl accident, a legal disposition was set up in the country in order to certify the absence of radioactive contamination by gamma emitters, performing gamma spectroscopy to every foodstuff sample either imported or to be exported. In this process is always detected the X rays (1461 KeV) natural radiation emitted by 11% of 40K nucleus decaying to 40Ar by EC. So, when the counts accumulated during a detection time from 12 to 24 hours in a low background scintillation detection system are expressed as cps, corrected for background and divided by the sample weight (g), detection efficiency (%), decay yielding (0.11) and constant specific activity of elementary K(31.19 Bq/gK), the K concentration in the sample .is obtained. This paper reports the results found in seven rice varieties and two more vegetables, coffee and tea, including the K fractions passing to infusions, as well as are discussed similarities and differences related to K concentration and the advantages of the method.

  20. Proliferation resistance of plutonium based on decay heat

    International Nuclear Information System (INIS)

    Proliferation resistance of plutonium can be enhanced by increasing the decay heat of plutonium. For example, it can be enhanced by increasing the isotopic fraction of 238Pu, which has the largest decay heat among plutonium isotopes, produced by transmutation of Minor Actinides (Protected Plutonium Production: P3). In the present paper, proliferation resistance of plutonium was evaluated based on decay heat with physical assessment model. As a summary of the evaluation, new criteria to evaluate proliferation resistance of plutonium based on its isotopic composition from the view point of decay heat were suggested. The present methodology and the criteria were applied to evaluate the impact of P3 by the transmutation of Minor Actinides in fast breeder reactor blanket on proliferation resistance of plutonium. (author)

  1. Is there a signal for Lorentz non-invariance in existing radioactive decay data?

    CERN Document Server

    Mueterthies, M J; Longman, A; Barnes, V E; Fischbach, E

    2016-01-01

    Measurements of the beta decay rates of nuclei have revealed annual periodicities with approximately the same relative amplitude even though the half-lives range over nine orders of magnitude. Here we show that this can be explained if the emitted neutrinos behave as if they propagate in a medium with a refractive index which varies as the Earth orbits the sun. This refractive index may be due to fundamental Lorentz non-invariance (LNI), or apparent LNI arising from interactions with solar or relic neutrinos, or dark matter. Additionally, this medium could have consequences for experiments attempting to measure the neutrino mass.

  2. Is there a signal for Lorentz non-invariance in existing radioactive decay data?

    OpenAIRE

    Mueterthies, M. J.; Krause, D. E.; Longman, A.; Barnes, V.E.; Fischbach, E.

    2016-01-01

    Measurements of the beta decay rates of nuclei have revealed annual periodicities with approximately the same relative amplitude even though the half-lives range over nine orders of magnitude. Here we show that this can be explained if the emitted neutrinos behave as if they propagate in a medium with a refractive index which varies as the Earth orbits the sun. This refractive index may be due to fundamental Lorentz non-invariance (LNI), or apparent LNI arising from interactions with solar or...

  3. Understanding the Radioactive Ingrowth and Decay of Naturally Occurring Radioactive Materials in the Environment: An Analysis of Produced Fluids from the Marcellus Shale

    OpenAIRE

    Andrew W. Nelson; Eitrheim, Eric S.; Knight, Andrew W; May, Dustin; Mehrhoff, Marinea A.; Shannon, Robert; Litman, Robert; Burnett, William C.; Forbes, Tori Z.; Schultz, Michael K

    2015-01-01

    Background The economic value of unconventional natural gas resources has stimulated rapid globalization of horizontal drilling and hydraulic fracturing. However, natural radioactivity found in the large volumes of “produced fluids” generated by these technologies is emerging as an international environmental health concern. Current assessments of the radioactivity concentration in liquid wastes focus on a single element—radium. However, the use of radium alone to predict radioactivity concen...

  4. Design of cycler trajectories and analysis of solar influences on radioactive decay rates during space missions

    Science.gov (United States)

    Rogers, Blake A.

    This thesis investigates the design of interplanetary missions for the continual habitation of Mars via Earth-Mars cyclers and for the detection of variations in nuclear decay rates due to solar influences. Several cycler concepts have been proposed to provide safe and comfortable quarters for astronauts traveling between the Earth and Mars. However, no literature has appeared to show how these massive vehicles might be placed into their cycler trajectories. Trajectories are designed that use either Vinfinity leveraging or low thrust to establish cycler vehicles in their desired orbits. In the cycler trajectory cases considered, the use of Vinfinity leveraging or low thrust substantially reduces the total propellant needed to achieve the cycler orbit compared to direct orbit insertion. In the case of the classic Aldrin cycler, the propellant savings due to Vinfinity leveraging can be as large as a 24 metric ton reduction for a cycler vehicle with a dry mass of 75 metric tons, and an additional 111 metric ton reduction by instead using low thrust. The two-synodic period cyclers considered benefit less from Vinfinity leveraging, but have a smaller total propellant mass due to their lower approach velocities at Earth and Mars. It turns out that, for low-thrust establishment, the propellant required is approximately the same for each of the cycler trajectories. The Aldrin cycler has been proposed as a transportation system for human missions between Earth and Mars. However, the hyperbolic excess velocity values at the planetary encounters for these orbits are infeasibly large, especially at Mars. In a new version of the Aldrin cycler, low thrust is used in the interplanetary trajectories to reduce the encounter velocities. Reducing the encounter velocities at both planets reduces the propellant needed by the taxis (astronauts use these taxis to transfer between the planetary surfaces and the cycler vehicle) to perform hyperbolic rendezvous. While the propellant

  5. Radioactivity Calculations

    Science.gov (United States)

    Onega, Ronald J.

    1969-01-01

    Three problems in radioactive buildup and decay are presented and solved. Matrix algebra is used to solve the second problem. The third problem deals with flux depression and is solved by the use of differential equations. (LC)

  6. Trophic position and metabolic rate predict the long-term decay process of radioactive cesium in fish: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Hideyuki Doi

    Full Text Available Understanding the long-term behavior of radionuclides in organisms is important for estimating possible associated risks to human beings and ecosystems. As radioactive cesium (¹³⁷Cs can be accumulated in organisms and has a long physical half-life, it is very important to understand its long-term decay in organisms; however, the underlying mechanisms determining the decay process are little known. We performed a meta-analysis to collect published data on the long-term ¹³⁷Cs decay process in fish species to estimate biological (metabolic rate and ecological (trophic position, habitat, and diet type influences on this process. From the linear mixed models, we found that 1 trophic position could predict the day of maximum ¹³⁷Cs activity concentration in fish; and 2 the metabolic rate of the fish species and environmental water temperature could predict ecological half-lives and decay rates for fish species. These findings revealed that ecological and biological traits are important to predict the long-term decay process of ¹³⁷Cs activity concentration in fish.

  7. Decay ring design

    CERN Document Server

    Chancé, A; Bouquerel, E; Hancock, S; Jensen, E

    The study of the neutrino oscillation between its different flavours needs pureand very intense fluxes of high energy, well collimated neutrinos with a welldetermined energy spectrum. A dedicated machine seems to be necessarynowadays to reach the required flux. A new concept based on the β-decayof radioactive ions which were accelerated in an accelerator chain was thenproposed. After ion production, stripping, bunching and acceleration, the unstableions are then stored in a racetrack-shaped superconducting decay ring.Finally, the ions are accumulated in the decay ring until being lost. The incomingbeam is merged to the stored beam by using a specific RF system, whichwill be presented here.We propose here to study some aspects of the decay ring, such as its opticalproperties, its RF system or the management of the losses which occur in thering (mainly by decay or by collimation).

  8. Fission approach to cluster radioactivity

    Indian Academy of Sciences (India)

    D N Poenaru; R A Gherghescu

    2015-09-01

    Fission theory is used to explain decay. Also, the analytical superasymmetric fission (ASAF) model is successfully employed to make a systematic search and to predict, with other models, cluster radioactivity. The macroscopic–microscopic method is illustrated for the superheavy nucleus 286Fl. Then a few results of the theoretical approach of decay (ASAF, UNIV and semFIS models), cluster decay (ASAF and UNIV) and spontaneous fission dynamics are described with Werner–Wheeler and cranking inertia. UNIV denotes universal curve and semFIS the fission-based semiempirical formula.

  9. A kinematic-based methodology for radiological protection: Runoff analysis to calculate the effective dose for internal exposure caused by ingestion of radioactive isotopes

    Science.gov (United States)

    Sasaki, Syota; Yamada, Tadashi; Yamada, Tomohito J.

    2014-05-01

    We aim to propose a kinematic-based methodology similar with runoff analysis for readily understandable radiological protection. A merit of this methodology is to produce sufficiently accurate effective doses by basic analysis. The great earthquake attacked the north-east area in Japan on March 11, 2011. The system of electrical facilities to control Fukushima Daiichi nuclear power plant was completely destroyed by the following tsunamis. From the damaged reactor containment vessels, an amount of radioactive isotopes had leaked and been diffused in the vicinity of the plant. Radiological internal exposure caused by ingestion of food containing radioactive isotopes has become an issue of great interest to the public, and has caused excessive anxiety because of a deficiency of fundamental knowledge concerning radioactivity. Concentrations of radioactivity in the human body and internal exposure have been studied extensively. Previous radiologic studies, for example, studies by International Commission on Radiological Protection(ICRP), employ a large-scale computational simulation including actual mechanism of metabolism in the human body. While computational simulation is a standard method for calculating exposure doses among radiology specialists, these methods, although exact, are too difficult for non-specialists to grasp the whole image owing to the sophistication. In this study, the human body is treated as a vessel. The number of radioactive atoms in the human body can be described by an equation of continuity, which is the only governing equation. Half-life, the period of time required for the amount of a substance decreases by half, is only parameter to calculate the number of radioactive isotopes in the human body. Half-life depends only on the kinds of nuclides, there are no arbitrary parameters. It is known that the number of radioactive isotopes decrease exponentially by radioactive decay (physical outflow). It is also known that radioactive isotopes

  10. Natural radioactivity in zirconia-based dental ceramics

    International Nuclear Information System (INIS)

    Zirconia-based ceramics are being increasingly used in dental prosthetics in substitution of metal cores, which are known to induce local toxic reactions and delayed allergic responses in the oral tissues. Some concerns have been however raised about the use of zirconia, since it is known that unpurified zirconia materials may contain non negligible levels of natural radionuclides of the U/Th series. Combined measurements of alpha and gamma spectrometry as well as beta dosimetry were conducted on zirconia samples used for dental applications. Samples were available in form of powder and/or solid blocks. The results showed that the beta dose rate in zirconia ceramics was on average only slightly higher than the levels measured in natural teeth, and generally lower than the values measured in feldspatic and glass ceramics. These materials are indeed known to deliver a beta dose significantly higher than that measured from natural teeth, due to the relatively high levels of 40K (between 2 and 3 kBq·kg-1). The content of radionuclides of the U/Th series in the zirconia sample was estimated to be lower than 15 Bq·kg-1, i.e. doubtlessly below the exclusion level of 1 kBq·kg-1 recommended by IAEA in the Safety Standard Series. Beta dosimetry measurements, however, gave indications of possible inhomogeneous clusters of radioactivity, which might give rise to local doses above the background. (author)

  11. Cluster radioactivity from Osmium isotopes

    International Nuclear Information System (INIS)

    The spontaneous emission of fragments heavier than alpha particle and lighter than the lightest fission fragment from a nucleus is called cluster radioactivity. It is a cold nuclear phenomenon predicted based on Quantum Mechanical Fragmentation Theory (QMFT). Cluster radioactivity is studied using Unified Fission Model (UFM). Present study is conducted using proton rich osmium isotopes with mass ranging from 162-190. The interacting potential chosen is the Effective Liquid Drop Model (ELDM). The total potential in one dimensional case is the sum of Coulomb, surface and centrifugal potential. Here centrifugal part is not considered. Barrier penetrability (P) is calculated using one dimensional WKB approximation. The decay constant is obtained as λ = νoP where νo is the assault frequency. From the calculated values we have found that osmium isotopes in the mass range between 162-168 is highly unstable against alpha decay. Mass range of osmium isotopes found favourable to 8Be decay are 162-170, to 12C decay are 162-172, to 16O decay are 162-172, to 20Ne decay are 163-169, and to 24Mg decay are 162-171

  12. -Decay and the electric dipole moment: Searches for time-reversal violation in radioactive nuclei and atoms

    Indian Academy of Sciences (India)

    H W Wilschut; U Dammalapati; D J Van Der Hoek; K Jungmann; W Kruithof; C J G Onderwater; B Santra; P D Shidling; L Willmann

    2010-07-01

    One of the greatest successes of the Standard Model of particle physics is the explanation of time-reversal violation (TRV) in heavy mesons. It also implies that TRV is immeasurably small in normal nuclear matter. However, unifying models beyond the Standard Model predict TRV to be within reach of measurement in nuclei and atoms, thus opening an important window to search for new physics. We will discuss two complementary experiments sensitive to TRV: Correlations in the -decay of 21Na and the search for an electric dipole moment (EDM) in radium.

  13. An Excel[TM] Model of a Radioactive Series

    Science.gov (United States)

    Andrews, D. G. H.

    2009-01-01

    A computer model of the decay of a radioactive series, written in Visual Basic in Excel[TM], is presented. The model is based on the random selection of cells in an array. The results compare well with the theoretical equations. The model is a useful tool in teaching this aspect of radioactivity. (Contains 4 figures.)

  14. Radiolysis in cement-based materials ; application to radioactive waste-forms

    International Nuclear Information System (INIS)

    Cement-based materials appear to be an original environment with respect to radiolysis, due to their intrinsic complexity (porous, multiphasic and evolutional medium) or their very specific physico-chemical conditions (hyper-alkaline medium with pH ≥ 13, high content in calcium) or by the fact of numerous couplings existing between different phenomenologies. At the level of a radioactive cemented wasteform, a high degree of complexity is reached, in particular if the system communicates with the atmosphere (open system allowing regulation of the pressures but also the admission of O2, strong reactive with regards to radiolysis). Then, the radiolysis description exceeds widely the only one aspect of the decomposition of alkaline water under irradiation and makes necessary a global phenomenological approach. In this context, some 'outlying' phenomena, highly coupled with radiation chemistry, have to be taken into account because they contribute to deeply modify the net result of the radiolysis: radioactive decay of multiple αβγ emitters with filiation, phase changes (for example H2 aq → H2 gas) within the pores, gas transport by convection (Darcy law) and by diffusion (Fick law), precipitation/dissolution of solid phases, effect of the ionic strength and the temperature, disturbances connected to the presence of some solutes with redox potentialities (iron, sulphur). The integration work carried out on the previous points leads to an operational model (DOREMI) allowing the estimate of H2 amounts produced by radiolysis in different cemented radioactive waste-forms. As the final expression of the model, numerical simulations constitute a relevant tool of expertise and prospecting, contributing to accompany the thought on radiolysis in cement matrices in general and in cemented waste-forms in particular. Starting from different examples, simulations can be so used in order to test some hypotheses or illustrate the greatest influence of gas transport, dose rate

  15. Review on Preservative Treatment and Decay Resistance of Wood-based Composites

    Institute of Scientific and Technical Information of China (English)

    LIU Zhi; CAO Jinzhen

    2006-01-01

    To extend the service life and explore the use of wood-based composites, it is quite necessary to improve the decay resistance of wood-based composites through preservative treatments. Researchers have studied the methods of preservative treatment and the decay resistance of treated wood-based composites. In this paper, the categories of wood-based composites are briefly summarized and the previous and present investigations on the preservative treatment and decay resistance of different categories of wood-based composites are introduced. Some problems are also put forward and suggestions are given for future studies.

  16. Research on Health Risk-Based Radioactive Acceptance Criteria of Municipal Solid Waste Landfill

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The article focuses on the topics of Health Risk-Based Radioactive Acceptance Criteria of Municipal Solid Waste Landfill (MSWL, including municipal refuse landfills or industrial solid waste landfills, MSWL). At first, health risk assessment

  17. Natural Radioactivity Source Term Based on Remote Sensing Data

    International Nuclear Information System (INIS)

    The paper describes the basic principles for applying satellite remote sensing technology to the investigation of natural radioactivity. The relationship between areas of natural background anomalies and geological characteristics is analysed systematically. The supervised classification method and spectral angle mapping are used for the extraction of remote sensing information. Geological features with elevated levels of gamma radiation can be identified on small scale maps. On-site inspections have been launched. The relationship between natural radiation level and radiation source term is becoming clearer. The study provides exact locations and targets for protection and control in areas with elevated levels of gamma radiation. The project has the potential for expanding the range of services in environmental geochemistry and remote sensing geology. It opens up a new approach for conducting research on natural radioactivity. (author)

  18. The full structure of the KLL Auger spectrum of La observed in the radioactive decay of {sup 139}Ce in a solid matrix

    Energy Technology Data Exchange (ETDEWEB)

    Inoyatov, A.Kh., E-mail: inoyatov@nusun.jinr.ru [Laboratory of Nuclear Problems, JINR, Dubna, Moscow Region (Russian Federation); Institute of Applied Physics, National University, Tashkent (Uzbekistan); Perevoshchikov, L.L. [Laboratory of Nuclear Problems, JINR, Dubna, Moscow Region (Russian Federation); Kovalík, A. [Laboratory of Nuclear Problems, JINR, Dubna, Moscow Region (Russian Federation); Nuclear Physics Institute of the ASCR, Řež near Prague (Czech Republic); Filosofov, D.V. [Laboratory of Nuclear Problems, JINR, Dubna, Moscow Region (Russian Federation); Zhdanov, V.S. [Institute of Nuclear Physics, Almaty (Kazakhstan); Lubashevskiy, A.V. [Laboratory of Nuclear Problems, JINR, Dubna, Moscow Region (Russian Federation); Hons, Z. [Nuclear Physics Institute of the ASCR, Řež near Prague (Czech Republic)

    2013-04-15

    Highlights: •The KLL Auger spectrum of Ce measured for the first time in detail. •Energies and relative intensities of the all nine basic spectrum components determined. •An influence of the “atomic structure effect” on the absolute KLL energies indicated. •A perceptible influence of the relativistic effects on the KLL spectrum found. -- Abstract: For the first time, the KLL Auger spectrum of La (Z = 57) following the electron capture decay of radioactive {sup 139,141}Ce in a solid source was measured. The all nine basic spectrum components were resolved and their energies and relative intensities were determined and compared with theoretical expectations. The absolute energy of 27 383.8 ± 2.2 eV derived for the dominant KL{sub 2}L{sub 3}({sup 1}D{sub 2}) transition was found to be higher by 7.7 ± 2.2 eV (i.e. more than 3σ) than a value predicted by the widely used relativistic semi-empirical calculations by Larkins. The possible reasons for this discrepancy are discussed. Despite of less accuracy of some measured data, the predicted strong influence of the relativistic effects on the KL{sub 1}L{sub 2}({sup 3}P{sub 0}) transition intensity was nevertheless proved.

  19. LUMINEU: a search for neutrinoless double beta decay based on ZnMoO4 scintillating bolometers

    Science.gov (United States)

    Armengaud, E.; Arnaud, Q.; Augier, C.; Benoît, A.; Benoît, A.; Boiko, L. Bergé S.; Bergmann, T.; Blümer, J.; Broniatowski, A.; Brudanin, V.; Camus, P.; Cazes, A.; Chapellier, M.; Charlieux, F.; Chernyak, D. M.; Coron, N.; Coulter, P.; Danevich, F. A.; de Boissiére, T.; Decourt, R.; De Jesus, M.; Devoyon, L.; Drillien, A.-A.; Dumoulin, L.; Eitel, K.; Enss, C.; Filosofov, D.; Fleischmann, A.; Foerster, N.; Fourches, N.; Gascon, J.; Gastaldo, L.; Gerbier, G.; Giuliani, A.; Gray, D.; Gros, M.; Hehn, L.; Henry, S.; Hervé, S.; Heuermann, G.; Humbert, V.; Ivanov, I. M.; Juillard, A.; Kéfélian, C.; Kleifges, M.; Kluck, H.; Kobychev, V. V.; Koskas, F.; Kozlov, V.; Kraus, H.; Kudryavtsev, V. A.; Le Sueur, H.; Loidl, M.; Magnier, P.; Makarov, E. P.; Mancuso, M.; de Marcillac, P.; Marnieros, S.; Marrache-Kikuchi, C.; Menshikov, A.; Nasonov, S. G.; Navick, X.-F.; Nones, C.; Olivieri, E.; Pari, P.; Paul, B.; Penichot, Y.; Pessina, G.; Piro, M. C.; Plantevin, O.; Poda, D. V.; Redon, T.; Robinson, M.; Rodrigues, M.; Rozov, S.; Sanglard, V.; Schmidt, B.; Scorza, S.; Shlegel, V. N.; Siebenborn, B.; Strazzer, O.; Tcherniakhovski, D.; Tenconi, M.; Torres, L.; Tretyak, V. I.; Vagneron, L.; Vasiliev, Ya V.; Velazquez, M.; Viraphong, O.; Walker, R. J.; Weber, M.; Yakushev, E.; Zhang, X.; Zhdankov, V. N.

    2016-05-01

    The LUMINEU is designed to investigate the possibility to search for neutrinoless double beta decay in 100 Mo by means of a large array of scintillating bolometers based on ZnMoO4 crystals enriched in 100 Mo. High energy resolution and relatively fast detectors, which are able to measure both the light and the heat generated upon the interaction of a particle in a crystal, are very promising for the recognition and rejection of background events. We present the LUMINEU concepts and the experimental results achieved aboveground and underground with large-mass natural and enriched crystals. The measured energy resolution, the α/β discrimination power and the radioactive internal contamination are all within the specifications for the projected final LUMINEU sensitivity. Simulations and preliminary results confirm that the LUMINEU technology can reach zero background in the region of interest (around 3 MeV) with exposures of the order of hundreds kgxyears, setting the bases for a next generation 0v2β decay experiment capable to explore the inverted hierarchy region of the neutrino mass pattern.

  20. Semiconductor-based experiments for neutrinoless double beta decay search

    Science.gov (United States)

    Barnabé Heider, Marik; Gerda Collaboration

    2012-08-01

    Three experiments are employing semiconductor detectors in the search for neutrinoless double beta (0νββ) decay: COBRA, Majorana and GERDA. COBRA is studying the prospects of using CdZnTe detectors in terms of achievable energy resolution and background suppression. These detectors contain several ββ emitters and the most promising for 0νββ-decay search is 116Cd. Majorana and GERDA will use isotopically enriched high purity Ge detectors to search for 0νββ-decay of 76Ge. Their aim is to achieve a background ⩽10-3 counts/(kgṡyṡkeV) at the Q improvement compared to the present state-of-art. Majorana will operate Ge detectors in electroformed-Cu vacuum cryostats. A first cryostat housing a natural-Ge detector array is currently under preparation. In contrast, GERDA is operating bare Ge detectors submerged in liquid argon. The construction of the GERDA experiment is completed and a commissioning run started in June 2010. A string of natural-Ge detectors is operated to test the complete experimental setup and to determine the background before submerging the detectors enriched in 76Ge. An overview and a comparison of these three experiments will be presented together with the latest results and developments.

  1. Derivation of a novel formula for α-decay half-life

    International Nuclear Information System (INIS)

    Based on the basic principle of quantal decay of particle, we derive a formula of logarithm of decay half-life of an alpha particle emitting from a radioactive nucleus. The process of decay is understood as the transition of the particle from an isolated quasi-bound state to a scattering state. In this picture, the decay width is a resonance width in the system consisting of an α-cluster and the residual nucleus

  2. Integrated data base report--1996: US spent nuclear fuel and radioactive waste inventories, projections, and characteristics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    The Integrated Data Base Program has compiled historic data on inventories and characteristics of both commercial and U.S. Department of Energy (DOE) spent nuclear fuel (SNF) and commercial and U.S. government-owned radioactive wastes. Inventories of most of these materials are reported as of the end of fiscal year (FY) 1996, which is September 30, 1996. Commercial SNF and commercial uranium mill tailings inventories are reported on an end-of-calendar year (CY) basis. All SNF and radioactive waste data reported are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The information forecasted is consistent with the latest DOE/Energy Information Administration (EIA) projections of U.S. commercial nuclear power growth and the expected DOE-related and private industrial and institutional activities. The radioactive materials considered, on a chapter-by-chapter basis, are SNF, high-level waste, transuranic waste, low-level waste, uranium mill tailings, DOE Environmental Restoration Program contaminated environmental media, naturally occurring and accelerator-produced radioactive material, and mixed (hazardous and radioactive) low-level waste. For most of these categories, current and projected inventories are given through FY 2030, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions.

  3. Integrated data base report - 1996: US spent nuclear fuel and radioactive waste inventories, projections, and characteristics

    International Nuclear Information System (INIS)

    The Integrated Data Base Program has compiled historic data on inventories and characteristics of both commercial and U.S. Department of Energy (DOE) spent nuclear fuel (SNF) and commercial and U.S. government-owned radioactive wastes. Inventories of most of these materials are reported as of the end of fiscal year (FY) 1996, which is September 30, 1996. Commercial SNF and commercial uranium mill tailings inventories are reported on an end-of-calendar year (CY) basis. All SNF and radioactive waste data reported are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The information forecasted is consistent with the latest DOE/Energy Information Administration (EIA) projections of U.S. commercial nuclear power growth and the expected DOE-related and private industrial and institutional activities. The radioactive materials considered, on a chapter-by-chapter basis, are SNF, high-level waste, transuranic waste, low-level waste, uranium mill tailings, DOE Environmental Restoration Program contaminated environmental media, naturally occurring and accelerator-produced radioactive material, and mixed (hazardous and radioactive) low-level waste. For most of these categories, current and projected inventories are given through FY 2030, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions

  4. On Error Analysis of ORIGEN Decay Data Library Based on ENDF/B-VII.1 via Decay Heat Estimation after a Fission Event

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do Heon; Gil, Choong-Sup; Lee, Young-Ouk [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The method is strongly dependent on the available nuclear structure data, i.e., fission product yield data and decay data. Consequently, the improvements in the nuclear structure data could have guaranteed more reliable decay heat estimation for short cooling times after fission. The SCALE-6.1.3 code package includes the ENDF/B-VII.0-based fission product yield data and ENDF/B-VII.1-based decay data libraries for the ORIGEN-S code. The generation and validation of the new ORIGEN-S yield data libraries based on the recently available fission product yield data such as ENDF/B-VII.1, JEFF-3.1.1, JENDL/FPY-2011, and JENDL-4.0 have been presented in the previous study. According to the study, the yield data library in the SCALE-6.1.3 could be regarded as the latest one because it resulted in almost the same outcomes as the ENDF/B-VII.1. A research project on the production of the nuclear structure data for decay heat estimation of nuclear fuel has been carried out in Korea Atomic Energy Research Institute (KAERI). The data errors contained in the ORIGEN-S decay data library of SCALE-6.1.3 have been clearly identified by their changing variables. Also, the impacts of the decay data errors have been analyzed by estimating the decay heats for the fission product nuclides and their daughters after {sup 235}U thermal-neutron fission. Although the impacts of decay data errors are quite small, it reminds us the possible importance of decay data when estimating the decay heat for short cooling times after a fission event.

  5. Study of glass ceramic material on the base of ash group simulating slag of plasma shaft furnace for high temperature reprocessing of radioactive wastes

    International Nuclear Information System (INIS)

    Using the methods of X-ray diffraction, differential thermal and micro-probe analysis it is shown that the processes of minerals formation and homogenization in ash residue based charge under the heating up to 1450 deg C take place with a high rate and completely finish during 10 minutes. Homogeneous materials containing besides glassy phase crystalline phases and metallic shots are formed in this process. The products obtained with fluxes (dolomite and clay) additions are more homogeneous than a flux-less fused slag. Losses of α-radioactive nuclides during the melting of ash residue at 1300 deg C do not exceed 1.5% and is likely attributed with the products of uranium decay. Hydrolytic stability of the slags estimated from the rate of α-radioactive elements lixiviation is on the level of (1.4-5.7)x10-4 g/(cm2 x day) at 95 deg C

  6. Microfluidic-Based Sample Chips for Radioactive Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Tripp, J. L.; Law, J. D.; Smith, T. E.; Rutledge, V. J.; Bauer, W. F.; Ball, R. D.; Hahn, P. A.

    2014-02-01

    Historical nuclear fuel cycle process sampling techniques required sample volumes ranging in the tens of milliliters. The radiation levels experienced by analytical personnel and equipment, in addition to the waste volumes generated from analysis of these samples, have been significant. These sample volumes also impacted accountability inventories of required analytes during process operations. To mitigate radiation dose and other issues associated with the historically larger sample volumes, a microcapillary sample chip was chosen for further investigation. The ability to obtain microliter volume samples coupled with a remote automated means of sample loading, tracking, and transporting to the analytical instrument would greatly improve analytical efficiency while reducing both personnel exposure and radioactive waste volumes. Sample chip testing was completed to determine the accuracy, repeatability, and issues associated with the use of microfluidic sample chips used to supply µL sample volumes of lanthanide analytes dissolved in nitric acid for introduction to an analytical instrument for elemental analysis.

  7. Fixation and mobilisation of uranium and its radioactive decay products in C-richwater sediments; Festlegung und Mobilisierung von Uran und seinen radioaktiven Zerfallsprodukten in kohlenstoffreichen Gewaessersedimenten

    Energy Technology Data Exchange (ETDEWEB)

    Nassour, Mohammad

    2014-05-27

    organic carbon as main metabolic energy source for low order lotic ecosystems on the fixation of uranium was investigated by analyzing, the effects of leaves (coarse particulate organic matter: CPOM) and their degradation products (mainly fine particulate organic matter: FPOM and biofilms etc.). It was found that the highly mobile fraction of uranium in the water pathway, preferably present under the given conditions in the form different uranyl-carbonato-complexes, is efficiently fixed on fresh organic plant material (plant litter, leaves) in the first steps of organic matter decomposition within a few days. But it also can be immobilized relatively stable. It was also found that CPOM is a temporary sink for uranium, which may be sedimented depending on the turbulence flow and discharge. This may contribute to the directional removal of uranium from the water into the sediment. Finally this work analyzed the conditions in the pelagic and benthic zone of the Neuensalz pre dam of the Poehl reservoir, which is located downstream of the mining site. It presents a periodically stagnant water body with seasonally continuous sedimentation, a possible stable sink of uranium and products of radioactive decay in early diagenesis. Water samples of the pelagic zone and undisturbed sediment cores were taken and analyzed during winter stagnation. The results are discussed in front of seasonal changes in water chemistry and load data. {sup 238}U and {sup 226}Ra showed a culmination of activity concentrations in the sediment horizons from 25 to 35 cm depth, in particular at a centrally located sampling point (K3). At this point highest activity concentrations of {sup 238}U were found with a median value of 770 Bq*kg{sup -1} at a depth of 30 cm. At the same location {sup 226}Ra shows activity concentrations of 250 Bq*kg{sup -1}(median). Based on the {sup 137}Cs dating method a sedimentation rate of 1.5 cm*yr{sup -1} was calculated for the pre-dam Neuensalz sediment. On average

  8. Integrated data base report - 1994: US spent nuclear fuel and radioactive waste inventories, projections, and characteristics

    International Nuclear Information System (INIS)

    The Integrated Data Base Program has compiled historic data on inventories and characteristics of both commercial and U.S. Department of Energy (DOE) spent nuclear fuel and commercial and U.S. government-owned radioactive wastes. Except for transuranic wastes, inventories of these materials are reported as of December 31, 1994. Transuranic waste inventories are reported as of December 31, 1993. All spent nuclear fuel and radioactive waste data reported are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The information forecasted is consistent with the latest DOE/Energy Information Administration (EIA) projections of U.S. commercial nuclear power growth and the expected DOE-related and private industrial and institutional activities. The radioactive materials considered, on a chapter-by-chapter basis, are spent nuclear fuel, high-level waste, transuranic waste, low-level waste, commercial uranium mill tailings, DOE Environmental Restoration Program contaminated environmental media, commercial reactor and fuel-cycle facility decommissioning wastes, and mixed (hazardous and radioactive) low-level waste. For most of these categories, current and projected inventories are given through the calendar-year 2030, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions

  9. Integrated data base report - 1994: US spent nuclear fuel and radioactive waste inventories, projections, and characteristics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The Integrated Data Base Program has compiled historic data on inventories and characteristics of both commercial and U.S. Department of Energy (DOE) spent nuclear fuel and commercial and U.S. government-owned radioactive wastes. Except for transuranic wastes, inventories of these materials are reported as of December 31, 1994. Transuranic waste inventories are reported as of December 31, 1993. All spent nuclear fuel and radioactive waste data reported are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The information forecasted is consistent with the latest DOE/Energy Information Administration (EIA) projections of U.S. commercial nuclear power growth and the expected DOE-related and private industrial and institutional activities. The radioactive materials considered, on a chapter-by-chapter basis, are spent nuclear fuel, high-level waste, transuranic waste, low-level waste, commercial uranium mill tailings, DOE Environmental Restoration Program contaminated environmental media, commercial reactor and fuel-cycle facility decommissioning wastes, and mixed (hazardous and radioactive) low-level waste. For most of these categories, current and projected inventories are given through the calendar-year 2030, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions.

  10. Integrated Data Base for 1992: US spent fuel and radioactive waste inventories, projections, and characteristics

    International Nuclear Information System (INIS)

    The Integrated Data Base (IDB) Program has compiled current data on inventories and characteristics of commercial spent fuel and both commercial and US government-owned radioactive wastes through December 31, 1991. These data are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The information forecasted is consistent with the latest US Department of Energy/Energy Information Administration (DOE/EIA) projections of US commercial nuclear power growth and the expected DOE-related and private industrial and institutional (I/I) activities. The radioactive materials considered, on a chapter-by-chapter basis, are spent nuclear fuel, high-level waste, transuranic waste, low-level waste, commercial uranium mill tailings, environmental restoration wastes, commercial reactor and fuel cycle facility decommissioning wastes, and mixed (hazardous and radioactive) low-level waste. For most of these categories, current and projected inventories are given through the year 2030, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions. In addition, characteristics and current inventories are reported for miscellaneous radioactive materials that may require geologic disposal

  11. Integrated data base for 1993: US spent fuel and radioactive waste inventories, projections, and characteristics

    International Nuclear Information System (INIS)

    The Integrated Data Base (IDB) Program has compiled historic data on inventories and characteristics of both commercial and DOE spent fuel; also, commercial and U.S. government-owned radioactive wastes through December 31, 1992. These data are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The information forecasted is consistent with the latest U.S. Department of Energy/Energy Information Administration (DOE/EIA) projections of U.S. commercial nuclear power growth and the expected DOE-related and private industrial and institutional (I/I) activities. The radioactive materials considered, on a chapter-by-chapter basis, are spent nuclear fuel, high-level waste (HLW), transuranic (TRU), waste, low-level waste (LLW), commercial uranium mill tailings, environmental restoration wastes, commercial reactor and fuel-cycle facility decommissioning wastes, and mixed (hazardous and radioactive) LLW. For most of these categories, current and projected inventories are given through the calendar-year (CY) 2030, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions. In addition, characteristics and current inventories are reported for miscellaneous radioactive materials that may require geologic disposal

  12. Cluster radioactivity - status and developments

    International Nuclear Information System (INIS)

    Cluster radioactivities are intermediate phenomena between fission and alpha decay. The spontaneously emitted light fragment is a small cluster heavier then α particle, by lighter than the lightest fission fragment. Our works unifying the theory of the cold fission, cluster radioactivities, and α decay, as well as other theoretical models and the experimental results have been recently reviewed. Some of the cluster decay modes, like 14 C, 20 O, 23 F, 24,25 Ne, 28-30 Mg, and 32,34 Si, in a region of trans-francium parent nuclei, leading to daughters around 208 Pb, have half-live in good agreement with our predictions within the analytical superasymmetric model. The superconducting spectrometer SOLENO at I.P.N. Orsay has been employed to detect and identify 14 C radioactivity. Its good energy resolution allowed to discover 'fine structure' in the kinetic energy spectrum of 14 C emitted by 223 Ra. It was shown that the transition towards the first excited state of the daughter nucleus is stronger than that to the ground state. The interpretation given by Sheline and Ragnarsson according to which the main spherical component of the deformed parent wave function has a i11/2 character, has been confirmed. An explanation based on the Landau-Zener effect has been recently proposed by Mirea

  13. Photon and decay data libraries for ORIGEN2 code based on JENDL FP decay data file 2000

    CERN Document Server

    Katakura, J I

    2002-01-01

    Photon and decay data libraries for the ORIGEN2 code have been updated by using JENDL FP Decay Data File 2000 (JENDL/FPD-00). As for the decay data, half-lives, branching ratios and recoverable energy values have been replaced with those of the JENDL/FPD-00 file. The data of the photon library has been also replaced with those of the JENDL/FPD-00 file in which photon data of the nuclides without measured data are calculated with a theoretical method. Using the updated photon library, the calculation of photon spectrum at a short time after fission event is able to be made.

  14. Photon and decay data libraries for ORIGEN2 code based on JENDL FP decay data file 2000

    Energy Technology Data Exchange (ETDEWEB)

    Katakura, Jun-ichi; Yanagisawa, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-11-01

    Photon and decay data libraries for the ORIGEN2 code have been updated by using JENDL FP Decay Data File 2000 (JENDL/FPD-00). As for the decay data, half-lives, branching ratios and recoverable energy values have been replaced with those of the JENDL/FPD-00 file. The data of the photon library has been also replaced with those of the JENDL/FPD-00 file in which photon data of the nuclides without measured data are calculated with a theoretical method. Using the updated photon library, the calculation of photon spectrum at a short time after fission event is able to be made. (author)

  15. Risk perception, risk evaluation and human values: cognitive bases of acceptability of a radioactive waste repository

    International Nuclear Information System (INIS)

    Public acceptance of radioactive waste management alternatives depends in part on public perception of the associated risks. Three aspects of those perceived risks were explored in this study: (1) synthetic measures of risk perception based on judgments of probability and consequences; (2) acceptability of hypothetical radioactive waste policies, and (3) effects of human values on risk perception. Both the work on synthetic measures of risk perception and on the acceptability of hypothetical policies included investigations of three categories of risk: (1) Short-term public risk (affecting persons living when the wastes are created), (2) Long-term public risk (affecting persons living after the time the wastes were created), and (3) Occupational risk (affecting persons working with the radioactive wastes). The human values work related to public risk perception in general, across categories of persons affected

  16. Use of sampling based correction for non-radioactivity X-ray energy calibration

    Institute of Scientific and Technical Information of China (English)

    CHENG Cheng; WEI Yong-Bo; JIANG Da-Zhen

    2005-01-01

    As the requirement of non-radioactivity measurement has increased in recent years, various energy calibration methods applied in portable X-ray fluorescence (XRF) spectrometers have been developed. In this paper, a sampling based correction energy calibration has been discussed. In this method both history information and current state of the instrument are considered and relative high precision and reliability can be obtained.

  17. Radioactive waste data base through the net: A tool to improve the development of waste management

    International Nuclear Information System (INIS)

    One of the duties in Chilean Commission for Nuclear Energy (CCHEN) is the timely reply to the International Atomic Energy Agency (IAEA) Net enable waste management data base (NEWMDB) in the waste management field. This duty is carried out by the Radioactive Waste Management Section. CCHEN has complete this data base from about one decade ago. Through the time, the data base has changed according to new available information technologies, to the point that the access using the international net is a need today. The NEWMDB objective is to exchange information and knowledge between member states related to radioactive waste management situation and to conform a world inventory of radioactive waste. The Chilean experience got from the NEWMDB first data collection cycle (1999-2000) is presented here, and recommendations to be considered for incorporation in the domestic waste management system are exposed. In so doing, the data base answer should be easy to do and totally understood by everyone whose job is waste management around the world, in the context of the glossary, criteria and conventions on this data base is supported. The composition of the NEWMDB considers a General Frame which indicates the way in which the waste management is enfaced in the country, regulations, authorities, policies, infrastructure; a Waste Classification matrix which give the equivalence between proper country waste classification and that recommended by IAEA; Waste Data which give the quantities and situation of waste in the different steps of the management such as: conditioned waste, unconditioned stored waste, etc. Finally, the Sustainable Development for radioactive waste management Indicators (SDI) for the safety and environmental radioactive waste management are estimated (Au)

  18. LUMINEU: a search for neutrinoless double beta decay based on ZnMoO$_4$ scintillating bolometers

    CERN Document Server

    Armengaud, E; Augier, C; Benoit, A; Berge, L; Boiko, R S; Bergmann, T; Blumer, J; Broniatowski, A; Brudanin, V; Camus, P; Cazes, A; Chapellier, M; Charlieux, F; Chernyak, D M; Coron, N; Coulter, P; Danevich, F A; de Boissiere, T; Decourt, R; De Jesus, M; Devoyon, L; Drillien, A -A; Dumoulin, L; Eitel, K; Enss, C; Filosofov, D; Fleischmann, A; Foerster, N; Fourches, N; Gascon, J; Gastaldo, L; Gerbier, G; Giuliani, A; Gray, D; Gros, M; Hehn, L; Henry, S; Herve, S; Heuermann, G; Humbert, V; Ivanov, I M; Juillard, A; Kefelian, C; Kleifges, M; Kluck, H; Kobychev, V V; Koskas, F; Kozlov, V; Kraus, H; Kudryavtsev, V A; Sueur, H Le; Loidl, M; Magnier, P; Makarov, E P; Mancuso, M; de Marcillac, P; Marnieros, S; Marrache-Kikuchi, C; Menshikov, A; Nasonov, S G; Navick, X -F; Nones, C; Olivieri, E; Pari, P; Paul, B; Penichot, Y; Pessina, G; Piro, M C; Plantevin, O; Poda, D V; Redon, T; Robinson, M; Rodrigues, M; Rozov, S; Sanglard, V; Schmidt, B; Shlegel, S Scorza V N; Siebenborn, B; Strazzer, O; Tcherniakhovski, D; Tenconi, M; Torres, L; Tretyak, V I; Vagneron, L; Vasiliev, Ya V; Velazquez, M; Viraphong, O; Walker, R J; Weber, M; Yakushev, E; Zhang, X; Zhdankov, V N

    2016-01-01

    The LUMINEU is designed to investigate the possibility to search for neutrinoless double beta decay in $^{100}$Mo by means of a large array of scintillating bolometers based on ZnMoO$_4$ crystals enriched in $^{100}$Mo. High energy resolution and relatively fast detectors, which are able to measure both the light and the heat generated upon the interaction of a particle in a crystal, are very promising for the recognition and rejection of background events. We present the LUMINEU concepts and the experimental results achieved aboveground and underground with large-mass natural and enriched crystals. The measured energy resolution, the $\\alpha/\\beta$ discrimination power and the radioactive internal contamination are all within the specifications for the projected final LUMINEU sensitivity. Simulations and preliminary results confirm that the LUMINEU technology can reach zero background in the region of interest (around 3 MeV) with exposures of the order of hundreds kg$\\times$years, setting the bases for a nex...

  19. Immobilization of radioactive waste in cement based matrices

    International Nuclear Information System (INIS)

    Experimental and theoretical studies of hydrated cement systems are described. The behaviour of slag-based cement is described with a view to predicting their long term pH, Esub(n) and mineralogical balance. Modelling studies which enable the prediction at long ages of cement composites are advanced and a base model of the CaO-SiO2-H2O system presented. The behaviour of U and I in cements is explored. The tolerance of cement systems for a wide range of miscellaneous waste stream components and environmental hazards is described. The redox potential in cements is effectively lowered by irradiation. (author)

  20. Microfluidic-Based Robotic Sampling System for Radioactive Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Jack D. Law; Julia L. Tripp; Tara E. Smith; Veronica J. Rutledge; Troy G. Garn; John Svoboda; Larry Macaluso

    2014-02-01

    A novel microfluidic based robotic sampling system has been developed for sampling and analysis of liquid solutions in nuclear processes. This system couples the use of a microfluidic sample chip with a robotic system designed to allow remote, automated sampling of process solutions in-cell and facilitates direct coupling of the microfluidic sample chip with analytical instrumentation. This system provides the capability for near real time analysis, reduces analytical waste, and minimizes the potential for personnel exposure associated with traditional sampling methods. A prototype sampling system was designed, built and tested. System testing demonstrated operability of the microfluidic based sample system and identified system modifications to optimize performance.

  1. Transportation legislative data base: State radioactive materials transportation statute compilation, 1989--1993

    International Nuclear Information System (INIS)

    The Transportation Legislative Data Base (TLDB) is a computer-based information service containing summaries of federal, state and certain local government statutes and regulations relating to the transportation of radioactive materials in the United States. The TLDB has been operated by the National Conference of State Legislatures (NCSL) under cooperative agreement with the US Department of Energy's (DOE) Office of Civilian Radioactive Waste Management since 1992. The data base system serves the legislative and regulatory information needs of federal, state, tribal and local governments, the affected private sector and interested members of the general public. Users must be approved by DOE and NCSL. This report is a state statute compilation that updates the 1989 compilation produced by Battelle Memorial Institute, the previous manager of the data base. This compilation includes statutes not included in the prior compilation, as well as newly enacted laws. Statutes not included in the prior compilation show an enactment date prior to 1989. Statutes that deal with low-level radioactive waste transportation are included in the data base as are statutes from the states of Alaska and Hawaii. Over 155 new entries to the data base are summarized in this compilation

  2. Management of radioactive waste: A review

    OpenAIRE

    Luis Paulo Sant'ana; Taynara Cristina Cordeiro

    2016-01-01

    The issue of disposal of radioactive waste around the world is not solved by now and the principal reason is the lack of an efficient technologic system. The fact that radioactive waste decays of radioactivity with time are the main reasons for setting nuclear or radioactive waste apart from the other common hazardous wastes management. Radioactive waste can be classified according to the state of matter and level of radioactivity and this classification can be differently interpreted from co...

  3. Cement-based grouts in geological disposal of radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Onofrei, M. [AECL Research, Pinnawa, Manitoba (Canada)

    1996-04-01

    The behavior and performance of a specially developed high-performance cement-based grout has been studied through a combined laboratory and in situ research program conducted under the auspices of the Canadian Nuclear Fuel Waste Management Program (CNFWMP). A new class of cement-based grouts - high-performance grouts-with the ability to penetrate and seal fine fractures was developed and investigated. These high-performance grouts, which were injected into fractures in the granitic rock at the Underground Research Laboratory (URL) in Canada, are shown to successfully reduce the hydraulic conductivity of the rock mass from <10{sup -7} m s{sup -1} to 10{sup -9} m s{sup -1} and to penetrate fissures in the rock with apertures as small as 10 {mu}m. Furthermore, the laboratory studies have shown that this high - performance grout has very low hydraulic conductivity and is highly leach resistant under repository conditions. Microcracks generated in this materials from shrinkage, overstressing or thermal loads are likely to self-seal. The results of these studies suggest that the high-performance grouts can be considered as viable materials in disposal-vault sealing applications. Further work is needed to fully justify extrapolation of the results of the laboratory studies to time scales relevant to performance assessment.

  4. Shell closure effects studied via cluster decay in heavy nuclei

    OpenAIRE

    Kumar, Sushil; Ramna; Kumar, Rajesh

    2011-01-01

    The effects of shell closure in nuclei via the cluster decay is studied. In this context, we have made use of the Preformed Cluster Model ($PCM$) of Gupta and collaborators based on the Quantum Mechanical Fragmentation Theory. The key point in the cluster radioactivity is that it involves the interplay of close shell effects of parent and daughter. Small half life for a parent indicates shell stabilized daughter and long half life indicates the stability of the parent against the decay. In th...

  5. Calibration of a radioactive ink-based stack phantom and its applications in nuclear medicine.

    Science.gov (United States)

    El-Ali, H; Ljungberg, M; Strand, S-E; Palmer, J; Malmgren, L; Nilsson, J

    2003-04-01

    This paper describes a stack phantom useful for imaging complex activity distributions. It is based on images printed with radioactive ink using a commercial ink-jet printer. The application for the phantom is in the evaluation of planar and SPECT scintillation camera images and for validation of Monte Carlo simulated images. The accuracy in generating the activity distributions on paper sheets is especially important. Here we describe the calibration procedure for the ink-jet printer. The goal of the printer calibration is to find the relationship between the digital image count (voxel grey level) and its corresponding activity on the paper sheets (radioactivity). The relationship between the voxel grey level and the radioactivity on the paper sheets (measured by scanning technique and well counter) was found to be logarithmic, and a 3rd degree polynomial was found to fit the relationship. The distribution of radioactivity in the ink cartridge was investigated by pinhole SPECT. The distribution of (99m)Tc solution was found to be homogeneous in the ink solution. Experimental studies were done directly on Monte Carlo simulated heart images from the NCAT phantom. The result showed that the simulated images are similar to the images measured using the ink-jet technique. This stack phantom could be a promising solution with an advantage that the exact geometry generated in Monte Carlo could be imitated in the phantom. The phantom is a very flexible device and clearly much more versatile than conventional phantoms which have a fixed geometry and spatial limitation.

  6. Identification of DNA base-pairing via tunnel-current decay

    OpenAIRE

    He, Jin; Lin, Lisha; Zhang, Peiming; Lindsay, Stuart

    2007-01-01

    We propose a new approach for reading the sequence of a DNA molecule passing between electrodes on a nanopore, using hydrogen-bond mediated tunneling signals. The base-electrode interaction is modeled using a nucleobase functionalized STM probe that is pulled away from a nucleoside monolayer. Watson-Crick recognition results in slow-decay of the tunnel current, uniquely characteristic of the base-pair in over half the reads. Thirteen independent reads would yield the desired 99.99% accuracy.

  7. Tomosynthesis-based localization of radioactive seeds in prostate brachytherapy

    International Nuclear Information System (INIS)

    Accurately assessing the quality of prostate brachytherapy intraoperatively would be valuable for improved clinical outcome by ensuring the delivery of a prescribed tumoricidal radiation dose to the entire prostate gland. One necessary step towards this goal is the robust and rapid localization of implanted seeds. Several methods have been developed to locate seeds from x-ray projection images, but they fail to detect completely-overlapping seeds, thus necessitating manual intervention. To overcome this limitation, we have developed a new method where (1) a three-dimensional volume is reconstructed from x-ray projection images using a brachytherapy-specific tomosynthesis reconstruction algorithm with built-in blur compensation and (2) the seeds are located in this reconstructed volume. In contrast to other projection-based methods, our method can detect completely overlapping seeds. Our simulation results indicate that we can locate all implanted seeds in the prostate using a tomosynthesis angle of 30 deg. and seven projection images. The mean localization error is 1.27 mm for a case with 100 seeds. We have also tested our method using a prostate phantom with 61 implanted seeds and succeeded in locating all seeds automatically. We believe this new method can be useful for the intraoperative quality assessment of prostate brachytherapy in the future

  8. Low-level radioactive waste source terms for the 1992 integrated data base

    Energy Technology Data Exchange (ETDEWEB)

    Loghry, S L; Kibbey, A H; Godbee, H W; Icenhour, A S; DePaoli, S M

    1995-01-01

    This technical manual presents updated generic source terms (i.e., unitized amounts and radionuclide compositions) which have been developed for use in the Integrated Data Base (IDB) Program of the U.S. Department of Energy (DOE). These source terms were used in the IDB annual report, Integrated Data Base for 1992: Spent Fuel and Radioactive Waste Inventories, Projections, and Characteristics, DOE/RW-0006, Rev. 8, October 1992. They are useful as a basis for projecting future amounts (volume and radioactivity) of low-level radioactive waste (LLW) shipped for disposal at commercial burial grounds or sent for storage at DOE solid-waste sites. Commercial fuel cycle LLW categories include boiling-water reactor, pressurized-water reactor, fuel fabrication, and uranium hexafluoride (UF{sub 6}) conversion. Commercial nonfuel cycle LLW includes institutional/industrial (I/I) waste. The LLW from DOE operations is category as uranium/thorium fission product, induced activity, tritium, alpha, and {open_quotes}other{close_quotes}. Fuel cycle commercial LLW source terms are normalized on the basis of net electrical output [MW(e)-year], except for UF{sub 6} conversion, which is normalized on the basis of heavy metal requirement [metric tons of initial heavy metal ]. The nonfuel cycle commercial LLW source term is normalized on the basis of volume (cubic meters) and radioactivity (curies) for each subclass within the I/I category. The DOE LLW is normalized in a manner similar to that for commercial I/I waste. The revised source terms are based on the best available historical data through 1992.

  9. An explanation of the "negative neutrino mass squared" anomaly in tritium $ \\beta$-decay based on a theory of mass

    CERN Document Server

    Ingraham, R L; Wilkes, J M

    2000-01-01

    A proposed solution of the anomalous behavior of the electron spectrum near the endpoint of tritium $\\beta$-decay is offered. It is based on a new theory of mass in which mass becomes a dynamical variable, and the electron in the tritium $\\beta$-decay has a narrow mass distribution. The predicted Kurie plots explain the main feature (``$m_{\

  10. In-trap decay spectroscopy for {beta}{beta} decays

    Energy Technology Data Exchange (ETDEWEB)

    Brunner, Thomas

    2011-01-18

    The presented work describes the implementation of a new technique to measure electron-capture (EC) branching ratios (BRs) of intermediate nuclei in {beta}{beta} decays. This technique has been developed at TRIUMF in Vancouver, Canada. It facilitates one of TRIUMF's Ion Traps for Atomic and Nuclear science (TITAN), the Electron Beam Ion Trap (EBIT) that is used as a spectroscopy Penning trap. Radioactive ions, produced at the radioactive isotope facility ISAC, are injected and stored in the spectroscopy Penning trap while their decays are observed. A key feature of this technique is the use of a strong magnetic field, required for trapping. It radially confines electrons from {beta} decays along the trap axis while X-rays, following an EC, are emitted isotropically. This provides spatial separation of X-ray and {beta} detection with almost no {beta}-induced background at the X-ray detector, allowing weak EC branches to be measured. Furthermore, the combination of several traps allows one to isobarically clean the sample prior to the in-trap decay spectroscopy measurement. This technique has been developed to measure ECBRs of transition nuclei in {beta}{beta} decays. Detailed knowledge of these electron capture branches is crucial for a better understanding of the underlying nuclear physics in {beta}{beta} decays. These branches are typically of the order of 10{sup -5} and therefore difficult to measure. Conventional measurements suffer from isobaric contamination and a dominating {beta} background at theX-ray detector. Additionally, X-rays are attenuated by the material where the radioactive sample is implanted. To overcome these limitations, the technique of in-trap decay spectroscopy has been developed. In this work, the EBIT was connected to the TITAN beam line and has been commissioned. Using the developed beam diagnostics, ions were injected into the Penning trap and systematic studies on injection and storage optimization were performed. Furthermore, Ge

  11. Remediation of the low-level radioactive waste burial site at Williams Air Force Base

    International Nuclear Information System (INIS)

    The Air Force initiated a contract to develop and prepare detailed work plans for the removal of five concrete cylinders and associated field activities at site RW-11 at Williams AFB. Cylinders were believed to contain low-level radioactive waste including radium-luminous painted dials and radium-bearing parts. Although the general location of the cylinders was known, the exact configuration and contents of the cylinders was unknown. Plans included site preparation, excavation, monitoring, packaging, disposal, closure, and health and safety. The Health and Safety Plan was developed based on the premise that Radium 226 was the primary isotope of concern. The primary health hazard for workers and the public associated with site excavation was inhalation of airborne radioactive dust. Contingency plans were prepared in the event any radiation activity was detected above background levels or other radioactive isotopes were detected at the site. Criteria used to determine whether the site posed a threat to human health or the environment was based on an action level of 10 millirem Total Effective Dose Equivalent. Williams AFB is a closed installation that was placed on the Superfund National Priorities List. This paper discusses the plans what were developed to remove the buried waste, the execution of the plans, and closure of the site RW-11

  12. Radioactive sources in chemical laboratories

    International Nuclear Information System (INIS)

    Radioactive sources including all radioactive materials exceeding exemption levels have to be registered in national databases according to international standards based on the recommendations ICRP 60 and a proper licensing should take place as described for example in the 96/29/EURATOM. In spite of that, unregistered sources could be found, usually due to the fact that the owner is not aware of radiation characteristics of sources. The material inventories of chemical laboratories are typical and most frequent example where radioactive sources could be found. Five different types of sources could be identified. The most frequent type are chemicals, namely thorium and uranium compounds. They are used not due to their radioactivity but due to their chemical properties. As for all other sources a stringent control is necessary in order to assure their safe use. Around hundred of stored radioactive chemical items were found during inspections of such laboratories performed by the Slovenian Nuclear Safety Administration or qualified experts in a period December 2006 - July 2007. Users of such chemicals are usually not aware that thorium and uranium chemicals are radioactive and, as unsealed sources, they could be easily spilled out and produce contamination of persons, surfaces, equipment etc. The external exposure as well as the internal exposure including exposure due to inhalation could be present. No knowledge about special precautions is usually present in laboratories and leads to underestimating of a potential risk and unintentional exposure of the laboratory personnel, students etc. Due to the long decay times in decay series of Th -232, U-238 and U- 235 the materials are also radioactive today. Even more, in case of thorium chemicals the radioactivity increased substantially from the time of their production. The implementation of safety measures has been under way and includes a survey of the qualified experts, establishment of organizational structure in a

  13. Two-proton radioactivity

    OpenAIRE

    Blank, Bertram; Ploszajczak, Marek

    2007-01-01

    In the first part of the present review paper, experimental results which lead to the discovery of two-proton radioactivity are reviewed. Beyond two-proton emission from nuclear ground states, we also discuss experimental studies of two-proton emission from excited states populated either by nuclear beta decay or by inelastic reactions. In the second part, we review the modern theory of two-proton radioactivity. An outlook to future experimental studies and theoretical developments will concl...

  14. Radioactive Threat Detection with Scattering Physics: A Model-Based Application

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J V; Chambers, D H; Breitfeller, E F; Guidry, B L; Verbeke, J M; Axelrod, M A; Sale, K E; Meyer, A M

    2010-01-21

    The detection of radioactive contraband is a critical problem in maintaining national security for any country. Emissions from threat materials challenge both detection and measurement technologies especially when concealed by various types of shielding complicating the transport physics significantly. The development of a model-based sequential Bayesian processor that captures both the underlying transport physics including scattering offers a physics-based approach to attack this challenging problem. It is shown that this processor can be used to develop an effective detection technique.

  15. Monitoring result of radioactivity level in external environment around Qinshan NPP base during past twenty years

    International Nuclear Information System (INIS)

    In the past twenty years, a continuous supervision monitoring of environmental radioactivity level around Qinshan NPP (QNPP) Base was carried out by Zhejiang Province Radiation Environmental Monitoring Center. The monitoring results show that the γ radiation dose rate around QNPP Base, the activity concentration of gross α, gross β, 40K, and 137Cs in aerosol samples, the gross β daily settlement in fallout, the activity concentration of 14CO2 in air, the activity concentration of gross α, gross β, 90Sr, and 137Cs in environmental freshwater (drinking water, lake water and well water), the average specific activity of 238U, 232Th, 226Ra, and 137Cs in soils, and the average specific activity of 40K, 137Cs, 90Sr, and 14C in edible plants, are not abnormal. The radionuclide contents in those samples are of the same levels compared with the background values before the operation of QNPP Base and the monitored values of Hangzhou reference site. However, the activity concentrations of 3H in air, rain water, drinking water, pond water, sea water of discharge site, and terrestrial plants are higher than the monitored values of Hangzhou reference site. and in some medium the activity concentrations of 3H outclass that of background around QNPP Base. The results indicate that after 20 years operation of QNPP Base, especially after the third phase heavy water reactors operation commercially, the external environment around QNPP Base has been affected by 3H in radioactive effluent. (authors)

  16. Radioactive sputter cathodes for {sup 32}P plasma-based ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Fortin, M.A. [INRS-EMT (Universite du Quebec), 1650 boul. Lionel Boulet, Varennes, Quebec, J3X 1S2 (Canada)]. E-mail: fortin@bms.uu.se; Paynter, R.W. [INRS-EMT (Universite du Quebec), 1650 boul. Lionel Boulet, Varennes, Quebec, J3X 1S2 (Canada); Sarkissian, A. [Plasmionique Inc., 1650 boul. Lionel Boulet, Varennes, Quebec, J3X 1S2 (Canada); Stansfield, B.L. [INRS-EMT (Universite du Quebec), 1650 boul. Lionel Boulet, Varennes, Quebec, J3X 1S2 (Canada)

    2006-05-15

    The development of clinical treatments involving the use of beta-emitting millimetric and sub-millimetric devices has been a continuing trend in nuclear medicine. Implanted a few nanometers below the surface of endovascular implants, seeds or beads, beta-emitting radioisotopes can be used in a variety of biomedical applications. Recently, new technologies have emerged to enable the rapid and efficient activation of such devices. A pulsed, coaxial electron cyclotron resonance plasma reactor was designed and tested to demonstrate the feasibility of plasma-based radioactive ion implantation (PBRII). It has been shown that such plasma reactors allow for the implantation of radioisotopes ({sup 32}P) into biomedical devices with higher efficiencies than those obtained with conventional ion beams. Fragments containing radioactive atoms are produced in the implanter by means of a negatively biased solid sputter cathode that is inserted into an argon plasma. Dilute orthophosphoric acid solutions (H{sub 3} {sup 32}PO{sub 4}) are used for the fabrication of flat sputter targets, since they offer a high radioisotope content. However, the aggregation of the radioactive solute into highly hygroscopic ring-like deposits rather than flat, thin radioactive films is observed on certain substrates. This article describes the effect of this nonuniform distribution of the radioisotopes on the efficiency of PBRII, and presents a technique which enables a better distribution of {sup 32}P by coating the substrates with iron. The iron coating is shown to enable optimal radioisotope sputtering rates, which are essential in {sup 32}P-PBRII for the efficient activation of millimetric biomedical devices such as stents or coils.

  17. Strengthening the inherent safety and security of radioactive sources: Accelerator based options

    International Nuclear Information System (INIS)

    First and foremost, radioactive sources are both useful and cost effective. If a technology can't be utilized in an effective manner, it won't be useful, no matter how clever and elegant it is. Secondly, there are safety and proliferation concerns that must be addressed. Accidents, contamination, dirty bombs, etc., all represent real concerns. A single incident can impact the cost of all uses. These issues and regulations devised to reduce these risks are driving up the costs and lowering efficiency. An alternative would be the accelerator based option, which is nothing new, it has been around for decades. Using accelerator technologies to produce radiation will address the issues I raise by limiting the production of radiation to only those times when a switch has been flipped. Producing radiation that way has one main advantage over the use of radioactive sources. When the switch is off, there is no radiation. Making instruments that are doubly fail-safe is straightforward. Issues associated with radiation safety during transport and storage disappear. There are also minimal issues of disposal and tracking of materials. There is very little potential for diverting a transportable radiography machine or portable neutron generator for nefarious uses. There is a need to carefully monitor the balance between the increasing number of radioactive sources in use, increasing concern for their location and condition, and the cost of employing radiation generators. In many cases there will be a natural progression away from using sources towards the use of radiation generators. Another key factor that would influence this balance is if an accident and or misuse of radioactive sources were to occur. The costs of dealing with sources would rapidly escalate, and would likely tip the balance sooner

  18. Neutrino, radioactivity and dating wines

    International Nuclear Information System (INIS)

    Wine is a witness of the radioactivity of the atmosphere at the moment of grapes were collected. The possibility of measuring very low radioactivity levels (that was developed for studying neutrinos) has permitted the design of a new non-destructive method of dating bottled wines. This method is based on the detection of the 661 keV photon released whenever an atom of cesium 137 decays. This photon has enough energy to cross the thickness of glass and be detected. The presence of cesium 137 in the atmosphere is mainly due to the military atomic tests performed from 1950 to 1963 and to the Chernobyl accident that took place in 1986, as a consequence this method is valid to date wines that were produced only after 1950. (A.C.)

  19. Application of γ spectrometry sourceless efficiency method in measuring radioactive rare earth residues in Jiangsu province

    International Nuclear Information System (INIS)

    Background: The radioactivity levels of rare earth residues in Jiangsu province are not well known, and there are no explicit laws on their regulation. Purpose: By analyzing the radioactive nuclides in rare earth residues of Jiangsu province, we plan to propose some suggestions on volume reduction. Methods: HPGe γ spectrometry sourceless efficiency calibration method is playing an important role in the radioactive analysis because of its high accuracy and efficiency. It can be used without standard radioactive source and is easy to be measured on the spot. The reliability of method was verified by using IAEA reference materials. Results: The results show that in the rare earth residues the radioactive equilibrium of uranium and thorium decay series has been broken, and the radioactive levels in different samples have obvious difference. Conclusions: Based on the results, this paper investigates and analyses the radioactive residues of rare earth smelting and separation plants in Jiangsu Province, and puts forward some suggestions on volume reduction. (authors)

  20. Beta-Decay Study of ^{150}Er, ^{152}Yb, and ^{156}Yb: Candidates for a Monoenergetic Neutrino Beam Facility

    Energy Technology Data Exchange (ETDEWEB)

    Estevez Aguado, M. E. [CSIC-Universidad de Valencia; Algora, A. [CSIC-Universidad de Valencia; Rubio, B. [CSIC-Universidad de Valencia; Bernabeu, J. [CSIC-Universidad de Valencia; Nacher, E. [CSIC-Universidad de Valencia; Tain, J. L. [CSIC-Universidad de Valencia; Gadea, A. [CSIC-Universidad de Valencia; Agramunt, J. [CSIC-Universidad de Valencia; Burkard, K. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Hueller, W. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Doring, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kirchner, R. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mukha, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Plettner, C. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Roeckl, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Grawe, H. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Collatz, R. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Hellstrom, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Cano-Ott, D. [CIEMAT, Madrid; Karny, M. [University of Warsaw; Janas, Z. [University of Warsaw; Gierlik, M. [University of Warsaw; Plochocki, A. [University of Warsaw; Rykaczewski, Krzysztof Piotr [ORNL; Batist, L. [Petersburg Nuclear Physics Institute, Gatchina, Russia; Moroz, F. [Petersburg Nuclear Physics Institute, Gatchina, Russia; Wittman, V. [Petersburg Nuclear Physics Institute, Gatchina, Russia; Blazhev, A. [University of Cologne; Valiente, J. J. [INFN, Laboratori Nazionali di Legnaro, Italy; Espinoza, C. [CFPT-IST, Lisbon

    2011-01-01

    The beta decays of ^{150}Er, ^{152}Yb, and ^{156}Yb nuclei are investigated using the total absorption spectroscopy technique. These nuclei can be considered possible candidates for forming the beam of a monoenergetic neutrino beam facility based on the electron capture (EC) decay of radioactive nuclei. Our measurements confirm that for the cases studied, the EC decay proceeds mainly to a single state in the daughter nucleus.

  1. Research on base rock mechanic characteristics of caverns for radioactive waste disposal

    International Nuclear Information System (INIS)

    It has been considered that underground space is mechanically stable as compared with on the ground, and superior for storing radioactive waste for long period. However, in order to utilize underground space for the place of radioactive waste disposal, its long term stability such as the aseismatic ability of base rocks must be ensured, and for this purpose, it is necessary to grasp the mechanical characteristics of the base rocks around caverns, and to advance the technology for measuring and evaluating minute deformation and earth pressure change. In this research, the study on the fracture mechanics characteristics of base rocks and the development of the technology for measuring long terms stress change of base rocks were carried out. In this research, what degree the memory of past stress is maintained by rocks was presumed by measuring AE and strain when stress was applied to rock test pieces. The rocks tested were tuff, sandstone and granite. The experimental method and the experimental results of the prestress by AE method and DRA are reported. (K.I.)

  2. Note: Real time optical sensing of alpha-radiation emitting radioactive aerosols based on solid state nuclear track detector

    International Nuclear Information System (INIS)

    A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO3)4 ⋅ 5H2O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories

  3. Integrated data base report--1995: US spent nuclear fuel and radioactive waste inventories, projections, and characteristics

    International Nuclear Information System (INIS)

    The information in this report summarizes the U.S. Department of Energy (DOE) data base for inventories, projections, and characteristics of domestic spent nuclear fuel and radioactive waste. This report is updated annually to keep abreast of continual waste inventory and projection changes in both the government and commercial sectors. Baseline information is provided for DOE program planning purposes and to support DOE program decisions. Although the primary purpose of this document is to provide background information for program planning within the DOE community, it has also been found useful by state and local governments, the academic community, and some private citizens

  4. A cheap and compact mass spectrometer for radioactive ions based on a Wien filter

    Science.gov (United States)

    Pierret, C.; Maunoury, L.; Pacquet, J. Y.; Saint-Laurent, M.-G.; Tuske, O.

    2008-10-01

    This paper presents simulations of a mass spectrometer composed of one or two Wien filters. The ion source used is MONO1000 ECRIS. This ion source can produce singly charged ions with high efficiency, especially for gaseous materials. After extraction, the ions are mass selected and can be injected either into a beam line towards an experiment area or in an N+ charge booster. Due to its compactness and simplicity the proposed spectrometer is well adapted for preparing and analyzing radioactive beams. The simulations are based on the SIMION 3D [www.simion.com/] software.

  5. A cheap and compact mass spectrometer for radioactive ions based on a Wien filter

    Energy Technology Data Exchange (ETDEWEB)

    Pierret, C. [CIRIL, CEA/DSM CNRS/IN2P3, Avenue Henri Becquerel, B.P. 5133, F-14070 Caen cedex 05 (France)], E-mail: Pierret@ganil.fr; Maunoury, L. [CIRIL, CEA/DSM CNRS/IN2P3, Avenue Henri Becquerel, B.P. 5133, F-14070 Caen cedex 05 (France); Pacquet, J.Y.; Saint-Laurent, M.-G. [GANIL, CEA/DSM CNRS/IN2P3, Boulevard Henri Becquerel, B.P. 55027, F-14076 Caen cedex 05 (France); Tuske, O. [CEA/Saclay, DSM/DAPNIA, 91191 Gif/Yvette (France)

    2008-10-15

    This paper presents simulations of a mass spectrometer composed of one or two Wien filters. The ion source used is MONO1000 ECRIS. This ion source can produce singly charged ions with high efficiency, especially for gaseous materials. After extraction, the ions are mass selected and can be injected either into a beam line towards an experiment area or in an N{sup +} charge booster. Due to its compactness and simplicity the proposed spectrometer is well adapted for preparing and analyzing radioactive beams. The simulations are based on the SIMION 3D [ (http://www.simion.com/)] software.

  6. Physics-based, Bayesian sequential detection method and system for radioactive contraband

    Science.gov (United States)

    Candy, James V; Axelrod, Michael C; Breitfeller, Eric F; Chambers, David H; Guidry, Brian L; Manatt, Douglas R; Meyer, Alan W; Sale, Kenneth E

    2014-03-18

    A distributed sequential method and system for detecting and identifying radioactive contraband from highly uncertain (noisy) low-count, radionuclide measurements, i.e. an event mode sequence (EMS), using a statistical approach based on Bayesian inference and physics-model-based signal processing based on the representation of a radionuclide as a monoenergetic decomposition of monoenergetic sources. For a given photon event of the EMS, the appropriate monoenergy processing channel is determined using a confidence interval condition-based discriminator for the energy amplitude and interarrival time and parameter estimates are used to update a measured probability density function estimate for a target radionuclide. A sequential likelihood ratio test is then used to determine one of two threshold conditions signifying that the EMS is either identified as the target radionuclide or not, and if not, then repeating the process for the next sequential photon event of the EMS until one of the two threshold conditions is satisfied.

  7. Study of tracking detector of NEMO experiment - Simulation of the measurement of the ultra low 208Tl radioactivity in the source foils used as neutrinoless double beta decay emitters in NEMO experiment

    International Nuclear Information System (INIS)

    The purpose of NEMO3 experiment is the research of the neutrinoless double beta decay. This low energy process can sign the massive and Majorana nature of neutrino. This experiment with a very low radioactive background and containing 10 kg of enriched isotopes, studies mainly 100Mo. Installed at the Frejus underground laboratory, NEMO3 is a cylindrical detector which consists in very thin central source foils in a tracking detector made up of vertical drift cells operating in Geiger mode in a calorimeter and in a suitable shielding. This thesis is divided in two different parts. The first part is a full study of the features of the tracking detector. With a prototype composed of 9 drift cells we characterised the longitudinal and transverse reconstruction of position of the ionisation created by a LASER. With the first 3 modules under operation we used radioactive external neutron sources to measure the transverse resolution of ionisation position in a drift cell for high energy electrons. To study the vertex reconstruction on the source foil, sources of 207Bi which produced conversion electrons, were used inside the 3 modules. The second part of this thesis we show with simulations that we can measure with NEMO3 detector itself, the ultra low level of contamination in 208Tl of the source foil which comes from the natural radioactive chain of thorium. Using electron-photons channels we can obtain the 208Tl activity in the sources. With an analysis on the energy and on the time of flight of particles, NEMO3 is able to reach a sensitivity of 20μBq/kg after only 2 months of measurement. This sensitivity is the maximum 208Tl activity which we accepted for the sources in the NEMO3 proposal. (author)

  8. Estimation of cost-saving for reducing radioactive waste from nuclear medicine facilities by implementing decay in storage (DIS) in Japan

    International Nuclear Information System (INIS)

    DIS has not yet been implemented in Japan as of 2011. Therefore, even if risk was negligible, medical institutions have to entrust radioactive temporal waste disposal to Japan Radio Isotopes Association (JRIA) in the current situation. To decide whether DIS should be implemented in Japan or not, cost-saving effect of DIS was estimated by comparing the cost that nuclear medical facilities pay. By implementing DIS, the total annual cost for all nuclear medical facilities in Japan is estimated to be decreased to 30 million yen or less from 710 million yen. DIS would save 680 million yen (96%) per year. (author)

  9. On-site radioactive soil contamination at the Andreeva Bay shore technical base, Northwest Russia

    NARCIS (Netherlands)

    Reistad, O.; Dowdall, M.; Selnaes, O. G.; Standring, W. J. F.; Hustveit, S.; Steenhuisen, F.; Sorlie, A.

    2008-01-01

    The radioactive waste (RAW) storage site at Andreeva Bay in the Russian Northwest has experienced radioactive contamination both as a result of activities carried out at the site and due to incidents that have occurred there in the past such as accidental releases of radioactive materials. The site

  10. Disposal of radioactive waste. Some ethical aspects

    International Nuclear Information System (INIS)

    The threat posed to humans and nature by radioactive material is a result of the ionizing radiation released during the radioactive decay. The present use of radioactivity in medicine research and technologies produces steadily radioactive waste. It is therefore necessary to safely store this waste, particularly high level waste from nuclear facilities. The decisive factors determining the necessary duration of isolation or confinement are the physical half-life times ranging with some radionuclides up to many million years. It has therefore been accepted worldwide that the radioactive material needs to be confined isolated from the biosphere, the habitat of humans and all other organisms, for very long time periods. Although it is generally accepted that repositories for the waste are necessary, strong public emotions have been built up against the strategies to erect such installations. Apparently transparent information and public participation has been insufficient or even lacking. These problems have led to endeavours to achieve public acceptance and to consider ethical acceptability. Some aspects of such discussions and possibilities will be taken up in this contribution. This article is based on the work of an interdisciplinary group. The results have been published in 'Radioactive Waste - Technical and Normative Aspects of its Disposal' by C. Streffer, C.F. Gethmann, G. Kamp et al. in 'Ethics of Sciences and Technology Assessment', Volume 38, Springer-Verlag Berlin Heidelberg 2011.

  11. Disposal of radioactive waste. Some ethical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Streffer, Christian

    2014-07-01

    The threat posed to humans and nature by radioactive material is a result of the ionizing radiation released during the radioactive decay. The present use of radioactivity in medicine research and technologies produces steadily radioactive waste. It is therefore necessary to safely store this waste, particularly high level waste from nuclear facilities. The decisive factors determining the necessary duration of isolation or confinement are the physical half-life times ranging with some radionuclides up to many million years. It has therefore been accepted worldwide that the radioactive material needs to be confined isolated from the biosphere, the habitat of humans and all other organisms, for very long time periods. Although it is generally accepted that repositories for the waste are necessary, strong public emotions have been built up against the strategies to erect such installations. Apparently transparent information and public participation has been insufficient or even lacking. These problems have led to endeavours to achieve public acceptance and to consider ethical acceptability. Some aspects of such discussions and possibilities will be taken up in this contribution. This article is based on the work of an interdisciplinary group. The results have been published in 'Radioactive Waste - Technical and Normative Aspects of its Disposal' by C. Streffer, C.F. Gethmann, G. Kamp et al. in 'Ethics of Sciences and Technology Assessment', Volume 38, Springer-Verlag Berlin Heidelberg 2011.

  12. Fracture mechanics based design for radioactive material transport packagings -- Historical review

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.A.; Salzbrenner, D.; Sorenson, K.; McConnell, P.

    1998-04-01

    The use of a fracture mechanics based design for the radioactive material transport (RAM) packagings has been the subject of extensive research for more than a decade. Sandia National Laboratories (SNL) has played an important role in the research and development of the application of this technology. Ductile iron has been internationally accepted as an exemplary material for the demonstration of a fracture mechanics based method of RAM packaging design and therefore is the subject of a large portion of the research discussed in this report. SNL`s extensive research and development program, funded primarily by the U. S. Department of Energy`s Office of Transportation, Energy Management and Analytical Services (EM-76) and in an auxiliary capacity, the office of Civilian Radioactive Waste Management, is summarized in this document along with a summary of the research conducted at other institutions throughout the world. In addition to the research and development work, code and standards development and regulatory positions are also discussed.

  13. Bases for an environmental liability management system: application to a repository for radioactive waste

    International Nuclear Information System (INIS)

    This thesis aims the establishment of conceptual bases for the development of Environmental Liability Management System - instruments designed to provide financial and managerial coverage to financial liabilities arising from activities that impact the environment. The document analyses the theories that link the evolution of economic thought and environment, as a means of establish the necessary framework for the development of up-to-date environmental policy instruments. From these concepts and from the analysis of environmental liability system being implemented in several countries, the bases for environmental liability systems development are drawn. Finally, a study is carried out on the application of these bases for the development of an environmental liability management system for a radioactive waste repository. (author)

  14. Travel in the depth of radioactivity

    International Nuclear Information System (INIS)

    This educational booklet gives a general presentation of radioactivity: origin of natural radioactivity, characteristics of atoms and isotopes, the radioactivity phenomenon, its decay and measurement units, the radiations and their use in medicine, industry, agriculture and food industry, biology etc.. (J.S.)

  15. Quantification of modeling uncertainties based on scaling laws in natural circulation decay heat removal

    International Nuclear Information System (INIS)

    A Best Estimate Plus Uncertainty (BEPU) analysis is one of the good methods to estimate the uncertainty of phenomenon in a nuclear power plant dynamics. In BEPU analysis, a number of numerical analyses, in which input parameters are varied based on their probabilistic distributions, are carried out to obtain statistical characteristics of the output result. In general, the uncertainty of input parameters, such as a probabilistic distribution form and variance, are estimated based on experimental knowledge and/or engineering judgment. In the present research, we focus on a scaling law (dimensionless number) in constitutive equations from a view point of phenomenological theory. An influence of uncertainty in the dimensionless number and its dependency on BEPU analysis has been investigated. Plant dynamics analyses of Super Safe, Small and Simple (4S) reactor, being developed by Toshiba, are carried out under a natural circulation decay heat removal condition. In the analysis, uncertainties of the dimensionless numbers such as Nusselt, Reynolds, and Prandtl numbers are taken into consideration, as well as an uncertainty of decay heat power. The Latin Hypercube Sampling is applied to determine the input deck set. As a result, it is demonstrated that the parameter dependency on the output result can be revealed by using the dimensionless numbers. (author)

  16. Moisture transport properties of cement-based materials for engineered barriers in radioactive waste disposal

    International Nuclear Information System (INIS)

    This paper reviews the multiphase modeling of moisture transport process in pore structure of cement-based materials used as engineered barriers in radioactive waste disposal. The emphasis is put on the fundamental relationship of moisture isotherm and the related hysteresis phenomenon. A typical cement-based material is retained for study and its properties for moisture transport were measured. The pore structure was characterized by mercury intrusion porosimetry (MIP) and gravimetry method. The moisture isotherm was measured in laboratory by humidity equilibrium method and the predicted isotherm from MIP pore structure is confronted with the measured isotherm. Afterwards, a numerical scheme is set up for the multiphase transport model and the model is applied to the moisture transport process of engineered barriers exposed to natural drying and drying-wetting cycles. It is observed that the ratio between drying and wetting periods has strong influence on the depth of surface convection zone. (authors)

  17. Raman Based Process Monitor For Continuous Real-Time Analysis Of High Level Radioactive Waste Components

    International Nuclear Information System (INIS)

    A new monitoring system was developed at Pacific Northwest National Laboratory (PNNL) to quickly generate real-time data/analysis to facilitate a timely response to the dynamic characteristics of a radioactive high level waste stream. The developed process monitor features Raman and Coriolis/conductivity instrumentation configured for the remote monitoring, MatLab-based chemometric data processing, and comprehensive software for data acquisition/storage/archiving/display. The monitoring system is capable of simultaneously and continuously quantifying the levels of all the chemically significant anions within the waste stream including nitrate, nitrite, phosphate, carbonate, chromate, hydroxide, sulfate, and aluminate. The total sodium ion concentration was also determined independently by modeling inputs from on-line conductivity and density meters. In addition to the chemical information, this monitoring system provides immediate real-time data on the flow parameters, such as flow rate and temperature, and cumulative mass/volume of the retrieved waste stream. The components and analytical tools of the new process monitor can be tailored for a variety of complex mixtures in chemically harsh environments, such as pulp and paper processing liquids, electroplating solutions, and radioactive tank wastes. The developed monitoring system was tested for acceptability before it was deployed for use in Hanford Tank S-109 retrieval activities. The acceptance tests included performance inspection of hardware, software, and chemometric data analysis to determine the expected measurement accuracy for the different chemical species that are encountered during S-109 retrieval.

  18. Raman Based Process Monitor for Continuous Real-Time Analysis Of High Level Radioactive Waste Components

    International Nuclear Information System (INIS)

    A new monitoring system was developed at Pacific Northwest National Laboratory (PNNL) to quickly generate real-time data/analysis to facilitate a timely response to the dynamic characteristics of a radioactive high level waste stream. The developed process monitor features Raman and Coriolis/conductivity instrumentation configured for the remote monitoring, MatLab-based chemometric data processing, and comprehensive software for data acquisition/storage/archiving/display. The monitoring system is capable of simultaneously and continuously quantifying the levels of all the chemically significant anions within the waste stream including nitrate, nitrite, phosphate, carbonate, chromate, hydroxide, sulfate, and aluminate. The total sodium ion concentration was also determined independently by modeling inputs from on-line conductivity and density meters. In addition to the chemical information, this monitoring system provides immediate real-time data on the flow parameters, such as flow rate and temperature, and cumulative mass/volume of the retrieved waste stream. The components and analytical tools of the new process monitor can be tailored for a variety of complex mixtures in chemically harsh environments, such as pulp and paper processing liquids, electroplating solutions, and radioactive tank wastes. The developed monitoring system was tested for acceptability before it was deployed for use in Hanford Tank S-109 retrieval activities. The acceptance tests included performance inspection of hardware, software, and chemometric data analysis to determine the expected measurement accuracy for the different chemical species that are encountered during S-109 retrieval. (authors)

  19. Low-energy nuclear reactions with double-solenoid- based radioactive nuclear beam

    Indian Academy of Sciences (India)

    Valdir Guimarães

    2010-07-01

    The University of Notre Dame, USA (Becchetti et al, Nucl. Instrum. Methods Res. A505, 377 (2003)) and later the University of São Paulo, Brazil (Lichtenthaler et al, Eur. Phys. J. A25, S-01, 733 (2005)) adopted a system based on superconducting solenoids to produce low-energy radioactive nuclear beams. In these systems the solenoids act as thick lenses to collect, select, and focus the secondary beam into a scattering chamber. Many experiments with radioactive light particle beams (RNB) such as 6He, 7Be, 8Li, 8B have been performed at these two facilities. These low-energy RNB have been used to investigate low-energy reactions such as elastic scattering, transfer and breakup, providing useful information on the structure of light nuclei near the drip line and on astrophysics. Total reaction cross-sections, derived from elastic scattering analysis, have also been investigated for light system as a function of energy and the role of breakup of weakly bound or exotic nuclei is discussed.

  20. Models for calculating the effects of isotopic exchange, radioactive decay, and of recycle in removing iodine from gas and liquid streams

    International Nuclear Information System (INIS)

    Different decontamination factors for 129I and 131I are frequently invoked in environmental impact reports concerned with nuclear fuel recycle. Selected differences, or ratios, have not been justified on the basis of mathematical models or experimental data. A description is given of the origins of these differences in terms of isotopic exchange and material balance equations for the short- and long-lived (or stable) isotopes. The ratios of decontamination factors can be calculated when there is complete attainment of isotopic exchange between gas- or liquid-phase iodine and iodine sorbed by a solid or liquid. If there is no exchange, decontamination factors are isotope-independent unless material recycle occurs within the system. Between these extremes, there can be decontamination factors whose explanation requires experimental determination of the extent of exchange. The model applies to other radioactive isotopes of iodine as well as to other elements with short- and long-lived (or stable) isotopes. (auth)

  1. Marked disequilibrium between {sup 234}Th and {sup 230}Th of the {sup 238}U natural radioactive decay chain in IAEA reference materials n. 312, 313 and 314

    Energy Technology Data Exchange (ETDEWEB)

    Colaianni, A. [Dipartimento di Geologia e Geofisica dell' Universita di Bari, Via Orabona, 4 - 70125 Bari (Italy); I.N.F.N. Sezione di Bari, Via G. Amendola, 173 - 70126 Bari (Italy); D' Erasmo, G. [Dipartimento Interateneo di Fisica dell' Universita di Bari, Via G. Amendola, 173 - 70126 Bari (Italy); I.N.F.N. Sezione di Bari, Via G. Amendola, 173 - 70126 Bari (Italy); Pantaleo, A., E-mail: pantaleo@ba.infn.i [I.N.F.N. Sezione di Bari, Via G. Amendola, 173 - 70126 Bari (Italy); Schiavulli, L. [Dipartimento Interateneo di Fisica dell' Universita di Bari, Via G. Amendola, 173 - 70126 Bari (Italy); I.N.F.N. Sezione di Bari, Via G. Amendola, 173 - 70126 Bari (Italy)

    2011-02-15

    A new laboratory for the spectroscopy of natural radioactivity with a good energy resolution is presented. It consists of two distinct parts equipped, respectively, the first one with a HpGe {gamma}-ray detector, whose setup has been already completed, and the second one with large area Silicon {alpha}-ray detectors and a radiochemical section for thin {alpha}-samples preparation, whose setup is yet in progress and will be the argument of a separate work. The {gamma}-ray spectrometer was calibrated by means of IAEA Reference Materials n. 312, 313, 314 and 375. A large difference from the predictions of secular equilibrium emerged between the activities of {sup 234}Th and {sup 230}Th in Materials n. 312, 313 and 314.

  2. Radioactivity and deep geothermal energy

    International Nuclear Information System (INIS)

    Due to recent developments in energy politics renewable energies get more and more importance in Germany. This is especially true for geothermal energy representing a promising option for the environmentally sound and secure generation of heat and electricity. But there are a lot of very emotional discussions due to radioactive residues and wastes produced by a geothermal plant. Thus this paper compares radioactivity resulting from geothermal energy with radioactivity coming from other natural sources. In doing so it becomes obvious that naturally radioactive sources exist in all parts of the ecosphere (i.e. air, water, soil). The paper shows also that the specific activities of radioactive elements from geothermal energy in form of residues and waste emerge from radioactive decay of nuclides and that their radiation is not higher than the radiation of other naturally occurring radioactive elements. (orig.)

  3. Integrated Data Base report--1993: U.S. spent nuclear fuel and radioactive waste inventories, projections, and characteristics. Revision 10

    International Nuclear Information System (INIS)

    The Integrated Data Base Program has compiled historic data on inventories and characteristics of both commercial and DOE spent nuclear fuel; also, commercial and US government-owned radioactive wastes through December 31, 1993. These data are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The information forecasted is consistent with the latest US Department of Energy/Energy Information Administration projections of US commercial nuclear power growth and the expected DOE-related and private industrial and institutional activities. The radioactive materials considered, on a chapter-by-chapter basis, are spent nuclear fuel, high-level waste, transuranic waste, low-level waste, commercial uranium mill tailings, DOE Environmental Restoration Program wastes, commercial reactor and fuel-cycle facility decommissioning wastes, and mixed (hazardous and radioactive) low-level waste. For most of these categories, current and projected inventories are given the calendar-year 2030, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions. In addition, characteristics and current inventories are reported for miscellaneous radioactive materials that may require geologic disposal. 256 refs., 38 figs., 141 tabs

  4. Integrated data base for 1993: US spent fuel and radioactive waste inventories, projections, and characteristics. Revision 9

    Energy Technology Data Exchange (ETDEWEB)

    Klein, J.A.; Storch, S.N.; Ashline, R.C. [and others

    1994-03-01

    The Integrated Data Base (IDB) Program has compiled historic data on inventories and characteristics of both commercial and DOE spent fuel; also, commercial and U.S. government-owned radioactive wastes through December 31, 1992. These data are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The information forecasted is consistent with the latest U.S. Department of Energy/Energy Information Administration (DOE/EIA) projections of U.S. commercial nuclear power growth and the expected DOE-related and private industrial and institutional (I/I) activities. The radioactive materials considered, on a chapter-by-chapter basis, are spent nuclear fuel, high-level waste (HLW), transuranic (TRU), waste, low-level waste (LLW), commercial uranium mill tailings, environmental restoration wastes, commercial reactor and fuel-cycle facility decommissioning wastes, and mixed (hazardous and radioactive) LLW. For most of these categories, current and projected inventories are given through the calendar-year (CY) 2030, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions. In addition, characteristics and current inventories are reported for miscellaneous radioactive materials that may require geologic disposal.

  5. Integrated Data Base report--1993: U.S. spent nuclear fuel and radioactive waste inventories, projections, and characteristics. Revision 10

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-01

    The Integrated Data Base Program has compiled historic data on inventories and characteristics of both commercial and DOE spent nuclear fuel; also, commercial and US government-owned radioactive wastes through December 31, 1993. These data are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The information forecasted is consistent with the latest US Department of Energy/Energy Information Administration projections of US commercial nuclear power growth and the expected DOE-related and private industrial and institutional activities. The radioactive materials considered, on a chapter-by-chapter basis, are spent nuclear fuel, high-level waste, transuranic waste, low-level waste, commercial uranium mill tailings, DOE Environmental Restoration Program wastes, commercial reactor and fuel-cycle facility decommissioning wastes, and mixed (hazardous and radioactive) low-level waste. For most of these categories, current and projected inventories are given the calendar-year 2030, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions. In addition, characteristics and current inventories are reported for miscellaneous radioactive materials that may require geologic disposal. 256 refs., 38 figs., 141 tabs.

  6. Integrated Data Base for 1992: US spent fuel and radioactive waste inventories, projections, and characteristics. Revision 8

    Energy Technology Data Exchange (ETDEWEB)

    Payton, M. L.; Williams, J. T.; Tolbert-Smith, M.; Klein, J. A.

    1992-10-01

    The Integrated Data Base (IDB) Program has compiled current data on inventories and characteristics of commercial spent fuel and both commercial and US government-owned radioactive wastes through December 31, 1991. These data are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The information forecasted is consistent with the latest US Department of Energy/Energy Information Administration (DOE/EIA) projections of US commercial nuclear power growth and the expected DOE-related and private industrial and institutional (I/I) activities. The radioactive materials considered, on a chapter-by-chapter basis, are spent nuclear fuel, high-level waste, transuranic waste, low-level waste, commercial uranium mill tailings, environmental restoration wastes, commercial reactor and fuel cycle facility decommissioning wastes, and mixed (hazardous and radioactive) low-level waste. For most of these categories, current and projected inventories are given through the year 2030, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions. In addition, characteristics and current inventories are reported for miscellaneous radioactive materials that may require geologic disposal.

  7. A genetic-algorithm-based neutral network approach for radioactive activity prediction

    International Nuclear Information System (INIS)

    In this paper, a genetic-algorithm-based artificial neural network (GAANN) model radioactivity prediction is proposed, which is verified by measuring results from Long Range Alpha Detector (LRAD). GAANN can integrate capabilities of approximation of Artificial Neural Networks (ANN) and of global optimization of Genetic Algorithms (GA) so that the hybrid model can enhance capability of generalization and prediction accuracy, theoretically. With this model, both the number of hidden nodes and connection weights matrix in ANN are optimized using genetic operation. The real data sets are applied to the introduced method and the results are discussed and compared with the traditional Back Propagation (BP) neural network, showing the feasibility and validity of the proposed approach. (authors)

  8. Spent fuel and radioactive waste: an integrated data base of inventories, projections, and characteristics

    International Nuclear Information System (INIS)

    The Integrated Data Base (IDB) Program provides official US Department of Energy (DOE) data on spent fuel and radioactive waste inventories, projections, and characteristics. This information is provided through the cooperative efforts of the IDB Program and DOE lead offices, lead sites, major programs, and generator sites. The program is entering its fifth year, and major accomplishments are summarized in three broad areas: (1) the annual inventory report, including ORIGEN2 applications and a Quality Assurance (QA) plan; (2) the summary data file and direct user access; and (3) data processing methodology and support to other programs. Plans for future work in these areas are outlined briefly, including increased utilization of personal computers. Some examples of spent fuel data are given in terms of projected quantities for two growth scenarios, burnup and age profile of the existing inventory, and the approximate specific thermal power relative to high-level waste (HLW) from various sources. 4 refs., 2 figs., 3 tabs

  9. Study on adsorption performance of coal based activated carbon to radioactive iodine and stable iodine

    International Nuclear Information System (INIS)

    Highlights: • The impregnated coal-based activated carbons as adsorbent for removing methyl iodide. • The coal-based activated carbons to remove stable iodine. • Iodine residues are under 0.5 μg/ml after adsorption treatment. • The decontamination factor is much higher than 1000. - Abstract: Nuclear power plant, nuclear reactors and nuclear powered ship exhaust contains a large amount of gaseous radioactive iodine, and can damage to the workplace and the surrounding environment. The quantitative test to remove methyl iodide and the qualitative test for removing stable iodine were investigated using the impregnated coal-based activated carbons and coal-based activated carbons as adsorbents. The research conducted in this work shows that iodine residues were under 0.5 μg/ml after adsorption treatment and the decontamination factor of the coal-based activated carbon for removing the stable iodine was more than 1000, which can achieve the purpose of removing harmful iodine, and satisfy the requirement of gaseous waste treatment of nuclear powered vessel and other nuclear plants

  10. Model-Based Detection of Radioactive Contraband for Harbor Defense Incorporating Compton Scattering Physics

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J V; Chambers, D H; Breitfeller, E F; Guidry, B L; Verbeke, J M; Axelrod, M A; Sale, K E; Meyer, A M

    2010-03-02

    The detection of radioactive contraband is a critical problem is maintaining national security for any country. Photon emissions from threat materials challenge both detection and measurement technologies especially when concealed by various types of shielding complicating the transport physics significantly. This problem becomes especially important when ships are intercepted by U.S. Coast Guard harbor patrols searching for contraband. The development of a sequential model-based processor that captures both the underlying transport physics of gamma-ray emissions including Compton scattering and the measurement of photon energies offers a physics-based approach to attack this challenging problem. The inclusion of a basic radionuclide representation of absorbed/scattered photons at a given energy along with interarrival times is used to extract the physics information available from the noisy measurements portable radiation detection systems used to interdict contraband. It is shown that this physics representation can incorporated scattering physics leading to an 'extended' model-based structure that can be used to develop an effective sequential detection technique. The resulting model-based processor is shown to perform quite well based on data obtained from a controlled experiment.

  11. Probing flavor models with Ge-76-based experiments on neutrinoless double-beta decay

    CERN Document Server

    Agostini, Matteo; Zuber, Kai

    2015-01-01

    The physics impact of a staged approach for double-beta decay experiments based on Ge-76 is studied. The scenario considered relies on realistic time schedules envisioned by the GERDA and the MAJORANA collaborations, which are jointly working towards the realization of a future larger scale Ge-76 experiment. Intermediate stages of the experiments are conceived to perform quasi background-free measurements, and different data sets can be reliably combined to maximize the physics outcome. The sensitivity for such a global analysis is presented, with focus on how neutrino flavor models can be probed already with preliminary phases of the experiments. The synergy between theory and experiment yields strong benefits for both sides: the model predictions can be used to sensibly plan the experimental stages, and results from intermediate stages can be used to constrain whole groups of theoretical scenarios. This strategy clearly generates added value to the experimental efforts, while at the same time it allows to a...

  12. Capacity decay and remediation of nafion-based all-vanadium redox flow batteries.

    Science.gov (United States)

    Luo, Qingtao; Li, Liyu; Wang, Wei; Nie, Zimin; Wei, Xiaoliang; Li, Bin; Chen, Baowei; Yang, Zhenguo; Sprenkle, Vincent

    2013-02-01

    The relationship between electrochemical performance of vanadium redox flow batteries (VRBs) and electrolyte composition is investigated, and the reasons for capacity decay over charge-discharge cycling are analyzed and discussed herein. The results show that the reasons for capacity fading over real charge-discharge cycling include not only the imbalanced vanadium active species, but also the asymmetrical valence of vanadium ions in positive and negative electrolytes. The asymmetrical valence of vanadium ions leads to a state-of-charge (SOC)-range decrease in positive electrolytes and a SOC-range increase in negative electrolytes. As a result, the higher SOC range in negative half-cells further aggravates capacity fading by creating a higher overpotential and possible hydrogen evolution. Based on this finding, we developed two methods for restoring lost capacity, thereby enabling long-term operation of VRBs to be achieved without the substantial loss of energy resulting from periodic total remixing of electrolytes. PMID:23208862

  13. Evolution of cement based materials in a repository for radioactive waste and their chemical barrier function

    Energy Technology Data Exchange (ETDEWEB)

    Kienzler, Bernhard; Metz, Volker; Schlieker, Martina; Bohnert, Elke [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. fuer Nukleare Entsorgung (INE)

    2015-07-01

    The use of cementitious materials in nuclear waste management is quite widespread. It covers the solidification of low/intermediate-level liquid as well as solid wastes (e.g. laboratory wastes) and serves as shielding. For both high-level and intermediate-low level activity repositories, cement/concrete likewise plays an important role. It is used as construction material for underground and surface disposals, but more importantly it serves as barrier or sealing material. For the requirements of waste conditioning, special cement mixtures have been developed. These include special mixtures for the solidification of evaporator concentrates, borate binding additives and for spilling solid wastes. In recent years, low-pH cements were strongly discussed especially for repository applications, e.g. (Celine CAU DIT COUMES 2008; Garcia-Sineriz, et al. 2008). Examples for relevant systems are Calcium Silicate Cements (ordinary Portland cement (OPC) based) or Calcium Aluminates Cements (CAC). Low-pH pore solutions are achieved by reduction of the portlandite content by partial substitution of OPC by mineral admixtures with high silica content. The blends follow the pozzolanic reaction consuming Ca(OH){sub 2}. Potential admixtures are silica fume (SF) and fly ashes (FA). In these mixtures, super plasticizers are required, consisting of polycarboxilate or naphthalene formaldehyde as well as various accelerating admixtures (Garcia-Sineriz, et al. 2008). The pH regime of concrete/cement materials may stabilize radionuclides in solution. Newly formed alteration products retain or release radionuclides. An important degradation product of celluloses in cement is iso-saccharin acid. According to Glaus 2004 (Glaus and van Loon 2004), it reacts with radionuclides forming dissolved complexes. Apart from potentially impacting radionuclide solubility limitations, concrete additives, radionuclides or other strong complexants compete for surface sites for sorbing onto cement phases. In

  14. Management of radioactive waste: A review

    Directory of Open Access Journals (Sweden)

    Luis Paulo Sant'ana

    2016-06-01

    Full Text Available The issue of disposal of radioactive waste around the world is not solved by now and the principal reason is the lack of an efficient technologic system. The fact that radioactive waste decays of radioactivity with time are the main reasons for setting nuclear or radioactive waste apart from the other common hazardous wastes management. Radioactive waste can be classified according to the state of matter and level of radioactivity and this classification can be differently interpreted from country to country. Furthermore, microbiological procedures, plasma vitrification process, chemical precipitation, ion exchange, evaporation and reverse osmosis are strategies used for the treatment of radioactive wastes. The major challenge is to manage these radioactive substances after being used and discharged. This report brings data from the literature published worldwide from 2009 to 2014 on radioactive waste management studies and it covers production, classification and management of radioactive solid, liquid and gas waste.

  15. Using radioactivity

    International Nuclear Information System (INIS)

    The leaflet discusses the following: radioactivity; radioisotopes; uses of ionising radiations; radioactivity from (a) naturally occurring radioactive elements, and (b) artificially produced radioisotopes; uses of radioactivity in medicine, (a) clinical diagnostic, (b) therapeutic (c) sterilization of medical equipment and materials; environmental uses as tracers; industrial applications, e.g. tracers and radiography; ensuring safety. (U.K.)

  16. Radioactivity yesterday and today

    International Nuclear Information System (INIS)

    As an exhibition on the history of radioactivity from Homer to Oppenheimer has been organised in the Palais de la Decouverte in Paris, this article first recalls some atom characteristics and interactions between electrostatic forces within the atom. The author recalls how radioactivity has been unexpectedly discovered at the end of the 19. century, recalls the first works of characterization performed by Marie Curie and those performed by other scientists who perceived the opportunities for various applications. More recent works are also addressed like other forms of nucleus disintegrations, the generation of heavy ion beams, and double beta decay

  17. Traditional blood irradiation facilities based on radioactive sources are phased out; Tradisjonelle blodbestraalingsanlegg basert paa radioaktive kilder fases ut

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-03-01

    Blood irradiation facilities containing radioactive sources are among the most powerful sources of radiation. As government we want to phase out this type of facility for the benefit of virtually risk-free blood irradiation facility based on X-ray technology.(eb)

  18. A feasibility study of ortho-positronium decays measurement with the J-PET scanner based on plastic scintillators

    Science.gov (United States)

    Kamińska, D.; Gajos, A.; Czerwiński, E.; Alfs, D.; Bednarski, T.; Białas, P.; Curceanu, C.; Dulski, K.; Głowacz, B.; Gupta-Sharma, N.; Gorgol, M.; Hiesmayr, B. C.; Jasińska, B.; Korcyl, G.; Kowalski, P.; Krzemień, W.; Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedźwiecki, Sz.; Pawlik-Niedźwiecka, M.; Raczyński, L.; Rudy, Z.; Silarski, M.; Wieczorek, A.; Wiślicki, W.; Zgardzińska, B.; Zieliński, M.; Moskal, P.

    2016-08-01

    We present a study of the application of the Jagiellonian positron emission tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the { o-Ps }→ 3γ decays with angular and energy resolution equal to σ (θ ) ≈ {0.4°} and σ (E) ≈ 4.1 {keV}, respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pile-ups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities.

  19. A novel approach to the systematization of α-decaying nuclei, based on shell structures

    Science.gov (United States)

    Yarman, Tolga; Zaim, Nimet; Amon Susam, Lidya; Kholmetskii, Alexander; Arık, Metin; Azmi Altıntaş, Ali; Ozaydin, Fatih

    2016-05-01

    We provide a novel systematization of α-decaying nuclei, starting with the classically adopted mechanism. The decay half-life of an α-disintegrating nucleus is framed, supposing that i) the α-particle is born inside the parent, then ii) it keeps on hitting the barrier, while it runs back and forth inside the parent, and hitting each time the barrier, and iii) it finally tunnels through the barrier. One can, knowing the decay half-life, consider the probability that the α-particle is born within the parent, before it is emitted, as a parameter. Under all circumstances, the decay appears to be governed by the shell structure of the given nucleus. Our approach well allows to incorporate (not only even-even nuclei, but) all nuclei, decaying via throwing an alpha particle. Though herein, we limit ourselves with just even-even nuclei, in the aim of comparing our results with the existing Geiger-Nuttal results.

  20. New particle-flow based reconstruction of hadronic tau decays with the ATLAS experiment

    CERN Document Server

    Winter, Benedict Tobias; The ATLAS collaboration

    2016-01-01

    A new method of reconstructing the individual charged and neutral hadrons in tau decays with the ATLAS detector is presented. The reconstructed hadrons are used to classify the tau decay mode and to calculate the visible four-momentum of reconstructed tau candidates, providing a significant improvement in the energy resolution. The high-purity tau decay mode selection and single hadron energy resolution afforded by the method will be particularly important for future measurements of the CP mixture of the Higgs boson via spin effects in H to ditau decays. The performance of the method is evaluated using simulation and validated using tau decays and jets selected from proton-proton collision data.

  1. Microtiterplate phosphate assay based on luminescence quenching of a terbium complex amenable to decay time detection

    International Nuclear Information System (INIS)

    We describe a terbium-ligand complex (TbL) for a microtiterplate assay for phosphate (P) in the 0.3-100 μmol L-1 range based on luminescence quenching. As the pH optimum is at neutral pH (7.4) the probe is quenched by both, primary (H2PO4-) and secondary phosphate (HPO42-). The LOD is 110 nmol L-1. A Stern-Volmer study revealed that quenching is mostly static. Due to the ms-decay time of TbL, the first luminescence lifetime assay for phosphate could also be developed. The lifetime-based calibration plot is linear between 0.5 and 5 μmol L-1 of P. The effect of various surfactants on assay performance and a study on interferents are presented. The probe was successfully applied to determination of P in commercial plant fertilizers and validated against the molybdenum blue test. The probe is the most sensitive lanthanide-based probe for phosphate.

  2. Decay constants in geochronology

    Institute of Scientific and Technical Information of China (English)

    IgorM.Villa; PaulR.Renne

    2005-01-01

    Geologic time is fundamental to the Earth Sciences, and progress in many disciplines depends critically on our ability to measure time with increasing accuracy and precision. Isotopic geochronology makes use of the decay of radioactive nuclides as a help to quantify the histories of rock, minerals, and other materials. Both accuracy and precision of radioisotopic ages are, at present, limited by those of radioactive decay constants. Modem mass spectrometers can measure isotope ratios with a precision of 10-4 or better. On the other hand, the uncertainties associated with direct half-life determinations are, in most cases, still at the percent level. The present short note briefly summarizes progress and problems that have been encountered during the Working Group's activity.

  3. Understanding Voltage Decay in Lithium-Rich Manganese-Based Layered Cathode Materials by Limiting Cutoff Voltage.

    Science.gov (United States)

    Yang, Jingsong; Xiao, Lifen; He, Wei; Fan, Jiangwei; Chen, Zhongxue; Ai, Xinping; Yang, Hanxi; Cao, Yuliang

    2016-07-27

    The effect of the cutoff voltages on the working voltage decay and cyclability of the lithium-rich manganese-based layered cathode (LRMO) was investigated by electrochemical measurements, electrochemical impedance spectroscopy, ex situ X-ray diffraction, transmission electron microscopy, and energy dispersive spectroscopy line scan technologies. It was found that both lower (2.0 V) and upper (4.8 V) cutoff voltages cause severe voltage decay with cycling due to formation of the spinel phase and migration of the transition metals inside the particles. Appropriate cutoff voltage between 2.8 and 4.4 V can effectively inhibit structural variation as the electrode demonstrates 92% capacity retention and indiscernible working voltage decay over 430 cycles. The results also show that phase transformation not only on high charge voltage but also on low discharge voltage should be addressed to obtain highly stable LRMO materials. PMID:27383918

  4. Study of proton radioactivities

    Energy Technology Data Exchange (ETDEWEB)

    Davids, C.N.; Back, B.B.; Henderson, D.J. [and others

    1995-08-01

    About a dozen nuclei are currently known to accomplish their radioactive decay by emitting a proton. These nuclei are situated far from the valley of stability, and mark the very limits of existence for proton-rich nuclei: the proton drip line. A new 39-ms proton radioactivity was observed following the bombardment of a {sup 96}Ru target by a beam of 420-MeV {sup 78}Kr. Using the double-sided Si strip detector implantation system at the FMA, a proton group having an energy of 1.05 MeV was observed, correlated with the implantation of ions having mass 167. The subsequent daughter decay was identified as {sup 166}Os by its characteristic alpha decay, and therefore the proton emitter is assigned to the {sup 167}Ir nucleus. Further analysis showed that a second weak proton group from the same nucleus is present, indicating an isomeric state. Two other proton emitters were discovered recently at the FMA: {sup 171}Au and {sup 185}Bi, which is the heaviest known proton radioactivity. The measured decay energies and half-lives will enable the angular momentum of the emitted protons to be determined, thus providing spectroscopic information on nuclei that are beyond the proton drip line. In addition, the decay energy yields the mass of the nucleus, providing a sensitive test of mass models in this extremely proton-rich region of the chart of the nuclides. Additional searches for proton emitters will be conducted in the future, in order to extend our knowledge of the location of the proton drip line.

  5. A fuzzy logic based method to monitor organizational resilience: application in a brazilian radioactive facility

    Energy Technology Data Exchange (ETDEWEB)

    Grecco, Claudio H.S.; Santos, Isaac J.A.L.; Carvalho, Paulo V.R., E-mail: grecco@ien.gov.br, E-mail: luquetti@ien.gov.br, E-mail: paulov@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Divisao de Instrumentacao e Confiabilidade Humana; Vidal, Mario C.R.; Cosenza, Carlos A.N., E-mail: mvidal@ergonomia.ufrj.br, E-mail: cosenza@pep.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEP/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia de Producao

    2013-07-01

    Resilience is the intrinsic ability of a system to adjust its functioning prior to, during, or following changes and disturbances, so that it can sustain required operations under expected and unexpected conditions. This definition focuses on the ability to function, rather than on being impervious to failure, and thereby overcomes the traditional conflict between productivity and safety. Resilience engineering (RE) has fast become recognized as a valuable complement to the established approaches to safety of complex socio-technical systems and methods to monitor organizational resilience are needed. However, few, if any, comprehensive and systematic research studies focus on developing an objective, reliable and practical assessment model for monitoring organizational resilience. Most methods cannot fully solve the subjectivity of resilience evaluation. In order to remedy this deficiency, the aim of this research is to adopt a Fuzzy Set Theory (FST) approach to establish a method for resilience assessment in organizations based on leading safety performance indicators, defined according to the resilience engineering principles. The method uses FST concepts and properties to model the indicators and to assess the results of their application. To exemplify the method we performed an exploratory case study at the process of radiopharmaceuticals dispatch package of a Brazilian radioactive facility. (author)

  6. Probing flavor models with 76Ge-based experiments on neutrinoless double-β decay

    International Nuclear Information System (INIS)

    The physics impact of a staged approach for double-β decay experiments based on 76Ge is studied. The scenario considered relies on realistic time schedules envisioned by the Gerda and the Majorana collaborations, which are jointly working towards the realization of a future larger scale 76Ge experiment. Intermediate stages of the experiments are conceived to perform quasi background-free measurements, and different data sets can be reliably combined to maximize the physics outcome. The sensitivity for such a global analysis is presented, with focus on how neutrino flavor models can be probed already with preliminary phases of the experiments. The synergy between theory and experiment yields strong benefits for both sides: the model predictions can be used to sensibly plan the experimental stages, and results from intermediate stages can be used to constrain whole groups of theoretical scenarios. This strategy clearly generates added value to the experimental efforts, while at the same time it allows to achieve valuable physics results as early as possible. (orig.)

  7. Real-time information feedback based on a sharp decay weighted function

    Science.gov (United States)

    Chen, Bokui; Dong, Chuanfei; Liu, Yike; Tong, Wei; Zhang, Wenyao; Liu, Jie; Wang, Binghong

    2012-10-01

    Information feedback strategy, serving as the critical part of intelligent traffic systems, has been treated with growing emphasis. In recent years, a variety of feedback strategies have been proposed. Despite the fact that these strategies have been proved to enhance the traffic efficiency, we find that the road capacity has not been saturated and there is still plenty of room for improvement. Based on the analytic approximations, we found the reason why corresponding angle feedback strategy is superior to weighted congestion coefficient feedback strategy. Given that the sharp decay of the weighted coefficient is the key point, we proposed an efficient feedback strategy called the exponential function feedback strategy (EFFS). We applied it to both the symmetrical two-route model with two exits and that with a single exit. The simulation results indicate that, compared with other strategies, EFFS has decided numerical advantages in average flow, a physical quantity used for depicting the road capacity. Even more importantly, EFFS stands out for its convenient application as well as its fitness for modeling the rugged roads.

  8. Probing flavor models with ^{ {76}}Ge-based experiments on neutrinoless double-β decay

    Science.gov (United States)

    Agostini, Matteo; Merle, Alexander; Zuber, Kai

    2016-04-01

    The physics impact of a staged approach for double-β decay experiments based on ^{ {76}}Ge is studied. The scenario considered relies on realistic time schedules envisioned by the Gerda and the Majorana collaborations, which are jointly working towards the realization of a future larger scale ^{ {76}}Ge experiment. Intermediate stages of the experiments are conceived to perform quasi background-free measurements, and different data sets can be reliably combined to maximize the physics outcome. The sensitivity for such a global analysis is presented, with focus on how neutrino flavor models can be probed already with preliminary phases of the experiments. The synergy between theory and experiment yields strong benefits for both sides: the model predictions can be used to sensibly plan the experimental stages, and results from intermediate stages can be used to constrain whole groups of theoretical scenarios. This strategy clearly generates added value to the experimental efforts, while at the same time it allows to achieve valuable physics results as early as possible.

  9. Probing flavor models with {sup 76}Ge-based experiments on neutrinoless double-β decay

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, Matteo [Technische Universitaet Muenchen, Physik Department and Excellence Cluster Universe, Munich (Germany); Gran Sasso Science Institute (INFN), L' Aquila (Italy); Merle, Alexander [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Munich (Germany); Zuber, Kai [Technische Universitaet Dresden, Institute for Nuclear and Particle Physics, Dresden (Germany)

    2016-04-15

    The physics impact of a staged approach for double-β decay experiments based on {sup 76}Ge is studied. The scenario considered relies on realistic time schedules envisioned by the Gerda and the Majorana collaborations, which are jointly working towards the realization of a future larger scale {sup 76}Ge experiment. Intermediate stages of the experiments are conceived to perform quasi background-free measurements, and different data sets can be reliably combined to maximize the physics outcome. The sensitivity for such a global analysis is presented, with focus on how neutrino flavor models can be probed already with preliminary phases of the experiments. The synergy between theory and experiment yields strong benefits for both sides: the model predictions can be used to sensibly plan the experimental stages, and results from intermediate stages can be used to constrain whole groups of theoretical scenarios. This strategy clearly generates added value to the experimental efforts, while at the same time it allows to achieve valuable physics results as early as possible. (orig.)

  10. A feasibility study of ortho-positronium decays measurement with the J-PET scanner based on plastic scintillators

    CERN Document Server

    Kamińska, D; Czerwiński, E; Alfs, D; Bednarski, T; Białas, P; Curceanu, C; Dulski, K; Głowacz, B; Gupta-Sharma, N; Gorgol, M; Hiesmayr, B C; Jasińska, B; Korcyl, G; Kowalski, P; Krzemień, W; Krawczyk, N; Kubicz, E; Mohammed, M; Niedźwiecki, Sz; Pawlik-Niedźwiecka, M; Raczyński, L; Rudy, Z; Silarski, M; Wieczorek, A; Wiślicki, W; Zgardzińska, B; Zieliński, M; Moskal, P

    2016-01-01

    We present a study of the application of the Jagiellonian Positron Emission Tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the o-Ps$\\to3\\gamma$ decays with angular and energy resolution equal to $\\sigma(\\theta) \\approx 0.4^{\\circ}$ and $\\sigma(E) \\approx 4.1$ keV, respect...

  11. Decay of 120Ba

    International Nuclear Information System (INIS)

    The decay of 120Ba has been studied with an on-line isotope separator. Its half-life was determined to be t1/2=24±2 s. A decay scheme is proposed, based on γ-γ, γ-X, and γ-β+ coincidence measurements, which takes account of all 16 observed γ rays. The total decay energy was measured to be QEC=50±0.3 MeV

  12. Biokinetics of radioactive compounds

    International Nuclear Information System (INIS)

    Biokinetics of radioactive compounds in the human organism represent the central notion in this work, consisting of a theoretical and an experimental part. The first chapter contains definitions and explanations on the importance of the biokinetics of radioactive compounds in clinical therapy and pharmaceuticals research as well as for assessing radiation exposure and radiation hazards. Chapter 2 describes the bases of the biokinetics of radioactive compounds in the medical and non-medical sector, and biokinetics. Chapter 3 deals with obtaining biokinetics data for radioactive compounds from investigations in animals and man, evaluation of measurements, transferring data obtained by animal experiments to man, and with the variability of biokinetics data. In Chapter 4 the results of comprehensive studies in literature on the biokinetics of radioactive compounds are summarized. They relate to three areas: professional and environmental incorporation of radioactive compounds, use of radioactive pharmaceuticals in therapy and research, and incorporation of radioactive compounds by embryo and fetus in consequence of the uptake of radioactive compounds by the mother. Chapter 5 gives an assessment of radiation hazards from radioactive compounds in connection with occupational radiation exposure and nuclear diagnostics in vivo, and a comparison with other risks. For that purpose the concept of effective dose equivalent is applied in connection with suitable risk coefficients to professional and nuclear-medical radiation exposure. Chapter 6 is dedicated to measurement of the biokinetics of radioactive compounds in man using conventional devices. The object of Chapter 7 is measurement of the biokinetics of radioactive pharmaceuticals in man by means of single photon emission computed tomography. (orig./MG)

  13. International workshop on scientific bases for decision making after a radioactive contamination of an urban environment. Book of abstracts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    This workshop aims to discuss the most important aspects of scientific bases for decision making after a radioactive contamination in urban environment and to identify some scientific, social and economic open questions. Papers explaining in more details the principles of intervention, computational capabilities and measurements after a contamination of urban areas are presented. A review on practical experiences from Chernobyl and Goiania accidents is also included.

  14. International workshop on scientific bases for decision making after a radioactive contamination of an urban environment. Book of abstracts

    International Nuclear Information System (INIS)

    This workshop aims to discuss the most important aspects of scientific bases for decision making after a radioactive contamination in urban environment and to identify some scientific, social and economic open questions. Papers explaining in more details the principles of intervention, computational capabilities and measurements after a contamination of urban areas are presented. A review on practical experiences from Chernobyl and Goiania accidents is also included

  15. A novel approach to the systematization of α-decaying nuclei, based on shell structures

    Energy Technology Data Exchange (ETDEWEB)

    Yarman, Tolga; Azmi Altintas, Ali [Okan University, Istanbul (Turkey); Zaim, Nimet [Trakya University, Edirne (Turkey); Amon Susam, Lidya [Istanbul University, Istanbul (Turkey); Kholmetskii, Alexander [Belarus State University, Minsk (Belarus); Arik, Metin [Bogazici University, Istanbul (Turkey); Ozaydin, Fatih [Isik University, Istanbul (Turkey)

    2016-05-15

    We provide a novel systematization of α-decaying nuclei, starting with the classically adopted mechanism. The decay half-life of an α-disintegrating nucleus is framed, supposing that i) the α-particle is born inside the parent, then ii) it keeps on hitting the barrier, while it runs back and forth inside the parent, and hitting each time the barrier, and iii) it finally tunnels through the barrier. One can, knowing the decay half-life, consider the probability that the α-particle is born within the parent, before it is emitted, as a parameter. Under all circumstances, the decay appears to be governed by the shell structure of the given nucleus. Our approach well allows to incorporate (not only even-even nuclei, but) all nuclei, decaying via throwing an alpha particle. Though herein, we limit ourselves with just even-even nuclei, in the aim of comparing our results with the existing Geiger-Nuttal results. (orig.)

  16. Radioactive waste conditioning by way of their introduction into clay base ceramic matrices

    International Nuclear Information System (INIS)

    Conditions for fixation of ash from radioactive wastes burnup, hydroxide pulps formed during precipitation-purification works in radiochemical technology, bottoms from NPPs liquid radioactive wastes evaporation are worked out primarily on simulators. It is shown that ceramics including 30-40% by wastes mass, roasted at the temperature of 1000-1050 deg C gas an apparent density of 2.1-2.5 g/cm3, compression endurance limit of 40-70 MPa and radionuclide leaching rate of 10-6-10-8 g(cm2xday). 9 refs.; 2 figs.; 6 tabs

  17. Optimization of the radioactive waste storage

    International Nuclear Information System (INIS)

    Radioactive waste storage is the practice adopted in countries where the production of small quantities of radioactive waste does not justify the immediate investment in the construction of a repository. Accordingly, at IPEN, treated radioactive wastes, mainly solid compacted, have been stored for more than 20 years, in 200 dm3 drums. The storage facility is almost complete and must be extended. Taking into account that a fraction of these wastes has decayed to a very low level due to the short half - life of some radionuclides and considering that 'retrieval for disposal as very low level radioactive waste' is one of the actions suggested to radioactive waste managers, the Laboratory of Waste Management of IPEN started a project to apply the concepts of clearance levels and exemption limits to optimize the radioactive waste storage capacity . This study has been carried out by determining the doses and costs related to two main options: either to maintain the present situation or to open the packages and segregate the wastes that may be subject to clearance, using the national, two international clearance levels and the annual public limit. Doses and costs were evaluated as well as the collective dose and the detriment cost. The analytical solution among the evaluated options was determined by using the technique to aid decision making known as cost-benefit analysis. At last, it was carried out the sensitivity analysis considering all criteria and parameters in order to assess the robustness of the analytical solution. This study can be used as base to other institutions or other countries with similar nuclear programs. (author)

  18. The ''invisible'' radioactive scale

    International Nuclear Information System (INIS)

    Production and up-concentration of naturally occurring radioactive material (NORM) in the petroleum industry has attracted steadily increasing attention during the last 15 years. Most production engineers today associate this radioactivity with precipitates (scales) and sludges in production tubing, pumps, valves, separators, settling tanks etc., wherever water is being transported or treated. 226Ra and 228Ra are the most well known radioactive constituents in scale. Surprisingly little known is the radioactive contamination by 210Pb and progeny 210Bi and 210Po. These are found in combination with 226Ra in ordinary scale, often in layer of non-radioactive metallic lead in water transportation systems, but also in pure gas and condensate handling systems ''unsupported'' by 226Ra, but due to transportation and decay of the noble gas 222Rn in NG/LNG. This latter contamination may be rather thin, in some cases virtually invisible. When, in addition, the radiation energies are low enough for not being detectable on the equipment outer surface, its existence has for most people in the industry been a secret. The report discusses transportation and deposition mechanisms, detection methods and provides some examples of measured results from the North Sea on equipment sent for maintenance. It is concluded that a regular measurement program for this type of contamination should be mandatory under all dismantling processes of transportation and fluid handling equipment for fluids and gases offshore and onshore

  19. Search for bound-state electron+positron pair decay

    Science.gov (United States)

    Bosch, F.; Hagmann, S.; Hillenbrand, P.-M.; Lane, G. J.; Litvinov, Yu. A.; Reed, M. W.; Sanjari, M. S.; Stöhlker, Th.; Torilov, S. Yu.; Tu, X. L.; Walke, P. M.

    2016-09-01

    The heavy ion storage rings coupled to in-flight radioactive-ion beam facilities, namely the ability to produce and store for extended periods of time radioactive nuclides in high atomic charge states, for the searchof yet unobserved decay mode - bound-state electron-positron pair decay.

  20. Actinide, Activation Product and Fission Product Decay Data for Reactor-based Applications

    International Nuclear Information System (INIS)

    The UK Activation Product Decay Data Library was first released in September 1977 as UK-PADD1, to be followed by regular improvements on an almost yearly basis up to the assembly of UKPADD6.12 in March 2013. Similarly, the UK Heavy Element and Actinide Decay Data Library followed in December 1981 as UKHEDD1, with the implementation of various modifications leading to UKHEDD2.6, February 2008. Both the data content and evaluation procedures are defined, and the most recent evaluations are described in terms of specific radionuclides and the resulting consistency of their recommended decay-data files. New versions of the UKPADD and UKHEDD libraries are regularly submitted to the NEA Data Bank for possible inclusion in the JEFF library

  1. Revisiting alpha decay-based near-light-speed particle propulsion.

    Science.gov (United States)

    Zhang, Wenwu; Liu, Zhen; Yang, Yang; Du, Shiyu

    2016-08-01

    Interplanet and interstellar travels require long-term propulsion of spacecrafts, whereas the conventional schemes of propulsion are limited by the velocity of the ejected mass. In this study, alpha particles released by nuclear decay are considered as a potential solution for long-time acceleration. The principle of near-light-speed particle propulsion (NcPP) was elucidated and the stopping and range of ions in matter (SRIM) was used to predict theoretical accelerations. The results show that NcPP by means of alpha decay is feasible for long-term spacecraft propulsion and posture adjustment in space. A practical NcPP sail can achieve a speed >150km/s and reach the brink of the solar system faster than a mass equivalent solar sail. Finally, to significantly improve the NcPP sail, the hypothesis of stimulated acceleration of nuclear decay (SAND) was proposed, which may shorten the travel time to Mars to within 20 days.

  2. TMD Parton Distributions based on Three-Body Decay Functions in NLL Order of QCD

    CERN Document Server

    Tanaka, Hidekazu

    2014-01-01

    Three-body decay functions in space-like parton branches are implemented to evaluate transverse-momentum-dependent (TMD) parton distribution functions in the next-to-leading logarithmic (NLL) order of quantum chromodynamics (QCD). Interference contributions due to the next-to-leading order contribution are taken into account for the evaluation of the transverse momenta in initial state parton radiations. Some properties of the decay functions are also examined. As an example, we compare our results with an algorithm proposed in Ref.1), in which a transverse momentum distributions are evaluated at the last step of parton evolutions.

  3. Development of windows based software to analyze fluorescence decay with time-correlated single photon counting (TCSPC) setup

    CERN Document Server

    Mallick, M B; Ravindranath, S V G

    2002-01-01

    A VUV spectroscopic facility for studies in photophysics and photochemistry is being set up at INDUS-I synchrotron source, CAT, Indore. For this purpose, a data acquisition system based on time-correlated single photon counting method is being developed for fluorescence lifetime measurement. To estimate fluorescence lifetime from the data collected with this sytem, a Windows based program has been developed using Visual Basic 5.0. It uses instrument response function (IRF) and observed decay curve and estimates parameters of single exponential decay by least square analysis and Marquardt method as convergence mechanism. Estimation of parameters was performed using data collected with a commercial setup. Goodness of fit was judged by evaluating chi R sup 2 , weighted residuals and autocorrelation function. Performance is compared with two commercial software packages and found to be satisfactory.

  4. Search for lost or orphan radioactive sources based on Nal gamma spectrometry

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C

    2003-01-01

    Within recent decades many radioactive sources have been lost, stolen, or abandoned, and some have caused contamination or irradiation of people. Therefore reliable methods for source recovery are needed. The use of car borne NaI(Tl) detectors is discussed. Standard processing of spectra in general...

  5. Risk-based financial assurance for low-level radioactive waste disposal facilities

    International Nuclear Information System (INIS)

    The paper presents a risk assessment to characterize the potential for liability costs associated with a facility for disposal of low-level radioactive waste (LLRW). Potential liability costs are grouped into two categories: corrective action costs (e.g., for cleanup of property and the environment) and third-party compensation costs (e.g., for bodily injury and property damage)

  6. Radioactive ion implantation of thermoplastic elastomers

    OpenAIRE

    Borcea, Veronica

    2008-01-01

    The radioactive ion implantation wear measuring method (RII) has been used for many years as a tool to make highly sensitive real-time in-situ measurements of wear and corrosion in metallic or ceramic materials. The method consists of the controlled implantation of radioactive ions of limited decay time in a thin layer at the surface of the material. The progressive abrasion of the material results in a decline in radioactivity which is followed to monitor material losses. The application ...

  7. Radioactive Carbon Isotope Monitoring System Based on Cavity Ring-down Laser Spectroscopy for Decommissioning Process of Nuclear Facilities

    Science.gov (United States)

    Tomita, Hideki; Watanabe, Kenichi; Takiguchi, Yu; Kawarabayashi, Jun; Iguchi, Tetsuo

    In decommissioning process of nuclear facilities, large amount of radioactive isotopes are discharged as waste. Radioactive carbon isotope (14C) is one of the key nuclides to determine the upper limit of concentration in the waste disposal. In particular, 14C on the graphite reactor decommissioning should be separated from stable carbon isotopes (12C and 13C) and monitored for the public health and safety. We propose an isotope analysis system based on cavity ring-down laser spectroscopy (CRDS) to monitor the carbon isotopes (12C, 13C and 14C) in the isotope separation process for the graphite reactor decommissioning. This system is compact and suitable for a continuous monitoring, because the concentration of molecules including the carbon isotope is derived from its photo absorbance with ultra high sensitive laser absorption spectroscopy. Here are presented the necessary conditions of CRDS system for 14C isotope analysis through the preliminary experimental results of 13C isotope analysis with a prototype system.

  8. A radioactive decay simulation (For Education)

    OpenAIRE

    Riad, Ihab F.; Elkatim, Mohammed El Shazali Sir

    2005-01-01

    This article is intended for physics educators and students at school and undergraduate level. It is used at our department to introduce students to simulation and offer a guide in using statistics in physics. The simulation code was created using Matlab, and was given a friendly interface with a Labview module.

  9. A passive decay heat removal system for LWRs based on air cooling

    Energy Technology Data Exchange (ETDEWEB)

    Mochizuki, Hiroyasu, E-mail: mochizki@u-fukui.ac.jp [Research Institute of Nuclear Engineering, University of Fukui, 1-2-4 Kanawa-cho, Tsuruga, Fukui 914-0055 (Japan); Yano, Takahiro [Graduate School of Engineering, University of Fukui, 1-2-4 Kanawa-cho, Tsuruga, Fukui 914-0055 (Japan)

    2015-05-15

    Highlights: • A passive decay heat removal system for LWRs is discussed. • An air cooler model which condenses steam is developed. • The decay heat can be removed by air coolers with forced convection. • The dimensions of the air cooler are proposed. - Abstract: The present paper describes the capability of an air cooling system (ACS) to remove decay heat from a core of LWR such as an advanced boiling water reactor (ABWR) and a pressurized water reactor (PWR). The motivation of the present research is the Fukushima severe accident (SA) on 11 March 2011. Since emergency cooling systems using electricity were not available due to station blackout (SBO) and malfunctions, many engineers might understand that water cooling was not completely reliable. Therefore, a passive decay heat removal (DHR) system would be proposed in order to prevent such an SA under the conditions of an SBO event. The plant behaviors during the SBO are calculated using the system code NETFLOW++ for the ABWR and PWR with the ACS. Two types of air coolers (ACs) are applied for the ABWR, i.e., a steam condensing air cooler (SCAC) of which intake for heat transfer tubes is provided in the steam region, and single-phase type of which intake is provided in the water region. The DHR characteristics are calculated under the conditions of the forced air circulation and also the natural air convection. As a result of the calculations, the decay heat can be removed safely by the reasonably sized ACS when heat transfer tubes are cooled with the forced air circulation. The heat removal rate per one finned heat transfer tube is evaluated as a function of air flow rate. The heat removal rate increases as a function of the air flow rate.

  10. Observation of Diproron Decay From Excited States of 28S

    Institute of Scientific and Technical Information of China (English)

    LIN; Cheng-jian; XU; Xin-xing; JIA; Hui-ming; YANG; Feng; WU; Zhen-dong; ZHANG; Huan-qiao; LIU; Zu-hua; YANG; Lei; BAO; Peng-fei; SUN; Li-jie; MA; Nan-ru

    2013-01-01

    The historic discovery of radioactivity by Henri Becquerel in 1896 opened a door to nuclear science.Since then,several types of nuclear decay,like?,?,?decays,fission,one-proton(1p)radioactivity,etc.have been discovered with the development of nuclear physics.The latest,two-proton(2p)radioactivity proposed by Goldanskii more than half century ago has been already observed experimentally in the last

  11. Uncertainty analysis of the radiological characteristics of radioactive waste using a method based on log-normal distributions

    International Nuclear Information System (INIS)

    Available in abstract form only. Full text of publication follows: The uncertainty on characteristics of radioactive LILW waste packages is difficult to determine and often very large. This results from a lack of knowledge of the constitution of the waste package and of the composition of the radioactive sources inside. To calculate a quantitative estimate of the uncertainty on a characteristic of a waste package one has to combine these various uncertainties. This paper discusses an approach to this problem, based on the use of the log-normal distribution, which is both elegant and easy to use. It can provide as example quantitative estimates of uncertainty intervals that 'make sense'. The purpose is to develop a pragmatic approach that can be integrated into existing characterization methods. In this paper we show how our method can be applied to the scaling factor method. We also explain how it can be used when estimating other more complex characteristics such as the total uncertainty of a collection of waste packages. This method could have applications in radioactive waste management, more in particular in those decision processes where the uncertainty on the amount of activity is considered to be important such as in probability risk assessment or the definition of criteria for acceptance or categorization. (author)

  12. Trilateration-based reconstruction of ortho-positronium decays into three photons with the J-PET detector

    CERN Document Server

    Gajos, A; Czerwiński, E; Alfs, D; Bednarski, T; Białas, P; Głowacz, B; Gorgol, M; Jasińska, B; Kapłon, Ł; Korcyl, G; Kowalski, P; Kozik, T; Krzemień, W; Kubicz, E; Mohammed, M; Niedźwiecki, Sz; Pałka, M; Pawlik-Niedźwiecka, M; Raczyński, L; Rudy, Z; Rundel, O; Sharma, N G; Silarski, M; Słomski, A; Strzelecki, A; Wieczorek, A; Wiślicki, W; Zgardzińska, B; Zieliński, M; Moskal, P

    2016-01-01

    This work reports on a new reconstruction algorithm allowing to reconstruct the decays of ortho-positronium atoms into three photons using the places and times of photons recorded in the detector. The method is based on trilateration and allows for a simultaneous reconstruction of both location and time of the decay. Results of resolution tests of the new reconstruction in the J-PET detector based on Monte Carlo simulations are presented, which yield a spatial resolution at the level of 2 cm (FWHM) for X and Y and at the level of 1 cm (FWHM) for Z available with the present resolution of J-PET after application of a kinematic fit. Prospects of employment of this method for studying angular correlations of photons in decays of polarized ortho-positronia for the needs of tests of CP and CPT discrete symmetries are also discussed. The new reconstruction method allows for discrimination of background from random three-photon coincidences as well as for application of a novel method for determination of the linear...

  13. Crude radioactivity measure of coal dust based on HPGe γ-ray spectrometer

    International Nuclear Information System (INIS)

    This paper introduced the composing and working principle of a low background anti-Compton HPGe γ spectrometer, then measured the crude radioactivity of five coal dust samples that collected from Da Tang thermoelectricity factory in Xi'an. The average contents of 238U, 226Ra, 232Th, 40K were 67.6 Bq/kg, 79.5Bq/kg, 72.7Bq/kg and 190 Bq/kg. The result reveals that the radioactivity level of coal dust is at a normal level and the coal dust can be used as the A kind building materials according to national standard GB6566-2001, its application range has no limit. (authors)

  14. Determination of radioactive emission origins based on analyses of isotopic composition

    International Nuclear Information System (INIS)

    The nature of radioactivity emissions can be determined through gamma spectroscopy of air samples with good precision, which means that the type of source of the emission may be found, e.g. nuclear weapons test, of nuclear power plant accident. Combined with information on wind trajectories it is normally possible to recognize time and area for the emission. In this preliminary study, the knowledge of and preparedness for such measurements are described. (L.E.)

  15. Evaluation of batch mixing equipment for producing cement-based radioactive waste hosts

    International Nuclear Information System (INIS)

    This report summarizes the general criteria needed to evaluate processing equipment for producing grouts to serve as radioactive waste hosts. An equipment evaluation procedure is also defined by establishing a systematic approach to numerical scoring of equipment performance against specific selection criteria. As an example, this procedure is then used to evaluate cement-mixing equipment for the proposed Process Experimental Pilot Plant. 2 references, 3 figures, 2 tables

  16. A PC-based discrete event simulation model of the civilian radioactive waste management system

    International Nuclear Information System (INIS)

    This paper discusses a System Simulation Model which has been developed for the Department of Energy to simulate the movement of individual waste packages (spent fuel assemblies and fuel containers) through the Civilian Radioactive Waste Management System (CRWMS). A discrete event simulation language, GPSS/PC, which runs on an IBM/PC and operates under DOS 5.0, mathematically represents the movement and processing of radioactive waste packages through the CRWMS and the interaction of these packages with the equipment in the various facilities. The major features of the System Simulation Model are: the ability to reference characteristics of the different types of radioactive waste (age, burnup, etc.) in order to make operational and/or system design decisions, the ability to place stochastic variations on operational parameters such as processing time and equipment outages, and the ability to include a rigorous simulation of the transportation system. Output from the model includes the numbers, types, and characteristics of waste packages at selected points in the CRWMS and the extent to which various resources will be utilized in order to transport, process, and emplace the waste

  17. Radioactive colloids

    International Nuclear Information System (INIS)

    Different techniques for the characterization of radioactive colloids, used in nuclear medicine, have been evaluated and compared. Several radioactive colloids have been characterized in vitro and in vivo and tested experimentally. Colloid biokinetics following interstitial or intravenous injection were evaluated with a scintillation camera technique. Lymphoscintigraphy with a Tc-99-labelled antimony sulphur colloid was performed in 32 patients with malignant melanoma in order to evaluate the technique. Based on the biokinetic results, absorbed doses in tissues and organs were calculated. The function of the reticuloendothelial system has been evaluated in rats after inoculation with tumour cells. Microfiltration and photon correlation spectroscopy were found to be suitable in determining activity-size and particle size distributions, respectively. Maximal lymph node uptake following subcutaneous injection was found to correspond to a colloid particle size between 10 and 50 nm. Lymphoscintigraphy was found to be useful in the study of lymphatic drainage from the primary tumour site in patients with malignant melanoma on the trunk. Quantitative analysis of ilio-inguinal lymph node uptake in patients with malignant melanoma on the lower extremities was, however, found to be of no value for the detection of metastatic disease in lymph nodes. High absorbed doses may be received in lymph nodes (up to 1 mGy/MBq) and at the injection site (about 10 mGy/MBq). In an experimental study it was found that the relative colloid uptake in bone marrow and spleen depended on the total number of intravenously injected particles. This may considerably affect the absorbed dose in these organs. (author)

  18. The thermal decay in the IrMn-based spin valve

    International Nuclear Information System (INIS)

    Thermal decay of the top spin valve with a structure of // Seed Ta (5nm) / Co75Fe25 (5nm) / Cu (2.5nm) / Co75Fe25 (5nm) /Ir20Mn80 (12nm) / Cap Ta (8nm) deposited at room temperature by magnetron sputtering has been investigated by means of holding the film in its negative saturation field at various temperatures. Vibrating sample magnetometer has been used to record the magnetic hysteresis loops at room temperature. The recoil loop of the pinned ferromagnetic layer shifts towards the positive field and the exchange bias field (Hex) decreases monotonously while holding the film in a negative saturation field. The decrease of Hex while holding the film in a negative saturation field indicates a thermally decay process. Due to the exchange coupling at the antiferromagnetic/ferromagnetic interface, the antiferromagnetic moments reverse by thermal activation over an energy barrier distribution, which may change in some way as the temperature increases.

  19. The landscape of two-proton radioactivity

    CERN Document Server

    Olsen, E; Birge, N; Brown, M; Nazarewicz, W; Perhac, A

    2013-01-01

    Ground-state two-proton (2p) radioactivity is a decay mode found in isotopes of elements with even atomic numbers located beyond the two-proton drip line. So far, this exotic process has been experimentally observed in a few light and medium-mass nuclides with Z less than or equal to 30. In this study, using state-of-the-art nuclear density functional theory, we globally analyze 2p radioactivity and for the first time identify 2p decay candidates in elements heavier than strontium. We predict a few cases where the competition between 2p emission and alpha decay may be observed. In nuclei above lead, the alpha decay mode is found to be dominating and no measurable candidates for the 2p radioactivity are expected.

  20. Revisiting alpha decay-based near-light-speed particle propulsion.

    Science.gov (United States)

    Zhang, Wenwu; Liu, Zhen; Yang, Yang; Du, Shiyu

    2016-08-01

    Interplanet and interstellar travels require long-term propulsion of spacecrafts, whereas the conventional schemes of propulsion are limited by the velocity of the ejected mass. In this study, alpha particles released by nuclear decay are considered as a potential solution for long-time acceleration. The principle of near-light-speed particle propulsion (NcPP) was elucidated and the stopping and range of ions in matter (SRIM) was used to predict theoretical accelerations. The results show that NcPP by means of alpha decay is feasible for long-term spacecraft propulsion and posture adjustment in space. A practical NcPP sail can achieve a speed >150km/s and reach the brink of the solar system faster than a mass equivalent solar sail. Finally, to significantly improve the NcPP sail, the hypothesis of stimulated acceleration of nuclear decay (SAND) was proposed, which may shorten the travel time to Mars to within 20 days. PMID:27161512

  1. Synthesis and decay properties of the heaviest nuclei

    Science.gov (United States)

    Oganessian, Yuri

    2006-07-01

    The formation and decay properties of the heaviest nuclei with Z=112-116 and 118 were studied in the reactions 238U, 242,244Pu, 243Am, 245,248Cm and 249Cf + 48Ca. The new nuclides mainly undergo sequential α-decay, which ends with spontaneous fission. The total time of decay ranges from 0.5 ms to ~1 day, depending on the proton and neutron numbers in the synthesized nuclei. The atomic number of the new elements 115 and 113 was confirmed also by an independent radiochemical experiment based on the identification of the neutron-rich isotope 268Db (TSF~30 h), the final product in the chain of α-decays of the odd-odd parent nucleus 288115. The comparison of the decay properties of 29 new nuclides with Z=104-118 and N=162-177 gives evidence of the decisive influence of the structure of superheavy elements on their stability with respect to different modes of radioactive decay. The investigations connected with the search for superheavy elements in Nature and prospects of superheavy element research are also presented. The experiments were carried out at the Flerov Laboratory of Nuclear Reactions (JINR, Dubna) in collaboration with the Analytical and Nuclear Chemistry Division of the Lawrence Livermore National Laboratory (USA).

  2. Radioactive thickness gauge (1962)

    International Nuclear Information System (INIS)

    The author describes a thickness gauge in which the scintillating crystal detector alternately 'sees' a radioactive source through the material which is to be measured and then a control source of the same material; the radiations are separated in time by an absorbing valve whose sections are alternately full and hollow. The currents corresponding to the two sources are separated beyond the photomultiplier tube by a detector synchronized with the rotation of the valve. The quotient of these two currents is then obtained with a standard recording potentiometer. It is found that the average value of the response which is in the form G = f(I1/I2) is not affected by decay of the radioactive sources, and that it is little influenced by variations of high tension, temperature, or properties of the air in the source detector interval. The performance of the gauge is given. (author)

  3. Development programs in the United States of America for the application of cement-based grouts in radioactive waste management

    Energy Technology Data Exchange (ETDEWEB)

    Dole, L.R.; Row, T.H.

    1984-01-01

    This paper briefly reviews seven cement-based waste form development programs at six of the US Department of Energy (DOE) sites. These sites have developed a variety of processes that range from producing 25 mm (1 in.) diameter pellets in a glove box to producing 240 m (800 ft.) diameter grout sheets within the bedding planes of a deep shale formation. These successful applications of cement-based waste forms to the many radioactive waste streams from nuclear facilities bear witness to the flexibility and reliability of this class of materials. This paper also discusses the major issues regarding the application of cement-based waste forms to radioactive waste management problems. These issues are (1) leachability, (2) radiation stability, (3) thermal stability, (4) phase complexity of the matrix, and (5) effects of the waste stream composition. A cursory review of current research in each of these areas is given This paper also discusses future trends in cement-based waste form development and applications. 31 references, 11 figures.

  4. Radioactivity, radionuclides, radiation

    CERN Document Server

    Magill, Joseph

    2005-01-01

    RADIOACTIVITY – RADIONUCLIDES – RADIATION is suitable for a general audience interested in topical environmental and human health radiological issues such as radiation exposure in aircraft, food sterilisation, nuclear medicine, radon gas, radiation dispersion devices ("dirty bombs")… It leads the interested reader through the three Rs of nuclear science, to the forefront of research and developments in the field. The book is also suitable for students and professionals in the related disciplines of nuclear and radiochemistry, health physics, environmental sciences, nuclear and astrophysics. Recent developments in the areas of exotic decay modes (bound beta decay of ‘bare’ or fully ionized nuclei), laser transmutation, nuclear forensics, radiation hormesis and the LNT hypothesis are covered. Atomic mass data for over 3000 nuclides from the most recent (2003) evaluation are included.

  5. Simpler radioactive wastewater processing.

    Science.gov (United States)

    Rodríguez, José Canga; Luh, Volker

    2011-11-01

    José Canga Rodríguez, key account manager, Pharmaceutical and Life Sciences, EnviroChemie, and Volker Luh, CEO of EnviroDTS, describe the development, and recent successful application, of a new technology for dealing safely and effectively with the radioactive "wastewater" generated by patients who have undergone radiotherapy in nuclear medicine facilities. The BioChroma process provides what is reportedly not only a more flexible means than traditional "delay and decay" systems of dealing with this "by-product" of medical treatment, but also one that requires less plant space, affords less risk of leakage or cross-contamination, and is easier to install. PMID:22368885

  6. Tau decays

    International Nuclear Information System (INIS)

    The most recent experimental results of τ physics are reviewed. The covered topics include precision measurements of semihadronic τ decay and their impact on tau branching ratio budget, the current status of the tau consistency test, a determination of Michel parameters and τ neutrino helicity, and upper limits on lepton-number violating τ decays. (orig.)

  7. Constraint-Based Routing Models for the Transport of Radioactive Materials

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Steven K [ORNL

    2015-01-01

    The Department of Energy (DOE) has a historic programmatic interest in the safe and secure routing, tracking, and transportation risk analysis of radiological materials in the United States. In order to address these program goals, DOE has funded the development of several tools and related systems designed to provide insight to planners and other professionals handling radioactive materials shipments. These systems include the WebTRAGIS (Transportation Routing Analysis Geographic Information System) platform. WebTRAGIS is a browser-based routing application developed at Oak Ridge National Laboratory (ORNL) focused primarily on the safe transport of spent nuclear fuel from US nuclear reactors via railway, highway, or waterway. It is also used for the transport planning of low-level radiological waste to depositories such as the Waste Isolation Pilot Plant (WIPP) facility. One particular feature of WebTRAGIS is its coupling with high-resolution population data from ORNL s LandScan project. This allows users to obtain highly accurate population count and density information for use in route planning and risk analysis. To perform the routing and risk analysis WebTRAGIS incorporates a basic routing model methodology, with the additional application of various constraints designed to mimic US Department of Transportation (DOT), DOE, and Nuclear Regulatory Commission (NRC) regulations. Aside from the routing models available in WebTRAGIS, the system relies on detailed or specialized modal networks for the route solutions. These include a highly detailed network model of the US railroad system, the inland and coastal waterways, and a specialized highway network that focuses on the US interstate system and the designated hazardous materials and Highway Route Controlled Quantity (HRCQ) -designated roadways. The route constraints in WebTRAGIS rely upon a series of attributes assigned to the various components of the different modal networks. Routes are determined via a

  8. Simulation for thick-target yields of transmutation reactions on radioactive targets, based on inverse kinematics

    Science.gov (United States)

    Ebata, Shuichiro; Aikawa, Masayuki; Imai, Shotaro

    2016-06-01

    To dispose of long-lived fission products (LLFP) ejected from nuclear reactor plants is one of the most important tasks on nuclear physics and engineering. The experiments with the radiative target are limited, due to the high radioactivity and chemical property of the target. In consequence, the nuclear reaction data for LLFP are insufficient. In this work, we propose a feasible method to obtain the data for radiative targets using inverse kinematics and simulate specific systems to evaluate the thick-target yields of the nuclear transmutation reactions for LLFP.

  9. Radioactive Barium Ion Trap Based on Metal-Organic Framework for Efficient and Irreversible Removal of Barium from Nuclear Wastewater.

    Science.gov (United States)

    Peng, Yaguang; Huang, Hongliang; Liu, Dahuan; Zhong, Chongli

    2016-04-01

    Highly efficient and irreversible capture of radioactive barium from aqueous media remains a serious task for nuclear waste disposal and environmental protection. To address this task, here we propose a concept of barium ion trap based on metal-organic framework (MOF) with a strong barium-chelating group (sulfate and sulfonic acid group) in the pore structures of MOFs. The functionalized MOF-based ion traps can remove >90% of the barium within the first 5 min, and the removal efficiency reaches 99% after equilibrium. Remarkably, the sulfate-group-functionalized ion trap demonstrates a high barium uptake capacity of 131.1 mg g(-1), which surpasses most of the reported sorbents and can selectively capture barium from nuclear wastewater, whereas the sulfonic-acid-group-functionalized ion trap exhibits ultrafast kinetics with a kinetic rate constant k2 of 27.77 g mg(-1) min(-1), which is 1-3 orders of magnitude higher than existing sorbents. Both of the two MOF-based ion traps can capture barium irreversibly. Our work proposes a new strategy to design barium adsorbent materials and provides a new perspective for removing radioactive barium and other radionuclides from nuclear wastewater for environment remediation. Besides, the concrete mechanisms of barium-sorbent interactions are also demonstrated in this contribution.

  10. Recent BES results on charmonium decays

    CERN Document Server

    Yuan, Chang-Zheng

    2007-01-01

    In this talk, we present the recent results on charmonium decays from the BES experiment at the BEPC collider. The analyses are based on a 14 million psi(2S) events data sample. We report results on leptonic decays, hadronic decays, and radiative decays of psi(2S), as well as hadronic decays of chi_cJ states and rare or forbidden decays of J/psi.

  11. Radioactive Wastes.

    Science.gov (United States)

    Choudri, B S; Baawain, Mahad

    2016-10-01

    Papers reviewed herein present a general overview of radioactive waste activities around the world in 2015. These include safety assessments, decommission and decontamination of nuclear facilities, fusion facilities, transportation and management solutions for the final disposal of low and high level radioactive wastes (LLW and HLW), interim storage and final disposal options for spent fuel (SF), and tritiated wastes, with a focus on environmental impacts due to the mobility of radionuclides in water, soil and ecosystem alongwith other progress made in the management of radioactive wastes. PMID:27620100

  12. Radioactive Wastes.

    Science.gov (United States)

    Choudri, B S; Baawain, Mahad

    2015-10-01

    Papers reviewed herein present a general overview of radioactive waste activities around the world in 2014. These include safety assessments, decommission and decontamination of nuclear facilities, fusion facilities, transportation and management solutions for the final disposal of low and high level radioactive wastes (LLW and HLW), interim storage and final disposal options for spent fuel (SF), and tritiated wastes, with a focus on environmental impacts due to the mobility of radionuclides in water, soil and ecosystem alongwith other progress made in the management of radioactive wastes. PMID:26420096

  13. Radioactive Wastes.

    Science.gov (United States)

    Choudri, B S; Baawain, Mahad

    2016-10-01

    Papers reviewed herein present a general overview of radioactive waste activities around the world in 2015. These include safety assessments, decommission and decontamination of nuclear facilities, fusion facilities, transportation and management solutions for the final disposal of low and high level radioactive wastes (LLW and HLW), interim storage and final disposal options for spent fuel (SF), and tritiated wastes, with a focus on environmental impacts due to the mobility of radionuclides in water, soil and ecosystem alongwith other progress made in the management of radioactive wastes.

  14. ISEF Based Identification of RCT/Filling in Dental Caries of Decayed Tooth

    OpenAIRE

    A. J. Solanki; K. R. Jain; N. P. Desai

    2013-01-01

    Dental image processing is one of the emerging fields in case of human identification in forensic sciences. Dental x-rays have been quiet effective for the diagnosis and detection of problems in tooth. This paper presents an add on approach in the same area of medical biometrics to detect and diagnose the dental caries in case of decayed tooth. The enhancement and segmentation of digital dental x-ray image is done by using Infinite Symmetric Exponential filter (Shen Castan Algorithm). The aim...

  15. Simulated Radioactivity

    Science.gov (United States)

    Boettler, James L.

    1972-01-01

    Describes the errors in the sugar-cube experiment related to radioactivity as described in Project Physics course. The discussion considers some of the steps overlooked in the experiment and generalizes the theory beyond the sugar-cube stage. (PS)

  16. Concentrating Radioactivity

    Science.gov (United States)

    Herrmann, Richard A.

    1974-01-01

    By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

  17. Radioactive waste management information for 1993 and record-to-date

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, K.A.

    1994-07-01

    This document presents detailed data, bar graphs, and pie charts on volume, radioactivity, isotopic identity, origin, and decay status of radioactive waste for the calendar year 1993. It also summarizes the radioactive waste data records compiled from 1952 to present for the Idaho National Engineering Laboratory (INEL). The data presented are from the INEL Radioactive Waste Management Information System.

  18. Proton Decay

    OpenAIRE

    Raby, Stuart

    2002-01-01

    We discuss the status of supersymmetric grand unified theories [SUSY GUTs] with regards to the observation of proton decay. In this talk we focus on SUSY GUTs in 4 dimensions. We outline the major theoretical uncertainties present in the calculation of the proton lifetime and then present our best estimate of an absolute upper bound on the predicted proton lifetime. Towards the end, we consider some new results in higher dimensional GUTs and the ramifications for proton decay.

  19. Utility decay rates of T1-weighted magnetic resonance imaging contrast based on redox-sensitive paramagnetic nitroxyl contrast agents

    International Nuclear Information System (INIS)

    The availability and applicability of the combination of paramagnetic nitroxyl contrast agent and T1-weighted gradient echo (GE)-based dynamic magnetic resonance imaging (MRI) measurement for redox imaging are described. The time courses of T1-weighted GE MRI signal intensities according to first-order paramagnetic loss of a nitroxyl contrast agent were simulated for several experimental conditions. The apparent decay rate calculated based on decreasing T1-weighted MRI contrast (kMRI) can show an approximate value of the original decay rate (ktrue) discretionarily given for simulation with suitable experimental parameters. The difference between kMRI and ktrue can be sufficiently small under T1-weighted spoiled gradient echo (SPGR) scan conditions (repetition time=75 ms, echo time=3 ms, and flip angle=45deg), with a conventional redox-sensitive nitroxyl contrast agent, such as 4-hydroxy-2,2,6,6,-tetramethylpiperidine-N-oxyl (TEMPOL) and/or 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-N-oxyl (carbamoyl-PROXYL), and with intravenous (i.v.) doses of below 1.5 γmol/g body weight (b.w.) for mice. The results of this simulation suggest that the kMRI of nitroxyl contrast agents can be the primary index of redox status under biological conditions. (author)

  20. The Wiener-Hermite expansion applied to decaying isotropic turbulence using a renormalized time-dependent base

    Science.gov (United States)

    Hogge, H. D.; Meecham, W. C.

    1978-01-01

    The problem of decaying isotropic turbulence has been studied using a Wiener-Hermite expansion with a renormalized time-dependent base. The theory is largely deductive and uses no modeling approximations. It has been found that many properties of large-Reynolds-number turbulence can be calculated (at least for moderate time) using the moving-base expansion alone. Such properties found are the spectrum shape in the dissipation range, the Kolmogorov constant, and the energy cascade in the inertial subrange. Furthermore, by using a renormalization scheme, it is possible to extend the calculation to larger times and to initial conditions significantly different from the equilibrium form. If the initial spectrum is the Kolmogorov spectrum perturbed with a spike or dip in the inertial subrange, the process proceeds to eliminate the perturbation and relax to the preferred spectrum shape. The turbulence decays with the proper dissipation rate, and several other properties are found to agree with measured data. The theory is also used to calculate the energy transfer and the flatness factor of turbulence.

  1. Semileptonic Decays

    Energy Technology Data Exchange (ETDEWEB)

    Luth, Vera G.; /SLAC

    2012-10-02

    The following is an overview of the measurements of the CKM matrix elements |V{sub cb}| and |V{sub ub}| that are based on detailed studies of semileptonic B decays by the BABAR and Belle Collaborations and major advances in QCD calculations. In addition, a new and improved measurement of the ratios R(D{sup (*)}) = {Beta}({bar B} {yields} D{sup (*)}{tau}{sup -}{bar {nu}}{sub {tau}})/{Beta}({bar B} {yields} D{sup (*)}{ell}{sup -}{bar {nu}}{sub {ell}}) is presented. Here D{sup (*)} refers to a D or a D* meson and {ell} is either e or {mu}. The results, R(D) = 0.440 {+-} 0.058 {+-} 0.042 and R(D*) = 0.332 {+-} 0.024 {+-} 0.018, exceed the Standard Model expectations by 2.0{sigma} and 2.7{sigma}, respectively. Taken together, they disagree with these expectations at the 3.4{sigma} level. The excess of events cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.

  2. Radioactive waste management profiles. Compilation of data from the waste management data base. No. 2, April 1994

    International Nuclear Information System (INIS)

    In 1989, the International Atomic Energy Agency began development of the Waste Management Data Base (WMDB) to, primarily, establish a mechanism for the collection, integration, storage, and retrieval of information relevant to radioactive waste management in Member States. This current report is a summary and compilation of of the data received during the 1991 biennial update which covers the period of January 1991 through March 1993. This Profile report is divided into two main parts. One part describes the Waste Management Data Base system and the type of information it contains. The second part contains data provided by Member States in response to the IAEA's 1991 WMDB Questionnaire. This report also contains data of Member States that did nor report to the Questionnaire

  3. Artificial Intelligence based Solver for Governing Model of Radioactivity Cooling, Self-gravitating Clouds and Clusters of Galaxies

    Directory of Open Access Journals (Sweden)

    Junaid Ali Khan

    2013-06-01

    Full Text Available In this study, a reliable alternate platform is developed based on artificial neural network optimized with soft computing technique for a non-linear singular system that can model complex physical phenomenas of the nature like radioactivity cooling, self-gravitating clouds and clusters of galaxies. The trial solution is mathematically represented by feed-forward neural network. A cost function is defined in an unsupervised manner that is optimized by a probabilistic meta-heuristic global search technique based on annealing in metallurgy. The results of the designed scheme are evaluated by comparing with the desired response of the system. The applicability, stability and reliability of the proposed method is validated by Monte Carlo simulations.

  4. Environmental impact of radioactive releases from recycle of thorium-based fuel using current containment technology

    International Nuclear Information System (INIS)

    The analysis of thorium mining and milling suggests that the resulting doses should be similar to those from uranium operations. An absolute comparison cannot be made at this time, however, due to differences in some assumptions utilized by the various investigators and the lack in some cases of site-specific meteorology and population data at thorium resource sites in the western United States. A distinct difference resulting from the short half-life of 220Rn (T/sub 1/2/ = 55.6 s) in the thorium decay chain compared to that for 222Rn (T/sub 1/2/ = 3.82 d) in uranium decay was noted for emissions following mill shutdown. This effect is to make potential releases following thorium mill shutdown of lesser consequence than in the uranium case. Thorium tailings activity would also decrease relatively rapidly due to the comparatively short half-life (T/sub 1/2 = 5.75 y) of 228Ra. Doses due to airborne releases from thorium-uranium carbide fuel refabrication are significantly less than that due to fuel reprocessing. Tritium is the principal contributor to reprocessing plant doses while carbon-14, 131Cs, and 232U account for most of the remaining dose. A tenfold increase in reprocessing plant CF for tritium reduces both individual and population doses by about 60%. For refabrication operations, a near linear dependence upon dose with 232U content of the fuel was calculated between concentrations of 10 ppM and 5000 ppM. Comparison of (Th, U)C and (U, Pu)C showed little difference in dose commitment, but the presence of 232U in the (Th, U) fuel causes a notable increase in the refabrication plant dose over that previously calculated for (U, Pu) type fuels

  5. Development of new types of geo cement binding materials based on natural minerals and technology of conditioning of radioactive absorbents (zeolites) and sludge immobilized in geo cement matrix

    International Nuclear Information System (INIS)

    Full text: Recently extensive work on development of decontamination technology of liquid radioactive waste (LRW) of the Armenian Nuclear Plant was carried out at the Yerevan State University within the frame of the project ISTC A-485 ('Efficient Treatment of Radioactive Liquid Waste by Zeolites Modified through Chemical and Radiation Methods '). Clinoptilolite based natural aluminosilicate and other zeolite-based sorbents were used for this purpose. During the work the optimization of the sorbent preparation procedures and of the Cs and Sr removal from radioactive effluents under dynamic and static conditions were implemented. Although a high degree LRW volume reduction (up to 400 - 600 times) was achieved. In the result of mentioned technology application a demand emerges to further management (conditioning) of used zeolites containing absorbed radionuclides which in the case of large-scale usage will be accumulated abundantly at NPPs. The new approach of the project (in the frame of ISTC project A- 1209) is a continuation of the above-mentioned project and it will be devoted to the development of technology of conditioning of spent zeolites which may be qualified as middle-active radioactive waste (MRW). The objectives of the project: the development of the low resource- and energy-saving technology for the conditioning of radioactive waste by immobilization into geo cement matrix materials based on readily available and inexpensive natural and technogenic materials of Armenia, the construction of the corresponding pilot plant and their testing at Armenian NPP

  6. Resonance shielding-factor cross-section processing technique validation based on tungsten decay heat experimental data

    CERN Document Server

    Cepraga, D G; Frisoni, M

    2000-01-01

    This study presents a method to obtain corrected self-shielded radiative capture cross-sections for tungsten isotopes to be used for activation calculations. The approach used is based on the application of the Bondarenko shielding factor method to the 175-group AMPX master library by means of the Bonami-Nitawl scale-4.3 sequence calculation. The ANITA-4M activation code calculates the tungsten radioisotopes production and the decay heat using the self-shielded cross-sections from ENDF/B-VI, JEF-2.2 and JENDL-3.2 data files. Two irradiation scenarios (5 min and 7 h) in the international thermonuclear experimental reactor (ITER)-like neutron flux spectrum defined by the fusion neutron source experiments are analyzed. The unshielded calculations result in discrepancy with experiment up to 70%, while the self-shielding treatment reduces drastically that discrepancy to less than few percents. In comparison to the experimental integral decay heat values provides a validation of the method used to deal with the sel...

  7. Speeding-up Thorium decay

    CERN Document Server

    Cardone, F; Petrucci, A

    2007-01-01

    We show that cavitation of a solution of thorium-228 in water induces its transformation at a rate 10000 times faster than the natural radioactive decay would do. This result agrees with the alteration of the secular equilibrium of thorium-234 obtained by a Russian team via explosion of titanium foils in water and solutions. These evidences further support some preliminary clues for the possibility of piezonuclear reactions (namely nuclear reactions induced by pressure waves) obtained in the last ten years.

  8. RADIOACTIVITY DOSAGE OF ORNAMENTAL GRANITIC ROCKS BASED ON CHEMICAL, MINERALOGICAL AND LITHOLOGICAL DATA

    Energy Technology Data Exchange (ETDEWEB)

    Salas, H.T.; Nalini, H.A. Jr.; Mendes, J.C.

    2004-10-03

    One hundred samples of granitic rock were collected from granite traders in Belo Horizonte. Autoradiography, optical microscopy, diffractometry, and chemical analysis (X-ray spectrometry, X-ray fluorescence, neutron activation, gravimetry and electron probe microanalysis) were used to determine the mineral assemblages and lithotypes. Autoradiographic results for several samples showed the presence of monazite, allanite and zircon. Chemical analysis revealed concentrations of uranium of {le} 30ppm, and thorium {le} 130ppm. Higher concentrations generally correlated with high concentrations of light rare earths in silica-rich rocks of granitic composition. Calculations were made of radioactive doses for floor tiles in a standard room for samples with total concentration of uranium and thorium greater than 60ppm. On the basis of calculations of {sup 232}Th, {sup 40}K and {sup 226}Ra from Th, K and U analysis, the doses calculated were between 0.11 and 0.34 mSv/year, which are much lower than the acceptable international exposure standard of 1.0 mSv/year.

  9. Low-level radioactive Hanford wastes immobilized by cement-based grouts

    International Nuclear Information System (INIS)

    More than 5,300,000 liters (1,400,000 gal) of phosphate/sulfate waste (PSW) grout were produced and placed in vault 101 at the Hanford Site. This waste was generated during decontamination operations and maintenance of the fuel storage basin at the N Reactor. The low-level radioactive liquid wastes were mixed with a blend of portland cement, fly ash, and clays. Through cementing and pozzolanic reactions with water, the grout was solidified to immobilize contaminants and retain low permeability to groundwater. Testing conducted before the campaign is described. The usefulness of each quality verification technique is discussed, focusing mainly on data from the core samples. These data provide the best information on PSW grout since core samples from all regions and depths in the vault were tested. The nondestructive testing data are also useful as they provide property data from broad regions of the vault. The mean compressive strength of the PSW grout cores is 4.17 MPa, much higher than the criterion value of 0.35 MPa. Results also show that the leachability indices for 137Cs, 60Co, sodium, and SO4 for PSW grout cores exceed the leachability criterion by at least one index point. This means that the ability of the grout to resist leaching of waste species is at least ten times greater than the limiting criterion

  10. The natural radioactivity of the biosphere

    International Nuclear Information System (INIS)

    Of the approximately 1200 isotopes presently known more than 900 are radioactive. The nuclei of these isotopes are unstable and decay spontaneously emitting ionizing gamma-, alpha- or beta-radiation. The overwhelming majority of known radioactive isotopes have been obtained artificially; only a few are natural. Numerous investigations have shown that many of the natural radioactive isotopes can be grouped into three radioactive families. Each such family is characterized by the existence of one long-lived isotope - the family parent, one gaseous isotope of radon, intermediate radioactive decay products and final stable isotopes of atomic weights 206, 207 and 208. No such generic relationship has been established among the remaining natural radioactive isotopes. The purpose of the book, in contrast to some recent review works, is to present, in addition to a summary of reference data characterizing the radioactivity levels of various components of the biosphere, a description of those phenomena and regularities which will apparently make it possible to understand more completely the basic dynamics of the natural radioactivity of the biosphere and, consequently, contribute to a more correct interpretation of radiation-hygiene in each specific case

  11. Applications of TAGS data in beta decay energies and decay heat calculations

    OpenAIRE

    Pham, N. S.; 片倉 純一

    2007-01-01

    The recent data of beta-decay intensity measured by using the total absorption gamma-ray spectrometer (TAGS), for several fission products (FP), has been applied for calculations of the average energies and spectra, and decay heat summations. The calculations were performed based on the Gross theory of beta decay, in which the beta strength functions were experimentally derived from TAGS data. The deviations of decay heat power predictions from the original decay data of JENDL Decay Data File...

  12. B decays

    CERN Document Server

    Stone, Sheldon

    1992-01-01

    The study of b quarks has now reached a stage where it is useful to review what has been learned so far and also to look at the implications of future studies. The most important observations thus far - measurement of the "B" lifetime, B 0 - B 0 mixing, and the observation of b? u transitions, as well as more mundane results on hadronic and semileptonic transitions - are described in detail by experimentalists who have been closely involved with the measurements. Theoretical progress in understanding b quark decays, including the mechanisms of hadronic and semileptonic decays, are described. S

  13. QCD Factorization Based on Six-Quark Operator Effective Hamiltonian from Perturbative QCD and Charmless Bottom Meson Decays $B_{(s)}\\to \\pi\\pi,\\pi K, KK$

    CERN Document Server

    Su, Fang; Yang, Yi-Bo; Zhuang, Ci

    2008-01-01

    The charmless bottom meson decays are systematically investigated based on an approximate six quark operator effective Hamiltonian from perturbative QCD. It is shown that within this framework the naive QCD factorization method provides a simple way to evaluate the hadronic matrix elements of two body mesonic decays. The singularities caused by on mass-shell quark propagator and gluon exchanging interaction are appropriately treated. Such a simple framework allows us to make theoretical predictions for the decay amplitudes with reasonable input parameters. The resulting theoretical predictions for all the branching ratios and CP asymmetries in the charmless $B^0, B^+, B_s\\to \\pi\\pi, \\pi K, KK$ decays are found to be consistent with the current experimental data except for a few decay modes. The observed large branching ratio in $B\\to \\pi^0\\pi^0$ decay remains a puzzle though the predicted branching ratio may be significantly improved by considering the large vertex corrections in the effective Wilson coeffici...

  14. Introduction to naturally occurring radioactive material

    Energy Technology Data Exchange (ETDEWEB)

    Egidi, P.

    1997-08-01

    Naturally occurring radioactive material (NORM) is everywhere; we are exposed to it every day. It is found in our bodies, the food we eat, the places where we live and work, and in products we use. We are also bathed in a sea of natural radiation coming from the sun and deep space. Living systems have adapted to these levels of radiation and radioactivity. But some industrial practices involving natural resources concentrate these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Other activities, such as flying at high altitudes, expose us to elevated levels of NORM. This session will concentrate on diffuse sources of technologically-enhanced (TE) NORM, which are generally large-volume, low-activity waste streams produced by industries such as mineral mining, ore benefication, production of phosphate Fertilizers, water treatment and purification, and oil and gas production. The majority of radionuclides in TENORM are found in the uranium and thorium decay chains. Radium and its subsequent decay products (radon) are the principal radionuclides used in characterizing the redistribution of TENORM in the environment by human activity. We will briefly review other radionuclides occurring in nature (potassium and rubidium) that contribute primarily to background doses. TENORM is found in many waste streams; for example, scrap metal, sludges, slags, fluids, and is being discovered in industries traditionally not thought of as affected by radionuclide contamination. Not only the forms and volumes, but the levels of radioactivity in TENORM vary. Current discussions about the validity of the linear no dose threshold theory are central to the TENORM issue. TENORM is not regulated by the Atomic Energy Act or other Federal regulations. Control and regulation of TENORM is not consistent from industry to industry nor from state to state. Proposed regulations are moving from concentration-based standards to dose-based

  15. The role of the California Base Closure Environmental Committee's (CBCEC) Radioactive and Mixed Waste Process Action Team (RMWPAT) in expediting site restoration and reuse

    International Nuclear Information System (INIS)

    The Base Realignment and Closure Act (BRAC) mandated the closing and transfer of Department of Defense (DoD) properties within specific timeframes. Due to requirements of federal and state laws, closing bases must be environmentally remediated to alleviate threats to human health and the environment upon transfer. Certain barriers such as legislative, regulatory, administrative, and technical issues, have been identified which threaten the timely restoration and transfer of these BRAC properties. The state of California, faced with the scheduled closure or realignment of 26 military bases, recognized the need to establish a base closure environmental committee to address issues affecting the timely cleanup and reuse of DoD properties and promote accelerated restoration. Accordingly, the California Base Closure Environmental Committee (CBCEC) was formed by executive order of Governor Pete Wilson. One of the barriers identified by the CBCEC is the potential contamination of DoD facilities with radioactive materials. As a result of the difficulties encountered in assessing the nature and extent of radioactive contamination at DoD sites in California, the CBCEC formed the Radioactive and Mixed Waste Process Action Team (RMWPAT). The RMWPAT was tasked with ''demystifying'' and working to address issues associated with radioactive contamination

  16. A proposed classification system for high-level and other radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Kocher, D. C.; Croff, A. G.

    1987-06-01

    This report presents a proposal for quantitative and generally applicable risk-based definitions of high-level and other radioactive wastes. On the basis of historical descriptions and definitions of high-level waste (HLW), in which HLW has been defined in terms of its source as waste from reprocessing of spent nuclear fuel, we propose a more general definition based on the concept that HLW has two distinct attributes: HLW is (1) highly radioactive and (2) requires permanent isolation. This concept leads to a two-dimensional waste classification system in which one axis, related to ''requires permanent isolation,'' is associated with long-term risks from waste disposal and the other axis, related to ''highly radioactive,'' is associated with shorter-term risks due to high levels of decay heat and external radiation. We define wastes that require permanent isolation as wastes with concentrations of radionuclides exceeding the Class-C limits that are generally acceptable for near-surface land disposal, as specified in the US Nuclear Regulatory Commission's rulemaking 10 CFR Part 61 and its supporting documentation. HLW then is waste requiring permanent isolation that also is highly radioactive, and we define ''highly radioactive'' as a decay heat (power density) in the waste greater than 50 W/m/sup 3/ or an external radiation dose rate at a distance of 1 m from the waste greater than 100 rem/h (1 Sv/h), whichever is the more restrictive. This proposal also results in a definition of Transuranic (TRU) Waste and Equivalent as waste that requires permanent isolation but is not highly radioactive and a definition of low-level waste (LLW) as waste that does not require permanent isolation without regard to whether or not it is highly radioactive.

  17. A proposed classification system for high-level and other radioactive wastes

    International Nuclear Information System (INIS)

    This report presents a proposal for quantitative and generally applicable risk-based definitions of high-level and other radioactive wastes. On the basis of historical descriptions and definitions of high-level waste (HLW), in which HLW has been defined in terms of its source as waste from reprocessing of spent nuclear fuel, we propose a more general definition based on the concept that HLW has two distinct attributes: HLW is (1) highly radioactive and (2) requires permanent isolation. This concept leads to a two-dimensional waste classification system in which one axis, related to ''requires permanent isolation,'' is associated with long-term risks from waste disposal and the other axis, related to ''highly radioactive,'' is associated with shorter-term risks due to high levels of decay heat and external radiation. We define wastes that require permanent isolation as wastes with concentrations of radionuclides exceeding the Class-C limits that are generally acceptable for near-surface land disposal, as specified in the US Nuclear Regulatory Commission's rulemaking 10 CFR Part 61 and its supporting documentation. HLW then is waste requiring permanent isolation that also is highly radioactive, and we define ''highly radioactive'' as a decay heat (power density) in the waste greater than 50 W/m3 or an external radiation dose rate at a distance of 1 m from the waste greater than 100 rem/h (1 Sv/h), whichever is the more restrictive. This proposal also results in a definition of Transuranic (TRU) Waste and Equivalent as waste that requires permanent isolation but is not highly radioactive and a definition of low-level waste (LLW) as waste that does not require permanent isolation without regard to whether or not it is highly radioactive

  18. Automated system for selective fission product separations; decays of /sup 113 -115/Pd

    Energy Technology Data Exchange (ETDEWEB)

    Meikrantz, D.H.; Gehrke, R.J.; McIsaac, L.D.; Baker, J.D.; Greenwood, R.C.

    1981-01-01

    A microcomputer controlled radiochemical separation system has been developed for the isolation and study of fission products with half-lives of approx. >= 10 s. The system is based upon solvent extraction with three centrifugal contactors coupled in series, which provides both rapid and highly efficient separations with large decontamination factors. This automated system was utilized to study the radioactive decays of /sup 113 -115/Pd via solvent extraction of the Pd-dimethylglyoxime complex from /sup 252/Cf fission products. As a result of this effort, ..gamma..-rays associated with the decay of approx. equal to 90-s sup(113,113m)Pd, 149-s /sup 114/Pd and 47-s /sup 115/Pd have been identified. The isotopic assignments to each of these Pd radioactivities have been confirmed from observation of the growth and decay curves of their respective Ag daughters. In addition, previously unreported Ag ..gamma..-rays have been assigned; one to the decay of 69-s /sup 113/Ag, and two to the decay of 19-s /sup 115/Ag.

  19. Low radioactivities '85. (The 7th Nuclear Science Colloquium)

    International Nuclear Information System (INIS)

    The conference proceedings contain 108 papers. The following topics are dealt with: accelerator mass spectroscopy, rare decays, underground laboratories, low level counting and spectroscopy, double beta-decay experiments, low level detectors, cosmogenic radionuclides and rare events, 14C counting and applications, 3H counting and hydrology appllications, natural radioactivity in the environment, gaseous detectors, anthropogenic radionuclides and radioactivity in the environment. (J.P.)

  20. Rare charm decays at LHCb

    CERN Document Server

    Kochebina, Olga

    2014-01-01

    Flavour-changing neutral current decays such as c ! ul + l are highly suppressed in the Standard Model, but may be enhanced by New Physics. The latest searches for such decays at LHCb based on 1.0 fb 1 of data collected in 2011 are presented in this document. Two decays, 2-body D 0 ! m + m and 3-body D + ( s ) ! p + m + m , are considered here

  1. Radioactivity in food crops

    International Nuclear Information System (INIS)

    Published levels of radioactivity in food crops from 21 countries and 4 island chains of Oceania are listed. The tabulation includes more than 3000 examples of 100 different crops. Data are arranged alphabetically by food crop and geographical origin. The sampling date, nuclide measured, mean radioactivity, range of radioactivities, sample basis, number of samples analyzed, and bibliographic citation are given for each entry, when available. Analyses were reported most frequently for 137Cs, 40K, 90Sr, 226Ra, 228Ra, plutonium, uranium, total alpha, and total beta, but a few authors also reported data for 241Am, 7Be, 60Co, 55Fe, 3H, 131I, 54Mn, 95Nb, 210Pb, 210Po, 106Ru, 125Sb, 228Th, 232Th, and 95Zr. Based on the reported data it appears that radioactivity from alpha emitters in food crops is usually low, on the order of 0.1 Bq.g-1 (wet weight) or less. Reported values of beta radiation in a given crop generally appear to be several orders of magnitude greater than those of alpha emitters. The most striking aspect of the data is the great range of radioactivity reported for a given nuclide in similar food crops with different geographical origins

  2. Radioactivity in food crops

    Energy Technology Data Exchange (ETDEWEB)

    Drury, J.S.; Baldauf, M.F.; Daniel, E.W.; Fore, C.S.; Uziel, M.S.

    1983-05-01

    Published levels of radioactivity in food crops from 21 countries and 4 island chains of Oceania are listed. The tabulation includes more than 3000 examples of 100 different crops. Data are arranged alphabetically by food crop and geographical origin. The sampling date, nuclide measured, mean radioactivity, range of radioactivities, sample basis, number of samples analyzed, and bibliographic citation are given for each entry, when available. Analyses were reported most frequently for /sup 137/Cs, /sup 40/K, /sup 90/Sr, /sup 226/Ra, /sup 228/Ra, plutonium, uranium, total alpha, and total beta, but a few authors also reported data for /sup 241/Am, /sup 7/Be, /sup 60/Co, /sup 55/Fe, /sup 3/H, /sup 131/I, /sup 54/Mn, /sup 95/Nb, /sup 210/Pb, /sup 210/Po, /sup 106/Ru, /sup 125/Sb, /sup 228/Th, /sup 232/Th, and /sup 95/Zr. Based on the reported data it appears that radioactivity from alpha emitters in food crops is usually low, on the order of 0.1 Bq.g/sup -1/ (wet weight) or less. Reported values of beta radiation in a given crop generally appear to be several orders of magnitude greater than those of alpha emitters. The most striking aspect of the data is the great range of radioactivity reported for a given nuclide in similar food crops with different geographical origins.

  3. Your radioactive garden

    International Nuclear Information System (INIS)

    The booklet on radiation risks from nuclear waste is based on lectures given by the author at Westminster School (United Kingdom) and elsewhere during 1986. A description is given of naturally-occurring radioactivity, and the health risks due to this radiation. The types of radioactive wastes produced by the nuclear industry are described, including low-level wastes, short-lived and long-lived intermediate-level wastes, and high level wastes. These wastes are discussed with respect to their potential health risks and their disposal underground. (U.K.)

  4. Radioactive alchemy

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2014-07-15

    For any entity involved in radioactive waste management, turning lead into gold means succeeding with minimising the volumes and optimizing the long-term containment of ultimate waste to be disposed of. With this purpose, they perform R and D on different sorting, treatment and disposal technology, as explained by Frederic Plas from Andra (France), Jan Deckers from Belgoprocess (Belgium) and Wilhelm Bollingerfehr from DBE Technology (Germany). (orig.)

  5. Radioactive alchemy

    International Nuclear Information System (INIS)

    For any entity involved in radioactive waste management, turning lead into gold means succeeding with minimising the volumes and optimizing the long-term containment of ultimate waste to be disposed of. With this purpose, they perform R and D on different sorting, treatment and disposal technology, as explained by Frederic Plas from Andra (France), Jan Deckers from Belgoprocess (Belgium) and Wilhelm Bollingerfehr from DBE Technology (Germany). (orig.)

  6. History of radioactivity

    International Nuclear Information System (INIS)

    The author describes the historical development of the physics of atoms and nuclei. After a consideration of the ancient Greek philosophy concerning atoms the behaviour of gases is discussed with regards to statistical mechanics. Then the developement of chemistry from alchemy is described. Thereafter the early studies of gas discharges are described with regards to the electronic structure of atoms. In this connection the periodic system of elements is considered. Then the detection of the α-radiation of Uranium by Becquerel and the detections of M. and P. Curie are described. Thereafter the radiactive decay of nuclei is discussed. Then a popular introduction into nuclear structure is given with special regards to artificial radioactivity and nuclear fission. Finally nuclear reactors, the atomic bombs, applications of radionuclides, and problems of radiation protection are described. (HSI)

  7. Application of risk-based approach to post-closure safety assessment in radioactive waste disposal: An integration of complex radiation exposure situations

    International Nuclear Information System (INIS)

    Highlights: ► Integrated approach for systematic risk assessment of radioactive waste disposal. ► Consideration of respective probability of initiating events, release, and transport in post-closure safety assessment. ► Advantage: modularity, i.e., respective evaluation and integration of risk elements. -- Abstract: Based on the concept of risk, the post-closure safety criteria for High Level Radioactive Waste (HLW) disposal are under development in Korea. For compliance with the safety criteria of disposal, the risk-based safety assessment methodology should be implemented. In this paper, the authors suggest a risk-based approach to safety assessment for Korea radioactive waste disposal to evaluate an aggregative radiological risk for scenarios of complex radiation exposure situations; accordingly, the most plausible three cases are carefully selected. This risk-based approach deals with the scenarios from the viewpoint of the receptor to estimate the total risk. For respective exposure situations, it considers the occurrence probabilities of the relevant exposure scenarios as the probability of giving rise to doses to estimate the total risk to a representative person by aggregating the respective risks. In addition, the probability of an exposure scenario is estimated on the assumption that the initiating events influence release mechanisms and transport pathways. This integrated approach enables a systematic risk assessment and is informative when judging the probable overall risk for complex exposure situations of radioactive waste disposal. In this paper, the risk-based approach is applied for the case of the Low and Intermediate Level Radioactive Waste (LILW) Disposal, and also the results should be applicable to the HLW disposal facilities.

  8. Analysis of the total activation cross section of all possible reactions producing the same radioactive nuclide for the%Analysis of the total activation cross section of all possible reactions producing the same radioactive nuclide for the

    Institute of Scientific and Technical Information of China (English)

    周丰群; 宋月丽; 拓飞; 孔祥忠

    2011-01-01

    Firstly, according to the regulation of growth and decay of radioactive nuclides produced in reactions, a formula used to calculate the total activation cross section of all possible reactions producing the same radioactive nuclide for the same element is

  9. Trap-assisted decay spectroscopy with ISOLTRAP

    CERN Document Server

    Kowalska, M; Agramunt, J.; Algora, A.; Beck, D.; Blank, B.; Blaum, K.; Böhm, Ch.; Borgmann, Ch.; Breitenfeldt, M.; Fraile, L.M.; George, S.; Herfurth, F.; Herlert, A.; Kreim, S.; Lunney, D.; Minaya-Ramirez, E.; Neidherr, D.; Rosenbusch, M.; Rubio, B.; Schweikhard, L.; Stanja, J.; Zuber, K.

    Penning traps are excellent high-precision mass spectrometers for radionuclides. The high-resolving power used for cleaning isobaric and even isomeric contaminants can be exploited to improve decay-spectroscopy studies by delivering purified samples. An apparatus allowing trap-assisted decay spectroscopy has been coupled to the ISOLTRAP mass spectrometer at ISOLDE/CERN. The results from studies with stable and radioactive ions show that the setup can be used to perform decay studies on purified short-lived nuclides and to assist mass measurements.

  10. Trap-assisted decay spectroscopy with ISOLTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Kowalska, M., E-mail: kowalska@cern.ch [CERN, Physics Department, 1211 Geneva 23 (Switzerland); Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Naimi, S. [CSNSM-IN2P3-CNRS, Universite de Paris Sud, 91405 Orsay (France); Agramunt, J.; Algora, A. [IFIC, CSIC-Universidad de Valencia, 46071 Valencia (Spain); Beck, D. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Blank, B. [CENBG, Universite Bordeaux 1/CNRS/IN2P3, 33175 Gradignan Cedex (France); Blaum, K.; Boehm, Ch.; Borgmann, Ch. [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Breitenfeldt, M. [Ernst-Moritz-Arndt-Universitaet, Institut fuer Physik, 17487 Greifswald (Germany); Fraile, L.M. [Universidad Complutense, Dep. de Fisica Atomica, Molecular y Nuclear, 28040 Madrid (Spain); George, S. [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Herfurth, F. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Herlert, A. [CERN, Physics Department, 1211 Geneva 23 (Switzerland); Kreim, S. [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Lunney, D.; Minaya-Ramirez, E. [CSNSM-IN2P3-CNRS, Universite de Paris Sud, 91405 Orsay (France); Neidherr, D. [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Rosenbusch, M. [Ernst-Moritz-Arndt-Universitaet, Institut fuer Physik, 17487 Greifswald (Germany); and others

    2012-10-11

    Penning traps are excellent high-precision mass spectrometers for radionuclides. The high-resolving power used for cleaning isobaric and even isomeric contaminants can be exploited to improve decay-spectroscopy studies by delivering purified samples. An apparatus allowing trap-assisted decay spectroscopy has been coupled to the ISOLTRAP mass spectrometer at ISOLDE/CERN. The results from studies with stable and radioactive ions show that the setup can be used to perform decay studies on purified short-lived nuclides and to assist mass measurements.

  11. Table of radioactifs isotopes and their main decay characteristics

    International Nuclear Information System (INIS)

    Table of radioactive isotopes and their main decay characteristics. Presented here are the half lives, desintegration energies, and main γ and α rays for all radioactive isotopes; these data are taken from a Data Bank, where are ranged all the γ and α rays

  12. Development and application of a radioactivity evaluation technique the to obtain radiation exposure dose of radioactivity evaluation technique when a severe accident occurs in the a power station of a severe accident. Accident management guidelines of knowledge-based maintenance

    International Nuclear Information System (INIS)

    As a One of the lessons learned from the nuclear accident at the Fukushima Daiichi Nuclear Power Stations of Tokyo Electric Power Company, the was the need for improvement of accident management guidelines is required. In this report study, we developed and applied a dose evaluation technique to evaluated the radiation dose in a nuclear power plant assuming three conditions: employees were evacuation evacuated at the time of a severe accident occurrence; operators carried out the accident management operation; of the operators, and the repair work was carried out for of the trouble damaged apparatuses in a the nuclear power plant using a dose evaluation system. The following knowledge findings were obtained and should to be reflected to in the knowledge base of the guidelines was obtained. (1) By making clearly identifying an areas beforehand becoming the that would receive high radiation doses at the time of a severe accident definitely beforehand, we can employees can be moved to the evacuation places through an areas having of low dose rate and it is also known it how much we long employees can safely stay in the evacuation places. (2) When they circulate CV containment vessel recirculation sump water is recirculated by for the accident management operation and the restoration of safety in the facilities, because the plumbing piping and the apparatuses become radioactive radioactivity sources, the dose evaluation of the shortest access route and detour access routes with should be made for effective the accident management operation is effective. Because the area where a dose rate rises changes which as safety apparatuses are restored, in consideration of a plant state, it is necessary to judge the rightness or wrongness of the work continuation from the spot radioactive dose of the actual apparatus area, with based on precedence of the need to restore with precedence, and to choose a system to be used for accident management. (author)

  13. Studies on dynamic compaction and hydraulic properties of Bentonite-based materials for geological disposal of radioactive wastes

    International Nuclear Information System (INIS)

    As the safe disposal method of high-level radioactive waste from nuclear power plants, there is the 'geological disposal' that buries the waste in the stable soil. For cushioning materials to be used for geological disposal, performances such as low permeability. self-sealing ability, and nuclide sorption ability are required, and bentonite has been picked up as a candidate for its main base material. This paper takes up granular bentonite and bentonite - silica sand mixed material as the bentonite-based materials used as cushioning materials for site application, and explains their dynamic compaction test and easy-to-use evaluation method. As for the granular bentonite, it was found that its compaction properties can be predicted from the plastic limit of pulverized sample of the original ore as a raw material for granular bentonite. As for bentonite - silica sand mixed material, the relationship between maximum dry density, optimum moisture content, and plastic limit showed a very good match between the measured results and calculated results. The permeability coefficient of granular bentonite can be predicted from the wet volume strain of montmorillonite, or the partial density of montmorillonite. As for the bentonite - silica sand mixed material, the permeability of Fe(III) type montmorillonite became significantly larger. (A.O.)

  14. Dark decay of Top quark

    CERN Document Server

    Kong, Kyoungchul; Park, Myeonghun

    2014-01-01

    We suggest top quark decays as a venue to search for light dark force carriers. Top quark is the heaviest particle in the standard model whose decays are relatively poorly measured, allowing sufficient room for new decay modes from new physics. A very light (GeV scale) dark gauge boson (Z') is a recently highlighted hypothetical particle that can address some astrophysical anomalies as well as the 3.6 sigma deviation in the muon g-2 measurement. We present and study a possible scenario that top quark decays as t -> b W + Z's. This is the same as the dominant top quark decay (t -> b W) accompanied by one or multiple dark force carriers. The Z' can be easily boosted, and it can decay into highly collimated leptons (lepton-jet) with large branching ratio. We discuss the implications for the Large Hadron Collider experiments including the analysis based on the lepton-jets.

  15. Signature of nonexponential nuclear decay

    CERN Document Server

    Ray, A; De, A

    2015-01-01

    Precision tests of decay law of radioactive nuclei have not so far found any deviation from the exponential decay law at early time, as predicted by quantum mechanics. In this paper, we show that the quantum decoherence time (i.e. the timescale of nonexponential decay) of the quasifission or fission process should be of the order of attosecond considering the atom of the fissioning nucleus as a quantum detector. Hence, the observed decay timescale of the quasifission or fission process of even highly excited (EX greater than 50 MeV) transuranium and uraniumlike complexes should be rather long (of the order of attosecond) in spite of their very fast exponential decay timescale (of the order of zeptosecond) as measured by the nuclear techniques. Recent controversy regarding the observation of very long (of the order of attosecond ) and very short (of the order of zeptosecond ) quasifission or fission timescales for similar systems at similar excitation energies as obtained by direct techniques (crystal blocking...

  16. Influence of natural radioactive aerosols on artificial radioactivity detection in the Spanish surveillance networks

    International Nuclear Information System (INIS)

    The device used for continuous measurements of artificial α and β activity in Spanish radiological surveillance networks is the LB BAI 9850 monitor from the Berthold Company. The temporal variation of radon decay product equilibrium introduces a varying background signal in the artificial radioactivity in these monitors. This unwanted background signal can be significantly reduced by analyzing natural radioactive aerosols and their influence on the monitor

  17. A field programmable gate array-based time-resolved scaler for collinear laser spectroscopy with bunched radioactive potassium beams

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, D. M., E-mail: rossi@nscl.msu.edu; Davis, M.; Ringle, R.; Rodriguez, J. A.; Ryder, C. A.; Schwarz, S.; Sumithrarachchi, C.; Zhao, S. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Minamisono, K., E-mail: minamiso@nscl.msu.edu; Barquest, B. R.; Bollen, G.; Hughes, M.; Strum, R.; Tarazona, D. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States); Cooper, K.; Hammerton, K.; Mantica, P. F.; Morrissey, D. J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Chemistry, Michigan State University, East Lansing, Michigan 48824 (United States)

    2014-09-15

    A new data acquisition system including a Field Programmable Gate Array (FPGA) based time-resolved scaler was developed for laser-induced fluorescence and beam bunch coincidence measurements. The FPGA scaler was tested in a collinear laser-spectroscopy experiment on radioactive {sup 37}K at the BEam COoler and LAser spectroscopy (BECOLA) facility at the National Superconducting Cyclotron Laboratory at Michigan State University. A 1.29 μs bunch width from the buncher and a bunch repetition rate of 2.5 Hz led to a background suppression factor of 3.1 × 10{sup 5} in resonant photon detection measurements. The hyperfine structure of {sup 37}K and its isotope shift relative to the stable {sup 39}K were determined using 5 × 10{sup 4} s{sup −1} {sup 37}K ions injected into the BECOLA beam line. The obtained hyperfine coupling constants A({sup 2}S{sub 1/2}) = 120.3(1.4) MHz, A({sup 2}P{sub 1/2}) = 15.2(1.1) MHz, and A({sup 2}P{sub 3/2}) = 1.4(8) MHz, and the isotope shift δν{sup 39,} {sup 37} = −264(3) MHz are consistent with the previously determined values, where available.

  18. A field programmable gate array-based time-resolved scaler for collinear laser spectroscopy with bunched radioactive potassium beams.

    Science.gov (United States)

    Rossi, D M; Minamisono, K; Barquest, B R; Bollen, G; Cooper, K; Davis, M; Hammerton, K; Hughes, M; Mantica, P F; Morrissey, D J; Ringle, R; Rodriguez, J A; Ryder, C A; Schwarz, S; Strum, R; Sumithrarachchi, C; Tarazona, D; Zhao, S

    2014-09-01

    A new data acquisition system including a Field Programmable Gate Array (FPGA) based time-resolved scaler was developed for laser-induced fluorescence and beam bunch coincidence measurements. The FPGA scaler was tested in a collinear laser-spectroscopy experiment on radioactive (37)K at the BEam COoler and LAser spectroscopy (BECOLA) facility at the National Superconducting Cyclotron Laboratory at Michigan State University. A 1.29 μs bunch width from the buncher and a bunch repetition rate of 2.5 Hz led to a background suppression factor of 3.1 × 10(5) in resonant photon detection measurements. The hyperfine structure of (37)K and its isotope shift relative to the stable (39)K were determined using 5 × 10(4) s(-1) (37)K ions injected into the BECOLA beam line. The obtained hyperfine coupling constants A((2)S(1/2)) = 120.3(1.4) MHz, A((2)P(1/2)) = 15.2(1.1) MHz, and A((2)P(3/2)) = 1.4(8) MHz, and the isotope shift δν(39, 37) = -264(3) MHz are consistent with the previously determined values, where available. PMID:25273722

  19. A field programmable gate array-based time-resolved scaler for collinear laser spectroscopy with bunched radioactive potassium beams.

    Science.gov (United States)

    Rossi, D M; Minamisono, K; Barquest, B R; Bollen, G; Cooper, K; Davis, M; Hammerton, K; Hughes, M; Mantica, P F; Morrissey, D J; Ringle, R; Rodriguez, J A; Ryder, C A; Schwarz, S; Strum, R; Sumithrarachchi, C; Tarazona, D; Zhao, S

    2014-09-01

    A new data acquisition system including a Field Programmable Gate Array (FPGA) based time-resolved scaler was developed for laser-induced fluorescence and beam bunch coincidence measurements. The FPGA scaler was tested in a collinear laser-spectroscopy experiment on radioactive (37)K at the BEam COoler and LAser spectroscopy (BECOLA) facility at the National Superconducting Cyclotron Laboratory at Michigan State University. A 1.29 μs bunch width from the buncher and a bunch repetition rate of 2.5 Hz led to a background suppression factor of 3.1 × 10(5) in resonant photon detection measurements. The hyperfine structure of (37)K and its isotope shift relative to the stable (39)K were determined using 5 × 10(4) s(-1) (37)K ions injected into the BECOLA beam line. The obtained hyperfine coupling constants A((2)S(1/2)) = 120.3(1.4) MHz, A((2)P(1/2)) = 15.2(1.1) MHz, and A((2)P(3/2)) = 1.4(8) MHz, and the isotope shift δν(39, 37) = -264(3) MHz are consistent with the previously determined values, where available.

  20. A field programmable gate array-based time-resolved scaler for collinear laser spectroscopy with bunched radioactive potassium beams

    Science.gov (United States)

    Rossi, D. M.; Minamisono, K.; Barquest, B. R.; Bollen, G.; Cooper, K.; Davis, M.; Hammerton, K.; Hughes, M.; Mantica, P. F.; Morrissey, D. J.; Ringle, R.; Rodriguez, J. A.; Ryder, C. A.; Schwarz, S.; Strum, R.; Sumithrarachchi, C.; Tarazona, D.; Zhao, S.

    2014-09-01

    A new data acquisition system including a Field Programmable Gate Array (FPGA) based time-resolved scaler was developed for laser-induced fluorescence and beam bunch coincidence measurements. The FPGA scaler was tested in a collinear laser-spectroscopy experiment on radioactive 37K at the BEam COoler and LAser spectroscopy (BECOLA) facility at the National Superconducting Cyclotron Laboratory at Michigan State University. A 1.29 μs bunch width from the buncher and a bunch repetition rate of 2.5 Hz led to a background suppression factor of 3.1 × 105 in resonant photon detection measurements. The hyperfine structure of 37K and its isotope shift relative to the stable 39K were determined using 5 × 104 s-1 37K ions injected into the BECOLA beam line. The obtained hyperfine coupling constants A(2S1/2) = 120.3(1.4) MHz, A(2P1/2) = 15.2(1.1) MHz, and A(2P3/2) = 1.4(8) MHz, and the isotope shift δν39, 37 = -264(3) MHz are consistent with the previously determined values, where available.

  1. Vibration-insensitive temperature sensing system based on fluorescence decay and using a digital processing approach

    Science.gov (United States)

    Dong, H.; Zhao, W.; Sun, T.; Grattan, K. T. V.; Al-Shamma'a, A. I.; Wei, C.; Mulrooney, J.; Clifford, J.; Fitzpatrick, C.; Lewis, E.; Degner, M.; Ewald, H.; Lochmann, S. I.; Bramann, G.; Merlone Borla, E.; Faraldi, P.; Pidria, M.

    2006-07-01

    A fluorescence-based temperature sensor system using a digital signal processing approach has been developed and evaluated in operation on a working automotive engine. The signal processing approach, using the least-squares method, makes the system relatively insensitive to intensity variations in the probe and thus provides more precise measurements when compared to a previous system designed using analogue phase-locked detection. Experiments carried out to determine the emission temperatures of a running car engine have demonstrated the effectiveness of the sensor system in monitoring exhaust temperatures up to 250 °C, and potentially higher. This paper was presented at the 13th International Conference on Sensors and Their Applications, held in Chatham, Kent, on 6-7 September 2005.

  2. Global α -decay study based on the mass table of the relativistic continuum Hartree-Bogoliubov theory

    Science.gov (United States)

    Zhang, Lin-Feng; Xia, Xue-Wei

    2016-05-01

    The α-decay energies (Q α ) are systematically investigated with the nuclear masses for 10 ⩽ Z ⩽ 120 isotopes obtained by the relativistic continuum Hartree-Bogoliubov (RCHB) theory with the covariant density functional PC-PK1, and compared with available experimental values. It is found that the α-decay energies deduced from the RCHB results present a similar pattern to those from available experiments. Owing to the large predicted Q α values (⩾ 4 MeV), many undiscovered heavy nuclei in the proton-rich side and super-heavy nuclei may have large possibilities for α-decay. The influence of nuclear shell structure on α-decay energies is also analysed. Supported by Major State 973 Program of China (2013CB834400), National Natural Science Foundation of China (11175002, 11335002, 11375015, 11461141002), Research Fund for the Doctoral Program of Higher Education (20110001110087) and National Undergraduate Innovation Training Programs of Peking University.

  3. Radioactive wastes

    International Nuclear Information System (INIS)

    Here are gathered 1)the decrees (99-686 and 99-687) of the 3 rd of August 1999 relative to the researches on radioactive waste management. A local committee of information and follow-up has to be established on the site of each underground facility. The composition of this committee is determined here (99-686). 3 people will from now on be jointly ordered by the Minister of Economy, Finance and Industry and by the Secretary of State of Industry to conduct a preliminary dialogue for the choice of one or several sites on which previous works should be made before the construction of an underground facility (99-687). They take the opinion of the people's representatives, the associations and the concerned population and inform the Ministers of Environment, Energy and Research of the collected information. 2)the decree of the 3 rd of August 1999 authorizing the 'Agence nationale pour la gestion des dechets radioactifs' (ANDRA) to install and exploit an underground facility located in Bure (Meuse) and intended to study the deep geological deposits where could be stored radioactive wastes. (O.M.)

  4. Sensitivity Increases for the TITAN Decay Spectroscopy Program

    Directory of Open Access Journals (Sweden)

    Leach K.G.

    2015-01-01

    Full Text Available The TITAN facility at TRIUMF has recently initiated a program of performing decay spectroscopy measurements in an electron-beam ion-trap (EBIT. The unique environment of the EBIT provides backingfree storage of the radioactive ions, while guiding charged decay particles from the trap centre via the strong magnetic field. This measurement technique is able to provide a significant increase in detection sensitivity for photons which result from radioactive decay. A brief overview of this device is presented, along with methods of improving the signal-to-background ratio for photon detection by reducing Compton scattered events, and eliminating vibrational noise.

  5. Travel in the depth of radioactivity; Voyage au coeur de la radioactivite

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    This educational booklet gives a general presentation of radioactivity: origin of natural radioactivity, characteristics of atoms and isotopes, the radioactivity phenomenon, its decay and measurement units, the radiations and their use in medicine, industry, agriculture and food industry, biology etc.. (J.S.)

  6. Preparations of PAN-based adsorbers for separation of cesium and cobalt from radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Nilchi, A. [Jaber Ibn Hayan Research Laboratories, Atomic Energy Organization of Iran, P.O. Box 11365/8486, Tehran (Iran, Islamic Republic of)]. E-mail: anilchi@aeoi.org.ir; Atashi, H. [Sistan and Baluchestan University, Zahedan (Iran, Islamic Republic of); Javid, A.H. [Azad University, Tehran (Iran, Islamic Republic of); Saberi, R. [Jaber Ibn Hayan Research Laboratories, Atomic Energy Organization of Iran, P.O. Box 11365/8486, Tehran (Iran, Islamic Republic of)

    2007-05-15

    Ion-exchange adsorbers are widely used for radioisotope separation, as well as for the removal of hazardous fission products from aqueous waste prior to discharge to the environment. Inorganic exchangers are of particular interest because of their resistance to radiolytic damage and selectivity for specific fission products. Composite inorganic-organic adsorbers represent a group of inorganic ion exchangers modified by using binding organic material, polyacrylonitrile, for preparation of larger size particles with higher granular strength. At the same time, kinetics of ion exchange and sorption capacity of such composite adsorbers are not influenced by the binding polymer. The contents of active component in composite adsorber were varied over a very broad range of 5-95% of the dry weight of the composite adsorber, and tested for separation and concentration of various stimulated wastes. Three different inorganic sorbents, granular hexacyanoferrate-based ion exchanger, were developed for the removal of Cs and Co ions from waste solutions containing different complexing agents as detergents. Radiation and thermal stability studies show that these adsorbents can be used for medium-active waste treatment.

  7. Introduction to naturally occurring radioactive material

    International Nuclear Information System (INIS)

    Naturally occurring radioactive material (NORM) is everywhere; we are exposed to it every day. It is found in our bodies, the food we eat, the places where we live and work, and in products we use. Some industrial practices involving natural resources concentrate these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. This session will concentrate on diffuse sources of technologically-enhanced (TE) NORM, which are generally large-volume, low-activity waste streams produced by industries such as mineral mining, ore benefication, production of phosphate Fertilizers, water treatment and purification, and oil and gas production. The majority of radionuclides in TENORM are found in the uranium and thorium decay chains. Radium and its subsequent decay products (radon) are the principal radionuclides used in characterizing the redistribution of TENORM in the environment by human activity. We will briefly review other radionuclides occurring in nature (potassium and rubidium) that contribute primarily to background doses. TENORM is found in many waste streams; for example, scrap metal, sludges, slags, fluids, and is being discovered in industries traditionally not thought of as affected by radionuclide contamination. Not only the forms and volumes, but the levels of radioactivity in TENORM vary. Current discussions about the validity of the linear no dose threshold theory are central to the TENORM issue. TENORM is not regulated by the Atomic Energy Act or other Federal regulations. Control and regulation of TENORM is not consistent from industry to industry nor from state to state. Proposed regulations are moving from concentration-based standards to dose-based standards. So when is TENORM a problem? Where is it a problem? That depends on when, where, and whom you talk to exclamation point We will start by reviewing background radioactivity, then we will proceed to the geology, mobility, and variability of these

  8. Application of Origen2.1 in the decay photon spectrum calculation of spallation products

    CERN Document Server

    Hong, Shuang; Xu, Hu-Shan; Meng, Hai-Yan; Zhang, Lu; Liu, Zhao-Qing; Gao, Yu-Cui; Chen, Kang

    2016-01-01

    Origen2.1 is a widely used computer code for calculating the burnup, decay, and processing of radioactive materials. However, the nuclide library of Origen2.1 is used for existing reactors like pressurized water reactor, to calculate the photon spectrum released by the decay of spallation products, we have made specific libraries for the ADS tungsten spallation target, based on the results given by a Monte Carlo code: FLUKA. All the data used to make the Origen2.1 libraries is obtained from Nuclear structure & decay Data (NuDat2.6). The accumulated activity of spallation products and the contribution of nuclides to photon emission are given in this paper.

  9. Polymer-based composite materials for the fabrication of containers for the disposal of radioactive waste

    International Nuclear Information System (INIS)

    The use of carbon fibre reinforced PEEK for the fabrication of a spent nuclear fuel storage container was investigated with the irradiation of samples in the mixed radiation field of the SLOWPOKE-2 nuclear reactor at various temperatures (20oC to 75oC) and doses (up to 1.0 MGy). Mechanical testing showed that the irradiated sample properties rarely deviated from the un-irradiated samples. Chemical testing showed that the irradiated samples exhibited a greater degree of crosslinking and improved mechanical strength. Polypropylene, nylon 6,6, polycarbonate, and polyurethane, all with and without glass fibre reinforcement were also irradiated using the SLOWPOKE-2 reactor at doses from 0.5 MGy to 6.0 MGy, followed by chemical and mechanical testing to determine their suitability for low level waste storage containers. Results indicated that the major effect of irradiation was an increase in crosslinking. Simulated groundwater conditions combined with irradiation for glass fibre reinforced polycarbonate and polyurethane included immersion in a 1 M NaOH (pH 1) or a 1 M HC1 (pH 13) solution for a one month period followed by irradiation at doses of 0.5 kGy to 3.0 kGy in the SLOWPOKE-2 reactor. Flexural testing showed that the combination of chemical exposure and irradiation on these systems resulted in decrease of approximately 10% in flexural yield stress for all pH conditions. Work is ongoing to determine the combined effects of irradiation, immersion, and temperature on Nylon 6,6, polyurethane, and epoxy based composite materials. Mechanical testing results combined with mathematical modeling will lead to the establishment of a system for the determination of a polymer composite's long term performance as a nuclear waste storage container. (author)

  10. Radioactive airborne effluents and the environmental impact assessment of CAP1400 nuclear power plant under normal operation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qiong; Guo, RuiPing; Zhang, ChunMing; Chen, XiaoQiu; Wang, Bo, E-mail: wangbo@chinansc.cn

    2014-12-15

    Highlights: • Typical radionuclides dispersion from CAP1400 under normal operation was simulated. • Modified Gaussian model considered radioactive decay, dry and wet deposition and so on. • The radioactive impact pathways on the public through atmosphere were compared. • The maximum individual effective dose was lower than the public irradiation limit. - Abstract: China Advanced Passive nuclear power plant with installed capacity reaching to 1400 MW (CAP1400) is independently designed as the China's state-of-the-art third generation nuclear power brand based on AP1000 technology digestion and absorption. The concentration of typical radionuclides dispersed from CAP1400 under normal operation was calculated with modified Gaussian model, considering mixed layer height, dry deposition, wet deposition, radioactive decay and so on. The atmospheric dispersion factors, ground deposition rate, individual dose and public dose were also investigated to estimate the radioactive effects of CAP1400 under normal operation on surrounding environment and human beings. The radioactive impact pathways on the public through atmosphere, such as immersion irradiation in the smoke plume, internal irradiation from ingestion and inhalation and external irradiation from surface deposition were briefly introduced with focus on the comparison of the maximum individual effective dose to different group from atmospheric dispersion. All computation results show that the maximum individual irradiation dose happened to children with total effective irradiation dose of 4.52E−03 mSv/y, which was lower than the public irradiation limit of 0.25 mSv/y.

  11. The detection and measurement of the electrical mobility size distributions associated with radon decay products

    International Nuclear Information System (INIS)

    The potential risk of lung cancer has evoked interest in the properties of radon decay products. There are two forms of this progeny: either attached to ambient aerosols, or still in the status of ions/molecules/small clusters. This ''unattached'' activity would give a higher dose per unit of airborne activity than the ''attached'' progeny that are rather poorly deposited. In this thesis, a system for determining unattached radon decay products electrical mobility size distribution by measuring their electrical mobilities was developed, based on the fact that about 88% of 218Po atoms have unit charge at the end of their recoil after decay from 222Rn, while the remainder are neutral. Essential part of the setup is the radon-aerosol chamber with the Circular Electrical Mobility Spectrometer (CEMS) inside. CEMS is used for sampling and classifying the charged radioactive clusters produced in the chamber. An alpha- sensitive plastic, CR-39 disk, is placed in CEMS as an inlaid disk electrode and the alpha particle detector. CEMS showed good performance in fine inactive particles' classification. If it also works well for radon decay products, it can offer a convenient size distribution measurement for radioactive ultrafine particles. However, the experiments did not obtain an acceptable resolution. Suggestions are made for solving this problem

  12. Measurement of the Perturbation of the Decay Rate of ~7Be

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    ~7Be is the lightest radioactive nucleus that decays by electron capture. It is a good candidate used forlooking for perturbation of nuclear decay rates because of its simple electronic structure : 1s~22s~2.Furthermore, the decay rate of ~7Be shows its importance in some fields such as basic nuclear physics,

  13. National facilities for the management of institutional radioactive waste in Romania: 25 years of operation of radioactive waste treatment plant, Bucharest-Magurele, 15 years of operation at national radioactive repository, Baita-Bihor

    International Nuclear Information System (INIS)

    The management of the non-fuel cycle radioactive wastes from all over Romania is centralised at IFIN-HH in the Radioactive Waste Treatment Plant (STDR). Final disposal is carried out at the National Repository of Radioactive Wastes (DNDR) at Baita-Bihor. Wastes containing short-lived radionuclides, which do not require any special treatment, after the temporary storage at the producer for decay period, are transferred as normal non-radioactive wastes. Wastes containing long-lived radionuclides are collected, treated and conditioned at IFIN-HH before final disposal. Radioactive wastes treated at STDR arise from three main sources: 1. Wastes arising from the WWR-S research reactor during operation and future decommissioning operations. 2. Local wastes from other facilities operating at IFIN-HH site. These latter sources include wastes generated during the normal activities of STDR. 3. Wastes from IFIN-HH off-site facilities and activities including medical, biological and industrial applications all over the country. The operational wastes are both liquids and solids. The paper takes into account the following matters: solid waste treatment, conditioning and storage of radioactive waste containers, STDR capacity, temporary storage and final disposal, updating the management infrastructure of institutional radioactive waste. From November 1974 to November 1999 there were treated at STDR nearly 26,000 m3 LLAW, 2,100 m3 LLSW and 4,000 spent sources resulting over 5,500 conditioned drums disposed at DNDR. After 25 years of operation for STDR and 15 years of operation for DNDR an updating programme started in 1990. The Research and Development activities are based on the bi- and multilateral co-operation with the International Atomic Energy Agency and nuclear developed countries through research contracts and technical assistance. In the last years STDR and DNDR benefited from IAEA assistance by a WAMAP mission, training courses and grants for international meetings

  14. Determination of the compound nucleus survival probability Psurv for various "hot" fusion reactions based on the dynamical cluster-decay model

    Science.gov (United States)

    Chopra, Sahila; Kaur, Arshdeep; Gupta, Raj K.

    2015-03-01

    After a successful attempt to define and determine recently the compound nucleus (CN) fusion/ formation probability PCN within the dynamical cluster-decay model (DCM), we introduce and estimate here for the first time the survival probability Psurv of CN against fission, again within the DCM. Calculated as the dynamical fragmentation process, Psurv is defined as the ratio of the evaporation residue (ER) cross section σER and the sum of σER and fusion-fission (ff) cross section σff, the CN formation cross section σCN, where each contributing fragmentation cross section is determined in terms of its formation and barrier penetration probabilities P0 and P . In DCM, the deformations up to hexadecapole and "compact" orientations for both in-plane (coplanar) and out-of-plane (noncoplanar) configurations are allowed. Some 16 "hot" fusion reactions, forming a CN of mass number ACN˜100 to superheavy nuclei, are analyzed for various different nuclear interaction potentials, and the variation of Psurv on CN excitation energy E*, fissility parameter χ , CN mass ACN, and Coulomb parameter Z1Z2 is investigated. Interesting results are that three groups, namely, weakly fissioning, radioactive, and strongly fissioning superheavy nuclei, are identified with Psurv, respectively, ˜1 ,˜10-6 , and ˜10-10 . For the weakly fissioning group (100 PCN belongs to the strongly fissioning superheavy group, Psurv belongs to weakly fissioning nuclei; for Pt* isotopes, the inverse of all the compound systems studied, both PCN and Psurv decrease with the increase of E*; for 213 ,215 ,217Fr* nuclei, though fissility χ is nearly the same, Psurv for 213 ,217Fr* is of the same order as for weakly fissioning nuclei, but that for 215Fr* is of the order of radioactive nuclei. Apparently, further calculations are called for.

  15. Hydro-mechanical behaviour of bentonite-based materials used for high-level radioactive waste disposal

    International Nuclear Information System (INIS)

    This study deals with the hydro-mechanical behaviour of compacted bentonite-based materials used as sealing materials in high-level radioactive waste repositories. The pure MX80 bentonite, mixtures of MX80/crushed clay-stone and MX80/sand were used in the investigation. An experimental study on the swelling pressure of the bentonite-based materials was first performed. The results evidenced the effects of water chemistry, hydration procedure and duration, pre-existing technological void and experimental methods. Emphasis was put on the relationship between the swelling pressure and the final dry density of bentonite. Afterwards, the water retention test, hydration test and suction controlled oedometer test were conducted on samples with different voids including the technological void and the void inside the soil. By introducing the parameters as bentonite void ratio and water volume ratio, an overall analysis of the effects of voids on the hydro-mechanical response of the compacted material was performed. To get better insight into the seal evolution in case of technological void, the effects of final dry density and hydration time on the microstructure features were also characterized. Then, the hydraulic properties under unsaturated state were investigated by carrying out water retention test and infiltration test as well as the microstructure observation. The results obtained allowed relating the variation of hydraulic conductivity to the microstructure changes. A small scale (1/10) mock up test of the SEALEX in situ experiment was also performed to study the recovery capacity of bentonite-based material with consideration of a technological void. The results were used for interpreting the in-situ observations. With a reduced time scale, it provides useful information for estimating the saturation duration and sealing effectiveness of the field design. Finally, the experimental data obtained in the laboratory on bentonite/sand mixture were interpreted in the

  16. The entropic enlightenment of organic photochemistry: strategic modifications of intrinsic decay pathways using an information-based approach.

    Science.gov (United States)

    García-Garibay, Miguel A

    2010-12-01

    Early photochemistry flourished with sunlight plus the experimental and intellectual infrastructure provided by the chemistry of organic compounds. Through the pioneering work of Giacomo Ciamician and Emanuele Paternò, it was shown that photochemical reactions give rise to products that are not accessible by thermal methods, and the green chemistry potential of organic photoreactions was already recognized at the time. Over the last century, the photochemical behavior of many chromophores and functional groups has been well documented in solution. From those studies, it has become clear that applications in organic synthesis suffer from complications arising from competing decay pathways that are intrinsic to those excited states. While there are few opportunities to control the outcome of excited molecules in solution, the potential of organic photochemistry under the influence of highly ordered structures can be appreciated with examples from photobiology. Knowing that nature can synthesize triglycerides with light, CO(2), H(2)O and a few thermal reactions, organic photochemistry should have a great potential and aim high. With that in mind, after exploring the modes of action used by living organisms to take advantage of sunlight, one can identify an approach that relies on entropic factors that result from changes in the information content of the reactant. Analogies with information theory suggest a strategy that may be used to manage chemical information to modify the intrinsic properties of chromophores. Extrapolating from recent examples, it is suggested that an information-based approach to organic photochemistry may result in important advances not only in chemical synthesis and green chemistry, but also in many other applications. PMID:21060939

  17. Spectrum correction algorithm for detectors in airborne radioactivity monitoring equipment NH-UAV based on a ratio processing method

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Ye [Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Tang, Xiao-Bin, E-mail: tangxiaobin@nuaa.edu.cn [Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Wang, Peng; Meng, Jia; Huang, Xi; Wen, Liang-Sheng [Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Chen, Da [Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

    2015-10-11

    The unmanned aerial vehicle (UAV) radiation monitoring method plays an important role in nuclear accidents emergency. In this research, a spectrum correction algorithm about the UAV airborne radioactivity monitoring equipment NH-UAV was studied to measure the radioactive nuclides within a small area in real time and in a fixed place. The simulation spectra of the high-purity germanium (HPGe) detector and the lanthanum bromide (LaBr{sub 3}) detector in the equipment were obtained using the Monte Carlo technique. Spectrum correction coefficients were calculated after performing ratio processing techniques about the net peak areas between the double detectors on the detection spectrum of the LaBr{sub 3} detector according to the accuracy of the detection spectrum of the HPGe detector. The relationship between the spectrum correction coefficient and the size of the source term was also investigated. A good linear relation exists between the spectrum correction coefficient and the corresponding energy (R{sup 2}=0.9765). The maximum relative deviation from the real condition reduced from 1.65 to 0.035. The spectrum correction method was verified as feasible. - Highlights: • An airborne radioactivity monitoring equipment NH-UAV was developed to measure radionuclide after a nuclear accident. • A spectrum correction algorithm was proposed to obtain precise information on the detected radioactivity within a small area. • The spectrum correction method was verified as feasible. • The corresponding spectrum correction coefficients increase first and then stay constant.

  18. Spectrum correction algorithm for detectors in airborne radioactivity monitoring equipment NH-UAV based on a ratio processing method

    International Nuclear Information System (INIS)

    The unmanned aerial vehicle (UAV) radiation monitoring method plays an important role in nuclear accidents emergency. In this research, a spectrum correction algorithm about the UAV airborne radioactivity monitoring equipment NH-UAV was studied to measure the radioactive nuclides within a small area in real time and in a fixed place. The simulation spectra of the high-purity germanium (HPGe) detector and the lanthanum bromide (LaBr3) detector in the equipment were obtained using the Monte Carlo technique. Spectrum correction coefficients were calculated after performing ratio processing techniques about the net peak areas between the double detectors on the detection spectrum of the LaBr3 detector according to the accuracy of the detection spectrum of the HPGe detector. The relationship between the spectrum correction coefficient and the size of the source term was also investigated. A good linear relation exists between the spectrum correction coefficient and the corresponding energy (R2=0.9765). The maximum relative deviation from the real condition reduced from 1.65 to 0.035. The spectrum correction method was verified as feasible. - Highlights: • An airborne radioactivity monitoring equipment NH-UAV was developed to measure radionuclide after a nuclear accident. • A spectrum correction algorithm was proposed to obtain precise information on the detected radioactivity within a small area. • The spectrum correction method was verified as feasible. • The corresponding spectrum correction coefficients increase first and then stay constant

  19. An Integrated Approach to Risk-Based Post-Closure Safety Evaluation of Complex Radiation Exposure Situations in Radioactive Waste Disposal

    International Nuclear Information System (INIS)

    Embodying the safety of radioactive waste disposal requires the relevant safety criteria and the corresponding stylized methods to demonstrate its compliance with the criteria. This paper proposes a conceptual model of risk-based safety evaluation for integrating complex potential radiation exposure situations in radioactive waste disposal. For demonstrating compliance with a risk constraint, the approach deals with important exposure scenarios from the viewpoint of the receptor to estimate the resulting risk. For respective exposure situations, it considers the occurrence probabilities of the relevant exposure scenarios as their probability of giving rise to doses to estimate the total risk to a representative person by aggregating the respective risks. In this model, an exposure scenario is simply constructed with three components: radionuclide release, radionuclide migration and environment contamination, and interaction between the contaminated media and the receptor. A set of exposure scenarios and the representative person are established from reasonable combinations of the components, based on a balance of their occurrence probabilities and the consequences. In addition, the probability of an exposure scenario is estimated on the assumption that the initiating external factors influence release mechanisms and transport pathways, and its effect on the interaction between the environment and the receptor may be covered in terms of the representative person. This integrated approach enables a systematic risk assessment for complex exposure situations of radioactive waste disposal and facilitates the evaluation of compliance with risk constraints

  20. Concentration Limits in the Cement Based Swiss Repository for Long-lived, Intermediate-level Radioactive Wastes (LMA)

    Energy Technology Data Exchange (ETDEWEB)

    Berner, Urs

    1999-12-01

    The Swiss repository concept for long-lived, intermediate-level radioactive wastes (LMA), in Swiss terminology) foresees cylindrical concrete silos surrounded by a ring of granulated bentonite to deposit the waste. As one of the possible options and similar to the repository for high level wastes, the silos will be located in a deep crystalline host rock. Solidified with concrete in steel drums, the waste is stacked into a silo and the silo is then backfilled with a porous mortar. To characterize the release of radionuclides from the repository, the safety assessment considers first the dissolution into the pore water of the concrete, and then diffusion through the outer bentonite ring into the deep crystalline groundwater. For 19 safety relevant radionuclides (isotopes of U, Th, Pa, Np, Pu, Am, Ni, Zr, Mo, Nb, Se, Sr, Ra, Tc, Sn, I, C, Cs, Cl) the report recommends maximum elemental concentrations to be expected in the cement pore water of the particularly considered repository. These limits will form the parameter base for subsequent release model chains. Concentration limits in a geochemical environment are usually obtained from thermodynamic equilibrium calculations performed with geochemical speciation codes. However, earlier studies revealed that this procedure does not always lead to reliable results. Main reasons for this are the complexity of the systems considered, as well as the lacking completeness of, and the uncertainty associated with the thermodynamic data. To improve the recommended maximum concentrations for a distinct repository design, this work includes additional design- and system-dependent criteria. The following processes, inventories and properties are considered in particular: a) recent experimental investigations, particularly from cement systems, b) thermodynamic model calculations when reliable data are available, c) total inventories of radionuclides, d) sorption- and co-precipitation processes, e) dilution with stable isotopes, f

  1. Environmental radioactivity. Measurement and monitoring

    International Nuclear Information System (INIS)

    The contribution on environmental radioactivity covers the following issues: natural and artificial radioactivity; continuous monitoring of radioactivity; monitoring authorities and measurement; radioactivity in the living environment; radioactivity in food and feeding stuff; radioactivity of game meat and wild-growing mushrooms; radioactivity in mines; radioactivity in the research center Rossendorf.

  2. An experimental investigation of M-subshell fluorescence yields and of the L1-L3 radiative transition in neptunium and curium from the radioactive decays of 241Am and 249Cf

    International Nuclear Information System (INIS)

    The construction and performance of a wall-less multiwire proportional counter (MWPC) is described. The absolute emission rate of M x rays from a 241Am source was measured with the MWPC and with a single-wire proportional counter and a value of (6.35 +- 0.60) x 10-2 M x rays per decay, or (0.470 +- 0.045) M x rays per L/sub α/ x ray is obtained. High resolution Ge(Li) and Si(Li) x-ray spectrometers and the multiwire proportional counter (MWPC) were used for measuring coincidences, respectively, between various L x rays and the M x rays of neptunium (Z = 93) from a 241Am source. In addition, M x rays of curium from a 249Cf source were measured with a Si(Li) detector in coincidence with various K and L x rays detected with a Ge(Li) spectrometer. 81 refs., 24 figs., 23 tabs

  3. Environmental radioactivity survey in Suwon

    Energy Technology Data Exchange (ETDEWEB)

    Park, Won Keun; Park, Jong Mi [Kyunghee Univ., Suwon (Korea, Republic of)

    2003-12-15

    The project is carried out to monitor the change of environmental radioactivity in Suwon, and to provide a systematic data for radiation monitoring and counter measurement at a radiological emergency situation. Also the survey of natural environmental radioactivities in the samples was conducted to make the reliable data base for evaluation of internal exposure and environmental contamination of radiation. This report contains the data of gamma exposure rates and radioactivities of airborne dust, fallout, precipitation and tap water which were analyzed periodically by Suwon regional monitoring station m 2003. Also it contains the data of natural radioactivity levels of environmental samples such as soil, drinking water, indicator plant(mugwort, pine-needle), agricultural and forest products, and processed food(tea)

  4. SABRE: a computer-based system for the assessment of body radioactivity by photon spectrometry. Part 4

    International Nuclear Information System (INIS)

    A PDP-11/10 computer system is described for the acquisition and processing of pulse height spectra from detectors used for the measurement of body radioactivity. Version 4 of SABRE (System for the Assessment of Body Radioactivity) provides control of multiple detection systems from visual display consoles by means of a command language. A wide range of facilities is available for the display, processing and storage of acquired spectra and complex operations may be pre-programmed by means of the SABRE MACRO language. The hardware includes a CAMAC interface to the detection systems, disc cartridge drives for mass storage of data and programs, and data-links to other computers. The software is written in assembler language and includes special features for the dynamic allocation of computer memory and for safeguarding acquired data. (author)

  5. Spectrometry techniques for radioactivity measurements

    International Nuclear Information System (INIS)

    The energy of the radiation emission following the nuclear decay is unique and the characteristic of the radio nuclide which undergoes decay. Thus measurement of the energy of the radiation offers a method of identifying the radio nuclides. The prime requirement of the energy measurement is a suitable detector which shows response proportional to the energy of the radiation rather than the presence of the radiation. The response from such detectors are suitably processed and distributed with respect to the signal strength which is proportional to incident energy. This distribution is normally referred as energy spectrum and is recorded in the multichannel analyser. The measurement of energy and intensity of radiation from the spectrum is called radiation spectrometry. Thus the radiation spectrometry allows the identification and quantification of radioactive isotopes in variety of matrices. The radiation spectrometry has now become a popular radioanalytical technique in wide area of nuclear fuel cycle programs. The popular spectrometry techniques commonly used for the radioactivity measurement and analysis are Alpha spectrometry, Gamma ray spectrometry and Beta spectrometry

  6. Electron screening effects on a-decay

    OpenAIRE

    Musumarra, A.; Farinon, F.; Nociforo, C.; Geissel, H.; Baur, G.; Behr, K-H; Bonasera, A.; Bosch, F.; Boutin, D.; Brünle, A; Chen, L.; Del Zoppo, A.; Dimopoulou, C; di Pietro, A.; Faestermann, T.

    2009-01-01

    An open problem in Nuclear Astrophysics concerns the understanding of electron‐screening effects on nuclear reaction rates at stellar energies. In this framework, we have proposed to investigate the influence of the electron cloud on α‐decay by measuring Q‐values and α‐decay half‐lives of fully stripped, H‐like and He‐like ions. These kinds of measurements have been feasible just recently for highly‐charged radioactive nuclides by fragmentation of 238U at relativistic energies at the FRS‐ESR ...

  7. Study of heavy particle decay from superheavy elements by SK model

    International Nuclear Information System (INIS)

    Heavy nuclei usually decay by alpha decay or spontaneous fission. These two decay modes are generally the most probable competing processes. Another less probable decay process is cluster radioactivity in which nuclei from carbon to silicon are emitted from Radium to Californium leading to the most stable daughter nucleus, lead. This work reports such a study using the cubic plus Yukawa plus exponential model of Shanmugam and Kamalaharan (SK)

  8. $D$ leptonic and semileptonic decays

    CERN Document Server

    Ma, Hailong

    2015-01-01

    Based on 2.92 fb$^{-1}$ data taken at the center-of-mass energy $\\sqrt s=3.773$ GeV with the BESIII detector, we report recent results on the decay constant $f_{D^+}$, the hadronic form factors, as well as the quark mixing matrix elements $|V_{cs(d)}|$, which are extracted from analyses of the leptonic decay $D^+ \\to \\mu^+\

  9. Generalized unscented Kalman filtering based radial basis function neural network for the prediction of ground radioactivity time series with missing data

    International Nuclear Information System (INIS)

    On the assumption that random interruptions in the observation process are modeled by a sequence of independent Bernoulli random variables, we firstly generalize two kinds of nonlinear filtering methods with random interruption failures in the observation based on the extended Kalman filtering (EKF) and the unscented Kalman filtering (UKF), which were shortened as GEKF and GUKF in this paper, respectively. Then the nonlinear filtering model is established by using the radial basis function neural network (RBFNN) prototypes and the network weights as state equation and the output of RBFNN to present the observation equation. Finally, we take the filtering problem under missing observed data as a special case of nonlinear filtering with random intermittent failures by setting each missing data to be zero without needing to pre-estimate the missing data, and use the GEKF-based RBFNN and the GUKF-based RBFNN to predict the ground radioactivity time series with missing data. Experimental results demonstrate that the prediction results of GUKF-based RBFNN accord well with the real ground radioactivity time series while the prediction results of GEKF-based RBFNN are divergent. (geophysics, astronomy, and astrophysics)

  10. Three-body charmless B decays workshop

    International Nuclear Information System (INIS)

    The purpose of this workshop was multifarious: -) to present and discuss the current experimental perspectives based on the full expected statistics from B-factories by 2008, -) to share and further develop analysis methods, -) to present and discuss the theoretical work on the subject, -) to discuss the future of B-factories, and -) to establish a work plan until 2009. The contributions have focused on 3 body charmless B decays and mostly 3 body hadronic charmless B decays, they have also dealt with semileptonic decays, radiative decays, charm and charmonium decays, and scattering processes. This document gathers the slides of the presentations

  11. Three-body charmless B decays workshop

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Haim, E.; Chauveau, J.; Hartfiel, B.; Ocariz, J. [Laboratoire de Physique Nucleaire et de Hautes Energies (LPNHE), 75 - Paris (France); Charles, J. [LPT, 13 - Marseille (France)

    2006-07-01

    The purpose of this workshop was multifarious: -) to present and discuss the current experimental perspectives based on the full expected statistics from B-factories by 2008, -) to share and further develop analysis methods, -) to present and discuss the theoretical work on the subject, -) to discuss the future of B-factories, and -) to establish a work plan until 2009. The contributions have focused on 3 body charmless B decays and mostly 3 body hadronic charmless B decays, they have also dealt with semileptonic decays, radiative decays, charm and charmonium decays, and scattering processes. This document gathers the slides of the presentations.

  12. Optimisation of the Hadronic Tau Identification Based on the Classification of Tau Decay Modes with the ATLAS Detector

    CERN Document Server

    Hanisch, Stefanie; Siegert, Frank

    Hadronically decaying tau leptons play an essential role in the LHC physics program. Final states involving tau leptons are important to verify processes of the Standard Model of particle physics at the TeV scale, but are also of high interest for Higgs physics and beyond Standard Model studies, like Higgs CP measurements and $A\\to Zh$ searches. Due to the high production cross section of QCD jets which are the dominant background, efficient reconstruction and identification techniques are crucial to guarantee an excellent selection of interesting physics events. Therefore, sophisticated multivariate algorithms are used. This thesis presents an advanced concept exploiting the information of reconstructed neutral and charged pions in the ATLAS detector, to access the tau decay substructure, and thus enhance the applicability of the tau identification to a broader field of physics analyses. First, several updates of the general algorithms used within the tau identification are implemented in order to provide...

  13. Capacity decay mechanism of microporous separator-based all-vanadium redox flow batteries and its recovery.

    Science.gov (United States)

    Li, Bin; Luo, Qingtao; Wei, Xiaoliang; Nie, Zimin; Thomsen, Edwin; Chen, Baowei; Sprenkle, Vincent; Wang, Wei

    2014-02-01

    The results of the investigation of the capacity decay mechanism of vanadium redox flow batteries with microporous separators as membranes are reported. The investigation focuses on the relationship between the electrochemical performance and electrolyte compositions at both the positive and negative half-cells. Although the concentration of total vanadium ions remains nearly constant at both sides over cycling, the net transfer of solution from one side to the other and thus the asymmetrical valance of vanadium ions caused by the subsequent disproportionate self-discharge reactions at both sides lead to capacity fading. Through in situ monitoring of the hydraulic pressure of the electrolyte during cycling at both sides, the convection was found to arise from differential hydraulic pressures at both sides of the separators and plays a dominant role in capacity decay. A capacity-stabilizing method is developed and was successfully demonstrated through the regulation of gas pressures in both electrolyte tanks. PMID:24488680

  14. Long-term stability of underground operated CZT detectors based on the analysis of intrinsic 113Cd β--decay

    Science.gov (United States)

    Ebert, J.; Gößling, C.; Gehre, D.; Hagner, C.; Heidrich, N.; Klingenberg, R.; Kröninger, K.; Nitsch, C.; Oldorf, C.; Quante, T.; Rajek, S.; Rebber, H.; Rohatsch, K.; Tebrügge, J.; Temminghoff, R.; Theinert, R.; Timm, J.; Wonsak, B.; Zatschler, S.; Zuber, K.

    2016-06-01

    The COBRA collaboration operates a demonstrator setup at the underground facility Laboratori Nazionali del Gran Sasso (LNGS, located in Italy) to prove the technological capabilities of this concept for the search for neutrinoless double beta-decay. The setup consists of 64 (1×1×1) cm3 Cadmium-Zinc-Telluride (CZT) detectors in Coplanar-Grid (CPG) configuration. One purpose of this demonstrator is to test if reliable long-term operation of CZT-CPG detectors in such a setup is possible. The demonstrator has been operated under ultra low-background conditions for more than three years and collected data corresponding to a total exposure of 218 kg days. The presented study focuses on the long-term stability of CZT detectors by analyzing the intrinsic, fourfold forbidden non-unique 113Cd single beta-decay. It can be shown that CZT detectors can be operated stably for long periods of time and that the 113Cd single beta-decay can be used as an internal monitor of the detector performance during the runtime of the experiment.

  15. Long-Term Stability of Underground Operated CZT Detectors Based on the Analysis of Intrinsic $^{113}$Cd \\beta$^{-}$-Decay

    CERN Document Server

    Ebert, J; Gehre, D; Hagner, C; Heidrich, N; Klingenberg, R; Kroeninger, K; Nitsch, C; Oldorf, C; Quante, T; Rajek, S; Rebber, H; Rohatsch, K; Tebruegge, J; Temminghoff, R; Theinert, R; Timm, J; Wonsak, B; Zatschler, S; Zuber, K

    2015-01-01

    The COBRA collaboration operates a demonstrator setup at the underground facility LNGS (Laboratori Nazionali del Gran Sasso, located in Italy) to prove the technological capabilities of this concept for the search for neutrinoless double beta-decay. The setup consists of 64 $(1\\times\\!1\\times\\!1)$ cm$^{3}$ CZT detectors in CPG configuration. One purpose of this demonstrator is to test if reliable long-term operation of CZT-CPG detectors in such a setup is possible. The demonstrator has been operated under ultra low-background conditions since more than three years and collected data corresponding to an exposure of 218 kg$\\cdot$days. The presented study focuses on the long-term stability of CZT detectors by analyzing the intrinsic, fourfold forbidden non-unique $^{113}$Cd single beta-decay. It can be shown that CZT detectors can be operated stably for long periods of time and that the $^{113}$Cd single beta-decay can be used as an internal monitor of the detector performance during the runtime of the experimen...

  16. Significant Isotopes Selection of Core Inventory Based on Decay Heat%基于衰变热的堆芯重要核素选取

    Institute of Scientific and Technical Information of China (English)

    李亢; 于悦海; 陈志宏

    2014-01-01

    衰变热在反应堆设计及安全分析中至关重要,目前计算衰变热主要基于行业标准和专用程序两种方法。通过对PWR燃料组件分别采用两种方法进行计算分析,相互验证了结果。详细分析了停堆不同时刻多种核素对衰变热的贡献,筛选出主要贡献者,为堆芯源项核素的选择提供参考。结果显示约50个核素即可包络停堆后100 h~50 a内95%以上的衰变热贡献。并对标准与程序结果的差异进行了分析,提出了标准适用范围的建议。%Decay heat is extremely important in core design and safety analysis .At pres-ent decay heat calculations are usually based on industrial standards or professional computer codes . Using the two methods to calculate the PWR assembly irradiation respectively ,the validation was done by comparing the results with the two methods and the results were reasonably close .The analytical work was carried out on specific contri-butions made by important isotopes to decay heat at different shutdow n time and the main contributors were screened out as a reference for the core source term inventory selection .The result shows that about 50 isotopes can bound 95% decay heat during 100 h-50 a after shutdown .Discrepancies between the standard and computer code were also investigated .Some instructive advices on suitable region were given for applying the standard .

  17. A kinematic model to estimate effective dose of radioactive substances in a human body

    Science.gov (United States)

    Sasaki, S.; Yamada, T.

    2013-05-01

    The great earthquake occurred in the north-east area in Japan in March 11, 2011. Facility system to control Fukushima Daiichi nuclear power station was completely destroyed by the following giant tsunami. From the damaged reactor containment vessels, an amount of radioactive substances had leaked and diffused in the vicinity of this station. Radiological internal exposure became a serious social issue both in Japan and all over the world. The present study provides an easily understandable, kinematic-based model to estimate the effective dose of radioactive substances in a human body by simplifying the complicated mechanism of metabolism. International Commission on Radiological Protection (ICRP) has developed a sophisticated model, which is well-known as a standard method to calculate the effective dose for radiological protection. However, owing to that ICRP method is fine, it is rather difficult for non-professional people of radiology to gasp the whole images of the movement and the influences of radioactive substances in a human body. Therefore, in the present paper we propose a newly-derived and easily-understandable model to estimate the effective dose. The present method is very similar with the traditional and conventional tank model in hydrology. Ingestion flux of radioactive substances corresponds to rain intensity and the storage of radioactive substances to the water storage in a basin in runoff analysis. The key of the present method is to estimate the energy radiated in the radioactive nuclear disintegration of an atom by using classical theory of β decay and special relativity for various kinds of radioactive atoms. The parameters used in this model are only physical half-time and biological half-time, and there are no operational parameters or coefficients to adjust our theoretical runoff to ICRP. Figure shows the time-varying effective dose with ingestion duration, and we can confirm the validity of our model. The time-varying effective dose with

  18. Mental Models of Radioactivity and Attitudes towards Radioactive Waste

    International Nuclear Information System (INIS)

    Siting of a radioactive waste repository presents a great problem in almost every country that produces such waste. The main problem is not a technical one, but socio-psychological, namely the acceptability of this kind of repository. Previous research on people's perception of the LILW repository construction, their attitudes towards radioactive waste, their willingness to accept it, indicated significant differences in answers of experts and lay persons, mainly regarding evaluation of the consequences of repository construction. Based on the findings of pilot investigations a mental model approach to the radioactivity, radioactive waste and repository was used as a method for development better risk communication strategies with local communities. The mental models were obtained by adjustment of the method developed by Morgan and co-workers where expert model of radioactivity is compared with mental model of lay people obtained through individual opened interviews. Additional information on trust, risk perception, role of main actors in the site selection process and their credibility was gained with the overall questionnaire on the representative sample of Slovenian population. Results of the survey confirm some already known findings, in addition we gained new cognitions and with analyses obtained the relationships and ratios between different factors, which are characteristics both for the general public and for the public, which is involved in the site selection process for a longer period and has been living beside a nuclear power plant for one generation. People have in general negative associations regarding the repository, the perceived risk for nuclear facilities is high, and trust in representatives of governmental institutions is low. Mental models of radioactivity, radioactive waste and the LILW repository are mostly irregular and differ from the experts' models. This is particularly valid for the models of radioactivity and the influences of

  19. Assessments of risk indices and decision-making support within risk based land management and sustainable rehabilitation of radioactive contaminated territories

    International Nuclear Information System (INIS)

    Description of the applied Geoinformation Decision-Support System PRANA for risk based land management and rehabilitation of territories of Bryansk region (Russia), subjected to radioactive contamination as a result of the Chernobyl accident, is presented. The main blocks of PRANA DSS, including electronic maps, databases and models are described. Implementation of vector land use map with corresponding integration of different models allows integrating both local and regional level of analysis and practical implementation (from each field and settlement up to farm and district and regional levels). Some examples of model assessments (map of countermeasures and doses) are presented

  20. Evaluation of dose arising from 222Rn, decay products of 222Rn and 220Rn to staff from a certain nuclear power plant

    International Nuclear Information System (INIS)

    The staff of the plant was grouped on their work ranges. The annual effective dose resulted from radon and the decay products of 222Rn/220Rn is studied by measuring radon concentration with double filter membrane method and by measuring the concentration of 222Rn/220Rn short life radioactive decay products with five-count method. Based on the results, specific protection measures are proposed for high radon areas. The study results show that the monitoring data for all areas except the spent fuel pool was smaller than the recommended values by ICRP. (authors)

  1. Radioactive waste management profiles

    International Nuclear Information System (INIS)

    In 1989, the International Atomic Energy Agency began development of the Waste Management Data Base (WMDB) to, primarily, establish a mechanism for the collection, integration, storage, and retrieval of information relevant to radioactive waste management in Member States. This report is a summary and compilation of the information contained in the data base. The WMDB contains information and data on several aspects of waste management and offer a ready source of information on such activities as R and D efforts, waste disposal plans and programmes, important programme milestones, waste volume projections, and national and regulatory policies. This report is divided into two parts. Part one describes the Waste Management Data Base system and the type of information it contains. The second part contains data provided by Member States between August 1989 and December 1990 in response to a questionnaire sent by the Agency. However, if a Member State did not respond to the questionnaire, data from IAEA sources, such as technical assistance mission reports, were used - where such data exist. The WMDB system became operational in January 1991. The type of information contained in the data base includes radioactive waste management plans, policies and activities in Member States

  2. Cluster decay in osmium isotopes using Hartree-Fock-Bogoliubov theory

    Science.gov (United States)

    Ashok, Nithu; Joseph, Deepthy Maria; Joseph, Antony

    2016-02-01

    Cluster radioactivity is a rare cold nuclear process which is intermediate between alpha decay and spontaneous fission. The present work is a theoretical investigation of the feasibility of alpha decay and cluster radioactivity from proton rich Osmium (Os) isotopes with mass number ranging from 162-190. Osmium forms a part of the transition region between highly deformed and spherical nuclei. Calculations have been done using unified fission model and Hartree-Fock-Bogoliubov (HFB) theory. We have chosen only those decays with half-lives falling in measurable range. Geiger-Nuttall plot has been successfully reproduced. The isotope which is most favorable to each decay mode has a magic daughter nucleus.

  3. GERDA, a GERmanium Detector Array for the search for neutrinoless ββ decay in 76Ge

    International Nuclear Information System (INIS)

    The GERDA project, searching for neutrinoless double beta-decay of 76Ge with enriched germanium detectors submerged in a cryogenic bath, has been approved for installation at the Gran Sasso National Laboratory (LNGS), Italy. The GERDA technique is aiming at a dramatic reduction of the background due to radioactive contaminations of the materials surrounding the detectors. This will lead to a sensitivity of about 1026 years on the half-life of neutrinoless double beta decay. Already in the first phase of the experiment, GERDA will be able to investigate with high statistical significance the claimed evidence for neutrinoless double beta decay of 76Ge based on the data of the Heidelberg-Moscow experiment

  4. 基于RFID/GPRS的放射源监控系统%Radioactive Source Monitoring System Based on RFID and GPRS

    Institute of Scientific and Technical Information of China (English)

    何海洋; 周洪亮; 张宏建; 张胜; 周俊儒; 翁国杰

    2011-01-01

    Nuclear radiation produced by radioactive source is harmful to the health of human body, and the lost and theft of radioactive source will cause environmental pollution and social panic. In order to solve the abnormal leaks, accidental loss, theft and other problems of the radioactive source, a radioactive source monitoring system based on RFID, GPS, GPRS and GSM technology is put forward. Radiation dose detector and GPS wireless location module are used to obtain the information of radiation dose and location respectively, RFID reader reads the status of a tag fixed on the bottom of the radioactive source. All information is transmitted to the remote monitoring center via GPRS wireless transmission. There will be an audible and visual alarm when radiation dose is out of limits or the state of radioactive source is abnormal, and the monitoring center will send a-larming text messages to the managers through GSM Modem at the same time. Thus, the functions of monitoring and alarming are achieved. The system has already been put into operation and is being kept in functional order. It can provide stable statistics as well as accurate alarm, improving the supervision of radioactive source effectively.%放射源产生的核辐射对人体的健康具有危害性,而放射源的丢失与被盗更会造成环境污染,引起社会恐慌.为了解决放射源的异常泄漏和意外丢失、被盗等问题,研制了基于RFID、GPS、GPRS和GSM等技术的放射源监控系统.辐射剂量检测仪和GPS无线定位模块分别实时获取放射源辐射剂量值与位置信息,RFID阅读器读取安装在放射源底部的电子标签状态信息.放射源辐射剂量值、位置与标签状态信息通过GPRS无线传输方式发送到远程监控中心.当辐射剂量超标或者放射源状态异常时,现场进行声光报警,同时监控中心通过GSM Modem向管理人员发送短信报警,从而实现对放射源的监控与报警.该系统投入运行效果良

  5. Indirect estimation of radioactivity in containerized cargo

    International Nuclear Information System (INIS)

    Naturally occurring radioactive material in containerized cargo challenges the state of the art in national and international efforts to detect illicit nuclear and radiological material in transported containers. Current systems are being evaluated and new systems envisioned to provide the high probability of detection necessary to thwart potential threats, combined with extremely low nuisance and false alarm rates necessary to maintain the flow of commerce impacted by the enormous volume of commodities imported in shipping containers. Maintaining flow of commerce also means that inspection must be rapid, requiring relatively non-intrusive, indirect measurements of cargo from outside containers to the extent possible. With increasing information content in such measurements, it is natural to ask how the information might be combined to improve detection. Toward this end, we present an approach to estimating isotopic activity of naturally occurring radioactive material in cargo grouped by commodity type, combining container manifest data with radiography and gamma-ray spectroscopy aligned to location along the container. The heart of this approach is our statistical model of gamma-ray counts within peak regions of interest, which captures the effects of background suppression, counting noise, convolution of neighboring cargo contributions, and down-scattered photons to provide estimates of counts due to decay of specific radioisotopes in cargo alone. Coupled to that model, we use a mechanistic model of self-attenuated radiation flux to estimate the isotopic activity within cargo, segmented by location within each container, that produces those counts. We test our approach by applying it to a set of measurements taken at the Port of Seattle in 2006. This approach to synthesizing disparate available data streams and extraction of cargo characteristics, while relying on several simplifying assumptions and approximations, holds the potential to support improvement of

  6. Research on the Compression Algorithm of the Infrared Thermal Image Sequence Based on Differential Evolution and Double Exponential Decay Model

    Directory of Open Access Journals (Sweden)

    Jin-Yu Zhang

    2014-01-01

    Full Text Available This paper has proposed a new thermal wave image sequence compression algorithm by combining double exponential decay fitting model and differential evolution algorithm. This study benchmarked fitting compression results and precision of the proposed method was benchmarked to that of the traditional methods via experiment; it investigated the fitting compression performance under the long time series and improved model and validated the algorithm by practical thermal image sequence compression and reconstruction. The results show that the proposed algorithm is a fast and highly precise infrared image data processing method.

  7. Comprehensive software for the assessment of {sup 222}Rn and {sup 220}Rn decay products based on air sampling measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sima, Octavian [Physics Department, University of Bucharest, Bucharest-Magurele, P.O. Box MG-11, RO-077125 (Romania)], E-mail: octavian.sima@ik.fzk.de

    2009-05-15

    A computational tool dedicated to the measurement of {sup 222}Rn and {sup 220}Rn decay products by air sampling is presented. {alpha}- or {gamma}-spectrometry measurements, gross {alpha} or {beta} counting, as well as a combination of them are considered. Special attention is given to the evaluation of the uncertainty budget of the results. Besides typical applications in the analysis of experimental data, the software can be used for assessing the expected quality of a measurement protocol and for optimizing it, by generating and analyzing sets of realistic synthetic data.

  8. Simulation of decays and secondary ion losses in a betabeam decay ring

    CERN Document Server

    Jones, F.W.; 10.1109/PAC.2007.4440382

    Radioactive ions injected into the decay ring of aBetabeam neutrino facility will constitute a continuoussource of decay products distributed around the ring.Secondary ions from beta decays will differ in chargestate from the primary ions and will follow widely offmomentumorbits. In the racetrack configuration of thering, they will be mismatched in the long straights and mayacquire large amplitudes, but the great majority of losseswill be in the arcs. We describe here a comprehensivemodel of ion decay, secondary ion tracking, and loss detection,which has been implemented in the tracking andsimulation code Accsim. Methods have been developed toaccurately follow ion trajectories at large momentum deviationsas well as to detect their impact coordinates on vacuumchamber walls and possibly inside magnetic elements.Using secondary-ion data from Accsim and postprocessingwith Mathematica, we have implemented afollow-on simulation in FLUKA with a 3D geometry ofdecay ring components and physics models for ion interacti...

  9. Spectrum correction algorithm for detectors in airborne radioactivity monitoring equipment NH-UAV based on a ratio processing method

    Science.gov (United States)

    Cao, Ye; Tang, Xiao-Bin; Wang, Peng; Meng, Jia; Huang, Xi; Wen, Liang-Sheng; Chen, Da

    2015-10-01

    The unmanned aerial vehicle (UAV) radiation monitoring method plays an important role in nuclear accidents emergency. In this research, a spectrum correction algorithm about the UAV airborne radioactivity monitoring equipment NH-UAV was studied to measure the radioactive nuclides within a small area in real time and in a fixed place. The simulation spectra of the high-purity germanium (HPGe) detector and the lanthanum bromide (LaBr3) detector in the equipment were obtained using the Monte Carlo technique. Spectrum correction coefficients were calculated after performing ratio processing techniques about the net peak areas between the double detectors on the detection spectrum of the LaBr3 detector according to the accuracy of the detection spectrum of the HPGe detector. The relationship between the spectrum correction coefficient and the size of the source term was also investigated. A good linear relation exists between the spectrum correction coefficient and the corresponding energy (R2=0.9765). The maximum relative deviation from the real condition reduced from 1.65 to 0.035. The spectrum correction method was verified as feasible.

  10. Heat amount measuring method for radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Takakura, Masahide

    1998-10-09

    The present invention provides a device for easily and accurately measuring the amount of heat generated from high level radioactive wastes generated upon reprocessing of spent fuels. Namely, radioactive wastes are contained in a measuring vessel formed by using thick-walled iron plates. Air is circulated in the measuring vessel. The temperatures of charged air and discharged air are measured. Then the amount of heat dissipated from the radioactive wastes and the amount of heat dissipated from the iron plates due to absorption of {gamma}-rays to the iron plates are obtained based on the temperature difference. Accordingly, the amount of heat generated from the radioactive wastes can be measured accurately. In addition, there is provided an effect that the amount of heat generated from radioactive wastes can be measured by simple procedures of charging radioactive wastes in the measuring vessel and driving air circulation fans. (I.S.)

  11. Radioactive Iodine (Radioiodine) Therapy

    Science.gov (United States)

    ... lymph nodes and other parts of the body. Radioactive iodine therapy improves the survival rate of patients with papillary ... and benefits of RAI therapy with your doctor. Radioactive iodine therapy cannot be used to treat anaplastic (undifferentiated) and ...

  12. Radioactivity in consumer products

    Energy Technology Data Exchange (ETDEWEB)

    Moghissi, A.A.; Paras, P.; Carter, M.W.; Barker, R.F. (eds.)

    1978-08-01

    Papers presented at the conference dealt with regulations and standards; general and biological risks; radioluminous materials; mining, agricultural, and construction materials containing radioactivity; and various products containing radioactive sources.

  13. Evidence for correlations between fluctuations in 54Mn decay rates and solar storms

    Science.gov (United States)

    Mohsinally, T.; Fancher, S.; Czerny, M.; Fischbach, E.; Gruenwald, J. T.; Heim, J.; Jenkins, J. H.; Nistor, J.; O'Keefe, D.

    2016-02-01

    Following recent indications that several radioactive isotopes show fluctuating decay rates which may be influenced by solar activity, we present findings from a 2 year period of data collection on 54Mn. Measurements were recorded hourly from a 1 μCi sample of 54Mn monitored from January 2010-December 2011. A series of signal-detection algorithms determine regions of statistically significant fluctuations in decay behaviour from the expected exponential form. The 239 decay flags identified during this interval were compared to daily distributions of multiple solar indices, generated by NOAA, which are associated with heightened solar activity. The indices were filtered to provide a list of the 413 strongest events during a coincident period. We find that 49% of the strongest solar events are preceded by at least 1 decay flag within a 48 h interval, and 37% of decay flags are followed by a reported solar event within 48 h. These results are significant at the 0.9σ and 2.8σ levels respectively, based on a comparison to results obtained from a shuffle test, in which the decay measurements were randomly shuffled in time 10,000 times. We also present results from a simulation combining constructed data reflecting 10 sites which compared and filtered decay flags generated from all sites. The results indicate a potential 35% reduction in the false positive rate in going from 1 to 10 sites. By implication, the improved statistics attest to the benefit of analysing data from a larger number of geographically distributed sites in parallel.

  14. 18Ne Excited States Two-Proton Decay

    Science.gov (United States)

    de Napoli, M.; Rapisarda, E.; Raciti, G.; Cardella, G.; Amorini, F.; Giacoppo, F.; Sfienti, C.

    2008-04-01

    Two-proton radioactivity studies have been performed on excited states of 18Ne produced by 20Ne fragmentation at the FRS of the Laboratori Nazionali del Sud and excited via Coulomb excitation on a 209Pb target. The 18Ne levels decay has been studied by complete kinematical reconstruction. In spite of the low statistic, the energy and angular correlations of the emitted proton pairs indicate the presence of 2He emission toghether with the democratic decay.

  15. Radioactive waste management

    International Nuclear Information System (INIS)

    This booklet is a publication by International Atomic Energy Agency for general awareness of citizens and policy-makers to clarify their concept of nuclear wastes. In a very simple way it tells what is radioactivity, radiations and radioactive wastes. It further hints on various medial and industrial uses of radiations. It discusses about different types of radioactive wastes and radioactive waste management. Status of nuclear power plants in Central and Eastern European countries are also discussed

  16. Thermodynamic stability of radioactivity standard solutions

    Energy Technology Data Exchange (ETDEWEB)

    Iroulard, M.G

    2007-04-15

    The basic requirement when preparing radioactivity standard solutions is to guarantee the concentration of a radionuclide or a radioelement, expressed in the form of activity concentration (Ac = A/m (Bq/g), with A: activity and m: mass of solution). Knowledge of the law of radioactive decay and the half-life of a radionuclide or radioelement makes it possible to determine the activity concentration at any time, and this must be confirmed subsequently by measurement. Furthermore, when radioactivity standard solutions are prepared, it is necessary to establish optimal conditions of thermodynamic stability of the standard solutions. Radioactivity standard solutions are prepared by metrology laboratories from original solutions obtained from a range of suppliers. These radioactivity standard solutions must enable preparation of liquid and/or solid radioactivity standard sources of which measurement by different methods can determine, at a given instant, the activity concentration of the radionuclide or radioelement present in the solution. There are a number of constraints associated with the preparation of such sources. Here only those that relate to the physical and chemical properties of the standard solution are considered, and therefore need to be taken into account when preparing a radioactivity standard solution. These issues are considered in this document in accordance with the following plan: - A first part devoted to the chemical properties of the solutions: - the solubilization media: ultra-pure water and acid media, - the carriers: concentration, oxidation state of the radioactive element and the carrier element. - A second part describing the methodology of the preparation, packaging and storage of standard solutions: - glass ampoules: the structure of glasses, the mechanisms of their dissolution, the sorption phenomenon at the solid-solution interface, - quartz ampoules, - cleaning and packaging: cleaning solutions, internal surface coatings and

  17. The GIS-based SafeAirView software for the concentration assessment of radioactive pollutants after an accidental release

    Energy Technology Data Exchange (ETDEWEB)

    Canepa, Elisa [CNR-INFM-CNISM- Department of Physics, University of Genova, Via Dodecaneso 33, I-16146 Genova (Italy); D' Alberti, Francesco; D' Amati, Francesco [Nuclear Decommissioning and Facilities Management Unit, Joint Research Centre of the European Commission, TP 510, I-21020 Ispra (Italy); Triacchini, Giuseppe [Catholic University of Brescia, CRASL or Center for Research on the Environment and Sustainable Development of the Lombardia region, Via Musei n. 41, I-25121 Brescia (Italy)

    2007-02-01

    The European Commission Joint Research Centre (JRC) in Ispra (Italy) has long been running nuclear installations for research purposes. The Nuclear Decommissioning and Facilities Management Unit (NDFM) is responsible for the surveillance of radioactivity levels in nuclear emergency conditions. The NDFM Unit has commissioned the implementation of a specifically developed decision support system, which can be used for quick emergency evaluation in the case of hypothetical accident and for emergency exercises. The requisites were to be a user-friendly software, able to quickly calculate and display values of air and ground radioactive contamination in the complex area around JRC, following an accidental release of radioactive substances from a JRC nuclear research installation. The developed software, named 'SafeAirView', is an advanced implementation of GIS technology applied to an existing MS-DOS mode dispersion model, SAFE{sub A}IR (Simulation of Air pollution From Emissions{sub A}bove Inhomogeneous Regions). SAFE{sub A}IR is a numerical model which simulates transport, diffusion, and deposition of airborne pollutants emitted in the low atmosphere above complex orography at both local and regional scale, under non-stationary and inhomogeneous emission and meteorological conditions. SafeAirView makes use of user-friendly MS-Windows type interface which drives the dispersion model by a sequential and continuous input-output process, allowing a real time simulation. The GIS environment allows a direct interaction with the territory elements in which the simulation takes place, using data for the JRC Ispra region represented in geo-referenced cartography. Furthermore it offers the possibility to relate concentrations with population distribution and other geo-referenced maps, in a geographic view. Output concentration and deposition patterns can be plotted and/or exported. In spite of the selected specific databases, the SafeAirView software architecture is a

  18. D rare/forbidden decays at BESIII

    CERN Document Server

    Zhao, Ming-Gang

    2016-01-01

    In this document we present the latest result on rare/forbidden decays for D mesons at the BESIII experiment. Based on 2.92/fb data taken at the center-of-mass energy 3.773 GeV with the BESIII detector, the flavor-changing neutral current process of neutral D decays into two gammas is searched using a double tag technique, while the decays of charged D decays into a charged kaon/pion plus two electrons/positrons are studied based on a single tag method. The resulting upper limits are still above the Standard Model predictions.

  19. Current status on storage, processing and risk communication of medical radioactive waste in Japan

    International Nuclear Information System (INIS)

    Decay-in-storage for radioactive waste including that of nuclear medicine has not been implemented in Japan. Therefore, all medical radioactive waste is collected and stored at the Japan Radioisotope Association Takizawa laboratory, even if the radioactivity has already decayed out. To clarify the current situation between Takizawa village and Takizawa laboratory, we investigated the radiation management status and risk communication activities at the laboratory via a questionnaire and site visiting survey in June 2010. Takizawa laboratory continues to maintain an interactive relationship with local residents. As a result, Takizawa village permitted the acceptance of new medical radioactive waste containing Sr-89 and Y-90. However, the village did not accept any non-medical radioactive waste such as waste from research laboratories. To implement decay-in-storage in Japan, it is important to obtain agreement with all stakeholders. We must continue to exert sincere efforts to acquire the trust of all stakeholders. (author)

  20. Simulation Studies of Diffusion-Release and Effusive-Flow of Short-Lived Radioactive Isotopes

    CERN Document Server

    Zhang, Yan; Kawai, Yoko

    2005-01-01

    Delay times associated with diffusion release from targets and effusive-flow transport of radioactive isotopes to ion sources are principal intensity limiters at ISOL-based radioactive ion beam facilities, and simulation studies with computer models are cost effective methods for designing targets and vapor transport systems with minimum delay times to avoid excessive decay losses of short lived ion species. A finite difference code, Diffuse II, was recently developed at the Oak Ridge National Laboratory to study diffusion-release of short-lived species from three principal target geometries. Simulation results are in close agreement with analytical solutions to Fick’s second equation. Complementary to the development of Diffuse II, the Monte-Carlo code, Effusion, was developed to address issues related to the design of fast vapor transport systems. Results, derived by using Effusion, are also found to closely agree with experimental measurements. In this presentation, the codes will be used in conc...

  1. Chromatographic separation of radioactive noble gases from xenon

    CERN Document Server

    Akerib, D S; Bai, X; Bailey, A J; Balajthy, J; Beltrame, P; Bernard, E P; Bernstein, A; Biesiadzinski, T P; Boulton, E M; Bramante, R; Cahn, S B; Carmona-Benitez, M C; Chan, C; Chiller, A A; Chiller, C; Coffey, T; Currie, A; Cutter, J E; Davison, T J R; Dobi, A; Dobson, J E Y; Druszkiewicz, E; Edwards, B N; Faham, C H; Fiorucci, S; Gaitskell, R J; Gehman, V M; Ghag, C; Gibson, K R; Gilchriese, M G D; Hall, C R; Hanhardt, M; Haselschwardt, S J; Hertel, S A; Hogan, D P; Horn, M; Huang, D Q; Ignarra, C M; Ihm, M; Jacobsen, R G; Ji, W; Kamdin, K; Kazkaz, K; Khaitan, D; Knoche, R; Larsen, N A; Lee, C; Lenardo, B G; Lesko, K T; Lindote, A; Lopes, M I; Manalaysay, A; Mannino, R L; Marzioni, M F; McKinsey, D N; Mei, D -M; Mock, J; Moongweluwan, M; Morad, J A; Murphy, A St J; Nehrkorn, C; Nelson, H N; Neves, F; O'Sullivan, K; Oliver-Mallory, K C; Palladino, K J; Pease, E K; Pech, K; Phelps, P; Reichhart, L; Rhyne, C; Shaw, S; Shutt, T A; Silva, C; Solovov, V N; Sorensen, P; Stephenson, S; Sumner, T J; Szydagis, M; Taylor, D J; Taylor, W; Tennyson, B P; Terman, P A; Tiedt, D R; To, W H; Tripathi, M; Tvrznikova, L; Uvarov, S; Verbus, J R; Webb, R C; White, J T; Whitis, T J; Witherell, M S; Wolfs, F L H; Yazdani, K; Young, S K; Zhang, C

    2016-01-01

    The Large Underground Xenon (LUX) experiment operates at the Sanford Underground Research Facility to detect nuclear recoils from the hypothetical Weakly Interacting Massive Particles (WIMPs) on a liquid xenon target. Liquid xenon typically contains trace amounts of the noble radioactive isotopes $^{85}$Kr and $^{39}$Ar that are not removed by the {\\em in situ} gas purification system. The decays of these isotopes at concentrations typical of research-grade xenon would be a dominant background for a WIMP search exmperiment. To remove these impurities from the liquid xenon, a chromatographic separation system based on adsorption on activated charcoal was built. 400\\,kg of xenon was processed, reducing the average concentration of krypton from 130\\,ppb to 3.5\\,ppt as measured by a cold-trap assisted mass spectroscopy system. A 50 kg batch spiked to 0.001 g/g of krypton was processed twice and reduced to an upper limit of 0.2 ppt.

  2. The X-Array and SATURN: A new decay-spectroscopy station for CARIBU

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, A.J., E-mail: alan_mitchell@uml.edu [Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA 01854 (United States); Bertone, P.F.; DiGiovine, B. [Physics Division, Argonne National Laboratory, Argonne, Il 60439 (United States); Lister, C.J. [Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA 01854 (United States); Carpenter, M.P. [Physics Division, Argonne National Laboratory, Argonne, Il 60439 (United States); Chowdhury, P. [Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA 01854 (United States); Clark, J.A. [Physics Division, Argonne National Laboratory, Argonne, Il 60439 (United States); D' Olympia, N.; Deo, A.Y. [Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA 01854 (United States); Kondev, F.G. [Physics Division, Argonne National Laboratory, Argonne, Il 60439 (United States); Nuclear Engineering Division, Argonne National Laboratory, Argonne, Il 60439 (United States); McCutchan, E.A.; Rohrer, J. [Physics Division, Argonne National Laboratory, Argonne, Il 60439 (United States); Savard, G. [Physics Division, Argonne National Laboratory, Argonne, Il 60439 (United States); Department of Physics, University of Chicago, Chicago, Il 60637 (United States); Seweryniak, D.; Zhu, S. [Physics Division, Argonne National Laboratory, Argonne, Il 60439 (United States)

    2014-11-01

    A new decay-spectroscopy station has been commissioned for experiments with low-energy, fission-fragment radioactive beams from the CARIBU ion source. The new set-up consists of the ‘X-Array’, a highly-efficient array of HPGe clover detectors, and ‘SATURN’ (Scintillator And Tape Using Radioactive Nuclei), a plastic scintillator detector combined with a tape-transport system for detection of β particles and removal of long-lived isobaric decay products.

  3. The X-Array and SATURN: A new decay-spectroscopy station for CARIBU

    CERN Document Server

    Mitchell, A J; DiGiovine, B; Lister, C J; Carpenter, M P; Chowdhury, P; Clark, J A; D'Olympia, N; Deo, A Y; Kondev, F G; McCutchan, E A; Rohrer, J; Savard, G; Seweryniak, D; Zhu, S

    2015-01-01

    A new decay-spectroscopy station has been commissioned for experiments with low-energy, fission-fragment radioactive beams from the CARIBU ion source. The new set-up consists of the 'X-array', a highly-efficient array of HPGe clover detectors, and 'SATURN' (Scintillator And Tape Using Radioactive Nuclei), a plastic scintillator detector combined with a tape-transport system for detection of beta particles and removal of long-lived isobaric decay products.

  4. SU-E-T-388: Estimating the Radioactivity Inventory of a Cyclotron Based Pencil Beam Proton Therapy Facility

    International Nuclear Information System (INIS)

    Purpose: Parts of the cyclotron and energy degrader are incidentally activated by protons lost during the acceleration and transport of protons for radiation therapy. An understanding of the radioactive material inventory is needed when regulatory requirements are assessed. Methods: First, the tumor dose and volume is used to determine the required energy deposition. For spot scanning, the tumor length along the beam path determines the number of required energy layers. For each energy layer the energy deposition per proton can be calculated from the residual proton range within the tumor. Assuming a typical layer weighting, an effective energy deposition per proton can then be calculated. The total number of required protons and the number of protons per energy layer can then be calculated. For each energy layer, proton losses in the energy degrader are calculated separately since its transmission efficiency, and hence the amount of protons lost, is energy dependent. The degrader efficiency also determines the number of protons requested from the cyclotron. The cyclotron extraction efficiency allows a calculation of the proton losses within the cyclotron. The saturation activity induced in the cyclotron and the degrader is equal to the production rate R for isotopes whose half-life is shorter that the projected cyclotron life time. R can be calculated from the proton loss rate and published production cross sections. Results: About 1/3 of the saturation activity is produced in the cyclotron and 2/3 in the energy degrader. For a projected case mix and a patient load of 1100 fractions per week at 1.8 Gy per fraction a combined activity of 180 mCi was estimated at saturation. Conclusion: Calculations were used to support to application of a radioactive materials license for the possession of 200 mCi of activity for isotopes with atomic numbers ranging from 1-83

  5. Levels of natural radioactivity in some commonly used fertilizers

    International Nuclear Information System (INIS)

    Fertilizers are used in increasing quantities to replenish natural nutrients depleted from the soil in agricultural practices. The phosphorous component of the fertilizer is responsible for most of the uranium and thorium decay series radionuclides. To determine the natural radioactivity levels three different commercial fertilizer blends and seven basic fertilizers were studied. Eppawela Apatite was found to contain the lowest concentrations of radioactivity, amongst the phosphate group of fertilizers studied. Levels of U and 40K were negligible. The phosphate fertilizer saphose contained the highest activity concentration. Urea had negligible levels of radioactivity. Selection of proper fertilizers will facilitate to reduce the pollution of the environment by radioelements

  6. Turi device for radioactive source transport in the MUK device

    International Nuclear Information System (INIS)

    The TURI radioactive source transport device for on-line studies with a mass spectrometer in a proton beam is described. This device is a part of the multidetector MUK-device the aim of which is the measurement of the angular correlations and lifetimes observed in radioactive decay of short-lived nuclei (T1/2>0.1 s). The TURY system ensures the velocity of the radioactive target movement 1 cm per 0.25 s, and microcomputer control of experiment the accuracy of the tape stop is 0.15 mm

  7. Sequence-specific DNA breaks produced by triplex-directed decay of iodine-125

    International Nuclear Information System (INIS)

    Triplex forming oligonucleotides (TFO) labeled with Auger emitters could be ideal vehicles to deliver radioactive-decay energy to specific DNA sequences, causing DNA breaks and, subsequently, inactivation of these sequences. To demonstrate this approach we labeled with 125I (two 125I per molecule on average) a purine-rich 38-mer which forms a stable triplex with a polypurine x polypyrimidine stretch in the human HPRT gene. Decay of 125I in the bound TFO was shown to cause sequence-specific double strand breaks (DSB) in the target HPRT sequence cloned into plasmid DNA. No sequence-specific breaks were observed if 125I-labeled TFO were not bound to the plasmid DNA. After 60 days of decay accumulation (one 125I half-life) approximately a quarter of all plasmid molecules contained sequence-specific DSB, corresponding to 0.3 site-specific DSB per decay. Sequencing gel analysis shows that the DNA breaks are distributed within a few bases of the maxima at those bases opposite to the positions of 125I in the TFO. (orig.)

  8. Sequence-specific DNA breaks produced by triplex-directed decay of iodine-125

    Energy Technology Data Exchange (ETDEWEB)

    Panyutin, I.G. [National Institutes of Health, Bethesda, MD (United States). Dept. of Nuclear Medicine; Neumann, R.D. [National Institutes of Health, Bethesda, MD (United States). Dept. of Nuclear Medicine

    1996-12-31

    Triplex forming oligonucleotides (TFO) labeled with Auger emitters could be ideal vehicles to deliver radioactive-decay energy to specific DNA sequences, causing DNA breaks and, subsequently, inactivation of these sequences. To demonstrate this approach we labeled with {sup 125}I (two {sup 125}I per molecule on average) a purine-rich 38-mer which forms a stable triplex with a polypurine x polypyrimidine stretch in the human HPRT gene. Decay of {sup 125}I in the bound TFO was shown to cause sequence-specific double strand breaks (DSB) in the target HPRT sequence cloned into plasmid DNA. No sequence-specific breaks were observed if {sup 125}I-labeled TFO were not bound to the plasmid DNA. After 60 days of decay accumulation (one {sup 125}I half-life) approximately a quarter of all plasmid molecules contained sequence-specific DSB, corresponding to 0.3 site-specific DSB per decay. Sequencing gel analysis shows that the DNA breaks are distributed within a few bases of the maxima at those bases opposite to the positions of {sup 125}I in the TFO. (orig.).

  9. Solidification of radioactive liquid wastes

    International Nuclear Information System (INIS)

    Purpose: To decrease the amount of surface active agents required for solidifying sodium sulfate-containing concentrated radioactive liquid wastes with asphalts. Method: Water soluble calcium compounds (calcium nitrate, etc.) are added to alkaline radioactive concentrated liquid wastes essentially consisting of sodium sulfate to adjust the pH value of the liquid wastes to 4.5 - 8.5. The addition amount of the water soluble calcium compounds (based on the weight of the calcium ions) is set to about 2 - 5% of the sulfate ions in the liquid wastes. Then, surface active agents are added by 3 - 10 weight % to the solid contents in the liquid wastes. (Ikeda, J.)

  10. Environmental radioactivity survey in Andong

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Zi Hong; Jo, Kum Ju [Andong Regional Radioactivity Monitoring Station, Andong National Univ., Andong (Korea, Republic of)

    2002-12-15

    The objectives of the project are to monitor an abnormal level in Andong area and to provide a base-line data on environmental radiation/radioactivity levels in case of any radiological emergency situation. The project is important in view of protecting the public health from the potential hazards of radiation and keeping up the clean environment. This report summarizes and interprets environmental radiation/radioactivity monitoring samples Gamma exposure rates, airborne dust, precipitation, fall-out and drinking-water. Environmental samples 2 kinds of indicator plant, 4 kinds of mushroom, 7 kinds of nut and seeds, and drinking waters. Among the all 2002 radiological monitoring and environmental data in Andong area were not found the extraordinary data. And a nation-wide environmental radiation/radioactivity level survey results were all background levels attributed to terrestrial and cosmic radiation.

  11. Radioactive ion beam development in Berkeley

    CERN Document Server

    Wutte, D C; Leitner, M A; Xie, Z Q

    1999-01-01

    Two radioactive ion beam projects are under development at the 88" Cyclotron, BEARS (Berkeley Experiment with accelerated radioactive species) and the 14O experiment. The projects are initially focused on the production of 11C and 14O, but it is planned to expand the program to 17F, 18F, 13N and 76Kr. For the BEARS project, the radioactivity is produced in form of either CO2 or N2O in a small medical 10 MeV proton cyclotron. The activity is then transported through a 300 m long He-jet line to the 88" cyclotron building, injected into the AECR-U ion source and accelerated through the 88" cyclotron to energies between 1 to 30 MeV/ nucleon. The 14O experiment is a new experiment at the 88" cyclotron to measure the energy-shape of the beta decay spectrum. For this purpose, a target transfer line and a radioactive ion beam test stand has been constructed. The radioactivity is produced in form of CO in a hot carbon target with a 20 MeV 3He from the 88" Cyclotron. The activity diffuses through an 8m long stainless s...

  12. Flow and Flow Decay of Refractory Castables

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhiqiang; Bjom Myhre; Bjorn Sandberg

    2003-01-01

    Installation of refractoty castables depend not only on flow, but also on how soon the flow is lost because of setting. The loss of flow (flow decay) has always been one of the main problems of refractory castable manufacturers,a problem that has not been too well described in literature. The flow decay has been studied for a castable system based on alumina, pointing out some general trends. The flow decay was found very temperature sensitive, being strongly accelerated by termperature increases. To compensate for excessive flow loss, a retarder like citric acid may be used. Thus flow decay was measured as a function of citric acid (retarder) addition at 35 ℃ .

  13. Weak decays. [Lectures, phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Wojcicki, S.

    1978-11-01

    Lectures are given on weak decays from a phenomenological point of view, emphasizing new results and ideas and the relation of recent results to the new standard theoretical model. The general framework within which the weak decay is viewed and relevant fundamental questions, weak decays of noncharmed hadrons, decays of muons and the tau, and the decays of charmed particles are covered. Limitation is made to the discussion of those topics that either have received recent experimental attention or are relevant to the new physics. (JFP) 178 references

  14. decays to baryons

    Indian Academy of Sciences (India)

    Torsten Leddig

    2012-11-01

    From inclusive measurements, it is known that about 7% of all mesons decay into final states with baryons. In these decays, some striking features become visible compared to mesonic decays. The largest branching fractions come with quite moderate multiplicities of 3–4 hadrons. We note that two-body decays to baryons are suppressed relative to three- and four-body decays. In most of these analyses, the invariant baryon–antibaryon mass shows an enhancement near the threshold. We propose a phenomenological interpretation of this quite common feature of hadronization to baryons.

  15. Radioactivity dosage evaluation of Brazilian ornamental granitic rocks based on chemical data, with mineralogical and lithological characterization

    Science.gov (United States)

    Salas, Humberto Terrazas; Nalini, Hermínio Arias; Mendes, Júlio César

    2006-02-01

    One hundred samples of granitic rock were collected from granite traders in Belo Horizonte. Autoradiography, optical microscopy, diffractometry, and chemical analysis (X-ray spectrometry, X-ray fluorescence, neutron activation, gravimetry, and electron probe microanalysis) were used to determine the mineral assemblages and lithotypes. Autoradiographic results for several samples showed the presence of monazite, allanite, and zircon. Chemical analysis revealed uranium concentrations ≤30 ppm and thorium ≤130 ppm. Higher concentrations generally correlated with high concentrations of light rare earths in silica-rich rocks of granitic composition. Calculations were made of radioactive doses for samples, of floor tiles in a standard room, with total concentration of uranium and thorium greater than 60 ppm. On the basis of calculations of 232 Th, 40 K, and 226 Ra from analysis of Th, K, and U, the doses calculated were between 0.11 and 0.34 mSv/year, which are much lower than the acceptable international exposure standard of 1.0 mSv/year.

  16. Assessment of the disposal of radioactive petroleum industry waste in nonhazardous landfills using risk-based modeling.

    Science.gov (United States)

    Smith, Karen P; Arnish, John J; Williams, Gustavious P; Blunt, Deborah L

    2003-05-15

    Certain petroleum production activities cause naturally occurring radioactive materials (NORM) to accumulate in concentrations above natural background levels, making safe and cost-effective management of such technologically enhanced NORM (TENORM) a key issue for the petroleum industry. As a result, both industry and regulators are interested in identifying cost-effective disposal alternatives that provide adequate protection of human health and the environment One such alternative, currently allowed in Michigan with restrictions, is the disposal of TENORM wastes in nonhazardous waste landfills. The disposal of petroleum industry wastes containing radium-226 (Ra-226) in nonhazardous landfills was modeled to evaluate the potential radiological doses and health risks to workers and the public. Multiple scenarios were considered in evaluating the potential risks associated with landfill operations and the future use of the property. The scenarios were defined, in part, to evaluate the Michigan policy; sensitivity analyses were conducted to evaluate the impact of key parameters on potential risks. The results indicate that the disposal of petroleum industry TENORM wastes in nonhazardous landfills in accordance with the Michigan policy and existing landfill regulations presents a negligible risk to most of the potential receptors considered in this study.

  17. Development of a low cost, GPS-based upgrade to a standard handheld gamma detector for mapping environmental radioactive contamination

    International Nuclear Information System (INIS)

    A low cost extension to a standard handheld radiation monitor was developed, allowing one to perform outdoor georeferenced gamma measurements. It consists of a commercial wireless Bluetooth[reg] GPS receiver, a commercial RS-232 to Bluetooth[reg] converter combined with a standard Bluetooth[reg] enabled pocket personal computer (PPC). The system is intended for use in difficult to access areas, typically for foot campaigns. As the operator walks, a straightforward homemade visual basic program alternately reads GPS position and gamma dose rate into the PPC, creating a data log. This allows a single operator on foot to map between 50 and 200 ha of environmental radiation per day in very rugged areas, depending on the accessibility of the terrain and the detail required. On a test field with known contamination, a spatial precision of about 5-10 m was obtainable. The device was also used to reveal complex contamination patterns in the flooding zones of a radioactively contaminated small river

  18. Radioactivity in the galactic plane

    Science.gov (United States)

    Walraven, G. D.; Haymes, R. C.

    1976-01-01

    The paper reports the detection of a large concentration of interstellar radioactivity during balloon-altitude measurements of gamma-ray energy spectra in the band between 0.02 and 12.27 MeV from galactic and extragalactic sources. Enhanced counting rates were observed in three directions towards the plane of the Galaxy; a power-law energy spectrum is computed for one of these directions (designated B 10). A large statistical deviation from the power law in a 1.0-FWHM interval centered near 1.16 MeV is discussed, and the existence of a nuclear gamma-ray line at 1.15 MeV in B 10 is postulated. It is suggested that Ca-44, which emits gamma radiation at 1.156 MeV following the decay of radioactive Sc-44, is a likely candidate for this line, noting that Sc-44 arises from Ti-44 according to explosive models of supernova nucleosynthesis. The 1.16-MeV line flux inferred from the present data is shown to equal the predicted flux for a supernova at a distance of approximately 3 kpc and an age not exceeding about 100 years.

  19. Capacity Decay Mechanism of Microporous Separator-Based All-Vanadium Redox Flow Batteries and its Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bin; Luo, Qingtao; Wei, Xiaoliang; Nie, Zimin; Thomsen, Edwin; Chen, Baowei; Sprenkle, Vincent; Wang, Wei

    2013-10-29

    For all vanadium redox flow batteries (VRBs) with porous separators as membranes, convection effect is found to play a dominant role in the capacity decay of the cells over cycling by investigating the relationship between electrical performances and electrolyte compositions at both positive and negative sides. Although the concentration of total vanadium ions hardly changes at both sides over cycling, the net transfer of solutions from one side to another and thus asymmetrical valance of vanadium ions at both sides lead to the capacity fading and lower energy efficiency, which is confirmed to result from the hydraulic pressure differential at both sides of separators. In this paper, the hydraulic pressures of solutions at both sides can be in-situ monitored, and regulated by varying the gas pressures in electrolyte tanks. It is found that the capacity can be stabilized and the net transfer of solutions can be prevented by slightly tailoring the hydraulic pressure differential at both sides of separators, which, however, doesn’t work for Nafion membranes, suggesting the negligible convection factor in flow cells using Nafion membranes. Therefore, the possibility of porous separators allows long-term running for VRBs without capacity loss, highlighting a new pathway to develop membranes used in VRBs.

  20. NATURAL RADIOACTIVITY IN SOME BUILDING MATERIALS USING A GAMMA-RAY SPECTROMETER

    OpenAIRE

    AKKURT, Iskender; Betül MAVİ

    2011-01-01

    The main reason for the natural radioactivity in the earth is decay series of 40K, 238U and 232Th radionuclides. Because all building materials are soil product, they contain these radionuclides as natural so that building materials have different amounts of radioactivity. In this study the concentrations of natural radioactivity levels of the commonly used natural building materials in Isparta region have been determined. The samples have been analysed using a NaI(Tl) ƒ×-ray spectrometer sy...

  1. Nuclear structure from radioactive decay. Annual progress report

    International Nuclear Information System (INIS)

    Studies of neutron-deficient nuclei around the Z = 82 shell closure, with special emphasis on the levels of the odd-mass Pt, Au, Hg, and Tl isotopes are described. Research on nuclear systematics and models is discussed, and publications are listed

  2. Wood decay at sea

    Science.gov (United States)

    Charles, François; Coston-Guarini, Jennifer; Guarini, Jean-Marc; Fanfard, Sandrine

    2016-08-01

    The oceans and seas receive coarse woody debris since the Devonian, but the kinetics of wood degradation remains one of many unanswered questions about the fate of driftwood in the marine environment. A simple gravimetric experiment was carried out at a monitoring station located at the exit of a steep, forested Mediterranean watershed in the Eastern Pyrenees. The objective was to describe and quantify, with standardized logs (in shape, structure and constitution), natural degradation of wood in the sea. Results show that the mass decrease of wood logs over time can be described by a sigmoidal curve. The primary process of wood decay observed at the monitoring station was due to the arrival and installation of wood-boring species that consumed more than half of the total wood mass in six months. Surprisingly, in a region where there is little remaining wood marine infrastructure, "shipworms", i.e. xylophagous bivalves, are responsible for an important part of this wood decay. This suggests that these communities are maintained probably by a frequent supply of a large quantity of riparian wood entering the marine environment adjacent to the watershed. By exploring this direct link between terrestrial and marine ecosystems, our long term objective is to determine how these supplies of terrestrial organic carbon can sustain wood-based marine communities as it is observed in the Mediterranean Sea.

  3. Experiments on the Effect of Atomic Electrons on the DecayConstant of Be7 II.

    Energy Technology Data Exchange (ETDEWEB)

    Leininger, R.F.; Segre, E.; Wiegand, C.

    1949-06-15

    A comparison of the decay constants of Be{sup 7} in beryllium oxide and in beryllium fluoride has given {lambda}{sub BeO}-{lambda}{sub BeF{sub 2}} = (+1.375 {+-} 0.053)10{sup -3}{lambda}{sub BeO} thus showing a definite effect of the chemical binding on the radioactive decay constant.

  4. CP-Violation in Neutrino Oscillations from EC/{beta}{sup +} decaying ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, Catalina [Centre for Theoretical Particle Physics, IST, Technical University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal)

    2012-08-15

    We discuss the separation of unknown neutrino properties by means of the energy dependence of the oscillation probability and we consider an hybrid setup which combines the electron capture and the {beta}{sup +} decay from the same radioactive proton-rich ion with the same boost. We conclude that the combination of the two decay channels, with different neutrino energies, achieves remarkable results.

  5. Ion traps for radioactive beam manipulation and precision experiments

    CERN Document Server

    Bollen, G

    2003-01-01

    Ion traps have become important experimental tools in nuclear physics. They can be used for precise determination of nuclear binding energies, decay studies and radioactive ion beam manipulation. This article will summarize their basic features and how they are employed and will present new developments.

  6. Constraining neutrinoless double beta decay

    International Nuclear Information System (INIS)

    A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum-rules (MSR). We show how these theories may constrain the absolute scale of neutrino mass, leading in most of the cases to a lower bound on the neutrinoless double beta decay effective amplitude.

  7. Alpha decay as a probe for the structure of neutron-deficient nuclei

    CERN Document Server

    Qi, Chong

    2016-01-01

    The advent of radioactive ion beam facilities and new detector technologies have opened up new possibilities to investigate the radioactive decays of highly unstable nuclei, in particular the proton emission, $\\alpha$ decay and heavy cluster decays from neutron-deficient (or proton-rich) nuclei around the proton drip line. It turns out that these decay measurements can serve as a unique probe for studying the structure of the nuclei involved. On the theoretical side, the development in nuclear many-body theories and supercomputing facilities have also made it possible to simulate the nuclear clusterization and decays from a microscopic and consistent perspective. In this article we would like to review the current status of these structure and decay studies in heavy nuclei, regarding both experimental and theoretical opportunities. We then discuss in detail the recent progress in our understanding of the nuclear $\\alpha$ formation probabilities in heavy nuclei and their indication on the underlying nuclear st...

  8. Broad resonances and beta-decay

    DEFF Research Database (Denmark)

    Riisager, K.; Fynbo, H. O. U.; Hyldegaard, S.;

    2015-01-01

    Beta-decay into broad resonances gives a distorted lineshape in the observed energy spectrum. Part of the distortion arises from the phase space factor, but we show that the beta-decay matrix element may also contribute. Based on a schematic model for p-wave continuum neutron states it is argued...

  9. Semileptonic D-decays at BESIII

    CERN Document Server

    An, Fenfen

    2015-01-01

    We present here three analyses of semileptonic $D$-meson decays based on the 2.92 fb$^{-1}$ of data collected by the BESIII experiment in 2010 and 2011 at the $\\psi$(3770) peak. For the decay $D^{+}\\to K^{-}\\pi^{+}e^{+}\

  10. Conceptual Design of Ultra-long-life Core Fast Reactor (UCFR) with Ga-based Passive Decay Heat Removal System (PDHRS)

    International Nuclear Information System (INIS)

    UCFR (Ultra-long-life Core Fast Reactor) is a 260MWth /100MWe sodium-cooled fast reactor which requires no on-site refueling and meets the need for future nuclear energy systems. UCFR is a pool type reactor with metallic fuels, four intermediate heat exchangers, two steam generators, and passive decay heat removal systems. Because gallium has the chemical reaction safety such as low oxygen reactivity compared to sodium, it can be used as a boundary material between sodium and atmosphere to enhance the nuclear safety of UCFR. In this research, design studied for neutronics and thermal-hydraulics are included. The safety performance of UCFR will be analyzed with MARS-LMR. Although MARS-LMR was originally intended for a safety analysis of liquid metal-cooled reactor, gallium properties were newly added to this code which is applicable for gallium-cooled systems. The properties of various liquid metals are indicated in table II. Considering needs to improve uranium utilization and solve the nuclear proliferation, ultra-long cycle fast reactor has been developed. UCFR is a 260MWth/100MWe sodium-cooled fast reactor which requires no on-site refueling during design period with metallic fuels (U-5Zr), HT-9 cladding, four intermediate heat exchangers, two steam generators, and Ga-based PDHRS. Through this paper, new PDHRS using gallium that can be remove decay heat passively for an infinite time is suggested. In Ga-based PDHRS, the both water and air as an ultimate heat sink will be can be considered because gallium has the chemical reaction safety. In this research, design study for neutronics and thermal-hydraulics were also included. For safety analysis of UCFR using MARS-LMR, detailed design of UCFR with Ga-based PDHRS will be required

  11. Nuclear Double Beta Decay, Fundamental Particle Physics, Hot Dark Matter, And Dark Energy

    CERN Document Server

    Klapdor-Kleingrothaus, Hans Volker

    2010-01-01

    Nuclear double beta decay, an extremely rare radioactive decay process, is - in one of its variants - one of the most exciting means of research into particle physics beyond the standard model. The large progress in sensitivity of experiments searching for neutrinoless double beta decay in the last two decades - based largely on the use of large amounts of enriched source material in "active source experiments" - has lead to the observation of the occurrence of this process in nature (on a 6.4 sigma level), with the largest half-life ever observed for a nuclear decay process (2.2 x 10^{25} y). This has fundamental consequences for particle physics - violation of lepton number, Majorana nature of the neutrino. These results are independent of any information on nuclear matrix elements (NME)*. It further leads to sharp restrictions for SUSY theories, sneutrino mass, right-handed W-boson mass, superheavy neutrino masses, compositeness, leptoquarks, violation of Lorentz invariance and equivalence principle in the...

  12. Influence of radioactivity on surface charging and aggregation kinetics of particles in the atmosphere.

    Science.gov (United States)

    Kim, Yong-Ha; Yiacoumi, Sotira; Lee, Ida; McFarlane, Joanna; Tsouris, Costas

    2014-01-01

    Radioactivity can influence surface interactions, but its effects on particle aggregation kinetics have not been included in transport modeling of radioactive particles. In this research, experimental and theoretical studies have been performed to investigate the influence of radioactivity on surface charging and aggregation kinetics of radioactive particles in the atmosphere. Radioactivity-induced charging mechanisms have been investigated at the microscopic level, and heterogeneous surface potential caused by radioactivity is reported. The radioactivity-induced surface charging is highly influenced by several parameters, such as rate and type of radioactive decay. A population balance model, including interparticle forces, has been employed to study the effects of radioactivity on particle aggregation kinetics in air. It has been found that radioactivity can hinder aggregation of particles because of similar surface charging caused by the decay process. Experimental and theoretical studies provide useful insights into the understanding of transport characteristics of radioactive particles emitted from severe nuclear events, such as the recent accident of Fukushima or deliberate explosions of radiological devices.

  13. Radioactive air sampling methods

    CERN Document Server

    Maiello, Mark L

    2010-01-01

    Although the field of radioactive air sampling has matured and evolved over decades, it has lacked a single resource that assimilates technical and background information on its many facets. Edited by experts and with contributions from top practitioners and researchers, Radioactive Air Sampling Methods provides authoritative guidance on measuring airborne radioactivity from industrial, research, and nuclear power operations, as well as naturally occuring radioactivity in the environment. Designed for industrial hygienists, air quality experts, and heath physicists, the book delves into the applied research advancing and transforming practice with improvements to measurement equipment, human dose modeling of inhaled radioactivity, and radiation safety regulations. To present a wide picture of the field, it covers the international and national standards that guide the quality of air sampling measurements and equipment. It discusses emergency response issues, including radioactive fallout and the assets used ...

  14. Comparisons between radioactive and non-radioactive gas lantern mantles.

    Science.gov (United States)

    Furuta, E; Yoshizawa, Y; Aburai, T

    2000-12-01

    Gas lantern mantles containing radioactive thorium have been used for more than 100 years. Although thorium was once believed to be indispensable for giving a bright light, non-radioactive mantles are now available. From the radioactivities of the daughter nuclides, we estimated the levels of radioactivity of 232Th and 228Th in 11 mantles. The mantles contained various levels of radioactivity from background levels to 1410 +/- 140 Bq. Our finding that radioactive and non-radioactive mantles are equally bright suggests that there is no advantage in using radioactive mantles. A remaining problem is that gas lantern mantles are sold without any information about radioactivity.

  15. Radioactive wastes and discharges

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The guide sets out the radiation safety requirements and limits for the treatment of radioactive waste. They shall be observed when discharging radioactive substances into the atmosphere or sewer system, or when delivering solid, low-activity waste to a landfill site without a separate waste treatment plan. The guide does not apply to the radioactive waste resulting from the utilisation of nuclear energy or natural resources.

  16. Radioactivity and its measurement

    CERN Document Server

    Mann, W B; Garfinkel, S B

    1980-01-01

    Begins with a description of the discovery of radioactivity and the historic research of such pioneers as the Curies and Rutherford. After a discussion of the interactions of &agr;, &bgr; and &ggr; rays with matter, the energetics of the different modes of nuclear disintegration are considered in relation to the Einstein mass-energy relationship as applied to radioactive transformations. Radiation detectors and radioactivity measurements are also discussed

  17. Drainage of radioactive areas

    International Nuclear Information System (INIS)

    This Code of Practice covers all the drainage systems which may occur in the radioactive classified area of an establishment, namely surface water, foul, process and radioactive drainage. It also deals with final discharge lines. The Code of Practice concentrates on those aspects of drainage which require particular attention because the systems are in or from radioactive areas and typical illustrations are given in appendices. The Code makes references to sources of information on conventional aspects of drainage design. (author)

  18. Radioactive wastes and discharges

    International Nuclear Information System (INIS)

    The guide sets out the radiation safety requirements and limits for the treatment of radioactive waste. They shall be observed when discharging radioactive substances into the atmosphere or sewer system, or when delivering solid, low-activity waste to a landfill site without a separate waste treatment plan. The guide does not apply to the radioactive waste resulting from the utilisation of nuclear energy or natural resources

  19. The formation and decay of superheavy nuclei produced in 48Ca-induced reactions

    Science.gov (United States)

    Kumar, Sushil; Balasubramaniam, M.; Gupta, Raj K.; Münzenberg, G.; Scheid, W.

    2003-04-01

    The formation of superheavy nuclei in 48Ca+232Th, 238U, 242,244Pu and 248Cm reactions and their subsequent decay are studied within the quantum mechanical fragmentation theory (QMFT) and the QMFT-based preformed cluster decay model (PCM) of Gupta and collaborators. According to QMFT, all these 48Ca-induced reactions are cold fusion reactions with relative excitation energies larger than those for the Pb-induced cold fusion reactions and smaller than those for the lighter beam, i.e. Mg, Si or S-induced hot fusion reactions. The same reactions were first suggested by Gupta et al in 1977 on the basis of QMFT, and this study re-establishes the same result. In fact, for such heavy isotopes of Z = 110 to 116, 50Ca is shown to be a better beam for cold fusion, but 50Ca is a radioactive nucleus. The alpha-decay half-lives of these nuclei after 3n and/or 4n evaporations, i.e. of the evaporation residues of these compound systems, calculated on PCM compare reasonably well with the experiments published by the Dubna group and another recent calculation. As expected for such rare decays, PCM calculations show that the alpha-preformation factors are small, ~10-8 to 10-10. The possible competition of alpha-decays with heavy cluster emissions from these superheavy nuclei is also probed from the point of view of searching for new nuclear structure information and possible future experiments with such exotic nuclei. The decay half-lives for some clusters are in fact shown to be lower than the limits of experiments for nuclei with enough available atoms.

  20. The formation and decay of superheavy nuclei produced in 48Ca-induced reactions

    International Nuclear Information System (INIS)

    The formation of superheavy nuclei in 48Ca+232Th, 238U, 242,244Pu and 248Cm reactions and their subsequent decay are studied within the quantum mechanical fragmentation theory (QMFT) and the QMFT-based preformed cluster decay model (PCM) of Gupta and collaborators. According to QMFT, all these 48Ca-induced reactions are cold fusion reactions with relative excitation energies larger than those for the Pb-induced cold fusion reactions and smaller than those for the lighter beam, i.e. Mg, Si or S-induced hot fusion reactions. The same reactions were first suggested by Gupta et al in 1977 on the basis of QMFT, and this study re-establishes the same result. In fact, for such heavy isotopes of Z = 110 to 116, 50Ca is shown to be a better beam for cold fusion, but 50Ca is a radioactive nucleus. The α-decay half-lives of these nuclei after 3n and/or 4n evaporations, i.e. of the evaporation residues of these compound systems, calculated on PCM compare reasonably well with the experiments published by the Dubna group and another recent calculation. As expected for such rare decays, PCM calculations show that the α-preformation factors are small, ∼10-8 to 10-10. The possible competition of α-decays with heavy cluster emissions from these superheavy nuclei is also probed from the point of view of searching for new nuclear structure information and possible future experiments with such exotic nuclei. The decay half-lives for some clusters are in fact shown to be lower than the limits of experiments for nuclei with enough available atoms

  1. Extraction of radioactive positive ions across the surface of superfluid helium : A new method to produce cold radioactive nuclear beams

    NARCIS (Netherlands)

    Huang, WX; Dendooven, P; Gloos, K; Takahashi, N; Pekola, JP; Aysto, J

    2003-01-01

    Alpha-decay recoils Rn-219 were stopped in superfluid helium and positive ions were extracted by electric field into the vapour phase. This first quantitative observation of extraction was successfully conducted using highly sensitive radioactivity detection. The efficiency for extraction across the

  2. Intrinsic Radiation in Lutetium Based PET Detector: Advantages and Disadvantages

    OpenAIRE

    Wei, Qingyang

    2015-01-01

    Lutetium (Lu) based scintillators such as LSO and LYSO, are widely used in modern PET detectors due to their high stopping power for 511 keV gamma rays, high light yield and short decay time. However, 2.6% of naturally occurring Lu is 176Lu, a long-lived radioactive element including a beta decay and three major simultaneous gamma decays. This phenomenon introduces random events to PET systems that affects the system performance. On the other hand, the advantages of intrinsic radiation of 176...

  3. Evaluation of using synthetic zeolite as a backfill material in radioactive waste disposal facility

    International Nuclear Information System (INIS)

    The fundamental safety concept for the disposal of radioactive wastes is to isolate the waste from the accessible environment for a period sufficiently long to allow substantial decay of the radionuclides and to limit release of residual radionuclides into the accessible environment. The underground disposal of radioactive waste is based upon a multi barrier concept. Backfill material is an important component of a multi-barrier disposal facility for low and intermediate level radioactive wastes. For long-term performance assessment of radioactive repositories, knowledge concerning the migration of radionuclides in the backfill material is required. Radionuclide migration through porous media (backfill materials) is governed by diffusion, advection, dispersion, retardation, and radionuclide decay. The work presented in this thesis is an examination of the feasibility of using synthetic zeolite NaA-X blend prepared from fly ash (FA) as backfill material in the proposed radioactive waste disposal facility in Egypt. The migration behavior of cesium and strontium ions, as two of the most important radionuclides commonly encountered in the Egyptian waste streams, through the proposed backfill material is studied using mathematical models. This approach considers the advective and dispersive transport of solutes dissolved in groundwater, which may undergo linear sorption (i.e retardation) and simple first order decay. To achieve these goals, the following investigations were carried out:1- Review of the materials most commonly used as engineered backfill to identify the important features to be considered in the examination of the proposed backfill material (zeolite Na A-X blend).2- Sorption experimental investigation aimed to study the sorption properties of the candidate backfill material towards the concerned radionuclides, cesium and strontium. Such studies are performed to establish clear understanding of the principle factors that control the sorption process, i

  4. Nested sampling applied in Bayesian room-acoustics decay analysis.

    Science.gov (United States)

    Jasa, Tomislav; Xiang, Ning

    2012-11-01

    Room-acoustic energy decays often exhibit single-rate or multiple-rate characteristics in a wide variety of rooms/halls. Both the energy decay order and decay parameter estimation are of practical significance in architectural acoustics applications, representing two different levels of Bayesian probabilistic inference. This paper discusses a model-based sound energy decay analysis within a Bayesian framework utilizing the nested sampling algorithm. The nested sampling algorithm is specifically developed to evaluate the Bayesian evidence required for determining the energy decay order with decay parameter estimates as a secondary result. Taking the energy decay analysis in architectural acoustics as an example, this paper demonstrates that two different levels of inference, decay model-selection and decay parameter estimation, can be cohesively accomplished by the nested sampling algorithm. PMID:23145609

  5. Marine sediments as a radioactive pollution repository in the world

    International Nuclear Information System (INIS)

    During a time period little longer than 60 years, it has been created a radioactive pollution background over the natural one, which started in 1945 and it has been growing up since then, due to several nuclear tests, minor nuclear reactors failure and four major accidents: Wind Scale, Three Mile Island, Chernobyl and Fukushima. This radioactive polluting background can be easily detected through 137Cs fission product, which by the effect of wind, river currents and rain has been accumulated in marine sediments, mainly because sea represents about 80 % of earth's surface. Since energy demand has been growing up with no interruption during last two centuries, and nuclear energy seems to be the largest available source, it is very likely a great expansion of nuclear energy during twenty-first century. So, this paper presents results obtained in strategic points of the two large littorals in Mexico: Gulf and Pacific Ocean, as an attempt to establish there some figure to evaluate the present radioactive pollution. An adequate figure to do it, seems to be the quotient of activity per gram of 137Cs in marine sediments (Bq137Cs/g), divided by activity per gram of 40K natural radioactivity (Bq40K/g). When this result is multiplied by 100 the percentage of polluting radioactivity (137Cs) related to natural radioactivity (40K) is obtained. This percentage seems to be useful to evaluate the importance of radioactive pollution from 4 points of view: a) calculate the extent of already radioactive pollution present in the seas of world; b) avoid the panic in case of nuclear accidents, c) what will be the growing up rate in the future; d) if it is possible to keep one decreasing rate at same decaying rate of 137Cs (t1/2 = 30.07 years), since from 1945, starting time of radioactive pollution, it has decayed only about 2.2 half lives. (author)

  6. Rare Decays at LHCb

    Science.gov (United States)

    Hall, Sam

    2014-04-01

    Rare decays of beauty and charm hadrons provide an effective method of testing the Standard Model and probing possible new physics scenarios. The LHCb experiment has published a variety of interesting results in this field, some of which are presented here. In particular the measurements of the branching fractions of B(s)0 → μ+μ- which, in combination with CMS, resulted in the first observation of the Bs0 → μ+μ- decay. Other topics include searches for the rare decay D0 → μ+μ-, the lepton flavour violating decays B(s)0 → e±μ∓, and the observation of the ψ(4160) resonance in the region of low recoil in B+ → K+μ+μ- decay. New results on the angular analysis of the decay B0 → K*0μ+μ- with form factor independent observables are also shown.

  7. Effective Majorana neutrino decay

    CERN Document Server

    Duarte, Lucía; Peressutti, Javier; Sampayo, Oscar A

    2016-01-01

    We study the decay of heavy sterile Majorana neutrinos according to the interactions obtained from an effective general theory. We describe the two and three-body decays for a wide range of neutrino masses. The results obtained and presented in this work could be useful for the study of the production and detection of this particles in a variety of high energy physics experiments and astrophysical observations. We show in different figures the dominant branching ratios and the total decay width.

  8. Transport of Radioactive Materials

    International Nuclear Information System (INIS)

    This address overviews the following aspects: concepts on transport of radioactive materials, quantities used to limit the transport, packages, types of packages, labeling, index transport calculation, tags, labeling, vehicle's requirements and documents required to authorize transportation. These requirements are considered in the regulation of transport of radioactive material that is in drafting step

  9. A Remote Radioactivity Experiment

    Science.gov (United States)

    Jona, Kemi; Vondracek, Mark

    2013-01-01

    Imagine a high school with very few experimental resources and limited budgets that prevent the purchase of even basic laboratory equipment. For example, many high schools do not have the means of experimentally studying radioactivity because they lack Geiger counters and/or good radioactive sources. This was the case at the first high school one…

  10. Induced radioactivity at CERN

    CERN Multimedia

    1970-01-01

    A description of some of the problems and some of the advantages associated with the phenomenon of induced radioactivity at accelerator centres such as CERN. The author has worked in this field for several years and has recently written a book 'Induced Radioactivity' published by North-Holland.

  11. An inter-comparison of sediment classification methods based on multi-beam echo-sounder backscatter and sediment natural radioactivity data.

    Science.gov (United States)

    Snellen, Mirjam; Eleftherakis, Dimitrios; Amiri-Simkooei, Alireza; Koomans, Ronald L; Simons, Dick G

    2013-08-01

    This contribution presents sediment classification results derived from different sources of data collected at the Dordtse Kil river, the Netherlands. The first source is a multi-beam echo-sounder (MBES). The second source is measurements taken with a gamma-ray scintillation detector, i.e., the Multi-Element Detection System for Underwater Sediment Activity (Medusa), towed over the sediments and measuring sediment natural radioactivity. Two analysis methods are employed for sediment classification based on the MBES data. The first is a Bayesian estimation method that uses the average backscatter data per beam and, therefore, is independent of the quality of the MBES calibration. The second is a model-based method that matches the measured backscatter curves to theoretical curves, predicted by a physics-based model. Medusa provides estimates for the concentrations of potassium, uranium, thorium, and cesium, known to be indicative for sediment properties, viz. mean grain size, silt content, and the presence of organic matter. In addition, a hydrophone attached to the Medusa system provides information regarding the sediment roughness. This paper presents an inter-comparison between the sediment classification results using the above-mentioned methods. It is shown that although originating from completely different sources, the MBES and Medusa provide similar information, revealing the same sediment distribution.

  12. Nuclear astrophysics with radioactive ions at FAIR

    CERN Document Server

    Reifarth, R; Göbel, K; Heftrich, T; Heil, M; Koloczek, A; Langer, C; Plag, R; Pohl, M; Sonnabend, K; Weigand, M; Adachi, T; Aksouh, F; Al-Khalili, J; AlGarawi, M; AlGhamdi, S; Alkhazov, G; Alkhomashi, N; Alvarez-Pol, H; Alvarez-Rodriguez, R; Andreev, V; Andrei, B; Atar, L; Aumann, T; Avdeichikov, V; Bacri, C; Bagchi, S; Barbieri, C; Beceiro, S; Beck, C; Beinrucker, C; Belier, G; Bemmerer, D; Bendel, M; Benlliure, J; Benzoni, G; Berjillos, R; Bertini, D; Bertulani, C; Bishop, S; Blasi, N; Bloch, T; Blumenfeld, Y; Bonaccorso, A; Boretzky, K; Botvina, A; Boudard, A; Boutachkov, P; Boztosun, I; Bracco, A; Brambilla, S; Monago, J Briz; Caamano, M; Caesar, C; Camera, F; Casarejos, E; Catford, W; Cederkall, J; Cederwall, B; Chartier, M; Chatillon, A; Cherciu, M; Chulkov, L; Coleman-Smith, P; Cortina-Gil, D; Crespi, F; Crespo, R; Cresswell, J; Csatlós, M; Déchery, F; Davids, B; Davinson, T; Derya, V; Detistov, P; Fernandez, P Diaz; DiJulio, D; Dmitry, S; Doré, D; nas, J Due\\; Dupont, E; Egelhof, P; Egorova, I; Elekes, Z; Enders, J; Endres, J; Ershov, S; Ershova, O; Fernandez-Dominguez, B; Fetisov, A; Fiori, E; Fomichev, A; Fonseca, M; Fraile, L; Freer, M; Friese, J; Borge, M G; Redondo, D Galaviz; Gannon, S; Garg, U; Gasparic, I; Gasques, L; Gastineau, B; Geissel, H; Gernhäuser, R; Ghosh, T; Gilbert, M; Glorius, J; Golubev, P; Gorshkov, A; Gourishetty, A; Grigorenko, L; Gulyas, J; Haiduc, M; Hammache, F; Harakeh, M; Hass, M; Heine, M; Hennig, A; Henriques, A; Herzberg, R; Holl, M; Ignatov, A; Ignatyuk, A; Ilieva, S; Ivanov, M; Iwasa, N; Jakobsson, B; Johansson, H; Jonson, B; Joshi, P; Junghans, A; Jurado, B; Körner, G; Kalantar, N; Kanungo, R; Kelic-Heil, A; Kezzar, K; Khan, E; Khanzadeev, A; Kiselev, O; Kogimtzis, M; Körper, D; Kräckmann, S; Kröll, T; Krücken, R; Krasznahorkay, A; Kratz, J; Kresan, D; Krings, T; Krumbholz, A; Krupko, S; Kulessa, R; Kumar, S; Kurz, N; Kuzmin, E; Labiche, M; Langanke, K; Lazarus, I; Bleis, T Le; Lederer, C; Lemasson, A; Lemmon, R; Liberati, V; Litvinov, Y; Löher, B; Herraiz, J Lopez; Münzenberg, G; Machado, J; Maev, E; Mahata, K; Mancusi, D; Marganiec, J; Perez, M Martinez; Marusov, V; Mengoni, D; Million, B; Morcelle, V; Moreno, O; Movsesyan, A; Nacher, E; Najafi, M; Nakamura, T; Naqvi, F; Nikolski, E; Nilsson, T; Nociforo, C; Nolan, P; Novatsky, B; Nyman, G; Ornelas, A; Palit, R; Pandit, S; Panin, V; Paradela, C; Parkar, V; Paschalis, S; Paw\\lowski, P; Perea, A; Pereira, J; Petrache, C; Petri, M; Pickstone, S; Pietralla, N; Pietri, S; Pivovarov, Y; Potlog, P; Prokofiev, A; Rastrepina, G; Rauscher, T; Ribeiro, G; Ricciardi, M; Richter, A; Rigollet, C; Riisager, K; Rios, A; Ritter, C; Frutos, T Rodríguez; Vignote, J Rodriguez; Röder, M; Romig, C; Rossi, D; Roussel-Chomaz, P; Rout, P; Roy, S; Söderström, P; Sarkar, M Saha; Sakuta, S; Salsac, M; Sampson, J; Saez, J Sanchez del Rio; Rosado, J Sanchez; Sanjari, S; Sarriguren, P; Sauerwein, A; Savran, D; Scheidenberger, C; Scheit, H; Schmidt, S; Schmitt, C; Schnorrenberger, L; Schrock, P; Schwengner, R; Seddon, D; Sherrill, B; Shrivastava, A; Sidorchuk, S; Silva, J; Simon, H; Simpson, E; Singh, P; Slobodan, D; Sohler, D; Spieker, M; Stach, D; Stan, E; Stanoiu, M; Stepantsov, S; Stevenson, P; Strieder, F; Stuhl, L; Suda, T; Sümmerer, K; Streicher, B; Taieb, J; Takechi, M; Tanihata, I; Taylor, J; Tengblad, O; Ter-Akopian, G; Terashima, S; Teubig, P; Thies, R; Thoennessen, M; Thomas, T; Thornhill, J; Thungstrom, G; Timar, J; Togano, Y; Tomohiro, U; Tornyi, T; Tostevin, J; Townsley, C; Trautmann, W; Trivedi, T; Typel, S; Uberseder, E; Udias, J; Uesaka, T; Uvarov, L; Vajta, Z; Velho, P; Vikhrov, V; Volknandt, M; Volkov, V; von Neumann-Cosel, P; von Schmid, M; Wagner, A; Wamers, F; Weick, H; Wells, D; Westerberg, L; Wieland, O; Wiescher, M; Wimmer, C; Wimmer, K; Winfield, J S; Winkel, M; Woods, P; Wyss, R; Yakorev, D; Yavor, M; Cardona, J Zamora; Zartova, I; Zerguerras, T; Zgura, I; Zhdanov, A; Zhukov, M; Zieblinski, M; Zilges, A; Zuber, K

    2016-01-01

    The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process beta-decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will offer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes.

  13. Standard Model tests with trapped radioactive atoms

    CERN Document Server

    Behr, J A; 10.1088/0954-3899/36/3/033101

    2009-01-01

    We review the use of laser cooling and trapping for Standard Model tests, focusing on trapping of radioactive isotopes. Experiments with neutral atoms trapped with modern laser cooling techniques are testing several basic predictions of electroweak unification. For nuclear $\\beta$ decay, demonstrated trap techniques include neutrino momentum measurements from beta-recoil coincidences, along with methods to produce highly polarized samples. These techniques have set the best general constraints on non-Standard Model scalar interactions in the first generation of particles. They also have the promise to test whether parity symmetry is maximally violated, to search for tensor interactions, and to search for new sources of time reversal violation. There are also possibilites for exotic particle searches. Measurements of the strength of the weak neutral current can be assisted by precision atomic experiments using traps of small numbers of radioactive atoms, and sensitivity to possible time-reversal violating elec...

  14. Evaluating airborne and ground based gamma spectrometry methods for detecting particulate radioactivity in the environment: A case study of Irish Sea beaches

    International Nuclear Information System (INIS)

    In several places, programmes are in place to locate and recover radioactive particles that have the potential to cause detrimental health effects in any member of the public who may encounter them. A model has been developed to evaluate the use of mobile gamma spectrometry systems within such programmes, with particular emphasis on large volume (16 l) NaI(Tl) detectors mounted in low flying helicopters. This model uses a validated Monte Carlo code with assessment of local geochemistry and natural and anthropogenic background radiation concentrations and distributions. The results of the model, applied to the example of particles recovered from beaches in the vicinity of Sellafield, clearly show the ability of rapid airborne surveys conducted at 75 m ground clearance and 120 kph speeds to demonstrate the absence of sources greater than 5 MBq 137Cs within large areas (10–20 km2 h−1), and identify areas requiring further ground based investigation. Lowering ground clearance for airborne surveys to 15 m whilst maintaining speeds covering 1–2 km2 h−1 can detect buried 137Cs sources of 0.5 MBq or greater activity. A survey design to detect 100 kBq 137Cs sources at 10 cm depth has also been defined, requiring surveys at −1 ground speed. The response of airborne systems to the Sellafield particles recovered to date has also been simulated, and the proportion of the existing radiocaesium background in the vicinity of the nuclear site has been established. Finally the rates of area coverage and sensitivities of both airborne and ground based approaches are compared, demonstrating the ability of airborne systems to increase the rate of particle recovery in a cost effective manner. The potential for equipment and methodological developments to improve performance are discussed. -- Highlights: ► Validated Monte Carlo simulations used to model mobile gamma spectrometry response to radioactive particless. ► Detection limits for airborne and ground based surveys

  15. Environmental radioactivity survey data in Cheonju

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mo Sung; Goo, Hyun Mi [Cheongju Univ., Cheongju (Korea, Republic of)

    2003-12-15

    We surveyed the en environmental radiation and radioactivity in Chungcheongbuk-do in order to provide baseline data in the year of 2003. Data generated from the project will be the information base for making decisions necessary to ensure the protection of public health. This report contains the data of gamma exposure rates and radioactivities of airborne dust, fallout, precipitation and tap water which were analyzed periodically by Cheongju regional monitoring station In the year 2003. Also it contains the data of natural radioactivity levels of environmental samples such as soil, drinking water, indicator plant(mugwort, pine-needle), agricultural and forest products, and processed food(tea)

  16. Optimum orientation versus orientation averaging description of cluster radioactivity

    CERN Document Server

    Seif, W M; Refaie, A I; Amer, L H

    2016-01-01

    Background: The deformation of the nuclei involved in the cluster decay of heavy nuclei affect seriously their half-lives against the decay. Purpose: We investigate the description of the different decay stages in both the optimum orientation and the orientation-averaged pictures of the cluster decay process. Method: We consider the decays of 232,233,234U and 236,238Pu isotopes. The quantum mechanical knocking frequency and penetration probability based on the Wentzel-Kramers-Brillouin approximation are used to find the decay width. Results: We found that the orientation-averaged decay width is one or two orders of magnitude less than its value along the non-compact optimum orientation. The difference between the two values increases with decreasing the mass number of the emitted cluster. Correspondingly, the extracted preformation probability based on the averaged decay width increases with the same orders of magnitude compared to its value obtained considering the optimum orientation. The cluster preformati...

  17. Estimation of radioactive contamination of soils from the "Balapan" and the "Experimental field" technical areas of the Semipalatinsk nuclear test site.

    Science.gov (United States)

    Evseeva, T; Belykh, E; Geras'kin, S; Majstrenko, T

    2012-07-01

    In spite of the long history of the research, radioactive contamination of the Semipalatinsk nuclear test site (SNTS) in the Republic of Kazakhstan has not been adequately characterized. Our cartographic investigation has demonstrated highly variable radioactive contamination of the SNTS. The Cs-137, Sr-90, Eu-152, Eu-154, Co-60, and Am-241 activity concentrations in soil samples from the "Balapan" site were 42.6-17646, 96-18250, 1.05-11222, 0.6-4865, 0.23-4893, and 1.2-1037 Bq kg(-1), correspondingly. Cs-137 and Sr-90 activity concentrations in soil samples from the "Experimental field" site were varied from 87 up to 400 and from 94 up to 1000 Bq kg(-1), respectively. Activity concentrations of Co-60, Eu-152, and Eu-154 were lower than the minimum detectable activity of the method used. Concentrations of naturally occurring radionuclides (K-40, Ra-226, U-238, and Th-232) in the majority of soil samples from the "Balapan" and the "Experimental field" sites did not exceed typical for surrounding of the SNTS areas levels. Estimation of risks associated with radioactive contamination based on the IAEA clearance levels for a number of key radionuclides in solid materials shows that soils sampled from the "Balapan" and the "Experimental field" sites might be considered as radioactive wastes. Decrease in specific activity of soil from the sites studied up to safety levels due to Co-60, Cs-137, Sr-90, Eu-152, Eu-154 radioactive decay and Am-241 accumulation-decay will occur not earlier than 100 years. In contrast, soils from the "Experimental field" and the "Balapan" sites (except 0.5-2.5 km distance from the "Chagan" explosion point) cannot be regarded as the radioactive wastes according safety norms valid in Russia and Kazakhstan.

  18. Germanium detectors and natural radioactivity in food

    Energy Technology Data Exchange (ETDEWEB)

    Garbini, Lucia [Max-Planck-Institut fuer Physik, Muenchen (Germany); Collaboration: GeDet-Collaboration

    2013-07-01

    Potassium is a very important mineral for many physiological processes, like fluid balance, protein synthesis and signal transmission in nerves. Many aliments like raisins, bananas or chocolate contain potassium. Natural potassium contains 0.012% of the radioactive isotope Potassium 40. This isotope decays via β{sup +} decay into a metastable state of Argon 40, which reaches its ground state emitting a gamma of 1460 keV. A commercially produced Germanium detector has been used to measure the energy spectra of different selected food samples. It was calibrated with KCl and potassium contents were extracted. Results verify the high potassium content of commonly recommended food samples. However, the measurement quantitatively differ from the expectations in several cases. One of the most interesting results concerns chocolate bars with different percentages of cacao.

  19. Radioactive waste disposal via electric propulsion

    Science.gov (United States)

    Burns, R. E.

    1975-01-01

    It is shown that space transportation is a feasible method of removal of radioactive wastes from the biosphere. The high decay heat of the isotopes powers a thermionic generator which provides electrical power for ion thrust engines. The massive shields (used to protect ground and flight personnel) are removed in orbit for subsequent reuse; the metallic fuel provides a shield for the avionics that guides the orbital stage to solar system escape. Performance calculations indicate that 4000 kg. of actinides may be removed per Shuttle flight. Subsidiary problems - such as cooling during ascent - are discussed.

  20. Characterization of radioactive hazardous waste

    International Nuclear Information System (INIS)

    The characterization of radioactive hazardous waste, also known as transuranic 'mixed waste' has to be completed before it can be classified for proper treatment (incinerator, mechanical compaction or thermal treatment), packing, and transport. The characterization of the TRU mixed waste is not only complex process but rather an expensive undertaking. The process knowledge is the basic foundation of characterization. It is the documented knowledge of processes and materials that generated the waste. The transuranic waste Quality Assurance Program Plan (QAPP) defines the Data Quality Objectives (DQO's) and provides the scope of analytical parameters and methods required to accurately characterize the radioactive mixed waste. Based on the historical data and process knowledge a sampling and analysis plan can be developed to characterize the radioactive hazardous waste. Based on the characterization, an assessment of the regulatory status can be made before the waste could be accepted for disposal at the WIPP facility. The Waste Acceptance Criteria (WAC) developed by WIPP defines the parameters for receiving and final disposal of the TRU waste. The sets of criteria, such as: heat generated, fissile gram equivalent (FGE), plutonium-equivalent (PE) curies, and specifications of a dose rate have to be met before the waste is accepted for deep geological disposal. The characterization of radioactive waste becomes even more complex due to the presence of iron base metals/alloys, aluminum base metals/alloys, organic, chelating agents that are mixed with plastic, rubber, cellulose, soils and cement. Some of the modern characterization technologies that are under development and currently used for TRU mixed wastes are: nondestructive examination, nondestructive assay, headspace gas analysis, and drum coring for Resources Conservation Recovery Act (RCRA) sampling. (author)

  1. Rare Semileptonic Charm Decays

    CERN Document Server

    de Boer, Stefan

    2015-01-01

    An analysis of charm mesons decaying semileptonically via Flavor Changing Neutral Currents is presented. We calculate the Wilson coefficients within the Standard Model. A window in the decay distribution, where physics beyond the Standard Model could be measured is identified. Exemplary, we study effects of leptoquark models.

  2. Environmental impact assessment of the nuclear reactor at Vinca, based on the data on emission of radioactivity from the literature: A modeling approach

    Directory of Open Access Journals (Sweden)

    Gršić Z.

    2015-01-01

    Full Text Available Research activities of Vinca Institite have been based on two heavy water research reactors: 10 MW one, RA and zero power RB. Reactor RA was operational from 1962 to 1982. In 2010, spent fuel have been sent to the country of origin, and reactor now is in decommissioning. During operational phase of the reactor there were no recorded accidental releases into the environment just operational ones. Results of the environmental impact assessment, of the assumed emission of radionuclides, from the ventilation of nuclear reactor "RA" in Vinca, to the atmospheric boundary layer are presented in this paper. Evaluation was done by using the Gaussian straight-line diffusion model and taking into account characteristics of the reactor ventilation system, the assumed emission release of radioactivity (from the literature, site-specific meteorological data for six-year period and local topography around nuclear reactor, and corresponding dose factors for inventory of radionuclides. Based on the described approach, and assuming that the range of appropriate meteorological data for six year period for the application of described mathematical model is enough for this kind of analysis, it can be concluded that the nuclear reactor "RA", in the course of its work from 1962 to 1982, had no influence on the surrounding environment through the air above regulatory limits. [Projekat Ministarstva nauke Republike Srbije, br. III 45003

  3. Radioactive Waste in Oil Exploration

    International Nuclear Information System (INIS)

    radioactivity and demand even higher degrees of separation from the general populace. Very low levels of NORM can be dispersed along the surface, but higher concentrations require containment in abandoned wells or salt domes1. 222Rn a product of the decay of 226Ra is also a major component of dose to oil and gas workers from NORM1. Radon buildup is particularly hazardous in places where air ventilation is limited, such as underground mining operations. In the oil and gas industry, radon tends to preferentially follow gas lines, and thus is a major concern in the extraction of natural gas where concentrations of 5 - 200,000 Bq/m3 can be reached8. US EPA has also placed the set rules for contaminated soil to be at 1.11 Bq/g (30 pCi/g). The obvious concern is that any elevated concentrations in radionuclides in soil may eventually leach into the ground water. Enviroklean Product Development, Inc. (EPDI) and the Nuclear Engineering Teaching Lab have been involved in the cleanup and identification of NORM wastes in west Texas

  4. Radioactive contamination and radionuclide migration in ground water. January 1970-May 1989 (Citations from the NTIS data base). Report for January 1970-May 1989

    International Nuclear Information System (INIS)

    This bibliography contains citations concerning the contamination of groundwater with radionuclides and their subsequent migration. Monitoring surveys of existing sites with actual or potential radioactive groundwater contamination are included. Transport and migration models for radionuclides in groundwater are discussed. Natural radiation and accidental releases are considered in addition to anthropogenic sources of radioactive pollution such as waste storage and disposal. Contributions to radioactive pollution from uranium mining and processing is discussed in a separate bibliography. (Contains 209 citations fully indexed and including a title list.)

  5. Alpha decay favoured isotopes of some superheavy nuclei: Spontaneous fission versus alpha decay

    CERN Document Server

    Kiren, O V; Bubbly, S G

    2013-01-01

    Spontaneous fission and alpha decay are the main decay modes for superheavy nuclei. The superheavy nuclei which have small alpha decay half-life compared to spontaneous fission half-life will survive fission and can be detected in the laboratory through alpha decay. We have studied the alpha decay half-life and spontaneous half-life of some superheavy elements in the atomic range Z = 100-130. Spontaneous fission half-lives of superheavy nuclei have been calculated using the phenomenological formula and the alpha decay half-lives using Viola-Seaborg-Sobiczewski formula (Sobiczewski et al. 1989), semi empirical relation of Brown (1992) and formula based on generalized liquid drop model proposed by Dasgupta-Schubert and Reyes (2007). The results are reported here.

  6. Maintaining knowledge of radioactive waste

    International Nuclear Information System (INIS)

    be ensuring future access to knowledge? Radioactive waste data, recorded in isolation, may have restricted value especially if its provenance is unknown, its significance is unclear, the originators cannot be consulted and its authenticity and trustworthiness are not verifiable. It is therefore necessary to combine this raw data with contextual information that will enable future generations to determine the significance of the record, distinguish it as valuable asset and create their own, contemporary knowledge base. Only when equipped with comprehensive, reliable and accurate knowledge will future generations have the confidence to make informed judgments about the impact of our waste on their society and environment. The mismanagement of our knowledge today could have significant repercussions in terms of cost, radiation dose and damage to the environment in the future. This presentation defines terms such as 'data', 'information', 'knowledge' and 'wisdom' and provides a simple model illustrating their relationship. This model is then used as the basis for an examination of the inputs and the ways in which they may be optimised. The nuclear industry, and even society, has developed an 'implicit' understanding of radioactive waste, at a variety of levels, and it may seem inconceivable that future societies would not retain this understanding in sufficient detail that it could adequately protect itself and the environment. History shows, however, that as societies evolve and other priorities emerge previously implicit knowledge can decline. This leads us towards identifying present 'implicit' radioactive waste knowledge and developing means for capturing it. The presentation will conclude with an argument for the development of strategies that encourage the sharing of trustworthy radioactive waste-related knowledge. These strategies, supported national governments, whilst being both practical and cost-effective to implement must be cognisant of the need for local

  7. Decay of hypernuclei

    International Nuclear Information System (INIS)

    The pionic and non-mesonic decays of hypernuclei are discussed. In the first part, various decay processes which could be useful to obtain information of hypernuclear structure are discussed. The experimental data concerning the pionic and non-mesonic decays are discussed in the second part. As the experimental data, there are only few lifetime data and some crude data on the non-mesonic to π decay ratio. In the third and the fourth parts, some theoretical analyses are made on the pionic and the nonmesonic decays. DDHF calculation was performed for Λ and N systems by using Skyrme type ΛN and NN effective interactions. A suppression factor of the order of 10-3 for A nearly equal 100 was obtained. (Aoki, K.)

  8. QCD in heavy quark production and decay

    Energy Technology Data Exchange (ETDEWEB)

    Wiss, J. [Univ. of Illinois, Urbana, IL (United States)

    1997-06-01

    The author discusses how QCD is used to understand the physics of heavy quark production and decay dynamics. His discussion of production dynamics primarily concentrates on charm photoproduction data which are compared to perturbative QCD calculations which incorporate fragmentation effects. He begins his discussion of heavy quark decay by reviewing data on charm and beauty lifetimes. Present data on fully leptonic and semileptonic charm decay are then reviewed. Measurements of the hadronic weak current form factors are compared to the nonperturbative QCD-based predictions of Lattice Gauge Theories. He next discusses polarization phenomena present in charmed baryon decay. Heavy Quark Effective Theory predicts that the daughter baryon will recoil from the charmed parent with nearly 100% left-handed polarization, which is in excellent agreement with present data. He concludes by discussing nonleptonic charm decay which is traditionally analyzed in a factorization framework applicable to two-body and quasi-two-body nonleptonic decays. This discussion emphasizes the important role of final state interactions in influencing both the observed decay width of various two-body final states as well as modifying the interference between interfering resonance channels which contribute to specific multibody decays. 50 refs., 77 figs.

  9. Natural radioactivity in groundwater--a review.

    Science.gov (United States)

    Dinh Chau, Nguyen; Dulinski, Marek; Jodlowski, Pawel; Nowak, Jakub; Rozanski, Kazimierz; Sleziak, Monika; Wachniew, Przemyslaw

    2011-12-01

    The issue of natural radioactivity in groundwater is reviewed, with emphasis on those radioisotopes which contribute in a significant way to the overall effective dose received by members of the public due to the intake of drinking water originating from groundwater systems. The term 'natural radioactivity' is used in this context to cover all radioactivity present in the environment, including man-made (anthropogenic) radioactivity. Comprehensive discussion of radiological aspects of the presence of natural radionuclides in groundwater, including an overview of current regulations dealing with radioactivity in drinking water, is provided. The presented data indicate that thorough assessments of the committed doses resulting from the presence of natural radioactivity in groundwater are needed, particularly when such water is envisaged for regular intake by infants. They should be based on a precise determination of radioactivity concentration levels of the whole suite of radionuclides, including characterisation of their temporal variability. Equally important is a realistic assessment of water intake values for specific age groups. Only such an evaluation may provide the basis for possible remedial actions.

  10. Diagnosis, care, and healing. Radioactivity serves medicine

    International Nuclear Information System (INIS)

    After a brief presentation of the main forms of radioactivity (alpha, beta, gamma, electronic capture) and having outlined that some nuclear properties other than radioactivity can be used in medicine (for example nuclear magnetic resonance), the author proposes an overview of principles and techniques based on radioactive atoms in medical studies, diagnosis and treatment. Radioactivity can indeed be used as a therapy tool to destroy cancerous cells, to obtain the image of an organ, to follow the evolution of a biochemical reaction in the body, to detect the dysfunction of an organ, and so on. He recalls the first uses of radioactivity as a diagnosis tool in 1925 to measure the time for blood to go from one arm to the other. He presents the gamma scintigraphy technique, its principles and application in tumour detection, briefly evokes the radionuclide scanning and computed tomographic scintigraphy techniques, and presents the Positron Emission Tomography (PET) which can be used to follow the evolution in time of a biological process. Then, he addresses the therapy aspect: historical aspects (Becquerel, Curie), effects of a particle emitted by a radioactive nucleus. He outlines that effects of radioactivity can be dangerous and that the irradiation must therefore be precisely controlled. He presents the various therapy techniques: radiotherapy, Curie-therapy, boron-therapy, and discusses the perspectives for the future

  11. Deep-sea burial of radioactive wastes

    International Nuclear Information System (INIS)

    State of the art of sea dumping of radioactive wastes, legal bases, problems of ecology and environmental safety, possibilities and prospects were the goal of this seminar. Moreover, experts in ministries and members of the parliament in the Federal Republic of Germany should be supported by the results and experiences given here in order to find the legal requirements for a marine disposal of special radioactive wastes. (RB)

  12. Predisposal Radioactive Waste Management

    International Nuclear Information System (INIS)

    Recognition of the importance of the safe management of radioactive waste means that, over the years, many well-established and effective techniques have been developed, and the nuclear industry and governments have gained considerable experience in this field. Minimization of waste is a fundamental principle underpinning the design and operation of all nuclear operations, together with waste reuse and recycling. For the remaining radioactive waste that will be produced, it is essential that there is a well defined plan (called a waste treatment path) to ensure the safe management and ultimately the safe disposal of radioactive waste so as to guarantee the sustainable long term deployment of nuclear technologies

  13. Radioactivity; La radioactivite

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This pedagogical document presents the origin, effects and uses of radioactivity: where does radioactivity comes from, effects on the body, measurement, protection against radiations, uses in the medical field, in the electric power industry, in the food (ionization, radio-mutagenesis, irradiations) and other industries (radiography, gauges, detectors, irradiations, tracers), and in research activities (dating, preservation of cultural objects). The document ends with some examples of irradiation levels (examples of natural radioactivity, distribution of the various sources of exposure in France). (J.S.)

  14. Radioactive waste disposal

    International Nuclear Information System (INIS)

    The current disposal concept for radioactive waste in the FRG was discussed in the framework of this seminar. In addition to this concept for the treatment of radioactive waste also the volume of this waste is indicated. The present state of the two repositories 'Konrad' and 'Gorleben' is explained, as well as the requirements on waste packages for transportation, intermediate and ultimate storage. The final part discusses the conditioning of this radioactive waste and the control of the barrels as regards the observance of the requirements. (orig.)

  15. CALDER: neutrinoless double-beta decay identification in TeO{sub 2} bolometers with kinetic inductance detectors

    Energy Technology Data Exchange (ETDEWEB)

    Battistelli, E. S. [Dipartimento di Fisica, Sapienza Università di Roma, Rome (Italy); Bellini, F. [Dipartimento di Fisica, Sapienza Università di Roma, Rome (Italy); INFN Sezione di Roma, Rome (Italy); Bucci, C. [INFN Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); Calvo, M. [Institut Néel, CNRS, Saint-Martin-d’Héres (France); Cardani, L. [Dipartimento di Fisica, Sapienza Università di Roma, Rome (Italy); Physics Department, Princeton University, Princeton, NJ (United States); Casali, N. [Dipartimento di Fisica, Sapienza Università di Roma, Rome (Italy); INFN Sezione di Roma, Rome (Italy); Castellano, M. G. [Istituto di Fotonica e Nanotecnologie, CNR, Rome (Italy); Colantoni, I.; Coppolecchia, A. [Dipartimento di Fisica, Sapienza Università di Roma, Rome (Italy); Cosmelli, C.; Cruciani, A.; Bernardis, P. de [Dipartimento di Fisica, Sapienza Università di Roma, Rome (Italy); INFN Sezione di Roma, Rome (Italy); Di Domizio, S. [Dipartimento di Fisica, Università di Genova, Genoa (Italy); INFN Sezione di Genova, Genoa (Italy); D’Addabbo, A. [INFN Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); Martinez, M.; Masi, S. [Dipartimento di Fisica, Sapienza Università di Roma, Rome (Italy); INFN Sezione di Roma, Rome (Italy); Pagnanini, L. [INFN Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); INFN Gran Sasso Science Institute, L’Aquila (Italy); Tomei, C. [INFN Sezione di Roma, Rome (Italy); Vignati, M., E-mail: marco.vignati@roma1.infn.it [Dipartimento di Fisica, Sapienza Università di Roma, Rome (Italy); INFN Sezione di Roma, Rome (Italy)

    2015-07-31

    Next-generation experiments searching for neutrinoless double-beta decay must be sensitive to a Majorana neutrino mass as low as 10 meV. CUORE , an array of 988 TeO{sub 2} bolometers being commissioned at Laboratori Nazionali del Gran Sasso, features an expected sensitivity of 50–130 meV at 90 % C.L. The background is expected to be dominated by α radioactivity, and can be in principle removed by detecting the small amount of Cherenkov light emitted by the β signal. The Cryogenic wide-Area Light Detectors with Excellent Resolution project aims at developing a small prototype experiment consisting of TeO{sub 2} bolometers coupled to high-sensitivity light detectors based on kinetic inductance detectors. The R&D is focused on the light detectors in view of the implementation in a next-generation neutrinoless double-beta decay experiment.

  16. CALDER: neutrinoless double-beta decay identification in TeO{sub 2} bolometers with kinetic inductance detectors

    Energy Technology Data Exchange (ETDEWEB)

    Battistelli, E.S.; Colantoni, I.; Coppolecchia, A. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); Bellini, F.; Casali, N.; Cosmelli, C.; Cruciani, A.; De Bernardis, P.; Martinez, M.; Masi, S.; Vignati, M. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN Sezione di Roma, Rome (Italy); Bucci, C.; D' Addabbo, A. [INFN Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); Calvo, M. [CNRS, Institut Neel, Saint-Martin-d' Heres (France); Cardani, L. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); Princeton University, Physics Department, NJ (United States); Castellano, M.G. [CNR, Istituto di Fotonica e Nanotecnologie, Rome (Italy); Di Domizio, S. [Universita di Genova, Dipartimento di Fisica, Genoa (Italy); INFN Sezione di Genova, Genoa (Italy); Pagnanini, L. [INFN Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); INFN Gran Sasso Science Institute, L' Aquila (Italy); Tomei, C. [INFN Sezione di Roma, Rome (Italy)

    2015-08-15

    Next-generation experiments searching for neutrinoless double-beta decay must be sensitive to a Majorana neutrino mass as low as 10 meV. CUORE, an array of 988 TeO{sub 2} bolometers being commissioned at Laboratori Nazionali del Gran Sasso, features an expected sensitivity of 50- 130 meV at 90 % C.L. The background is expected to be dominated by α radioactivity, and can be in principle removed by detecting the small amount of Cherenkov light emitted by the β signal. The Cryogenic wide-Area Light Detectors with Excellent Resolution project aims at developing a small prototype experiment consisting of TeO{sub 2} bolometers coupled to high-sensitivity light detectors based on kinetic inductance detectors. The R and D is focused on the light detectors in view of the implementation in a next-generation neutrinoless double-beta decay experiment. (orig.)

  17. Systematic study of α decay half-lives for even-even nuclei within a two-potential approach

    Science.gov (United States)

    Sun, Xiao-Dong; Guo, Ping; Li, Xiao-Hua

    2016-03-01

    α decay is a common and important process of natural radioactivity of heavy and superheavy nuclei. The α decay half-lives for even-even nuclei from Z =62 to Z =118 are systematically studied based on the two-potential approach with a quasistationary state approximation. As for the nuclear potential, the isospin effect is considered, which slightly improves the results by 6.8%. To reduce the deviations between experimental half-lives and calculated results due to the nuclear shell structure, the analytic expression of hindrance factors is employed. Our results can reproduce the experimental half-lives as good as using the density-dependent cluster model and the generalized liquid drop model.

  18. Systematic study of $\\alpha$ decay half-lives for even-even nuclei within a two-potential approach

    CERN Document Server

    Sun, Xiao-Dong; Li, Xiao-Hua

    2015-01-01

    $\\alpha$ decay is a common and important process for natural radioactivity of heavy and superheavy nuclei. The $\\alpha$ decay half-lives for even-even nuclei from Z=62 to Z=118 are systematically researched based on the two-potential approach with a quasi-stationary state approximation. To describe the deviations between experimental half-lives and calculated results due to the nuclear shell structure, a hindrance factor related with $\\alpha$ particle preformation probability is introduced. Our results can well reproduce the experimental data equally to the density-dependent cluster model and the generalized liquid drop model. We also study the isospin effect of nuclear potential in this work. Considering the isospin effect the calculated results improved about 7.3$\\%$.

  19. Decay-Assisted Laser Spectroscopy of Neutron-Deficient Francium

    CERN Document Server

    Lynch, K M; Bissell, M L; Budincevic, I; Cocolios, T E; De Groote, R P; De Schepper, S; Fedosseev, V N; Flanagan, K T; Franchoo, S; Garcia Ruiz, R F; Heylen, H; Marsh, B A; Neyens, G; Procter, T J; Rossel, R E; Rothe, S; Strashnov, I; Stroke, H H; Wendt, K D A

    2014-01-01

    This paper reports on the hyperfine-structure and radioactive-decay studies of the neutron-deficient francium isotopes $^{202-206}$Fr performed with the Collinear Resonance Ionization Spectroscopy (CRIS) experiment at the ISOLDE facility, CERN. The high resolution innate to collinear laser spectroscopy is combined with the high efficiency of ion detection to provide a highly-sensitive technique to probe the hyperfine structure of exotic isotopes. The technique of decay-assisted laser spectroscopy is presented, whereby the isomeric ion beam is deflected to a decay spectroscopy station for alpha-decay tagging of the hyperfine components. Here, we present the first hyperfine-structure measurements of the neutron-deficient francium isotopes $^{202-206}$Fr, in addition to the identification of the low-lying states of $^{202,204}$Fr performed at the CRIS experiment.

  20. Analysis of hydrological trend for radioactivity content in bore-hole water samples using wavelet based denoising

    International Nuclear Information System (INIS)

    A wavelet transform based denoising methodology has been applied to detect the presence of any discernable trend in 137Cs and 90Sr activity levels in bore-hole water samples collected four times a year over a period of eight years, from 2002 to 2009, in the vicinity of typical nuclear facilities inside the restricted access zones. The conventional non-parametric methods viz., Mann–Kendall and Spearman rho, along with linear regression when applied for detecting the linear trend in the time series data do not yield results conclusive for trend detection with a confidence of 95% for most of the samples. The stationary wavelet based hard thresholding data pruning method with Haar as the analyzing wavelet was applied to remove the noise present in the same data. Results indicate that confidence interval of the established trend has significantly improved after pre-processing to more than 98% compared to the conventional non-parametric methods when applied to direct measurements. -- Highlights: ► Environmental trend analysis with wavelet pre-processing was carried out. ► Removal of local fluctuations to obtain the trend in a time series with various mother wavelets. ► Theoretical validation of the methodology with model outputs. ► Efficient detection of trend for 137Cs, 90Sr in bore-hole water samples improves the associated confidence interval to more than 98%. ► Wavelet based pre-processing reduces the indecisive nature of the detected trend

  1. Development of JENDL Decay and Fission Yield Data Libraries

    Science.gov (United States)

    Katakura, J.

    2014-04-01

    Decay and fission yield data of fission products have been developed for decay heat calculations to constitute one of the special purpose files of JENDL (Japanese Nuclear Data Library). The decay data in the previous JENDL decay data file have been updated based on the data extracted from ENSDF (Evaluated Nuclear Structure Data File) and those by Total Absorption Gamma-ray Spectroscopy (TAGS) measurements reported recently. Fission yield data have also been updated in order to maintain consistency between the decay and yield data files. Decay heat calculations were performed using the updated decay and yield data, and the results were compared with measured decay heat data to demonstrate their applicability. The uncertainties of the calculated results were obtained by sensitivity analyses. The resulting JENDL calculations and their uncertainty were compared with those from the ENDF and JEFF evaluated files.

  2. Bases for an environmental liability management system: application to a repository for radioactive waste; Bases para um sistema de gerenciamento de responsabilidades ambientais: aplicacao a um repositorio de rejeitos radioativos

    Energy Technology Data Exchange (ETDEWEB)

    Tostes, Marcelo Mallat

    1999-03-15

    This thesis aims the establishment of conceptual bases for the development of Environmental Liability Management System - instruments designed to provide financial and managerial coverage to financial liabilities arising from activities that impact the environment. The document analyses the theories that link the evolution of economic thought and environment, as a means of establish the necessary framework for the development of up-to-date environmental policy instruments. From these concepts and from the analysis of environmental liability system being implemented in several countries, the bases for environmental liability systems development are drawn. Finally, a study is carried out on the application of these bases for the development of an environmental liability management system for a radioactive waste repository. (author)

  3. Truck transportation of radioactive materials

    International Nuclear Information System (INIS)

    Analytical models in RADTRAN II are used to calculate risks to population subgroups such as people along transport routes, people at stops, and crewman. The stops model, which calculates the dose to persons adjacent to the transport vehicle while it is stopped, frequently provides the largest contribution to incident-free radiological impacts. Components such as distances from the vehicle containing radioactive material to nearby people at stops, stop duration, and number of crew members are required for the stops model as well as other incident-free models. To provide supporting data for RADTRAN II based on operational experience, selected truck shipments of radioactive material were observed from origin to destination. Other important aspects of this program were to correlate package size to effective shipment transport index (TI) using radiological surveys and to characterize population distributions and proximities of people to the shipment at a generic truck stop

  4. Weak Decay of Hypernuclei

    CERN Document Server

    Alberico, W M

    2004-01-01

    The focus of these Lectures is on the weak decay modes of hypernuclei, with special attention to Lambda-hypernuclei. The subject involves many fields of modern theoretical and experimental physics, from nuclear structure to the fundamental constituents of matter and their interactions. The various weak decay modes of Lambda-hypernuclei are described: the mesonic mode and the non-mesonic ones. The latter are the dominant decay channels of medium--heavy hypernuclei, where, on the contrary, the mesonic decay is disfavoured by Pauli blocking effect on the outgoing nucleon. In particular, one can distinguish between one-body and two-body induced decays. Theoretical models employed to evaluate the (partial and total) decay widths of hypernuclei are illustrated, and their results compared with existing experimental data. Open problems and recent achievements are extensively discussed, in particular the determination of the ratio Gamma_n/Gamma_p, possible tests of the Delta I=1/2 rule in non-mesonic decays and the pu...

  5. Geological predictions for the long-term isolation of radioactive waste based on extrapolating uniform mode and rate of crustal movements

    International Nuclear Information System (INIS)

    Long-term predictions of geological and tectonic disturbances are key issues for the safety assessment of radioactive waste disposal, especially on the Japanese Islands. Geological predictions of disturbances should be performed by extrapolating uniform mode and rate of crustal movements under the current framework. Multiple lines of geological evidence in Japan strongly suggest that the present mode of tectonics began during the late Pliocene to early Quaternary, and was fully developed by the middle Pleistocene. The uplift rates of mountains in Japan are determined to have been approximately constant until the middle Pleistocene based on simulations of temporal changes in mean altitude developed under concurrent tectonics and denudation processes. The onset of the neotectonic mode of deformation was probably triggered by the initiation of the eastward movement of the Amur Plate and the collision of the Izu block with central Honshu. The uncertainty of predictions beyond steady-state crustal deformation would, in general, increase for long-term predictions using the extrapolation procedure. Consequently, future geological and tectonic disturbances in Japan can be estimated with relatively high reliability for the next 100,000 years. (author)

  6. Liquid pathway generic study. Impacts of accidental radioactive releases to the hydrosphere from floating and land-based nuclear power plants

    International Nuclear Information System (INIS)

    The staff concludes that for representative sites, there are differences in the impacts of accidental radioactive releases to the hydrosphere between floating nuclear plants (FNPs) and land-based plants (LBPs) of the ice-condenser type. The consequences of releases from design basis accidents are found to be lower for an FNP than for an LBP. For core-melt events which we consider to be of very low probability, the staff results indicate that the expected liquid pathway consequences are higher at an FNP than at an LBP, and that interdiction at the site is not likely for an FNP. The staff considers this combination of differences in release magnitude and interdiction potential to be significant. An assessment of the overall significance of the total risk associated with potential releases to liquid and airborne pathways will be considered in a forthcoming environmental impact statement for the FNP. This environmental impact statement will include a consideration of the environmental, social, and economic impacts of the operation of the FNP, as well as a value-impact analysis of alternatives which may avoid or mitigate radiological impacts to the environment

  7. Tectonic and radioactivity impacts of 238U on groundwater-based drinking water at Gosa and Lugbe areas of Abuja, North Central Nigeria

    International Nuclear Information System (INIS)

    Tectonic contribution of activity level of 238U in groundwater-based drinking water in Gosa and Lugbe areas of Abuja was measured using inductively coupled plasma mass spectrometry (ICP-MS). The highest activity level of 2736 µBq L-1 reported in Lugbe borehole, whereas the lowest value of 443 µBq L-1 reported at Gosa borehole. The inhabitants permanently used water from the boreholes for daily consumption. The group receives 5.55 × 10-5 mSv of the annual collective effective dose due to 238U in drinking water. The radiological risks of 238U in the water samples were found to be low, typically in magnitude of 10-7 with cancer mortality value of 1.03 × 10-7 and morbidity value of 1.57 × 10-7. The chemical toxicity risk of 238U in drinking water over a lifetime consumption has a mean value of 4.0 × 10-3 μg kg-1 day-1. It could be that the human risk due to 238U content in groundwater supplies from ingestion may likely be the chemical toxicity of 238U as a heavy metal rather than radiological risk. Significantly, Lugbe subsurface may have developed some fractions of granitic strata that contributed to the distribution of radioactive of 238U in tectonically weak zones. (author)

  8. Radioactive wastes and discharges

    International Nuclear Information System (INIS)

    According to the Section 24 of the Finnish Radiation Decree (1512/91), the Finnish Centre for Radiation and Nuclear Safety shall specify the concentration and activity limits and principles for the determination whether a waste can be defined as a radioactive waste or not. The radiation safety requirements and limits for the disposal of radioactive waste are given in the guide. They must be observed when discharging radioactive waste into the atmosphere or sewer system, or when delivering solid low-activity waste to a landfill site without a separate waste disposal plan. The guide does not apply to the radioactive waste resulting from the utilization of nuclear energy of natural resources. (4 refs., 1 tab.)

  9. Understanding radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Murray, R.L.

    1981-12-01

    This document contains information on all aspects of radioactive wastes. Facts are presented about radioactive wastes simply, clearly and in an unbiased manner which makes the information readily accessible to the interested public. The contents are as follows: questions and concerns about wastes; atoms and chemistry; radioactivity; kinds of radiation; biological effects of radiation; radiation standards and protection; fission and fission products; the Manhattan Project; defense and development; uses of isotopes and radiation; classification of wastes; spent fuels from nuclear reactors; storage of spent fuel; reprocessing, recycling, and resources; uranium mill tailings; low-level wastes; transportation; methods of handling high-level nuclear wastes; project salt vault; multiple barrier approach; research on waste isolation; legal requiremnts; the national waste management program; societal aspects of radioactive wastes; perspectives; glossary; appendix A (scientific American articles); appendix B (reference material on wastes). (ATT)

  10. Understanding radioactive waste

    International Nuclear Information System (INIS)

    This document contains information on all aspects of radioactive wastes. Facts are presented about radioactive wastes simply, clearly and in an unbiased manner which makes the information readily accessible to the interested public. The contents are as follows: questions and concerns about wastes; atoms and chemistry; radioactivity; kinds of radiation; biological effects of radiation; radiation standards and protection; fission and fission products; the Manhattan Project; defense and development; uses of isotopes and radiation; classification of wastes; spent fuels from nuclear reactors; storage of spent fuel; reprocessing, recycling, and resources; uranium mill tailings; low-level wastes; transportation; methods of handling high-level nuclear wastes; project salt vault; multiple barrier approach; research on waste isolation; legal requiremnts; the national waste management program; societal aspects of radioactive wastes; perspectives; glossary; appendix A (scientific American articles); appendix B (reference material on wastes)

  11. Law of radioactive minerals

    International Nuclear Information System (INIS)

    Legal device done in order to standardize and promote the exploration and explotation of radioactive minerals by peruvian and foreign investors. This device include the whole process, since the prospection until the development, after previous auction given by IPEN

  12. Development of limiting decay heat values

    International Nuclear Information System (INIS)

    A number of tools are used in the assessment of decay heat during an outage of the CANDU-6. Currently, the technical basis for all of these tools is 'CANDU Channel Decay Power', Reference 1. The methods used in that document were limited to channel decay powers. However, for most outage support analysis, decay heat limits are based on bundle heats. Since the production of that document in 1977, new versions of codes, and updates of general-purpose and CANDU-specific libraries have become available. These tools and libraries have both a more formal technical basis than Reference 1, and also a more formal validation base. Using these tools it is now possible to derive decay heat with more specific input parameters, such as fuel composition, heat per unit of fuel, and irradiation history, and to assign systematically derived uncertainty allowances to such decay heat values. In particular, we sought to examine a broad range of likely bundle histories, and thus establish a set of limiting bundle decay beat values, that could serve as a bounding envelope for use in Nuclear Safety Analysis. (author)

  13. Weak radiative hyperon decays

    International Nuclear Information System (INIS)

    New measurements of the Σ+ and Λ weak radiative decays are discussed. The hyperons were produced at rest by the reaction K-p → Yπ where Y = Σ+ or Λ. The monoenergetic pion was used to tag the hyperon production, and the branching ratios were determined from the relative amplitudes of Σ+ → pγ to Σ+ → pπ0 and Λ → nγ to Λ → nπ0. The photons from weak radiative decays and from π0 decays were detected with modular NaI arrays. (orig.)

  14. Axions from wall decay

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S; Hagmann, C; Sikivie, P

    2001-01-08

    The authors discuss the decay of axion walls bounded by strings and present numerical simulations of the decay process. In these simulations, the decay happens immediately, in a time scale of order the light travel time, and the average energy of the radiated axions is {approx_equal} 7m{sub a} for v{sub a}/m{sub a} {approx_equal} 500. is found to increase approximately linearly with ln(v{sub a}/m{sub a}). Extrapolation of this behavior yields {approx_equal} 60 m{sub a} in axion models of interest.

  15. Rare decays at LHCb

    CERN Document Server

    Lafferty, George

    2015-01-01

    We review recent results from the LHCb experiment on studies of particle decays that are forbidden or rare in the Standard Model. The studies include searches for lepton flavour violating decays of the $\\tau$ lepton and the $B$ and $D$ mesons, and of $B$ and $D$ meson decays that would be mediated by Majorana neutrinos. Results are also presented for the rare processes $B_s \\to \\mu^+\\mu^-$ and $B^0 \\to \\mu^+\\mu^-$, $D^0 \\to \\pi^+\\pi^-\\mu^+\\mu^-$, $b \\to s\\gamma$ transitions, and $B \\to K^{(*)}\\mu^+\\mu^-$.

  16. Transport of radioactive materials

    International Nuclear Information System (INIS)

    The purpose of this Norm is to establish, relating to the TRANSPORT OF RADIOACTIVE MATERIALS, safety and radiological protection requirements to ensure an adequate control level of the eventual exposure of persons, properties and environment to the ionizing radiation comprising: specifications on radioactive materials for transport; package type selection; specification of the package design and acceptance test requirements; arrangements relating to the transport itself; administrative requirements and responsibilities. (author)

  17. Temporary Personal Radioactivity

    Science.gov (United States)

    Myers, Fred

    2012-01-01

    As part of a bone scan procedure to look for the spread of prostate cancer, I was injected with radioactive technetium. In an effort to occupy/distract my mind, I used a Geiger counter to determine if the radioactive count obeyed the inverse-square law as a sensor was moved away from my bladder by incremental distances. (Contains 1 table and 2…

  18. Dynamic radioactive particle source

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Murray E.; Gauss, Adam Benjamin; Justus, Alan Lawrence

    2012-06-26

    A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.

  19. Radioactive waste disposal policy

    International Nuclear Information System (INIS)

    The responsibilities of the Minister of Agriculture, Fisheries and Food and Ministry policy on radioactive waste disposal are described. The disposal of solid radioactive waste at sea is subject to detailed safeguards developed within two international agreements to which the United Kingdom is a contracting party. The agreements are discussed together with a research and monitoring programme to provide scientific data for informed decisions on waste disposal authorisations and dumping licences. (U.K.)

  20. Radioactive sources service

    CERN Multimedia

    2006-01-01

    Dear Users, A new web interface is now available for requesting radioactive sources: http://cern.ch/rp-sources/request This link is also available from the radioactive sources service main page: http://cern.ch/rp-sources From now on, please submit your request via the above interface, which has been developed in order to improve the service. Thank you in advance for your collaboration!

  1. Non-leptonic decays of beauty decays

    CERN Document Server

    Bigi, Ikaros I; Shifman, M; Uraltsev, N; Vainshtein, A I

    1994-01-01

    "Anyone who keeps the ability to see beauty never grows old" (Franz Kafka). In the last few years considerable progress has been achieved in our understanding of the decays of heavy flavour hadrons. One can now calculate inclusive transition rates in QCD proper through an expansion in inverse powers of the heavy flavour quark mass without recourse to phenomenological assumptions. The non-perturbative contributions are treated systematically in this way; they are found to produce corrections of order a few percent in beauty decays, i.e. typically somewhat smaller than the perturbative corrections. One finds, among other things: (a) The lifetime of $B^-$ mesons is predicted to be longer than that of $B^0$ mesons by several percent. (b) The QCD prediction for the semileptonic branching ratio of $B$ mesons appears to exceed present experimental values.

  2. Radioactive dust sampling

    International Nuclear Information System (INIS)

    This technical report is the second of a five part series on the technical evaluation of a number of dust monitoring instruments and the characterization of Long-Lived Radioactive Dust (LLRD). The data reported here pertain to an experimental study conducted under laboratory controlled conditions in a Long-Lived Radioactive Dust Test Facility (LLRDTF) designed for this purpose. This study was carried out with a twofold purpose in mind, namely, for the characterization of dust and LLRD, and for the evaluation of a variety of monitoring instruments, including cascade impactors, optical particle counters, nylon cyclones, open face filter samplers, and α-particle personal dosimeters, the latter normally used for α-particle radiation exposure purposes. Several non-radioactive and radioactive dusts were characterized. The non-radioactive dusts were SiC, Al2O3, talcum powder, corn starch and flour, while uranium tailings were used as a radioactive dust. Clear differences in instrument performance were observed for the various measurements made

  3. An investigation into what students think and how they learn about ionizing radiation and radioactivity

    Science.gov (United States)

    Prather, Edward E.

    2000-11-01

    Recent curriculum reform projects, national science standards and state curriculum frameworks have called for a greater emphasis on teaching topics related to modern physics, even though little is known about student beliefs and difficulties with these topics. In this dissertation, we describe a research project conducted at The University of Maine by members of the Laboratory of Research in Physics Education (LRPE) on what students think and how they learn about radiation and radioactivity. The research focused on: (1)the identification of common conceptual and reasoning difficulties that college students have prior to instruction, (2)the development of a framework for understanding the source of these difficulties, and (3)the development of specific instructional strategies and materials to target these difficulties. We investigated student understanding of radiation sources, the processes of irradiation and contamination, the nature of atoms in the radioactive decay processes, and radioactive half-life. Results from this research were used to guide the development of instructional strategies including interactive lectures, hands-on laboratory based activities, and tutorial worksheets structured around directed inquiry. Our primary instructional goal was to actively engage students and promote conceptual change. Assessment of these instructional strategies and materials consisted of classroom observations, individual interviews and the analysis of written questions given before and after instruction.

  4. Heavy flavour decay properties with ATLAS

    CERN Document Server

    Carli, Ina; The ATLAS collaboration

    2016-01-01

    We present the results on CP-violation searches in the Bs system, studied in the decay into J/psi phi, and the Bd system through the comparison of the decay time distributions in the flavour specific state J/psi K* and in the CP eigenstate J/psi KS. We additionally present new results in the search for the rare decays of Bs and Bd into mu+mu-. These searches are based on the full sample of data collected by ATLAS at 7 and 8 TeV collision energy. The consistency with the SM and with other available measurements is discussed.

  5. Transport security of radioactive material in Paraguay

    International Nuclear Information System (INIS)

    Paraguay has implemented diverse mechanisms for the safe transport of radioactive material. Among the first of these was the adoption and implementation of national regulations based on the latest edition of the IAEA's Regulations for the Safe Transport of Radioactive Material (IAEA Safety Standards Series No. TS-R-1). The National Regulation for Protection against Ionizing Radiation and for the Safety of Radiation Sources, in Article 34, states that any transport of radioactive materials must fulfil the IAEA's Transport Regulations. In addition, Resolution No. 4097/00 of the Rector of the National University of Asuncion approved the latest edition of the IAEA's Transport Regulations, as the only instrument to be used by the National Commission of Atomic Energy - the competent authority - in authorizing the safe transport of radioactive material, for exports and especially within MERCOSUR, the Common Market of the South. (author)

  6. Inorganic ion exchanger based on tin/titanium mixed oxide doped with europium to be used in radioactive waste

    International Nuclear Information System (INIS)

    This work presents the results of synthesis and characterization of an inorganic ion exchanger based on tin/titanium mixed oxides doped with europium (SnO2/TiO2:Eu3+) to be used in environmental field. The adsorption study of nickel was realized in this exchanger to recover the nickel metal which is in thorium-nickel alloys used as electrode of discharge lamps. The studied exchanger was synthesized by neutralization of tin chloride (IV) and titanium chloride (III) mixed solution and characterized by thermogravimetric measurement (TG), Differential Scanning Calorimetry (DSC), X-Ray Powder Diffraction (XRD), Infrared Spectroscopy (IR) and Scanning Electron Microscopy (SEM). The adsorption study showed that these inorganic ion exchangers are good materials to recovery nickel with high weight distribution ratios (DwNi2+) and percent adsorption. (author)

  7. Preparation and leaching of radioactive INEL waste forms

    International Nuclear Information System (INIS)

    Appreciable quantities of radioactive waste are in storage at the Idaho National Engineering Laboratory (INEL). Plans are being made to convert this waste into durable solid forms for final disposal in a geological repository. Part of the inventory consists of low- and intermediate-level fission, activation, and decay products and transuranic (TRU) wastes, either stored retrievably or buried at the INEL Radioactive Waste Management area. One of the TRU wastes is a sludge from the Department of Energy Rocky Flats Plant, currently stored retrievably in 55-gallon drums. Immobilizing the TRU sludge is the primary concern of the work reported here

  8. TIBSO, Nuclear Transitions and Radioactivity Migration in Technological System

    International Nuclear Information System (INIS)

    1 - Description of program or function: TIBSO follows the nuclear transition and the spatial migration of radioactive materials in an arbitrary technological system. By coupling with the codes RELAP and CONTAIN radioactive release in case of nuclear accidents can be calculated. The output can be used in environmental codes such as CRAC2. 2 - Methods: The spatial migration is modeled by transitions between nodes. The system of first-order differential equations describing the nuclear decay and activation process and the nodal transitions is solved by numerical integration. 3 - Restrictions on the complexity of the problem: Due to dynamic programming techniques, only available memory can restrict the number of isotopes and nodes

  9. CLEO Results B Decays

    CERN Document Server

    Cassel, David G

    2001-01-01

    Measurements of many Standard Model constants are clouded by uncertainties in nonperturbative QCD parameters that relate measurable quantities to the underlying parton-level processes. Generally these QCD parameters have been obtained from model calculations with large uncertainties that are difficult to quantify. The CLEO Collaboration has taken a major step towards reducing these uncertainties in determining the CKM matrix elements Vcb and Vub using new measurements of the branching fraction and photon energy spectrum of B -> s gamma decays. This report includes: the new CLEO measurements of B -> s gamma decays, Vcb, and Vub; the first results from CLEO III data -- studies of B -> K pi, pi pi, and K Kbar decays; mention of some other recent CLEO B decay results; and plans for operating CESR and CLEO in the charm threshold region.

  10. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Kai Zuber

    2012-10-01

    The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  11. Inflaton decay in supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Endo, M.; Takahashi, F. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yanagida, T.T. [Tokyo Univ. (Japan). Dept. of Physics]|[Tokyo Univ. (Japan). Research Center for the Early Universe

    2007-06-15

    We discuss inflaton decay in supergravity, taking account of the gravitational effects. It is shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential at the tree level, and to any gauge sectors through anomalies in the supergravity. Through these processes, the inflaton generically decays into the supersymmetry breaking sector, producing many gravitinos. The inflaton also directly decays into a pair of the gravitinos. We derive constraints on both inflation models and supersymmetry breaking scenarios for avoiding overproduction of the gravitinos. Furthermore, the inflaton naturally decays into the visible sector via the top Yukawa coupling and SU(3){sub C} gauge interactions. (orig.)

  12. Detection and assessment of wood decay in glulam beams using a decay rate approach

    Science.gov (United States)

    Senalik, Adam; Beall, Frank C.; Reis, Henrique

    2010-04-01

    A glulam beam retired from the field and without visible indications of wood decay was used. Towards detection and assessing wood decay, X-ray computer tomography and ultrasonic measurements were carried out. It was observed that decrease in mass density with increasing levels of wood decay affects x-rays attenuation and allows radioscopy to detect and assess wood decay. To detect and assess decay when only one lateral side of the beam is available, a modified impulse-echo is presented. The modified impulse-echo approach is based on observing the dynamic response of each lamina in the glulam beam to the drop of a steel sphere onto a steel plate coupled to the glulam beam lamina and upon a decay rate analysis of the corresponding time domain signal in a frequency band of interest. The selection of the frequency band of interest only requires knowledge of the nominal transverse dimensions of each lamina in the beam and of the corresponding wood species. It was observed that decay rate analysis allows detection and assessment of wood decay. The decay rate approach leads to an overall rate of false calls of 7.2%. Considering the variability that exists in wood including the presence of splits, orientation and thickness of growth rings, etc., this relative low rate of false calls makes this approach very attractive. Results show that results from both X-ray computer tomography and impulse-echo decay-rated based measurements are consistent with each other and can be used to detect and assess wood decay in structural lumber.

  13. Open Flavor Strong Decays

    Science.gov (United States)

    García-Tecocoatzi, H.; Bijker, R.; Ferretti, J.; Galatà, G.; Santopinto, E.

    2016-10-01

    In this contribution, we discuss the results of a QM calculation of the open-flavor strong decays of **** light nucleon resonances. These are the results of a recent calculation, where we used a modified ^3P_0 model for the amplitudes and the U(7) algebraic model and the hypercentral quark model to predict the baryon spectrum. The decay amplitudes are compared with the existing experimental data.

  14. Aspects of B decays

    Energy Technology Data Exchange (ETDEWEB)

    Faller, Sven

    2011-03-04

    B-meson decays are a good probe for testing the flavour sector of the standard model of particle physics. The standard model describes at present all experimental data satisfactorily, although some ''tensions'' exist, i.e. two to three sigma deviations from the predictions, in particular in B decays. The arguments against the standard model are thus purely theoretical. These tensions between experimental data and theoretical predictions provide an extension of the standard model by new physics contributions. Within the flavour sector main theoretical uncertainties are related to the hadronic matrix elements. For exclusive semileptonic anti B {yields} D{sup (*)}l anti {nu} decays QCD sum rule techniques, which are suitable for studying hadronic matrix elements, however, with substantial, but estimable hadronic uncertainties, are used. The exploration of new physics effects in B-meson decays is done in an twofold way. In exclusive semileptonic anti B {yields} D{sup (*)}l anti {nu} decays the effect of additional right-handed vector as well as left- and right-handed scalar and tensor hadronic current structures in the decay rates and the form factors are studied at the non-recoil point. As a second approach one studied the non-leptonic B{sup 0}{sub s}{yields}J/{psi}{phi} and B{sup 0}{yields}J/{psi}K{sub S,L} decays discussing CP violating effects in the time-dependent decay amplitudes by considering new physics phase in the B{sup 0}- anti B{sup 0} mixing phase. (orig.)

  15. Open flavor strong decays

    CERN Document Server

    García-Tecocoatzi, H; Ferretti, J; Galatà, G; Santopinto, E

    2016-01-01

    In this contribution, we discuss the results of a QM calculation of the open-flavor strong decays of **** light nucleon resonances. These are the results of a recent calculation, where we used a modified $^3P_0$ model for the amplitudes and the U(7) algebraic model and the Hypercentral Quark Model to predict the baryon spectrum. The decay amplitudes are compared with the existing experimental data.

  16. Radioactivity of spent TRIGA fuel

    International Nuclear Information System (INIS)

    Some of the oldest TRIGA fuel in the Malaysian Reaktor TRIGA PUSPATI (RTP) is approaching the limit of its end of life with burn-up of around 20%. Hence it is prudent for us to start planning on the replacement of the fuel in the reactor and other derivative activities associated with it. In this regard, we need to understand all of the risk associated with such operation and one of them is to predict the radioactivity of the fuel, so as to estimate the safety of our working conditions. The radioactivity of several fuels are measured and compared with simulation results to confirm the burnup levels of the selected fuels. The radioactivity measurement are conducted inside the water tank to reduce the risk of exposure and in this case the detector wrapped in plastics are lowered under water. In nuclear power plant, the general practice was to continuously burn the fuel. In research reactor, most operations are based on the immediate needs of the reactor and our RTP for example operate periodically. By integrating the burnup contribution for each core configuration, we simplify the simulation of burn up for each core configuration. Our results for two (2) fuel however indicates that the dose from simulation underestimate the actual dose from our measurements. Several postulates are investigated but the underlying reason remain inconclusive

  17. Radioactivity of spent TRIGA fuel

    Energy Technology Data Exchange (ETDEWEB)

    Usang, M. D., E-mail: mark-dennis@nuclearmalaysia.gov.my; Nabil, A. R. A.; Alfred, S. L.; Hamzah, N. S.; Abi, M. J. B.; Rawi, M. Z. M.; Abu, M. P. [Reactor Department, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia)

    2015-04-29

    Some of the oldest TRIGA fuel in the Malaysian Reaktor TRIGA PUSPATI (RTP) is approaching the limit of its end of life with burn-up of around 20%. Hence it is prudent for us to start planning on the replacement of the fuel in the reactor and other derivative activities associated with it. In this regard, we need to understand all of the risk associated with such operation and one of them is to predict the radioactivity of the fuel, so as to estimate the safety of our working conditions. The radioactivity of several fuels are measured and compared with simulation results to confirm the burnup levels of the selected fuels. The radioactivity measurement are conducted inside the water tank to reduce the risk of exposure and in this case the detector wrapped in plastics are lowered under water. In nuclear power plant, the general practice was to continuously burn the fuel. In research reactor, most operations are based on the immediate needs of the reactor and our RTP for example operate periodically. By integrating the burnup contribution for each core configuration, we simplify the simulation of burn up for each core configuration. Our results for two (2) fuel however indicates that the dose from simulation underestimate the actual dose from our measurements. Several postulates are investigated but the underlying reason remain inconclusive.

  18. Radioactivity of spent TRIGA fuel

    Science.gov (United States)

    Usang, M. D.; Nabil, A. R. A.; Alfred, S. L.; Hamzah, N. S.; Abi, M. J. B.; Rawi, M. Z. M.; Abu, M. P.

    2015-04-01

    Some of the oldest TRIGA fuel in the Malaysian Reaktor TRIGA PUSPATI (RTP) is approaching the limit of its end of life with burn-up of around 20%. Hence it is prudent for us to start planning on the replacement of the fuel in the reactor and other derivative activities associated with it. In this regard, we need to understand all of the risk associated with such operation and one of them is to predict the radioactivity of the fuel, so as to estimate the safety of our working conditions. The radioactivity of several fuels are measured and compared with simulation results to confirm the burnup levels of the selected fuels. The radioactivity measurement are conducted inside the water tank to reduce the risk of exposure and in this case the detector wrapped in plastics are lowered under water. In nuclear power plant, the general practice was to continuously burn the fuel. In research reactor, most operations are based on the immediate needs of the reactor and our RTP for example operate periodically. By integrating the burnup contribution for each core configuration, we simplify the simulation of burn up for each core configuration. Our results for two (2) fuel however indicates that the dose from simulation underestimate the actual dose from our measurements. Several postulates are investigated but the underlying reason remain inconclusive.

  19. Radiotoxicity and decay heat power of spent nuclear fuel of VVER type reactors at long-term storage.

    Science.gov (United States)

    Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

    2005-01-01

    Radiotoxicity and decay heat power of the spent nuclear fuel of VVER-1000 type reactors are calculated during storage time up to 300,000 y. Decay heat power of radioactive waste (radwaste) determines parameters of the heat removal system for the safe storage of spent nuclear fuel. Radiotoxicity determines the radiological hazard of radwaste after its leakage and penetration into the environment.

  20. The formation and decay of superheavy nuclei produced in $^{48}Ca$-induced reactions

    CERN Document Server

    Kumar, Sushil; Gupta, Raj K; Munzenberg, G; Scheid, W; 10.1088/0954-3899/29/4/303

    2011-01-01

    The formation of superheavy nuclei in $^{48}Ca+^{232}Th$, $^{238}U$, $^{242,244}Pu$ and $^{248}Cm$ reactions and their subsequent decay are studied within the quantum mechanical fragmentation theory (QMFT) and the QMFT based preformed cluster-decay model (PCM) of Gupta and collaborators. According to QMFT, all these $^{48}Ca$-induced reactions are cold fusion reactions with relative excitation energies larger than for the $Pb$-induced cold fusion reactions and smaller than for the lighter beam i.e. $Mg$, $Si$ or $S$-induced hot fusion reactions. The same reactions were first suggested by Gupta et al. in 1977 on the basis of QMFT, and this study re-establishes the same result. In fact, for such heavy isotopes of Z=110 to 116, $^{50}Ca$ is shown to be a better beam for cold fusion, but $^{50}Ca$ is a radioactive nucleus. The $\\alpha$-decay half-lives of these nuclei after 3n and/ or 4n evaporations, i.e. of the evaporation residues of these compound systems, calculated on PCM compare reasonably well with experi...

  1. Leptonic Decays of Charged Pseudoscalar Mesons - 2015

    CERN Document Server

    Rosner, Jonathan L; Van de Water, Ruth S

    2015-01-01

    We review the physics of purely leptonic decays of $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak-interaction-based CKM matrix element of the constituent quarks and a strong interaction parameter related to the overlap of the quark and antiquark wave-functions in the meson, called the decay constant $f_P$. The leptonic decay constants for $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ mesons can be obtained with controlled theoretical uncertainties and high precision from {\\it ab initio} lattice-QCD simulations. The combination of experimental leptonic decay-rate measurements and theoretical decay-constant calculations enables the determination of several elements of the CKM matrix within the standard model. These determinations are competitive with those obtained from semileptonic decays, and also complementary because they are sensitive to different quark flavor-changing currents. They can also be use...

  2. Far Field Sorption Data Bases for Performance Assessment of a High-Level Radioactive Waste Repository in an Undisturbed Opalinus Clay Host Rock

    International Nuclear Information System (INIS)

    An Opalinus Clay formation in the Zuercher Weinland is under consideration by Nagra as a potential location for a high-level and long-Iived intermediate-level radioactive waste repository. Performance assessment studies will be performed for this site and the purpose of this report is to describe the procedures used to develop sorption data bases appropriate for an undisturbed Opalinus Clay host rock which are required for such safety analysis calculations. In tight, low water content argillaceous rock formations such as Opalinus Clay, there is uncertainty concerning the in situ pH/PCO2. In order to take this intrinsic uncertainty into account porewater chemistries were calculated for a reference case, pH = 7.24, and for two other pH values, 6.3 and 7.8. Sorption data bases are given for the three cases. The basis for the sorption data bases is 'in-house' sorption measurements for Cs(I), Sr(II), Ni(II), Eu(III), Sn(IV), Se(IV), Th(IV) and I(-I) carried out on Opalinus Clay samples from Mont Terri (Canton Jura) since at the time the experiments were performed no core samples from the Benken borehole (Zuercher Weinland) were available. The Opalinus Clay at Mont Terri and Benken are part of the same geological formation . Despite having directly measured data for the above key radionuclides, some of the required distribution ratios (Rd) used to generate the sorption data bases still came from the open literature. An important part of this report is concerned with describing the procedures whereby these selected literature Rd values were modified so as to apply to the Benken Opalinus Clay mineralogy and groundwater chemistries calculated at the three pH values given above. The resulting Rd values were then further modified using so-called Lab→Field transfer factors to produce sorption values which were appropriate to the in situ bulk rock for the selected range of water chemistry conditions. Finally, it is important to have some appreciation of the uncertainties

  3. Far Field Sorption Data Bases for Performance Assessment of a High-Level Radioactive Waste Repository in an Undisturbed Opalinus Clay Host Rock

    Energy Technology Data Exchange (ETDEWEB)

    Bradburry, M.; Baeyens, B

    2003-08-01

    An Opalinus Clay formation in the Zuercher Weinland is under consideration by Nagra as a potential location for a high-level and long-Iived intermediate-level radioactive waste repository. Performance assessment studies will be performed for this site and the purpose of this report is to describe the procedures used to develop sorption data bases appropriate for an undisturbed Opalinus Clay host rock which are required for such safety analysis calculations. In tight, low water content argillaceous rock formations such as Opalinus Clay, there is uncertainty concerning the in situ pH/P{sub CO{sub 2}}. In order to take this intrinsic uncertainty into account porewater chemistries were calculated for a reference case, pH = 7.24, and for two other pH values, 6.3 and 7.8. Sorption data bases are given for the three cases. The basis for the sorption data bases is 'in-house' sorption measurements for Cs(I), Sr(II), Ni(II), Eu(III), Sn(IV), Se(IV), Th(IV) and I(-I) carried out on Opalinus Clay samples from Mont Terri (Canton Jura) since at the time the experiments were performed no core samples from the Benken borehole (Zuercher Weinland) were available. The Opalinus Clay at Mont Terri and Benken are part of the same geological formation . Despite having directly measured data for the above key radionuclides, some of the required distribution ratios (Rd) used to generate the sorption data bases still came from the open literature. An important part of this report is concerned with describing the procedures whereby these selected literature Rd values were modified so as to apply to the Benken Opalinus Clay mineralogy and groundwater chemistries calculated at the three pH values given above. The resulting Rd values were then further modified using so-called Lab{yields}Field transfer factors to produce sorption values which were appropriate to the in situ bulk rock for the selected range of water chemistry conditions. Finally, it is important to have some

  4. Evil radioactivity. Subjective perception of radioactivity in patients with thyroid disease prior to treatment with radioiodine

    Energy Technology Data Exchange (ETDEWEB)

    Freudenberg, L.S. [Universitaetsklinikum Essen (Germany). Klinik fuer Nuklearmedizin; Radiologisch-Nuklearmedizinische Gemeinschaftspraxis, Grevenbroich (Germany); Beyer, T.; Mueller, S.P.; Goerges, R.; Bockisch, A. [Universitaetsklinikum Essen (Germany). Klinik fuer Nuklearmedizin; Hopfenbach, A. [Radiologisch-Nuklearmedizinische Gemeinschaftspraxis, Grevenbroich (Germany)

    2006-07-01

    Aim: We assess the perspective of patients with thyroid disease towards radiation and radioactivity by means of a cultural-anthropological approach based on qualitative measures and quantitative scores. From the interviews with the patients we evaluate as to how much radioactivity is accepted as an abstract term or as a benefit within the medical context. Patients, methods: 68 patients with autonomously functioning thyroid lesions (35 women, 33 men, 32-81 years) were included in this study. All patients were interviewed in an open dialogue with the principal investigator. Patients were asked to describe their attitude towards radioactivity in general and towards radioiodine therapy in particular. Patients were asked to use a scoring system (1=positive, 5=negative) to quantify their attitudes. Results: The responses of all patients towards radioactivity in general were heterogeneous with most responses reflecting a negative perception. Many patients expressed their associated fears about atomic energy, malignant diseases and radioactive contamination. The scoring system reflected a mostly negative opinion base. However, patients became more positive once they assumed an immediate benefit of radioactivity for the treatment of their own disease (p=0.01). Conclusions: Knowing about significant differences in patient's perception about radioactivity in general or in the clinical context may help to optimise and tailor the initial, pre-therapeutical interview towards the patient. (orig.)

  5. Towards new proton radioactivities with radioactive beams and digital signal processing

    CERN Document Server

    Rykaczewski, K; Bingham, C R; Grzywacz, R; Karny, M; Batchelder, J C; Gross, C J; Janas, Z; Momayezi, M; Wahl, J; Piechaczek, A; Zganjar, E F; Ginter, T N; Hamilton, J H; Walters, W B; Kulp, W D; Winger, J A

    2002-01-01

    Particle radioactivity studies using the XIA DGF-4C digital signal processing units at the Recoil Mass Separator of Oak Ridge National Laboratory are presented. Proton emission signals were observed starting from 500 ns after recoil implantation. An energy threshold below 100 keV for particle detection was achieved. For the sup 1 sup 4 sup 5 Tm and sup 1 sup 4 sup 6 Tm decay, evidence for the fine structure in proton emission was obtained. An experiment to search for a new proton emitter sup 1 sup 4 sup 9 Lu is described as an example where the combination of a sup 5 sup 6 Ni radioactive beam and digital signal processing is a major advantage.

  6. Radioactive waste disposal in the United Kingdom

    International Nuclear Information System (INIS)

    Currently the policy of the United Kingdom Government is that HLW should be stored in a suitable facility for at least fifty years before considering further storage or final disposal. This period allows many short-lived radionuclides, but more importantly, the associated radioactive decay heat, to diminish ahead of disposal. For intermediate-level solid wastes current policy is to develop, as soon as possible, a suitable deep geological facility for its permanent disposal. LLW constitutes the majority by volume of all radioactive waste. The waste arises not only from the nuclear industry, but also from all users of radioactive substances, such as hospitals, research establishments and industry. At present, it is mainly disposed of at a 300-acre site at Drigg in Cumbria, operated by British Nuclear Fuels plc (BNEL). It is packed into containers and placed in concrete-lined trenches which are subsequently sealed. Drigg is expected to continue to take solid low-level wastes for many years. Original plans-term disposal route for LLW involved disposal in a new near-surface repository. However, in 1987, this proposal was abandoned, on cost-benefit arguments, and the Government agreed that a yet to be developed national deep repository should also be used for some LLW. Drigg is expected to continue to take solid low-level wastes for many years.

  7. Processing system for low level radioactive waste

    International Nuclear Information System (INIS)

    Low level radioactive wastes are successively charged into a container while sliding a partition plate such that the wastes are kept substantially in a fully charged state in the direction of the height. Radiation rays from the low level radioactive wastes contained in the container are measured by a radiation dose measuring means constituted so as to be slidable together with the partition plate. Further, the weight of the low level radioactive wastes in the container is measured by the weight measuring means, and the radioactivity concentration per unit container is calculated by a calculation means based on the result of the measurement. Accordingly, the optimum storage period and the radioactivity level can be estimated on every containers. Further, since the measuring vessel is used also as a storage vessel, long time measurement can be conducted by measuring the radioactivity for the wastes successively to enable exact evaluation. Accordingly, it is possible to save the labors for processing operation and save the storage facility. (T.M.)

  8. Transport regulations for radioactive material in Germany

    International Nuclear Information System (INIS)

    The transport of radioactive material in Germany is regulated by the dangerous goods transport regulations and the regulations of the Atomic Energy Act and the Radiation Protection Ordinance. For radioactive material shipments by road, rail, sea and air the modal regulations on the transport of dangerous goods for class 7 of the ADR, RID, ADNR, IMO and ICAO are implemented in Germany and have to be complied with. In parallel with this the Atomic Energy Act requirements and the provisions of the Radiation Protection Ordinance concerning the transport of radioactive material have to be met. They contain provisions regarding the reliability of transport organisations and persons, training of persons involved in transport nuclear liability insurance, physical protection and public interest in addition to the need to fulfil the dangerous goods transport regulations. According to these requirements shipment approvals which are presented in the paper, are necessary for nuclear material, large sources and other radioactive materials. Based on this some practical implications for radioactive material shipments will be discussed as well as some aspects of the future developments. The paper also gives an overview of the responsibilities for approval and inspection of radioactive material shipments in Germany. (author)

  9. Spot evolution on the red giant star XX Triangulum. A starspot-decay analysis based on time-series Doppler imaging

    CERN Document Server

    Künstler, A; Strassmeier, K G

    2015-01-01

    Solar spots appear to decay linearly proportional to their size. The decay rate of solar spots is directly related to magnetic diffusivity, which itself is a key quantity for the length of a magnetic-activity cycle. Is a linear spot decay also seen on other stars, and is this in agreement with the large range of solar and stellar activity cycle lengths? We investigate the evolution of starspots on the rapidly-rotating ($P_{\\rm rot}$ $\\approx$ 24 d) K0 giant XX Tri, using consecutive time-series Doppler images. Our aim is to obtain a well-sampled movie of the stellar surface over many years, and thereby detect and quantify a starspot decay law for further comparison with the Sun. We obtained continuous high-resolution and phase-resolved spectroscopy with the 1.2-m robotic STELLA telescope on Tenerife over six years. For each observing season, we obtained between 5 to 7 independent Doppler images, one per stellar rotation, making up a total of 36 maps. To quantify starspot area decay and growth, we match the ob...

  10. Benchmark calculation for radioactivity inventory using MAXS library based on JENDL-4.0 and JEFF-3.0/A for decommissioning BWR plants

    Science.gov (United States)

    Tanaka, Ken-ichi

    2016-06-01

    We performed benchmark calculation for radioactivity activated in a Primary Containment Vessel (PCV) of a Boiling Water Reactor (BWR) by using MAXS library, which was developed by collapsing with neutron energy spectra in the PCV of the BWR. Radioactivities due to neutron irradiation were measured by using activation foil detector of Gold (Au) and Nickel (Ni) at thirty locations in the PCV. We performed activation calculations of the foils with SCALE5.1/ORIGEN-S code with irradiation conditions of each foil location as the benchmark calculation. We compared calculations and measurements to estimate an effectiveness of MAXS library.

  11. Benchmark calculation for radioactivity inventory using MAXS library based on JENDL-4.0 and JEFF-3.0/A for decommissioning BWR plants

    Directory of Open Access Journals (Sweden)

    Tanaka Ken-ichi

    2016-01-01

    Full Text Available We performed benchmark calculation for radioactivity activated in a Primary Containment Vessel (PCV of a Boiling Water Reactor (BWR by using MAXS library, which was developed by collapsing with neutron energy spectra in the PCV of the BWR. Radioactivities due to neutron irradiation were measured by using activation foil detector of Gold (Au and Nickel (Ni at thirty locations in the PCV. We performed activation calculations of the foils with SCALE5.1/ORIGEN-S code with irradiation conditions of each foil location as the benchmark calculation. We compared calculations and measurements to estimate an effectiveness of MAXS library.

  12. Natural and induced radioactivity in food

    International Nuclear Information System (INIS)

    One of the first questions often asked about irradiated food is whether it is radioactive. Not many people understand that food and any natural substance contains natural radioactivity which can be measurable. It is therefore important to put the issue on natural radioactivity and possible induced radioactivity in food in perspective. While there is a clear consensus among the scientific community that no radioactivity is induced when food is irradiated by gamma rays from cobalt-60 or cesium-137, electron generated by a machine with energy less than 10 million electron volt (MeV) or X rays produced generated by a machine with energy less than 5 MeV. However, data to this effect were published many years ago and are not easy to find. As food irradiation is gaining wide acceptance in many countries, it was considered timely to compile data on natural and induced radioactivity in food into one document. We are grateful to A. Brynjolfsson, one of the few experts who have the knowledge on this subject as well as wide experience on food irradiation, who collected, compiled and evaluated all data on this subject into one report. This publication provides clear explanations not only why radioactivity cannot be induced in food irradiated by radiation sources mentioned above but to what extent the increase in dose or energy level of radiation sources would induce significantly radioactivity in food. The compilation of such data was prompted by a desire to increase the energy limit and the absorbed dose based on the need to irradiate thicker samples of food and to use sterilizing dose up to 60 kGy. This publication concluded that the increase in radiation background dose from consumption of food irradiated to an average dose up to 60 kGy with gamma rays from cobalt- 60 or cesium-137, with 10 MeV electrons or with 5 MeV X rays is insignificant. In addition, food irradiated with X ray with energy up to 7.5 MeV to a dose of 30 kGy has radioactivity well below natural

  13. RETADD-II: a long-range atmospheric trajectory model with consistent treatment of deposition loss and species growth and decay

    International Nuclear Information System (INIS)

    A versatile model is described which estimates long-range atmospheric dispersion based on plume trajectories. This model allows the treatment of the dispersal from a source at an arbitrary height while taking account of plume depletion by dry and wet deposition together with the decay of material to successor species. The plume depletion, decay and growth equations are solved in an efficient manner which can accommodate up to eight pollutants (i.e., a parent and seven serial decay products). The code is particularly suitable for applications involving radioactive chain decay or for cases involving chemical species with successor decay products. Arbitrary emission rates can be specified for the members of the chain or, as is commonly the case, a sole emission rate can be specified for the first member. The code uses readily available upper-air wind data for the North American continent and it is therefore intended for the estimation of regional or continental scale dispersion patterns. This code is one of a group of codes, the Computerized Radiological Risk Investigation System (Baes and Miller, 1981), designed to simulate the transport of radionuclides through environmental pathways. 24 references, 5 figures

  14. Radioactivity - superstition and science

    International Nuclear Information System (INIS)

    Fairy-tales, myths, superstition - how was it fair, when we could still be afraid for witches and goblins. Where demons floated and nicks danced, the dry science has spreaded and disenchanted the life. If there would not be things like radioactivity, against which can be struggled in the collective well being. Then it is bad, clear, or good, it heals sicks, also clear. But what is now correct? In his usual humorous way the author, Dr. Hermann Hinsch, explains by means of numerous examples the phenomenon ''radioactivity'' and its effects on life. Provocantly but illustratively he illuminates, which position radioactive radiation has in our life and how and where we have already met it wantedly or unwantedly. Perhaps we must then something less shudder, but something more realism at such theme is surely not harmful.

  15. Theoretical study of cluster radioactivity in Re isotopes

    International Nuclear Information System (INIS)

    Cluster radioactivity or exotic decay is the emission of an entity as a cluster of nucleons with mass number heavier than that of an alpha particle and lighter than that of the lightest fission fragment, without being accompanied by neutron emission. The purpose of the present work is to investigate the probable cluster decays of different proton-rich and neutron-rich isotopes of Re (Z=75) using a fission model approach. Phenomenological fission model is used for the study. The half lives for various types of decay of different Re isotopes are calculated considering the interacting potential as the effective liquid drop one, which is the sum of Coulomb and surface potentials. All possible combinations of parent and cluster for which the Q-value is positive have been considered and found that the probable decay modes in proton-rich isotopes are proton, alpha, 8Be, 12C, and 16O emissions since the half lives for these decays are found to be well within the measurable range (T1/2 30s). The paper shows the plots of calculated half lives and Q values for alpha and probable cluster emissions from neutron-deficient Re isotopes against neutron number of daughter nuclei. It is found that plots for alpha, 8Be, 12C, and 16O decays are similar and appear as mirror reflections. The plots for 8Be, 12C and 16O decays indicate the shell closure at or near N= 82, which is a magic number. This confirms the role of neutron magicity in cluster radioactivity. It is also evident that cluster emissions slow down with increasing neutron number

  16. Co-Decaying Dark Matter

    OpenAIRE

    Dror, Jeff Asaf; Kuflik, Eric; Ng, Wee Hao

    2016-01-01

    We propose a new mechanism for thermal dark matter freezeout, termed Co-Decaying Dark Matter. Multi-component dark sectors with degenerate particles and out-of-equilibrium decays can co-decay to obtain the observed relic density. The dark matter density is exponentially depleted through the decay of nearly degenerate particles, rather than from Boltzmann suppression. The relic abundance is set by the dark matter annihilation cross-section, which is predicted to be boosted, and the decay rate ...

  17. Radon Natural Radioactivity Measurements for Evaluation of Primary Pollutants

    OpenAIRE

    Fenjuan Wang; Zhenyi Zhang; Maria Pia Ancora; Xiaodong Deng; Hua Zhang

    2013-01-01

    Radon is naturally released from the soil into the surface layer of the atmosphere, and by monitoring the natural radioactivity data of radon and its shot-live decay products we can get valuable information about the dilution properties of the lower boundary layer. This paper explores the dispersion characteristics of the lower layer of the atmosphere in Lanzhou, China, and the close relationship with the patterns of primary pollutants’ concentrations. Measurements were conducted from July 20...

  18. Radioactive waste disposal

    International Nuclear Information System (INIS)

    A deep gap, reflecting a persisting fear, separates the viewpoints of the experts and that of the public on the issue of the disposal of nuclear WASTES. The history of this field is that of the proliferation with time of spokesmen who pretend to speak in the name of the both humans and non humans involved. Three periods can be distinguished: 1940-1970, an era of contestation and confusion when the experts alone represents the interest of all; 1970-1990, an era of contestation and confusion when spokespersons multiply themselves, generating the controversy and the slowing down of most technological projects; 1990-, an era of negotiation, when viewpoints, both technical and non technical, tend to get closer and, let us be optimistic, leading to the overcome of the crisis. We show that, despite major differences, the options and concepts developed by the different actors are base on two categories of resources, namely Nature and Society, and that the consensus is built up through their 'hydridation'. we show in this part that the perception of nuclear power and, in particular of the underground disposal of nuclear wastes, involves a very deep psychological substrate. Trying to change mentalities in the domain by purely scientific and technical arguments is thus in vain. The practically instinctive fear of radioactivity, far from being due only to lack of information (and education), as often postulated by scientists and engineers, is rooted in archetypical structures. These were, without doubt, reactivated in the 40 s by the traumatizing experience of the atomic bomb. In addition, anthropological-linked considerations allow us to conclude that he underground disposal of wastes is seen as a 'rape' and soiling of Mother Earth. This contributes to explaining, beyond any rationality, the refusal of this technical option by some persons. However, it would naturally be simplistic and counter-productive to limit all controversy in this domain to these psychological aspects

  19. Method of packaging radioactive wastes

    International Nuclear Information System (INIS)

    Purpose: To decrease the leaching of radioactive waste in marine environment. Method: Fillers are placed between a drum can and an inner cage for charging radioactive wastes in order to prevent the leakage of the radioactive wastes from the drum can. Leaching inhibitors for radioactive materials are mixed with the fillers made of organic substance such as asphalts and plastics. The leaching inhibitors are made of materials in the similar chemical form to that of the radioactive materials in the wastes and mixed into the fillers to the saturation limit of dissolution. For the radioactive wastes containing spent adsorbents for iodine, the inhibitors are made of silver nitrates. (Ikeda, J.)

  20. The radioactive wastes management

    International Nuclear Information System (INIS)

    The different types of radioactive waste are presented in this paper in the frame of the official categories which take into account their dangerousness and the lifetimes of their radioactivity. It is indicated how the less dangerous of them are handled in France. The ways of protecting the environment from the more dangerous ones (high activity and long lifetimes) are object of studies. Scientific questions, in the field of chemistry and physical chemistry, related to the implementation of deep underground repository facilities with full respect of nuclear safety are presented. (authors)

  1. Radioactive waste processing method

    International Nuclear Information System (INIS)

    When granular materials comprising radioactive wastes containing phosphorus are processed at first in a fluidized bed type furnace, if the granular materials are phosphorus-containing activated carbon, granular materials comprising alkali compound such as calcium hydroxide and barium hydroxide are used as fluidizing media. Even granular materials of slow burning speed can be burnt stably in a fluidizing state by high temperature heat of the fluidizing media, thereby enabling to take a long burning processing time. Accordingly, radioactive activated carbon wastes can be processed by burning treatment. (T.M.)

  2. Radioactive wastes in Oklo

    International Nuclear Information System (INIS)

    The acceptance of the Nuclear Energy as electric power supply implies to give answer to the population on the two main challenges to conquer in the public opinion: the nuclear accidents and the radioactive wastes. Several of the questions that are made on the radioactive wastes, its are the mobility migration of them, the geologic stability of the place where its are deposited and the possible migration toward the aquifer mantels. Since the half lives of the radioactive waste of a Nuclear Reactor are of several hundred of thousands of years, the technical explanations to the previous questions little convince to the public in general. In this work summary the results of the radioactive waste generated in a natural reactor, denominated Oklo effect that took place in Gabon, Africa, it makes several thousands of millions of years, a lot before the man appeared in the Earth. The identification of at least 17 reactors in Oklo it was carried out thanks to the difference in the concentrations of Uranium 235 and 238 prospective, and to the analysis of the non-mobility of the radioactive waste in the site. It was able by this way to determine that the reactors with sizes of hardly some decimeter and powers of around 100 kilowatts were operating in intermittent and spontaneous form for space of 150,000 years, with operation cycles of around 30 minutes. Recent studies have contributed information valuable on the natural confinement of the radioactive waste of the Oklo reactors in matrixes of minerals of aluminum phosphate that caught and immobilized them for thousands of millions of years. This extracted information from the nature contributes guides and it allows 'to verify' the validity of the current proposals on the immobilization of radioactive wastes of a nuclear reactor. This work presents in clear and accessible form to the public in general on the secure 'design', operation, 'decommissioning' and 'storage' of the radioactive waste of the reactors that the nature put

  3. Radioactive waste management

    International Nuclear Information System (INIS)

    The purpose of this document is to set out the Government's current strategy for the long term in the management of radioactive wastes. It takes account of the latest developments, and will be subject to review in the light of future developments and studies. The subject is discussed under the headings: what are radioactive wastes; who is responsible; what monitoring takes place; disposal as the objective; low-level wastes; intermediate-level wastes; discharges from Sellafield; heat generating wastes; how will waste management systems and procedures be assessed; how much more waste is there going to be in future; conclusion. (U.K.)

  4. Near Field sorption Data Bases for Compacted MX-80 Bentonite for Performance Assessment of a High-Level Radioactive Waste Repository in Opalinus Clay Host Rock

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, M.; Baeyens, B

    2003-08-01

    Bentonites of various types and compacted forms are being investigated in many countries as backfill materials in high-level radioactive waste disposal concepts. Nagra is currently considering an Opalinus clay (OPA) formation in the Zuercher Weinland as a potential location for a high-level radioactive waste repository. A compacted MX-80 bentonite is foreseen as a potential backfill material. Performance assessment studies will be performed for this site and one of the requirements for such an assessment are sorption data bases (SDB) for the bentonite near-field. The purpose of this report is to describe the procedures used to develop the SDB. One of the pre-requisites for developing a SDB is a water chemistry for the compacted bentonite porewater. For a number of reasons mentioned in the report, and discussed in more detail elsewhere, this is not a straightforward task. There are considerable uncertainties associated with the major ion concentrations and in particular with the system pH and Eh. The MX-80 SDB was developed for a reference bentonite porewater (pH = 7.25) which was calculated using the reference OPA porewater. In addition, two further SDBs are presented for porewaters calculated at pH values of 6.9 and 7.9 corresponding to lower and upper bound values calculated for the range of groundwater compositions anticipated for the OPA host rock. 'In house' sorption isotherm data were measured for Cs(I), Ni(II), Eu(III), Th(IV), Se(IV) and 1(-1) on the 'as received' MX-80 material equilibrated with a simulated porewater composition. Complementary 'in house' sorption edge and isotherm measurements on conditioned Na/Ca montmorillonites were also available for many of these radionuclides. These data formed the core of the SDB. Nevertheless, some of the required sorption data still had to be obtained from the open literature. An important part of this report is concerned with describing selection procedures and the modifications

  5. Near Field sorption Data Bases for Compacted MX-80 Bentonite for Performance Assessment of a High-Level Radioactive Waste Repository in Opalinus Clay Host Rock

    International Nuclear Information System (INIS)

    Bentonites of various types and compacted forms are being investigated in many countries as backfill materials in high-level radioactive waste disposal concepts. Nagra is currently considering an Opalinus clay (OPA) formation in the Zuercher Weinland as a potential location for a high-level radioactive waste repository. A compacted MX-80 bentonite is foreseen as a potential backfill material. Performance assessment studies will be performed for this site and one of the requirements for such an assessment are sorption data bases (SDB) for the bentonite near-field. The purpose of this report is to describe the procedures used to develop the SDB. One of the pre-requisites for developing a SDB is a water chemistry for the compacted bentonite porewater. For a number of reasons mentioned in the report, and discussed in more detail elsewhere, this is not a straightforward task. There are considerable uncertainties associated with the major ion concentrations and in particular with the system pH and Eh. The MX-80 SDB was developed for a reference bentonite porewater (pH = 7.25) which was calculated using the reference OPA porewater. In addition, two further SDBs are presented for porewaters calculated at pH values of 6.9 and 7.9 corresponding to lower and upper bound values calculated for the range of groundwater compositions anticipated for the OPA host rock. 'In house' sorption isotherm data were measured for Cs(I), Ni(II), Eu(III), Th(IV), Se(IV) and 1(-1) on the 'as received' MX-80 material equilibrated with a simulated porewater composition. Complementary 'in house' sorption edge and isotherm measurements on conditioned Na/Ca montmorillonites were also available for many of these radionuclides. These data formed the core of the SDB. Nevertheless, some of the required sorption data still had to be obtained from the open literature. An important part of this report is concerned with describing selection procedures and the modifications applied to the chosen values so

  6. Calculation and analysis of radioactive source term in PWR assemblies

    International Nuclear Information System (INIS)

    Background: When fission occurs in fuel of reactor core, it produces a large amount of radioactive materials, which may cause harm to the environment and human health. Purpose: The radioactive materials in fuel could provide input data for shielding design of reactor coolant radioactive source term, analysis of accident source term and radioactive consequence assessment. Methods: The calculation of radioactive source in fuel was studied for pressurized water reactor: the calculation methods and models were established using ORIGEN-S, and the difference of nuclides radioactivity under different burnup was also studied. The effect of different versions of ENDF/B cross-section database on the calculation results was analyzed, so as to provide a basis for the calculation of radioactive source in fuel. Results: The results showed that the method established by ORIGEN-ARP was more suitable for calculating radioactive source term in fuel assemblies and the different versions of ENDF/B database had a great impact on radioactivity calculation. Conclusion: Based on the ENDF/B-VII database, using ORIGEN-ARP to calculate radioactive source term in fuel assemblies could not only improve efficiency, but also improve the calculation accuracy. (authors)

  7. Radioactive inventories from the Kyshtym and Karachay accidents: estimates based on soil samples collected in the South Urals (1990-1995)

    DEFF Research Database (Denmark)

    Aarkrog, A.; Dahlgaard, H.; Nielsen, S.P.;

    1997-01-01

    The implementation of the nuclear programme in the Cheliabinsk region in the Ural, where plutonium for the first Soviet nuclear weapons was produced, involved radioactive contamination of the environment. The end of the cold war in the late 1980s initiated a fruitful co-operation between Russian...

  8. Supersymmetric top quark decays

    International Nuclear Information System (INIS)

    The supersymmetric decays of the top quark into charged Higgs plus bottom, t → H+b, and into the supersymmetric partner of the top (u1) plus the lightest neutralino (χ10), t → u1χ10, are discussed within the framework of the Minimal Supersymmetric Standard Model with radiatively induced breaking of the gauge group SU(2) x U(1). The possibility of detecting these decays at present, i.e. given the available bounds on supersymmetric parameters, is compared with the situation a Next e+e- Linear Collider would face if supersymmetric particles were still undiscovered at LEP II. The indirect implications for t → H+b and t → u1χ10 of a measurement of the bottom quark decay b → sγ at the Standard Model level are taken into account. (orig.)

  9. Suppressed Charmed B Decay

    Energy Technology Data Exchange (ETDEWEB)

    Snoek, Hella Leonie [Vrije Univ., Amsterdam (Netherlands)

    2009-06-02

    This thesis describes the measurement of the branching fractions of the suppressed charmed B0 → D*- a0+ decays and the non-resonant B0 → D*- ηπ+ decays in approximately 230 million Υ(4S) → B$\\bar{B}$ events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B0 → D*- a{sub 0}+ decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10-6. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle γ, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle γ can be performed using the decays of neutral B mesons. The B0 → D*- a0+ decay is sensitive to the angle γ and, in comparison to the current decays that are being employed, could significantly

  10. Implantation of a databank of radioactive sources

    International Nuclear Information System (INIS)

    Radionuclides are isotopes that emit radiation. They can be safely applied in medicine, industry, basic research, for metrology and for environmental control. In most applications each radionuclide needs to be characterized regarding their activity concentration (AC) in Becquerel per gram (Bq / g) and also their measurement uncertainty. The Radionuclide Laboratory in the Institute of Radiation Protection and Dosimetry, belonging to the National Nuclear Energy Commission (CNEN), has a number of standardization systems, where the activity concentrations and the measurement uncertainty are determined. Some radionuclides are stored in glass vials for later use; they have billions of years’ half-lives. These standard solutions are identified by their symbol radioactive element followed by a number. There are hundreds of light bulbs with radioactive sources that periodically need their concentration of activity to be inventoried. The previously deployed control system only allowed access from a unique laboratory point. The inventory was done individually and then was integrated to individual activities in order to determine the overall activity of each radionuclide. This work aims to implement an integrated standards database to an information system that allows users to gain access from various lab points. Thus, the inventory of radioactive sources can be performed in order to signal the need to acquire new solutions. Also, it can indicate, through new activities concentrations, after decay, when different solutions may be discarded in accordance with legal standards of radiation protection and management of the CNEN waste, in order to protect the population and the environment. The adjustment of the existing deficiencies in the system previously used will allow better control related to the use of radioactive materials, minimizing the risks of improper disposal of radionuclides in the environment and can be considered the greatest contribution this work. (author)

  11. Radioactivity and thermalization in the ejecta of compact object mergers and their impact on kilonova light curves

    CERN Document Server

    Barnes, Jennifer; Wu, Meng-Ru; Mart'inez-Pinedo, Gabriel

    2016-01-01

    One of the most promising electromagnetic signatures of compact object mergers are kilonovae: approximately isotropic radioactively-powered transients that peak days to weeks post-merger. Key uncertainties in modeling kilonovae include the emission profiles of the radioactive decay products---non-thermal beta- and alpha-particles, fission fragments, and gamma-rays---and the efficiency with which they deposit their energy in the ejecta. The total radioactive energy and the efficiency of its thermalization sets the luminosity budget and is therefore necessary for predicting kilonova light curves. We outline the uncertainties in r-process decay, describe the physical processes by which the energy of the decay products is absorbed in the ejecta, and present time-dependent thermalization efficiencies for each particle type. We determine the net heating efficiency and explore its dependence on r-process yields---in particular, the production of translead nuclei that undergo alpha-decay---and on the ejecta's mass, v...

  12. Nuclear chemistry research and spectroscopy with radioactive sources. Nineteenth annual progress report

    International Nuclear Information System (INIS)

    Our effort is centered on radioactive decay studies of far-from-stable nuclides produced with heavy ions from the Holifield Heavy Ion Research Facility (HHIRF) and studied on-line with the University Isotope Separator at Oak Ridge (UNISOR). Progress is reported on the following studies: lifetime of the g/sub 7/2/ level in 109Ag; halflife of the h/sub 9/2/ level in 187Au; decay of 8.4 min 187Au → 187Pt; orbital EC probabilities and decay energy of 207Bi; decay of 9 min /sup 201m/Po and 16 min /sup 201g/Po; decay of 2.5 min 125Ba; decay of 7.4 min 203At; exploration of neutron-deficient Sm, Pm, and Nd nuclides; preparation of thoron active deposit conversion electron sources; inception of nuclear laser spectroscopy at UNISOR; and nuclear structure calculations with nuclear models. Publications are listed

  13. Double beta decay experiments

    International Nuclear Information System (INIS)

    The great sensitivity of double beta decay to neutrino mass and right handed currents has motivated many new and exciting attempts to observe this elusive nuclear phenomenon directly. Experiments in operation and other coming on line in the next one or two years are expected to result in order-of-magnitude improvements in detectable half lives for both the two-neutrino and no-neutrino modes. A brief history of double beta decay experiments is presented together with a discussion of current experimental efforts, including a gas filled time projection chamber being used to study selenium-82. (author)

  14. Fast Proton Decay

    OpenAIRE

    Li, Tianjun; Nanopoulos, Dimitri V.; Walker, Joel W.

    2009-01-01

    We consider proton decay in the testable flipped SU(5) X U(1)_X models with TeV-scale vector-like particles which can be realized in free fermionic string constructions and F-theory model building. We significantly improve upon the determination of light threshold effects from prior studies, and perform a fresh calculation of the second loop for the process p \\to e^+ \\pi^0 from the heavy gauge boson exchange. The cumulative result is comparatively fast proton decay, with a majority of the mos...

  15. Monitoring of airborne radioactivity (radon, thoron and daughters; radioactive dust)

    International Nuclear Information System (INIS)

    The processes resulting in airborne radioactivity from uranium and thorium ores are discussed. Measurement methods for radioactive dust, radon and thoron gas and radon and thoron daughters are described and assessed. The monitoring equipment required for measurement of airborne radioactivity is described

  16. Moessbauer Effect applications using intense radioactive ion beams

    International Nuclear Information System (INIS)

    The Moessbauer Effect is reviewed as a promising tool for a number of new solid state studies when used in combination with radioactive beam/implantation facilities. The usual Moessbauer Effect involves long-lived radioactive parents (days to years) that populate low-lying nuclear excited states that subsequently decay to the ground state. Resonant emission/absorption of recoil-free gamma rays from these states provide information on a number of properties of the host materials. Radioactive ion beams (RIB) produced on-line allow new Moessbauer nuclei to be studied where there is no suitable parent. The technique allows useful sources to be made having extremely low local concentrations. The ability to separate the beams in both Z and A should provide high specific activity ''conventional'' sources, a feature important in some applications such as Moessbauer studies in diamond anvil high pressure cells. Exotic chemistry is proposed using RIB and certain Krypton and Xenon Moessbauer isotopes

  17. LRT 2006: 2. topical workshop in low radioactivity techniques

    International Nuclear Information System (INIS)

    This second topical workshop in low radioactivity techniques is intended to bring together experts in the field of low background techniques, especially applied to dark matter experiments, double beta decay experiments and neutrino detection in underground laboratories. This workshop has been organized into 7 sessions: 1) underground facilities (where a worldwide review is made), 2) neutron and muon induced background, isotope production, 3) low background counting techniques and low background detectors, 4) techniques for radon reduction, purified noble gases and liquid scintillator purification, 5) low levels on Pb-Bi-Po210 and surface background, 6) low radioactivity detector components and material purification, and 7) low radioactive techniques in other applications (particularly to check the geographical origin of food-products or to date wine. This document is made up of the slides of the presentations

  18. LRT 2006: 2. topical workshop in low radioactivity techniques

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, P.; Piquemal, F.; Ford, R.; Yakushev, E.; Pandola, L.; Franco, D.; Bellini, F.; Hubert, Ph.; Laubenstein, M.; Abt, I.; Bongrand, M.; Schnee, R.; Dusan, B.; Chen, M.; Piquemal, F.; Nachab, A.; Zuzel, G.; Simgen, H.; Navick, X.F.; Pedretti, M.; Wojcik, M.; Sekiya, H.; Kim, Y.; Kishimoto, T.; Dawson, J.; Borjabad, S.; Perrot, F.; Gurriaran, R.; Nikolayko, A.; Hubert, Ph

    2006-07-01

    This second topical workshop in low radioactivity techniques is intended to bring together experts in the field of low background techniques, especially applied to dark matter experiments, double beta decay experiments and neutrino detection in underground laboratories. This workshop has been organized into 7 sessions: 1) underground facilities (where a worldwide review is made), 2) neutron and muon induced background, isotope production, 3) low background counting techniques and low background detectors, 4) techniques for radon reduction, purified noble gases and liquid scintillator purification, 5) low levels on Pb-Bi-Po{sup 210} and surface background, 6) low radioactivity detector components and material purification, and 7) low radioactive techniques in other applications (particularly to check the geographical origin of food-products or to date wine. This document is made up of the slides of the presentations.

  19. Assessment of temporal trend of radiation dose to the public living in the large area contaminated with radioactive materials after a nuclear power plant accident

    Energy Technology Data Exchange (ETDEWEB)

    Go, A Ra; Kim, Min Jun; Kim, Kwang Pyo [Dept. of Nuclear Engineering, Kyung Hee University, Seoul (Korea, Republic of); Cho, Nam Chan; Seol, Jeung Gun [Radiation Safety Team, Korea Electric Power Corporation Nuclear Fuel, Seoul (Korea, Republic of)

    2015-12-15

    It has been about 5 years since the Fukushima nuclear power plant accident, which contaminated large area with radioactive materials. It is necessary to assess radiation dose to establish evacuation areas and to set decontamination goal for the large contaminated area. In this study, we assessed temporal trend of radiation dose to the public living in the large area contaminated with radioactive materials after the Fukushima nuclear power plant accident. The dose assessment was performed based on Chernobyl model and RESRAD model for two evacuation lift areas, Kawauchi and Naraha. It was reported that deposition densities in the areas were 4.3-96 kBq m{sup -2} for {sup 134}Cs, 1.4-300 kBq m{sup -2} for {sup 137}Cs, respectively. Radiation dose to the residents depended on radioactive cesium concentrations in the soil, ranging 0.11-2.4 mSv y{sup -1} at Kawauchi area and 0.69-1.1 mSv y{sup -1} at Naraha area in July 2014. The difference was less than 5% in radiation doses estimated by two different models. Radiation dose decreased with calendar time and the decreasing slope varied depending on dose assessment models. Based on the Chernobyl dosimetry model, radiation doses decreased with calendar time to about 65% level of the radiation dose in 2014 after 1 year, 11% level after 10 years, and 5.6% level after 30 years. RESRAD dosimetry model more slowly decreased radiation dose with time to about 85% level after 1 year, 40% level after 10 years, and 15% level after 30 years. The decrease of radiation dose can be mainly attributed into radioactive decays and environmental transport of the radioactive cesium. Only environmental transports of radioactive cesium without consideration of radioactive decays decreased radiation dose additionally 43% after 1 year, 72% after 3 years, 80% after 10 years, and 83% after 30 years. Radiation doses estimated with cesium concentration in the soil based on Chernobyl dosimetry model were compared with directly measured radiation doses

  20. SHIPPING OF RADIOACTIVE ITEMS

    CERN Multimedia

    TIS/RP Group

    2001-01-01

    The TIS-RP group informs users that shipping of small radioactive items is normally guaranteed within 24 hours from the time the material is handed in at the TIS-RP service. This time is imposed by the necessary procedures (identification of the radionuclides, determination of dose rate and massive objects require a longer procedure and will therefore take longer.

  1. Encapsulation of radioactive waste

    International Nuclear Information System (INIS)

    A method is described for encapsulating a particular radioactive waste which consists of suspending the waste in a viscous liquid encapsulating material, of synthetic resin monomers or prepolymers, and setting the encapsulating material by addition or condensation polymerization to form a solid material in which the waste is dispersed. (author)

  2. AIR RADIOACTIVITY MONITOR

    Science.gov (United States)

    Bradshaw, R.L.; Thomas, J.W.

    1961-04-11

    The monitor is designed to minimize undesirable background buildup. It consists of an elongated column containing peripheral electrodes in a central portion of the column, and conduits directing an axial flow of radioactively contaminated air through the center of the column and pure air through the annular portion of the column about the electrodes. (AEC)

  3. Radioactivity: A Natural Phenomenon.

    Science.gov (United States)

    Ronneau, C.

    1990-01-01

    Discussed is misinformation people have on the subject of radiation. The importance of comparing artificial source levels of radiation to natural levels is emphasized. Measurements of radioactivity, its consequences, and comparisons between the risks induced by radiation in the environment and from artificial sources are included. (KR)

  4. Viewer Makes Radioactivity "Visible"

    Science.gov (United States)

    Yin, L. I.

    1983-01-01

    Battery operated viewer demonstrates feasibility of generating threedimensional visible light simulations of objects that emit X-ray or gamma rays. Ray paths are traced for two pinhold positions to show location of reconstructed image. Images formed by pinholes are converted to intensified visible-light images. Applications range from radioactivity contamination surveys to monitoring radioisotope absorption in tumors.

  5. Environmental radioactivity in Hungary

    International Nuclear Information System (INIS)

    A comprehensive examination of radioactive contamination in air, soil, surface waters and food products, and of natural radioactiviy in air, soil, and building materials has been carried out. The investigated factors were as follows: a) air samples: yearly and monthly beta- and gamma activities of fallout, precipitation and aerosols in the period 1955-1976 in Budapest and some other towns; b) soil samples: 90Sr concentration of soils of different quality and cultivation originating from sixteen regions of Hungary measured in the period 1974-1976; c) surface waters: annual mean beta activity of five rivers and of the Lake Balaton in the period 1965-1976, 3H, 137Cs and 90Sr activity of the Danube in the year 1976; d) food products: radioactive contamination of spinach, lettuce and oxalis, originating from three different regions in the period 1959-1976 and mean radioactivity of fodder, corn, tobacco, milk, fish and animal bones in a period of 5-10 years; e) natural radioactivity: radon- and toron concentration of air, activity of 226Ra fallout of the soil in the vicinity of power plants, 226Ra, 228Th and 40K activity of different building materials, radiation doses inside buildings constructed by different technics. (L.E.)

  6. Radioactivity and food preservation

    International Nuclear Information System (INIS)

    In food irradiation, electrons or electromagnetic radiation are used to destroy microorganisms and insects or to prevent seed germination. The economic advantages and health benefits of sterilizing food in this manner are clear, and numerous studies have confirmed that under strictly controlled conditions no undesirable changes or induced radioactivity are produced in the irradiated food

  7. Radioactive Sources Service

    CERN Multimedia

    2007-01-01

    Please note that the radioactive sources service will be open by appointment only every Monday, Wednesday and Friday during CERN working hours (instead of alternate weeks). In addition, please note that our 2007 schedule is available on our web site: http://cern.ch/service-rp-sources

  8. Radioactive Sources Service

    CERN Multimedia

    2007-01-01

    Please note that the radioactive sources service will be open by appointment only every Monday, Wednesday and Friday during CERN working hours (instead of alternate weeks). In addition, please note that our 2007 schedule is available on our web site. http://cern.ch/service-rp-sources

  9. Measurement of radioactive nuclides from geological samples and radiation hazards due to environmental radon

    International Nuclear Information System (INIS)

    The naturally occurring radio nuclides present in the environment may result in external and internal doses received by a population exposed to them directly and via the ingestion/inhalation pathways. Human beings are exposed to low levels of ionizing radiation from natural sources during their daily lives. The basic component of our life support system is considered to be in the soil, water, plants and air. These environmental components contain measurable amount of radioactivity. Radon and its progeny are radioactive and is the major contributor to environmental radioactivity. Radon is formed from the decay of radium which in turn is formed from uranium. The gaseous radioactive isotope of radon, from natural sources has a significant share in the total quantum of natural sources exposure to human beings. Gamma radiations are spontaneously emitted by naturally occurring radioactive material like 226Ra, 232Th and 40K, ever since their existence on earth. Natural radioactive materials under certain conditions can reach hazardous radiological levels. So, it becomes necessary to study the natural radioactivity in different materials to assess the dose for the population in order to know the health risks and future changes in the environmental radioactivity due to human activities. The present study deals with the measurement of radioactivity in some naturally occurring radioactive materials (NORMs). (author)

  10. Survey monitoring of environmental radioactivity in Jeju area

    Energy Technology Data Exchange (ETDEWEB)

    U, Zang Kual; Kang, Tae Woo; Park, Won Pyo [Jeju National Univ., Jeju (Korea, Republic of)

    2003-12-15

    The project is carried out to monitor the change of environmental radioactivity in Jeju, and to provide a systematic data for radiation monitoring and counter measurement at a radiological emergency situation. Also the survey of natural environmental radioactivities in the samples was conducted to make the reliable data base for evaluation of internal exposure and environmental contamination of radiation. This report contains the data of gamma exposure rates and radioactivities of airborne dust, fallout, precipitation and tap water which were analyzed periodically by Jeju Regional Monitoring Station in 2002. Also it contains the data of natural radioactivity levels of food stuff such as agricultural and marine products, including drinking waters.

  11. Radioactive waste disposal fees—Methodology for calculation

    International Nuclear Information System (INIS)

    This paper summarizes the methodological approach used for calculation of fee for low- and intermediate-level radioactive waste disposal and for spent fuel disposal. The methodology itself is based on simulation of cash flows related to the operation of system for waste disposal. The paper includes demonstration of methodology application on the conditions of the Czech Republic. - Highlights: • Policy of radioactive waste management in the Czech Republic. • Methodology for calculation of fees for radioactive waste disposal. • Comparison of fee for radioactive waste disposal for selected countries. • The most important factors influencing fee-case example of the Czech Republic

  12. Identification of radioactive materials in moving objects

    International Nuclear Information System (INIS)

    Control over the transportation of the radioactive materials crossing the borders of Uzbekistan is actually today not like before because of increased threat of terrorism.and urges of terrorist organizations to use radioactive materials in their terrorist activities. There are many companies producing radiation control systems. All such systems existing nowadays are based on the principles of intensity comparison for radiation detected by the system in the absence of control object and the intensity of the radiation when object appears. This method works well only in the conditions of constant or weakly changing background. However, at significant deviation in the value of background the number of false alarms set off by the systems increases. The present work describes the method for radioactive materials detection in the moving objects independent of the significant background deviations and present radiation monitoring establishment based on this principle

  13. Environmental Radioactivity, Temperature, and Precipitation.

    Science.gov (United States)

    Riland, Carson A.

    1996-01-01

    Reports that environmental radioactivity levels vary with temperature and precipitation and these effects are due to radon. Discusses the measurement of this environmental radioactivity and the theory behind it. (JRH)

  14. Management of radioactive waste from reprocessing plants

    International Nuclear Information System (INIS)

    Reprocessing and recycling of both fissile and fertile components back into appropriate reactor systems is an integral part of three stage nuclear energy programme of India. Different steps involved in processing of spent nuclear fuel (SNF) are decladding, dissolution and recovery of fissile and fertile materials. Reprocessing of SNF is a complex process involving handling of large quantity of radioactive materials and processing chemicals. There are three reprocessing plants in operation in the country at Trombay, Tarapur and Kalpakkam. Out of these plants, Trombay reprocessing plant is engaged in reprocessing of SNF from research reactors and other two plants are processing of SNF from PHWRs. A facility is being built for reprocessing of thorium based spent fuel at BARC, Trombay based on the experience of pilot plant scale. Like other industrial activities of nuclear fuel cycle, fuel reprocessing facilities too generate various types of radioactive waste streams. These are generated in all the three physical forms namely solid, liquid and gas. These waste streams are primarily categorized on the basis of concentration of radionuclides, their half lives and toxicity. Management of these wastes aims at (a) recovery and recycle of useful materials, (b) concentration and confinement of radioactivity in inert and stable matrices, (c) minimization of final waste volume for disposal, (d) decontamination of effluents following ALARA principle and (e) minimization of radioactive discharge to the environment. The present paper outlines the salient features of management of different types of radioactive waste generated in reprocessing plants handling SNF from research reactors and PHWR

  15. A Generic Safety assessment code for geologic disposal of Radioactive Waste: GSRW computer code user's manual

    International Nuclear Information System (INIS)

    The computer code system GSRW (Generic Safety assessment code for geologic disposal of Radioactive Waste) was developed as in interim version of safety assessment methodology for geologic disposal of high-level radioactive waste. Scenarios used here are based on normal evolution scenarios which assume that the performance of a disposal system is not affected by probabilistic events. The code consists of three parts. The first part evaluates a source term from a disposal facility which consists mainly of a vitrified waste, a metallic container and a buffer zone. Two kinds of source term models are provided: Model 1 which simulate the dissolution of silicate component of glass and the diffusive transport of radionuclides in the buffere zone, and Model 2 which assumes that the concentration of a radionuclide is limited by the solubility of its specific chemical form at the interface between the buffer and a vitrified wastes. The second part analyses the transport of radionuclides in the geosphere, which is based on analytical solutions or numerical solutions of a mass transport equation involving the advection, dispersion, linear sorption and decay chain. The third part assesses the transport of radionuclides in the biosphere and the resulting radiological consequences to the man, which is based on a dynamic compartment model for the biosphere and a dose factor method for dose calculations. This report describes mathematical models used, the structure of the code system, and user information and instructions for execution of the code. (author)

  16. Development of whole energy absorption spectrometer for decay heat measurement on fusion reactor materials

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Fujio; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    To measure decay heat on fusion reactor materials irradiated by D-T neutrons, a Whole Energy Absorption Spectrometer (WEAS) consisting of a pair of large BGO (bismuth-germanate) scintillators was developed. Feasibility of decay heat measurement with WEAS for various materials and for a wide range of half-lives (seconds - years) was demonstrated by experiments at FNS. Features of WEAS, such as high sensitivity, radioactivity identification, and reasonably low experimental uncertainty of {approx} 10 %, were found. (author)

  17. Leptonic Decays of Charged Pseudoscalar Mesons - 2015

    Energy Technology Data Exchange (ETDEWEB)

    Rosner, Jonathan L. [Chicago U., EFI; Stone, Sheldon [Syracuse U.; Van de Water, Ruth S. [Fermilab

    2015-09-07

    We review the physics of purely leptonic decays of $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak-interaction-based CKM matrix element of the constituent quarks and a strong interaction parameter related to the overlap of the quark and antiquark wave-functions in the meson, called the decay constant $f_P$. The leptonic decay constants for $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ mesons can be obtained with controlled theoretical uncertainties and high precision from {\\it ab initio} lattice-QCD simulations. The combination of experimental leptonic decay-rate measurements and theoretical decay-constant calculations enables the determination of several elements of the CKM matrix within the standard model. These determinations are competitive with those obtained from semileptonic decays, and also complementary because they are sensitive to different quark flavor-changing currents. They can also be used to test the unitarity of the first and second rows of the CKM matrix. Conversely, taking the CKM elements predicted by unitarity, one can infer "experimental" values for $f_P$ that can be compared with theory. These provide tests of lattice-QCD methods, provided new-physics contributions to leptonic decays are negligible at the current level of precision. This review is the basis of the article in the Particle Data Group's 2016 edition, updating the versions in Refs. [1-3].

  18. Radiative Neutrino Decay in Media

    CERN Document Server

    Grasso, D; Grasso, Dario; Semikoz, Victor

    1999-01-01

    In this letter we introduce a new method to determine the radiative neutrino decay rate in the presence of a medium. Our approach is based on the generalisation of the optical theorem at finite temperature and density. Differently from previous works on this subject, our method allows to account for dispersive and dissipative electromagnetic properties of the medium. Some inconsistencies that are present in the literature are pointed-out and corrected here. We shortly discuss the relevance of our results for neutrino evolution in the early universe.

  19. Probing new physics with underground accelerators and radioactive sources

    International Nuclear Information System (INIS)

    New light, weakly coupled particles can be efficiently produced at existing and future high-intensity accelerators and radioactive sources in deep underground laboratories. Once produced, these particles can scatter or decay in large neutrino detectors (e.g. Super-K and Borexino) housed in the same facilities. We discuss the production of weakly coupled scalars ϕ via nuclear de-excitation of an excited element into the ground state in two viable concrete reactions: the decay of the 0+ excited state of 16O populated via a (p,α) reaction on fluorine and from radioactive 144Ce decay where the scalar is produced in the de-excitation of 144Nd⁎, which occurs along the decay chain. Subsequent scattering on electrons, e(ϕ,γ)e, yields a mono-energetic signal that is observable in neutrino detectors. We show that this proposed experimental setup can cover new territory for masses 250 keV≤mϕ≤2me and couplings to protons and electrons, 10−11≤gegp≤10−7. This parameter space is motivated by explanations of the “proton charge radius puzzle”, thus this strategy adds a viable new physics component to the neutrino and nuclear astrophysics programs at underground facilities

  20. Baryogenesis and proton decay

    International Nuclear Information System (INIS)

    The constraints are analyzed that proton decay experiments and cosmologically sound unification models impose on each other. An intermediate scale of around 1010 GeV arises from considerations on baryogenesis, inflation and supersymmetry breaking. An upper bound to the gravitino mass of about 50 TeV follows from current proton lifetime limits