WorldWideScience

Sample records for based radioactive decay

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. Is Radioactive Decay Really Exponential?

    OpenAIRE

    Aston, PJ

    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 ...

  6. JEF-2.2 radioactive decay data

    International Nuclear Information System (INIS)

    This work deals with the JEF-2.2 radioactive decay data and is divided into four tables. The first table presents the origin of the JEF-2.2 radioactive decay data and subsequent modifications. The second one is a summary of the JEF-2.2 radioactive decay data file. The third one describes the JEF-2.2 fission products and the main decay and fission yield data. The last one consists of the main decay parameters from the JEF-2.2, ENDF/B-VI and JNDC-2.0 libraries. (O.L.). 100 figs., 4 tabs

  7. 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.

  8. The RMF theory based 3-Yukawas (R3Y) vs. the Michigan 3-Yukawas (M3Y) NN interactions for the cluster radioactive decay studies

    International Nuclear Information System (INIS)

    Using the double folding model, the nucleon-nucleon (NN) interaction, say, the phenomenological M3Y effective NN interaction, can be used to obtain the nucleus-nucleus optical potential. In this contribution, the double folding model has been used to obtain the optical potentials for both RMF-based R3Y and M3Y interactions, and apply the same to study the exotic cluster radioactive decays in trans-lead region having doubly magic 208Pb as daughters

  9. Nuclear structure from radioactive decay

    International Nuclear Information System (INIS)

    The most important aspect of the wind-up of UNISOR-based research is completion of student theses. Analysis is proceeding on extensive studies in the neutron-deficient rare earth isotopes with N 50 open shell region and shape coexistence in the N ∼ 104, Z ≤ 82 region, respectively. The main ongoing topics are shape coexistence in nuclei and the microscopic structure of collective motion in nuclei from a phenomenological point of view. New topics this year focus on the structure of nuclei near the N = Z line. Two topics have been chosen for detailed study: shape coexistence and electric monopole transition strengths

  10. ZZ DRALIST, Radioactive Decay Data for Dosimetry and Hazard Assessment

    International Nuclear Information System (INIS)

    1 - Description of program or function: Format: DLC-46/MEDLIST output format and in an abbreviated form. Nuclides: 561; Origin: Evaluated Nuclear Data Structure Fil (ENSDF). DRALIST is a data set of radioactive decay energies, spectra, half lives, and other information for 561 radionuclides in DLC-46/MEDLIST output format and also in an abbreviated form. The data are derived from the Evaluated Nuclear Data Structure File (ENSDF) using the MEDLIST program. A modified version of the MEDPRINT program with improved editing capability plus a file of decay branching information are provided. 2 - Method of solution: The radioactive decay data tabulated for the report result from the continual expansion and updating of the data base published in ORNL/NUREG/TM-102. In addition to the radionuclides of interest in the nuclear fuel cycle, the data base comprises most of the nuclides occurring naturally in the environment, those of current interest in nuclear medicine and fusion reactor technology, and some additional radionuclides of use in the estimation of annual limits of intake and derived air concentrations for accupationally exposed individuals. The current data base contains approximately 500 radionuclides

  11. R and D on the Geant4 radioactive decay physics

    International Nuclear Information System (INIS)

    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.

  12. 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.

  13. The fitting of radioactive decay data by covariance methods

    International Nuclear Information System (INIS)

    The fitting of radioactive decay data is examined when radiations from two or more processes are indistinguishable. The model is a nonlinear sum of exponentials which cannot be linearized by transformations. Simple and generalized least-squares procedures utilizing covariance matrices are applied. The validity of the midpoint approximation is demonstrated. Guidelines for acquiring adequate radioactive decay data are suggested. The relevance to activation cross section determination is discussed

  14. 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)

  15. 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...

  16. Radioactive decays of highly-charged ions

    Directory of Open Access Journals (Sweden)

    Gao B. S.

    2015-01-01

    Full Text Available Access to stored and cooled highly-charged radionuclides offers unprecedented opportunities to perform high-precision investigations of their decays. Since the few-electron ions, e.g. hydrogen- or helium-like ions, are quantum mechanical systems with clear electronic ground state configurations, the decay studies of such ions are performed under well-defined conditions and allow for addressing fundamental aspects of the decay process. Presented here is a compact review of the relevant experiments conducted at the Experimental Storage Ring ESR of GSI. A particular emphasis is given to the investigations of the two-body beta decay, namely the bound-state β-decay and its time-mirrored counterpart, orbital electron-capture.

  17. 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.

  18. Decay of radioactive nuclei in intense radiation fields

    International Nuclear Information System (INIS)

    The influence of intense electromagnetic fields on the decay of radioactive nuclei, an area which has recently received much attention, is examined in this thesis. In particular, the possibility of shortening nuclear lifetimes is of special interest, as it could lead to important applications (e.g. in the problem of nuclear waste). Different nuclear decay modes such as beta decay, gamma decay and electron capture in external fields of different frequencies (radio-, laser-, X-ray- and gamma-fields) are dealt with in this work. The emphasis is on ''low-frequency'' fields (e.g. photon energy << nuclear transition energy) since at present only these fields can be produced with sufficient intensity in the laboratory. The most favorable decay mode in a low-frequency field is nuclear beta decay, since the emitted electron is influenced. (orig./HSI)

  19. Method for removal of decay heat of radioactive substances

    International Nuclear Information System (INIS)

    In this process, the decay heat from radioactive substances is removed by means of a liquid carried in the coolant loop. The liquid is partially evaporated by the decay heat. The steam is used to drive the liquid through the loop. When a static pressure level equivalent to the pressure drop in the loop is exceeded, the steam is separated from the liquid, condensed, and the condensate is reunited with the return flow of liquid for partial evaporation. (orig.)

  20. Quantitative imaging of disease signatures through radioactive decay signal conversion

    OpenAIRE

    Thorek, Daniel LJ; Ogirala, Anuja; Beattie, Bradley J.; Grimm, Jan

    2013-01-01

    In the era of personalized medicine there is an urgent need for in vivo techniques able to sensitively detect and quantify molecular activities. Sensitive imaging of gamma rays is widely used, but radioactive decay is a physical constant and signal is independent of biological interactions. Here we introduce a framework of novel targeted and activatable probes excited by a nuclear decay-derived signal to identify and measure molecular signatures of disease. This was accomplished utilizing Cer...

  1. Cluster radioactivity and alpha decay of superheavy nuclei

    International Nuclear Information System (INIS)

    The competition of cluster radioactivity and α decay is investigated in the region of superheavy (SH) nuclei with atomic numbers Z = 104 - 124. Calculations of half-lives within analytical super-asymmetrical fission (ASAF) model are performed by using different theoretical mass tables to determine the energy released, Q. For α decay the ASAF calculations are compared with semFIS (semi-empirical fission model). A trend toward shorter half-lives and larger branching ratios relative to alpha decay for heavier SHs was observed

  2. 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.

  3. Catalog of gamma-rays unplaced in radioactive decay schemes

    International Nuclear Information System (INIS)

    A catalog is made for gamma-rays emitted in decay of radioactive nuclides but not placed in their decay schemes. It consists of two tables. In Table 1, the number of these unplaced gamma-ray components by a nuclide is given together with the fraction of total intensity of these gamma-rays to that of all observed gamma-rays. In Table 2, the unplaced gamma-rays are arranged in order of increasing energy. Each line of this table contains the gamma-ray energy, intensity, nuclide identification, and energies and intensities of the most prominent gamma-rays from the decay of the radionuclides. This catalog is a compilation from Evaluated Nuclear Structure Data File (ENSDF) maintained by National Nuclear Data Center at Brookhaven National Laboratory, of at February 1990. (author)

  4. 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.)

  5. 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.

  6. 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.

  7. The Schroedinger-Chetaev equation in Bohmian mechanics and diffusion mechanism of alpha decay, cluster radioactivity and spontaneous fission

    International Nuclear Information System (INIS)

    In the framework of Bohmian quantum mechanics supplemented with the Chetaev theorem on stable trajectories in dynamics in the presence of dissipative forces we have shown the possibility of the classical (without tunneling) universal description of radioactive decay of heavy nuclei, in which under certain conditions the so-called noise-induced transition is generated or, in other words, the stochastic channel of alpha decay, cluster radioactivity and spontaneous fission conditioned by the Kramers diffusion mechanism. Based on the ENSDF database we have found the parametrized solutions of the Kramers equation of Langevin type by Alexandrov dynamic auto--regularization method (FORTRAN code REGN-Dubna). These solutions describe with high accuracy the dependence of the half-life (decay probability) of heavy radioactive nuclei on total kinetic energy of daughter decay products. The verification of inverse problem solution in the framework of the universal Kramers description of the alpha decay, cluster radioactivity and spontaneous fission, which was based on the newest experimental data for alpha decay of even-even superheavy nuclei (Z = 114, 116, 118), has shown good coincidence of the experimental and theoretical half-life dependence on alpha-decay energy

  8. Quantitative imaging of disease signatures through radioactive decay signal conversion.

    Science.gov (United States)

    Thorek, Daniel L J; Ogirala, Anuja; Beattie, Bradley J; Grimm, Jan

    2013-10-01

    In the era of personalized medicine, there is an urgent need for in vivo techniques able to sensitively detect and quantify molecular activities. Sensitive imaging of gamma rays is widely used; however, radioactive decay is a physical constant, and its signal is independent of biological interactions. Here, we introduce a framework of previously uncharacterized targeted and activatable probes that are excited by a nuclear decay-derived signal to identify and measure molecular signatures of disease. We accomplished this by using Cerenkov luminescence, the light produced by β-particle-emitting radionuclides such as clinical positron emission tomography (PET) tracers. Disease markers were detected using nanoparticles to produce secondary Cerenkov-induced fluorescence. This approach reduces background signal compared to conventional fluorescence imaging. In addition to tumor identification from a conventional PET scan, we demonstrate the medical utility of our approach by quantitatively determining prognostically relevant enzymatic activity. This technique can be applied to monitor other markers and represents a shift toward activatable nuclear medicine agents. PMID:24013701

  9. Cluster radioactive decay within the preformed cluster model using relativistic mean-field theory densities

    International Nuclear Information System (INIS)

    We have studied the (ground-state) cluster radioactive decays within the preformed cluster model (PCM) of Gupta and collaborators [R. K. Gupta, in Proceedings of the 5th International Conference on Nuclear Reaction Mechanisms, Varenna, edited by E. Gadioli (Ricerca Scientifica ed Educazione Permanente, Milano, 1988), p. 416; S. S. Malik and R. K. Gupta, Phys. Rev. C 39, 1992 (1989)]. The relativistic mean-field (RMF) theory is used to obtain the nuclear matter densities for the double folding procedure used to construct the cluster-daughter potential with M3Y nucleon-nucleon interaction including exchange effects. Following the PCM approach, we have deduced empirically the preformation probability P0emp from the experimental data on both the α- and exotic cluster-decays, specifically of parents in the trans-lead region having doubly magic 208Pb or its neighboring nuclei as daughters. Interestingly, the RMF-densities-based nuclear potential supports the concept of preformation for both the α and heavier clusters in radioactive nuclei. P0α(emp) for α decays is almost constant (∼10-2-10-3) for all the parent nuclei considered here, and P0c(emp) for cluster decays of the same parents decrease with the size of clusters emitted from different parents. The results obtained for P0c(emp) are reasonable and are within two to three orders of magnitude of the well-accepted phenomenological model of Blendowske-Walliser for light clusters.

  10. 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

  11. Experimental and theoretical aspects of proton radioactivity - proton decay of spherical and deformed nuclei

    International Nuclear Information System (INIS)

    Proton radioactivity is a decay mode found only in nuclei beyond the proton drip line.It competes with alpha decay, positron decay and electron capture. Proton decay is a quantum tunnelling phenomenon, and the decay rateis governed by a delicate interplay between the Coulomb and centrifugalbarriers. This presents the opportunity to extract spectroscopic informationon a nuclide beyond the proton drip line. Recent experimental developmentswill be presented, including gamma spectroscopy of proton emitters, and fine structure in proton decay. Theoretical attempts to calculate protondecay rates for spherical and deformed proton emitters will be discussed,and the various models will be compared. (author)

  12. 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)

  13. Phenomenological formula for cluster preformation probability in exotic radioactive nuclear decays

    International Nuclear Information System (INIS)

    Recently, using the preformed cluster model (PCM) of Gupta and collaborators, we have deduced the preformation probabilities empirically P0emp from experimental data on both the α and exotic-cluster radioactive decays in the trans-lead region, using the relativistic mean field (RMF) densities in the double folding procedure. Phenomenological formula for cluster preformation probability in exotic radioactive nuclear decays is discussed

  14. Radioactive decay simulation with Geant4: experimental benchmarks and developments for X-ray astronomy applications

    CERN Document Server

    Hauf, S; Hoffmann, Dieter H H; Bell, Z W; Pia, M G; Weidenspointner, Georg; Zoglauer, A

    2010-01-01

    We present {\\gamma} spectroscopy validation measurements for the Geant4 radioactive decay simulation for a selected range of isotopes using a simple experimental setup. Using these results we point out problems in the decay simulation and where they may originate from.

  15. Radioactive decay simulation with Geant4. Experimental benchmarks and developments for X-ray astronomy applications

    International Nuclear Information System (INIS)

    We present γ spectroscopy validation measurements for the Geant4 radioactive decay simulation for a selected range of isotopes using a simple experimental setup. Using these results we point out problems in the decay simulation and where they may originate from. (author)

  16. 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

  17. An operator equation and relativistic alterations in the time for radioactive decay

    Directory of Open Access Journals (Sweden)

    Robert A. Herrmann

    1996-06-01

    Full Text Available In this paper, using concepts from the nonstandard physical world, the linear effect line element is derived. Previously, this line element was employed to obtain, with the exception of radioactive decay, all of the experimentally verified special theory relativistic alterations in physical measures. This line element is now used to derive, by means of separation of variables, an expression that predicts the same increase in the decay time for radioactive material as that predicted by the Einstein time dilation assumption. This indicates that such an increase in lifetime can be attributed to an interaction of the radioactive material with a nonstandard electromagnetic field rather than to a basic time dilation.

  18. Radioactivity around naval nuclear bases

    International Nuclear Information System (INIS)

    Between 12th July and 2nd August 1988, Greenpeace took sediment samples from around four Royal Navy bases in the United Kingdom. Faslane, where nuclear powered submarines are berthed; Devonport and Rosyth where refit work is carried out and Portsmouth where US and UK nuclear submarines often visit. Samples were also taken from the US Navy base at Holy Loch, Scotland, where nuclear powered ballistic missile submarines are based. The samples were analysed at St Bartholomew Hospital Medical School, London. Identical samples were provided to the MoD personnel at Faslane and Devonport on the date taken. The purpose of carrying out the sampling programme was to highlight the fact that publicly available statistics from Ministry of Agriculture Fisheries and Food (MAFF) are too limited in range, concentrating as they do merely on radioactive levels found between tides. The findings point to the necessity of monitoring subtidal as well as intertidal areas since levels of radioactivity found in the samples at Faslane and Holy Loch were four to nine times the figures published by MAFF. Until such time as nuclear power is no longer used at sea, it is the contention of Greenpeace that a more independent and comprehensive picture of the nature of radioactive contamination from around UK naval establishments must be obtained, than that presently available from MAFF. (author)

  19. 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.

  20. The importance of the radioactive decay study on prospecting, research and plough of uranium

    International Nuclear Information System (INIS)

    A radioactive decay series such as that of U-238 is said to be in a state of secular equilibrium when the number of atoms of each daughter being produced in the series is equal to the number of atoms of that daughter being lost be radioactive decay. When this condition exists, it is possible to determine the amount of the parent of the decay series by measuring the radiation from daughter element. Radioactive disequilibrium is quite a common occurrence in roll-front or sandstone-type uranium deposits. The reason is that uranium may be mobile when oxidized and daughter products formation lags behind. This leads to a distribution of radioelements wherein the daughter products (e.g. Bi - 214) are left behind, creating a daughter excess or parent-deficiency state, with strong gamma ray activity. Miners should receive from geologists a precise and sufficiently detailed geological report, including all the informations about disequilibrium problems of the uranium, deposits. (author)

  1. 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.

  2. 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)

  3. Levels in 160Yb from the radioactive decay of 160Lu

    International Nuclear Information System (INIS)

    The γ-rays following the radioactive decay of 160Lu into 160Yb have been studied. The Lu source was produced in the 144Sm(19F, 3n) reaction at 85 MeV. Excitation functions, half-lives, γ-γ and γ-X-ray coincidences and conversion electrons were measured. Two β+ decaying states in 160Lu were found with half-lives of 36.2(3)s and 40(1)s. 160Yb levels deduced from the decay of 160Lu are presented. (orig.)

  4. 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.)

  5. Effects of atomic electrons on nuclear stability and radioactive decay

    International Nuclear Information System (INIS)

    Despite the energy-space-time scale of nuclear processes considerably differs from that of atomic ones, a lot of experimental evidences for a strong effect of atomic electrons on nuclear processes is documented. In the present paper we analyze how the change of atomic electronic states may influence the rate of nuclear decay and the condition of nuclear stability, and how it may redistribute the channels of nuclear decay. The changes of atomic electronic states may be caused by application of a strong magnetic field. It is known that under full ionization of the atom the bound-state β-decay (i.e. when β-electron does not escape from the atom and occupies the bound atomic state) appears to be energetically preferable in contrast to the case of β-decay of the neutral atom. Our analysis of the database of nuclear masses gives the following conclusion: a number of nuclei are found, which are stable in the neutral atom and should be unstable with respect to bound-state β-decay if the nucleus is bare (i.e. under full ionization of the atom): 163Dy, 193Ir, 205Tl. Under high degree of atom's ionization, the β-stability threshold moves towards larger values of Z, i.e. towards decreasing the neutron/proton ratio in the nucleus. We show that the clearance of electron atomic states in a certain number of atoms whose nucleus emits the delayed neutron may increase the fraction of delayed neutrons. It is also shown, that while considering the nuclear processes - both known and novel ones - which proceed with participation of weak interactions, one has to take into account the mass of electron in spite of its smallness in comparison with the nuclear binding energy. Within the frame of the respectively enhanced accuracy, it is shown that the necessary and sufficient condition of nuclear stability with respect to β-decay and K-capture appears to be the minimum of the mass defect on isobars, that not always coincides with the widespread condition of the minimum of nuclear mass

  6. 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.

  7. Flicker-noise fluctuations in α-radioactive decay

    International Nuclear Information System (INIS)

    Counting statistics of α particles from three sources, one containing 241Am; one containing 239Pu, 241Am, and 244Cu; and a source containing 148Gd, were determined over periods of 1-4000 min. In particular, the two-sample variance or Allan variance was determined for many sample runs. According to a recent theorem, there is a unique relation between the particle-flux spectral noise density and the Allan variance. It was found that for small counting periods, the statistics were Poissonian, corresponding to shot noise of the particle flux. For long periods (> ≅ 200 min), the counting statistics were found to be non-Poissonian, indicating the presence of 1/f noise and (or) Lorentzian noise. The 1/f noise gave flicker floors of (0.5-0.7) x 10-7 for 239Pu, (1.0-1.3) x 10-7 for 241Am, and 3.0 x 10-7 for 244Cm. The Lorentzians were not reproducible in different runs and are probably associated with chemical oxidation-reduction rate processes in the source. The 1/f noise is likely inherent in the process of α-particle decay, indicating that the classical picture of alpha decay as a Poisson process is incomplete. Some forms of quantum 1/f noise associated with the tunnel-emission process are briefly discussed

  8. Competition between α-decay and proton radioactivity within a generalized liquid drop model

    International Nuclear Information System (INIS)

    The α-decay and proton radioactivity half-lives of a number of spherical nuclei in the proton range Z = 51–83 were investigated within a generalized liquid drop model (GLDM), including the proximity effects between nuclei in a neck and the mass and charge asymmetry. The penetrability on potential barrier constructed by the GLDM is calculated by the WKB approximation for the two decay modes. The spectroscopic factors (Sp) evaluated by the relativistic mean field theory combined with the BCS method for the proton radioactivity. The agreement between theoretical results and experimental data is satisfactory for both α and proton emission, which allows us to make predictions about the half-lives of the two decay modes for some unstable nuclei in the same theoretical framework. (paper)

  9. Radioactive decay viewed through an extending dead time

    International Nuclear Information System (INIS)

    Theories of the effect of extending dead times, either single or in series, on a stationary Poisson process have been adapted to the case of a decaying Poisson emitter. The theoretical results obtained are displayed in a general form so that they are independent of the actual value of the nuclide half-life. The theories were confirmed by undertaking measurements with sup(99m)Tc and sup(116m)In which resulted in values for their respective half-lives which are in agreement with those obtained by conventional means. Details of a generator which can impose a controlling dead time of either the extending or non-extending type on a train of pulses are presented in the appendix. (orig.)

  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. Decay heat calculations with the CEA radioactivity data bauk and the code PEPIN

    International Nuclear Information System (INIS)

    The CEA radioactivity data bank, has been updated mainly from ENSDF and from some recent experimental results. This library contains the decay data for about 700 fission products (F.P.), 220 actinides and more than 1400 other nuclides. A comparison between our data and ENDF/B5 is shown for the fission products. The fission products part of this library is currently used for shielding and decay heat calculations with the PEPIN code. Calculations and spectral comparisons of the available experiments (Dickens, Lott, Yarmell ...) and other recent calculations is made for thermal fission of 235U and 239Pu using our data bank as input

  12. DCHAIN: A user-friendly computer program for radioactive decay and reaction chain calculations

    International Nuclear Information System (INIS)

    A computer program for calculating the time-dependent daughter populations in radioactive decay and nuclear reaction chains is described. Chain members can have non-zero initial populations and be produced from the preceding chain member as the result of radioactive decay, a nuclear reaction, or both. As presently implemented, chains can contain up to 15 members. Program input can be supplied interactively or read from ASCII data files. Time units for half-lives, etc. can be specified during data entry. Input values are verified and can be modified if necessary, before used in calculations. Output results can be saved in ASCII files in a format suitable for including in reports or other documents. The calculational method, described in some detail, utilizes a generalized form of the Bateman equations. The program is written in the C language in conformance with current ANSI standards and can be used on multiple hardware platforms

  13. Interactive information system on the nuclear physics properties of nuclides and radioactive decay chains

    International Nuclear Information System (INIS)

    A brief review is given of a computerized information system on the nuclear physics properties of nuclides and radioactive decay chains. The main difference between the system presented here and those already in existence is that these evaluated databases of nuclear physics constants are linked to a set of programs, thus enabling analysis of a wide range of problems regarding various nuclear physics applications. (author)

  14. Interactive information system on the nuclear physics properties of nuclides and radioactive decay chains

    Energy Technology Data Exchange (ETDEWEB)

    Plyaskin, V.I.; Kosilov, R.A. [Institute of Nuclear Power Engineering, Obninsk (Russian Federation); Manturov, G.N. [Russian Federation National Research Centre - Institute for Physics and Power Engineering, Obninsk (Russian Federation)

    2002-08-01

    A brief review is given of a computerized information system on the nuclear physics properties of nuclides and radioactive decay chains. The main difference between the system presented here and those already in existence is that these evaluated databases of nuclear physics constants are linked to a set of programs, thus enabling analysis of a wide range of problems regarding various nuclear physics applications. (author)

  15. Radioactive decay properties of Bruce 'A' CANDUTM UO2 fuel and fuel recycle waste

    International Nuclear Information System (INIS)

    This report is a compilation of the radioactive decay properties of irradiated CANDU fuel of the type used at the Bruce Nuclear Power Generating Station. The report is similar to AECL-4436/1 and AECL-4436/2, which describe the decay properties of Pickering fuel. Using revised reference input data, the computer codes LATREP and CANIGEN II were employed to calculate the mass, activity and decay heat of the component isotopes in irradiated Bruce fuel. The decay properties of the fuel are tabulated for burnup levels of 550, 685, 865 and 1045 GJ/kg U (150, 190, 240 and 290 MWh/kg U). The decay properties for the waste that would be produced from recycling the fuel in a Purex-type process are tabulated for a burnup of 685 GJ/kg U. The total alpha, beta and gamma activity, the gamma spectra and neutron emissions of the used fuel and recycle waste are also presented. The report also presents a comparison of the CANIGEN II generated data with other codes such as ISOGEN, ORIGEN, FISSPROD-2 and earlier CANIGEN data. A detailed analysis of the differences between codes is presented along with a comparison of the ability of the codes to correctly predicts measured decay heats, radiation fields and actinide concentrations. This report is intended to provide a reference source to assist both research programs and safety assessment studies within the Canadian Nuclear Waste Management Program

  16. 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

  17. 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.

  18. 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)

  19. 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.

  20. 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

  1. Consequences of helium production from the radioactive decay of tritium on the properties of palladium tritide

    International Nuclear Information System (INIS)

    Tritium is an element of considerable interest in the nuclear industry. Since it is radioactive, it needs to be stored in a safe but easily recoverable manner. It is an isotope of H, and hence some of the techniques used for hydrogen storage can be employed, the safest being its storage in the form of a tritide. However, in contrast to the case of hydrogen, tritium decays into 3He and thus modifies the properties of the tritide. The recoil energy of 3He in this decay process is very small, ∼1.03 eV, and not enough for atomic displacements to occur. We show in this paper, on the basis of our electronic structure calculations, that in the case of PdT, the 3He produced from the radioactive decay of tritium, although not soluble in the tritide, can be easily retained, in a metastable state, in surprisingly large quantities at the octahedral interstitial sites where it is born. This can explain the expansion of the lattice parameter, the lowering of the plateau pressure, and the fragility of the tritide observed experimentally. We also find that the lowering of the plateau pressure is not entirely due to the lattice expansion as usually assumed and that electronic interactions also play a role

  2. Study of 138La radioactive decays using LaBr3 scintillators

    International Nuclear Information System (INIS)

    We present a detailed investigation of the intrinsic activity of LaBr3 scintillators from the natural abundance of radioactive isotope 138La. Compared to earlier studies of lanthanum halides intrinsic activity, we gained a sharper insight by using samples of different sizes, ranging from 0.16 cm3 to 347 cm3, and by applying in our recent analysis results on the non-proportionality of scintillation response. In addition, we took advantage of the fact that LaBr3 spectrometers offer a unique opportunity, never available before, to study the characteristics of the 138La electron capture and β radioactive decays that are 2nd order unique forbidden transitions. The observed shape of the β continuum, measured down to the energy of 2 keV, is found to be different than expected from standard nuclear theory, indicating a possible underestimation of the screening effect for β energies below 75 keV.

  3. 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

  4. 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.

  5. 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

  6. The ENSDF radioactivity data base for IBM-PC and computer network access

    International Nuclear Information System (INIS)

    A data base system for radioactivity gamma rays is described. A base with approximately 15000 gamma rays from 2777 decays is available for installation on the hard disk of a PC, and a complete system with approximately 73000 gamma rays is available for on-line access via the NORDic University computer NETwork (NORDUNET) and the Swedish University computer NETwork (SUNET)

  7. 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

  8. Radioactivity

    International Nuclear Information System (INIS)

    This educative booklet give a general overview of radioactivity: history, structure of matter, radiations, radioactivity law, origin of radioactivity, radioactivity uses, radioprotection and measurement units. (J.S.)

  9. 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

  10. Induced radioactivity in the target station and decay tunnel from a 4MW proton beam

    CERN Document Server

    Agosteo, S; Otto, T; Silari, Marco

    2003-01-01

    An important aspect of a future CERN Neutrino Factory is the material activation arising from a 2.2 GeV, 4 MW proton beam striking a mercury target. A first estimation of the hadronic inelastic interactions and the production of residual nuclei in the target, the magnetic horn, the decay tunnel, the surrounding rock and a downstream dump has been performed by the Monte Carlo hadronic cascade code FLUKA. The aim is both to assess the dose equivalent rate to be expected during maintenance work and to evaluate the amount of residual radioactivity, which will have to be disposed of after the facility has ceased operation. This paper discusses the first results of such calculations.

  11. 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.)

  12. 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.

  13. 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.

  14. Cluster radioactive-decay using the relativistic mean field theory within the preformed cluster model

    International Nuclear Information System (INIS)

    In this paper, based on PCM, for the first time we use the relativistic mean field (RMF) theory, which is already shown to support the clustering effects in various heavy parents with observed cluster decays. For the present study, we have chosen the parents 222Ra, 226,228Th, 230,232,234U, 236,238Pu, and 242Cm which decay, respectively, in to 14C, 18,20O, 22,24,26Ne, 28,30Mg, and 34Si clusters, having always the doubly magic 208Pb as the daughter nucleus

  15. 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

  16. Atomic-Scale Picture of the Composition, Decay, and Oxidation of Two-Dimensional Radioactive Films.

    Science.gov (United States)

    Pronschinske, Alex; Pedevilla, Philipp; Coughlin, Benjamin; Murphy, Colin J; Lucci, Felicia R; Payne, Matthew A; Gellman, Andrew J; Michaelides, Angelos; Sykes, E Charles H

    2016-02-23

    Two-dimensional radioactive (125)I monolayers are a recent development that combines the fields of radiochemistry and nanoscience. These Au-supported monolayers show great promise for understanding the local interaction of radiation with 2D molecular layers, offer different directions for surface patterning, and enhance the emission of chemically and biologically relevant low-energy electrons. However, the elemental composition of these monolayers is in constant flux due to the nuclear transmutation of (125)I to (125)Te, and their precise composition and stability under ambient conditions has yet to be elucidated. Unlike I, which is stable and unreactive when bound to Au, the newly formed Te atoms would be expected to be more reactive. We have used electron emission and X-ray photoelectron spectroscopy (XPS) to quantify the emitted electron energies and to track the film composition in vacuum and the effect of exposure to ambient conditions. Our results reveal that the Auger electrons emitted during the ultrafast radioactive decay process have a kinetic energy corresponding to neutral Te. By combining XPS and scanning tunneling microscopy experiments with density functional theory, we are able to identify the reaction of newly formed Te to TeO2 and its subsequent dimerization. The fact that the Te2O4 units stay intact during major lateral rearrangement of the monolayer illustrates their stability. These results provide an atomic-scale picture of the composition and mobility of surface species in a radioactive monolayer as well as an understanding of the stability of the films under ambient conditions, which is a critical aspect in their future applications. PMID:26735687

  17. Schemes of radioactive decay, its interpretations in the scope of the radiological protection

    International Nuclear Information System (INIS)

    Full text: In our teaching experience we have verified that the interpretation of the symbols of radioactive decay schemes is one of the most difficult subject in the study of radioisotope methodologies for almost all professionals, and specially for those who have no solid background in mathematics or physics. The correct interpretation of decay schemes has fundamental importance for the proper election of measurement conditions and for performing the dosimetric and shielding calculations. Nuclides employed in Nuclear Medicine and Biomedicine are beta, gamma or beta/gamma emitters. Interpretation of decay schemes of beta emitters, by β+, β- or electronic capture are not difficult. In gamma emitting nuclides it is frequent that a particular level of energy is de-excited through more than one gamma transition of a given percentage and energy. On the other hand, it is also frequent that conversion electrons are emitted together with gamma photons, the proportion of which is usually given as the conversion factor, e/γ. The fraction of emitted photons is calculated as: 1 / [1+ (e/γ)], whereas the fraction of emitted conversion electrons is equal to: (e/γ) / [1+ (e/γ)]. Special attention should be given to the post-accommodation mechanism after disintegration in which orbital vacancies are produced: electron conversion or electron capture, in which the emission of X-rays and Auger electrons occur. All this information should be taken into account for the correct choice of measurement conditions, as well as internal and external dose calculations. In the present work we describe the analysis and interpretation of disintegration schemes in general and that of the most employed nuclides in Nuclear Medicine and Biomedicine. (author)

  18. Selective Determination of Gaseous Fission Products in a Radioactive Decay Chain

    International Nuclear Information System (INIS)

    We have developed equipment for the selective determination of gaseous fission products in a radioactive decay chain. A circulating pump is used to pass the gases being analysed through equipment consisting of an input filter for removing solid particles, a sealed enclosure, referred to as the disintegration chamber, in which some of the radioactive gases disintegrate, and a filter at the outlet of the enclosure for retaining the daughter products produced in the disintegration chamber. After suction, the activity of the daughter products collected by the filter is analysed. We have studied the families of seven fission gases whose half-lives range between 2.8 hours and 10 secs: 88Kr, 138Xe, 89Kr, 139Xe, 90Kr, 140Xe, 91Kr. 88Kr, 138Xe and 89Kr are measured by cycling without a source; this procedure involves three operations: the fission gases are formed in the generator; after the production of fission gases ceases, the gases with the shortest half-lives are eliminated during a delay time; the air containing the remaining fission gases is recycled in the equipment. By altering the irradiation, delay and cycling times, one improves the relative concentration of the gas daughter product one wants to determine. The gases with the shortest half-lives, i.e. 139Xe, 90Kr, 140Xe and 91Kr, are measured in a single pass: as the fission gases are produced, they are passed through the installation and vented to the surroundings. In this case, the suction time and the delay time after suction are varied to improve the relative concentration of the gas daughter product being measured. The activity of the outlet filter is measured by gamma spectrometry with subtraction of the Compton effect. It is thus possible to separate the isotopes of solid elements which are daughter products of the different gases. (author)

  19. A computer code for calculation of radioactive nuclide generation and depletion, decay heat and γ ray spectrum. FPGS90

    International Nuclear Information System (INIS)

    In a nuclear reactor radioactive nuclides are generated and depleted with burning up of nuclear fuel. The radioactive nuclides, emitting γ ray and β ray, play role of radioactive source of decay heat in a reactor and radiation exposure. In safety evaluation of nuclear reactor and nuclear fuel cycle, it is needed to estimate the number of nuclides generated in nuclear fuel under various burn-up condition of many kinds of nuclear fuel used in a nuclear reactor. FPGS90 is a code calculating the number of nuclides, decay heat and spectrum of emitted γ ray from fission products produced in a nuclear fuel under the various kinds of burn-up condition. The nuclear data library used in FPGS90 code is the library 'JNDC Nuclear Data Library of Fission Products - second version -', which is compiled by working group of Japanese Nuclear Data Committee for evaluating decay heat in a reactor. The code has a function of processing a so-called evaluated nuclear data file such as ENDF/B, JENDL, ENSDF and so on. It also has a function of making figures of calculated results. Using FPGS90 code it is possible to do all works from making library, calculating nuclide generation and decay heat through making figures of the calculated results. (author)

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

    International Nuclear Information System (INIS)

    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 235U, 238U, 239Pu and 241Pu, to be used in quick LWR reactor accident decay heat calculation tools. (authors)

  1. 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

  2. Chemical effects of the radioactive decay 7677Kr→7677Br reactions of recoil bromine in the gas phase

    International Nuclear Information System (INIS)

    This thesis describes the chemical reactions of 76Br and 77Br recoil species, formed by radioactive decay of 76Kr and 77Kr, with various gaseous compounds. Due to differences in decay energy and decay mode the resulting 76Br and 77Br isotopes obtain different kinetic energies and carry different charges; 76Kr decays completely via electron capture and the resulting 76Br is formed with a multiple positive charge and a kinetic energy of 7.2 eV at the most. 77Kr decays for only 16% via electron capture, resulting in 77Brsup(n+) ions with a maximal kinetic energy of 56.9 eV. 84% of the 77Kr decays via #betta#+ particle emission, which leads to 77Br species, that are mainly negative or uncharged and that possess a maximal kinetic energy of 36.4 eV. The aim of this study was to explore whether these initial differences in charge and kinetic energy are reflected in the products, formed after chemical reactions of 76Br and 77Br. (Auth.)

  3. Half-lives for proton emission, alpha decay, cluster radioactivity, and cold fission processes calculated in a unified theoretical framework

    International Nuclear Information System (INIS)

    Half-life values of spontaneous nuclear decay processes are presented in the framework of the Effective Liquid Drop Model (ELDM) using the combination of varying mass asymmetry shape description for the mass transfer with Werner-Wheeler's inertia coefficient VMAS/WW. The calculated half-lives of ground-state to ground-state transitions for the proton emission, alpha decay, cluster radioactivity, and cold fission processes are compared with experimental data. Results have shown that the ELDM is a very efficient model to describe these different decay processes in a same, unified theoretical framework. A Table listing the predicted half-life values, τc is presented for all possible cases of spontaneous nuclear break-up such that -7.30 10 τc [S] 10(τ/τc) > -17.0, where τ is the total half-life of the parent nucleus. (author)

  4. Ethernet-based automation in radioactivity measurements

    International Nuclear Information System (INIS)

    The paper describes an integrated radioactivity measurements laboratory involved in a New York State program of monitoring environmental radioactivity and bioassay samples. The laboratory is set up as a comprehensive Ethernet network that integrates radiation detectors, electronics hardware components as well as software automation and communications. Two DEC VAXstations 3100 and 3200 are central to the system. The VAXstation 3100 runs the Canberra/Nuclear Data Genie data-acquisition program. The Acquisition Interface Modules interface the ADCs to the Ethernet. Using the DEC Pathworks, the VAXstation 3100 is also a server for the Ethernet-based network of several 486 and 386 PCs. A designated PC can display the Genie acquisition window, in addition to the main window at VAXstation 3100. Another PC collects data from several NaI detectors using the Oxford/Nucleus DMR-II program. The paper also describe the plans for the future upgrades such as installation of VAXstation 4000/90 as well as interfacing the proportional counters and surface barrier detectors to the network

  5. Measurement of the absolute activity of alpha or beta emitters by measuring product nuclei (daughter) activity increase or by studing its radioactive decay

    International Nuclear Information System (INIS)

    A new method for determining absolute activity of alpha or beta emitters by measuring daughter product radioactive decay is presented. The separation method of UX from hexahydrated uranyl nitrate UO2(NO3)2 6H2O based on its dissolution in ethyl ether is described and the accuracy of this method is shown. The factors which accuate on total efficiency of a Geiger Mueller detector for beta particles are determined. The possibility to determine the mass of precursor element by daughter nuclei activity is shown. The results are compared with the one obtained by direct measurement of the mass (or number of atoms) of precursor radioactive substance and with theoretical values calculated for isotopes in secular equilibrium. (Author)

  6. 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)

  7. Chemical and biological consequences of the radioactive decay of iodine-125 in plasmid DNA

    International Nuclear Information System (INIS)

    Doubly labeled [U-14C, 5-125I]iododeoxycytidine (IdC) triphosphate was synthesized and incorporated enzymatically into defined positions of the plasmid pBR322. After storage under various conditions, the stable end products were analyzed using radio-GC, radio-HPLC, and electron microscopy. In addition, solutions of 14C-IdC-labeled DNA containing Na125I as an internal radiation source were studied to investigate the influence of internal radiolysis. Transmutation of the covalently bound 125I leads to complete destruction of the labeled nucleotide, giving rise to 14CO2 and 14CO as major products. Electron microscopy studies reveal that decay-induced double strand breaks (dsb) occur both at the site of decay and in areas as far as hundreds of base pairs apart from that site. Number and distribution of the breaks is strongly dependent on solvent and DNA configuration. A direct correlation exists between the extent of fragmentation of the nucleotide and the mean number of dsb

  8. 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)

  9. Data base about 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), a mature data base, documents accident incident experience from 1971 to the present from data acquired from the U.S. 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

  10. Chemical and biological consequences of the radioactive decay of iodine-125 in plasmid DNA

    International Nuclear Information System (INIS)

    The consequences of the decay of iodine-125 incorporated into DNA were studied on a molecular basis. Doubly (14C and 125I) labelled 5-iodo-2'-deoxycytidine 5'-triphosphate (IdCTP) was synthesized and incorporated enzymatically into the SalI-cutting site of the plasmid pBR 322. Part of the radioiodinated DNA was treated with T4-DNA ligase in order to restore the circular structure of the native plasmid molecule. After 4 months of storage under various conditions the stable end products were analyzed by radio GC, radio HPLC and electron microscopy. The experiments were not only carried out with doubly-labelled DNA but also with solutions of 14C-labelled DNA containing Na125I as internal radiation source. The results clearly indicate that radiolysis alone causes only minor damage. Transmutation of the covalently bound iodine, on the other hand, leads to complete destruction of the labelled nucleotide, giving rise to 14CO2 and 14CO as main products. The production of 14CO2 which originates from both the base as well as the sugar component shows a strong solvent effect. The electron microscopy analysis of the DNA reveals that the local effects are always connected with at least one double strand break directly at the site of decay. In addition, one finds DNA double strand breaks in areas which are hundreds of base pairs apart from that site. Under certain circumstances most of the DNA molecules exhibit up to 10 breaks. A comparison between ligase-treated and untreated DNA shows that the configuration of the DNA and the position of the labelled nucleotide play in important role in the extent of the overall damage. It could be demonstrated that there is a linear correlation between gaseous fragmentation products and the number of double strand breaks. (orig./MG)

  11. 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

  12. 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.)

  13. Comment on: Flicker-noise fluctuations in α-radioactive decay

    International Nuclear Information System (INIS)

    A discrepancy between experiments to establish the existence of 1/f fluctuations in α decay is discussed. It is argued that the flicker floor reported for direct α counting cannot be due to fluctuations intrinsic to the decay process. (2 refs.)

  14. 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)

  15. Experimental Studies Of An Exotic Decay Mode At The Proton Drip-Line: The Two-Proton Radioactivity

    International Nuclear Information System (INIS)

    Two-proton radioactivity is an exotic decay mode for very proton-rich nuclei. It was observed experimentally for the first time in 2002 for the nucleus 45Fe but the two protons could not be directly detected. So a new detector has been developed, a Time Projection Chamber, to individually observe the two protons emitted. It was used successfully during two experiments for the study of 45Fe and 54Zn. Energy correlations have been studied and the relative angle between the two protons is calculated.

  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. 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)

  18. New ISOL-based radioactive nuclear beam facility at INS

    International Nuclear Information System (INIS)

    An ISOL-based radioactive nuclear beam facility is just about to come into operation at INS. The present status of the INS radioactive nuclear beam project is reported. The capability of the facility and possible experiments are also discussed, including research programs of nuclear physics and nuclear astrophysics. (orig.)

  19. Importance of preformation probability in cluster radioactive-decays using relativistic mean field theory within the preformed cluster model

    International Nuclear Information System (INIS)

    Using the preformed cluster model (PCM) of Gupta and collaborators, we have deduced empirically the preformation probability P0emp from experimental data on both the α and exotic-cluster radioactive decays in the trans-lead region having doubly magic 208Pb or its neighboring nuclei as daughters, using the spherical and (in some cases) deformed relativistic mean field (RMF) densities. For spherical considerations, the P0α(emp) for alpha-decays is almost constant ~ 10-2 - 10-3 for all the parent nuclei studied, and P0c(emp) for cluster-decays of the same parents decrease with increasing size of cluster. The results obtained for spherical P0c(emp) are within two to three orders of magnitude of the well accepted phenomenological formula of Blendowske-Walliser (BW), which led us to propose a new empirical formula. The use of deformed RMF densities, however, tend to bring the results closer to BW formula. (author)

  20. Half-lives for proton emission, alpha decay, cluster radioactivity, and cold fission processes calculated in a unified theoretical framework

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, S.B.; Tavares, O.A.P.; Guzman, F.; Dimarco, A. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Garcia, F. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Universidade Estadual de Santa Cruz, Ilheus, BA (Brazil). Dept. de Ciencias Exatas e Tecnologicas; Rodriguez, O. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Instituto Superior de Ciencias e Tecnologia Nucleares, La Habana (Cuba); Goncalves, M. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil)

    2002-01-01

    Half-life values of spontaneous nuclear decay processes are presented in the framework of the Effective Liquid Drop Model (ELDM) using the combination of varying mass asymmetry shape description for the mass transfer with Werner-Wheeler's inertia coefficient V{sub MAS}/WW. The calculated half-lives of ground-state to ground-state transitions for the proton emission, alpha decay, cluster radioactivity, and cold fission processes are compared with experimental data. Results have shown that the ELDM is a very efficient model to describe these different decay processes in a same, unified theoretical framework. A Table listing the predicted half-life values, {tau}{sub c} is presented for all possible cases of spontaneous nuclear break-up such that -7.30 <{approx_equal} log{sub 10} {tau}{sub c} [S] <{approx_equal} 27.50 and log {sub 10}({tau}/{tau}{sub c}) > -17.0, where {tau} is the total half-life of the parent nucleus. (author)

  1. Gamma-spectrometric analysis of high salinity fluids - how to analyze radionuclides of the thorium decay chain far from radioactive equilibrium?

    Energy Technology Data Exchange (ETDEWEB)

    Degering, Detlev, E-mail: detlev.degering@vkta.de [Verein fuer Kernverfahrenstechnik und Analytik Rossendorf e.V., P.O. Box 510119, D-01314 Dresden (Germany); Koehler, Matthias, E-mail: matthias.koehler@vkta.de [Verein fuer Kernverfahrenstechnik und Analytik Rossendorf e.V., P.O. Box 510119, D-01314 Dresden (Germany)

    2011-11-15

    Highly saline brines from a geothermal plant in Neustadt-Glewe, Germany, were investigated with respect to their radionuclide concentrations. The natural decay series in these fluids are far from radioactive equilibrium with main activity contributions from the radium isotopes {sup 226}Ra, {sup 228}Ra and {sup 224}Ra. A general mathematical formulation for the coupled radionuclide activities within one decay chain is applied on the system {sup 228}Ra...{sup 212}Pb and tested on real samples in order to evaluate several radionuclide concentrations at the moment of sampling. - Highlights: > Highly saline brines of geothermal plants are far from radioactive equilibrium. > General mathematical formulation for the coupled radionuclide activities within one decay series was established. > Model was applied to the system Ra-228-Pb-212 and tested on real fluid samples from Neustadt-Glewe, Germany. > Method allows the calculation of radionuclide concentrations at the moment of sampling in systems with radioactive disequilibria.

  2. Simultaneous resolution of reactive radioactive decay, non-isothermal flow, and migration with application to the performance assessment for HLW repositories

    International Nuclear Information System (INIS)

    Radioactive decay is an important subject to take into account when studying the thermo-hydro-dynamic behavior of the buffer clay material used in the containment of radioactive waste. The modern concepts for the multibarrier design of a repository of high level waste in deep geologic formations consider that once canisters have failed, the buffer clay material must ensure the retention and/or delay of radionuclides within the time framework given in the assessment studies. Within the clay buffer, different chemical species are retarded/fixed according to several physicochemical processes (ion exchange, surface complexation, precipitation, matrix diffusion,..) but typical approaches do not consider the eventuality that radioactive species change their chemical nature (i.e. phase) thereby affecting their reactive behavior. The radioactive decay of an element takes place independently of the phase (aqueous, solid or gaseous) to which it belongs. This means that, in terms of radionuclide fixation, some geochemical processes will be effective scavengers (for instance mineral precipitation of crystal growth) while others will not (for instance ion exchange and/or sorption). In this contribution we present a reactive radioactive decay model of any number of chemical components including those that belong to decay series. The model, which is named FLOW-DECAY, also takes into account flow and isotopic migration and it has been applied considering a hypothetical model scenario provided by the project ENRESA 2000 and direct comparison with the results generated by the probabilistic code GoldSim. Results indicate that FLOW-DECAY may simulate the decay processes in a similar way that GoldSim, being the differences related to factors associated to code architecture. (orig.)

  3. 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.

  4. Improved measurement precision in decay time-based phosphor thermometry

    Science.gov (United States)

    Abou Nada, F.; Knappe, C.; Aldén, M.; Richter, M.

    2016-06-01

    This study comprises a continuation of the previous efforts of the authors to characterize different sources of errors in phosphor thermometry based on the determination of luminescence decays from thermographic phosphors. Whereas earlier investigations focused on point detectors utilizing different sensor technology, this work presents a comparison of four PMTs that are identical in terms of their product type. These detectors are supposedly identical, but the investigations revealed that their response is strictly individual. This study also shows a linear excitation energy dependence for the decay time of cadmium tungstate (CdWO4), the phosphor being used in this work. In addition, the potential influence of the intense and short fluorescence peak preceding the weaker and longer exponential decay in some phosphor materials was investigated using the electrical signal gating capability of the PMT. Finally, the evaluated decay time also appeared to be affected by the oscilloscope settings used when recording the phosphorescence signals. The presented results indicate that all operating parameters from the calibration measurement need to be rigorously reproduced in order to avoid systematic temperature errors in phosphor thermometry experiments that are based on reproducible measurements of the decay time. These results should be of more general interest also outside the phosphor community as the findings, presented herein, in principal concern all kinds of measurements that are dependent on reproducible measurements of signal shapes or time transients.

  5. Radioactivity

    International Nuclear Information System (INIS)

    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.)

  6. Radioactivity

    International Nuclear Information System (INIS)

    Tables are presented of trends in annual emissions of radioactive gaseous effluents at sites of civil establishments in the U.K. Trends in the discharge to surface and coastal water sites in the U.K. and trends in the radioactivity of solid wastes dumped in the N.E. Atlantic and in the volume and activity level of wastes disposed at sites in the U.K. are presented. Tables of radioactivity in samples of fish and shellfish at selected sites are presented. Radioactivity from global fallout and the annual mean ratio of 90Sr to calcium, and concentrations of 137Cs in milk are given. Trends in estimated collective doses from the consumption of fish and shellfish in the U.K. and Europe are presented. (U.K.)

  7. Radioactive decay properties of CANDU fuel. Volume 1: the natural uranium fuel cycle

    International Nuclear Information System (INIS)

    The computer code CANIGEN was used to obtain the mass, activity, decay heat and toxicity of CANDU fuel and its component isotopes. Data are also presented on gamma spectra and neutron emissions. Part 1 presents these data for unirradiated fuel, uranium ore and uranium mill tailings. In Part 2 they have been computed for fuel irradiated to levels of burnup ranging from 140 GJ/kg U to 1150 GJ/kg U. (author)

  8. Lethal Effect on Bacterium of Decay of Incorporated Radioactive Atoms (3H, 14C, 32P)

    International Nuclear Information System (INIS)

    The biological effect of decay of 3H, 14C and 32P incorporated into a bacterium depends on the nature of the organic molecule labelled, on the position of the isotope within it and on the isotope itself. In sum, results obtained to date show that: The decay of 3H atoms incorporated into certain macromolecules of a bacterium causes sterilization through ionization by the ß- particle emitted; transmutation is of negligible importance. This self-irradiation is comparable in effect with X-rays and is affected in a similar manner by the same factors: temperature, presence of a radioprotector, radiosensitivity of the strain. Decay of 14C or 32P atoms incorporated into bacterial DNA is lethal because of the transmutation effect; ionizations produced by emitted ß- particles may be disregarded. Survival curves for 32P transmutations depend on the experimental conditions. Some of the results obtained with 32P are similar to those obtained with X-rays, e.g. effects of temperature, radical capture and oxygen, while others are similar to those of u.v. light, e.g., effect of growth conditions. Comparative tests made with 32P indicate that the recoil energy of transmutation is not the phenomenon responsible for the lethal effect observed. Comparison of the results obtained after X-irradiation or decay of 3H or 32P incorporated into the DNA of bacteria of the same strain of E. coli shows that the efficiency of a 32P transmutation is about four times greater than that of an ionization produced at random within the same DNA. (author)

  9. Radioactive source monitoring system based on RFID and GPRS

    International Nuclear Information System (INIS)

    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 alarming 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. (authors)

  10. 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

  11. 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.

  12. Development of Data Base on Radioactive Discharges and Environmental Activity Levels in Slovenia

    International Nuclear Information System (INIS)

    Radioactivity monitoring in the environment in Slovenia has been currently performed on a regular basis as a monitoring of global radioactive contamination and as operational monitoring in the surroundings of facilities with radioactive discharges. Environmental radioactivity monitoring due to atmospheric nuclear bomb tests in Slovenia started in 1961, while monitoring of radioactive discharges from nuclear facilities in Slovenia started in early 1980s with the extent programmes: in the Krsko nuclear power plant in 1981, in the uranium mining and milling facility at Zirovski vrh (1985) and in the research reactor at Brinje near Ljubljana (1986). Both categories of the results are documented in written reports and sent to the competent authorities, mostly on annual basis. According to the requirements of the European Commission (Commission Recommendation of 8. June 2000 on the application of Article 36 of the Euratom Treaty concerning the monitoring of the levels of the radioactivity in the environment for the purpose of assessing the exposure of the population as a whole (2000/473/Euratom) and Commission Recommendation of 6. December 1999 on the application of Article 37 of the Euratom Treaty (1999/829/Euratom)) and on initiative of the IAEA (IAEA Document International Atomic Energy Agency (IAEA). Project International Data base on Discharges of Radioactive Material to the Environment, 2000) the Slovenian Nuclear Safety Administration (SNSA) started in 2002 with development of the computerised data base on environmental data and radioactive discharges data for the most facilities, specially for the nuclear fuel cycle. At present the environmental database contains the data on global contamination of air, surface waters, tap water sources and food chain (137Cs, 90Sr) and also on levels of major natural radionuclides (7Be, 210Pb, 226Ra, 40K). Data base on radioactive discharges for the recent years comprises the activities of fission and activation products (Nuclear

  13. 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.

  14. 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...

  15. Gaseous release of radioactive iodine from decaying plants. I. Release following foliar and root uptake

    International Nuclear Information System (INIS)

    Iodine uptake by plants is a significant link in the contamination of the food chain. Long half-live iodine was studied considering foliar and root uptake, loss by rain scavenging, residue decay or outgassing in order to assess two aspects of the problem: the importance of outgassing and the effect of the route of transfer on iodine losses. It appeared that iodine release was a function of the vegetal type, there were differences according to the pattern of absorption (via leaf or root) and the processes of iodine release were usually related to biochemical mechanisms

  16. 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

  17. Methods of capturing and immobilizing radioactive nuclei with metal fluorite-based inorganic materials

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yifeng; Miller, Andy; Bryan, Charles R.; Kruichak, Jessica Nicole

    2015-11-17

    Methods of capturing and immobilizing radioactive nuclei with metal fluorite-based inorganic materials are described. For example, a method of capturing and immobilizing radioactive nuclei includes flowing a gas stream through an exhaust apparatus. The exhaust apparatus includes a metal fluorite-based inorganic material. The gas stream includes a radioactive species. The radioactive species is removed from the gas stream by adsorbing the radioactive species to the metal fluorite-based inorganic material of the exhaust apparatus.

  18. 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...

  19. Methodical Base of Experimental Studies of Collinear Multibody Decays

    Science.gov (United States)

    Kamanin, D. V.; Zhuchko, V. E.; Kondtatyev, N. A.; Alexandrov, A. A.; Alexandrova, I. A.; Kuznetsova, E. A.; Strekalovsky, A. O.; Strekalovsky, O. V.; Pyatkov, Yu. V.; Jacobs, N.; Malaza, V.; Mulgin, S. I.

    2013-06-01

    Our recent experiments dedicated to study of the CCT of 252Cf (sf) were carried out at the COMETA setup based on the mosaics of PIN diodes and special array of 3He filled neutron counters. Principal peculiarity of the experiment consists in measuring of the heavy ions masses in the frame of the TOF-E (time-of-flight vs. energy) method in the wide range of masses and energies and almost collinear recession of the decay partners. The methodical questions of such experiment are under discussion here.

  20. Algorithms for modeling radioactive decays of π-and μ-mesons by the Monte-Carlo method

    International Nuclear Information System (INIS)

    Effective algorithms for modeling decays of μsup(→e) ννγ and πsup(→e)νγ by the Monte-Carlo method are described. The algorithms developed allowed to considerably reduce time needed to calculate the efficiency of decay detection. They were used for modeling in experiments on the study of pions and muons rare decays

  1. 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.

  2. 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)

  3. Radioactive threat detection using scintillant-based detectors

    Science.gov (United States)

    Chalmers, Alex

    2004-09-01

    An update to the performance of AS&E's Radioactive Threat Detection sensor technology. A model is presented detailing the components of the scintillant-based RTD system employed in AS&E products aimed at detecting radiological WMD. An overview of recent improvements in the sensors, electrical subsystems and software algorithms are presented. The resulting improvements in performance are described and sample results shown from existing systems. Advanced and future capabilities are described with an assessment of their feasibility and their application to Homeland Defense.

  4. The model of the decay of a radioactive tracer introduced to the muscle involving considerable variation of the muscle blood flow

    International Nuclear Information System (INIS)

    The paper describes an electronic analogous model simulating the activity decay curve of a radioactive sample of 133Xe injected to the muscle and washed out by the blood flow. The model experiments aimed at estimating the accuracy of the isotope method of determining the speed of blood flow in the heart muscle involving considerable flow variations. From the results and experimental data it was found that the periodical changes in the blood flow resulting from the heart action do not effect significantly the activity decay curve. The changes in the blood flow caused by other factors such as changes in the heart rate and perfusion pressure can be determined from the changes in the shape of the curve provided they are big enough. (author)

  5. Study of the e0-electron yield from the surface of 64Cu radioactive sources of various thicknesses at their positron decay

    International Nuclear Information System (INIS)

    The (eγ)-coincidence method was used to study the yield of e0-electrons from the surface of 64Cu radioactive sources of various thicknesses. The values of 0.120 (7), 0.076 (4), 0.044 (4), 0.034 (10), and 0.034 (2) for the e0-electron yield per a single event of β+-decay were obtained for the source thicknesses of 1.1, 2.0, 4.8, 11.0, and 14.5 μg/cm2, respectively. These values are several times lower than the known e0-electron yield at β- -decay under the same experimental conditions

  6. 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).

  7. 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.

  8. Computer code for double beta decay QRPA based calculations

    International Nuclear Information System (INIS)

    The computer code developed by our group some years ago for the evaluation of nuclear matrix elements, within the QRPA and PQRPA nuclear structure models, involved in neutrino-nucleus reactions, muon capture and β± processes, is extended to include also the nuclear double beta decay

  9. Development of radioactive source scanner based on PLC

    International Nuclear Information System (INIS)

    The radioactive radial uniformity of 68Ge line radioactive sources is a critical quality parameter. The radioactive source scanner with linear scanning function is developed by making use of high-speed pulse counters, high-speed pulse output ports, and the powerful instruction system of Siemens S7-200 series programmable logic controller (PLC). A computer used as a host computer of the instrument communicate with. the PLC by point to point interface (PPI) protocol, The instrument with functions of data collection, transmission, displaying, saving, motion control and instrument parameter settings, can be used to measure the radioactive radial uniformity and total activity of line radioactive source. The advantages of Using the PLC to develop nuclear instrumentation are development speed, strong anti-interference ability, and low-cost. This paper mainly describes the control system implementation and feature of the instrument. (authors)

  10. 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.

  11. 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.

  12. Decay heat calculations for reactors

    International Nuclear Information System (INIS)

    Estimation of release of energy (decay heat) over an extended period of time after termination of neutron induced fission is necessary for determining the heat removal requirements when the reactor is shutdown, and for fuel storage and transport facilities as well as for accident studies. The method of decay heat estimation relies on the measurements over practical time intervals as well as on calculation for predictions over very long time intervals. Neutron cross-sections, fission yields and decay data together with operational history are the basic inputs to such. A code used to calculate decay heat would require to generate isotopic inventory that would be present at the shutdown based on operational history of the reactor and follow up the decay over an extended period of time. Aspects of decay heat estimation based on standards like ANS 5.1 and by fuel cycle analysis codes shall be discussed. A Fuel Cycle Analysis Code, ADWITA (Activation, Decay, Waste Incineration and Transmutation Analysis) which can generate inventory based on irradiation history and calculate radioactivity and decay heat for extended period of cooling, has been written. The method and data involved in Fuel Cycle Analysis Code ADWITA and some results obtained shall also be presented. (author)

  13. 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

  14. 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)

  15. 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)

  16. -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.

  17. 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.

  18. 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

  19. 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

  20. Reconstruction of tau decays based on particle flow techniques at ATLAS

    International Nuclear Information System (INIS)

    The reconstruction of the substructure of tau decays can improve the tau energy resolution and is important for various measurements involving tau polarization, such as the spin-parity state of the newly discovered Boson in the tau decay channel. A tau reconstruction algorithm for ATLAS based on particle flow is scheduled to be ready in 2013. This presentation introduces ongoing efforts and compares possible implementations.

  1. Composite Stress Rupture: A New Reliability Model Based on Strength Decay

    Science.gov (United States)

    Reeder, James R.

    2012-01-01

    A model is proposed to estimate reliability for stress rupture of composite overwrap pressure vessels (COPVs) and similar composite structures. This new reliability model is generated by assuming a strength degradation (or decay) over time. The model suggests that most of the strength decay occurs late in life. The strength decay model will be shown to predict a response similar to that predicted by a traditional reliability model for stress rupture based on tests at a single stress level. In addition, the model predicts that even though there is strength decay due to proof loading, a significant overall increase in reliability is gained by eliminating any weak vessels, which would fail early. The model predicts that there should be significant periods of safe life following proof loading, because time is required for the strength to decay from the proof stress level to the subsequent loading level. Suggestions for testing the strength decay reliability model have been made. If the strength decay reliability model predictions are shown through testing to be accurate, COPVs may be designed to carry a higher level of stress than is currently allowed, which will enable the production of lighter structures

  2. 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.)

  3. Security system of radioactive sources based on ZigBee

    International Nuclear Information System (INIS)

    This public government and research section are paying more and more attention on the security of radioactive sources, which belongs to the realm of physical protection of small civil nuclear facilities. An application using the newly developed WLAN technology ZigBee is presented, which brings about many benefits to the sources and the whole facilities. At last, several key factors are analyzed. (authors)

  4. Design and development of the network based system for the supervision of radioactive sources

    International Nuclear Information System (INIS)

    Objective: To help the environmental protection authorities to upgrade the management of the related organizations and radioactive sources and improve the information level of nuclear technology utilization's supervision. Methods: On the basis of investigation of requirements, the network based system for the supervision of radioactive sources was divided into application system and supervision system, based on MYSQL and SQL Server2005 respectively. Results: The system satisfied the current requirements of the nuclear technology utilization's supervision and is in nationwide operation. Conclusion: The system achieved the dynamic tracking management of radioactive sources and improved the efficiency and level of radiation safety supervision in nuclear technology utilizations. (authors)

  5. 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

  6. Airborne radioactive contamination monitoring

    International Nuclear Information System (INIS)

    Current technologies for the detection of airborne radioactive contamination do not provide real-time capability. Most of these techniques are based on the capture of particulate matter in air onto filters which are then processed in the laboratory; thus, the turnaround time for detection of contamination can be many days. To address this shortcoming, an effort is underway to adapt LRAD (Long-Range-Alpha-Detection) technology for real-time monitoring of airborne releases of alpa-emitting radionuclides. Alpha decays in air create ionization that can be subsequently collected on electrodes, producing a current that is proportional to the amount of radioactive material present. Using external fans on a pipe containing LRAD detectors, controlled samples of ambient air can be continuously tested for the presence of radioactive contamination. Current prototypes include a two-chamber model. Sampled air is drawn through a particulate filter and then through the first chamber, which uses an electrostatic filter at its entrance to remove ambient ionization. At its exit, ionization that occurred due to the presence of radon is collected and recorded. The air then passes through a length of pipe to allow some decay of short-lived radon species. A second chamber identical to the first monitors the remaining activity. Further development is necessary on air samples without the use of particulate filtering, both to distinguish ionization that can pass through the initial electrostatic filter on otherwise inert particulate matter from that produced through the decay of radioactive material and to separate both of these from the radon contribution. The end product could provide a sensitive, cost-effective, real-time method of determining the presence of airborne radioactive contamination

  7. Properties of radioactive aerosols produced by interactions of indoor radon decay products with cigarette smoke and burning cigarettes

    International Nuclear Information System (INIS)

    Risks of lung cancer to smokers, attributable in part to exposure to indoor radon decay products, are dependent on properties of radon progeny-tagged smoke particles. The authors have investigated the properties and interactions of radon progeny-tagged smoke particles as they pass through burning cigarettes into mainstream smoke, using /sup 212/Pb-tagged smoke particles as tracers, cascade impactors for particle size determinations, and low-level β/sup -/ counting techniques. /sup 212/Pb-tagged particles of submicron size are destroyed in the burning zone of cigarettes. However, /sup 212/Pb-tagged smoke particles exceeding 1.0 μm diameter pass readily through the burning zone and tobacco rod into mainstream smoke. /sup 212/ Pb- tagged particles in mainstream smoke have an activity median aerodynamic diameter between 1.0 and 2.0 μm diameter. Particles > 2.0 μm diameter carry about 10 percent of the total activity, are selectively deposited at the carina of bifurcations, and are resistant to dissolution in lung fluid. These results indicate that indoor radon progeny on large particles in mainstream smoke can contribute substantially to the cumulative alpha radiation dose at ''hot spots'' in the bronchi of smokers

  8. 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

  9. Nuclear decay processes

    International Nuclear Information System (INIS)

    Radioactive decay processes involve nuclear reactions that generally involve specific emissions from the nucleus and result in the transmutations of elements. This article discusses types of nuclear reactions according to their modes of decay. Included in the text are the following: α decay; β decay; negatron decay; positron decay; orbital electron capture; isomeric transitions. Each has a text/diagram explanation, examples, and characteristics summary. Also included are sources of nuclear and atomic data and a five problem set. 4 refs., 7 figs., 1 tab

  10. 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)

  11. Double beta radioactivity and physics of the neutrino. Study of the background noise at 3 MeV in the search of 100Mo beta beta decay

    International Nuclear Information System (INIS)

    Double beta decay without neutrino emission provides a test of the mass and nature of neutrinos (Majorana or Dirac). Experimental proof would be the observation of a peak at the transition energy in the spectrum of the two emitted electrons. The expected half-life of the process is extremely long (about 1025 years for 100Mo). So, being thus, it is very important to get a good knowledge of the origins and contributions of background noise in the region where the signal could occur. The main origins of the background noise in the region where the signal could occur. The main origins of the background noise are found to be e+ - e- pairs induced by heavy energy gamma rays. These gamma rays follow the thermal neutron capture by the components of the detector. Another factor in the production of background noise is natural radio-activity. For example, the presence of Radon in the laboratory has been observed to produce deposits of 214Bi on the sides of the detector. Data taken with the NEMO 2 prototype and an enriched molybdenum source foil indicates that the background limit reached is of the order of 1 event per year in the 3 MeV region. Results of this work have proven the necessity to have a magnetic field in NEMO 3 in order to reject e+ - e-pairs. (author)

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

    International Nuclear Information System (INIS)

    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)

  13. 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)

  14. 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

  15. 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.

  16. Exponential decay of shearing stress during jerky flows in a Zr-based bulk metallic glass

    Directory of Open Access Journals (Sweden)

    J. W. Qiao

    2013-03-01

    Full Text Available Presently, an exponential decay of shearing stresses with the time during jerky flows in a Zr-based bulk metallic glass is revealed. The flow stresses with the time satisfy the following equation: σ = A · e−B · x, where A = −158.24*exp ( − N/47.60 + 1939.63 (N = 1, 2, 3…, and the mean value of obtained B is −0.13 with a Normal distribution. During jerky flows, the viscous shearing layer is formed, and the exponential decay of shear banding is present. The evolvement of shear bands is explained by the consumption of free volumes during flows.

  17. Vertex based missing mass calculator for 3-prong hadronically decaying tau leptons in the ATLAS detector

    CERN Document Server

    Maddocks, Harvey

    In this thesis my personal contributions to the ATLAS experiment are presented, these consist of studies and analyses relating to tau leptons. The first main section contains work on the identification of hadronically decaying tau leptons, and my specific contribution the electron veto. This work involved improving the choice of variables to discriminate against electrons that had been incorrectly identified as tau leptons. These variables were optimised to be robust against increasing pile-up, which is present in this data period. The resulting efficiencies are independent of this pile-up. The second main section contains an analysis of Z → τ τ decays, my specific contribution was the calculation of the detector acceptance factors and systematics. The third, and final section contains an analysis of the performance of a new vertex based missing mass calculator for 3-prong hadronically decaying tau leptons. It was found that in its current state it performs just as well as the existing methods. However it...

  18. 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

  19. Microfluidic-Based sample chips for radioactive solutions

    International Nuclear Information System (INIS)

    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

  20. 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.

  1. High polymer-based composite containers for the disposal/storage of high radioactive waste

    International Nuclear Information System (INIS)

    Spent fuel disposal is one of the hottest topics in nuclear news, getting considerable amount of media coverage around the world. Canada as well as many other countries with nuclear electric generation plants has therefore been pushed to develop policy on this issue. One of the proposed and most widely supported strategies is to dispose of this so-called waste permanently in deep underground vaults. Through the use of engineered barriers including vault seals, vault composition, backfill and sophisticated containers this radioactive matter is isolated from the natural environment. According to a design developed by Atomic Energy of Canada, the seclusion must be maintained for approximately 500 years, which is a representative length of time it takes for the radioactive elements to decay to natural background levels. The purpose of the current study is to determine the feasibility of using poly(ether ether ketone), an advanced polymer, and continuous carbon fibre in a consolidated composite as a principal container component. Feasibility was determined by simulating the ultimate radioactive environment that the containers will be exposed to by exposing test specimens to neutron and gamma radiation fields at various temperatures (20oC - 75oC) for a variety of time intervals. (author)

  2. 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...

  3. Purity and radioactive decay behaviour of industrial 2D-reinforced SiCf/SiC composites

    International Nuclear Information System (INIS)

    Ceramic matrix composites based on SiC with continuous fibres (SiCf/SiC) are considered promising structural materials for future fusion devices. It was still to clarify, whether impurities in industrial SiCf/SiC could jeopardise radiological advantages. Experimental impurity analyses revealed a two-dimensionally reinforced SiCf/SiC with the matrix produced by CVI as very pure. Chemo-spectrometric methods were combined with radioactivation methods (CPAA, NAA). A quantification of the main constituents Si, C and O was added. Calculations with the FISPACT-2.4 code and EAF-2 library identified elements detrimental for different low-activation criteria. For the neutron exposure, EEF reactor-study first wall and blanket conditions were simulated. The calculated SiCf/SiC included 48 trace elements. Even under conservative assumptions, all low-activation limits of European interest are fulfilled. Exclusively the hands-on recycling limit for the First Wall can intrinsically not be satisfied with SiC. The theoretical goal of a SiCf/SiC depleted of 28Si (isotopic tailoring) is critically discussed. ((orig.))

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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

  9. 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

  10. Integrated Data Base for 1989: 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, 1988. These data are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The current projections of future waste and spent fuel to be generated through the year 2020 and characteristics of these materials are also presented. 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 defense-related and private industrial and institutional (I/I) activities. The radioactive materials considered, on a chapter-by-chapter basis, are spent fuel, high-level waste, transuranic waste, low-level waste, commercial uranium mill tailings, remedial action waste, commercial reactor and fuel cycle facility decommissioning waste, and mixed (hazardous and radioactive) low-level waste. For most of these categories, current and projected inventories are given through the year 2020, 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, highly radioactive materials that may require geologic disposal. 45 figs., 119 tabs

  11. Integrated Data Base for 1991: 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, 1990. These data are based on the most reliable information available form government sources, the open literature, technical reports, and direct contacts. The current projections of future waste and spent fuel to be generated generally through the year 2020 and characteristics of these materials are also presented. 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 are spent 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 2020, 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. 160 refs., 61 figs., 142 tabs

  12. Integrated data base for 1990: 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, 1989. These data are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The current projections of future waste and spent fuel to be generated through the year 2020 and characteristics of these materials are also presented. 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 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 2020, 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. 22 refs., 48 figs., 109 tabs

  13. Evaluation procedures for experimental decay data

    International Nuclear Information System (INIS)

    The file of radioactive-nuclide decay data included in ENDF/B is intended to provide a commonly available base of evaluated decay data relevant to reactor research and technology and to nuclear-power applications. Consequently, the types of data it contains have been carefully chosen to permit their application to a wide variety of reactor-related problems while still retaining a relatively compact size. The history and purpose of the decay-data evaluations for ENDF/B are reviewed together with the sources and types of experimental data considered. The importance of the generic relationships of the radiations emitted following nuclear decay is discussed and their treatment in ENDF/B is illustrated. For purposes of illustration, an example of an experimental decay-data evaluation is presented. The procedures for accounting for the various atomic processes associated with nuclear decay are presented. The increasing availability of data from the study of the complex decay schemes of nuclides with large decay energies (e.g., short-lived fission products) presents a special challenge for reactor-related decay-data evaluations. The unique problems posed by inherent limitations in these data are pointed out. The need for new data types and expermental techniques specially tailored to prodice the information required for reactor-technology applications is indicated. The potential relevance of existing beta-strength-function measurements as one means of addressing these problems is discussed

  14. Measuring music transcription results based on a hybrid decay/sustain evaluation

    OpenAIRE

    Fonseca, Nuno; Ferreira, Aníbal

    2009-01-01

    Although much work is being done in music transcription research, the evaluation of these techniques is less addressed by the research community. The lack of widely accepted metrics and databases presents an obstacle to the assessment of existing music transcription approaches. This paper presents an analysis of existing metrics and proposes a new method for measuring the results of music transcription. Based on the idea that decay and sustained music instruments may have different requiremen...

  15. The electroluminescent decay mechanism of rare-earth ions in OLEDs based on a terbium complex

    OpenAIRE

    Liang, CJ; Choy, WCH; Huang, C.

    2007-01-01

    The organic light-emitting diodes (OLEDs) based on terbium (Tb) complexes show sharp green emission spectrum with excellent color purity. However, the brightness of Tb-OLEDs is generally weak. Here, the electroluminescent (EL) decay mechanism of TB-OLEDs is studied by arbitrarily using tris-(1-phenyl-3-methyl-4-isobutyryl-5-pyrozolone)-bis(triphenyl phosphine oxide) terbium as the emitting layer. The device shows high EL efficiency at low current density but rapid reduction of device efficien...

  16. Experience base for Radioactive Waste Thermal Processing Systems: A preliminary survey

    International Nuclear Information System (INIS)

    In the process of considering thermal technologies for potential treatment of the Idaho National Engineering Laboratory mixed transuranic contaminated wastes, a preliminary survey of the experience base available from Radioactive Waste Thermal Processing Systems is reported. A list of known commercial radioactive waste facilities in the United States and some international thermal treatment facilities are provided. Survey focus is upon the US Department of Energy thermal treatment facilities. A brief facility description and a preliminary summary of facility status, and problems experienced is provided for a selected subset of the DOE facilities

  17. Remote monitoring of radioactive sources based on i.MX27 platform

    International Nuclear Information System (INIS)

    It based on the ASIC solutions, has chosen Freescale's i.MX27 development system as a platform for designing video capture and transmission system. The article uses the latest H.264 video compression standard and complete the entire system of hardware and software design, which is successfully applied to remote monitoring of radioactive sources. (authors)

  18. 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.

  19. Computer-based supervisory control and data acquisition system for the radioactive waste evaporator

    International Nuclear Information System (INIS)

    The evaporator process at TA-55 reduces the amount of transuranic liquid radioactive waste by separating radioactive salts from relatively low-level radioactive nitric acid solution. A computer-based supervisory control and data acquisition (SCADA) system has been installed on the process that allows the operators to easily interface with process equipment. Individual single-loop controllers in the SCADA system allow more precise process operation with less human intervention. With this system, process data can be archieved in computer files for later analysis. Data are distributed throughout the TA-55 site through a local area network so that real-time process conditions can be monitored at multiple locations. The entire system has been built using commercially available hardware and software components

  20. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Earle, T.C.; Lindell, M.K.; Rankin, W.L.

    1981-07-01

    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. Respondents were selected according to a purposive sampling strategy.

  2. The Calculation Of Total Radioactivity Of Kartini Reactor Fuel Element

    International Nuclear Information System (INIS)

    The total radioactivity of Kartini reactor fuel element has been calculated by using ORIGEN2. In this case, the total radioactivity is the sum of alpha, beta, and gamma radioactivity from activation products nuclides, actinide nuclides and fission products nuclides in the fuel element. The calculation was based on irradiation history of fuel in the reactor core. The fuel element no 3203 has location history at D, E, and F core zone. The result is expressed in graphics form of total radioactivity and photon radiations as function of irradiation time and decay time. It can be concluded that the Kartini reactor fuel element in zone D, E, and F has total radioactivity range from 10 Curie to 3000 Curie. This range is for radioactivity after decaying for 84 days and that after reactor shut down. This radioactivity is happened in the fuel element for every reactor operation and decayed until the fuel burn up reach 39.31 MWh. The total radioactivity emitted photon at the power of 0.02 Watt until 10 Watt

  3. 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)

  4. Laser based remote diameter measurement in radioactive area

    International Nuclear Information System (INIS)

    A non-contact laser based instrument for fuel pellet diameter measurement from outside the glass walled glove box has been developed at LPTD, BARC. Its optical design allows separation of 1 meter between its two measuring units thus suitable for 1 meter wide glove box. The instrument is based on beam scanning principle and calculates the diameter by measuring object shadow pulse width. A micro controller based circuit has been designed along with high speed counters for diameter calculation and display purpose. This stand alone instrument has been tested for diameter range of interest from 4.12mm to 4.23 mm and gives an accuracy of ± 4 μm. (author)

  5. 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)

  6. 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.

  7. Enhancing usability of augmented-reality-based mobile escape guidelines for radioactive accidents

    International Nuclear Information System (INIS)

    When radioactive accidents occur, modern tools in information technology for emergency response are good solutions to reduce the impact. Since few information-technology-based applications were developed for people during radioactive accidents, a previous study (Tsai et al., 2012) proposed augmented-reality-based mobile escape guidelines. However, because of the lack of transparent escape routes and indoor escape guidelines, the usability of the guidelines is limited. Therefore, this study introduces route planning and mobile three-dimensional (3D) graphics techniques to address the identified problems. The proposed approach could correctly present the geographical relationship from user locations to the anticipated shelters, and quickly show the floor-plan drawings as users are in the buildings. Based on the testing results, in contrast to the previous study, this study offered better escape routes, when the participants performed self-evacuation in outdoor and indoor environments. Overall, this study is not only a useful reference for similar studies, but also a beneficial tool for emergency response during radioactive accidents. -- Highlights: ► Enhancing the efficiency when people escape from radioactive accidents. ► The spatial relationship is transparently displayed in real time. ► In contrast to a previous study, this study offers better escape guidelines

  8. Integrated data base for 1987: 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, 1986. These data are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. Current projections of future waste and spent fuel to be generated through the year 2020 and characteristics of these materials are also presented. 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 defense-related and private industrial and institutional activities. The radioactive materials considered, on a chapter-by-chapter basis, are spent fuel, high-level waste, transuranic waste, low-level waste, commercial uranium mill tailings, remedial action waste, and decommissioning waste. For each category, current and projected inventories are given through the year 2020, 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, highly radioactive materials that may require geologic disposal. 82 refs., 57 figs., 121 tabs

  9. Integrated data base for 1988: 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, 1987. These data are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The current projections of future waste and spent fuel to be generated through the year 2020 and characteristics of these materials are also presented. 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 defense-related and private industrial and institutional (I/I) activities. The radioactive materials considered, on a chapter-by-chapter basis are: spent fuel, high-level waste, transuranic waste, low-level waste, commercial uranium mill tailings, remedial action waste, and decommissioning waste. For each category, current and projected inventories are given through the year 2020, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions. In addition, characteristics and current inventories are reportd for miscellaneous, highly radioactive materials that may require geologic disposal. 89 refs., 46 figs., 104 tabs

  10. 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...

  11. Radioactive measurement technology of two-surface source based on LRAD inside pipes

    International Nuclear Information System (INIS)

    Background: The development of measuring technologies of radioactive contamination becomes more and more important. Long Range Alpha Detector (LRAD) can effectively solve some problems such as the short ranges of alpha particles, weak penetration ability and so on. LRAD also has advantages that the alpha radioactivity of interior surface of irregular pipes or just irregular surface can be measured nondestructively and precisely. Purpose: This paper attempts to obtain the measured value of multi-point sources and large contamination areas in pipes. And the comparative experiments of impact factors of two different radioactive surface sources (different nuclides and radioactivities) have been done. Methods: In the experiment, a new domestic LRAD is utilized to measure the alpha activity of interior surface of steel pipes. Here, the inner diameter of pipes is 78 mm and there are two kinds of pipes: straight pipe and U-bend pipe. The radioactive sources include 241Am (3 772.2 Bq) and 239Pu (224.4 Bq). The distance between different sources takes values of o cm, 10 cm, 20 cm and 40 cm, respectively, and the distance between the whole mixed radioactive source and detector increases by step of 20 cm. Results: When the relative distance of the two surface sources is 10 cm, the detection efficiency of LRAD is higher than that of relative distance of 0 cm, 20 cm and 40 cm, which matches the result of theoretical analysis. When 241Am is closer to the detector than 239Pu, measuring results are much higher than those of the opposite situation. And in the same position, when the two sources are put together, the measured results are lower than those of the sum of each single source. Conclusion: Based on the experimental results, a self-developed new LRAD measurement system has been used to measure two non-point sources in pipes. (authors)

  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. 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.

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

    International Nuclear Information System (INIS)

    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 -7 m s-1 to 10-9 m s-1 and to penetrate fissures in the rock with apertures as small as 10 μm. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-04-01

    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.

  16. 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

  17. MIRD radionuclide data and decay schemes

    CERN Document Server

    Eckerman, Keith F

    2007-01-01

    For all physicians, scientists, and physicists working in the nuclear medicine field, the MIRD: Radionuclide Data and Decay Schemes updated edition is an essential sourcebook for radiation dosimetry and understanding the properties of radionuclides. Includes CD Table of Contents Decay schemes listed by atomic number Radioactive decay processes Serial decay schemes Decay schemes and decay tables This essential reference for nuclear medicine physicians, scientists and physicists also includes a CD with tabulations of the radionuclide data necessary for dosimetry calculations.

  18. 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

  19. In-trap decay spectroscopy for ββ decays

    International Nuclear Information System (INIS)

    The presented work describes the implementation of a new technique to measure electron-capture (EC) branching ratios (BRs) of intermediate nuclei in ββ 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 β decays along the trap axis while X-rays, following an EC, are emitted isotropically. This provides spatial separation of X-ray and β detection with almost no β-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 ββ decays. Detailed knowledge of these electron capture branches is crucial for a better understanding of the underlying nuclear physics in ββ decays. These branches are typically of the order of 10-5 and therefore difficult to measure. Conventional measurements suffer from isobaric contamination and a dominating β 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 detectors, for the detection of X-rays, were tested

  20. 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

  1. Radioactive waste disposal sites: Two successful closures at Tinker Air Force Base

    International Nuclear Information System (INIS)

    This article describes remediation and closure of two radioactive waste disposal sites at Tinker Air Force Base, Oklahoma, making them exemption regulatory control. The approach consisted of careful exhumation and assessment of soils in sites expected to be contaminated based on historical documentation, word of mouth, and geophysical surveys; removal of buried objects that had gamma radiation exposure levels above background; and confirmation that the soil containing residual radium-226 was below an activity level equal to no more than a 10 mrem/yr annual dose equivalent. In addition, 4464 kg of chemically contaminated excavated soils were removed for disposal. After remediation, the sites met standards for unrestricted use. These sites were two of the first three Air Force radioactive disposal sites to be closed and were the first to be closed under Draft NUREG/CR-5512

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

    International Nuclear Information System (INIS)

    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

  3. Radioactive Material Detection System (RMDS) Based on Advanced Spectroscopic Portal Technology

    International Nuclear Information System (INIS)

    Since the attacks of September 11, 2001, combating terrorism has been one of the world's highest priorities. As part of that effort, preventing radioactive material from being smuggled through the national borders may be used by terrorists in a nuclear weapon or in a radiological dispersal device (a ''dirty bomb'') has become a key national security objective in many countries. During the last years (1991-2007) more than 20 incidents of Special Nuclear Material (SNM) seizures worldwide were registered and published in the media.(l)(2)Q) In order to supply an appropriate solution for the challenge of preventing such illicit nuclear trafficking, Totem Plus has developed the Radioactive Material Detection System (RMDS) in cooperation with Rotem Ind. which provides the testing according the standard requirements and the marketing services. The RMDS is based on the so-called Advanced Spectroscopic Portal (ASP)(4) concept which was mainly driven by the US Domestic Nuclear Detection Office (DNDO) in the last few years.(5) This kind of Portal Monitor is capable of the isotopic identification of radioactive material within a vehicle or a container for the purpose of identifying vehicles carrying non threatening radioactive sources: Naturally Occurring Radioactive Material (NORM), radioisotopes utilized for medical and industrial purposes and those carrying the threatening Special Nuclear Materials (SNM), The characteristics of the RMDS have been tested with compliance to international standards(<3), and are described in this report. Nowadays, the RMDS is being utilized as part of the Mega port Initiative (MPI) in the Haifa Port, Israel. The MPI is a worldwide effort to prevent nuclear smuggling in sea containers and is motivated mainly by the US Department of Energy (DOE). The performance of the system and the collective experience from other installation sites is being studied and compared to other methods, like hand-held instruments which are used for the same purpose

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

    International Nuclear Information System (INIS)

    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 (UF6) 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 otherclose quotes. Fuel cycle commercial LLW source terms are normalized on the basis of net electrical output [MW(e)-year], except for UF6 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

  5. 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)

  6. Introduction to Astronomy with Radioactivity

    CERN Document Server

    Diehl, Roland

    2010-01-01

    In the late nineteenth century, Antoine Henri Becquerel discovered radioactivity and thus the physics of weak interactions, well before atomic and quantum physics was known. The different types of radioactive decay, alpha, beta, and gamma decay, all are different types of interactions causing the same, spontaneous, and time-independent decay of an unstable nucleus into another and more stable nucleus. Nuclear reactions in cosmic sites re-arrange the basic constituents of atomic nuclei (neutrons and protons) among the different configurations which are allowed by Nature, thus producing radioactive isotopes as a by-product. Throughout cosmic history, such reactions occur in different sites, and lead to rearrangements of the relative abundances of cosmic nuclei, a process called cosmic chemical evolution, which can be studied through the observations of radioactivity. The special role of radioactivity in such studies is contributed by the intrinsic decay of such material after it has been produced in cosmic site...

  7. Information model of data base of system for tracking burial of radioactive wastes

    International Nuclear Information System (INIS)

    In recent years, agencies have worked out directives on an order for inventory-taking, recording mines sites and enterprises, transportation, processing, use collection, storage, and burial of radioactive substances and sources of ionizing radiation. ONe stage in solving this problem concerns management of radioactive wastes: making allowance for them during collection, processing, and burial, which at the present scientific and technical level requires an integrated data base capable of storing and processing large arrays of primary data. The main task in the conceptual design of the data base is to analyze the overall information requirements and to form the initial version of the information model. An analysis of the universe of discourse reflecting the enrichment process with radioactive wastes from the time they are formed in organizations until they are stored in repositories (REPOS), given, has made it possible to specify the following sets data elements, categorized by their essential nature, to give them the labels SUPPLIER, PERSONNEL, INSTRUMENT, WASTES, TRANSPORT, FACILITY, END PRODUCT, REPOSITORY, and PREMISES. Each entity is determined by an ensemble of properties (attributes)

  8. 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

  9. Ion exchanger material based on Titanium phosphate for liquid radioactive waste treatment

    International Nuclear Information System (INIS)

    A comparative study of the physicochemical and service properties of samples of Ti(OH) 1.36(HPO4) 1.32 * 2.3H2O sorbent in the finely dispersed and granulated forms, mastered for commercial production, was made. The sorption of Cs and Sr cations from solutions of various, compositions was studied in batch experiments, and the diffusion coefficients of the exchanging ions were determined. The hydrolytic stability of the. sorbents was examined with the aim to determine the optimal operation conditions. Experiments showed that the cation exchangers based on titanium phosphate are the most efficient in removal from liquid radioactive waste of induced radioactive isotopes of corrosion products, which is due to formation of weakly dissociating compounds of nonferrous metal ions with functional groups of the ion exchangers in the sorbent phase. (author)

  10. 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...

  11. Based on particle size distribution of radioactive aerosol of screen diffusion battery measuring software

    International Nuclear Information System (INIS)

    Based on screen diffusion battery of particle size distribution of the radioactive aerosol measuring system developed a measurement and analysis software, the software operating environment was the embedded ARM-based hardware system and embedded linux operating system. The software is developed by the open source package QT. System functions included the measurement process control, screen diffusion battery transmittance calculations, particle size distribution measurement, measurement data analysed by the EM algorithm and Twomey algorithms, particle size distribution showed, system communication and other functions. (authors)

  12. 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.

  13. 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)

  14. The first experimental investigation of the KLL Auger spectrum of Ni generated in the electron capture decay of radioactive Cu-64 in a solid state matrix

    Czech Academy of Sciences Publication Activity Database

    Inoyatov, A. K.; Perevoshchikov, L. L.; Kovalík, Alojz; Filosofov, D. V.; Gorozhankin, V. M.; Ryšavý, Miloš

    2012-01-01

    Roč. 66, č. 234 (2012), s. 1-5. ISSN 1434-6060 R&D Projects: GA ČR(CZ) GAP203/12/1896; GA MŠk LA08002 Institutional support: RVO:61389005 Keywords : atomic-structure * ec decay * relativity Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.513, year: 2012

  15. OREX reg-sign based ''point of generation'' low-level radioactive waste reduction program

    International Nuclear Information System (INIS)

    Nuclear power facilities generate material called Dry Active Waste (DAW). DAW can be any material contaminated with radioactive particles as long as it is not a fluid, typically: paper, cardboard, wood, plastics, cloth, and any other solid which is contaminated and determined to be dry. Facilities that generate low-level radioactive waste need to dramatically reduce their waste volumes. In order to address this issue, the industry must look to the application of ''point of generation'' technologies. For the purposes of this discussion, point of generation is a concept that will allow the DAW wastes generated at a facility to be processed at that same facility. There are two specific issues to address with this concept. The first issue deals with the establishment of a line of products which can be used for personnel protection and particle barriers that offers easy disposal at the point of generation. The second issue involves the technology for the disposal. The first issue has been resolved by the development of Isolyser's OREX materials. The OREX product is a hot-water soluble, biodegradable, polyvinyl alcohol (PVA) based material. When Isolyser's OREX product is placed in an aqueous environment maintained at a temperature of approximately 88 C, the OREX material will decompose and go into solution. After the OREX has been dissolved, any radioactive contaminants are collected by passing them through specially designed resin columns. Once the contaminants have been collected, the dissolved OREX solution can be monitored and discharged from the facility

  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. Radioactive sputter cathodes for 32P plasma-based ion implantation

    International Nuclear Information System (INIS)

    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 (32P) 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 (H332PO4) 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 32P by coating the substrates with iron. The iron coating is shown to enable optimal radioisotope sputtering rates, which are essential in 32P-PBRII for the efficient activation of millimetric biomedical devices such as stents or coils

  19. HALF-LIVES OF LONG-LIVED ALPHA DECAY, BETA DECAY, ELECTRON CAPTURE DECAY, BETA BETA-DECAY, PROTON DECAY AND SPONTANEOUS FISSION DECAY NUCLIDES.

    Energy Technology Data Exchange (ETDEWEB)

    HOLDEN, H.E.

    2003-08-08

    In his review of radionuclides for dating purposes, Roth noted that there were a large number of nuclides, normally considered ''stable'' but which are radioactive with a very long half-life. Roth suggested that I review the data on the half-life values of these long-lived nuclides for the 2001 Atomic Weights Commission meeting in Brisbane. I provided a report, BNL-NCS-68377, to fulfill Roth's request. Peiser has now made a similar suggestion that I review these data for our next Commission meeting in Ottawa for their possible inclusion in our Tables. These half-life values for long-lived nuclides include those due to various decay modes, {alpha}-decay, {beta}-decay, electron capture decay, {beta}{beta}-decay, proton decay and spontaneous fission decay. This data review (post Brisbane) provides an update to the recommendation of the 2001 review.

  20. DP-THOT - a calculational tool for bundle-specific decay power based on actual irradiation history

    International Nuclear Information System (INIS)

    A tool has been created for calculating the decay power of an individual fuel bundle to take account of its actual irradiation history, as tracked by the fuel management code SORO. The DP-THOT tool was developed in two phases: first as a standalone executable code for decay power calculation, which could accept as input an entirely arbitrary irradiation history; then as a module integrated with SORO auxiliary codes, which directly accesses SORO history files to retrieve the operating power history of the bundle since it first entered the core. The methodology implemented in the standalone code is based on the ANSI/ANS-5.1-1994 formulation, which has been specifically adapted for calculating decay power in irradiated CANDU reactor fuel, by making use of fuel type specific parameters derived from WIMS lattice cell simulations for both 37 element and 28 element CANDU fuel bundle types. The approach also yields estimates of uncertainty in the calculated decay power quantities, based on the evaluated error in the decay heat correlations built-in for each fissile isotope, in combination with the estimated uncertainty in user-supplied inputs. The method was first implemented in the form of a spreadsheet, and following successful testing against decay powers estimated using the code ORIGEN-S, the algorithm was coded in FORTRAN to create an executable program. The resulting standalone code, DP-THOT, accepts an arbitrary irradiation history and provides the calculated decay power and estimated uncertainty over any user-specified range of cooling times, for either 37 element or 28 element fuel bundles. The overall objective was to produce an integrated tool which could be used to find the decay power associated with any identified fuel bundle or channel in the core, taking into account the actual operating history of the bundles involved. The benefit is that the tool would allow a more realistic calculation of bundle and channel decay powers for outage heat sink planning

  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. 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...

  3. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    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.

  5. 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

  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. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kulkarni, A.; Bak, M. S., E-mail: tkim@skku.edu, E-mail: moonsoo@skku.edu [School of Mechanical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Ha, S. [SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Joshirao, P.; Manchanda, V. [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, T., E-mail: tkim@skku.edu, E-mail: moonsoo@skku.edu [School of Mechanical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-06-15

    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(NO{sub 3}){sub 4} ⋅ 5H{sub 2}O) 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.

  9. 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

  10. Development of risk-based computer models for deriving criteria on residual radioactivity and recycling

    International Nuclear Information System (INIS)

    Argonne National Laboratory (ANL) is developing multimedia environmental pathway and health risk computer models to assess radiological risks to human health and to derive cleanup guidelines for environmental restoration, decommissioning, and recycling activities. These models are based on the existing RESRAD code, although each has a separate design and serves different objectives. Two such codes are RESRAD-BUILD and RESRAD-PROBABILISTIC. The RESRAD code was originally developed to implement the U.S. Department of Energy's (DOE's) residual radioactive materials guidelines for contaminated soils. RESRAD has been successfully used by DOE and its contractors to assess health risks and develop cleanup criteria for several sites selected for cleanup or restoration programs. RESRAD-BUILD analyzes human health risks from radioactive releases during decommissioning or rehabilitation of contaminated buildings. Risks to workers are assessed for dismantling activities; risks to the public are assessed for occupancy. RESRAD-BUILD is based on a room compartmental model analyzing the effects on room air quality of contaminant emission and resuspension (as well as radon emanation), the external radiation pathway, and other exposure pathways. RESRAD-PROBABILISTIC, currently under development, is intended to perform uncertainty analysis for RESRAD by using the Monte Carlo approach based on the Latin-Hypercube sampling scheme. The codes being developed at ANL are tailored to meet a specific objective of human health risk assessment and require specific parameter definition and data gathering. The combined capabilities of these codes satisfy various risk assessment requirements in environmental restoration and remediation activities. (author)

  11. Development of risk-based computer models for deriving criteria on residual radioactivity and recycling

    International Nuclear Information System (INIS)

    Argonne National Laboratory (ANL) is developing multimedia environmental pathway and health risk computer models to assess radiological risks to human health and to derive cleanup guidelines for environmental restoration, decommissioning, and recycling activities. These models are based on the existing RESRAD code, although each has a separate design and serves different objectives. Two such codes are RESRAD-BUILD and RESRAD-PROBABILISTIC. The RESRAD code was originally developed to implement the US Department of Energy's (DOE's) residual radioactive materials guidelines for contaminated soils. RESRAD has been successfully used by DOE and its contractors to assess health risks and develop cleanup criteria for several sites selected for cleanup or restoration programs. RESRAD-BUILD analyzes human health risks from radioactive releases during decommissioning or rehabilitation of contaminated buildings. Risks to workers are assessed for dismantling activities; risks to the public are assessed for occupancy. RESRAD-BUILD is based on a room compartmental model analyzing the effects on room air quality of contaminant emission and resuspension (as well as radon emanation), the external radiation pathway, and other exposure pathways. RESRAD-PROBABILISTIC, currently under development, is intended to perform uncertainty analysis for RESRAD by using the Monte Carlo approach based on the Latin-Hypercube sampling scheme. The codes being developed at ANL are tailored to meet a specific objective of human health risk assessment and require specific parameter definition and data gathering. The combined capabilities of these codes satisfy various risk assessment requirements in environmental restoration and remediation activities

  12. 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...

  13. 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.)

  14. 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)

  15. 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)

  16. 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.

  17. Project 8: Determining neutrino mass from tritium beta decay using a frequency-based method

    Energy Technology Data Exchange (ETDEWEB)

    Doe, Peter J.; Kofron, Jared N.; MCBride, Lisa; Robertson, R. G. H.; Rosenberg, Leslie; Rybka, Gray; Doelman, S.; Rogers, Alan E.; Formaggio, Joseph; Furse, Daniel; Oblath, Noah S.; LaRoque, Benjamin; Leber, Michelle; Monreal, Ben; Bahr, Matthew; Asner, David M.; Jones, Anthony M.; Fernandes, Justin L.; VanDevender, Brent A.; Patterson, Ryan B.; Bradley, Rich; Thummler, Thomas

    2013-10-04

    A general description is given of Project 8, a new approach to measuring the neutrino mass scale via the beta decay of tritium. In Project 8, the energy of electrons emitted in beta decay is determined from the frequency of cyclotron radiation emitted as the electrons spiral in a uniform magnetic field

  18. Project 8: Determining neutrino mass from tritium beta decay using a frequency-based method

    CERN Document Server

    Doe, P J; McBride, E L; Robertson, R G H; Rosenberg, L J; Rybka, G; Doelman, S; Rogers, A; Formaggio, J A; Furse, D; Oblath, N S; LaRoque, B H; Leber, M; Monreal, B; Bahr, M; Asner, D M; Jones, A M; Fernandes, J; VanDevender, B A; Patterson, R; Bradley, R; Thuemmler, T

    2013-01-01

    A general description is given of Project 8, a new approach to measuring the neutrino mass scale via the beta decay of tritium. In Project 8, the energy of electrons emitted in beta decay is determined from the frequency of cyclotron radiation emitted as the electrons spiral in a uniform magnetic field.

  19. 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.

  20. 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)

  1. 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.

  2. 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.

  3. 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)

  4. Determination of neutrino mass ordering in future $^{76}$Ge-based neutrinoless double-beta decay experiments

    CERN Document Server

    Zhang, Jue

    2016-01-01

    Motivated by recent intensive experimental efforts on searching for neutrinoless double-beta decays, we perform a detailed analysis of the physics potential of the experiments based on $^{76}{\\rm Ge}$. Assuming no signals, current and future experiments could place a $90\\%$ lower limit on the half life $T^{0\

  5. 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)

  6. 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

  7. Low level radioactive waste disposal: An evaluation of reports comparing ocean and land based disposal options

    International Nuclear Information System (INIS)

    This document evaluates reports presenting comparative assessments of land and sea disposal options for low and intermediate level radioactive waste. It was performed following a request by the LDC to the IAEA. In this evaluation, IAEA Safety Series No. 65 ''Environmental Assessment Methodologies for Sea Dumping of Radioactive Wastes'', was used as the main reference in reviewing the comparative assessments made to date. IAEA Safety Series No. 65 gives guidance on the performance of comparative assessments of the different options, and provides a list and scheme of factors to be considered. 5 studies were transmitted by the Contracting Parties and considered in this review. A larger number of reports was not considered in this effort on the basis that the evaluation would be most effective if directed at those studies which specifically compared ocean disposal with land based disposal in a consistent manner. It is not the purpose of this report to state whether one document is better than another or whether one report forms a good blueprint for future assessments. This would require a different type of review and is outside the scope of this document. Indeed since the purposes of the five reports were originally so different it would not be possible to produce such a ranking and any attempts in that direction would be very misleading. 11 refs, 3 tabs

  8. 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.

  9. 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.

  10. 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)

  11. Porous materials based on cenospheres for immobilization and long-term isolation of liquid radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    A.G. Anshits; T.A. Vereshchagina; O.M. Sharonova; N.N. Anshits; N.G. Vasilieva; M.V. Burdin; I.D. Zykova; S.V. Podoinitsyn [Institute of Chemistry and Chemical Technology (Russian Federation)

    2003-07-01

    Cenospheres, or hollow silica-alumina microspheres, is one of the valuable components within coal combustion fly ash. One of the promising areas of cenosphere application is conditioning liquid radioactive waste (LRW) to reduce waste volumes and to transform waste into a solid form suitable for transport and/or storage and/or long-term disposal. It was found that chemical composition of cenosphere material is similar to the composition of a granite rock in the Earth lithosphere. Due to this property in combination with the high mechanical strength, spherical design, thermal and chemical stability, cenospheres are considered to be the suitable material for LRW long-term isolation in the form of stable mineral-like silicaalumina ceramics (feldspars, pyroxene, polucite, and nepheline). Two types of engineering forms for the cenosphere material have been developed, such as molded block porous material (porous matrices) and microspherical porous material, which can be activated by impregnation with additives trapping radionuclides (Cs-137, Sr-90). Different glass crystalline materials based on the cenospheres for immobilization and longterm isolation of liquid radioactive waste will be presented in the report including porous matrices of 40-90% open-cell porosity, microspherical porous glasses and specific sorbents. Variants to use these materials for conditioning LRW and reducing their volume by a factor of 1500 are discussed. 14 refs., 4 figs., 1 tab.

  12. 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)

  13. Investigation of possibility of magnesium-mineral composition production on the base of dolomite for immobilization of radioactive waste

    International Nuclear Information System (INIS)

    Process features of producing of magnesium astringent substances on the base of magnesite and dolomite and their characteristic arc examined. The potential possibility of creation of compositional material based on caustic dolomite, that was obtained from natural dolomite raw materials of Belarus, for immobilization of radioactive waste is presented. (authors).

  14. 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.

  15. 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.

  16. 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.)

  17. Using pixel and object based IKONOS image analysis for studying decay in silver fir stands

    OpenAIRE

    Ionut Barnoaiea; Ovidiu Iacobescu

    2009-01-01

    The problem of old silver fir stands decay has appeared in the last decades of the last century with symptoms such as defoliation, wood decay and parasites attacks. The problems in monitoring this phenomenon is that the defoliation and mistletoe attack appear on the crown top, triggering the coronation process - tree develop branches on their lower stem part in order to resist to the defoliation. This reaction makes the attack difficult to notice on aerial or satellite images, due to the refl...

  18. Lower fungi and radioactivity

    International Nuclear Information System (INIS)

    Sorption activities for radioactive elements were observed in molds Penicillinum muszynsky, Aspergillus versicolor and Alternaria tenius. Aspergillus flavus, Aspergillus fumigatus and Aspergillus niger were isolated in laboratory and cultivated on a modified substrate containing uranyl nitrate and uranyl acetate. They were found to be capable of absorbing in the biomass some members of the uranium decay series. (E.J.). 4 tabs., 11 refs

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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)

  6. 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...

  7. 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

  8. Waste-acceptance criteria and risk-based thinking for radioactive-waste classification

    International Nuclear Information System (INIS)

    The US system of radioactive-waste classification and its development provide a reference point for the discussion of risk-based thinking in waste classification. The official US system is described and waste-acceptance criteria for disposal sites are introduced because they constitute a form of de facto waste classification. Risk-based classification is explored and it is found that a truly risk-based system is context-dependent: risk depends not only on the waste-management activity but, for some activities such as disposal, it depends on the specific physical context. Some of the elements of the official US system incorporate risk-based thinking, but like many proposed alternative schemes, the physical context of disposal is ignored. The waste-acceptance criteria for disposal sites do account for this context dependence and could be used as a risk-based classification scheme for disposal. While different classes would be necessary for different management activities, the waste-acceptance criteria would obviate the need for the current system and could better match wastes to disposal environments saving money or improving safety or both

  9. 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.

  10. Study of radioactive inventory generated from W-based components in ITER and PPCS fusion designs

    International Nuclear Information System (INIS)

    Highlights: ► Recycling and clearance would be a potential solution to reduce the radioactive inventory. ► Both ITER and PPCS divertors ultimately classify MA-VL according to French regulations. ► The most attractive alloys appear to be W–1%Ta, W–TiC, W–K and W–La2O3. ► W transmutation strongly depends on the neutron spectrum and fluence. -- Abstract: Tungsten and its alloys are currently considered as prime candidates for plasma facing components in many fusion experimental devices and power plants, but some issues regarding the activation of these materials remain to be clarified. This study has addressed the activation concerns of seven candidate W-alloys (W–W composites, W–La2O3, W–TiC, W–Ta, W–K, VM tungsten and W–Re) that could be used for W-based divertors and W-armors under the operating conditions of the ITER experimental facility and the PPCS power plant (EU power plant design studies). More specifically, the three radioactive waste management options (disposal, recycling, and clearance) as well as the transmutation of W have been examined. The latter is quite sensitive to the divertor and blanket materials. About 5–8 at.% of the W-armor transmute at the end of the PPCS blanket lifetime while the transmutation in the W-based divertor is <1%. Such a low transmutation level may not impair the physical properties of divertor W-alloys

  11. 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

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

    International Nuclear Information System (INIS)

    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)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 Germany

  13. 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.)

  14. 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.

  15. 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

  16. Acoustic emission monitoring of cement-based structures immobilising radioactive waste

    International Nuclear Information System (INIS)

    The long term performance of cementitious structures immobilising radioactive waste can be affected by physical and chemical processes within the encapsulating materials such as formation of new phases (e.g., vaterite, brucite), degradation of cement phases (e.g., CSH gel, portlandite), degradation of some waste components (e.g., organics), corrosion of metallic constituents (aluminium, magnesium), gas emission, further hydration etc. The corrosion of metals in the high pH cementitious environment is of especial concern as it can potentially cause wasteform cracking. One of the perspective non-destructive methods used to monitor and assess the mechanical properties of materials and structures is based on an acoustic emission (AE) technique. In this study an AE non-destructive technique was used to evaluate the mechanical performance of cementitious structures with encapsulated metallic waste such as aluminium. AE signals generated as a result of aluminium corrosion in a small-size blast furnace slag (BFS)/ordinary Portland cement (OPC) sample were detected, recorded and analysed. A procedure for AE data analysis including conventional parameter-based AE approach and signal-based analysis was applied and demonstrated to provide information on the aluminium corrosion process and its impact on the mechanical performance of the encapsulating cement matrix. (authors)

  17. Automation of the liquid wastes chemical treatment plant of the radioactive waste management plant

    International Nuclear Information System (INIS)

    This report shows the goals achieved in the elaboration and implementation of a pilot program of processes supervision and control based in the use of a programmable logic controller (PLC) which is carried out in the plant of liquid effluent (water) chemical treatment containing radioactive elements such as Co-60, Cs-137, I-131, Sr-90, Tc-99m, Mo-99 from the radioactive decay tanks of the RP-10 reactor and the Radioisotopes Production Plant (PPR)

  18. 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.

  19. 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.

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

    International Nuclear Information System (INIS)

    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 χR2, weighted residuals and autocorrelation function. Performance is compared with two commercial software packages and found to be satisfactory. (author)

  1. 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)

  2. 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

  3. 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.)

  4. Time-based forgetting in visual working memory reflects temporal distinctiveness, not decay.

    Science.gov (United States)

    Souza, Alessandra S; Oberauer, Klaus

    2015-02-01

    Is forgetting from working memory (WM) better explained by decay or interference? The answer to this question is the topic of an ongoing debate. Recently, a number of studies showed that performance in tests of visual WM declines with an increasing unfilled retention interval. This finding was interpreted as revealing decay. Alternatively, it can be explained by interference theories as an effect of temporal distinctiveness. According to decay theories, forgetting depends on the absolute time elapsed since the event to be retrieved. In contrast, temporal distinctiveness theories predict that memory depends on relative time, that is, the time since the to-be-retrieved event relative to the time since other, potentially interfering events. In the present study, we contrasted the effects of absolute time and relative time on forgetting from visual WM, using a continuous color recall task. To this end, we varied the retention interval and the inter-trial interval. The error in reporting the target color was a function of the ratio of the retention interval to the inter-trial interval, as predicted by temporal distinctiveness theories. Mixture modeling revealed that lower temporal distinctiveness produced a lower probability of reporting the target, but no changes in its precision in memory. These data challenge the role of decay in accounting for performance in tests of visual WM, and show that the relative spacing of events in time determines the degree of interference. PMID:24825306

  5. Radon adsorbed in activated charcoal- a simple and safe radiation source for teaching practical radioactivity in schools and colleges

    International Nuclear Information System (INIS)

    Simple procedures for teaching practical radioactivity are presented in a way that attracts students' attention and does not make them apprehensive about their safety. The radiation source is derived from the natural environment. It is based on the radioactivity of radon, an ubiquitous inert gas, and the adsorptive property of activated charcoal. Radon gas from ambient air in the laboratory was adsorbed into about 70 gram of activated charcoal inside metallic canisters. Gamma radiation was subsequently emitted from the canisters, following the radioactive decay of radon and its progenies. The intensities of the emitted gamma-rays were measured at suitable intervals using a NaI gamma-ray detector. The counts obtained were analysed and used to demonstrate the radioactive decay law and determine the half-life of radon. In addition to learning the basic properties of radioactivity, the students also get practical experience about the existence of natural sources of radiation in the environment. (author)

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

    International Nuclear Information System (INIS)

    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

  7. 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.

  8. Coastal maintenance base Gremikha: management of spent nuclear fuel and radioactive waste

    International Nuclear Information System (INIS)

    One deals with the situation at the shore engineering service unit located in the Gremikha settlement. The fuel assemblies of the unloaded water-moderated water cooled reactor cores (the first generation nuclear-powered submarines) in the containers and the solid and the liquid radioactive waste are stored in the open site. Paper reports both on the number and the conditions of the stored fuel assemblies and on the amount of the solid and liquid radioactive waste. Paper analyzes ways of further management of the mentioned fuel assemblies and radioactive waste

  9. 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...

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

    Science.gov (United States)

    Gajos, A.; Kamińska, D.; 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.

    2016-05-01

    This work reports on a new reconstruction algorithm allowing us 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 polarization of ortho-positronium atoms, which is also introduced in this work.

  11. The design of radioactive source tracking management system based on RFID

    International Nuclear Information System (INIS)

    The paper introduces a solution of safety and security management system of radioactive source in storage and use by employing advanced RFID technology and computer database technology. And make some suggestions for further improvement. (authors)

  12. Innovative alpha-radioactivity monitor for clearance level inspection based on ionized air transportation technology (1). Comparison with mass spectral analysis using uranium-attached samples

    International Nuclear Information System (INIS)

    We have been developing an alpha-radioactivity monitor based on ionized air transportation technology (alpha clearance monitor) for efficiently performing clearance level inspection of massive amounts of uranium-contaminated waste. This paper is one of a series related to a method for quantitatively evaluating alpha radioactivity from a measured ion current value. Using a prototype alpha clearance monitor, we measured alpha radioactivities of uranium-attached components used in back-end facilities of the nuclear fuel cycle (uranium-attached samples). We compared the measured radioactivities with reference radioactivities by assaying the samples with an inductively coupled plasma mass spectrometer and the radioactivities measured with a scintillation survey meter. The radioactivities of curved plate samples measured with the prototype monitor were highly linear with respect to the reference radioactivities (a residual standard deviation of 8%). Absolute values of the radioactivities obtained with the prototype monitor and with the survey meter were about 40% and 50% smaller than the reference radioactivities, respectively. Measurements of complex-shaped samples indicated that, to measure diverse-shaped waste, it was necessary to classify the waste by shape and determine conversion coefficients corresponding to each group in advance, experimentally and theoretically. (author)

  13. 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)

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

    International Nuclear Information System (INIS)

    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)

  15. 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.

  16. 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.

  17. A self-organized model for cell-differentiation based on variations of molecular decay rates.

    Directory of Open Access Journals (Sweden)

    Rudolf Hanel

    Full Text Available Systemic properties of living cells are the result of molecular dynamics governed by so-called genetic regulatory networks (GRN. These networks capture all possible features of cells and are responsible for the immense levels of adaptation characteristic to living systems. At any point in time only small subsets of these networks are active. Any active subset of the GRN leads to the expression of particular sets of molecules (expression modes. The subsets of active networks change over time, leading to the observed complex dynamics of expression patterns. Understanding of these dynamics becomes increasingly important in systems biology and medicine. While the importance of transcription rates and catalytic interactions has been widely recognized in modeling genetic regulatory systems, the understanding of the role of degradation of biochemical agents (mRNA, protein in regulatory dynamics remains limited. Recent experimental data suggests that there exists a functional relation between mRNA and protein decay rates and expression modes. In this paper we propose a model for the dynamics of successions of sequences of active subnetworks of the GRN. The model is able to reproduce key characteristics of molecular dynamics, including homeostasis, multi-stability, periodic dynamics, alternating activity, differentiability, and self-organized critical dynamics. Moreover the model allows to naturally understand the mechanism behind the relation between decay rates and expression modes. The model explains recent experimental observations that decay-rates (or turnovers vary between differentiated tissue-classes at a general systemic level and highlights the role of intracellular decay rate control mechanisms in cell differentiation.

  18. 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

  19. 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

  20. A coding method for decay pathways in successive decay chain

    International Nuclear Information System (INIS)

    The decay pathways in successive decay chain were coded with binary digits. Based the coding approach and by using the E-factor method and recursion algorithm, a general purpose computer code DecayChain for calculation of the growth and decay of any member in a successive decay chain was written. The usage of decay chain code was demonstrated by the calculation of individual activities of each progenies and the total activity for the successive decay chain 228Th through 208Pb (9 members). When the relative detection efficiencies of chain members happen to meet an equation deduced in this paper the total counting rate will exponentially decrease with time with a single half-life. This conclusion was verified by the calculation performed with DecayChain for a 4-membered decay chain. (authors)

  1. 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.)

  2. Radioactive Plumes Monitoring Simulator

    International Nuclear Information System (INIS)

    The Airborne Radiation Monitoring System (ARMS) monitors air or ground radioactive contamination. The contamination source can be a radioactive plume or an area contaminated with radionuclides. The system is based on two major parts, an airborne unit carried by a helicopter and a ground station carried by a truck. The system enables real time measurement and analysis of radioactive plumes as well as post flight processing. The Radioactive Plumes Monitoring Simulator purpose is to create a virtual space where the trained operators experience full radiation field conditions, without real radiation hazard. The ARMS is based on a flying platform and hence the simulator allows a significant reduction of flight time costs

  3. 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...

  4. Mixed radioactive and chemotoxic wastes (RMW)

    International Nuclear Information System (INIS)

    During the first decades of development of nuclear energy, organizations involved in the management of nuclear wastes had their attention focused essentially on radioactive components. The impression may have prevailed that, considering the severe restrictions on radioactive materials, the protection measured applied for radioactive components of wastes would be more than adequate to cope with potential hazards from non radioactive components associated with radioactive wastes. More recently it was acknowledged that such interpretation is not necessarily justified in all cases since certain radioactive wastes also contain non-negligible amounts of heavy metals or hazardous organic components which, either, do not decay, or are subject to completely different decay (decomposition) mechanisms. The main purposes of the present study are to analyze whether mixed radioactive wastes are likely to occur in Europe and in what form, whether one needs a basis for integration for evaluating various forms of toxicity and by which practical interventions possible problems can be avoided or at least reduced. (au)

  5. 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

  6. 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.

  7. Practical designs for clay based engineered barrier systems for heat emitting radioactive wastes

    International Nuclear Information System (INIS)

    Many of the present designs of repositories for radioactive wastes derive from generic feasibility studies which emphasize post-closure safety. These include little (or no) treatment of the practicality of safe and quality-assured construction of engineered barriers under the conditions (humidity, dust, etc.) and requirements (emplacement rate, remote handling, etc.) of an operational underground facility. Indeed, as soon as attempts are made to demonstrate such concepts in-situ at full scale, considerable practical problems are encountered and, in many cases, additional engineering components are introduced (liners, borehole caps, grouts, rock-bolts, drainage systems, etc.) which could be detrimental to - or at leas t complicate - the long-term safety case. As the discrepancy between the idealized concepts illustrated in performance assessment and the actual systems which are shown to be feasible grows, there is a critical need for design rationalization. Such a process needs to include careful balancing of factors influencing safety during the operational phase - which should not be compromised - with those which contribute to potential hazards which occur only in the distant future. Apart from such almost philosophical considerations, the robustness of the EBS construction procedure to possible operational perturbations needs serious consideration. Even if closed and sealed repositories are very insensitive to disruptive events such as earthquakes, hurricanes, industrial actions and terrorist actions, the operational system may be more vulnerable to perturbation. Designs should be introduced which, to the greatest extent possible, not only fail safe, but are also easy to remedy (or reverse) in case the assurance of EBS quality is lost. This paper will expand on ideas for a second generation of clay-based EBS designs, which are both practical and safe. Associated requirements for R and D and performance assessment model development will also be outlined, with a

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

    International Nuclear Information System (INIS)

    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 is an interesting case study for decommissioning due to the extremely large amounts of radioactivity present at the site and the conditions under which it is stored; very little has been previously published in the scientific literature about this site. This paper complements the paper describing dose rates at Andreeva Bay which is published in this issue of Journal of Environmental Radioactivity by the same authors. This study presents new data related to the activity concentrations of 137Cs and 90Sr in surface soils and measurements of α- and β-particle fluxes taken at different areas around the site. Limited data on 60Co is also presented. The results of the study indicate that the main areas of site contamination are associated with the former spent nuclear fuel storage facility at Building 5, due to accidental discharges which began in 1982. Substantial contamination is also observed at the solid radioactive waste storage facilities, probably due to the ingress of water into these facilities. More than 240 samples were measured: maximum contamination levels were 1 x 106 Bq/kg 137Cs (mean value 4.1 x 105 Bq/kg) and 4 x 106 Bq/kg 90Sr (mean value 1.2 x 105 Bq/kg). Localised patches of α and β contamination were also observed throughout the site

  9. Application of multi-singlechip based on radioactive reagent diluting and dividing system

    International Nuclear Information System (INIS)

    The radioactive reagent diluting and dividing system exchanges information with human by using LCD screen and keyboard. Five high precision step-motors are used to make the mechanical arm with two injectors moving to three-dimensional location, and control the inhalation volume of the two injectors. There are six singlechips in this system. All of the singlechips are united to a cooperative system by serial-bus. This system can be used to divide and dilute the radioactive reagent with high precision and no contamination. (authors)

  10. 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

  11. Shadowing-based reliability decay in softened n-body simulations

    CERN Document Server

    Hayes, W

    2003-01-01

    A shadow of a numerical solution to a chaotic system is an_exact_ solution to the equations of motion that remains close to the numerical solution for a long time. In a collisionless n-body system, we know that particle motion is governed by the global potential rather than by inter-particle interactions. As a result, the trajectory of each individual particle in the system is independently shadowable. It is thus meaningful to measure the number of particles that have shadowable trajectories as a function of time. We find that the number of shadowable particles decays exponentially with time as exp(-mu t), and that for eps in [~0.2,1] (in units of the local mean inter-particle separation $\\bar n$), there is an explicit relationship between the decay constant mu, the timestep h of the leapfrog integrator, the softening eps, and the number of particles N in the simulation. Thus, given N and eps, it is possible to pre-compute the timestep h necessary to acheive a desired fraction of shadowable particles after a ...

  12. 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.

  13. ZZ RADDECAY, Decay Data Library for Radiological Assessment

    International Nuclear Information System (INIS)

    Description of program or function: - Format: special format defined in documentation. - Nuclides: 500 nuclides of interest in the nuclear fuel cycle, environmental problems, nuclear medicine, fusion reactor technology, and radiological protection assessment. - Origin: DLC-80/DRALIST. ZZ-RADDECAY is a data library of half-lives, radioactive daughter nuclides, probabilities per decay and decay product energies for alpha particles, positrons, electrons, X-rays, and gamma-rays. The current data base contains approximately 500 nuclides of interest in the nuclear fuel cycle, environmental problems, nuclear medicine, fusion reactor technology, and radiological protection assessment. RADIATION DECAY VERSION 2 March 1997: This application is being provided by Aptec as 'Freeware' with permission of the author Mr. Charles Hacker, Engineering and Applied Science, Griffith University, Australia

  14. 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.)

  15. 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)

  16. Application of clay-based sorbents for cleaning radioactively contaminated water

    International Nuclear Information System (INIS)

    Under a special program of ecological rehabilitation of surface water bodies radioactively contaminated due to nuclear tests a study is in progress to investigate properties of various sorbents to remove radionuclides from water running out of tunnels. Search for and application of natural sorbents locally available are preferable. (author)

  17. 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.

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

    Directory of Open Access Journals (Sweden)

    A. J. Solanki

    2013-04-01

    Full Text Available 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 of this paper will be to enhance the extracted part of the tooth from digital dental x-ray, finding edges corresponding to caries affected tooth and decide the dental treatment like filling or Root Canal Treatment.

  19. Using pixel and object based IKONOS image analysis for studying decay in silver fir stands

    Directory of Open Access Journals (Sweden)

    Ionuț Barnoaiea

    2009-12-01

    Full Text Available The problem of old silver fir stands decay has appeared in the last decades of the last century with symptoms such as defoliation, wood decay and parasites attacks. The problems in monitoring this phenomenon is that the defoliation and mistletoe attack appear on the crown top, triggering the coronation process - tree develop branches on their lower stem part in order to resist to the defoliation. This reaction makes the attack difficult to notice on aerial or satellite images, due to the reflection of light on the lower branches. The objective of the article is to find a research methodology for identifying and even mapping the mistletoe attack phenomenon at a tree or stand level. For a tree-level analysis, a comparison between the data obtained in a 1 ha sample plot and the data extracted from an IKONOS satellite image has been used. The simple spectral response is less correlated at tree level with the defoliation and mistletoe attacks. We found a very significant correlation in the infrared channel but with low correlation coefficients. Better results have been obtained in a stand-level analysis. In order to improve the separability, the methodology for extracting the remote sensing data did not resume only to the mean spectral response, but we also performed a variability and texture analysis. The obtained correlation coefficients were around 0.7, very significant for the data used in the research. The results obtained with the texture analysis are also related to the biometric characteristics of the stands, mistletoe attacks occurring in stands with a low canopy closure index and is usually accompanied by distorted crowns. The model of forest health analysis should also be tested in similar conditions in order to validate and apply on a large scale inventory.

  20. Using pixel and object based IKONOS image analysis for studying decay in silver fir stands

    Directory of Open Access Journals (Sweden)

    Ionut Barnoaiea

    2009-11-01

    Full Text Available The problem of old silver fir stands decay has appeared in the lastdecades of the last century with symptoms such as defoliation, wood decay and parasites attacks. The problems in monitoring this phenomenon is that the defoliation and mistletoe attack appear on the crown top, triggering the coronation process - tree develop branches on their lower stem part in order to resist to the defoliation. Thisreaction makes the attack difficult to notice on aerial or satellite images, due to the reflection of light on the lower branches. The objective of the article is to find a research methodology for identifying and even mapping the mistletoe attack phenomenonat a tree or stand level. For a tree-level analysis, a comparison between the data obtained in a 1 ha sample plot and the data extracted from an IKONOS satellite image has been used. The simple spectral response is less correlated at tree level with the defoliation and mistletoe attacks. We found a very significant correlation in the infrared channel but with low correlation coefficients. Better results have been obtained in a stand-level analysis. In order to improve the separability, the methodologyfor extracting the remote sensing data did not resume only to the mean spectral response, but we also performed a variability and texture analysis. The obtained correlation coefficients were around 0.7, very significant for the data used in the research. The results obtained with the texture analysis are also related to the biometriccharacteristics of the stands, mistletoe attacks occurring in stands with a low canopy closure index and is usually accompanied by distorted crowns. The model of forest health analysis should also be tested in similar conditions in order to validate and apply on a large scale inventory.

  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. 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)

  3. 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

  4. 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.

  5. Nano size Aerosols of Radon Decay Products in Various Environments

    International Nuclear Information System (INIS)

    The radioactive noble gas radon (222Rn, alpha decay, t1/2 = 3.82 days) is always accompanied by its short-lived decay products (RnDP): 218Po (alpha decay, t1/2 = 3.10 min), 214Pb (beta/gamma decay, t1/2 = 26.8 min), 214Bi (beta/gamma decay, t1/2 = 19.9 min), and 214Po (alpha decay, t1/2 = 164 μs). In indoor and outdoor air, they appear as unattached RnDP in the form of clusters in the size range 0.5-3 nm and as attached RnDP between 200 and 800 nm. Because of plate-out of aerosols on the walls and floor of a room, as well as air movement and entry of fresh air, radioactive equilibrium between RnDP and Rn in indoor air is only partly achieved and is expressed as a fraction between 0 and 1, called the equilibrium factor, F. Birchall and James elaborated a dosimetric approach to calculate the dose conversion factor, DCFD, based on fun. In this paper, the results of our studies on fun in 29 rooms of kindergartens and 26 rooms of elementary and high schools, at the lowest point and the railway station in the Postojna Cave, and in 4 rooms in wineries in Slovenia are reported, and DCFD values based on the Porstendorfer formulae are discussed and compared with the DCFE value recommended by ICRP-65

  6. Risk-based approach to long-term safety assessment for near surface disposal of radioactive waste in Korea

    International Nuclear Information System (INIS)

    This paper presents the Korean regulatory approach to safety assessment consistent with probabilistic, risk-based long-term safety requirements for near surface disposal facilities. The approach is based on: (1) From the standpoint of risk limitation, normal processes and probabilistic disruptive events should be integrated in a similar manner in terms of potential exposures; and (2) The uncertainties inherent in the safety assessment should be reduced using appropriate exposure scenarios. In addition, this paper emphasizes the necessity of international guidance for quantifying potential exposures and the corresponding risks from radioactive waste disposal. (author)

  7. The coagulation of radioactive aerosols

    International Nuclear Information System (INIS)

    Radioactive aerosols can become charged by emitting charges during the decay process, and the resulting electrostatic forces will modify coagulation rates. For Brownian coagulation, calculations for nuclear containment aerosols show that rates averaged over charge distributions can be strongly reduced between particles of the same size, but that increases in average rates can occur for particles of different sizes. The increases arise from small, but significant, negative charging of non-radioactive and small-sized radioactive particles, and are sensitive to the asymmetry between the positive and negative ion mobilities. (Author)

  8. 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)

  9. TRIUMF - The Swedish data base system for radioactive waste in SFR

    International Nuclear Information System (INIS)

    All short lived LLW/ILW from the operation and maintenance of all Swedish Nuclear Power Plants are disposed in SFR, the Swedish final repository for radioactive operational waste. It is important to save all the information about radioactive waste that is needed now and in the future. To be secure that, we have developed a database system in Sweden called Triumf, consisting information about all the waste packages that are disposed in SFR. The waste producers register data concerning individual waste package during production. Before transport to SFR a data file with all information about the individual waste packages is transferred to Triumf. When transferred, the data are checked against accepted limitations before the waste can be loaded on the ship for transport to SFR. After disposal at SFR the deposition location in the repository is added to the database for each waste package. (author)

  10. 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)

  11. 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.)

  12. 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

  13. A PC-based discrete event simulation model of the Civilian Radioactive Waste Management System

    International Nuclear Information System (INIS)

    A System Simulation Model 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. This model can be used to quantify the impacts of different operating schedules, operational rules, system configurations, and equipment reliability and availability considerations on the performance of processes comprising the CRWMS and how these factors combine to determine overall system performance for the purpose of making system design decisions. 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

  14. 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

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

    International Nuclear Information System (INIS)

    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 self-shielding treatment

  16. 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...

  17. The decay data in ENDF/B: History and current status

    International Nuclear Information System (INIS)

    In recognition of the importance of radioactive-nuclide decay data for a variety of reactor-related applications, the scope of the Evaluated Nuclear Data File/B (ENDF/B) was expanded in 1973 to include such information. The impetus for this expansion was provided by the need for a common base of evaluated decay data for input to the computer codes developed to carry out 'summation-type' calculations of the fission product decay-heat source term in nuclear reactors. In its original formulation, this data base was called the Fission Product File, and an ad hoc group, the Decay Heat Task Force, was set up under the Fission Product Subcommittee of the Cross Sections Evaluation Working Group to prepare it. This group began work on the project early in 1973. The ENDF/B data file is profiled from its formation through various evaluation, developments, and changes to the present Version VI

  18. 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)

  19. 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)

  20. 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.

  1. 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.

  2. 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

  3. 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 ...

  4. Metallurgical characterizations of Fe–Cr–Ni–Zr base alloys developed for geological disposal of radioactive hulls

    International Nuclear Information System (INIS)

    Highlights: ► Immobilization of Zr-rich radioactive metallic wastes via alloy melting route. ► First detail report on metallurgical characterizations of Fe–Cr–Ni–Zr alloys. ► Identification of suitable base alloy composition. - Abstract: Alloy melting route is currently being considered for radioactive hulls immobilization. Towards this, wide range of alloys, belonging to Zirconium–Iron binary and Zirconium–Stainless steel pseudo-binary systems have been prepared through vacuum arc melting route. Detail microstructural characterization and quantitative phase analyses of these alloys along with interaction study between Zirconium and Stainless steel coupons at elevated temperatures identify Zr(Fe,Cr)2, Zr(Fe,Cr), Zr2(Fe,Cr), Zr3(Fe,Ni), Zr3(Fe,Cr), Zr3(Fe,Cr,Ni), β-Zr and α-Zr as the most commonly occurring phases within the system for Zirconium rich bulk compositions. Nano-indentation studies found Zr(Fe,Cr)2 and Zr(Fe,Cr) as extremely hard, Zr3(Fe,Ni) as moderately ductile and β-Zr, Zr2(Fe,Cr) as most ductile ones among the phases present. Steam oxidation studies of the alloys, based on weight gain/loss procedure and microstructural characterization of the mixed oxide layers, suggest that each of the alloys responded to the corrosive environment differently. Fe2O3, NiFe2O4, NiO, monoclinic ZrO2 and tetragonal ZrO2 are found to be most common constituents of the oxide layers developed on the alloys. Integrating the microstructural, mechanical and corrosion properties, ZrFeCrNi3 (Zr: 84.00, Fe: 11.20, Cr: 3.20, Ni: 1.60, in wt.%) is identified as the acceptable base alloy for disposal of radioactive hulls.

  5. Novel techniques to search for neutron radioactivity

    CERN Document Server

    Thoennessen, M; Kohley, Z; Baumann, T; Jones, M; Smith, J K; Snyder, J; Spyrou, A

    2013-01-01

    Two new methods to observe neutron radioactivity are presented. Both methods rely on the production and decay of the parent nucleus in flight. The relative velocity measured between the neutron and the fragment is sensitive to half-lives between ~1 and ~100 ps for the Decay in Target (DiT) method. The transverse position measurement of the neutron in the Decay in a Magnetic Field (DiMF) method is sensitive to half-lives between 10 ps and 1 ns.

  6. Non-destructive evaluation of curing effect on the quality of cement-based engineered barrier for radioactive waste disposal

    International Nuclear Information System (INIS)

    Cement-based engineered barrier for use of geological underground disposal of high-level radioactive wastes must be assured for long-time maintenance. The present report concerns the curing effect and its adequate non-destructive evaluation methods. For barrier materials with low-heat portland cement and fly-ash (LPC-FA), retarding the demolded-material age from 7-days to 15- and further to 28-days was found to effectively improve the material quality. Furthermore, surface permeability test was found to be used for non-destructive evaluation method of the quality of the engineered-barrier. (S. Ohno)

  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. Numerical Techniques for Radioactive Waste Repository Safety Assessment Based on Transport in Geological Media Models - 12083

    International Nuclear Information System (INIS)

    Radionuclide migration in geological media is considered within the framework of safety assessment of radioactive waste disposal facility. In this context groundwater flow and transport models are necessary. Computational technologies allowing for semiautomatic generation of unstructured meshes with different cell types, i.e. tetrahedra, hexahedra and pyramids and the subsequent solution of groundwater flow problems on these meshes are introduced. The application of methods is demonstrated in the groundwater flow model for a decommissioned subsurface reactor vessel, buried on its current location. (authors)

  9. Vietnam Project For Production Of Radioactive Beam Based On ISOL Technique With The Dalat Reactor

    International Nuclear Information System (INIS)

    The presence in Vietnam of Dalat nuclear reactor dedicated to fundamental studies is a unique opportunity to produce Radioactive Ion (RI) Beams with the fission of a 235U induced by the thermal neutrons produced by the reactor. We propose to produce RI beams at the Dalat nuclear reactor using ISOL (Isotope Separation On-Line) technique. This project should be a unique opportunity for Vietnamese nuclear physics community to use its own facilities to produce RI beams for studying nuclear physics at an international level. (author)

  10. 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. PMID:26999358

  11. Radioactivity: a tool to explore the past

    International Nuclear Information System (INIS)

    The use of the radioactive decay for dating purposes is reviewed. The most important dating methods are discussed. They include radioactive time markers (e.g. 137Cs), cosmogenic radionuclides (e.g., 14C, 10Be), decay products of 226Ra (e.g., 222Rn, 210Pb), uranium-thorium-lead chronometers, rubidium-strontium and potassium-argon nuclide pairs, applications of radioactive disequilibrium, dating with fission tracks, and thermoluminescence. Some important results, for instance the age of the Earth and the Moon, are also presented. (orig.)

  12. Effects of natural radioactivity on food radioactivity measurement

    International Nuclear Information System (INIS)

    Since the accident of the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Company, groups and individuals including local governments, food manufacturers, distribution circles, retail circles, and citizens are eager to measure the radioactivity of food, in order to confirm the safety of food from the concerns about radioactive contamination. The measurement of radioactivity of food is done by quantitatively determining gamma rays due to radioactive cesium that was incorporated into the biosphere cycle after having been released into the environment. As for the radioactivity measurement of food using gamma-ray spectrometry with a potassium iodide scintillation detector, which is very commonly used, this paper describes the handling method of obtained data, the principle of erroneous detection of radioactive cesium and iodine interrupted by natural radionuclides, and countermeasures for it. Major natural radioactivity sources are uranium series and thorium series. This paper explains gamma rays, which are characteristic in the decay process of uranium series and often affect the measurement of radioactive cesium in food and water. (O.A.)

  13. 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...

  14. 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

  15. Development of Labview based data acquisition and multichannel analyzer software for radioactive particle tracking system

    Science.gov (United States)

    Rahman, Nur Aira Abd; Yussup, Nolida; Abdullah, Jaafar B.; Ibrahim, Maslina Bt. Mohd; Abdullah, Nor Arymaswati; Mokhtar, Mukhlis B.; Hassan, Hearie B.

    2015-04-01

    A DAQ (data acquisition) software called RPTv2.0 has been developed for Radioactive Particle Tracking System in Malaysian Nuclear Agency. RPTv2.0 that features scanning control GUI, data acquisition from 12-channel counter via RS-232 interface, and multichannel analyzer (MCA). This software is fully developed on National Instruments Labview 8.6 platform. Ludlum Model 4612 Counter is used to count the signals from the scintillation detectors while a host computer is used to send control parameters, acquire and display data, and compute results. Each detector channel consists of independent high voltage control, threshold or sensitivity value and window settings. The counter is configured with a host board and twelve slave boards. The host board collects the counts from each slave board and communicates with the computer via RS-232 data interface.

  16. SCADA based radioactive sample bottle delivery system for fuel reprocessing project

    International Nuclear Information System (INIS)

    Radioactive samples of process streams need to be analyzed in centralized control lab for measuring concentration of heavy elements as well as activity at various stages of re-processing plants. The sample is taken from biologically shielded process cells remotely through sampling blisters in sample bottles. These are then transferred to control lab located about 50 meters using vacuum transfer system. The bottle movement is tracked from origin to destination in rich HMI SCADA system using Infra-red non contact type proximity sensors located along sampling line and these sensors are connected to PLC in a fail-safe mode. The sample bottle travels at a speed of 10 m/s under vacuum motive force and the detection time is of the order of 1 mS. The contact time Flow meters have been used to know the air flow in sampling line

  17. SCADA based radioactive sample bottle delivery system for fuel reprocessing project

    International Nuclear Information System (INIS)

    Radioactive samples of process streams need to be analyzed in centralized control lab for measuring concentration of heavy elements as well as activity at various stages of re-processing plants. The sample is taken from biologically shielded process cells remotely through sampling blisters in sample bottles. These are then transferred to control lab located about 50 meters using vacuum transfer system. The bottle movement is tracked from origin to destination in rich HMI SCADA system using Infra-red non contact type proximity sensors located along sampling line and these sensors are connected to PLC in a fail-safe mode. The sample bottle travels at a speed of 10 m/s under vacuum motive force and the detection time is of the order of 1 mS. The flow meters have been used to know the air flow in sampling line. The system has been designed, developed, tested and commissioned and in use for four years. (author)

  18. Development of Labview based data acquisition and multichannel analyzer software for radioactive particle tracking system

    International Nuclear Information System (INIS)

    A DAQ (data acquisition) software called RPTv2.0 has been developed for Radioactive Particle Tracking System in Malaysian Nuclear Agency. RPTv2.0 that features scanning control GUI, data acquisition from 12-channel counter via RS-232 interface, and multichannel analyzer (MCA). This software is fully developed on National Instruments Labview 8.6 platform. Ludlum Model 4612 Counter is used to count the signals from the scintillation detectors while a host computer is used to send control parameters, acquire and display data, and compute results. Each detector channel consists of independent high voltage control, threshold or sensitivity value and window settings. The counter is configured with a host board and twelve slave boards. The host board collects the counts from each slave board and communicates with the computer via RS-232 data interface

  19. Fabrication, characterization and radiation damage stability of hollandite based ceramics devoted to radioactive immobilisation

    International Nuclear Information System (INIS)

    Research on treating specifically the long-lived and high level nuclear wastes, notably cesium, is currently carried out in France. Cesium immobilization in host matrices of high chemical durability constitutes the favoured option. Hollandite matrix is a good candidate because of its high cesium incorporation ability and its excellent chemical stability. During this study, different compositions of hollandite ceramics BaxCsyCzTi8-zO16 (C = Al3+, Cr3+, Ga3+, Fe3+, Mg2+, Sc3+), synthesized by oxide route, were characterized in terms of structure, microstructure and physical and chemical properties. Iron ions seems to be the most suitable of the studied C cations to get high-performance hollandites. The stability of these ceramics under external electron irradiation, simulating the β particles emitted by radioactive cesium, were also estimated, at the macroscopic and atomic scale. The point defects creation and their thermal stability were followed by electron paramagnetic resonance. (author)

  20. Development of Labview based data acquisition and multichannel analyzer software for radioactive particle tracking system

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Nur Aira Abd, E-mail: nur-aira@nuclearmalaysia.gov.my; Yussup, Nolida; Ibrahim, Maslina Bt. Mohd; Abdullah, Nor Arymaswati; Mokhtar, Mukhlis B. [Technical Support Division, Malaysian Nuclear Agency, 43000, Kajang, Selangor (Malaysia); Abdullah, Jaafar B.; Hassan, Hearie B. [Industrial Technology Division, Malaysian Nuclear Agency, 43000, Kajang, Selangor (Malaysia)

    2015-04-29

    A DAQ (data acquisition) software called RPTv2.0 has been developed for Radioactive Particle Tracking System in Malaysian Nuclear Agency. RPTv2.0 that features scanning control GUI, data acquisition from 12-channel counter via RS-232 interface, and multichannel analyzer (MCA). This software is fully developed on National Instruments Labview 8.6 platform. Ludlum Model 4612 Counter is used to count the signals from the scintillation detectors while a host computer is used to send control parameters, acquire and display data, and compute results. Each detector channel consists of independent high voltage control, threshold or sensitivity value and window settings. The counter is configured with a host board and twelve slave boards. The host board collects the counts from each slave board and communicates with the computer via RS-232 data interface.

  1. 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

  2. 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.

  3. 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)

  4. Radioactive thickness gauge

    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 sourcedetector interval. The performance of the gauge is given. (author)

  5. 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)

  6. 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.

  7. Development of a sorption data base for the cementitious near-field of a repository for radioactive waste

    International Nuclear Information System (INIS)

    The migration of radionuclides within a repository for radioactive waste is retarded due to interaction with the engineered barrier system. Sorption processes play a decisive role in the retardation of radionuclides in the repository environment, and thus, the development of sorption data bases (SDBs) is an important task and an integral part of performance assessment. The methodology applied in the development of a SDB for the cementitious near-field of a repository for long-lived intermediate-level waste is presented in this study. The development of such a SDB requires knowledge of the chemical conditions of the near-field and information on the uptake process of radionuclides by hardened cement paste. The principles upon which the selection of the 'best available' laboratory sorption values is based are outlined. The influence of cellulose degradation products, cement additives and cement-derived colloids on the sorption behaviour of radionuclides is addressed in conjunction with the development of the SDB. (author)

  8. 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.

  9. Radioactive europium-chelate-based silica nanoparticles as a probe for stability, incorporation efficiency and trace analysis

    International Nuclear Information System (INIS)

    Two luminescent terbium and europium lanthanide chelates were efficiently embedded into silica nanoparticles by using a reverse microemulsion process. The incorporation was achieved without covalent bonding between the lanthanide chelates and the silica matrix. To investigate the efficiency of the incorporation process and the stability of the silica encapsulated lanthanide complex, a method based on a radioactive probe was developed; γ-emitting europium (152) chelates were synthesized and incorporated into silica nano-particles. Measurements of the γ activity through the entire synthesis allowed the accurate characterization of the incorporation efficiency of the used chelates. A clear correlation was established between the physicochemical properties of the different chelates and the measured incorporation efficiencies. A very efficient noncovalent incorporation of lanthanide chelates in highly stable nanoparticles was achieved by tuning the chelate properties, thus rendering the development of lanthanide-based fluorescent nanoparticles easier. (authors)

  10. 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

  11. The Integrated Data Base program: An executive-level data base of spent fuel and radioactive waste inventories, projections, and characteristics

    International Nuclear Information System (INIS)

    The Integrated Data Base (IDB) is the official US Department of Energy (DOE) data base for spent fuel and radioactive waste inventories and projections. As such, it should be as convenient to utilize as is practical. Examples of summary-level tables and figures are presented, as well as more-detailed graphics describing waste-form distribution by site and line charts illustrating historical and projected volume (or mass) changes. This information is readily accessible through the annual IDB publication. Other presentation formats are also available to the DOE community through a simple request to the IDB Program

  12. 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

  13. Environmental radioactivity analyses

    International Nuclear Information System (INIS)

    A survey with appropriate references about monitoring of radioactivities encountered in the environment is presented. The first part is concerned with different sources of cosmogenic and terrestrial radionuclides on one side and, on the other, with radionuclides released into the environment by activities of people. Afterwards, attention is focused on the physical, chemical and technical aspects of advanced measuring techniques including sample treatments. The most important primordial radionuclides are 238U, 235U, 232Th and they decay products in transformation series, and 40K as well as 87Rb

  14. Radioactive waste gas processing systems

    International Nuclear Information System (INIS)

    Purpose: To effectively separate and remove only hydrogen from hydrogen gas-containing radioactive waste gases produced from nuclear power plants without using large scaled facilities. Constitution: From hydrogen gas-enriched waste gases which contain radioactive rare gases (Kr, Xe) sent from the volume control tank of a chemical volume control system, only the hydrogen is separated in a hydrogen separator using palladium alloy membrane and rare gases are concentrated, volume-decreased and then stored. In this case, an activated carbon adsorption device is connected at its inlet to the radioactive gas outlet of the hydrogen separator and opened at its outlet to external atmosphere. In this system, while only the hydrogen gas permeates through the palladium alloy membrane, other gases are introduced, without permeation, into the activated carbon adsorption device. Then, the radioactive rare gases are decayed by the adsorption on the activated carbon and then released to the external atmosphere. (Furukawa, Y.)

  15. 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

  16. 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.

  17. Risk-based financial assurance for transport of low-level radioactive waste

    International Nuclear Information System (INIS)

    The purpose of this paper is two-fold: (1) assess the risks associated with the transportation of low-level radioactive wastes (LLRW) in New York State; and (2) evaluate financial assurance requirements to cover those risks. The risk assessment uses as inputs characterizations of the following: (1) waste shipments by vehicle category (i.e., type of vehicle); and (2) environmental settings by generic route. Once LLRW shipments and environmental settings have been characterized, the risk assessment proceeds to analyze potential events (e.g., small accident enroute) and their consequences (e.g., dispersion of released materials and subsequent human exposure) for each combination of vehicle category and generic route (i.e., transport configuration). Finally, for each transport configuration, the risk assessment estimates the probability and magnitude of corrective action costs and third-party compensation costs attached to the consequences of each event, and combines these estimates with the estimates of the probability of each event to construct a cost curve for corrective action, third-part compensation, and combined liabilities

  18. 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

  19. A data base for low-level radioactive waste disposal sites

    International Nuclear Information System (INIS)

    A computerized database was developed to assist the US Environmental Protection Agency (EPA) in evaluating methods and data for characterizing health hazards associated with land and ocean disposal options for low-level radioactive wastes. The data cover 1984 to 1987. The types of sites considered include Nuclear Regulatory Commission (NRC) licensed commercial disposal sites, EPA National Priority List (NPL) sites, US Department of Energy (DOE) Formerly Utilized Sites Remedial Action Project (FUSRAP) and DOE Surplus Facilities Management Program (SFMP) sites, inactive US ocean disposal sites, and DOE/Department of Defense facilities. Sources of information include reports from EPA, the US Department of Energy (DOE) and the Nuclear Regulatory Commission (NRC), as well as direct communication with individuals associated with specific programs. The data include site descriptions, waste volumes and activity levels, and physical and radiological characterization of low-level wastes. Additional information on mixed waste, packaging forms, and disposal methods were compiled, but are not yet included in the database. 55 refs., 4 figs., 2 tabs

  20. 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

  1. Decay heat analysis of MNSR reactor core using ORIGEN-2 code

    International Nuclear Information System (INIS)

    Highlights: • Analysis of the decay heat parameters of the MNSR reactor was performed using the ORIGEN-2 code. • A new one-group cross-section data base of the ORlGEN-2 computer code for the MNSR was developed. • It is recommended to adopt the results of the ORIGIEN-2 code for future reactor safety analysis of MNSR. - Abstract: The knowledge of the decay heat of nuclear fuel is necessary for performing the reactor safety analysis, determining the heating load in fuel pools, shielding requirements on fuel discharge and transport routes when irradiated reactor fuel is transferred from the reactor, via some intermediate storage location, to the final disposal or the chemical reprocessing plant. In this study, analysis of the decay heat parameters of the Miniature Neutron Source Reactor (MNSR) including radioactivity, decay heat and the isotopic mass variation with time since reactor shutdown for the potential Low Enriched Uranium (LEU) (UO2-Zircaloy and U3Si-Al) and the standard Highly Enriched Uranium (HEU) (HEU-Al4) cores has been performed using the ORIGEN-2 code. For this purpose, a new one-group cross-section data base of the ORlGEN-2 computer code for the MNSR with LEU and HEU fuels has been developed using the MCNP-4C code. The variation of fission products, actinides and daughters and activation products with post shutdown time for the standard core and the potential LEU cores have been considered in the analysis of the decay heat power resources. It was found that, all the three types of MNSR fuels show close agreement in the total decay heat, which is mainly due to the fission products. This behavior continued for about 1.0E05 days. After this time, the fission products decay heat became comparable with the corresponding actinides decay heat in which the standard HEU UAl4-Al fuel showed the smallest decay heat values while the potential LEU-UO2 fuel had the highest decay heat followed by the LEU-U3Si fuel. The time variation of the total radioactivity

  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. Global $\\alpha$-decay study based on the mass table of the relativistic continuum Hartree-Bogoliubov theory

    CERN Document Server

    Zhang, Linfeng

    2015-01-01

    The $\\alpha$-decay energies ($Q_\\alpha$) are systematically investigated with the nuclear masses for $10 \\leq Z \\leq 120$ 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 $\\alpha$-decay energies deduced from the RCHB results present similar pattern as those from available experiments. Owing to the large predicted $Q_\\alpha$ values ($\\geq$ 4 MeV), many undiscovered heavy nuclei in the proton-rich side and super-heavy nuclei may have large possibilities for $\\alpha$-decay. The influence of nuclear shell structure on $\\alpha$-decay energies is also analysed.

  4. 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

  5. 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

  6. A computer-based continuous monitor for the determination of the short-lived decay products of radon and thoron

    International Nuclear Information System (INIS)

    A portable, rugged, monitor has been designed for measuring the short-lived decay products of radon and thoron. The monitor is computer-based and uses a continuous filter strip which can be advanced at programmable time intervals to allow unattended continuous operation with automatic sampling, analysis and recording of radiation levels. Radionuclide analysis is carried out by two silicon diffused-junction alph-detectors and electronic circuitry with multi-channel spectral analysis capabilities. Standard gross α-count methods and α-spectroscopy methods can easily be implemented. The built-in computer performs a variety of operations via a specially designed interface module, including control and data recording functions, and computations, program storage and display functions. Programs and data are stored in the built-in cassette tape drive and the computer integrated CRT display and keyboard allow simple, prompted menu-type operation of standard software. Graphical presentation of α-spectra can be shown on the computer CRT and printed on the computer built-in thermal printer. In addition to implementing the specially developed radionuclide analysis software, the operator can modify existing software, and program new ones, through BASIC language programming, or employ the computer in a totally unrelated general purpose mode. Although the monitor is ideally suited for radon (thoron) daughter monitoring, it could also be used in the determination of other airborne radionuclides

  7. 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.

  8. 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.

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

    International Nuclear Information System (INIS)

    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

  10. Geologic disposal of radioactive waste

    International Nuclear Information System (INIS)

    The heat dissipation arising from the radioactive decay constitutes an important problem of the geological disposal of high level radioactive waste. A heating experiment was carried out in a clay quarry near Monterotondo (Rome), at 6.4 M in depth by means of a heater whose thermal power ranged from 250 to 500 watt. The experimental results fit well the theoretical values and show that the clay is a homogeneous and isotropic medium. The clay thermal conductivity, which was deducted by means of the ''curve fitting'' method, ranges from 0.015 to 0.017 watt/C

  11. Proceedings of the conference on advances in radioactive isotope science (ARIS2014)

    International Nuclear Information System (INIS)

    These web-based proceedings represent a collection of the presentations given at the Second Conference on Advances in Radioactive Isotope Science (ARIS2014), including the following topics: 1) nuclear structure, 2) nuclear astrophysics, 3) fundamental symmetries and interactions, 4) nuclear reactions and responses, 5) nuclear properties including atomic masses and fundamental constants, nuclear moments and radii, rare decay modes, and nuclei at the driplines, 6) nuclear EOS and its implications, 7) heaviest elements and fission, 8) radioactive isotope production and developments of experimental devices, 9) computational developments, 10) applications, and 11) other related issues. The 229 of 369 papers presented at the entitled meeting are indexed individually. (J.P.N.)

  12. 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)

  13. 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)

  14. Activities for data base construction by Technical Committee for Investigation of Dielectric and Insulating Material in Radioactive Environment

    International Nuclear Information System (INIS)

    The Technical Committee for Investigation of Dielectric and Insulating Material in Radioactive Environment in May 1990 started activities for the collection of information and surveys and studies for the construction of a data base. The studies cover the mechanism of deterioration in electric mediums, communications equipment, materials and devices in a special environment; simulation of material in a special environment; prediction of the service life of material in a special environment; and feasibility of the construction of a data base. These surveys and studies are intended to determine the resistance of dielectric and insulating materials and devices to special environments, to achieve an increase in their reliability and service life, to provide techniques for accurate life prediction, to establish a data base from collected information, and to study the feasibility of the construction of an expert system. In particular, the report describes the activities for the construction of the data base, focusing on the data format, problems to be solved to permit its construction, etc. (N.K.)

  15. 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.

  16. 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.

  17. 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

  18. 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...

  19. Feasibility of immobilizing simulated radioactive slurry based on alkali-activated slag-clay minerals composite cement

    International Nuclear Information System (INIS)

    The feasibility of immobilizing simulated radioactive slurry (SRS) by alkali-activated slag-clay minerals composite cement (AASCM) was studied under the experimental conditions. The results show that the flowability of the mixture of AASCM and SRS is highly dependent on the dosage of SRS and water cement ratio and the setting time is more dependent on temperature but less dependent on sorts of anions in the experiment. The application of AASCM in solidification engineering is suitable below 20 degree C. When cement-sand ratio is 1:1 and water-cement ratio is 0.45, the flowability of the mixture meets the case of solidification engineering and the compressive strength of the waste forms containing 20% SRS meets the needs of GB 14569.1-93. The leaching rate of AASCM based waste forms is lower than that of ordinary Portland cement (OPC) based waste forms. Silicon fume can improve the workability of the mixture of AASCM and SRS and decrease the leaching rate of waste forms based on AASCM as well. (authors)

  20. Review of international radioactive waste management based on a report of the International Nuclear Societies Council (INSC)

    International Nuclear Information System (INIS)

    The INSC is an international group of 42 nuclear societies with the aim of promoting the peaceful uses of nuclear science and technology. It has a number of working groups addressing important issues and publishes the reports of these groups. The latest report of the working group on radioactive waste management was published in August 2002. The main aim of the report is to provide the latest information on radioactive waste management among the member societies and particularly to provide access to internet resources on this topic including access to the radioactive waste management organisations in the several countries.The major topics addressed in the report are: what is radioactive waste management?; where does radioactive waste come from?; principles and objectives; management strategies - options and ethics; current worldwide status; international cooperation; and international instruments, including treaties and legislation

  1. BREST-1200 reactor fuel cycle based on the principles of nuclear arm non-proliferation and radiation-equivalent disposal of radioactive wastes

    International Nuclear Information System (INIS)

    The BREST-reactor fuel cycle, based on the principles of the nuclear arm non-proliferation and radiation-equivalent radioactive waste disposal, is described. The peculiarities of the BREST reactor, meeting the requirements of the nonproliferation of the nuclear materials, suitable for the nuclear arm production, are considered. The technological aspects of the fissile materials non-proliferation are discussed

  2. Storage of radioactive wastes

    International Nuclear Information System (INIS)

    Even if the best waste minimization measures are undertaken throughout radioisotope production or usage, significant radioactive wastes arise to make management measures essential. For developing countries with low isotope usage and little or no generation of nuclear materials, it may be possible to handle the generated waste by simply practicing decay storage for several half-lives of the radionuclides involved, followed by discharge or disposal without further processing. For those countries with much larger facilities, longer lived isotopes are produced and used. In this situation, storage is used not only for decay storage but also for in-process retention steps and for the key stage of interim storage of conditioned wastes pending final disposal. The report will serve as a technical manual providing reference material and direct step-by-step know-how to staff in radioisotope user establishments and research centres in the developing Member States without nuclear power generation. Considerations are limited to the simpler storage facilities. The restricted quantities and low activity associated with the relevant wastes will generally permit contact-handling and avoid the need for shielding requirements in the storage facilities or equipment used for handling. A small quantity of wastes from some radioisotope production cells and from reactor cooling water treatment may contain sufficient short lived activity from activated corrosion products to require some separate decay storage before contact-handling is suitable. 16 refs, 12 figs, 8 tabs

  3. 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

  4. Radioactive waste management

    International Nuclear Information System (INIS)

    This book highlights the main issues of public concern related to radioactive waste management and puts them into perspective. It provides an overview of radioactive waste management covering, among other themes, policies, implementation and public communication based on national experiences. Its purpose is to assists in increasing the understanding of radioactive waste management issues by public and national authorities, organizations involved in radioactive waste management and the nuclear industry; it may also serve as a source book for those who communicate with the public. Even in the unlikely event that nuclear power does not further develop around the world, the necessity for dealing with nuclear waste from past usages, from uranium mining and milling, decontamination and decommissioning of existing nuclear facilities and from the uses of radioactive materials in medicine, industry and research would still exist. In many countries, radioactive waste management planning involves making effective institutional arrangements in which responsibilities and liabilities are well established for the technical operation and long term surveillance of disposal systems. Financing mechanisms are part of the arrangements. Continuous quality assurance and quality control, at all levels of radioactive waste management, are essential to ensure the required integrity of the system. As with any other human activity, improvements in technology and economics may be possible and secondary problems avoided. Improvements and confirmation of the efficiency of processes and reduction of uncertainties can only be achieved by continued active research, development and demonstration, which are the goals of many national programmes. International co-operation, also in the form of reviews, can contribute to increasing confidence in the ongoing work. The problem of radioactive wastes is not a unique one; it may be compared with other problems of toxic wastes resulting from many other

  5. Wrong low level radioactive waste management in hospitals and improvement steps

    International Nuclear Information System (INIS)

    Hospitals are producers of great amounts of all kind of waste, including dangerous waste. The dangerous waste can be toxic, biological, radioactive, or a mixture of several kinds. There are clear procedures how to store and treat every kind of waste separately, according to its characteristics. Radioactive waste should be disposed only to a central radwaste disposal site. If the radioactive waste is mixed with biological waste, and contains long half-life isotopes, it should be neutralized from biological hazards before disposal to radwaste storage site. If the waste contains short half-life isotopes, it should be stored in a proper intermediate storage facility till a complete decay of the radioactive elements, and then treated as not radioactive. The existing procedures are old and a new proposal for radwaste procedures was prepared but not implemented. After several repetitive violations of the old regulations by some hospitals, it was decided to advance the implementation of the new proposal. This proposal consists of a detailed procedures for segregation, storage, decay and disposal of radwaste. It is based on the new recommendations of the IAEA. The responsibility for implementing the regulations is on the producers of the waste. This paper summarizes the violations and describes the main recommendations for improving procedures. The competent authority used moderate enforcement steps because of the delay in the implementation of the new procedures. As a matter of fact, the competent authority concluded that it's own investigation procedures should improve, but we shall not discuss it in this paper. (author)

  6. Direct measurements of neutron capture on radioactive isotopes

    CERN Document Server

    Couture, A

    2009-01-01

    We simulated the response of a 4p calorimetric g-detector array to decays of radioactive isotopes on the s-process path. The GEANT 3.21 simulation package was used. The main table contains estimates on the maximum sample size and required neutron flux based on the latest available neutron capture cross section at 30 keV. The results are intended to be used to estimate the feasibility of neutron capture measurements with 4p arrays using the time of flight technique.

  7. A time projection chamber to study two-proton radioactivity

    International Nuclear Information System (INIS)

    Two-proton radioactivity was observed in two experiments in 2002 in the decay of 45Fe. However, these experiments did not allow the observation of the two protons directly. In the present paper, we present a new setup based on the principle of a time projection chamber which enabled us for the first time to identify directly the two protons. The new setup permits the observation and reconstruction in three dimensions of the traces of the protons. We will discuss the setup and describe its performances.

  8. 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

  9. 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.

  10. Radioactivity in the hydrologic environment

    International Nuclear Information System (INIS)

    Certain proposed uses of nuclear explosives for peaceful purposes will introduce radioactive debris into the natural hydrologic environment. Consideration must therefore be given in each situation to the extent and significance to man of resulting radioactively contaminated water. For contained underground detonations, space-time - concentration predictions of radioactive materials in ground water are dependent on several factors: radionuclide production and initial distribution, radioactive decay, sorption on geologic materials, and dispersion during hydrologic transport. For uncontained (cratering) detonations, other aspects of the hydrologic cycle, particularly rainfall, and watershed characteristics must be considered. Programs sponsored principally by the U.S. Atomic Energy Commission have investigated these factors. Examination of their net effects on radioactivity concentration in water shows that areas if any, underlain by water exceeding permissible concentrations tend first to increase in size, then decrease, and finally disappear. Hydrologic processes at the surface remove or redistribute radioactive debris deposited on a watershed to other locations. Where sufficient information is available, predictions of location and concentration of radionuclides in natural waters can be made. Any potentially hazardous conditions arising from a particular detonation can then be evaluated. (author)

  11. 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.)

  12. Instantaneous Canopy Photosynthesis: Analytical Expressions for Sun and Shade Leaves Based on Exponential Light Decay Down the Canopy and an Acclimated Non‐rectangular Hyperbola for Leaf Photosynthesis

    OpenAIRE

    THORNLEY, J. H. M.

    2002-01-01

    Analytical expressions for the contributions of sun and shade leaves to instantaneous canopy photosynthesis are derived. The analysis is based on four assumptions. First, that the canopy is closed in the sense that it is horizontally uniform. Secondly, that there is an exponential profile of light down the canopy with the same decay constant for light from different parts of the sky. Thirdly, that the leaf photosynthetic response to incident irradiance can be described by a three‐parameter no...

  13. 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

    can disclose strong and medium level signals from manmade nuclides. But methods for detecting low level signals from weak, distant or shielded sources can be improved. New methods for source detection and identification based on noise adjusted singular value decomposition and on area specific...

  14. 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

  15. Off-site dose calculation computer code based on ICRP-60(II) - liquid radioactive effluents -

    International Nuclear Information System (INIS)

    The development of computer code for calculating off-site doses(K-DOSE60) was based on ICRP-60 and the dose calculationi equations of Reg. Guide 1.109. In this paper, the methodology to compute dose for liquid effluents was described. To examine reliability of the K-DOSE60 code the results obtained from K-DOSE60 were compared with analytic solutions. For liquid effluents. The results by K-DOSE60 are in agreement with analytic solution

  16. Data for decay Heat Predictions

    International Nuclear Information System (INIS)

    These proceedings of a specialists' meeting on data for decay heat predictions are based on fission products yields, on delayed neutrons and on comparative evaluations on evaluated and experimental data for thermal and fast fission. Fourteen conferences were analysed

  17. 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)

  18. 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.

  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. 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.

  1. Sensitivity Increases for the TITAN Decay Spectroscopy Program

    CERN Document Server

    Leach, K G; Grossheim, A; Andreoiu, C; Dilling, J; Frekers, D; Good, M; Seeraji, S

    2014-01-01

    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 backing-free 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.

  2. A new method of testing space-based high-energy electron detectors with radioactive electron sources

    Science.gov (United States)

    Zhang, S. Y.; Shen, G. H.; Sun, Y.; Zhou, D. Z.; Zhang, X. X.; Li, J. W.; Huang, C.; Zhang, X. G.; Dong, Y. J.; Zhang, W. J.; Zhang, B. Q.; Shi, C. Y.

    2016-05-01

    Space-based electron detectors are commonly tested using radioactive β-sources which emit a continuous spectrum without spectral lines. Therefore, the tests are often to be considered only qualitative. This paper introduces a method, which results in more than a qualitative test even when using a β-source. The basic idea is to use the simulated response function of the instrument to invert the measured spectrum and compare this inverted spectrum with a reference spectrum obtained from the same source. Here we have used Geant4 to simulate the instrument response function (IRF) and a 3.5 mm thick Li-drifted Si detector to obtain the reference 90Sr/90Yi source spectrum to test and verify the geometric factors of the Omni-Direction Particle Detector (ODPD) on the Tiangong-1 (TG-1) and Tiangong-2 (TG-2) spacecraft. The TG spacecraft are experimental space laboratories and prototypes of the Chinese space station. The excellent agreement between the measured and reference spectra demonstrates that this test method can be used to quantitatively assess the quality of the instrument. Due to its simplicity, the method is faster and therefore more efficient than traditional full calibrations using an electron accelerator.

  3. Seabed radioactivity based on in situ measurements and Monte Carlo simulations

    International Nuclear Information System (INIS)

    Activity concentration measurements were carried out on the seabed, by implementing the underwater detection system KATERINA. The efficiency calibration was performed in the energy range 350–2600 keV, using in situ and laboratory measurements. The efficiency results were reproduced and extended in a broadened range of energies from 150 to 2600 keV, by Monte Carlo simulations, using the MCNP5 code. The concentrations of 40K, 214Bi and 208Tl were determined utilizing the present approach. The results were validated by laboratory measurements. - Highlights: • The KATERINA system was applied for marine sediments. • MC simulations using MCNP5 reproduced experimental energy spectra and efficiency. • The in-situ method provided quantitative measurements. • The measurements were validated with lab-based methods

  4. Natural radioactivity and cancer risk

    International Nuclear Information System (INIS)

    The report is a review of physical and biological parameters important in the calculation of the risk for cancer induction by natural radioactivity. Based on cited assumptions, natural radioactivity may cause 375 to 530 cases of cancer in Norway per year

  5. 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

  6. 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)

  7. 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...

  8. 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

  9. Determination of the radioactive aerosols transport coefficients generated in open pit uranium mining areas

    International Nuclear Information System (INIS)

    The classical atmospheric transport model is applied to uranium mining operations. Among the transport parameters there is one concerned with radioactive decay, but it does not include the radioactive decay series which is the specific case for uranium. Therefore, an extension of the transport theory is developed and tested, giving results greater than the ones obtained with the classical model, as expected. (author)

  10. ANITA-2000 activation code package - updating of the decay data libraries and validation on the experimental data of the 14 MeV Frascati Neutron Generator

    Directory of Open Access Journals (Sweden)

    Frisoni Manuela

    2016-01-01

    Full Text Available ANITA-2000 is a code package for the activation characterization of materials exposed to neutron irradiation released by ENEA to OECD-NEADB and ORNL-RSICC. The main component of the package is the activation code ANITA-4M that computes the radioactive inventory of a material exposed to neutron irradiation. The code requires the decay data library (file fl1 containing the quantities describing the decay properties of the unstable nuclides and the library (file fl2 containing the gamma ray spectra emitted by the radioactive nuclei. The fl1 and fl2 files of the ANITA-2000 code package, originally based on the evaluated nuclear data library FENDL/D-2.0, were recently updated on the basis of the JEFF-3.1.1 Radioactive Decay Data Library. This paper presents the results of the validation of the new fl1 decay data library through the comparison of the ANITA-4M calculated values with the measured electron and photon decay heats and activities of fusion material samples irradiated at the 14 MeV Frascati Neutron Generator (FNG of the NEA-Frascati Research Centre. Twelve material samples were considered, namely: Mo, Cu, Hf, Mg, Ni, Cd, Sn, Re, Ti, W, Ag and Al. The ratios between calculated and experimental values (C/E are shown and discussed in this paper.

  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. Saltstone: cement-based waste form for disposal of Savannah River Plant low-level radioactive salt waste

    International Nuclear Information System (INIS)

    Defense waste processing at the Savannah River Plant will include decontamination and disposal of approximately 400 million liters of waste containing NaNO3, NaOH, Na2SO4, and NaNO2. After decontamination, the salt solution is classified as low-level waste. A cement-based waste form, saltstone, has been designed for disposal of Savannah River Plant low-level radioactive salt waste. Bulk properties of this material have been tailored with respect to salt leach rate, permeability, and compressive strength. Microstructure and mineralogy of leached and unleached specimens were characterized by SEM and x-ray diffraction analyses. The disposal system for the DWPF salt waste includes reconstitution of the crystallized salt as a solution containing 32 wt % solids. This solution will be decontaminated to remove 137Cs and 90Sr and then stabilized in a cement-based waste form. Laboratory and field tests indicate that this stabilization process greatly reduces the mobility of all of the waste constitutents in the surface and near-surface environment. Engineered trenches for subsurface burial of the saltstone have been designed to ensure compatibility between the waste form and the environment. The total disposal sytem, saltstone-trench-surrounding soil, has been designed to contain radionuclides, Cr, and Hg by both physical encapsulation and chemical fixation mechanisms. Physical encapsulation of the salts is the mechanism employed for controlling N and OH releases. In this way, final disposal of the SRP low-level waste can be achieved and the quality of the groundwater at the perimeter of the disposal site meets EPA drinking water standards

  13. Saltstone: cement-based waste form for disposal of Savannah River Plant low-level radioactive salt waste

    International Nuclear Information System (INIS)

    Defense waste processing at the Savannah River Plant will include decontamination and disposal of approximately 400 million liters of waste containing NaNO3, NaOH, Na2SO4, and NaNO2. After decontamination, the salt solution is classified as low-level waste. A cement-based waste form, saltstone, has been designed for disposal of Savannah River Plant low-level radioactive salt waste. Bulk properties of this material have been tailored with respect to salt leach rate, permeability, and compressive strength. Microstructure and mineralogy of leached and unleached specimens were characterized by SEM and x-ray diffraction analyses. The disposal system for the DWPF salt waste includes reconstitution of the crystallized salt as a solution containing 32 wt % solids. This solution will be decontaminated to remove 137Cs and 90Sr and then stabilized in a cement-based waste form. Laboratory and field tests indicate that this stabilization process greatly reduces the mobility of all of the waste constitutents in the surface and near surface environment. Engineered trenches for subsurface burial of the saltstone have been designed to ensure compatibility between the waste form and the environment. The total disposal system, saltstone-trench- surrounding soil, has been designed to contain radionuclides, Cr, and Hg by both physical encapsulation and chemical fixation mechanisms. Physical encapsulation of the salts is the mechanism employed for controlling N and OH releases. In this way, final disposal of the SRP low-level waste can be achieved and the quality of the ground water at the perimeter of the disposal site meets EPA drinking water standards

  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. 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)

  17. Purifications of calcium carbonate and molybdenum oxide powders for neutrinoless double beta decay experiment, AMoRE

    International Nuclear Information System (INIS)

    The AMoRE (Advanced Mo based Rare process Experiment) collaboration is going to use calcium molybdate crystals to search for neutrinoless double beta decay of 100Mo isotope. In order to make the crystal, we use calcium carbonate and molybdenum oxide powders as raw materials. Therefore it is highly necessary to reduce potential sources for radioactive backgrounds such as U and Th in the powders. In this talk, we will present our studies for purification of calcium carbonate and molybdenum oxide powders

  18. 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.)

  19. 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,

  20. 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.

  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 and the French uranium bearing minerals

    International Nuclear Information System (INIS)

    This special issue of Regne Mineral journal is entirely devoted to the French uranium mining industry. It comprises 4 parts dealing with: the uranium mining industry in France (history, uranium rush, deposits, geologic setting, prosperity and recession, situation in 1998, ore processing); radioactivity and the uranium and its descendants (discovery, first French uranium bearing ores, discovery of radioactivity, radium and other uranium descendants, radium mines, uranium mines, atoms, elements and isotopes, uranium genesis, uranium decay, isotopes in an uranium ore, spontaneous fission, selective migration of radionuclides, radon in mines and houses, radioactivity units, radioprotection standards, new standards and controversies, natural and artificial radioactivity, hazards linked with the handling and collecting of uranium ores, conformability with radioprotection standards, radioactivity of natural uranium minerals); the French uranium bearing minerals (composition, crystal structure, reference, etymology, fluorescence). (J.S.)

  3. Radioactive waste management

    International Nuclear Information System (INIS)

    This eighth chapter presents the radioactive wastes and waste disposal; classification of radioactive wastes; basis requests of the radioactive waste management; conditions for a radioactive waste disposal; registers and inventories; transport of radioactive wastes from a facility to another and the radioactive waste management plan

  4. Radioactive waste

    International Nuclear Information System (INIS)

    Focusing on radioactive waste management and disposal policies in the United Kingdom, Sweden and the Federal Republic of Germany, this book gives a detailed historical account of the policy process in these three countries, and draws out the implications for theory and public policy. This comparative approach underlines how profoundly different the policy process has been in different countries. By comparing the evolution of policy in three countries, fundamental questions about the formation and resolution of technical decisions under uncertainty are clarified. The analysis of nuclear strategy, the politics of nuclear power, and the shifting emphasis of government regulation redefines the issue of radwaste management and sets it at the heat of the current debate about power, the environment and society. The combination of up-to-date technological assessment with an account of the social and political implications of radwaste management makes'Radioactive Waste'particularly useful to students of environmental studies, geography and public administration. (author)

  5. 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 .

  6. 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.)

  7. 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.)

  8. 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

  9. 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

  10. 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.

  11. 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

  12. α decay and recoil decay tagging studies of 183Tl

    International Nuclear Information System (INIS)

    High-spin states in the nucleus 183Tl have been studied using the recoil decay tagging and recoil tagging techniques. The data have enabled new structures to be identified which are believed to be based on prolate f7/2, h9/2, and oblate h9/2 configurations. In addition, the prolate i3/2 structure has also been extended. The systematics of the newly identified structures will be discussed. The α decay of 183Tl has also been investigated. Examination of both delayed and prompt γ rays in coincidence with the prominent 6333-keV α decay, together with an investigation of the effects of the summing of L electrons, allow assignment of transitions and the construction of tentative low-spin decay schemes for 179Au and 175Ir

  13. Radioactivity: A tool to explore the past

    International Nuclear Information System (INIS)

    The use of the radioactive decay for dating purposes is reviewed. The most important dating methods are discussed. They include radioactive time markers (e.g. sup 1 sup 3 sup 7 Cs), cosmogenic radionuclides (e.g., sup 1 sup 4 C, sup 1 sup 0 Be), decay products of sup 2 sup 2 sup 6 Ra (e.g., sup 2 sup 2 sup 2 Rn, sup 2 sup 1 sup 0 Pb), uranium-thorium-lead chronometers, rubidium-strontium and potassium-argon nuclide pairs, applications of radioactive disequilibrium, dating with fission tracks, and thermoluminescence. Some important results, for instance the age of the Earth and the Moon, are also presented. (author)

  14. A general formula for α-decay life-time

    International Nuclear Information System (INIS)

    In the approach we have proposed recently for calculation of Q-value energy and decay half-life T1/2 on the α decay of radioactive heavy ions, the α+nucleus system is considered as a Coulomb-nuclear potential scattering problem and the accurately determined resonance energy (E) of the quasibound state is taken as the Q-value of the decaying system. The width or life time of the resonance state accounts for the decay half-life. The normalized regular solution u(r) of the modified Schrödinger equation is matched

  15. 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

  16. Source-term development for commercial low-level radioactive waste

    International Nuclear Information System (INIS)

    Generic source terms base don historical data have been developed for commerical low-level radioactive waste (LLRW) from fuel-cycle and non-fuel-cycle facilities. These source terms are used in DOE's Integrated Data Base (IDB) Program to estimate historical and projected volumes, radioactivity, and thermal power (from radioactive decay) of LLRW to the year 2020. Periodically, the source terms are updated as new waste is generated and as information on older waste is reviewed, redefined, and upgraded by the generator. Other segments of the nuclear industry also use source terms in planning for waste treatment, transportation, and storage systems. Several uses of source terms are illustrated. For example, the reported volume and radioactivity of LLRW added annually to commerical burial sites are compared with the calculated annual values obtained by summing contributions based on source terms for each generator. Likewise, accumulative radioactivity and thermal power of buried LLRW obtained by using an average source term and a synthesis of individual source terms are compared. 6 refs., 8 figs, 5 tabs

  17. Dose model for stent-based delivery of a radioactive compound for the treatment of restenosis in coronary arteries

    International Nuclear Information System (INIS)

    Radiolabeled drug-eluting stents have been proposed recently as a novel method to potentially reduce restenosis in coronary arteries. A P-32 labeled oligonucleotide (ODN) loaded on a polymer coated stent is slowly released in the arterial wall to deliver a therapeutic dose to the target tissue. However, the relatively low proportion of drugs transferred to the arterial wall (<2%-5% typically) raises questions about the degree to which radiolabeled drugs eluted from the stent can contribute to the total radiation dose delivered to tissues. A three-dimensional diffusion-convection transport model is used to model the transport of a hydrophilic drug released from the surface of a stent to the arterial media. Large drug concentration gradients are observed near the stent struts giving rise to a nonuniform radiation activity distribution for the drug in the tissues as a function of time. A voxel-based kernel convolution method is used to calculate the radiation dose rate resulting from this activity build-up in the arterial wall based on the medical internal radiation dose formalism. Measured residence time for the P-32 ODN in the arterial wall and at the stent surface obtained from animal studies are used to normalize the results in terms of absolute dose to tissue. The results indicate that radiation due to drug eluted from the stent contributes only a small fraction of the total radiation delivered to the arterial wall, the main contribution coming from the activity that remains embedded in the stent coating. For hydrophilic compounds with rapid transit times in arterial tissue and minimal binding interactions, the activity build-up in the arterial wall contributes only a small fraction to the total dose delivered by the P-32 ODN stent. For these compounds, it is concluded that radiolabeled drug-eluting stent will not likely improve the performance of radioactive stents for the treatment of restenosis. Also, variability in the delivery efficacy of drug delivery

  18. 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

  19. 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.

  20. 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

  1. Radioactive Waste Management Information for 1991 and Record-to-Date

    International Nuclear Information System (INIS)

    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 1991. It also summarizes the radiative 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

  2. Radioactive ion beams at SPIRAL

    International Nuclear Information System (INIS)

    The radioactive ion beam facility SPIRAL, presently under construction, will be based on the very high intensity heavy-ion beams (96AMeV at 6kW from He to Ar) at GANIL, France. The facility will produce radioactive ion beams using the ISOL method and a permanent magnet ECRIS which will allow for the production of multiple charged radioactive ions. The beam will be accelerated by a K=265 compact cyclotron and delivered into the existing experimental areas. The first tests for the production of radioactive ion beams have been undertaken with the test bench separator SIRa. A description of the facility, including the first results for the production of radioactive ion beams and perspectives are given. ((orig.))

  3. Radioactive ion beams at Spiral

    International Nuclear Information System (INIS)

    The radioactive ion beam facility SPIRAL, presently under construction, will be based on the very high intensity heavy-ion beams (96A MeV at 6kW from He to Ar) at GANIL, France. The facility will produce radioactive ion beams using the ISOL method and a permanent magnet ECRIS which will allow for the production of multiple charged radioactive ions. The beam will be accelerated by a K = 265 compact cyclotron and delivered into the existing experimental areas. The first tests for the production of radioactive ion beams has been undertaken with the test bench separator SIRa. A description of the facility, including the first results for the production of radioactive ion beams and perspectives are given. (authors). 10 refs., 3 figs., 1 tab

  4. 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

  5. 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 ...

  6. 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.

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

    International Nuclear Information System (INIS)

    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

  8. Comparison of the Results of the Whole Core Decay Power Using the ORIGEN Code and ANS-1979 for the Uljin Unit 6

    International Nuclear Information System (INIS)

    When a detailed tracking of the nuclide is not required-, i.e., only the whole core decay heat information is required, then the RN package is not activated and the DCH package is solely used, whereas both the RN and DCH packages are used when we need a fission product transport simulation and location information. For DCH only mode, there are four options to calculate the whole core decay heat calculation for the time after a shut-down. The first is using a summation of the decay heat data from ORIGEN-based fission product inventories for the representative BWRs and PWRs, which are scaled if necessary. The second is using the ANS-1979 standard for the decay heat power. The third is using a user-specified tabular function of the whole-core decay as a function of time. The fourth is using a user-specified control function to define the decay heat. In this research, for option 2, the ANS-1979 standard for the whole core decay heat calculation is compared with the result of the ORIGEN calculation for Uljin Unit 6 after arranging the ORIGEN result based on the mass, radioactivity, and decay heat for the elements and nuclides. The MELCOR code is currently using the ANS-1979 standard, the lasted version for decay heat in ANS standards is not mainly dealt with in this research. The goal of the examination is to find the necessity of changing old standard for the enhancement of the accuracy. The ANS-1979 is an old standard about decay heat, thus recent standards which are ANSI/ANS-5.1-1994 and ANSI/ANS-5.1-2005 should be investigated in the long term research. This research has certain drawback in that the mere multiplication of the number of assemblies is done for the whole core decay heat calculation in the arrangement of the ORIGEN result

  9. 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

  10. 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.)

  11. 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)

  12. Treatment and conditioning of radioactive organic liquids

    International Nuclear Information System (INIS)

    Liquid organic radioactive wastes are generated from the use of radioisotopes in nuclear research centres and in medical and industrial applications. The volume of these wastes is small by comparison with aqueous radioactive wastes, for example; nevertheless, a strategy for the effective management of these wastes is necessary in order to ensure their safe handling, processing, storage and disposal. A aqueous radioactive wastes may be discharged to the environment after the radioactivity has decayed or been removed. By contrast, organic radioactive wastes require management steps that not only take account of their radioactivity, but also of their chemical content. This is because both the radioactivity and the organic chemical nature can have detrimental effects on health and the environment. Liquid radioactive wastes from these applications typically include vacuum pump oil, lubricating oil and hydraulic fluids, scintillation cocktails from analytical laboratories, solvents from solvent extraction research and uranium refining, and miscellaneous organic solvents. The report describes the factors which should be considered in the development of appropriate strategies for managing this class of wastes from generation to final disposal. Waste sources and characterization, treatment and conditioning processes, packaging, interim storage and the required quality assurance are all discussed. The report is intended to provide guidance to developing Member States which do not have nuclear power generation. A range of processes and procedures is presented, though emphasis is given to simple, easy-to-operate processes requiring less sophisticated and relatively inexpensive equipment. 31 refs, 16 figs, 3 tabs

  13. Weak decays of strongly decaying mesons

    International Nuclear Information System (INIS)

    Weak decays of the light mesons η, η', ρ, ω and κ* are considered. It is pointed out that a measurement of the decays η' → κπ, ρ → π, ω → κπ and κ* → ππ is within reach at LEAR. This would give valuable information on the mechanism behind the ΔI = 1/2 rule in weak nonleptonic decays. A possible strangeness asymmetry in these decays is proposed as a manifestation of CP violation. However, this asymmetry is estimated in the standard electroweak model to be too minute to be measurable at present. (orig.)

  14. Systematics of half-lives for proton radioactivity

    International Nuclear Information System (INIS)

    Half-life measurements for both ground-state and isomeric transitions in proton radioactivity are systematized by using a semiempirical, one-parameter model based on tunneling through a potential barrier, where the centrifugal and overlapping effects are taken into account within the spherical nucleus approximation. This approach, which has been successfully applied to alpha decay cases covering ∼ 30 orders of magnitude in half-life, has shown, in addition, very adequate at fitting all existing data on partial half-life, T1/2p, of proton emission from nuclei. Nearly 70 measured half-life values have been analysed, and the data could be described by two straight lines relating the pure Coulomb contribution to half life with the quantity Zd(μ0/Qp)1/2 (Zd is the atomic number of the daughter nucleus, μ0 is the reduced mass, and Qp is the total nuclear energy available for decay). These straight lines are shown to correspond to different degrees of deformation, namely, very prolate (δ> approx. 0.1), and other shaped (delta < approx. 0.1) parent nuclei. The goodness in reproducing the data attained in the present systematics allows for half-life predictions for a few possible cases of proton radioactivity not yet experimentally accessed. (author)

  15. 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

  16. User's guide for the KBERT 1.0 code: For the knowledge-based estimation of hazards of radioactive material releases from DOE nuclear facilities

    International Nuclear Information System (INIS)

    The possibility of worker exposure to radioactive materials during accidents at nuclear facilities is a principal concern of the DOE. The KBERT software has been developed at Sandia National Laboratories under DOE support to address this issue by assisting in the estimation of risks posed by accidents at chemical and nuclear facilities. KBERT is an acronym for Knowledge-Based system for Estimating hazards of Radioactive material release Transients. The current prototype version of KBERT focuses on calculation of doses and consequences to in-facility workers due to accidental releases of radioactivity. This report gives detailed instructions on how a user who is familiar with the design, layout and potential hazards of a facility can use KBERT to assess the risks to workers in that facility. KBERT is a tool that allows a user to simulate possible accidents and observe the predicted consequences. Potential applications of KBERT include the evaluation of the efficacy of evacuation practices, worker shielding, personal protection equipment and the containment of hazardous materials

  17. 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)

  18. A complete process for the treatment of low level radioactive wastes using composite ion exchange resins based on polyurethane foam

    International Nuclear Information System (INIS)

    The CFC-PU foam and HMO-PU foams have been employed for the removal of radioactive cesium and strontium respectively from actual Cat. III radioactive liquid waste received from reprocessing plant. Batch studies have been carried out in order to optimize the loading of above chemicals. The results of column and batch studies have indicated that there is a good agreement between them. After passing about 1000 bed volumes, the average DF and volume reduction factor obtained were 20 and 200 respectively. A method has been developed for the wet digestion of spent resins in alkaline KMnO4 medium. The digested foam has been immobilized in cement matrix and the matrices were characterized with respect to compressive strength and leach resistance. (author)

  19. Natural Radioactivity of Quarry Raw Material in Israel

    International Nuclear Information System (INIS)

    During the past decades Natural Occurring Radioactive Material has been receiving growing attention by radiation protection agencies, including chronic exposure to radon and radiation from building materials. A new Israeli Standard (IS 5098)(1) which limits the radionuclide concentration in building material entered into force in 2003. Building materials are made of natural raw materials which contain natural radionuclides from the 238U-226Ra decay series, 232Th decay series and 40K. The radionuclide concentration in the building material depends on the source of the raw material, manufacturing process and the addition of technically enhanced Natural Occurring Radioactive Material like fly ash, phospho-gypsum, etc. The radioactivity in building materials in Israel have been investigated, but not the raw materials from local quarries. In this paper we present the natural radioactivity in quarries substances in Israel and an assessment of the radioactivity in concrete according to IS 5098

  20. Environmental radioactivity

    International Nuclear Information System (INIS)

    The evaluation of more than 50 official points of measurement for the control of environmental radioactivity in the German Federal Republic showed a marked decrease of activity concentration in the surveyed fields of precipitation, air, water, milk, and humans as compared to 1972. This decrease can be attributed to the stop of above-ground nuclear weapons tests effected in 1963. In 1973, a survey of the environment of nuclear power stations again did not show any significant difference between these regions and others. The mean genetic radiation exposure in the year 1973 is given in a chart. Selected data from different places of measurement give mean values and annual balances of the radionuclides 137Cs and 90Sr for men, women, and children, as well as for cistern water, milk, and hospital food. Finally, a balance of the import and export of radionuclides in 1973 is given. (ORU/AK)

  1. 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)

  2. Recommended decay data for 235-neptunium

    International Nuclear Information System (INIS)

    An evaluation has been made of the decay of 235Np, a nuclide that has become popular for monitoring neptunium chemistry in the environment. Compared with other radioactive nuclides, 235Np produces few emissions that are suitable for quantitative analysis. A semi-theoretical study was undertaken, and it is recommended that four K-shell X rays are used to monitor 235Np. (U.K.)

  3. 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.

  4. 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

  5. Radioactive material air transportation

    International Nuclear Information System (INIS)

    As function of the high aggregated value, safety regulations and the useful life time, the air transportation has been used more regularly because is fast, reliable, and by giving great security to the cargo. Based on the International Atomic Energy Agency (IAEA), the IATA (International Air Transportation Association) has reproduced in his dangerous goods manual (Dangerous Goods Regulations - DGR IATA), the regulation for the radioactive material air transportation. Those documents support this presentation

  6. Nanosecond decay-time techniques

    International Nuclear Information System (INIS)

    The repetitive time-selection technique of fluorescence decay-time measurement as devised by Becquerel in 1859 is limited by the mechanics of the apparatus to a decay-time range of ≥10-4 s. In the original device the fluorescent spot was permitted to move repeatedly past an area of constant illumination and the spot was thereafter observed repeatedly at predetermined time intervals after passage through the illuminated area. In an electronic equivalent of this technique (cf. Dreeskamp and Burton, Phys. Rev. Letters, 2, (1959) 45, the luminescent region remains in constant position but the beam from a 30-kV X-ray tube is interrupted after ∼ 0.8 ns and the luminescence produced (during a time of ∼ 0.4 ns) is thereafter observed repetitively, at predetermined time intervals after the beginning of the cut-off of illumination by the X-ray tube, via an image converter and photomultiplier system. By the use of this technique we have observed decay phenomena which are complete in several nanoseconds and the decay times of which can be established, for example, as 2.2 ± 0.1 ns. The special virtues of this technique are that the decay curve established is, in principle, not affected by the decay constants of the various parts of the electronic system and is extendable over a broad range of intensity (a factor of 100). Further, the actual curve can be established with a high degree of accuracy so that one is not constrained by preconceived notions to assuming a first-power decay law and the selection of a decay constant based on such a notion. Indeed, although we have now found that in many cases (e.g., p-terphenyl scintillator in benzene or cyclohexane solvent) an initial part of the decay curve is apparently first order, we are yet to observe a case in which the decay is singularly first order over the entire observation range made accessible by this technique. Recent improvements in the accuracy of the technique have made possible a clearer understanding of the

  7. Random numbers spring from alpha decay

    Energy Technology Data Exchange (ETDEWEB)

    Frigerio, N.A.; Sanathanan, L.P.; Morley, M.; Clark, N.A.; Tyler, S.A.

    1980-05-01

    Congruential random number generators, which are widely used in Monte Carlo simulations, are deficient in that the number they generate are concentrated in a relatively small number of hyperplanes. While this deficiency may not be a limitation in small Monte Carlo studies involving a few variables, it introduces a significant bias in large simulations requiring high resolution. This bias was recognized and assessed during preparations for an accident analysis study of nuclear power plants. This report describes a random number device based on the radioactive decay of alpha particles from a /sup 235/U source in a high-resolution gas proportional counter. The signals were fed to a 4096-channel analyzer and for each channel the frequency of signals registered in a 20,000-microsecond interval was recorded. The parity bits of these frequency counts (0 for an even count and 1 for an odd count) were then assembled in sequence to form 31-bit binary random numbers and transcribed to a magnetic tape. This cycle was repeated as many times as were necessary to create 3 million random numbers. The frequency distribution of counts from the present device conforms to the Brockwell-Moyal distribution, which takes into account the dead time of the counter (both the dead time and decay constant of the underlying Poisson process were estimated). Analysis of the count data and tests of randomness on a sample set of the 31-bit binary numbers indicate that this random number device is a highly reliable source of truly random numbers. Its use is, therefore, recommended in Monte Carlo simulations for which the congruential pseudorandom number generators are found to be inadequate. 6 figures, 5 tables.

  8. Random numbers spring from alpha decay

    International Nuclear Information System (INIS)

    Congruential random number generators, which are widely used in Monte Carlo simulations, are deficient in that the number they generate are concentrated in a relatively small number of hyperplanes. While this deficiency may not be a limitation in small Monte Carlo studies involving a few variables, it introduces a significant bias in large simulations requiring high resolution. This bias was recognized and assessed during preparations for an accident analysis study of nuclear power plants. This report describes a random number device based on the radioactive decay of alpha particles from a 235U source in a high-resolution gas proportional counter. The signals were fed to a 4096-channel analyzer and for each channel the frequency of signals registered in a 20,000-microsecond interval was recorded. The parity bits of these frequency counts (0 for an even count and 1 for an odd count) were then assembled in sequence to form 31-bit binary random numbers and transcribed to a magnetic tape. This cycle was repeated as many times as were necessary to create 3 million random numbers. The frequency distribution of counts from the present device conforms to the Brockwell-Moyal distribution, which takes into account the dead time of the counter (both the dead time and decay constant of the underlying Poisson process were estimated). Analysis of the count data and tests of randomness on a sample set of the 31-bit binary numbers indicate that this random number device is a highly reliable source of truly random numbers. Its use is, therefore, recommended in Monte Carlo simulations for which the congruential pseudorandom number generators are found to be inadequate. 6 figures, 5 tables

  9. 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)

  10. 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...

  11. α-decay chains and cluster-decays of superheavy 269-27110 nuclei

    International Nuclear Information System (INIS)

    Due to the availability of radioactive nuclear beams (RNB) and the advancement in accelerator technology, it is now possible to synthesize very heavy elements (Z> 100), called superheavy elements. It is a well established fact that these superheavy elements, due to their shorter lifetime, decay via successive alpha emissions and at a later stage undergo spontaneous fission. Several such decay chains are now observed. An attempt is made to fit all such known decay chains and the results of the three observed α-decay chains of Z=110 (269-27110) nuclei are presented. The model used is the preformed cluster model (PCM). Also, an attempt is made for the first time to find the possibility of any branching to heavy-cluster emissions in these chains

  12. 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.

  13. 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.

  14. NRI's research on radioactive wastes

    International Nuclear Information System (INIS)

    A survey is given (including 41 references) of work carried out at the Nuclear Research Institute. Discussed are sorption processes (a selective sorbent for 90Sr based on BaSO4, etc.), sorption on inorganic ion exchangers (heteropolyacid salts, ferrocyanides for 137Cs capture), on organic cation exchangers (separation of lanthanides), electrocoagulation. The process is described of vitrification of highly radioactive wastes, the arrest of emissions, the deposition of radioactive wastes and surface decontamination. (M.K.)

  15. 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.

  16. Radioactive waste management information, 1982 summary and record-to-date

    International Nuclear Information System (INIS)

    This document summarizes radioactive waste data records for the Idaho National Engineering Laboratory (INEL) compiled since 1952. Kinds of information include volume, radioactivity, isotopic identity, origin, and decay status. The radioactive waste data presented was obtained from the INEL Radioactive Waste Management Information System (RWMIS). This report is updated annually to incorporate waste management data for the current year and reflects changes in previous annual reports. Changes are made to more accurately reflect the current status of waste operations at the INEL

  17. 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

  18. Study of the radiation and radioactivity in dairy formulas

    International Nuclear Information System (INIS)

    The radiation and natural radioactivity is present in the man's food chain, like it is the case of the milk, and it comes from the natural series of radioactive decay of the 238 U, 235 U and 232 Th, and of the 40 K radioisotope. Since the radioisotopes can be found in floor of where its are transferred to the grasses and in the water that serve as food and of drinking to the cows, then to enter the milk and its derived to the human consumption. In this work it is presented the study of the radiation and gamma radioactivity of 40 samples of dairy formulas of the trademarks and presentations more sold in the market of the private and public sectors. The measurements of the gamma ray spectra were carried out with a spectrometry system based on an Hyper pure Germanium detector (HPGe). The detector has a resolution (FWHM) of 1.9 keV for an energy of the gamma ray of 1.332 keV of the 60 Co. This study presents the results of the concentration in activity of dairy formulations of the radioisotopes of interest. Also, the results are related with possible damages to the health. (Author)

  19. Radioactive graphite management at UK Magnox nuclear power stations

    International Nuclear Information System (INIS)

    The UK nuclear power industry is predominantly based on gas-cooled, graphite moderated reactors with their being 20 operating and 6 shutdown Magnox reactors. The radioactive graphite issues associated with the Magnox reactors relate mainly to the reactor core graphite but, at two of the stations, there is also another graphite waste stream which results from the handling of their particular design of fuel elements which incorporate graphite fittings. The decommissioning plan for the Magnox reactors is to apply the Safestore strategy in which the defuelled reactors will be maintained in a quiescent state, e.g. to gain benefit from radioactive decay, with their dismantling being deferred for a period of time. In preparing for and developing the decommissioning strategy detailed studies have been undertaken on all relevant aspects. These have resulted in, for example, extensive information on the graphite radioactive inventories, the condition of the graphite throughout the quiescent deferral period, safety assessment, and, dismantling, waste management and disposal plans. Significant work has also been undertaken on the management of the graphite fuel element debris that has accumulated at the two stations. For example, work is well advanced at one of the stations to install equipment to retrieve this waste and package it in a form suitable for eventual deep geological disposal. (author)

  20. 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