WorldWideScience

Sample records for deposition radioactive decay

  1. Radioactive decay data tables

    Energy Technology Data Exchange (ETDEWEB)

    Kocher, D.C.

    1981-01-01

    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.

  2. Is Radioactive Decay Really Exponential?

    CERN Document Server

    Aston, Philip J

    2012-01-01

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

  3. Radioactive decays at limits of nuclear stability

    DEFF Research Database (Denmark)

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

    2012-01-01

    The last decades brought impressive progress in synthesizing and studying properties of nuclides located very far from the beta stability line. Among the most fundamental properties of such exotic nuclides, the ones usually established first are the half-life, possible radioactive decay modes...... description of the most recently discovered and most complex radioactive process—the two-proton radioactivity—is discussed in more detail....

  4. Examination of radioactive decay methodology in the HASCAL code

    Energy Technology Data Exchange (ETDEWEB)

    Steffler, R.S. [Texas A and M Univ., College Station, TX (United States). Dept. of Nuclear Engineering; Ryman, J.C.; Gehin, J.C.; Worley, B.A. [Oak Ridge National Lab., TN (United States)

    1998-01-01

    The HASCAL 2.0 code provides dose estimates for nuclear, chemical, and biological facility accident and terrorist weapon strike scenarios. In the analysis of accidents involving radioactive material, an approximate method is used to account for decay during transport. Rather than perform the nuclide decay during the atmospheric transport calculation, the decay is performed a priori and a table look up method is used during the transport of a depositing tracer particle and non depositing (gaseous) tracer particle. In order to investigate the accuracy of this decay methodology two decay models were created using the ORIGEN2 computer program. The first is a HASCAL like model that treats decay and growth of all nuclide explicitly over the time interval specified for atmospheric transport, but does not change the relative mix of depositing and non-depositing nuclides due to deposition to the ground, nor does it treat resuspension. The second model explicitly includes resuspension as well as separate decay of the nuclides in the atmosphere and on the ground at each deposition time step. For simplicity, both of these models uses a one-dimensional layer model for the atmospheric transport. An additional investigation was performed to determine the accuracy of the HASCAL like model in separately following Cs-137 and I-131. The results from this study show that the HASCAL decay model compares closely with the more rigorous model with the computed doses are generally within one percent (maximum error of 7 percent) over 48 hours following the release. The models showed no difference for Cs-137 and a maximum error of 2.5 percent for I-131 over the 96 hours following release.

  5. Nuclide radioactive decay data uncertainties library

    Science.gov (United States)

    Barabanova, D. S.; Zherdev, G. M.

    2017-01-01

    The results of the developing the library of uncertainties of radioactive decay data in the ABBN data library format are described. Different evaluations of uncertainties were compared and their effects on the results of calculations of residual energy release were determined using the test problems and experiment. Tables were generated in the ABBN format with the data obtained on the basis of libraries in ENDF-6 format. 3821 isotopes from the ENDF/B-7 data library, 3852 isotopes from the JEFF-3.11 data library and 1264 isotopes from the JENDL-4.0 data library were processed. It was revealed that the differences in the evaluations accepted in different decay data libraries are not so big, although they sometimes exceed the uncertainties assigned to the data in the ENDF/B-7 and JEFF-3.11 libraries, which as a rule, they agree with each other. On the basis of developed method it is supposed to create a library of data uncertainties for radioactive decay within the constant data system in FSUE RFNC-VNIIEF with its further connection with CRYSTAL module.

  6. Development of a New Method in Teaching of Physics Experiment : Simulation of Radioactive Decays

    OpenAIRE

    山下, 太利; 前田, 健悟; 桃井, 凡夫; ヤマシタ, タイリ; マエダ, ケンゴ; モモイ, ツネオ; Yamashita, Tairi; Maeda, Kengo; Momoi, Tsuneo

    1985-01-01

    The radioactive source used in the experiment of radioactive decay consists of the natural radioactive materials which are springing from the ground.This paper showed that the nuclides in the source were easily identified by the simulation of radioactive decays. Besides, it was also found that the simulation of radioactive series decays was useful for the students to understand the radioactive equilibrium.

  7. 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.

  8. Radioactive decay by the emission of heavy nuclear fragments

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, O.A.P.; Roberto, L.A.M.; Medeiros, E.L. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mails: oaptavares@cbpf.br; emil@cbpf.br

    2007-07-01

    Radioactive decay of nuclei by the emission of heavy ions of C, N, O, F, Ne, Na, Mg, Al, Si, and P isotopes (known as exotic decay or cluster radioactivity) is reinvestigated within the framework of a semiempirical, one-parameter model based on a quantum mechanical, tunnelling mechanism through a potential barrier, where both centrifugal and overlapping effects are considered to half-life evaluations. This treatment appeared to be very adequate at fitting all measured half-life values for the cluster emission cases observed to date. Predictions for new heavy-ion decay cases susceptible of being detected are also reported. (author)

  9. Simulations of Radioactive Decays: an Application of Low-Energy Electromagnetic Packages for the Nuclear Medicine

    Directory of Open Access Journals (Sweden)

    Munkhbaatar Batmunkh

    2015-12-01

    Full Text Available Problems of the radiobiology and the nuclear medicine require clarifying the specifi cs of radionuclides interactions with unhealthy cells. In this work we aimed to simulate emitting particles tracks of radionuclides and their radioactive decays at DNA level inside the cell nucleus. Accordingly, using the Monte Carlo-based track structure simulation technique, we estimated the radial distribution of deposited energy and kinetic energy spectra of electrons produced by primary particles resulting from radioactive decays of diff erent radionuclides within cell nucleus. To address the possibility of DNA damage, we performed the cluster analysis of track structures of emitted particles inside the volumes corresponding to the size of the native double-stranded DNA. For this purpose, G4-RadioactiveDecay and low- energy electromagnetic packages form Geant4 Monte-Carlo toolkit were combined together. Besides, a comparative analysis was performed for various low-energy electromagnetic packages as G4-DNA and G4-Livermore

  10. 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...

  11. 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.

  12. Radioactive decay as a forced nuclear chemical process: Phenomenology

    Science.gov (United States)

    Timashev, S. F.

    2015-11-01

    Concepts regarding the mechanism of radioactive decay of nuclei are developed on the basis of a hypothesis that there is a dynamic relationship between the electronic and nuclear subsystems of an atom, and that fluctuating initiating effects of the electronic subsystem on a nucleus are possible. Such relationship is reflected in experimental findings that show the radioactive decay of nuclei might be determined by a positive difference between the mass of an initial nucleus and the mass of an atom's electronic subsystem, i.e., the mass of the entire atom (rather than that of its nucleus) and the total mass of the decay products. It is established that an intermediate nucleus whose charge is lower by unity than the charge of the initial radioactive nucleus is formed as a result of the above fluctuating stimuli that initiate radioactive decay, and its nuclear matter is thus in an unbalanced metastable state of inner shakeup, affecting the quark subsystem of nucleons. The intermediate nucleus thus experiences radioactive decay with the emission of α or β particles. At the same time, the high energy (with respect to the chemical scale) of electrons in plasma served as a factor initiating the processes in different nuclear chemical transformations and radioactive decays in low-temperature plasma studied earlier, particularly during the laser ablation of metals in aqueous solutions of different compositions and in near-surface cathode layers upon glow discharge. It is shown that a wide variety of nucleosynthesis processes in the Universe can be understood on the same basis, and a great many questions regarding the formation of light elements in the solar atmosphere and some heavy elements (particularly p-nuclei) in the interiors of massive stars at late stages of their evolution can also be resolved.

  13. 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.

  14. Metastable Dark Energy with Radioactive-like Decay

    CERN Document Server

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

    2016-01-01

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

  15. 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...

  16. Unified formula of half-lives for α decay and cluster radioactivity

    Science.gov (United States)

    Ni, Dongdong; Ren, Zhongzhou; Dong, Tiekuang; Xu, Chang

    2008-10-01

    In view of the fact that α decay and cluster radioactivity are physically analogical processes, we propose a general formula of half-lives and decay energies for α decay and cluster radioactivity. This new formula is directly deduced from the WKB barrier penetration probability with some approximations. It is not only simple in form and easy to see the physical meanings but also shows excellent agreement with the experimental values. Moreover, the difference between two sets of parameters to separately describe α decay and cluster radioactivity is small. Therefore, we use only one set of adjustable parameters to simultaneously describe the α decay and cluster radioactivity data for even-even nuclei. The results are also satisfactory. This indicates that this formula successfully combines the phenomenological laws of α decay and cluster radioactivity. We expect it to be a significant step toward a unified phenomenological law of α decay and cluster radioactivity.

  17. PKA distributions: Contributions from transmutation products and from radioactive decay

    Directory of Open Access Journals (Sweden)

    M.R. Gilbert

    2016-12-01

    Full Text Available The neutrons generated in fusion plasmas interact with materials via nuclear reactions. The resulting transmutations and atomic displacements have life-limiting consequences for fusion reactor components. A detailed understanding of the production, evolution and material consequences of the damage created by cascades of atomic displacements requires, as a vital primary input, a complete description of the energy-spectrum of initial (prompt atomic displacement events (the primary knock on atoms or PKAs produced by direct neutron nuclear interactions. There is also the possibility that the radionuclides produced under transmutation will create further PKAs as they decay, and so the rate of these must also be quantified. This paper presents the latest results from the analysis of PKA spectra under neutron irradiation, focussing particularly on the variation in PKA distributions due to changes in composition under transmutation, but also on the PKA contributions from radioactive decay of materials that become activated under irradiation.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-01-15

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

  20. Electroweak Decay Studies of Highly Charged Radioactive Ions with TITAN at TRIUMF

    CERN Document Server

    Leach, K G; Klawitter, R; Leistenschneider, E; Lennarz, A; Brunner, T; Frekers, D; Andreiou, C; Kwiatkowski, A A; Dilling, J

    2016-01-01

    Several modes of electroweak radioactive decay require an interaction between the nucleus and bound electrons within the constituent atom. Thus, the probabilities of the respective decays are not only influenced by the structure of the initial and final states in the nucleus, but can also depend strongly on the atomic charge. Conditions suitable for the partial or complete ionization of these rare isotopes occur naturally in hot, dense astrophysical environments, but can also be artificially generated in the laboratory to selectively block certain radioactive decay modes. Direct experimental studies on such scenarios are extremely difficult due to the laboratory conditions required to generate and store radioactive ions at high charge states. A new electron-beam ion trap (EBIT) decay setup with the TITAN experiment at TRIUMF has successfully demonstrated such techniques for performing spectroscopy on the radioactive decay of highly charged ions.

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

    CERN Document Server

    Zaninetti, L

    2014-01-01

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

  2. Competition between α decay and proton radioactivity of neutron-deficient nuclei

    Science.gov (United States)

    Wang, Y. Z.; Cui, J. P.; Zhang, Y. L.; Zhang, S.; Gu, J. Z.

    2017-01-01

    The α decay and proton radioactivity half-lives of some neutron-deficient nuclei are calculated using an effective liquid drop model (ELDM). It is found that the experimental half-lives of the two decay modes and the dominant decay mode can be well reproduced by the ELDM. Moreover, the predicted penetration probabilities (P ) of proton radioactivity by the ELDM are in agreement with those by a microscopic model (MM). This allows us to make predictions on the competition of the two decay modes for nuclei whose experimental data are not available, which are useful for future measurements. In addition, the comparison between the predicted reduced proton radioactivity half-lives by the ELDM and the ones by a standard formula suggests that one is unlikely to observe large angular momentum transfers for nuclei with a very large Coulomb parameter χ . Last, we find that in most isotope chains the proton radioactivity is the dominant decay mode for nuclei that are very close to the proton drip line. But with increasing neutron number N the main decay mode is changed into α decay. With the decay energies the decay mode anomaly of 184Bi is discussed.

  3. In-situ measurements of the radioactive fallout deposit

    Science.gov (United States)

    Korun, M.; Martinčič, R.; Pucelj, B.

    1991-02-01

    An improved method to determine radionuclide concentrations in soil and the radioactive fallout deposit is presented. The approach is based on in-situ gamma-ray spectrometric measurements performed with a portable high resolution gamma spectrometer and on calculations of the depth distribution based on the energy dependence of the attenuation of gamma rays in soil. The results are compared with laboratory analysis of collected soil samples.

  4. 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.

  5. Theory of cluster radioactive decay and of cluster formation in nuclei

    Science.gov (United States)

    Malik, S. S.; Gupta, Raj K.

    1989-05-01

    A new model is proposed for the mechanism of cluster formation and then penetration of the confining nuclear interaction barrier in radioactive nuclei. The cluster formation is treated as a quantum-mechanical fragmentation process and the WKB penetrability is found analytically. Applications of the model are made to 14C decay of 222-224Ra and 24Ne decay of 232U. The branching ratio for 14C decay of 232U is also calculated and is found to be incredibly small as compared to that for its 24Ne decay.

  6. Deposition and removal of radioactive isotopes from LMFBR components

    Energy Technology Data Exchange (ETDEWEB)

    Hill, E.F.; Lutton, J.M.; Maffei, H.P.

    1980-01-01

    The development of an analytical model to describe the production, transport and eventual removal of radioactive materials in the primary sodium of LMFBR's is a continuing Sodium Technology activity sponsored by the Department of Energy. This paper describes studies directed toward obtaining an understanding of the deposition from sodium of fuel cladding activated corrosion products onto stainless steel alloys and the effect of their diffusion into the base metal on the process required to decontaminate it. The objective of the decontamination operation is to reduce the activity to a level allowing hands on maintenance without causing unacceptable damage to the component.

  7. An Amended Formula for the Decay of Radioactive Material for Cosmic Times

    CERN Document Server

    Carmeli, M; Carmeli, Moshe; Malin, Shimon

    1999-01-01

    An amended formula for the decay of radioactive material is presented. It is a modification of the standard exponential formula. The new formula applies for long cosmic times that are comparable to the Hubble time. It reduces to the standard formula for short times. It is shown that the material decays faster than expected. The application of the new formula to direct measurements of the age of the Universe and its implications is briefly discussed.

  8. Comment on ``Interpretation of the fine structure in the 14C radioactive decay of 223'

    Science.gov (United States)

    Hussonnois, M.; Le Du, J. F.; Brillard, L.; Ardisson, G.

    1991-12-01

    Priority of our interpretation of the fine structure in the 14C radioactive decay of 223Ra is asserted. It seems that the deformation parameter values, used in the framework of ARM to interpret properties of both 223Ra ground and excited states, partly allow for the qualitative interpretation of the experimental hindrance factors to the 209Pb states.

  9. Searching for modifications to the exponential radioactive decay law with the Cassini spacecraft

    CERN Document Server

    Cooper, Peter S

    2008-01-01

    Data from the power output of the radioisotope thermoelectric generators aboard the Cassini spacecraft are used to test the conjecture that small deviations observed in terrestrial measurements of the exponential radioactive decay law are correlated with the Earth-Sun distance. No significant deviations from exponential decay are observed over a range of 0.7 - 1.6 A.U. A 90% Cl upper limit of 0.84 x 10^-4 is set on a term in the decay rate of Pu-238 proportional to 1/R^2 and 0.99 x 10^-4 for a term proportional to 1/R.

  10. 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.

  11. Regional deposition of radon decay products in human airways

    Energy Technology Data Exchange (ETDEWEB)

    Falk, R.; Moere, H.; Nyblom, L.; Oestergren, I. (Swedish Radiation Protection Inst., Stockholm (Sweden))

    1992-01-01

    Experimental studies of the uptake and deposition pattern in the human airways of inhaled radon decay products have been carried out using two different techniques. The deposition in the nasal, bronchial and lung regions was assessed by external gamma measurements on the subject. The exposure of the subject was performed in a 'walk-in' radon chamber with controlled conditions. Results from exposure with high and low aerosol concentrations show that no rapid clearance occurred for the deposited decay products. About 20% of the attached inhaled decay products are retained and deposited in the lungs when mouth breathing during resting conditions, while nasal breathing gave about 26% retention, of which 5% was deposited in the nasal region and about 21% in the lungs. Exposure at low aerosol concentration with unattached fraction of about 80% shows a total retention of about 90% indicating a 100% retention of the unattached fraction. Only about 20% of the unattached fraction is found to penetrate the nasal cavity and it seems to be deposited in the bronchial region. (author).

  12. Cluster emission in the radioactive decay of 223Ac

    CERN Document Server

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

    2010-01-01

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

  13. User`s manual for the radioactive decay and accumulation code RADAC

    Energy Technology Data Exchange (ETDEWEB)

    Salmon, R.; Loghry, S.L.; Ashline, R.C.

    1995-11-01

    The RADAC computer code calculates radioactive decay and accumulation of decayed products using an algorithm based on the direct use of the Bateman equations and referred to here as the yield factor method. This report explains the yield factor method, gives an overview of the various modules in the RADAC code system, and describes the decay and accumulation code in detail. The RADAC code has capacity for two waste types and can accommodate up to 60 years of annual waste inputs. Decay times as high as 1 million years can be calculated. The user supplies the undecayed composition and radioactivity of the waste placed in storage each year. The code calculates the decayed composition, radioactivity, and thermal power of the accumulated waste at the end of each year and gives the results in terms of grams and curies of individual radionuclides. Calculations can be made for up to 19 waste storage sites in a single run. For each site and each waste type, calculations can be made by 1-year steps up to 60 years, by 10-year steps to 160 years, and by 6 discrete steps to 1 million years. Detailed outputs can be printed for each waste site and each time step by individual radionuclides. Summarized outputs are also available. Excluding data-preparation time, RADAC requires about 2 min to run 19 waste sites with two types of transuranic waste at each site, using a 486 DX computer with a clock speed of 33 MHz. Because RADAC uses a preselected set of decay times and does not make in-reactor calculations, it should not be viewed as a substitute for ORIGEN2. RADAC is intended for use in applications in which accumulations at the decay times provided by the code are sufficient for the user`s purposes.

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

    Energy Technology Data Exchange (ETDEWEB)

    East, L.V.

    1994-05-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Brantley, P S

    2006-09-27

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

  16. Abnormal Radioactive Decays out of Long-Lived Super- and Hyper-Deformed Isomeric States

    CERN Document Server

    Marinov, A; Kolb, D

    2000-01-01

    Long-lived high-spin super- and hyper-deformed isomeric states, which exhibit themselves by abnormal radioactive decays, have been observed using the 16O + 197Au and 28Si + 181Ta reactions. They make it possible to understand the production, via secondary reactions, of the long-lived superheavy element with Z = 112 and of the abnormally low energy and very enhanced alpha-particles seen in various actinide sources. They may also explain some puzzling phenomena seen in nature.

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

    CERN Document Server

    Shen, Ken J

    2016-01-01

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

  18. Simulation of decay processes and radiation transport times in radioactivity measurements

    Science.gov (United States)

    García-Toraño, E.; Peyres, V.; Bé, M.-M.; Dulieu, C.; Lépy, M.-C.; Salvat, F.

    2017-04-01

    The Fortran subroutine package PENNUC, which simulates random decay pathways of radioactive nuclides, is described. The decay scheme of the active nuclide is obtained from the NUCLEIDE database, whose web application has been complemented with the option of exporting nuclear decay data (possible nuclear transitions, branching ratios, type and energy of emitted particles) in a format that is readable by the simulation subroutines. In the case of beta emitters, the initial energy of the electron or positron is sampled from the theoretical Fermi spectrum. De-excitation of the atomic electron cloud following electron capture and internal conversion is described using transition probabilities from the LLNL Evaluated Atomic Data Library and empirical or calculated energies of released X rays and Auger electrons. The time evolution of radiation showers is determined by considering the lifetimes of nuclear and atomic levels, as well as radiation propagation times. Although PENNUC is designed to operate independently, here it is used in conjunction with the electron-photon transport code PENELOPE, and both together allow the simulation of experiments with radioactive sources in complex material structures consisting of homogeneous bodies limited by quadric surfaces. The reliability of these simulation tools is demonstrated through comparisons of simulated and measured energy spectra from radionuclides with complex multi-gamma spectra, nuclides with metastable levels in their decay pathways, nuclides with two daughters, and beta plus emitters.

  19. 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.

  20. Wait for It: Post-supernova Winds Driven by Delayed Radioactive Decays

    Science.gov (United States)

    Shen, Ken J.; Schwab, Josiah

    2017-01-01

    In most astrophysical situations, the radioactive decay of {}56{Ni} to {}56{Co} occurs via electron capture with a fixed half-life of 6.1 days. However, this decay rate is significantly slowed when the nuclei are fully ionized because K-shell electrons are unavailable for capture. In this paper, we explore the effect of these delayed decays on white dwarfs (WDs) that may survive Type Ia and Type Iax supernovae (SNe Ia and SNe Iax). The energy released by the delayed radioactive decays of {}56{Ni} and {}56{Co} drives a persistent wind from the surviving WD’s surface that contributes to the late-time appearance of these SNe after emission from the bulk of the SN ejecta has faded. We use the stellar evolution code MESA to calculate the hydrodynamic evolution and resulting light curves of these winds. Our post-SN Ia models conflict with late-time observations of SN 2011fe, but uncertainties in our initial conditions prevent us from ruling out the existence of surviving WD donors. Much better agreement with observations is achieved with our models of post-SN Iax bound remnants, providing evidence that these explosions are due to deflagrations in accreting WDs that fail to completely unbind the WDs. Future radiative transfer calculations and wind models utilizing simulations of explosions for more accurate initial conditions will extend our study of radioactively powered winds from post-SN surviving WDs and enable their use as powerful discriminants among the various SN Ia and SN Iax progenitor scenarios.

  1. Exponentially Decaying Electric Pulses for Improving Radioactive Iodine uptake in human thyroid cancer cells

    Directory of Open Access Journals (Sweden)

    Amr A. Abd-Elghany

    2016-09-01

    Full Text Available Radioactive iodine (radioiodine is an effective nuclear medicine treatment used to eradicate thyroid cancer cells. The problem was the inability of thyroid cells to retain radioiodine which causes the thyroid cancer cells to be resistant to radioactive iodine treatment. Therefore, there are different methods that have been established to enhance the radioiodine uptake within the thyroid cancer cells for therapeutic purposes. Exposure of human cells to exponentially decaying high intensity, short duration electric pulses permeabilizes the plasma membrane to impermeable molecules. Electroporation is a physical modality that involves high intensity, short duration electric pulses to facilitate the entry of impermeable molecules by increasing the plasma membrane permeability. The purpose of this study was to use exponentially decaying high intensity, short duration electric pulses in incorporating radioactive iodine into non-iodine retaining follicular thyroid carcinoma cell line FTC133. Results showed that the uptake of radioiodine by electroporation has a dependence on the electric field, external concentration of the iodine, time and the temperature of incubation. The incorporated radioiodine was retained over a period of 24 h. The permanent concentration of the incorporated iodine may have a significant effect on the tumoricidal properties if approved in vivo.

  2. 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.

  3. Reconnaissance for radioactive deposits in the Nixon Fork mining district, Medfra Quadrangle, central Alaska, 1949

    Science.gov (United States)

    White, Max G.; Stevens, John M.

    1953-01-01

    Reconnaissance for radioactive deposits in the Nixon Fork mining district, Medfra quadrangle, central Alaska, in 1949 disclosed the occurrence of allanite in sampled containing as much as 0.05 percent equivalent uranium from the dump of the Whalen mine; the presence of radioactive parisite (a rare-earth fluocarbonate) in a highly altered limestone containing about 0.025 percent equivalent uranium near the Whalen shaft; and radioactive idocrase in samples of altered garnet rock with about 0.025 percent equivalent uranium, form the Crystal shaft of the Nixon Fork mine. This radioactivity is due mostly to thorium rather than uranium. Placer concentrates

  4. Detailed deposition density maps constructed by large-scale soil sampling for gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant accident.

    Science.gov (United States)

    Saito, Kimiaki; Tanihata, Isao; Fujiwara, Mamoru; Saito, Takashi; Shimoura, Susumu; Otsuka, Takaharu; Onda, Yuichi; Hoshi, Masaharu; Ikeuchi, Yoshihiro; Takahashi, Fumiaki; Kinouchi, Nobuyuki; Saegusa, Jun; Seki, Akiyuki; Takemiya, Hiroshi; Shibata, Tokushi

    2015-01-01

    Soil deposition density maps of gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant (NPP) accident were constructed on the basis of results from large-scale soil sampling. In total 10,915 soil samples were collected at 2168 locations. Gamma rays emitted from the samples were measured by Ge detectors and analyzed using a reliable unified method. The determined radioactivity was corrected to that of June 14, 2011 by considering the intrinsic decay constant of each nuclide. Finally the deposition maps were created for (134)Cs, (137)Cs, (131)I, (129m)Te and (110m)Ag. The radioactivity ratio of (134)Cs-(137)Cs was almost constant at 0.91 regardless of the locations of soil sampling. The radioactivity ratios of (131)I and (129m)Te-(137)Cs were relatively high in the regions south of the Fukushima NPP site. Effective doses for 50 y after the accident were evaluated for external and inhalation exposures due to the observed radioactive nuclides. The radiation doses from radioactive cesium were found to be much higher than those from the other radioactive nuclides.

  5. Multi-day radon signals with a radioactive decay limb-Occurrence and geophysical significance

    Energy Technology Data Exchange (ETDEWEB)

    Steinitz, G. [Geological Survey of Israel, Jerusalem (Israel)]. E-mail: steinitz@mail.gsi.gov.il; Martin, M.C. [University of La Laguna, La Laguna, Tenerife (Spain); Gazit-Yaari, N. [Geological Survey of Israel, Jerusalem (Israel); Quesada, M.L. [University of La Laguna, La Laguna, Tenerife (Spain); Nuez, J. de la [University of La Laguna, La Laguna, Tenerife (Spain); Casillas, R. [University of La Laguna, La Laguna, Tenerife (Spain); Malik, U. [Geological Survey of Israel, Jerusalem (Israel); Begin, Z.B. [Geological Survey of Israel, Jerusalem (Israel)

    2006-04-15

    Multi-day signals, generally with duration of 2-10 days, are a prominent temporal variation type of radon (Rn) in geo gas in the unsaturated zone. Rare multi-day Rn signals have been found which are characterized by: (a) a declining limb lasting up to 10 days which conforms to the radioactive decay of Rn (b) recurs at the same location and (c) is recorded in diverse situations-volcanic and seismogenic. It suggested that a Rn blob is injected at a lower level on a steady upward flow of geogas whereby the rise and final fall of the signal are attributed to the edges of the blob while the central Rn-decay segment records the passing of the decaying blob itself. Rn-decay signals are a small subset of multi-day Rn signals which are considered as highly irregular and unusable for the understanding of geophysical processes. In difference, it is concluded that multi-day Rn signals are probably proxies of subtle geodynamic processes at upper crustal levels and are therefore significant for studying such processes.

  6. Multi-day radon signals with a radioactive decay limb -- occurrence and geophysical significance.

    Science.gov (United States)

    Steinitz, G; Martín, M C; Gazit-Yaari, N; Quesada, M L; de la Nuez, J; Casillas, R; Malik, U; Begin, Z B

    2006-04-01

    Multi-day signals, generally with duration of 2-10 days, are a prominent temporal variation type of radon (Rn) in geogas in the unsaturated zone. Rare multi-day Rn signals have been found which are characterized by: (a) a declining limb lasting up to 10 days which conforms to the radioactive decay of Rn, (b) recurs at the same location and (c) is recorded in diverse situations-volcanic and seismogenic. It suggested that a Rn blob is injected at a lower level on a steady upward flow of geogas whereby the rise and final fall of the signal are attributed to the edges of the blob while the central Rn-decay segment records the passing of the decaying blob itself. Rn-decay signals are a small subset of multi-day Rn signals which are considered as highly irregular and unusable for the understanding of geophysical processes. In difference, it is concluded that multi-day Rn signals are probably proxies of subtle geodynamic processes at upper crustal levels and are therefore significant for studying such processes.

  7. New experimental data on the influence of extranuclear factors on the probability of radioactive decay

    CERN Document Server

    Bondarevskij, S I; Skorobogatov, G A

    2002-01-01

    New experimental data on influence of various extranuclear factors on probability (lambda) of radioactive decay are presented. During redox processes in solutions containing sup 1 sup 3 sup 9 Ce relative change in lambda measured by the DELTA I/I method was [I(Ce sup I sup V)-I(Ce sup I sup I sup I)]/I sub m sub e sub a sub n +(1.4+-0.6)x10 sup - sup 4. Using a modification of the method based on displacement of the age-old radioactive equilibrium, when a source MgO( sup 1 sup 2 sup 1 sup m Te) was cooled to 78 K, growth of lambda of tellurium nuclear isomer by 0.04+-0.02% was detected. New experimental data on increase in gamma-radioactivity of sample Be sup 1 sup 2 sup 3 sup m Te at the expense of low-temperature induced reaction, i.e. collective nuclear superluminescence, are provided

  8. Mineral sources of water and their influence on the safe disposal of radioactive wastes in bedded salt deposits

    Energy Technology Data Exchange (ETDEWEB)

    Fallis, S.M.

    1973-12-01

    With the increased use of nuclear energy, there will be subsequent increases in high-level radioactive wastes such as Sr/sup 90/, Cs/sup 137/, and Pu/sup 239/. Several agencies have considered the safest possible means to store or dispose of wastes in geologic environments such as underground storage in salt deposits, shale beds, abandoned dry mines, and in clay and shale pits. Salt deposits have received the most favorable attention because they exist in dry environments and because of other desirable properties of halite (its plasticity, gamma-ray shielding, heat dissipation ability, low mining cost, and worldwide abundance). Much work has been done on bedded salt deposits, particularly the Hutchinson Salt Member of the Wellington Formation at Lyons, Kansas. Salt beds heated by the decay of the radioactive wastes may release water by dehydration of hydrous minerals commonly present in evaporite sequences or water present in other forms such as fluid inclusions. More than 80 hydrous minerals are known to occur in evaporite deposits. The occurrences, total water contents (up to 63%) and dehydration temperatures (often less that 150/sup 0/C) of these minerals are given. Since it is desirable to dispose of radioactive wastes in a dry environment, care must be taken that large quantities of water are not released through the heating of hydrous minerals. Seventy-four samples from four cores taken at Lyons, Kansas, were analyzed by x-ray diffraction. The minerals detected were halite, anhydrite, gypsum, polyhalite, dolomite, magnesite, quartz, feldspar, and the clay minerals illite, chlorite, kaolinite, vermiculite, smectite, mixed-layer clay, and corrensite (interstratified chlorite-vermiculite). Of these, gypsum, polyhalite and the clay minerals are all capable of releasing water when heated.

  9. 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.

  10. Interdisciplinary Cooperation in the Exploration of appropriate sites for the Radioactive Waste Deposition

    Directory of Open Access Journals (Sweden)

    Jozef Slavkovský

    2007-01-01

    Full Text Available The article deals with the interdisciplinary cooperation in the processes of exploration of appropriate sites for radioactive waste deposits. This work is based on trends in the environmental laws for radioactive wastes. For the exploration, a knowledge about the geological structures, properties of rocks and safety manipulation with radioactive wastes are necessary. The interdisciplinary cooperation is needed with geophysics to define the particularly hazardous areas of an earthquake shaking. In this article, a method of the seismic analysis by Ricker impuls and Gabor´s function are presented.

  11. 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.

  12. Effect of forest edges on deposition of radioactive aerosols

    Science.gov (United States)

    Ould-Dada, Z.; Copplestone, D.; Toal, M.; Shaw, G.

    The possible enhancement of aerosol deposition at forest edges was investigated in a wind tunnel and in the field. The wind tunnel study was carried out using 0.82 μm mass median aerodynamic diameter uranium particles and a composite canopy of rye grass and spruce saplings. The field study was undertaken at a coniferous woodland near to BNFL Sellafield, Cumbria, UK. Two transects were set through the woodland to determine the influence of the forest edge on atmospheric deposition of radionuclides released under authorisation from the Sellafield site. Results from the wind tunnel study showed that the deposition flux of uranium particles decreased with distance downwind from the grass-tree edge towards the interior of the canopy. The deposition flux at the edge was maximal at about 4×10 -7 μg of U cm -2 s -1. This was 3 times higher than that observed over grass where a constant flux of about 1.32×10 -7 μg of U cm -2 s -1 occurred. Results from the field study showed a clear influence of the forest edge on the atmospheric deposition of 241Am and 137Cs. Activity depositions of around 4750 and 230 Bqm -2 for 137Cs and 241Am, respectively, were measured in front of the woodland. Activity deposition inside the forest edge, however, rose to levels of between 20,200 and 50,900 Bq m -2 and 1100 and 3200 Bq m -2 for 137Cs and 241Am, respectively, depending upon the transect. Similar activity concentrations were measured in the pasture to the front and behind Lady Wood. Results from these studies corroborate those obtained from various studies on air pollutants including radionuclides. This underlines the importance of deposition at the edge of forests and its contribution to the overall canopy deposition. The edge effect is therefore an important factor that should be considered in the assessment of fallout impact, whether this is to be made by either direct sampling or by modelling.

  13. 2011 Fukushima Dai-ichi nuclear power plant accident: summary of regional radioactive deposition monitoring results.

    Science.gov (United States)

    Hirose, Katsumi

    2012-09-01

    After the Great East Japan Earthquake and resulting Tsunami on March 11, 2011, serious accident of the Fukushima Dai-ichi Nuclear Power Plant has been occurred. Huge amounts of radionuclides were released in atmosphere and ocean. Japanese prefectural governments have carried out environmental radioactivity monitoring; external dose rate, radioactivity measurements in environmental samples and others. Since March 18, 2011, daily and monthly deposition samples were collected in 45 stations covering Japanese Islands and radionuclides in the deposition samples were determined. We summarize radioactive deposition data reported by Japanese Government and study the depositional behaviors of the Fukushima-derived radionuclides. The results revealed that Fukushima-derived radioactive cloud dominantly affected in the central and eastern part of Honshu-Island, although it affected all of Japanese land area and also western North Pacific. The temporal change of the Fukushima-derived (137)Cs revealed that the apparent atmospheric residence time of the Fukushima-derived (137)Cs in sites within 300 km from the Fukushima Dai-ichi NPPis about 10 d.

  14. Concrete and cement composites used for radioactive waste deposition.

    Science.gov (United States)

    Koťátková, Jaroslava; Zatloukal, Jan; Reiterman, Pavel; Kolář, Karel

    2017-08-23

    This review article presents the current state-of-knowledge of the use of cementitious materials for radioactive waste disposal. An overview of radwaste management processes with respect to the classification of the waste type is given. The application of cementitious materials for waste disposal is divided into two main lines: i) as a matrix for direct immobilization of treated waste form; and ii) as an engineered barrier of secondary protection in the form of concrete or grout. In the first part the immobilization mechanisms of the waste by cement hydration products is briefly described and an up-to date knowledge about the performance of different cementitious materials is given, including both traditional cements and alternative binder systems. The advantages, disadvantages as well as gaps in the base of information in relation to individual materials are stated. The following part of the article is aimed at description of multi-barrier systems for intermediate level waste repositories. It provides examples of proposed concepts by countries with advanced waste management programmes. In the paper summary, the good knowledge of the material durability due to its vast experience from civil engineering is highlighted however with the urge for specific approach during design and construction of a repository in terms of stringent safety requirements. Copyright © 2017. Published by Elsevier Ltd.

  15. A computer code for calculation of radioactive nuclide generation and depletion, decay heat and {gamma} ray spectrum. FPGS90

    Energy Technology Data Exchange (ETDEWEB)

    Ihara, Hitoshi; Katakura, Jun-ichi; Nakagawa, Tsuneo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1995-11-01

    In a nuclear reactor radioactive nuclides are generated and depleted with burning up of nuclear fuel. The radioactive nuclides, emitting {gamma} ray and {beta} 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 {gamma} 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).

  16. Pulsational Pair-instability Model for Superluminous Supernova PTF12dam: Interaction and Radioactive Decay

    Science.gov (United States)

    Tolstov, Alexey; Nomoto, Ken’ichi; Blinnikov, Sergei; Sorokina, Elena; Quimby, Robert; Baklanov, Petr

    2017-02-01

    Being a superluminous supernova, PTF12dam can be explained by a 56Ni-powered model, a magnetar-powered model, or an interaction model. We propose that PTF12dam is a pulsational pair-instability supernova, where the outer envelope of a progenitor is ejected during the pulsations. Thus, it is powered by a double energy source: radioactive decay of 56Ni and a radiative shock in a dense circumstellar medium. To describe multicolor light curves and spectra, we use radiation-hydrodynamics calculations of the STELLA code. We found that light curves are well described in the model with 40 M⊙ ejecta and 20–40 M⊙ circumstellar medium. The ejected 56Ni mass is about 6 M⊙, which results from explosive nucleosynthesis with large explosion energy (2–3) × 1052 erg. In comparison with alternative scenarios of pair-instability supernova and magnetar-powered supernova, in the interaction model, all the observed main photometric characteristics are well reproduced: multicolor light curves, color temperatures, and photospheric velocities.

  17. Decay of charge deposited on the wall of gaseous void

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson

    1992-01-01

    After partial discharge activity within a gaseous void, charges accumulate on the wall of the void. The decay of such charges due to surface currents at the void wall is studied analytically, and the factors affecting this decay are indicated. The results show that in terms of the basic time...... constant, the decay can take a considerable amount of time. The decay rate is significantly reduced by an increase in the permittivity of the bulk medium. The dominating influence of this permittivity is likewise reflected in the increased duration and thereby prolonged inhomogeneity of the electric field...

  18. Natural Radioactivity in Soil and Water from Likuyu Village in the Neighborhood of Mkuju Uranium Deposit

    Directory of Open Access Journals (Sweden)

    Najat K. Mohammed

    2013-01-01

    Full Text Available The discovery of high concentration uranium deposit at Mkuju, southern part of Tanzania, has brought concern about the levels of natural radioactivity at villages in the neighborhood of the deposit. This study determined the radioactivity levels of 30 soil samples and 20 water samples from Likuyu village which is 54 km east of the uranium deposit. The concentrations of the natural radionuclides 238U, 232Th, and 40K were determined using low level gamma spectrometry of the Tanzania Atomic Energy Commission (TAEC Laboratory in Arusha. The average radioactivity concentrations obtained in soil samples for 238U (51.7 Bq/kg, 232Th (36.4 Bq/kg, and 40K (564.3 Bq/kg were higher than the worldwide average concentrations value of these radionuclides reported by UNSCEAR, 2000. The average activity concentration value of 238U (2.35 Bq/L and 232Th (1.85 Bq/L in water samples was similar and comparable to their mean concentrations in the control sample collected from Nduluma River in Arusha.

  19. Cold reaction valleys in the radioactive decay of superheavy {286}^112, {292}^114 and {296}^116 nuclei

    CERN Document Server

    Santhosh, K P

    2012-01-01

    Cold reaction valleys in the radioactive decay of superheavy nuclei {286}^112, {292}^114 and {296}^116 are studied taking Coulomb and Proximity Potential as the interacting barrier. It is found that in addition to alpha particle, 8^Be, 14^C, 28^Mg, 34^Si, 50^Ca, etc. are optimal cases of cluster radioactivity since they lie in the cold valleys. Two other regions of deep minima centered on 208^Pb and 132^Sn are also found. Within our Coulomb and Proximity Potential Model half-life times and other characteristics such as barrier penetrability, decay constant for clusters ranging from alpha particle to 68^Ni are calculated. The computed alpha half-lives match with the values calculated using Viola--Seaborg--Sobiczewski systematics. The clusters 8^Be and 14^C are found to be most probable for emission with T_1/2 < 1030s. The alpha-decay chains of the three superheavy nuclei are also studied. The computed alpha decay half-lives are compared with the values predicted by Generalized Liquid Drop Model and they are...

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

    CERN Document Server

    Duarte, S B; Guzmán, F; Di Marco, A; García, F; Rodríguez, O; Gonçalves, M

    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 (VMAS) and Werner-Wheeler's inertia coefficient (WW). The calculated half lives of ground-state to ground-state transitions for proton emission, alpha decay, cluster radioactivity, and cold fission processes are compared with experimental data. These comparisons show 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 breakup such that -7.30 -17.0, where tau is the total half life of the parent nucleus.

  1. Reconnaissance geology of placer deposits containing radioactive minerals in the Bear Valley district, Valley County, Idaho

    Science.gov (United States)

    Mackin, J. Hoover; Schmidt, Dwight Lyman

    1953-01-01

    A reconnaissance of the Bear Valley district was undertaken to provide a geologic interpretation of placer deposits drilled by the U.S. Bureau of Mines. The placer minerals are monazite and a group of uranium bearing rare earth columbates and tantalates here referred to loosely as radioactive blacks. The monazite is an accessory mineral in the granitic country rock; the radioactive blacks occur in pegmatite dikes. The supply of these minerals to the placers was controlled (1) by the geography of their occurrence in the parent rock, and (2) by the distribution of alpine glaciers during two late Pleistocene glacial stages. By reason of a favorable combination of these factors, the richest placer deposits of the district are in Big Meadow, a valley fill formed as a result of the blocking of Bear Creek by a glacier from a tributary valley during the Illinoian (?) stage. The Big Meadow fill consists of intertonguing depositional units formed by Bear Creek and its tributaries, including both normal alluvium and glacial outwash, and ranging from rich to barren. The richest phase that has been blocked out by drilling was derived from the drainage basin of Casner Creek, an east tributary of Bear Creek. The geologic relations suggest that a neighboring stream, Howard Creek, should have supplied equally rich material, but the part of the valley fill formed by Howard Creek has not been tested. The Howard Creek deposits and shallow alluvium in the upper valleys of Casner and Howard Creeks may considerably increase the reserves of the district.

  2. Assessment of dry and wet atmospheric deposits of radioactive aerosols: application to Fukushima radiocaesium fallout.

    Science.gov (United States)

    Gonze, Marc-André; Renaud, Philippe; Korsakissok, Irène; Kato, Hiroaki; Hinton, Thomas G; Mourlon, Christophe; Simon-Cornu, Marie

    2014-10-07

    The Fukushima Dai-ichi nuclear accident led to massive atmospheric deposition of radioactive substances onto the land surfaces. The spatial distribution of deposits has been estimated by Japanese authorities for gamma-emitting radionuclides through either airborne monitoring surveys (since April 2011) or in situ gamma-ray spectrometry of bare soil areas (since summer 2011). We demonstrate that significant differences exist between the two surveys for radiocaesium isotopes and that these differences can be related to dry deposits through the use of physically based relationships involving aerosol deposition velocities. The methodology, which has been applied to cesium-134 and cesium-137 deposits within 80-km of the nuclear site, provides reasonable spatial estimations of dry and wet deposits that are discussed and compared to atmospheric numerical simulations from the Japanese Atomic Energy Agency and the French Institute of Radioprotection and Nuclear Safety. As a complementary approach to numerical simulations, this field-based analysis has the possibility to contribute information that can be applied to the understanding and assessment of dose impacts to human populations and the environment around Fukushima.

  3. Effect of uncertainty in nasal airway deposition of radioactive particles on effective dose

    Energy Technology Data Exchange (ETDEWEB)

    Guilmette, R.A.; Birchall, A.; Jarvis, N.S

    1998-07-01

    In the current ICRP human respiratory tract (RT) model (ICRP Publication 66), the deposition of particles in various regions of the RT during natural breathing is modelled by considering the RT as a series of filters, resulting in deposition probabilities for distal portions of the RT being dependent on those of the proximal segments. Thus, uncertainties in regional deposition in proximal segments of the RT are reflected or propagated in uncertainties in deposition in the distal segments of the lung. Experimental data on aerosol particle deposition have demonstrated significant variability in nasal airway (NA) deposition for different individuals studied. This report summarises the impact of introducing variability in NA deposition efficiency on the calculation of effective doses using the ICRP 66 model for selected radionuclides. The computer software LUDEP, modified for this purpose, was used to customise deposition patterns, and effective doses were calculated for several radionuclides ({sup 111}In, {sup 106}Ru, {sup 60}Co, {sup 210}Po, {sup 238}U and {sup 239}Pu) chosen to represent isotopes with various decay schemes and half-lives. The results indicated significant but particle-size-specific effects of assumed NA deposition efficiencies on the calculated effective doses, which varied typically by factors of five to six. The majority of the variability was associated with direct effects on deposition patterns, but in some cases, alterations of radiation dose distribution within the various target organs also contributed to the variability. These results provide a basis for evaluating uncertainties due to inter-individual differences in deposition patterns for radiation protection and risk analysis. (author)

  4. Determination of the isomeric fraction in a postaccelerated radioactive ion beam using the coupled decay-chain equations

    CERN Document Server

    Ekstrom, A; Dijulio, D D; Cederkall, J; Van de Walle, J

    2010-01-01

    A method based on the coupled decay-chain equations for extracting the isotopic and the isomeric composition of a postaccelerated radioactive ion beam is presented and demonstrated on a data set from a Coulomb excitation experiment. This is the first attempt of analyzing the content of a postaccelerated radioactive ion beam using this technique. The beam composition is required for an absolute normalization of the measurement. The strength of the method, as compared to present online-based methods, lies in the determination of the isomeric fraction of a partially isomeric beam using all data accumulated during the experiment. We discuss the limitations and sensitivity of the method with respect to the gamma-ray detection efficiency and the accumulated flux. (C) 2010 Elsevier B.V. All rights reserved.

  5. Microscopic approach to the rates of radioactive decay by emission of heavy clusters

    Energy Technology Data Exchange (ETDEWEB)

    Ivascu, M.; Silisteanu, I.

    1988-08-08

    We have applied a simple microscopic decay theory to the analysis of the rare decay modes. The absolute decay rates are estimated by using the shell model and resonance formation factors and optical model penetrabilities. The resonance formation factors are deduced from the strong interaction form of the theory where the wave function in the internal region is represented in terms of compound nucleus decay. In order to account fully for the data, the implication of internal degrees of freedom was found to be necessary, but no adjustment of Gamow factor was needed. The results have been discussed in the light of the previously reported results and data.

  6. Anthropogenic N deposition slows decay by favoring bacterial metabolism: Insights from metagenomic analyses

    Directory of Open Access Journals (Sweden)

    Zachary B. Freedman

    2016-03-01

    Full Text Available Litter decomposition is an enzymatically-complex process that is mediated by a diverse assemblage of saprophytic microorganisms. It is a globally important biogeochemical process that can be suppressed by anthropogenic N deposition. In a northern hardwood forest ecosystem located in Michigan, USA, 20 years of experimentally increased atmospheric N deposition has reduced forest floor decay and increased soil C storage. Here, we paired extracellular enzyme assays with shotgun metagenomics to assess if anthropogenic N deposition has altered the functional potential of microbial communities inhabiting decaying forest floor. Experimental N deposition significantly reduced the activity of extracellular enzymes mediating plant cell wall decay, which occurred concurrently with changes in the relative abundance of metagenomic functional gene pathways mediating the metabolism of carbohydrates, aromatic compounds, as well as microbial respiration. Moreover, experimental N deposition increased the relative abundance of 50 of the 60 gene pathways, the majority of which were associated with saprotrophic bacteria. Conversely, the relative abundance and composition of fungal genes mediating the metabolism of plant litter was not affected by experimental N deposition. Future rates of atmospheric N deposition have favored saprotrophic soil bacteria, whereas the metabolic potential of saprotrophic fungi appears resilient to this agent of environmental change. Results presented here provide evidence that changes in the functional capacity of saprotrophic soil microorganisms mediate how anthropogenic N deposition increases C storage in soil.

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

    CERN Document Server

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

    2015-01-01

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

  8. Understanding of amount and dynamics of radioactive cesium deposited on trees in Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Izuki; Ohte, Nobuhito; Iseda, Kohei; Tanoi, Keitaro; Hirose, Atsushi; Kobayashi, Natsuko I. [The University of Tokyo, 113-8657, 1-1-1 Yayoi Bunkyo-ku, Tokyo (Japan); Ishii, Nobuyoshi [National Institute of Radiological Sciences, 263-8555, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba (Japan); Ohashi, Mizue [University of Hyogo, 670-0092, 1-1-12 Shinzaike-Honcho, Himeji, Hyogo (Japan)

    2014-07-01

    The accident of Fukushima Daiichi nuclear power plant after the earthquake and Tsunami in March 11, 2011 caused large amount of radioactive cesium ({sup 134}Cs, {sup 137}Cs) deposition onto the forest in the surrounding areas. River water from the forest area is used for food production and also for drinking water in these regions. In order to predict how radioactive Cs diffuse and discharge from the forest catchments, it is important to understand the amount and dynamics of radioactive Cs deposited on the trees. In this report, we show our preliminary results of {sup 137}Cs deposition in forest. Study was conducted in the forest at the upstream of Kami-Oguni River catchment, northern part of Fukushima Prefecture. Three plots (2 deciduous stands and 1 Japanese cedar (Cryptomeria japonica) plantation) were set in the forest. Quercus serrata and C. japonica, a representative of deciduous and evergreen tree species in this region, were chosen from each plot. Sample trees were logged in October 2012. Stem samples were collected every 2 m from above the ground to tree top and separated into bark, sapwood and heartwood. Litter traps were set in each plot and collected every month. Leaf litter was classified among species. Also, soil samples were collected in the cylinder of 5 cm in diameter and maximum 30 cm in depth from the forest floor every month. {sup 137}Cs concentration of all samples were measured by germanium semiconductor detector or NaI(Tl) scintillation counter. Deposited {sup 137}Cs was attached strongly on the bark of Q. serrata at high concentration (9-18 kBq/kg) but there were no clear relationship with tree height. In C. japonica, {sup 137}Cs concentration was about half times lower than that of Q. serrata at 0-10 m part of the tree. {sup 137}Cs concentration in wood of C. japonica was higher than Q. serrata. {sup 137}Cs concentration of sapwood was as high as that of heartwood in C. japonica, but in Q. serrata, {sup 137}Cs concentration in sapwood was

  9. Extraction of Aerosol-Deposited Yersinia pestis from Indoor Surfaces To Determine Bacterial Environmental Decay

    OpenAIRE

    Gut, Ian M.; Bartlett, Ryan A.; Yeager, John J.; Leroux, Brian; Ratnesar-Shumate, Shanna; Dabisch, Paul; Karaolis, David K. R.

    2016-01-01

    Public health and decontamination decisions following an event that causes indoor contamination with a biological agent require knowledge of the environmental persistence of the agent. The goals of this study were to develop methods for experimentally depositing bacteria onto indoor surfaces via aerosol, evaluate methods for sampling and enumerating the agent on surfaces, and use these methods to determine bacterial surface decay. A specialized aerosol deposition chamber was constructed, and ...

  10. Extraction of Aerosol-Deposited Yersinia pestis from Indoor Surfaces To Determine Bacterial Environmental Decay

    Science.gov (United States)

    Bartlett, Ryan A.; Yeager, John J.; Leroux, Brian; Ratnesar-Shumate, Shanna; Dabisch, Paul

    2016-01-01

    ABSTRACT Public health and decontamination decisions following an event that causes indoor contamination with a biological agent require knowledge of the environmental persistence of the agent. The goals of this study were to develop methods for experimentally depositing bacteria onto indoor surfaces via aerosol, evaluate methods for sampling and enumerating the agent on surfaces, and use these methods to determine bacterial surface decay. A specialized aerosol deposition chamber was constructed, and methods were established for reproducible and uniform aerosol deposition of bacteria onto four coupon types. The deposition chamber facilitated the control of relative humidity (RH; 10 to 70%) following particle deposition to mimic the conditions of indoor environments, as RH is not controlled by standard heating, ventilation, and air conditioning (HVAC) systems. Extraction and culture-based enumeration methods to quantify the viable bacteria on coupons were shown to be highly sensitive and reproducible. To demonstrate the usefulness of the system for decay studies, Yersinia pestis persistence as a function of surface type at 21°C and 40% RH was determined to be >40%/min for all surfaces. Based upon these results, at typical indoor temperature and RH, a 6-log reduction in titer would expected to be achieved within 1 h as the result of environmental decay on surfaces without active decontamination. The developed approach will facilitate future persistence and decontamination studies with a broad range of biological agents and surfaces, providing agent decay data to inform both assessments of risk to personnel entering a contaminated site and decontamination decisions following biological contamination of an indoor environment. IMPORTANCE Public health and decontamination decisions following contamination of an indoor environment with a biological agent require knowledge of the environmental persistence of the agent. Previous studies on Y. pestis persistence have

  11. 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)

  12. Evolution of radioactive dose rates in fresh sediment deposits along coastal rivers draining Fukushima contamination plume.

    Science.gov (United States)

    Evrard, Olivier; Chartin, Caroline; Onda, Yuichi; Patin, Jeremy; Lepage, Hugo; Lefèvre, Irène; Ayrault, Sophie; Ottlé, Catherine; Bonté, Philippe

    2013-10-29

    Measurement of radioactive dose rates in fine sediment that has recently deposited on channel bed-sand provides a solution to address the lack of continuous river monitoring in Fukushima Prefecture after Fukushima Dai-ichi nuclear power plant (FDNPP) accident. We show that coastal rivers of Eastern Fukushima Prefecture were rapidly supplied with sediment contaminated by radionuclides originating from inland mountain ranges, and that this contaminated material was partly exported by typhoons to the coastal plains as soon as by November 2011. This export was amplified during snowmelt and typhoons in 2012. In 2013, contamination levels measured in sediment found in the upper parts of the catchments were almost systematically lower than the ones measured in nearby soils, whereas their contamination was higher in the coastal plains. We thereby suggest that storage of contaminated sediment in reservoirs and in coastal sections of the river channels now represents the most crucial issue.

  13. An improved method of lifetime measurement of nuclei in radioactive decay chain

    Science.gov (United States)

    Puzović, J. M.; Manić, D.; Nađđerđ, L. J.

    2017-04-01

    We present an improved statistical method for the calculation of mean lifetime of nuclei in a decay chain with an uncertain relation between mother and daughter nuclei. The method is based on the 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, the 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. 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.

  15. 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.

  16. 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.

  17. MESOI Version 2. 0: an interactive mesoscale Lagrangian puff dispersion model with deposition and decay

    Energy Technology Data Exchange (ETDEWEB)

    Ramsdell, J.V.; Athey, G.F.; Glantz, C.S.

    1983-11-01

    MESOI Version 2.0 is an interactive Lagrangian puff model for estimating the transport, diffusion, deposition and decay of effluents released to the atmosphere. The model is capable of treating simultaneous releases from as many as four release points, which may be elevated or at ground-level. The puffs are advected by a horizontal wind field that is defined in three dimensions. The wind field may be adjusted for expected topographic effects. The concentration distribution within the puffs is initially assumed to be Gaussian in the horizontal and vertical. However, the vertical concentration distribution is modified by assuming reflection at the ground and the top of the atmospheric mixing layer. Material is deposited on the surface using a source depletion, dry deposition model and a washout coefficient model. The model also treats the decay of a primary effluent species and the ingrowth and decay of a single daughter species using a first order decay process. This report is divided into two parts. The first part discusses the theoretical and mathematical bases upon which MESOI Version 2.0 is based. The second part contains the MESOI computer code. The programs were written in the ANSI standard FORTRAN 77 and were developed on a VAX 11/780 computer. 43 references, 14 figures, 13 tables.

  18. Deposits of naturally occurring radioactivity in production of oil and natural gas; Radioaktive avleiringer i olje- og gassproduksjon

    Energy Technology Data Exchange (ETDEWEB)

    Strand, T.; Lysebo, I.; Kristensen, D.; Birovljev, A.

    1997-01-01

    Deposits of naturally occurring radioactive materials is an increasing problem in Norwegian oil and gas production. Activity concentration in solid-state samples and production water, and doses to workers involved in different operations off-shore, have been measured. The report also includes a discussion of different methods of monitoring and alternatives for final disposal of wastes. 154 refs.

  19. Numerical Studies of Radioactive Sediment Deposition on Reservoirs in Fukushima Coastal Area

    Science.gov (United States)

    Yamada, Susumu; Itakura, Mitsuhiro; Okumura, Masahiko; Machida, Masahiko; Kitamura, Akihiro

    2014-05-01

    The transportation of radioactive Cs is mainly brought about by movement of silt- and clay-sized particles in rivers. Therefore, predicting such a fine sediment flow and deposition in rivers has been one of central issues toward environmental recovery after the Fukushima Dai-ichi nuclear power plant (FDNPP) accident. For the purpose of the Cs transport prediction, we concentrate on a few reservoirs in Fukushima costal area, since they are temporal destinations for contaminated silt and clay transported by rivers. We numerically study how the river water together with floating silt and clays penetrate into the reservoirs and where the sediments settle on the bottom surface of the reservoirs by using 2D river simulation framework named iRIC developed by Shimizu et al. In this presentation, we reveal the typical deposition pattern in the target reservoirs and compare the results with direct sampling data for the sediments on the reservoir bottom surfaces. We believe that the obtained information is useful in planning the water supply and treatment for highly-contaminated districts in Fukushima costal area.

  20. 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)

  1. Airborne and deposited radioactivity from the Chernobyl accident. A review of investigations in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Paatero, J. (Finnish Meteorogical Inst., Helsinki (Finland)); Haemeri, K. (Helsinki Univ., Dept. of Physics (Finland)); Jaakkola, T. (Helsinki Univ., Lab. of Radiochemistry (Finland)); Jantunen, M. (National Public Health Inst., Kuopio (Finland)); Koivukoski, J. (Ministry of the Interior, Rescue Dept., Government (Finland)); Saxen, R. (STUK Radiation and Nuclear Safety Authority, Helsinki (Finland))

    2010-07-01

    The Chernobyl nuclear accident happened in the former Soviet Union on 26 April 1986. The accident destroyed one of the RBMK-1000 type reactors and released significant radioactive contamination into the environment. At first the emissions were transported north-westwards over Poland, the Baltic States, Finland, Sweden and Norway. During 27 April 1986 emissions were spreading to eastern-central Europe, southern Germany, Italy and Yugoslavia. Radioactivity mapping over Finland between 29 April and 16 May 1986 showed that the ground deposition in Finland covered southern and central parts of the country but had an irregular distribution. The highest (over 100 muR h-1 [1 muSv h-1]) contamination disclosed by the mapping was around the city of Uusikaupunki in western Finland and the city of Kotka in southeastern Finland. The Uusikaupunki region was an area of heavy fallout associated with the air mass that was located in the Chernobyl area at the time of the accident. The fallout pattern of reftractory nuclides, e.g. plutonium isotopes, had their spatial maximum in this region. Medical consequences in Finland were luckily mild, the most important symptoms being psychological ones. No increase in thyroid cancer or birth defect occurrence has been observed. The Chernobyl accident boosted the radioecological research which had already been calming down after the last atmospheric nuclear test in China in October 1980. Important new results concerning e.g. hot particles have been achieved. The most important effects of the accident in Finland were, however, the increase of public awareness of environmental issues in general and especially of nuclear energy. In Finland, the nuclear energy programme was halted until 2002 when the Parliament of Finland granted a licence to build the fifth nuclear reactor in Finland. (orig.)

  2. Mimicking lung dose by wire-mesh-capped deposition sensors: a new dosimetric strategy of radon (thoron) decay products.

    Science.gov (United States)

    Mishra, Rosaline; Mayya, Y S; Tommasino, L

    2012-06-01

    The dose conversion factor (DCF) of radon decay products may vary by a factor of ∼40 within the particle size range from ∼0.5 nm to tens of micrometres. An ideal detector should have a response, which closely mimics the strong dependence of the DCF on the particle size. This dependence is essentially determined by the different deposition rates of the particles with different sizes on the trachea-bronchial tree and alveoli. These deposition rates versus the particle sizes are similar to those of the decay products onto indoor surfaces. These conclusions are conducive to a new strategy for the dosimetry of radon (thoron) decay products, which is simply based on the detection of decay products deposited on flat surfaces. The dependence of the deposition rate of radon decay products onto flat surfaces versus the particle size is necessarily different from that of the deposition rate on the trachea-bronchial region, especially for particle sizes smaller than a few nanometres and larger than a few micrometres. In the present work, in order to obtain a better mimic between the measurement of flat-surface-deposited radon (thoron) decay products and the DCF at any given particle size, a suitable screen is placed against the surrogate surface, used for the assessment of the radon (thoron) decay products deposition.

  3. Decay Time Measurement for Different Energy Depositions of Plastic Scintillator Fabricated by High Temperature Polymerization Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Cheol Ho; Son, Jaebum; Lee, Sangmin; Kim, Tae Hoon; Kim, Yong-Kyun [Hanyang University, Seoul (Korea, Republic of)

    2016-10-15

    Plastic scintillators are based on organic fluorite. They have many advantages such as fast rise and decay time, high optical transmission, ease of manufacturing, low cost, and large available size. For these reasons they are widely used for particle identification. Also, protection of people against a variety of threats (such as nuclear, radiological, and explosive) represents a true challenge along with the continuing development of science and technology. The plastic scintillator is widely used in various devise, which serves for nuclear, photonics, quantum, and high-energy physics. The plastic scintillator is probably the most widely used organic detector, and polystyrene is one of the most widely used materials in the making of the plastic scintillator detector. Thus, a styrene monomer as a solvent was used to fabricate the plastic scintillator by using high temperature polymerization reaction, and then the emission wavelength and the decay times for different energy depositions were measured by using the fabricated plastic scintillator. A plastic scintillator was fabricated to measure decay time for different energy depositions using the high temperature polymerization. Emission wavelength was measured of 426.05 nm to confirm a scintillator property using the spectrophotometer. Four gamma-ray sources (Cs-137, Co-60, Na-22, and Ba-133) were used to evaluate effect for decay time of different energy depositions. The average decay time of the fabricated plastic scintillator was measured to approximately 4.72 ns slightly higher more than commercial plastic scintillator. In future, light output and linearity will be measured to evaluate other property compared with the commercial scintillator.

  4. 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.

  5. Beta Beams for Neutrino Production Heat Deposition from Decaying Ions in Superconducting Magnets

    CERN Document Server

    Wildner, Elena; Cerutti, F

    2008-01-01

    This report describes studies of energy deposition in superconducting magnets from secondary ions in the "beta beam" decay ring as described in the base-line scenario of the EURISOL Beta Beam Design Study. The lattice structure proposed in the Design Study has absorber elements inserted between the superconducting magnets to protect the magnet coils. We describe an efficient and small model made to carry out the study. The specially developed options in the beam code "ACCSIM" to track largely off-momentum particles has permitted to extract the necessary information to interface the transport and interaction code "FLUKA" with the aim to calculate the heat deposition in the magnets and the absorbers. The two beta emitters 18Ne10+ and 6He2+ used for neutrino and anti-neutrino production and their daughter ions have been tracked. The absorber system proposed in the Design Study is efficient to intercept the ions decayed in the arc straight sections as foreseen, however, the continuous decay in the dipoles induce ...

  6. Beta Beams for neutrino production: Heat deposition from decaying ions in superconducting magnets

    CERN Document Server

    Wildner, Elena; Cerutti, Francesco

    This note describes studies of energy deposition in superconducting magnets from secondary ions in the “beta beam” decay ring as described in the base-line scenario of the EURISOL Beta Beam Design Study. The lattice structure proposed in the Design Study has absorber elements inserted between the superconducting magnets to protect the magnet coils. We describe an efficient and small model made to carry out the study. The specially developed options in the beam code “ACCSIM” to track largely off-momentum particles has permitted to extract the necessary information to interface the transport and interaction code “FLUKA” with the aim to calculate the heat deposition in the magnets and the absorbers. The two beta emitters 18Ne10+ and 6He2+ used for neutrino and anti-neutrino production and their daughter ions have been tracked. The absorber system proposed in the Design Study is efficient to intercept the ions decayed in the arc straight sections as foreseen, however, the continuous decay in the dipol...

  7. Cluster Radioactivity

    Science.gov (United States)

    Poenaru, Dorin N.; Greiner, Walter

    One of the rare examples of phenomena predicted before experimental discovery, offers the opportunity to introduce fission theory based on the asymmetric two center shell model. The valleys within the potential energy surfaces are due to the shell effects and are clearly showing why cluster radioactivity was mostly detected in parent nuclei leading to a doubly magic lead daughter. Saddle point shapes can be determined by solving an integro-differential equation. Nuclear dynamics allows us to calculate the half-lives. The following cluster decay modes (or heavy particle radioactivities) have been experimentally confirmed: 14C, 20O, 23F, 22,24-26Ne, 28,30Mg, 32,34Si with half-lives in good agreement with predicted values within our analytical superasymmetric fission model. The preformation probability is calculated as the internal barrier penetrability. An universal curve is described and used as an alternative for the estimation of the half-lives. The macroscopic-microscopic method was extended to investigate two-alpha accompanied fission and true ternary fission. The methods developed in nuclear physics are also adapted to study the stability of deposited atomic clusters on the planar surfaces.

  8. Research of the multibarrier system for an underground deposition of radioactive wastes

    Directory of Open Access Journals (Sweden)

    Marian Šofranko

    2007-01-01

    Full Text Available The paper deals in brief with research problems of multiple protection barrier systems for an underground storage of highly radioactive waste in connection with the problem of resolving a definite liquidation of this waste. This problem has a worlwide importance and is comprehensively investigated, evaluated and resolved in many well accepted research centers. Present the experts agree, that the most suitable way of the long-lived radioactive wastes liquidation is their storage into suitable underground geological formations. The core insulation of radioactive wastes from the biosphere for an extremly long time can be achieved by using a technical isolation barrier in combination with an appropriate rock mass.

  9. 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

  10. Cold reaction valleys in the radioactive decay of superheavy {sup 286}112, {sup 292}114, and {sup 296}116 nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Santhosh, K. P.; Sabina, S. [Kannur University, School of Pure and Applied Physics (India)

    2012-08-15

    Cold reaction valleys in the radioactive decay of superheavy nuclei {sup 286}112, {sup 292}114, and {sup 296}116 are studied taking Coulomb and Proximity Potential as the interacting barrier. It is found that in addition to alpha particle, {sup 8}Be, {sup 14}C, {sup 28}Mg, {sup 34}Si, {sup 50}Ca, etc. are optimal cases of cluster radioactivity since they lie in the cold valleys. Two other regions of deep minima centered on {sup 208}Pb and {sup 132}Sn are also found. Within our Coulomb and Proximity Potential Model half-life times and other characteristics such as barrier penetrability, decay constant for clusters ranging from alpha particle to {sup 68}Ni are calculated. The computed alpha half-lives match with the values calculated using Viola-Seaborg-Sobiczewski systematics. The clusters {sup 8}Be and {sup 14}C are found to be most probable for emission with T{sub 1/2} < 10{sup 30} s. The alpha-decay chains of the three superheavy nuclei are also studied. The computed alpha-decay half-lives are compared with the values predicted by Generalized Liquid Drop Model and they are found to match reasonably well.

  11. Evaluation of external exposure in a radioactive waste deposit; Avaliacao da exposicao externa em um deposito de rejeitos radioativos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Sergio Quinet de; Pereira, Wagner de Souza; Py Junior, Delcy de Azevedo; Dores, Luis Augusto de Carvalho Bresser; Dantas, Marcelino Vicente de Almeida; Silva, Ana Claudia Antunes; Garcia Filho, Oswaldo, E-mail: wspereira@inb.gov.b, E-mail: sergioquinet@inb.gov.b, E-mail: delcy@inb.gov.b, E-mail: luisdores@inb.gov.b, E-mail: marcelino@inb.go.b, E-mail: anasilva@inb.gov.b, E-mail: ogarcia@inb.gov.b [Industrias Nucleares do Brasil (UTM/INB), Pocos de Caldas, MG (Brazil). Unidade de Tratamento de Minerio

    2011-10-26

    The ore treatment unit (OTU) of Industrias Nucleares do Brasil (INB), located at Caldas municipality - Minas Gerais, Brazil, posses a radioactive deposit, coming mainly from the chemical processing of monazite sands for obtention of 'rare earths'. The main components of these waste are the 'torta II (thorium rich residues) and the 'mesothorium' ({sup 228}Ra rich residues) - conditioned in steel drums (200 liters), plastic pumps (100 liters) or underground silos. These loaders are deposited in waste loading warehouses existent at the OTU and periodic evaluations of the external exposure rates (mR/h) are part of the 'Programa de Monitoracao Radiologica Ocupacional' of the unit. This paper presents a brief history of origins of this waste deposit and the material found there, and also the result of a routine monitoring of the external exposure rates

  12. Naturally occurring radioactive materials in the gas and oil industry : origin, transport and deposition of stable lead and 210Pb from Dutch gas reservoirs

    NARCIS (Netherlands)

    Schmidt, A.P.

    2000-01-01

    The omnipresence of Naturally Occurring Radionuclides (NORs) within the Earth is well-known. Since long, radioactive decay of NORs has been recognised as the primary source of our internal planetary heat, and driving force of volcanism and the movement of plates forming the Earth's crust. Since

  13. Naturally occurring radioactive materials in the gas and oil industry : origin, transport and deposition of stable lead and 210Pb from Dutch gas reservoirs

    NARCIS (Netherlands)

    Schmidt, A.P.

    2000-01-01

    The omnipresence of Naturally Occurring Radionuclides (NORs) within the Earth is well-known. Since long, radioactive decay of NORs has been recognised as the primary source of our internal planetary heat, and driving force of volcanism and the movement of plates forming the Earth's crust. Since NORs

  14. Naturally occurring radioactive materials in the gas and oil industry : origin, transport and deposition of stable lead and 210Pb from Dutch gas reservoirs

    NARCIS (Netherlands)

    Schmidt, A.P.

    2000-01-01

    The omnipresence of Naturally Occurring Radionuclides (NORs) within the Earth is well-known. Since long, radioactive decay of NORs has been recognised as the primary source of our internal planetary heat, and driving force of volcanism and the movement of plates forming the Earth's crust. Since NORs

  15. Numerical simulation of regional scale dispersion and deposition of radioactive pollutants from the accident at the Chernobyl nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Satomura, Takehiko [Kyoto Univ. (Japan)

    1996-12-01

    The dispersion and deposition of radioactive pollutants from the Chernobyl accident was simulated according to a transfer model for air pollutants, which was made by Meteorological Research Institute. The observation data and the data of emission source used here were obtained from the document distributed by ATMES (Atmospheric Transport Model Evaluation Study). The numerical model used consisted of two parts. One is an atmospheric estimation model which allows to predict meteorological factors and the other is a part to calculate the advection diffusion based on the predicted meteorological factors. The time-course changes in {sup 137}Cs concentration in the air determined in Stockholm, Mol, Budapest and Attikis were well coincident with the calculated {sup 137}Cs levels for the respective cities. For atmospheric {sup 137}Cs concentrations at Bilthoven and Berlin, the estimation was also satisfactory, but the calculated deposition levels in both cities did not agree with the respective observation levels. (M.N.)

  16. Contribution of Asian dust to atmospheric deposition of radioactive cesium ((137)Cs).

    Science.gov (United States)

    Fukuyama, Taijiro; Fujiwara, Hideshi

    2008-11-01

    Both Asian dust (kosa) transported from the East Asian continent and locally suspended dust near monitoring sites contribute to the observed atmospheric deposition of (137)Cs in Japan. To estimate the relative contribution of these dust phenomena to the total (137)Cs deposition, we monitored weekly deposition of mineral particles and (137)Cs in spring. Deposition of (137)Cs from a single Asian dust event was 62.3 mBq m(-2) and accounted for 67% of the total (137)Cs deposition during the entire monitoring period. Furthermore, we found high (137)Cs specific activity in the Asian dust deposition sample. Although local dust events contributed to (137)Cs deposition, their contribution was considerably smaller than that of Asian dust. We conclude that the primary source of atmospheric (137)Cs in Japan is dust transported from the East Asian continent.

  17. Problems concerning food production, supply and use caused by radioactive deposition: A study directed towards needs for early decision making after radioactive fallout; Radiakproblem inom livsmedelssektorn: En studie inriktad paa behoven foer beslutsfattande i tidigt skede efter radioaktivt nedfall

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, R.

    1995-12-01

    The primary aim of this study is to analyze and describe how a radioactive deposition after nuclear weapons employment outside Sweden would affect the domestic food production in a short time perspective and in the sequence of events from primary production over processing and transport to food consumption. The study is an attempt at a comprehensive treatment of knowledge needed as a basis for decisions on operative issues, often of a time-urgent nature. Actions to alleviate the problems pertinent to the food supply in the event of radioactive fallout are also discussed, although without any claim of exhaustive coverage. Other aspects, as the economical consequences of the disturbances due to the fallout situation (or of possible counteractions) are not dealt with, however. With certain restrictions mentioned in the text the results are also applicable in connection with radioactive deposition caused by accidental release from a nuclear power plant. 60 refs, 32 figs.

  18. Revisit to Two-Proton Radioactivity of 19Mg and Observation of Two-Proton Decay of 30 Ar

    Institute of Scientific and Technical Information of China (English)

    徐晓栋; A. Estrad´e; F. Farinon; H. Geissel; A. Fomichev; T. A. Golubkova; A. Gorshkov; L. V. Grigorenko; Z. Janas; G. Kami´nski; O. Kiselev; I. Mukha; R. Kn¨obel; S. Krupko; M. Kuich; Yu. A. Litvinov; G. Marquinez-Dur´an; I. Martel; C. Mazzocchi; C. Nociforo; A. K. Ord´uz; M. Pf¨utzner; L. Acosta; S. Pietri; M. Pomorski; A. Prochazka; S. Rymzhanova; A. M. S´anchez-Ben´ıtez; C. Scheidenberger; P. Sharov; H. Simon; B. Sitar; R. Slepnev; E. Casarejos; M. Stanoiu; P. Strmen; I. Szarka; M. Takechi; Y. K. Tanaka; H. Weick; M. Winkler; J. S. Winfield; A. A. Ciemny; W. Dominik; J. Du´enas-D´ıaz; V. Dunin; J. M. Espino

    2016-01-01

    An experiment aimed to investigate the two-proton (2p) decay of the previously unknown nucleus 30Ar was performed at GSI. By tracking the decay products in-flight with silicon micro-strip detectors, the 2p decays of 30Ar were observed for the first time. For the calibration purpose, 2p decays of 19Mg were also remeasured by tracking the coincident 17Ne+p+p trajectories. By comparing the mea-sured angular p-17Ne correlations with those obtained from the corresponding Monte Carlo simulations, the simultaneous 2p decay of 19Mg ground state and the sequential 2p emission of several known excited states of 19Mg were confirmed. One new excited state in 19Mg and two new excited states in 18Na were observed.

  19. The influence of soil moisture, temperature and oxygen on the oxic decay of organic archaeological deposits

    DEFF Research Database (Denmark)

    Hollesen, Jørgen; Matthiesen, H.

    2015-01-01

    using a one-pool decomposition model. The results show that the model can be used to elucidate the current in situ decay and to evaluate where and when the decay takes place. Future investigations need to include long-term incubation experiments and decay studies at zero or very low oxygen contents...

  20. Studies on deposition, adhesion and resuspension of radioactive substances on the ground surface and ground cover

    Energy Technology Data Exchange (ETDEWEB)

    Kurita, Susumu; Kurihara, Kazuo [Meteorological Research Inst., Tsukuba, Ibaraki (Japan)

    1999-03-01

    After the Chernobyl` nuclear power plant accident, resuspension of radioactive nuclei into the atmosphere is recognized as the one of the important processes that must be considered in the estimation of inhalation doses to humans. In this study, resuspensions of particles from soil and grass have been studied. The resuspension of particles from bare soil was modelized by using Shao`s method. The resuspension of particles from grass was studied by a wind tunnel and a field experiment. Dependencies of the resuspension rate on time and on friction velocity were obtained clearly. And it was also found that the other meteorological parameters, such as temperature, relative humidity, solar radiation and condensation, affected the resuspension rate in the field. (author)

  1. A partial analysis of using the melting of flame technoogy for the production of a deep shaft to rocks for the deposition of radioactive wastes

    Directory of Open Access Journals (Sweden)

    Rolf Bielecki

    2007-01-01

    Full Text Available The paper deals with serious objectives, which handle to the economical valuation of vertical drilling. Simultaneously, are inter alia, a questions is answered if the LITO-JET method allows, under some economical conditions, a deposition of high radioactive waste into the depth more than 1000 meters and an increasing research is be necessary.

  2. {beta}-decay and the electric dipole moment: searches for time-reversal violation in radioactive nuclei and atoms

    Energy Technology Data Exchange (ETDEWEB)

    Wilschut, H.W.; Hoek, D.J. van der; Jungmann, K.; Kruithof, W.; Onderwater, C.J.G.; Santra, B.; Shidling, P.; Willmann, L. [Kernfysisch Versneller Instituut, University of Groningen (Netherlands)

    2010-11-01

    At the KVI preparations are underway to study time-reversal violation. We will discuss two complementary experiments: Correlations in {beta} decay of {sup 21}Na and the search for an electric dipole moment in Radium. We discuss the complementarity of these measurements and put them in the context of current research.

  3. Evaluation of the natural radioactivity level of Nigerian tar sand deposits, eastern Dahomey basin, southwestern Nigeria

    Directory of Open Access Journals (Sweden)

    Akinmosin Adewale

    2016-01-01

    Full Text Available The specific activities of natural radionuclides in twenty seven samples collected from the eastern Dahomey basin in southwestern Nigeria were evaluated. Experimental results were obtained by using a 3" x 3" sodium iodide NaI(Tl detector. A major trace element assessment of the samples was made by Inductively Coupled Plasma Mass Spectrometry techniques. Gamma ray radioactive standard sources, 137Cs and 60Co, were used to calibrate the measurement system and the International Atomic Energy Agency SOIL-375 radioactive standard source was also used to analyze and compute the specific activities of desired natural radionuclides. Three radioelements, viz. 238U, 232Th and 40K, were identified in the samples with the following specific activities of 238U ranging from 9.88 ± 4.70 Bq/kg to 69.15 ± 12.37 Bq/kg with an average of 26.50 ± 7.18 Bq/kg; 232Th from 12.78 ± 5.16 Bq/kg to 36.86 ± 13.35 Bq/kg with an average of 22.77 ± 4.28 Bq/kg; 40K ranging from 189.82 ± 79.51 Bq/kg to 518.77 ± ± 119.54 Bq/kg with an average of 297.69 ± 16.21 Bq/kg. The result was compared with the world mean values of 35, 30 and 400 Bq/kg, respectively, specified by the United Nations Scientific Committee on the Effects of Atomic Radiation. The mean result obtained for the radium equivalent, total absorbed dose rate, external hazard index, internal hazard index, and the annual effective dose equivalent, were 79.90 Bq/kg, 38.50 μSv/h, 0.22 Bq/kg, 0.29 Bq/kg, and 47.22 μSv, respectively. With respect to radiological risk to human health, the absorbed gamma dose rate in air was estimated to be in the range of 21.7 ± 0.4 to 155.7 ± 2.2 μSv/h; the outdoor annual effective dose equivalent was evaluated to vary from 26.6 ± 0.4 to 190.9 ± ± 2.7 μSv with the arithmetic mean value of 79.06 ± 33.23 μSv and compared to the world-wide effective dose of 70 μSv. Also, the values of the radium equivalent and the external hazard index for all samples in the study area were

  4. Scenario and parameter studies on global deposition of radioactivity using the computer model GLODEP2

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, C.S.

    1984-08-01

    The GLODEP2 computer code was utilized to determine biological impact to humans on a global scale using up-to-date estimates of biological risk. These risk factors use varied biological damage models for assessing effects. All the doses reported are the unsheltered, unweathered, smooth terrain, external gamma dose. We assume the unperturbed atmosphere in determining injection and deposition. Effects due to ''nuclear winter'' may invalidate this assumption. The calculations also include scenarios that attempt to assess the impact of the changing nature of the nuclear stockpile. In particular, the shift from larger to smaller yield nuclear devices significantly changes the injection pattern into the atmosphere, and hence significantly affects the radiation doses that ensue. We have also looked at injections into the equatorial atmosphere. In total, we report here the results for 8 scenarios. 10 refs., 6 figs., 11 tabs.

  5. Radon transfer and intracorporal deposition of radon decay products under balneotherapeutic conditions; Radon-Transfer und intrakorporale Deposition von Radon-Folgeprodukten unter balneotherapeutischen Bedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Grunewald, Wolfgang A. [Kurmittelhaus Sibyllenbad, Neualbenreuth (Germany); Just, Guenther [Forschungsbuero Radon, Grosspoesna (Germany); Petzold, Juergen [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum, Leipzig (Germany); Philipsborn, Henning von [Radiometrisches Seminar, Univ. Regensburg (Germany)

    2009-07-01

    The intracorporal deposition of radon decay products was determined on four persons after 40 and 30 min respectively in radon water with about 1500 Bq/L by whole-body gamma spectrometry. The measurements started about 2 1/2h after exposure. In addition, the radon activity concentration of inspiratory and expiratory air was measured on one person during and after exposure and the deposition of radon decay products on the skin was measured on another person. The radon activity leaving the body with the expiratory air during exposure in the water (called ''radon transfer'') amounts to about 800 Bq. An intracorporal radon activity immediately after therapeutic exposure of about 3000 Bq was obtained as a result of first measurements by extrapolation from measurements starting about 2 1/2 hours later. Additional studies are necessary. There are indications that both the radon transfer and the intracorporal deposition can be increased by exposure in mixed radon-CO{sub 2} water. (orig.)

  6. Natural Radioactivity at the Sin Quyen Iron-Oxide-Copper-Gold Deposit in North Vietnam

    Science.gov (United States)

    Nguyen, Dinh Chau; Khanh, Phon Le; Jodłowski, Paweł; Pieczonka, Jadwiga; Piestrzyński, Adam; Van, Hao Duong; Nowak, Jakub

    2016-12-01

    The field radiometric and laboratory measurements were performed at the Sin Quyen copper deposit in North Vietnam. The field gamma-ray spectrometry indicated the concentration of uranium ranging from 5.5 to 87 ppm, thorium from 5.6 to 33.2 ppm, and potassium from 0.3 to 4.7%. The measured dose rates ranged from 115 to 582 nGy/h, the highest doses being at the copper ore. Concentrations in the solid samples were in the range of 20-1700 Bq/kg for uranium, 20-92.7 Bq/kg for thorium, and 7-1345 Bq/kg for potassium. The calculated doses were from 22 to 896 nGy/h; both measured and calculated dose rates are mostly related to uranium. Concentrations of radium in water samples were below 0. 17 Bq/L. Uranium in water samples was significantly higher than the hydrogeological background; the maximum of 13 Bq/L was at the waste zone pool, but neither radium nor uranium were present in tap water. Radon concentration in the dwelling air was from 42 to 278 Bq/m3 for 222Rn and from 8 to 193 Bq/m3 for 220Rn. The estimated committed dose rates were principally related to 222Rn concentration and ranged from 1.1 to 8.1 mSv/y.

  7. Natural Radioactivity at the Sin Quyen Iron-Oxide-Copper-Gold Deposit in North Vietnam

    Directory of Open Access Journals (Sweden)

    Nguyen Dinh Chau

    2016-12-01

    Full Text Available The field radiometric and laboratory measurements were performed at the Sin Quyen copper deposit in North Vietnam. The field gamma-ray spectrometry indicated the concentration of uranium ranging from 5.5 to 87 ppm, thorium from 5.6 to 33.2 ppm, and potassium from 0.3 to 4.7%. The measured dose rates ranged from 115 to 582 nGy/h, the highest doses being at the copper ore. Concentrations in the solid samples were in the range of 20-1700 Bq/kg for uranium, 20-92.7 Bq/kg for thorium, and 7-1345 Bq/kg for potassium. The calculated doses were from 22 to 896 nGy/h; both measured and calculated dose rates are mostly related to uranium. Concentrations of radium in water samples were below 0. 17 Bq/L. Uranium in water samples was significantly higher than the hydrogeological background; the maximum of 13 Bq/L was at the waste zone pool, but neither radium nor uranium were present in tap water. Radon concentration in the dwelling air was from 42 to 278 Bq/m3 for 222Rn and from 8 to 193 Bq/m3 for 220Rn. The estimated committed dose rates were principally related to 222Rn concentration and ranged from 1.1 to 8.1 mSv/y.

  8. Resuspension of deposited radioactive material from the Fukushima Daiichi NPP site

    Science.gov (United States)

    Steinhauser, Georg; Niisoe, Tamon; Harada, Kouji H.; Shozugawa, Katsumi; Schneider, Stephanie; Synal, Hans-Arno; Walther, Clemens; Christl, Marcus; Nanba, Kenji; Ishikawa, Hirohiko; Koizumi, Akio

    2016-04-01

    Releases of radionuclides from the Fukushima nuclear accident are typically associated with the atmospheric discharges in the early phase of the accident in spring 2011. Analysis of weekly air filters, however, has revealed sporadic releases of radionuclides long after the Fukushima Daiichi reactors were stabilized. One major discharge was observed in August 2013 in monitoring stations in the Minamisoma area north of the Fukushima Daiichi nuclear power plant (FDNPP). During this event, an air monitoring station in this previously scarcely contaminated area suddenly reported 137Cs activity levels that were 30-fold above the background. Together with atmospheric dispersion and deposition simulation, radionuclide analysis in soil indicated that debris removal operations conducted on the FDNPP site on August 19, 2013 are likely to be responsible for this late release of radionuclides. One soil sample in the center of the simulated plume exhibited a high 90Sr contamination (78 ± 8 Bq kg-1) as well as a high 90Sr/137Cs ratio (0.04); both phenomena have usually been observed only in very close vicinity around the FDNPP. We estimate that through the resuspension of highly contaminated particles in the course of these earthmoving operations, gross 137Cs activity of ca. 2.8 × 1011 Bq has been released.

  9. -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.

  10. Accounting of 131l decomposition under retrospective assessment of its deposition on the basis of determination of 129l deposition

    Directory of Open Access Journals (Sweden)

    Gavrilin Yu.l.

    2013-12-01

    given article aimed a justification of approaches to account of radioactive decay of 131l in the course of determination of its ground deposition density on the basis of determination of the ground deposition density of 129l at the late stage after the accident.

  11. 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

  12. Virtual reality in simulation of operational procedures in radioactive waste deposits; Realidade virtual na simulacao de procedimentos operacionais em depositos de rejeitos radioativos

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Victor Goncalves Gloria

    2016-07-01

    One of the biggest problems in the nuclear area are still the radioactive waste generated in the various applications of this form of energy, all these tailings are stored in warehouses that often are monitored and restructured for better allocation of then. These tailings are stored until it is safe to release into the environment. This work presents a methodology based on virtual reality, for the development of virtual deposits of radioactive waste in order to enable virtual simulations in these deposits. As application will be developed virtually the nuclear waste repository located at the Institute of Nuclear Engineering IEN/CNEN. The development of a virtual warehouse, more specifically, makes it possible to simulate/train the allocation and reallocation of materials with low and medium level of radioactivity, seen the possibility of locomotion of virtual objects and dynamic calculation of the rate of radiation in this environment. Using this methodology it also possible know the accumulated dose, by the virtual character, during the procedures run in the virtual environment. (author)

  13. 陶瓷材料放射性核素测量样品衰变时间研究及最短平衡周期的确定%The Radioactive Decay Time of Ceramic Materials Radionuclide Test Specimen and Determination of the Shortest Decay Balance Cycle

    Institute of Scientific and Technical Information of China (English)

    李文杰; 鲁学军; 杨宝星

    2016-01-01

    This paper sketched the theory of radioactive samples’ decay balance cycle The speciifc activity of three groups of specimens with the radioactive decay balance time between 0 to 27 days was tested by sodium iodideγ-ray detector, then the differences between test results of the same specimen after different decay balance time were analyzed using t-test method. Researches show that if the signiifcant difference between the test results is 5%, the shortest radioactive decay time should not be less than 12 days.%简述了陶瓷材料放射性衰变平衡的基本理论,利用碘化钠γ谱仪对0-27 d内不同衰变时长的3组样品进行比活度测定,采用t检验法分析了同一组样品在不同衰变时间条件下放射性测量结果之间的差异程度。研究表明,若确保检测结果数据的显著性差异水平为5%,则样品最短衰变时间应不小于12 d。

  14. 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...

  15. [Contrast study on natural radioactive nuclides contents of rice between Xiangshan uranium deposit area, Jiangxi and non-uranium depsoit area].

    Science.gov (United States)

    Liu, Ping-Hui; Ye, Chang-Sheng; Xie, Shu-Rong; Rui, Yu-Kui

    2009-07-01

    The contents of natural radioactive nuclides such as uranium and thorium in paddies were analyzed and compared by means of ICP-MS. Totally 14 paddy samples were distinguished into two groups and collected from two rice planting area. One group (12 paddy samples) was collected from the Xiangshan uranium deposit area, Jiangxi province; while the other group (2 samples) collected from non-uranium deposit suburban area of Fuzhou city, Jiangxi, as comparison samples. The distance between the two sampling areas is about 80 kilometers. Before analysis, those paddy samples were continuously carbonized by two hours first, then continuously incinerated for 8 hours at the temperature of 600 degrees centigrade. The results show that the uranium contents in the paddy ash of samples gotten from Xiangshan uranium deposit area range from 0.053 to 1.482 microg x g(-1). The uranium contents of two comparison paddy samples ash are 0.059 and 0.061 microg x g(-1), respectiovely. The average uranium content of paddy ash of uranium deposit area is 0.323 microg x g(-1). Compared with the comparison samples, the uranium contents of paddy ash of uranium deposit area are considerably high, 5.30 times that of non-uranium deposit area. The thorium contents in paddy ash of the uranium deposit area, however, are relatively low and less than that of samples collected from non-uranium deposit area, which range from 0.029 to 0.311 microg x g(-1); The average level is 0.104 microg x g(-1), only about 50% of that of paddy ash sampled from non-urnaium deposit area. Moreover, there is significant linearity correlation between uranium and thorium contents of paddy sampled from Xiangshan uranium deposit area. The positive effects show that the thorium contents of paddy increase as uranium contents of paddy in uranium deposit area increase. The causes for the remarkable difference in uranium contents in paddy between urianium deposit area and non-uranium deposit area are not clear yet. The research on

  16. Radioactivity and thermalization in the ejecta of compact object mergers and their impact on kilonova light curves

    CERN Document Server

    Barnes, Jennifer; Wu, Meng-Ru; Mart'inez-Pinedo, Gabriel

    2016-01-01

    One of the most promising electromagnetic signatures of compact object mergers are kilonovae: approximately isotropic radioactively-powered transients that peak days to weeks post-merger. Key uncertainties in modeling kilonovae include the emission profiles of the radioactive decay products---non-thermal beta- and alpha-particles, fission fragments, and gamma-rays---and the efficiency with which they deposit their energy in the ejecta. The total radioactive energy and the efficiency of its thermalization sets the luminosity budget and is therefore necessary for predicting kilonova light curves. We outline the uncertainties in r-process decay, describe the physical processes by which the energy of the decay products is absorbed in the ejecta, and present time-dependent thermalization efficiencies for each particle type. We determine the net heating efficiency and explore its dependence on r-process yields---in particular, the production of translead nuclei that undergo alpha-decay---and on the ejecta's mass, v...

  17. Geologic investigation of the Virgin River Valley salt deposits, Clark County, southeastern Nevada, to investigate their suitability for possible storage of radioactive waste material as of September 1977

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1977-12-31

    The results from a geologic investigation of the Virgin River Valley salt deposits, Clark County, southeastern Nevada, to examine their suitability for further study and consideration in connection with the possible storage of radioactive waste material are given. The results indicate that (1) approximately one-half of the salt body underlies the Overton Arm of Lake Mead and that the dry land portion of the salt body that has a thickness of 1,000 feet or more covers an area of about four and one-half square miles; (2) current tectonic activity in the area of the salt deposits is believed to be confined to seismic events associated with crustal adjustments following the filling of Lake Mead; (3) detailed information on the hydrology of the salt deposit area is not available at present but it is reported that a groundwater study by the U.S. Geological Survey is now in progress; (4) there is no evidence of exploitable minerals in the salt deposit area other than evaporites such as salt, gypsum, and possibly sand and gravel; (5) the salt deposit area is located inside the Lake Mead Recreation Area, outlined on the accompanying Location Plat, and several Federal, State, and Local agencies share regulatory responsibilities for the activities in the area; (6) other salt deposit areas of Arizona and Nevada, such as the Detrital Valley, Red Lake Dome, Luke Dome, and Mormon Mesa area, and several playa lake areas of central Nevada may merit further study; and (7) additional information, as outlined, is needed to more thoroughly evaluate the salt deposits of the Virgin River Valley and other areas referred to above.

  18. Radioactivity doubles up

    Science.gov (United States)

    Blank, Bertram

    2008-05-01

    More than a century after Henri Becquerel discovered radioactivity, there is still much that physicists do not understand about this spontaneous natural phenomenon. Through Becquerel's use of simple photographic plates to the sophisticated nuclear experiments carried out in today's laboratories, researchers have unearthed a total of nine different ways in which an atomic nucleus can decay. The most well known of these decay modes - alpha (α), beta (β) and gamma (γ) radioactivity - are widely used in applications ranging from medicine to archaeology; the others are much rarer.

  19. Predicted halflives for cluster radioactivities

    Science.gov (United States)

    Poenaru, D. N.; Greiner, W.; Ivascu, M.

    1989-10-01

    The main results of the analytical superasymmetric fission model, describing in a unified manner cluster radioactivities, alpha-decay and cold fission processes, are briefly reviewed. Predicted halflives for 14C, 24, 25, 26Ne, 28, 30Mg and 32Si radioactivities in the range 10 11-10 26 s and the corresponding branching ratios relative to α-decay 10 -16 - 10 -9 have been experimentally confirmed within 1.5 orders of magnitude.

  20. Contribution of the radioactive decay to the study of the structure of N=Z nuclei of mass A>70; Apport de la decroissance radioactive a l'etude de la structure des noyaux N=Z de masse A>70

    Energy Technology Data Exchange (ETDEWEB)

    Longour, Christophe [Institut de Recherches Subatomiques, B.P.28, 23, Rue du Loess, F-67037 Strasbourg Cedex 2 (France)

    1999-04-21

    Radioactive decay study gives an access to the interaction which rules the {beta} 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 {sup 78}Y, {sup 82}Nb and {sup 86}Tc, 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 {sup 72}Kr 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 {beta} particles to energy distribution observed in germanium detector. The tests we have performed show that this prototype can identify and reject 80% of the {beta} 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.

  1. A review of job-exposure matrix methodology for application to workers exposed to radiation from internally deposited plutonium or other radioactive materials.

    Science.gov (United States)

    Liu, Hanhua; Wakeford, Richard; Riddell, Anthony; O'Hagan, Jacqueline; MacGregor, David; Agius, Raymond; Wilson, Christine; Peace, Mark; de Vocht, Frank

    2016-03-01

    Any potential health effects of radiation emitted from radionuclides deposited in the bodies of workers exposed to radioactive materials can be directly investigated through epidemiological studies. However, estimates of radionuclide exposure and consequent tissue-specific doses, particularly for early workers for whom monitoring was relatively crude but exposures tended to be highest, can be uncertain, limiting the accuracy of risk estimates. We review the use of job-exposure matrices (JEMs) in peer-reviewed epidemiological and exposure assessment studies of nuclear industry workers exposed to radioactive materials as a method for addressing gaps in exposure data, and discuss methodology and comparability between studies. We identified nine studies of nuclear worker cohorts in France, Russia, the USA and the UK that had incorporated JEMs in their exposure assessments. All these JEMs were study or cohort-specific, and although broadly comparable methodologies were used in their construction, this is insufficient to enable the transfer of any one JEM to another study. Moreover there was often inadequate detail on whether, or how, JEMs were validated. JEMs have become more detailed and more quantitative, and this trend may eventually enable better comparison across, and the pooling of, studies. We conclude that JEMs have been shown to be a valuable exposure assessment methodology for imputation of missing exposure data for nuclear worker cohorts with data not missing at random. The next step forward for direct comparison or pooled analysis of complete cohorts would be the use of transparent and transferable methods.

  2. A Radon Progeny Deposition Model

    CERN Document Server

    Guiseppe, V E; Hime, A; Rielage, K; Westerdale, S

    2011-01-01

    The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly Rn-222) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of Pb-210 on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to depos...

  3. Use of GIS in hydrological study and impact assessment for heavy metals in area next to radioactive wastes deposit, Rio de Janeiro, RJ, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Renata Coura; Santos, Fabio Ventura dos; Vieira, Paloma da Conceicao; Cabral, Denise Cunha; Barros, Marcio Paes de, E-mail: rcborges@hotmail.com, E-mail: fabio.ventura.santos@gmail.com, E-mail: dcunha@ien.gov.br, E-mail: paloma.c.vieira@gmail.com [Instituto de Engenharia Nuclear (LIMA/IEN/CNEN-RJ), RJ (Brazil). Departamento Lab. de Impactos Ambientais

    2013-07-01

    Studies around the management and disposal of radioactive waste have been conducted for decades. In Brazil, the National Nuclear Energy Commission (CNEN) is responsible for Intermediate Radioactive Waste deposits, located in Fundao Island, Rio de Janeiro (RJ). According to CNEN 8.01 norm, it is necessary to characterize and to study the location area around the deposit. Within this context, the objective of this study was to characterize the Canal Cunha Basin, the western of Guanabara Bay and study the Environmental Impact, with determination of heavy metals (Pb, Cu, Cd, Zn and Ni) in said river basin and bay. The work involves collecting water and sediment samples in five georeferenced points. The sediment samples was collected using the EPA Method 3051 and the reading of the concentrations of heavy metals in water and sediment was performed by ICP-OES. Maps were generated for characterization and spatial distribution of these metals on Canal Cunha Basin. The Canal Cunha's drainage composes a territory with 62.85 km{sup 2} (approximated area) and 37.01 km of perimeter The high occupancy rates in the urban area that decrease the rate of infiltration and changes in physiography caused by construction of embankments because a reverse behavior expected, which increases the runoff coefficient of 0.74. The results show that in periods of high river discharge, there is a drift of large amounts of Pb, Cu and Cd to the waters of the Canal Cunha and Guanabara Bay. Zn and Ni presented higher concentrations in the dry season. The Pb, Cu, Cd, Zn and Ni concentrations are smaller than the concentrations found in the sediment. This probably happens because Cunha Canal Basin and western of Guanabara Bay receive high organic load, and also because of the high percentage of fine sediment in this, thus promoting the adsorption of metals, not contaminating the water and thus not reaching the food chain. (author)

  4. Simulation of Rn-222 decay products concentration deposited on a filter. Description of radon1.pas computer program; Symulacja koncentracji produktow rozpadu Rn-222 osadzanych na filtrze. Opis programu komputerowego radon1.pas

    Energy Technology Data Exchange (ETDEWEB)

    Machaj, B. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1996-12-31

    A computer program allowing simulation of activity distribution of {sup 222}Rn short lived decay products deposited on a filter against time is presented, for any radiation equilibrium degree of the decay products. Deposition of the decay products is simulated by summing discrete samples every 1/10 min in the sampling time from 1 to 10 min. The concentration (activity) of the decay products is computed in one minute intervals in the range 1 - 100 min. The alpha concentration and the total activity of {sup 218}Po + {sup 214}Po produced are computed in the range 1 to 100 min as well. (author). 10 refs, 4 figs.

  5. 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.

  6. Measuring the scintillation decay time for different energy deposited by γ-rays and neutrons in a Cs2LiYCl6:Ce3+ detector

    Science.gov (United States)

    Wen, Xianfei; Enqvist, Andreas

    2017-05-01

    In nuclear safeguards and homeland security applications, it is greatly beneficial to simultaneously detect γ-rays, thermal neutrons, and fast neutrons using a single detector with reasonable pulse shape discrimination capability, energy resolution comparable with or even better than NaI(Tl) detectors, and high detection efficiency. Cs2LiYCl6:Ce3+(CLYC) scintillation detectors have been proven to be one promising candidate to meet these requirements. In this work, the decay time and fraction of each scintillation component for different energy deposition and incident particle type (γ-ray, thermal neutron, and fast neutron) were investigated based on fitting the PMT anode output with exponential functions. For γ-rays, four components were determined with ultrafast decay time of less than one nanosecond and slow time in the order of magnitude of microsecond. It was found that the dependence on the energy deposited by γ-rays of the fraction as well as the decay time of the three slow components was small. However, significant dependence was observed for the ultrafast component. Two or three components were determined for thermal neutrons and fast neutrons without observing a component with fast decay time. To verify the approach used it was first applied to scintillation pulses induced by γ-rays in a NaI(Tl) detector. The results were consistent with well-known data already published in the literature.

  7. Dose rate mapping and quantitative analysis of radioactive deposition with simple monitoring instruments in Finland after the Chernobyl accident.

    Energy Technology Data Exchange (ETDEWEB)

    Koivukoski, J. [Ministry of the Interior, Rescue Dept., Helsinki (Finland); Paatero, J. [Finnish Meteorological Inst., Helsinki (Finland)], E-mail: janne.koivukoski@intermin.fi

    2013-03-01

    This article reviews the Finnish dose-rate mapping equipment and the system to process the obtained results, which were used immediately after the 1986 Chernobyl accident. We present the results of the external gamma-radiation monitoring carried out with simple civil-defence gamma monitoring instruments and compare them with the subsequent deposition mapping performed with research-grade instruments. The analysis shows that the quality of radiation mapping is good enough for decision makers to direct protective measures to the right areas. This review also demonstrates that a simple stationary external gamma radiation monitoring network can be effectively used for early warning in radiation emergency situations. (orig.)

  8. 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.

  9. Radioactive waste caracterisation by neutron activation

    OpenAIRE

    Nicol, Tangi

    2016-01-01

    Nuclear activities produce radioactive wastes classified following their radioactive level and decay time. An accurate characterization is necessary for efficient classification and management. Medium and high level wastes containing long lived radioactive isotopes will be stored in deep geological storage for hundreds of thousands years. At the end of this period, it is essential to ensure that the wastes do not represent any risk for humans and environment, not only from radioactive point o...

  10. Studies for the H0/H− dump for Linac4: energy deposition, induced radioactivity and BLM signal

    CERN Document Server

    Versaci, R; Silari, M; Chamizo, R

    2010-01-01

    This note presents an estimate of the energy deposition and activation for the H0/H− dump for Linac4, the new CERN 160 MeV injector linac. Residual dose rates at different cooling times were calculated as well. The aim of the first part of this study was to compare the behavior of three different materials (graphite, boron nitride and aluminum nitride), in order to identify the most suitable for the dump. For the second part, a dedicated study has been done in order to test whether it could be feasible to insert Beam Loss Monitors to check the status of the beam, All calculations were performed with the Monte Carlo particle transport code FLUKA.

  11. Measuring the scintillation decay time for different energy depositions in NaI:Tl, LSO:Ce and CeBr{sub 3} scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Swiderski, Lukasz, E-mail: lukasz.swiderski@ncbj.gov.pl; Moszynski, Marek; Syntfeld-Kazuch, Agnieszka; Szawlowski, Marek; Szczesniak, Tomasz

    2014-06-01

    This study presents a simple experimental setup for precise inspection of scintillation decay characteristics as a function of the energy deposited in scintillators. The results are discussed for NaI:Tl, LSO:Ce and CeBr{sub 3} crystals. The tested samples were coupled to a fast response R5320 photomultiplier from Hamamatsu. The decay time constants were measured by fitting the anode pulses of the PMT registered directly with a TDS5054B digital oscilloscope from Tektronix. Simple analog electronics composed of timing single channel analyzers, gate generators and coincidence/logic unit was used for selection of the deposited energy converted into light within the scintillator, and for triggering the scope to register relevant scintillation pulses. High precision of the experimental setup allowed for registration of non-proportionality curves for all samples. Moreover, non-proportionality was measured for fast and slow decay mode of NaI:Tl separately. The measurement was also used for inspection of possible differences in the pulse shapes originating from Compton scattering events and photoabsorption.

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

    Science.gov (United States)

    Kida, Tetsuo; Hiraki, Hitoshi; Yamaguchi, Ichirou; Fujibuchi, Toshioh; Watanabe, Hiroshi

    2012-01-01

    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.

  13. Radioactive liquid wastes discharged to ground in the 200 Areas during 1976

    Energy Technology Data Exchange (ETDEWEB)

    Mirabella, J.E.

    1977-05-09

    An overall summary is presented giving the radioactive liquid wastes discharged to ground during 1976 and since startup (for both total and decayed depositions) within the Production and Waste Management Division control zone (200 Area plateau). Overall summaries are also presented for 200 East Area and for 200 West Area. The data contain an estimate of the radioactivity discharged to individual ponds, cribs and specific retention sites within the Production and Waste Management Division during 1976 and from startup through December 31, 1976; an estimate of the decayed activities from startup through 1976; the location and reference drawings of each disposal site; and the usage dates of each disposal site. The estimates for the radioactivity discharged and for decayed activities dicharged from startup through December 31, 1976 are based upon Item 4 of the Bibliography. The volume of liquid discharged to the ponds also includes major nonradioactive streams. The wastes discharged during 1976 to each active disposal site are detailed on a month-to-month basis, along with the monthly maximum concentration and average concentration data. An estimate of the radioactivity discharged to each active site along with the remaining decayed activities is given.

  14. Trapping radioactive ions

    CERN Document Server

    Kluge, Heinz-Jürgen

    2004-01-01

    Trapping devices for atomic and nuclear physics experiments with radioactive ions are becoming more and more important at accelerator facilities. While about ten years ago only one online Penning trap experiment existed, namely ISOLTRAP at ISOLDE/CERN, meanwhile almost every radioactive beam facility has installed or plans an ion trap setup. This article gives an overview on ion traps in the operation, construction or planing phase which will be used for fundamental studies with short-lived radioactive nuclides such as mass spectrometry, laser spectroscopy and nuclear decay spectroscopy. In addition, this article summarizes the use of gas cells and radiofrequency quadrupole (Paul) traps at different facilities as a versatile tool for ion beam manipulation like retardation, cooling, bunching, and cleaning.

  15. Handling of natural occurring radioactive deposits in the oil and gas industry in Norway, United Kingdom and the Netherlands; Haandtering av radioaktive avleiringer i olje- og gassproduksjon i Norge, Storbritania og Nederland

    Energy Technology Data Exchange (ETDEWEB)

    Lysebo, I.; Tufto, P

    1999-03-01

    Deposits containing naturally occurring radioactive materials is an increasing problem in oil and gas production. Laws and regulations in thisarea is under preparation, and it is a wish for harmonization with the other oil and gas producing countries in the North Sea. The report gives an overview of amounts of waste and activity levels, decontamination methods and waste handling in Norway, Great Britain and the Netherlands.

  16. Treatment and disposal of radioactive wastes from nuclear power plants. Program for encapsulation, deep geologic deposition and research, development and demonstration; Kaernkraftavfallets behandling och slutfoervaring. Program foer inkapsling, geologisk djupfoervaring samt forskning, utveckling och demonstration

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    Programs for RD and D concerning disposal of radioactive waste are presented. Main topics include: Design, testing and manufacture of canisters for the spent fuels; Design of equipment for deposition of waste canisters; Material and process for backfilling rock caverns; Evaluation of accuracy and validation of methods for safety analyses; Development of methods for defining scenarios for the safety analyses. 471 refs, 67 figs, 21 tabs.

  17. The ''invisible'' radioactive scale

    Energy Technology Data Exchange (ETDEWEB)

    Bjoernstad, T.; Ramsoey, T

    1999-04-01

    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. {sup 226}Ra and {sup 228}Ra are the most well known radioactive constituents in scale. Surprisingly little known is the radioactive contamination by {sup 210}Pb and progeny {sup 210}Bi and {sup 210}Po. These are found in combination with {sup 226}Ra 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 {sup 226}Ra, but due to transportation and decay of the noble gas {sup 222}Rn 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.

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

    Science.gov (United States)

    Colaianni, A; D'Erasmo, G; Pantaleo, A; Schiavulli, L

    2011-02-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-15

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

  20. 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.

  1. 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.

  2. Radioactive Waste Material From Tapping Natural Resources ...

    Science.gov (United States)

    2017-08-07

    Rocks around oil and gas and mineral deposits may contain natural radioactivity. Drilling through these rocks and bringing them to the surface creates radioactive waste materials. Once desired minerals have been removed from ore, the radionuclides left in the waste are more concentrated. Scientists call this waste Technologically Enhanced Naturally Occurring Radioactive Material or simply TENORM.

  3. Predicted halflives for cluster radioactivities

    Energy Technology Data Exchange (ETDEWEB)

    Poenaru, D.N. (Institutul Central de Fizica, Bucharest (Romania); Frankfurt Univ. (Germany, F.R.). Inst. fuer Theoretische Physik); Greiner, W. (Frankfurt Univ. (Germany, F.R.). Inst. fuer Theoretische Physik); Ivascu, M. (Institutul Central de Fizica, Bucharest (Romania))

    1989-10-09

    The main results of the analytical superasymmetric fission model, describing in a unified manner cluster radioactivities, alpha-decay and cold fission processes, are briefly reviewed. Predicted halflives for {sup 14}C, {sup 24,25,26}Ne, {sup 28,30}Mg and {sup 32}Si radioactivities in the range 10{sup 11}-10{sup 26} s and the corresponding branching ratios relative to {alpha}-decay 10{sup -16}-10{sup -9} have been experimentally confirmed within 1.5 orders of magnitude. (orig.).

  4. Radioactive Material

    CERN Multimedia

    2004-01-01

    The Radiation Protection Group of the Safety Commission is responsible for shipping of radioactive material from CERN to any external institute or organisation. The RP group is equally responsible for the reception of radioactive material shipped to any of the CERN sites. Anyone who needs to ship from or import into CERN radioactive material must contact the Radioactive Shipping Service of the RP group in advance. Instructions are available at: http://cern.ch/rp-shipping or in the Radiation Protection Procedure PRP13: https://edms.cern.ch/document/346823 Radiation Protection Group

  5. Radioactive Material

    CERN Multimedia

    2004-01-01

    The Radiation Protection Group of the Safety Commission is responsible for shipping of radioactive material from CERN to any external institute or organisation. The RP group is equally responsible for the reception of radioactive material shipped to any of the CERN sites. Anyone who needs to ship from or import into CERN radioactive material must contact the Radioactive Shipping Service of the RP group in advance. Instructions are available at: http://cern.ch/rp-shipping or in the Radiation Protection Procedure PRP13: https://edms.cern.ch/document/346823 Radiation Protection Group

  6. The IRSN publishes an assessment of doses received in Japan by external irradiation due to radioactive deposits caused by the Fukushima-Daiichi power plant accident; L'IRSN publie une estimation des doses recues au Japon par irradiation externe due aux depots radioactifs provoques par l'accident de la centrale de Fukushima-Daiichi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This document first describes how dry and wet radioactive deposits are formed. It also indicates their main components: iodine 131 and 132, caesium 134, 136 and 137, tellurium 132, and barium 140. It describes the different exposure ways due to radioactive deposits in the environment. A map indicates dose level assessments few tens of kilometres around the Fukushima power plant. A brief comment of this map is proposed

  7. 氟保护剂预防鼻咽癌放疗后放射性龋齿的临床研究%Preventive Effect of Fluor Protector for Radioactive Decay in the Radiotherapy of Nasopharynx Cancer

    Institute of Scientific and Technical Information of China (English)

    余雅云; 王根桃

    2016-01-01

    Objective To explore the preventive effect of fluor protector for radioactive decay in the radiotherapy of nasopharynx cancer Methods The 112 patients with nasopharynx cancer received radiotherapy were divided into the fluor protector group and the sodium chloride group by self-control method The test began in 1,3,5 d before radiotherapy Fluor protector and sodium chloride were coated on the tooth surface after cleaning,disinfecting and drying the tooth surface every time The decayed-missing-filled tooth(DMFT)and decayed-missing-filled surface (DMFS)were examined before and one year after the radiotherapy Results Before the radiotherapy,the DMFT and DMFS of the two groups showed no significant difference(P > 0 05) However,one year after the radiothera-py,DMFT and DMFS of the two groups increased significantly(P < 0 05)and more increase was found in the so-dium chloride group(P < 0 05) The DMFT and DMFS of the sodium chloride group were more greater than those of the fluor protector group(P < 0 05)Conclusion Fluor protector could significantly reduce the occurrence of radioactive decay in the radiotherapy of nasopharynx cancer.%目的:探讨鼻咽癌患者放疗前牙面用氟保护剂预防放疗后放射性龋齿的效果。方法选择首次接受放疗的鼻咽癌患者112例,采用自身对照方法分为氟保护剂组和生理盐水组。在放疗前1、3、5 d 开始试验,每次清洁牙面,消毒干燥后,用小毛刷将氟保护剂涂抹在一侧牙面(氟保护剂组),同时将生理盐水涂抹在另一侧牙面(生理盐水组),观察并记录放疗前和放疗后1 a 2组的龋失补牙数(DMFT)和龋失补牙面数(DMFS)。结果放疗前,氟保护剂组和生理盐水组 DMFT 和 DMFS 比较差异均无统计学意义( P 均>005)。与放疗前比较,2组 DMFT 和 DMFS 在放疗后1 a 均明显升高(P 均<005),但生理盐水组 DMFT 和DMFS 升高更为明显,且生理盐水组 DMFT 和 DMFS 明

  8. An Excel™ 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™, 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.

  9. IN-SITU RADIONUCLIDE TRANSPORT NEAR THE NOPAL I URANIUM DEPOSIT AT PENA BLANCA, MEXICO: CONSTRAINTS FROM SHORT-LIVED DECAY-SERIES RADIONUCLIDES

    Energy Technology Data Exchange (ETDEWEB)

    S. Luo; T.L. Ku; V. Todd; M. Murrell; J. Alfredo Rodriguez Pineda; J. Dinsmoor; A. Mitchell

    2005-07-11

    For nuclear waste management, an important mechanism by which radioactive waste components are isolated from returning to the human environment, the biosphere, is by the geological barrier in which the effectiveness of the barrier is characterized by in-situ retardation factor, i.e., the transport rate of a radionuclide relative to that of groundwater. As part of natural analog studies of the Yucca Mountain Project of the U. S. Department of Energy, we propose such characterization by using naturally-occurring decay-series radioisotopes as an analog. We collected large-volume (>1000 liters) groundwater samples from three wells (PB, Pozos, and PB4, respectively) near the Nopal I Uranium Ore site at Pena Blanca, Mexico, by using an in-situ Mn-cartridge filtration technique for analysis of short-lived decay-series radionuclides. Results show that the activities of short-lived radioisotopes ({sup 228}Ra, {sup 224}Ra and {sup 223}Ra) and activity ratios of {sup 224}Ra/{sup 228}Ra and {sup 224}Ra/{sup 223}Ra are higher at PB and Pozos than at PB4. In contrast, the {sup 210}Po activity is much lower at PB and Pozos than at PB4. The high Ra activities and activities ratios at PB and Pozos are attributable to the high alpha-recoil input from the aquifer rocks, while the high {sup 210}Po activity at PB4 is due to the enhanced colloidal transport. Based on a uranium-series transport model, we estimate that the in-situ retardation factor of Ra is (0.43 {+-} 0.02) x 10{sup 3} at PB, (1.68 {+-} 0.08) x 10{sup 3} at Pozos, and (1.19 {+-} 0.08) x 10{sup 3} at PB4 and that the mean fracture width in the aquifer rocks is about 0.23 {micro}m at PB, 0.37 {micro}m at Posos, and 4.0 {micro}m at PB4, respectively. The large fracture width at PB4 as derived from the model provides an additional evidence to the inference from the Po measurements that particle-reactive radionuclides are transported mainly as colloidal forms through the large fractures in rocks. Our model also suggests that

  10. 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.

  11. 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)

  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. 5He radioactivity

    OpenAIRE

    Poenaru, D.N.; Ivaşcu, M.

    1984-01-01

    The disintegration of a metastable nuclear state by emission of a light particle can be considered to be a very asymmetric fission process. An approximation of the potential barrier in the overlapping region of the two fragments leads to an analytic relationship for the life-time, allowing us to handle a large number of cases to search for new kinds of radioactivities. In this way, it is predicted that some nuclei with Z = 83-92, N = 127-137 and 97-105,145-157 are able to decay spontaneously ...

  14. 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.

  15. Determining redox properties of clay-rich sedimentary deposits in the context of performance assessment of radioactive waste repositories : Conceptual and practical aspects

    NARCIS (Netherlands)

    Behrends, T.; Bruggeman, Christophe

    2016-01-01

    Redox reactions play a key factor controlling the mobility of redox sensitive radionuclides in clay-rich sediments which might serve as host formations for radioactive waste repositories. Assessing the redox speciation of radionuclides requires information about the redox conditions in the formation

  16. Increased Concentrations of Short-Lived Decay-Series Radionuclides in Groundwaters Underneath the Nopal I Uranium Deposit at Pena Blanca, Mexico

    Science.gov (United States)

    Luo, S.; Ku, T.; Todd, V.; Murrell, M. T.; Dinsmoor, J. C.

    2007-05-01

    The Nopal I uranium ore deposit at Pena Blanca, Mexico, located at > 200 meters above the groundwater table, provides an ideal natural analog for quantifying the effectiveness of geological barrier for isolation of radioactive waste nuclides from reaching the human environments through ground water transport. To fulfill such natural analog studies, three wells (PB1, PB2, and PB3 respectively) were drilled at the site from the land surface down to the saturated groundwater zone and ground waters were collected from each of these wells through large- volume sampling/in-situ Mn-filter filtration for analyses of short-lived uranium/thorium-series radionuclides. Our measurements from PB1 show that the groundwater standing in the hole has much lower 222Rn activity than the freshly pumped groundwater. From this change in 222Rn activity, we estimate the residence time of groundwater in PB1 to be about 20 days. Our measurements also show that the activities of short-lived radioisotopes of Th (234Th), Ra (228Ra, 224Ra, 223Ra), Rn (222Rn), Pb (210Pb), and Po (210Po) in PB1, PB2, and PB3 are all significantly higher than those from the other wells near the Nopal I site. These high activities provide evidence for the enrichment of long-lived U and Ra isotopes in the groundwater as well as in the associated adsorbed phases on the fractured aquifer rocks underneath the ore deposit. Such enrichment suggests a rapid dissolution of U and Ra isotopes from the uranium ore deposit in the vadose zone and the subsequent migration to the groundwater underneath. A reactive transport model can be established to characterize the in-situ transport of radionuclides at the site. The observed change of 222Rn activity at PB1 also suggests that the measured high radioactivityies in ground waters from the site isare not an artifact of drilling operations. However, further studies are needed to assess if or to what extent the radionuclide migration is affected by the previous mining activities at

  17. Radioactive Waste.

    Science.gov (United States)

    Blaylock, B. G.

    1978-01-01

    Presents a literature review of radioactive waste disposal, covering publications of 1976-77. Some of the studies included are: (1) high-level and long-lived wastes, and (2) release and burial of low-level wastes. A list of 42 references is also presented. (HM)

  18. Ternary fission and cluster radioactivities

    CERN Document Server

    Poenaru, D N; Greiner, W; Gherghescu, R A; Hamilton, J H; Ramayya, A V

    2002-01-01

    Ternary fission yield for different kinds of light particle accompanied fission processes is compared to the Q-values for the corresponding cold phenomena, showing a striking correlation. The experimental evidence for the existence of a quasimolecular state in sup 1 sup 0 Be accompanied fission of sup 2 sup 5 sup 2 Cf may be explained using a three-center phenomenological model which generates a third minimum in the deformation energy at a separation distance very close to the touching point. This model is a natural extension of the unified approach to three groups of binary decay modes (cold fission, cluster radioactivities and alpha decay), illustrated by sup 2 sup 3 sup 4 U decay modes, and the alpha valley on the potential energy surfaces of sup 1 sup 0 sup 6 Te. New measurements of cluster decay modes, confirming earlier predictions within analytical superasymmetric fission model, are included in a comprehensive half-life systematics. (authors)

  19. 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).

  20. Radiation protection in transference of radioactive wastes among buildings of an intermediary deposit; Radioprotecao na transferencia de rejeitos radioativos entre edificios de um deposito intermediario

    Energy Technology Data Exchange (ETDEWEB)

    Mitake, Malvina Boni; Suzuki, Fabio Fumio, E-mail: mbmitake@ipen.b, E-mail: ffsuzuki@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/-CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Radioprotecao

    2011-10-26

    This paper describes the planning of radioprotection realized for transfer operation of radioactive wastes from two old buildings for a one of the new buildings. For planning purposes the operation was divided into nine stages and, for evaluation of collective dose, it was considered various relevant factors. The result of radioprotection optimization it was expected a total collective dose of 58.6 mSv per person. The measured dose per dosemeter of direct reading was of 3.9 mSv per person. These difference among the values is due to conservative factors used in the calculation

  1. 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.

  2. Distribution of long-lived radioactive iodine isotope (I-129) in pore waters from the gas hydrate fields on the continental margins: Indication for methane source of gas hydrate deposits

    Science.gov (United States)

    Tomaru, H.; Lu, Z.; Fehn, U.

    2011-12-01

    Because iodine has a strong association with organic matters in marine environments, pore waters in high methane potential region, in particular gas hydrate occurrences on the continental margins, are enriched significantly in iodine compared with seawater. Natural iodine system is composed of stable and radioactive species, I-129 (half-life of 15.7 Myr) has been used for estimating the age of source formations both for methane and iodine, because iodine can be liberated into pore water during the degradation of organic matter to methane in deep sediments. Here we present I-129 age data in pore waters collected from variety of gas hydrate occurrences on the continental margins. The I-129 ages in pore waters from these locations are significantly older than those of host sediments, indicating long-term transport and accumulation from deep/old sediments. The I-129 ages in the Japan Sea and Okhotsk Sea along the plate boundary between the North American and Amurian Plates correspond to the ages of initial spreading of these marginal seas, pointing to the massive deposition of organic matter for methane generation in deep sediments within limited periods. On the Pacific side of these areas, organic matter-rich back stop is responsible for methane in deep-seated gas hydrate deposits along the Nankai Trough. Deep coaly sequences responsible for deep conventional natural gas deposits are also responsible for overlying gas hydrate deposits off Shimokita Peninsula, NE Japan. Those in the Gulf of Mexico are correlative to the ages of sediments where the top of salt diapirs intrude. Marine sediments on the Pacific Plate subducting beneath the Australian Plate are likely responsible for the methane and iodine in the Hikurangi Trough, New Zealand. These ages reflect well the regional geological settings responsible for generation, transport, and accumulation of methane, I-129 is a key to understand the geological history of gas hydrate deposition.

  3. Aspects relating to use of radioactively labelled bacteria in animal experiments. 7. Intake and deposition of aerosols of /sup 59/Fe-labelled Pasteurella multocida germ suspensions in lungs of piglets and calves

    Energy Technology Data Exchange (ETDEWEB)

    Heilmann, P.; Flossmann, K.D.; Mueller, G.; Finsterbusch, L. (Akademie der Landwirtschaftswissenschaften der DDR, Jena. Inst. fuer Bakterielle Tierseuchenforschung)

    1983-03-01

    Two different types of aerosol dispensers were used in an aerosol compartment to apply /sup 59/Fe-labelled bacteria (Pasteurella multocida) to SPE Mini-LEWE piglets as well as to conventionally raised piglets and calves. Germ intake was verified by detection of radioactivity in the lungs. Antigen deposition on each lung amounted to 2-3 . 10/sup 8/ in mini-piglets, 6-8 . 10/sup 8/ in ordinary piglets, and 2 . 10/sup 9/ in conventionally raised calves, as determined by SAG-1, a Soviet model of aerosol dispenser. More or less equally high concentrations of aerosol particles were retained in the pulmonary lobes, independent of the animal species used. Antigen intake could not be influenced by addition of skim milk or by restriction of germ suspensions.

  4. APPLICATION OF RADIOACTIVE GEOPHYSICAL METHOD FOR MUOZIBA URANIUM DEPOSIT%放射性物探方法在甘肃磨子坝铀矿中的应用

    Institute of Scientific and Technical Information of China (English)

    毛祖永; 张多运

    2011-01-01

    通过磨子坝地区开展放射性场晕测定,地表伽玛晕圈及活性炭剖面测量异常较好地段可以指导深部找矿工作。根据放射性物探场晕特征,采用伽玛总量扫面,能谱测量确定异常性质,活性炭剖面测量对比,在找矿勘探工作中有较好的成效。%The survey of radioactive field haloes carried out in Moziba region shows that the obvious anomalies determined by surface gamma and active charcoal section survey can be applied to guide the exploration of deep buried uranium deposit.

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

    Science.gov (United States)

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

    2016-09-01

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

  6. 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

  7. A new technique for elucidating $\\beta$-decay schemes which involve daughter nuclei with very low energy excited states

    CERN Document Server

    Venhart, M; Boston, A J; Cocolios, T E; Harkness-Brennan, L J; Herzberg, R -D; Joss, D T; Judson, D S; Kliman, J; Matousek, V; Motycak, S; Page, R D; Patel, A; Petrik, K; Sedlak, M; Veselsky, M

    2016-01-01

    A new technique of elucidating $\\beta$-decay schemes of isotopes with large density of states at low excitation energies has been developed, in which a Broad Energy Germanium (BEGe) detector is used in conjunction with coaxial hyper-pure germanium detectors. The power of this technique has been demonstrated on the example of 183Hg decay. Mass-separated samples of 183Hg were produced by a deposition of the low-energy radioactive-ion beam delivered by the ISOLDE facility at CERN. The excellent energy resolution of the BEGe detector allowed $\\gamma$ rays energies to be determined with a precision of a few tens of electronvolts, which was sufficient for the analysis of the Rydberg-Ritz combinations in the level scheme. The timestamped structure of the data was used for unambiguous separation of $\\gamma$ rays arising from the decay of 183Hg from those due to the daughter decays.

  8. Latest results of NEXT-DEMO, the prototype of the NEXT 100 double beta decay experiment

    CERN Document Server

    Serra, L; Martin-Albo, J; Sorel, M; Gomez-Cadenas, J J

    2014-01-01

    NEXT-DEMO is a 1:4.5 scale prototype of the NEXT100 detector, a high-pressure xenon gas TPC that will search for the neutrinoless double beta decay of $^{136}$Xe. X-ray energy depositions produced by the de-excitation of Xenon atoms after the interaction of gamma rays from radioactive sources have been used to characterize the response of the detector obtaining the spatial calibration needed for close-to-optimal energy resolution. Our result, 5.5% FWHM at 30 keV, extrapolates to 0.6% FWHM at the Q value of $^{136}$Xe. Additionally, alpha decays from radon have been used to measure several detection properties and parameters of xenon gas such as electron-ion recombination, electron drift velocity, diffusion and primary scintillation light yield. Alpha spectroscopy is also used to quantify the activity of radon inside the detector, a potential source of background for most double beta decay experiments.

  9. 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.)

  10. Transport and extraction of radioactive ions stopped in superfluid helium

    NARCIS (Netherlands)

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

    2003-01-01

    A new approach to convert a high energy beam to a low energy one, which is essential for the next generation radioactive ion beam facilities, has been proposed and tested at Jyvaskyla, Finland. An open Ra-223 alpha-decay-recoil source has been used to produce radioactive ions in superfluid helium. T

  11. Evaluation of radioactive cesium impact from atmospheric deposition and direct release fluxes into the North Pacific from the Fukushima Daiichi nuclear power plant

    Science.gov (United States)

    Tsubono, Takaki; Misumi, Kazuhiro; Tsumune, Daisuke; Bryan, Frank O.; Hirose, Katsumi; Aoyama, Michio

    2016-09-01

    The North Pacific distribution of 134Cs released from the Fukushima Daiichi nuclear power plant (F1NPP) has been investigated using an eddy-resolving model. We conducted simulations based on two scenarios: (1) an input flux that was a combination of atmospheric deposition and direct release from the F1NPP (combination-flux scenario) and (2) an input flux that took account only of the direct release of 134Cs (single-flux scenario). The combination-flux scenario simulation successfully reproduced the distribution of 134Cs activity observed in the surface layer from April 2011 to January 2014. The results indicate that 134Cs deposited via atmospheric deposition into the Kuroshio-Oyashio Interfrontal Zone and 134Cs directly released from F1NPP were both transported to south of the Subarctic Front around 42°N in June of 2012. The combination-flux scenario suggests that the 134Cs activities observed in the area north of 42°N in 2012 originated from atmospheric deposition and that the 134Cs activity was subducted in Central Mode Water during the winters of 2011 and 2012. We directly compared simulated and observed 134Cs activities in the surface layer at 179 points across a wide area to the east of 155°E from 2011 to 2013 to evaluate the accuracy of the two scenarios. The root-mean-square error and correlation coefficient, R, were 7.3 Bq m-3 and 0.86, respectively, for the combination-flux scenario and 13.8 Bq m-3 and 0.46, respectively, for the single-flux scenario, confirming that reproduction of the 134Cs activity in the North Pacific after the F1NPP accident requires taking both fluxes into consideration. Based on a linear least-squares regression between simulated and observed 134Cs activity, the total 134Cs flux into the North Pacific was estimated at 16.1±1.4 PBq.

  12. 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

  13. Radioactive Fallout From Nuclear Weapons Testing ...

    Science.gov (United States)

    2017-08-07

    Detonating nuclear weapons above ground sends radioactive materials into the atmosphere from the ground level up to very high elevations. Overtime, these materials settle out of the atmosphere and fall to the ground. Fallout typically contains hundreds of different radionuclides. Since the end of aboveground nuclear weapons testing, radionuclides have largely decayed away.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

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

  15. Comparison of the accident process, radioactivity release and ground contamination between Chernobyl and Fukushima-1.

    Science.gov (United States)

    Imanaka, Tetsuji; Hayashi, Gohei; Endo, Satoru

    2015-12-01

    In this report, we have reviewed the basic features of the accident processes and radioactivity releases that occurred in the Chernobyl accident (1986) and in the Fukushima-1 accident (2011). The Chernobyl accident was a power-surge accident that was caused by a failure of control of a fission chain reaction, which instantaneously destroyed the reactor and building, whereas the Fukushima-1 accident was a loss-of-coolant accident in which the reactor cores of three units were melted by decay heat after losing the electricity supply. Although the quantity of radioactive noble gases released from Fukushima-1 exceeded the amount released from Chernobyl, the size of land area severely contaminated by (137)Cesium ((137)Cs) was 10 times smaller around Fukushima-1 compared with around Chernobyl. The differences in the accident process are reflected in the composition of the discharged radioactivity as well as in the composition of the ground contamination. Volatile radionuclides (such as (132)Te-(132)I, (131)I, (134)Cs and (137)Cs) contributed to the gamma-ray exposure from the ground contamination around Fukishima-1, whereas a greater variety of radionuclides contributed significantly around Chernobyl. When radioactivity deposition occurred, the radiation exposure rate near Chernobyl is estimated to have been 770 μGy h(-1) per initial (137)Cs deposition of 1000 kBq m(-2), whereas it was 100 μGy h(-1) around Fukushima-1. Estimates of the cumulative exposure for 30 years are 970 and 570 mGy per initial deposition of 1000 kBq m(-2) for Chernobyl and Fukusima-1, respectively. Of these exposures, 49 and 98% were contributed by radiocesiums ((134)Cs + (137)Cs) around Chernobyl and Fukushima-1, respectively. © The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  16. Comparison of the accident process, radioactivity release and ground contamination between Chernobyl and Fukushima-1

    Science.gov (United States)

    Imanaka, Tetsuji; Hayashi, Gohei; Endo, Satoru

    2015-01-01

    In this report, we have reviewed the basic features of the accident processes and radioactivity releases that occurred in the Chernobyl accident (1986) and in the Fukushima-1 accident (2011). The Chernobyl accident was a power-surge accident that was caused by a failure of control of a fission chain reaction, which instantaneously destroyed the reactor and building, whereas the Fukushima-1 accident was a loss-of-coolant accident in which the reactor cores of three units were melted by decay heat after losing the electricity supply. Although the quantity of radioactive noble gases released from Fukushima-1 exceeded the amount released from Chernobyl, the size of land area severely contaminated by 137Cesium (137Cs) was 10 times smaller around Fukushima-1 compared with around Chernobyl. The differences in the accident process are reflected in the composition of the discharged radioactivity as well as in the composition of the ground contamination. Volatile radionuclides (such as 132Te-132I, 131I, 134Cs and 137Cs) contributed to the gamma-ray exposure from the ground contamination around Fukishima-1, whereas a greater variety of radionuclides contributed significantly around Chernobyl. When radioactivity deposition occurred, the radiation exposure rate near Chernobyl is estimated to have been 770 μGy h−1 per initial 137Cs deposition of 1000 kBq m−2, whereas it was 100 μGy h−1 around Fukushima-1. Estimates of the cumulative exposure for 30 years are 970 and 570 mGy per initial deposition of 1000 kBq m−2 for Chernobyl and Fukusima-1, respectively. Of these exposures, 49 and 98% were contributed by radiocesiums (134Cs + 137Cs) around Chernobyl and Fukushima-1, respectively. PMID:26568603

  17. Application of the Broad Energy Germanium detector: A technique for elucidating β-decay schemes which involve daughter nuclei with very low energy excited states

    Science.gov (United States)

    Venhart, M.; Wood, J. L.; Boston, A. J.; Cocolios, T. E.; Harkness-Brennan, L. J.; Herzberg, R.-D.; Joss, D. T.; Judson, D. S.; Kliman, J.; Matoušek, V.; Motyčák, Š.; Page, R. D.; Patel, A.; Petrík, K.; Sedlák, M.; Veselský, M.

    2017-03-01

    A technique for elucidating β-decay schemes of isotopes with a large density of states at low excitation energy has been developed, in which a Broad Energy Germanium (BEGe) detector is used in conjunction with coaxial hyper-pure germanium detectors. The power of this technique is demonstrated using the example of 183Hg decay. Mass-separated samples of 183Hg were produced by a deposition of the low-energy radioactive-ion beam delivered by the ISOLDE facility at CERN. The excellent energy resolution of the BEGe detector allowed γ-ray energies to be determined with a precision of a few tens of eV, which was sufficient for the analysis of the Rydberg-Ritz combinations (in conjunction with γ-γ coincidences) in the level scheme. The timestamped structure of the data was used for unambiguous separation of γ rays arising from the decay of 183Hg from those due to the daughter decays.

  18. An experiment on radioactive equilibrium and its modelling using the ‘radioactive dice’ approach

    Science.gov (United States)

    Santostasi, Davide; Malgieri, Massimiliano; Montagna, Paolo; Vitulo, Paolo

    2017-07-01

    In this article we describe an educational activity on radioactive equilibrium we performed with secondary school students (17-18 years old) in the context of a vocational guidance stage for talented students at the Department of Physics of the University of Pavia. Radioactive equilibrium is investigated experimentally by having students measure the activity of 214Bi from two different samples, obtained using different preparation procedures from an uraniferous rock. Students are guided in understanding the mathematical structure of radioactive equilibrium through a modelling activity in two parts. Before the lab measurements, a dice game, which extends the traditional ‘radioactive dice’ activity to the case of a chain of two decaying nuclides, is performed by students divided into small groups. At the end of the laboratory work, students design and run a simple spreadsheet simulation modelling the same basic radioactive chain with user defined decay constants. By setting the constants to realistic values corresponding to nuclides of the uranium decay chain, students can deepen their understanding of the meaning of the experimental data, and also explore the difference between cases of non-equilibrium, transient and secular equilibrium.

  19. RADIO-ACTIVE TRANSDUCER

    Science.gov (United States)

    Wanetick, S.

    1962-03-01

    ABS>ure the change in velocity of a moving object. The transducer includes a radioactive source having a collimated beam of radioactive particles, a shield which can block the passage of the radioactive beam, and a scintillation detector to measure the number of radioactive particles in the beam which are not blocked by the shield. The shield is operatively placed across the radioactive beam so that any motion normal to the beam will cause the shield to move in the opposite direction thereby allowing more radioactive particles to reach the detector. The number of particles detected indicates the acceleration. (AEC)

  20. /sup 5/He radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Poenaru, D.N.; Ivascu, M. (Institute for Physics and Nuclear Engineering, Bucharest (Romania))

    1984-07-01

    The disintegration of a metastable nuclear state by emission of a light particle can be considered to be a very asymmetric fission process. An approximation of the potential barrier in the overlapping region of the two fragments leads to an analytic relationship for the life-time, allowing us to handle a large number of cases to search for new kinds of radioactivities. In this way, it is predicted that some nuclei with Z=83-92, N=127-137 and 97-105, 145-157 are able to decay spontaneously by emission of /sup 5/He particles. A tentative optimistic estimation leads to the result that only 15 radionuclides should have partial life-times in the range 10/sup 14/-10/sup 38/ years; all others, except some superheavies, are longer lived. The best candidate is /sup 213/Po for which the daughter is a double magic nucleus. Smaller life-times, with a better chance to be experimentally confirmed have some ..beta..-delayed /sup 5/He emitters, as for example /sup 155/Yb, /sup 175/Pt, /sup 209 -217/Ra, /sup 9 -11/Be, /sup 13 -14/B, /sup 13 -17/C and /sup 19 -21/O.

  1. Radioactivity in consumer products

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-08-01

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

  2. 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

    decrease exponentially by excretion (biological outflow). The total outflow is the sum of physical outflow and biological outflow. As a result, the number of radioactive atoms in the human body also decreases exponentially. Half-life can be determined by outflow flux from the definition. Intensity of radioactivity is linear respect to the number of radioactive atoms, both are equivalent analytically. Internal total exposure can be calculated by the time integral of intensity of radioactivity. The absorbed energy into the human body per radioactive decay and the effective dose are calculated by aid of Fermi's theory of beta decay and special relativity. The effective doses calculated by the present method almost agree with those of a study by ICRP. The present method shows that standard limit in general foods for radioactive cesium enforced in Japan, 100 Bq/kg, is too excessive. When we eat foods which contain cesium-137 of 100 Bq/kg at 1 kg/d during 50 years, we receive the effective dose less than natural exposure. Similarly, it is shown that we cannot find significant health damage medically and statistically by ingestion of rice which is harvested from a paddy field deposited current (January, 2014) radioactive cesium.

  3. Future double beta decay experiments

    Energy Technology Data Exchange (ETDEWEB)

    Piquemal, F. [Laboratoire Souterrain de Modane, Modane (France); Centre d' Etudes Nucleaire, Bordeaux-Gradignan (France)

    2013-02-15

    The search of neutrinoless double beta decay is very challenging because of the expected half-life of the process and the backgrounds from the natural radioactivity. Many projects exist to try to reach a sensitivity of ∼50 meV on the effective neutrino mass corresponding to a mass of isotopes of ∼100 kg. In this article some of the futur projects are presented.

  4. 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.

  5. Threedimensional dynamics of nuclear decay modes

    Science.gov (United States)

    Mirea, M.; Poenaru, D. N.; Greiner, W.

    1994-03-01

    We study nondissipative fission dynamics in a wide range of mass asymmetry, covering three groups of nuclear decay modes: cluster radioactivities; alpha-decay and cold fission. The WKB action integral is calculated by using the Werner-Wheeler inertia tensor and the deformation energy within Yukawa-plus-exponential model extended to binary systems with different charge densities. The optimum dynamical trajectory in a threedimensional deformation space (elongation, necking-in and mass-asymmetry) is determined by solving a nonlinear system of differential equations. This new method is illustrated for three decay modes of234U: α-decay, Mg-radioactivity and cold fission with100Zr as a light fragment.

  6. HALF-LIVES OF LONG-LIVED A-DECAY, B-DECAY, BB-DECAY AND SPONTANEOUS FISSION NUCLIDES.

    Energy Technology Data Exchange (ETDEWEB)

    HOLDEN,N.E.

    2001-06-29

    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 a discussion session at the next meeting. 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 and spontaneous fission decay. This report is preliminary but will provide a quick overview of the extensive table of data on the recommendations from that review.

  7. Thermodynamic stability of radioactivity standard solutions

    Energy Technology Data Exchange (ETDEWEB)

    Iroulard, M.G

    2007-04-15

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

  8. Radioactive isotopes in solid-state physics

    CERN Document Server

    Deicher, M

    2002-01-01

    Radioactive atoms have been used in solid-state physics and in material science for many decades. Besides their classical application as tracer for diffusion studies, nuclear techniques such as M\\"ossbauer spectroscopy, perturbed angular correlation, $\\beta$-NMR, and emission channelling have used nuclear properties (via hyperfine interactions or emitted particles) to gain microscopical information on the structural and dynamical properties of solids. During the last decade, the availability of many different radioactive isotopes as a clean ion beam at ISOL facilities such as ISOLDE at CERN has triggered a new era involving methods sensitive for the optical and electronic properties of solids, especially in the field of semiconductor physics. Extremely sensitive spectroscopic techniques like deep-level transient spectroscopy (DLTS), photoluminescence (PL), and Hall effect have gained a new quality by using radioactive isotopes. Because of their decay the chemical origin of an observed electronic and optical b...

  9. MONITORING OF RADIOACTIVITY AT DNURT CAMPUS

    Directory of Open Access Journals (Sweden)

    L. F. Dolina

    2016-06-01

    Full Text Available Purpose. The research paper aims to determine radioactive contamination on the territory of campus of Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan (DNURT. Methodology. The dosimeters measured the radioactive contamination in different places (points of DNURT campus, focusing on public places. The centres of measurements became dormitories, monuments, stops, main entrances of the new and the old buildings, classrooms, basements, a swimming pool, boiler room and others. Findings. The conducted radiation monitoring for the first time in the history of the University discovered the source of radioactive contamination on DNURT territory and campus. The highest radiation background is observed on three points, namely: the pedestal of the monument, the monument to students-soldiers, the main entrance of the new building (columns. This can be explained by granite materials, which the pedestals and the stairs are made of. Originality. The largest contribution to the total value of annual effective dose of human exposure is made by ionizing radiation sources (IRS of building materials (65 - 70%. The radioactivity level of building materials is determined by the content of natural radionuclides that are included in uranium-radium and thorium decay series (18 and 12 radionuclides as well as potassium-40. Radioactivity of building materials is evaluated by the content of dominant radionuclides radium-226, thorium-232 and potassium-40. Their dominant role is explained by the fact that these long-lived high-energy - emitters are the products of decay of radium-226 in uranium series of and radium-224 in thorium series, exposing radioactive gases (radon-222 and radon-220. Radioactive gases are accumulated in the basements of educational buildings; their decay is accompanied by 100% alpha radiation, which is the most dangerous. Practical value. It is necessary to set radioactivity signs near the objects with high

  10. Nuclear astrophysics with radioactive ions at FAIR

    OpenAIRE

    2016-01-01

    The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process beta-decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular ...

  11. Poster — Thur Eve — 41: Considerations for Patients with Permanently Implant Radioactive Sources Requiring Unrelated Surgery

    Energy Technology Data Exchange (ETDEWEB)

    Basran, P. S; Beckham, WA [Dept. Medical Physics, BC Cancer Agency- Vancouver Island Centre and Dept. Physics and Astronomy, University of Victoria, BC (Canada); Baxter, P [Vancouver Island Health Authority, Victoria, BC (Canada)

    2014-08-15

    Permanent implant of sealed radioactive sources is an effective technique for treating cancer. Typically, the radioactive sources are implanted in and near the disease, depositing dose locally over several months. There may be instances where these patients must undergo unrelated surgical procedures when the radioactive material remains active enough to pose risks. This work explores these risks, discusses strategies to mitigate those risks, and describes a case study for a permanent I-125 prostate brachytherapy implant patient who developed colo-rectal cancer and required surgery 6 months after brachytherapy. The first consideration is identifying the risk from unwarranted radiation to the patient and staff before, during, and after the surgical procedure. The second is identifying the risk the surgical procedure may have on the efficacy of the brachytherapy implant. Finally, there are considerations for controlling for radioactive substances from a regulatory perspective. After these risks are defined, strategies to mitigate those risks are considered. These strategies may include applying the concepts of ALARA, the use of protective equipment and developing a best practice strategy with the operating room team. We summarize this experience with some guidelines: If the surgical procedure is near (ex: 5 cm) of the implant; and, the surgical intervention may dislodge radioisotopes enough to compromise treatment or introduces radiation safety risks; and, the radioisotope has not sufficiently decayed to background levels; and, the surgery cannot be postponed, then a detailed analysis of risk is advised.

  12. 10 CFR 72.104 - Criteria for radioactive materials in effluents and direct radiation from an ISFSI or MRS.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Criteria for radioactive materials in effluents and direct... radioactive materials, radon and its decay products excepted, to the general environment, (2) Direct radiation... objectives for radioactive materials in effluents and direct radiation levels associated with ISFSI or...

  13. Convivial Decay

    DEFF Research Database (Denmark)

    Cohn, Marisa

    2016-01-01

    in the life of infrastructure we can observe common issues associated with aging infrastructures – hardware’s material decay, programming languages and software tools reaching end of support, obsolete managerial methodologies, etc. Such a case of infrastructural decay reveals how work of infrastructure...... maintenance may reach the limits of repair and shift from repair-as-sustaining into a mode of repair- into-decay, actively working towards the end-of-life. What this reveals is that, rather than infrastructural decay being a natural by-product of time’s passing, there is active work that goes into producing......This paper discusses the empirical case of an aging and obsolescent infrastructure supporting a space science mission that is currently approaching a known end. Such a case contributes to our understanding of the degrading path at the end-of-life of an infrastructure. During this later stage...

  14. Proton Decay

    OpenAIRE

    Hikosaka, Koki

    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.

  15. Radioactive air sampling methods

    CERN Document Server

    Maiello, Mark L

    2010-01-01

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

  16. Radioactivity in fossils at the Hagerman Fossil Beds National Monument.

    Science.gov (United States)

    Farmer, C Neal; Kathren, Ronald L; Christensen, Craig

    2008-08-01

    Since 1996, higher than background levels of naturally occurring radioactivity have been documented in both fossil and mineral deposits at Hagerman Fossil Beds National Monument in south-central Idaho. Radioactive fossil sites occur primarily within an elevation zone of 900-1000 m above sea level and are most commonly found associated with ancient river channels filled with sand. Fossils found in clay rich deposits do not exhibit discernable levels of radioactivity. Out of 300 randomly selected fossils, approximately three-fourths exhibit detectable levels of natural radioactivity ranging from 1 to 2 orders of magnitude above ambient background levels when surveyed with a portable hand held Geiger-Muller survey instrument. Mineral deposits in geologic strata also show above ambient background levels of radioactivity. Radiochemical lab analysis has documented the presence of numerous natural radioactive isotopes. It is postulated that ancient groundwater transported radioactive elements through sand bodies containing fossils which precipitated out of solution during the fossilization process. The elevated levels of natural radioactivity in fossils may require special precautions to ensure that exposures to personnel from stored or displayed items are kept as low as reasonably achievable (ALARA).

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

    Science.gov (United States)

    Furuta, E; Yoshizawa, Y; Aburai, T

    2000-12-01

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

  18. Radioactivity in groundwater along the borders of Oman and UAE

    DEFF Research Database (Denmark)

    Murad, A.; Alshamsi, D.; Hou, Xiaolin;

    2014-01-01

    are alluvium deposits (silt, sand and gravel) and the measured groundwater radioactivity (including 232Th, 238U, 235U, 226Ra, 222Rn, gross-α and gross-β) indicates values below the WHO permissible limits for drinking water. The results also show large difference in radioactivity fingerprints, in particular...... for 226Ra and 222Rn within the investigated aquifers. The data further indicate lower radioactivity in groundwater of the alluviums compared to the carbonate aquifers in the region. This feature makes the alluvium aquifers valuable reservoirs that should be carefully exploited as a source of groundwater....... As this is the first investigation on the radioactivity of groundwater in alluvial aquifers in the region, it suggests that other alluvial deposits, particularly those inland and far from the marine water intrusion or seepage from carbonate rocks would have low radioactivity fingerprints....

  19. Radioactivity and its measurement

    CERN Document Server

    Mann, W B; Garfinkel, S B

    1980-01-01

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

  20. Radioactive ion beam development in Berkeley

    CERN Document Server

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

    1999-01-01

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

  1. Seal Out Tooth Decay

    Science.gov (United States)

    ... Decay (Caries) > Seal Out Tooth Decay Seal Out Tooth Decay Main Content What are dental sealants? How are ... fix decayed teeth. Back to Top What causes tooth decay? Germs in the mouth use the sugar in ...

  2. 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.

  3. Modeling and sensitivity analysis of transport and deposition of radionuclides from the Fukushima Daiichi accident

    Directory of Open Access Journals (Sweden)

    X. Hu

    2014-01-01

    Full Text Available The atmospheric transport and ground deposition of radioactive isotopes 131I and 137Cs during and after the Fukushima Daiichi Nuclear Power Plant (FDNPP accident (March 2011 are investigated using the Weather Research and Forecasting/Chemistry (WRF/Chem model. The aim is to assess the skill of WRF in simulating these processes and the sensitivity of the model's performance to various parameterizations of unresolved physics. The WRF/Chem model is first upgraded by implementing a radioactive decay term into the advection-diffusion solver and adding three parameterizations for dry deposition and two parameterizations for wet deposition. Different microphysics and horizontal turbulent diffusion schemes are then tested for their ability to reproduce observed meteorological conditions. Subsequently, the influence on the simulated transport and deposition of the characteristics of the emission source, including the emission rate, the gas partitioning of 131I and the size distribution of 137Cs, is examined. The results show that the model can predict the wind fields and rainfall realistically. The ground deposition of the radionuclides can also potentially be captured well but it is very sensitive to the emission characterization. It is found that the total deposition is most influenced by the emission rate for both 131I and 137Cs; while it is less sensitive to the dry deposition parameterizations. Moreover, for 131I, the deposition is also sensitive to the microphysics schemes, the horizontal diffusion schemes, gas partitioning and wet deposition parameterizations; while for 137Cs, the deposition is very sensitive to the microphysics schemes and wet deposition parameterizations, and it is also sensitive to the horizontal diffusion schemes and the size distribution.

  4. Correlative analysis of the in situ changes of carrier decay and proton induced photoluminescence characteristics in chemical vapor deposition grown GaN

    Energy Technology Data Exchange (ETDEWEB)

    Gaubas, E., E-mail: eugenijus.gaubas@ff.vu.lt; Ceponis, T.; Jasiunas, A.; Meskauskaite, D.; Pavlov, J.; Tekorius, A.; Vaitkus, J. [Vilnius University, Institute of Applied Research, Vilnius LT-10222 (Lithuania); Kovalevskij, V.; Remeikis, V. [Centre for Physical Sciences and Technology, Vilnius LT-02300 (Lithuania)

    2014-02-10

    In order to evaluate carrier densities created by 1.6 MeV protons and to trace radiation damage of the 2.5 μm thick GaN epi-layers grown by metalorganic chemical vapor deposition technique, a correlation between the photoconductivity transients and the steady-state photoluminescence spectra have been examined. Comparison of luminescence spectra induced by proton beam and by laser pulse enabled us to evaluate the efficiency of a single proton generation being of 1 × 10{sup 7} cm{sup −3} per 1.6 MeV proton and 40 carrier pairs per micrometer of layer depth. This result indicates that GaN layers can be an efficient material for detection of particle flows. It has been demonstrated that GaN material can also be a rather efficient scintillating material within several wavelength ranges.

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

    Science.gov (United States)

    Watanabe, Hiroshi; Yamaguchi, Ichiro; Kida, Tetsuo; Hiraki, Hitoshi; Fujibuchi, Toshioh; Maehara, Yoshiaki; Tsukamoto, Atsuko; Koizumi, Mitsue; Kimura, Yumi; Horitsugi, Genki

    2013-03-01

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

  6. Radioactivity in the galactic plane

    Science.gov (United States)

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

    1976-01-01

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

  7. 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

  8. B decays

    CERN Document Server

    Stone, Sheldon

    1994-01-01

    This book reviews the study of b quarks and also looks at the implications of future studies. The most important observations thus far - including measurement of the ""B"" lifetime and observations of b -> u transitions - as well as the more mundane results of 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. Synthesizing the experimental and theoretical information, the authors d

  9. 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

  10. 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.

  11. 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.

  12. A simple decay-spectroscopy station at CRIS-ISOLDE

    Science.gov (United States)

    Lynch, K. M.; Cocolios, T. E.; Althubiti, N.; Farooq-Smith, G. J.; Gins, W.; Smith, A. J.

    2017-02-01

    A new decay-spectroscopy station (DSS2.0) has been designed by the CRIS collaboration for use at the radioactive ion beam facility, ISOLDE. With the design optimised for both charged-particle and γ-ray detection, the DDS2.0 allows high-efficiency decay spectroscopy to be performed. The DSS2.0 complements the existing decay-spectroscopy system at the CRIS experiment, and together provide the ability to perform laser-assisted nuclear decay spectroscopy on both ground state and long-lived isomeric species. This paper describes the new decay-spectroscopy station and presents the characterisation studies that have recently been performed.

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

    Energy Technology Data Exchange (ETDEWEB)

    1987-12-01

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

  14. Radioactive Wastes. Revised.

    Science.gov (United States)

    Fox, Charles H.

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. This booklet deals with the handling, processing and disposal of radioactive wastes. Among the topics discussed are: The Nature of Radioactive Wastes; Waste Management; and Research and Development. There are…

  15. Induced radioactivity at CERN

    CERN Multimedia

    1970-01-01

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

  16. A Remote Radioactivity Experiment

    Science.gov (United States)

    Jona, Kemi; Vondracek, Mark

    2013-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  18. Skeletal sup 210 Pb from inhalation of sup 222 Rn and its decay products

    Energy Technology Data Exchange (ETDEWEB)

    Keane, A.T.; Schlenker, R.A.; Stebbings, J.H.

    1990-01-01

    Concern about health effects of radon and its decay products has recently broadened to include the potential role of radon in the causation of myeloid leukemia, multiple myeloma, and melanoma, kidney cancer, and certain childhood cancers. Description of the distribution of radon and its daughters in the skeleton and the marrow, and the dose delivered to red marrow, are of particular relevance. Our interest in a metabolic model for inhaled radon and radon decay products originated with an interest in the use of radioactivity measurement techniques in vivo to quantify the {sup 210}Pb activity of bone. In this paper we estimate the rates of transfer to body fluids of {sup 210}Pb originating from inhaled radon and radon decay products and the quantity of {sup 210}Pb deposited in compact and in cancellous bone for the ideal case of continuous exposure to a constant level of radon and its daughters. We review the contributions of ambient airborne {sup 210}Pb, diet, and active and passive smoking to skeletal levels of {sup 210}Pb, and finally, from the magnitude and the variability of the natural {sup 210}Pb content of the skeleton, we estimate the minimal rate of exposure to airborne radon and its decay products that is required to elevate the skeletal {sup 210}Pb content of an individual to a statistically significant level above the population mean skeletal {sup 210}Pb content derived from all the other environmental sources combined. 55 refs., 4 tabs.

  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. Radioactive waste today - an asset tomorrow

    Energy Technology Data Exchange (ETDEWEB)

    Holmstrand, M. [Norwegian Radiation Protection Authority (Norway)

    2014-07-01

    Mining of Rare Earth Elements (REE) causes radioactive pollution, as ores which contain REE also contain an elevated concentration of naturally occurring radioactive materials (NORM). Wastes from REE mining are therefore regarded as being inherently radioactive. One of the potential economically viable REE resources in Norway is in the Fensfield area in Telemark County, which is recognized as one of the world's largest thorium resources. If REE was mined in this area, a large volume of radioactive waste would be created. The authorities would then need to know how to regulate the waste so that the environmental impact would be as low as reasonably achievable when societal and economic factors having been accounted for (ALARA). Radioactive pollution from REE tailings could be a threat to the environment, biota and humans. However, naturally occurring thorium is practically not mobile nor bioavailable and has a relatively low specific activity and might therefore safely be deposited in a landfill. An environmental risk assessment should be used to evaluate if it is justifiable to deposit the radioactive tailings in a landfill or if alternative ways of handling, such as extraction of thorium in addition to extraction of REE from the ore, might be better. The risk assessment must start with a source term, the native carbonatite rocks, and an investigation on how the chemical properties of the rock changes when it's milled and treated with chemicals. Changes in the physical and chemical properties and changes in the environment where the processed rock are deposited might mobilize and/or make thorium bioavailable, thus increasing the environmental risk. Removal of thorium from the raw materials or tailings from the REE mining industry prior to deposition could be seen as one form of environmental protection with many benefits, for instance reducing the potential of external and internal radiation in biota and humans. We could also speculate about the

  1. [Migration of industrial radionuclides in soils and benthal deposits at the coastal margins of the temporary waste storage facility (TWSF) of the Northwest Center for Radioactive Waste Management (SevRAO) and its influence on the possible contamination of the sea offshore waters].

    Science.gov (United States)

    Filonova, A A; Seregin, V A

    2014-01-01

    For obtaining the integral information about the current radiation situation in the sea offshore waters of the temporary waste storage facility (TWSF) of the Northwest Center for Radioactive Waste Management "SevRAO" in the Andreeva Bay and in the settle Gremikha with a purpose of a comprehensive assessment of its condition there was performed radiation-ecological monitoring of the adjacent sea offshore waters of the TWSF. It was shown that in the territory of industrial sites of the TWSF as a result of industrial activity there are localized areas of pollution by man-made radionuclides. As a result of leaching of radionuclides by tidal stream, snowmelt and rainwater radioactive contamination extends beyond the territory of the sanitary protection zone and to the coastal sea offshore waters. To confirm the coastal pollution of the sea offshore waters the levels of mobility of 90Sr and 137Cs in environmental chains and bond strength of them with the soil and benthal deposits were clarified by determining with the method of detection of the forms of the presence of radionuclides in these media. There was established a high mobility of 137Cs and 90Sr in soils and benthal deposits (desorption coefficient (Kd) of 137Cs and 90Sr (in soils - 0.56 and 0.98), in the sediments - 0.82). The migration of radionuclides in environmental chains can lead to the contamination of the environment, including the sea offshore waters.

  2. Radioactivity; La radioactivite

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

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

  3. Endangered and Extinct Radioactivity

    Science.gov (United States)

    Leising, M. D.

    1993-07-01

    Gamma ray spectroscopy holds great promise for probing nucleosynthesis in individual nucleosynthesis events, via observations of short-lived radioactivity, and for measuring global galactic nucleosynthesis today with detections of longer-lived radioactivity. Many of the astrophysical issues addressed by these observations are precisely those that must be understood in order to interpret observations of extinct radioactivity in meteorites. It was somewhat surprising that the former case was realized first for a Type II supernova, when both 56Co [1] and 57Co [2] were detected in SN 1987A. These provide unprecedented constraints on models of Type II explosions. Live 26Al in the galaxy might come from Type II supernovae and their progenitors, and if this is eventually shown to be the case, can constrain massive star evolution, supernova nucleosynthesis, the galactic Type II supernova rate, and even models of the chemical evolution of the galaxy [3]. Titanium-44 is produced primarily in the alpha-rich freezeout from nuclear statistical equilibrium, possibly in Type Ia [4] and almost certainly in Type II supernovae [5]. The galactic recurrence time of these events is comparable to the 44Ti lifetime, so we expect to be able to see at most a few otherwise unseen 44Ti remnants at any given time. No such remnants have been detected yet [6]. Very simple arguments lead to the expectation that about 4 x 10^-4 M(sub)solar mass of 44Ca are produced per century. The product of the supernova frequency times the 44Ti yield per event must equal this number. Even assuming that only the latest event would be seen, rates in excess of 2 century^-1 are ruled out at >=99% confidence by the gamma ray limits. Only rates less than 0.3 century^-1 are acceptable at >5% confidence, and this means that the yield per event must be >10^-3 M(sub)solar mass to produce the requisite 44Ca. Rates this low are incompatible with current estimates for Type II supernovae and yields this high are also very

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

    NARCIS (Netherlands)

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

    2003-01-01

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

  5. Understanding radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Murray, R.L.

    1981-12-01

    This document contains information on all aspects of radioactive wastes. Facts are presented about radioactive wastes simply, clearly and in an unbiased manner which makes the information readily accessible to the interested public. The contents are as follows: questions and concerns about wastes; atoms and chemistry; radioactivity; kinds of radiation; biological effects of radiation; radiation standards and protection; fission and fission products; the Manhattan Project; defense and development; uses of isotopes and radiation; classification of wastes; spent fuels from nuclear reactors; storage of spent fuel; reprocessing, recycling, and resources; uranium mill tailings; low-level wastes; transportation; methods of handling high-level nuclear wastes; project salt vault; multiple barrier approach; research on waste isolation; legal requiremnts; the national waste management program; societal aspects of radioactive wastes; perspectives; glossary; appendix A (scientific American articles); appendix B (reference material on wastes). (ATT)

  6. Nuclear astrophysics with radioactive ions at FAIR

    Science.gov (United States)

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

    2016-01-01

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

  7. Nuclear astrophysics with radioactive ions at FAIR

    CERN Document Server

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

    2016-01-01

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

  8. Temporary Personal Radioactivity

    Science.gov (United States)

    Myers, Fred

    2012-01-01

    As part of a bone scan procedure to look for the spread of prostate cancer, I was injected with radioactive technetium. In an effort to occupy/distract my mind, I used a Geiger counter to determine if the radioactive count obeyed the inverse-square law as a sensor was moved away from my bladder by incremental distances. (Contains 1 table and 2…

  9. Radioactive waste management in Brazil: a realistic view

    Energy Technology Data Exchange (ETDEWEB)

    Heilbron Filho, Paulo Fernando Lavalle; Perez Guerrero, Jesus Salvador, E-mail: paulo@cnen.gov.br, E-mail: jperez@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Xavier, Ana Maria, E-mail: axavier@cnen.gov.br [Comissao Nacional de Energia Nuclear (ESPOA/CNEN-RS), Porto Alegre, RS (Brazil)

    2014-07-01

    The objective of this article is to present a realistic view of the main issues related to the management of radioactive waste in Brazil as well as a comprehensive picture of the regulatory waste management status in the country and internationally. Technical aspects that must be considered to ensure a safe construction of near surface disposal facilities for radioactive waste of low and medium levels of radiation are addressed. Different types of deposits, the basic regulatory issues involving the licensing of these facilities, the development of a financial compensation model for the Brazilian Municipalities where deposits are to be placed, the importance of the participation of the scientific community and society in the process of radioactive waste site selection and disposal, guidance for the application of the basic requirements of safety and radiation protection, the general safety aspects involved and the current actions for the disposal of radioactive waste in Brazil are highlighted. (author)

  10. In-Trap Spectroscopy of Charge-Bred Radioactive Ions

    Science.gov (United States)

    Lennarz, A.; Grossheim, A.; Leach, K. G.; Alanssari, M.; Brunner, T.; Chaudhuri, A.; Chowdhury, U.; Crespo López-Urrutia, J. R.; Gallant, A. T.; Holl, M.; Kwiatkowski, A. A.; Lassen, J.; Macdonald, T. D.; Schultz, B. E.; Seeraji, S.; Simon, M. C.; Andreoiu, C.; Dilling, J.; Frekers, D.

    2014-08-01

    In this Letter, we introduce the concept of in-trap nuclear decay spectroscopy of highly charged radioactive ions and describe its successful application as a novel spectroscopic tool. This is demonstrated by a measurement of the decay properties of radioactive mass A=124 ions (here, In124 and Cs124) in the electron-beam ion trap of the TITAN facility at TRIUMF. By subjecting the trapped ions to an intense electron beam, the ions are charge bred to high charge states (i.e., equivalent to the removal of N-shell electrons), and an increase of storage times to the level of minutes without significant ion losses is achieved. The present technique opens the venue for precision spectroscopy of low branching ratios and is being developed in the context of measuring electron-capture branching ratios needed for determining the nuclear ground-state properties of the intermediate odd-odd nuclei in double-beta (ββ) decay.

  11. Determining radioactive aerosol concentrations using a surface radioactive contamination measurement device.

    Science.gov (United States)

    Cerny, R; Johnova, K; Kozlovska, M; Otahal, P; Vosahlikova, I

    2015-06-01

    For experiments with dispersed radioactive aerosols in a radon-aerosol chamber (RAC), it is desirable to know the activity of the radioactive aerosols applied in the RAC. A COLIBRI TTC survey metre with an SABG-15+ probe (Canberra, USA) was purchased for this purpose. The probe is designed for surface contamination measurements, and it is intended to measure the activity of aerosols deposited on the filters during experiments in the RAC. Since the probe is calibrated in a different geometry, its response in the authors' experimental geometry was simulated by a Monte Carlo method. The authors present a Monte Carlo model using MCNPX and an experimental verification of this probe model.

  12. Radioactive waste disposal via electric propulsion

    Science.gov (United States)

    Burns, R. E.

    1975-01-01

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

  13. Relativistic mean field description of cluster radioactivity

    Science.gov (United States)

    Bhagwat, A.; Gambhir, Y. K.

    2005-01-01

    Comprehensive investigations of the observed cluster radioactivity are carried out. First, the relativistic mean field (RMF) theory is employed for the calculations of the ground-state properties of relevant nuclei. The calculations reproduce the experiment well. The calculated RMF point densities are folded with the density-dependent M3Y nucleon-nucleon interaction to obtain the cluster-daughter interaction potential. This, along with the calculated and experimental Q values, is used in the WKB approximation for estimating the half-lives of the parent nuclei against cluster decay. The calculations qualitatively agree with the experiment. Sensitive dependence of the half-lives on Q values is explicitly demonstrated.

  14. Germanium detectors and natural radioactivity in food

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  15. Accelerated radioactive beams from REX-ISOLDE

    Energy Technology Data Exchange (ETDEWEB)

    Kester, O. E-mail: oliver.kester@physik.uni-muenchen.de; Sieber, T.; Emhofer, S.; Ames, F.; Reisinger, K.; Reiter, P.; Thirolf, P.G.; Lutter, R.; Habs, D.; Wolf, B.H.; Huber, G.; Schmidt, P.; Ostrowski, A.N.; Hahn, R. von; Repnow, R.; Fitting, J.; Lauer, M.; Scheit, H.; Schwalm, D.; Podlech, H.; Schempp, A.; Ratzinger, U.; Forstner, O.; Wenander, F.; Cederkaell, J.; Nilsson, T.; Lindroos, M.; Fynbo, H.; Franchoo, S.; Bergmann, U.; Oinonen, M.; Aeystoe, J.; Den Bergh, P. Van; Duppen, P. Van; Huyse, M.; Warr, N.; Weisshaar, D.; Eberth, J.; Jonson, B.; Nyman, G.; Pantea, M.; Simon, H.; Shrieder, G.; Richter, A.; Tengblad, O.; Davinson, T.; Woods, P.J.; Bollen, G.; Weissmann, L.; Liljeby, L.; Rensfelt, K.G

    2003-05-01

    In 2001 the linear accelerator of the Radioactive beam EXperiment (REX-ISOLDE) delivered for the first time accelerated radioactive ion beams, at a beam energy of 2 MeV/u. REX-ISOLDE uses the method of charge-state breeding, in order to enhance the charge state of the ions before injection into the LINAC. Radioactive singly-charged ions from the on-line mass separator ISOLDE are first accumulated in a Penning trap, then charge bred to an A/q<4.5 in an electron beam ion source (EBIS) and finally accelerated in a LINAC from 5 keV/u to energies between 0.8 and 2.2 MeV/u. Dedicated measurements with REXTRAP, the transfer line and the EBIS have been carried out in conjunction with the first commissioning of the accelerator. Thus the properties of the different elements could be determined for further optimization of the system. In two test beam times in 2001 stable and radioactive Na isotopes ({sup 23}Na-{sup 26}Na) have been accelerated and transmitted to a preliminary target station. There {sup 58}Ni- and {sup 9}Be- and {sup 2}H-targets have been used to study exited states via Coulomb excitation and neutron transfer reactions. One MINIBALL triple cluster detector was used together with a double sided silicon strip detector to detect scattered particles in coincidence with {gamma}-rays. The aim was to study the operation of the detector under realistic conditions with {gamma}-background from the {beta}-decay of the radioactive ions and from the cavities. Recently for efficient detection eight tripple Ge-detectors of MINIBALL and a double sided silicon strip detector have been installed. We will present the first results obtained in the commissioning experiments and will give an overview of realistic beam parameters for future experiments to be started in the spring 2002.

  16. 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.

  17. Study of tracking detector of NEMO3 experiment - simulation of the measurement of the ultra low {sup 208}Tl radioactivity in the source foils used as neutrinoless double beta decay emitters in NEMO3 experiment; Etude du detecteur de traces de l'experience NEMO3. Simulation de la mesure de l'ultra-faible radioactivite en {sup 208}Tl des sources de l'experience NEMO3 candidates a la double desintegration {beta} sans emission de neutrino

    Energy Technology Data Exchange (ETDEWEB)

    Errahmane, K

    2001-04-01

    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 {sup 100}Mo. 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 {sup 207}Bi, 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 {sup 208}Tl of the source foil, which comes from the natural radioactive chain of thorium. Using electron-photons channels, we can obtain the {sup 208}Tl 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 20{mu}Bq/kg after only 2 months of measurement. This sensitivity is the maximum {sup 208}Tl activity, which we accepted for the sources in the NEMO3 proposal. (author)

  18. Rapid screening of radioactivity in food for emergency response.

    Science.gov (United States)

    Bari, A; Khan, A J; Semkow, T M; Syed, U-F; Roselan, A; Haines, D K; Roth, G; West, L; Arndt, M

    2011-06-01

    This paper describes the development of methods for the rapid screening of gross alpha (GA) and gross beta (GB) radioactivity in liquid foods, specifically, Tang drink mix, apple juice, and milk, as well as screening of GA, GB, and gamma radioactivity from surface deposition on apples. Detailed procedures were developed for spiking of matrices with (241)Am (alpha radioactivity), (90)Sr/(90)Y (beta radioactivity), and (60)Co, (137)Cs, and (241)Am (gamma radioactivity). Matrix stability studies were performed for 43 days after spiking. The method for liquid foods is based upon rapid digestion, evaporation, and flaming, followed by gas proportional (GP) counting. For the apple matrix, surface radioactivity was acid-leached, followed by GP counting and/or gamma spectrometry. The average leaching recoveries from four different apple brands were between 63% and 96%, and have been interpreted on the basis of ion transport through the apple cuticle. The minimum detectable concentrations (MDCs) were calculated from either the background or method-blank (MB) measurements. They were found to satisfy the required U.S. FDA's Derived Intervention Levels (DILs) in all but one case. The newly developed methods can perform radioactivity screening in foods within a few hours and have the potential to capacity with further automation. They are especially applicable to emergency response following accidental or intentional contamination of food with radioactivity.

  19. Radioactivity of Consumer Products

    Science.gov (United States)

    Peterson, David; Jokisch, Derek; Fulmer, Philip

    2006-11-01

    A variety of consumer products and household items contain varying amounts of radioactivity. Examples of these items include: FiestaWare and similar glazed china, salt substitute, bananas, brazil nuts, lantern mantles, smoke detectors and depression glass. Many of these items contain natural sources of radioactivity such as Uranium, Thorium, Radium and Potassium. A few contain man-made sources like Americium. This presentation will detail the sources and relative radioactivity of these items (including demonstrations). Further, measurements of the isotopic ratios of Uranium-235 and Uranium-238 in several pieces of china will be compared to historical uses of natural and depleted Uranium. Finally, the presenters will discuss radiation safety as it pertains to the use of these items.

  20. Assessment of temporal trend of radiation dose to the public living in the large area contaminated with radioactive materials after a nuclear power plant accident

    Energy Technology Data Exchange (ETDEWEB)

    Go, A Ra; Kim, Min Jun; Kim, Kwang Pyo [Dept. of Nuclear Engineering, Kyung Hee University, Seoul (Korea, Republic of); Cho, Nam Chan; Seol, Jeung Gun [Radiation Safety Team, Korea Electric Power Corporation Nuclear Fuel, Seoul (Korea, Republic of)

    2015-12-15

    It has been about 5 years since the Fukushima nuclear power plant accident, which contaminated large area with radioactive materials. It is necessary to assess radiation dose to establish evacuation areas and to set decontamination goal for the large contaminated area. In this study, we assessed temporal trend of radiation dose to the public living in the large area contaminated with radioactive materials after the Fukushima nuclear power plant accident. The dose assessment was performed based on Chernobyl model and RESRAD model for two evacuation lift areas, Kawauchi and Naraha. It was reported that deposition densities in the areas were 4.3-96 kBq m{sup -2} for {sup 134}Cs, 1.4-300 kBq m{sup -2} for {sup 137}Cs, respectively. Radiation dose to the residents depended on radioactive cesium concentrations in the soil, ranging 0.11-2.4 mSv y{sup -1} at Kawauchi area and 0.69-1.1 mSv y{sup -1} at Naraha area in July 2014. The difference was less than 5% in radiation doses estimated by two different models. Radiation dose decreased with calendar time and the decreasing slope varied depending on dose assessment models. Based on the Chernobyl dosimetry model, radiation doses decreased with calendar time to about 65% level of the radiation dose in 2014 after 1 year, 11% level after 10 years, and 5.6% level after 30 years. RESRAD dosimetry model more slowly decreased radiation dose with time to about 85% level after 1 year, 40% level after 10 years, and 15% level after 30 years. The decrease of radiation dose can be mainly attributed into radioactive decays and environmental transport of the radioactive cesium. Only environmental transports of radioactive cesium without consideration of radioactive decays decreased radiation dose additionally 43% after 1 year, 72% after 3 years, 80% after 10 years, and 83% after 30 years. Radiation doses estimated with cesium concentration in the soil based on Chernobyl dosimetry model were compared with directly measured radiation doses

  1. Radioactive Ions for Surface Characterization

    CERN Multimedia

    2002-01-01

    The collaboration has completed a set of pilot experiments with the aim to develop techniques for using radioactive nuclei in surface physics. The first result was a method for thermal deposition of isolated atoms (Cd, In, Rb) on clean metallic surfaces. \\\\ \\\\ Then the diffusion history of deposited Cd and In atoms on two model surfaces, Mo(110) and Pd(111), was followed through the electric field gradients (efg) acting at the probe nuclei as measured with the Perturbed Angular Correlation technique. For Mo(110) a rather simple history of the adatoms was inferred from the experiments: Atoms initially landing at terrace sites diffuse from there to ledges and then to kinks, defects always present at real surfaces. The next stage is desorption from the surface. For Pd a scenario that goes still further was found. Following the kink stage the adatoms get incorporated into ledges and finally into the top surface layer. For all these five sites the efg's could be measured.\\\\ \\\\ In preparation for a further series o...

  2. Unconformity-related uranium deposits, Athabasca area, Saskatchewan, and East Alligator Rivers area, Northern Territory, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Clark, L.A.; Burrill, G.H.R. (Saskatchewan Mining Development Corp., Saskatoon (Canada))

    1981-07-01

    Most unconformity-type uranium deposits in Saskatchewan occur within a few tens of metres above and/or below the basal unconformity of the 1.45 b.y. Athabasca Sandstone. Graphitic basement rocks coincident with post-Athabasca faulting or brecciation at or near the unconformity are important in localizing uranium deposits which form as tabular, ribbon-like bodies with grades averaging over 2 percent uranium and containing up to 50,000 tonnes U/sub 3/O/sub 8/. Some of these deposits have similar contents of nickel and arsenic. In the genetic model used to explain these deposits, traces of uranium were leached from the sandstone and basement rocks by oxidized formation waters. A thick clay regolith absorbed uranium from the solution, and the fixed uranium was reduced through an indirect reaction with graphite. The clay mineral surfaces were thus continuously cleared to allow further adsorption. Fluid convection was induced by topographic relief and/or crustal heating from radioactive decay, and would continue uranium deposition until all permeability was plugged by minerals. The East Alligator Rivers uranium deposits in Northern Territory, Australia occur within Middle Proterozoic quartz-chlorite and quartz-muscovite schists overlain by sandstone. Highest grades occur in silicified breccias where carbonate beds were leached out. Mineralization ages are both pre- and post-Kombolgie Sandstone, but, to date, no significant uranium mineralization has been found in the sandstone. There are many similarities with Saskatchewan deposits, but also important differences.

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

    CERN Document Server

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-01

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

  5. RESRAD. Site-Specific Residual Radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Yu, C. [Argonne National Laboratory, IL (United States)

    1989-06-01

    RESRAD is designed to derive site-specific guidelines for allowable residual concentrations of radionuclides in soil. A guideline is defined as a radionuclide concentration or a level of radiation or radioactivity that is acceptable if a site is to be used without radiological restrictions. Guidelines are expressed as (1) concentrations of residual radionuclides in soil, (2) concentrations of airborne radon decay products, (3) levels of external gamma radiation, (4) levels of radioactivity from surface contamination, and (5) concentrations of residual radionuclides in air and water. Soil is defined as unconsolidated earth material, including rubble and debris that may be present. The controlling principles of all guidelines are (1) the annual radiation dose received by a member of the critical population group from the residual radioactive material - predicted by a realistic but reasonably conservative analysis and averaged over a 50 year period - should not exceed 100 mrem/yr, and (2) doses should be kept as low as reasonably achievable. All significant exposure pathways for the critical population group are considered in deriving soil guidelines. These pathways include direct exposure to external radiation from the contaminated soil material; internal radiation from inhalation of airborne radionuclides; and internal radiation from ingestion of plant foods grown in the contaminated soil, meat and milk from livestock fed with contaminated fodder and water, drinking water from a contaminated well, and fish from a contaminated pond.

  6. Disposal of radioactive waste

    Science.gov (United States)

    Van Dorp, Frits; Grogan, Helen; McCombie, Charles

    The aim of radioactive and non-radioactive waste management is to protect man and the environment from unacceptable risks. Protection criteria for both should therefore be based on similar considerations. From overall protection criteria, performance criteria for subsystems in waste management can be derived, for example for waste disposal. International developments in this field are summarized. A brief overview of radioactive waste sorts and disposal concepts is given. Currently being implemented are trench disposal and engineered near-surface facilities for low-level wastes. For low-and intermediate-level waste underground facilities are under construction. For high-level waste site selection and investigation is being carried out in several countries. In all countries with nuclear programmes, the predicted performance of waste disposal systems is being assessed in scenario and consequence analyses. The influences of variability and uncertainty of parameter values are increasingly being treated by probabilistic methods. Results of selected performance assessments show that radioactive waste disposal sites can be found and suitable repositories can be designed so that defined radioprotection limits are not exceeded.

  7. Radioactivity: A Natural Phenomenon.

    Science.gov (United States)

    Ronneau, C.

    1990-01-01

    Discussed is misinformation people have on the subject of radiation. The importance of comparing artificial source levels of radiation to natural levels is emphasized. Measurements of radioactivity, its consequences, and comparisons between the risks induced by radiation in the environment and from artificial sources are included. (KR)

  8. Viewer Makes Radioactivity "Visible"

    Science.gov (United States)

    Yin, L. I.

    1983-01-01

    Battery operated viewer demonstrates feasibility of generating threedimensional visible light simulations of objects that emit X-ray or gamma rays. Ray paths are traced for two pinhold positions to show location of reconstructed image. Images formed by pinholes are converted to intensified visible-light images. Applications range from radioactivity contamination surveys to monitoring radioisotope absorption in tumors.

  9. AIR RADIOACTIVITY MONITOR

    Science.gov (United States)

    Bradshaw, R.L.; Thomas, J.W.

    1961-04-11

    The monitor is designed to minimize undesirable background buildup. It consists of an elongated column containing peripheral electrodes in a central portion of the column, and conduits directing an axial flow of radioactively contaminated air through the center of the column and pure air through the annular portion of the column about the electrodes. (AEC)

  10. SHIPPING OF RADIOACTIVE ITEMS

    CERN Multimedia

    TIS/RP Group

    2001-01-01

    The TIS-RP group informs users that shipping of small radioactive items is normally guaranteed within 24 hours from the time the material is handed in at the TIS-RP service. This time is imposed by the necessary procedures (identification of the radionuclides, determination of dose rate and massive objects require a longer procedure and will therefore take longer.

  11. Radioactive Sources Service

    CERN Multimedia

    2007-01-01

    Please note that the radioactive sources service will be open by appointment only every Monday, Wednesday and Friday during CERN working hours (instead of alternate weeks). In addition, please note that our 2007 schedule is available on our web site: http://cern.ch/service-rp-sources

  12. Radioactive Sources Service

    CERN Multimedia

    2007-01-01

    Please note that the radioactive sources service will be open by appointment only every Monday, Wednesday and Friday during CERN working hours (instead of alternate weeks). In addition, please note that our 2007 schedule is available on our web site. http://cern.ch/service-rp-sources

  13. Dental Caries (Tooth Decay)

    Science.gov (United States)

    ... Find Data by Topic > Dental Caries (Tooth Decay) Dental Caries (Tooth Decay) Main Content Dental caries (tooth decay) remains the most prevalent chronic ... important source of information on oral health and dental care in the United States since the early ...

  14. 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.

  15. Acceptance criteria for deposition of low-level and intermediate-level radiation levels radioactive wastes; Criterios de aceitacao para deposicao de rejeitos radioativos de baixo e medio niveis de radiacao

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-09-15

    This norm establishes the criteria for acceptance low and intermediate radiation level for safe deposition in repositories, for assuring the protection of workers, population and environment against the hazardous effects of the ionizing radiations. The criteria of this norm applies to the low and intermediate radiation levels.

  16. Highly efficient method for production of radioactive silver seed cores for brachytherapy.

    Science.gov (United States)

    Cardoso, Roberta Mansini; de Souza, Carla Daruich; Rostelato, Maria Elisa Chuery Martins; Araki, Koiti

    2017-02-01

    A simple and highly efficient (shorter reaction time and almost no rework) method for production of iodine based radioactive silver seed cores for brachytherapy is described. The method allows almost quantitative deposition of iodine-131 on dozens of silver substrates at once, with even distribution of activity per core and insignificant amounts of liquid and solid radioactive wastes, allowing the fabrication of cheaper radioactive iodine seeds for brachytherapy.

  17. Atomic nuclei decay modes by spontaneous emission of heavy ions

    OpenAIRE

    Poenaru, Dorin N.; Ivaşcu, Marin; Săndulescu, Aurel; Greiner, Walter

    2006-01-01

    The great majority of the known nuclides with Z>40, including the so-called stable nuclides, are metastable with respect to several modes of spontaneous superasymmetric splitting. A model extended from the fission theory of alpha decay allows one to estimate the lifetimes and the branching ratios relative to the alpha decay for these natural radioactivities. From a huge amount of systematic calculations it is concluded that the process should proceed with maximum intensity in the trans-lead n...

  18. Health and environmental concerns on the radioactivity of phosphogypsum storage in Israel

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey-Smith, D. [Defence R and D Canada, 101 Colonel By Drive (Canada); Nassar, H.; Steiner, V. [Ministry of Environmental Protection (Israel); Moinester, M.; Malki, A. [School of Physics and Astronomy (Israel); Kronfeld, J. [Dept Geophysics and Planetary Sci. (Israel)

    2014-07-01

    Phosphate fertilizer is produced in Israel using the Negev phosphorites as the raw material. These phosphates are part of a broad band of phosphorites that were deposited extending from Turkey across North Africa during the Upper Cretaceous These phosphorites contain uranium and are moderately radioactive. The uranium concentration varies in direct proportion to the P{sub 2}O{sub 5} content. In Israel it averages approximately 140 ppm U. Sufficient time has passed since the deposits were laid down for secular equilibrium to have been achieved in the uranium decay-series. Thus, these deposits now include the radioactive daughters Th-230, Ra-226, Rn-222, Pb-210, and Po-210. Besides being radioactive, these are biologically deleterious elements. During fertilizer production using sulfuric acid, phosphoric acid (liquid) and an acidic phosphogypsum (PG) sludge are produced. The Pb-210 and Po-210 and most of the Ra-226 congregate in the PG. Though the activity of the sludge varies, it is generally well above the 370 Bq/kg permissible limit for Ra-226 as set by the USEPA for agricultural application, thereby obviating its use in soil amelioration or as gypsum in the making of drywall for building material. Thus, this PG becomes a large volume waste product that cannot be dumped into the sea. In Israel, large PG stacks are stored at Rotem in the Negev and near the Kishon River at Haifa Bay. The large (millions of tons) PG stacks can build up significant radiation emissions as well as serving as a large source of various radio-nuclides. Of particular concern would be the potentially mobile radium and radon. However, detailed investigation shows that the Israeli PG stacks are situated at a distance far enough away from the population around the Haifa Bay region so as not to present an environmental problem today, either through the release of gamma-radiation, radon emanation, or the release of contaminated gypsum dust. No elevated radiation was found in the channel or along

  19. 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...

  20. Radioactive particles in the 234-5 Building ventilation exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Postma, A.K.; Schwendiman, L.C.

    1959-07-13

    The 234-5 Building ventilation exhaust is continuously sampled for the purpose of estimating the amount of radioactive (alpha emitting) material discharged to the atmosphere. Although a record is kept of the gross amount of radioactive material discharged, few data are available concerning the size and kind of active particles in the exhaust air. Knowledge of the particle size permits: (1) an estimate of the validity of samples drawn through the sampling system, (2) a better knowledge of what the active particle ground deposition pattern might be, and (3) may provide information relating to filter performance. The kind of radioactive material discharged is important in determining relative health hazards. The object of this work was to determine the size and kind of radioactive particles in the 234-5 Building ventilation exhaust. A secondary objective was to review present routine sampling of the stream with particular regard to the particulates to be sampled.

  1. GEMS: Underwater spectrometer for long-term radioactivity measurements

    OpenAIRE

    2010-01-01

    GEMS (Gamma Energy Marine Spectrometer) is a prototype of an autonomous radioactivity sensor for underwater measurements, developed in the framework of the KM3NeT Design Study (DS) EC project. The spectrometer is sensitive to gamma rays produced by 40K decays and it is also able to detect other natural (e.g., 238U, 232Th) and anthropogenic radionuclides (e.g. 137Cs). The decay of 40K, contained in sea salt, particulate and sediments, is one of the main sources of photon background...

  2. Radioactive waste management; Gerencia de rejeitos radioativos

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-11-15

    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.

  3. Handbook of radioactivity analysis

    CERN Document Server

    2012-01-01

    The updated and much expanded Third Edition of the "Handbook of Radioactivity Analysis" is an authoritative reference providing the principles, practical techniques, and procedures for the accurate measurement of radioactivity from the very low levels encountered in the environment to higher levels measured in radioisotope research, clinical laboratories, biological sciences, radionuclide standardization, nuclear medicine, nuclear power, fuel cycle facilities and in the implementation of nuclear forensic analysis and nuclear safeguards. The Third Edition contains seven new chapters providing a reference text much broader in scope than the previous Second Edition, and all of the other chapters have been updated and expanded many with new authors. The book describes the basic principles of radiation detection and measurement, the preparation of samples from a wide variety of matrices, assists the investigator or technician in the selection and use of appropriate radiation detectors, and presents state-of-the-ar...

  4. SHIPPING OF RADIOACTIVE ITEMS

    CERN Multimedia

    TIS/RP Group

    2001-01-01

    The TIS-RP group informs users that shipping of small radioactive items is normally guaranteed within 24 hours from the time the material is handed in at the TIS-RP service. This time is imposed by the necessary procedures (identification of the radionuclides, determination of dose rate, preparation of the package and related paperwork). Large and massive objects require a longer procedure and will therefore take longer.

  5. White sea radioactivity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Aliev, R.A. [Lomonosov Moscow State Univ. (Russian Federation). Skobeltsyn Inst. of Nuclear Physics]|[Lomonosov Moscow State Univ. (Russian Federation). Chemistry Dept.]|[Russian Academy of Sciences, Moscow (Russian Federation). Shirshov Inst. of Oceanology; Kalmykov, S.N.; Lisitzin, A.P. [Lomonosov Moscow State Univ. (Russian Federation). Chemistry Dept.

    2004-07-01

    The aim of the present work is to estimate potential sources and chronology of pollution of the White Sea (Russia) by artificial radionuclides. White Sea is semi-closed water body connected with Barents Sea by a narrow strait. Thus, pollution of White Sea may be caused by highly polluted Barents waters and river (mainly Northern Dvina) run-off. This is the first detailed investigation of radioactivity of White Sea sediment records. (orig.)

  6. Radioactive waste storage issues

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, Daniel E. [Colorado Christian Univ., Lakewood, CO (United States)

    1994-08-15

    In the United States we generate greater than 500 million tons of toxic waste per year which pose a threat to human health and the environment. Some of the most toxic of these wastes are those that are radioactively contaminated. This thesis explores the need for permanent disposal facilities to isolate radioactive waste materials that are being stored temporarily, and therefore potentially unsafely, at generating facilities. Because of current controversies involving the interstate transfer of toxic waste, more states are restricting the flow of wastes into - their borders with the resultant outcome of requiring the management (storage and disposal) of wastes generated solely within a state`s boundary to remain there. The purpose of this project is to study nuclear waste storage issues and public perceptions of this important matter. Temporary storage at generating facilities is a cause for safety concerns and underscores, the need for the opening of permanent disposal sites. Political controversies and public concern are forcing states to look within their own borders to find solutions to this difficult problem. Permanent disposal or retrievable storage for radioactive waste may become a necessity in the near future in Colorado. Suitable areas that could support - a nuclear storage/disposal site need to be explored to make certain the health, safety and environment of our citizens now, and that of future generations, will be protected.

  7. LRT 2006: 2. topical workshop in low radioactivity techniques

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, P.; Piquemal, F.; Ford, R.; Yakushev, E.; Pandola, L.; Franco, D.; Bellini, F.; Hubert, Ph.; Laubenstein, M.; Abt, I.; Bongrand, M.; Schnee, R.; Dusan, B.; Chen, M.; Piquemal, F.; Nachab, A.; Zuzel, G.; Simgen, H.; Navick, X.F.; Pedretti, M.; Wojcik, M.; Sekiya, H.; Kim, Y.; Kishimoto, T.; Dawson, J.; Borjabad, S.; Perrot, F.; Gurriaran, R.; Nikolayko, A.; Hubert, Ph

    2006-07-01

    This second topical workshop in low radioactivity techniques is intended to bring together experts in the field of low background techniques, especially applied to dark matter experiments, double beta decay experiments and neutrino detection in underground laboratories. This workshop has been organized into 7 sessions: 1) underground facilities (where a worldwide review is made), 2) neutron and muon induced background, isotope production, 3) low background counting techniques and low background detectors, 4) techniques for radon reduction, purified noble gases and liquid scintillator purification, 5) low levels on Pb-Bi-Po{sup 210} and surface background, 6) low radioactivity detector components and material purification, and 7) low radioactive techniques in other applications (particularly to check the geographical origin of food-products or to date wine. This document is made up of the slides of the presentations.

  8. Characterization of defects in semiconductors using radioactive isotopes

    CERN Document Server

    Deicher, Manfred

    2007-01-01

    Radioactive atoms have been used in solid-state physics and in material science for many decades. Besides their classical application as tracer for diffusion studies, nuclear techniques such as Mossbauer spectroscopy, perturbed angular correlation, and emission channeling have used nuclear properties to gain microscopical information on the structural and dynamical properties of solids. The availability of many different radioactive isotopes as a clean ion beam at facilities like ISOLDE/CERN has triggered a new era involving methods sensitive for the optical and electronic properties of solids, especially in the field of semiconductor physics. Spectroscopic techniques like photoluminescence (PL), deep-level transient spectroscopy (DLTS), and Hall effect gain a new quality by using radioactive isotopes. Due to their decay the chemical origin of an observed electronic and optical behavior of a specific defect or dopant can be unambiguously identified. This contribution will highlight a few examples to illustrat...

  9. Transport and extraction of radioactive ions stopped in superfluid helium

    CERN Document Server

    Huang Wan Xia; Gloos, K; Takahashi, N; Arutyunov, K; Pekola, J P; Äystö, J

    2003-01-01

    A new approach to convert a high energy beam to a low energy one, which is essential for the next generation radioactive ion beam facilities, has been proposed and tested at Jyvaeskylae, Finland. An open sup 2 sup 2 sup 3 Ra alpha-decay-recoil source has been used to produce radioactive ions in superfluid helium. The alpha spectra demonstrate that the recoiling sup 2 sup 1 sup 9 Rn ions have been extracted out of liquid helium. This first observation of the extraction of heavy positive ions across the superfluid helium surface was possible thanks to the high sensitivity of radioactivity detection. An efficiency of 36% was obtained for the ion extraction out of liquid helium.

  10. assessment of radioactivity concentration in soil of some mining ...

    African Journals Online (AJOL)

    INTRODUCTION. Natural radioactive mineral deposits are found in suitable ... radiation protection and safety regulations are adhered to. Several ... (NORM) in the earth and in the mining by-products, and wastes derived from ... MATERIALS AND METHODS ... random escape and you stored for a minimum of 24 days. This.

  11. Radiometric survey of radioactive minerals in the Matias Romero dam, in Oaxaca; Exploracion radiometrica de minerales radiactivos en la presa Matias Romero, en Oaxaca

    Energy Technology Data Exchange (ETDEWEB)

    Flores, J.H.; Pena, P.; Balcazar, M.; Lopez, A.M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Juarez, S.F.; Cabrera, M.O. [IGEFUNAM, 04510 Mexico D.F. (Mexico); Huizar, R. [IGEUNAM, 04510 Mexico D.F. (Mexico)

    2006-07-01

    Migration of radioactive Uranium and Thorium minerals from the old mine El Muerto, to the dam Matias Romero in Oaxaca was detected in dam sediments. The identified elements were Th and U, from the decay series of the last one; {sup 234}Th, {sup 234}Pa and {sup 214}Bi from the radioactive series of {sup 238}U. The mineral was in the past extracted from high fractured zones. Total activity measurements in sediments from the dam increases as the particle size decrease, which indicates that main reason of the movement is produced by erosion of small particles from high altitude deposits to lower parts where the dam is located. Geo statistical analysis gives a general picture of mineral distribution. ICP-MS, Ge(hp) detector, and X-ray diffraction techniques were used for associated minerals and radioactive content evaluation. Oaxaca State presents a complex geology. Pre cambric metamorphic rocks (600 ma) are present at the southern part, covering 25% of the state surface; intrusive metamorphic and igneous rocks form the Paleozoic (375 m.a.) cover 6 % of the surface. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-08-15

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

  13. NEW GAMMA RAYS FROM DECAY OF 189W

    Institute of Scientific and Technical Information of China (English)

    杨维凡; 赵之正; 等

    1995-01-01

    Radioactivities of 189W are produced through an 192Os(n,α189W reaction.Gamma ray spectroscopy from chemically separated tungsten sources using HPGe detector has revealed the presence of 22 gamma rays assigned to the decay of 189W,of them,18 gamma rays are new ones unreported until now.

  14. Introduction to naturally occurring radioactive material

    Energy Technology Data Exchange (ETDEWEB)

    Egidi, P.

    1997-08-01

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

  15. Introduction to naturally occurring radioactive material

    Energy Technology Data Exchange (ETDEWEB)

    Egidi, P.

    1997-08-01

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

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

    CERN Document Server

    Qi, Chong

    2016-01-01

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

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

    Science.gov (United States)

    Al-Azmi, Darwish; Mustapha, Amidu O.; Karunakara, N.

    2012-07-01

    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, a ubiquitous inert gas, and the adsorptive property of activated charcoal. Radon gas from ambient air in the laboratory was adsorbed into about 70 g 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.

  18. Radioactive Materials Analytical Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Laing, W.R.; Corbin, L.T.

    1979-01-01

    The Radioactive Materials Analytical Laboratory was completed 15 years ago and has been used since as an analytical chemistry support lab for reactor, fuel development, and reprocessing programs. Additions have been made to the building on two occasions, and a third addition is planned for the future. Major maintenance items include replacement of ZnBr/sub 2/ windows, cleanup of lead glass windows, and servicing of the intercell conveyor. An upgrading program, now in progress, includes construction of new hot-cell instrumentation and the installation of new equipment such as an x-ray fluorescence analyzer and a spark source mass spectrometer.

  19. Radioactivity measurements principles and practice

    CERN Document Server

    Mann, W B; Spernol, A

    2012-01-01

    The authors have addressed the basic need for internationally consistent standards and methods demanded by the new and increasing use of radioactive materials, radiopharmaceuticals and labelled compounds. Particular emphasis is given to the basic and practical problems that may be encountered in measuring radioactivity. The text provides information and recommendations in the areas of radiation protection, focusing on quality control and the precautions necessary for the preparation and handling of radioactive substances. New information is also presented on the applications of both traditiona

  20. Radioactivities in Low- and Intermediate-Mass Stars

    CERN Document Server

    Lugaro, Maria

    2010-01-01

    Energy in stars is provided by nuclear reactions, which, in many cases, produce radioactive nuclei. When stable nuclei are irradiated by a flux of protons or neutrons, capture reactions push stable matter out of stability into the regime of unstable species. The ongoing production of radioactive nuclei in the deep interior of the Sun via proton-capture reactions is recorded by neutrinos emitted during radioactive decay and detected on Earth. Radioactive nuclei that have relatively long half lives may also be detected in stars via spectroscopic observations and in stardust recovered from primitive meteorites via laboratory analysis. The vast majority of these stardust grains originated from Asymptotic Giant Branch (AGB) stars. This is the final phase in the evolution of stars initially less massive than ~10 solar masses, during which nuclear energy is produced by alternate hydrogen and helium burning in shells above the core. The long-lived radioactive nucleus 26Al is produced in massive AGB stars (>4:5 solar ...

  1. Can transmutation replace deep radioactive repositories?; Ersetzt Transmutation die Tiefenlagerung radioaktiver Abfaelle?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-03-15

    This illustrated brief report issued by the Swiss Federal Nuclear Safety Inspectorate (ENSI) takes a look at transmutation - a method to reduce the time taken for the radioactivity of radioactive wastes to decay. The aim of such a reduction is to reduce the amount of space needed for special underground repositories for highly radioactive wastes. Transmutation is briefly described. Nuclear fuel cycles with spent fuel separation and reprocessing is examined. The large-scale feasibility of such methods is looked at and the advantages offered in connection with the design and implementation of deep nuclear waste repositories are discussed.

  2. Radioactivity-synchronized fluorescence enhancement using a radionuclide fluorescence-quenched dye.

    Science.gov (United States)

    Berezin, Mikhail Y; Guo, Kevin; Teng, Bao; Edwards, W Barry; Anderson, Carolyn J; Vasalatiy, Olga; Gandjbakhche, Amir; Griffiths, Gary L; Achilefu, Samuel

    2009-07-08

    We demonstrate the first evidence of radioactivity-synchronized fluorescence quenching of a near-infrared light-emitting dye by a radionuclide, (64)Cu, and subsequent fluorescence enhancement upon (64)Cu decay to the daughter isotopes (64)Ni and (64)Zn. The dynamic switch from high radioactivity and low fluorescence to low radioactivity and high fluorescence is potentially useful for developing complementary multimodal imaging and detection platforms for chemical, environmental, and biomedical applications as well as for unraveling the mechanisms of metal-induced dynamic fluorescence changes.

  3. Can transmutation replace deep radioactive repositories?; Ersetzt Transmutation die Tiefenlagerung radioaktiver Abfaelle?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-03-15

    This illustrated brief report issued by the Swiss Federal Nuclear Safety Inspectorate (ENSI) takes a look at transmutation - a method to reduce the time taken for the radioactivity of radioactive wastes to decay. The aim of such a reduction is to reduce the amount of space needed for special underground repositories for highly radioactive wastes. Transmutation is briefly described. Nuclear fuel cycles with spent fuel separation and reprocessing is examined. The large-scale feasibility of such methods is looked at and the advantages offered in connection with the design and implementation of deep nuclear waste repositories are discussed.

  4. Method for radioactivity monitoring

    Science.gov (United States)

    Umbarger, C. John; Cowder, Leo R.

    1976-10-26

    The disclosure relates to a method for analyzing uranium and/or thorium contents of liquid effluents preferably utilizing a sample containing counting chamber. Basically, 185.7-keV gamma rays following .sup.235 U alpha decay to .sup.231 Th which indicate .sup.235 U content and a 63-keV gamma ray doublet found in the nucleus of .sup.234 Pa, a granddaughter of .sup.238 U, are monitored and the ratio thereof taken to derive uranium content and isotopic enrichment .sup.235 U/.sup.235 U + .sup.238 U) in the liquid effluent. Thorium content is determined by monitoring the intensity of 238-keV gamma rays from the nucleus of .sup.212 Bi in the decay chain of .sup.232 Th.

  5. Radioactivity a very short introduction

    CERN Document Server

    Tuniz, Claudio

    2012-01-01

    Radioactivity: A Very Short Introduction explains radioactivity and discusses its fundamental role in nature. Radioactivity remains misunderstood and feared perhaps because nuclear radiation cannot be detected by human senses, and can undoubtedly do great harm if appropriate precautions are not taken. Radioactivity in the stars and in the Earth and its wide range of applications in biomedicine, science, industry, agriculture are described, as well as the mechanisms of nuclear fission and fusion, and the harnessing of nuclear power. The issues surrounding safety and security and the increasing concerns about nuclear terrorism are also considered.

  6. Radioactive sample effects on EDXRF spectra

    Energy Technology Data Exchange (ETDEWEB)

    Worley, Christopher G [Los Alamos National Laboratory

    2008-01-01

    Energy dispersive X-ray fluorescence (EDXRF) is a rapid, straightforward method to determine sample elemental composition. A spectrum can be collected in a few minutes or less, and elemental content can be determined easily if there is adequate energy resolution. Radioactive alpha emitters, however, emit X-rays during the alpha decay process that complicate spectral interpretation. This is particularly noticeable when using a portable instrument where the detector is located in close proximity to the instrument analysis window held against the sample. A portable EDXRF instrument was used to collect spectra from specimens containing plutonium-239 (a moderate alpha emitter) and americium-241 (a heavy alpha emitter). These specimens were then analyzed with a wavelength dispersive XRF (WDXRF) instrument to demonstrate the differences to which sample radiation-induced X-ray emission affects the detectors on these two types of XRF instruments.

  7. Short-lived radioactivity and magma genesis

    Science.gov (United States)

    Gill, James; Condomines, Michel

    1992-09-01

    Short-lived decay products of uranium and thorium have half-lives and chemistries sensitive to the processes and time scales of magma genesis, including partial melting in the mantle and magmatic differentiation in the crust. Radioactive disequilibrium between U-238, Th-230, and Ra-226 is widespread in volcanic rocks. These disequilibria and the isotopic composition of thorium depend especially on the extent and rate of melting as well as the presence and composition of vapor during melting. The duration of mantle melting may be several hundred millennia, whereas ascent times are a few decades to thousands of years. Differentiation of most magmas commonly occurs within a few millennia, but felsic ones can be tens of millennia old upon eruption.

  8. Radiological Assessments and Enhanced Natural Radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Zeevaert, T.; Vanmaercke, H.; Paridaens, K

    2001-04-01

    The objectives of the research in the field of the environmental impact assessment models performed the Belgian Nuclear Research Centre SCK-CEN are (1) to elaborate and to improve methods and guidelines for the evaluation of restoration options for contaminated sites; (2) to develop, test and improve biosphere models for the performance assessment of radioactive waste disposal in near-surface or geological repositories; (3) to asses the impact of releases from nuclear or industrial installations; (4) to apply new techniques for retrospective radon measurements and to assess radon decay product exposure by combining these techniques; and (5) to increase capabilities in mapping and surveying sites possibly or likely contaminated with enhanced levels of natural radiation. Main achievements in these areas for 2000 are summarised.

  9. Toward a comprehensive description of decay properties for uranium isotopes

    Science.gov (United States)

    Qian, Yibin; Ren, Zhongzhou

    2016-12-01

    Within the enhanced density dependent cluster model, with specific concern for density distributions in related nuclei, we investigate α decay and cluster radioactivity in uranium isotopes in the range 217 ≤A ≤243 . The available experimental data are found to be well reproduced, especially including the very recently measured values of new neutron-deficient isotopes. The half-lives of possible cluster emissions are consequently predicted as well, and will be somewhat valuable for future detection. Moreover, β decay half-lives of these nuclei are also evaluated with respect to all kinds of β processes, while their spontaneous fission lifetimes are provided via an effective relationship between the half-life and crucial quantities, namely the fissility parameter and fission barriers. In this sense, a full understanding of decay properties in uranium isotopes is expected to be achieved by combining their various radioactive features.

  10. Current and future searches for neutrinoless double beta decay

    Science.gov (United States)

    Dolinski, Michelle J.

    2016-09-01

    With the discovery of neutrino oscillations and neutrino mass, it has become a pressing question whether neutrinos have distinct antiparticle states. The most practical experimental approach to answering this question is the search for neutrinoless double beta decay, a version of a rare nuclear process that would violate lepton number conservation. The observation of neutrinoless double beta decay would prove that neutrinos are their own antiparticles. Neutrinoless double beta decay experiments deploy large source masses consisting of a select few (usually enriched) isotopes of interest. Detectors must achieve extremely low levels of radioactive background to detect this rare decay. I will report on recent searches for neutrinoless double beta decay and discuss the technical challenges that the next generation of experiments will overcome.

  11. Status of outdoor radioactive contamination at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    McKinney, S.M.; Markes, B.M.

    1994-12-01

    This document summarizes the status of outdoor radioactive contamination near Hanford Site facilities and disposal sites. It defines the nature and areal extend of the radioactively contaminated areas and describes the historical, ongoing, and planned radiological monitoring and control activities. Radioactive waste has been disposed of to the soil column since shortly after the reactors and production facilities began operating. Radioactive liquid wastes were placed directly into the ground via liquid discharges to cribs, ponds, ditches, and reverse wells. Solid wastes were placed in trenches, burial vaults, and caissons. Although the Hanford Site covers 1,450 km{sup 2}, the radioactively contaminated area is only about 36 km{sup 2} or 2.5% of the original site. Over time, contamination has migrated from some of the waste management sites through various vectors (e.g., burrowing animals, deep-rooted vegetation, erosion, containment system failure) or has been deposited to the surface soil via spills and unplanned releases (e.g., line leaks/breaks, tank leaks, and stack discharges) and created areas of outdoor radioactivity both on and below the surface. Currently 26 km{sup 2} are posted as surface contamination and 10 km{sup 2} are posted as underground contamination.

  12. A measurement of the 2 neutrino double beta decay rate of Te-130 in the CUORICINO experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kogler, Laura K. [Univ. of California, Berkeley, CA (United States)

    2011-11-30

    CUORICINO was a cryogenic bolometer experiment designed to search for neutrinoless double beta decay and other rare processes, including double beta decay with two neutrinos (2vββ). The experiment was located at Laboratori Nazionali del Gran Sasso and ran for a period of about 5 years, from 2003 to 2008. The detector consisted of an array of 62 TeO2 crystals arranged in a tower and operated at a temperature of 10 mK. Events depositing energy in the detectors, such as radioactive decays or impinging particles, produced thermal pulses in the crystals which were read out using sensitive thermistors. The experiment included 4 enriched crystals, 2 enriched with 130Te and 2 with 128Te, in order to aid in the measurement of the 2vββ rate. The enriched crystals contained a total of 350 g 130Te. The 128-enriched (130-depleted) crystals were used as background monitors, so that the shared backgrounds could be subtracted from the energy spectrum of the 130- enriched crystals. Residual backgrounds in the subtracted spectrum were fit using spectra generated by Monte-Carlo simulations of natural radioactive contaminants located in and on the crystals. The 2vββ half-life was measured to be T2v1/2 = [9.81± 0.96(stat)± 0.49(syst)] x1020 y.

  13. Cavities/Tooth Decay

    Science.gov (United States)

    Cavities/tooth decay Overview By Mayo Clinic Staff Cavities are permanently damaged areas in the hard surface of your teeth ... into tiny openings or holes. Cavities, also called tooth decay or caries, are caused by a combination of ...

  14. Cs-134 and Cs-137 radioactivity in river waters in Fukushima, Miyagi, Ibaraki and Gunma Prefectures in August 2012 after the Fukuhsima Daiichi Nuclear Power Plant accident

    Energy Technology Data Exchange (ETDEWEB)

    Nagao, S.; Ochiai, S.; Yamamoto, M. [Low Level Radioactivity Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Wake, Nomi, Ishikawa 923-1224(Japan); Kanamori, M. [Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Ishikawa 921-1192 (Japan); Tomihara, S. [Environmental Aquarium Aquamarine Fukushima, 50 Tatsumi, Onahama, Iwaki, Fukushima 971-8101(Japan); Suzuki, K. [Gunma Prefectural Fisheries Experimental Station, 13 Shikishima, Maebashi, Gunma 371-1036 (Japan)

    2014-07-01

    detector at the Kanazawa University. The {sup 134}Cs/{sup 137}Cs activity ratio of all samples was nearly 1.0 within measurement error after the decay correction to March 11 in 2011. Therefore, a major part of radiocesium is derived from the Fukushima Dai-ichi NPP accident. The {sup 137}Cs radioactivity ranges from 0.014 Bq/L to 0.103 Bq/L and shows maximum value at the lower middle site in the Abukuma River. The {sup 137}Cs radioactivity ranges from 0.004 Bq/L to 0.254 Bq/L for river water samples from the six rivers (Uta, Niida, Ntsui, Kuji and Naka Rivers) flowing to Pacific Ocean. Tone River systems have 0.008-0.016 Bq/L at the upper site and 0.028 Bq/L at the lower site. The Niida River indicates the highest value because it is running through the upper higher contaminated area. The upper Tone River systems resemble {sup 137}Cs radioactivity of the Natsui, Kuji and Naka Rivers. However, the {sup 137}Cs radioactivity in the lower Tone River is almost similar with that of the upper and middle of Abukuma River, and Natsui River. Their horizontal distributions were consistent with those of material that had been deposited on the ground surface, though the research was carried out 18 months after the accident. (authors)

  15. Radioactive cesium dynamics derived from hydrographic observations in the Abukuma River Estuary, Japan.

    Science.gov (United States)

    Kakehi, Shigeho; Kaeriyama, Hideki; Ambe, Daisuke; Ono, Tsuneo; Ito, Shin-ichi; Shimizu, Yugo; Watanabe, Tomowo

    2016-03-01

    Large quantities of radioactive materials were released into the air and the ocean as a result of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, caused by the 2011 Tohoku earthquake and the subsequent major tsunami off the Pacific coast. There is much concern about radioactive contamination in both the watershed of the Abukuma River, which flows through Fukushima Prefecture, and its estuary, where it discharges into the sea in Miyagi Prefecture. We investigated radioactive cesium dynamics using mixing diagrams obtained from hydrographic observations of the Abukuma River Estuary. Particulate radioactive cesium dominates the cesium load in the river, whereas the dissolved form dominates in the sea. As the salinity increased from <0.1 to 0.1-2.3, the mixing diagram showed that dissolved radioactive cesium concentrations increased, because of desorption. Desorption from suspended particles explained 36% of dissolved radioactive cesium in estuarine water. However, the dissolved and particulate radioactive cesium concentrations in the sea decreased sharply because of dilution. It is thought that more than 80% of the discharged particulate radioactive cesium was deposited off the river mouth, where the radioactive cesium concentrations in sediment were relatively high (217-2440 Bq kg(-1)). Radioactive cesium that was discharged to the sea was transported southward by currents driven by the density distribution.

  16. Alpha decay and cluster decay of some neutron-rich actinide nuclei

    Indian Academy of Sciences (India)

    G M CARMEL VIGILA BAI; R NITHYA AGNES

    2017-03-01

    Nuclei in the actinide region are good in exhibiting cluster radioactivity. In the present work, the half-lives of $\\alpha$-decay and heavy cluster emission from certain actinide nuclei have been calculated using cubic plus Yukawa plus exponential model ($\\bf{CYEM}$). Our model has a cubic potential for the overlapping region which is smoothly connected by a Yukawa plus exponential potential for the region after separation. The computed half-lives are compared with those of other theoretical models and are found to be in good agreement with each other. In this work, we have also studied the deformation effects on half-lives of cluster decay. These deformation effects lower the half-life values and it is also found that the neutron-rich parent nuclei slow down the cluster decay process. Geiger–Nuttal plots for various clusters are found to be linear and most of the emitted clusters are $\\alpha$-like nuclei.

  17. Radioactive waste: show time?

    Energy Technology Data Exchange (ETDEWEB)

    Verhoef, E.V. [COVRA N.V., Spanjeweg 1, 4455 TW Nieuwdorp (Netherlands); McCombie, Charles; Chapman, Neil [Arius Association, Taefernstrasse 1, CH-4050 Baden (Switzerland)

    2010-07-01

    The basic concept within both EC funded SAPIERR I and SAPIERR II projects (FP6) is that of one or more geological repositories developed in collaboration by two or more European countries to accept spent nuclear fuel, vitrified high-level waste and other long-lived radioactive waste from those partner countries. The SAPIERR II project (Strategic Action Plan for Implementation of Regional European Repositories) examines in detail issues that directly influence the practicability and acceptability of such facilities. This paper describes the work in the SAPIERR II project (2006-2008) on the development of a possible practical implementation strategy for shared, regional repositories in Europe and lays out the first steps in implementing that strategy. (authors)

  18. Arduino based radioactive tracking system

    Science.gov (United States)

    Rahman, Nur Aira Abd; Rashid, Mohd Fazlie Bin Abdul; Rahman, Anwar Bin Abdul; Ramlan, Atikah

    2017-01-01

    There is a clear need to strengthen security measures to prevent any malevolent use or accidental misuse of radioactive sources. Some of these radioactive sources are regularly transported outside of office or laboratory premises for work and consultation purposes. This paper present the initial development of radioactive source tracking system, which combined Arduino microcontroller, Global Positioning System (GPS) and Global System for Mobile communication (GSM) technologies. The tracking system will help the owner to monitor the movement of the radioactive sources. Currently, the system is capable of tracking the movement of radioactive source through the GPS satellite signals. The GPS co-ordinate could either be transmitted to headquarters at fixed interval via Short Messaging Service (SMS) to enable real time monitoring, or stored in a memory card for offline monitoring and data logging.

  19. PERSPECTIVE: Fireworks and radioactivity

    Science.gov (United States)

    Breitenecker, Katharina

    2009-09-01

    both reaction products and unburnt constituents of a pyrotechnic mixture. One major environmental concern in pyrotechnics focuses on the emission of heavy metals. This is the topic discussed in the article by Georg Steinhauser and Andreas Musilek in this issue [4]. A possible interrelationship between respiratory effects and fireworks emissions of barium-rich aerosols was also raised last year [5]. In recent years the potential hazard of naturally occurring radioactive material has become of importance to the scientific community. Naturally occurring radionuclides can be of terrestrial or cosmological origin. Terrestrial radionuclides were present in the presolar cloud that later contracted in order to build our solar system. These radionuclides—mainly heavy metals—and their non-radioactive isotopes are nowadays fixed in the matrix of the Earth's structure. Usually, their percentage is quite small compared to their respective stable isotopes—though there are exceptions like in the case of radium. The problem with environmental pollution due to naturally occurring radioactive material begins when this material is concentrated due to mining and milling, and later further processed [6]. Environmental pollution due to radioactive material goes back as far as the Copper and Iron Ages, when the first mines were erected in order to mine ores (gold, silver, copper, iron, etc), resulting in naturally occurring radioactive material being set free with other dusts into the atmosphere. So where is the link between pyrotechnics and radioactivity? In this article presented by Georg Steinhauser and Andreas Musilek [4], the pyrotechnic ingredients barium nitrate and strontium nitrate are explored with respect to their chemical similarities to radium. The fundamental question, therefore, was whether radium can be processed together with barium and strontium. If so, the production and ignition of these pyrotechnic ingredients could cause atmospheric pollution with radium aerosols

  20. Progress on Radioactive Waste Treatment Facilities Construction

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In 2011, five projects were undertaken by radioactive waste projects management department, which are "Cold Commissioning of the Pilot Project on Radioactive Waste Retrieval and Conditioning (abbreviation 'Pilot Project')", "Radioactive Ventilation Project Construction (abbreviation 'Ventilation

  1. Multivariate statistical analysis of radioactive variables in two phosphate ores from Sudan.

    Science.gov (United States)

    Adam, Abdel Majid A; Eltayeb, Mohamed Ahmed H

    2012-05-01

    Multivariate statistical techniques are efficient ways to display complex relationships among many objects. An attempt was made to study the radioactive data in two types of Sudanese phosphate deposits; Kurun and Uro phosphate, using several multivariate statistical methods. Pearson correlation coefficient revealed that a U-238 distribution in Kurun phosphate is controlled by the variation of K-40 concentration, whereas in Uro phosphate it is controlled by the variation of U-235 and U-234 concentration. Histograms and normal Q-Q plots clearly show that the radioactive variables did not follow a normal distribution. This non-normality feature observed may be attributed to complicating influence of geological factors. The principal components analysis (PCA) gives a model of five components for representing the acquired data from Kurun phosphate, where 89.5% of the total variance is explained. A model of four components was sufficient to represent the acquired data from Uro phosphate, where 87.5% of the total data variance is explained. The hierarchical cluster analysis (HCA) indicates that U-238 behaves in the same manner in the two types of phosphates; it associated with a group of four radionuclides; U-234, Po-210, Ra-226, Th-230, which the most abundant radionuclides, and all belong to the uranium-238 decay series. Two parameters have been adapted for the direct differentiate between the two phosphates. Firstly, U-238 in Uro phosphate have shown higher degree of mobility (CV% = 82.6) than that in Kurun phosphate (CV% = 64.7), and secondly, the activity ratio of Th-230/Th-232 in Uro phosphate is nine times than that in Kurun phosphate.

  2. Trapping of radioactive {sup 21}Na

    Energy Technology Data Exchange (ETDEWEB)

    Kruithof, Wilbert L.; Hoek, Duurt J. van der; Giri, Gouri S.; Hoekstra, Ronnie; Hoekstra, Steven; Jungmann, Klaus; Onderwater, Gerco; Santra, Bodhaditya; Shildling, Praveen D.; Sohani, Moslem; Versolato, Oscar O.; Willmann, Lorenz; Wilschut, Hans W. [Kernfysisch Versneller Instituut, University Groningen (Netherlands)

    2010-07-01

    Radioactive {sup 21}Na atoms in a magneto-optical trap (MOT) provide an excellent opportunity to search for non-Standard Model contributions in the weak interactions. In particular, correlations between the {beta}-particle and the neutrino are sensitive to time reversal symmetry violating effects. The Na isotope is produced at the TRI{mu}P facility of the KVI using intense {sup 20}Ne beams from the AGOR cyclotron on a cooled deuterium target. The isotopes are stopped and re-thermalized in a Thermal Ionizer. They are transported as a low energy ion beam to a MOT cell where they are neutralized and subsequently captured by laser light. The trapped Na atoms will be transferred to a second MOT which is placed inside a reaction microscope to measure the momentum distribution of the recoiling daughter nuclei after the {beta}-decay. The {beta}-particle will be detected in a scintillation detector. These two devices have been characterized. A pulsed UV laser was used to ionize trapped Na atoms in order to simulate the {beta}-decay in the reaction microscope. The momentum distribution of the recoil ions is measured. The setup of the whole experiment will be presented.

  3. Weak decays. [Lectures, phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Wojcicki, S.

    1978-11-01

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

  4. decays to baryons

    Indian Academy of Sciences (India)

    Torsten Leddig

    2012-11-01

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

  5. Environmental radioactive intercomparison program and radioactive standards program

    Energy Technology Data Exchange (ETDEWEB)

    Dilbeck, G. [Environmental Monitoring Systems Laboratory, Las Vegas, NV (United States)

    1993-12-31

    The Environmental Radioactivity Intercomparison Program described herein provides quality assurance support for laboratories involved in analyzing public drinking water under the Safe Drinking Water Act (SDWA) Regulations, and to the environmental radiation monitoring activities of various agencies. More than 300 federal and state nuclear facilities and private laboratories participate in some phase of the program. This presentation describes the Intercomparison Program studies and matrices involved, summarizes the precision and accuracy requirements of various radioactive analytes, and describes the traceability determinations involved with radioactive calibration standards distributed to the participants. A summary of program participants, sample and report distributions, and additional responsibilities of this program are discussed.

  6. Fundamental symmetries in {sup 21}Na decay

    Energy Technology Data Exchange (ETDEWEB)

    Hoek, D.J. van der; Hoekstra, R.; Jungmann, K.; Kruithof, W.L.; Onderwater, C.J.G.; Sohani, M.; Willmann, L.; Wilschut, H.W. [KVI, University of Groningen, Groningen (Netherlands)

    2009-07-01

    The {beta}-{nu} correlations in {beta}-decay allows searching for contributions that go beyond the V-A description of the Standard Model for the electroweak interaction. We are developing an experimental setup to measure correlations in the {beta}-decay of {sup 21}Na. By trapping the radioactive atoms, the recoiling nucleus (kinetic energy <230 eV) can be measured in a reaction microscope in coincidence with the emitted {beta} particle. The first step is to study {beta}-{nu} correlations that allows to set limits on scalar and tensor contributions. By polarizing the parent nucleus it becomes possible to search for time reversal violation. The production and trapping of {sup 21}Na has been accomplished. Details of the setup with a two laser system and the status of this phase of the program are described.

  7. Terrestrial Radioactivity and Gamma-ray Exposure in the United States and Canada: Gridded geographic images

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Aerial gamma-ray surveys measure the gamma-ray flux produced by the radioactive decay of the naturally occurring elements K-40, U-238, and Th-232 in the top few...

  8. Radioactive liquid wastes discharged to ground in the 200 Areas during 1978

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, J. D.; Poremba, B. E.

    1979-03-26

    This document is issued quarterly for the purpose of summarizing the radioactive liquid wastes that have been discharged to the ground in the 200 Areas. In addition to data for 1978, cumulative data since plant startup are presented. Also, in this document is a listing of decayed activity to the various plant sites.

  9. Radioactive sup 2 sup 2 sup 2 Rn daughter nuclides on a paper strip

    CERN Document Server

    Peralta, L; Ortigão, C

    2003-01-01

    The isotope sup 2 sup 2 sup 2 Rn belongs to the sup 2 sup 3 sup 8 U decay chain and can be obtained from natural mineral sources. The fact that radon is a gas and its radionuclide daughters get implanted on surrounding materials allows a set of different experiments in radiation physics. These experiments range from isotope decay time measurement to alpha, beta and gamma spectroscopy. To solve the radioactive decay chain equations, a simple iterative method is used as an alternative to the exact analytical solution.

  10. SELF SINTERING OF RADIOACTIVE WASTES

    Science.gov (United States)

    McVay, T.N.; Johnson, J.R.; Struxness, E.G.; Morgan, K.Z.

    1959-12-29

    A method is described for disposal of radioactive liquid waste materials. The wastes are mixed with clays and fluxes to form a ceramic slip and disposed in a thermally insulated container in a layer. The temperature of the layer rises due to conversion of the energy of radioactivity to heat boillng off the liquid to fomn a dry mass. The dry mass is then covered with thermal insulation, and the mass is self-sintered into a leach-resistant ceramic cake by further conversion of the energy of radioactivity to heat.

  11. Final disposal of radioactive waste

    Science.gov (United States)

    Freiesleben, H.

    2013-06-01

    In this paper the origin and properties of radioactive waste as well as its classification scheme (low-level waste - LLW, intermediate-level waste - ILW, high-level waste - HLW) are presented. The various options for conditioning of waste of different levels of radioactivity are reviewed. The composition, radiotoxicity and reprocessing of spent fuel and their effect on storage and options for final disposal are discussed. The current situation of final waste disposal in a selected number of countries is mentioned. Also, the role of the International Atomic Energy Agency with regard to the development and monitoring of international safety standards for both spent nuclear fuel and radioactive waste management is described.

  12. Hydrogeochemical and spectroscopic studies of radioactive materials in Ayrakan and Cheshmeh Shotori areas, northeastern Isfahan province

    Directory of Open Access Journals (Sweden)

    Mostafa Esmaeili Vardanjani

    2011-11-01

    Full Text Available Groundwaters hydrochemistry of Ayrakan and Cheshmeh Shotori areas and geochemistry of rare earth elements, indicate Ayrakan alkali granite as the origin of uranium and other dissolved elements in groundwaters of these areas. Geochemical and hydrogeochemical studies as well as the trend of uranium and thorium transition and mobility in aqueous environments of these areas indicate uranium adsorption by iron hydroxide (goethite as the deterrent agent against uranium transition and mobility from depth to surface. Gamma-ray spectroscopic study of sediments from Cheshmeh Shotori area by HPGe detector indicates the presence of 226Ra in high contents and as the radioactive nuclide that is the reason for high activity of these sediments. Production of 226Ra from 238U decay, shorter half-life of 226Ra compared to 238U, radium transition by groundwaters from depth to surface as well as hydrogeochemical evidences, all suggest the possibility of existence of hidden uranium deposit and uranium mineralization in depth and the distance between Ayrakan and Cheshmeh Shotori areas.

  13. Evaluated decay data for 206TI.

    Energy Technology Data Exchange (ETDEWEB)

    Kondev, F. G.; Nuclear Engineering Division

    2007-01-03

    Evaluated decay data for the {sup 206}Tl nuclide are presented, including recommended values for the half-life, {beta}- and {gamma}-ray emission energies and probabilities. Data on X-ray radiations, Auger and conversion electron energies and emission probabilities are also tabulated. Carefully evaluated data for radioactive nuclides refer to complex nuclear level schemes and tables of numerical values, which quantify fundamental nuclear structure information such as level energies and quantum numbers, lifetimes, decay modes, and other associated properties. These data are not only at the core of basic nuclear structure and nuclear astrophysics research, but they are also relevant to many applied technologies, including nuclear energy production, reactor design and safety, medical diagnostic and radiotherapy, health physics, environmental research and monitoring, safeguards and material analysis. The evaluation process results in numerous sets of recommended values on half-lives, radiation energies and emission probabilities. The work on evaluation of decay properties of {sup 206}Tl was completed in September 2006 with a literature cut off by the same date. The Saisinuc software (2002BeXX) and associated supporting programs were used in assembling the data following the established protocol within the International Decay Data Evaluation Project (DDEP) collaboration.

  14. Reference decay data, tools and applications

    Energy Technology Data Exchange (ETDEWEB)

    Dulieu, C.; Be, M. M.; Chiste, V.; Mougeot, X. [Laboratoire National Henri Becquerel, LIST, CEA-Saclay, F-91191 Gif-sur-Yvette Cedex (France)

    2009-07-01

    As a primary laboratory in the field of ionizing radiation metrology, the LNE-CEA/LNHB is involved in measurement, evaluation and dissemination of radioactive decay data. A database and associate software, known as 'NUCLEIDE' and 'NUCLEIDE-LARA', have been developed with the aim of offering to users easy access to nuclear and atomic data. Results of data measurements, obtained by various laboratories, are scrutinized by an international group of experts (Decay Data Evaluation Project) in order to provide recommended data for nuclides of special interest for metrology or practical applications, such as nuclear medicine, monitoring and reactor shielding, etc. Primary recommended data comprise half-lives, decay modes, branching ratios, X-rays, gamma-rays, electron emissions, alpha- and beta-particle emissions, and their uncertainties. Those data are subsequently distributed to users through various tools developed in our laboratory and well suited to each application domain, such as a Mini Table, which summarized the main decay properties of a nuclide, a specific library (NUCLEIDE-LARA) dedicated to alpha and gamma spectrometry measurements and in a comprehensive publication known as Monograph BIPM-5. This paper intends to describe some features of these tools and publications and, how they are used, or can be used, as entry data for specific end-user libraries or simulation codes for example. (authors)

  15. New Decay Studies of 66Ga

    Science.gov (United States)

    Kumar, Suresh; Ahmad, I.; Carpenter, M. P.; Chen, J.; Greene, J. P.; Kondev, F. G.; Zhu, S.

    2014-03-01

    High-energy γ rays with energies up to 5.0 MeV are emitted in the radioactive decay of 66Ga (T1/2 = 9.49 h). Thus, this radionuclide appears to be a suitable candidate for energy and efficiency calibrations of high-resolution, γ-ray spectrometers that are employed in studies of very neutron-rich nuclei which have large Qβ values. In addition, accurate emission probabilities of this isotope are of interest to medical imaging applications, owing to the existence of large β+ decay branches, which need to be characterized with better accuracy. Decay studies of 66Ga were initiated using the γ-ray spectroscopy technique. The source was produced by means of the 66Zn(p,n) reaction at a beam energy of 12 MeV. Singles and γ - γ coincidences measurements were carried out using a single Ge detector and Gammasphere, respectively. The previously known 66Ga decay scheme was extended and many new γ rays were placed in the daughter nuclide 66Zn. The work at ANL was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. S. Kumar acknowledges support from the Indo-US Science and Technology Forum for the award of a Research Fellowship.

  16. [Radioactivity of phosphorus implanted TiNi alloy].

    Science.gov (United States)

    Zhao, Xingke; Cai, Wei; Zhao, Liancheng

    2003-09-01

    Exposed to neutron flow, the phosphorus implanted TiNi alloy gets radioactive. This radioactive material is used in vascular stent for prevention and cure of restenosis. Phosphorus implantation is carried out in a plasma immerged ion implantation system, and the dose of phosphorus implantation is in the range of 2-10 x 10(17) cm-2. After ion implantation, the alloy is exposed to the slow neutron flow in a nuclear reactor, the dose of the slow neutron is 1.39-5.88 x 10(19) n/cm2. The radioactivity of the TiNi alloy was measured by liquid scintillation spectrometry and radio-chromic-film dosimetry. The result shows that whether the phosphorus is implanted or not, the TiNi alloy comes to be radioactive after exposure to neutron flow. Just after neutron irradiation, the radiation dose of phosphorus implanted TiNi alloy is about one hundred times higher than that of un-phosphorus implanted TiNi alloy. The radiation difference between phosphorus and un-phosphorus implanted alloy decreases as time elapses. Within three months after neutron irradiation, the average half-decay period of phosphorus implanted TiNi alloy is about 62 days. The radiation ray penetration of phosphorus implanted TiNi alloy is deeper than that of pure 32P; this is of benefit to making radiation uniformity between stent struts and reducing radiation grads beyond the edge of stent.

  17. Gamma-ray transfer and energy deposition in supernovae

    CERN Document Server

    Swartz, D A; Harkness, R P; Swartz, Douglas A; Sutherland, Peter G; Harkness, Robert P

    1995-01-01

    Solutions to the energy-independent (gray) radiative transfer equations are compared to results of Monte Carlo simulations of the \\Ni\\ and \\Co\\ radioactive decay \\GR\\ energy deposition in supernovae. The comparison shows that an effective, purely absorptive, gray opacity, \\KG\\ \\sim (0.06 \\pm 0.01)Y_e cm^2 g^{-1}, where Y_e is the total number of electrons per baryon, accurately describes the interaction of \\GRs\\ with the cool supernova gas and the local \\GR\\ energy deposition within the gas. The nature of the \\GR\\ interaction process (dominated by Compton scattering in the relativistic regime) creates a weak dependence of \\KG\\ on the optical thickness of the (spherically symmetric) supernova atmosphere: The maximum value of \\KG\\ applies during optically thick conditions when individual \\GRs\\ undergo multiple scattering encounters and the lower bound is reached at the phase characterized by a total Thomson optical depth to the center of the atmosphere \\te\\ \\LA\\ 1. Our results quantitatively confirm that the qu...

  18. Radiotoxicity and decay heat power of spent nuclear fuel of VVER type reactors at long-term storage.

    Science.gov (United States)

    Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

    2005-01-01

    Radiotoxicity and decay heat power of the spent nuclear fuel of VVER-1000 type reactors are calculated during storage time up to 300,000 y. Decay heat power of radioactive waste (radwaste) determines parameters of the heat removal system for the safe storage of spent nuclear fuel. Radiotoxicity determines the radiological hazard of radwaste after its leakage and penetration into the environment.

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

    CERN Document Server

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

    2014-01-01

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

  20. Low-Activity Radioactive Wastes

    Science.gov (United States)

    In 2003 EPA published an Advance Notice of Proposed Rulemaking (ANPR) to collect public comment on alternatives for disposal of waste containing low concentrations of radioactive material ('low-activity' waste).

  1. Radioactivity standardization in South Africa

    CSIR Research Space (South Africa)

    Simpson, BRS

    2002-01-01

    Full Text Available South Africa's national radioactivity measurement standard is maintained at a satellite laboratory in Cape Town by the National Metrology Laboratory (NML) of the Council-for Scientific and Industrial Research. Standardizations are undertaken by a...

  2. Consumer Products Containing Radioactive Materials

    Science.gov (United States)

    ... 2010 Health Physics Society Specialists in Radiation Safety Consumer Products Containing Radioactive Materials Everything we encounter in ... eat, the ground we walk upon, and the consumer products we purchase and use. Although many might ...

  3. Environmental radioactivity survey in Suwon

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-12-15

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

  4. Radioactive waste material melter apparatus

    Science.gov (United States)

    Newman, D.F.; Ross, W.A.

    1990-04-24

    An apparatus for preparing metallic radioactive waste material for storage is disclosed. The radioactive waste material is placed in a radiation shielded enclosure. The waste material is then melted with a plasma torch and cast into a plurality of successive horizontal layers in a mold to form a radioactive ingot in the shape of a spent nuclear fuel rod storage canister. The apparatus comprises a radiation shielded enclosure having an opening adapted for receiving a conventional transfer cask within which radioactive waste material is transferred to the apparatus. A plasma torch is mounted within the enclosure. A mold is also received within the enclosure for receiving the melted waste material and cooling it to form an ingot. The enclosure is preferably constructed in at least two parts to enable easy transport of the apparatus from one nuclear site to another. 8 figs.

  5. Naturally Occurring Radioactive Materials (NORM)

    Energy Technology Data Exchange (ETDEWEB)

    Gray, P. [ed.

    1997-02-01

    This paper discusses the broad problems presented by Naturally Occuring Radioactive Materials (NORM). Technologically Enhanced naturally occuring radioactive material includes any radionuclides whose physical, chemical, radiological properties or radionuclide concentration have been altered from their natural state. With regard to NORM in particular, radioactive contamination is radioactive material in an undesired location. This is a concern in a range of industries: petroleum; uranium mining; phosphorus and phosphates; fertilizers; fossil fuels; forestry products; water treatment; metal mining and processing; geothermal energy. The author discusses in more detail the problem in the petroleum industry, including the isotopes of concern, the hazards they present, the contamination which they cause, ways to dispose of contaminated materials, and regulatory issues. He points out there are three key programs to reduce legal exposure and problems due to these contaminants: waste minimization; NORM assesment (surveys); NORM compliance (training).

  6. GEMS: Underwater spectrometer for long-term radioactivity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sartini, Ludovica, E-mail: ludovica.sartini@ingv.i [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Genoa University, Genoa (Italy); Simeone, Francesco; Pani, Priscilla [' Sapienza' University and Istituto Nazionale di Fisica Nucleare (INFN), Sect.Roma, Roma (Italy); Lo Bue, Nadia; Marinaro, Giuditta [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Grubich, Andry; Lobko, Alexander [Institute for Nuclear Problems (INP), Belarus State University, Minsk (Belarus); Etiope, Giuseppe [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Capone, Antonio [' Sapienza' University and Istituto Nazionale di Fisica Nucleare (INFN), Sect.Roma, Roma (Italy); Favali, Paolo [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Gasparoni, Francesco; Bruni, Federico [Tecnomare S.p.A., Venice (Italy)

    2011-01-21

    GEMS (Gamma Energy Marine Spectrometer) is a prototype of an autonomous radioactivity sensor for underwater measurements, developed in the framework for a development of a submarine telescope for neutrino detection (KM3NeT Design Study Project). The spectrometer is highly sensitive to gamma rays produced by {sup 40}K decays but it can detect other natural (e.g., {sup 238}U,{sup 232}Th) and anthropogenic radio-nuclides (e.g., {sup 137}Cs). GEMS was firstly tested and calibrated in the laboratory using known sources and it was successfully deployed for a long-term (6 months) monitoring at a depth of 3200 m in the Ionian Sea (Capo Passero, offshore Eastern Sicily). The instrument recorded data for the whole deployment period within the expected specifications. This monitoring provided, for the first time, a continuous time-series of radioactivity in deep-sea.

  7. Radioactive waste engineering and management

    CERN Document Server

    Nakayama, Shinichi

    2015-01-01

    This book describes essential and effective management for reliably ensuring public safety from radioactive wastes in Japan. This is the first book to cover many aspects of wastes from the nuclear fuel cycle to research and medical use, allowing readers to understand the characterization, treatment and final disposal of generated wastes, performance assessment, institutional systems, and social issues such as intergenerational ethics. Exercises at the end of each chapter help to understand radioactive waste management in context.

  8. Radioactivity of the Cooling Water

    Science.gov (United States)

    Wigner, E. P.

    1943-03-01

    The most important source of radioactivity at the exit manifold of the pile will be due to O{sup 19}, formed by neutron absorption of O{sup 18}. A recent measurement of Fermi and Weil permits to estimate that it will be safe to stay about 80 minutes daily close to the exit manifolds without any shield. Estimates are given for the radioactivities from other sources both in the neighborhood and farther away from the pile.

  9. Atomic Batteries: Energy from Radioactivity

    OpenAIRE

    Kumar, Suhas

    2015-01-01

    With alternate, sustainable, natural sources of energy being sought after, there is new interest in energy from radioactivity, including natural and waste radioactive materials. A study of various atomic batteries is presented with perspectives of development and comparisons of performance parameters and cost. We discuss radioisotope thermal generators, indirect conversion batteries, direct conversion batteries, and direct charge batteries. We qualitatively describe their principles of operat...

  10. Final disposal of radioactive waste

    OpenAIRE

    Freiesleben H.

    2013-01-01

    In this paper the origin and properties of radioactive waste as well as its classification scheme (low-level waste – LLW, intermediate-level waste – ILW, high-level waste – HLW) are presented. The various options for conditioning of waste of different levels of radioactivity are reviewed. The composition, radiotoxicity and reprocessing of spent fuel and their effect on storage and options for final disposal are discussed. The current situation of final waste disposal in a selected number of c...

  11. Effective Majorana neutrino decay

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Lucia [Instituto de Fisica, Facultad de Ingenieria,Universidad de la Republica, Montevideo (Uruguay); Romero, Ismael; Peressutti, Javier; Sampayo, Oscar A. [Universidad Nacional de Mar del Plata, Departamento de Fisica, Instituto de Investigaciones Fisicas de Mar del Plata (IFIMAR) CONICET, UNMDP, Mar del Plata (Argentina)

    2016-08-15

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

  12. $\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with radioactive At beams

    CERN Multimedia

    We propose to study the $\\beta$-delayed fission, laser spectroscopy and radioactive decay of the newly available pure beams of neutron-deficient and neutron-rich astatine (Z=85) isotopes. The fission probability and the fission fragment distribution of the even-even isotopes $^{194,196}$Po following the $\\beta$-decay of the isotopes $^{194,196}$At will be studied with the Windmill setup. In-source laser spectroscopy will be performed on the entire astatine isotopic chain, using a combination of the Windmill setup, ISOLTRAP MR-ToF and ISOLDE Faraday. Radioactive decay data will be acquired at the Windmill setup throughout those studies and contribute to the global understanding of the phenomenon of shape coexistence in the neutron-deficient lead region.

  13. Review of Monte Carlo simulations for backgrounds from radioactivity

    Science.gov (United States)

    Selvi, Marco

    2013-08-01

    For all experiments dealing with the rare event searches (neutrino, dark matter, neutrino-less double-beta decay), the reduction of the radioactive background is one of the most important and difficult tasks. There are basically two types of background, electron recoils and nuclear recoils. The electron recoil background is mostly from the gamma rays through the radioactive decay. The nuclear recoil background is from neutrons from spontaneous fission, (α, n) reactions and muoninduced interactions (spallations, photo-nuclear and hadronic interaction). The external gammas and neutrons from the muons and laboratory environment, can be reduced by operating the detector at deep underground laboratories and by placing active or passive shield materials around the detector. The radioactivity of the detector materials also contributes to the background; in order to reduce it a careful screening campaign is mandatory to select highly radio-pure materials. In this review I present the status of current Monte Carlo simulations aimed to estimate and reproduce the background induced by gamma and neutron radioactivity of the materials and the shield of rare event search experiment. For the electromagnetic background a good level of agreement between the data and the MC simulation has been reached by the XENON100 and EDELWEISS experiments, using the GEANT4 toolkit. For the neutron background, a comparison between the yield of neutrons from spontaneous fission and (α, n) obtained with two dedicated softwares, SOURCES-4A and the one developed by Mei-Zhang-Hime, show a good overall agreement, with total yields within a factor 2 difference. The energy spectra from SOURCES-4A are in general smoother, while those from MZH presents sharp peaks. The neutron propagation through various materials has been studied with two MC codes, GEANT4 and MCNPX, showing a reasonably good agreement, inside 50% discrepancy.

  14. Exact method for determining subsurface radioactivity depth profiles from gamma spectroscopy measurements

    CERN Document Server

    Van Siclen, Clinton DeW

    2011-01-01

    Subsurface radioactivity may be due to transport of radionuclides from a contaminated surface into the solid volume, as occurs for radioactive fallout deposited on soil, or from fast neutron activation of a solid volume, as occurs in concrete blocks used for radiation shielding. For purposes including fate and transport studies of radionuclides in the environment, decommissioning and decontamination of radiation facilities, and nuclear forensics, an in situ, nondestructive method for ascertaining the subsurface distribution of radioactivity is desired. The method developed here obtains a polynomial expression for the radioactivity depth profile, using a small set of gamma-ray count rates measured by a collimated detector directed towards the surface at a variety of angles with respect to the surface normal. To demonstrate its capabilities, this polynomial method is applied to the simple case where the radioactivity is maximal at the surface and decreases exponentially with depth below the surface, and to the ...

  15. Formation and decay of the compound nucleus *220Th within the dynamical cluster-decay model

    Science.gov (United States)

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

    2017-01-01

    Background: The radioactive *220Th compound nucleus (CN) is of interest since the evaporation residue (ER) cross sections are available for various entrance channels 16O+204Pb , 40Ar+180Hf , 48Ca+172Yb , and 82Se+138Ba at near barrier energies. Within the dynamical cluster-decay model (DCM), the radioactive CNs *215Fr, *242Pu, *246Bk, and *254Fm are studied where the main decay mode is fission, with very small predicted ER cross section. *220Th provides a first case with experimentally observed ER cross section instead of fission. Purpose: To look for the optimum "hot-compact" target-projectile (t-p) combinations for the synthesis of "cold"*. For best fitting of the measured ER cross sections, with quasifission (qf) content, if any, the fusion-fission (ff) component is predicted. The magic-shell structure and entrance channel mass-asymmetry effects are analyzed, and the behavior of CN formation and survival probabilities PCN and Psurv is studied. Methods: The quantum-mechanical fragmentation theory (QMFT) is used to predict the possible cold t-p combinations for synthesizing *220Th, and the QMFT-based DCM is used to analyze its decay channels for the experimentally studied entrance channels. The only parameter of the model, the neck length Δ R , varies smoothly with the excitation energy E* of CN and is used to best fit the ER data and predict qf and ff cross sections. Results: The hot-compact and "cold-elongated" fragmentation paths show dissimilar results, whose comparisons with measured fission yields result in t-p combinations, the cold reaction valleys. For the decay process, the fixed Δ R fit the measured ER cross section nicely, but not the individual decay-channel cross sections, which require the presence of qf effects, less so for asymmetric t-p combinations, and large (predicted) ff cross section. Conclusions: The calculated yields for hot-compact fragmentation path compared favorably with the observed asymmetric fission-mass distribution, resulting in

  16. Laser assisted nuclear decay spectroscopy: A new method for studying neutron-deficient francium

    CERN Document Server

    Lynch, Kara Marie

    2015-01-01

    Radioactive decay studies of rare isotopes produced at radioactive ion beam facilities have often been hindered by the presence of isobaric and isomeric contamination. The Collinear Resonance Ionization Spectroscopy (CRIS) experiment at ISOLDE, CERN uses laser radiation to stepwise excite and ionize an atomic beam in a particular isomeric state. Deflection of this selectively ionized beam of exotic nuclei, from the remaining neutral contaminants, allows ultra-sensitive detection of rare isotopes and nuclear structure measurements in background-free conditions.\

  17. Environmental radioactive monitoring in Itu, Sao Paulo, Brazil; Monitoramento de radioatividade ambiental no municipio de Itu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-01-01

    The results of the environmental monitoring of a region near to a radioactive materials deposit in Sao Paulo State, Brazil, are presented. The radioactive materials are uranium and thorium hydroxides from monazite processing. The temporal variation of {sup 226} Ra was determined in the superficial and underground water, showing no increase for the former and a maximum concentration of 0,306 Bq/L for the latter. 21 figs., 17 tabs.

  18. Short-term seasonal variability in 7Be wet deposition in a semiarid ecosystem of central Argentina.

    Science.gov (United States)

    Juri Ayub, J; Di Gregorio, D E; Velasco, H; Huck, H; Rizzotto, M; Lohaiza, F

    2009-11-01

    The (7)Be wet deposition has been intensively investigated in a semiarid region at San Luis Province, Argentina. From November 2006 to May 2008, the (7)Be content in rainwater was determined in 58 individual rain events, randomly comprising more than 50% of all individual precipitations at the sampling period. (7)Be activity concentration in rainwater ranged from 0.7+/-0.3 Bq l(-1) to 3.2+/-0.7 Bq l(-1), with a mean value of 1.7 Bq l(-1) (sd=0.53 Bq l(-1)). No relationship was found between (7)Be content in rainwater and (a) rainfall amount, (b) precipitation intensity and (c) elapsed time between events. (7)Be ground deposition was found to be well correlated with rainfall amount (R=0.92). For the precipitation events considered, the (7)Be depositional fluxes ranged from 1.1 to 120 Bq m(-2), with a mean value of 32.7 Bq m(-2) (sd=29.9 Bq m(-2)). The annual depositional flux was estimated at 1140+/-120 Bq m(-2)y(-1). Assuming the same monthly deposition pattern and that the (7)Be content in soil decreases only through radioactive decay, the seasonal variation of (7)Be areal activity density in soil was estimated. Results of this investigation may contribute to a valuable characterization of (7)Be input in the explored semiarid ecosystem and its potential use as tracer of environmental processes.

  19. Induced radioactivity in a 4 MW target and its surroundings

    CERN Document Server

    Agosteo, Stefano; Otto, Thomas; 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. An 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 was performed by the Monte Carlo hadronic cascade code FLUKA. The aim was 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-01-01

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

  1. Measurements of Natural Radioactivity in Submicron Aerosols in Mexico City.

    Science.gov (United States)

    Gaffney, J. S.; Marley, N. A.; Sterling, K.; Sturchio, N. C.

    2003-12-01

    Natural radionuclides can be useful in evaluating the transport of ozone and aerosols in the troposphere. Beryllium-7, which is produced by cosmic ray interactions in the upper troposphere and lower stratosphere and becomes adsorbed on fine aerosols, can be a useful indicator of upper air transport into a region. Lead-210 is produced by the decay of radon-222 out-gassed into the lower atmosphere from ground-based uranium deposits. Potassium-40, found in soils, can act as a measure of wind-blown dust and also comes from burning of wood and other biomass that is enriched in this natural radioisotope. Thus, both lead-210 and potassium-40 can aid in identification of aerosols sourced in the lower atmosphere. As part of our continuing interest in the lifetimes and sources of aerosols and their radiative effects, we report here measurements of fine aerosol radioactivity in Mexico City, one of the largest megacities in the world. Samples were collected on quartz fiber filters by using cascade impactors (Sierra type, Anderson Instruments) and high-volume air samplers from the rooftop of the main laboratory of El Centro Nacional de Investigacion y Capacitacion Ambiental (CENICA). By using stage 4 of the impactor and timers, we were able to collect integrated samples of sizes > 1 micrometer and < 1 micrometer over 12-hr time periods daily for approximately one month in April 2003. Samples were counted at the University of Illinois at Chicago by using state-of-the-art gamma counting (beryllium-7, 477.6 keV; potassium-40, 1460.8 keV; lead-210, 46.5 keV). The beryllium-7 data indicate one possible upper-air transport event during April 2003. As expected, the lead-210 data indicate very little soil contribution to the fine aerosol. The potassium-40 data showed an increase in fine aerosol potassium during Holy Week that might be attributed to local combustion of biomass fuels. The data will be presented and discussed in light of future data analysis and comparison with other

  2. [Nationwide survey on radioactive waste management related to positron emission tomography in Japan].

    Science.gov (United States)

    Nagaoka, Hiroaki; Watanabe, Hiroshi; Yamaguchi, Ichiro; Fujibuchi, Toshioh; Kida, Tetsuo; Tanaka, Shinji

    2009-12-20

    A clearance system for medical radioactive solid waste has not yet been implemented in Japan. Since 2004 new regulations have allowed institutions using positron emission tomography(PET)to handle totally decayed radioactive waste as non-radioactive waste after decay-in-storage. It was expected that this new regulation would mediate the installation of clearance systems in Japan. In order to assess the current situation of radiation safety management in PET institutions, we conducted a nationwide survey. The study design was a cross-sectional descriptive study conducted by questionnaire. The subjects of this survey were all the PET institutions in Japan. Among 224 institutes, 128 institutes are equipped with cyclotrons and 96 institutes are not. The number of returned questionnaires was 138. Among institutes that are using delivered radiopharmaceuticals, 80% treat their waste as non-radioactive according to the new regulation. The impact of new regulations for reducing radioactive waste in PET institutes without a cyclotron was estimated at about $400 thousand per year. The main concern of medical institutes was assessment of the contamination caused by by-products of radioactive nuclides generated in target water during the operation of a cyclotron. It was thought that a rational rule based on scientific risk management should be established because these by-products of radioactive nuclides are negligible for radiation safety. New regulation has had a good influence on medical PET institutes, and it is expected that a clearance system for medical radioactive waste will be introduced in the near future, following these recent experiences in PET institutes.

  3. Mining of Radioactive Raw Materials as an Origin of the Nuclear Fuel Chain

    Directory of Open Access Journals (Sweden)

    Bedřich Michálek

    2007-01-01

    Full Text Available The mining of radioactive raw materials may be considered as an origin of the nuclear fuel chain and thus determines the amount of radioactive wastes which have to be stored safety in the final stage of the fuel chain. The paper informs about the existing trends in mining of radioactive raw materials in the world, provides an overview of development in mining in the Czech Republic and of possibilities of future exploiting some uranium deposits. It points a possibility of non-traditional obtaining uranium from mine waters from underground uranium mines closed and flooded earlier.

  4. Improving evaluation criteria for monitoring networks of weak radioactive plumes after nuclear emergencies

    DEFF Research Database (Denmark)

    Urso, L.; Astrup, Poul; Helle, K.B.

    2012-01-01

    . Germany and the Netherlands decided to set up relatively dense networks for the detection of weak radioactive plumes and, additionally, environmental radioactivity from deposited aerosols. Plausible evaluation criteria are presented here to assess important properties which determine the reliability......Networks of monitoring stations have been set up in many European countries to detect the passage of a radioactive cloud in the event of a large-scale nuclear emergency. The layout and spatial density of these networks differs according to the needs and criteria defined by national authorities...

  5. Radioactive contamination of BaF2 crystal scintillator

    CERN Document Server

    Polischuk, O G; Bernabei, R; Cappella, F; Caracciolo, V; Cerulli, R; Di Marco, A; Danevich, F A; Incicchitti, A; Poda, D V; Tretyak, V I

    2013-01-01

    Barium fluoride (BaF$_2$) crystal scintillators are promising detectors to search for double beta decay processes in $^{130}$Ba ($Q_{2{\\beta}}$ = 2619(3) keV) and $^{132}$Ba ($Q_{2{\\beta}}$ = 844(1) keV). The $^{130}$Ba isotope is of particular interest because of the indications on 2${\\beta}$ decay found in two geochemical experiments. The radioactive contamination of BaF$_2$ scintillation crystal with mass of 1.714 kg was measured over 113.4 hours in a low-background DAMA/R&D set-up deep underground (3600 m w.e.) at the Gran Sasso National Laboratories of INFN (LNGS, Italy). The half-life of $^{212}$Po (present in the crystal scintillator due to contamination by radium) was estimated as $T_{1/2}$ = 298.8 $\\pm$ 0.8(stat.) $\\pm$ 1.4(syst.) ns by analysis of the events pulse profiles.

  6. Observation of semileptonic decay

    Science.gov (United States)

    Albrecht, H.; Cronström, H. I.; Ehrlichmann, H.; Hamacher, T.; Hofmann, R. P.; Kirchhoff, T.; Nau, A.; Nowak, S.; Reidenbach, M.; Reiner, R.; Schröder, H.; Schulz, H. D.; Walter, M.; Wurth, R.; Appuhn, R. D.; Hast, C.; Kolanoski, H.; Lange, A.; Lindner, A.; Mankel, R.; Schieber, M.; Siegmund, T.; Spaan, B.; Thurn, H.; Töpfer, D.; Walther, A.; Wegener, D.; Paulini, M.; Reim, K.; Wegener, H.; Mundt, R.; Oest, T.; Schmidt-Parzefall, W.; Funk, W.; Stiewe, J.; Werner, S.; Ehret, K.; Hölscher, A.; Hofmann, W.; Hüpper, A.; Khan, S.; Knöpfle, K. T.; Spengler, J.; Britton, D. I.; Charlesworth, C. E. K.; Edwards, K. W.; Hyatt, E. R. F.; Kapitza, H.; Krieger, P.; Macfarlane, D. B.; Patel, P. M.; Prentice, J. D.; Saull, P. R. B.; Seidel, S. C.; Tzamariudaki, K.; van de Water, R. G.; Yoon, T.-S.; Reβing, D.; Schmidtler, M.; Schneider, M.; Schubert, K. R.; Strahl, K.; Waldi, R.; Weseler, S.; Kernel, G.; Križan, P.; Križnič, E.; Podobnik, T.; Živko, T.; Jönsson, L.; Balagura, V.; Belyaev, I.; Danilov, M.; Droutskoy, A.; Golutvin, A.; Gorelov, I.; Kostina, G.; Lubimov, V.; Murat, P.; Pakhlov, P.; Ratnikov, F.; Semenov, S.; Shibaev, V.; Soloshenko, V.; Tichomirov, I.; Zaitsev, Yu.; Argus Collaboration

    1993-04-01

    Observation of the semileptonic decay of the charmed baryon ? in the decay channel ? has been made using the ARGUS detector at the e+e- storage ring DORIS II at DESY. The cross section times branching ratio was found to be ?.

  7. Double beta decay experiments

    CERN Document Server

    Barabash, A S

    2011-01-01

    The present status of double beta decay experiments is reviewed. The results of the most sensitive experiments are discussed. Proposals for future double beta decay experiments with a sensitivity to the $$ at the level of (0.01--0.1) eV are considered.

  8. Rare Semileptonic Charm Decays

    CERN Document Server

    de Boer, Stefan

    2015-01-01

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

  9. The CARDS array for neutron-rich decay spectroscopy at HRIBF

    CERN Document Server

    Batchelder, J C; Bingham, C R; Carter, H K; Cole, J D; Fong, D; Garrett, P E; Grzywacz, R; Hamilton, J H; Hartley, D J; Hwang, J K; Krolas, W; Kulp, D C; Larochelle, Y; Piechaczek, A; Ramayya, A V; Rykaczewski, K; Spejewski, E H; Stracener, D W; Tantawy, M N; Winger, J A; Wood, J; Zganjar, E F

    2003-01-01

    An array for decay studies of neutron-rich nuclei has been commissioned for use at the UNISOR separator at Holifield Radioactive Ion Beam Facility. This array consists of three segmented clover Ge detectors, plastic scintillators, and a high-resolution (approx 1 keV) Si conversion electron spectrometer. These detectors are mounted on a support that surrounds a moving tape collector. This system has been named clover array for radioactive decay studies. The detectors have been outfitted with digital flash ADCs (XIA DGFs) that fit the preamp signals, with built-in pileup rejection.

  10. Modelling seasonal variations of natural radioactivity in soils: A case study in southern Italy

    Indian Academy of Sciences (India)

    Ilaria Guagliardi; Natalia Rovella; Carmine Apollaro; Andrea Bloise; Rosanna De Rosa; Fabio Scarciglia; Gabriele Buttafuoco

    2016-12-01

    The activity of natural radionuclides in soil has become an environmental concern for local public and national authorities because of the harmful effects of radiation exposure on human health. In this context, modelling and mapping the activity of natural radionuclides in soil is an important research topic. The study was aimed to model, in a spatial sense, the soil radioactivity in an urban and peri-urban soils area in southern Italy to analyse the seasonal influence on soil radioactivity. Measures of gamma radiation naturally emitted through the decay of radioactive isotopes (potassium, uranium and thorium) were analysed using a geostatistical approach to map the spatial distribution of soil radioactivity. The activity of three radionuclides was measured at 181 locations using a high-resolution γ-ray spectrometry. To take into account the influence of season, the measurements were carried out in summer and in winter. Activity data were analysed by using a geostatistical approach and zones of relatively high or low radioactivity were delineated. Among the main processes which influence natural radioactivity such as geology, geochemical, pedological, and ecological processes, results of this study showed a prominent control of radio-emission measurements by seasonal changes. Low natural radioactivity levels were measured in December associated with winter weather and moist soil conditions (due to high rainfall and low temperature), and higher activity values in July, when the soil was dry and no precipitations occurred.

  11. Modelling seasonal variations of natural radioactivity in soils: A case study in southern Italy

    Science.gov (United States)

    Guagliardi, Ilaria; Rovella, Natalia; Apollaro, Carmine; Bloise, Andrea; Rosa, Rosanna De; Scarciglia, Fabio; Buttafuoco, Gabriele

    2016-12-01

    The activity of natural radionuclides in soil has become an environmental concern for local public and national authorities because of the harmful effects of radiation exposure on human health. In this context, modelling and mapping the activity of natural radionuclides in soil is an important research topic. The study was aimed to model, in a spatial sense, the soil radioactivity in an urban and peri-urban soils area in southern Italy to analyse the seasonal influence on soil radioactivity. Measures of gamma radiation naturally emitted through the decay of radioactive isotopes (potassium, uranium and thorium) were analysed using a geostatistical approach to map the spatial distribution of soil radioactivity. The activity of three radionuclides was measured at 181 locations using a high-resolution ?-ray spectrometry. To take into account the influence of season, the measurements were carried out in summer and in winter. Activity data were analysed by using a geostatistical approach and zones of relatively high or low radioactivity were delineated. Among the main processes which influence natural radioactivity such as geology, geochemical, pedological, and ecological processes, results of this study showed a prominent control of radio-emission measurements by seasonal changes. Low natural radioactivity levels were measured in December associated with winter weather and moist soil conditions (due to high rainfall and low temperature), and higher activity values in July, when the soil was dry and no precipitations occurred.

  12. Radioactivity monitoring of Irish dairy produce

    Energy Technology Data Exchange (ETDEWEB)

    Kelleher, K. (Radiological Protection Institute of Ireland. Radiation Monitoring, Dublin (Ireland))

    2010-03-15

    Full text: The RPII has been carrying out monitoring of milk and dairy produce since 1986. Milk samples are routinely analysed for radiocaesium and strontium-90 as part of the RPII's environmental monitoring programme to determine the doses received to the Irish population from milk consumption. The method the RPII utilises for determining the Sr-90 activity in milk is by measuring the Cerenkov radiation produced by its daughter 90Y isolated from interfering nuclides such as uranium, thorium, radium and their decay products as well as isotopes of caesium, potassium and strontium by extraction with 10% di-(2-ethylhexyl)phosphate (HDEHP) in toluene. The chemical yield of 90Y is determined by the acidmetric titration of yttrium nitrate carrier with titriplex III. The levels of Sr-90 and dose to the Irish population from milk consumption have been negligible when compared to other radioactive sources in the Irish environment. Other dairy products are analysed for radiocaesium on a routine basis for commercial customers to ensure the levels of radioactivity in the dairy products fall within EC regulations governing the export/import of dairy produce. The export of milk and milk produce from Ireland is a very important industry, 80% of dairy products produced in Ireland are exported and these exports are worth Euro 2.2 billion annually to the Irish economy. The dairy products are analysed by gamma spectroscopy and include full and skim milk powders, butter, casein, cheese, cream, whey and lactose. The levels of radiocaesium in these products are typically below 5 Bk/kg and fall well within the limit of 370 Bq/kg laid down by the European Community in Council Regulation 737/90. Although the levels of these radionuclides are relatively low the RPII recognises the importance of analysing these samples for radioactivity to inform the public, ensure consumer confidence and, more importantly, to maintain a level of expertise in the RPII in these analytical techniques so

  13. Imaging of radioactive material and its host particle from the nuclear power plant accident in Japan by using imaging plate and electron microscopy

    Science.gov (United States)

    Adachi, Kouji; Zaizen, Yuji; Kimura, Tohru; Sakoh, Hiroshi; Igarashi, Yasuhito

    2013-04-01

    The Fukushima Daiichi Nuclear Power Plant accident in Japan on March, 2012, dispersed radioactive materials. In the Meteorological Research Institute, where locates 170 km south west from the power plant, we collected two types of filter aerosol samples and wet and dry deposition particles before and after the accident. Using these samples, we analyzed 1) radioactivity using an imaging plate (IP), which visualizes the radioactivity of samples in a two-dimensional plane with space resolution ~0.05 mm and 2) shape and compositions of particles that host radioactive materials using a scanning electron microscope (SEM) with energy-dispersive X-ray spectrometer (EDS). From the samples collected on March 15 and 21, we found radioactive spots on the filter samples using the IP, suggesting that radioactive materials, presumably Cs, were carried from the power plant. Radioactivity was also detected over the aggregates of dust particles in wet and dry deposition samples collected from March 2011. We did not find any detectable radioactive materials after the April when using the IP. We further investigated the radioactive spots using the SEM to identify the host particles of the radioactive materials and to detect radioactive materials from the EDS analysis. From the SEM analysis, we found that the particles on the filters include sulfate, mineral dust, and metals, but there were no particular particles or materials in the radioactive spots comparing to those in other area. The result suggests that the radioactive materials are hosted on the surface of other particles or inside them. We, so far, did not obtain any evidences that the radioactive materials are particulate with larger than 0.1 micro meter. Further analysis will need to identify the source of radioactive spots from individual particles using a manipulator as well as SEM and IP. Such studies will reveal where the radioactive materials exist in the environment, how they resuspend in the air, and how they could

  14. Non-exponential and oscillatory decays in quantum mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Peshkin, Murray [Argonne National Lab. (ANL), Argonne, IL (United States); Volya, Alexander [Florida State Univ., Tallahassee, FL (United States); Zelevinsky, Vladimir [Michigan State Univ., East Lansing, MI (United States)

    2014-08-07

    The quantum-mechanical theory of the decay of unstable states is revisited. We show that the decay is non-exponential both in the short-time and long-time limits using a more physical definition of the decay rate than the one usually used. We report results of numerical studies based on Winter's model that may elucidate qualitative features of exponential and non-exponential decay more generally. The main exponential stage is related to the formation of a radiating state that maintains the shape of its wave function with exponentially diminishing normalization. We discuss situations where the radioactive decay displays several exponents. The transient stages between different regimes are typically accompanied by interference of various contributions and resulting oscillations in the decay curve. The decay curve can be fully oscillatory in a two-flavor generalization of Winter's model with some values of the parameters. We consider the implications of that result for models of the oscillations reported by GSI.

  15. United role of radon decay products and nano-aerosols in radon dosimetry

    Science.gov (United States)

    Smerajec, M.; Vaupotič, J.

    2012-04-01

    The major part of human exposure to natural radiation originates from inhalation of radon (Rn) and radon short-lived decay products (RnDP: 218Po, 214Pb, 214Bi and 214Po). RnDP are formed as a result of α-transformation of radon. In the beginning they are positive ions which neutralize and form clusters with air molecules, and later partly attach to background aerosol particles in indoor air. Eventually, they appear as radioactive nano-aerosols with a bimodal size distribution in ranges of 1-10 nm (unattached RnDP) and of 200-800 nm (attached RnDP). When inhaled, they are deposited in the respiratory tract. Deposition is more efficient for smaller particles. Therefore, the fraction (fun) of the unattached RnDP, which appears to be influenced by the number concentration and size distribution of general (background) aerosols in the ambient air, has a crucial role in radon dosimetry. Radon, radon decay products and general aerosols have been monitored simultaneously in the kitchen of a typical rural house under real living conditions, also comprising four human activities generating particular matter: cooking and baking, as two typical activities in kitchen, and cigarette smoking and candle burning. In periods without any human activity, the total number concentration of general aerosol ranged from 1000 to 3000 cm-3,with the geometric mean of particle diameter in the range of 60-68 nm and with 0.1-1 % of particles smaller than 10 nm. Preparation of coffee changed the concentration to 193,000 cm-3, the geometric mean of diameter to 20 nm and fraction of particles smaller than 10 nm to 11 %. The respective changes were for baking cake: 503,000 cm-3, 17 nm and 19 %, for smoking:423,000 cm-3, 83 nm and 0.4 %, and forcandle burning: 945,000 cm-3, 8 nm and 85 %. While, as expected, a reduction of fun was observed during cooking, baking and smoking, when larger particles were emitted, fun did not increase during candle burning with mostly particles smaller than 10 nm

  16. Correlation of gravestone decay and air quality 1960-2010

    Science.gov (United States)

    Mooers, H. D.; Carlson, M. J.; Harrison, R. M.; Inkpen, R. J.; Loeffler, S.

    2017-03-01

    Evaluation of spatial and temporal variability in surface recession of lead-lettered Carrara marble gravestones provides a quantitative measure of acid flux to the stone surfaces and is closely related to local land use and air quality. Correlation of stone decay, land use, and air quality for the period after 1960 when reliable estimates of atmospheric pollution are available is evaluated. Gravestone decay and SO2 measurements are interpolated spatially using deterministic and geostatistical techniques. A general lack of spatial correlation was identified and therefore a land-use-based technique for correlation of stone decay and air quality is employed. Decadally averaged stone decay is highly correlated with land use averaged spatially over an optimum radius of ≈7 km even though air quality, determined by records from the UK monitoring network, is not highly correlated with gravestone decay. The relationships among stone decay, air-quality, and land use is complicated by the relatively low spatial density of both gravestone decay and air quality data and the fact that air quality data is available only as annual averages and therefore seasonal dependence cannot be evaluated. However, acid deposition calculated from gravestone decay suggests that the deposition efficiency of SO2 has increased appreciably since 1980 indicating an increase in the SO2 oxidation process possibly related to reactions with ammonia.

  17. Contamination analysis of radioactive samples in focused ion beam instruments.

    Science.gov (United States)

    Evelan, Audrey Ruth; Brey, Richard R

    2013-02-01

    The use of Focused Ion Beam (FIB) instrument's to analyze and prepare samples that are radioactive requires attentiveness to the materials that are dislodged and free inside the chamber. Radioactive sputtered material must be understood even when observed at trace concentrations. Measurements using liquid scintillation counting and high purity germanium detectors were used to evaluate contamination on accessible surfaces inside a focused ion beam chamber that was used in the preparation of samples that were radioactive. The maximum removable contamination found was 0.27 0.4 Bq cm(-2), on the focused ion beam wall with 0.24 0.019 Bq cm(-2) on the door. Although these magnitudes of removable contamination are inconsequential for activation products, these same magnitudes of actinides, for example 239Pu, would represent 3.2% of an Annual Limit of Intake. This might be considered significant if one examines the relatively infrequent use of this device for the preparation of radioactive samples. Predicted activities of sputtered material were found using the software Transport of Ions in Matter, estimating that 0.003% of a radioactive samples activity is released into the FIB chamber. A used secondary electron detector's activity was measured to be 383.7 8.1 Bq. Preferential build-up of sputtered materials due to temperature or static charge gradients was considered. No temperature gradients were observed. Static charge gradients were measured inside the chamber varying between 0.057% below the mean to 34% higher than the mean. However, the magnitudes of contamination measured did not correlate to static charge gradients. Deposition in the chamber appears to have no mechanical cause but rather is sporadic however, measureable. Experience to date has been limited to samples of low activity; nevertheless, contamination inside the chamber was observed. Users should anticipate higher levels of readily dispersible radioactive contamination within the FIB as sample activity

  18. Laboratory Enrichment of Radioactive Assemblages and Estimation of Thorium and Uranium Radioactivity in Fractions Separated from Placer Sands in Southeast Bangladesh

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Takayuki, E-mail: sasaki@nucleng.kyoto-u.ac.jp [Kyoto University, Department of Nuclear Engineering (Japan); Rajib, Mohammad [Bangladesh Atomic Energy Commission, Nuclear Minerals Unit, Atomic Energy Research Establishment (Bangladesh); Akiyoshi, Masafumi; Kobayashi, Taishi; Takagi, Ikuji [Kyoto University, Department of Nuclear Engineering (Japan); Fujii, Toshiyuki [Kyoto University, Research Reactor Institute (Japan); Zaman, Md. Mashrur [Bangladesh Atomic Energy Commission, Nuclear Minerals Unit, Atomic Energy Research Establishment (Bangladesh)

    2015-06-15

    The present study reports the likely first attempt of separating radioactive minerals for estimation of activity concentration in the beach placer sands of Bangladesh. Several sand samples from heavy mineral deposits located at the south-eastern coastal belt of Bangladesh were processed to physically upgrade their radioactivity concentrations using plant and laboratory equipment. Following some modified flow procedure, individual fractions were separated and investigated using gamma-ray spectrometry and powder-XRD analysis. The radioactivity measurements indicated contributions of the thorium and uranium radioactive series and of {sup 40}K. The maximum values of {sup 232}Th and {sup 238}U, estimated from the radioactivity of {sup 208}Tl and {sup 234}Th in secular equilibrium, were found to be 152,000 and 63,300 Bq/kg, respectively. The fraction of the moderately conductive part in electric separation contained thorium predominantly, while that of the non-conductive part was found to be uranium rich. The present arrangement of the pilot plant cascade and the fine tuning of setting parameters were found to be effective and economic separation process of the radioactive minerals from placer sands in Bangladesh. Probable radiological impacts and extraction potentiality of such radioactive materials are also discussed.

  19. Neutron radioactivity-Lifetime measurements of neutron-unbound states

    Science.gov (United States)

    Kahlbow, J.; Caesar, C.; Aumann, T.; Panin, V.; Paschalis, S.; Scheit, H.; Simon, H.

    2017-09-01

    A new technique to measure the lifetime τ of a neutron-radioactive nucleus that decays in-flight via neutron emission is presented and demonstrated utilizing MonteCarlo simulations. The method is based on the production of the neutron-unbound nucleus in a target, which at the same time slows down the produced nucleus and the residual nucleus after (multi-) neutron emission. The spectrum of the velocity difference of neutron(s) and the residual nucleus has a characteristic shape, that allows to extract the lifetime. If the decay happens outside the target there will be a peak in the spectrum, while events where the decay is in the target show a broad flat distribution due to the continuous slowing down of the residual nucleus. The method itself and the analysis procedure are discussed in detail for the specific candidate 26O. A stack of targets with decreasing target thicknesses can expand the measurable lifetime range and improve the sensitivity by increasing the ratio between decays outside and inside the target. The simulations indicate a lower limit of measurable lifetime τ ∼ 0 . 2 ps for the given conditions.

  20. Environmental radioactivity survey in Andong

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-12-15

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

  1. Final disposal of radioactive waste

    Directory of Open Access Journals (Sweden)

    Freiesleben H.

    2013-06-01

    Full Text Available In this paper the origin and properties of radioactive waste as well as its classification scheme (low-level waste – LLW, intermediate-level waste – ILW, high-level waste – HLW are presented. The various options for conditioning of waste of different levels of radioactivity are reviewed. The composition, radiotoxicity and reprocessing of spent fuel and their effect on storage and options for final disposal are discussed. The current situation of final waste disposal in a selected number of countries is mentioned. Also, the role of the International Atomic Energy Agency with regard to the development and monitoring of international safety standards for both spent nuclear fuel and radioactive waste management is described.

  2. Low-level Radioactivity Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Hurtgen, C

    2001-04-01

    The objectives of the research performed in the area of low-level radioactivity measurements are (1) to maintain and develop techniques for the measurement of low-level environmental and biological samples, (2) to measure these samples by means of low-background counters (liquid scintillators, proportional counters, ZnS counters, alpha spectrometry), (3) to support and advice the nuclear and non-nuclear industry in matters concerning radioactive contamination and/or low-level radioactivity measurements; (4) to maintain the quality assurance system according to the EN45001/ISO17025 standard; and (5) to assess the internal dose from occupational intakes of radionuclides of workers of the nuclear industry. Progress and achievements in these areas in 2000 are reported.

  3. Low-level Radioactivity Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Hurtgen, C

    2002-04-01

    The objectives of the research performed in the area of low-level radioactivity measurements are (1) to maintain and develop techniques for the measurement of low-level environmental and biological samples, (2) to measure these samples by means of low-background counters (liquid scintillators, proportional counters, ZnS counters, alpha spectrometry), (3) to support and advise the nuclear and non-nuclear industry on problems of radioactive contamination and low-level radioactivity measurements; (4) to maintain and improve the quality assurance system according to the ISO17025 standard; and (5) to assess the internal dose from occupational intakes of radionuclides of workers of the nuclear industry. Progress and achievements in these areas in 2001 are reported.

  4. Weak Decay of Hypernuclei

    CERN Document Server

    Alberico, W M

    2004-01-01

    The focus of these Lectures is on the weak decay modes of hypernuclei, with special attention to Lambda-hypernuclei. The subject involves many fields of modern theoretical and experimental physics, from nuclear structure to the fundamental constituents of matter and their interactions. The various weak decay modes of Lambda-hypernuclei are described: the mesonic mode and the non-mesonic ones. The latter are the dominant decay channels of medium--heavy hypernuclei, where, on the contrary, the mesonic decay is disfavoured by Pauli blocking effect on the outgoing nucleon. In particular, one can distinguish between one-body and two-body induced decays. Theoretical models employed to evaluate the (partial and total) decay widths of hypernuclei are illustrated, and their results compared with existing experimental data. Open problems and recent achievements are extensively discussed, in particular the determination of the ratio Gamma_n/Gamma_p, possible tests of the Delta I=1/2 rule in non-mesonic decays and the pu...

  5. Radioactive fallout from Chinese nuclear weapons test

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, C.W.; Soldat, J.K.; Silker, W.B.; Perkins, R.W.

    1976-09-26

    Radioactive fallout from this Chinese nuclear test resulted in measurable deposition of short-lived debris over much of the United States. The fallout levels varied by more than 1000-fold and showed significant temporary or spatial fractionation with higher levels of deposition being associated with rain. The particle size with which the airborne debris was associated decreased continuously with time following detonation and a substantial fraction of the {sup 131}I was associated with inorganic and organic gases. The potential radiation dose to an infant consuming milk produced at the location of the highest concentration of {sup 131}I measured on grass was estimated to be {approximately}l rem. This dose is about 50 times the annual dose received in the vicinity of a power reactor operating under the existing US Nuclear Regulatory Commission design guides. The potential upper limit thyroid dose for the population of 17 eastern seaboard states from this single test was estimated to be about 2.4 {times} 10{sup 6} man-thyroid-rem under the assumption that all dairy cows remained on fresh pasture throughout the month following the initial decomposition of fallout debris. This dose is about 200 times the estimated dose from currently operating nuclear power reactors and about 50 times the annual US population thyroid dose that would be received from 500 GWe of nuclear power reactors in the year 2000.

  6. Radioactive Ion Beams and Radiopharmaceuticals

    Science.gov (United States)

    Laxdal, R. E.; Morton, A. C.; Schaffer, P.

    2014-02-01

    Experiments performed at radioactive ion beam facilities shed new light on nuclear physics and nuclear structure, as well as nuclear astrophysics, materials science and medical science. The many existing facilities, as well as the new generation of facilities being built and those proposed for the future, are a testament to the high interest in this rapidly expanding field. The opportunities inherent in radioactive beam facilities have enabled the search for radioisotopes suitable for medical diagnosis or therapy. In this article, an overview of the production techniques and the current status of RIB facilities and proposals will be presented. In addition, accelerator-generated radiopharmaceuticals will be reviewed.

  7. Induced radioactivity in LDEF components

    Science.gov (United States)

    Harmon, B. A.; Fishman, G. J.; Parnell, T. A.; Laird, C. E.

    1992-01-01

    A systematic study of the induced radioactivity of the Long Duration Exposure Facility (LDEF) is being carried out in order to gather information about the low earth orbit radiation environment and its effects on materials. The large mass of the LDEF spacecraft, its stabilized configuration, and long mission duration have presented an opportunity to determine space radiation-induced radioactivities with a precision not possible before. Data presented include preliminary activities for steel and aluminum structural samples, and activation subexperiment foils. Effects seen in the data show a clear indication of the trapped proton anisotropy in the South Atlantic Anomaly and suggest contributions from different sources of external radiation fluxes.

  8. New measurement of exotic decay of 225Ac by 14C emission

    Science.gov (United States)

    Guglielmetti, A.; Bonetti, R.; Ardisson, G.; Barci, V.; Giles, T.; Hussonnois, M.; Le Du, J. F.; Le Naour, C.; Mikheev, V. L.; Pasinetti, A. L.; Ravn, H. L.; Tretyakova, S. P.; Trubert, D.

    The branching ratio of 225Ac decay by emission of 14C was remeasured under improved experimental conditions by using a radioactive source produced at the ISOLDE mass-separator at CERN and a nuclear track detector technique. The result, B = λ14C/λα = (4.5+/-1.4)10-12, is consistent with the anomalously high value obtained in the 1993 experiment, thus confirming the importance of nuclear-structure effects in this exotic decay.

  9. Development of whole energy absorption spectrometer for decay heat measurement on fusion reactor materials

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Fujio; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    To measure decay heat on fusion reactor materials irradiated by D-T neutrons, a Whole Energy Absorption Spectrometer (WEAS) consisting of a pair of large BGO (bismuth-germanate) scintillators was developed. Feasibility of decay heat measurement with WEAS for various materials and for a wide range of half-lives (seconds - years) was demonstrated by experiments at FNS. Features of WEAS, such as high sensitivity, radioactivity identification, and reasonably low experimental uncertainty of {approx} 10 %, were found. (author)

  10. Tools and publications for reference decay data

    Energy Technology Data Exchange (ETDEWEB)

    Dulieu, C.; Be, M.M.; Chiste, V. [CEA Saclay, Lab. National Henri Becquerel (LNE-CEA/LNHB), 91 - Gif sur Yvette (France)

    2008-07-01

    As a primary laboratory in the field of ionizing radiation metrology, the LNE-CEA/LNHB is involved in measurement, evaluation and dissemination of radioactive decay data. Data measurements obtained by various laboratories are evaluated by an international group of experts (Decay Data Evaluation Project) in order to establish a set of recommended decay scheme data. Those data are subsequently distributed to users through various tools developed in our laboratory and well suited to each application domain. They are presented in an exhaustive and documented way through the publication of a multi-volume printed monograph (Monographie BIPM-5), for which a new issue has been released by the end of 2006. This monograph is recommended as a reference database by the CCRI (Ionizing Radiation Consultative Committee) of the BIPM. Those data can also be accessed via a specific software NUCLEIDE whose database contains more than 300 nuclides of particular interest. In the field of alpha and gamma spectrometry, a web application has been specially developed in order to present the major emissions of a given nuclide. Moreover, it allows us to find nuclides corresponding to search criteria on their emission energies or intensities. Finally a booklet version of this database will soon be published. It will present in a concise way the main alpha, X, gamma and electron emissions and their half-life, for some 250 nuclides. This paper intends to describe some features of these tools and publications. (authors)

  11. Axions from wall decay

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S; Hagmann, C; Sikivie, P

    2001-01-08

    The authors discuss the decay of axion walls bounded by strings and present numerical simulations of the decay process. In these simulations, the decay happens immediately, in a time scale of order the light travel time, and the average energy of the radiated axions is {approx_equal} 7m{sub a} for v{sub a}/m{sub a} {approx_equal} 500. is found to increase approximately linearly with ln(v{sub a}/m{sub a}). Extrapolation of this behavior yields {approx_equal} 60 m{sub a} in axion models of interest.

  12. Rare decays at LHCb

    CERN Document Server

    Lafferty, George

    2015-01-01

    We review recent results from the LHCb experiment on studies of particle decays that are forbidden or rare in the Standard Model. The studies include searches for lepton flavour violating decays of the $\\tau$ lepton and the $B$ and $D$ mesons, and of $B$ and $D$ meson decays that would be mediated by Majorana neutrinos. Results are also presented for the rare processes $B_s \\to \\mu^+\\mu^-$ and $B^0 \\to \\mu^+\\mu^-$, $D^0 \\to \\pi^+\\pi^-\\mu^+\\mu^-$, $b \\to s\\gamma$ transitions, and $B \\to K^{(*)}\\mu^+\\mu^-$.

  13. Global risk of radioactive fallout after nuclear reactor accidents

    Science.gov (United States)

    Kunkel, D.; Lelieveld, J.; Lawrence, M. G.

    2012-04-01

    Reactor core meltdowns of nuclear power plants are rare, yet the consequences are catastrophic. But what is meant by "rare"? And what can be learned from the Chernobyl and Fukushima incidents? Here we assess the risk of exposure to radioactivity due to atmospheric dispersion of gases and particles following severe nuclear accidents, using particulate 137Cs and gaseous 131I as proxies for the fallout. It appears that previously the occurrence of major accidents and the risks of radioactive contamination have been underestimated. Using a global model of the atmosphere we compute that on average, in the event of a core melt of any nuclear power plant worldwide, more than 90 % of emitted 137Cs would be transported beyond 50 km and about 50 % beyond 1000 km distance. This corroborates that such accidents have large-scale and trans-boundary impacts. Although the emission strengths and atmospheric removal processes of 137Cs and 131I are quite different, the radioactive contamination patterns over land and the human deposition exposure are computed to be similar. High human exposure risks occur around reactors in densely populated regions, notably in southern Asia where a core melt can subject 55 million people to radioactive contamination. The recent decision by Germany to phase out its nuclear reactors will reduce the national risk, though a large risk will still remain from the reactors in neighbouring countries.

  14. Non-leptonic decays of beauty decays

    CERN Document Server

    Bigi, Ikaros I; Shifman, M; Uraltsev, N; Vainshtein, A I

    1994-01-01

    "Anyone who keeps the ability to see beauty never grows old" (Franz Kafka). In the last few years considerable progress has been achieved in our understanding of the decays of heavy flavour hadrons. One can now calculate inclusive transition rates in QCD proper through an expansion in inverse powers of the heavy flavour quark mass without recourse to phenomenological assumptions. The non-perturbative contributions are treated systematically in this way; they are found to produce corrections of order a few percent in beauty decays, i.e. typically somewhat smaller than the perturbative corrections. One finds, among other things: (a) The lifetime of $B^-$ mesons is predicted to be longer than that of $B^0$ mesons by several percent. (b) The QCD prediction for the semileptonic branching ratio of $B$ mesons appears to exceed present experimental values.

  15. Weak decays and double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Nicholson, H.W.

    1983-08-01

    Work to measure the ..sigma../sup +/ 0 degree differential cross section in the reaction K/sup -/p ..-->.. ..sigma../sup +/..pi../sup -/ at several incident K/sup -/ momenta between 600 and 800 MeV/c as well as the asymmetries in the decays of polarized ..sigma../sup +/'s into protons and neutral pions and of polarized ..sigma../sup -/'s into neutrons and negative pions in collaboration with experimenters from Yale, Brookhaven, and the University of Pittsburgh (Brookhaven experiment 702) has been completed. Data from this experiment is currently being analyzed at Yale. Work is currently underway to develop and construct an experiment to search for neutrinoless double beta decay in thin foils of Mo/sup 100/ in collaboration with experimenters from Lawrence Berkeley Laboratory. Development work on the solid state silicon detectors should be complete in the next six months and construction should e well underway within the next year.

  16. Modelling the Effects of Radioactive Effluent on Thunnus orientalis and Oncorhynchus gorbuscha

    Directory of Open Access Journals (Sweden)

    Zhixiong Chen

    2013-01-01

    Full Text Available The contamination of the Pacific Ocean by the radioactive pollutants released from the Fukushima Daiichi Nuclear Power Plant has raised legitimate concerns over the viability of marine wildlife. We develop a modified Crank-Nicholson method to approximate a solution to the diffusion-advection-decay equation in time and three spatial dimensions to explore the extent of the effects of the radioactive effluent on two marine species: the Pacific Bluefin Tuna (Thunnus orientalis and the Pacific Pink Salmon (Oncorhynchus gorbuscha.

  17. Reper Radioactive Sources for Time and Energy Calibration of Single Crystal Scintillation Time Spectrometers

    CERN Document Server

    Lebedev, N A; Morozova, N V; Novgorodov, A F; Filossofov, D V

    2000-01-01

    There was made a set of reper radioactive sources for time and energy calibration of the single crystal scintillation time spectrometer. The set consists of ^{73}As, ^{153}Gd, ^{169}Yb, ^{241}Am sources and sources of ^{225}Ac and ^{232}Th including the products of their decay. This set of radioactive sources covers the time interval from 4 ns to 4 mus and energy interval starting from 10 keV. Some of these sources were included in the small size plastic scintillators providing the 4 pi geometry for radiation measurements.

  18. Theoretical Studies of Proton Radioactivity

    Institute of Scientific and Technical Information of China (English)

    Ldia S Ferreira; Enrico Maglione

    2016-01-01

    In the paper, we will discuss the most recent theoretical approaches developed by our group, to understand the mechanisms of decay by one proton emission, and the structure and shape of exotic nuclei at the limits of stability.

  19. Systematics of half-lives for proton radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, E.L.; Rodrigues, M.M.N.; Duarte, S.B.; Tavares, O.A.P. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mails: emil@cbpf.br; sbd@cbpf.br; oaptavares@cbpf.br

    2007-07-01

    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 {approx} 30 orders of magnitude in half-life, has shown, in addition, very adequate at fitting all existing data on partial half-life, T{sub 1/2p}, 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 Z{sub d}({mu}{sub 0}/Q{sub p}){sub 1/2} (Z{sub d} is the atomic number of the daughter nucleus, {mu}{sub 0} is the reduced mass, and Q{sub p} is the total nuclear energy available for decay). These straight lines are shown to correspond to different degrees of deformation, namely, very prolate ({delta}> 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)

  20. IGRIS for characterizing low-level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Peters, C.W. [Nuclear Diagnostic Systems, Springfield, VA (United States); Swanson, P.J. [Concord Associates, Knoxville, TN (United States)

    1993-03-01

    A recently developed neutron diagnostic probe system has the potential to noninvasively characterize low-level radioactive waste in bulk soil samples, containers such as 55-gallon barrels, and in pipes, valves, etc. The probe interrogates the target with a low-intensity beam of 14-MeV neutrons produced from the deuterium-tritium reaction in a specially designed sealed-tube neutron-generator (STNG) that incorporates an alpha detector to detect the alpha particle associated with each neutron. These neutrons interact with the nuclei in the target to produce inelastic-, capture-, and decay-gamma rays that are detected by gamma-ray detectors. Time-of-flight methods are used to separate the inelastic-gamma rays from other gamma rays and to determine the origin of each inelastic-gamma ray in three dimensions through Inelastic-Gamma Ray Imaging and Spectroscopy (IGRIS). The capture-gamma ray spectrum is measured simultaneously with the IGRIS measurements. The decay-gamma ray spectrum is measured with the STNG turned off. Laboratory proof-of-concept measurements were used to design prototype systems for Bulk Soil Assay, Barrel Inspection, and Decontamination and Decommissioning and to predict their minimum detectable levels for heavy toxic metals (As, Hg, Cr, Zn, Pb, Ni, and Cd), uranium and transuranics, gamma-ray emitters, and elements such as chlorine, which is found in PCBs and other pollutants. These systems are expected to be complementary and synergistic with other technologies used to characterize low-level radioactive waste.

  1. Radioactive wastes in Oklo; Desechos radiactivos en Oklo

    Energy Technology Data Exchange (ETDEWEB)

    Balcazar, M.; Flores R, J.H.; Pena, P.; Lopez, A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2006-07-01

    The acceptance of the Nuclear Energy as electric power supply implies to give answer to the population on the two main challenges to conquer in the public opinion: the nuclear accidents and the radioactive wastes. Several of the questions that are made on the radioactive wastes, its are the mobility migration of them, the geologic stability of the place where its are deposited and the possible migration toward the aquifer mantels. Since the half lives of the radioactive waste of a Nuclear Reactor are of several hundred of thousands of years, the technical explanations to the previous questions little convince to the public in general. In this work summary the results of the radioactive waste generated in a natural reactor, denominated Oklo effect that took place in Gabon, Africa, it makes several thousands of millions of years, a lot before the man appeared in the Earth. The identification of at least 17 reactors in Oklo it was carried out thanks to the difference in the concentrations of Uranium 235 and 238 prospective, and to the analysis of the non-mobility of the radioactive waste in the site. It was able by this way to determine that the reactors with sizes of hardly some decimeter and powers of around 100 kilowatts were operating in intermittent and spontaneous form for space of 150,000 years, with operation cycles of around 30 minutes. Recent studies have contributed information valuable on the natural confinement of the radioactive waste of the Oklo reactors in matrixes of minerals of aluminum phosphate that caught and immobilized them for thousands of millions of years. This extracted information from the nature contributes guides and it allows 'to verify' the validity of the current proposals on the immobilization of radioactive wastes of a nuclear reactor. This work presents in clear and accessible form to the public in general on the secure 'design', operation, 'decommissioning' and 'storage' of the radioactive

  2. CLEO Results B Decays

    CERN Document Server

    Cassel, David G

    2001-01-01

    Measurements of many Standard Model constants are clouded by uncertainties in nonperturbative QCD parameters that relate measurable quantities to the underlying parton-level processes. Generally these QCD parameters have been obtained from model calculations with large uncertainties that are difficult to quantify. The CLEO Collaboration has taken a major step towards reducing these uncertainties in determining the CKM matrix elements Vcb and Vub using new measurements of the branching fraction and photon energy spectrum of B -> s gamma decays. This report includes: the new CLEO measurements of B -> s gamma decays, Vcb, and Vub; the first results from CLEO III data -- studies of B -> K pi, pi pi, and K Kbar decays; mention of some other recent CLEO B decay results; and plans for operating CESR and CLEO in the charm threshold region.

  3. RARE KAON DECAYS.

    Energy Technology Data Exchange (ETDEWEB)

    LITTENBERG, L.

    2005-07-19

    Lepton flavor violation (LFV) experiments have probed sensitivities corresponding to mass scales of well over 100 TeV, making life difficult for models predicting accessible LFV in kaon decay and discouraging new dedicated experiments of this type.

  4. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Kai Zuber

    2012-10-01

    The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  5. Inflaton decay in supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Endo, M.; Takahashi, F. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yanagida, T.T. [Tokyo Univ. (Japan). Dept. of Physics]|[Tokyo Univ. (Japan). Research Center for the Early Universe

    2007-06-15

    We discuss inflaton decay in supergravity, taking account of the gravitational effects. It is shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential at the tree level, and to any gauge sectors through anomalies in the supergravity. Through these processes, the inflaton generically decays into the supersymmetry breaking sector, producing many gravitinos. The inflaton also directly decays into a pair of the gravitinos. We derive constraints on both inflation models and supersymmetry breaking scenarios for avoiding overproduction of the gravitinos. Furthermore, the inflaton naturally decays into the visible sector via the top Yukawa coupling and SU(3){sub C} gauge interactions. (orig.)

  6. Inflaton decay in supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Endo, M.; Takahashi, F. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yanagida, T.T. [Tokyo Univ. (Japan). Dept. of Physics]|[Tokyo Univ. (Japan). Research Center for the Early Universe

    2007-06-15

    We discuss inflaton decay in supergravity, taking account of the gravitational effects. It is shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential at the tree level, and to any gauge sectors through anomalies in the supergravity. Through these processes, the inflaton generically decays into the supersymmetry breaking sector, producing many gravitinos. The inflaton also directly decays into a pair of the gravitinos. We derive constraints on both inflation models and supersymmetry breaking scenarios for avoiding overproduction of the gravitinos. Furthermore, the inflaton naturally decays into the visible sector via the top Yukawa coupling and SU(3){sub C} gauge interactions. (orig.)

  7. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>20070291 Gong Ping (Northern Fujian Geological Party, Shaozou 354000) Discussion on Geological Characteristics and Control Factors of the Shimen Au-polymetallic Deposit in Zhenghe County, Fujian Province (Geology of Fujian, ISSN1001-3970, CN38-1080/P, 25(1), 2006, p.18-24, 2 illus., 2 tables, 1 ref.) Key words: gold deposits, polymetallic deposits, Fujian Province

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-06-01

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

  9. Radioactive Ages of Metal-Poor Halo Stars

    Institute of Scientific and Technical Information of China (English)

    Ji Li; Gang Zhao

    2004-01-01

    The abundances of long-lived radioactive elements Th and U observed in metal-poor halo stars can be used as chronometers to determine the age of individual stars, and hence set a lower limit on the age of the Galaxy and hence of the universe.This radioactive dating requires the zero-decay productions of Th and U, which involves complicated r-process nucleosynthesis calculations. Several parametric rprocess models have been used to calculate the initial abundance ratios of Th/Eu and U/Th, but, due to the sharp sensitivity of these models to nuclear physics inputs, the calculations have relatively large uncertainties which lead to large uncertainties in the age determinations. In order to reduce these uncertainties, we present a simple method to estimate the initial productions of Th and U, which only depends on the solar system abundances and the stellar abundances of stable r-process elements.From our calculations of the initial abundance ratios of Th/Eu and U/Th, we reestimate the ages of those very metal-poor halo stars with published abundances of Th and U. Our age estimates are consistent, within the errors, with the other age determinations derived from r-process models, and offer useful constrains for r-process theoretical calculations. The advantages and limitations of our simple method of radioactive dating are discussed.

  10. Streamer chamber: pion decay

    CERN Multimedia

    1992-01-01

    The real particles produced in the decay of a positive pion can be seen in this image from a streamer chamber. Streamer chambers consist of a gas chamber through which a strong pulsed electric field is passed, creating sparks as a charged particle passes through it. A magnetic field is added to cause the decay products to follow curved paths so that their charge and momentum can be measured.

  11. Open Flavor Strong Decays

    Science.gov (United States)

    García-Tecocoatzi, H.; Bijker, R.; Ferretti, J.; Galatà, G.; Santopinto, E.

    2016-10-01

    In this contribution, we discuss the results of a QM calculation of the open-flavor strong decays of **** light nucleon resonances. These are the results of a recent calculation, where we used a modified ^3P_0 model for the amplitudes and the U(7) algebraic model and the hypercentral quark model to predict the baryon spectrum. The decay amplitudes are compared with the existing experimental data.

  12. Laser assisted {alpha} decay

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda Cortes, Hector Mauricio

    2012-02-01

    Excited or short-lived nuclei often decay by emitting alpha particles that are assumed to be preformed inside the nucleus and confined in the nuclear potential well. In this picture, {alpha} decay refers to the tunneling of the alpha particle through the potential barrier. In this thesis we investigate for the first time how strong laser fields can assist the tunneling of the alpha particle and thus influence the nuclear decay. Generally speaking, laser-assisted {alpha} decay can be described as laser-assisted tunneling of a quasistationary state, i.e, a slowly decaying state. Our theoretical treatment is developed starting from the complex trajectory formulation of the well-known strong-field approximation used to describe laser-induced ionization. We extend this formulation and develop a method to treat the decay of quasistationary states. The effect of both static and optical and X-ray monochromatic fields on the lifetimes and {alpha}-particle emission spectra are investigated for a number of {alpha}-emitting nuclei. We find that even at strong intensities, the laser-induced acceleration of the {alpha} decay is negligible, ranging from a relative modification in the decay rate of 10{sup -3} for static fields of electric field strengths of 10{sup 15} V/m, to 10{sup -8} for strong optical fields with intensities of 10{sup 22} W/cm{sup 2}, and to 10{sup -6} for strong X-ray fields with laser intensities around 10{sup 24} W/cm{sup 2}. However, the effect of the external field is visible in the spectrum of emitted alpha particles, leading in the case of optical fields even to rescattering phenomena for intensities approaching 6 x 10{sup 22} W/cm{sup 2}. The dynamics of the alpha particle in laser fields of intensities below the rescattering limit is investigated.

  13. Solar Neutrino Decay

    CERN Document Server

    Acker, A; Acker, Andy; Pakvasa, Sandip

    1994-01-01

    We re-examine the neutrino decay solution to the solar neutrino problem in light of the new data from Gallex II and Kamiokande III. We compare the experimental data with the solar models of Bahcall and Pinsonneault and Turck-Chieze and find that neutrino decay is ruled out as a solution to the solar neutrino problem at better than the 98\\% c.l. even when solar model uncertainties are taken into account.

  14. Aspects of B decays

    Energy Technology Data Exchange (ETDEWEB)

    Faller, Sven

    2011-03-04

    B-meson decays are a good probe for testing the flavour sector of the standard model of particle physics. The standard model describes at present all experimental data satisfactorily, although some ''tensions'' exist, i.e. two to three sigma deviations from the predictions, in particular in B decays. The arguments against the standard model are thus purely theoretical. These tensions between experimental data and theoretical predictions provide an extension of the standard model by new physics contributions. Within the flavour sector main theoretical uncertainties are related to the hadronic matrix elements. For exclusive semileptonic anti B {yields} D{sup (*)}l anti {nu} decays QCD sum rule techniques, which are suitable for studying hadronic matrix elements, however, with substantial, but estimable hadronic uncertainties, are used. The exploration of new physics effects in B-meson decays is done in an twofold way. In exclusive semileptonic anti B {yields} D{sup (*)}l anti {nu} decays the effect of additional right-handed vector as well as left- and right-handed scalar and tensor hadronic current structures in the decay rates and the form factors are studied at the non-recoil point. As a second approach one studied the non-leptonic B{sup 0}{sub s}{yields}J/{psi}{phi} and B{sup 0}{yields}J/{psi}K{sub S,L} decays discussing CP violating effects in the time-dependent decay amplitudes by considering new physics phase in the B{sup 0}- anti B{sup 0} mixing phase. (orig.)

  15. High-Level Radioactive Waste.

    Science.gov (United States)

    Hayden, Howard C.

    1995-01-01

    Presents a method to calculate the amount of high-level radioactive waste by taking into consideration the following factors: the fission process that yields the waste, identification of the waste, the energy required to run a 1-GWe plant for one year, and the uranium mass required to produce that energy. Briefly discusses waste disposal and…

  16. Radioactivity in Dutch consumer products

    CERN Document Server

    Janssen, M P M

    2002-01-01

    This study took place within the framework of a general update of the average radiation dose for the Dutch population. It focuses on consumer products in which radionuclides have been intentionally incorporated and on radiation-emitting devices that can be supplied to members of the public without special surveillance. Eleven consumer products were studied in more detail. The radiation from these products determined 90% of the total collective dose due to consumer products in the Netherlands in 1988. Individual and collective doses are presented here for each product. The total collective dose has decreased from 130 personSv in 1988 to 4.6 personSv at present. This reduction was attributed to: a decrease in the number of radioactive products (gas mantles), lower estimates of the number of radioactive products present in the Netherlands thanks to new information (camera lenses, smoke detectors containing Ra-226), replacement of radioactive by non-radioactive products (gas mantles, dental protheses), and a lowe...

  17. Traps for neutral radioactive atoms

    CERN Document Server

    Sprouse, G D; Grossman, J S; Orozco, L A; Pearson, M R

    2002-01-01

    We describe several methods for efficiently injecting a small number of radioactive atoms into a laser trap. The characteristics of laser traps that make them desirable for physics experiments are discussed and several different experimental directions are described. We describe recent experiments with the alkali element Fr and point to future directions of the neutral atom trapping program.

  18. Keeping an Eye on Radioactivity

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    China sets up a national testing system for levels of radiation from various sources Radioactive iodine had been detected in the air above several regions of China,said China’s National Nuclear Emergency Coordination Committee on March 29.The regions include Heilongjiang

  19. Mass measurement of radioactive isotopes

    CERN Document Server

    Kluge, H J; Scheidenberger, C

    2004-01-01

    The highest precision in mass measurements on short-lived radionuclides is obtained using trapping and cooling techniques. Here, the experimental storage ring (ESR) at GSI/Darmstadt and the tandem Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN play an important role. Status and recent results on mass measurements of radioactive nuclides with ESR and ISOLTRAP are summarized.

  20. Indian programme on radioactive waste management

    Indian Academy of Sciences (India)

    P K Wattal

    2013-10-01

    The primary objective of radioactive waste management is protection of human health, environment and future generation. This article describes, briefly, the Indian programme on management of different radioactive wastes arising in the entire nuclear fuel cycle adhering to this objective.

  1. Nuclear Structure Studies from Hg and Au Alpha Decay Chains

    Science.gov (United States)

    Goon, J. Tm.; Bingham, C. R.; Hartley, D. J.; Zhang, Jing-Ye; Riedinger, L. L.; Danchev, M.; Kondev, F. G.; Carpenter, M. P.; Janssens, R. V. F.; Abu Saleem, K. H.; Ahmad, I.; Davids, C. N.; Heinz, A.; Khoo, T. L.; Lauritsen, T.; Lister, C. J.; Poli, G. L.; Seweryniak, D.; Wiedenhover, I.; Ma, W. C.; Amro, H.; Reviol, W.; Cizewski, J. A.; Smith, M.

    2003-04-01

    Neutron deficient nuclei near the Z = 82 shell gap have been a source of great interest. This region is known to exhibit the phenomena of shape-coexistence and triaxiality. Alpha decay study of these nuclei coupled with gamma-rayspectroscopy data can give a better understanding of their nuclear structure properties. The decay chains of ^173-177Au and ^175-179Hg were studied following the bombardment of ^92,94,96Mo targets with ^84Sr beam from the ATLAS accelerator at the Argonne National Laboratory. The experiment utilized the Gammasphere array in conjunction with the Fragment Mass Analyzer (FMA) for mass identification and a Double-sided Silicon Strip Detector (DSSD) that was used to detect the recoiling implants and the alpha particles associated with each nuclide. An array of four Ge detectors and a low-energy photon spectrometer (LEPS) was used at the focal plane of the FMA to detect γ rays in coincidence with the α particles. This information was used to elucidate the α-decay fine structures. Inverse radioactive decay tagging was also useful in assigning certain fine structure α peaks to a particular nuclide. New α decay lines were observed and their energies, and half-lives were measured. These include fine structure lines in the α decays of ^174,176Au and ^173Pt. The decay schemes resulting from the fine structure observations will be presented. The α decay reduced widths are used to suggest spin and parity assignments. The structure of these states will be discussed in the framework of the Nilsson model and alpha decay selection rules. * This work is supported by the Department of Energy through contract numbers DE-FG02-96ER40983 (UT), W-31-109-ENG-38 (ANL), DE-FG02-95ER40939 (MSU), DE-FG05-88ER40406 (WU), and by the National Science Foundation (RU

  2. Environmental aspects of commercial radioactive waste management

    Energy Technology Data Exchange (ETDEWEB)

    1979-05-01

    Volume 2 contains chapters 6 through 10: environmental effects related to radioactive waste management associated with LWR fuel reprocessing - mixed-oxide fuel fabrication plant; environmental effects related to transporting radioactive wastes associated with LWR fuel reprocessing and fabrication; environmental effects related to radioactive waste management associated with LWR fuel reprocessing - retrievable waste storage facility; environmental effects related to geologic isolation of LWR fuel reprocessing wastes; and integrated systems for commercial radioactive waste management. (LK)

  3. Unexpected high-energy γ emission from decaying exotic nuclei

    Directory of Open Access Journals (Sweden)

    A. Gottardo

    2017-09-01

    Full Text Available The N=52 Ga83 β decay was studied at ALTO. The radioactive 83Ga beam was produced through the ISOL photofission technique and collected on a movable tape for the measurement of γ-ray emission following β decay. While β-delayed neutron emission has been measured to be 56–85% of the decay path, in this experiment an unexpected high-energy 5–9 MeV γ-ray yield of 16(4% was observed, coming from states several MeVs above the neutron separation threshold. This result is compared with cutting-edge QRPA calculations, which show that when neutrons deeply bound in the core of the nucleus decay into protons via a Gamow–Teller transition, they give rise to a dipolar oscillation of nuclear matter in the nucleus. This leads to large electromagnetic transition probabilities which can compete with neutron emission, thus affecting the β-decay path. This process is enhanced by an excess of neutrons on the nuclear surface and may thus be a common feature for very neutron-rich isotopes, challenging the present understanding of decay properties of exotic nuclei.

  4. 49 CFR 175.705 - Radioactive contamination.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Radioactive contamination. 175.705 Section 175.705... Regulations Applicable According to Classification of Material § 175.705 Radioactive contamination. (a) A... (radioactive) materials that may have been released from their packagings. (b) When contamination is present...

  5. 46 CFR 147.100 - Radioactive materials.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Radioactive materials. 147.100 Section 147.100 Shipping... Stowage and Other Special Requirements for Particular Materials § 147.100 Radioactive materials. (a) Radioactive materials must not be brought on board, used in any manner, or stored on the vessel, unless the...

  6. Treatment of Radioactive Contaminated Soil and Concrete Wastes Using the Regulatory Clearance

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Il Sik; Ryu, W. S.; Kim, T. K.; Shon, J. S.; Ahn, S. J.; Lee, Y. H.; Bae, S. M.; Hong, D. S.; Ji, Y. Y.; Lee, B. C

    2008-11-15

    In the radioactive waste storage facilities at the Korea Atomic Energy Research Institute (KAERI) in Daejoen, there are thousands drums of radioactive contaminated soil and concrete wastes. The soil and concrete wastes were generated in 1988 during the decommissioning process of the research reactor and the attached radioactive waste treatment facility which were located in Seoul. The wastes were transported to Daejeon and have been stored since then. At the generation time, the radioactive contamination of the wastes was very low, and the radionuclides in the wastes was Co-60 and Cs-137. As the wastes have been stored for more than 20 years, the radioactivity concentration of the wastes has been decayed to become very extremely low. The wastes are needed to be treated because they take up large spaces at the storage facility. Also by treating the wastes, final disposal cost can be saved. So, the regulatory clearance was considered as a treatment method for the soil and concrete wastes with extremely low radioactivity concentration.

  7. Treatment of Radioactive Contaminated Soil and Concrete Wastes Using the Regulatory Clearance

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Il Sik; Ryu, W. S.; Kim, T. K.; Shon, J. S.; Ahn, S. J.; Lee, Y. H.; Bae, S. M.; Hong, D. S.; Ji, Y. Y.; Lee, B. C

    2008-11-15

    In the radioactive waste storage facilities at the Korea Atomic Energy Research Institute (KAERI) in Daejoen, there are thousands drums of radioactive contaminated soil and concrete wastes. The soil and concrete wastes were generated in 1988 during the decommissioning process of the research reactor and the attached radioactive waste treatment facility which were located in Seoul. The wastes were transported to Daejeon and have been stored since then. At the generation time, the radioactive contamination of the wastes was very low, and the radionuclides in the wastes was Co-60 and Cs-137. As the wastes have been stored for more than 20 years, the radioactivity concentration of the wastes has been decayed to become very extremely low. The wastes are needed to be treated because they take up large spaces at the storage facility. Also by treating the wastes, final disposal cost can be saved. So, the regulatory clearance was considered as a treatment method for the soil and concrete wastes with extremely low radioactivity concentration.

  8. A system for aerodynamically sizing ultrafine environmental radioactive particles

    Energy Technology Data Exchange (ETDEWEB)

    Olawoyin, L.

    1995-09-01

    The unattached environmental radioactive particles/clusters, produced mainly by {sup 222}Rn in indoor air, are usually few nanometers in size. The inhalation of these radioactive clusters can lead to deposition of radioactivity on the mucosal surface of the tracheobronchial tree. The ultimate size of the cluster together with the flow characteristics will determine the depositional site in the human lung and thus, the extent of damage that can be caused. Thus, there exists the need for the determination of the size of the radioactive clusters. However, the existing particle measuring device have low resolution in the sub-nanometer range. In this research, a system for the alternative detection and measurement of the size of particles/cluster in the less than 2 nm range have been developed. The system is a one stage impactor which has a solid state spectrometer as its impaction plate. It`s major feature is the nozzle-to-plate separation, L. The particle size collected changes with L and thus, particle size spectroscopy is achieved by varying L. The number of collected particles is determined by alpha spectroscopy. The size-discriminating ability of the system was tested with laboratory generated radon particles and it was subsequently used to characterize the physical (size) changes associated with the interaction of radon progeny with water vapor and short chain alcohols in various support gases. The theory of both traditional and high velocity jet impactors together with the design and evaluation of the system developed in this study are discussed in various chapters of this dissertation. The major results obtained in the course of the study are also presented.

  9. Global risk of radioactive fallout after major nuclear reactor accidents

    Science.gov (United States)

    Lelieveld, J.; Kunkel, D.; Lawrence, M. G.

    2012-05-01

    Major reactor accidents of nuclear power plants are rare, yet the consequences are catastrophic. But what is meant by "rare"? And what can be learned from the Chernobyl and Fukushima incidents? Here we assess the cumulative, global risk of exposure to radioactivity due to atmospheric dispersion of gases and particles following severe nuclear accidents (the most severe ones on the International Nuclear Event Scale, INES 7), using particulate 137Cs and gaseous 131I as proxies for the fallout. Our results indicate that previously the occurrence of INES 7 major accidents and the risks of radioactive contamination have been underestimated. Using a global model of the atmosphere we compute that on average, in the event of a major reactor accident of any nuclear power plant worldwide, more than 90% of emitted 137Cs would be transported beyond 50 km and about 50% beyond 1000 km distance before being deposited. This corroborates that such accidents have large-scale and trans-boundary impacts. Although the emission strengths and atmospheric removal processes of 137Cs and 131I are quite different, the radioactive contamination patterns over land and the human exposure due to deposition are computed to be similar. High human exposure risks occur around reactors in densely populated regions, notably in West Europe and South Asia, where a major reactor accident can subject around 30 million people to radioactive contamination. The recent decision by Germany to phase out its nuclear reactors will reduce the national risk, though a large risk will still remain from the reactors in neighbouring countries.

  10. Global risk of radioactive fallout after major nuclear reactor accidents

    Directory of Open Access Journals (Sweden)

    J. Lelieveld

    2012-05-01

    Full Text Available Major reactor accidents of nuclear power plants are rare, yet the consequences are catastrophic. But what is meant by "rare"? And what can be learned from the Chernobyl and Fukushima incidents? Here we assess the cumulative, global risk of exposure to radioactivity due to atmospheric dispersion of gases and particles following severe nuclear accidents (the most severe ones on the International Nuclear Event Scale, INES 7, using particulate 137Cs and gaseous 131I as proxies for the fallout. Our results indicate that previously the occurrence of INES 7 major accidents and the risks of radioactive contamination have been underestimated. Using a global model of the atmosphere we compute that on average, in the event of a major reactor accident of any nuclear power plant worldwide, more than 90% of emitted 137Cs would be transported beyond 50 km and about 50% beyond 1000 km distance before being deposited. This corroborates that such accidents have large-scale and trans-boundary impacts. Although the emission strengths and atmospheric removal processes of 137Cs and 131I are quite different, the radioactive contamination patterns over land and the human exposure due to deposition are computed to be similar. High human exposure risks occur around reactors in densely populated regions, notably in West Europe and South Asia, where a major reactor accident can subject around 30 million people to radioactive contamination. The recent decision by Germany to phase out its nuclear reactors will reduce the national risk, though a large risk will still remain from the reactors in neighbouring countries.

  11. Background radioactivity of construction materials, raw substance and ready-made CaMoO4 crystals

    CERN Document Server

    Busanov, O A; Gavriljuk, Yu M; Gezhaev, A M; Kazalov, V V; Kornoukhov, V N; Kuzminov, V V; Moseev, P S; Panasenko, S I; Ratkevich, S S; Yakimenko, S P

    2013-01-01

    The results of measurements of natural radioactive isotopes content in different source materials of natural and enriched composition used for CaMoO4 scintillation crystal growing are presented. The crystals are to be used in the experiment to search for double neutrinoless betas-decay of Mo-100.

  12. Background radioactivity of construction materials, raw substance and ready-made CaMoO4 crystals

    Directory of Open Access Journals (Sweden)

    Busanov O.A.

    2014-01-01

    Full Text Available The results of measurements of natural radioactive isotopes content in different source materials of natural and enriched composition used for CaMoO4 scintillation crystal growing are presented. The crystals are to be used in the experiment to search for neutrinoless double beta decay of 100Mo.

  13. Measurement of radioactive contamination in the high-resistivity silicon CCDs of the DAMIC experiment

    CERN Document Server

    Aguilar-Arevalo, A; Bertou, X; Bole, D; Butner, M; Cancelo, G; Vázquez, A Castañeda; Chavarria, A E; Neto, J R T de Mello; Dixon, S; D'Olivo, J C; Estrada, J; Moroni, G Fernandez; Torres, K P Hernández; Izraelevitch, F; Kavner, A; Kilminster, B; Lawson, I; Liao, J; López, M; Molina, J; Moreno-Granados, G; Pena, J; Privitera, P; Sarkis, Y; Scarpine, V; Schwarz, T; Haro, M Sofo; Tiffenberg, J; Machado, D Torres; Trillaud, F; You, X; Zhou, J

    2015-01-01

    We present measurements of radioactive contamination in the high-resistivity silicon charge-coupled devices (CCDs) used by the DAMIC experiment to search for dark matter particles. Novel analysis methods, which exploit the unique spatial resolution of CCDs, were developed to identify $\\alpha$ and $\\beta$ particles. Uranium and thorium contamination in the CCD bulk was measured through $\\alpha$ spectroscopy, with an upper limit on the $^{238}$U ($^{232}$Th) decay rate of 5 (15) kg$^{-1}$ d$^{-1}$ at 95% CL. We also searched for pairs of spatially correlated electron tracks separated in time by up to tens of days, as expected from $^{32}$Si-$^{32}$P or $^{210}$Pb-$^{210}$Bi sequences of $\\beta$ decays. The decay rate of $^{32}$Si was found to be $80^{+110}_{-65}$ kg$^{-1}$ d$^{-1}$ (95% CI). An upper limit of $\\sim$35 kg$^{-1}$ d$^{-1}$ (95% CL) on the $^{210}$Pb decay rate was obtained independently by $\\alpha$ spectroscopy and the $\\beta$ decay sequence search. These levels of radioactive contamination are su...

  14. Characterization of Aged Radioactive Pollucite

    Energy Technology Data Exchange (ETDEWEB)

    Fortner, Jeffrey [Argonne National Lab. (ANL), Argonne, IL (United States); Kropf, A. Jeremy [Argonne National Lab. (ANL), Argonne, IL (United States); Kaminski, Michael [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-10-01

    The objective of this task was to provide information to better understand the long-term effects of decay on the stability of crystalline pollucite (CsAlSi2O6, also known as Cs-leucite). This decay is a key scientific issue in the assessment of the long-term stability, and hence performance, of pollucite as a waste form for 137Cs. Most previous work on radiation effects in waste forms focused on alpha radiation, which produces more displacements per decay than beta radiation. However, the results of decay with beta radiation, which changes both the ionic radius and the valence of the element undergoing decay (0.160 nm for Ba2+ vs. 0.188 nm for Cs+), are likely to predominate over cascade damage. The resulting changes in coordination chemistry may destabilize the waste form, permitting release of radionuclides to the accessible environment.

  15. The safe transport of radioactive materials

    CERN Document Server

    Gibson, R

    1966-01-01

    The Safe Transport of Radioactive Materials is a handbook that details the safety guidelines in transporting radioactive materials. The title covers the various regulations and policies, along with the safety measures and procedures of radioactive material transport. The text first details the 1963 version of the IAEA regulation for the safe transport of radioactive materials; the regulation covers the classification of radionuclides for transport purposes and the control of external radiation hazards during the transport of radioactive materials. The next chapter deals with concerns in the im

  16. Cluster radioactivity and very asymmetric fission through quasi-molecular shapes

    Energy Technology Data Exchange (ETDEWEB)

    Royer, G. [Centre National de la Recherche Scientifique, 44 - Nantes (France). Lab. de Physique Subatomique et des Technologies Associees; Gupta, R.K. [Panjab Univ., Chandigarh (India). Dept. of Physics; Denisov, V.Yu. [Akademyiya Nauk Ukrayini, Kiev (Ukraine)

    1997-12-31

    The decay of radioactive nuclei which emit heavy clusters like C, O, Ne, Mg and Si has been studied in the fission valley which leads one spherical nucleus towards two spherical touching nuclei before crossing the barrier. Assuming volume conservation, the deformation energy has been calculated within a generalized liquid drop model taking into account the proximity effects between the cluster and the daughter nucleus. The theoretical partial half-lives obtained within the WKB barrier penetration probability are in good agreement with the experimental data for the heaviest clusters. The Ne, Mg and Si emission looks like a very-asymmetric spontaneous fission. The {sup 14}C radioactivity is not correctly described within the fission hypothesis. The {sup 14}C and apparently also the {sup 20}O are probably pre-born in the parent nucleus, the emission being similar to the {alpha} decay process. (author). 27 refs.

  17. Decay spectroscopy of exotic fission products

    Science.gov (United States)

    Rykaczewski, Krzysztof

    2014-09-01

    The beta decay studies of exotic fission products have been performed at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory. The scientific program was focused on the beta-strength function measurements and resulting new half-lives and beta-delayed neutron properties. These observables are important for nuclear structure analysis and modeling of the nucleosynthesis within rapid neutron capture process. The highlights include ten new beta half-lives and several Pn branching ratios including an observation of beta-delayed two-neutron emitter 86Ga. In addition, the measurements of the beta-strength within beta-gamma emission window were performed using a Modular Total Absorption Spectrometer for 22 fission products. These MTAS results are also important for the analysis of reactor anti-neutrino anomaly. The beta decay studies of exotic fission products have been performed at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory. The scientific program was focused on the beta-strength function measurements and resulting new half-lives and beta-delayed neutron properties. These observables are important for nuclear structure analysis and modeling of the nucleosynthesis within rapid neutron capture process. The highlights include ten new beta half-lives and several Pn branching ratios including an observation of beta-delayed two-neutron emitter 86Ga. In addition, the measurements of the beta-strength within beta-gamma emission window were performed using a Modular Total Absorption Spectrometer for 22 fission products. These MTAS results are also important for the analysis of reactor anti-neutrino anomaly. Supported by the U.S. DOE Office of Nuclear Physics under Contracts DE-AC05-00R22725 (ORNL), DE-FG02-96ER40983 (UTK).

  18. Radioactive waste management in Austria

    Directory of Open Access Journals (Sweden)

    Neubauer Josef

    2004-01-01

    Full Text Available At the Austrian Research Centers Seibersdorf, there are several facilities in stalled for treatment of waste of low and intermediate radioactivity level (radwaste. A separate company within Centers, Nuclear Engineering Seibersdorf, has been formed recently, acting as a centralized facility for treatment, conditioning and storing of such waste within the country. The relevant treatment technology is applied depending on the waste category. In total about 6900 m3 of solid waste of low and intermediate radioactivity level originating from Austria was treated in the period between 1976 and 2002. Presently, there exists no final repository for radwaste in Austria. A study is under way to identify the structure for a long term storage facility.

  19. Decay spectroscopy for nuclear astrophysics: β- and β-delayed proton decay

    Science.gov (United States)

    Trache, L.; Banu, A.; Hardy, J. C.; Iacob, V. E.; McCleskey, M.; Roeder, B. T.; Simmons, E.; Spiridon, A.; Tribble, R. E.; Saastamoinen, A.; Jokinen, A.; Äysto, J.; Davinson, T.; Lotay, G.; Woods, P. J.; Pollacco, E.

    2012-02-01

    In several radiative proton capture reactions important in novae and XRBs, the resonant parts play the capital role. We use decay spectroscopy techniques to find these resonances and study their properties. We have developed techniques to measure beta- and beta-delayed proton decay of sd-shell, proton-rich nuclei produced and separated with the MARS recoil spectrometer of Texas A&M University. The short-lived radioactive species are produced in-flight, separated, then slowed down (from about 40 MeV/u) and implanted in the middle of very thin Si detectors. This allows us to measure protons with energies as low as 200 keV from nuclei with lifetimes of 100 ms or less. At the same time we measure gamma-rays up to 8 MeV with high resolution HPGe detectors. We have studied the decay of 23Al, 27P, 31Cl, all important for understanding explosive H-burning in novae. The technique has shown a remarkable selectivity to beta-delayed charged-particle emission and works even at radioactive beam rates of a few pps. The states populated are resonances for the radiative proton capture reactions 22Na(p,γ)23Mg (crucial for the depletion of 22Na in novae), 26mAl(p,γ)27Si and 30P(p,γ)31S (bottleneck in novae and XRB burning), respectively. Lastly, results with a new detector that allowed us to measure down to about 80 keV proton energy are announced.

  20. Radioactive Waste Management BasisApril 2006

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, B K

    2011-08-31

    This Radioactive Waste Management Basis (RWMB) documents radioactive waste management practices adopted at Lawrence Livermore National Laboratory (LLNL) pursuant to Department of Energy (DOE) Order 435.1, Radioactive Waste Management. The purpose of this Radioactive Waste Management Basis is to describe the systematic approach for planning, executing, and evaluating the management of radioactive waste at LLNL. The implementation of this document will ensure that waste management activities at LLNL are conducted in compliance with the requirements of DOE Order 435.1, Radioactive Waste Management, and the Implementation Guide for DOE Manual 435.1-1, Radioactive Waste Management Manual. Technical justification is provided where methods for meeting the requirements of DOE Order 435.1 deviate from the DOE Manual 435.1-1 and Implementation Guide.

  1. Analysis methods for airborne radioactivity

    OpenAIRE

    Ala-Heikkilä, Jarmo J

    2008-01-01

    High-resolution gamma-ray spectrometry is an analysis method well suitable for monitoring airborne radioactivity. Many of the natural radionuclides and a majority of anthropogenic nuclides are prominent gamma-ray emitters. With gamma-ray spectrometry different radionuclides are readily observed at minute concentrations that are far from health hazards. The gamma-ray spectrometric analyses applied in air monitoring programmes can be divided into particulate measurements and gas measurements. I...

  2. Clays in radioactive waste disposal

    OpenAIRE

    Delage, Pierre; Cui, Yu-Jun; Tang, Anh-Minh

    2010-01-01

    Clays and argillites are considered in some countries as possible host rocks for nuclear waste disposal at great depth. The use of compacted swelling clays as engineered barriers is also considered within the framework of the multi-barrier concept. In relation to these concepts, various research programs have been conducted to assess the thermo-hydro-mechanical properties of radioactive waste disposal at great depth. After introducing the concepts of waste isolation developed in Belgium, Fran...

  3. HMPT: Basic Radioactive Material Transportation

    Energy Technology Data Exchange (ETDEWEB)

    Hypes, Philip A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-02-29

    Hazardous Materials and Packaging and Transportation (HMPT): Basic Radioactive Material Transportation Live (#30462, suggested one time) and Test (#30463, required initially and every 36 months) address the Department of Transportation’s (DOT’s) function-specific [required for hazardous material (HAZMAT) handlers, packagers, and shippers] training requirements of the HMPT Los Alamos National Laboratory (LANL) Labwide training. This course meets the requirements of 49 CFR 172, Subpart H, Section 172.704(a)(ii), Function-Specific Training.

  4. Radioactive waste management in Austria

    OpenAIRE

    Neubauer Josef

    2004-01-01

    At the Austrian Research Centers Seibersdorf, there are several facilities in stalled for treatment of waste of low and intermediate radioactivity level (radwaste). A separate company within Centers, Nuclear Engineering Seibersdorf, has been formed recently, acting as a centralized facility for treatment, conditioning and storing of such waste within the country. The relevant treatment technology is applied depending on the waste category. In total about 6900 m3 of solid waste of low and inte...

  5. Suppressed Charmed B Decay

    Energy Technology Data Exchange (ETDEWEB)

    Snoek, Hella Leonie [Vrije Univ., Amsterdam (Netherlands)

    2009-06-02

    This thesis describes the measurement of the branching fractions of the suppressed charmed B0 → D*- a0+ decays and the non-resonant B0 → D*- ηπ+ decays in approximately 230 million Υ(4S) → B$\\bar{B}$ events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B0 → D*- a{sub 0}+ decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10-6. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle γ, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle γ can be performed using the decays of neutral B mesons. The B0 → D*- a0+ decay is sensitive to the angle γ and, in comparison to the current decays that are being employed, could significantly

  6. Holographic Glueball Decay

    CERN Document Server

    Brünner, Frederic; Rebhan, Anton

    2014-01-01

    We announce new results on glueball decay rates in the Sakai-Sugimoto model, a realization of holographic QCD from first principles that has only one coupling constant and an overall mass scale as free parameters. We extend a previous investigation by Hashimoto, Tan, and Terashima who have considered the lowest scalar glueball which arises from a somewhat exotic polarization of supergravity modes and whose mass is uncomfortably small in comparison with lattice results. On the other hand, the scalar glueball dual to the dilaton turns out to have a mass of about twice the mass of the rho meson (1487 MeV), very close to the scalar meson $f_0(1500)$ that is frequently interpreted as predominantly glue. Calculating the decay rate into two pions we find a surprisingly good agreement with experimental data for the $f_0(1500)$. We have also obtained decay widths for tensor and excited scalar glueballs, indicating universal narrowness.

  7. Beta and muon decays

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, A.; Pascual, P.

    1967-07-01

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  8. Cluster Radioactivity in 127I

    Directory of Open Access Journals (Sweden)

    K. Manimaran

    2013-08-01

    Full Text Available Using the preformation cluster model of Gupta and collaborators we have studied all the possible cluster decay modes of 127 I. The calculated half-lives are compared with recently measured lower limits of cluster decay half-lives (for the clusters like 24Ne, 28Mg, 30Mg, 32Si, 34Si, 48Ca and 49Sc of 127I. Our calculated half-life values lies well above the experimentally measured lower limits and the trend of the values also matches with experimental ones.

  9. Radioactive materials transport accident analysis

    Energy Technology Data Exchange (ETDEWEB)

    McSweeney, T.I.; Maheras, S.J.; Ross, S.B. [Battelle Memorial Inst. (United States)

    2004-07-01

    Over the last 25 years, one of the major issues raised regarding radioactive material transportation has been the risk of severe accidents. While numerous studies have shown that traffic fatalities dominate the risk, modeling the risk of severe accidents has remained one of the most difficult analysis problems. This paper will show how models that were developed for nuclear spent fuel transport accident analysis can be adopted to obtain estimates of release fractions for other types of radioactive material such as vitrified highlevel radioactive waste. The paper will also show how some experimental results from fire experiments involving low level waste packaging can be used in modeling transport accident analysis with this waste form. The results of the analysis enable an analyst to clearly show the differences in the release fractions as a function of accident severity. The paper will also show that by placing the data in a database such as ACCESS trademark, it is possible to obtain risk measures for transporting the waste forms along proposed routes from the generator site to potential final disposal sites.

  10. IRACM : A code system to calculate induced radioactivity produced by ions and neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Susumu; Fukuda, Mitsuhiro; Nishimura, Koichi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Watanabe, Hiromasa; Yamano, Naoki

    1997-05-01

    It is essential to estimate of radioactivity induced in accelerator components and samples bombarded by energetic ion beams and the secondary neutrons of high-energy accelerator facilities in order to reduce the amount of radioactive wastes and to minimize radiation exposure to personnel. A computer code system IRACM has been developed to estimate product nuclides and induced radioactivity in various radiation environments of accelerator facilities. Nuclide transmutation with incident particles of neutron, proton, deuteron, alpha, {sup 12}C, {sup 14}N, {sup 16}O, {sup 20}Ne and {sup 40}Ar can be computed for arbitrary multi-layer target system in a one-dimensional geometry. The code system consists of calculation modules and libraries including activation cross sections, decay data and photon emission data. The system can be executed in both FACOM-M780 mainframe and DEC workstations. (author)

  11. Radioactivity: conception to birth. The Health Physics Society 1995 Radiology Centennial Hartman Oration.

    Science.gov (United States)

    Frame, P W

    1996-05-01

    Röntgen's description of his discovery of x rays was convincing and comprehensive. The response of the scientific community and public was immediate and intense. In contrast, the discovery of radioactivity was a muddled affair that excited little interest. While it would prove far more revolutionary than that of x rays, the discovery of radioactivity began, in the words of Alfred Romer, as something of a dead horse. There it lay, too big to ignore, but what did you do with it? Even the discoverer, Henri Becquerel, left it to decay and went on to pursue other interests. For various reasons, others chose to investigate: Marie and Pierre Curie in France, William Crookes in England, and Ernest Rutherford in Canada. But it was Frederick Soddy, a young chemist with a fascination for alchemy, who, together with Rutherford, revealed the true nature of radioactivity: transmutation.

  12. Laboratory measurement of radioactivity purification for 212Pb in liquid scintillator

    Science.gov (United States)

    Hu, Wei; Fang, Jian; Yu, Bo-Xiang; Zhang, Xuan; Zhou, Li; Cai, Xiao; Sun, Li-Jun; Liu, Wan-Jin; Wang, Lan; Lü, Jun-Guang

    2016-09-01

    Liquid scintillator (LS) has been widely used in past and running neutrino experiments, and is expected also to be used in future experiments. Requirements on LS radio-purity have become higher and higher. Water extraction is a powerful method to remove soluble radioactive nuclei, and a mini-extraction station has been constructed. To evaluate the extraction efficiency and optimize the operation parameters, a setup to load radioactivity to LS and a laboratory scale setup to measure radioactivity using the 212Bi-212Po-208Pb cascade decay have been developed. Experience from this laboratory study will be useful for the design of large scale water extraction plants and the optimization of working conditions in the future. Supported by The Strategic Priority Research Program of the Chinese Academy of Sciences (XDA10010500), Natural Science Foundation of China (11390384)

  13. Half-lives for α and cluster radioactivity in a simple model

    Science.gov (United States)

    Zdeb, A.; Warda, M.; Pomorski, K.

    2013-05-01

    A simple phenomenological model based on the WKB theory for the evaluation of half-lives for α and cluster radioactivity is proposed. The model contains only one adjustable parameter, the nuclear radius constant, common for both kinds of decay and three additional hindrance factors for odd-even, even-odd and odd-odd nuclei. A good agreement with the experimental data is achieved.

  14. Discussions about whether radioactive half life can be changed by mechanic motion

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this essay, some discussions and comments about the paper entitled "Can the decay rate of 32P be changed by mechanic motion?" (Ding et al., Science in China Series B:Chemistry (Chinese version), 2008, 38(11):1035-1037) are given. It was strongly suggested that its experimental methods, data calculations and conclusion should be reconsidered. After the data were recalculated, the new results supported that the chiral mechanic motion could induce the changes of radioactive half life.

  15. Activity Concentration Monitoring for Alpha Radioactive Aerosol in CRARL after Reprocessing Experiments

    Institute of Scientific and Technical Information of China (English)

    WANG; Xiang-li; LIU; Ning; WANG; Xiao-rong; BAI; Yang; JIAO; Xiao-yan; XU; Xin; MA; Hao-ran

    2015-01-01

    The activity concentration for alpha radioactive aerosol in CRARL after reprocessing experiments was analyzed.Through the decay method of activity concentration monitoring,the processed result shows the background is 3.05×10-3 s-1,σ(0)=2.25×10-3,LC=2.33×10-3 Bq/m3,LD=4.66×10-3 Bq/m3.The result indicated

  16. Systematic Study of Trace Radioactive Impurities in Candidate Construction Materials for EXO-200

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, D.S.; Grinberg, P.; Weber, P.; Baussan, E.; Djurcic, Z.; Keefer, G.; Piepke, A.; Pocar, A.; Vuilleumier, J.-L.; Vuilleumier, J.-M.; Akimov, D.; Bellerive, A.; Bowcock, M.; Breidenbach, M.; Burenkov, A.; Conley, R.; Craddock, W.; Danilov, M.; DeVoe, R.; Dixit, M.; Dolgolenko, A.; /Alabama U. /NRC-INMS /Neuchatel U. /Stanford U., Phys. Dept. /SLAC /Colorado State U. /Laurentian U. /Maryland U. /UC, Irvine

    2007-10-24

    The Enriched Xenon Observatory (EXO) will search for double beta decays of 136Xe. We report the results of a systematic study of trace concentrations of radioactive impurities in a wide range of raw materials and finished parts considered for use in the construction of EXO-200, the first stage of the EXO experimental program. Analysis techniques employed, and described here, include direct gamma counting, alpha counting, neutron activation analysis, and high-sensitivity mass spectrometry.

  17. Flavor changing nucleon decay

    Science.gov (United States)

    Maekawa, Nobuhiro; Muramatsu, Yu

    2017-04-01

    Recent discovery of neutrino large mixings implies the large mixings in the diagonalizing matrices of 5 bar fields in SU (5) grand unified theory (GUT), while the diagonalizing matrices of 10 fields of SU (5) are expected to have small mixings like Cabibbo-Kobayashi-Maskawa matrix. We calculate the predictions of flavor changing nucleon decays (FCND) in SU (5), SO (10), and E6 GUT models which have the above features for mixings. We found that FCND can be the main decay mode and play an important role to test GUT models.

  18. Double Beta Decay

    CERN Document Server

    Elliott, Steven R

    2011-01-01

    At least one neutrino has a mass of about 50 meV or larger. However, the absolute mass scale for the neutrino remains unknown. Furthermore, the critical question: Is the neutrino its own antiparticle? is unanswered. Studies of double beta decay offer hope for determining the absolute mass scale. In particular, zero-neutrino double beta decay (\\BBz) can address the issues of lepton number conservation, the particle-antiparticle nature of the neutrino, and its mass. A summary of the recent results in \\BBz, and the related technologies will be discussed in the context of the future \\BBz\\ program.

  19. A century of oil and gas exploration in Albania: assessment of Naturally Occurring Radioactive Materials (NORMs).

    Science.gov (United States)

    Xhixha, G; Baldoncini, M; Callegari, I; Colonna, T; Hasani, F; Mantovani, F; Shala, F; Strati, V; Xhixha Kaçeli, M

    2015-11-01

    The Naturally Occurring Radioactive Materials (NORMs) that are potentially generated from oil and gas extractions in Albania have been disposed of without regulations for many decades, and therefore, an extensive survey in one of the most productive regions (Vlora-Elbasan) was performed. A total of 52 gamma ray spectrometry measurements of soil, oil-sand, sludge, produced water and crude oil samples were performed. We discovered that relatively low activity concentrations of (226)Ra, (228)Ra, (228)Th and (40)K, with concentrations of 23±2Bq/kg, 23±2Bq/kg, 24±3Bq/kg and 549±12Bq/kg, respectively, came from the oil-sands produced by the hydrocarbon extraction of the molasses formations. The mineralogical characterizations and the (228)Ra/(40)K and (226)Ra/(40)K ratios of these Neogene deposits confirmed the predictions of the geological and geodynamic models of a dismantling of the Mesozoic source rocks. The average activity concentrations (±standard deviations) of the radium isotopes ((226)Ra and (228)Ra) and of the (228)Th and (40)K radionuclides in soil samples were 20±5Bq/kg, 25±10Bq/kg, 25±9Bq/kg and 326±83Bq/kg, respectively. Based on the measurements in this study, the future radiological assessments of other fields in the region should be strategically planned to focus on the oil-sands from the molasses sediments. Disequilibrium in the (228)Ra decay segment was not observed in the soil, sludge or oil-sand samples within the standard uncertainties. After a detailed radiological characterization of the four primary oil fields, we concluded that the outdoor absorbed dose rate never exceeded the worldwide population weighted average absorbed dose rate in outdoor air from terrestrial gamma radiation.

  20. Unified description of the proton, alpha, cluster decays and spontaneously fissions half- life

    CERN Document Server

    Mavrodiev, Strachimir Cht

    2016-01-01

    Some time ago the possibility of classical (without Gamow tunneling) universal description of radioactive nuclei decay was demonstrated. Such possibility is basis on the classical interpretation of Bohmian Psi-field reality in Bohmian-Chetaev mechanics and the hypothesis for the presence of dissipative forces, generated from the Gryzinski translational precession of the charged particles spin, in Langevin- Kramers diffusion mechanism. In this paper is present an unified model of proton, alpha decay, cluster radioactivity and spontaneous fission half-life as explicit function which depends on the total decay energy and kinetic energy, the number of protons and neutrons of daughter product, the number of protons and neutrons of mother nuclei and from a set) unknown digital parameters. The Half- lifes of the 573 nuclei taken from NuDat database together with the recent experimental data from Oganessian provide a basis for discovering the explicit form of the Kramers solution of Langevin type equation in a framew...

  1. Analysis of Experiments Exhibiting Time-Varying Nuclear Decay Rates: Systematic Effects or New Physics?

    CERN Document Server

    Jenkins, Jere H; Sturrock, Peter A; Mundy, Daniel W

    2011-01-01

    Since the 1930s, and with very few exceptions, it has been assumed that the process of radioactive decay is a random process, unaffected by the environment in which the decaying nucleus resides. There have been instances within the past few decades, however, where changes in the chemical environment or physical environment brought about small changes in the decay rates. But even in light of these instances, decaying nuclei that were undisturbed or un-"pressured" were thought to behave in the expected random way, subject to the normal decay probabilities which are specific to each nuclide. Moreover, any "non-random" behavior was assumed automatically to be the fault of the detection systems, the environment surrounding the detectors, or changes in the background radiation to which the detector was exposed. Recently, however, evidence has emerged from a variety of sources, including measurements taken by independent groups at Brookhaven National Laboratory, Physikalisch-Technische Bundesanstalt, and Purdue Univ...

  2. [Decorporation agents for internal radioactive contamination].

    Science.gov (United States)

    Ohmachi, Yasushi

    2015-01-01

    When radionuclides are accidentally ingested or inhaled, blood circulation or tissue/organ deposition of the radionuclides causes systemic or local radiation effects. In such cases, decorporation therapy is used to reduce the health risks due to their intake. Decorporation therapy includes reduction and/or inhibition of absorption from the gastrointestinal tract, isotopic dilution, and the use of diuretics, adsorbents, and chelating agents. For example, penicillamine is recommended as a chelating agent for copper contamination, and diethylene triamine pentaacetic acid is approved for the treatment of internal contamination with plutonium. During chelation therapy, the removal effect of the drugs should be monitored using a whole-body counter and/or bioassay. Some authorities, such as the National Council on Radiation Protection and Measurements and International Atomic Energy Agency, have reported recommended decorporation agents for each radionuclide. However, few drugs are approved by the US Food and Drug Administration, and many are off-label-use agents. Because many decontamination agents are drugs that have been available for a long time and have limited efficacy, the development of new, higher-efficacy drugs has been carried out mainly in the USA and France. In this article, in addition to an outline of decorporation agents for internal radioactive contamination, an outline of our research on decorporation agents for actinide (uranium and plutonium) contamination and for radio-cesium contamination is also presented.

  3. Attention decay in science

    CERN Document Server

    Parolo, Pietro Della Briotta; Ghosh, Rumi; Huberman, Bernardo A; Kaski, Kimmo; Fortunato, Santo

    2015-01-01

    The exponential growth in the number of scientific papers makes it increasingly difficult for researchers to keep track of all the publications relevant to their work. Consequently, the attention that can be devoted to individual papers, measured by their citation counts, is bound to decay rapidly. In this work we make a thorough study of the life-cycle of papers in different disciplines. Typically, the citation rate of a paper increases up to a few years after its publication, reaches a peak and then decreases rapidly. This decay can be described by an exponential or a power law behavior, as in ultradiffusive processes, with exponential fitting better than power law for the majority of cases. The decay is also becoming faster over the years, signaling that nowadays papers are forgotten more quickly. However, when time is counted in terms of the number of published papers, the rate of decay of citations is fairly independent of the period considered. This indicates that the attention of scholars depends on th...

  4. Recent advances in β-decay spectroscopy at CARIBU

    Directory of Open Access Journals (Sweden)

    Mitchell A. J.

    2016-01-01

    Full Text Available β-decay spectroscopy of nuclei far from stability can provide powerful insight into a broad variety of topics in nuclear science, ranging from exotic nuclear structure phenomena, stellar nucleosynthesis processes, and applied topics such as quantifying “decay heat” discrepancies for advanced nuclear fuel cycles. Neutronrich nuclei approaching the drip-line are difficult to access experimentally, leaving many key examples largely under studied. The CARIBU radioactive beam facility at Argonne National Laboratory exploits spontaneous fission of 252Cf in production of such beams. The X-Array and SATURN decay station have been commissioned to perform detailed decay spectroscopy of low-energy CARIBU beams. An extended science campaign was started during 2015; with projects investigating nuclear shape changes, collective octupole vibrations, β-delayed neutron emission, and decay-scheme properties which could explain the reactor antineutrino puzzle. In this article we review the current status of the setup, update on the first results and recent hardware upgrades, and look forward to future possibilities.

  5. Recent advances in β-decay spectroscopy at CARIBU

    Science.gov (United States)

    Mitchell, A. J.; Copp, P.; Savard, G.; Lister, C. J.; Lane, G. J.; Carpenter, M. P.; Clark, J. A.; Zhu, S.; Ayangeakaa, A. D.; Bottoni, S.; Brown, T. B.; Chowdhury, P.; Chillery, T. W.; David, H. M.; Hartley, D. J.; Heckmaier, E.; Janssens, R. V. F.; Kolos, K.; Kondev, F. G.; Lauritsen, T.; McCutchan, E. A.; Norman, E. B.; Padgett, S.; Scielzo, N. D.; Seweryniak, D.; Smith, M. L.; Wilson, G. L.

    2016-09-01

    β-decay spectroscopy of nuclei far from stability can provide powerful insight into a broad variety of topics in nuclear science, ranging from exotic nuclear structure phenomena, stellar nucleosynthesis processes, and applied topics such as quantifying "decay heat" discrepancies for advanced nuclear fuel cycles. Neutronrich nuclei approaching the drip-line are difficult to access experimentally, leaving many key examples largely under studied. The CARIBU radioactive beam facility at Argonne National Laboratory exploits spontaneous fission of 252Cf in production of such beams. The X-Array and SATURN decay station have been commissioned to perform detailed decay spectroscopy of low-energy CARIBU beams. An extended science campaign was started during 2015; with projects investigating nuclear shape changes, collective octupole vibrations, β-delayed neutron emission, and decay-scheme properties which could explain the reactor antineutrino puzzle. In this article we review the current status of the setup, update on the first results and recent hardware upgrades, and look forward to future possibilities.

  6. Impact of dark matter decays and annihilations on structure formation

    NARCIS (Netherlands)

    Mapelli, M.; Ripamonti, E.

    2007-01-01

    Abstract: We derived the evolution of the energy deposition in the intergalactic medium (IGM) by different decaying (or annihilating) dark matter (DM) candidates. Heavy annihilating DM particles (with mass larger than a few GeV) have no influence on reionization and heating, even if we assume that a

  7. Radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Baratta, E.J. [Winchester Engineering and Analytical Center, Winchester, MA (United States)

    1997-01-01

    Cesium-134 and -137 in Foods, Gamma-Ray Spectrophotometric Methods. The method entitled {open_quotes}Cs-134 and Cs-137 in Foods, Gamma-Ray Spectrophotometric Method{close_quotes} has been adopted official first action, with minor revisions. Iodine 131: The method {open_quotes}Iodine-131 in Milk, Radiochemical Separation Method{close_quotes} has been accepted by the Committee on Residues and Related Topics and has been recommended to the Methods Committee for adoption first action. Search is continuing for a new Associated Referee. Plutonium-239: The Associate Referee is doing a literature search for a method for the determination of plutonium in foods. When one is selected, she will prepared a protocol for a collaborative study and submit it for approval. Radium-228: Search is ongoing for a new Associate Referee. When one is appointed, a method should be selected and tested. Strontium-89 and -90: The Associate Referee is investigating methods using resin discs and/or resin columns for these radionuclides. These methods are now being used in analyses for strontium-89 and -90 in water. She will now attempt to apply it to milk. If successful, she will prepare a protocol for a collaborative study and submit it for approval. Tritium: Search is continuing for a new Associate Referee for this topic.

  8. Rare B decays at LEP

    CERN Document Server

    Kluit, P M

    2001-01-01

    The results of the LEP experiments for rare B decays will be reviewed, covering hadronic final states, radiative and other rare decays and results for the inclusive charmless branching ratio. (8 refs).

  9. Radioactive geochronometry from the treatise on geochemistry

    CERN Document Server

    Holland, H D

    2011-01-01

    The history of Earth in the Solar System has been unraveled using natural radioactivity. The sources of this radioactivity are the original creation of the elements and the subsequent bombardment of objects, including Earth, in the Solar System by cosmic rays. Both radioactive and radiogenic nuclides are harnessed to arrive at ages of various events and processes on Earth. This collection of chapters from the "Treatise on Geochemistry" displays the range of radioactive geochronometric studies that have been addressed by researchers in various fields of Earth science. These range from the age of Earth and the Solar System to the dating of the history of Earth that assists us in defining the major events in Earth history. In addition, the use of radioactive geochronometry in describing rates of Earth surface processes, including the climate history recorded in ocean sediments and the patterns of circulation of the fluid Earth, has extended the range of utility of radioactive isotopes as chronometric and tracer ...

  10. Communication from the Radioactive Shipping Service

    CERN Multimedia

    DDGS Unit

    2011-01-01

    The radioactive materials Import/Export service reminds you that all movements of potentially radioactive material must be declared in advance. For exports, shipping requests must be made via the EDH request form, ticking the box “radioactive material”. For imports, an electronic form must be completed before the arrival of the material. Requests which do not comply with the above procedure and any unauthorized imports of radioactive material will be refused.The same applies to imports/exports of radioactive sources. All necessary information is given in the web site: http://cern.ch/service-rp-shipping Yann Donjoux / Radioactive Shipping Service Phone: +41 22 767.31.71 Fax: +41 22 766.92.00 Email: service-rp-shipping@cern.ch

  11. CMS: Higgs boson decays to four muons

    CERN Multimedia

    Taylor, Lucas

    1997-01-01

    This track is an example of simulated data modelled for the CMS detector on the Large Hadron Collider (LHC) at CERN, which will begin taking data in 2008. The Higgs boson is produced in the collision of two protons at 14 TeV and quickly decays into four muons, a type of heavy electron which is not absorbed by the detector. The tracks of the other products of the collision are shown by lines and the energy deposited in the detector is shown in blue. Image creator : Lucas Taylor.

  12. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20102406 Chen Gang(China University of Geosciences,Beijing 100083,China);Li Fengming Discussion on Geological Characteristics and Genesis of Yuquanshan Graphite Deposit of Xinjiang(Xinjiang Geology,ISSN1000-8845,CN65-1092/P,27(4),2009,p.325-329,4 illus.,4 tables,5 refs.)Key words:graphite deposit,XinjiangYuquanshan graphite deposit of Xinjiang occurs in mica-quartz schist of Xingeer Information which belongs to Xinditate Group of Lower Pt in Kuluketage Block of Tarim paleo-continent,and experiences two mineralizing periods of

  13. Radioactive Probes on Ferromagnetic Surfaces

    CERN Multimedia

    2002-01-01

    On the (broad) basis of our studies of nonmagnetic radioactive probe atoms on magnetic surfaces and at interfaces, we propose to investigate the magnetic interaction of magnetic probe atoms with their immediate environment, in particular of rare earth (RE) elements positioned on and in ferromagnetic surfaces. The preparation and analysis of the structural properties of such samples will be performed in the UHV chamber HYDRA at the HMI/Berlin. For the investigations of the magnetic properties of RE atoms on surfaces Perturbed Angular Correlation (PAC) measurements and Mössbauer Spectroscopy (MS) in the UHV chamber ASPIC (Apparatus for Surface Physics and Interfaces at CERN) are proposed.

  14. Benchmarking Microwave Cavity Dark Matter Searches using a Radioactive Source

    CERN Multimedia

    Caspers, F

    2014-01-01

    A radioactive source is proposed as a calibration device to verify the sensitivity of a microwave dark matter search experiment. The interaction of e.g., electrons travelling in an arbitrary direction and velocity through an electromagnetically “empty” microwave cavity can be calculated numerically. We give an estimation of the energy deposited by a charged particle into a particular mode. Numerical examples are given for beta emitters and two particular cases: interaction with a field free cavity and interaction with a cavity which already contains an electromagnetic field. Each particle delivers a certain amount of energy related to the modal R/Q value of the cavity. The transferred energy is a function of the particles trajectory and its velocity. It results in a resonant response of the cavity, which can be observed using a sensitive microwave receiver, provided that the deposited energy is significantly above the single photon threshold.

  15. CP-violations in decays

    Indian Academy of Sciences (India)

    Y Sakai

    2006-11-01

    Recent results on CP-violation measurements in decays from energy asymmetric -factory experiments are reported. Thanks to large accumulated data samples, CP-violations in decays in mixing-decay interference and direct CP-violation are now firmly established. The measurements of three angles of the unitarity triangle from CP-violations of decays are quite consistent with the Standard Model expectations. These results strongly support the validity of the Kobayashi-Maskawa prescription of CP-violation.

  16. Visible neutrino decay at DUNE

    Energy Technology Data Exchange (ETDEWEB)

    Coloma, Pilar [Fermilab; Peres, Orlando G. [ICTP, Trieste

    2017-05-09

    If the heaviest neutrino mass eigenstate is unstable, its decay modes could include lighter neutrino eigenstates. In this case part of the decay products could be visible, as they would interact at neutrino detectors via mixing. At neutrino oscillation experiments, a characteristic signature of such \\emph{visible neutrino decay} would be an apparent excess of events at low energies. We focus on a simple phenomenological model in which the heaviest neutrino decays as $\

  17. Rare beauty decays at LHCb

    CERN Document Server

    INSPIRE-00258140

    2015-01-01

    In this contribution we review the most recent measurements of the LHCb experiment in the field of rare decays of B mesons. In particular the first observation of the $B^0_s \\to µ^+ µ^-$,­ decay, the angular analysis of $B^0_d \\to K*l^+l^-$ decays and the test of lepton universality in $B^+ \\to K^+ l^+ l^-$ decays are presented.

  18. Radioactive source materials in Los Estados Unidos de Venezuela

    Science.gov (United States)

    Wyant, Donald G.; Sharp, William N.; Rodriguez, Carlos Ponte

    1953-01-01

    This report summarizes the data available on radioactive source materials in Los Estados Unidos de Venezuela accumulated by geologists of the Direccions Tecnica de Geolgia and antecedent agencies prior to June 1951, and the writers from June to November 1951. The investigation comprised preliminary study, field examination, office studies, and the preparation of this report, in which the areas and localities examined are described in detail, the uranium potentialities of Venezuela are summarized, and recommendations are made. Preliminary study was made to select areas and rock types that were known or reported to be radioactive or that geologic experience suggests would be favorable host for uranium deposits, In the office, a study of gamma-ray well logs was started as one means of amassing general radiometric data and of rapidly scanning many of ye rocks in northern Venezuela; gamma-ray logs from about 140 representative wells were examined and their peaks of gamma intensity evaluated; in addition samples were analyzed radiometrically, and petrographically. Radiometic reconnaissance was made in the field during about 3 months of 1951, or about 12 areas, including over 100 localities in the State of Miranda, Carabobo, Yaracuy, Falcon, Lara, Trujillo, Zulia, Merida, Tachira, Bolivar, and Territory Delta Amacuro. During the course of the investigation, both in the filed and office, information was given about geology of uranium deposits, and in techniques used in prospecting and analysis. All studies and this report are designed to supplement and to strengthen the Direccion Tecnica de Geologias's program of investigation of radioactive source in Venezuela now in progress. The uranium potentialities of Los Estados de Venezuela are excellent for large, low-grade deposits of uraniferous phospahtic shales containing from 0.002 to 0.027 percent uranium; fair, for small or moderate-sized, low-grade placer deposits of thorium, rare-earth, and uranium minerals; poor, for

  19. Radioactive Waste and Clean-up: Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Collard, G

    2000-07-01

    SCK-CEN's Radioactive Waste and Clean-up Division performs studies and develops strategies, techniques and technologies in the area of radioactive waste management, the decontamination and decommissioning of nuclear installations and the remediation of radioactive-contaminated sites. These activities are performed in the context of our responsibility towards the safety of present and future generations and contribute to achieve intrageneration equity.

  20. Radioactive Waste Management in A Hospital

    OpenAIRE

    Khan, Shoukat; Syed, AT; Ahmad, Reyaz; Rather, Tanveer A; Ajaz, M.; Jan, FA

    2010-01-01

    Most of the tertiary care hospitals use radioisotopes for diagnostic and therapeutic applications. Safe disposal of the radioactive waste is a vital component of the overall management of the hospital waste. An important objective in radioactive waste management is to ensure that the radiation exposure to an individual (Public, Radiation worker, Patient) and the environment does not exceed the prescribed safe limits. Disposal of Radioactive waste in public domain is undertaken in accordance w...

  1. Size measurement of radioactive aerosol particles in intense radiation fields using wire screens and imaging plates

    Energy Technology Data Exchange (ETDEWEB)

    Oki, Yuichi; Tanaka, Toru; Takamiya, Koichi; Ishi, Yoshihiro; UesugI, Tomonori; Kuriyama, Yasutoshi; Sakamoto, Masaaki; Ohtsuki, Tsutomu [Kyoto University Research Reactor Institute, Osaka (Japan); Nitta, Shinnosuke [Graduate School of Engineering, Kyoto University, Kyoto (Japan); Osada, Naoyuki [Advanced Science Research Center, Okayama University, Okayama (Japan)

    2016-09-15

    Very fine radiation-induced aerosol particles are produced in intense radiation fields, such as high-intensity accelerator rooms and containment vessels such as those in the Fukushima Daiichi nuclear power plant (FDNPP). Size measurement of the aerosol particles is very important for understanding the behavior of radioactive aerosols released in the FDNPP accident and radiation safety in high-energy accelerators. A combined technique using wire screens and imaging plates was developed for size measurement of fine radioactive aerosol particles smaller than 100 nm in diameter. This technique was applied to the radiation field of a proton accelerator room, in which radioactive atoms produced in air during machine operation are incorporated into radiation-induced aerosol particles. The size of 11C-bearing aerosol particles was analyzed using the wire screen technique in distinction from other positron emitters in combination with a radioactive decay analysis. The size distribution for 11C-bearing aerosol particles was found to be ca. 70 μm in geometric mean diameter. The size was similar to that for 7Be-bearing particles obtained by a Ge detector measurement, and was slightly larger than the number-based size distribution measured with a scanning mobility particle sizer. The particle size measuring method using wire screens and imaging plates was successfully applied to the fine aerosol particles produced in an intense radiation field of a proton accelerator. This technique is applicable to size measurement of radioactive aerosol particles produced in the intense radiation fields of radiation facilities.

  2. An analytical model for radioactive pollutant release simulation in the atmospheric boundary layer

    Energy Technology Data Exchange (ETDEWEB)

    Weymar, Guilherme J.; Vilhena, Marco T.; Bodmann, Bardo E.J., E-mail: guicefetrs@gmail.com, E-mail: mtmbvilhena@gmail.com, E-mail: bejbodmann@gmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica; Buske, Daniela; Quadros, Regis, E-mail: danielabuske@gmail.com, E-mail: quadros99@gmail.com [Universidade Federal de Pelotas (UFPel), Capao do Leao, RS (Brazil). Programa de Pos-Graduacao em Modelagem Matematica

    2013-07-01

    Simulations of emission of radioactive substances in the atmosphere from the Brazilian nuclear power plant Angra 1 are a necessary tool for control and elaboration of emergency plans as a preventive action for possible accidents. In the present work we present an analytical solution for radioactive pollutant dispersion in the atmosphere, solving the time-dependent three-dimensional advection-diffusion equation. The experiment here used as a reference in the simulations consisted of the controlled releases of radioactive tritiated water vapor from the meteorological tower close to the power plant at Itaorna Beach. The wind profile was determined using experimental meteorological data and the micrometeorological parameters were calculated from empirical equations obtained in the literature. We report on a novel analytical formulation for the concentration of products of a radioactive chain released in the atmospheric boundary layer and solve the set of coupled equations for each chain radionuclide by the GILTT solution, assuming the decay of all progenitors radionuclide for each equation as source term. Further we report on numerical simulations, as an explicit but fictitious example and consider three radionuclides in the radioactive chain of Uranium 235. (author)

  3. An experimental method for quantitatively evaluating the elemental processes of indoor radioactive aerosol behavior.

    Science.gov (United States)

    Yamazawa, H; Yamada, S; Xu, Y; Hirao, S; Moriizumi, J

    2015-11-01

    An experimental method for quantitatively evaluating the elemental processes governing the indoor behaviour of naturally occurring radioactive aerosols was proposed. This method utilises transient response of aerosol concentrations to an artificial change in aerosol removal rate by turning on and off an air purifier. It was shown that the indoor-outdoor exchange rate and the indoor deposition rate could be estimated by a continuous measurement of outdoor and indoor aerosol number concentration measurements and by the method proposed in this study. Although the scatter of the estimated parameters is relatively large, both the methods gave consistent results. It was also found that the size distribution of radioactive aerosol particles and hence activity median aerodynamic diameter remained not largely affected by the operation of the air purifier, implying the predominance of the exchange and deposition processes over other processes causing change in the size distribution such as the size growth by coagulation and the size dependence of deposition.

  4. Use of flow scintillation analyzer combined with amino acid analyzer for measuring low-level radioactivity of tritium-labelled amino acids

    CERN Document Server

    Lukashina, E V; Fedoseev, V M; Ksenofontov, A L; Baratova, L A; Dobrov, E N

    2002-01-01

    Potential application of the Radiomatic 150TR Flow Scintillation Analyzer (Packard Instrument Co., USA) for measuring low radioactivity of tritium-labelled amino acids in eluate from the Amino Acid Analyzer 835 (Hitachi, Japan) was studied. Six scintillating cocktails were tested and the Hionic-Fluor and Ultima-Flo AP cocktails proved the most appropriate for flow measurement of radioactivity. Efficiency of tritium radioactivity recording under various conditions of analysis was determined. Under optimal conditions the lower detection limit for the Hionic-Fluor was 150, while for Ultima-Flo AP-100 decays/min in the peak of amino acid

  5. [Microbiological Aspects of Radioactive Waste Storage].

    Science.gov (United States)

    Safonov, A V; Gorbunova, O A; German, K E; Zakharova, E V; Tregubova, V E; Ershov, B G; Nazina, T N

    2015-01-01

    The article gives information about the microorganisms inhabiting in surface storages of solid radioactive waste and deep disposal sites of liquid radioactive waste. It was shown that intensification of microbial processes can lead to significant changes in the chemical composition and physical state of the radioactive waste. It was concluded that the biogeochemical processes can have both a positive effect on the safety of radioactive waste storages (immobilization of RW macrocomponents, a decreased migration ability of radionuclides) and a negative one (biogenic gas production in subterranean formations and destruction of cement matrix).

  6. MANAGEMENT OF RADIOACTIVE WASTES IN CHINA

    Institute of Scientific and Technical Information of China (English)

    潘自强

    1994-01-01

    The policy and principles on management of radioactive wastes are stipulated.Cement solidification and bituminization unit has come into trial run.Solid radioactive waste is stored in tentative storage vault built in each of nuclear facilities.Seventeen storages associated with applications of nuclear technology and radioisotopes have been built for provinces.Disposal of low and intermediate level radioactive wastes pursues the policy of “regional disposal”.Four repositories have been planned to be built in northwest.southwest,south and east China respectively.A program for treatment and disposal of high level radioactive waste has been made.

  7. Residual radioactivity of treated green diamonds.

    Science.gov (United States)

    Cassette, Philippe; Notari, Franck; Lépy, Marie-Christine; Caplan, Candice; Pierre, Sylvie; Hainschwang, Thomas; Fritsch, Emmanuel

    2017-08-01

    Treated green diamonds can show residual radioactivity, generally due to immersion in radium salts. We report various activity measurements on two radioactive diamonds. The activity was characterized by alpha and gamma ray spectrometry, and the radon emanation was measured by alpha counting of a frozen source. Even when no residual radium contamination can be identified, measurable alpha and high-energy beta emissions could be detected. The potential health impact of radioactive diamonds and their status with regard to the regulatory policy for radioactive products are discussed. Copyright © 2017. Published by Elsevier Ltd.

  8. The Model 9977 Radioactive Material Packaging Primer

    Energy Technology Data Exchange (ETDEWEB)

    Abramczyk, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-09

    The Model 9977 Packaging is a single containment drum style radioactive material (RAM) shipping container designed, tested and analyzed to meet the performance requirements of Title 10 the Code of Federal Regulations Part 71. A radioactive material shipping package, in combination with its contents, must perform three functions (please note that the performance criteria specified in the Code of Federal Regulations have alternate limits for normal operations and after accident conditions): Containment, the package must “contain” the radioactive material within it; Shielding, the packaging must limit its users and the public to radiation doses within specified limits; and Subcriticality, the package must maintain its radioactive material as subcritical

  9. Common errors in transport of radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Fabio F.; Boni-Mitake, Malvina; Dellamano, Jos C. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: ffsuzuki@ipen.br; mbmitake@ipen.br; jcdellam@ipen.br

    2007-07-01

    The transport of radioactive waste is a stage of the waste management and must fit the same protection and safety requirements of any radioactive material shipment. In Brazil, the radioactive waste shipments must comply with the national regulations for transport of dangerous goods and the specific regulation for the safe transport of radioactive material of the nuclear regulatory authority. In these regulations, the consignor is responsible for the safety during the transport, however, the unload operations are consignee's responsibility. The Radioactive Waste Laboratory of the Nuclear and Energy Research Institute, IPEN-CNEN/SP, receives institutional radioactive waste from several radioactive facilities in the country. During the unload operations, protection and safety items are verified, such as the data written into the transport documents and the maximum levels of radiation on packages. The records show that almost all shipments of radioactive waste presented irregularities that varied from mistakes in fulfilling transport documents, up to the total disregard to the regulations. The shipments that could result in radiological risk to the operators of IPEN-CNEN/SP gave origin to reports that had been sent to the nuclear regulatory authority to take steps to prevent new occurrences and to enforce consignors and carriers. The adoption of this procedure in any type of occurrence, as well as its institutionalization in all radioactive waste management facilities of the nuclear regulatory authority could be an improvement against the errors observed in this type of transport. (author)

  10. Radioactive contamination in the Hanford environs. October-December 1955

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, B.V.; Soldat, J.K.

    1956-02-06

    This document summarizes the results obtained from monitoring the Hanford environs for radioactive contamination during the period October, November, and December 1955. Samples were collected by Regional Monitoring forces. These samples were analyzed by Radio-Analysis Laboratory forces. Counting rates obtained from these analyses were corrected for geometry, backscatter, air-window absorption, source size, selfabsorption, chemical yield, and collection efficiency by Radio-Analysis Laboratory forces. Additional corrections for decay were applied to those samples in which significant amounts of short half-life beta particle emitters were found. The findings obtained from analyzing the direct samples were supplemented with readings obtained from portable and fixed instrumentation. The results obtained from the described efforts are presented in Sections I through VII. These sections discuss the amounts of active material discharged from plant facilities and their effect on the contamination of vegetation, air, soil, and water. 5 refs.

  11. Radioactive contamination in the Hanford environs, July-September 1954

    Energy Technology Data Exchange (ETDEWEB)

    Pilcher, G.E.; Soldat, J.K.; Carey, Z.E.

    1955-04-20

    This publication summarizes the results obtained from monitoring the Hanford environs for radioactive contamination during the period July, August, and September 1954. Samples were collected by Regional Survey forces. These samples were analyzed by the Control Laboratory of the Control Unit. Counting rates obtained from these analyses were corrected for geometry, back-scatter, air-window absorption, source size, self-absorption, chemical yield, and collection efficiency by the Control Services group. Additional corrections for decay were applied to those samples in which significant amounts of short half-life beta particle emitters were found. The findings obtained from analyzing the direct smples were supplemented with readings obtained from portable and fixed instrumentation. The results obtained from the described efforts are presented in Sections I through VII which discuss the amounts of active material discharged from plant facilities and its effect on the contamination of vegetation, air, soil and water. 9 refs.

  12. Radioactive contamination in the Hanford environs, July-September 1957

    Energy Technology Data Exchange (ETDEWEB)

    McConiga, M.W.; Selby, J.M.; Soldat, J.K.

    1958-02-24

    This document summarizes the results obtained from monitoring the Hanford environs for radioactive contamination during the period July, August, September, 1957. Samples were collected by Regional Monitoring forces. These samples were analyzed by Radiological Chemical Analysis forces. Counting rates obtained from these analyses were corrected for geometry, backscatter, air-window absorption, source size, self-absorption, chemical yield, and collection efficiency by Radiological Chemical Analysis forces. Additional corrections for decay were applied to those samples in which significant amounts of short half-life beta particle emitters were found. The findings obtained from analyzing the direct samples were supplemented with readings obtained from portable and fixed instrumentation. The results obtained from the described efforts are presented in Sections I through VI. These sections discuss the amounts of active material discharged from plant facilities and their effect on the contamination of vegetation, air, soil, and water. 10 refs.

  13. Radioactive contamination in the Hanford environs, July-September 1955

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, B.V.; Soldat, J.K.

    1955-10-10

    This document summarizes the results obtained from monitoring the Hanford environs for radioactive contamination during the period July, August, and September, 1955. Samples were collected by Regional Monitoring forces. These samples were analyzed by Radio-Analysis Laboratory forces. Counting rates obtained from these analyses were corrected for geometry, backscatter, air-window absorption, source size, self-absorption, chemical yield, and collection efficiency by Radio-Analysis Laboratory forces. Additional corrections for decay were applied to those samples in which significant amounts of short half-life beta particle emitters were found. The findings obtained from analyzing the direct samples were supplemented with readings obtained from portable and fixed instrumentation. The results obtained from the described efforts are presented in Sections I through VII. These sections discuss the amounts of active material discharged from plant facilities and their effect on the contamination of vegetation, air, soil, and water. 6 refs.

  14. Radioactive contamination in the Hanford environs, April-June 1956

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, B.V.; Soldat, J.K.

    1956-08-07

    This document summarized the results obtained from monitoring the Hanford environs for radioactive contamination during the period April, May, and June, 1956. Samples were collected by Regional Monitoring forces. These samples were analyzed by Radio-Analysis Laboratory forces. Counting rates obtained from these analyses were corrected for geometry, backscatter, air-window absorption, source size, self-absorption, chemical yield, and collection efficiency by Radio-Analysis Laboratory forces. Additional corrections for decay were applied to those samples in which significant amounts of short half-life beta particle emitters were found. The findings obtained from analyzing the direct samples were supplemented with readings obtained from portable and fixed instrumentation. The results obtained from the described efforts are presented in Sections I through VII. These sections discuss the amounts of active material discharged from plant facilities and their effect on the contamination of vegetation, air, soil, and water. 8 refs.

  15. Radioactive contamination in the Hanford environs, October-December 1956

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, B.V.; McConiga, M.W.; Soldat, J.K.

    1957-02-25

    This document summarizes the results obtained from monitoring the Hanford environs for radioactive contamination during the period October, November, and December, 1956. Samples were collected by Regional Monitoring forces. These samples were analyzed by Radiological Chemical Analysis forces. Counting rates obtained from these analyses were corrected for geometry, backscatter, air-window absorption, source size, self-absorption, chemical yield, and collection efficiency by Radiological Chemical Analysis forces. Additional corrections for decay were applied to those samples in which significant amounts of short half-life beta particle emitters were found. The findings obtained from analyzing the direct samples were supplemented with readings obtained from portable and fixed instrumentation. The results obtained from the described efforts are presented in Sections I through VII. These sections discuss the amounts of active material discharged from plant facilities and their effect on the contamination of vegetation, air, soil, and water. 8 refs.

  16. Radioactive contamination in the Hanford environs, October-December 1957

    Energy Technology Data Exchange (ETDEWEB)

    McConiga, M.W.; Selby, J.M.; Soldat, J.K.

    1958-02-28

    This document summarizes the results obtained from monitoring the Hanford environs for radioactive contamination during the period October, November, December, 1957. Samples were collected by Regional Monitoring forces. These samples were analyzed by Radiological Chemical Analysis forces. Counting rates obtained from these analyses were corrected for geometry, backscatter, air-window absorption, source size, self-absorption, chemical yield, and collection efficiency by Radiological Chemical Analysis forces. Additional corrections for decay were applied to those samples in which significant amounts of sort half-life beta particle emitters were found. The findings obtained from analyzing the direct samples were supplemented with readings obtained from portable and fixed instrumentation. The results obtained from the described efforts are presented in Sections I through VI. These sections discuss the amounts of active material discharged from plant facilities and their effect on the contamination of vegetation, air, soil, and water. 8 refs.

  17. Radioactive contamination in the Hanford environs, January-March 1956

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, B.V.; Soldat, J.K.

    1956-05-28

    This document summarizes the results obtained from monitoring the Hanford environs for radioactive contamination during the period January, February, and March 1956. Samples were collected by Regional Monitoring forces. These samples were analyzed by Radio-Analysis Laboratory forces. Counting rates obtained from these analyses were corrected for geometry, backscatter, air-window absorption, source size, self-absorption, chemical yield, and collection efficiency by Radio-Analysis Laboratory forces. Additional corrections for decay were applied to those samples in which significant amounts of short half-life beta particle emitters were found. The findings obtained from analyzing the direct samples were supplemented with readings obtained from portable and fixed instrumentation. The results obtained from the described efforts are presented in Sections I through VII. These sections discuss the amounts of active material discharged from plant facilities and their effect on the contamination of vegetation, air, soil, and water. 7 refs.

  18. Radioactive contamination in the Hanford environs, January-March 1957

    Energy Technology Data Exchange (ETDEWEB)

    McConiga, M.W.; Soldat, J.K.

    1957-06-17

    The document summarizes the results obtained from monitoring the Hanford environs for radioactive contamination during the period January, February, and March, 1957. Samples were collected by Regional Monitoring forces. These samples were analyzed by Radiological Chemical Analysis forces. Counting rates obtained from these analyses were corrected for geometry, backscatter, air-window absorption, source size, self-absorption, chemical yield, and collection efficiency by Radiological Chemical Analysis forces. Additional corrections for decay were applied to those samples in which significant amounts of short half-life beta particle emitters were found. The findings obtained from analyzing the direct samples were supplemented with readings obtained from portable and fixed instrumentation. The results obtained from the described efforts are presented in Sections I through VII. These sections discuss the amounts of active material discharged from plant facilities and their effect on the contamination of vegetation, air, soil, and water. 9 refs.

  19. Chromatographic separation of radioactive noble gases from xenon

    CERN Document Server

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

    2016-01-01

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

  20. THERMAL PERFORMANCE OF RADIOACTIVE MATERIAL PACKAGES IN TRANSPORT CONFIGURATION

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, N.

    2010-03-04

    Drum type packages are routinely used to transport radioactive material (RAM) in the U.S. Department of Energy (DOE) complex. These packages are designed to meet the federal regulations described in 10 CFR Part 71. The packages are transported in specially designed vehicles like Safe Secure Transport (SST) for safety and security. In the transport vehicles, the packages are placed close to each other to maximize the number of units in the vehicle. Since the RAM contents in the packagings produce decay heat, it is important that they are spaced sufficiently apart to prevent overheating of the containment vessel (CV) seals and the impact limiter to ensure the structural integrity of the package. This paper presents a simple methodology to assess thermal performance of a typical 9975 packaging in a transport configuration.

  1. Cesium-137 global fallout into the Ob river basin and its influence on the Kara sea contamination - Weapons fallout cesium-137 in the Ob' catchment landscapes and its influence on radioactive contamination of the Kara sea: Western Siberia, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Semenkov, Ivan N.; Miroshnikov, Alexey Yu. [The Organization of Russian Academy of Sciences Institute of geology of ore deposits, petrography, mineralogy and geochemistry Russian Academy of Sciences (Russian Federation)

    2014-07-01

    There are several high level {sup 137}Cs anomaly zones detected in the deposits of the SW part of the Kara Sea. These anomaly zones were formed in the Ob' and the Enisey river estuaries due to the geochemical 'river-sea' boarder barrier. Level of radiocaesium specific activity reaches 120 Bq*kg{sup -1} in the deposits from these zones. Radiochemical enterprises occur in the both river basins. Their activity results in caesium-137 transfer into the river net. Vast area is contaminated by {sup 137}Cs after nuclear weapons in Semipalatinsk test-site and Kyshtym disaster in the Ob' river basin. Moreover, caesium comes to the Ob' and the Enisey river basins with global atmospheric fallout. The inflow of global fallout caesium-137 to the catchments is 660 kCi (320 kCi including radioactive decay) that is 4 times higher than {sup 137}Cs emission due to Fukushima disaster. Therefore, these river basins as any other huge catchment are an important sources of radioactive contamination of the Arctic Ocean. The aim of our research is to study behavior of global fallout caesium-137 in the landscapes of the Ob and the Enisey river basins. We studied caesium-137 behavior on the example of first order catchments in taiga, wetland, forest-steppe, steppe, and semi-arid landscapes. Geographic information system (GIS) was made. The tenth-order catchments (n=154, Horton coding system) shape 20-groups due to topsoil properties controlling cesium mobility. Eleven first-order basins, characterized 7 groups of tenth order catchments, were studied. And 700 bulk-core soil samples were collected in 2011-2013. Cesium runoff is calculated for 3 first-order river basins in taiga and forest-steppe landscapes. Storage of global fallout caesium-137 declines from undisturbing taiga first-order river basin (90% of cumulative fallout including radioactive decay)> arable steppe and fores-steppe (70 - 75%)> undisturbing wetland (60%). Caesium-137 transfer is high in arable lands

  2. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>20140876 Gao Junbo(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,China);Yang Ruidong Study on the Strontium Isotopic Composition of Large Devonian Barite Deposits from Zhenning,Guizhou Province(Geochimica,

  3. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>20122457 Cai Jianshe ( Fujian Institute of Geological Survey and Drawing,Fuzhou 350011,China ) On the Geologic Characteristics and Genesis of the Longtangsi Fluorite Deposit in Pucheng County,Fujian Province ( Geology of Fujian,ISSN1001-3970,CN35-1080 / P,30 ( 4 ), 2011,p.301-306,3illus.,1table,6 refs.,with English abstract ) Key words:fluorspar deposit,Fujian Province

  4. Electroweak penguin B decays

    CERN Document Server

    Nikodem, Thomas

    2016-01-01

    Flavour Changing Neutral Currents (FCNC) are sensitive probes for physics beyond the Standard Model (SM), so-called New Physics. An example of a FCNC is the $b \\to s$ quark transition described by the electroweak penguin Feynman diagram shown in Figure 1. In the SM such FCNC are only allowed with a loop structure (as e:g: shown in the figure) and not by tree level processes. In the loops heavy particles appear virtually and do not need to be on shell. Therefore also not yet discovered heavy particles with up to a mass $\\mathcal{O}$(TeV) could virtually contribute significantly to observables. Several recent measurements of electroweak penguin B decays exhibit interesting tensions with SM predictions, most prominently in the angular observable $P'_5$ 5 of the decay $B^0 \\to K^{*0} \\mu^+ \\mu^1$[1], which triggered a lot of discussion in the theory community [2]-[14].

  5. Decay of Hoyle state

    Indian Academy of Sciences (India)

    S Bhattacharya; T K Rana; C Bhattacharya; S Kundu; K Banerjee; T K Ghosh; G Mukherjee; R Pandey; P Roy

    2014-11-01

    The prediction of Hoyle state was necessitated to explain the abundance of carbon, which is crucial for the existence of life on Earth and is the stepping stone for understanding the abundance of other heavier elements. After the experimental confirmation of its existence, soon it was realized that the Hoyle state was `different’ from other excited states of carbon, which led to intense theoretical and experimental activities over the past few decades to understand its structure. In recent times, precision, high statistics experiments on the decay of Hoyle state have been performed at the Variable Energy Cyclotron Centre, to determine the quantitative contributions of various direct 3 decay mechanisms of the Hoyle state. The present results have been critically compared with those obtained in other recent experiments and their implications have been discussed.

  6. Selection and Basic Properties of the Buffer Material for High-Level Radioactive Waste Repository in China

    Institute of Scientific and Technical Information of China (English)

    WEN Zhijian

    2008-01-01

    Radioactive wastes arising from a wide range of human activities are in many different physical and chemical forms, contaminated with varying radioactivity. Their common features are the potential hazard associated with their radioactivity and the need to manage them in such a way as to protect the human environment. The geological disposal is regarded as the most reasonable and effective way to safely disposing high-level radioactive wastes in the world. The conceptual model of geological disposal in China is based on a multi-barrier system that combines an isolating geological environment with an engineered barrier system. The buffer is one of the main engineered barriers for HLW repository. It is expected to maintain its low water permeability, self-sealing property, radio nuclides adsorption and retardation properties, thermal conductivity, chemical buffering property,canister supporting property, and stress buffering property over a long period of time. Bentonite is selected as the main content of buffer material that can satisfy the above requirements. The Gaomiaozi deposit is selected as the candidate supplier for China's buffer material of high level radioactive waste repository. This paper presents the geological features of the GMZ deposit and basic properties of the GMZ Na-bentonite. It is a super-large deposit with a high content of montmorillonite (about 75%), and GMZ-1, which is Na-bentonite produced from GMZ deposit is selected as the reference material for China's buffer material study.

  7. Import/Export Service of Radioactive Material and Radioactive Sources Service

    CERN Multimedia

    2004-01-01

    Please note that the Import/Export Service of radioactive material (http://cern.ch/service-rp-shipping/ - e-mail : service-rp-shipping@cern.ch) and the Radioactive Sources Service (http://cern.ch/service-radioactive-sources - e-mail : service-radioactive-sources@cern.ch) at bldg. 24/E-024 will be closed on FRIDAY 10 SEPTEMBER 2004. Tel. 73171

  8. Charge Breeding of Radioactive Ions

    CERN Document Server

    Wenander, F J C

    2013-01-01

    Charge breeding is a technique to increase the charge state of ions, in many cases radioactive ions. The singly charged radioactive ions, produced in an isotope separator on-line facility, and extracted with a low kinetic energy of some tens of keV, are injected into a charge breeder, where the charge state is increased to Q. The transformed ions are either directed towards a dedicated experiment requiring highly charged ions, or post-accelerated to higher beam energies. In this paper the physics processes involved in the production of highly charged ions will be introduced, and the injection and extraction beam parameters of the charge breeder defined. A description of the three main charge-breeding methods is given, namely: electron stripping in gas jet or foil; external ion injection into an electron-beam ion source/trap (EBIS/T); and external ion injection into an electron cyclotron resonance ion source (ECRIS). In addition, some preparatory devices for charge breeding and practical beam delivery aspects ...

  9. [Determination of radioactivity by smartphones].

    Science.gov (United States)

    Hartmann, H; Freudenberg, R; Andreeff, M; Kotzerke, J

    2013-01-01

    The interest in the detection of radioactive materials has strongly increased after the accident in the nuclear power plant Fukushima and has led to a bottleneck of suitable measuring instruments. Smartphones equipped with a commercially available software tool could be used for dose rate measurements following a calibration according to the specific camera module. We examined whether such measurements provide reliable data for typical activities and radionuclides in nuclear medicine. For the nuclides 99mTc (10 - 1000 MBq), 131I (3.7 - 1800 MBq, therapy capsule) and 68Ga (50 - 600 MBq) radioactivity with defined geometry in different distances was measured. The smartphones Milestone Droid 1 (Motorola) and HTC Desire (HTC Corporation) were compared with the standard instruments AD6 (automess) and DoseGUARD (AEA Technology). Measurements with the smartphones and the other devices show a good agreement: linear signal increase with rising activity and dose rate. The long time measurement (131I, 729 MBq, 0.5 m, 60 min) demonstrates a considerably higher variation (by 20%) of the measured smartphone data values compared with the AD6. For low dose rates (rates resulting from typical nuclear medicine procedures can be measured reliably (e. g., dismissal dose after radioiodine therapy). The signal shows a high correlation to measured values of conventional dose measurement devices.

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

    Science.gov (United States)

    Sasaki, S.; Yamada, T.

    2013-05-01

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

  11. Teleportation via decay

    Indian Academy of Sciences (India)

    S Bose; P L Knight; M B Plenio; V Vedral

    2001-02-01

    We present a rare example of a decay mechanism playing a constructive role in quantum information processing. We show how the state of an atom trapped in a cavity can be teleported to a second atom trapped in a distant cavity by the joint detection of photon leakage from the cavities. The scheme, which is probabilistic, requires only a single three level atom in a cavity. We also show how this scheme can be modified to a teleportation with insurance.

  12. Charmless B decays

    Directory of Open Access Journals (Sweden)

    Martens Aurélien

    2014-04-01

    Full Text Available During 2011, LHCb has collected an integrated luminosity of 1.1 fb−1, giving rise to a large variety of measurements. Amongst these, measurements of CP violation in B decays play a central role. In particular CP violation measurements in charmless transitions of B mesons are of interest since they provide new or improved constraints on new physics contributions. These proceedings concentrate on LHCb results made publicin the first half of the year 2012.

  13. Decays of s neutrinos

    CERN Document Server

    Barradas, J E

    2003-01-01

    Based on the Minimal Supersymmetric Standard Model (MSSM), we discussed possible two body decay modes for the s neutrino v, one charged and other neutral: v -> l sub x sub 1 sup + sup - and v -> vx sub 1 sup 0 , respectively. Exploring a range of possible values for its mass, and for the chargino x sub i sup + sup - and neutralino x sub j sup 0 masses as well. We present the specific calculation for branching ratios, which are analyzed numerically. (Author)

  14. Multifluid magnetohydrodynamic turbulent decay

    CERN Document Server

    Downes, Turlough P

    2011-01-01

    It is generally believed that turbulence has a significant impact on the dynamics and evolution of molecular clouds and the star formation which occurs within them. Non-ideal magnetohydrodynamic effects are known to influence the nature of this turbulence. We present the results of a suite of 512-cubed resolution simulations of the decay of initially super-Alfvenic and supersonic fully multifluid MHD turbulence. We find that ambipolar diffusion increases the rate of decay of the turbulence while the Hall effect has virtually no impact. The decay of the kinetic energy can be fitted as a power-law in time and the exponent is found to be -1.34 for fully multifluid MHD turbulence. The power spectra of density, velocity and magnetic field are all steepened significantly by the inclusion of non-ideal terms. The dominant reason for this steepening is ambipolar diffusion with the Hall effect again playing a minimal role except at short length scales where it creates extra structure in the magnetic field. Interestingl...

  15. Decays of heavy quarks

    CERN Document Server

    Rizzo, T G

    1979-01-01

    The weak decay of heavy b and t quarks is discussed using the mixing angles obtained in Fritzsch's model (1978). The author finds that the decay b to c dominates over b to u for 7decay is found to be an insignificant source of multimuons in nu interactions and suitably small in nu interactions, consistent with the data of the CERN-Dortmund-Heidelberg-Saclay and Harvard-Pennsylvania-Wisconsin- Fermilab collaborations. Several branching ratios for exotic final states produced via b quarks in e/sup +/e/sup -/ annihilation are discussed. (23 refs).

  16. Alpha-Decay Half-Lives of Superheavy Nuclei

    Science.gov (United States)

    Budaca, A. I.; Silişteanu, I.; Silişteanu, A. O.; Anghel, C. I.

    2010-11-01

    Half-lives given by self-consistent models for the α-clustering and resonance scattering are calculated and compared with data and empirical estimates. The major influence of the pairing, deformed shell closures and screening corrections is evidenced in the systematics of half-lives and provides a convenient basis for the interpretation of observed trends of the data and for prediction of new results. The very small widths of α-resonances observed experimentally in fusion-evaporation reactions, are interpreted as resonance levels of radioactive products, and such a correlation contributes directly to the study of the nuclear structure on the basis of decay data.

  17. Cluster Decay of 208-238Th Isotopes

    Science.gov (United States)

    Oudih, M. R.; Saidi, F.; Fellah, M.; Allal, N. H.

    2015-11-01

    The cluster radioactivity of 208-238Th was studied by using a fission-like model taking interacting potential as the sum of coulomb and proximity potentials. The emission of the particle is considered as a quantum tunneling penetration of the potential barrier in the semi-classical WKB approximation. The released energy is deduced from the new table of atomic mass evaluation (AME12) and from the Finite Range Droplet Model. The obtained decay half-lives are compared with the few available experimental values and those of the effective liquid drop model.

  18. Charmless b decays at CDF

    Energy Technology Data Exchange (ETDEWEB)

    Donega, Mauro; /Geneva U.

    2005-07-01

    The authors report on the charmless B decays measurements performed on 180 pb{sup -1} of data collected with the CDF II detector at the Fermilab Tevatron collider. This paper describes: the first observation of the decay mode B{sub s} {yields} K{sup +}K{sup -} and the measurement of the direct Cp asymmetry in the ({bar B}){sub d} {yields} K{sup {+-}}{pi}{sup {-+}} decay; the first evidence of the decay mode B{sub s} {yields} {phi}{phi} and the branching ratio and Cp asymmetry for the B{sup {+-}} {yields} {phi}K{sup {+-}} decay.

  19. THERMAL UPGRADING OF 9977 RADIOACTIVE MATERIAL (RAM) TYPE B PACKAGE

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, N.; Abramczyk, G.

    2012-03-26

    The 9977 package is a radioactive material package that was originally certified to ship Heat Sources and RTG contents up to 19 watts and it is now being reviewed to significantly expand its contents in support of additional DOE missions. Thermal upgrading will be accomplished by employing stacked 3013 containers, a 3013 aluminum spacer and an external aluminum sleeve for enhanced heat transfer. The 7th Addendum to the original 9977 package Safety Basis Report describing these modifications is under review for the DOE certification. The analyses described in this paper show that this well-designed and conservatively analyzed package can be upgraded to carry contents with decay heat up to 38 watts with some simple design modifications. The Model 9977 package has been designed as a replacement for the Department of Transportation (DOT) Fissile Specification 6M package. The 9977 package is a very versatile Type B package which is certified to transport and store a wide spectrum of radioactive materials. The package was analyzed quite conservatively to increase its usefulness and store different payload configurations. Its versatility is evident from several daughter packages such as the 9978 and H1700, and several addendums where the payloads have been modified to suit the Shipper's needs without additional testing.

  20. Updated model for radionuclide transport in the near-surface till at Forsmark - Implementation of decay chains and sensitivity analyses

    Energy Technology Data Exchange (ETDEWEB)

    Pique, Angels; Pekala, Marek; Molinero, Jorge; Duro, Lara; Trinchero, Paolo; Vries, Luis Manuel de [Amphos 21 Consulting S.L., Barcelona (Spain)

    2013-02-15

    The Forsmark area has been proposed for potential siting of a deep underground (geological) repository for radioactive waste in Sweden. Safety assessment of the repository requires radionuclide transport from the disposal depth to recipients at the surface to be studied quantitatively. The near-surface quaternary deposits at Forsmark are considered a pathway for potential discharge of radioactivity from the underground facility to the biosphere, thus radionuclide transport in this system has been extensively investigated over the last years. The most recent work of Pique and co-workers (reported in SKB report R-10-30) demonstrated that in case of release of radioactivity the near-surface sedimentary system at Forsmark would act as an important geochemical barrier, retarding the transport of reactive radionuclides through a combination of retention processes. In this report the conceptual model of radionuclide transport in the quaternary till at Forsmark has been updated, by considering recent revisions regarding the near-surface lithology. In addition, the impact of important conceptual assumptions made in the model has been evaluated through a series of deterministic and probabilistic (Monte Carlo) sensitivity calculations. The sensitivity study focused on the following effects: 1. Radioactive decay of {sup 135}Cs, {sup 59}Ni, {sup 230}Th and {sup 226}Ra and effects on their transport. 2. Variability in key geochemical parameters, such as the composition of the deep groundwater, availability of sorbing materials in the till, and mineral equilibria. 3. Variability in hydraulic parameters, such as the definition of hydraulic boundaries, and values of hydraulic conductivity, dispersivity and the deep groundwater inflow rate. The overarching conclusion from this study is that the current implementation of the model is robust (the model is largely insensitive to variations in the parameters within the studied ranges) and conservative (the Base Case calculations have a