WorldWideScience

Sample records for based radioactive decay

  1. Radioactive Decay

    Science.gov (United States)

    Radioactive decay is the emission of energy in the form of ionizing radiation. Example decay chains illustrate how radioactive atoms can go through many transformations as they become stable and no longer radioactive.

  2. MODEL RADIOACTIVE RADON DECAY

    Directory of Open Access Journals (Sweden)

    R.I. Parovik

    2012-06-01

    Full Text Available In a model of radioactive decay of radon in the sample (222Rn. The model assumes that the probability of the decay of radon and its half-life depends on the fractal properties of the geological environment. The dependencies of the decay parameters of the fractal dimension of the medium.

  3. Teaching Radioactive Decay and Radiometric Dating: An Analog Activity Based on Fluid Dynamics

    Science.gov (United States)

    Claiborne, Lily L.; Miller, Calvin F.

    2012-01-01

    We present a new laboratory activity for teaching radioactive decay by using hydrodynamic processes as an analog and an evaluation of its efficacy in the classroom. A fluid flowing from an upper beaker into a lower beaker (shampoo in this case) behaves mathematically identically to radioactive decay, mimicking the exponential decay process,…

  4. 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.

  5. Precise Calculation of Complex Radioactive Decay Chains

    National Research Council Canada - National Science Library

    Harr, Logan J

    2007-01-01

    ...). An application of the exponential moments function is used with a transmutation matrix in the calculation of complex radioactive decay chains to achieve greater precision than can be attained through current methods...

  6. 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.

  7. 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...... state. A review of the decay modes occurring close to the limits of stability is presented. The experimental methods used to produce, identify, and detect new species and their radiation are discussed. The current theoretical understanding of these decay processes is reviewed. The theoretical...... description of the most recently discovered and most complex radioactive process—the two-proton radioactivity—is discussed in more detail....

  8. Simplifying the Mathematical Treatment of Radioactive Decay

    Science.gov (United States)

    Auty, Geoff

    2011-01-01

    Derivation of the law of radioactive decay is considered without prior knowledge of calculus or the exponential series. Calculus notation and exponential functions are used because ultimately they cannot be avoided, but they are introduced in a simple way and explained as needed. (Contains 10 figures, 1 box, and 1 table.)

  9. Nuclide radioactive decay data uncertainties library

    International Nuclear Information System (INIS)

    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. (paper)

  10. Deterministic computational modeling of the radioactive decay phenomenon

    International Nuclear Information System (INIS)

    Dias, Hugo Rafael; Barros, Ricardo C.

    2007-01-01

    Based on the deterministic mathematical model, we develop a computational modeling for the problem of radioactivity, and also emphasizing the development of a computational application, i.e., a construction of algorithms, programing and results presentation for this mathematical modeling. The application models the single or composed radioactive decay using classical numeric methods such as the trapezoidal implicit, and the most recent numerical methods, which are free of time truncation, signifying more safety of the calculated values, such as speed and efficiency in the results obtaining. (author)

  11. Radioactive-nuclide decay data in science and technology

    International Nuclear Information System (INIS)

    Reich, C.W.; Helmer, R.G.

    1975-01-01

    The scope of ENDF/B has recently been expanded to include radioactive-nuclide decay data. In this paper, the content and organization of the decay data which are included in ENDF/B are presented and discussed. The application of decay data in a wide variety of nuclear-related activities is illustrated by a number of examples. Two items pointed up by the ENDF/B decay-data compilation effort are treated: the identification of deficiencies in the data; and the importance of a radioactive-nuclide metrology effort oriented toward supplying these needs in a systematic fashion. (3 figures, 1 table)

  12. Radioactive-nuclide decay data in science and technology

    International Nuclear Information System (INIS)

    Reich, C.W.; Helmer, R.G.

    1975-01-01

    The scope of ENDF/B has recently been expanded to include radioactive-nuclide decay data. In this paper, the content and organization of the decay data which are included in ENDF/B are presented and discussed. The application of decay data in a wide variety of nuclear-related activities is illustrated by a number of examples. Two items pointed up by the ENDF/B decay-data compilation effort are treated: the identification of deficiencies in the data; and the importance of a radioactive-nuclide metrology effort oriented toward supplying these needs in a systematic fashion. 3 figures, 2 tables

  13. R and D on the Geant4 radioactive decay physics

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  14. 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

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

    International Nuclear Information System (INIS)

    Narita, Tsutomu; Kitao, Kensuke.

    1991-03-01

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

  16. 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.

  17. Radioactive decay of sup(91m)Nb

    International Nuclear Information System (INIS)

    Lakshminarayana, V.; Venkataratnam, S.; Rao, B.V.T.; Narasimham, K.L.

    1987-01-01

    The radioactive decay of sup(91m)Nb, produced by the reaction 89 Y(α, 2n), is studied using Ge(Li), HPGe and Si(Li) detectors. The K-conversion coefficient, αsub(K), of the 104.5 keV transition is determined accurately, for the first time, from the Nb Ksub(α) x-ray and 104.5 keV gamma-ray intensities. The experimental value of αsub(K) thus determined is 115(5), in agreement with the value expected for an M4 transition. (author)

  18. Radioactive decay of sup(91m)Nb

    Energy Technology Data Exchange (ETDEWEB)

    Lakshminarayana, V.; Venkataratnam, S.; Rao, B.V.T.; Narasimham, K.L.; Chintalapudi, S.N.

    1987-08-01

    The radioactive decay of sup(91m)Nb, produced by the reaction /sup 89/Y(..cap alpha.., 2n), is studied using Ge(Li), HPGe and Si(Li) detectors. The K-conversion coefficient, ..cap alpha..sub(K), of the 104.5 keV transition is determined accurately, for the first time, from the Nb Ksub(..cap alpha..) x-ray and 104.5 keV gamma-ray intensities. The experimental value of ..cap alpha..sub(K) thus determined is 115(5), in agreement with the value expected for an M4 transition.

  19. Calculation of radioactive decay chains produced by neutron irradiation

    International Nuclear Information System (INIS)

    Ponti, C.

    1984-01-01

    The calculation of the decay chains of radioactive isotopes may be solved by different computer codes that apply similar numerical methods. Analytical forms of solution of this problem are known since a long time, but their implementation has always been hindered by the possible occurrence of large numerical errors or by the need, to avoid them, of very high numerical precision. In this paper the reason of these difficulties has been pointed out and solved. In particular a new family of mathematical identities has been found

  20. 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.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

    We have studied the (ground-state) cluster radioactive decays within the preformed cluster model (PCM) of Gupta and collaborators [R. K. Gupta, in Proceedings of the 5th International Conference on Nuclear Reaction Mechanisms, Varenna, edited by E. Gadioli (Ricerca Scientifica ed Educazione Permanente, Milano, 1988), p. 416; S. S. Malik and R. K. Gupta, Phys. Rev. C 39, 1992 (1989)]. The relativistic mean-field (RMF) theory is used to obtain the nuclear matter densities for the double folding procedure used to construct the cluster-daughter potential with M3Y nucleon-nucleon interaction including exchange effects. Following the PCM approach, we have deduced empirically the preformation probability P 0 emp from the experimental data on both the α- and exotic cluster-decays, specifically of parents in the trans-lead region having doubly magic 208 Pb or its neighboring nuclei as daughters. Interestingly, the RMF-densities-based nuclear potential supports the concept of preformation for both the α and heavier clusters in radioactive nuclei. P 0 α(emp) for α decays is almost constant (∼10 -2 -10 -3 ) for all the parent nuclei considered here, and P 0 c(emp) for cluster decays of the same parents decrease with the size of clusters emitted from different parents. The results obtained for P 0 c(emp) are reasonable and are within two to three orders of magnitude of the well-accepted phenomenological model of Blendowske-Walliser for light clusters.

  2. Radioactive decay data tables: A handbook of decay data for application to radiation dosimetry and radiological assessments

    Science.gov (United States)

    Kocher, D. C.; Smith, J. S.

    Decay data are presented for approximately 500 radionuclides including 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. Physical processes involved in radioactive decay which produce the different types of radiation observed, methods used to prepare the decay data sets for each radionuclide in the format of the computerized evaluated nuclear structure data file, the tables of radioactive decay data, and the computer code MEDLIST used to produce the tables are described. Applications of the data to problems of interest in radiation dosimetry and radiological assessments are considered as well as the calculations of the activity of a daughter radionuclide relative to the activity of its parent in a radioactive decay chain.

  3. Quantum mechanical look at the radioactive-like decay of metastable dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Szydlowski, Marek [Jagiellonian University, Astronomical Observatory, Krakow (Poland); Jagiellonian University, Mark Kac Complex Systems Research Centre, Krakow (Poland); Stachowski, Aleksander [Jagiellonian University, Astronomical Observatory, Krakow (Poland); Urbanowski, Krzysztof [University of Zielona Gora, Institute of Physics, Zielona Gora (Poland)

    2017-12-15

    We derive the Shafieloo, Hazra, Sahni and Starobinsky (SHSS) phenomenological formula for the radioactive-like decay of metastable dark energy directly from the principles of quantum mechanics. To this aim we use the Fock-Krylov theory of quantum unstable states. We obtain deeper insight on the decay process as having three basic phases: the phase of radioactive decay, the next phase of damping oscillations, and finally the phase of power-law decay. We consider the cosmological model with matter and dark energy in the form of decaying metastable dark energy and study its dynamics in the framework of non-conservative cosmology with an interacting term determined by the running cosmological parameter. We study the cosmological implications of metastable dark energy and estimate the characteristic time of ending of the radioactive-like decay epoch to be 2.2 x 10{sup 4} of the present age of the Universe. We also confront the model with astronomical data which show that the model is in good agreement with the observations. Our general conclusion is that we are living in the epoch of the radioactive-like decay of metastable dark energy which is a relict of the quantum age of the Universe. (orig.)

  4. Critically evaluated half-life for 222Rn radioactive decay and associated uncertainties

    International Nuclear Information System (INIS)

    A critical review and evaluation of 17 independent determinations of the half-life for 222 Rn decay made over the past 90 years (c. 1902-1994) indicates that a five-significant figure value of the half-life with a relative uncertainty of approximately 10 -4 is justified, but not for the reasoning usually invoked. Although the commonly adopted and tabulated high-precision value of T = 3.8235 ± 0.0003 d, which is based almost exclusively on the 1972 measurements of Butt and Wilson, is consistent and virtually indistinct; a value of T = 3.8232 ± 0.0004 d, obtained by considering the entire available data base, is more supportable. Even in the extreme of a very conservative evaluation, the half-life is certainly known to a relative uncertainty interval of ±0.03 percent which contradicts some other extant data compilations that contend that no adopted half-life value for any radionuclide has a relative uncertainty of less than ±0.1 percent. Resulting propagated uncertainty contributions for either 222 Rn radioactive decay or 222 Rn growth accumulations from 226 Ra decay due to the uncertainty in the 222 Rn half-life is thereby clearly negligible in nearly all 222 Rn measurement applications

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

    International Nuclear Information System (INIS)

    Juliao, B.

    1990-01-01

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

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

    International Nuclear Information System (INIS)

    Laugier, J. M.

    2009-01-01

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

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

    International Nuclear Information System (INIS)

    Klueh, R.L.; Bloom, E.E.

    1984-01-01

    During the operation of a fusion reactor, the structural material of the first wall and blanket structure will become highly radioactive from activation by the high-energy fusion neutrons. A difficult radioactive waste management problem will be involved in the disposal of this material after the service lifetime is complete. One way to minimize the management problem is the use of structural materials where the radioactive isotopes in the irradiated material decay to levels that allow for simplified disposal techniques. We are exploring how ferritic and austenitic steels could be developed to meet this objective

  8. The Decay Data Evaluation Project (DDEP) and the JEFF-3.3 radioactive decay data library: Combining international collaborative efforts on evaluated decay data

    Science.gov (United States)

    Kellett, Mark A.; Bersillon, Olivier

    2017-09-01

    The Decay Data Evaluation Project (DDEP), is an international collaboration of decay data evaluators formed with groups from France, Germany, USA, China, Romania, Russia, Spain and the UK, mainly from the metrology community. DDEP members have evaluated over 220 radionuclides, following an agreed upon methodology, including a peer review. Evaluations include all relevant parameters relating to the nuclear decay and the associated atomic processes. An important output of these evaluations are recommendations for new measurements, which can serve as a basis for future measurement programmes. Recently evaluated radionuclides include: 18F, 59Fe, 82Rb, 82Sr, 88Y, 90Y, 89Zr, 94mTc, 109Cd, 133Ba, 140Ba, 140La, 151Sm and 169Er. The DDEP recommended data have recently been incorporated into the JEFF-3.3 Radioactive Decay Data Library. Other sources of nuclear data include 900 or so radionuclides converted from the Evaluated Nuclear Structure Data File (ENSDF), 500 from two UK libraries (UKPADD6.12 and UKHEDD2.6), the IAEA Actinide Decay Data Library, with the remainder converted from the NUBASE evaluation of nuclear properties. Mean decay energies for a number of radionuclides determined from total absorption gamma-ray spectroscopy (TAGS) have also been included, as well as more recent European results from TAGS measurements performed at the University of Jyväskylä by groups from the University of Valencia, Spain and SUBATECH, the University of Nantes, France. The current status of the DDEP collaboration and the JEFF Radioactive Decay Data Library will be presented. Note to the reader: the pdf file has been changed on September 22, 2017.

  9. Cold valleys in the radioactive decay of 248− 254Cf isotopes

    Indian Academy of Sciences (India)

    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 ...

  10. Comments on equilibrium, transient equilibrium, and secular equilibrium in serial radioactive decay

    International Nuclear Information System (INIS)

    Prince, J.R.

    1979-01-01

    Equations describing serial radioactive decay are reviewed along with published descriptions or transient and secular equilibrium. It is shown that terms describing equilibrium are not used in the same way by various authors. Specific definitions are proposed; they suggest that secular equilibrium is a subset of transient equilibrium

  11. Controlled study of the evolution of radon and its decay products in radioactive mine environments

    International Nuclear Information System (INIS)

    Calizaya A, F.

    1985-01-01

    This thesis discusses three aspects related to radon emissions and control of radon decay products in mine environments: (1) measurement of the effects of environmental parameters on radiation levels, (2) analysis of the data using ordinary linear regression and transfer function models and (3) prediction of the concentration of radioactive contaminants in the mine air. In-mine and laboratory experiments were conducted to develop the research data. In mine tests were conducted in a bulkhead isolated mine drift containing low grade uranium ore at the Colorado School of Mines, Experimental Mine with the US Bureau of Mines - Spokane Research Center (USBM, SRC) micro-computer based radiation monitoring system. Parameters such as amount of ore, amount of condensation nuclei in the mine air, temperature, air velocity, and barometric pressure were studied. The laboratory tests were conducted in an air-tight radon chamber equipped with a container of the radioactive material, various monitors, and the USBM, SRC Data Acquisition System. The effect of parameters such as ore grade, particle size, rock moisture, air temperature and relative humidity on radon concentrations were measured in the laboratory. Radiation levels, together with parameters affecting these levels, were measured over a period of one year (June 1984-July 1985) both in the laboratory model and in the field

  12. Flicker-noise fluctuations in α-radioactive decay

    International Nuclear Information System (INIS)

    Kousik, G.S.; Gong, J.; Vanvliet, C.M.; Bosman, G.; Ellis, W.H.; Carroll, E.E.; Handel, P.H.

    1987-01-01

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

  13. Nuclear structure and radioactive decay resources at the US National Nuclear Data Center

    International Nuclear Information System (INIS)

    Sonzogni, A.A.; Burrows, T.W.; Pritychenko, B.; Tuli, J.K.; Winchell, D.F.

    2008-01-01

    The National Nuclear Data Center has a long tradition of evaluating nuclear structure and decay data as well as offering tools to assist in nuclear science research and applications. With these tools, users can obtain recommended values for nuclear structure and radioactive decay observables as well as links to the relevant articles. The main databases or tools are ENSDF, NSR, NuDat and the new Endf decay data library. The Evaluated Nuclear Structure Data File (ENSDF) stores recommended nuclear structure and decay data for all nuclei. ENSDF deals with properties such as: -) nuclear level energies, spin and parity, half-life and decay modes, -) nuclear radiation energy and intensity for different types, -) nuclear decay modes and their probabilities. The Nuclear Science References (NSR) is a bibliographic database containing nearly 200.000 nuclear sciences articles indexed according to content. About 4000 are added each year covering 80 journals as well as conference proceedings and laboratory reports. NuDat is a software product with 2 main goals, to present nuclear structure and decay information from ENSDF in a user-friendly way and to allow users to execute complex search operations in the wealth of data contained in ENSDF. The recently released Endf-B7.0 contains a decay data sub-library which has been derived from ENSDF. The way all these databases and tools have been offered to the public has undergone a drastic improvement due to advancements in information technology

  14. Nuclear structure from radioactive decay: Annual progress report

    International Nuclear Information System (INIS)

    Wood, J.L.

    1987-01-01

    The primary focus this year has been studies of intruder states and shape coexistence in the neutron-deficient Z ∼ 82 region. Most notably, the existence and conditions for the occurrence of electric monopole (E0) transitions have been considerably clarified. This has been a topic of considerable confusion. On-line decay scheme spectroscopy of mass-separated isotopes at UNISOR (in a collaboration with LSU) has now completely resolved all points of disagreement. These studies are part of a larger program directed towards building a complete picture of shape coexistence. It is becoming evident that E0 transitions are a key signature to shape coexistence. Thus, their correct identification and location are crucial

  15. Radioactivity around naval nuclear bases

    International Nuclear Information System (INIS)

    1989-02-01

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

  16. Observation of Two-Proton Radioactivity of 19Mg by Tracking the Decay Products

    International Nuclear Information System (INIS)

    Mukha, I.; Alvarez, M. A. G.; Espino, J.; Gomez-Camacho, J.; Suemmerer, K.; Chatillon, A.; Geissel, H.; Hoffmann, J.; Kurz, N.; Litvinov, Yu.; Nociforo, C.; Ott, W.; Roeckl, E.; Weick, H.; Acosta, L.; Garcia-Ramos, J. E.; Martel, I.; Casarejos, E.; Cortina-Gil, D.; Rodriguez-Tajes, C.

    2007-01-01

    We have observed the two-proton radioactivity of the previously unknown 19 Mg ground state by tracking the decay products in-flight. For the first time, the trajectories of the 2p-decay products, 17 Ne+p+p, have been measured by using tracking microstrip detectors which allowed us to reconstruct the 2p-decay vertices and fragment correlations. The half-life of 19 Mg deduced from the measured vertex distribution is 4.0(15) ps in the system of 19 Mg. The Q value of the 2p decay of the 19 Mg ground state inferred from the measured p-p- 17 Ne correlations is 0.75(5) MeV

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

    International Nuclear Information System (INIS)

    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

  18. 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.

  19. 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.

  20. Fireball as a Macroscopic Manifestation of the beta-Decay of the Radioactive Phosphor into Bound States

    CERN Document Server

    Ratis, Yu L

    2004-01-01

    This paper substantiates a hypothesis that the natural fireball represents an area of space where the chain nuclear reaction of the bound state beta-decay of radioactive phosphorus nuclei takes place.

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

    International Nuclear Information System (INIS)

    Thorne, M.C.

    1982-12-01

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

  2. 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.

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

    International Nuclear Information System (INIS)

    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

  4. 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.

  5. The real-time fitting of radioactive decay curves. Pt. 2

    International Nuclear Information System (INIS)

    Hartley, B.M.

    1994-01-01

    The method of time evolved least squares (TELS) fitting of radioactive decay curves has been developed in a previous paper. That paper contained the general method for determining the activities of a number of different isotopes present in a sample when counted by different counting systems. The method allows for the determination of the numbers of atoms of isotopes present in a sample when they form part of a decay chain, as well as in a mixture of isotopes. The theory given allows for different efficiencies of detection of radiation in different counting systems to be used and for the detection of radiation from one type of decay in different detectors. This paper shows the potential application of the method to the counting of radiation from the descendants of radon and the determination of the numbers of atoms of each isotope in the decay chain. Two examples illustrate the use of the methodology in the determination of the numbers of atoms of the descendants of radon in a sample. The statistical uncertainty in the results of the determination have been found by Monte Carlo simulations of the decay and the counting. (orig.)

  6. Between atomic and nuclear physics: radioactive decays of highly-charged ions

    International Nuclear Information System (INIS)

    Atanasov, Dinko; Bosch, Fritz; Brandau, Carsten; Chen, Xiangcheng; Dillmann, Iris; Gao, Bingshui; Geissel, Hans; Hagmann, Siegbert; Hillenbrand, Pierre-Michel; Kozhuharov, Christophor; Litvinov, Sergey A; Litvinov, Yuri A; Münzenberg, Gottfried; Blaum, Klaus; Bühler, Paul; Faestermann, Thomas; Gernhäuser, Roman; Izumikawa, Takuji; Kurcewicz, Jan; Ma, Xinwen

    2015-01-01

    Highly charged radioactive ions can be stored for extended periods of time in storage rings which allows for precision measurements of their decay modes. The straightforward motivation for performing such studies is that fully ionised nuclei or few-electron ions can be viewed as clean quantum-mechanical systems, in which the interactions of the many electrons can be either excluded or treated precisely. Thus, the influence of the electron shell on the decay probability can be investigated. Another important motivation is stellar nucleosynthesis, which proceeds at high temperatures and the involved atoms are therefore highly ionised. Presented here is a compact review of the relevant experiments conducted at heavy-ion storage rings. Furthermore, we outline the perspectives for future experiments at new-generation storage-ring facilities. (paper)

  7. Study of two-neutron radioactivity in the decay of 26O.

    Science.gov (United States)

    Kohley, Z; Baumann, T; Bazin, D; Christian, G; DeYoung, P A; Finck, J E; Frank, N; Jones, M; Lunderberg, E; Luther, B; Mosby, S; Nagi, T; Smith, J K; Snyder, J; Spyrou, A; Thoennessen, M

    2013-04-12

    A new technique was developed to measure the lifetimes of neutron unbound nuclei in the picosecond range. The decay of 26O→24O+n+n was examined as it had been predicted to have an appreciable lifetime due to the unique structure of the neutron-rich oxygen isotopes. The half-life of 26O was extracted as 4.5(-1.5)(+1.1)(stat)±3(syst)  ps. This corresponds to 26O having a finite lifetime at an 82% confidence level and, thus, suggests the possibility of two-neutron radioactivity.

  8. Study of Two-Neutron Radioactivity in the Decay of O26

    Science.gov (United States)

    Kohley, Z.; Baumann, T.; Bazin, D.; Christian, G.; DeYoung, P. A.; Finck, J. E.; Frank, N.; Jones, M.; Lunderberg, E.; Luther, B.; Mosby, S.; Nagi, T.; Smith, J. K.; Snyder, J.; Spyrou, A.; Thoennessen, M.

    2013-04-01

    A new technique was developed to measure the lifetimes of neutron unbound nuclei in the picosecond range. The decay of O26→O24+n+n was examined as it had been predicted to have an appreciable lifetime due to the unique structure of the neutron-rich oxygen isotopes. The half-life of O26 was extracted as 4.5-1.5+1.1(stat)±3(syst)ps. This corresponds to O26 having a finite lifetime at an 82% confidence level and, thus, suggests the possibility of two-neutron radioactivity.

  9. Method and apparatus for indicating the radioactive decay products of radium in an environment

    International Nuclear Information System (INIS)

    Shreve, J.D. Jr.; Trowsdale, L.S.; Hill, A.

    1976-01-01

    An improved method and apparatus for providing an indication of the radiation activity of the radioactive decay products of radium in an environment wherein the alpha particle activity and the beta particle activity at a test site are detected and the detected alpha particle and the beta particle activities provide the indication of the radiation activity of radon and the decay products of radon at the test site. The background radiation activity at the test site is detected, and the detected alpha particle and the beta particle activities less the detected background radiation activity provide the indication of the radiation activity of radon and the decay products of radon. The sum of the detected alpha particle and beta particle activities provides an indication of the working level (WL); the difference between the detected alpha particle and the beta particle activities provides an indication of the radon concentration at the test site and the equivalent ingrowth time of the radon decay products (radon daughters) from the earlier existence of the radon as a gas; and the detected background radiation activity provides an indication of the penetrating radiation hazard at the test site. 40 claims, 8 figures

  10. Method and apparatus for indicating the radioactive decay products of radium in an environment

    Energy Technology Data Exchange (ETDEWEB)

    Shreve, J.D. Jr.; Trowsdale, L.S.; Hill, A.

    1976-10-26

    An improved method and apparatus for providing an indication of the radiation activity of the radioactive decay products of radium in an environment wherein the alpha particle activity and the beta particle activity at a test site are detected and the detected alpha particle and the beta particle activities provide the indication of the radiation activity of radon and the decay products of radon at the test site. The background radiation activity at the test site is detected, and the detected alpha particle and the beta particle activities less the detected background radiation activity provide the indication of the radiation activity of radon and the decay products of radon. The sum of the detected alpha particle and beta particle activities provides an indication of the working level (WL); the difference between the detected alpha particle and the beta particle activities provides an indication of the radon concentration at the test site and the equivalent ingrowth time of the radon decay products (radon daughters) from the earlier existence of the radon as a gas; and the detected background radiation activity provides an indication of the penetrating radiation hazard at the test site. 40 claims, 8 figures.

  11. 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.

  12. 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.

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

    International Nuclear Information System (INIS)

    Klueh, R.L.; Bloom, E.E.

    1984-03-01

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

  14. A general algorithm for radioactive decay with branching and loss from a medium

    International Nuclear Information System (INIS)

    Strenge, D.L.

    1995-07-01

    Many areas in the field of health physics require evaluation of the change of radionuclide quantity in a medium with time. A general solution to first-order compartmental models is presented in this paper for application to systems consisting of one physical medium that contains any number of radionuclide decay chain members. The general analytical solution to the problem is first described mathematically, and then extended to four applications: (1) evaluation of the quantity of radionuclides as a function of time, (2) evaluation of the time integral of the quantity during a time period, (3) evaluation of the amount in a medium as a function of time following deposition at a constant rate, and (4) evaluation of the time integral of the amount in a medium after deposition at a constant rate for a time. The solution can be applied to any system involving physical transfers from the medium and radioactive chain decay with branching in the medium. The general solution is presented for quantities expressed in units of atoms and activity. Unlike many earlier mathematical solutions, this solution includes chain decay with branching explicitly in the equations

  15. Discovery of the radioactive decay of 223Ra by 14C emission and experiments with the magnetic spectrometer Soleno

    International Nuclear Information System (INIS)

    Hourani, E.; Hussonnois, M.

    1987-01-01

    The aim of this report is to review the experiment of Rose and Jones (discovery in 1984 of radioactive decay of 223 Ra by 14 C nuclei emission) with the subsequent one of Alexandrov (et al) performed with the same technique. The experiments performed by the group at Orsay on 14 C radioactivity of radium isotopes with the magnetic spectrometer Soleno are also reviewed. This review comprises the presentation and comments of the original results and arguments taken in their historical context

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

    International Nuclear Information System (INIS)

    Lung, H.C.; Chambre, P.L.; Pigford, T.H.; Lee, W.W.L.

    1987-09-01

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

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

    International Nuclear Information System (INIS)

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

    2017-01-01

    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.

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

    International Nuclear Information System (INIS)

    Roa, W.H.Y.; Chapman, J.D.

    1987-01-01

    Nitroaromatic radiosensitizers become metabolically bound preferentially to hypoxic cells and at least 10/sup 9/ adducts/cell can be tolerated as non-toxic. EMT-6 tumor cells have been incubated in hypoxia in the presence of /sup 3/H-Misonidazole and /sup 125/I-Azomycin Riboside for various times and the amount of /sup 3/H or /sup 125/I bound/cell was determined. Cells were stored as monolayers at 25 0 C for up to 96 hr to accumulate radioactive decays and transferred at various times to 37 0 C for colony-forming assays. No radiation inactivation was measured in cells which had incorporated at least 10/sup 6/ /sup 3/H or 10/sup 5/ /sup 125/I atoms. Previous studies had shown that -- 1% of MISO adducts to EMT-6 cells was associated with cellular DNA. These data indicate that the radiation-induced damage produced by these quantities of bound /sup 3/H or /sup 125/I causes little or not cell inactivation. The results of current studies to measure the colony-forming ability of sensitizer-labelled cells which have been stored in liquid nitrogen to facilitate the accumulation of more decays will be reported. These data suggest that a ''sensitizer-adduct suicide technique'' as a hypoxic cell selective adjunct to other cancer therapies is not feasible. These data are also instructive for those who attempt to develop radiolabelled ''tumor specific'' antibodies for therapeutic purposes

  19. Cold valleys in the radioactive decay of 248−254Cf isotopes

    Indian Academy of Sciences (India)

    Abstract. Based on the concept of cold valley in cold fission and fusion, we have in- vestigated 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 ...

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

    Indian Academy of Sciences (India)

    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 ...

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

    International Nuclear Information System (INIS)

    Mohamad, N.; Caro, R.A.; Bergoc, R.M.

    1998-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Tolstov, Alexey; Nomoto, Ken’ichi; Blinnikov, Sergei; Quimby, Robert [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Sorokina, Elena [Sternberg Astronomical Institute, M.V.Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Baklanov, Petr, E-mail: alexey.tolstov@ipmu.jp [Institute for Theoretical and Experimental Physics (ITEP), 117218 Moscow (Russian Federation)

    2017-02-01

    Being a superluminous supernova, PTF12dam can be explained by a {sup 56}Ni-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 {sup 56}Ni 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 {sub ⊙} ejecta and 20–40 M {sub ⊙} circumstellar medium. The ejected {sup 56}Ni mass is about 6 M {sub ⊙}, which results from explosive nucleosynthesis with large explosion energy (2–3)×10{sup 52} 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.

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

    International Nuclear Information System (INIS)

    Dillman, L.T.

    1980-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Dillman, L.T.

    1980-01-01

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

  5. Search for proton decay and supernova neutrino bursts with a lunar base neutron detector

    International Nuclear Information System (INIS)

    Cline, D.B.

    1989-06-01

    We describe the current status of the search for proton decay on earth, emphasizing the decay mode P → K + ν - and discuss the possibility of detecting this mode with a single detector on a lunar base station. The same detector could be used to search for neutrino bursts from distant supernova using the neutral current signature ν μ,τ +N → n+ν x by detecting the produced neutrons. The key advantage of the lunar experiment is the low neutrino flux and possible low radioactive background. (author). 5 refs, 4 tabs, 3 figs

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

    International Nuclear Information System (INIS)

    Jong, D. de.

    1982-01-01

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

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

    International Nuclear Information System (INIS)

    Duarte, S.B.; Tavares, O.A.P.; Guzman, F.; Dimarco, A.; Garcia, F.; Goncalves, 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 with Werner-Wheeler's inertia coefficient V 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, τ c is presented for all possible cases of spontaneous nuclear break-up such that -7.30 10 τ c [S] 10 (τ/τ c ) > -17.0, where τ is the total half-life of the parent nucleus. (author)

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

    International Nuclear Information System (INIS)

    Campos, L.C. de.

    1981-01-01

    A new method for determining absolute activity of alpha or beta emitters by measuring daughter product radioactive decay is presented. The separation method of UX from hexahydrated uranyl nitrate UO 2 (NO 3 ) 2 6H 2 O based on its dissolution in ethyl ether is described and the accuracy of this method is shown. The factors which accuate on total efficiency of a Geiger Mueller detector for beta particles are determined. The possibility to determine the mass of precursor element by daughter nuclei activity is shown. The results are compared with the one obtained by direct measurement of the mass (or number of atoms) of precursor radioactive substance and with theoretical values calculated for isotopes in secular equilibrium. (Author) [pt

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

    International Nuclear Information System (INIS)

    Prestwych, W.V.; Kennett, T.J.; Pepper, G.T.

    1988-01-01

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

  10. No evidence for a decrease of nuclear decay rates with increasing heliocentric distance based on radiochronology of meteorites

    Science.gov (United States)

    Meier, Matthias M. M.; Wieler, Rainer

    2014-03-01

    It has been argued that the decay rates of several radioactive nuclides are slightly lower at Earth's aphelion than at perihelion, and that this effect might depend on heliocentric distance. It might then be expected that nuclear decay rates be considerably lower at larger distances from the sun, e.g., in the asteroid belt at 2-3 AU from where most meteorites originate. If so, ages of meteorites obtained by analyses of radioactive nuclides and their stable daughter isotopes might be in error, since these ages are based on decay rates determined on Earth. Here we evaluate whether the large data base on nuclear cosmochronology offers any hint for discrepancies which might be due to radially variable decay rates. Chlorine-36 (t1/2 = 301,000 a) is produced in meteorites by interactions with cosmic rays and is the nuclide for which a decay rate dependence from heliocentric distance has been proposed, which, in principle, can be tested with our approach and the current data base. We show that compilations of 36Cl concentrations measured in meteorites offer no support for a spatially variable 36Cl decay rate. For very short-lived cosmic-ray produced radionuclides (half-lives uranium decay rates in different meteorite parent bodies in the asteroid belt. Moreover, the oldest U-Pb ages of meteorites agree with the main-sequence age of the sun derived from helioseismology within the formal ˜1% uncertainty of the latter. Meteorite ages also provide no evidence for a decrease of decay rates with heliocentric distance for nuclides such as 87Rb (decay mode β-) 40K (β- and electron capture), and 147Sm (α).

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

    International Nuclear Information System (INIS)

    Juncosa, R.; Delgado, J.; Font, I.

    2010-01-01

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

  13. Critical evaluation of radioactive decay constants for 99Mo, 144Ce, 144Pr and 144Pm

    International Nuclear Information System (INIS)

    Grigor'yan, Yu.I.; Sokolovskij, L.L.; Chukreev, F.E.

    1976-01-01

    The decay schemes of 99 Mo, 144 Ce, 144 Pr, 144 Pm are reviewed on the basis of analysis of a large number of published experimental works. A knowledge of the decay constants of the first three nuclei, which are fission products, is of great importance in developing safeguards methods. Quantities characterizing the β-decay of 99 Mo, 144 Ce, 144 Pr and K-electron capture ( 144 Pm) are evaluated. Level schemes are plotted for the daughter nuclei. Evaluations are made in respect of the energies and intensities of γ-rays and conversion electrons accompanying β-decay and K-electron capture, internal conversion coefficients and transition multipolarities, level energies, spins, parities, and lifetimes of the ground and excited states of 99 Tc, 144 Pr, and 144 Nd. From the results obtained the 99 Mo- 99 Tc mass difference can be deduced and a new value of 1358.0 +- 3.0 keV is established instead of the previously used value of 1372.2 +- 3.9 keV. The analagous quantity for the nuclei 144 Pr- 144 Nd is taken as 2994.6 +- 3.2 keV instead of the value 2997.0 +- 3.0 keV. (author)

  14. Branching fraction in the radioactive decay of /sup 85m/Kr

    International Nuclear Information System (INIS)

    Jaffey, A.H.; Steinberg, E.P.; Gindler, J.E.; Gray, J. Jr.; Horwitz, E.P.; Hughes, J.P.; Schmitz, F.J.

    1980-02-01

    The branching fraction in the decay of the fission product /sup 85m/Kr to the ground state 85 Kr (10.75 y) was measured relative to the total decay to both 85 Kr and 85 Rb. Samples of 235 U were highly irradiated in a high-flux reactor and dissolved. The 85 Rb was measured by isotope-dilution mass spectrometry, and the 85 Kr was counted in GM tubes the counting efficiencies of which were calibrated with a standardized 85 Kr gas of known disintegration rate. The branching fraction measured with both a low-burnup sample and a high-burnup sample was 0.2160 +- 0.0019, the largest error arising from the uncertainty in the caibration of the standardized gas. 1 figure, 9 tables

  15. Siphons, Water Clocks, Cooling Coffee, and Leaking Capacitors: Classroom Activities and a Few Equations to Help Students Understand Radioactive Decay and Other Exponential Processes

    Science.gov (United States)

    Brady, John B.

    2009-01-01

    Although an understanding of radiometric dating is central to the preparation of every geologist, many students struggle with the concepts and mathematics of radioactive decay. Physical demonstrations and hands-on experiments can be used to good effect in addressing this teaching conundrum. Water, heat, and electrons all move or flow in response…

  16. Radioactivity

    International Nuclear Information System (INIS)

    2002-01-01

    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.)

  17. 1/f noise in the radioactive β- decay of /sup 204/Tl

    International Nuclear Information System (INIS)

    Azhar, M.A.; Gopala, K.

    1989-01-01

    An attempt has been made to detect the presence of 1/f fluctuations in β - decay using the Allan variance theorem. For counting periods less than about 800 min, the counting statistics were found to be Poissonian and for periods greater than about 800 min, the statistics were found to be non-Poissonian. 1/f fluctuations in the β - emissions were observed leading to a flicker floor. It was also found that the flicker floor varies with energy of the emitted β - particles from /sup 204/Tl used in the experiment

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

    International Nuclear Information System (INIS)

    Saas, Arsene; Grauby, Andre

    1975-12-01

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

  19. Radioactivity

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

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

  20. Electron capture detector based on a non-radioactive electron source: operating parameters vs. analytical performance

    Directory of Open Access Journals (Sweden)

    E. Bunert

    2017-12-01

    Full Text Available Gas chromatographs with electron capture detectors are widely used for the analysis of electron affine substances such as pesticides or chlorofluorocarbons. With detection limits in the low pptv range, electron capture detectors are the most sensitive detectors available for such compounds. Based on their operating principle, they require free electrons at atmospheric pressure, which are usually generated by a β− decay. However, the use of radioactive materials leads to regulatory restrictions regarding purchase, operation, and disposal. Here, we present a novel electron capture detector based on a non-radioactive electron source that shows similar detection limits compared to radioactive detectors but that is not subject to these limitations and offers further advantages such as adjustable electron densities and energies. In this work we show first experimental results using 1,1,2-trichloroethane and sevoflurane, and investigate the effect of several operating parameters on the analytical performance of this new non-radioactive electron capture detector (ECD.

  1. The impact of radioactive radon and its decay products on human health

    Directory of Open Access Journals (Sweden)

    Izabela Bilska

    2016-03-01

    Full Text Available Ionizing radiation derived from radon isotopes and their derivatives is responsible for approx. 40% of the annual dose that every human being takes from all sources of radiation. These are alpha-emitting isotopes, which is important in terms of human health harms. In the article, the sources of radioactive radon entering the air in residential rooms are presented. It also shows the mechanism of forming its derivatives and their impact on human health. Moreover, it provides a list of diseases which these substances can trigger or stimulate and enumerates their medical, beneficial uses. In order to differentiate between positive and negative effects of radon on human body, the article brings together recommendations of international organizations and Polish legal norms.

  2. Fast Radioactive Nuclide Recognition Method Study Based on Pattern Recognition

    Directory of Open Access Journals (Sweden)

    Yonggang Huo

    2014-01-01

    Full Text Available Based on pattern recognition method, applied the nuclear radiation digital measurement and analysis system platform, through synthetically making use of the radioactive nuclide’s ray information, selected radiation characteristic information of the radioactive nuclide, established the characteristic arrays database of radioactive nuclides, the recognition method is designed and applied to the identification of radionuclide radiation while using middle or low-resolution detector in this paper. Verified by experiments, when the count value of the traditional low-resolution spectrometer system is not reach single full energy peak’s statistical lower limit value, the three kinds of mixed radioactive nuclides’ true discrimination rate reached more than 90 % in the digital measurement and analysis system using fast radionuclide recognition method. The results show that this method is obviously superior to the traditional methods, and effectively improve the rapid identification ability to radioactive nuclide.

  3. 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

  4. Radioactive source monitoring system based on RFID and GPRS

    International Nuclear Information System (INIS)

    He Haiyang; Zhou Hongliang; Zhang Hongjian; Zhang Sheng; Zhou Junru; Weng Guojie

    2011-01-01

    Nuclear radiation produced by radioactive source is harmful to the health of human body, and the lost and theft of radioactive source will cause environmental pollution and social panic. In order to solve the abnormal leaks, accidental loss, theft and other problems of the radioactive source, a radioactive source monitoring system based on RFID, GPS, GPRS and GSM technology is put forward. Radiation dose detector and GPS wireless location module are used to obtain the information of radiation dose and location respectively, RFID reader reads the status of a tag fixed on the bottom of the radioactive source. All information is transmitted to the remote monitoring center via GPRS wireless transmission. There will be an audible and visual alarm when radiation dose is out of limits or the state of radioactive source is abnormal, and the monitoring center will send alarming text messages to the managers through GSM Modem at the same time. Thus, the functions of monitoring and alarming are achieved. The system has already been put into operation and is being kept in functional order. It can provide stable statistics as well as accurate alarm, improving the supervision of radioactive source effectively. (authors)

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

    International Nuclear Information System (INIS)

    Vokal, B.; Krizman, M.

    2003-01-01

    Radioactivity monitoring in the environment in Slovenia has been currently performed on a regular basis as a monitoring of global radioactive contamination and as operational monitoring in the surroundings of facilities with radioactive discharges. Environmental radioactivity monitoring due to atmospheric nuclear bomb tests in Slovenia started in 1961, while monitoring of radioactive discharges from nuclear facilities in Slovenia started in early 1980s with the extent programmes: in the Krsko nuclear power plant in 1981, in the uranium mining and milling facility at Zirovski vrh (1985) and in the research reactor at Brinje near Ljubljana (1986). Both categories of the results are documented in written reports and sent to the competent authorities, mostly on annual basis. According to the requirements of the European Commission (Commission Recommendation of 8. June 2000 on the application of Article 36 of the Euratom Treaty concerning the monitoring of the levels of the radioactivity in the environment for the purpose of assessing the exposure of the population as a whole (2000/473/Euratom) and Commission Recommendation of 6. December 1999 on the application of Article 37 of the Euratom Treaty (1999/829/Euratom)) and on initiative of the IAEA (IAEA Document International Atomic Energy Agency (IAEA). Project International Data base on Discharges of Radioactive Material to the Environment, 2000) the Slovenian Nuclear Safety Administration (SNSA) started in 2002 with development of the computerised data base on environmental data and radioactive discharges data for the most facilities, specially for the nuclear fuel cycle. At present the environmental database contains the data on global contamination of air, surface waters, tap water sources and food chain (1 37C s, 9 0S r) and also on levels of major natural radionuclides (7 B e, 2 10P b, 2 26R a, 4 0K ). Data base on radioactive discharges for the recent years comprises the activities of fission and activation

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

    Directory of Open Access Journals (Sweden)

    Hideyuki Doi

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

  7. Data processing in the integrated data base for spent fuel and radioactive waste

    International Nuclear Information System (INIS)

    Forsberg, C.W.; Morrison, G.W.; Notz, K.J.

    1984-01-01

    The Integrated Data Base (IDB) Program at Oak Ridge National Laboratory (ORNL) produces for the U.S. Department of Energy (DOE) the official spent fuel and radioactive waste inventories and projections for the United States through the year 2020. Inventory data are collected and checked for consistency, projection data are calculated based on specified assumptions, and both are converted to a standard format. Spent fuel and waste radionclides are decayed as a function of time. The resulting information constitutes the core data files called the Past/Present/Future (P/P/F) data base. A data file management system, SAS /sup R/, is used to retrieve the data and create several types of output: an annual report, an electronic summary data file designed for IBM-PC /sup R/ -compatible computers, and special-request reports

  8. 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).

  9. A comparison of specific effective energies values obtained for some radioactive element using 3 different decay data banks

    International Nuclear Information System (INIS)

    Nascimento, J.E.C.; Bertelli Neto, L.

    1990-01-01

    The Specific Effective Energies (SEE) are the dose equivalents received by each of the body organs (targets organs) per nuclear transformation of a radionuclide deposited in an organ or tissue (source organ) after an intake of this isotope. The SEE values were calculated on basis of the dosimetric concepts of Publication 30 of the International Comission on Radiological Protection (ICRP). The results were evaluated using two of the three most known decay data banks. This study shows considerables discrepancies in the evaluation of the SEE values for some radionuclides. In theses cases it is recommended the use of the most complete and detailed decay data bank to perform the SEE calculations. (author) [pt

  10. Calibration method based on direct radioactivity measurement for radioactive gas monitoring instruments

    International Nuclear Information System (INIS)

    Yoshida, Makoto; Ohi, Yoshihiro; Chida, Tohru; Wu, Youyang.

    1993-01-01

    A calibration method for radioactive gas monitoring instruments was studied. In the method, gaseous radioactivity standards were provided on the basis of the direct radioactivity measurement by the diffusion-in long proportional counter method (DLPC method). The radioactivity concentration of the gas mixture through a monitoring instrument was determined by sampling the known volume of the gas mixture into the proportional counter used for the DLPC method. Since oxygen in the gas mixture decreased the counting efficiency in a proportional counter, the influence on calibration was experimentally estimated. It was not serious and able to be easily corrected. By the present method, the relation between radioactivity concentration and ionization current was determined for a gas-flow ionization chamber with 1.5 l effective volume. It showed good agreement with the results in other works. (author)

  11. Rapid heating tensile tests of high-energy-rate-forged 316L stainless steel containing internal helium from radioactive decay of absorbed tritium

    International Nuclear Information System (INIS)

    Mosley, W.C.

    1990-01-01

    316L stainless steel is a candidate material for construction of equipment that will be exposed to tritium. This austenitic stainless steel is frequently used in the high-energy-rate-forged (HERF) metallurgical condition to take advantage of increased strength produced by cold work introduced by this process. Proper design of tritium-handling equipment will require an understanding of how helium-3, the product of radioactive decay of tritium, affects mechanical properties. This report describes results of elevated-temperature tensile testing of HERF 316L stainless steel specimens containing helium concentrations of 171 (calculated) atomic parts per million (appm). Results are compared with those reported previously for specimens containing 0 and 94 (measured) appm helium

  12. 37-Active rods fuel element for Atucha 1 nuclear power plant. Effects of this change in design over the neutronic behavior, decay power and radioactive inventory

    International Nuclear Information System (INIS)

    Villar, Javier E.

    1999-01-01

    The influence of the use of 37-rods fuel element on the behavior of the Atucha 1 nuclear power plant homogeneous core with slightly enriched fuel to 0.85 w % were studied through representative parameters such as average discharge burnup, channel powers, reactivity coefficients, kinetic parameters, radioactive inventory and decay power. In general, the values of mentioned parameters are similar to those corresponding to a core with the 36-rods fuel element actually in use, although it must be emphasized a decrease both in linear power and, in minor degree, in the efficiency of shut-off and control rods and a slight increase in the discharge burnup. The fuel management strategy developed for a core with 36-rods elements can be maintained. (author)

  13. An UPF3-based nonsense-mediated decay in Paramecium.

    Science.gov (United States)

    Contreras, Julia; Begley, Victoria; Macias, Sandra; Villalobo, Eduardo

    2014-12-01

    Nonsense-mediated decay recognises mRNAs containing premature termination codons. One of its components, UPF3, is a molecular link bridging through its binding to the exon junction complex nonsense-mediated decay and splicing. In protists UPF3 has not been identified yet. We report that Paramecium tetraurelia bears an UPF3 gene and that it has a role in nonsense-mediated decay. Interestingly, the identified UPF3 has not conserved the essential amino acids required to bind the exon junction complex. Though, our data indicates that this ciliate bears genes coding for core proteins of the exon junction complex. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  14. Neutron emission from 9Be nucleus under the action of β+ and γ radiation emitted in radioactive decay

    International Nuclear Information System (INIS)

    Vo Dak Bang; Gangrskij, Yu.P.; Miller, M.B.; Mikhajlov, L.V.; Fam Zui Khien; Kharisov, I.F.

    1980-01-01

    The neutron yield from the 9 Be nucleus under the action of beta and gamma-radiation emitted at the radiative decay of 11 C, 62 Cu, 66 Ga, 74 Br isotopes is measured. These isotopes differ essentially by the emitted radiation spectra. The contribution of various processes ((γ, n)-reactions, inelastic scattering and positron nonradiative annihilation) to the neutron yield observed is determined [ru

  15. Cluster and alpha decay of superheavy nuclei

    Science.gov (United States)

    Poenaru, D. N.; Stöcker, H.; Gherghescu, R. A.

    2018-02-01

    We investigated cluster radioactivity and alpha decay of some superheavy nuclei with atomic numbers Z = 119, 120 , which may be produced in the future. Two models are used to calculate the half-lives against cluster radioactivity: ASAF (Analytical Super-Asymmetric Fission) and UNIV (Universal Formula). For α decay half-lives we are based on four models: ASAF, UNIV, semFIS (semi-empirical formula based on Fission Theory) and AKRA (first author Akrawy). The Q -values are calculated using the theoretical model of atomic masses WS10, which sometimes is called W4.

  16. Detecting decay fungi with antibody-based tests and immunoassays

    Science.gov (United States)

    Carol A. Clausen

    2003-01-01

    Early detection of wood decay can prolong the service life of wood. Antibodies are the ideal probe for detecting fungi that cause biodeterioration because they are highly specific and can quantitatively determine the fungal antigen concentration from highly complex structures, such as wood. Polyclonal antibodies recognize multiple chemical sites of the targeted...

  17. Investigation of nuclei near N = 82 and Z = 64 VIA radioactive decay of high-spin isomers

    International Nuclear Information System (INIS)

    Toth, K.S.

    1979-01-01

    An island of very high spin isomers was found recently in neutron-deficient Gd-Lu nuclei near the N = 82 closed shell in (H.I.,xn) measurements. This exciting discovery has led to a large number of experiments trying to identify the structures of these isomers and the nuclei in which they occur. These attempts have been helped in many instances by available spectroscopic information at low excitation energies. A systematic investigation of the low-lying structure of nuclei near N = 82 and Z greater than or equal to 64 was carried out. Heavy-ion beams were used to produce proton-rich isotopes which were then transported, with the use of gas-jet systems, to shielded areas where singles and coincidence γ-ray measurements could be made. Earlier investigations dealt with the decay of terbium ( 146-149 Tb) and dysprosium ( 147-152 Dy) nuclei. During the past two years the research program was extended to holmium nuclides (A less than or equal to 152) produced in 10 B bombardments of samarium. Two new isotopes, 149 Ho and 148 Ho, were identified. The decay data of 21-s 149 Ho supplement in-beam results and locate the hg/ 2 neutron state in 149 Dy to be at 1091 keV. The most intense γ-ray associated with 9-s 148 Ho has an energy of 1688 keV. It is possibly the first-excited to ground-state transition in 148 Dy. Recent in-beam measurements have shown that the first-excited state in 146 Gd is, unespectedly, 3 - in contrast to doubly evenN = 82 nuclei below gadolinium where it is 2 + . It would be interesting to determine whether the 1688-keV level in 148 Dy, the next nucleus in this isotonic series, is 2reverse arrow or 3 - in character. 12 references

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

    Science.gov (United States)

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

    2014-05-01

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

  19. The analysis of natural uranium decay based on gamma-ray measurements

    International Nuclear Information System (INIS)

    Kim, K. W.; Kim, D. G.; No, W. S.; Park, P. W.; Yang, S. W.; Park, G. H.

    2004-01-01

    Measurements of gamma-radiations from natural uranium dioxide were performed to analyze the decay chain of natural uranium. 10.1g of natural uranium dioxide was used as a specimen and the measurement was done for 24 hours. Genie-2000 was used for the analysis of gamma ray energy from uranium. Theoretical estimation of gamma rays from the decay chain and data from the measurement were compared quantitatively. Based on these comparisons, the gamma rays from the decay chain of natural uranium were analyzed

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

    International Nuclear Information System (INIS)

    Martell, E.A.; Sweder, K.S.

    1984-01-01

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

  1. TENORM (Technologically Enhanced Naturally Occurring Radioactive Materials)

    Science.gov (United States)

    ... the beginning of time, naturally occurring. radionuclides or radioactive elements as they occur in nature, such as radium , uranium , thorium , potassium, and their radioactive decay products decay products The atoms formed and ...

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

    International Nuclear Information System (INIS)

    Piquemal, F.

    1994-05-01

    Double beta decay without neutrino emission provides a test of the mass and nature of neutrinos (Majorana or Dirac). Experimental proof would be the observation of a peak at the transition energy in the spectrum of the two emitted electrons. The expected half-life of the process is extremely long (about 10 25 years for 100 Mo). So, being thus, it is very important to get a good knowledge of the origins and contributions of background noise in the region where the signal could occur. The main origins of the background noise in the region where the signal could occur. The main origins of the background noise are found to be e + - e - pairs induced by heavy energy gamma rays. These gamma rays follow the thermal neutron capture by the components of the detector. Another factor in the production of background noise is natural radio-activity. For example, the presence of Radon in the laboratory has been observed to produce deposits of 214 Bi on the sides of the detector. Data taken with the NEMO 2 prototype and an enriched molybdenum source foil indicates that the background limit reached is of the order of 1 event per year in the 3 MeV region. Results of this work have proven the necessity to have a magnetic field in NEMO 3 in order to reject e + - e - pairs. (author)

  3. Development of plastic scintillator based food radioactivity contamination monitoring system

    International Nuclear Information System (INIS)

    Parihar, A.; Sahani, R.M.; Mahala, V.K.; Vaijapurkar, S.G.

    2016-01-01

    Radioactivity is naturally present in soil, water and food stuffs. Food can be contaminated after discharge of radioactivity into the environment from industries that concentrate natural radionuclide and from civil or military nuclear operations. The contamination can be in three ways; by direct deposition, through the food chain and induced radioactivity due to exposure of high neutron flux. The health effects on human depend on the type of radionuclide and the length of time people are exposed to it. The studies of fission product behaviour in the food chain have revealed radionuclide Strontium-90, Caesium 137 and Iodine-131 are of major concern. Plastic scintillator is already developed indigenously at Defence Laboratory, Jodhpur. Efforts has been made to develop a portable field instrument using plastic scintillator for assessment of beta ( 90 Sr) and gamma ( 137 Cs and 131 I) radioactivity in food

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

    International Nuclear Information System (INIS)

    Bouniol, P.

    2014-01-01

    Cement-based materials appear to be an original environment with respect to radiolysis, due to their intrinsic complexity (porous, multiphasic and evolutional medium) or their very specific physico-chemical conditions (hyper-alkaline medium with pH ≥ 13, high content in calcium) or by the fact of numerous couplings existing between different phenomenologies. At the level of a radioactive cemented wasteform, a high degree of complexity is reached, in particular if the system communicates with the atmosphere (open system allowing regulation of the pressures but also the admission of O 2 , strong reactive with regards to radiolysis). Then, the radiolysis description exceeds widely the only one aspect of the decomposition of alkaline water under irradiation and makes necessary a global phenomenological approach. In this context, some 'outlying' phenomena, highly coupled with radiation chemistry, have to be taken into account because they contribute to deeply modify the net result of the radiolysis: radioactive decay of multiple αβγ emitters with filiation, phase changes (for example H 2 aq → H 2 gas) within the pores, gas transport by convection (Darcy law) and by diffusion (Fick law), precipitation/dissolution of solid phases, effect of the ionic strength and the temperature, disturbances connected to the presence of some solutes with redox potentialities (iron, sulphur). The integration work carried out on the previous points leads to an operational model (DOREMI) allowing the estimate of H 2 amounts produced by radiolysis in different cemented radioactive waste-forms. As the final expression of the model, numerical simulations constitute a relevant tool of expertise and prospecting, contributing to accompany the thought on radiolysis in cement matrices in general and in cemented waste-forms in particular. Starting from different examples, simulations can be so used in order to test some hypotheses or illustrate the greatest influence of gas transport, dose

  5. Natural radioactivity in zirconia-based dental ceramics

    International Nuclear Information System (INIS)

    Giussani, Augusto; Gerstmann, Udo; La Porta, Caterina; Cantone, Marie C.; Veronese, Ivan

    2008-01-01

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

  6. Transportation legislative data base : state radioactive materials transportation statute compilation, 1989-1993

    Science.gov (United States)

    1994-04-30

    The Transportation Legislative Data Base (TLDB) is a computer-based information service containing summaries of federal, state and certain local government statutes and regulations relating to the transportation of radioactive materials in the United...

  7. Radioactive nuclear beam facilities based on projectile fragmentation

    International Nuclear Information System (INIS)

    Sherrill, B.M.

    1992-01-01

    The production of radioactive beams using direct separation techniques is discussed. The reaction mechanisms which can be used to produce radioactive beams with these techniques can be broadly divided into three groups, projectile fragmentation, nucleon transfer, and Coulomb disassociation. Radioactive nuclei produced in these ways have large forward momenta with relatively sharp angular distributions peaked near zero degrees which are suitable for collection with magnetic devices. Secondary beam intensities of up to a few percent of the primary beam intensity are possible, although depending on the production mechanism the beam emittance may be poor. Further beam purification can be achieved using atomic processes with profiled energy degraders. The features of the production reaction mechanism, separation techniques, and a review of world wide efforts are presented. The advantages and disadvantages of the method are presented, with discussion of techniques to overcome some of the disadvantages. (Author)

  8. Enhanced control of DFIG wind turbine based on stator flux decay compensation

    DEFF Research Database (Denmark)

    Zhu, Rongwu; Deng, Fujin; Chen, Zhe

    2016-01-01

    For the doubly-fed induction generator (DFIG)- based wind energy conversion system (WECS), the decaying flux and negative flux are the main reasons to cause the DFIG rotor overcurrent, during grid faults. The stator decaying flux characteristics versus the depth and instant of the stator voltage...... variation are analyzed firstly. On the basis of the stator flux performances, the enhanced control strategy is proposed to limit the decaying flux approximately into zero in half fundamental period by changing the stator voltage drop and recovery mode, and consequently the rotor transient current pulse...... is significantly reduced during grid faults. The experimental results based on the 7.5 kW DFIG setup is carried to validate the correctness and feasibility of the proposed strategy. Dynamic voltage restorer (DVR) can be one of the applications. With the proposed strategy, the DVR only works in a half fundamental...

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

    International Nuclear Information System (INIS)

    Yang Yaoyun; Su Genghua; Zhang Hui; Li Junli; Zhu Li

    2010-01-01

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

  10. Evaluation procedures for experimental decay data

    International Nuclear Information System (INIS)

    Bunting, R.L.; Reich, C.W.

    1981-01-01

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

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

    International Nuclear Information System (INIS)

    Scholz, H.W.; Zucchetti, M.; Casteleyn, K.; Adelhelm, C.

    1994-01-01

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

  12. Estimates for the ionization and mass of type I supernova envelopes, based on the radioactivity hypothesis

    International Nuclear Information System (INIS)

    Shklovskii, I.

    1981-01-01

    Analysis of spectroscopic evidence for supernova 1972e fully confirms the hypothesis that radioactive 56 Ni decay produces the exponential tail in type I light curves. Relativistic positrons formed through the β decay of 56 Co will interact with material in the envelope thrown off by the supernova outburst; hence the ionization of the envelope can be estimated. The chief supplier of free electrons to the envelope will evidently be helium, the most abundant element there; iron, on the other hand, will mainly be in the Fe II state. The envelope would then have a mass of roughly-equal0.6 M/sub sun/ and a kinetic energy of roughly-equal5 x 10 50 erg, in agreement with observation. Accordingly, neutron stars should develop in type I as well as type II outbursts. Only type I supernovae, however, will synthesize the iron in the universe

  13. 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

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

    CERN Document Server

    Maddocks, Harvey

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

  15. Natural radioactive phon

    International Nuclear Information System (INIS)

    Birjukovs, V.; Birjukov, P.

    2004-01-01

    The natural radiating phon is determined by radioactive isotopes of elements which time of half-decay is commensurable in due course existence of the Earth, dispersing in rocks, ground, water and air, and also space radiation. (authors)

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

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

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

    International Nuclear Information System (INIS)

    1997-12-01

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

  18. Accelerator development for a radioactive beam facility based on ATLAS

    International Nuclear Information System (INIS)

    Shepard, K. W.

    1998-01-01

    The existing superconducting linac ATLAS is in many respects an ideal secondary beam accelerator for an ISOL (Isotope separator on-line) type radioactive beam facility. Such a facility would require the addition of two major accelerator elements: a low charge state injector for the existing heavy ion linac, and a primary beam accelerator providing 220 MV of acceleration for protons and light ions. Development work for both of these elements, including the option of superconducting cavities for the primary beam accelerator is discussed

  19. Accelerator development for a radioactive beam facility based on ATLAS.

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K. W.

    1998-01-08

    The existing superconducting linac ATLAS is in many respects an ideal secondary beam accelerator for an ISOL (Isotope separator on-line) type radioactive beam facility. Such a facility would require the addition of two major accelerator elements: a low charge state injector for the existing heavy ion linac, and a primary beam accelerator providing 220 MV of acceleration for protons and light ions. Development work for both of these elements, including the option of superconducting cavities for the primary beam accelerator is discussed.

  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. The Calculation Of Total Radioactivity Of Kartini Reactor Fuel Element

    International Nuclear Information System (INIS)

    Budisantoso, Edi Trijono; Sardjono, Y.

    1996-01-01

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

  2. 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

  3. Baryonic B decays

    Energy Technology Data Exchange (ETDEWEB)

    Kichimi, H. [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan). Institute of Particle and Nuclear Studies

    2005-07-01

    We present recent results of Baryonic B decays from Belle, which contain charmed and charmless baryonic decays into two to four body final states. We report the branching fractions, including new observations of the baryonic decays into two charmed baryons in the final states, and the charmless baryonic decay proceeding through b {yields} s{gamma} transition, and the low di-baryon mass enhancement structures observed in the three-body decays, based on 357 fb{sup -1} data. (author)

  4. Integrated Data Base for 1989: Spent fuel and radioactive waste inventories, projections, and characteristics

    International Nuclear Information System (INIS)

    1989-11-01

    The Integrated Data Base (IDB) Program has compiled current data on inventories and characteristics of commercial spent fuel and both commercial and US government-owned radioactive wastes through December 31, 1988. These data are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The current projections of future waste and spent fuel to be generated through the year 2020 and characteristics of these materials are also presented. The information forecasted is consistent with the latest US Department of Energy/Energy Information Administration (DOE/EIA) projections of US commercial nuclear power growth and the expected defense-related and private industrial and institutional (I/I) activities. The radioactive materials considered, on a chapter-by-chapter basis, are spent fuel, high-level waste, transuranic waste, low-level waste, commercial uranium mill tailings, remedial action waste, commercial reactor and fuel cycle facility decommissioning waste, and mixed (hazardous and radioactive) low-level waste. For most of these categories, current and projected inventories are given through the year 2020, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions. In addition, characteristics and current inventories are reported for miscellaneous, highly radioactive materials that may require geologic disposal. 45 figs., 119 tabs

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

    International Nuclear Information System (INIS)

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

    1994-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

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

  7. Integrated Data Base for 1991: US spent fuel and radioactive waste inventories, projections, and characteristics

    International Nuclear Information System (INIS)

    1991-10-01

    The Integrated Data Base (IDB) Program has compiled current data on inventories and characteristics of commercial spent fuel and both commercial and US government-owned radioactive wastes through December 31, 1990. These data are based on the most reliable information available form government sources, the open literature, technical reports, and direct contacts. The current projections of future waste and spent fuel to be generated generally through the year 2020 and characteristics of these materials are also presented. The information forecasted is consistent with the latest US Department of Energy/Energy Information Administration (DOE/EIA) projections of US commercial nuclear power growth and the expected DOE-related and private industrial and institutional (I/I) activities. The radioactive materials considered are spent fuel, high-level waste, transuranic waste, low-level waste, commercial uranium mill tailings, environmental restoration wastes, commercial reactor and fuel cycle facility decommissioning wastes, and mixed (hazardous and radioactive) low-level waste. For most of these categories, current and projected inventories are given through the year 2020, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions. In addition, characteristics and current inventories are reported for miscellaneous radioactive materials that may require geologic disposal. 160 refs., 61 figs., 142 tabs

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

    International Nuclear Information System (INIS)

    1992-10-01

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

  9. Integrated data base for 1990: US spent fuel and radioactive waste inventories, projections, and characteristics

    International Nuclear Information System (INIS)

    1990-10-01

    The Integrated Data Base (IDB) Program has compiled current data on inventories and characteristics of commercial spent fuel and both commercial and US government-owned radioactive wastes through December 31, 1989. These data are based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. The current projections of future waste and spent fuel to be generated through the year 2020 and characteristics of these materials are also presented. The information forecasted is consistent with the latest US Department of Energy/Energy Information Administration (DOE/EIA) projections of US commercial nuclear power growth and the expected DOE-related and private industrial and institutional (I/I) activities. The radioactive materials considered, on a chapter-by-chapter basis, are spent fuel, high-level waste, transuranic waste, low-level waste, commercial uranium mill tailings, environmental restoration wastes, commercial reactor and fuel cycle facility decommissioning wastes, and mixed (hazardous and radioactive) low-level waste. For most of these categories, current and projected inventories are given through the year 2020, and the radioactivity and thermal power are calculated based on reported or estimated isotopic compositions. In addition, characteristics and current inventories are reported for miscellaneous radioactive materials that may require geologic disposal. 22 refs., 48 figs., 109 tabs

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

    International Nuclear Information System (INIS)

    1995-09-01

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

  11. The sorption of 210Pb, 210Bi and 210Po on montmorillonite: a study with emphasis on reversibility aspects and on the effect of the radioactive decay of adsorbed nuclides

    International Nuclear Information System (INIS)

    Ulrich, H.J.; Degueldre, C.

    1993-01-01

    The influence of the ionic strength and of pH on the adsorption/desorption processes of Pb, Bi and Po on montmorillonite has been investigated. For Pb, a strong dependence of the adsorption and desorption processes on the ionic strength was observed at pH d ) are measured. They range from 10 3 to 10 5 ml . g -1 for Pb and from 10 4 to 10 7 ml . g -1 for 210 Bi and 210 Po. When adsorption and desorption coefficients are compared, an agreement is found for both adsorption/desorption R d 's of Pb, whereas, for Bi and Po adsorption R d 's were several orders of magnitude lower than those obtained for desorption. The chemical activities of free Bi and Po in the liquid phase are limited by the formation of Bi and Po-colloids prior to the sorption step. This fact could explain the differences in the R d values. While the adsorption of Pb was reversible, only very small amounts of BI and Po could be desorbed from the montmorillonite (quasi-irreversible adsorption). The radioactive decay of adsorbed 210 Pb to 210 Bi, which in turn decays to 210 Po, can lead to significant changes in the desorption behaviour of the daughter nuclides. Whereas the sorption is nearly irreversible if Bi and Po adsorb on montmorillonite from the aqueous phase, they desorb more easily if they are generated by the radioactive decay of adsorbed 210 Pb. The difference in the distribution coefficients R d is approximately one order of magnitude in the case of Po, and more than 2 orders of magnitude in the case of Bi. (orig.)

  12. A dental public health approach based on computational mathematics: Monte Carlo simulation of childhood dental decay.

    Science.gov (United States)

    Tennant, Marc; Kruger, Estie

    2013-02-01

    This study developed a Monte Carlo simulation approach to examining the prevalence and incidence of dental decay using Australian children as a test environment. Monte Carlo simulation has been used for a half a century in particle physics (and elsewhere); put simply, it is the probability for various population-level outcomes seeded randomly to drive the production of individual level data. A total of five runs of the simulation model for all 275,000 12-year-olds in Australia were completed based on 2005-2006 data. Measured on average decayed/missing/filled teeth (DMFT) and DMFT of highest 10% of sample (Sic10) the runs did not differ from each other by more than 2% and the outcome was within 5% of the reported sampled population data. The simulations rested on the population probabilities that are known to be strongly linked to dental decay, namely, socio-economic status and Indigenous heritage. Testing the simulated population found DMFT of all cases where DMFT0 was 2.3 (n = 128,609) and DMFT for Indigenous cases only was 1.9 (n = 13,749). In the simulation population the Sic25 was 3.3 (n = 68,750). Monte Carlo simulations were created in particle physics as a computational mathematical approach to unknown individual-level effects by resting a simulation on known population-level probabilities. In this study a Monte Carlo simulation approach to childhood dental decay was built, tested and validated. © 2013 FDI World Dental Federation.

  13. Low-level radioactive wastes. A bibliography of additions to the Energy Data Base in 1981

    International Nuclear Information System (INIS)

    Grissom, M.C.

    1981-12-01

    Access to information on management of low-level radioactive wastes is provided by this special bibliography and other products of the Technical Information Center. Citations to 215 references on low-level radioactive wastes added to the Energy Data Base in 1981 are presented. The abstracts are grouped in broad subject categories. Within each category the arrangement is by report number for reports, followed by non-reports in reverse chronological order. These citations are to research reports, journal articles, books, patents, theses, and conference papers. Five indexes, each preceded by a brief description, are provided: Corporate Author, Personal Author, Subject, Contract Number, and Report Number

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

    International Nuclear Information System (INIS)

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

    1981-07-01

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

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

    International Nuclear Information System (INIS)

    Pope, N.G.; Schreiber, S.B.; Yarbro, S.L.; Gomez, B.G.; Nekimken, H.L.; Sanchez, D.E.; Bibeau, R.A.; Macdonald, J.M.

    1994-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-07-01

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

  17. Management of radioactive waste: A review

    OpenAIRE

    Luis Paulo Sant'ana; Taynara Cristina Cordeiro

    2016-01-01

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

  18. Estimating the mean and variance of measurements from serial radioactive decay schemes with emphasis on 222Rn and its short-lived progeny

    International Nuclear Information System (INIS)

    Inkret, W.C.; Borak, T.B.; Boes, D.C.

    1990-01-01

    Classically, the mean and variance of radioactivity measurements are estimated from poisson distributions. However, the random distribution of observed events is not poisson when the half-life is short compared with the interval of observation or when more than one event can be associated with a single initial atom. Procedures were developed to estimate the mean and variance of single measurements of serial radioactive processes. Results revealed that observations from the three consecutive alpha emissions beginning with 222 Rn are positively correlated. Since the poisson estimator ignores covariance terms, it underestimates the true variance of the measurement. The reverse is true for mixtures of radon daughters only. (author)

  19. Radioactive measurements in industry

    International Nuclear Information System (INIS)

    Rozsa, S.

    1979-01-01

    The book reviews the industrial applications of radioactive isotopes. The introduction refreshes the reader's knowledge of radioactive decay, radioactive radiations and measuring techniques. Then the special problems of threshold detection, level indication, thickness measurements, measurements of layer thickness applying beta-reflexion, density measurements, humidity measurements, and the determination of the composition of different materials are detailed. In each chapter the principle of a given technique, the available equipment, the possibilities of controlling systems and results of concrete measurements are discussed. The last chapter deals with the practical aspects of the industrial installation of radioactive measuring systems. (L.E.)

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

    International Nuclear Information System (INIS)

    Sanhueza Mir, Azucena

    2003-01-01

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

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

    International Nuclear Information System (INIS)

    Tsai, Ming-Kuan; Yau, Nie-Jia

    2013-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2012-01-01

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

  3. Immobilization of radioactive waste in cement based matrices

    International Nuclear Information System (INIS)

    Glasser, F.P.; Rahman, A.A.; Macphee, S.; Atkins, M.; Beckley, N.; Carson, S.

    1986-11-01

    Experimental and theoretical studies of hydrated cement systems are described. The behaviour of slag-based cement is described with a view to predicting their long term pH, Esub(n) and mineralogical balance. Modelling studies which enable the prediction at long ages of cement composites are advanced and a base model of the CaO-SiO 2 -H 2 O system presented. The behaviour of U and I in cements is explored. The tolerance of cement systems for a wide range of miscellaneous waste stream components and environmental hazards is described. The redox potential in cements is effectively lowered by irradiation. (author)

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

    International Nuclear Information System (INIS)

    1994-04-01

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

  5. Low-level radioactive waste data base management

    International Nuclear Information System (INIS)

    Roles, G.W.

    1987-01-01

    This paper outlines the uses of information obtained from a national system for management of low-level waste shipment manifest information from the perspective of the NRC Division of Waste Management (DWM). A background section is first presented which briefly reviews some of the basic attributes of a workable system, as well as the existing data management systems established by the disposal facility operators. This background leads into a more detailed discussion of the major uses to which a regulatory agency would put the manifest information, including technical studies and analyses of a broad nature as well as day-to-day compliance with regulations and disposal site license conditions. The next two sections respectively summarize NRC's current data base capabilities as well as the limitations in these capabilities. The final section addresses the question: Where do we go from Here? One option under consideration is a rule making which would: (1) set forth the minimum information to be included in shipment manifests in greater detail than that currently specified in 10 CFR 20.311, and (2) require that operators of all low-level waste disposal facilities reduce the information on incoming shipment manifests to an electronic data format which would be periodically forwarded to a centralized location. However, this option would conflict with other NRC priorities and probably require considerable time to implement. Much of the groundwork for a national system has already been prepared, and NRC's preferred approach is to work with States, Compacts, disposal site operators, and DOE to upgrade these existing capabilities. 8 references, 1 figure, 2 tables

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

    International Nuclear Information System (INIS)

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

    1998-04-01

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

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

    International Nuclear Information System (INIS)

    McKenzie, G.; Mohatt, J.V.; Kowall, S.J.; Jarvis, M.F.

    1993-06-01

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

  8. The deterministic computational modelling of radioactivity

    International Nuclear Information System (INIS)

    Damasceno, Ralf M.; Barros, Ricardo C.

    2009-01-01

    This paper describes a computational applicative (software) that modelling the simply radioactive decay, the stable nuclei decay, and tbe chain decay directly coupled with superior limit of thirteen radioactive decays, and a internal data bank with the decay constants of the various existent decays, facilitating considerably the use of program by people who does not have access to the program are not connected to the nuclear area; this makes access of the program to people that do not have acknowledgment of that area. The paper presents numerical results for typical problem-models

  9. Radioactive sources in chemical laboratories

    International Nuclear Information System (INIS)

    Janzekovic, H.; Krizman, M.

    2007-01-01

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

  10. Effect of self-glazing on reducing the radioactivity levels of red mud based ceramic materials

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Shuo [College of Material Science and Engineering, Guilin University of Technology, Guilin, Guangxi 541004 (China); Wu, Bolin, E-mail: wubolin3211@gmail.com [College of Material Science and Engineering, Guilin University of Technology, Guilin, Guangxi 541004 (China)

    2011-12-30

    Graphical abstract: Self-glazing red mud based ceramic materials (RMCM) were produced by normal pressure sintering process using the main raw materials of red mud. The properties of the RMCM samples were investigated by the measurements of mechanical properties, radiation measurement, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the self-glazing RMCM have good mechanical properties (water absorption and apparent porosity approached zero; bulk density, 2.94 g/cm{sup 3}; compressive strength, 78.12 MPa). The radiation level has clear change regularity that the radioactivity levels of red mud (6360 Bq) are obvious declined, and can be reduced to that of the natural radioactive background of Guilin Karst landform, China (3600 Bq). It will not only consume large quantities of red mud, but also decrease the production cost of self-glazing RMCM. And the statement of this paper will offer effective ways to reduce the radioactivity level of red mud. Highlights: Black-Right-Pointing-Pointer The self-glazing phenomenon in red mud system was first discovered in our research. Black-Right-Pointing-Pointer Radiation levels of red mud can be reduced efficiently by self-glazing layer. Black-Right-Pointing-Pointer Red mud based ceramic materials will not cause harm to environment and humans. Black-Right-Pointing-Pointer This research possesses important economic significances to aluminum companies. - Abstract: Self-glazing red mud based ceramic materials (RMCM) were produced by normal pressure sintering process using the main raw materials of red mud. The properties of the RMCM samples were investigated by the measurements of mechanical properties, radiation measurement, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the self-glazing RMCM have good mechanical properties (water absorption and apparent porosity approached zero; bulk density, 2.94 g/cm{sup 3}; compressive strength, 78.12 MPa). The radiation

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

    International Nuclear Information System (INIS)

    Johnston, S.; Morrison, C.A.; Albasha, H.; Arguner, D.

    2005-01-01

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

  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. Simple description of cluster radioactivity

    International Nuclear Information System (INIS)

    Tavares, O.A.P.; Medeiros, E.L.

    2012-05-01

    The partial half-life of radioactive decay of nuclei by the emission of fragments heavier than the alpha particle, such as the emission of carbon, oxygen, neon, magnesium, and silicon isotopes from translead nuclei (known as cluster radioactivity), is re-evaluated in the framework of a semiempirical, one-parameter model based on the quantum mechanical tunneling mechanism through a potential barrier where the Coulomb, centrifugal, and overlapping contributions to the barrier are considered within the spherical nucleus approximation. This treatment has shown not only very adequate to t all the existing half-life data, but also to give more reliable half-life predictions for new, yet unmeasured cases of spontaneous emission of massive nuclear fragments both from heavy and intermediate-mass parent nuclei as well. (author)

  14. Neutrino, radioactivity and dating wines

    International Nuclear Information System (INIS)

    Hubert, Ph.

    2004-01-01

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

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

    Science.gov (United States)

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

    2016-08-01

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

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

    International Nuclear Information System (INIS)

    Kaminska, D.; Gajos, A.; Czerwinski, E.; Alfs, D.; Bednarski, T.; Bialas, P.; Dulski, K.; Glowacz, B.; Gupta-Sharma, N.; Korcyl, G.; Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedzwiecki, Sz.; Pawlik-Niedzwiecka, M.; Rudy, Z.; Wieczorek, A.; Zielinski, M.; Moskal, P.; Curceanu, C.; Silarski, M.; Gorgol, M.; Jasinska, B.; Zgardzinska, B.; Hiesmayr, B.C.; Kowalski, P.; Raczynski, L.; Wislicki, W.; Krzemien, W.

    2016-01-01

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

  17. Effect of self-glazing on reducing the radioactivity levels of red mud based ceramic materials.

    Science.gov (United States)

    Qin, Shuo; Wu, Bolin

    2011-12-30

    Self-glazing red mud based ceramic materials (RMCM) were produced by normal pressure sintering process using the main raw materials of red mud. The properties of the RMCM samples were investigated by the measurements of mechanical properties, radiation measurement, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the self-glazing RMCM have good mechanical properties (water absorption and apparent porosity approached zero; bulk density, 2.94 g/cm(3); compressive strength, 78.12 MPa). The radiation level has clear change regularity that the radioactivity levels of red mud (6360 Bq) is obvious declined, and can be reduced to that of the natural radioactive background of Guilin Karst landform, China (3600 Bq). It will not only consume large quantities of red mud, but also decrease the production cost of self-glazing RMCM. And the statement of this paper will offer effective ways to reduce the radioactivity level of red mud. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. RSS-based localization of isotropically decaying source with unknown power and pathloss factor

    International Nuclear Information System (INIS)

    Sun, Shunyuan; Sun, Li; Ding, Zhiguo

    2016-01-01

    This paper addresses the localization of an isotropically decaying source based on the received signal strength (RSS) measurements that are collected from nearby active sensors that are position-known and wirelessly connected, and it propose a novel iterative algorithm for RSS-based source localization in order to improve the location accuracy and realize real-time location and automatic monitoring for hospital patients and medical equipment in the smart hospital. In particular, we consider the general case where the source power and pathloss factor are both unknown. For such a source localization problem, we propose an iterative algorithm, in which the unknown source position and two other unknown parameters (i.e. the source power and pathloss factor) are estimated in an alternating way based on each other, with our proposed sub-optimum initial estimate on source position obtained based on the RSS measurements that are collected from a few (closest) active sensors with largest RSS values. Analysis and simulation study show that our proposed iterative algorithm guarantees globally convergence to the least-squares (LS) solution, where for our suitably assumed independent and identically distributed (i.i.d.) zero-mean Gaussian RSS measurement errors the converged localization performance achieves the optimum that corresponds to the Cramer–Rao lower bound (CRLB).

  19. Optimisation of the neutron source based on gas dynamic trap for transmutation of radioactive wastes

    Science.gov (United States)

    Anikeev, Andrey V.

    2012-06-01

    The Budker Institute of Nuclear Physics in collaboration with the Russian and foreign organizations develop the project of 14 MeV neutron source, which can be used for fusion material studies and for other application. The projected neutron source of plasma type is based on the plasma Gas Dynamic Trap (GDT), which is a special magnetic mirror system for plasma confinement. Presented work continues the subject of development the GDT-based neutron source (GDT-NS) for hybrid fusion-fission reactors. The paper presents the results of recent numerical optimization of such neutron source for transmutation of the long-lives radioactive wastes in spent nuclear fuel.

  20. Present status of intermediate energy data evaluation for accelerator-based transmutation of radioactive waste

    International Nuclear Information System (INIS)

    Koning, A.J.

    1994-05-01

    The recent developments in the field of nuclear data evaluation for energies above 20 MeV are outlined. As a particularly interesting application we consider accelerator-based transmutation of radioactive waste. The most urgent data needs for accelerator-based transmutation have been prioritized and translated in terms of intermediate-energy data libraries. Priorities are assigned to the materials relevant to an incineration system and to the most important associated nuclear reactions (notably reactions involving nucleons). In this contribution, the proposed actions as indicated in previous work are further discussed and a sample intermediate-energy ''starter'' data file is presented. (orig.)

  1. Radioactivity and geophysics

    International Nuclear Information System (INIS)

    Radvanyi, P.

    1992-01-01

    The paper recalls a few steps of the introduction of radioactivity in geophysics and astrophysics: contribution of radioelements to energy balance of the Earth, age of the Earth based on radioactive disintegration and the discovery of cosmic radiations

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

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00371046; The ATLAS collaboration

    2016-01-01

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

  3. Study of ^{14}C Cluster Decay Half-Lives of Heavy Deformed Nuclei

    Science.gov (United States)

    Shamami, S. Rahimi; Pahlavani, M. R.

    2018-01-01

    A theoretical model based on deformed Woods-Saxon, Coulomb and centrifugal terms are constructed to evaluate the half-lives for the cluster radioactivity of various super heavy nuclei. Deformation have been applied on all parts of their potential containing nuclear barrier for cluster decay. Also, both parent and daughter nuclei are considered to be deformed. The calculated results of ^{14}C cluster radioactivity half-lives are compared with available experimental data. A satisfactory agreement between theoretical and measured data is achieved. Also, obtained half-lives for each decay family is agreed with Geiger-Nuttall law.

  4. Lower fungi and radioactivity

    International Nuclear Information System (INIS)

    Adamek, M.

    1989-01-01

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

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

    International Nuclear Information System (INIS)

    Kulkarni, A.; Bak, M. S.; Ha, S.; Joshirao, P.; Manchanda, V.; Kim, T.

    2015-01-01

    A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO 3 ) 4 ⋅ 5H 2 O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories

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

    Science.gov (United States)

    Kulkarni, A.; Ha, S.; Joshirao, P.; Manchanda, V.; Bak, M. S.; Kim, T.

    2015-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-15

    A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO{sub 3}){sub 4} ⋅ 5H{sub 2}O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories.

  8. Disposal of radioactive waste. Some ethical aspects

    International Nuclear Information System (INIS)

    Streffer, Christian

    2014-01-01

    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.

  9. 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.

  10. Improved metamodel-based importance sampling for the performance assessment of radioactive waste repositories

    International Nuclear Information System (INIS)

    Cadini, F.; Gioletta, A.; Zio, E.

    2015-01-01

    In the context of a probabilistic performance assessment of a radioactive waste repository, the estimation of the probability of exceeding the dose threshold set by a regulatory body is a fundamental task. This may become difficult when the probabilities involved are very small, since the classically used sampling-based Monte Carlo methods may become computationally impractical. This issue is further complicated by the fact that the computer codes typically adopted in this context requires large computational efforts, both in terms of time and memory. This work proposes an original use of a Monte Carlo-based algorithm for (small) failure probability estimation in the context of the performance assessment of a near surface radioactive waste repository. The algorithm, developed within the context of structural reliability, makes use of an estimated optimal importance density and a surrogate, kriging-based metamodel approximating the system response. On the basis of an accurate analytic analysis of the algorithm, a modification is proposed which allows further reducing the computational efforts by a more effective training of the metamodel. - Highlights: • We tackle uncertainty propagation in a radwaste repository performance assessment. • We improve a kriging-based importance sampling for estimating failure probabilities. • We justify the modification by an analytic, comparative analysis of the algorithms. • The probability of exceeding dose thresholds in radwaste repositories is estimated. • The algorithm is further improved reducing the number of its free parameters

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

    Science.gov (United States)

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

    2008-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-10-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

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

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

    International Nuclear Information System (INIS)

    1996-12-01

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

  15. Search for lost or orphan radioactive sources based on NaI gamma spectrometry

    International Nuclear Information System (INIS)

    Aage, H.K.; Korsbech, U.

    2003-01-01

    Within recent decades many radioactive sources have been lost, stolen, or abandoned, and some have caused contamination or irradiation of people. Therefore reliable methods for source recovery are needed. The use of car borne NaI(Tl) detectors is discussed. Standard processing of spectra in general can disclose strong and medium level signals from manmade nuclides. But methods for detecting low level signals from weak, distant or shielded sources can be improved. New methods for source detection and identification based on noise adjusted singular value decomposition and on area specific stripping of spectra are presented

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

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C

    2003-01-01

    Within recent decades many radioactive sources have been lost, stolen, or abandoned, and some have caused contamination or irradiation of people. Therefore reliable methods for source recovery are needed. The use of car borne NaI(Tl) detectors is discussed. Standard processing of spectra in general...... can disclose strong and medium level signals from manmade nuclides. But methods for detecting low level signals from weak, distant or shielded sources can be improved. New methods for source detection and identification based on noise adjusted singular value decomposition and on area specific...

  17. Assessment of inhalation risk due to radioactivity released from coal-based thermal power plant

    International Nuclear Information System (INIS)

    Sahu, S.K.; Pandit, G.G.; Shukla, V.K.; Puranik, V.D.; Kushwaha, H.S.

    2006-01-01

    In India, the coal based thermal power plants have been the major source of power generation in the past and would continue for decades to come. As the coal contains naturally occurring primordial radionuclides the burning of pulverized coal to produce energy for generation of electricity in thermal power plants will result in the emission of a variety of natural radioactive elements into the environment in the vicinity of thermal power plants. In this paper we have used two different methods for characterization of uncertainty in inhalation risk to the general public around 10 Kms radius in the neighborhood of a coal-fired thermal power plant. (author)

  18. Radiolytic gas generation from cement-based waste hosts for DOE low-level radioactive wastes

    International Nuclear Information System (INIS)

    Dole, L.R.; Friedman, H.A.

    1986-01-01

    Using cement-based immobilization binders with simulated radioactive waste containing sulfate, nitrate, nitrite, phosphate, and fluoride anions, the gamma- and alpha-radiolytic gas generation factors (G/sub t/, molecules/100 eV) and gas compositions were measured on specimens of cured grouts. These tests studied the effects of; (1) waste composition; (2) the sample surface-to-volume ratio; (3) the waste slurry particle size; and (4) the water content of the waste host formula. The radiolysis test vessels were designed to minimize the ''dead'' volume and to simulate the configuration of waste packages

  19. Integrated data base for 1986: spent fuel and radioactive waste inventories, projections, and characteristics. Revision 2

    International Nuclear Information System (INIS)

    1986-09-01

    The Integrated Data Base (IDB) Program has compiled current data on inventories and characteristics of commercial spent fuel and both commercial and US Department of Energy (DOE) radioactive wastes through December 31, 1985, based on the most reliable information available from government sources, the open literature, technical reports, and direct contacts. Current projections of future waste and spent fuel to be generated through the year 2020 and characteristics of these materials are also presented. The information forecasted is consistent with the expected defense-related and private industrial and institutional activities and the latest DOE/Energy Information Administration (EIA) projections of US commercial nuclear power growth. The materials considered, on a chapter-by-chapter basis, are: spent fuel, high-level waste, transuranic waste, low-level waste, commercial uranium mill tailings, remedial action waste, and decommissioning waste. For each category, current and projected inventories are given through the year 2020, and the radioactivity and thermal power are calculated based on reported or calculated isotopic compositions

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

    International Nuclear Information System (INIS)

    Chen, S.Y.

    1994-01-01

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

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

    International Nuclear Information System (INIS)

    Chen, Shih-Yew

    1995-01-01

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

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

    Science.gov (United States)

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

    2014-03-18

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

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

    NARCIS (Netherlands)

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

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

  4. Weak decays

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-04-01

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

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

    International Nuclear Information System (INIS)

    Tostes, Marcelo Mallat

    1999-03-01

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

  7. 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.

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

    International Nuclear Information System (INIS)

    Al-Azmi, D.S.

    2014-01-01

    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, an ubiquitous inert gas, and the adsorptive property of activated charcoal. Radon gas from ambient air in the laboratory was adsorbed into about 70 gram of activated charcoal inside metallic canisters. Gamma radiation was subsequently emitted from the canisters, following the radioactive decay of radon and its progenies. The intensities of the emitted gamma-rays were measured at suitable intervals using a NaI gamma-ray detector. The counts obtained were analysed and used to demonstrate the radioactive decay law and determine the half-life of radon. In addition to learning the basic properties of radioactivity, the students also get practical experience about the existence of natural sources of radiation in the environment. (author)

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

    International Nuclear Information System (INIS)

    1990-05-01

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

  10. Radiation dose evaluation based on exposure scenario during the operation of radioactive waste disposal facility

    International Nuclear Information System (INIS)

    Yoon, Jeong Hyoun; Kim Chang Lak; Choi, Heui Joo; Park, Joo Wan

    1999-01-01

    Radiation dose to worker in disposal facility was calculated by using point kernel MICROSHIELD V5.02 computer code based on exposure scenarios. An conceptual design model for disposal vaults in disposal facility was used for object of shielding calculation model. Selected radionuclides and their activities among radioactive wastes from nuclear power plants were assumed as radiation sources for the exposure calculation. Annual radiation doses to crane workers and to people working on disposal vaults were calculated according to exposure time and distance from the sources with conservative operation scenarios. The scenarios used for this study were based on assumption for representing disposal activities in a future Korean near surface disposal facility. Calculated exposure rates to worker during normal disposal work were very low comparing with annual allowable limit for radiation worker

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-10-01

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

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

    International Nuclear Information System (INIS)

    1994-12-01

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

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

    CERN Document Server

    Mallick, M B; Ravindranath, S V G

    2002-01-01

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

  16. Potential of decaying wood to restore root-available base cations in depleted forest soils

    Science.gov (United States)

    Walter C. Shortle; Kevin T. Smith; Jody Jellison; Jonathan S. Schilling

    2012-01-01

    The depletion of root-available Ca in northern forest soils exposed to decades of increased acid deposition adversely affects forest health and productivity. Laboratory studies indicated the potential of wood-decay fungi to restore lost Ca. This study presents changes in concentration of Ca, Mg, and K in sapwood of red spruce (Picea rubens Sarg.),...

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

    International Nuclear Information System (INIS)

    Notz, K.J.; Forsberg, C.W.; Mastal, E.F.

    1984-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Notz, K.J.; Forsberg, C.W.; Mastal, E.F.

    1984-01-01

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

  19. Colorimetric detection and removal of radioactive Co ions using sodium alginate-based composite beads

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Daigeun; Jo, Ara [Organic and Optoelectronic Materials Laboratory, Department of Organic Materials Engineering, Chungnam National University, Daejeon 34134 (Korea, Republic of); Yang, Hee-Man; Seo, Bum-Kyoung; Lee, Kune-Woo [Decontamination and Decommissioning Research Division, Korea Atomic Energy Research Institute, Daejeon 34057 (Korea, Republic of); Lee, Taek Seung, E-mail: tslee@cnu.ac.kr [Organic and Optoelectronic Materials Laboratory, Department of Organic Materials Engineering, Chungnam National University, Daejeon 34134 (Korea, Republic of)

    2017-03-15

    Highlights: • Organic/inorganic hybridized alginate beads were newly synthesized via sol-gel chemistry. • Interaction between the azopyridine and metal ion is the main cause of Co ion detection. • The beads showed improved stability and least leakage of azopyridine during use. • Removal of Co ion was assessed by the ion-exchange of carboxylate groups in alginate. • The beads with dual functions of detection and removal of Co ion were successfully accomplished. - Abstract: We demonstrate a simple method for the visual determination and removal of Co ions using a bead-shaped, capturing probe based on hybridized sodium alginate. For Co ions, the designed protocol consisted of three main constituents: an azopyridine-based Co ion-probe for visual detection; sodium alginate as an adsorbent for the Co ion and a bead construct for removal and structure; silica as a linker for the probe and the alginate, leading to a robust structure. When the composite beads were exposed to Co ions, the yellow color of the beads turned to intensive violet and the color intensity was associated with the Co ion concentration. The color variation was quantified using red-green-blue (RGB) color values that were obtained with a scanner and evaluated with Photoshop. The technique achieved both visual recognition with obvious color change of the beads and efficient removal of the radioactive {sup 60}Co ion. The sensing and removal of any radioactive isotope could be achieved with an appropriate sensing probe, to provide a simple and universal platform for remediation.

  20. Colorimetric detection and removal of radioactive Co ions using sodium alginate-based composite beads

    International Nuclear Information System (INIS)

    Kim, Daigeun; Jo, Ara; Yang, Hee-Man; Seo, Bum-Kyoung; Lee, Kune-Woo; Lee, Taek Seung

    2017-01-01

    Highlights: • Organic/inorganic hybridized alginate beads were newly synthesized via sol-gel chemistry. • Interaction between the azopyridine and metal ion is the main cause of Co ion detection. • The beads showed improved stability and least leakage of azopyridine during use. • Removal of Co ion was assessed by the ion-exchange of carboxylate groups in alginate. • The beads with dual functions of detection and removal of Co ion were successfully accomplished. - Abstract: We demonstrate a simple method for the visual determination and removal of Co ions using a bead-shaped, capturing probe based on hybridized sodium alginate. For Co ions, the designed protocol consisted of three main constituents: an azopyridine-based Co ion-probe for visual detection; sodium alginate as an adsorbent for the Co ion and a bead construct for removal and structure; silica as a linker for the probe and the alginate, leading to a robust structure. When the composite beads were exposed to Co ions, the yellow color of the beads turned to intensive violet and the color intensity was associated with the Co ion concentration. The color variation was quantified using red-green-blue (RGB) color values that were obtained with a scanner and evaluated with Photoshop. The technique achieved both visual recognition with obvious color change of the beads and efficient removal of the radioactive 60 Co ion. The sensing and removal of any radioactive isotope could be achieved with an appropriate sensing probe, to provide a simple and universal platform for remediation.

  1. A Characteristics-Based Approach to Radioactive Waste Classification in Advanced Nuclear Fuel Cycles

    Science.gov (United States)

    Djokic, Denia

    The radioactive waste classification system currently used in the United States primarily relies on a source-based framework. This has lead to numerous issues, such as wastes that are not categorized by their intrinsic risk, or wastes that do not fall under a category within the framework and therefore are without a legal imperative for responsible management. Furthermore, in the possible case that advanced fuel cycles were to be deployed in the United States, the shortcomings of the source-based classification system would be exacerbated: advanced fuel cycles implement processes such as the separation of used nuclear fuel, which introduce new waste streams of varying characteristics. To be able to manage and dispose of these potential new wastes properly, development of a classification system that would assign appropriate level of management to each type of waste based on its physical properties is imperative. This dissertation explores how characteristics from wastes generated from potential future nuclear fuel cycles could be coupled with a characteristics-based classification framework. A static mass flow model developed under the Department of Energy's Fuel Cycle Research & Development program, called the Fuel-cycle Integration and Tradeoffs (FIT) model, was used to calculate the composition of waste streams resulting from different nuclear fuel cycle choices: two modified open fuel cycle cases (recycle in MOX reactor) and two different continuous-recycle fast reactor recycle cases (oxide and metal fuel fast reactors). This analysis focuses on the impact of waste heat load on waste classification practices, although future work could involve coupling waste heat load with metrics of radiotoxicity and longevity. The value of separation of heat-generating fission products and actinides in different fuel cycles and how it could inform long- and short-term disposal management is discussed. It is shown that the benefits of reducing the short-term fission

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

    International Nuclear Information System (INIS)

    Lowenthal, M.D.

    1998-01-01

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

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

    International Nuclear Information System (INIS)

    Gajos, A.; Kamińska, D.; Czerwiński, E.; Alfs, D.; Bednarski, T.; Białas, P.; Głowacz, B.; Gorgol, M.; Jasińska, B.; Kapłon, Ł.; Korcyl, G.; Kowalski, P.; Kozik, T.; Krzemień, W.; Kubicz, E.; Mohammed, M.; Niedźwiecki, Sz.; Pałka, M.; Pawlik-Niedźwiecka, M.

    2016-01-01

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

  4. A passive decay-heat removal system for an ABWR based on air cooling

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-01-15

    Highlights: • A passive decay heat removal system for an ABWR is discussed using combined system of the reactor and an air cooler. • Effect of number of pass of the finned heat transfer tubes on heat removal is investigated. • The decay heat can be removed by air coolers with natural convection. • Two types of air cooler are evaluated, i.e., steam condensing and water cooling types. • Measures how to improve the heat removal rate and to make compact air cooler are discussed. - Abstract: This paper describes the capability of an air cooling system (ACS) operated under natural convection conditions to remove decay heat from the core of an Advanced Boiling Water Reactor (ABWR). The motivation of the present research is the Fukushima Severe Accident (SA). The plant suffered damages due to the tsunami and entered a state of Station Blackout (SBO) during which seawater cooling was not available. To prevent this kind of situation, we proposed a passive decay heat removal system (DHRS) in the previous study. The plant behavior during the SBO was calculated using the system code NETFLOW++ assuming an ABWR with the ACS. However, decay heat removal under an air natural convection was difficult. In the present study, a countermeasure to increase heat removal rate is proposed and plant transients with the ACS are calculated under natural convection conditions. The key issue is decreasing pressure drop over the tube banks in order to increase air flow rate. The results of the calculations indicate that the decay heat can be removed by the air natural convection after safety relief valves are actuated many times during a day. Duct height and heat transfer tube arrangement of the AC are discussed in order to design a compact and efficient AC for the natural convection mode. As a result, a 4-pass heat transfer tubes with 2-row staggered arrangement is the candidate of the AC for the DHRS under the air natural convection conditions. The heat removal rate is re-evaluated as

  5. BioRadBase: A database for bioremediation of radioactive waste ...

    African Journals Online (AJOL)

    Radioactive waste from different sectors such as nuclear energy, health care and food has become a discernible part of our environment. Several dumping methods are in routine practice to dispose radioactive wastes. Huge chemical and energy input in various skillful physico-chemical methods has limited their use while ...

  6. Classification of decays involving variable decay chains with convolutional architectures

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Vidyo contribution We present a technique to perform classification of decays that exhibit decay chains involving a variable number of particles, which include a broad class of $B$ meson decays sensitive to new physics. The utility of such decays as a probe of the Standard Model is dependent upon accurate determination of the decay rate, which is challenged by the combinatorial background arising in high-multiplicity decay modes. In our model, each particle in the decay event is represented as a fixed-dimensional vector of feature attributes, forming an $n \\times k$ representation of the event, where $n$ is the number of particles in the event and $k$ is the dimensionality of the feature vector. A convolutional architecture is used to capture dependencies between the embedded particle representations and perform the final classification. The proposed model performs outperforms standard machine learning approaches based on Monte Carlo studies across a range of variable final-state decays with the Belle II det...

  7. Radioactive aerosols

    International Nuclear Information System (INIS)

    Chamberlain, A.C.

    1991-01-01

    Radon. Fission product aerosols. Radioiodine. Tritium. Plutonium. Mass transfer of radioactive vapours and aerosols. Studies with radioactive particles and human subjects. Index. This paper explores the environmental and health aspects of radioactive aerosols. Covers radioactive nuclides of potential concern to public health and applications to the study of boundary layer transport. Contains bibliographic references. Suitable for environmental chemistry collections in academic and research libraries

  8. Radioactive wastes

    International Nuclear Information System (INIS)

    Boegly, W.J.; Alexander, H.J.

    1983-01-01

    A literature review on studies concerning radioactive wastes is presented. Literature on radioactive wastes available from the National Technical Information Service, Washington, DC, was not included in the review. Studies were reviewed that dealt with general programs for radioactive wastes; isolation of radioactive wastes; waste management; waste storage; environmental transport; transportation; risk assessment; and remedial action are reviewed

  9. Using radioactivity

    International Nuclear Information System (INIS)

    1982-10-01

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

  10. Decay ring status / studies

    CERN Document Server

    Chance, A

    2008-01-01

    The aim of "beta-beams" is to produce highly energetic pure electron neutrino and anti-neutrino beams coming from β-decay of radioactive ions. In CERN baseline, after accelerating, the ions 6He2+ and 18Ne10+ are stored in a racetrack-shaped-decay ring until they are lost [1]. Consequently, the injection compensates the losses which occurred between two cycles. Two main loss sources were identified: the β decay and the injection scheme. After giving the optics, we will see how to protect the magnetic elements from the decay products. The injections scheme will be then detailed with its implications. We will see that the injection process makes a collimation section in energy necessary. Since the magnetic elements are not perfect, we will take into account the magnet misalignment and the multipole defects in the dipoles. We will talk then about the closed orbit distortion due to misalignment defects and about the long-term transverse stability with the dynamic aperture.

  11. Chemical Kinetic Analysis of Thermal Decay of Rhodopsin Reveals Unusual Energetics of Thermal Isomerization and Hydrolysis of Schiff Base*

    Science.gov (United States)

    Liu, Jian; Liu, Monica Yun; Fu, Li; Zhu, Gefei Alex; Yan, Elsa C. Y.

    2011-01-01

    The thermal properties of rhodopsin, which set the threshold of our vision, have long been investigated, but the chemical kinetics of the thermal decay of rhodopsin has not been revealed in detail. To understand thermal decay quantitatively, we propose a kinetic model consisting of two pathways: 1) thermal isomerization of 11-cis-retinal followed by hydrolysis of Schiff base (SB) and 2) hydrolysis of SB in dark state rhodopsin followed by opsin-catalyzed isomerization of free 11-cis-retinal. We solve the kinetic model mathematically and use it to analyze kinetic data from four experiments that we designed to assay thermal decay, isomerization, hydrolysis of SB using dark state rhodopsin, and hydrolysis of SB using photoactivated rhodopsin. We apply the model to WT rhodopsin and E181Q and S186A mutants at 55 °C, as well as WT rhodopsin in H2O and D2O at 59 °C. The results show that the hydrogen-bonding network strongly restrains thermal isomerization but is less important in opsin and activated rhodopsin. Furthermore, the ability to obtain individual rate constants allows comparison of thermal processes under various conditions. Our kinetic model and experiments reveal two unusual energetic properties: the steep temperature dependence of the rates of thermal isomerization and SB hydrolysis in the dark state and a strong deuterium isotope effect on dark state SB hydrolysis. These findings can be applied to study pathogenic rhodopsin mutants and other visual pigments. PMID:21921035

  12. Radioactive Plumes Monitoring Simulator

    International Nuclear Information System (INIS)

    Kapelushnik, I.; Sheinfeld, M.; Avida, R.; Kadmon, Y.; Ellenbogen, M.; Tirosh, D.

    1999-01-01

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

  13. Development of a computerized data base for low-level radioactive waste leaching data: Topical report

    International Nuclear Information System (INIS)

    Dougherty, D.R.; Colombo, P.

    1986-09-01

    This report documents the development of a computerized data base (db) of leaching data for solidified low-level radioactive waste (LLW) forms. Brookhaven National Lab performed this work under contract with the US Department of Energy's Low-Level Waste Management Program as part of an effort to develop an accelerated leach test(s) that can be used to predict leachabilities of LLW forms over long time periods, i.e., hundreds of years. The accelerated leach test(s) is (are) to be developed based on knowledge of leaching mechanisms and factors that affect leaching. Although developed specifically for the Accelerated Leach Test(s) Program, this db may be useful to others concerned with the management of low-level waste. The db is being developed to provide efficient data compilation and analysis capabilities. The data compiled in the db, which include data from the Accelerated Leach Test(s) Program and selected data from the literature, have been selected to elucidate leaching mechanisms and factors that affect leaching and are not meant to be a comprehensive compilation of leaching data. This report presents the data compilation aspect of the db. It does not present the programmatic results obtained from analysis of the data regarding leaching mechanisms and factors that affect leaching, which will be presented in reports from the Accelerated Leach Test(s) Program. 6 refs

  14. Handling of radioactive waste

    International Nuclear Information System (INIS)

    Sanhueza Mir, Azucena

    1998-01-01

    Based on characteristics and quantities of different types of radioactive waste produced in the country, achievements in infrastructure and the way to solve problems related with radioactive waste handling and management, are presented in this paper. Objectives of maintaining facilities and capacities for controlling, processing and storing radioactive waste in a conditioned form, are attained, within a great range of legal framework, so defined to contribute with safety to people and environment (au)

  15. Review of the bases for regulations governing the transport of fissile and other radioactive material

    International Nuclear Information System (INIS)

    Smith, D.R.; Thomas, J.T.

    1978-01-01

    The outstanding record of transport of radioactive materials prompted this brief review of the history of the regulations. IAEA as well as DOT regulations are discussed, as are all classes of shipments and materials (Class I, II, III)

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

    International Nuclear Information System (INIS)

    Yan Yongjun; Zhou Jianliang

    2008-01-01

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

  17. Radioactive waste produced by DEMO and commerical fusion reactors extrapolated from ITER and advanced data bases

    International Nuclear Information System (INIS)

    Stacey, W.M.; Hertel, N.E.; Hoffman, E.A.

    1994-01-01

    The potential for providing energy with minimal environmental impact is a powerful motivation for the development of fusion and is the long-term objective of most fusion programs. However, the societal acceptability of magnetic fusion may well be decided in the near-term when decisions are taken on the construction of DEMO to follow ITER (if not when the construction decision is taken on ITER). Component wastes were calculated for DEMOs based on each data base by first calculating reactor sizes needed to satisfy the physics, stress and radiation attenuation requirements, and then calculating component replacement rates based on radiation damage and erosion limits. Then, radioactive inventories were calculated and compared to a number of international criteria for open-quote near-surface close-quote burial. None of the components in either type of design would meet the Japanese LLW criterion ( 3 ) within 10 years of shutdown, although the advanced (V/Li) blanket would do so soon afterwards. The vanadium first wall, divertor and blanket would satisfy the IAEA LLW criterion (<2 mSv/h contact dose) within about 10 years after shutdown, but none of the stainless steel or copper components would. All the components in the advanced data base designs except the stainless steel vacuum vessel and shield readily satisfy the US extended 10CFR61 intruder dose criterion, but none of the components in the open-quotes ITER data baseclose quotes designs do so. It seems unlikely that a stainless steel first wall or a copper divertor plate could satisfy the US (class C) criterion for near surface burial, much less the more stringent international, criteria. On the other hand, the first wall, divertor and blanket of the V/Li system would still satisfy the intruder dose concentration limits even if the dose criterion was reduced by two orders of magnitude

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

    International Nuclear Information System (INIS)

    Grecco, Claudio H.S.; Santos, Isaac J.A.L.; Carvalho, Paulo V.R.; Vidal, Mario C.R.; Cosenza, Carlos A.N.

    2013-01-01

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

  19. GPU-based parallel computing in real-time modeling of atmospheric transport and diffusion of radioactive material

    International Nuclear Information System (INIS)

    Santos, Marcelo C. dos; Pereira, Claudio M.N.A.; Schirru, Roberto; Pinheiro, André Coordenacao de Pos-Graduacao e Pesquisa de Engenharia

    2017-01-01

    Atmospheric radionuclide dispersion systems (ARDS) are essential mechanisms to predict the consequences of unexpected radioactive releases from nuclear power plants. Considering, that during an eventuality of an accident with a radioactive material release, an accurate forecast is vital to guide the evacuation plan of the possible affected areas. However, in order to predict the dispersion of the radioactive material and its impact on the environment, the model must process information about source term (radioactive materials released, activities and location), weather condition (wind, humidity and precipitation) and geographical characteristics (topography). Furthermore, ARDS is basically composed of 4 main modules: Source Term, Wind Field, Plume Dispersion and Doses Calculations. The Wind Field and Plume Dispersion modules are the ones that require a high computational performance to achieve accurate results within an acceptable time. Taking this into account, this work focuses on the development of a GPU-based parallel Plume Dispersion module, focusing on the radionuclide transport and diffusion calculations, which use a given wind field and a released source term as parameters. The program is being developed using the C ++ programming language, allied with CUDA libraries. In comparative case study between a parallel and sequential version of the slower function of the Plume Dispersion module, a speedup of 11.63 times could be observed. (author)

  20. GPU-based parallel computing in real-time modeling of atmospheric transport and diffusion of radioactive material

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Marcelo C. dos; Pereira, Claudio M.N.A.; Schirru, Roberto; Pinheiro, André, E-mail: jovitamarcelo@gmail.com, E-mail: cmnap@ien.gov.br, E-mail: schirru@lmp.ufrj.br, E-mail: apinheiro99@gmail.com [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2017-07-01

    Atmospheric radionuclide dispersion systems (ARDS) are essential mechanisms to predict the consequences of unexpected radioactive releases from nuclear power plants. Considering, that during an eventuality of an accident with a radioactive material release, an accurate forecast is vital to guide the evacuation plan of the possible affected areas. However, in order to predict the dispersion of the radioactive material and its impact on the environment, the model must process information about source term (radioactive materials released, activities and location), weather condition (wind, humidity and precipitation) and geographical characteristics (topography). Furthermore, ARDS is basically composed of 4 main modules: Source Term, Wind Field, Plume Dispersion and Doses Calculations. The Wind Field and Plume Dispersion modules are the ones that require a high computational performance to achieve accurate results within an acceptable time. Taking this into account, this work focuses on the development of a GPU-based parallel Plume Dispersion module, focusing on the radionuclide transport and diffusion calculations, which use a given wind field and a released source term as parameters. The program is being developed using the C ++ programming language, allied with CUDA libraries. In comparative case study between a parallel and sequential version of the slower function of the Plume Dispersion module, a speedup of 11.63 times could be observed. (author)

  1. Optimization of the radioactive waste storage

    International Nuclear Information System (INIS)

    Dellamano, Jose Claudio

    2005-01-01

    Radioactive waste storage is the practice adopted in countries where the production of small quantities of radioactive waste does not justify the immediate investment in the construction of a repository. Accordingly, at IPEN, treated radioactive wastes, mainly solid compacted, have been stored for more than 20 years, in 200 dm 3 drums. The storage facility is almost complete and must be extended. Taking into account that a fraction of these wastes has decayed to a very low level due to the short half - life of some radionuclides and considering that 'retrieval for disposal as very low level radioactive waste' is one of the actions suggested to radioactive waste managers, the Laboratory of Waste Management of IPEN started a project to apply the concepts of clearance levels and exemption limits to optimize the radioactive waste storage capacity . This study has been carried out by determining the doses and costs related to two main options: either to maintain the present situation or to open the packages and segregate the wastes that may be subject to clearance, using the national, two international clearance levels and the annual public limit. Doses and costs were evaluated as well as the collective dose and the detriment cost. The analytical solution among the evaluated options was determined by using the technique to aid decision making known as cost-benefit analysis. At last, it was carried out the sensitivity analysis considering all criteria and parameters in order to assess the robustness of the analytical solution. This study can be used as base to other institutions or other countries with similar nuclear programs. (author)

  2. 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

  3. 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

  4. The ''invisible'' radioactive scale

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

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

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

    International Nuclear Information System (INIS)

    1994-01-01

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

  7. Radioactive battery

    International Nuclear Information System (INIS)

    Deaton, R.L.; Silver, G.L.

    1975-01-01

    A radioactive battery is described that is comprised of a container housing an electrolyte, two electrodes immersed in the electrolyte and insoluble radioactive material disposed adjacent one electrode. Insoluble radioactive material of different intensity of radioactivity may be disposed adjacent the second electrode. If hydrobromic acid is used as the electrolyte, Br 2 will be generated by the radioactivity and is reduced at the cathode: Br 2 + 2e = 2 Br - . At the anode Br - is oxidized: 2Br - = Br 2 + 2e. (U.S.)

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

    Science.gov (United States)

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

    2008-07-01

    The radioactive waste (RAW) storage site at Andreeva Bay in the Russian Northwest has experienced radioactive contamination both as a result of activities carried out at the site and due to incidents that have occurred there in the past such as accidental releases of radioactive materials. The site is an interesting case study for decommissioning due to the extremely large amounts of radioactivity present at the site and the conditions under which it is stored; very little has been previously published in the scientific literature about this site. This paper complements the paper describing dose rates at Andreeva Bay which is published in this issue of Journal of Environmental Radioactivity by the same authors. This study presents new data related to the activity concentrations of (137)Cs and (90)Sr in surface soils and measurements of alpha- and beta-particle fluxes taken at different areas around the site. Limited data on 60Co is also presented. The results of the study indicate that the main areas of site contamination are associated with the former spent nuclear fuel storage facility at Building 5, due to accidental discharges which began in 1982. Substantial contamination is also observed at the solid radioactive waste storage facilities, probably due to the ingress of water into these facilities. More than 240 samples were measured: maximum contamination levels were 1 x 10(6)Bq/kg (137)Cs (mean value 4.1 x 10(5)Bq/kg) and 4 x 10(6)Bq/kg (90)Sr (mean value 1.2 x1 0(5)Bq/kg). Localised patches of alpha and beta contamination were also observed throughout the site.

  9. The Discovery of Artificial Radioactivity

    Science.gov (United States)

    Guerra, Francesco; Leone, Matteo; Robotti, Nadia

    2012-03-01

    We reconstruct Frédéric Joliot and Irène Curie's discovery of artificial radioactivity in January 1934 based in part on documents preserved in the Joliot-Curie Archives in Paris, France. We argue that their discovery followed from the convergence of two parallel lines of research, on the neutron and on the positron, that were focused on a well-defined experimental problem, the nuclear transmutation of aluminum and other light elements. We suggest that a key role was played by a suggestion that Francis Perrin made at the seventh Solvay Conference at the end of October 1933, that the alpha-particle bombardment of aluminum produces an intermediate unstable isotope of phosphorus, which then decays by positron emission. We also suggest that a further idea that Perrin published in December 1933, and the pioneering theory of beta decay that Enrico Fermi also first published in December 1933, established a new theoretical framework that stimulated Joliot to resume the researches that he and Curie had interrupted after the Solvay Conference, now for the first time using a Geiger-Müller counter to detect the positrons emitted when he bombarded aluminum with polonium alpha particles.

  10. Optimization of the Transport Shield for Neutrinoless Double Beta-decay Enriched Germanium

    Energy Technology Data Exchange (ETDEWEB)

    Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Orrell, John L.; Reid, Douglas J.; Fast, James E.

    2012-04-15

    This document presents results of an investigation of the material and geometry choice for the transport shield of germanium, the active detector material used in 76Ge neutrinoless double beta decay searches. The objective of this work is to select the optimal material and geometry to minimize cosmogenic production of radioactive isotopes in the germanium material. The design of such a shield is based on the calculation of the cosmogenic production rate of isotopes that are known to cause interfering backgrounds in 76Ge neutrinoless double beta decay searches.

  11. Some problems of parametric neutron activation analysis based on the use of radioactive daughters of longer-lived mothers with low mother/daughter half-life ratios

    International Nuclear Information System (INIS)

    Cohen, I.M.

    2012-01-01

    The theoretical and practical aspects of the use of radioactive daughters originated from the decay of longer-lived radioactive mothers in parametric activation analysis, when the ratio: mother half-life to daughter half-life is less than 10, are discussed. The mother-daughter relationships: 47 Ca/ 47 Sc; 95 Zr/ 95 Nb; 140 Ba/ 140 La; 99 Mo/ 99m Tc and 115 Cd/ 115m In are selected as models for the study. The cases when the radionuclide of interest is formed through both direct and indirect routes are also analyzed. As illustrative example, the direct reaction and the reaction chain: 47 Ti(n,p) 47 Sc/ 46 Ca(n,γ) 47 Ca(β - ) 47 Sc are evaluated with respect to the determination of the elements involved and their reciprocal interferences. (author)

  12. Wealth distribution, Pareto law, and stretched exponential decay of money: Computer simulations analysis of agent-based models

    Science.gov (United States)

    Aydiner, Ekrem; Cherstvy, Andrey G.; Metzler, Ralf

    2018-01-01

    We study by Monte Carlo simulations a kinetic exchange trading model for both fixed and distributed saving propensities of the agents and rationalize the person and wealth distributions. We show that the newly introduced wealth distribution - that may be more amenable in certain situations - features a different power-law exponent, particularly for distributed saving propensities of the agents. For open agent-based systems, we analyze the person and wealth distributions and find that the presence of trap agents alters their amplitude, leaving however the scaling exponents nearly unaffected. For an open system, we show that the total wealth - for different trap agent densities and saving propensities of the agents - decreases in time according to the classical Kohlrausch-Williams-Watts stretched exponential law. Interestingly, this decay does not depend on the trap agent density, but rather on saving propensities. The system relaxation for fixed and distributed saving schemes are found to be different.

  13. Radioactive Emissions from Fission-Based Medical Isotope Production and Their Effect on Global Nuclear Explosion Detection

    International Nuclear Information System (INIS)

    Bowyer, T.; Saey, P.

    2015-01-01

    The use of medical isotopes, such as Tc-99m, is widespread with over 30 million procedures being performed every year, but the fission-based production of isotopes used for medical procedures causes emissions into the environment. This paper will show that gaseous radioactive isotopes of xenon, such as Xe-133, are released in high quantities, because they have a high fission cross section and they are difficult to scrub from the processes used to produce the medical isotopes due to their largely unreactive nature. Unfortunately, the reasons that large amounts of radioactive xenon isotopes are emitted from isotope production are the same as those that make these isotopes the most useful isotopes for the detection of underground nuclear explosions. Relatively recently, the nuclear explosion monitoring community has established a provisional monitoring network for the Comprehensive Nuclear-Test-Ban Treaty (CTBT) that includes radioactive xenon monitoring as a major component. This community has discovered that emissions from medical isotope production present a more serious problem to nuclear explosion monitoring than thought when the network was first conceived. To address the growing problem, a group of scientists in both the monitoring and the isotope production communities have come together to attempt to find scientific and pragmatic ways to address the emissions problems, recognizing that medical isotope production should not be adversely affected, while monitoring for nuclear explosions should remain effective as isotope production grows, changes, and spreads globally. (author)

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

    International Nuclear Information System (INIS)

    Jeong, C.W.; Kim, K.I.; Lee, J.I.

    2000-01-01

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

  15. Radioactive Material Containment Bags

    National Research Council Canada - National Science Library

    2000-01-01

    The audit was requested by Senator Joseph I. Lieberman based on allegations made by a contractor, Defense Apparel Services, about the Navy's actions on three contracts for radioactive material containment bags...

  16. Two-proton radioactivity of 45Fe

    International Nuclear Information System (INIS)

    Miernik, K.; Dominik, W.; Janas, Z.; Pfutzner, M.; Grigorenko, L.; Bingham, C.R.; Czyrkowski, H.; Cwiok, Mikolaj; Darby, Iain; Dabrowski, Ryszard; Ginter, T.N.; Grzywacz, R.; Karny, M.; Korgul, A.; Kusmierz, W.; Liddick, Sean; Rajabali, Mustafa; Rykaczewski, Krzysztof Piotr; Stolz, A.

    2009-01-01

    In an experiment at the SISSI-LISE3 facility of GANIL, the decay of the proton drip line nucleus 45Fe has been studied. Fragment-implantation events have been correlated with radioactive decay events in a 16x16 pixel silicon-strip detector. The decay-energy spectrum of 45Fe implants shows a distinct peak at (1.14+/-0.04) MeV with a half-life of T(1/2)=(4.7(+3.4)(-1.4)) ms. None of the events in this peak is in coincidence with beta particles. For a longer correlation interval, daughter decays of the two-proton daughter 43Cr can be observed after 45Fe implantation. The decay energy for 45Fe agrees nicely with several theoretical predictions for two-proton radioactivity.

  17. Two-proton radioactivity of 45Fe

    International Nuclear Information System (INIS)

    Giovinazzo, J.; Blank, B.; Chartier, M.; Czajkowski, S.; Fleury, A.; Lopez Jimenez, M.J.; Pravikoff, M.S.; Thomas, J.-C.; Oliveira Santos, F. de; Lewitowicz, M.; Maslov, V.; Stanoiu, M.; Grzywacz, R.; Pfuetzner, M.; Borcea, C.; Brown, B.A.

    2002-01-01

    In an experiment at the SISSI-LISE3 facility of GANIL, the decay of the proton drip line nucleus 45 Fe has been studied. Fragment-implantation events have been correlated with radioactive decay events in a 16x16 pixel silicon-strip detector. The decay-energy spectrum of 45 Fe implants shows a distinct peak at (1.14±0.04) MeV with a half-life of T 1/2 =(4.7 -1.4 +3.4 ) ms. None of the events in this peak is in coincidence with β particles. For a longer correlation interval, daughter decays of the two-proton daughter 43 Cr can be observed after 45 Fe implantation. The decay energy for 45 Fe agrees nicely with several theoretical predictions for two-proton radioactivity

  18. A computer-based spectrometry system for assessment of body radioactivity

    International Nuclear Information System (INIS)

    Venn, J.B.

    1985-01-01

    This paper describes a PDP-11 computer system operating under RT-11 for the acquisition and processing of pulse height spectra in the measurement of body radioactivity. SABRA (system for the assessment of body radioactivity) provides control of multiple detection systems from visual display consoles by means of a command language. A wide range of facilities is available for the display, processing and storage of acquired spectra and complex operations may be pre-programmed by means of the SABRE MACRO language. The hardware includes a CAMAC interface to the detection systems, disc cartridge drives for mass storage of data and programs, and data-links to other computers. The software is written in assembler language and includes special features for the dynamic allocation of computer memory and for safeguarding acquired data. (orig.)

  19. Radioactive thickness gauge (1962)

    International Nuclear Information System (INIS)

    Guizerix, J.

    1962-01-01

    The author describes a thickness gauge in which the scintillating crystal detector alternately 'sees' a radioactive source through the material which is to be measured and then a control source of the same material; the radiations are separated in time by an absorbing valve whose sections are alternately full and hollow. The currents corresponding to the two sources are separated beyond the photomultiplier tube by a detector synchronized with the rotation of the valve. The quotient of these two currents is then obtained with a standard recording potentiometer. It is found that the average value of the response which is in the form G = f(I 1 /I 2 ) is not affected by decay of the radioactive sources, and that it is little influenced by variations of high tension, temperature, or properties of the air in the source detector interval. The performance of the gauge is given. (author) [fr

  20. 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.

  1. A PLS-Based Weighted Artificial Neural Network Approach for Alpha Radioactivity Prediction inside Contaminated Pipes

    Directory of Open Access Journals (Sweden)

    Xianguo Tuo

    2014-01-01

    Full Text Available Long-range alpha detection (LRAD has been used to measure alpha particles emitting contamination inside decommissioned steel pipes. There exists a complex nonlinear relationship between input parameters and measuring results. The input parameters, for example, pipe diameter, pipe length, distance to radioactive source, radioactive source strength, wind speed, and flux, exhibit different contributions to the measuring results. To reflect these characteristics and estimate alpha radioactivity as exactly as possible, a hybrid partial least square back propagation (PLSBP neural network approach is presented in this paper. In this model, each node in the input layer is weighted, which indicates that different input nodes have different contributions on the system and this finding has been little reported. The weights are determined by the PLS. After this modification, a variety of normal three-layered BP networks are developed. The comparison of computational results of the proposed approach with traditional BP model and experiments confirms its clear advantage for dealing with this complex nonlinear estimation. Thus, an integrated picture of alpha particle activity inside contaminated pipes can be obtained.

  2. Draft directive on the management of radioactive wastes based on deep geological disposal

    International Nuclear Information System (INIS)

    Anon.

    2010-01-01

    The European Commission works on a legal framework to assure that all the member states apply the same standards in all the stages of the management of spent fuels and radioactive wastes till their definitive disposal. The draft propositions are the following. The standards to follow are those proposed by the IAEA. First, each member state has to set a national program dedicated to the management of radioactive wastes. This program will have to detail: the chosen solution, the description of the project, a time schedule, costs and financing. Secondly, the exportation of nuclear wastes for definitive disposal is not allowed unless the 2 countries have agreed to build a common nuclear waste disposal center. Thirdly, the population will have to be informed on the project and will have to take part in the decision process. Fourthly, the standards set by IAEA will be enforced by law. There is a broad consensus between scientists and international organizations like IAEA to consider that the disposal in deep geological layers of high-level radioactive wastes is the most adequate solution. (A.C.)

  3. Radioactive waste gas processing systems

    International Nuclear Information System (INIS)

    Kita, Kaoru; Minemoto, Masaki; Takezawa, Kazuaki.

    1981-01-01

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

  4. World ocean and radioactive wastes

    International Nuclear Information System (INIS)

    Kiknadze, O.E.; Sivintsev, Yu.V.

    2000-01-01

    The radioecological situation that took shape in the Arctic, North Atlantic Ocean and Far East regions as a result of radioactive waste marine disposal was assessed. Accurate account of radionuclides formation and decay in submerged water-water reactors of nuclear submarines suggests that total activity of radioactive waste disposed near the Novaya Zemlya amounted to 107 kCi by the end of 1999. Activity of radioactive waste disposed in the North Atlantic currently is not in excess of 430 kCi. It is pointed out that the Far East region heads the list in terms of total activity disposed (529 kCi). Effective individual dose for critical groups of population in the Arctic, North Atlantic and Far East regions was determined. The conclusion was made that there is no detrimental effect of the radioactive waste disposed on radioecological situation in the relevant areas [ru

  5. Some discussions on micrometeorology and atmospheric diffusion of classic and radioactive industrial pollutions. 6

    International Nuclear Information System (INIS)

    Veverka, O.; Valenta, V.; Vlachovsky, K.

    1976-01-01

    Plume depletion and deposition is discussed for the cases of stack disposal of conventional and radioactive wastes. Dry and wet deposition processes and general radioactive decay chains including isomeric transitions are taken into account. (author)

  6. Genetic bases of fungal white rot wood decay predicted by phylogenomic analysis of correlated gene-phenotype evolution

    Science.gov (United States)

    László G. Nagy; Robert Riley; Philip J. Bergmann; Krisztina Krizsán; Francis M. Martin; Igor V. Grigoriev; Dan Cullen; David S. Hibbett

    2016-01-01

    Fungal decomposition of plant cell walls (PCW) is a complex process that has diverse industrial applications and huge impacts on the carbon cycle. White rot (WR) is a powerful mode of PCW decay in which lignin and carbohydrates are both degraded. Mechanistic studies of decay coupled with comparative genomic analyses have provided clues to the enzymatic components of WR...

  7. 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)

  8. Radioactivity. Centenary of radioactivity discovery

    International Nuclear Information System (INIS)

    Charpak, G.; Tubiana, M.; Bimbot, R.

    1997-01-01

    This small booklet was edited for the occasion of the exhibitions of the celebration of the centenary of radioactivity discovery which took place in various locations in France from 1996 to 1998. It recalls some basic knowledge concerning radioactivity and its applications: history of discovery, atoms and isotopes, radiations, measurement of ionizing radiations, natural and artificial radioactivity, isotope dating and labelling, radiotherapy, nuclear power and reactors, fission and fusion, nuclear wastes, dosimetry, effects and radioprotection. (J.S.)

  9. Trap-assisted decay spectroscopy with ISOLTRAP

    CERN Document Server

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

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

  10. Radioactive colloids

    International Nuclear Information System (INIS)

    Bergqvist, L.

    1987-01-01

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

  11. Irradiance Decay in Fluorescent and Light-emitting Diode-based Phototherapy Devices: A Pilot Study.

    OpenAIRE

    Olusanya, Bolajoko

    2016-01-01

    We set out to determine the rate of decline of irradiance for fluorescent tube (FT) and light-emitting diode (LED) phototherapy devices in resource-limited settings where routine irradiance monitoring is uncommon. Irradiance levels (μW/cm 2 /nm) were measured weekly using BiliBlanket ® II Meter on three FT-based and two LED-based phototherapy devices over a 19 week period. The two LED devices showed stable irradiance levels and did not require any lamp changes. The three FT-based devices show...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-01-01

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

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  14. Beauty hadron decays at LHCb

    CERN Document Server

    Poluektov, Anton

    2016-01-01

    In these proceedings, I will report the recent results on properties, production and decays of beauty baryons, as well as measurements of B + c meson decays, based on data collected by the LHCb collaboration at the LHC collider in 2011–2012.

  15. Impacts of accidental radioactive releases to the hydrosphere from floating and land-based nuclear power plants

    International Nuclear Information System (INIS)

    Vollmer, R.H.

    1978-01-01

    To assess the impacts of accidental radioactive releases to the hydrosphere from floating and land-based nuclear power plants, the Liquid Pathway Generic Study was initiated. The objective of this study was to compare the risks associated with releases through the liquid pathway from accidents that may reasonably be expected and those that are very improbable. Consequences were estimated in terms of radiation dose to man from drinking water ingestion, shell-fish and fish flesh consumption, and direct exposure (swimming, beach) as well as long-term effects, such as genetic effects or aquatic species degradation. (author)

  16. Decay heat uncertainty quantification of MYRRHA

    Science.gov (United States)

    Fiorito, Luca; Buss, Oliver; Hoefer, Axel; Stankovskiy, Alexey; Eynde, Gert Van den

    2017-09-01

    MYRRHA is a lead-bismuth cooled MOX-fueled accelerator driven system (ADS) currently in the design phase at SCK·CEN in Belgium. The correct evaluation of the decay heat and of its uncertainty level is very important for the safety demonstration of the reactor. In the first part of this work we assessed the decay heat released by the MYRRHA core using the ALEPH-2 burnup code. The second part of the study focused on the nuclear data uncertainty and covariance propagation to the MYRRHA decay heat. Radioactive decay data, independent fission yield and cross section uncertainties/covariances were propagated using two nuclear data sampling codes, namely NUDUNA and SANDY. According to the results, 238U cross sections and fission yield data are the largest contributors to the MYRRHA decay heat uncertainty. The calculated uncertainty values are deemed acceptable from the safety point of view as they are well within the available regulatory limits.

  17. Decay heat uncertainty quantification of MYRRHA

    Directory of Open Access Journals (Sweden)

    Fiorito Luca

    2017-01-01

    Full Text Available MYRRHA is a lead-bismuth cooled MOX-fueled accelerator driven system (ADS currently in the design phase at SCK·CEN in Belgium. The correct evaluation of the decay heat and of its uncertainty level is very important for the safety demonstration of the reactor. In the first part of this work we assessed the decay heat released by the MYRRHA core using the ALEPH-2 burnup code. The second part of the study focused on the nuclear data uncertainty and covariance propagation to the MYRRHA decay heat. Radioactive decay data, independent fission yield and cross section uncertainties/covariances were propagated using two nuclear data sampling codes, namely NUDUNA and SANDY. According to the results, 238U cross sections and fission yield data are the largest contributors to the MYRRHA decay heat uncertainty. The calculated uncertainty values are deemed acceptable from the safety point of view as they are well within the available regulatory limits.

  18. Lepton decay constants of light mesons

    International Nuclear Information System (INIS)

    Simonov, Yu. A.

    2016-01-01

    A theory of lepton decay constants based on the path-integral formalism is given for chiral and vector mesons. Decay constants of the pseudoscalar and vector mesons are calculated and compared to other existing results.

  19. School-Based Caries Prevention, Tooth Decay, and the Community Environment.

    Science.gov (United States)

    Ruff, R R; Niederman, R

    2018-04-01

    The school and community context can contribute to inequity in child oral health. Whether the school and community affect the effectiveness of school-based caries prevention is unknown. The association between the school and community environment and dental caries, as well as their moderating effects with school-based caries prevention, was assessed using multilevel mixed-effects regression. Data were derived from a 6-y prospective cohort study of children participating in a school-based caries prevention program. For the school and community, living in a dental-shortage area and the proportion of children receiving free or reduced lunch were significantly related to an increased risk of dental caries at baseline. Caries prevention was associated with a significant per-visit decrease in the risk of untreated caries, but the rate of total caries experience increased over time. Caries prevention was more effective in children who had prior dental care at baseline and in schools with a higher proportion of low socioeconomic status students. There was significant variation across schools in the baseline prevalence of dental caries and the effect of prevention over time, although effects were modest. The school and community environment have a direct impact on oral health and moderate the association between school-based caries prevention and dental caries. Knowledge Transfer Statement: School-based caries prevention can be an effective means to reduce oral health inequity by embedding dental care within schools. However, the socioeconomic makeup of schools and characteristics of the surrounding community can affect the impact of school-based care.

  20. Reactors physics. Bases of nuclear physics

    International Nuclear Information System (INIS)

    Diop, Ch.M.

    2006-01-01

    The aim of nuclear reactor physics is to quantify the relevant macroscopic data for the characterization of the neutronic state of a reactor core and to evaluate the effects of radiations (neutrons and gamma radiations) on organic matter and on inorganic materials. This first article presents the bases of nuclear physics in the context of nuclear reactors: 1 - reactor physics and nuclear physics; 2 - atomic nucleus - basic definitions: nucleus constituents, dimensions and mass of the atomic nucleus, mass defect, binding energy and stability of the nucleus, strong interaction, nuclear momentums of nucleons and nucleus; 3 - nucleus stability and radioactivity: equation of evolution with time - radioactive decay law; alpha decay, stability limit of spontaneous fission, beta decay, electronic capture, gamma emission, internal conversion, radioactivity, two-body problem and notion of radioactive equilibrium. (J.S.)

  1. Irradiance Decay in Fluorescent and Light-emitting Diode-based Phototherapy Devices: A Pilot Study.

    Science.gov (United States)

    Olusanya, Bolajoko O; Osibanjo, Folashade B; Emokpae, Abieyuwa A; Slusher, Tina M

    2016-10-01

    We set out to determine the rate of decline of irradiance for fluorescent tube (FT) and light-emitting diode (LED) phototherapy devices in resource-limited settings where routine irradiance monitoring is uncommon. Irradiance levels (μW/cm(2)/nm) were measured weekly using BiliBlanket(®) II Meter on three FT-based and two LED-based phototherapy devices over a 19 week period. The two LED devices showed stable irradiance levels and did not require any lamp changes. The three FT-based devices showed rapid decline in irradiance, and all required three complete lamp exchanges approximately every 5-6 weeks. FT-based devices are associated with more rapid decline in irradiance to sub-therapeutic levels and require more frequent lamp changes than LED devices. Clinicians should be alert to the maintenance requirements of the phototherapy devices available in their settings to ensure efficacy of treatment. © The Author [2016]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Geologic disposal of radioactive waste

    International Nuclear Information System (INIS)

    Tassoni, E.; Giulianelli, G.; Testa, L.; Bocola, W.; Girolimetti, G.; Giacani, G.

    1983-01-01

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

  3. Minority participation in a school-based randomized clinical trial of tooth decay prevention in the United States.

    Science.gov (United States)

    Nelson, Suchitra; Milgrom, Peter

    2012-01-01

    To describe the strategies-based on the social triad concept of a partnership of researchers, school personnel and community-employed to recruit low-income, minority parent/caregivers of kindergarten children into a school-based tooth decay prevention trial in the United States. The study site was an urban school district with five elementary schools. Recruitment was carried out once each year for three years. Recruitment involved strategies at the school district, school, classroom, and student-parent level. A coalition of researchers, school personnel and community individuals was established for communication and recruitment. Outreach workers from the community were hired to promote, recruit, and disseminate oral health information. Study promotion included both print materials (logos, flyers, pictorial story boards) and presentations at school and community events. The School District Superintendent and administrators approved the study, and all five school principals and kindergarten teachers participated. All children within the classrooms were eligible: the overall participation rate of was 86% (580/672). Community outreach workers actively facilitated the recruitment and participants were recruited at open house for parent-teacher meeting (37% of all participants), sending letters and consent forms home (31%), at a prearranged convenient time during drop off and pick up of the child at their respective schools (30%), curriculum nights and health fairs (2%). Utilizing the social triad concept led to success in planning and carrying out the recruitment of predominantly minority school children with high participation rates. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Radiation and environmental radioactivity

    International Nuclear Information System (INIS)

    Muhamat Omar; Ismail Sulaiman; Zalina Laili

    2015-01-01

    This book is written based on 25 years authors experience especially in scientifc research of radiation and environmental radioactivity field at Malaysian Nuclear Agency (Nuklear Malaysia). Interestingly, from the authors experience in managing the services and consultancies for radiological environmental monitoring, it is also helpful in preparing the ideas for this book. Although this book focuses on Malaysian radiation information environmental radioactivity, but the data collected by the international bodies are also included in this book.

  5. Soil radioactivity levels and radiation hazard assessment around a Thermal Power Plant

    International Nuclear Information System (INIS)

    Kumar, Mukesh; Kumar, Pankaj; Sharma, Somdutt; Agrawal, Anshu; Kumar, Rajesh; Prajith, Rama; Sahoo, B.K.

    2016-01-01

    Coal based thermal power plants further enhance the level of radioactivity in the environment, as burning of coal produces fly ash that can be released into the environment containing traces of 238 U, 232 Th and their decay products. Therefore, coal fired power plants are one of the major contributor towards the Technologically Enhanced Natural Radiation (TENR). Keeping this in view, a study of natural radioactivity in the soil of twenty five villages within 5 km radius around the Harduaganj Thermal Power Plant, Aligarh, UP, India is going on under a BRNS major project, to know the radiological implications on general population living around this plant

  6. Broad resonances and beta-decay

    DEFF Research Database (Denmark)

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

    2015-01-01

    Beta-decay into broad resonances gives a distorted lineshape in the observed energy spectrum. Part of the distortion arises from the phase space factor, but we show that the beta-decay matrix element may also contribute. Based on a schematic model for p-wave continuum neutron states it is argued...... that beta-decay directly to the continuum should be considered as a possible contributing mechanism in many decays close to the driplines. The signatures in R-matrix fits for such decays directly to continuum states are discussed and illustrated through an analysis of the beta-decay of $^8$B into $2...

  7. Management of the Area 5 Radioactive Waste Management Site using Decision-based, Probabilistic Performance Assessment Modeling

    International Nuclear Information System (INIS)

    Carilli, J.; Crowe, B.; Black, P.; Tauxe, J.; Stockton, T.; Catlett, K.; Yucel, V.

    2003-01-01

    Low-level radioactive waste from cleanup activities at the Nevada Test Site and from multiple sites across the U.S. Department of Energy (DOE) complex is disposed at two active Radioactive Waste Management Sites (RWMS) on the Nevada Test Site. These facilities, which are managed by the DOE National Nuclear Security Administration Nevada Site Office, were recently designated as one of two regional disposal centers and yearly volumes of disposed waste now exceed 50,000 m3 (> 2 million ft3). To safely and cost-effectively manage the disposal facilities, the Waste Management Division of Environmental Management has implemented decision-based management practices using flexible and problem-oriented probabilistic performance assessment modeling. Deterministic performance assessments and composite analyses were completed originally for the Area 5 and Area 3 RWMSs located in, respectively, Frenchman Flat and Yucca Flat on the Nevada Test Site. These documents provide the technical bases for issuance of disposal authorization statements for continuing operation of the disposal facilities. Both facilities are now in a maintenance phase that requires testing of conceptual models, reduction of uncertainty, and site monitoring all leading to eventual closure of the facilities and transition to long-term stewardship

  8. Two proton decay in 12O

    International Nuclear Information System (INIS)

    Kumawat, M.; Singh, U.K.; Jain, S.K.; Saxena, G.; Kaushik, M.; Aggarwal, Mamta

    2017-01-01

    Two-proton radioactivity was observed experimentally in the decay of 45 Fe, 54 Zn and 48 Ni. From then many theoretical studies of one and two-proton radioactivity have been carried out within the framework of different models including RMF+BCS approach for medium mass region. Towards light mass region proton-proton correlations were observed in two-proton decay of 19 Mg and 16 Ne. Recently, different mechanism of two-proton emission from proton-rich nuclei 23 Al and 22 Mg has been investigated and transition from direct to sequential two-proton decay in sd shell nuclei is observed. Encouraged with these recent studies of two proton emission in light mass nuclei, we have applied our RMF+BCS approach for the study of two proton emission in light mass region and in this paper we present our result of two proton emission in 12 O

  9. 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)

  10. 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)

  11. Genetics of the DST-mediated mRNA decay pathway using a transgene-based selection.

    Science.gov (United States)

    Lidder, P; Johnson, M A; Sullivan, M L; Thompson, D M; Pérez-Amador, M A; Howard, C J; Green, P J

    2004-08-01

    mRNA sequences that control abundance, localization and translation initiation have been identified, yet the factors that recognize these sequences are largely unknown. In this report, a transgene-based strategy designed to isolate mutants of Arabidopsis thaliana that fail to recognize these sequences is described. In this strategy, a selectable gene and a screenable marker gene are put under the control of the sequence element being analysed and mutants are selected with altered abundance of the corresponding marker RNAs. The selection of mutants deficient in recognition of the DST (downstream) mRNA degradation signal is used as a test-case to illustrate some of the technical aspects that have facilitated success. Using this strategy, we report the isolation of a new mutant, dst3, deficient in the DST-mediated mRNA decay pathway. The targeted genetic strategy described circumvents certain technical limitations of biochemical approaches. Hence, it provides a means to investigate a variety of other mechanisms responsible for post-transcriptional regulation.

  12. Radioactive wastes. Safety of storage facilities

    International Nuclear Information System (INIS)

    Devillers, Ch.

    2001-01-01

    A radioactive waste storage facility is designed in a way that ensures the isolation of wastes with respect to the biosphere. This function comprises the damping of the gamma and neutron radiations from the wastes, and the confinement of the radionuclides content of the wastes. The safety approach is based on two time scales: the safety of the insulation system during the main phase of radioactive decay, and the assessment of the radiological risks following this phase. The safety of a surface storage facility is based on a three-barrier concept (container, storage structures, site). The confidence in the safety of the facility is based on the quality assurance of the barriers and on their surveillance and maintenance. The safety of a deep repository will be based on the site quality, on the design and construction of structures and on the quality of the safety demonstration. This article deals with the safety approach and principles of storage facilities: 1 - recall of the different types of storage facilities; 2 - different phases of the life of a storage facility and regulatory steps; 3 - safety and radiation protection goals (time scales, radiation protection goals); 4 - safety approach and principles of storage facilities: safety of the isolation system (confinement system, safety analysis, scenarios, radiological consequences, safety principles), assessment of the radiation risks after the main phase of decay; 5 - safety of surface storage facilities: safety analysis of the confinement system of the Aube plant (barriers, scenarios, modeling, efficiency), evaluation of radiological risks after the main phase of decay; experience feedback of the Manche plant; variants of surface storage facilities in France and abroad (very low activity wastes, mine wastes, short living wastes with low and average activity); 6 - safety of deep geological disposal facilities: legal framework of the French research; international context; safety analysis of the confinement system

  13. 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.

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

    International Nuclear Information System (INIS)

    Kaushik, Subrat; Munj, Niket; Chauhan, R.K.; Kumar, Pramod; Mishra, A.C.

    2011-01-01

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

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

    International Nuclear Information System (INIS)

    Aubin-Chevaldonnet, V.

    2004-11-01

    Research on treating specifically the long-lived and high level nuclear wastes, notably cesium, is currently carried out in France. Cesium immobilization in host matrices of high chemical durability constitutes the favoured option. Hollandite matrix is a good candidate because of its high cesium incorporation ability and its excellent chemical stability. During this study, different compositions of hollandite ceramics Ba x Cs y C z Ti 8-z O 16 (C = Al 3+ , Cr 3+ , Ga 3+ , Fe 3+ , Mg 2+ , Sc 3+ ), synthesized by oxide route, were characterized in terms of structure, microstructure and physical and chemical properties. Iron ions seems to be the most suitable of the studied C cations to get high-performance hollandites. The stability of these ceramics under external electron irradiation, simulating the β particles emitted by radioactive cesium, were also estimated, at the macroscopic and atomic scale. The point defects creation and their thermal stability were followed by electron paramagnetic resonance. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-29

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

  17. Application of [sup 57]Fe emission Moessbauer spectroscopy to the investigation of the physico-chemical consequences of the double radioactive decay [sup 57]Ni[yields][sup 57]Co[yields][sup 57]Fe in the solid state

    Energy Technology Data Exchange (ETDEWEB)

    Devillers, M.; Ladriere, J. (Univ. Catholique de Louvain, Louvain-la-Neuve (Belgium). Lab. de Chimie Inorganique et Nucleaire)

    1994-04-01

    [sup 57]Fe emission Mossbauer spectroscopy is shown to be a useful technique for investigating the cumulative recoil and Auger after-effects associated with the double electron capture decay, [sup 57]Ni[yields][sup 57]Co''->[sup 57]Fe, in the solid state. Experimental results collected in several types of nickel-containing matrices are surveyed: conducting materials (Ni metal), ionic compounds with monoatomic ligands [potassium trifluoronickelate (II)] and coordination compounds with polyatomic ligands (carboxylates). (Author).

  18. Storage of radioactive wastes

    International Nuclear Information System (INIS)

    1992-07-01

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

  19. The natural radioactivity of the biosphere

    International Nuclear Information System (INIS)

    Pertsov, L.A.

    1967-01-01

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

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

    International Nuclear Information System (INIS)

    1994-01-01

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

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

    Science.gov (United States)

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

    2016-11-01

    Origen2.1 is a widely used computer code for calculating the burnup, decay, and processing of radioactive materials. However, the nuclide library of Origen2.1 is used for existing reactors like pressurized water reactors. To calculate the photon spectrum released by the decay of spallation products, we have made specific libraries for the ADS tungsten spallation target, based on the results given by the FLUKA Monte Carlo code. All the data used to make the Origen2.1 libraries are obtained from Nuclear structure & decay Data (NuDat2.6). The accumulated activity of spallation products and the contribution of nuclides to photon emission are given in this paper. Supported by Strategic Priority Research Program of Chinese Academy of Sciences (XDA03030102)

  2. Assessment of Radioactivity Concentration in Soil of some Mining

    African Journals Online (AJOL)

    232Th) and Potassium (40K). Areas at ... radionuclides; mainly potassium, rubidium and the radionuclides in the decay chains of thorium and uranium. ..... Radiometry in Radioactive Metal Exploration. Physics. Lab, Eastern Region, AMD Complex, ...

  3. Data for decay Heat Predictions

    International Nuclear Information System (INIS)

    1987-01-01

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

  4. Weak Decays of Charmed Particles

    Energy Technology Data Exchange (ETDEWEB)

    Turcotte, Marc Gilles [McGill Univ., Montreal, QC (Canada)

    1986-05-01

    The lifetimes of charmed particles produced in interactions of high energy neutrinos with nucleons have been measured using a combination of a very high resolution emulsion-based vertex detector and a spectrometer allowing full kinematical reconstruction of the decays.

  5. Role of shell corrections in doubly magic 208Pb radioactivity within quantum mechanical fragmentation theory

    International Nuclear Information System (INIS)

    Mandeep Kaur; Singh, BirBikram; Sukhmanpreet Kaur

    2017-01-01

    The liquid drop energy (V LDM ) along with shell corrections (δU) plays an important role to give the proper understanding of binding energies of atomic nuclei. It is relevant mention here that to study the excited state decay of nuclear systems Gupta and collaborators developed dynamical cluster decay model (DCM) by refitting the binding energies at T=0, to get temperature dependent binding energies with shell corrections included, for the same. Also, in literature different types of temperature dependent binding energies formulas are available. In DCM, the temperature dependent binding energies have been included as given by Davidson et al. In the process, shell corrections, δU were also calculated along with VLDM to reproduce the available experimental binding energies at T=0. It is relevant to mention here that the nuclear shell structure plays main role in the process of cluster radioactivity (CR) as very well explored by the quantum mechanical fragmentation theory (QMFT)-based preformed cluster decay model (PCM), which is the special case of DCM at T=0. Within PCM, Gupta and collaborators also studied the role of deformations or orientations in the decay of number of radioactive nuclei in trans-lead region, specifically, which lead to doubly magic 208 Pb daughter nucleus through emission of clusters i.e. 14 C, 18,20 O, 22 Ne, 23 F, 24,26 Ne, 28,30 Mg and 32,34 Si, along with many other CR decays. As mentioned earlier, the nuclear shell structure plays an important role in the decay of radioactive nuclei to doubly magic 208 Pb through cluster

  6. Radioactivity in the hydrologic environment

    International Nuclear Information System (INIS)

    Werner, L.B.

    1969-01-01

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

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

    International Nuclear Information System (INIS)

    Klein, J.A.

    1987-01-01

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

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

    International Nuclear Information System (INIS)

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

    International Nuclear Information System (INIS)

    1985-01-01

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

  10. Introduction to naturally occurring radioactive material

    Energy Technology Data Exchange (ETDEWEB)

    Egidi, P.

    1997-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Frisoni Manuela

    2016-01-01

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

  12. UNIDOSE - a computer program for the calculation of individual and collective doses from airborne radioactive pollutants

    International Nuclear Information System (INIS)

    Karlberg, O.; Schwartz, H.; Forssen, B.-H.; Marklund, J.-E.

    1979-01-01

    UNIDOSE is a program system for calculating the consequences of a radioactive release to the atmosphere. The program is applicable for computation of dispersion in a rnage of 0 - 50 km from the release point. The Gaussion plume model is used for calculating the external dose from activity in the atmosphere, on the ground and the internal dose via inhalation. Radioactive decay, as well as growth and decay of daughter products are accounted for. The influence of dry deposition and wash-out are also considered. It is possible to treat time-dependent release-rates of 1 - 24 hours duration and constant release-rates for up to one year. The program system also contains routines for the calculation of collective dose and health effects. The system operates in a statistical manner. Many weather-situations, based on measured data, can be analysed and statistical properties, such as cumulative frequences, can be calculated. (author)

  13. Radiobiological significance of radioactive contamination - summary assessment based on great number of measurements

    International Nuclear Information System (INIS)

    Angelov, V.; Bonchev, Ts.; Mavrodiev, V.; Kyrdzhilov, N.

    1995-01-01

    In order to facilitate quantitative and qualitative characterisation of radioactive contamination the authors introduce a relative estimate of radionuclide activity by setting as a reference the most abundant element -Co-60 in the case of the Kozloduy NPP. The ratio η i of the mean annual permissible concentration in air for each radionuclide (RPC-92) to that of Co-60 is calculated. It is found that η i has the same or close values for groups of radionuclides, e.g. η i = 2.10 -4 for 238 Pu, 239 Pu, 240 Pu, 241 Am, 244 Cm; η i = 5 for 89 Sr, 91 Y; 93 Nb, 134 Cs, 137 Cs; η i = 50 for 55 Fe, 63 Ni, 95 Zr, 95 Nb, 140 Ba, 140 La. Then it is compared to the experimentally measured values of the same quantity η iexp , derived from surface contamination data. The ratio η iexp /η i is plotted against log η i . The resulting nomograms give graphic representation of the radiobiological significance of various radionuclide groups. Data from different locations at the Kozloduy NPP are presented. It is found that the alpha emitter contamination has highest values in the Unit 1 (WWER-440) control rooms after repair. The Unit 5 (WWER-1000) has lower alpha contamination compared to WWER-440 units. 1 ref., 5 figs., 1 tab

  14. Scalar mesons and radiative vector meson decays

    International Nuclear Information System (INIS)

    Gokalp, A.; Ylmaz, O

    2002-01-01

    The light scalar mesons with vacuum quantum numbers J p =0 ++ have fundamental importance in understanding low energy QCD phenomenology and the symmetry breaking mechanisms in QCD. The nature and quark substructure of the best known scalar mesons, isoscalar σ(500), f0(980) and isovector a0(980) have been a subject of continuous controversy. The radioactive decay of neutral vector mesons ρ, w and φ into a single photon and a pair of neutral pseudoscalar mesons have been studied in order to obtain information on the nature of these scalar mesons. For such studies, it is essential that a reliable understanding of the mechanisms for these decays should be at hand. In this work, we investigate the particularly interesting mechanism of the exchange of scalar mesons for the radiative vector meson decays by analysing the experimental results such as measured decay rates and invariant mass spectra and compare them with the theoretical prediction of different reaction mechanisms

  15. Muon decay channelling and the Mu* site in silicon

    International Nuclear Information System (INIS)

    Bosshard, A.; Patterson, B.D.; Straumann, U.; Truoel, P.; Wueest, A.; Wichert, Th.

    1983-01-01

    An implanted radioactive impurity such as a positive muon in silicon will exhibit the steering or channelling effect of the host lattice on the trajectory of its charged decay particle. A measurement of the angular distribution of such decay particles along crystal directions close to high symmetry axes and planes will show maxima and minima due to the coherent small angle scattering. Such channelling features can be used to determine the site of the radioactive impurity in the host lattice. For positively charged decay particles, a maximum (minimum) in the angular distribution will occur for a site which is in a channel (host atom shadow) for a projection along the observation direction. The authors have performed such angular distribution measurements for 30 to 50 MeV decay positrons from positive muon decay. (Auth.)

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

    International Nuclear Information System (INIS)

    Azevedo Py Junior, D. de.

    1978-01-01

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

  17. Alternative risk-based criteria for transportation of radioactive materials on the United States Department of Energy Hanford Site

    International Nuclear Information System (INIS)

    Mercado, J.E.; Field, J.G.; Smith, R.J.; Wang, O.S.

    1993-01-01

    This paper presents the development of an alternative method to evaluate packaging safety for radioactive material transported solely within the boundaries of a restricted site; the method uses risk-based criteria to assess and document packaging safety. These criteria offer a standard against which the results of a risk assessment are compared to evaluate the safety of a transportation operation. Numerous payloads are transported entirely within the U.S. Department of Energy's Hanford Site boundaries. The U.S. Department of Energy requires that the safety of onsite transportation be equivalent to the safety provided for transporting radioactive materials in commerce as regulated by the U.S. Department of Transportation and the U.S. Nuclear Regulatory Commission. Some onsite packaging configurations do not meet the performance criteria that form the basis of these regulations, necessitating the establishment of alternative criteria to evaluate safety. Quantitatively defined criteria have been derived from the U.S. Department of Transportation limits for package radiation levels, curie content, activity release, and external contamination levels. Recommendations of the International Committee on Radiation Protection may further restrict the criteria. The proposed method documents packaging safety in a transportation risk assessment. The assessment estimates accident frequencies, conservatively evaluates the dose consequences of these accidents, and compares the results to the established risk acceptance criteria. Specific Hanford Site onsite packaging and transportation issues illustrate the alternative method. The paper compares the solutions resulting from the application of risk-based criteria to those resulting from strict compliance with commercial transportation regulations. (author)

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

    Indian Academy of Sciences (India)

    2017-02-09

    Feb 9, 2017 ... Abstract. Nuclei in the actinide region are good in exhibiting cluster radioactivity. In the present work, the half-lives of α-decay and heavy cluster emission from certain actinide nuclei have been calculated using cubic plus Yukawa plus exponential model (CYEM). Our model has a cubic potential for the ...

  19. Three-body decays: structure, decay mechanism and fragment properties

    International Nuclear Information System (INIS)

    Alvarez-Rodriguez, R.; Jensen, A.S.; Fedorov, D.V.; Fynbo, H.O.U.; Kirsebom, O.S.; Garrido, E.

    2009-01-01

    We discuss the three-body decay mechanisms of many-body resonances. R-matrix sequential description is compared with full Faddeev computation. The role of the angular momentum and boson symmetries is also studied. As an illustration we show the computed ?-particle energy distribution after the decay of 12 C(1 + ) resonance at 12.7 MeV. This article is based on the presentation by R. Alvarez-Rodriguez at the Fifth Workshop on Critical Stability, Erice, Sicily. (author)

  20. Method and program for decay scheme reconstruction based on formal logical analysis of gamma-gamma coincidence matrix

    International Nuclear Information System (INIS)

    Adam, J.; Tsupko-Sitnikov, V.M.

    1996-01-01

    A new, rigorously substantiated approach to construction of decay schemes on the basis of γ-γ coincidence data is described. Complete decay modes (concrete cascades of transitions from excited to the ground-state of a nucleus excited in a decay or a reaction) and continuity regions in complete modes (regions of successive transitions) are isolated by logical operations with rows (columns) of a symmetrical coincidence matrix where rows (columns) correspond to energies of coinciding transitions and matrix elements are unities and zeros, depending on the presence or absence of the given coincidence. To reject false complete modes and continuity regions arising from incompleteness of the coincidence data and errors in them, energy selection is introduced for complete modes and continuity regions, which demands that total energy of their constituent transitions should be equal to total energy of some other complete modes and continuity regions and to the energies of singles. With the continuity regions found, it is possible to order transitions in the selected complete modes and to algorithmize matching of complete modes into a decay scheme. 10 refs., 3 figs

  1. Proposals of new basic concepts on safety and radioactive waste and of new High Temperature Gas-cooled Reactor based on these basic concepts

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Masuro, E-mail: ogawa.masuro@jaea.go.jp

    2016-11-15

    Highlights: • The author proposed new basic concepts on safety and radioactive waste. • A principle of ‘continue confining’ to realize the basic concept on safety is also proposed. • It is indicated that only a HTGR can attain the conditions required from the principle. • Technologies to realize the basic concept on radioactive waste are also discussed. • A New HTGR system based on the new basic concepts is proposed. - Abstract: A new basic concept on safety of ‘Not causing any serious catastrophe by any means’ and a new basic concept on radioactive waste of ‘Not returning any waste that possibly affects the environment’ are proposed in the present study, aiming at nuclear power plants which everybody can accept, in consideration of the serious catastrophe that happened at Fukushima Japan in 2011. These new basic concepts can be found to be valid in comparison with basic concepts on safety and waste in other industries. The principle to realize the new basic concept on safety is, as known well as the inherent safety, to use physical phenomena such as Doppler Effect and so on which never fail to work even if all equipment and facilities for safety lose their functions. In the present study, physical phenomena are used to ‘continue confining’, rather than ‘confine’, because the consequence of emission of radioactive substances to the environment cannot be mitigated. To ‘continue confining’ is meant to apply natural correction to fulfill inherent safety function. Fission products must be detoxified to realize the new basic concept on radioactive waste, aiming at the final processing and disposal of radioactive wastes as same as that in the other wastes such as PCB, together with much efforts not to produce radioactive wastes and to reduce their volume nevertheless if they are emitted. Technology development on the detoxification is one of the most important subjects. A new High Temperature Gas-cooled Reactor, namely the New HTGR

  2. Proposals of new basic concepts on safety and radioactive waste and of new High Temperature Gas-cooled Reactor based on these basic concepts

    International Nuclear Information System (INIS)

    Ogawa, Masuro

    2016-01-01

    Highlights: • The author proposed new basic concepts on safety and radioactive waste. • A principle of ‘continue confining’ to realize the basic concept on safety is also proposed. • It is indicated that only a HTGR can attain the conditions required from the principle. • Technologies to realize the basic concept on radioactive waste are also discussed. • A New HTGR system based on the new basic concepts is proposed. - Abstract: A new basic concept on safety of ‘Not causing any serious catastrophe by any means’ and a new basic concept on radioactive waste of ‘Not returning any waste that possibly affects the environment’ are proposed in the present study, aiming at nuclear power plants which everybody can accept, in consideration of the serious catastrophe that happened at Fukushima Japan in 2011. These new basic concepts can be found to be valid in comparison with basic concepts on safety and waste in other industries. The principle to realize the new basic concept on safety is, as known well as the inherent safety, to use physical phenomena such as Doppler Effect and so on which never fail to work even if all equipment and facilities for safety lose their functions. In the present study, physical phenomena are used to ‘continue confining’, rather than ‘confine’, because the consequence of emission of radioactive substances to the environment cannot be mitigated. To ‘continue confining’ is meant to apply natural correction to fulfill inherent safety function. Fission products must be detoxified to realize the new basic concept on radioactive waste, aiming at the final processing and disposal of radioactive wastes as same as that in the other wastes such as PCB, together with much efforts not to produce radioactive wastes and to reduce their volume nevertheless if they are emitted. Technology development on the detoxification is one of the most important subjects. A new High Temperature Gas-cooled Reactor, namely the New HTGR

  3. 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

    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.

  4. Removal of bulk contaminants from radioactive waste water at Bruce A using a clay based flocculent system

    International Nuclear Information System (INIS)

    Davloor, R.; Harper, B.

    2011-01-01

    implement a clay-based flocculation Pre-Treatment System. In-service since late 2000, the system has been able to reliably treat a broad range of contaminants in the waste water before being sent to the downstream ROS. This clay-based system is unique in its application; it is able to remove bulk oil and grease, suspended solids, and metal contaminants in a waste stream that contains a high amount of surfactants originating from the laundering of plastic suits (personal protective equipment for working in radioactive environments) and other waste waters from the station. The treated water from the PTS consistently meets the strict requirements for subsequent treatment by the system RO membranes. This paper describes the laboratory and pilot scale testing that led to the development of the process, as well as the full scale implementation of this unique Pre-Treatment System. (author)

  5. Low and intermediate radioactive waste characterization using MICROSHIELD 5 code

    International Nuclear Information System (INIS)

    Mateescu, Silvia; Pantazi, Doina; Stanciu, Marcela

    2002-01-01

    Low and intermediate radioactive gaseous, liquid and solid waste produced at Cernavoda Nuclear Power Plant must be known from the point of view of contained radionuclide activity, during all steps of their processing, storage and transport, to ensure the nuclear safety of radioactive waste management. As the waste activity changes by radioactive decay and nuclear transmutation, the evolution in time of these sources is necessary to be assess, for the purpose of biological shielding determination at any time. On the other hand, during the transport of waste package at the repository, the external dose rates must meet the national and international requirements concerning radioactive materials transportation on public roads. In this paper, a calculation methodology for waste characterization based on external exposure rate measurement and on sample analysis results is presented. The time evolution of waste activity, as well as the corresponding shielding at different moments of management process, has been performed using MICROSHIELD-5 code. The spent resins proceeded from systems for clean-up and purification of cooling water and moderator, water from spent fuel storage bays, etc. have been analyzed. In this paper an example of spent ionic resins characterization, using the MICROSHIELD 5 code, is presented. (authors)

  6. Three-body charmless B decays workshop

    International Nuclear Information System (INIS)

    Ben-Haim, E.; Chauveau, J.; Hartfiel, B.; Ocariz, J.; Charles, J.

    2006-01-01

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

  7. Three-body charmless B decays workshop

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  8. HALF-LIVES OF LONG-LIVED α-DECAY, β-DECAY, ββ-DECAY AND SPONTANEOUS FISSION NUCLIDES

    International Nuclear Information System (INIS)

    HOLDEN, N.E.

    2001-01-01

    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, α-decay, β-decay, electron capture decay, ββ-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

  9. Efficient and compact mobile equipment based on the new RADEON-NWM technology to process liquid radioactive wastes resulted from the accidents of the nuclear installations

    International Nuclear Information System (INIS)

    Martoyan, Gagik; Nalbandyan, Garik; Gagiyan, Lavrenti; Karamyan, Gagik; Brutyan, Gagik

    2013-01-01

    During the operation of nuclear reactors important volume of liquid and solid radioactive wastes are generated, which, in normal conditions, becomes processed by stationary equipment by different methods to minimize their volume and then sent to specially constructed storages. The cases of accidents of Chernobyl and Fukushima showed that the localization of rejected big quantity of radioactive wastes is a prior problem for their further processing by stationary equipment. In this regard it is very important the processing of radioactive wastes on the contaminated areas to localize them by mobile equipment based on the efficient technologies. RADEONNWM new technology allows resolving this problem. This technology is compact, completely automated, which makes possible to assemble it on a standard 40-ft by 7-ft trailer driven by heavy-duty truck. The new technology is fully elaborated, the necessary tests are conducted. (authors)

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

    International Nuclear Information System (INIS)

    Hardy, C.

    2003-01-01

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

  11. History of radioactivity

    International Nuclear Information System (INIS)

    Minder, W.

    1981-01-01

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

  12. 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.

  13. PRAMANA Cluster radioactivity in xenon isotopes

    Indian Academy of Sciences (India)

    exotic decay or cluster radioactivity was first predicted by sandulescu et al [1] in. 1980 on the basis of ... separator by 58Ni(58Ni, 2n) reaction and carbon clusters were searched for by means of solid state nuclear ..... Lett. 55, 582 (1985). [22] D N Poenaru, W Greiner, K Depta, M Ivascu, D Mazilu and A Sandulescu, At. Data.

  14. Radioactivity, radiation protection and monitoring during dismantling of light-water reactors

    International Nuclear Information System (INIS)

    Hummel, L.; Zech, J.B.

    2005-01-01

    Based on the radioactivity inventory in the systems and components of light-water reactors observed during operation, the impact of actions during plant emptying after the conclusion of power operation and possible subsequent long-term safe enclosure concerning the composition of the nuclide inventory of the plant to be dismantled will be described. Derived from this will be the effects on radioactivity monitoring in the plant, physical radiation protection monitoring, and the measured characterization of the residual materials resulting from the dismantling. The impact of long-term interim storage will also be addressed in the discussion. The talk should provide an overview of the interrelationships between source terms, decay times and the radioactivity monitoring requirements of the various dismantling concepts for commercial light-water reactors. (orig.)

  15. 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.

  16. Radioactivity in food crops

    International Nuclear Information System (INIS)

    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 137 Cs, 40 K, 90 Sr, 226 Ra, 228 Ra, plutonium, uranium, total alpha, and total beta, but a few authors also reported data for 241 Am, 7 Be, 60 Co, 55 Fe, 3 H, 131 I, 54 Mn, 95 Nb, 210 Pb, 210 Po, 106 Ru, 125 Sb, 228 Th, 232 Th, and 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 -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. Your radioactive garden

    International Nuclear Information System (INIS)

    Marshall, W.G.

    1986-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Litteer, D.L.; Peterson, C.N.; Sims, A.M.

    1993-04-01

    This document presents detailed data, bar graphs, and pie charts on volume, radioactivity, isotopic identity, origin, and decay status of radioactive waste for the calendar year 1991. It also summarizes the radiative waste data records compiled from 1952 to present for the Idaho National Engineering Laboratory (INEL). The data presented are from the INEL Radioactive Waste Management Information System.

  19. 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.)

  20. Radioactive waste management

    International Nuclear Information System (INIS)

    Alfredson, P.G.; Levins, D.M.

    1975-08-01

    Present and future methods of managing radioactive wastes in the nuclear industry are reviewed. In the stages from uranium mining to fuel fabrication, the main purpose of waste management is to limit and control dispersal into the environment of uranium and its decay products, particularly radium and radon. Nuclear reactors produce large amounts of radioactivity but release rates from commercial power reactors have been low and well within legal limits. The principal waste from reprocessing is a high activity liquid containing essentially all the fission products along with the transuranium elements. Most high activity wastes are currently stored as liquids in tanks but there is agreement that future wastes must be converted into solids. Processes to solidify wastes have been demonstrated in pilot plant facilities in the United States and Europe. After solidification, wastes may be stored for some time in man-made structures at or near the Earth's surface. The best method for ultimate disposal appears to be placing solid wastes in a suitable geological formation on land. (author)

  1. Radioactive waste

    International Nuclear Information System (INIS)

    Berkhout, F.

    1991-01-01

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

  2. Radioactive transformations

    CERN Document Server

    Rutherford, Ernest

    2012-01-01

    Radioactive Transformations describes Ernest Rutherford's Nobel Prize-winning investigations into the mysteries of radioactive matter. In this historic work, Rutherford outlines the scientific investigations that led to and coincided with his own research--including the work of Wilhelm Rӧntgen, J. J. Thomson, and Marie Curie--and explains in detail the experiments that provided a glimpse at special relativity, quantum mechanics, and other concepts that would shape modern physics. This new edition features a comprehensive introduction by Nobel Laureate Frank Wilczek which engagingly explains how Rutherford's early research led to a better understanding of topics as diverse as the workings of the atom's nucleus, the age of our planet, and the fusion in stars.

  3. Radioactive alchemy

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2014-07-15

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

  4. Radioactive hazards

    International Nuclear Information System (INIS)

    Gill, J.R.

    1980-01-01

    The use of radioactive substances in hospital laboratories is discussed and the attendant hazards and necessary precautions examined. The new legislation under the Health and Safety at Work Act which, it is proposed, will replace existing legal requirements in the field of health and safety at work by a system of regulations and approved codes of practice designed to maintain or improve the standards of health, safety and welfare already established, is considered with particular reference to protection against ionising radiations. (UK)

  5. Development of Public Training System for Emergency Exercise Using Virtual Reality Technology Based on Radioactive Release Accident

    International Nuclear Information System (INIS)

    Lee, Byung Il; Park, Seong Jun; Lee, Dewhey; Song, Sub Lee; Park, Younwon

    2016-01-01

    An exercise is normally conducted for a day or two days depending on the scale of the exercise. What we have experienced up to date there are several limitations in the radiological emergency exercises such as low public acceptance, poor enthusiasm in the exercise participation, not very attracting exercise scenarios, low efficiency in conducting an exercise, and so on. In order to overcome the limitations of the present exercising system, we would like to develop a radiological emergency exercise system using VR (virtual reality) technology based on a radioactive release accident. In this paper, we just introduce some basic development methods and event tree based scenario as a beginning stage. After the accident in Fukushima Daiichi NPP, the importance of emergency exercise especially for the public is far more emphasized around the world more and more. However, the human labor focused radiological emergency exercise up to now has many limitations. After developing this system properly and by using it, we could even expect to estimate the weak points of the emergency arrangements and strategy we have

  6. Development of Public Training System for Emergency Exercise Using Virtual Reality Technology Based on Radioactive Release Accident

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Il; Park, Seong Jun; Lee, Dewhey; Song, Sub Lee; Park, Younwon [BEES Inc., Daejeon (Korea, Republic of)

    2016-10-15

    An exercise is normally conducted for a day or two days depending on the scale of the exercise. What we have experienced up to date there are several limitations in the radiological emergency exercises such as low public acceptance, poor enthusiasm in the exercise participation, not very attracting exercise scenarios, low efficiency in conducting an exercise, and so on. In order to overcome the limitations of the present exercising system, we would like to develop a radiological emergency exercise system using VR (virtual reality) technology based on a radioactive release accident. In this paper, we just introduce some basic development methods and event tree based scenario as a beginning stage. After the accident in Fukushima Daiichi NPP, the importance of emergency exercise especially for the public is far more emphasized around the world more and more. However, the human labor focused radiological emergency exercise up to now has many limitations. After developing this system properly and by using it, we could even expect to estimate the weak points of the emergency arrangements and strategy we have.

  7. A simple model for the dispersion of radioactive wastes dumped on the deep-sea bed

    International Nuclear Information System (INIS)

    Shepherd, J.G.

    1976-01-01

    A simple model has been developed for the dispersion of radioactive materials in a closed and finite ocean. It allows for the simultaneous action of both diffusion and horizontal (but not vertical) advection, and thus avoids the major limitations of previous models. It is sufficiently versatile to handle non-Fickian diffusion and radioactive decay, but requires numerical integration using some semi-empirical form for the Green function of diffusion from a point source. The model has been used to estimate equilibrium concentrations of radioactive materials in sea water arising from the continuous release of material from a dump on the bottom of the deep ocean, using parameters appropriate for the North Atlantic. It is found that except under rather extreme conditions the surface concentrations do not exceed the long-term average value which would be established in a perfectly mixed ocean. The concentrations are also rather insensitive to the values of the diffusion and advection parameters used, except for that for vertical diffusion, but depend strongly on the overall removal rate of material from the ocean, including processes other than radioactive decay. It is suggested that safety assessments of deep-sea dumping should utilize estimates of the environmental capacities of the oceans based on the long-term 'well-mixed' average concentrations (which are very easily calculated) using a safety factor of no more than ten to allow for the possible effects of pluming and upwelling. (author)

  8. Recommended decay data for 235-neptunium

    International Nuclear Information System (INIS)

    Nichols, A.L.

    1981-11-01

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

  9. Remote detection and ecological monitoring of the industrial and natural nuclei activity of radioactive elements based on passive microwave radiometry

    Science.gov (United States)

    Chistyakova, Liliya K.; Chistyakov, Vyacheslav Y.; Losev, Dmitry V.; Penin, Sergei T.; Tarabrin, Yurij K.; Yakubov, Vladimir P.; Yurjev, Igor A.

    1998-12-01

    The passive remote method of microwave radiometry and its instrumental realization for express diagnostics of radioactive elements in the atmosphere have been discussed. Analysis of the microwave radiation due to ionization and dissociation of atmospheric components interacting with radioactive elements is carried out. The photochemical processes resulting in background microwave radiation power have been discussed. As an example, the results of natural experiment of detecting the atomic hydrogen radiation in the plume of emissions of nuclear cycle processing plants have been presented.

  10. Alpha radioactivity in Indian cement samples

    International Nuclear Information System (INIS)

    Nain, M.; Chauhan, R. P.; Chakarvarti, S. K.

    2006-01-01

    The essential constituents of radioactive and each of cements like lime, silica and alumina are derived from earth's crust in which radioactive elements like uranium, thorium etc are also present in varying amounts almost everywhere. These two elements are considered as the parent elements of uranium and thorium radioactive decay series in which radon and thoron are produced respectively as decay products. In the present study the samples of ordinary Portland cement , Portland pozzolana cement and some other cementious finishing materials like white cement, Plaster of Paris , cement putty etc were collected and analysed for radium and radon concentrations along with radon exhalation rates. Materials and Methods: Alpha sensitive LR-115 Type II plastic track detectors commonly known as S olid State Nuclear Track Detectors w ere used to measure the radium and radon concentration. The alpha particles emitted from the radon causes the radiation damaged tracks. The Chemical etching in NaOH at 60 C for about 90 minutes was done to reveal these latent tracks, which were then scanned and counted by an optical microscope of suitable magnification. By calculating the track density of registered tracks, the radon and radium concentrations along with exhalation rate of radon, were determined using required formulae. Results: The radon and radium concentration in various brands of cements found to vary from 333±9.9 to 506±13.3 Bq m-3 and from 3.7±0.1 to 5.6±0.2 Bq k g-1 while in various cementious finishing materials used in the construction, these were found to vary from 378±19.7 to 550±9.8 Bq m-3 and from 4.2±0.2 to 6.1±0.1 Bq Kg-1, respectively. Based on the data the mass and surface exhalation rates were also calculated Conclusion: The measurements indicate that there is marginal variation of the concentration of radium and radon in various brands of cements in India with lower levels in the cement samples having red oxide and higher levels in fly ash based cement

  11. Introduction to naturally occurring radioactive material

    International Nuclear Information System (INIS)

    Egidi, P.

    1997-01-01

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

  12. Radioactive Release from Aluminum-Based Spent Nuclear Fuel in Basin Storage

    International Nuclear Information System (INIS)

    Sindelar, R.L.

    1999-01-01

    The report provides an evaluation of: (1) the release rate of radionuclides through minor cladding penetrations (breaches) on aluminum-based spent nuclear fuel (AL SNF), and (2) the consequences of direct storage of breached AL SNF relative to the authorization basis for SRS basin operation

  13. Experimental proof of quantum non-separability based on the transition of the atom in beta-decay

    International Nuclear Information System (INIS)

    Vatai, E.

    1988-01-01

    The basic non-local character of the quantum processes is a continuously discussed and doubted problem of quantum theory. Recent experimental proofs of the Bell inequalities are questioned in the literature, using local theories of hidden variables. Present paper shows a simple and direct proof of non-locality of quantum processes, analyzing the case of the beta decay. The hypothetical energy transfer between shell electrons and beta electron-neutrino system is proved to be superluminal but necessary for the energy balance of the process. This argumentation proves the nonseparability and nonlocality of quantum processes. (D.G.) 8 refs

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

    Directory of Open Access Journals (Sweden)

    Jin-Yu Zhang

    2014-01-01

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

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

    Science.gov (United States)

    Zhang, Jin-Yu; Meng, Xiang-Bing; Xu, Wei; Zhang, Wei; Zhang, Yong

    2014-01-01

    This paper has proposed a new thermal wave image sequence compression algorithm by combining double exponential decay fitting model and differential evolution algorithm. This study benchmarked fitting compression results and precision of the proposed method was benchmarked to that of the traditional methods via experiment; it investigated the fitting compression performance under the long time series and improved model and validated the algorithm by practical thermal image sequence compression and reconstruction. The results show that the proposed algorithm is a fast and highly precise infrared image data processing method. PMID:24696649

  16. Random numbers spring from alpha decay

    International Nuclear Information System (INIS)

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

    1980-05-01

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

  17. Concentration and immobilization of 137Cs from liquid radioactive waste using sorbents based on hydrated titanium and zirconium oxides

    Science.gov (United States)

    Voronina, A. V.; Noskova, A. Y.; Gritskevich, E. Y.; Mashkovtsev, M. A.; Semenishchev, V. S.

    2017-09-01

    The possibility of use of sorbents based on hydrated titanium and zirconium oxides (T-3A, T-35, NPF-HTD) for concentration and immobilization of 137Cs from liquid radioactive waste of various chemical composition (fresh water, seawater, solutions containing NaNO3, ammonium acetate, EDTA) was evaluated. It was shown that the NPF-HTD and T-35 sorbents separate 137Cs from fresh water and seawater with distribution coefficients as high as 6.2.104 and 6.1.104, 4.0.105 and 1.6.105 L kg-1 respectively; in 1 M ammonium acetate these values were 2.0.103 and 1.0.103 L kg-1. The NPF-HTD sorbent showed the highest selectivity for cesium in NaNO3 solution: cesium distribution coefficients in 1M NaNO3 was 1.4.106 L kg-1. All studied sorbents are suitable for deactivation of solutions containing EDTA. Cesium distribution coefficients were around 102-103 L kg-1 depending on EDTA concentration. Chemical stability of the sorbents was also studied. It was shown that 137Cs leaching rate from all sorbents meet the requirements for matrix materials.

  18. Patient positioning based on a radioactive tracer implanted in patients with localized prostate cancer: a performance and safety evaluation.

    Science.gov (United States)

    de Kruijf, Willy J M; Verstraete, Jan; Neustadter, David; Corn, Benjamin W; Hol, Sandra; Venselaar, Jack L M; Davits, Rob J; Wijsman, Bart P; Van den Bergh, Laura; Budiharto, Tom; Oyen, Raymond; Haustermans, Karin; Poortmans, Philip M P

    2013-02-01

    To evaluate the performance and safety of a radiation therapy positioning system (RealEye) based on tracking a radioactive marker (Tracer) implanted in patients with localized prostate cancer. We performed a single-arm multi-institutional trial in 20 patients. The iridium-192 ((192)Ir)-containing Tracer was implanted in the patient together with 4 standard gold seed fiducials. Patient prostate-related symptoms were evaluated with the International Prostate Symptom Score (IPSS) questionnaire. Computed tomography (CT) was performed for treatment planning, during treatment, and after treatment to evaluate the migration stability of the Tracer. At 5 treatment sessions, cone beam CT was performed to test the positioning accuracy of the RealEye. The Tracer was successfully implanted in all patients. No device or procedure-related adverse events occurred. Changes in IPSS scores were limited. The difference between the mean change in Tracer-fiducial distance and the mean change in fiducial-fiducial distance was -0.39 mm (95% confidence interval [CI] upper boundary, -0.22 mm). The adjusted mean difference between Tracer position according to RealEye and the Tracer position on the CBCT for all patients was 1.34 mm (95% CI upper boundary, 1.41 mm). Implantation of the Tracer is feasible and safe. Migration stability of the Tracer is good. Prostate patients can be positioned and monitored accurately by using RealEye. Copyright © 2013 Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  20. Limitation of radioactive discharges from NPP based on radionuclide specific monitoring

    International Nuclear Information System (INIS)

    Bucina, I.; Malatova, I.; Vidlakova, J.

    1998-01-01

    Monitoring of gaseous and liquid discharges from nuclear power plants based on particulate-iodine-gas measurements and gross beta or gamma plus tritium measurements is being improved by performing radionuclide specific measurements using semiconductor gamma and beta spectrometers and radiochemical methods. A new concept of regulatory effluent limits is being developed. The activities of all the relevant radionuclides discharged during a years, multiplied by the appropriate Sv/Bq conversion coefficient based on a standard multi-pathway model, are summed up, and the effective dose is compared with the new limit. Such limits should be laid down as the per capita collective commitment effective dose in the plant surroundings for atmospheric discharges, and as the committed effective dose to a critical group member for the hydrospheric releases

  1. Radioactive waste management from nuclear facilities

    International Nuclear Information System (INIS)

    2005-06-01

    This report has been published as a NSA (Nuclear Systems Association, Japan) commentary series, No. 13, and documents the present status on management of radioactive wastes produced from nuclear facilities in Japan and other countries as well. Risks for radiation accidents coming from radioactive waste disposal and storage together with risks for reactor accidents from nuclear power plants are now causing public anxiety. This commentary concerns among all high-level radioactive waste management from nuclear fuel cycle facilities, with including radioactive wastes from research institutes or hospitals. Also included is wastes produced from reactor decommissioning. For low-level radioactive wastes, the wastes is reduced in volume, solidified, and removed to the sites of storage depending on their radioactivities. For high-level radioactive wastes, some ten thousand years must be necessary before the radioactivity decays to the natural level and protection against seismic or volcanic activities, and terrorist attacks is unavoidable for final disposals. This inevitably results in underground disposal at least 300 m below the ground. Various proposals for the disposal and management for this and their evaluation techniques are described in the present document. (S. Ohno)

  2. Treatment and conditioning of radioactive organic liquids

    International Nuclear Information System (INIS)

    1992-07-01

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

  3. Cement-based processes for the immobilization of intermediate level radioactive waste

    International Nuclear Information System (INIS)

    Brown, D.J.; Lee, D.J.; Price, M.S.T.; Smith, D.L.G.

    1985-01-01

    Increasing attention is being paid to the use of cement-based materials for the immobilisation of intermediate level wastes. Various cementitious materials are surveyed and the use of blast furnace slag is shown to be advantageous. The properties of cemented wastes are surveyed both during processing and as solid products. The application of Winfrith Cementation Laboratory technology to plant and flowsheet development for Winfrith Reactor sludge immobilisation is described. (author)

  4. Radioactivity telemetry

    International Nuclear Information System (INIS)

    Bouras, Florent; Legrand, Bernard; Montigaud, Jean-Marie; Grandin, Marc

    1969-05-01

    The authors present an assembly which aims at radio-transmitting from mobile stations information on radioactivity. It comprises 20 mobile stations which can be located within the Cadarache Centre or outside of it within a 10 km radius, and a central station which centralises information. The report proposes a general presentation of these stations, their characteristics and principles of operation. It describes operation sequences, central station functions (call programmer, address and memory management, recording, peripherals) and its energy supply, and mobile station functions. The last part presents the installation, its start-up and exploitation, its threshold devices and its safety device

  5. QED based on self-energy: The relativistic 2S1/2→1S1/2+1γ decay rates of hydrogenlike atoms

    International Nuclear Information System (INIS)

    Barut, A.O.; Salamin, Y.I.

    1991-01-01

    Within the framework of the recently advanced formulation of QED based on self-energy, we calculate the relativistic rates of the 2S 1/2 →1S 1/2 +1γ transition in the hydrogen isoelectronic sequence for values of Z ranging between 1 and 92. We compare our results with those of Johnson [Phys. Rev. Lett. 29, 1123 (1972)] and Parpia and Johnson [Phys. Rev. A 26, 1142 (1982)], analytically and numerically. Although the two approaches are quite different, the formulas for decay rates are shown to be equivalent

  6. Double beta radioactivity and physics of the neutrino. Study of the background noise at 3 MeV in the search of {sup 100}Mo beta beta decay; Double radioactivite beta et physique du neutrino. Etude du bruit de fond a 3 MeV dans la recherche de la desintegration beta beta du {sup 100}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Piquemal, F.

    1994-05-01

    Double beta decay without neutrino emission provides a test of the mass and nature of neutrinos (Majorana or Dirac). Experimental proof would be the observation of a peak at the transition energy in the spectrum of the two emitted electrons. The expected half-life of the process is extremely long (about 10{sup 25} years for {sup 100}Mo). So, being thus, it is very important to get a good knowledge of the origins and contributions of background noise in the region where the signal could occur. The main origins of the background noise in the region where the signal could occur. The main origins of the background noise are found to be e{sup +} - e{sup -} pairs induced by heavy energy gamma rays. These gamma rays follow the thermal neutron capture by the components of the detector. Another factor in the production of background noise is natural radio-activity. For example, the presence of Radon in the laboratory has been observed to produce deposits of {sup 214}Bi on the sides of the detector. Data taken with the NEMO 2 prototype and an enriched molybdenum source foil indicates that the background limit reached is of the order of 1 event per year in the 3 MeV region. Results of this work have proven the necessity to have a magnetic field in NEMO 3 in order to reject e{sup +} - e{sup -}pairs. (author).

  7. 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)

  8. Neutral atom traps of radioactives

    International Nuclear Information System (INIS)

    Behr, J.A.

    2003-01-01

    Neutral atoms trapped with modern laser cooling techniques offer the promise of improving several broad classes of experiments with radioactive isotopes. In nuclear β decay, neutrino spectroscopy from beta-recoil coincidences, along with highly polarized samples, enable experiments to search for non-Standard Model interactions, test whether parity symmetry is maximally violated, and search for new sources of time reversal violation. Ongoing efforts at TRIUMF, Los Alamos and Berkeley will be highlighted. The traps also offer bright sources for Doppler-free spectroscopy, particularly in high-Z atoms where precision measurements could measure the strength of weak neutral nucleon-nucleon and electron-nucleon interactions. Physics with francium atoms has been vigorously pursued at Stony Brook. Several facilities plan work with radioactive atom traps; concrete plans and efforts at KVI Groningen and Legnaro will be among those summarized. Contributions to the multidisciplinary field of trace analysis will be left up to other presenters

  9. Neutral atom traps of radioactives

    CERN Document Server

    Behr, J A

    2003-01-01

    Neutral atoms trapped with modern laser cooling techniques offer the promise of improving several broad classes of experiments with radioactive isotopes. In nuclear beta decay, neutrino spectroscopy from beta-recoil coincidences, along with highly polarized samples, enable experiments to search for non-Standard Model interactions, test whether parity symmetry is maximally violated, and search for new sources of time reversal violation. Ongoing efforts at TRIUMF, Los Alamos and Berkeley will be highlighted. The traps also offer bright sources for Doppler-free spectroscopy, particularly in high-Z atoms where precision measurements could measure the strength of weak neutral nucleon-nucleon and electron-nucleon interactions. Physics with francium atoms has been vigorously pursued at Stony Brook. Several facilities plan work with radioactive atom traps; concrete plans and efforts at KVI Groningen and Legnaro will be among those summarized. Contributions to the multidisciplinary field of trace analysis will be left...

  10. First observation of two-proton radioactivity of 45Fe

    International Nuclear Information System (INIS)

    Blank, B.; Giovinazzo, J.; Chartier, M.; Czajkowski, S.; Fleury, A.; Lalleman, A.S.; Jimenez, M.J. Lopez; Pravikoff, M.S.; Thomas, J.-C.; Pfuetzner, M.; Grzywacz, R.; Janas, Z.; Kurcewicz, J.; Badura, E.; Geissel, H.; Grigorenko, L.V.; Hellstroem, M.; Mazzocchi, C.; Mukha, I.; Muenzenberg, G.

    2003-01-01

    In experiments at the FRS of GSI and at the SISSI-LISE3 facility of GANIL, the decay of the proton drip-line nucleus 45Fe has been studied after projectile fragmentation of a 58Ni primary beam. Fragment-implantation events have been correlated with radioactive decay events in silicon telescopes on an event-by-event basis. The decay-energy spectrum of 45Fe implants shows a distinct peak consistent with a two-proton ground-state decay of 45Fe. None of the events in the peak were found to be in coincidence with γ radiation or with β particles which were searched for in the telescope-surrounding detectors. The decay energy for 45Fe agrees nicely with several theoretical predictions for two-proton emission. These predictions strongly support the observed decay to be a simultaneous two-proton ground-state decay

  11. Source of radioactivity in the ocean environment

    International Nuclear Information System (INIS)

    Solomon, K.A.

    1988-01-01

    This paper summarizes both natural and man-made radioactivity in the marine environment. Radioactivity occurs naturally in both the sea water and in the ocean sediment. Radioactivity in the sea water is fairly uniform geographically and is dominated by the naturally occurring isotope 40/K (potassium-40). Unlike sea water, sediment radiation levels vary with sediment type and location. The primary source of natural radiation in the sediment results from deposition of insoluble thorium isotopes formed by the decay of water-soluble uranium. Man-made sources of radioactivity arise from, in descending order of importance: - sinking of two U.S. and two Soviet nuclear submarines; fallout from nuclear weapons testing; dumping of primarily British and Americal low-level nuclear waste; and dumping of reprocessing plant radiated effluents from the British Windscale facility and other European and Indian reprocessing facilities. 1 table

  12. Radioactive wastes: sources, treatment, and disposal

    International Nuclear Information System (INIS)

    Wymer, R.G.; Blomeke, J.O.

    1975-01-01

    Sources, treatment, and disposal of radioactive wastes are analyzed in an attempt to place a consideration of the problem of permanent disposal at the level of established or easily attainable technology. In addition to citing the natural radioactivity present in the biosphere, the radioactive waste generated at each phase of the fuel cycle (mills, fabrication plants, reactors, reprocessing plants) is evaluated. The three treatment processes discussed are preliminary storage to permit decay of the short-lived radioisotopes, solidification of aqueous wastes, and partitioning the long-lived α emitters for separate and long-term storage. Dispersion of radioactive gases to the atmosphere is already being done, and storage in geologically stable structures such as salt mines is under active study. The transmutation of high-level wastes appears feasible in principle, but exceedingly difficult to develop

  13. First observation of two-proton radioactivity in 48Ni

    Energy Technology Data Exchange (ETDEWEB)

    Pomorski, M. [University of Warsaw; Pfutzner, M. [University of Warsaw; Dominik, W. [University of Warsaw; Grzywacz, Robert Kazimierz [ORNL; Baumann, T. [Michigan State University, East Lansing; Berryman, J. S. [Michigan State University, East Lansing; Czyrkowski, H. [University of Warsaw; Dabrowski, Ryszard [Warsaw University; Ginter, T. N. [Michigan State University, East Lansing; Johnson, James W [ORNL; Kaminski, A. [PAN, Krakow, Poland; Kuzniak, A. [University of Tennessee, Knoxville (UTK); Larson, N. [Michigan State University, East Lansing; Liddick, S. N. [Michigan State University, East Lansing; Madurga, M [University of Tennessee, Knoxville (UTK); Mazzocchi, C. [University of Warsaw; Miernik, K. [Oak Ridge National Laboratory (ORNL); Miller, D [University of Tennessee, Knoxville (UTK); Paulauskas, S. [University of Tennessee, Knoxville (UTK); Pereira, J. [National Superconducting Cyclotron Laboratory (NSCL); Rykaczewski, Krzysztof Piotr [ORNL; Stolz, A. [Michigan State University, East Lansing; Suchyta, S. [Michigan State University, East Lansing

    2011-01-01

    The decay of the extremely neutron deficient 48Ni was studied by means of an imaging time projection chamber which allowed the recording of tracks of charged particles. Decays of 6 atoms were observed. Four of them clearly correspond to two-proton radioactivity providing the first direct evidence for this decay mode in 48Ni. Two decays represent -delayed proton emission. The half-life of 48Ni is determined to be T1=2 = 2:1+1:4 0:4 ms.

  14. 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.

  15. Conception and design data of decay units in nuclear medical wards

    International Nuclear Information System (INIS)

    Strueter, H.D.; Hermsdorf, H.C.

    1981-01-01

    Authorities, users, and planners of sanitary equipment are given an insight into the various viewpoints of releasing radioactive effluents from the nuclear medical activities. Furthermore, a guideline for a reasonable establishing of nuclide-specific active effluents is shown which takes into consideration the legal and clinical concerns. In the second point, a modern, cost-saving technical solution is introduced which is based on an integrated compact decay storage concept (vacuum-toilet-system) which includes saving and controlling measures for water consumption. (DG) [de

  16. On the decay of homogeneous isotropic turbulence

    Science.gov (United States)

    Skrbek, L.; Stalp, Steven R.

    2000-08-01

    Decaying homogeneous, isotropic turbulence is investigated using a phenomenological model based on the three-dimensional turbulent energy spectra. We generalize the approach first used by Comte-Bellot and Corrsin [J. Fluid Mech. 25, 657 (1966)] and revised by Saffman [J. Fluid Mech. 27, 581 (1967); Phys. Fluids 10, 1349 (1967)]. At small wave numbers we assume the spectral energy is proportional to the wave number to an arbitrary power. The specific case of power 2, which follows from the Saffman invariant, is discussed in detail and is later shown to best describe experimental data. For the spectral energy density in the inertial range we apply both the Kolmogorov -5/3 law, E(k)=Cɛ2/3k-5/3, and the refined Kolmogorov law by taking into account intermittency. We show that intermittency affects the energy decay mainly by shifting the position of the virtual origin rather than altering the power law of the energy decay. Additionally, the spectrum is naturally truncated due to the size of the wind tunnel test section, as eddies larger than the physical size of the system cannot exist. We discuss effects associated with the energy-containing length scale saturating at the size of the test section and predict a change in the power law decay of both energy and vorticity. To incorporate viscous corrections to the model, we truncate the spectrum at an effective Kolmogorov wave number kη=γ(ɛ/v3)1/4, where γ is a dimensionless parameter of order unity. We show that as the turbulence decays, viscous corrections gradually become more important and a simple power law can no longer describe the decay. We discuss the final period of decay within the framework of our model, and show that care must be taken to distinguish between the final period of decay and the change of the character of decay due to the saturation of the energy containing length scale. The model is applied to a number of experiments on decaying turbulence. These include the downstream decay of turbulence in

  17. Decree no. 2003-30 of the 10 january 2003 authorizing the national agency for the radioactive wastes management (ANDRA) to modify, for the survey step, the radioactive wastes storage center of the Manche (base nuclear installation no. 66), located on the Digulleville municipality territory (Manche)

    International Nuclear Information System (INIS)

    2003-01-01

    This document, took out from the Official Journal, is the law text relative to the decree no. 2003-30 of the 10 january 2003 authorizing the national agency for the radioactive wastes management (ANDRA) to modify, for the survey step, the radioactive wastes storage center of the Manche (base nuclear installation no. 66), located on the Digulleville municipality territory (Manche). (A.L.B.)

  18. Rare B Decays in BABAR

    Energy Technology Data Exchange (ETDEWEB)

    Hicheur, A

    2004-08-25

    Measurements and searches for rare B decays have been performed with the BaBar detector at the PEP-II e{sup +}e{sup -} asymmetric B Factory, operating at the {Upsilon}(4S) resonance. The authors report some recent branching fraction measurements on hadronic and radiative B decays, occurring from b --> s/d and b --> u transitions. Most of the results presented here are based on a data sample corresponding to a luminosity of 81.9 fb{sup -1}.

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

    International Nuclear Information System (INIS)

    Wang, Q.

    2012-01-01

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

  20. Natural and Artificial Radioactivity in Drinking Water in Malaga, Spain

    International Nuclear Information System (INIS)

    Duenas, C.; Fernandez, M.C.; Gordo, E.; Canete, S.; Perez, M.

    2011-01-01

    Water has a vast importance for numerous human activities, so that securing supplies of drinking water of a standard quality is becoming more and more difficult. The measurement of radioactivity in drinking water permits us to determine the exposure of the population to radiation from the habitual consumption of water. The occurrence of radionuclides in drinking water gives rise to internal exposure of humans, directly on the decay of radionuclides taken into the body through ingestion and inhalation and indirectly when they are incorporated as part of the food-chain The measurement of radioactivity in drinking water permits us to determine the exposure of population to radiation from the habitual consumption of water. An intensive study of the water supply in the city of Malaga during 2002-2010 has been carried out in order to determine the gross alpha activities, gross beta activities and natural and artificial radionuclides present in drinking water. A data base on natural and artificial radioactivity in water was produced. The results indicated that a high percentage of the water sample contains a total gross alpha and beta less than 0.10 Bq/l and 1 Bq/l respectively. The main objectives were: 1) to analyses gross alpha and gross beta activities and to know the statistical distributions. 2) to study the levels of natural and artificial radionuclides 3) to determine a possible mathematical correlation between the radionuclides and several factors.

  1. Study of the radiation and radioactivity in dairy formulas

    International Nuclear Information System (INIS)

    Mireles G, F.; Pinedo V, J.L.; Quirino T, L.L.; Davila R, J.I.; Rios M, C.; Leal A, B.; Lopez del Rio, H.

    2006-01-01

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

  2. Time depending assessment of low and intermediate radioactive waste characteristics from Cernavoda NPP

    International Nuclear Information System (INIS)

    Mateescu, S.; Pantazi, D.; Stanciu, M.

    2002-01-01

    Low and intermediate radioactive gaseous, liquid and solid waste produced at Cernavoda Nuclear Power Plant must be well known from the point of view of contained radionuclide activity, during all steps of their processing, storage and transport, to ensure the nuclear safety of radioactive waste management. As in intermediate storage stage, the waste activity changes by radioactive decay and nuclear transmutation, the evolution in time of these sources is necessary to be assessed, for the purpose of biological shielding determination at any time. On the other hand, during the transport of waste package at the repository, the external dose rates must meet the national and international requirements concerning radioactive materials transportation on public roads. In this paper, a calculation methodology for waste characterization based on external exposure rate measurement and on sample analysis results is presented. The time evolution of waste activity, as well as the corresponding shielding at different moments of management process, have been performed using MICROSHIELD-5 code. The spent resins proceeded from clean-up and purification systems and solutions from decontamination have been analyzed. The proposed methodology helps us to assess radiation protection during the handling of low and intermediate - level radioactive waste drums, ensuring safety conditions for the public and environment.(author)

  3. Radioactive material air transportation

    International Nuclear Information System (INIS)

    Pader y Terry, Claudio Cosme

    2002-01-01

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

  4. Rare decay searches at CDF

    Energy Technology Data Exchange (ETDEWEB)

    Maestro, Paolo [Siena U.

    2012-07-01

    In the last decade the CDF experiment at the Tevatron clearly demonstrated that it is possible to study extensively heavy flavour physics in hadron collisions and achieve remarkable results, competitive and complementary to $B$-factories. In this paper we report on the indirect searches for physics beyond the standard model via measurements of rare $b$-hadron decays. The final limits, based on the analysis of the full CDF data set, on the branching fraction of the $B^0_{(s)}$ decay into a pair of muons are presented and discussed. Moreover we review the latest measurements, with 6.8 fb$^{-1}$ of collected data, of the total and differential branching fractions and angular observables of rare $b$-hadron decays proceeding via the flavour-changing neutral-current process $b \\rightarrow s \\mu^+ \\mu^-$. PACS numbers: 13.20.He, 13.30.-a, 12.15.Mn

  5. Observable signatures of inflaton decays

    Energy Technology Data Exchange (ETDEWEB)

    Battefeld, Diana; Battefeld, Thorsten [Institute for Astrophysics, University of Goettingen, Friedrich Hund Platz 1, D-37077 Gottingen (Germany); Giblin, John T. Jr.; Pease, Evan K., E-mail: dbattefe@astro.physik.uni-goettingen.de, E-mail: tbattefe@astro.physik.uni-goettingen.de, E-mail: giblinj@kenyon.edu, E-mail: peasee@kenyon.edu [Department of Physics, Kenyon College, Gambier, OH 43022, U.S.A (United States)

    2011-02-01

    We numerically compute features in the power-spectrum that originate from the decay of fields during inflation. Using a simple, phenomenological, multi-field setup, we increase the number of fields from a few to thousands. Whenever a field decays, its associated potential energy is transferred into radiation, causing a jump in the equation of state parameter and mode mixing at the perturbed level. We observe discrete steps in the power-spectrum if the number of fields is low, in agreement with analytic arguments in the literature. These features become increasingly smeared out once many fields decay within a given Hubble time. In this regime we confirm the validity of the analytic approach to staggered inflation, which is based on a coarse-graining procedure. Our numerical approach bridges the aforementioned analytic treatments, and can be used in more complicated scenarios.

  6. Constraining neutrinoless double beta decay

    International Nuclear Information System (INIS)

    Dorame, L.; Meloni, D.; Morisi, S.; Peinado, E.; Valle, J.W.F.

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-11

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

  8. Beta decay of highly charged ions

    International Nuclear Information System (INIS)

    Litvinov, Yuri A; Bosch, Fritz

    2011-01-01

    Beta decay of highly charged ions has attracted much attention in recent years. An obvious motivation for this research is that stellar nucleosynthesis proceeds at high temperatures where the involved atoms are highly ionized. Another important reason is addressing decays of well-defined quantum-mechanical systems, such as one-electron ions where all interactions with other electrons are excluded. The largest modifications of nuclear half-lives with respect to neutral atoms have been observed in beta decay of highly charged ions. These studies can be performed solely at ion storage rings and ion traps, because there high atomic charge states can be preserved for extended periods of time (up to several hours). Currently, all experimental results available in this field originate from experiments at the heavy-ion complex GSI in Darmstadt. There, the fragment separator facility FRS allows the production and separation of exotic, highly charged nuclides, which can then be stored and investigated in the storage ring facility ESR. In this review, we present and discuss in particular two-body beta decays, namely bound-state beta decay and orbital electron capture. Although we focus on experiments conducted at GSI, we will also attempt to provide general requirements common to any other experiment in this context. Finally, we address challenging but not yet performed experiments and we give prospects for the new radioactive beam facilities, such as FAIR in Darmstadt, IMP in Lanzhou and RIKEN in Wako.

  9. Rare B Decays at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Datta, M

    2005-03-14

    The authors present recent results on rare B meson decays based on data taken by the BABAR detector at the PEP-II asymmetric e{sup +}e{sup -} collider. Included in this report are measurements of branching fractions and other quantities of interest for several hadronic, radiative, electroweak, and purely leptonic decays of B mesons.

  10. Development of probabilistic assessment methodology for geologic disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Kimura, H.; Takahashi, T.

    1998-01-01

    The probabilistic assessment methodology is essential to evaluate uncertainties of long-term radiological consequences associated with geologic disposal of radioactive wastes. We have developed a probabilistic assessment methodology to estimate the influences of parameter uncertainties/variabilities. An exposure scenario considered here is based on a groundwater migration scenario. A computer code system GSRW-PSA thus developed is based on a non site-specific model, and consists of a set of sub modules for sampling of model parameters, calculating the release of radionuclides from engineered barriers, calculating the transport of radionuclides through the geosphere, calculating radiation exposures of the public, and calculating the statistical values relating the uncertainties and sensitivities. The results of uncertainty analyses for α-nuclides quantitatively indicate that natural uranium ( 238 U) concentration is suitable for an alternative safety indicator of long-lived radioactive waste disposal, because the estimated range of individual dose equivalent due to 238 U decay chain is narrower that that due to other decay chain ( 237 Np decay chain). It is internationally necessary to have detailed discussion on the PDF of model parameters and the PSA methodology to evaluated the uncertainties due to conceptual models and scenarios. (author)

  11. Fine structure in the cluster decays of the translead nuclei

    International Nuclear Information System (INIS)

    Dumitrescu, O.; Cioaca, C.

    1994-06-01

    Within the one level R-matrix approach several hindrance factors for the radioactive decays in which are emitted α and other nuclei (such as 14 C and 20 O) are calculated. The interior wave functions are supposed to be given by the shell model with effective residual interactions. The exterior wave functions are calculated from a cluster - nucleus double - folding model potential with the M3Y interaction. As examples of the cluster decay fine structure we analyzed the particular cases of α - decay of 255 Fm, 14 C - decay of 223 Ra and 20 O - decay of 229 Th and 225 Fm. Good agreement with the experimental data is obtained. (author). 38 refs, 6 tabs

  12. Environmental radioactivity. Measurement and monitoring

    International Nuclear Information System (INIS)

    2009-11-01

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

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

    International Nuclear Information System (INIS)

    Berner, Urs

    1999-12-01

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

  14. An FPGA-based trigger system for the search of μ+→e++γ decay in the MEG experiment

    International Nuclear Information System (INIS)

    Galli, L; Cei, F; Galeotti, S; Magazzù, C; Morsani, F; Nicolò, D; Signorelli, G; Grassi, M

    2013-01-01

    The MEG experiment at PSI aims at investigating the μ + → e + + γ decay with improved sensitivity on the branching ratio (BR) by two orders of magnitude with respect to the previous experimental limit (BR(μ + → e + + γ) ≈ 10 −13 ). The use of the most intense continuous muon beam world wide ( ≈ 10 8 μ/s) to search for such a rare event must be accompanied by an efficient trigger system, able to suppress the huge beam-related background to sustainable rates while preserving the efficiency on signal close to unity. In order to accomplish both objectives, a digital approach was exploited by means of Field Programmable Gate Arrays (FPGA), working as a real-time processors of detector signals to perform an accurate event reconstruction within a 450 ns latency. This approach eventually turned out to be flexible enough to allow us to record calibration events in parallel with the main data acquisition and monitor the detector behavior throughout the data taking. We describe here the hardware implementation of the trigger and its main features as well: signal digitization, online waveform processing, reconstruction algorithms. A detailed description is given of the system architecture, the feature of the boards and their use. The trigger algorithms will be described in details in a dedicated article to be published afterwards.

  15. The management of radioactive waste

    International Nuclear Information System (INIS)

    1991-08-01

    One of the key questions asked about nuclear power production is whether the industry can manage its waste safely and economically. Management must take account of long term safety, since some radioisotopes take a very long time to decay. This long term decay, which can take millions of years, focused attention for the first time on the need for some wastes to be managed for a very long time beyond the lifetime of those who generated the waste. This paper reviews what the different types of waste are, what the technical consensus is on the requirements for their safe management, and how the present state of knowledge developed. It describes how radioactive waste management is practised and planned within the fuel cycle and indicates the moderate scale of the costs in relation to the total cost of producing electricity. Country annexes give more information about what is being done in a selection of countries, in order to indicate how radioactive waste management is carried out in practice. (Author)

  16. Spectrometry techniques for radioactivity measurements

    International Nuclear Information System (INIS)

    Anilkumar, S.

    2016-01-01

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

  17. Rare Decays at LHCb

    Science.gov (United States)

    Hall, Sam

    2014-04-01

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

  18. Regulation of radioactive waste management

    International Nuclear Information System (INIS)

    2002-01-01

    This bulletin contains information about activities of the Nuclear Regulatory Authority of the Slovak Republic (UJD). In this leaflet the regulation of radioactive waste management of the UJD are presented. Radioactive waste (RAW) is the gaseous, liquid or solid material that contains or is contaminated with radionuclides at concentrations or activities greater than clearance levels and for which no use is foreseen. The classification of radioactive waste on the basis of type and activity level is: - transition waste; - short lived low and intermediate level waste (LlLW-SL); - long lived low and intermediate level waste (LlLW-LL); - high level waste. Waste management (in accordance with Act 130/98 Coll.) involves collection, sorting, treatment, conditioning, transport and disposal of radioactive waste originated by nuclear facilities and conditioning, transport to repository and disposal of other radioactive waste (originated during medical, research and industrial use of radioactive sources). The final goal of radioactive waste management is RAW isolation using a system of engineered and natural barriers to protect population and environment. Nuclear Regulatory Authority of the Slovak Republic regulates radioactive waste management in accordance with Act 130/98 Coll. Inspectors regularly inspect and evaluate how the requirements for nuclear safety at nuclear facilities are fulfilled. On the basis of safety documentation evaluation, UJD issued permission for operation of four radioactive waste management facilities. Nuclear facility 'Technologies for treatment and conditioning contains bituminization plants and Bohunice conditioning centre with sorting, fragmentation, evaporation, incineration, supercompaction and cementation. Final product is waste package (Fibre reinforced container with solidified waste) acceptable for near surface repository in Mochovce. Republic repository in Mochovce is built for disposal of short lived low and intermediate level waste. Next

  19. β-Decay and the electric dipole moment: Searches for time-reversal ...

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... -Decay and the electric dipole moment: Searches for time-reversal violation in radioactive nuclei and atoms. 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. Physics with Radioactive Ion Beams Volume 75 Issue 1 July 2010 pp ...

  20. Cluster decay of Ba isotopes from ground state and as an excited ...

    Indian Academy of Sciences (India)

    In 1984, Rose and. Jones [2] experimentally observed this phenomenon in the radioactive decay of 223Ra by emitting 14C. Much efforts have been done on both experimental and theoretical fronts. Pramana – J. Phys. ... radioactive parents, the 12C emission from 112−120Ba nuclei has been subjected to many theoretical ...

  1. Decay energy of Fe from its inner Bremsstrahlung spectrum

    Indian Academy of Sciences (India)

    The inner Bremsstrahlung (IB) with reference to electron capture radioactive decay is a higher order process in which the orbital electron capture process will be accompanied by the emission of a continuous spectrum of electromagnetic radiation. This process is also called as 'radiative electron capture'. The energy ...

  2. Status of μ decays

    International Nuclear Information System (INIS)

    Kinnison, W.W.

    1983-01-01

    A short theoretical review of the weak interaction is presented with particular emphasis on the implications to normal and rare muon decay processes. This review addresses the standard theory, left-right symmetry theories, theories with horizontal symmetries, and composite models. A survey of experiments currently in progress to study both rare and normal muon decays is then presented with particular emphasis on the Los Alamos high statistics muon decay experiment and its implications for left-right symmetric theories. 16 references

  3. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    2012-10-06

    Oct 6, 2012 ... nuclear decay of neutrinoless double beta decay typically leading to sub-eV values as well. (Z, A) → (Z + 2, A) + 2e .... Here again energy resolution matters, because of the continuous spectrum of the 2νββ- decay mode, its high .... The benefit of using Te is its high natural abundance. This experiment is in ...

  4. 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.)

  5. Axigluon decays of toponium

    International Nuclear Information System (INIS)

    Faustov, R.N.; Vasilevskaya, I.G.

    1990-01-01

    Chiral-colour model predicts the existence of axigluons which is an octet of massive axial-vector gauge bosons. In this respect toponium decays into axigluons and gluons are of interest. The following toponium decays are considered: θ → Ag, θ → AAg, θ → ggg → AAg. The width of toponium S-state decays is calculated under various possible values of axigluon mass

  6. Radioactive ores from Agostinho field, Pocos de Caldas (MG), Brazil

    International Nuclear Information System (INIS)

    Fujimori, K.

    1974-01-01

    Aiming to characterize the radioactive minerals of Campo Agostinho, Pocos de Caldas - Brazil, the survey of all natural radiactive elements and their geochemical behaviors, decays and radioactive equilibrium was done. Several models of radioactive instability of the minerals or the radioactive samples were proposed to characterize the geochemistry and the mineralization of radioactive elements. The complete isotopic analysis of the elements was done by high resolution gamma spectrometry, using a Ge(Li) detector, at the temperature of liquid nitrogen, coupled to a multichannel analyser. The sample in radioactive equilibrium of Atomic Energy Comission of United States - A.S. n.6, NBL - New Brunswick Laboratory, was considered as standard sample. Fluorite, zircons, pirite, molibinite, rutile, anatase, niobophyllite, and in small ratio (bellow 0.1%) uranothorianite, coffinite, pyrochlore, monazite and apatite. (M.C.K.) [pt

  7. Security of Radioactive Waste

    International Nuclear Information System (INIS)

    Goldammer, W.

    2003-01-01

    Measures to achieve radioactive waste security are discussed. Categorization of waste in order to implement adequate and consistent security measures based on potential consequences is made. The measures include appropriate treatment/storage/disposal of waste to minimize the potential and consequences of malicious acts; management of waste only within an authorised, regulated, legal framework; management of the security of personnel and information; measures to minimize the acquisition of radioactive waste by those with malicious intent. The specific measures are: deter unauthorized access to the waste; detect any such attempt or any loss or theft of waste; delay unauthorized access; provide timely response to counter any attempt to gain unauthorised access; measures to minimize acts of sabotage; efforts to recover any lost or stolen waste; mitigation and emergency plans in case of release of radioactivity. An approach to develop guidance, starting with the categorisation of sources and identification of dangerous sources, is presented. Dosimetric criteria for internal and external irradiation are set. Different exposure scenarios are considered. Waste categories and security categories based on the IAEA INFCIRC/225/Rev.4 are presented

  8. Natural radioactivity of wastes

    International Nuclear Information System (INIS)

    Zak, A.; Isajenko, K.; Piotrowska, B.; Kuczbajska, M.; Zabek, A.; Szczygielski, T.

    2010-01-01

    By-products of the combustion of coal (wastes) are often used for various types of construction (dwellings, roads, etc.). The legal regulations (The Ordinance of the Council of Ministers of 2 January 2007 'On the requirements for the content of natural radioactive isotopes of potassium K-40, radium Ra-226 and thorium Th-228 in raws and materials used in buildings for the residence of people and livestock, as well as in the industrial by-products used in the construction, and the control of the content of the aforementioned isotopes' - Law Gazette no. 4/2007 item 29) are in force in Poland. The regulations permit the possibility of utilization of raws and by-products basing upon the level of the natural radioactivity of the examined raws and materials. The article is a survey of the results obtained during the measurements of many types of raws and building materials for almost 30 years by the network of the laboratories in Poland. It is based upon the results stored in the database of the Central Laboratory for Radiological Protection (CLRP), Warsaw. The article tends to outline the radioactivity of the waste materials with respect to other raws and materials used in the construction industry. The article shows the possibilities for the use of by-products originating in the power stations and heat- and power stations (mainly ashes, slag and hinter) in the construction of dwellings and roads. (authors)

  9. Rare Kaon Decays

    International Nuclear Information System (INIS)

    Kudenko, Y.

    1999-01-01

    The past few years have seen an evolution in the study of rare K decays from a concentration on explicitly Standard Model (SM) violating decays such as K L 0 → μe, to one on SM-allowed but suppressed decays such as K → πν| ν, in which short-distance interactions are dominant. There are also a number of recent experimental and theoretical studies of long-distance-dominated decays, but they do not have space to cover these, with the exception of those that are needed in the discussion of the short-distance-dominated processes

  10. Deviations from exponential decay

    Science.gov (United States)

    Petridis, Athanasios; Staunton, Lawrence; Luban, Marshall; Vermedahl, Jon

    2003-10-01

    We study deviations from exponetial decay in cases when the initial wavefunction is set in a potential well and is not an eigenstate of this potential. We numerically solve the time-dependent Schroedinger equation and observe a decaying but oscillatory behavior of the survival probability. Analytical calculations have been performed proving that even in the case of a simple finite square-well potential deviations from exponential decay persist for large times. Possible explanations for the limiting exponential decay for many-particle systems are developed.

  11. A New Approach for the Determination of Dose Rate and Radioactivity for Detected Gamma Nuclides Using an Environmental Radiation Monitor Based on an NaI(Tl) Detector.

    Science.gov (United States)

    Ji, Young-Yong; Kim, Chang-Jong; Lim, Kyo-Sun; Lee, Wanno; Chang, Hyon-Sock; Chung, Kun Ho

    2017-10-01

    To expand the application of dose rate spectroscopy to the environment, the method using an environmental radiation monitor (ERM) based on a 3' × 3' NaI(Tl) detector was used to perform real-time monitoring of the dose rate and radioactivity for detected gamma nuclides in the ground around an ERM. Full-energy absorption peaks in the energy spectrum for dose rate were first identified to calculate the individual dose rates of Bi, Ac, Tl, and K distributed in the ground through interference correction because of the finite energy resolution of the NaI(Tl) detector used in an ERM. The radioactivity of the four natural radionuclides was then calculated from the in situ calibration factor-that is, the dose rate per unit curie-of the used ERM for the geometry of the ground in infinite half-space, which was theoretically estimated by Monte Carlo simulation. By an intercomparison using a portable HPGe and samples taken from the ground around an ERM, this method to calculate the dose rate and radioactivity of four nuclides using an ERM was experimentally verified and finally applied to remotely monitor them in real-time in the area in which the ERM had been installed.

  12. Decays of the vector glueball

    Science.gov (United States)

    Giacosa, Francesco; Sammet, Julia; Janowski, Stanislaus

    2017-06-01

    We calculate two- and three-body decays of the (lightest) vector glueball into (pseudo)scalar, (axial-)vector, as well as pseudovector and excited vector mesons in the framework of a model of QCD. While absolute values of widths cannot be predicted because the corresponding coupling constants are unknown, some interesting branching ratios can be evaluated by setting the mass of the yet hypothetical vector glueball to 3.8 GeV as predicted by quenched lattice QCD. We find that the decay mode ω π π should be one of the largest (both through the decay chain O →b1π →ω π π and through the direct coupling O →ω π π ). Similarly, the (direct and indirect) decay into π K K*(892 ) is sizable. Moreover, the decays into ρ π and K*(892 )K are, although subleading, possible and could play a role in explaining the ρ π puzzle of the charmonium state ψ (2 S ) thanks to a (small) mixing with the vector glueball. The vector glueball can be directly formed at the ongoing BESIII experiment as well as at the future PANDA experiment at the FAIR facility. If the width is sufficiently small (≲100 MeV ) it should not escape future detection. It should be stressed that the employed model is based on some inputs and simplifying assumptions: the value of glueball mass (at present, the quenched lattice value is used), the lack of mixing of the glueball with other quarkonium states, and the use of few interaction terms. It then represents a first step toward the identification of the main decay channels of the vector glueball, but shall be improved when corresponding experimental candidates and/or new lattice results will be available.

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

    International Nuclear Information System (INIS)

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

    1989-01-01

    On the basis of the definition of high-level wastes (HLW) in the Nuclear Waste Policy Act of 1982 and previous descriptions of reprocessing wastes, a definition is proposed based on the concept that HLW is any waste which is highly radioactive and requires permanent isolation. This conceptual definition of HLW leads to a two-dimensional waste classification system in which one axis, related to 'highly radioactive', is associated with shorter-term risks from waste management and disposal due to high levels of decay heat and external radiation, and the other axis, related to 'requires permanent isolation', is associated with longer-term risks from waste disposal. Wastes that are highly radioactive are defined quantitatively as wastes with a decay heat (power density) greater than 50 W/m 3 or an external dose-equivalent rate greater than 100 rem/h (1 Sv/h) at a distance of 1 m from the waste, whichever is more restrictive. Wastes that require permanent isolation are defined quantitatively as wastes with concentrations of radionuclides greater than the Class-C limits that are generally acceptable for near-surface land disposal, as obtained from the Nuclear Regulatory Commission's 10 CFR Part 61 and its associated methodology. This proposal leads to similar definitions of two other waste classes: transuranic (TRU) waste and equivalent is any waste that requires permanent isolation but is not highly radioactive; and low-level waste (LLW) is any waste that does not require permanent isolation, without regard to whether or not it is highly radioactive. 31 refs.; 3 figs.; 4 tabs

  14. Disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Blomeke, J.O.

    1979-01-01

    Radioactive waste management and disposal requirements options available are discussed. The possibility of beneficial utilization of radioactive wastes is covered. Methods of interim storage of transuranium wastes are listed. Methods of shipment of low-level and high-level radioactive wastes are presented. Various methods of radioactive waste disposal are discussed

  15. 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)

  16. Radioactive preparation of defects in solids

    International Nuclear Information System (INIS)

    Lambe, J.

    1962-01-01

    One of the major areas of interest in solid state physics is the study of defects in nearly perfect crystals. The controlled formation of such defects is thus an important aspect of these studies. Chemical additions and radiation damage are among the techniques which have been widely used to make such defects. In the present work some possibilities have been examined of using radioactive decay to form defects in solids. The technique is simply to make as perfect a material as possible but with some of the host crystal atoms radioactive. When these atoms decay the daughter product essentially forms the defect. As a simple means of testing the feasibility of this technique, it was used to prepare tritium atoms trapped in a crystal of solid molecular tritium. The experiments indicate that the technique is feasible and should have particular application to the preparation of free radicals in organic materials which are fairly resistant to radiation damage. (author) [fr

  17. On the strategies for radioactive waste management in Vietnam

    International Nuclear Information System (INIS)

    Tran Hong Ha; Kenji shimooka

    2002-01-01

    Arising of radioactive waste and the current status of radioactive waste management in Vietnam are analyzed, addressing the need for the establishment of a national managerial system for radioactive waste. Based upon the objective and principles of radioactive waste management, which are international agreed on, key matters of a national framework for radioactive waste management are presented, including such principal aspects of waste management as policy, national system, strategies and allocation of responsibilities. (Author)

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

    International Nuclear Information System (INIS)

    Venn, J.B.

    1982-02-01

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

  19. Identification of heavy and radioactive metals in drinking water by an indirect analysis method based on scale tests

    International Nuclear Information System (INIS)

    Rajkovic, M.; Lacnjevac, C.; Stojanovic, M.; Toskovic, D.; Pantelic, G.; Jovanic, S.

    2009-01-01

    Full text of publication follows: The analysis of water quality, regarding the content of metals, especially heavy and radioactive ones, has been carried out in an indirect way, by testing scale formed in a hot-water heater, using water from the water-supply network of the city of Belgrade - the district of New Belgrade. The determination of the composition and the structure of the scale has resulted in its complete identification, and its crystallochemical formula has been defined. It has unequivocally been established that the obtained results are within the tolerance boundary with the results acquired by a conventional analysis of water, when it is a matter of very low concentrations. The presence of radioactive elements of uranium and strontium in a scale sample has been found and the way of their penetrating its composition and structure has been explained. Applying the fractional extraction method, uranium has been established to be of an anthropogenic origin

  20. Radioactive pollution

    International Nuclear Information System (INIS)

    Pohl, R.O.

    1976-01-01

    The widely published claims that the public health effects resulting from routine emissions are between 0.01 and 0.1 serious health effects per gigawattyear, and hence are at least a thousand times smaller than those resulting from air pollution by the burning of coal, cannot be true, for two reasons. The authors of these claims have ignored at least two of the more important isotopes, radon-222 and carbon-14, which are presently released to the environment, and thus contribute greatly to the health impact of nuclear energy. The health effects calculated in the earlier work cover only those which occur during the year in which the energy is generated. This means, figuratively speaking, that the authors have confused an annual installment payment with the full cost. This is unacceptable. The contribution to the health impact of nuclear energy arising from the single isotopic species radon-222 emanating from the mill tailings is estimated to 400 lung cancer deaths/GW(e)y, larger even than the most pessimistic estimates of the health impact of energy from coal through atmospheric pollution. We have no assurance that other long-lived isotopes do not contribute comparable amounts to the health impact of nuclear energy. The discussion of the health impact of radon-222 raises the fundamental moral question--how far into the future our responsibility extends. If such a long-termresponsibility is rejected, then we must at least try to predict the environmental buildup of radioactive pollutants, in order to avoid unacceptable and irreversible levels of radiation dose rate. The potential health consequences from long-lived radioisotopes seem to have been largely ignored so far, and should be explored in detail

  1. Radioactive waste generation in the nuclear reactors in Romania

    International Nuclear Information System (INIS)

    Popescu, I.V.

    2002-01-01

    The successful use of nuclear fission as major source of energy for this century is based upon the technological capabilities acquired to face the issue of radioactive waste and spent fuel. The management of radioactive waste is complex and implies solving the following major problems: - isolation of the radioisotopes from the complex of effluents released in the environment; - processing the separated radioisotopes for subsequent storing and final disposal; - transport of processed and conditioned wastes towards disposal repository; - selecting the sites for storage and final disposal. During reactor operation liquid and gaseous effluents are released to the environment as well as radioactive materials. All these may have an dangerous impact upon the environment when the international regulations, i.e. the ALARA principle are not strictly observed. The maximal values for the radioactive release are established by national regulations which are concordant with the IAEA principles. The amount of radioactive materials released depends of the reactor type and the measures adopted to reduce these releases. The average values of these releases during the normal operation of the reactor constitute the 'source term'. Its calculation implies several factors such as: the reactor type; the radionuclide concentration in the primary cooling systems; the transport mechanisms and leaks resulting in liquid and gaseous radionuclide emissions; the efficiency of the barriers and engineered safety systems built to reduce the amounts of radionuclide in the effluents. The concentration of radionuclides in the primary cooling circuit depends on the reactor power level, fuel burnup, fuel sheath type, tightness of the fuel cans, impurity concentration, chemical additives in the fluid of the primary cooling system, the total volume of this fluid, as well as its purification system. The methods applied to facilitate the calculation of the source term are described. In 1998 the spent fuel

  2. Did you know, … Amazing facts on radioactivity and waste disposal

    International Nuclear Information System (INIS)

    2013-05-01

    This brochure published by the Swiss National Cooperative for the Disposal of Radioactive Waste (NAGRA) provides some interesting information on several themes regarding radioactivity. Under the title of ‘Did you know that…’ various lesser-known facts on radioactivity are examined. These include information on radiation emitted by men and women, radioactive radon in buildings as well as the use of radiation to make pepper and spices non-perishable. Also, the use of radioactivity in medicine is discussed. Radioactivity in the earth’s core as the source of geothermal energy is also looked at, as is radioactivity in rock. Also, rock as a material used to screen ionizing radiation sources such as radioactive wastes is discussed. Finally, the time scales involved in radioactive decay are discussed

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

    International Nuclear Information System (INIS)

    Wu Xue-Dong; Liu Wei-Ting; Zhu Zhi-Yu; Wang Yao-Nan

    2011-01-01

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

  4. Development of computer-based function to estimate radioactive source term by coupling atmospheric model with monitoring data

    International Nuclear Information System (INIS)

    Akiko, Furuno; Hideyuki, Kitabata

    2003-01-01

    Full text: The importance of computer-based decision support systems for local and regional scale accidents has been recognized by many countries with the experiences of accidental atmospheric releases of radionuclides at Chernobyl in 1986 in the former Soviet Union. The recent increase of nuclear power plants in the Asian region also necessitates an emergency response system for Japan to predict the long-range atmospheric dispersion of radionuclides due to overseas accident. On the basis of these backgrounds, WSPEEDI (Worldwide version of System for Prediction of Environmental Emergency Dose Information) at Japan Atomic Energy Research Institute is developed to forecast long-range atmospheric dispersions of radionuclides during nuclear emergency. Although the source condition is critical parameter for accurate prediction, it is rarely that the condition can be acquired in the early stage of overseas accident. Thus, we have been developing a computer-based function to estimate radioactive source term, e.g. the release point, time and amount, as a part of WSPEEDI. This function consists of atmospheric transport simulations and statistical analysis for the prediction and monitoring of air dose rates. Atmospheric transport simulations are carried out for the matrix of possible release points in Eastern Asia and possible release times. The simulation results of air dose rates are compared with monitoring data and the best fitted release condition is defined as source term. This paper describes the source term estimation method and the application to Eastern Asia. The latest version of WSPEEDI accommodates following two models: an atmospheric meteorological model MM5 and a particle random walk model GEARN. MM5 is a non-hydrostatic meteorological model developed by the Pennsylvania State University and the National Center for Atmospheric Research (NCAR). MM5 physically calculates more than 40 meteorological parameters with high resolution in time and space based an

  5. Rare decays at LHCb

    CERN Document Server

    Adrover Pacheco, Cosme

    2012-01-01

    Rare decays are excellent tests to infer the presence of physics beyond the Standard Model (BSM), as they occur through processes prohibited at tree level in the SM. Any deviation from the SM prediction in branching fraction or angular distributions of such decays can lead to indications of new physics.

  6. Aspects of B decays

    International Nuclear Information System (INIS)

    Faller, Sven

    2011-01-01

    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 → D (*) l anti ν 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 → D (*) l anti ν 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 0 s →J/ψφ and B 0 →J/ψK S,L decays discussing CP violating effects in the time-dependent decay amplitudes by considering new physics phase in the B 0 - anti B 0 mixing phase. (orig.)

  7. Induced nuclear beta decay

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1986-01-01

    Certain nuclear beta decay transitions normally inhibited by angular momentum or parity considerations can be induced to occur by the application of an electromagnetic field. Such decays can be useful in the controlled production of power, and in fission waste disposal

  8. Multiple preequilibrium decay processes

    International Nuclear Information System (INIS)

    Blann, M.

    1987-11-01

    Several treatments of multiple preequilibrium decay are reviewed with emphasis on the exciton and hybrid models. We show the expected behavior of this decay mode as a function of incident nucleon energy. The algorithms used in the hybrid model treatment are reviewed, and comparisons are made between predictions of the hybrid model and a broad range of experimental results. 24 refs., 20 figs

  9. B decays to baryons

    Indian Academy of Sciences (India)

    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.

  10. Chapter 3: Wood Decay

    Science.gov (United States)

    Dan Cullen

    2014-01-01

    A significant portion of global carbon is sequestered in forest systems. Specialized fungi have evolved to efficiently deconstruct woody plant cell walls. These important decay processes generate litter, soil bound humic substances, or carbon dioxide and water. This chapter reviews the enzymology and molecular genetics of wood decay fungi, most of which are members of...

  11. Cavities/Tooth Decay

    Science.gov (United States)

    ... a process that occurs over time. Here's how tooth decay develops: Plaque forms. Dental plaque is a clear sticky film that coats ... by a lack of saliva, which helps prevent tooth decay by washing away food and plaque from your teeth. Substances found in saliva also help counter the ...

  12. Mixed incineration of RAIW and liquid scintillator waste after storage for decay

    International Nuclear Information System (INIS)

    Naba, K.; Nakazato, K.; Kataoka, K.

    1993-01-01

    Most medical radioactive waste is combustible after radioactive decay. Moreover mixed incineration of LLW with biomedical radioactive waste will lessen radiation exposure to the public. This paper describes the total system flowsheet for the processing of liquid scintillator wastes and radioimmunoassay tube wastes containing iodine 125 (after a two-year storage for decay). The process was tested with a 60 kg/hr capacity incinerator from 1987 to 1991; this has been upgraded to a 150 kg/hr incinerator which is used for nonradioactive biomedical waste incineration as well

  13. Decay of hypernuclei

    International Nuclear Information System (INIS)

    Bando, H.

    1985-01-01

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

  14. Indirect estimation of radioactivity in containerized cargo

    International Nuclear Information System (INIS)

    Jarman, K.D.; Scherrer, C.; Smith, L.E.; Chilton, L.K.; Anderson, K.K.; Ressler, J.J.; Trease, L.L.

    2011-01-01

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

  15. Towards a theory of weak hadronic decays of charmed particles

    International Nuclear Information System (INIS)

    Blok, B.Yu.; Shifman, M.A.

    1986-01-01

    Weak decays of charmed mesons are considered. A new quantitative framework for theoretical analysis of nonleptonic two-body decays based on the QCD sum rules are proposed. This is the first of a series of papers devoted to the subject. Theoretical foundations of the approach ensuring model-independent predictions for the partial decay widths are discussed

  16. Semileptonic B-meson decays in SU(3)

    International Nuclear Information System (INIS)

    Li Zuohong; Hou Yunzhi

    1994-01-01

    Based on the SU(3) approximate symmetry in the strong interaction three-body and four-body semileptonic B-meson decays are analyzed. Relations between decay rates are derived. Some of these relations may provide information on the nature of various competing dynamical effects that can occur in semileptonic B-meson decays

  17. Development of an application simulating radioactive sources; Conception d'une application de simulation de sources radioactives

    Energy Technology Data Exchange (ETDEWEB)

    Riffault, V.; Locoge, N. [Ecole des Mines de Douai, Dept. Chimie et Environnement, 59 - Douai (France); Leblanc, E.; Vermeulen, M. [Ecole des Mines de Douai, 59 (France)

    2011-05-15

    This paper presents an application simulating radioactive gamma sources developed in the 'Ecole des Mines' of Douai (France). It generates raw counting data as an XML file which can then be statistically exploited to illustrate the various concepts of radioactivity (exponential decay law, isotropy of the radiation, attenuation of radiation in matter). The application, with a spread sheet for data analysis and lab procedures, has been released under free license. (authors)

  18. QCD in heavy quark production and decay

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-06-01

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

  19. QCD in heavy quark production and decay

    International Nuclear Information System (INIS)

    Wiss, J.

    1997-01-01

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

  20. Mental Models of Radioactivity and Attitudes towards Radioactive Waste

    International Nuclear Information System (INIS)

    Zeleznik, N.

    2010-01-01

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

  1. Handbook of radioactivity analysis. Second edition

    International Nuclear Information System (INIS)

    L'Annunziata, M.

    2003-07-01

    This updated and much expanded Second Edition is an authoritative handbook 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 safeguards. The book describes 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-art methods of analysis. Fundamentals of radioactivity properties, radionuclide decay, the calculations involved, and methods of detection provide the basis for a thorough understanding of the analytical procedures. The Handbook of Radioactivity Analysis, Second Edition is suitable as a teaching text for university and professional training courses

  2. Natural occurring radioactive substances. Vol. 1

    International Nuclear Information System (INIS)

    Emara, A.E.

    1996-01-01

    Naturally occurring radioactive substances produced by cosmic rays of those of terrestrial origin are surveyed. The different radioactive decay series are discussed. Special emphasis is given to the element radium as regards its properties and distribution in different environmental samples. The properties of naturally occurring k-40 and its distribution in different natural media are also outlined. Induced radionuclides which are formed as a result of the interaction of cosmic rays with the constituents of the atmosphere are mentioned. In this respect the intensity of natural background radiation and the dose at different locations and levels is surveyed. Some regions of exceptionally high radioactivity which result in high exposure rates are mentioned. Monazite deposits and water springs are mentioned in some detail. The Oklo phenomenon as a natural reactor is also discussed. 8 tabs

  3. Calculation problems of atmospheric dispersion of radioactivity

    International Nuclear Information System (INIS)

    Veverka, O.; Valenta, V.

    1976-01-01

    A problem solution related to activity distribution in the atmosphere on the basis of the Paskuille method is presented. Considered is an effect of the following factors: choice of coordinate system for the calculation; choice of dispersion coefficients, effect of roughness of underlying surface and buildings; effect of radioactive product precipitation rate, as well as wash-out constants; effect of radioactive decay and radioactive transformations. The solution for concentration determination in the case of ''fumigation'' (compressed jet) and ''loffing'' (elevated jet) is given. On the basis of the method the complex METEO program is developed to calculate activities distribution. Adduced is a list of formulae used in the METEO program both for normal operations of nuclear industry enterprises and accident situations [ru

  4. 238Pu - Comments on Evaluation of Decay Data

    International Nuclear Information System (INIS)

    Chechev, V. P.

    2013-01-01

    This evaluation was done originally in March 2003, corrected in June 2004, and then updated in June 2009 with a literature cut-off by the same date. Decay Scheme: The decay scheme is based on 2007Br04. Some expected weak gamma-ray transitions were not observed directly in 238 Pu α-decay but have been adopted from decay of 234 Pa and 234 Np

  5. A study on the adsorption and subsurface transport of radioactive solutes in the presence of chelating agents

    International Nuclear Information System (INIS)

    Baik, Min Hoon

    1994-02-01

    In this study, adsorption and transport models were developed to analyze the effect of chelating agents on the adsorption and subsurface transport of radioactive solutes. The effect of chelating agents on the adsorption of radioactive solutes was analyzed by developing an adsorption model based upon the extended concept of distribution coefficient reflecting the presence of chelating agents. Also, a batch adsorption experiment was conducted in order to validate the developed adsorption model and to investigate the effect of chelating agent on the adsorption of radioactive metal solutes. In this experiment, a Cobalt(II)/EDTA/Bentonite system was considered as a representative chelation/adsorption system. It was found from the results that the presence of chelating agents significantly reduced the adsorbing capacity of geologic media such as clay minerals and soils. Thus it was concluded that the presence of chelating agents even in a small amount could contribute to the mobilization of radioactive solutes from radioactive waste burial sites by reducing the adsorbing capacity of geologic media. The effect of chelating agents on the transport of radioactive solutes in subsurface porous media was analyzed by formulating an advective-dispersive transport model which incorporated chelate formation, adsorption, decay, and degradations and by introducing the concept of a tenad. Particularly the governing equation for the tenad of radioactive solutes, M, was presented as a linear partial differential form by introducing the extended distribution coefficient, K D . The calculated results from the model showed that the transport rate of the chelated radionuclides was much greater than that of the free ionic radionuclides. This much faster transport of the chelated radionuclides was found to be due to the lower retardation factor of the chelated radionuclides than the free ionic radionuclides. The effect of parameters on the transport of radioactive solutes was also analyzed

  6. 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.

  7. 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)

  8. Development of ACBIO: A Biosphere Template Using AMBER for a Potential Radioactive Waste Repository

    International Nuclear Information System (INIS)

    Lee, Youn Myoung; Hwang, Yong Soo; Kang, Chul Hyung; Hahn, Pil Soo

    2005-01-01

    Nuclides in radioactive wastes are assumed to be transported in the geosphere by groundwater and probably discharged into the biosphere. Quantitative evaluation of doses to human beings due to nuclide transport in the geosphere and through the various pathways in the biosphere is the final step of safety assessment of the radioactive waste repository. To calculate the flux to dose conversion factors (DCFs) for nuclides appearing at GBIs with their decay chains, a template ACBIO which is an AMBER case file based on mathematical model for the mass transfer coefficients between the compartments has been developed considering material balance among the compartments in biosphere and then implementing to AMBER, a general and flexible software tool that allows to build dynamic compartment models. An illustrative calculation with ACBIO is shown.

  9. Modeling Radioactive Decay Chains with Branching Fraction Uncertainties

    Science.gov (United States)

    2013-03-01

    the numerical integration solution and the program had maximums of 10 -2 . 39 Performance All runs and development were done on a Dell XPS 8300...53 Figure 15 . Empirical CDFs of Te124 from Pu239 fast at 0.1 seconds with φ = 20%, as compared to a Normal CDFs with the same mean...concentration parameter to the sum of the 15 concentration parameters. In the case of interest, this is simply the branching fraction mean times

  10. Nuclear structure from radioactive decay. Annual progress report

    International Nuclear Information System (INIS)

    Wood, J.L.

    1982-01-01

    The most exciting development during this year has been the formulation of a unified description of shape coexistence in nuclei. The picture is built on the idea that deformation in nuclei is due to an attractive proton-neutron force acting in the valence shell model space. The excitation of nucleon pairs across closed shells effectively increases the number of valence nucleons, giving rise to a set of coexisting states with larger deformation. The major area of activity is the study of neutron-deficient nuclei around the Z = 82 shell closure, with special emphasis on the levels of the odd-mass Pt, Au, Hg and Tl isotopes. Progress is reported

  11. Development of ferritic steels for fast induced-radioactivity decay

    International Nuclear Information System (INIS)

    Klueh, R.L.; Vitek, J.M.

    1985-01-01

    Tempering studies were conducted on eight heats of normalized chromium-tungsten steel that contained variations in the composition of chromium, tungsten, vanadium, and tantalum. Hardness measurements and optical metallographic observations were used to determine alloying effects on tempering resistance between 650 to 780 0 C. The results were compared to results for analogous chromium-molybdenum steels. 6 references, 6 figures, 1 table

  12. Natural radioactivity in environmental studies

    International Nuclear Information System (INIS)

    Heijnis, H.; Jenkinson, A.; Chisari, R.

    1998-01-01

    Full text: The use natural radioactivity in environmental studies has proven a very powerful tool to determine the dynamics of both natural and antrophogenic processes in our environment. The use of 14 C in archeology and past climate studies has led to many scientific discoveries (i.e. shroud of Turin and Utze 'the ice-man' from Austria). The use of the 238 U-decay series is of at least equal value to studies in archeology and past climates. Some of the Isotopes studied supplement 14 C (which is limited to 40,000 years) up to 350,000 years and others can be utilized to date very young sediments, which can't be dated by 14 C. The so-called 210 Pb dating method has been used over the past 3 decades to date recent sediment. The method uses the disequilibrium in the 238 U decay chain, caused by the escape of the intermediate daughter 222 Rn (a noble gas) from the earth's crust. In the atmosphere the 222 Rn decays via short-lived daughter isotopes to 210 Pb. This 210 Pb with a very convenient half-life of 22,3 years decays to stable 206 Pb. By measuring the surface activity of a sediment core and subsequent samples at regular intervals one can establish a chronology for the sediment core. By studying the trace metals in these cores, one could deduce a contamination history for the region. Examples of studies supported by AINSE and ANSTO will be given

  13. Charm Decays at BABAR

    International Nuclear Information System (INIS)

    Charles, M.

    2004-01-01

    The results of several studies of charmed mesons and baryons at BABAR are presented. First, searches for the rare decays D 0 → l + l - are presented and new upper limits on these processes are established. Second, a measurement of the branching fraction of the isospin-violating hadronic decay D* s (2112) + → D s + π 0 relative to the radiative decay D* s (2112) + → D s + γ is made. Third, the decays of D* sJ (2317) + and D sJ (2460) + mesons are studied and ratios of branching fractions are measured. Fourth, Cabibbo-suppressed decays of the Λ c + are examined and their branching fractions measured relative to Cabibbo-allowed modes. Fifth, the Χ c 0 is studied through its decays to Χ - π + and (Omega) - K + ; in addition to measuring the ratio of branching fractions for Χ c 0 produced from the c(bar c) continuum, the uncorrected momentum spectrum is measured, providing clear confirmation of Χ c 0 production in B decays

  14. Limitations in the use of Barrier Buckets in a Beta Beam Decay Ring

    CERN Document Server

    Hansen, C; Fernandez Martinez, E F

    2010-01-01

    Beta Beam, the concept of letting accelerated radioactive ions generate a pure and intense (anti-) neutrino beam by beta decay, is the base of one of the pro- posed next generation neutrino oscillation facilities, necessary for a complete study of the neutrino oscillation parameter space. The first CERN based sce- nario, using 18Ne and 6He as !e and ¯!e emitters respectively, has shown a shortfall in 18Ne production. We have now entered the era of the studies of an alternative CERN based baseline. This alternative investigates how the ions 8B and 8Li can be produced in high quantities in a ”Production Ring”, accel- erated and then accumulated in a ”Decay Ring”. The idea of an alternative RF scheme for the Decay Ring, to use RF barriers to collect all ions in one ”Bar- rier Bucket”, has been tested. Longitudinal phase space simulations show that with the Barrier Bucket method it is unfeasible to optimize between ion inten- sity in the bucket and the duty cycle the bucket occupy. Therefore the prio...

  15. Radioactive waste management profiles

    International Nuclear Information System (INIS)

    1991-10-01

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

  16. Thermodynamic stability of radioactivity standard solutions

    Energy Technology Data Exchange (ETDEWEB)

    Iroulard, M.G

    2007-04-15

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

  17. Thermodynamic stability of radioactivity standard solutions

    International Nuclear Information System (INIS)

    Iroulard, M.G.

    2007-04-01

    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

  18. SYMPOSIUM: Rare decays

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    Late last year, a symposium entitled 'Rare Decays' attracted 115 participants to a hotel in Vancouver, Canada. These participants were particle physicists interested in checking conventional selection rules to look for clues of possible new behaviour outside today's accepted 'Standard Model'. For physicists, 'rare decays' include processes that have so far not been seen, explicitly forbidden by the rules of the Standard Model, or processes highly suppressed because the decay is dominated by an easier route, or includes processes resulting from multiple transitions

  19. Weak radiative hyperon decays

    International Nuclear Information System (INIS)

    Roberts, B.L.; Booth, E.C.; Gall, K.P.; McIntyre, E.K.; Miller, J.P.; Whitehouse, D.A.; Bassalleck, B.; Hall, J.R.; Larson, K.D.; Wolfe, D.M.; Fickinger, W.J.; Robinson, D.K.; Hallin, A.L.; Hasinoff, M.D.; Measday, D.F.; Noble, A.J.; Waltham, C.E.; Hessey, N.P.; Lowe, J.; Horvath, D.; Salomon, M.

    1990-01-01

    New measurements of the Σ + and Λ weak radiative decays are discussed. The hyperons were produced at rest by the reaction K - p → Yπ where Y = Σ + or Λ. The monoenergetic pion was used to tag the hyperon production, and the branching ratios were determined from the relative amplitudes of Σ + → pγ to Σ + → pπ 0 and Λ → nγ to Λ → nπ 0 . The photons from weak radiative decays and from π 0 decays were detected with modular NaI arrays. (orig.)

  20. 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.

  1. The decay width of stringy hadrons

    Science.gov (United States)

    Sonnenschein, Jacob; Weissman, Dorin

    2018-02-01

    In this paper we further develop a string model of hadrons by computing their strong decay widths and comparing them to experiment. The main decay mechanism is that of a string splitting into two strings. The corresponding total decay width behaves as Γ = π/2 ATL where T and L are the tension and length of the string and A is a dimensionless universal constant. We show that this result holds for a bosonic string not only in the critical dimension. The partial width of a given decay mode is given by Γi / Γ =Φi exp ⁡ (- 2 πCmsep2 / T) where Φi is a phase space factor, msep is the mass of the "quark" and "antiquark" created at the splitting point, and C is a dimensionless coefficient close to unity. Based on the spectra of hadrons we observe that their (modified) Regge trajectories are characterized by a negative intercept. This implies a repulsive Casimir force that gives the string a "zero point length". We fit the theoretical decay width to experimental data for mesons on the trajectories of ρ, ω, π, η, K*, ϕ, D, and Ds*, and of the baryons N, Δ, Λ, and Σ. We examine both the linearity in L and the exponential suppression factor. The linearity was found to agree with the data well for mesons but less for baryons. The extracted coefficient for mesons A = 0.095 ± 0.015 is indeed quite universal. The exponential suppression was applied to both strong and radiative decays. We discuss the relation with string fragmentation and jet formation. We extract the quark-diquark structure of baryons from their decays. A stringy mechanism for Zweig suppressed decays of quarkonia is proposed and is shown to reproduce the decay width of ϒ states. The dependence of the width on spin and flavor symmetry is discussed. We further apply this model to the decays of glueballs and exotic hadrons.

  2. Development of limiting decay heat values

    International Nuclear Information System (INIS)

    Khotylev, V.A.; Thompson, J.W.; Gibb, R.A.

    1999-01-01

    A number of tools are used in the assessment of decay heat during an outage of the CANDU-6. Currently, the technical basis for all of these tools is 'CANDU Channel Decay Power', Reference 1. The methods used in that document were limited to channel decay powers. However, for most outage support analysis, decay heat limits are based on bundle heats. Since the production of that document in 1977, new versions of codes, and updates of general-purpose and CANDU-specific libraries have become available. These tools and libraries have both a more formal technical basis than Reference 1, and also a more formal validation base. Using these tools it is now possible to derive decay heat with more specific input parameters, such as fuel composition, heat per unit of fuel, and irradiation history, and to assign systematically derived uncertainty allowances to such decay heat values. In particular, we sought to examine a broad range of likely bundle histories, and thus establish a set of limiting bundle decay beat values, that could serve as a bounding envelope for use in Nuclear Safety Analysis. (author)

  3. Searching for Double Beta Decay with the Enriched Xenon Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Hall, C.; /SLAC

    2007-03-16

    The Enriched Xenon Observatory (EXO) Collaboration is building a series of experiments to search for the neutrinoless double beta decay of {sup 136}Xe. The first experiment, known as EXO-200, will utilize 200 kg of xenon enriched to 80% in the isotope of interest, making it the largest double beta decay experiment to date by one order of magnitude. This experiment is rapidly being constructed, and will begin data taking in 2007. The EXO collaboration is also developing a technique to identify on an event-by-event basis the daughter barium ion of the double beta decay. If successful, this method would eliminate all conventional radioactive backgrounds to the decay, resulting in an ideal experiment. We summarize here the current status of EXO-200 construction and the barium tag R&D program.

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

    Directory of Open Access Journals (Sweden)

    K. M. Lynch

    2014-03-01

    Full Text Available 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.

  5. 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.

  6. Discovery of the Two-Proton Decay of 45Fe

    International Nuclear Information System (INIS)

    Pfuetzner, M.; Blank, B.; Giovinazzo, J.

    2003-01-01

    In experiments performed at the GSI Fragment Separator and at the GANIL SISSI-LISE3 facility the decay of 45 Fe has been investigated. Implantation events of 45 Fe ions, stopped in silicon telescopes, were correlated with radioactive decay events. The decay energy spectra exhibit a peak of an average energy of (1.14 ± 0.05 ) MeV. This observation, together with the non-observation of coincident γ or β events, represent clear evidence for the two-proton ground state decay of 45 Fe. The average half-life of 45 Fe, deduced from both experiments, is T 1/2 =3.8 +2.0 0.8 ms. (author)

  7. Inflaton decay in supergravity

    International Nuclear Information System (INIS)

    Endo, M.; Takahashi, F.; Yanagida, T.T.; Tokyo Univ.

    2007-06-01

    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) C gauge interactions. (orig.)

  8. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Abstract. 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.

  9. Time-Based Loss in Visual Short-Term Memory Is from Trace Decay, Not Temporal Distinctiveness

    Science.gov (United States)

    Ricker, Timothy J.; Spiegel, Lauren R.; Cowan, Nelson

    2014-01-01

    There is no consensus as to why forgetting occurs in short-term memory tasks. In past work, we have shown that forgetting occurs with the passage of time, but there are 2 classes of theories that can explain this effect. In the present work, we investigate the reason for time-based forgetting by contrasting the predictions of temporal…

  10. Radioactive waste computerized management

    International Nuclear Information System (INIS)

    Communaux, M.; Lantes, B.

    1993-01-01

    Since December 31, 1990, the management of the nuclear wastes for all the power stations has been computerized, using the DRA module of the Power Generation and Transmission Group's data processing master plan. So now EDF has a software package which centralizes all the data, enabling it to declare the characteristics of the nuclear wastes which are to be stored on the sites operated by the National Radioactive Waste Management Agency (ANDRA). Among other uses, this application makes it possible for EDF, by real time data exchange with ANDRA, to constitute an inventory of validated, shippable packs. It also constitutes a data base for all the wastes produced on the various sites. This application was developed to meet the following requirements: give the producers of radioactive waste a means to fully manage all the characteristics and materials that are necessary to condition their waste correctly; guarantee the traceability and safety of data and automatically assure the transmission of this data in real time between the producers and the ANDRA; give the Central Services of EDF an operation and statistical tool permitting an experienced feed-back based on the complete national production (single, centralized data base); and integrate the application within the products of the processing master plan in order to assure its maintenance and evolution

  11. Radioactive waste in perspective

    National Research Council Canada - National Science Library

    2010-01-01

    ... radioactive. While disposal options for hazardous wastes are generally well established, some types of hazardous waste face issues similar to those for radioactive waste and also require long-term disposal arrangements...

  12. Radioactive Waste Management Strategy

    International Nuclear Information System (INIS)

    2002-01-01

    This strategy defines methods and means how collect, transport and bury radioactive waste safely. It includes low level radiation waste and high level radiation waste. In the strategy are foreseen main principles and ways of storage radioactive waste

  13. 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.

  14. Observation and investigation of the new proton-unbound nuclei {sup 30}Ar and {sup 29}Cl with in-flight decay spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xiaodong

    2016-06-30

    Two-proton (2p) radioactivity is an exotic nuclear decay mode resulting in the simultaneous emission of two protons. The ground-state 2p radioactivity was discovered in the decay of {sup 45}Fe in 2002. Later, this novel decay mode was also found in the decays of {sup 48}Ni, {sup 54}Zn, and {sup 19}Mg. In order to study a promising 2p radioactivity candidate {sup 30}Ar, an experiment was performed at the Fragment Separator of GSI in Darmstadt (Germany). The in-flight decay technique, which is based on the tracking of the in-flight decay products by using the silicon strip detectors, was employed. Several calibration and alignment procedures were performed to achieve the best-possible accuracy of position and angle measurements. In order to determine the angular and half-life resolutions as well as the detection efficiency, the decays of the previously-known 2p emitter {sup 19}Mg were remeasured. The 2p radioactivity of {sup 19}Mg ground state and sequential emission of protons from several known excited states in {sup 19}Mg were confirmed. The deduced 2p decay energies are consistent with previous data. The evidence on a new excited state in {sup 19}Mg at 8.9{sup +0.8}{sub -0.7} MeV above the 2p threshold was found. It was tentatively suggested that this new {sup 19}Mg state decays by sequential emission of protons via two unknown 18Na resonances at 2.5{sup +0.7}{sub -0.3} MeV and 4.0{sup +1.5}{sub -0.6} MeV above the 1p threshold, respectively. Two previously-unknown proton-unbound nuclei {sup 30}Ar and {sup 29}Cl were identified by measuring the trajectories of their in-flight decay products {sup 28}S+p+p and {sup 28}S+p, respectively. The analysis of {sup 28}S-proton angular correlations provided information on the decay energies and structure of the observed states in {sup 30}Ar and {sup 29}Cl. The assigned ground state and first excited state of {sup 29}Cl were found at 1.8{sup +0.1}{sub -0.1} MeV and 2.3{sup +0.1}{sub 0.1} MeV above the one-proton threshold

  15. 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.

  16. 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.)

  17. Tau decays into kaons

    International Nuclear Information System (INIS)

    Finkemeier, M.; Mirkes, E.

    1995-04-01

    Predictions for semi-leptonic decay rates of the τ lepton into two meson final states and three meson final states are derived. The hadronic matrix elements are expressed in terms of form factors, which can be predicted by chiral Lagrangians supplemented by informations about all possible low-lying resonances in the different channels. Isospin symmetry relations among the different final states are carefully taken into account. The calculated brancing ratios are compared with measured decay rates where data are available

  18. 'aspect' - a new spectrometer for the measurement of the angular correlation coefficient a in neutron beta decay

    CERN Document Server

    Zimmer, O; Grinten, M G D; Heil, W; Glück, F

    2000-01-01

    The combination of the coefficient a of the antineutrino/electron angular correlation with the beta asymmetry of the neutron provides a sensitive test for scalar and tensor contributions to the electroweak Lagrangian, as well as for right-handed currents. A method is given for measuring a with high sensitivity from the proton recoil spectrum. The method is based on a magnetic spectrometer with electrostatic retardation potentials such as used for searches of the neutrino mass in tritium beta decay. The spectrometer can also be used for similar studies using radioactive nuclei.

  19. Radioactive waste management

    International Nuclear Information System (INIS)

    Balek, V.

    1994-01-01

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

  20. Radioactive consumer products

    International Nuclear Information System (INIS)

    Sato, Otomaru

    1981-01-01

    Present situation of utilizing the radioactive consumer products and exposure dose were reviewed with published data. Practically, consumer products are divided into three categories, (1) radioactive nuclides intentionally incorporated into radioluminous dye, ionization chambers for smoke detector, eliminator of static electricity, and glow lamp (2) natural radioactive nuclides contained in false teeth, porcelain, glass, and gas mantle (3) natural radioactive nuclides accumulated as industrial waste at the consumption of coal, petroleum, and natural gas or in fertilizer and materials for construction. (Nakanishi, T.)

  1. Tracking of Radioactive Sources in Malaysian Nuclear Agency

    International Nuclear Information System (INIS)

    Mohd Fazlie Abdul Rashid; Noor Fadilla Ismail; Khairuddin Mohamad Kontol; Hairul Nizam Idris; Azimawati Ahmad; Suzilawati Muhd Sarowi; Raymond, Y.T.L.

    2014-01-01

    Radioactive materials are used in Malaysian Nuclear Agency for various purposes such as research and development, calibration, tracer and irradiation. Inventory of radioactive materials is crucial for ensuring the security and control of all radioactive materials owned and used so as not to be lost or fall into the hands of people who do not have permission to possess or use it. Experience in many countries around the world proves that the improper inventory of radioactive material would lead to loss of control of radioactive materials and will eventually cause an accident of radiation exposure. Radioactive material database has been developed for the need to ensure traceability of radioactive materials in Malaysian Nuclear Agency. Records of radioactive materials are regularly updated based on the classification of the type of radionuclide, the total distribution in each building and the initial activity of radioactive sources. (author)

  2. Environmental radioactivity in the antarctic station

    International Nuclear Information System (INIS)

    Gonzalez, S.; Osores, J.; Martinez, J.; Lopez, E.; Jara, R.

    1998-01-01

    Study about environmental radioactivity in the Peruvian antarctic station Machu Pichu they were carried out during the last three periods to the southern summer. The objective of the project it is to evaluate environmental component in order to elaborate a study it base on the levels background radioactivity and artificial in the antarctic region

  3. Evidence Theory Based Uncertainty Quantification in Radiological Risk due to Accidental Release of Radioactivity from a Nuclear Power Plant

    International Nuclear Information System (INIS)

    Ingale, S. V.; Datta, D.

    2010-01-01

    Consequence of the accidental release of radioactivity from a nuclear power plant is assessed in terms of exposure or dose to the members of the public. Assessment of risk is routed through this dose computation. Dose computation basically depends on the basic dose assessment model and exposure pathways. One of the exposure pathways is the ingestion of contaminated food. The aim of the present paper is to compute the uncertainty associated with the risk to the members of the public due to the ingestion of contaminated food. The governing parameters of the ingestion dose assessment model being imprecise, we have approached evidence theory to compute the bound of the risk. The uncertainty is addressed by the belief and plausibility fuzzy measures.

  4. Decay of Plutonium isotopes via spontaneous and heavy-ion induced fission paths

    Science.gov (United States)

    Sharma, Kanishka; Sawhney, Gudveen; Sharma, Manoj K.; Gupta, Raj K.

    2018-04-01

    Based on the collective clusterization approach, we have extended our earlier study on α-decay, exotic cluster-decay, and heavy particle radioactivity, to the phenomenon of spontaneous fission (SF) in the ground-state (g.s.) decays of even mass 234-246Pu parents. The calculations for the SF half-lives of these Pu-isotopes have been made within the framework of preformed cluster model (PCM), both for spherical as well as β2-deformed choices of shapes, and a comparison is made with the relevant available experimental data, which prefer spherical shapes. The importance of the orientation degree of freedom (hot compact or cold elongated configurations) is also explored. Next, in order to look for the exclusive role of heavy-ion induced fission, the dynamics of 6He + 238U reaction forming 244Pu* is studied over the center of mass energy range of E c . m . = 15.0- 28.8MeV, using the dynamical cluster-decay model (DCM), an extension of the PCM with temperature T- and angular momentum ℓ-effects included. The β2-deformed fragments of 244Pu* in the mass range A2 = 106- 113 (plus their complementary heavy fragments), corresponding to asymmetric fission peaks, are found contributing towards the fission cross-section. Finally, the potential energy surfaces and barrier modification effects are presented for the relative comparison of spontaneous and the heavy-ion induced fission processes. Both are found to behave similar with respect to the probable emission of fragments and hence point out to the shell closure property of the decay fragments.

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

    Energy Technology Data Exchange (ETDEWEB)

    Langen, K; Chen, S [University of Maryland School of Medicine, Baltimore, MD (United States)

    2014-06-01

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

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

    International Nuclear Information System (INIS)

    Langen, K; Chen, S

    2014-01-01

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

  7. JUSTIFICATION FOR THE RADIOLOGICAL CRITERIA FOR THE USE OF AREAS WITH RESIDUAL RADIOACTIVE CONTAMINATION BASED ON THE DOSE APPROACH

    Directory of Open Access Journals (Sweden)

    V. Yu. Golikov

    2017-01-01

    Full Text Available The article presents a methodology for assessing the radiological criteria for the use of the territory (a land plot with buildings with residual radioactive contamination from the so-called “green area”, i.e., complete release from radiation control until a number of restrictions are imposed on the use of the territory. In accordance with the further use of the territory, a range of scenarios and pathways for the exposure of the population was considered. A set of models and their parameters, corresponding to the number of the considered pathways of exposure, was defined. Assuming a uniform distribution of a radionuclide with a unit concentration in the source zone, the distribution of effective doses for the population living in the territory with the residual radioactive contamination for different irradiation scenarios was calculated by stochastic modeling, 95% of the quantile of which was attributed to the dose in the representatives of the critical population group. Next, the value of radiological criteria, depending on the implemented scenario, was determined as the ratio of the dose constraint EL = 0,3 mSv/yr and 95% quantile in the distribution of the effective dose from a unit contamination. The numerical values of radiological criteria for the presence of radionuclides in the soil are presented, both for the radiation scenarios that correspond to the permanent residence of the population in the contaminated territory and for recreational use. A further consideration is given to the so-called worker scenario, which corresponds to the limited time spent on the contaminated territory and the simultaneous effects of radionuclides contained both in the soil and in the construction of the buildings. A comparison of the results of the own calculations with the data of other authors was carried out.

  8. Rare B decays at CMS

    CERN Document Server

    Li, Linwei

    2017-01-01

    The flavour changing neutral current decays can be interesting probes for searching for New Physics. Angular distributions of the decay $\\mathrm{B}^0 \\to \\mathrm{K}^{*0} \\mu^ +\\mu^-$ are studied using a sample of proton-proton collisions at $\\sqrt{s} = 8~\\mathrm{TeV}$ collected with the CMS detector at the LHC, corresponding to an integrated luminosity of $20.5~\\mathrm{fb}^{-1}$. An angular analysis is performed to determine $P_1$ and $P_5'$, where $P_5'$ is of particular interest due to recent measurements that indicate a potential discrepancy with the standard model. Based on a sample of 1397 signal events, $P_1$ and $P_5'$ angular parameters are determined as a function of the dimuon invariant mass squared. The measurements are in agreement with standard model predictions.

  9. Radiative decay of the pion

    International Nuclear Information System (INIS)

    Bay, A.; Joseph, C.; Loude, J.-F.; Perroud, J.-P.; Rueegger, D.; Schoeri, O.; Steiner, D.; Tran, M.T.

    1982-01-01

    So far, only two experimental studies of the radiative decay of the pion (π + →e + γγ) have been reported. From these studies the ratio γ of the axial and the vector weak form factors of the pion can be extracted. The present knowledge of γ is based on 121 events and 226 events only; furthermore an ambiguity in the absolute value of γ associated with its sign still remains. The authors therefore undertook a measurement of this rare decay using a magnetic spectrometer and a large array of 64 NaI modules each with a square cross section of 63 x 63 mm 2 and a length of 406 mm to detect in coincidence the positron and the photon respectively. (Auth.)

  10. Natural Radioactivity of Thermal Springs in Croatia

    International Nuclear Information System (INIS)

    Marovic, G.; Sencar, J.; Cesar, D.

    1998-01-01

    The Republic of Croatia is rich in thermal and mineral springs, which are widely popular for medical therapy, tourism, recreation, rehabilitation and drinking. Considering the popularity of the spas and the habits of our population to use the beneficial effects of these springs it is of interest to estimate the radiation doses received by patients or tourists staying in the spas. In view of this, the Radiation Protection Unit of the Institute for Medical Research and Occupational Health in Zagreb has been engaged in a research programme dealing with the natural radioactivity concentration in the Croatian thermal and mineral waters. The aim of this paper was to estimate total natural radioactivity (Ra, Ra decay) in thermal and mineral waters from the several spas in Croatia. On basis of the obtained data the Ra and Ra activity ratio was calculated for each investigated spa. In this study possible effects of natural radioactivity were determined for each radionuclide using a derived concentration (DC) for a group of individuals for municipal drinking water supplies. Values exceeding DC represent radionuclide concentrations for radioactive waste. Total percentage ratio for each spring was also calculated. Since natural radioactivity in some spas exceeds DC value the practise of using these waters should be regularly estimated and monitored in order to avoid any possible health effects. (author)

  11. Radioactive waste management and disposal in Australia

    International Nuclear Information System (INIS)

    Harries, J.R.

    1997-01-01

    A national near-surface repository at a remote and arid location is proposed for the disposal of solid low-level and short-lived intermediate-level radioactive wastes in Australia. The repository will be designed to isolate the radioactive waste from the human environment under controlled conditions and for a period long enough for the radioactivity to decay to low levels. Compared to countries that have nuclear power programs, the amount of waste in Australia is relatively small. Nevertheless, the need for a national disposal facility for solid low-level radioactive and short-lived intermediate-level radioactive wastes is widely recognised and the Federal Government is in the process of selecting a site for a national near-surface disposal facility for low and short-lived intermediate level wastes. Some near surface disposal facilities already exist in Australia, including tailings dams at uranium mines and the Mt Walton East Intractable Waste Disposal Facility in Western Australia which includes a near surface repository for low level wastes originating in Western Australia. 7 refs, 1 fig., 2 tabs

  12. Some of the bases of the IAEA definition and recommendations concerning high-level radioactive waste unsuitable for dumping at sea and some of the Japanese findings of deep sea survey in the Pacific

    International Nuclear Information System (INIS)

    Nishiwaki, Y.

    1980-01-01

    The Provisional Definition and Recommendations Concerning Radioactive Wastes and Other Radioactive Matter referred to in Annexes I and II to the London Convention of 1972 on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter have been reviewed and revised by the IAEA during 1975-1978. The Revised Definition and Recommendations and of the Annex thereto for the purposes of the Convention emphasize that the definition and recommendations set forth by the IAEA should not be interpreted as precluding the adoption of more restrictive requirements by any Party to the Convention or appropriate national authorities, and that nothing in the document shall be construed as encouraging the dumping at sea of radioactive waste or other radioactive matter. With these reservations, the Definition of High-Level Radioacive Wastes or Other High-Level Radioactive Matter Unsuitable for Dumping at Sea is given, distinguishing between α-emitters, β/γ-emitters with half-lives of at least 0.5 years and of unknown half-lives; and tritium and β/γ-emitters with half-lives of less than 0.5 years. Bases of the IAEA definition and recommendations concerning high level radioactive waste unsuitable for dumping at sea and reservations attached to the given concentration limits are discussed. (orig.) [de

  13. Disposal of liquid radioactive waste - discharge of radioactive waste waters from hospitals

    International Nuclear Information System (INIS)

    Ludwieg, F.

    1976-01-01

    A survey is given about legal prescriptions in the FRG concerning composition and amount of the liquid waste substances and waste water disposal by emitting into the sewerage, waste water decay systems and collecting and storage of patients excretions. The radiation exposure of the population due to drainage of radioactive waste water from hospitals lower by more than two orders than the mean exposure due to nuclear-medical use. (HP) [de

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-31

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

  16. Radioactive source simulation for half-life experiment

    International Nuclear Information System (INIS)

    Wanitsuksombut, Warapon; Decthyothin, Chanti

    1999-01-01

    A simulation of radioactivity decay by using programmable light source with a few minutes half-life is suggested. A photodiode with digital meter label in cps is use instead of radiation detector. Both light source and photodiode are installed in a black box to avoid surrounding room light. The simulation set can also demonstrate Inverse Square Law experiment of radiation penetration. (author)

  17. Radioactive source simulation for half-life experiment

    Energy Technology Data Exchange (ETDEWEB)

    Wanitsuksombut, Warapon; Decthyothin, Chanti [Office of Atomic Energy for Peace, Chatuchak, Bangkok (Thailand)

    1999-09-01

    A simulation of radioactivity decay by using programmable light source with a few minutes half-life is suggested. A photodiode with digital meter label in cps is use instead of radiation detector. Both light source and photodiode are installed in a black box to avoid surrounding room light. The simulation set can also demonstrate Inverse Square Law experiment of radiation penetration. (author)

  18. Reduction of releases of radioactive effluents from light-water-power-reactors in Japan

    International Nuclear Information System (INIS)

    Yoshida, Y.; Itakura, T.; Kanai, T.

    1977-01-01

    Japan Atomic Energy Commission established the dose objectives to the population around the light-water-reactors in May, 1975, based on the ''ALAP'' concept. These values are respectively, 5 mrems per year for total body and 15 mrems per year for thyroid of an individual in the critical group in the environs, due to both gaseous and liquid effluents from LWRs in one site. The present paper describes the implications of the dose objective values, control measures which have been adopted to reduce releases of radioactive materials and related technical developments in Japan. The main control measures for reduction of radioactive gaseous effluents are an installation of a charcoal gas holdup system for decay of noble gases and a supply of clean steam for the gland seal of a turbine in BWR, and a storage tank system allowing decay of noble gases in PWR. For liquid effluents are taken measures to re-use them as the primary coolant. Consequently, the amounts of radioactivity released to the environment from any LWR during normal operation have been maintained under the level to meet the above dose objective values. For research reactors, reduction of release of effluents has also been carried out in a similar way to LWRs. In order to establish the techniques applicable for further reduction, studies are being made on the control measures to reduce leakage of radioiodine, an apparatus for removal of krypton, the treatment of laundry waste and measures to remove the crud in the primary coolant. Presentation is also made on the energy-integrated gas monitor for gaseous effluent and systems of measuring γ dose from radioactive cloud descriminating from natural background, which have been developed for effective monitoring thus reduced environmental dose

  19. A simple model for the dispersion of radioactive wastes dumped on the deep-sea bed

    International Nuclear Information System (INIS)

    Shepherd, J.G.

    1976-01-01

    A simple model has been developed for the dispersion of radioactive materials in a closed and finite ocean. It allows for the simultaneous action of both diffusion and horizontal (but not vertical) advection, and thus avoids the major limitations of previous models such as that of Webb and Morley. It is sufficiently versatile to handle non-Fickian diffusion and radioactive decay, but requires numerical integration using some semi-empirical form for the Green's function of diffusion from a point source. The model has been used to estimate equilibrium concentrations of radioactive materials in sea water arising from the continuous release of material from a dump on the bottom of the deep ocean, using parameters appropriate for the North Atlantic. It is found that except under rather extreme conditions the surface concentrations do not exceed the long-term average value which would be established in a perfectly mixed ocean. The concentrations are also rather insensitive to the values of the diffusion and advection parameters used, except for that for vertical diffusion, but depend strongly on the overall removal rate of material from the ocean, including processes other than radioactive decay. It is suggested that safety assessments of deep-sea dumping should utilize estimates of the environmental capacities of the oceans based on the long-term 'well-mixed' average concentrations (which are very easily calculated) using a safety factor of no more than ten to allow for the possible effects of pluming and upwelling. In so far as their results are comparable, the present model yields estimates which are close to those of the Webb-Morley model for overall half-lives between 30 and 3000 years, but which become increasingly more restrictive for longer-lived materials. (author)

  20. Statistical Approach for Determination of Compliance with Clearance Criteria Based upon Types of Radionuclide Distributions in a Very Low-Level Radioactive Waste

    International Nuclear Information System (INIS)

    Cheong, Jae Hak

    2010-01-01

    A statistical evaluation methodology was developed to determine the compliance of candidate waste stream with clearance criteria based upon distribution of radionuclide in a waste stream at a certain confidence level. For the cases where any information on the radionuclide distribution is not available, the relation between arithmetic mean of radioactivity concentration and its acceptable maximum standard deviation was demonstrated by applying widely-known Markov Inequality and One-side Chebyshev Inequality. The relations between arithmetic mean and its acceptable maximum standard deviation were newly derived for normally or lognormally distributed radionuclide in a waste stream, using probability density function, cumulative density function, and other statistical relations. The evaluation methodology was tested for a representative case at 95% of confidence level and 100 Bq/g of clearance level of radioactivity concentration, and then the acceptable range of standard deviation at a given arithmetic mean was quantitatively shown and compared, by varying the type of radionuclide distribution. Furthermore, it was statistically demonstrated that the allowable range of clearance can be expanded, even at the same confidence level, if information on the radionuclide distribution is available.

  1. Strength loss in decayed wood

    Science.gov (United States)

    Rebecca E. Ibach; Patricia K. Lebow

    2014-01-01

    Wood is a durable engineering material when used in an appropriate manner, but it is susceptible to biological decay when a log, sawn product, or final product is not stored, handled, or designed properly. Even before the biological decay of wood becomes visually apparent, the decay can cause the wood to become structurally unsound. The progression of decay to that...

  2. CP violation in B decay

    OpenAIRE

    Yamamoto, Hitoshi

    2001-01-01

    We review the physics of CP violation in B decays. After introducing the CKM matrix and how it causes CP violation, we cover three types of CP violation that can occur in B decays: CP violation in mixing, CP violation by mixing-decay interference, and CP violation in decay.

  3. 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.

  4. Classification of solid wastes as non-radioactive wastes

    International Nuclear Information System (INIS)

    Suzuki, Masahiro; Tomioka, Hideo; Kamike, Kozo; Komatu, Junji

    1995-01-01

    The radioactive wastes generally include nuclear fuels, materials contaminated with radioactive contaminants or neutron activation to be discarded. The solid wastes arising from the radiation control area in nuclear facilities are used to treat and stored as radioactive solid wastes at the operation of nuclear facilities in Japan. However, these wastes include many non-radioactive wastes. Especially, a large amount of wastes is expected to generate at the decommissioning of nuclear facilities in the near future. It is important to classify these wastes into non-radioactive and radioactive wastes. The exemption or recycling criteria of radioactive solid wastes is under discussion and not decided yet in Japan. Under these circumstances, the Nuclear Safety Committee recently decided the concept on the category of non-radioactive waste for the wastes arising from decommissioning of nuclear facilities. The concept is based on the separation and removal of the radioactively contaminated parts from radioactive solid wastes. The residual parts of these solid wastes will be treated as non-radioactive waste if no significant difference in radioactivity between the similar natural materials and materials removed the radioactive contaminants. The paper describes the procedures of classification of solid wastes as non-radioactive wastes. (author)

  5. Solidification of radioactive liquid wastes

    International Nuclear Information System (INIS)

    Hayashi, Tadamasa; Sano, Katsunori.

    1980-01-01

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

  6. Precision Gamma-Ray Branching Ratios for Long-Lived Radioactive Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Tonchev, Anton [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-10-19

    Many properties of the high-energy-density environments in nuclear weapons tests, advanced laser-fusion experiments, the interior of stars, and other astrophysical bodies must be inferred from the resulting long-lived radioactive nuclei that are produced. These radioactive nuclei are most easily and sensitively identified by studying the characteristic gamma rays emitted during decay. Measuring a number of decays via detection of the characteristic gamma-rays emitted during the gamma-decay (the gamma-ray branching ratio) of the long-lived fission products is one of the most straightforward and reliable ways to determine the number of fissions that occurred in a nuclear weapon test. The fission products 147Nd, 144Ce, 156Eu, and certain other long-lived isotopes play a crucial role in science-based stockpile stewardship, however, the large uncertainties (about 8%) on the branching ratios measured for these isotopes are currently limiting the usefulness of the existing data [1,2]. We performed highly accurate gamma-ray branching-ratio measurements for a group of high-atomic-number rare earth isotopes to greatly improve the precision and reliability with which the fission yield and reaction products in high-energy-density environments can be determined. We have developed techniques that take advantage of new radioactive-beam facilities, such as DOE's CARIBU located at Argonne National Laboratory, to produce radioactive samples and perform decay spectroscopy measurements. The absolute gamma-ray branching ratios for 147Nd and 144Ce are reduced <2% precision. In addition, high-energy monoenergetic neutron beams from the FN Tandem accelerator in TUNL at Duke University was used to produce 167Tm using the 169Tm(n,3n) reaction. Fourtime improved branching ratio of 167Tm is used now to measure reaction-in-flight (RIF) neutrons from a burning DT capsule at NIF [10]. This represents the

  7. Design and development of a computer-based continuous monitor for the determination of the short-lived decay products of radon and thoron

    International Nuclear Information System (INIS)

    Bigu, J.

    1984-01-01

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

  8. The hell of a radioactivity

    International Nuclear Information System (INIS)

    Lambert, G.

    2004-01-01

    Nuclear accident, contaminations, pollutions and never-ending hazards: nuclear energy and especially radioactivity frightens the collective unconscious in an unreasoned way. The object of this book is to explain in a simple manner the bases and real values of natural radioactivity, nuclear energy and even of nuclear bombs. Without any will of proselytism, but with all the necessary scientific exactness, the author uses a novel style and the fancied story of a young couple for the exploration of the industrial and natural environment of radioactivity. From field measurements to laboratory visits, the reader, whatever his scientific culture, will be able to make his own opinion about this important question of science and society. (J.S.)

  9. 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.

  10. High Level Radioactive Waste Management

    International Nuclear Information System (INIS)

    1991-01-01

    The proceedings of the second annual international conference on High Level Radioactive Waste Management, held on April 28--May 3, 1991, Las Vegas, Nevada, provides information on the current technical issue related to international high level radioactive waste management activities and how they relate to society as a whole. Besides discussing such technical topics as the best form of the waste, the integrity of storage containers, design and construction of a repository, the broader social aspects of these issues are explored in papers on such subjects as conformance to regulations, transportation safety, and public education. By providing this wider perspective of high level radioactive waste management, it becomes apparent that the various disciplines involved in this field are interrelated and that they should work to integrate their waste management activities. Individual records are processed separately for the data bases

  11. Microscopic beta and gamma data for decay-heat needs

    International Nuclear Information System (INIS)

    Dickens, J.K.

    1983-01-01

    Microscopic beta and gamma data for decay-heat needs are defined as absolute-intensity spectral distributions of beta and gamma rays following radioactive decay of radionuclides created by, or following, the fission process. Four well-known evaluated data files, namely the US ENDF/B-V, the UK UKFPDD-2, the French BDN (for fission products), and the Japanese JNDC Nuclear Data Library, are reviewed. Comments regarding the analyses of experimental data (particularly gamma-ray data) are given; the need for complete beta-ray spectral measurements is emphasized. Suggestions on goals for near-term future experimental measurements are presented. 34 references

  12. High-level radioactive wastes

    International Nuclear Information System (INIS)

    Grissom, M.C.

    1982-10-01

    This bibliography contains 812 citations on high-level radioactive wastes included in the Department of Energy's Energy Data Base from January 1981 through July 1982. These citations are to research reports, journal articles, books, patents, theses, and conference papers from worldwide sources. Five indexes are provided: Corporate Author, Personal Author, Subject, Contract Number, and Report Number

  13. 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.

  14. beta decay of (78)Sr

    OpenAIRE

    Pérez-Cerdán, Ana Belén; Rubio, Berta; Gelletly, W.; Algora, Alejandro; Agramunt, Jorge; Burkard, K.; Huller W.; Nácher, Enrique; Sarriguren, Pedro; Caballero Ontanaya, Luis; Molina Palacios, Francisco Gabriel; Fraile, Luis M.; Reillo, E.; García Borge, María José; Dessagne, Ph.

    2011-01-01

    The gamma rays and conversion electrons emitted in the beta decay of (78)Sr to levels in (78)Rb have been studied using Ge detectors and a mini-orange spectrometer. A reliable level scheme based on the results of these experiments has been established. The properties of the levels in (78)Rb have been compared with calculations based on deformed Hartree-Fock with Skyrme interactions and pairing correlations in the BCS approximation. This has allowed an interpretation of the nature of the obser...

  15. On the claim of modulations in radon decay and their association with solar rotation

    Science.gov (United States)

    Pommé, S.; Lutter, G.; Marouli, M.; Kossert, K.; Nähle, O.

    2018-01-01

    Claims were made by Sturrock et al. that radioactive decay can be induced by interaction of the nucleus with solar neutrinos and that cyclic modulations in decay rates are indicative of the dynamics of the solar interior. They analysed a series of measurements of gamma radiation associated with the emanation and decay of radon in a sealed container at the Geological Survey of Israel (GSI) laboratory. The integral count rates in the NaI detector showed strong variations in time of year and time of day. From time-series analysis, Sturrock et al. claim the presence of small oscillations at frequencies in a range between 7.4 a-1 and 12.5 a-1, which they speculatively associated with rotational influence on the solar neutrino flux. In this work, it is argued that the GSI radon measurements are unsuited for studying the variability of decay constants, because the data are strongly influenced by environmental conditions, such as solar irradiance and rainfall. At the JRC and PTB, decay rate measurements of the radon decay chain were performed with ionisation chambers, gamma-ray spectrometers and an alpha spectrometer. No deviation from the exponential-decay law was observed. The existence of cyclic variations in the decay constants is refuted, as well as the concept of measuring solar rotation through radioactive decay.

  16. Radioactive waste sealing container

    International Nuclear Information System (INIS)

    Tozawa, S.; Kitamura, T.; Sugimoto, S.

    1984-01-01

    A low- to medium-level radioactive waste sealing container is constructed by depositing a foundation coating consisting essentially of zinc, cadmium or a zinc-aluminum alloy over a steel base, then coating an organic synthetic resin paint containing a metal phosphate over the foundation coating, and thereafter coating an acryl resin, epoxy resin, and/or polyurethane paint. The sealing container can consist of a main container body, a lid placed over the main body, and fixing members for clamping and fixing the lid to the main body. Each fixing member may consist of a material obtained by depositing a coating consisting essentially of cadmium or a zinc-aluminum alloy over a steel base

  17. Diffusion and decay chain of radioisotopes in stagnant water in saturated porous media.

    Science.gov (United States)

    Guzmán, Juan; Alvarez-Ramirez, Jose; Escarela-Pérez, Rafael; Vargas, Raúl Alejandro

    2014-09-01

    The analysis of the diffusion of radioisotopes in stagnant water in saturated porous media is important to validate the performance of barrier systems used in radioactive repositories. In this work a methodology is developed to determine the radioisotope concentration in a two-reservoir configuration: a saturated porous medium with stagnant water is surrounded by two reservoirs. The concentrations are obtained for all the radioisotopes of the decay chain using the concept of overvalued concentration. A methodology, based on the variable separation method, is proposed for the solution of the transport equation. The novelty of the proposed methodology involves the factorization of the overvalued concentration in two factors: one that describes the diffusion without decay and another one that describes the decay without diffusion. It is possible with the proposed methodology to determine the required time to obtain equal injective and diffusive concentrations in reservoirs. In fact, this time is inversely proportional to the diffusion coefficient. In addition, the proposed methodology allows finding the required time to get a linear and constant space distribution of the concentration in porous mediums. This time is inversely proportional to the diffusion coefficient. In order to validate the proposed methodology, the distributions in the radioisotope concentrations are compared with other experimental and numerical works. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Decay of 49Cr

    International Nuclear Information System (INIS)

    Jackson, S.V.; Henry, E.A.; Meyer, R.A.

    1975-01-01

    For the decay of 49 Cr the intensities of the 1361-, 1423-, 1508-, 1514-, and 1570-keV γ rays are found to be 0.85, 0.19, 0.15, 0.49, and 0.37, respectively, relative to I/sub gamma/ = 1000 for the 90-keV γ ray. Four other previously reported γ rays are shown to be sum peaks or contaminants. The recalculated β-decay branches and logft values (in parentheses) for 49 Cr decay are ground state (5.51), 90.639- (4.94), 152.928- (4.74), 1514.5- (5.71), 1661.1- (6.06), 2181.7- (7.0), 2236- (6.6), and 2310-keV (7.1). The known 3/2 + level at 748 keV was not observed to be populated and a limit of logft > 9 was found for that level

  19. 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)

  20. 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