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Sample records for radioactive decay school

  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. The law of radioactive decay

    International Nuclear Information System (INIS)

    Bouyrie, G

    2004-01-01

    This article deals with the law of radioactive decay (Rutherford-Sody's law) and the way to explain it to high-school or grammar-school students. The mathematical content of the law is recalled and its experimental validation is proposed through the study of the decay of a population of radon-220 atoms. The analysis of the experimental data is made easier by using software such as Generis, Regressi or even Excel

  4. Radioactive decay and labeled compounds

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This chapter on radioactive decay and labeled compounds has numerous intext equations and worked, sample problems. Topics covered include the following: terms and mathematics of radioactive decay; examples of calculations; graphs of decay equations; radioactivity or activity; activity measurements; activity decay; half-life determinations; labeled compounds. A 20 problem set is also included. 1 ref., 4 figs., 1 tab

  5. Is Radioactive Decay Really Exponential?

    OpenAIRE

    Aston, Philip J.

    2012-01-01

    Radioactive decay of an unstable isotope is widely believed to be exponential. This view is supported by experiments on rapidly decaying isotopes but is more difficult to verify for slowly decaying isotopes. The decay of 14C can be calibrated over a period of 12,550 years by comparing radiocarbon dates with dates obtained from dendrochronology. It is well known that this approach shows that radiocarbon dates of over 3,000 years are in error, which is generally attributed to past variation in ...

  6. Nuclear structure from radioactive decay

    International Nuclear Information System (INIS)

    Wood, J.L.

    1991-01-01

    This report discusses nuclear structure from radioactive decay of the following: Neutron-Deficient Iridium Isotopes; Neutron-Deficient Platinum Isotopes; Neutron-Deficient Gold Isotopes; Neutron-Deficient Mercury Isotopes; Neutron-Deficient Thallium Isotopes; Neutron-Deficient Lead Isotopes; Neutron-Deficient Samarium Isotopes; Neutron-Deficient Promethium Isotopes; Neutron-Deficient Neodymium Isotopes; and Neutron-Deficient Praseodymium Isotopes. Also discussed are Nuclear Systematics and Models

  7. JEF-2.2 radioactive decay data

    International Nuclear Information System (INIS)

    1994-08-01

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

  8. 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...

  9. 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.)

  10. Generating cryptographic keys by radioactive decays

    International Nuclear Information System (INIS)

    Grupen, Claus; Maurer, Ingo; Schmidt, Dieter; Smolik, Ludek

    2001-01-01

    We are presenting a new method for the generation of statistically genuine random bitstream with very high frequency which can be employed for cryptographic purposes. The method uses the feature of statistically unpredictable radioactive decays as the source of randomness. The measured quantity is the time distance between the responses of a small ionisation chamber due to the recording of ionising decay products. This time measurement is converted into states representing 0o r 1. The data generated in our experiment successfully passed FIPS PUB 140-1 and die hard statistical tests. For the simulation of systematic effects Monte Carlo techniques were used

  11. 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)

  12. Explicit solutions for exit-only radioactive decay chains

    International Nuclear Information System (INIS)

    Yuan, Ding; Kernan, Warnick

    2007-01-01

    In this study, we extended Bateman's [Proc. Cambridge Philos. Soc. 15, 423 (1910)] original work for solving radioactive decay chains and explicitly derived analytic solutions for generic exit-only radioactive decay problems under given initial conditions. Instead of using the conventional Laplace transform for solving Bateman's equations, we used a much simpler algebraic approach. Finally, we discuss methods of breaking down certain classes of large decay chains into collections of simpler chains for easy handling

  13. Moderation of the 119mSn isomer radioactive decay

    International Nuclear Information System (INIS)

    Godovikov, S.K.

    1999-01-01

    The evaluation of the constant of the braked 119m Sn nuclei decay in the Moessbauer source, being for a long time in contact with a resonance shield, is carried out. The high stability of these nuclei relative to decay is established. The 119m Sn subjected to prolonged impact of the standing electromagnetic wave field become resistant to radioactive decay [ru

  14. 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

  15. 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)

  16. Experimental investigation of statistical density function of decaying radioactive sources

    International Nuclear Information System (INIS)

    Salma, I.; Zemplen-Papp, E.

    1991-01-01

    The validity of the Poisson and the λ P(k) modified Poisson statistical density functions of observing k events in a short time interval is investigated experimentally in radioactive decay detection for various measuring times. The experiments to measure radioactive decay were performed with 89m Y, using a multichannel analyzer. According to the results, Poisson statistics adequately describes the counting experiment for short measuring times. (author) 13 refs.; 4 figs

  17. Radioactive decays at limits of nuclear stability

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  18. Method for removal of decay heat of radioactive substances

    International Nuclear Information System (INIS)

    Hesky, H.; Wunderer, A.

    1981-01-01

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

  19. User's manual for the radioactive decay and accumulation code RADAC

    International Nuclear Information System (INIS)

    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

  20. Noncharacteristic half-lives in radioactive decay

    International Nuclear Information System (INIS)

    Corral, Alvaro; Font, Francesc; Camacho, Juan

    2011-01-01

    Half-lives of radionuclides span more than 50 orders of magnitude. We characterize the probability distribution of this broad-range data set at the same time that we explore a method for fitting power laws and testing goodness-of-fit. It is found that the procedure proposed recently by Clauset et al.[SIAM Rev. 51, 661 (2009)] does not perform well as it rejects the power-law hypothesis even for power-law synthetic data. In contrast, we establish the existence of a power-law exponent with a value around 1.1 for the half-life density, which can be explained by the sharp relationship between decay rate and released energy, for different disintegration types. For the case of alpha emission, this relationship constitutes an original mechanism of power-law generation.

  1. Limitations of Poisson statistics in describing radioactive decay.

    Science.gov (United States)

    Sitek, Arkadiusz; Celler, Anna M

    2015-12-01

    The assumption that nuclear decays are governed by Poisson statistics is an approximation. This approximation becomes unjustified when data acquisition times longer than or even comparable with the half-lives of the radioisotope in the sample are considered. In this work, the limits of the Poisson-statistics approximation are investigated. The formalism for the statistics of radioactive decay based on binomial distribution is derived. The theoretical factor describing the deviation of variance of the number of decays predicated by the Poisson distribution from the true variance is defined and investigated for several commonly used radiotracers such as (18)F, (15)O, (82)Rb, (13)N, (99m)Tc, (123)I, and (201)Tl. The variance of the number of decays estimated using the Poisson distribution is significantly different than the true variance for a 5-minute observation time of (11)C, (15)O, (13)N, and (82)Rb. Durations of nuclear medicine studies often are relatively long; they may be even a few times longer than the half-lives of some short-lived radiotracers. Our study shows that in such situations the Poisson statistics is unsuitable and should not be applied to describe the statistics of the number of decays in radioactive samples. However, the above statement does not directly apply to counting statistics at the level of event detection. Low sensitivities of detectors which are used in imaging studies make the Poisson approximation near perfect. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  2. Radioactive decay of 223Ra by 14C emission

    International Nuclear Information System (INIS)

    Yashita, S.; Gregorich, K.; Ghiorso, A.

    1985-01-01

    Recently H.J. Rose and G.A. Jones at the University of Oxford reported the very difficult observation of an exotic radioactive decay mode in 233 Ra, its spontaneous disintegration by the emission of 14 C particles. The authors have confirmed their somewhat surprising discovery by an independent method. Within the present experimental accuracy the magnetic rigidity, energy and branching ratio support the assignment of 14 C emission from 223 Ra as proposed by the Oxford experiment

  3. 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)

  4. A simulation for radioactive decay and the absorption of radiation

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    The purpose of this article is to derive and discuss these exponential laws for the benefit of teachers and interested pupils, and to discuss a simulation of the above phenoma should radioactive sources and Geiger-Mueller counters not be available in any particular school laboratory. The simulation can also be done by computer

  5. 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.

  6. 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.

  7. 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

  8. 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)

  9. 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.

  10. Laser enhanced radioactive decay and selective transmutation of nuclear waste

    International Nuclear Information System (INIS)

    Saloman, R.; Aarnio, P.; Ala-Heikkila, J.; Hakola, A.; Santala, M.

    2007-01-01

    We have investigated narrow-band coherent laser radiation - ranging from visible to X- and to gamma-ray wave length region - and their interactions both directly with photon-nuclear couplings and indirectly through the photon-electron and electron-nucleus interactions. In particular we discuss various means of selective excitation of nuclear resonance states by narrowband lasers. During the relaxation process the active nucleus may return to its initial ground-state or find another final state. In the latter case the nucleus is transmuted into a state which may have beneficial properties for instance concerning radioactivity. One ideal case would be the destruction of long-lived nuclear waste isotopes into faster decaying ones. The essential presumption is that the excitation process is selective and efficient as regards background processes due to unwanted excitation channels of the primary isotope and due to other surrounding nuclides. The paper consists of 1) a short review of generating short-wave length coherent light sources, 2) a survey of potential photon-induced nuclear states and their decay channels, and 3) a determination of the selectivity of the transmutation process

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

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1982-01-01

    Reviews compendium containing recommended decay data for approx. 500 radionuclides of interest in nuclear medicine and fusion reactor technology or of potential importance in routine or accidental releases from the nuclear fuel cycle. Primary source of the decay data presented in this handbook is the Evaluated Nuclear Structure Data File (ENSDF), developed and maintained by the US Nuclear Data Network. Topics covered include various radioactive decay processes; evaluation process and standards of ENSDF; tables and computer code MEDLIST used to produce ENSDF tables; radiation dosimetry and radiological assessments; parent-daughter activity ratios wherever the adopted decay data may contain significant uncertainties or errors due to the lack of appropriate experimental data

  12. Optimized collection, storage and measurement of radon and radon decay products - school experiments

    International Nuclear Information System (INIS)

    Philipsborn, H. von; Geipel, R.; Just, G.

    1998-01-01

    Schools are expected more than ever to teach in physics and chemistry an understanding of radioactivity in its many aspects. Simple experiments on the occurrence, the measurement and the properties of radionuclides are necessary for true understanding. Such experiments are now possible with novel methods of collection and storage of ubiquitous radon and radon decay products from air, water and solids. (orig.) [de

  13. 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.

  14. General decay law for emission of charged particles and exotic cluster radioactivity

    International Nuclear Information System (INIS)

    Sahu, Basudeb; Paira, Ramkrishna; Rath, Biswanath

    2013-01-01

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

  15. 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.)

  16. Is the basic law of radioactive decay exponential?

    International Nuclear Information System (INIS)

    Gopych, P.M.; Zalyubovskii, I.I.

    1988-01-01

    Basic theoretical approaches to the explanation of the observed exponential nature of the decay law are discussed together with the hypothesis that it is not exponential. The significance of this question and its connection with fundamental problems of modern physics are considered. The results of experiments relating to investigation of the form of the decay law are given

  17. 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

  18. Physical limits on steam generation by radioactive decay heat

    International Nuclear Information System (INIS)

    Chesnut, D.A.

    1991-12-01

    This report briefly discusses the possibilities that flood water contacting the hot radioactive waste and rock at Yucca Mountain could produce enough steam to lift the top of the mountain off the repository

  19. 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)

  20. Agency practice and future policy in decay storage of radioactive wastes

    International Nuclear Information System (INIS)

    Mitchell, N.G.

    2002-01-01

    The Environment Agency issues authorisations under the Radioactive Substances Act 1993 for the accumulation of radioactive waste at non-nuclear sites prior to disposal. Radioactive decay during the accumulation period reduces the radioactive content of waste packages and provides a waste management option that has become known as decay-in-storage or decay storage. The project brief excluded nuclear licensed sites. A database of information in authorisations and application forms has been constructed. This information has been used alongside a literature review, international contacts, input from the Small Users Liaison Group and a dose assessment to look at the practice of decay storage. The basic principles behind decay storage are presented with specific sections on general safety, waste characterisation and segregation, storage containers, waste stores, and waste treatment and conditioning. The regulatory approach in seven other countries is described. The information collected from Agency public registers is summarised with particular attention given to storage periods of greater than 60 days and the corresponding information available from application forms. Operational experiences are presented. IAEA recommendations are compared with current practice based on the conditions found in authorisations, on the information from application forms and details provided by the Small Users Liaison Group

  1. Basic School Teachers' Knowledge and Attitude about Tooth Decay ...

    African Journals Online (AJOL)

    Basic School Teachers' Knowledge and Attitude about Tooth Decay and Practice ... Background: The important role of teachers in oral health education cannot be ... 60.3% of the teachers claimed spending time promoting for oral health.

  2. Improvement on a science curriculum including experimental demonstration of environmental radioactivity for secondary school students

    International Nuclear Information System (INIS)

    Watanabe, Kenji; Matsubara, Shizuo; Aiba, Yoshio; Eriguchi, Hiroshi; Kiyota, Saburo; Takeyama, Tetsuji.

    1988-01-01

    A science curriculum previously prepared for teaching environmental radioactivity was modified on the basis of the results of trial instructions in secondary schools. The main subject of the revised curriculum is an understanding of the natural radioactivity through the experimental demonstration about air-borne β and γ ray emitters. The other subjects included are the radioactive decay, the biological effects of radiation, the concept of risk-benefit balance (acceptable level) and the peaceful uses of nuclear energy and radiation. The work sheets and reference data prepared as learning materials are in two levels corresponding to the ability of students for this curriculum. (author)

  3. 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.

  4. Nuclear structure from radioactive decay: Annual progress report

    International Nuclear Information System (INIS)

    Wood, J.L.

    1988-01-01

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

  5. 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

  6. Radioactive decay of the late-time light curves of GRB-SNe

    Science.gov (United States)

    Misra, Kuntal; Fruchte, Andrew Steven

    2018-04-01

    We present the late-time Hubble Space Telescope observations of two GRB associated supernovae, GRB 030329/SN 2003dh and XRF 060218/SN 2006aj. Using the multi-color data upto ˜ 320 days after the burst, we constrain the late-time decay nature of these supernovae. The decay rates of SN 2003dh are steeper than SN 2006aj. A comparison with two other GRB supernovae, GRB 980425/SN 1998bw and the supernova associated with XRF 020903, shows that the decay rates of SN 2003dh are similar to XRF 020903 and those of SN 2006aj are similar to SN 1998bw. The late-time decay rates are steeper than the 56Co?56Fe radioactive decay rate (0.0098 mag day-1) indicating that there is some leakage of gamma-rays.

  7. 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

  8. Method for utilizing decay heat from radioactive nuclear wastes

    International Nuclear Information System (INIS)

    Busey, H.M.

    1974-01-01

    Management of radioactive heat-producing waste material while safely utilizing the heat thereof is accomplished by encapsulating the wastes after a cooling period, transporting the capsules to a facility including a plurality of vertically disposed storage tubes, lowering the capsules as they arrive at the facility into the storage tubes, cooling the storage tubes by circulating a gas thereover, employing the so heated gas to obtain an economically beneficial result, and continually adding waste capsules to the facility as they arrive thereat over a substantial period of time

  9. 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

  10. Nuclear structure from radioactive decay. Annual progress report

    International Nuclear Information System (INIS)

    Wood, J.L.

    1986-01-01

    The primary focus has been studies of intruder states and shape coexistence in the neutron-deficient Z equal to 82 region. Most notably, the structure of the neutron-deficient Au isotopes has been studied by on-line decay scheme spectroscopy of mass-separated isotopes at UNISOR, by on-line low-temperature nuclear orientation of mass-separated isotopes at LISOL, and by on-line laser atomic hyperfine spectroscopy of mass-separated isotopes at ISOLDE. Theoretical studies of neutron-deficient Au isotopes have been made. The most dramatic result is the observation of a sudden large increase in the mean-square charge radius between 187 Au and 186 Au, seen in the laser spectroscopy measurements as ISOLDE

  11. 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

  12. 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

  13. Application of the Laplace transform method for computational modelling of radioactive decay series

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Deise L.; Damasceno, Ralf M.; Barros, Ricardo C. [Univ. do Estado do Rio de Janeiro (IME/UERJ) (Brazil). Programa de Pos-graduacao em Ciencias Computacionais

    2012-03-15

    It is well known that when spent fuel is removed from the core, it is still composed of considerable amount of radioactive elements with significant half-lives. Most actinides, in particular plutonium, fall into this category, and have to be safely disposed of. One solution is to store the long-lived spent fuel as it is, by encasing and burying it deep underground in a stable geological formation. This implies estimating the transmutation of these radioactive elements with time. Therefore, we describe in this paper the application of the Laplace transform technique in matrix formulation to analytically solve initial value problems that mathematically model radioactive decay series. Given the initial amount of each type of radioactive isotopes in the decay series, the computer code generates the amount at a given time of interest, or may plot a graph of the evolution in time of the amount of each type of isotopes in the series. This computer code, that we refer to as the LTRad{sub L} code, where L is the number of types of isotopes belonging to the series, was developed using the Scilab free platform for numerical computation and can model one segment or the entire chain of any of the three radioactive series existing on Earth today. Numerical results are given to typical model problems to illustrate the computer code efficiency and accuracy. (orig.)

  14. Application of the Laplace transform method for computational modelling of radioactive decay series

    International Nuclear Information System (INIS)

    Oliveira, Deise L.; Damasceno, Ralf M.; Barros, Ricardo C.

    2012-01-01

    It is well known that when spent fuel is removed from the core, it is still composed of considerable amount of radioactive elements with significant half-lives. Most actinides, in particular plutonium, fall into this category, and have to be safely disposed of. One solution is to store the long-lived spent fuel as it is, by encasing and burying it deep underground in a stable geological formation. This implies estimating the transmutation of these radioactive elements with time. Therefore, we describe in this paper the application of the Laplace transform technique in matrix formulation to analytically solve initial value problems that mathematically model radioactive decay series. Given the initial amount of each type of radioactive isotopes in the decay series, the computer code generates the amount at a given time of interest, or may plot a graph of the evolution in time of the amount of each type of isotopes in the series. This computer code, that we refer to as the LTRad L code, where L is the number of types of isotopes belonging to the series, was developed using the Scilab free platform for numerical computation and can model one segment or the entire chain of any of the three radioactive series existing on Earth today. Numerical results are given to typical model problems to illustrate the computer code efficiency and accuracy. (orig.)

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

    International Nuclear Information System (INIS)

    Clegg, L.J.; Coady, J.R.

    1977-01-01

    The two books of Volume 1 comprise the first in a three-volume series of compilations on the radioactive decay propertis of CANDU fuel and deal with the natural uranium fuel cycle. Succeeding volumes will deal with fuel cycles based on plutonium recycle and thorium. In Volume 1 which is divided into three parts, the computer code CANIGEN was used to obtain the mass, activity, decay heat and toxicity of CANDU fuel and its component isotopes. Data are also presented on gamma spectra and neutron emissions. Part 3 contains the data relating to the plutonium product and the high level wastes produced during fuel reprocessing. (author)

  16. Radioactive decay pattern of actinides present in waste from Mo-99 production

    Energy Technology Data Exchange (ETDEWEB)

    Hiromoto, Goro; Dellamano, José Claudio, E-mail: hiromoto@ipen.br, E-mail: jcdellam@ipen.br [Instituto de PesquisasEnergéticas e Nucleares (GRR/IPEN/CNEN-SP), São Paulo, SP (Brazil). Gerência de Rejeitos Radioativos

    2017-07-01

    Brazil is currently planning to produce {sup 99}Mo from fission of LEU targets to meet the present national demand of {sup 99m}Tc. The {sup 99}Mo activity planned at the end of irradiation is 5000 Ci (185 TBq) per weekly cycle, in order to meet the present demand of 1000 Ci (37 TBq) per week, after target cooling and processing. To predict the activities that will be handled in the waste treatment facility, the computational code SCALE 6.0 was used to simulate the irradiation of the uranium targets and the decay of radioactive products. This study presents the findings of this research, mainly focused on the actinides activity that will be present in the waste and the respective radioactive decay pattern over a period of one hundred thousand years. (author)

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

    International Nuclear Information System (INIS)

    Plyaskin, V.I.; Kosilov, R.A.; Manturov, G.N.

    2001-01-01

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

  19. Effect of chemical structure on the radioactive decay rate of 71Ge

    International Nuclear Information System (INIS)

    Makariunas, K.; Makariuniene, E.; Dragunas, A.

    1979-01-01

    The influence of the chemical structure on the electron capture radioactive decay rate of 71 Ge was observed. 71 Ge nuclei in bivalent sulphide GeS decay faster than in quadrivalent sulphide GeS 2 . The relative change Δlambda/lambda of the decay constant lambda is + (11.4 +- 1.7) X 10 -4 . A possibility to use the experimental values of Δlambda/lambda to determine the chemical changes in the electron density at germanium nuclei in germanium chemical compounds is discussed. Quantitative determination of the changes in the electron density is complicated because of insufficient reliability of the published values of exchange and overlap corrections to the electron capture probabilities. (Auth.)

  20. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    García-Toraño, E., E-mail: e.garciatorano@ciemat.es [Laboratorio de Metrología de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Peyres, V. [Laboratorio de Metrología de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Bé, M.-M.; Dulieu, C.; Lépy, M.-C. [CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), Bldg 602, PC111, 91191 Gif-sur-Yvette Cedex (France); Salvat, F. [Facultat de Física (FQA and ICC), Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain)

    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.

  2. Chemical aspects of the radioactive decay 38S to 38Cl

    International Nuclear Information System (INIS)

    Leurs, C.J.

    1978-01-01

    The cyclotron-production of 38 S with the reaction 40 Ar(p,3p) 38 S is described. An excitation curve for this nuclear reaction is given and the chemistry used to produce sulfates labeled with 38 S and H 2 38 S is described. The probability distribution of the recoil energy of 38 Cl, produced by beta-decay of 38 S, is given. The probability for rupture of the original bonds due to the radioactive decay process, is estimated for gaseous H 2 38 S and for crystalline sulfates- 38 S. The results are given for the β,γ-decay of 38 S to 38 Cl under different circumstances in inorganic solid sulfates (with and without water of crystallization) and in the mixed crystal K 2 SO 4 .K 2 BeF 4 (1 : 2500). Finally, the reactions of 38 Cl, produced by radioactive decay of 38 S (as H 2 38 S) with gaseous 1,2-dichloroethylene are discussed

  3. 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)

  4. 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

  5. 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)

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

    International Nuclear Information System (INIS)

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

    2006-01-01

    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

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

    International Nuclear Information System (INIS)

    Batyrmurzaev, A.S.; Alibekov, G.I.; Bekieva, A.A.

    2003-01-01

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

  8. Apparatus and method for depressurizing, degassing, and affording decay of the radioactivity of weakly radioactive condensates in nuclear power plants

    International Nuclear Information System (INIS)

    Gross, R.; Plotz, J.

    1976-01-01

    Described is an apparatus for depressurizing, degassing and affording decay of weakly radioactive condensates in nuclear power plants having a turbine and a main condenser turbine wherein exhaust steam of the turbine is condensed and forms a main condensate, and includes a collecting tank for the condensate situated below the condenser. A plurality of horizontal degassing channels, each having a lateral overflow, are disposed in the upper part of the condensate collecting tank and are filled with the main condensate up to the level of the overflow. At least one feedwater preheater which is heated by bleeder steam from the turbine provides a secondary condensate. Below the overflow height of the degassing channels extend horizontal feed pipes for the secondary condensate. The feed pipes are connected to the output of pressure relieving expanding devices and are provided on their underside with discharge openings for the bubbling of the secondary condensate into the main condensate to thereby degass the main condensate. The condensate collecting tank has mutually offset partitions therein providing an adequately long path for the decay of the main and secondary condensates. The condensate which is discharged from the condensate collecting tank is returned into the cycle as feedwater. Also disclosed is a method of operating the foregoing apparatus

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

    International Nuclear Information System (INIS)

    Biju, R.K.; Sahadevan, Sabina; Santhosh, K.P.; Joseph, Antony

    2008-01-01

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

  10. 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

  11. 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

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

    CERN Document Server

    Bondarevskij, S I; Skorobogatov, G A

    2002-01-01

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

  13. 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

  14. Initiation to radioactivity in third form of grammar schools

    International Nuclear Information System (INIS)

    Moulin, G.; Blanc, J.C.; Juste, G.

    2001-01-01

    The initiation to radioactivity can be aimed at adolescents to sensitive them to radiation field and to allow them to fabricate a pertinent opinion about the use of nuclear energy. The pupils of the third form of grammar school make a research on radioactivity and the different kind of radiations. The pupils participate to the measurement of the radiation emitted by the radon daughter and find the usual experimental protocol. (N.C.)

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

    CERN Document Server

    Agosteo, S; Otto, T; Silari, Marco

    2003-01-01

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

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

    International Nuclear Information System (INIS)

    Tepel, J.W.; Mueller, H.W.

    1990-01-01

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

  17. 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

  18. The real-time fitting of radioactive decay curves. Pt. 3. Counting during sampling

    International Nuclear Information System (INIS)

    Hartley, B.M.

    1994-01-01

    An analysis of a least-squares method for the real-time fitting of the theoretical total count function to the actual total count from radioactive decays has been given previously for the case where counting takes place after a sample is taken. The counting may be done in a number of different counting systems which distinguish between different types or energies of radiation emitted from the sample. The method would allow real-time determination of the numbers of atoms and hence activities of the individual isotopes present and has been designated the Time Evolved Least-Squares method (TELS). If the radioactivity which is to be measured exists as an aerosol or in a form where a sample is taken at a constant rate it may be possible to count during sampling and by so doing reduce the total time required to determine the activity of the individual isotopes present. The TELS method is extended here to the case where counting and the evaluation of the activity takes place concurrently with the sampling. The functions which need to be evaluated are derived and the calculations required to implement the method are discussed. As with the TELS method of counting after sampling the technique of counting during sampling and the simultaneous evaluation of activity could be achieved in real-time. Results of testing the method by computer simulation for two counting schemes for the descendants of radon are presented. ((orig.))

  19. 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

  20. Source term evaluation model for high-level radioactive waste repository with decay chain build-up.

    Science.gov (United States)

    Chopra, Manish; Sunny, Faby; Oza, R B

    2016-09-18

    A source term model based on two-component leach flux concept is developed for a high-level radioactive waste repository. The long-lived radionuclides associated with high-level waste may give rise to the build-up of activity because of radioactive decay chains. The ingrowths of progeny are incorporated in the model using Bateman decay chain build-up equations. The model is applied to different radionuclides present in the high-level radioactive waste, which form a part of decay chains (4n to 4n + 3 series), and the activity of the parent and daughter radionuclides leaching out of the waste matrix is estimated. Two cases are considered: one when only parent is present initially in the waste and another where daughters are also initially present in the waste matrix. The incorporation of in situ production of daughter radionuclides in the source is important to carry out realistic estimates. It is shown that the inclusion of decay chain build-up is essential to avoid underestimation of the radiological impact assessment of the repository. The model can be a useful tool for evaluating the source term of the radionuclide transport models used for the radiological impact assessment of high-level radioactive waste repositories.

  1. α decay and cluster radioactivity of nuclei of interest to the synthesis of Z =119 , 120 isotopes

    Science.gov (United States)

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

    2018-04-01

    Super-heavy nuclei of interest for the forthcoming synthesis of the isotopes with Z =119 , 120 are investigated. One of the very interesting latest experiments was performed at the velocity filter SHIP (GSI Darmstadt) trying to produce 299120 in a fusion reaction 248Cm(54Cr,3 n )299120 . We report calculations of α -decay half-lives using four models: AKRA (Akrawy), ASAF (analytical superasymmetric fission), UNIV (universal formula), and semFIS (semi-empirical formula based on fission theory). The released energy, Q , is calculated using the theoretical model of atomic masses, WS4. For Sr,9492 cluster radioactivity of 120,302300 we predict a branching ratio relative to α decay of -0.10 and 0.49, respectively, meaning that it is worth trying to detect such kinds of decay modes in competition with α decay.

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

    International Nuclear Information System (INIS)

    Ihara, Hitoshi; Katakura, Jun-ichi; Nakagawa, Tsuneo

    1995-11-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-11-01

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

  4. Anomalous effects of radioactive decay rates and capacitance values measured inside a modified Faraday cage: Correlations with space weather

    Science.gov (United States)

    Scholkmann, F.; Milián-Sánchez, V.; Mocholí-Salcedo, A.; Milián, C.; Kolombet, V. A.; Verdú, G.

    2017-03-01

    Recently we reported (Milián-Sánchez V. et al., Nucl. Instrum. Methods A, 828 (2016) 210) our experimental results involving 226Ra decay rate and capacitance measurements inside a modified Faraday cage. Our measurements exhibited anomalous effects of unknown origin. In this letter we report new results regarding our investigation into the origins of the observed effects. We report preliminary findings of a correlation analysis between the radioactive decay rates and capacitance time series and space weather related variables (geomagnetic field disturbances and cosmic-ray neutron counts). A significant correlation was observed for specific data sets. The results are presented and possible implications for future work discussed.

  5. Decay schemes of the radioactive nuclei A = 225 to 229. Skhemy raspada radioaktivnykh yader A = 225 - 229

    Energy Technology Data Exchange (ETDEWEB)

    Dzhelepov, B S; Ivanov, R B; Mikhailova, M A

    1976-01-01

    This monograph is devoted to properties of atomic nuclei with mass numbers A = 225 to 229. The book collects and systematizes all of the experimental data characterizing properties of radioactive isotopes: information concerning masses of nuclei, magnetic and electric moments, lifetimes of nuclear states, the most reliable information on characteristics of radiations, quantum characteristics of levels and other properties of the studied nuclei. On basis of a critical analysis of the totality of information, decay schemes of radioactive nuclei with mass numbers A = 225 to 229 were constructed, as well as the series of excited states of the isotopes which lie in this region of nuclei.

  6. Measurement of relative L X-ray intensity ratio following radioactive decay and photoionization

    Energy Technology Data Exchange (ETDEWEB)

    Yalcin, P. [Department of Science Education, Faculty of Education, Erzincan University, 24030 Erzincan (Turkey)], E-mail: pasayalcin@hotmail.com; Porikli, S.; Kurucu, Y.; Sahin, Y. [Department of Physics, Faculty of Sciences, Atatuerk University, 25240 Erzurum (Turkey)

    2008-05-22

    The measurements of the L X-ray intensity ratio I(L{alpha})/I(L{beta}), I(L{alpha})/I(L{gamma}), I(L{alpha})/I(L{iota}), I(L{beta})/I(L{gamma}) and I(L{iota})/I(L{gamma}) for elements Dy, Ho, Yb, W, Hg, Tl and Pb were experimentally determined both by photon excitation, in which 59.5 keV {gamma}-rays from a filtered radioisotope {sup 241}Am was used, and by the radioactive decay of {sup 160}Tb, {sup 160}Er, {sup 173}Lu, {sup 182}Re, {sup 201}Tl, {sup 203}Pb and {sup 207}Bi. L X-rays emitted by samples were counted by a Si(Li) detector with resolution 160 eV at 5.9 keV. Obtained values were compared with the calculated theoretical values. Theoretical values of the I(L{alpha}/L{beta}), I(L{alpha}/L{gamma}), I(L{alpha}/L{iota}), I(L{beta}/L{gamma}) and I(L{iota}/L{gamma}) intensity ratios were calculated using theoretically tabulated values of subshell photoionization cross-section, fluorescence yield, fractional X-ray emission rates, Coster-Kronig transition probabilities. It was observed that present values agree with previous theoretical and other available experimental results.

  7. 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.

  8. 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.)

  9. 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)

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

    International Nuclear Information System (INIS)

    Longour, Christophe

    1999-01-01

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

  11. Computer simulation of the natural U 238 and U 235 radioactive series decay

    International Nuclear Information System (INIS)

    Barna, A.; Oncescu, M.

    1980-01-01

    The principles of the computer simulation of a radionuclide decay - its decay scheme adoption and codification -, and the adoption principle of a radionuclide chain in a series are applied to the natural U 238 and U 235 series radionuclide decay computer simulation. Using the computer simulation data of these two series adopted chains, the decay characteristic quantities of the series radionuclides, the gamma spectra and the basic characteristics of each of these series are determined and compared with the experimental values given in the literature. (author)

  12. Developing an education programme for schools on radioactive waste management

    International Nuclear Information System (INIS)

    Curd, P.J.; Hutchins, J.S.

    1991-01-01

    United Kingdom Nirex Ltd. is responsible for the development of a deep disposal facility for Britain's solid low and intermediate-level radioactive wastes. In line with their technical programme Nirex has a substantial public information programme costing in excess of Brit-pounds 1M per year. An important part of this programme is the need to develop an effective education programme for schools. This paper details the development and content of this education programme and the rationale behind the development in its current form

  13. 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.

  14. Prospects for studies of ground-state proton decays with the Holifield Radioactive Ion Beam Facility

    International Nuclear Information System (INIS)

    Toth, K.S.

    1994-01-01

    By using radioactive ions from the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory it should be possible to identify many new ground-state proton emitters in the mass region from Sn to Pb. During this production and search process the limits of stability on the proton-rich side of the nuclidic chart will be delineated for a significant fraction of medium-weight elements and our understanding of the proton-emission process will be expanded and improved

  15. The use of radioactive materials in German schools. Obstacles and chances

    International Nuclear Information System (INIS)

    Vahlbruch, Jan-Willem

    2015-01-01

    The basics for the understanding of radioactivity and radioprotection are set in the secondary school. Therefore the German-Swiss Radiation Protection Association already is trying to support the appropriate teaching of relevant topics in school for a long time. Unfortunately experiments with radioactive material are hampered in Germany by complex and confusing legislation. In this contribution the framework is described which is given by the German legislation for the use of radioactive sources in secondary schools. Additionally proposals for different simple experiments with radioactivity are presented which can be easily implemented in teaching and alternative methods are introduced like e.g. virtual experiments.

  16. 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)

  17. Paul Trapping of Radioactive 6He+ Ions and Direct Observation of Their β Decay

    International Nuclear Information System (INIS)

    Flechard, X.; Lienard, E.; Mery, A.; Rodriguez, D.; Ban, G.; Durand, D.; Duval, F.; Herbane, M.; Labalme, M.; Mauger, F.; Naviliat-Cuncic, O.; Velten, Ph.; Thomas, J. C.

    2008-01-01

    We demonstrate that abundant quantities of short-lived β unstable ions can be trapped in a novel transparent Paul trap and that their decay products can directly be detected in coincidence. Low energy 6 He + (807 ms half-life) ions were extracted from the SPIRAL source at GANIL, then decelerated, cooled, and bunched by means of the buffer gas cooling technique. More than 10 8 ions have been stored over a measuring period of six days, and about 10 5 decay coincidences between the beta particles and the 6 Li ++ recoiling ions have been recorded. The technique can be extended to other short-lived species, opening new possibilities for trap assisted decay experiments

  18. 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.)

  19. 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)

  20. Abnormal radioactive decays out of long-lived super- and hyper-deformed isomeric states

    International Nuclear Information System (INIS)

    Marinov, A.; Gelberg, S.; Kolb, D.

    2000-01-01

    Complete text of publication follows. Recently (1-3) long-lived isomeric states have been found in the super- and hyper-deformed wells of the potential. These isomers manifested themselves by abnormal particle decays. An isomeric state in the superdeformed well of the potential in the parent nucleus can decay by very enhanced α-particle groups to superdeformed states in the daughter (1) or by very retarded α-particles (3) and also by protons (2) to normal states in the daughters. Similarly an isomeric state in the hyper-deformed well may decay by very retarded α-particle groups to superdeformed states (3), or by very enhanced α-groups to hyper-deformed states in the daughter nucleus (4). All these very unusual decay modes have been observed experimentally (1-4). For instance, a very high energy α-group of 8.6 MeV with 40d ≤ t 1/2 ≤ 2y (retardation factor of ∼10 13 ) has been observed in 195 Hg and interpreted as a III min → II min α-transition (3). Likewise, relatively low-energy and very enhanced α-particle groups (enhancement factors of 10 5 to 10 7 ) have been seen in several actinide sources and interpreted as due to II min → II min and III min → III min transitions (4). These unusual decay modes introduce new considerations in the study of heavy and superheavy elements. For instance, if low-energy α-particle groups around 4.4 - 4.6 MeV have been seen in nature (5), they may be interpreted as due to very enhanced III min → III min transitions in the superheavy element region around Z = 108 (eka-Os) with t 1/2 ∼10 8 y rather than ∼10 15 y as expected for normal α-transitions of such energies in this region, or due to very retarded III min → II min or II min → I min decays in nuclei around Os itself. In both cases, if such activities have been seen in nature, they indicate that the existence of the II min and III min isomeric states may be important in the nucleosynthesis process. It should be mentioned that long-lived high

  1. 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.

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

    International Nuclear Information System (INIS)

    Clegg, L.J.; Coady, J.R.

    1977-01-01

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

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

    International Nuclear Information System (INIS)

    Apelgot, Sonia

    1968-01-01

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

  4. Studies of new modes of radioactive decay by spontaneous emission of complex nuclei

    International Nuclear Information System (INIS)

    Barwick, S.W.; Hulet, E.K.; Moody, K.; Price, P.B.; Ravn, H.L.

    1990-01-01

    Impressive progress has been made in the two years since Rose and Jones first reported the novel spontaneous decay mode 223 Ra → 14 C + 209 Pb. Since then, the isotopes 222 Ra, 224 Ra, and 226 Ra have been observed to emit 14 C, and stringent upper limits have been set on branching ratios B( 14 C/α) for 221 Ra and 225 Ac. The discoveries of emission of 24 Ne from 232 U, and 231 Pa, and 233 U show that the phenomenon of heavy ion emission is a general one. A goal of recent experiments by the authors collaboration is to test models that differ by as much as 10 5 in predicted half-lives for the emission of complex nuclei with Z ≥ 12. Due to small branching ratios B approx-lt 10 -14 , and large fission background, they are developing new techniques to insure reliable identification of such rare decay modes. Experimental support for the unified models of alpha decay, complex nuclei emission, and spontaneous fission are addressed

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

    International Nuclear Information System (INIS)

    Navarrete, J.M.; Cabrera, L.; Martinez, T.

    2005-01-01

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

  6. Preventing Tooth Decay: A Guide for Implementing Self-Applied Fluoride in Schools.

    Science.gov (United States)

    National Inst. of Dental Research (NIH), Bethesda, MD.

    This guidebook was developed to assist citizens in initiating programs to prevent tooth decay in young children through the use of fluoridation. It contains outlines for determining the needs of the school and community for fluoride in drinking water, and presents the various steps and activities that are necessary for developing and implementing…

  7. 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

  8. Decay tank

    International Nuclear Information System (INIS)

    Matsumura, Seiichi; Tagishi, Akinori; Sakata, Yuji; Kontani, Koji; Sudo, Yukio; Kaminaga, Masanori; Kameyama, Iwao; Ando, Koei; Ishiki, Masahiko.

    1990-01-01

    The present invention concerns an decay tank for decaying a radioactivity concentration of a fluid containing radioactive material. The inside of an decay tank body is partitioned by partitioning plates to form a flow channel. A porous plate is attached at the portion above the end of the partitioning plate, that is, a portion where the flow is just turned. A part of the porous plate has a slit-like opening on the side close to the partitioning plate, that is, the inner side of the flow at the turning portion thereof. Accordingly, the primary coolants passed through the pool type nuclear reactor and flown into the decay tank are flow caused to uniformly over the entire part of the tank without causing swirling. Since a distribution in a staying time is thus decreased, the effect of decaying 16 N as radioactive nuclides in the primary coolants is increased even in a limited volume of the tank. (I.N.)

  9. The problem in 180 deg data sampling and radioactivity decay correction in gated cardiac blood pool scanning using SPECT

    International Nuclear Information System (INIS)

    Ohtake, Tohru; Watanabe, Toshiaki; Nishikawa, Junichi

    1986-01-01

    In cardiac blood pool scanning using SPECT, half 180 deg data collection (HD) vs. full 360 deg data collection (FD) and Tc-99m decay are problems in quantifying the ejection count (EC) (end-diastolic count - end-systolic count) of both ventricles and the ratio of the ejection count of the right and left ventricles (RVEC/LVEC). We studied the change produced by altering the starting position of data sampling in HD scans. In our results of phantom and 4 clinical cases, when the cardiac axis deviation was not large and there was not remarkable cardiac enlargement, the change in LVEC, RVEC and RVEC/LVEC was small (1 - 4 %) within 12 degree change of the starting position, and the difference between the results of HD scan with a good starting position (the average of LV peak and RV peak) and FD scan was not large (less than 7 %). Because of this, we think HD scan can be used in those cases. But when the cardiac axis deviation was large or there was remarkable cardiac enlargement, the change of LVEC, RVEC and RVEC/LVEC was large (more than 10 %) even within 12 degree change of the starting position. So we think FD scan would be better in those cases. In our results of 6 patients, the half-life of Tc-99m labeled albumin in blood varied from 2 to 4 hr (3.03 ± 0.59 hr, mean ± s.d.). Using a program for radioactivity (RA) decay correction, we studied the change in LVEC, RVEC and LVEC/RVEC in 11 cases. When RA decay correction was performed using a halflife of 3.0 hr, LVEC increased 7.5 %, RVEC increased 8.7 % and RVEC/LVEC increased 0.9 % on the average in HD scans of 8 cases (LPO to RAO, 32 views, 60 beat/1 view). We think RA decay correction would not be needed in quantifying RVEC/LVEC in most cases because the change of RVEC/LVEC was very small. (author)

  10. Radioactivity of radon and its short-lived decay products in room air, 2

    International Nuclear Information System (INIS)

    Shimo, Michikuni; Katoh, Takao

    1983-01-01

    In the reactor room of the Kyoto University Research Reactor Institute, the measurements of radon (Rn) and its short-lived decay products (Rn-Dts) were carried out under ventilated and non-ventilated conditions. The indoor activities were equal to outdoor ones under ventilated condition and those activities increased till about 10 times of outdoors under non-ventilated condition. We attempted to explain these results on a basis of a simple model. The calculations were performed taking into account: (1) supply of Rn and Rn-Dts from outdoor, (2) the emanation rate of Rn from the wall materials of building, (3) the removal rate of Rn-Dts by ventilation and wall deposition, and (4) the attachment rate of unattached atom to aerosols. In addition, natural ventilation were considered during periods without artificial ventilation. (author)

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

    International Nuclear Information System (INIS)

    Linz, U.

    1983-09-01

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

  12. 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

  13. Radioactive contamination status of an elementary school in southern Miyagi Prefecture, Japan, four years after decontamination

    International Nuclear Information System (INIS)

    Yamaguchi, Toshiro; Sato, Mitsuyoshi; Nagakubo, Kazuyoshi

    2017-01-01

    We investigated the radioactive contamination status of an elementary school in southern Miyagi Prefecture, Japan, four years after decontamination. The radioactive dose rate was measured in the playground (n = 36), back yard (n = 1), parking lot (n = 3), and gutters (n = 30) with a thallium-activated sodium iodide scintillation detector. In addition, topsoil from the playground and gutters sediment were measured with a high-purity germanium semiconductor detector, and sand from the parking lot and sediment from gutters was imaged following an autoradiography method. The mean radioactive dose rate in the playground was almost 0.08 μSv/h. The dose rate was higher at sites facing the mountains, near the main gate, and by the front entrance of the school building. Meanwhile, the radioactive cesium (Cs) concentration of sediment imaged using autoradiography was > 8,000 Bq/kg. These results indicated that the radioactive dose rates in the decontaminated school were below the threshold for being a health hazard. However, the topsoil in the playground had been re-contaminated with radioactive Cs, which had likely been transported via dirt attached to children's shoes and car tires. In addition, the radioactive sediment in the gutters had likely been contaminated by rainwater, suggesting that radioactive protection is necessary when handling gutter sediment. (author)

  14. Decays of 22Al and 26P: discovery of beta-delayed two-proton radioactivity

    International Nuclear Information System (INIS)

    Cable, M.D.

    1983-02-01

    A helium-jet system and the 24 Mg( 3 He,p4n) 22 Al and 28 Si( 3 He,p4n) 26 P reactions have been used to discover the only known odd-odd, T/sub Z/ = -2 nuclides, 22 Al(t/sub 1/2/ approx. 70ms) and 26 P(t/sub 1/2/ approx. 20 ms). Observations of beta-delayed protons from each isotope (laboratory energies 7.839 +- 0.015 MeV and 8.149 +- 0.021 MeV for 22 Al and 7.269 +- 0.015 MeV and 6.827 +- 0.050 MeV for 26 P) established the existence of these nuclides and provided a measurement of the mass excesses of the lowest T = 2 states in their beta decay daughters, 22 Mg and 26 Si (13.650 +- 0.015 MeV and 5.936 +- 0.015 MeV, respectively). Measurement of these masses confirmed that these T = 2 states were unbound to two-proton emission as had been predicted theoretically

  15. Application of the equations of radioactive growth and decay to geochronological models and explicit solution of the equations by Laplace transformation

    International Nuclear Information System (INIS)

    Catchen, G.L.

    1984-01-01

    A recently developed method of pore-fluid age determination assumes secular equilibrium in the 238 U decay chain. The efficacy of this approximation is investigated using computer evaluations of the equations that give the time evolution of the 238 U decay chain, i.e. the solution of the equations of radioactive growth and decay. This analysis is performed considering two alternative geochemical scenarios to that of secular equilibrium - only 238 U present initially and 238 U and 234 U present initially. In addition, the effects of the 235 U decay chain are also determined in a similar fashion. These particular examples were chosen to show that more sophisticated geochronological models for many dating applications can be developed using such computer calculations. To facilitate such analyses, a solution of the equations of radioactive growth and decay for an arbitrary initial condition is derived using the Laplace transformation method and matrix algebra. Other solutions - both general and special - that are found in some well-known textbooks are reviewed. (orig.)

  16. Radioactivity

    International Nuclear Information System (INIS)

    Chelet, Y.

    2006-01-01

    The beginning of this book explains the why and how of the radioactivity, with a presentation of the different modes of disintegration. Are tackled the reports between radioactivity and time before explaining how the mass-energy equivalence appears during disintegrations. Two chapters treat natural radioisotopes and artificial ones. This book makes an important part to the use of radioisotopes in medicine (scintigraphy, radiotherapy), in archaeology and earth sciences (dating) before giving an inventory of radioactive products that form in the nuclear power plants. (N.C.)

  17. 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.)

  18. 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.

  19. 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)

  20. Radioactivity in school lunch. Concrete proposal for protecting children from unnecessary internal exposure

    International Nuclear Information System (INIS)

    Nakagawa, Naoko; Hasui, Seiichiro; Haraguchi, Yayoi

    2012-01-01

    After the reactor accident of Fukushima nuclear power plant in Japan on March 11, 2011, many food adopted widely in school food service such as rice, wheat, milk are known to have risk for radioactivity contamination. To protect all children from exposure, the authors quantitatively examined risk assessment coming from food and conclude that radioactivity due to cesium 137 in rice, wheat, and milk for school lunch should be less than 10 Bq/kg and, furthermore from 2013, as lower as possible and less than 5 Bq/kg. (S. Ohno)

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

    Directory of Open Access Journals (Sweden)

    Hideyuki Doi

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

  2. 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

  3. [Dynamics of tooth decay prevalence in children receiving long-term preventive program in school dental facilities].

    Science.gov (United States)

    Avraamova, O G; Kulazhenko, T V; Gabitova, K F

    2016-01-01

    The paper presents the assessment of tooth decay prevalence in clinically homogenous groups of children receiving long-term preventive program (PP) in school dental facilities. Five-years PP were introduced in clinical practice in 2 Moscow schools. Preventive treatment was performed by dental hygienist. The results show that systematic preventive treatment in school dental offices starting from elementary school allows reducing dental caries incidence 46-53% and stabilize the incidence of caries complications. It should be mentioned though that analysis of individualized outcomes proves heterogeneity of study results despite of equal conditions of PP. Potentially significant hence is early diagnostics and treatment of initial caries forms as demineralization foci, especially in children with intensive tooth decay. Optimization of pediatric dentist and dental hygienist activity in school dental facilities is the main factor of caries prevention efficiency.

  4. Vital Signs: Dental Sealant Use and Untreated Tooth Decay Among U.S. School-Aged Children.

    Science.gov (United States)

    Griffin, Susan O; Wei, Liang; Gooch, Barbara F; Weno, Katherine; Espinoza, Lorena

    2016-10-21

    Tooth decay is one of the greatest unmet treatment needs among children. Pain and suffering associated with untreated dental disease can lead to problems with eating, speaking, and learning. School-based dental sealant programs (SBSP) deliver a highly effective intervention to prevent tooth decay in children who might not receive regular dental care. SBSPs benefits exceed their costs when they target children at high risk for tooth decay. CDC used data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 to estimate current prevalences of sealant use and untreated tooth decay among low-income (≤185% of federal poverty level) and higher-income children aged 6-11 years and compared these estimates with 1999-2004 NHANES data. The mean number of decayed and filled first molars (DFFM) was estimated for children with and without sealants. Averted tooth decay resulting from increasing sealant use prevalence was also estimated. All reported differences are significant at pdental sealant use has increased; however, most children have not received sealants. Increasing sealant use prevalence could substantially reduce untreated decay, associated problems, and dental treatment costs.

  5. How the schools can participate in measuring radon, thoron and radioactive fallout

    International Nuclear Information System (INIS)

    Storruste, A.; Larsen, E.

    1989-12-01

    The Chernobyl accident revealed that people in general have very little knowledge about radioactivity. The general knowledge should be improved rather cheaply and with small efforts through the introduction of a few experiments into the school curriculum. In the report some simple experiments of this kind are described. All the main apparatus needed are an ordinary GM counter and a vacuum cleaner. By using the same method at many schools, the data from the measurement of natural radioactivity variations in the air throughout the year could be usefully collected and collated. This would make the experiments more interesting than an experiments having no other purpose than the learning process itself. 12 refs.; 5 figs

  6. 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

  7. [Experimental model of tooth decay as an educational tool for school-age children].

    Science.gov (United States)

    de Araújo Silva, Thiago Fernando; Feitosa, José Leonilson; Medeiros Dantas, Rodrigo Maristony; Dantas de Medeiros, Fabianna da Conceição; Cavalcanti Lima, Isabela Pinheiro; Guerra Seabra, Eduardo José

    2016-04-01

    Objective This work consisted of the construction of an educational in vitro model of dental caries that started with an adaptation of Miller's classic experiment. Methods In a sterilized and sealed glass jar, a sample paste of human saliva was collected and a substrate of manufactured sugar (sucrose) was added. In addition, a human tooth with healthy dental crown extracted in dental treatment but otherwise healthy was added. Research phase I had the negative control sample test (tooth + saliva without added) and the others were opened after 1, 2, 3 and 4 months of incubation. This phase was essential for the next experimental time development. In phase II, two saliva donors with poor levels of oral health habits were recruited. The incubation time (defined by phase I) was 2 and 3 months for each donor. Results This research data gives the possibility of building educational materials about the etiology of tooth decay and its clinical evolution. It also makes possible the production of an explanatory sheet about how to reproduce this experimental model to be used by school children in secondary education. Conclusions Doing this kind of work together at school can help reduce inequities in oral health, especially since there is an approximation toward the discourses, facilitating the process of information dissemination.

  8. Radioactivity decontamination in and around school facilities in Fukushima

    International Nuclear Information System (INIS)

    Saegusa, Jun; Tagawa, Akihiro; Kurikami, Hiroshi; Iijima, Kazuki; Yoshikawa, Hideki; Tokizawa, Takayuki; Nakayama, Shinichi; Ishida, Junichiro

    2016-01-01

    Approximately two months after the Fukushima nuclear accident, the Japan Atomic Energy Agency (JAEA) led off a series of demonstration tests to develop effective but easily applicable decontamination methods for various school facilities in Fukushima. This effort included (1) dose reduction measures in schoolyards, (2) purification of swimming pool water, and (3) removal of surface contamination from playground equipment. Through these demonstration tests, they established practical methods suitable for each situation: (1) In schoolyards, dose rates were drastically reduced by removing topsoil, which was then placed in 1-m-deep trenches at a corner of the schoolyard. (2) For the purification of pool water, the flocculation coagulation treatment was found to be effective for collecting radiocesium dissolved in the water. (3) Demonstration tests for playground equipment, such as horizontal bars and a sandbox wood frame indicated that the decontamination effectiveness considerably varied depending on the material, paint or coating condition of each equipment piece. These findings were summarized in reports, some of which were compiled in local/national guidelines or handbooks for decontaminating the living environment in Fukushima. (author)

  9. Radioactivity decontamination in and around school facilities in Fukushima

    International Nuclear Information System (INIS)

    Saegusa, Jun; Iijima, Kazuki; Yoshikawa, Hideki; Ishida, Junichiro; Tagawa, Akihiro; Kurikami, Hiroshi; Nakayama, Shinichi; Tokizawa, Takayuki

    2015-01-01

    Approximately two months after the Fukushima nuclear accident, the Japan Atomic Energy Agency (JAEA) led off a series of demonstration tests to develop effective but easily applicable decontamination methods for various school facilities in Fukushima. This effort included (1) dose reduction measures in schoolyards, (2) purification of swimming pool water, and (3) removal of surface contamination from playground equipment. Through these demonstration tests, they established practical methods suitable for each situation: (1) In schoolyards, dose rates were drastically reduced by removing topsoil, which was then placed in 1-m-deep trenches at a corner of the schoolyard. (2) For the purification of pool water, the flocculation coagulation treatment was found to be effective for collecting radiocesium dissolved in the water. (3) Demonstration tests for playground equipment, such as horizontal bars and a sandbox wood frame indicated that the decontamination effectiveness considerably varied depending on the material, paint or coating condition of each equipment piece. These findings were summarized in reports, some of which were compiled in local/national guidelines or handbooks for decontaminating the living environment in Fukushima. (author)

  10. Toward improvements of the education concerning radiation, radioactivity, and nuclear energy in high schools in Japan

    International Nuclear Information System (INIS)

    Matsuura, Tatsuo

    1996-01-01

    Despite the high scientific and technical level of research and practical applications of radiation, radioactivity, and nuclear energy in Japan, the level of education concerning these matters at primary school and junior and high schools seems to be considerably behind the world, according to a recent comparative survey among six European countries and Japan. It has also been found that the description of these matters in current textbooks of science and social studies in senior high schools in Japan is generally not satisfactory, both in scope and in correctness. There are many reasons for this observation. One is the fact that many Japanese people including writers of textbooks have an excessive fear for radiation and radioactivity, and consequently are critical of the use of nuclear energy. Another is that Japanese teachers also have similar feeling and tend to avoid teaching about such controversial subject. This comes from the educational policy of Monbusho, Ministry of Education, Science and Culture; the nuclear-related matters are not being given an appropriate educational position, despite their importance in the national energy policy determined by the Atomic Energy Commission of Japan. In addition, there are several unfortunate educational circumstances. These include, limitations of hours of teaching allotted to the subject of science, the system of choosing curricula among several menus in the subject, the shortage of experimental instruments available in classroom, the severe safety regulation in handling even a very small amount of radioactivity, extraordinary fear for radiation and radioactivity by students, teachers, and their supervisors, the rare appearance of these topics in the problems at the entrance examination of universities. This paper discusses various ways to correct the situation and reports on our recent activities for improving means of education such as textbooks and the official guidelines. (J.P.N.)

  11. 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)

  12. 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

  13. 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

  14. Ratio of thyroid radioiodine uptake calculated via the physic decay rate of the standard radioactive source: a preliminary study

    International Nuclear Information System (INIS)

    Zeng Yu; Zhou Luyi

    2010-01-01

    Objectives: To compare the difference of the ratio of thyroid radioiodine ( 131 I) uptake calculated by actually measuring counts of the standard radioactive source(method 1) and by computing counts of the standard radioactive source via physic half life of 131 I (method 2). Methods: Two hundred and nine consecutive patients with Graves' Disease were prospectively recruited. The ratio of thyroid 131 I uptake was calculated by two methods at 4 h and 24 h after administration of 1.48 MBq 131 I, respectively. Paired t-test was used to compare the difference between the two methods. Results: The ratio of thyroid 131 I uptake at 4h was (32±16)% and ( 35±10)% (t=1.98, P=0.20), at 24h (72±19)% and (69±24)% ( t=1.49, P=0.23), respectively, by the two methods. Conclusion: To calculate the ratio of thyroid 131 I uptake via the physic half life of the standard radioactive resource is feasible, and can both reduce the risk of ionizing radiation to technical staff and act as verifying method for quality control of thyroid function equipment. (authors)

  15. 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

  16. Education in the radioactivity field: a project for the italian schools

    International Nuclear Information System (INIS)

    Venoso, G.; Bertucci, A.; Balzano, E.; Giberti, G.; Pugliese, M.; Roca, V.; Romano, M.; Venoso, G.; Balzano, E.; D'Onofrio, A.; Gialanella, L.; Giberti, G.; Pugliese, M.; Roca, V.; Romano, M.; Sabbarese, C.; D'Onofrio, A.; Sabbarese, C.; Bertucci, A.

    2006-01-01

    Environmental topics are today at the centre of the public attention, but people mostly does not have cultural tools for an adequate knowledge. The radioactivity, in particular, is generally misunderstood and this had negatively influence debate about the energy. To fill this gap science subjects need to be study in school with a more efficient approach. Many efforts have spent to obtain this goal: in this framework the Envirad project was developed with the aim to make students of high schools of Campania Region (south-Italy) able to practice experimental method involving directly them in a real environmental physics experiment [1]. The aim of this project, developed by the grant of the Istituto Nazionale di Fisica Nucleare, is that the effective experimental activity is the best way to provide for an adequate scientific background. (N.C.)

  17. New type of natural radioactivity

    International Nuclear Information System (INIS)

    Rubchenya, V.A.; Chechev, V.P.; Yavshits, S.G.

    1987-01-01

    Consideration is being given in popular form to investigations of a new type of natural radioactivity - spontaneous emission of fragments, more massive than α-particles, by heavy element nuclei, called f-decay by analogy with known α and γ decays. Some data on radioactivity, origin of the decay are presented. Possibilities of f-decay, predictions and hypotheses are discussed. The reason of late discovery of f-decay lies in low f-decay probability 10 -9 with respect to α-decay and in a certain sluggishness of settled knowledge about possible types of radioactive decay. The idea of f-decay is presented. It differs from the idea about a new type of decay as modification of asymmetric fission and contains an attempt to explain the intermediate position of f-decay between α-decay and

  18. 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

  19. Studies od radioactive decay after-effects by the method of perturbed angular γγ-correlation

    International Nuclear Information System (INIS)

    Shpinkova, L.G.

    2002-01-01

    One of the methods applied for electron capture (Ec) after-effects studied is the time differential perturbed angular γγ-correlation (Tdpa( technique, which allows investigating hyperfine interactions of electromagnetic moments of nuclei with extranuclear fields created by electrons and ions around the probe atom in the studied matrix. After-effects can differentially affect the observed angular correlation and, thus, be studied by this method. The experiments performed so far with different nuclei in different matrixes showed that the after-effects are not important in TDPAC studies of metallic systems because of a considerable lag caused by a finite lifetime of the initial state of the γγ-cascade and the fast relaxation due to conduction electrons. In insulators and oxides. the after-effects should be taken into account while interpreting experimental data . A problem of molecular dynamic studies in liquids obscured by after-effects was also mentioned in the literature. A possibility of molecule disintegration caused by EC after-effects, initiated by the Auger-process was studied for 111 In-complexes with diethylenetriaminepentaacetic acid in neutral aqueous solutions. The results of the work showed directly that the AC after-effects could cause the metal-legand complexes disintegration. The observation of the non-equilibrium fraction with presumably high transient gradients caused by both a relaxation from the highly ionised state od 111 Cd (the daughter nucleus in the EC decay of 111 In) and rearrangement of the chemical bonds allowed assessing the time required for these transient processes (before complex disintegration or complex relaxation to the equilibrium state)

  20. The use of radioactive materials in German schools. Obstacles and chances; Anwendung von radioaktiven Stoffen in Schulen in Deutschland. Hindernisse und Chancen

    Energy Technology Data Exchange (ETDEWEB)

    Vahlbruch, Jan-Willem [Hannover Univ. (Germany). Inst. fuer Radiooekologie und Strahlenschutz

    2015-07-01

    The basics for the understanding of radioactivity and radioprotection are set in the secondary school. Therefore the German-Swiss Radiation Protection Association already is trying to support the appropriate teaching of relevant topics in school for a long time. Unfortunately experiments with radioactive material are hampered in Germany by complex and confusing legislation. In this contribution the framework is described which is given by the German legislation for the use of radioactive sources in secondary schools. Additionally proposals for different simple experiments with radioactivity are presented which can be easily implemented in teaching and alternative methods are introduced like e.g. virtual experiments.

  1. Experiments with radioactive materials at schools. Didactically important and possible without risk; Experimente mit radioaktiven Stoffen an Schulen. Didaktisch wichtig und gefahrlos moeglich.

    Energy Technology Data Exchange (ETDEWEB)

    Vahlbruch, Jan-Willem [Hannover Univ. (Germany). Inst. fuer Radiooekologie und Strahlenschutz

    2017-04-01

    The basis for the understanding of radioactivity and radioprotection is formed in the secondary school. Therefore, the German-Swiss Radiation Protection Association has been trying to support the appropriate teaching of relevant topics in school for a long time. Unfortunately experiments with radioactive materials are hampered in Germany by complex and confusing legislation. In this contribution the framework is described which is given by the German legislation for the use of radioactive sources in secondary schools. Additionally, proposals for different simple experiments with radioactivity are presented, alternative methods like e.g. virtual experiments are introduced and a recommendation for a simplified regulatory framework is made.

  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. The importance of early-school radioactivity education in cultivating proper reflexive judgement on radiation

    International Nuclear Information System (INIS)

    Nishina, Kojiro

    1999-01-01

    An attempt is made to draw a preliminary conclusion on the effectiveness of early-school education on radioactivity, based on two cases of student responses. The first is the returns of questionnaires circulated at two colleges, which were typical of an engineering college and a liberal-arts college, respectively. The second is the reactions of liberal arts students to observed, unexpected levels of radiation in their environment. Their reaction was dominated by their preoccupation on radiation, rather than by the quantitative data they themselves collected on the spot. Thus classes in early schooldays are considered to play a vital role in cultivating proper judgement they are to rely on as general citizens. (author)

  4. The importance of early-school radioactivity education in cultivating proper reflexive judgement on radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nishina, Kojiro [Aichi Shukutoku Univ., The College of Contemporary Social Studies, Nagakute, Aichi (Japan)

    1999-09-01

    An attempt is made to draw a preliminary conclusion on the effectiveness of early-school education on radioactivity, based on two cases of student responses. The first is the returns of questionnaires circulated at two colleges, which were typical of an engineering college and a liberal-arts college, respectively. The second is the reactions of liberal arts students to observed, unexpected levels of radiation in their environment. Their reaction was dominated by their preoccupation on radiation, rather than by the quantitative data they themselves collected on the spot. Thus classes in early schooldays are considered to play a vital role in cultivating proper judgement they are to rely on as general citizens. (author)

  5. 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.

  6. Helium 3 precipitation in AISI 316L stainless steel induced by radioactive decay of tritium: Microstructural study of helium bubble precipitation

    International Nuclear Information System (INIS)

    Brass, A.M.; Chene, J.

    1994-01-01

    The development of the thermonuclear technology has given rise to a renewed interest in the study of the behavior of helium in metals. A great amount of work is still required for the understanding of the role of helium on the mechanical properties of structural materials for fusion technology, especially austenitic stainless steels. This article deals with the study of the influence of thermomechanical heat treatments, aging conditions (temperature and time), and helium concentration of helium bubble precipitation in a 316L austenitic steel. Helium was generated by the radioactive decay of tritium (tritium trick). Helium bubbles impede the grain growth in 316L steel aged at 1,373 K and also the recrystallization reaction at this temperature if cold working is performed prior to aging. Transmission electron microscopy (TEM) observations indicated a weak helium precipitation at 1,073 and 1,223 K, presumably due to the presence of trapping sites for tritium, and no bubble growth after aging up to 100 hours. Precipitation sites are mainly dislocations in the matrix at 1,073 K and grain boundaries and individual dislocations in the matrix at 1,223 K. The large bubble size (50 nm) observed at 1,373 K, even for short aging times (0.083), can partly be attributed to bubble dragging by dislocations toward the grain boundaries. Cold deformation prior to aging leads to a larger bubble size due to growth enhancement during recrystallization. Decreasing the helium content leads to a smaller helium bubble size and density. Tritium trapping at helium bubbles may favor helium 3 accumulation on defects such as grain boundaries, as observed by tritium autoradiography

  7. Nuclear structure from radioactive decay

    International Nuclear Information System (INIS)

    Wood, J.L.

    1992-01-01

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

  8. Radioactive Decay: Audio Data Collection

    Science.gov (United States)

    Struthers, Allan

    2009-01-01

    Many phenomena generate interesting audible time series. This data can be collected and processed using audio software. The free software package "Audacity" is used to demonstrate the process by recording, processing, and extracting click times from an inexpensive radiation detector. The high quality of the data is demonstrated with a simple…

  9. Usefulness of the decay rate in the management of radioactive waste stocks; De l'interet de la decroissance pour la gestion des dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Rodier, J; Cohendy, G [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule

    1969-07-01

    It became apparent, during first few years operation of the Marcoule Centre, that it was very useful to exploit the natural decay rate of the radioactive element contaminating the waste. The storage of this waste under the best possible conditions in each case, was first of all favorable for the radiological safety point of view; it led, furthermore, to a marked reduction in the cost price since it made it possible to avoid employing protection means which would have proved to be excessively outsize after a few years. Finally, even when the half-life of the radioelements involved seemed to annul any possible advantages of this method, the temporary storage made it possible to develop treatment processes which were unknown at the time. The overall result of this policy is that at the present time over 98 per cent of the solid waste produced by the Marcoule Centre has been processed in such a way that it can, at any moment, be discharged from the site without difficulty. (authors) [French] Des les premieres annees de fonctionnement du Centre de Marcoule, il est apparu qu'il etait extremement benefique de mettre a profit la decroissance naturelle des elements radioactifs contaminant les dechets. Le stockage de ces dechets dans des conditions appropriees a chaque cas d'espece a tout d'abord ete favorable a la surete radiologique; en outre, il a abouti a une reduction sensible des prix de revient, du fait qu'il a evite de mettre en oeuvre des moyens de protection qui se seraient reveles surdimensionnes au bout de quelques annees. Enfin, meme lorsque la periode des radioelements en cause semblait enlever tout interet a cette methode, le stockage d'attente a permis de mettre au point des procedes de traitement inconnus a l'epoque. Le resultat global de cette politique est que, actuellement, plus de 98 pour cent des dechets solides produits depuis l'origine du Centre de Marcoule ont ete conditionnes de telle sorte qu'ils peuvent, a tout moment, etre evacues hors du Site

  10. 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.

  11. Correction of dynamic time-activity curves for gamma-camera dead time, radiotracer delivery, and radioactive decay: special considerations with ultrashort-lived radioisotopes

    International Nuclear Information System (INIS)

    Kuruc, A.; Zimmerman, R.E.; Treves, S.

    1985-01-01

    Time-vs.-activity curves obtained by using ultrashort-lived radioisotopes often need to be corrected for the effects of gamma-camera dead time and physical decay. Count loss due to gamma-camera dead time can be monitored by using an electronic oscillator incorporated into the gamma camera. Two algorithms that use this information to correct time-activity curves are discussed. It is also shown that the effect of physical decay on a time-activity curve is dependent on the time course of delivery of the radioisotope to the organ of interest. A mathematical technique that corrects physical decay is described

  12. A Remote Radioactivity Experiment

    Science.gov (United States)

    Jona, Kemi; Vondracek, Mark

    2013-01-01

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

  13. In sæcula sæculorum: A lab activity to create with students a radioactive secular equilibrium model⋆

    Science.gov (United States)

    Santostasi, D.

    2017-03-01

    The teaching of radioactivity in the high school is often difficult to implement, especially from an experimental point of view. In this paper an activity based on a laboratory experiment on radioactivity is presented. The activity was proposed to high school students in their fourth year of studies attending the summer internship organized by the University of Pavia at the Department of Physics. The experiement concerns the radon decay chain, and in particular the measurement of the activity of 214Bi , both in absence and in presence of its progenitor 222Rn . This way it is possible to observe two different decay curves: the first provides a 214Bi decay constant in agreement with the theoretical one, whereas the trend of the second one can be understood only through the hypothesis of secular equilibrium with 222Rn . Using an engaging and interesting game with dice, a model of radioactive decay was developed and performed with students divided in small groups.

  14. 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.)

  15. Search of the chemical change of the sup(119m)Sn (Tsub(1/2) = 293 days) radioactive decay rate

    International Nuclear Information System (INIS)

    Makariunas, K.; Makariuniene, E.; Dragunas, A.

    1983-01-01

    The differences in decay rates of the nuclear isomer sup(119m)Sn (Tsub(1/2) = 293 days; the strongly converted M4 transition) have been measured for different chemical compounds. The experimental results show that the sup(119m)Sn nuclei in the telluride SnTe decay faster than in the metal β-Sn and in the dioxide SnO 2 [the relative change Δlambda/lambda the decay probability lambda is +(3.6+-1.4)x10 -4 ]. No measurable difference between the decay rates of sup(119m)Sn in β-Sn and SnO 2 has been observed [Δlambda/lambda = -(0.1+-1.2)x10 -4 ], irrespective of the great difference in electronic structure of the tin atoms. The results cannot be explained by considering the internal conversion of the valence electrons only. It is necessary to assume that the chemical changes of the decay rate are strongly influenced by the chemical changes of the probabilities of the internal conversion of electrons of the inner shells of the atom. This conclusion is confirmed by theoretical calculations. (Auth.)

  16. 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)

  17. 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

  18. 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

  19. Prevalence of plaque and dental decay in the first permanent molar in a school population of south Mexico City.

    Science.gov (United States)

    Taboada-Aranza, Olga; Rodríguez-Nieto, Karen

    2018-01-01

    The first permanent molar is susceptible to acquire tooth decay since its eruption, due to its anatomy and because it has been exposed before other teeth. An observational, prolective, transversal and comparative study in 194 students, with an average age of 9.9 ± 1.8 years. The evaluation of the dentobacterial plate (DBP) was analyzed using the O'Leary index and the tooth decay experience with the DMFS (sum of decayed, missing, extracted and filling dental surfaces) and DMFT (sum of decayed, missing, extracted and filling per tooth) indexes. The prevalence of DBP in the first permanent molar was of 99.4% and tooth decay of 57.2%. The value of DMFT was 1.4 ± 1.4. The tooth decay experience was higher in children from 7.10 years old with a value of 2.2 ± 2.3, who are 7.9 times more likely to develop lesions than younger children (odds ratio: 8.9; 95% confidence interval: 4.1-19.5; p tooth decay experience indexes; even though these were weak in the case of DMF (r = 0.439), the model allowed to explain 19% of the association, and 22% for DMFT (r = 0.464). Tooth decay develops rapidly in the first permanent molars; however, it does not receive the necessary care because it is usually unknown that it is a permanent tooth. Copyright: © 2018 Permanyer.

  20. Libraries of decay data and fission product yields in the ABBN-93 constant set

    International Nuclear Information System (INIS)

    Zabrodskaya, S.V.; Nikolaev, M.N.; Tsibulya, A.M.

    2001-01-01

    This paper describes three new libraries in the Abb. constant set which are essential for calculating radioactivity: basic decay data, radioactive decay photon spectra and fission product yields. (author)

  1. 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...

  2. [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.

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

    International Nuclear Information System (INIS)

    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. (author)

  4. 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

  5. Rare psi decays

    International Nuclear Information System (INIS)

    Partridge, R.

    1986-01-01

    Slightly more than ten years have passed since the psi was discovered, yet the study of psi decays continues to be an active and fruitful area of research. One reason for such longevity is that each successive experiment has increased their sensitivity over previous experiments either by improving detection efficiency or by increasing statistics. This has allowed the observation and, in some cases, detailed studies of rare psi decays. Branching ratios of ≅10-/sup 4/ are now routinely studied, while certain decay channels are beginning to show interesting effects at the 10-/sup 5/ level. Future experiments at the Beijing Electron Positron Collider (BEPC) have the potential for increasing sensitivities by one or two orders of magnitude, thus enabling many interesting studies impossible with current data samples. The author first examines the extent to which psi decays can be used to study electroweak phenomena. The remainder of this work is devoted to the more traditional task of using the psi to study quarks, gluons, and the properties of the strong interaction. Of particular interest is the study of radioactive psi decays, where a number of new particles have been discovered. Recent results regarding two of these particles, the θ(1700) and iota(1450), are discussed, as well as a study of the quark content of the eta and eta' using decays of the psi to vector-pseudoscalar final states

  6. Handbook of radioactivity measurements procedures. Second edition

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    This report is concerned with the measurement of radioactivity in general, but specifically it deals with radioactive materials that have become available in the last three decades, from nuclear reactors and particle accelerators, for applications in medicine, scientific research, and industry. It is also concerned with low-level radioactivity measurements for the monitoring of radioactivity in environmental media, such as air and water, in connection with the control of radioactive effluents associated with the production of nuclear power or the use of radionuclides. Included in appendices are nuclear decay data for selected radionuclides and statistics of radioactive decay. An extensive bibliography is also included

  7. Chemical consequences of radioactive decay. 1. Study of 249Cf ingrowth into crystalline 249BkBr3: a new crystalline phase of CfBr3

    International Nuclear Information System (INIS)

    Young, J.P.; Haire, R.G.; Peterson, J.R.; Ensor, D.D.; Fellows, R.L.

    1980-01-01

    Spectrophotometric and x-ray powder diffraction methods have been applied to a study of the ingrowth of californium-249 by β - decay of berkelium-249 in crystalline 249 BkBr 3 . It was found that the Cf daughter grows in with the same oxidation state and crystal structure as the parent. Thus, six-coordinate BkBr 3 (AlCl 3 -type monoclinic structure) generates six-coordinate CfBr 3 , and eight-coordinate BkBr 3 (PuBr 3 -type orthorhombic structure) generates eight-coordinate CfBr 3 , a previously unknown form of CfBr 3 . It was also found that the daughter Cf(III) in the BkBr 3 parent compound can be reduced to Cf(II) by treatment with H 2 , as it can in pure CfBr 3 . 5 figures

  8. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-15

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

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

    International Nuclear Information System (INIS)

    Vaupotic, J.

    2008-01-01

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

  11. Radioactive waste management solutions

    International Nuclear Information System (INIS)

    Siemann, Michael

    2015-01-01

    One of the more frequent questions that arise when discussing nuclear energy's potential contribution to mitigating climate change concerns that of how to manage radioactive waste. Radioactive waste is produced through nuclear power generation, but also - although to a significantly lesser extent - in a variety of other sectors including medicine, agriculture, research, industry and education. The amount, type and physical form of radioactive waste varies considerably. Some forms of radioactive waste, for example, need only be stored for a relatively short period while their radioactivity naturally decays to safe levels. Others remain radioactive for hundreds or even hundreds of thousands of years. Public concerns surrounding radioactive waste are largely related to long-lived high-level radioactive waste. Countries around the world with existing nuclear programmes are developing longer-term plans for final disposal of such waste, with an international consensus developing that the geological disposal of high-level waste (HLW) is the most technically feasible and safe solution. This article provides a brief overview of the different forms of radioactive waste, examines storage and disposal solutions, and briefly explores fuel recycling and stakeholder involvement in radioactive waste management decision making

  12. Heavy fragment radioactivity

    International Nuclear Information System (INIS)

    Silisteanu, I.

    1991-06-01

    The effect of collective mode excitation in heavy fragment radioactivity (HFR) is explored and discussed in the light of current experimental data. It is found that the coupling and resonance effects in fragment interaction and also the proper angular momentum effects may lead to an important enhancing of the emission process. New useful procedures are proposed for the study of nuclear decay properties. The relations between different decay processes are investigated in detail. We are also trying to understand and explain in a unified way the reaction mechanisms in decay phenomena. (author). 17 refs, 4 figs, 3 tabs

  13. Radioactive waste management

    International Nuclear Information System (INIS)

    Blomek, D.

    1980-01-01

    The prospects of nuclear power development in the USA up to 2000 and the problems of the fuel cycle high-level radioactive waste processing and storage are considered. The problems of liquid and solidified radioactive waste transportation and their disposal in salt deposits and other geologic formations are discussed. It is pointed out that the main part of the high-level radioactive wastes are produced at spent fuel reprocessing plants in the form of complex aqueous mixtures. These mixtures contain the decay products of about 35 isotopes which are the nuclear fuel fission products, about 18 actinides and their daughter products as well as corrosion products of fuel cans and structural materials and chemical reagents added in the process of fuel reprocessing. The high-level radioactive waste management includes the liquid waste cooling which is necessary for the short and middle living isotope decay, separation of some most dangerous components from the waste mixture, waste solidification, their storage and disposal. The conclusion is drawn that the seccessful solution of the high-level radioactive waste management problem will permit to solve the problem of the fuel cycle radioactive waste management as a whole. The salt deposits, shales and clays are the most suitable for radioactive waste disposal [ru

  14. 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

  15. Tau decays

    International Nuclear Information System (INIS)

    Golutvin, A.

    1994-09-01

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

  16. Travel in the depth of radioactivity

    International Nuclear Information System (INIS)

    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.)

  17. Impacts and issues of the radioactive substances due to the nuclear disaster. Cases of municipalities and elementary schools in Fukushima prefecture

    International Nuclear Information System (INIS)

    Murayama, Takehiko; Itaya, Sohei

    2012-01-01

    While all stakeholders make efforts by all means for mitigating impacts induced by radioactive substances after the accident, we would have to have a long way to restore the situation. Particularly, it would be difficult to promote meaningful communication about various risks. For making clear of current situation and issues to be resolved, we conducted a questionnaire survey for local governments and elementary schools in Fukushima prefecture. While local governments' officials and schools' teachers are willing to promote communication with public, they have substantial difficulties to do so. One reason is insufficient volume of information dissemination from national and prefectural governments. It would be important to increase manpower to promote better communication. (author)

  18. 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.

    2012-01-01

    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, a ubiquitous inert gas, and the adsorptive property of activated charcoal.…

  19. Low level radioactive waste management and discharge policies in Turkey

    International Nuclear Information System (INIS)

    Oezdemir, T.; Oezdemir, C.; Uslu, I.

    2005-01-01

    The legal infrastructure in Turkey for the management of low-level radioactive waste covers the liquid, solid and gaseous wastes. Management of these radioactive wastes is briefly described in this paper. Moreover, delay and decay tank systems that are used to collect and store the low level radioactive wastes as a part of low-level radioactive effluent discharge policy are introduced. (author)

  20. Fine structure of cluster decays

    International Nuclear Information System (INIS)

    Dumitrescu, O.

    1993-07-01

    Within the one level R-matrix approach the hindrance factors of the radioactive decays in which are emitted α and 14 C - nuclei are calculated. The generalization to radioactive decays in which are emitted heavier clusters such as e.g. 20 O, 24 Ne, 25 Ne, 28 Mg. 30 Mg, 32 Si and 34 Si is straightforward. The interior wave functions are supposed to be given by the shell model with effective residual interactions (e.g. the large scale shell model code-OXBASH - in the Michigan State University version for nearly spherical nuclei or by the enlarged superfluid model - ESM - recently proposed for deformed nuclei). The exterior wave functions are calculated from a cluster - nucleus double - folding model potential obtained with the M3Y interaction. As examples of the cluster decay fine structure we analyzed the particular cases of α - decay of 241 Am and 14 C -decay of 233 Ra. Good agreement with the experimental data is obtained. (author). 78 refs, 2 figs, 6 tabs

  1. Terms and definitions in the field of radiological technique. Radioactivity. Draft. Begriffe und Benennungen in der radiologischen Technik. Radioaktivitaet. Entwurf

    Energy Technology Data Exchange (ETDEWEB)

    1978-04-01

    Nuclides and their symbols: Nuclide, symbol for nuclides; Nuclear processes: Nuclear transformation, isomeric transition; Radioactive substances; Radiation of radioactive substances: Alpha radiation, beta radiation, k radiation, gamma radiation, conversion electrons, annihilation radiation, neutron radiation; Activity, specific activity, and activity concentration; Characteristic constants of radio nuclides: Decay constant, lifetime, half-life, specific gamma-ray constant, conversion coefficient; Decay series: Radioactive decay series, radioactive equilibrium; Nuclides with special names and symbols: Hydrogen isotopes, nuclides of the natural decay series.

  2. 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

  3. 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

  4. Mixed radioactive and chemotoxic wastes (RMW)

    International Nuclear Information System (INIS)

    Dejonghe, I.P.

    1991-01-01

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

  5. Study of proton radioactivities

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-08-01

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

  6. Cluster decay of 218U isotope

    International Nuclear Information System (INIS)

    Shivakumaraswamy, G.; Umesh, T.K.

    2012-01-01

    The phenomenon of spontaneous emission of charged particles heavier than alpha particle and lighter than a fission fragment from radioactive nuclei without accompanied by the emission of neutrons is known as cluster radioactivity or exotic radioactivity. The process of emission of charged particles heavier than alpha particle and lighter than a fission fragment is called exotic decay or cluster decay. The phenomenon of cluster radioactivity was first predicted theoretically by Sandulescu et al in 1980. Rose and Jones made first experimental observations of 14 C emission from 223 Ra in 1984. Several cluster decay modes in trans-lead region have been experimentally observed. The half-life values for different modes of cluster decay from different isotopes of uranium have been calculated using different theoretical models such as the analytical super asymmetric model (ASAFM), Preformed cluster model (PCM) and Coulomb and Proximity potential model (CPPM) etc. Recently some semi-empirical formulae, i.e, single line of universal curve (UNIV), Universal decay law (UDL) for both alpha and cluster radioactivity have also been proposed to explain cluster decay data. The alpha decay half-life of 218-219 U isotopes has been experimentally measured in 2007. The half-life values for different cluster decay modes of 218 U isotopes have been calculated PCM model. Recently in 2011, the half-life values have also been calculated for some cluster decay modes of 222-236 U isotopes using the effective liquid drop description with the varying mass asymmetry (VMAS) shape and effective inertial coefficient. In the light of this, in the present work we have studied the cluster radioactivity of 218 U isotope. The logarithmic half-lives for few cluster decay modes from 218 U isotope have been calculated by using three different approaches, i.e, UNIV proposed by Poenaru et al in 2011, UDL proposed by Qi et al in 2009 and the CPPM model proposed by Santhosh et al in 2002. The CPPM based

  7. 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.)

  8. 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

  9. Waste water plant for radioactive polluted media, for example faeces

    International Nuclear Information System (INIS)

    Galler, L.

    1985-01-01

    In order to provide simple transport of radioactive polluted wastewater to a decay container using simple structural means, where aerobic decay is to take place during storage in the decay container, it is proposed that a sub-pressure source should be connected to the place of origin via a pressure-tight and closed decay container and that the gasous fluid extracted by the subpressure source should be returned to the decay container. (orig./PW) [de

  10. Caries y pérdida dental en estudiantes preuniversitarios mexicanos Dental decay and tooth loss at the high school level in Mexican students

    Directory of Open Access Journals (Sweden)

    Javier de la Fuente-Hernández

    2008-06-01

    Full Text Available OBJETIVOS: Conocer la prevalencia de caries y pérdida dental para calcular las necesidades terapéuticas en estudiantes de educación media superior que ingresan a la Universidad Nacional Autónoma de México (UNAM. MATERIAL Y MÉTODOS: Se realizó un estudio transversal descriptivo en el que se obtuvo una muestra de 77 191 estudiantes correspondientes a las generaciones de ingreso al bachillerato 2003, 2004 y 2005. Los datos de salud bucal se obtuvieron a partir del índice CPOD incluido en el Examen Médico Automatizado (EMA, instrumento de autorrespuesta estandarizado que aplica la Dirección General de Servicios Médicos (DGSM. El análisis del EMA fue univariado con la finalidad de identificar la distribución y la frecuencia de las variables. RESULTADOS: La prevalencia de caries y pérdida dental fue de 48.0 y 34.2%, respectivamente, con una cuantificación del índice CPOD de 5. Las necesidades de tratamiento para caries y pérdida dental se obtuvieron en al menos un diente por estudiante. CONCLUSIONES: Cerca de la mitad de los alumnos que ingresan al bachillerato de la UNAM requiere al menos la atención de una caries o prótesis dental. Lo anterior evidencia que las políticas en salud bucal instrumentadas no han alcanzado los índices en salud esperados en relación con los objetivos internacionales, así como la necesidad de impulsar nuevas líneas de investigación orientadas a identificar la gravedad de la enfermedad y factores vinculados con el deterioro de la salud bucal.OBJECTIVE: To determine the prevalence of dental decay and tooth loss, and to consider the treatment needs for students at the Mexican National Autonomous University (UNAM. MATERIALS AND METHODS: A cross sectional study was designed including 77 191 students corresponding to the years of entrance to high school 2003, 2004 and 2005. Oral health data were obtained from the DMF-T index included in the Automatized Medical Exam (AME, a student self-answer instrument

  11. Trapping radioactive ions

    CERN Document Server

    Kluge, Heinz-Jürgen

    2004-01-01

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

  12. Trapping radioactive ions

    International Nuclear Information System (INIS)

    Kluge, H.-J.; Blaum, K.

    2004-01-01

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

  13. Laypeople's understanding of radioactivity and radiation

    International Nuclear Information System (INIS)

    Henriksen, E.K.

    1996-01-01

    It may be argued that the population should have sufficient understanding of radiation phenomena to secure individual safety as well as democratic decisions. To attain this, it is necessary for the communicators of radiation information to be familiar with the lay person's perceptions of these phenomena. A questionnaire survey was conducted to examine non-experts' conceptions of radiation phenomena. The survey revealed incomplete understanding of concepts such as radioactive decay, half-life and absorption of radiation and a lack of differentiation between radiation and radioactive material. Many respondents did not distinguish between sources of ionising radiation and other environmental hazards. Nuclear power plants and submarines were the most feared sources of radiation. There are indications that the lay understanding of radiation phenomena and risk is to a large extent formed by mass media and that 'school knowledge' of these phenomena is not applied in situations belonging to the 'real world'. To resolve this problem, new teaching and information procedures are needed. These should take into account the learners' preconceptions and should integrate 'school knowledge' with considerations belonging to the 'real world'. (author)

  14. Proton decay theory

    International Nuclear Information System (INIS)

    Marciano, W.J.

    1983-01-01

    Topics include minimal SU(5) predictions, gauge boson mediated proton decay, uncertainties in tau/sub p/, Higgs scalar effects, proton decay via Higgs scalars, supersymmetric SU(5), dimension 5 operators and proton decay, and Higgs scalars and proton decay

  15. Decay correction methods in dynamic PET studies

    International Nuclear Information System (INIS)

    Chen, K.; Reiman, E.; Lawson, M.

    1995-01-01

    In order to reconstruct positron emission tomography (PET) images in quantitative dynamic studies, the data must be corrected for radioactive decay. One of the two commonly used methods ignores physiological processes including blood flow that occur at the same time as radioactive decay; the other makes incorrect use of time-accumulated PET counts. In simulated dynamic PET studies using 11 C-acetate and 18 F-fluorodeoxyglucose (FDG), these methods are shown to result in biased estimates of the time-activity curve (TAC) and model parameters. New methods described in this article provide significantly improved parameter estimates in dynamic PET studies

  16. GALIST, Decay Gamma Spectra Retrieval from ENSDF

    International Nuclear Information System (INIS)

    Ichimiya, Tsutomu

    2002-01-01

    Description of program or function: GALIST consists of two main programs, GAMRET and GNOI. - GAMRET retrieves from ENSDF or files with ENSDF-like format gamma rays following radioactive decay. GAMRET uses two auxiliary programs, ENSORT and AMSORT (see below under item 8). - GNOI makes a list of radionuclides and their gamma rays. In the decay data of ENSDF, however, not all gamma-ray intensities are included

  17. 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

  18. In-trap decay spectroscopy for ββ decays

    International Nuclear Information System (INIS)

    Brunner, Thomas

    2011-01-01

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

  19. Radioactive source

    International Nuclear Information System (INIS)

    Drabkina, L.E.; Mazurek, V.; Myascedov, D.N.; Prokhorov, P.; Kachalov, V.A.; Ziv, D.M.

    1976-01-01

    A radioactive layer in a radioactive source is sealed by the application of a sealing layer on the radioactive layer. The sealing layer can consist of a film of oxide of titanium, tin, zirconium, aluminum, or chromium. Preferably, the sealing layer is pure titanium dioxide. The radioactive layer is embedded in a finish enamel which, in turn, is on a priming enamel which surrounds a substrate

  20. 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

  1. 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.

  2. Decay Spectroscopy for Nuclear Astrophysics: {beta}-delayed Proton Decay

    Energy Technology Data Exchange (ETDEWEB)

    Trache, L.; Simmons, E.; Spiridon, A.; McCleskey, M.; Roeder, B. T.; Tribble, R. E. [Texas A and M University, College Station, TX 77845 (United States); Saastamoinen, A.; Jokinen, A.; Aysto, J. [University of Jyvaskyla, Jyvaskyla (Finland); Davinson, T.; Woods, P. J. [University of Edinburgh, Edinburgh (United Kingdom); Pollacco, E.; Kebbiri, M. [CEA/IRFU Saclay (France); Pascovici, G. [IKP, Universitaet zu Koeln (Germany)

    2011-11-30

    Decay spectroscopy is one of the oldest indirect methods in nuclear astrophysics. We have developed at TAMU techniques to measure beta- and beta-delayed proton decay of sd-shell, proton-rich nuclei. The short-lived radioactive species are produced in-flight, separated, then slowed down (from about 40 MeV/u) and implanted in the middle of very thin Si detectors. These allowed us to measure protons with energies as low as 200 keV from nuclei with lifetimes of 100 ms or less. At the same time we measure gamma-rays up to 8 MeV with high resolution HPGe detectors. We have studied the decay of {sup 23}Al, {sup 27}P, {sup 31}Cl, all important for understanding explosive H-burning in novae. The technique has shown a remarkable selectivity to beta-delayed charged-particle emission and works even at radioactive beam rates of a few pps. The states populated are resonances for the radiative proton capture reactions {sup 22}Na(p,{gamma}){sup 23}Mg(crucial for the depletion of {sup 22}Na in novae), {sup 26m}Al(p,{gamma}){sup 27}Si and {sup 30}P(p,{gamma}){sup 31}S(bottleneck in novae and XRB burning), respectively. More recently we have radically improved the technique using a gas based detector we call AstroBox.

  3. Radioactivity metrology

    International Nuclear Information System (INIS)

    Legrand, J.

    1979-01-01

    Some aspects of the radioactivity metrology are reviewed. Radioactivity primary references; absolute methods of radioactivity measurements used in the Laboratoire de Metrologie des Rayonnements Ionisants; relative measurement methods; traceability through international comparisons and interlaboratory tests; production and distribution of secondary standards [fr

  4. Radioactive wastes

    International Nuclear Information System (INIS)

    Teillac, J.

    1988-01-01

    This study of general interest is an evaluation of the safety of radioactive waste management and consequently the preservation of the environment for the protection of man against ionizing radiations. The following topics were developed: radiation effects on man; radioactive waste inventory; radioactive waste processing, disposal and storage; the present state and future prospects [fr

  5. The radioactive earth

    International Nuclear Information System (INIS)

    Plant, J.A.; Saunders, A.D.

    1996-01-01

    Uranium, thorium and potassium are the main elements contributing to natural terrestrial radioactivity. The isotopes 238 U, 235 U, 232 Th and 40 K decay with half-lives so long that significant amounts remain in the earth, providing a continuing source of heat. The slow decay of these isotopes also provides the basis for radiometric age dating and isotopic modelling of the evolution of the earth and its crust. There is a complex interplay between their heat production and the processes involved in crust formation. Phenomena such as volcanism, earthquakes, and large-scale hydrothermal activity associated with ore deposition reflect the dissipation of heat energy from the earth, much of which is derived from natural radioactivity. The higher levels of radioactive elements during the early history of the earth resulted in higher heat flow. All three of the radioactive elements are strongly partitioned into the continental crust, but within the crust their distribution is determined by their different chemical properties. The behaviour of U, which has two commonly occurring oxidation states, is more complex than that of Th and K. Uranium deposits are diverse, and are mostly associated with granites, acid volcanics, or detrital sedimentary rocks. The most important U deposits economically are unconformity-type ores of Proterozoic age, in which U is enriched by up to 5 x 10 6 with respect to bulk earth values. In some cases natural radioactivity can be of environmental concern. The most significant risk is posed by accumulations of radon, the gaseous daughter product of U. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, K.M., E-mail: kara.marie.lynch@cern.ch [KU Leuven, Instituut voor Kern, en Stralingsfysica, BE-3001 Leuven (Belgium); EP Department, CERN, CH-1211 Geneva 23 (Switzerland); Cocolios, T.E. [KU Leuven, Instituut voor Kern, en Stralingsfysica, BE-3001 Leuven (Belgium); School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Althubiti, N. [School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Farooq-Smith, G.J. [KU Leuven, Instituut voor Kern, en Stralingsfysica, BE-3001 Leuven (Belgium); School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Gins, W. [KU Leuven, Instituut voor Kern, en Stralingsfysica, BE-3001 Leuven (Belgium); Smith, A.J. [School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom)

    2017-02-01

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

  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. Using Analogue Computers in Schools

    Science.gov (United States)

    Hinson, D. J.

    1974-01-01

    Discusses the procedures of using operational amplifiers to conduct student projects and teach physical phenomena such as oscillation, radioactive decay, terminal velocity, projectile and ball bouncing. (CC)

  9. Effects of natural radioactivity on food radioactivity measurement

    International Nuclear Information System (INIS)

    Ennyu, Atsuhito

    2012-01-01

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

  10. Nuclear parameters determination of the 127Te β - decay: a proposal for teaching nuclear physics

    International Nuclear Information System (INIS)

    Batista, Wagner Fonseca

    2011-01-01

    A study of the 127 Te β - decay was carried out by means of gamma spectroscopy measurements using high resolution HPGe detector, in the region from 30 keV to 1.0 MeV, aiming to get a better understanding of the 127 Te nuclear structure. The radioactive sources of 12 7Te were obtained from the 126 Te(n,γ) 1 '2 7 Te nuclear reaction produced in the IEA- R1 nuclear reactor at IPEN/CNEN-SP. Five gamma t ransitions previously attributed to this decay were confirmed with a better precision than previously. The half-life of 127 Te was also studied resulting in data with lower uncertainty. Using a set of data selected from gamma spectroscopy measurements was developed and applied a didactic proposal for high school students using the Excel software. (author)

  11. 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

  12. 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)

  13. 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.

  14. 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.

  15. 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

  16. Absolute radioactivity measurements

    International Nuclear Information System (INIS)

    Weiss, H.M.

    1983-01-01

    The radioactivity of a thin specimen can be determined directly, i.e. without reference to a standard and without knowing decay data, except for half-life, by means of counting at a given solid angle and by 4 πβ-γ coincidence measurement. In accordance with section 7 of the law on units, it is the task of PTB not only to represent the units and its derivation, but also to work out methods of adjusting national prototypes and normals to international prototypes and etalons in accordance with the international metre convention. (DG) [de

  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 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.)

  19. 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

  20. Radioactive waste management information for 1990 and record-to-date

    International Nuclear Information System (INIS)

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

    1991-07-01

    This document presents detailed data and graphics on volume, radioactivity, isotopic identity, origin, and decay status of radioactive waste for the calendar year 1990. It also summarizes the radioactive waste data records compiled from 1952 to present for the Idaho National Engineering Laboratory (INEL). The data presented are from the INEL Radioactive Waste Management Information System (RWMIS)

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

    International Nuclear Information System (INIS)

    Taylor, K.A.

    1994-07-01

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

  2. New radioactivities

    International Nuclear Information System (INIS)

    Greiner, W.; Sandulescu, A.

    1996-01-01

    Some atomic nuclei reorganize their structure by ejection of big protons and neutrons aggregates. The observation of these new radioactivities specifies the theories of the nuclear dynamics. (authors)

  3. Radioactive materials

    International Nuclear Information System (INIS)

    Sugiura, Yoshio; Shimizu, Makoto.

    1975-01-01

    The problems of radioactivity in the ocean with marine life are various. Activities in this field, especially the measurements of the radioactivity in sea water and marine life are described. The works first started in Japan concerning nuclear weapon tests. Then the port call to Japan by U.S. nuclear-powered naval ships began. On the other hand, nuclear power generation is advancing with its discharge of warm water. The radioactive pollution of sea water, and hence the contamination of marine life are now major problems. Surveys of the sea areas concerned and study of the radioactivity intake by fishes and others are carried out extensively in Japan. (Mori, K.)

  4. Radioactivity Handbook

    International Nuclear Information System (INIS)

    Firestone, R.B.; Browne, E.

    1985-01-01

    The Radioactivity Handbook will be published in 1985. This handbook is intended primarily for applied users of nuclear data. It will contain recommended radiation data for all radioactive isotopes. Pages from the Radioactivity Handbook for A = 221 are shown as examples. These have been produced from the LBL Isotopes Project extended ENDSF data-base. The skeleton schemes have been manually updated from the Table of Isotopes and the tabular data are prepared using UNIX with a phototypesetter. Some of the features of the Radioactivity Handbook are discussed here

  5. 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).

  6. 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.)

  7. 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

  8. 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 ...

  9. ELECTRONIC ANALOG COMPUTER FOR DETERMINING RADIOACTIVE DISINTEGRATION

    Science.gov (United States)

    Robinson, H.P.

    1959-07-14

    A computer is presented for determining growth and decay curves for elements in a radioactive disintegration series wherein one unstable element decays to form a second unstable element or isotope, which in turn forms a third element, etc. The growth and decay curves of radioactive elements are simulated by the charge and discharge curves of a resistance-capacitance network. Several such networks having readily adjustable values are connected in series with an amplifier between each successive pair. The time constant of each of the various networks is set proportional to the half-life of a corresponding element in the series represented and the charge and discharge curves of each of the networks simulates the element growth and decay curve.

  10. Management of radioactive medical waste

    International Nuclear Information System (INIS)

    Deschamps, S.; Mathey, J.C.

    1996-01-01

    Hospitals are producers of small amounts of radioactive waste. Current legislation details exactly how hospitals should manage it. Sealed sources are returned to suppliers. Disposal of unsealed sources, liquid or solid, depends upon their half-life: short-lived radioisotopes (half-life less than two months) are stocked on site while they decay; isotopes with longer half-lives (greater than two months) are handled by a specialist organization (ANDRA). (authors). 8 refs

  11. Radioactivity measurement of soil and vegetables contaminated from low level radioactive fall out arised from Fukushima Daiichi nuclear accident. A study on Institute for Sustainable Agro-ecosystem Services, Graduate School of Agricultural and Life Sciences, The University of Tokyo

    International Nuclear Information System (INIS)

    Oshita, Seiichi; Kawagoe, Yoshinori; Nakanishi, Tomoko M.; Tanoi, Keitaro; Makino, Yoshio; Yasunaga, Eriko; Takata, Daisuke; Sasaki, Haruto

    2011-01-01

    After the accident of Fukushima nuclear power plant, vegetables were grown at an experimental farm of Nishi-Tokyo City in Tokyo, which was located about 230km away from the power plant. The outer leaves of cabbages and leaves of potatoes were taken after 47 and 40 days, respectively, and the radioactivity of 134 Cs and 137 Cs was measured. The total radioactivity of 134 Cs and 137 Cs in both plants was less than 9Bq/kg, which was far lower than that of the regulated value, 500Bq/kg, for human to intake. The radioactivity of soil was about 130Bq/kg, less than that of the natural activity of 40 K, about 290Bq/kg. The difference of the radioactivity image of cabbage outer leaves, washed and without washing, was not observed using an imaging plate. (author)

  12. 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

  13. Radioactivity: ''small users, big problems''

    International Nuclear Information System (INIS)

    McDonnell, C.

    1993-01-01

    In the United Kingdom there are at least one thousand small users of radioactivity in industry, in medicine, in higher education establishments and even schools. These users of small amounts of radioactivity, covering a wide variety of forms and applications, have difficulty in disposing of their wastes. Disposal provisions for users outside the nuclear industry, the practical problems they encounter and the future developments likely are discussed. (UK)

  14. A computer method for simulating the decay of radon daughters

    International Nuclear Information System (INIS)

    Hartley, B.M.

    1988-01-01

    The analytical equations representing the decay of a series of radioactive atoms through a number of daughter products are well known. These equations are for an idealized case in which the expectation value of the number of atoms which decay in a certain time can be represented by a smooth curve. The real curve of the total number of disintegrations from a radioactive species consists of a series of Heaviside step functions, with the steps occurring at the time of the disintegration. The disintegration of radioactive atoms is said to be random but this random behaviour is such that a single species forms an ensemble of which the times of disintegration give a geometric distribution. Numbers which have a geometric distribution can be generated by computer and can be used to simulate the decay of one or more radioactive species. A computer method is described for simulating such decay of radioactive atoms and this method is applied specifically to the decay of the short half life daughters of radon 222 and the emission of alpha particles from polonium 218 and polonium 214. Repeating the simulation of the decay a number of times provides a method for investigating the statistical uncertainty inherent in methods for measurement of exposure to radon daughters. This statistical uncertainty is difficult to investigate analytically since the time of decay of an atom of polonium 218 is not independent of the time of decay of subsequent polonium 214. The method is currently being used to investigate the statistical uncertainties of a number of commonly used methods for the counting of alpha particles from radon daughters and the calculations of exposure

  15. The natural radioactivity of the biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Pertsov, L A

    1967-07-01

    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.

  16. 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

  17. 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)

  18. 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)

  19. Development of an application simulating radioactive sources

    International Nuclear Information System (INIS)

    Riffault, V.; Locoge, N.; Leblanc, E.; Vermeulen, M.

    2011-01-01

    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)

  20. Analytical method for solving radioactive transformations

    International Nuclear Information System (INIS)

    Vudakin, Z.

    1999-01-01

    Analytical method for solving radioactive transformations is presented in this paper. High accuracy series expansion of the depletion function and nonsingular Bateman coefficients are used to overcome numerical difficulties when applying well-known Bateman solution of a simple radioactive decay. Generality and simplicity of the method are found to be useful in evaluating nuclide chains with one hundred or more nuclides in the chain. Method enables evaluation of complete chain, without elimination of short-lives nuclides. It is efficient and accurate

  1. Radioactive wastes

    International Nuclear Information System (INIS)

    Grass, F.

    1982-01-01

    Following a definition of the term 'radioactive waste', including a discussion of possible criteria allowing a delimitation of low-level radioactive against inactive wastes, present techniques of handling high-level, intermediate-level and low-level wastes are described. The factors relevant for the establishment of definitive disposals for high-level wastes are discussed in some detail. Finally, the waste management organization currently operative in Austria is described. (G.G.)

  2. Radioactive pollution

    International Nuclear Information System (INIS)

    Steiner, R.

    1987-01-01

    In the wake of the Chernobyl reactor accident on April 26, 1986, many individual values for radioactivity in the air, in foodstuffs and in the soil were measured and published. Prof. Dr. Rolf Steiner, Wiesbaden, the author of this paper, evaluated the host of data - mostly official pollution data -, drew conclusions regarding the radioactivity actually released at Chernobyl, and used the data to test the calculation model adotped by the Radiation Protection Ordinance. (orig./RB) [de

  3. 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.)

  4. 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)

  5. Radioactivity in the hydrologic environment

    Energy Technology Data Exchange (ETDEWEB)

    Werner, L B [Isotopes, Inc., Palo Alto, CA (United States)

    1969-07-01

    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)

  6. 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)

  7. Dental Caries (Tooth Decay)

    Science.gov (United States)

    ... Materials Contact Us Home Research Data & Statistics Dental Caries (Tooth Decay) Dental caries (tooth decay) remains the most prevalent chronic disease ... adults, even though it is largely preventable. Although caries has significantly decreased for most Americans over the ...

  8. Dental Caries (Tooth Decay)

    Science.gov (United States)

    ... Contact Us Home Research Data & Statistics Share Dental Caries (Tooth Decay) Dental caries (tooth decay) remains the most prevalent chronic disease ... adults, even though it is largely preventable. Although caries has significantly decreased for most Americans over the ...

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

    International Nuclear Information System (INIS)

    Sushil Kumar; Rajesh Kumar; Balasubramaniam, M.; Gupta, Raj K.

    2001-01-01

    Due to the availability of radioactive nuclear beams (RNB) and the advancement in accelerator technology, it is now possible to synthesize very heavy elements (Z> 100), called superheavy elements. It is a well established fact that these superheavy elements, due to their shorter lifetime, decay via successive alpha emissions and at a later stage undergo spontaneous fission. Several such decay chains are now observed. An attempt is made to fit all such known decay chains and the results of the three observed α-decay chains of Z=110 ( 269-271 10) nuclei are presented. The model used is the preformed cluster model (PCM). Also, an attempt is made for the first time to find the possibility of any branching to heavy-cluster emissions in these chains

  10. Educational experiment for university students using natural radioactivity. Development of an additional experiment to measure the increase in 214Pb and 214Bi produced from 222Rn

    International Nuclear Information System (INIS)

    Nakamura, Mariko; Esaka, Takao; Kamata, Masahiro

    2005-01-01

    Although several works have been published to date regarding radiochemistry, most of them have been designed for those who major in subjects related to chemistry or physics and use rather sophisticated methods and apparatus. Education about radiation and radioactivity is also very important for other students because a basic knowledge of radiation and radioactivity is indispensable for understanding environmental problems or energy problems in the future. However, it is not easy to conduct practical work using radioactivity in students' experiments at school or at university because the use of radioactivity is strictly regulated by the law, and equipment such as radiation counters is too expensive for school budgets. From such a viewpoint, we developed several kinds of safe and inexpensive experiments for education using natural radioactivity so that university (or senior high school) students can learn through their practical work without being regulated by the law. For this purpose, radioactive species belonging to the uranium decay series are suitable because these species can be easily obtained from mineral spring water or soil samples. In addition, some of the species such as 214 Pb and 214 Bi emit beta rays, which are easy to detect, and the half-lives of these which are easy to detect, and the half-lives of these elements can be measured in one or two-hour school activities. This kind of experiment was employed as an ''Educational experiment for radiochemistry'' at Tottori University for nearly fifty students every year. Although the experiment itself was essentially complete, the students did not have the chance to observe how radioactive equilibrium was established. Therefore, we have developed an additional work plan to enable students to observe how 214 Pb and 214 Bi are produced from 222 Rn, and have made this experiment more complete. The educational usefulness of this additional experiment was evaluated and will be presented in section 5. (author)

  11. 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.

  12. Radioactive wastes

    International Nuclear Information System (INIS)

    Dupuis, M.C.

    2007-01-01

    Managing radioactive wastes used to be a peripheral activity for the French atomic energy commission (Cea). Over the past 40 years, it has become a full-fledged phase in the fuel cycle of producing electricity from the atom. In 2005, the national radioactive waste management agency (ANDRA) presented to the government a comprehensive overview of the results drawn from 15 years of research. This landmark report has received recognition beyond France's borders. By broadening this agency's powers, an act of 28 June 2006 acknowledges the progress made and the quality of the results. It also sets an objective for the coming years: work out solutions for managing all forms of radioactive wastes. The possibility of recovering wastes packages from the disposal site must be assured as it was asked by the government in 1998. The next step will be the official demand for the creation of a geological disposal site in 2016

  13. Radioactivity measurement

    International Nuclear Information System (INIS)

    Bohme, R.F.; Lazerson, M.M.

    1984-01-01

    A problem with ore sorting arrangements is that radiation is difficult to measure accurately while particles are moving at speed past the detector. This is particulary so when dealing with ores such as gold ores which have weak emissions. A method of measuring radioactive emissions from moving radioactive material includes the steps of shielding the radiation detector(s) so that the angle of acceptance of the receptor surface is restricted, and further shielding the shielded portion of the detector with a second material which is less radiation emissive than the material of the first shield. This second shield is between the first shield and the detector

  14. Radioactivity and the French uranium bearing minerals

    International Nuclear Information System (INIS)

    Guiollard, P.Ch.; Boisson, J.M.; Leydet, J.C.; Meisser, N.

    1998-01-01

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

  15. Radioactive waste disposal process geological structure for the waste disposal

    International Nuclear Information System (INIS)

    Courtois, G.; Jaouen, C.

    1983-01-01

    The process described here consists to carry out the two phases of storage operation (intermediate and definitive) of radioactive wastes (especially the vitrified ones) in a geological dispositif (horizontal shafts) at an adequate deepness but suitable for a natural convection ventilation with fresh air from the land surface and moved only with the calorific heat released by the burried radioactive wastes when the radioactive decay has reached the adequate level, the shafts are totally and definitely occluded [fr

  16. 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.

  17. 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

  18. Radioactive Waste.

    Science.gov (United States)

    Blaylock, B. G.

    1978-01-01

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

  19. Radioactivity measurements

    International Nuclear Information System (INIS)

    Schwach, G.

    1986-01-01

    This is an overview of radioactivity monitoring work done in the Austrian Research Centre Seibersdorf in the wake of the Chernobyl accident. It consists of air, rainwater, food and personnel monitoring. Additional services to the public are: information and development of a database and a computer code for predicting future radionuclide concentration in air, soil, water and food. (G.Q.)

  20. Beta decay of polarized nuclei and the decay asymmetry of 8Li

    International Nuclear Information System (INIS)

    Bigelow, R.; Freedman, S.J.; Napolitano, J.; Quin, P.A.

    1985-01-01

    Under certain conditions, it is possible to produce vector-polarized radioactive nuclei in reactions with a polarized projectile and an unpolarized target. Using the intense polarized beams at the University of Wisconsin, the authors have begun a program to study the weak interaction through the beta decay of polarized nuclei produced in this way. Such experiments bear on tests of CVC in light nuclei, sensitive searches for second-class weak currents, and measurements of the weak vector-coupling constant. One may also deduce the values of certain matrix elements. Our effort is presently centering on a study of the energy dependence of the beta-decay asymmetry of 8 Li

  1. 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.)

  2. Disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Dlouhy, Z.

    1982-01-01

    This book provides information on the origin, characteristics and methods of processing of radioactive wastes, as well as the philosophy and practice of their storage and disposal. Chapters are devoted to the following topics: radioactive wastes, characteristics of radioactive wastes, processing liquid and solid radioactive wastes, processing wastes from spent fuel reprocessing, processing gaseous radioactive wastes, fixation of radioactive concentrates, solidification of high-level radioactive wastes, use of radioactive wastes as raw material, radioactive waste disposal, transport of radioactive wastes and economic problems of radioactive wastes disposal. (C.F.)

  3. Update and evaluation of decay data for spent nuclear fuel analyses

    Directory of Open Access Journals (Sweden)

    Simeonov Teodosi

    2017-01-01

    Full Text Available Studsvik’s approach to spent nuclear fuel analyses combines isotopic concentrations and multi-group cross-sections, calculated by the CASMO5 or HELIOS2 lattice transport codes, with core irradiation history data from the SIMULATE5 reactor core simulator and tabulated isotopic decay data. These data sources are used and processed by the code SNF to predict spent nuclear fuel characteristics. Recent advances in the generation procedure for the SNF decay data are presented. The SNF decay data includes basic data, such as decay constants, atomic masses and nuclide transmutation chains; radiation emission spectra for photons from radioactive decay, alpha-n reactions, bremsstrahlung, and spontaneous fission, electrons and alpha particles from radioactive decay, and neutrons from radioactive decay, spontaneous fission, and alpha-n reactions; decay heat production; and electro-atomic interaction data for bremsstrahlung production. These data are compiled from fundamental (ENDF, ENSDF, TENDL and processed (ESTAR sources for nearly 3700 nuclides. A rigorous evaluation procedure of internal consistency checks and comparisons to measurements and benchmarks, and code-to-code verifications is performed at the individual isotope level and using integral characteristics on a fuel assembly level (e.g., decay heat, radioactivity, neutron and gamma sources. Significant challenges are presented by the scope and complexity of the data processing, a dearth of relevant detailed measurements, and reliance on theoretical models for some data.

  4. Update and evaluation of decay data for spent nuclear fuel analyses

    Science.gov (United States)

    Simeonov, Teodosi; Wemple, Charles

    2017-09-01

    Studsvik's approach to spent nuclear fuel analyses combines isotopic concentrations and multi-group cross-sections, calculated by the CASMO5 or HELIOS2 lattice transport codes, with core irradiation history data from the SIMULATE5 reactor core simulator and tabulated isotopic decay data. These data sources are used and processed by the code SNF to predict spent nuclear fuel characteristics. Recent advances in the generation procedure for the SNF decay data are presented. The SNF decay data includes basic data, such as decay constants, atomic masses and nuclide transmutation chains; radiation emission spectra for photons from radioactive decay, alpha-n reactions, bremsstrahlung, and spontaneous fission, electrons and alpha particles from radioactive decay, and neutrons from radioactive decay, spontaneous fission, and alpha-n reactions; decay heat production; and electro-atomic interaction data for bremsstrahlung production. These data are compiled from fundamental (ENDF, ENSDF, TENDL) and processed (ESTAR) sources for nearly 3700 nuclides. A rigorous evaluation procedure of internal consistency checks and comparisons to measurements and benchmarks, and code-to-code verifications is performed at the individual isotope level and using integral characteristics on a fuel assembly level (e.g., decay heat, radioactivity, neutron and gamma sources). Significant challenges are presented by the scope and complexity of the data processing, a dearth of relevant detailed measurements, and reliance on theoretical models for some data.

  5. Assessment of naturally occurring radioactive materials and trace elements in playgrounds of selected basic schools in the Ga-East municipal district, Accra, Ghana

    International Nuclear Information System (INIS)

    Taapopi, E.E.

    2015-07-01

    The 235 U, 232 Th series and natural 40 K are the main source of natural radioactivity in soil and have long half-lives up to 10 10 years. Therefore their presence in soils and rocks is simply considered as permanent. Also due to rapid urbanization, most of Basic School playgrounds in Accra are built close to major roads or industrial areas for which they are subject to many potential pollution sources, including vehicle exhaust and industrial emissions. A study has been carried out on playgrounds of basic schools in the Ga East municipal district in order to determine the exposure of the school children to naturally occurring radioactive materials ( 238 U, 232 Th and 40 K) and trace elements [aluminum (Al), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), potassium (K), lanthanum (La), manganese (Mn), sodium (Na), nickel (Ni), lead (Pb), titanium (Ti), vanadium (V), zinc (Zn)]. The activity concentrations were determined using high‐purity germanium (HPGe) detector. The average activity concentrations of 238 U, 232 Th and 40 K determined were 19.8 ± 8.7, 29.1 ± 16.3 and 119.4 ± 97.9 Bq.kg-1 respectively. The average annual effective dose was 0.039 ± 0.021 mSv and it is below the dose limit of 1 mSv/year recommended by International Commission on Radiological Protection (ICRP) for public exposure control. Radiological hazard assessments arising from the natural radionuclides were carried out. The average concentration of 222 Rn and exhalation rate were estimated to be 32.13 kBq.m -3 and 0.016 Bq.m -2 .s -1 respectively, which compared well with the world average values [78 kBq.m -3 and 0.033 Bq.m -2 .s -1 reported by (UNSCEAR, 2000)]. Soil samples were also analyzed for trace elements by Instrumental Neutron Activation Analysis and Atomic Absorption Spectrometry in order to assess the potential adverse health effects of the exposure of children to trace elements during their games at school. Doses incurred via ingestion and inhalation and

  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. 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

  8. Radioactive waste management

    International Nuclear Information System (INIS)

    2013-01-01

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

  9. 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)

  10. Superallowed Fermi β decay studies at TRIUMF-ISAC

    Science.gov (United States)

    Svensson, C. E.; Dunlop, R.; Finlay, P.; Ball, G. C.; Ettenauer, S.; Leslie, J. R.; Towner, I. S.; Andreoiu, C.; Austin, R. A. E.; Bandyopadhyay, D.; Chagnon-Lessard, S.; Chester, A.; Cross, D. S.; Demand, G.; Djongolov, M.; Garnsworthy, A. B.; Garrett, P. E.; Green, K. L.; Glister, J.; Grinyer, G. F.; Hackman, G.; Hadinia, B.; Leach, K. G.; Pearson, C. J.; Phillips, A. A.; Rand, E. T.; Starosta, K.; Sumithrarachchi, C. S.; Tardiff, E. R.; Triambak, S.; Williams, S. J.; Wong, J.; Yates, S. W.; Zganjar, E. F.

    2013-10-01

    A program of high-precision superallowed Fermi β decay studies is being carried out at the Isotope Separator and Accelerator (ISAC) radioactive ion beam facility at TRIUMF. Recent high-precision branching ratio measurements for the superallowed decays of 74Rb and 26Alm, as well as a half-life measurement for 26Alm that is the most precise half-life measurement for any superallowed emitter to date, are reported. These results provide demanding tests of the theoretical isospin symmetry breaking corrections in superallowed Fermi β decays.

  11. 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.

  12. SYMPOSIUM: Rare decays

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1989-04-15

    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.

  13. 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.)

  14. 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

  15. Decay of 143La

    International Nuclear Information System (INIS)

    Blachot, J.; Dousson, S.; Monnand, E.; Schussler, F.

    1976-01-01

    The decay of 143 La has been investigated. Sources have been obtained from 2 isotope separators (ISERE, OSIRIS). 12 gamma rays, with the most intense at 620keV representing only 1.4% of decay, have been attributed to the 143 La decay. A level scheme has been found and compared with the one deduced from (d,p) and (n,γ) reactions on 142 Ce [fr

  16. 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)

  17. Radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    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).

  18. 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.

  19. 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)

  20. Radioactive substances

    International Nuclear Information System (INIS)

    Butler, G.C.; Hyslop, C.

    1980-01-01

    The purpose of this chapter is to show how to assess the detriment resulting from the release of radioactive materials to the environment. The minimum information required for the assessments is given for seven radionuclides of interest from the point of view of environmental contamination. The seven radionuclides are tritium, krypton-85, strontium-90, iodine-131, cesium-137, radium-226 and plutonium-239. Information is given on the radiation doses and the radiation effects on man due to these radioisotopes. (AN)

  1. Radioactive wastes

    International Nuclear Information System (INIS)

    Devarakonda, M.S.; Melvin, J.M.

    1994-01-01

    This paper is part of the Annual Literature Review issue of Water Environment Research. The review attempts to provide a concise summary of important water-related environmental science and engineering literature of the past year, of which 40 separate topics are discussed. On the topic of radioactive wastes, the present paper deals with the following aspects: national programs; waste repositories; mixed wastes; waste processing and decommissioning; environmental occurrence and transport of radionuclides; and remedial actions and treatment. 178 refs

  2. 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

  3. 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)

  4. 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

  5. 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

  6. Decay Studies of Very Neutron Rich Nuclei near 78Ni

    International Nuclear Information System (INIS)

    Winger, J. A.; Ilyushkin, S.; Korgul, A.; Gross, Carl J; Rykaczewski, Krzysztof Piotr; Batchelder, J. C.; Goodin, C.; Grzywacz, R.; Hamilton, J. H.; Krolas, W.; Liddick, Sean; Mazzocchi, C.; Nelson, C.; Padgett, Stephen; Piechaczek, A.; Rajabali, M. M.; Shapira, Dan; Zganjar, E. F.

    2008-01-01

    The properties of beta-gamma and beta-delayed neutron emission from 76-79 Cu and 83-85 Ga were measured at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory. Selected results on the decay properties of copper isotopes are briefly presented and discussed

  7. Decay studies of neutron-deficient lawrencium isotopes

    International Nuclear Information System (INIS)

    Antalic, S.; Saro, S.; Streicher, B.; Venhart, M.; Hessberger, F.P.; Ackermann, D.; Heinz, S.; Kindler, B.; Kojouharov, I.; Lommel, B.; Mann, R.; Hofmann, S.; Kuusiniemi, P.; Leino, M.; Nishio, K.; Sulignano, B.

    2008-01-01

    The radioactive decay of the isotopes 254-256 Lr and their daughter products was investigated by means of α, prompt α-γ and delayed conversion electron-γ coincidence spectroscopy. The isotopes were produced using the reaction 48 Ca+ 209 Bi. (orig.)

  8. Radioactivity and deep geothermal energy; Radioaktivitaet und tiefe Geothermie

    Energy Technology Data Exchange (ETDEWEB)

    Janczik, Sebastian; Kaltschmitt, Martin [Technische Univ. Hamburg-Harburg (Germany). Inst. fuer Umwelttechnik und Energiewirtschaft; Merkel, Broder [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Geologie

    2012-02-15

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

  9. 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

  10. 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.

  11. 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

  12. 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.)

  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. 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.)

  15. Rare Decays at LHCb

    CERN Document Server

    Belyaev, Ivan

    2006-01-01

    Rare loop-induced decays are sensitive to New Physics in many Standard Model extensions. In this paper we discuss the reconstruction of the radiative penguin decays $B^0_d \\to K^{*0} \\gamma, B^0_s \\to \\phi \\gamma , B^0_d \\to \\omega \\gamma, \\Lambda_b \\to \\Lambda \\gamma$, the electroweak penguin decays $B^0_d \\to K^{*0} \\mu^+ \\mu^-, B^+_u \\to K^+ \\mu^+ \\mu^-$, the gluonic penguin decays $B^0_d \\to \\phi K^0_S, B^0_s \\to \\phi \\phi$, and the decay $B^0_s \\to \\mu^+\\mu^-$ at LHCb. The selection criteria, evaluated efficiencies, expected annual yields and $B/S$ estimates are presented.

  16. 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)

  17. 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

  18. 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...

  19. Treatment of short-lived radioactive wastes

    International Nuclear Information System (INIS)

    Yamaguchi, Chiri

    1976-01-01

    Recently short life nuclides have come to be utilized increasingly as diagnostic radioisotopes, and Tc-99m (half-life; 6.05 hours) and Ga-67 (half-life 7.79 hours) are replacing the most nuclides fomerly used in vivo test. Such development of radioactive products inevitably causes the rapid increase of their wastes. At present, the radioactive wastes produced by hospitals and university laboratories in Japan are collected by the Japan Radioisotope Association, and treated by the Japan Atomic Energy Research Institute. These wastes are divided into combustibles and incombustibles to store in the store house in the Japan Atomic Energy Research Institute. The present law in Japan contains the contradiction which treats the matter with one several millionth of radioactivity after decay same as the original radioactive matter. Thus solid must be stored permanently, while gas and liquid can be discharged after dilution. (Kobatake, H.)

  20. 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

  1. 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

  2. Transporting Radioactive Waste: An Engineering Activity. Grades 5-12.

    Science.gov (United States)

    HAZWRAP, The Hazardous Waste Remedial Actions Program.

    This brochure contains an engineering activity for upper elementary, middle school, and high school students that examines the transportation of radioactive waste. The activity is designed to inform students about the existence of radioactive waste and its transportation to disposal sites. Students experiment with methods to contain the waste and…

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

    International Nuclear Information System (INIS)

    Cassidy, G.B.

    1983-07-01

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

  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. New systematics of cluster- and alpha-decay half lives

    International Nuclear Information System (INIS)

    Poenaru, D.N.; Greiner, W.

    1994-01-01

    Available as short communication only. The cluster (or 'exotic') radioactivities belong to a rich variety of nuclear decay modes which are phenomena intermediate between fission and alpha decay. In this contribution a single universal curve for the logarithm of the partial half-life for each kind of cluster radioactivity of even-even parent nuclei is presented. This handy relationship reproduces well the up to now 14 even-even half-life measurements within a ratio of 3.86 or rms=0.587 orders of magnitude. Its universality consists in the fact that instead of having different lines for various parent nuclei, like in the 'classical' systematics (Geiger-Nuttall plot) one can get practically only one line for each decay mode. (Author) 1 Fig., 2 Refs

  6. Radon survey in twenty schools of Campania Region (South Italy) carried out from students in the frame of a project on the study of environmental radioactivity: preliminary results

    International Nuclear Information System (INIS)

    Pugliese, M.; Roca, V.; Sabbarese, C.; Venoso, G.; Gialanella, L.; Pugliese, M.; Roca, V.; Venoso, G.; Sabbarese, C.

    2006-01-01

    School may be the second largest contributor to radon exposure of students, teachers and stuff,. About 500 measurements have been started in 20 schools located in Campania. Preliminary results showed that higher radon concentrations are in the scientific laboratory. (authors)

  7. Environmental Radioactivity. Chapter 4

    International Nuclear Information System (INIS)

    Muhamat Omar; Ismail Sulaiman; Zalina Laili

    2015-01-01

    This chapter explains several things which consist radioactivity measurements, regular and high background radioactivity, radioactive contaminated soil and radioactivity in fertilizers, rocks, building materials, food, water, environments, sediments, flora and fauna. Besides, the natural radioactive gas concentration of radon and toron in the environment also been discussed specifically in this chapter.

  8. Radioactive wastes

    International Nuclear Information System (INIS)

    Straub, C.P.

    1975-01-01

    A review is presented on the environmental behavior of radioactive wastes. The management of high-level wastes and waste disposal methods were discussed. Some topics included were ore processing, coagulation, absorption and ion exchange, fixation, ground disposal, flotation, evaporation, transmutation and extraterrestrial disposal. Reports were given of the 226 Ra, 224 Ra and tritium activity in hot springs, 90 Sr concentrations in the groundwater and in White Oak Creek, radionuclide content of algae, grasses and plankton, radionuclides in the Danube River, Hudson River, Pacific Ocean, Atlantic Ocean, Lake Michigan, Columbia River and other surface waters. Analysis showed that 239 Pu was scavenged from Lake Michigan water by phytoplankton and algae by a concentration factor of up to 10,000. Benthic invertebrates and fish showed higher 239 Pu concentrations than did their pelagic counterparts. Concentration factors are also given for 234 Th, 60 Co, Fe and Mr in marine organisms. Two models for predicting the impact of radioactivity in the food chain on man were mentioned. In an accidental release from a light-water power reactor to the ocean, the most important radionuclides discharged were found to be 90 Sr, 137 Cs, 239 Pu and activation products 65 Zr, 59 Fe, and 95 Zr

  9. 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

  10. Iconic decay in schizophrenia.

    Science.gov (United States)

    Hahn, Britta; Kappenman, Emily S; Robinson, Benjamin M; Fuller, Rebecca L; Luck, Steven J; Gold, James M

    2011-09-01

    Working memory impairment is considered a core deficit in schizophrenia, but the precise nature of this deficit has not been determined. Multiple lines of evidence implicate deficits at the encoding stage. During encoding, information is held in a precategorical sensory store termed iconic memory, a literal image of the stimulus with high capacity but rapid decay. Pathologically increased iconic decay could reduce the number of items that can be transferred into working memory before the information is lost and could thus contribute to the working memory deficit seen in the illness. The current study used a partial report procedure to test the hypothesis that patients with schizophrenia (n = 37) display faster iconic memory decay than matched healthy control participants (n = 28). Six letters, arranged in a circle, were presented for 50 ms. Following a variable delay of 0-1000 ms, a central arrow cue indicated the item to be reported. In both patients and control subjects, recall accuracy decreased with increasing cue delay, reflecting decay of the iconic representation of the stimulus array. Patients displayed impaired memory performance across all cue delays, consistent with an impairment in working memory, but the rate of iconic memory decay did not differ between patients and controls. This provides clear evidence against faster loss of iconic memory representations in schizophrenia, ruling out iconic decay as an underlying source of the working memory impairment in this population. Thus, iconic decay rate can be added to a growing list of unimpaired cognitive building blocks in schizophrenia.

  11. Puzzling Two-Proton Decay of 67Kr

    Science.gov (United States)

    Wang, S. M.; Nazarewicz, W.

    2018-05-01

    Ground-state two-proton (2 p ) radioactivity is a rare decay mode found in a few very proton-rich isotopes. The 2 p decay lifetime and properties of emitted protons carry invaluable information on nuclear structure in the presence of a low-lying proton continuum. The recently measured 2 p decay of 67Kr turned out to be unexpectedly fast. Since 67Kr is expected to be a deformed system, we investigate the impact of deformation effects on the 2 p radioactivity. We apply the recently developed Gamow coupled-channel framework, which allows for a precise description of three-body systems in the presence of rotational and vibrational couplings. This is the first application of a three-body approach to a two-nucleon decay from a deformed nucleus. We show that deformation couplings significantly increase the 2 p decay width of 67Kr; this finding explains the puzzling experimental data. The calculated angular proton-proton correlations reflect a competition between 1 p and 2 p decay modes in this nucleus.

  12. Radionuclide decay data-evaluation and dissemination

    International Nuclear Information System (INIS)

    Helmer, R.G.

    1994-01-01

    There are many applications of nuclear chemistry and physics, as the variety of contents of this symposium demonstrate. Many of these applications require a knowledge of data on the decay of radionuclides, e.g., half-lives and radiation energies and emission probabilities. For over 50 years, people have been compiling and evaluating the measured data to obtain recommended values of these quantities. This has resulted in numerous sets of recommended values, many of which still have scientific, historical, or national reasons for existing. This history provides a background to the current situation which involves the coexistence of the Table of Radioactive isotopes, the ENSDF file and the Nuclear Data Sheets, the Table de Radionucleides, IAEA Coordinated Research Program results, the ENDF/B-VI decay data file, etc. Visions of the future include new styles of evaluations and feedback from interested users

  13. 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.)

  14. 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

  15. New Decay Studies of 66Ga

    Science.gov (United States)

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

    2014-03-01

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

  16. 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

  17. Study on the transmutation of some radioactive wastes using the Bateman equations

    International Nuclear Information System (INIS)

    Orlandi, Horus Ibrahim; Moreira, Joao M.L.

    2009-01-01

    In this work, a numerical solution for the nuclear transmutation equations using the Bateman algorithm. The numerical solution was implemented using the JAVA language and the program gives the time variation of isotope chain decays population which appears due to nuclear transmutation. With the present results it is possible to understand the radioactive decay and the need of storage the radioactive decay along the years. The chain decay studied were the 99 Tc, 99 Zr, 135 Cs, 137 Cs and the 90 Sr, due to their long half-lives and the high fission yield

  18. Teleportation via decay

    Indian Academy of Sciences (India)

    therefore normally plays a negative role in quantum information processing [1]. ... of a decay be used in a fruitful way for quantum information process- ing? ..... The model independent portions of the analysis of communication through a noisy.

  19. Decay of Hoyle state

    Indian Academy of Sciences (India)

    2014-11-02

    Nov 2, 2014 ... T K RANA, C BHATTACHARYA, S KUNDU, ... of various direct 3α decay mechanisms of the Hoyle state. ... Pramana – J. Phys., Vol. ... FMD predicts a compact triangle shape and LEFT predicts a bent arm chain structure,.

  20. RARE KAON DECAYS

    International Nuclear Information System (INIS)

    LITTENBERG, L.

    2005-01-01

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

  1. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    2012-10-06

    Oct 6, 2012 ... Anyhow, the 'multi-isotope' ansatz is needed to compensate for matrix element ... The neccessary half-life requirement to touch this ... site energy depositions (like double beta decay) and multiple site interactions (most of.

  2. Cavities/Tooth Decay

    Science.gov (United States)

    ... milk, ice cream, honey, sugar, soda, dried fruit, cake, cookies, hard candy and mints, dry cereal, and ... teeth can wear down and gums may recede, making teeth more vulnerable to root decay. Older adults ...

  3. Inflaton decay in supergravity

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-06-15

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

  4. 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.)

  5. Double beta decay: experiments

    International Nuclear Information System (INIS)

    Fiorini, Ettore

    2006-01-01

    The results obtained so far and those of the running experiments on neutrinoless double beta decay are reviewed. The plans for second generation experiments, the techniques to be adopted and the expected sensitivities are compared and discussed

  6. 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)

  7. 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.

  8. 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.)

  9. 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

  10. Iconic Decay in Schizophrenia

    OpenAIRE

    Hahn, Britta; Kappenman, Emily S.; Robinson, Benjamin M.; Fuller, Rebecca L.; Luck, Steven J.; Gold, James M.

    2010-01-01

    Working memory impairment is considered a core deficit in schizophrenia, but the precise nature of this deficit has not been determined. Multiple lines of evidence implicate deficits at the encoding stage. During encoding, information is held in a precategorical sensory store termed iconic memory, a literal image of the stimulus with high capacity but rapid decay. Pathologically increased iconic decay could reduce the number of items that can be transferred into working memory before the info...

  11. Annihilation decays of bottomonium

    International Nuclear Information System (INIS)

    Monteiro, Antony Prakash; Bhat, Manjunath; D'Souza, Praveen P.; Vijaya Kumar, K.B.

    2016-01-01

    The bound state of a bottom quark b and its anti quark b-bar known as bottomonium was first seen in the spectrum of μμ"- pairs produced in 400 GeV proton-nucleus collisions at Fermilab. It was discovered as spin triplet states ϒ(1S), ϒ(2S) and ϒ(3S) by E288 collaboration at Fermilab. We have calculated annihilation decay widths of bottomonium states. The calculated decay widths are presented

  12. Decays of supernova neutrinos

    International Nuclear Information System (INIS)

    Lindner, Manfred; Ohlsson, Tommy; Winter, Walter

    2002-01-01

    Supernova neutrinos could be well-suited for probing neutrino decay, since decay may be observed even for very small decay rates or coupling constants. We will introduce an effective operator framework for the combined description of neutrino decay and neutrino oscillations for supernova neutrinos, which can especially take into account two properties: one is the radially symmetric neutrino flux, allowing a decay product to be re-directed towards the observer even if the parent neutrino had a different original direction of propagation. The other is decoherence because of the long baselines for coherently produced neutrinos. We will demonstrate how to use this effective theory to calculate the time-dependent fluxes at the detector. In addition, we will show the implications of a Majoron-like decay model. As a result, we will demonstrate that for certain parameter values one may observe some effects which could also mimic signals similar to the ones expected from supernova models, making it in general harder to separate neutrino and supernova properties

  13. Rare and forbidden decays

    CERN Document Server

    Trampetic, Josip

    2002-01-01

    In these lectures I first cover radiative and semileptonic B decays, including the QCD corrections for the quark subprocesses. The exclusive modes and the evaluation of the hadronic matrix elements, i.e. the relevant hadronic form factors, are the second step. Small effects due to the long-distance, spectator contributions, etc. are discussed next. The second section we started with non-leptonic decays, typically $B \\to \\pi\\pi, K\\pi, \\rho\\pi,...$ We describe in more detail our prediction for decays dominated by the $b\\to s \\eta_c$ transition. Reports on the most recent experimental results are given at the end of each subsection. In the second part of the lectures I discuss decays forbidden by the Lorentz and gauge invariance, and due to the violation of the angular moment conservation, generally called the Standard Model-forbiden decays. However, the non-commutative QED and/or non-commutative Standard Model (NCSM), developed in a series of works in the last few years allow some of those decay modes. These ar...

  14. 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

  15. Radioactive gas waste processing device

    International Nuclear Information System (INIS)

    Soma, Koichi.

    1996-01-01

    The present invention concerns a radioactive gas waste processing device which extracts exhaust gases from a turbine condensator in a BWR type reactor and releases them after decaying radioactivity thereof during temporary storage. The turbine condensator is connected with an extracting ejector, a preheater, a recombiner for converting hydrogen gas into steams, an off gas condensator for removing water content, a flow rate control valve, a dehumidifier, a hold up device for removing radiation contaminated materials, a vacuum pump for sucking radiation decayed-off gases, a circulation water tank for final purification and an exhaustion cylinder by way of connection pipelines in this order. An exhaust gas circulation pipeline is disposed to circulate exhaust gases from an exhaust gas exit pipeline of the recycling water tank to an exhaust gas exit pipeline of the exhaust gas condensator, and a pressure control valve is disposed to the exhaust gas circulation pipeline. This enable to perform a system test for the dehumidification device under a test condition approximate to the load of the dehumidification device under actual operation state, and stabilize both of system flow rate and pressure. (T.M.)

  16. 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)

  17. 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

  18. Neutron decay, semileptonic hyperon decay and the Cabibbo model

    International Nuclear Information System (INIS)

    Siebert, H.W.

    1989-01-01

    The decay rates and formfactor ratios of neutron decay and semileptonic hyperon decays are compared in the framework of the Cabibbo model. The results indicate SU(3) symmetry breaking. The Kobayashi-Maskawa matrix element V us determined from these decays is in good agreement with the value determined from K→πeν decays, and with unitarity of the KM-matrix. (orig.)

  19. 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.

  20. 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.

  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. Electron-capture ratios in radio-active decay

    International Nuclear Information System (INIS)

    Pelt, J. van.

    1978-01-01

    A review of the theory of electron capture is given and expressions for the electron-capture ratios derived. Attention is paid to the calculations of exchange and overlap correction factors. The theoretical results are then compared with experimental values on the basis of two recently published compilations. The experimental set-up used in this investigation is described and the analysis of the scintillation spectra discussed. Measurements on 131 Ba, 106 Agsup(m) and 196 Au are described and values derived for the exchange and overlap corrections and for the atomic electron-capture transition energy Qsub(EC). (Auth.)

  3. Nuclear structure from radioactive decay. Annual progress report

    International Nuclear Information System (INIS)

    Wood, J.L.

    1983-01-01

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

  4. 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

  5. Estimation of radioactivity in tobacco

    International Nuclear Information System (INIS)

    Nain, Mahabir; Gupta, Monika; Chauhan, R.P.; Chakarvarti, S.K.; Kant, K.; Sonkawade, R.G.

    2010-01-01

    The link between cigarette smoke and cancer has long been established. Smokers are ten times at greater risk of developing lung cancer than that of non-smokers. Tobacco fields and plants also have higher concentration of uranium and consequently large contents of 210 Po and 210 Pb belonging to uranium and radium decay series. These radio-nuclides have long association with tobacco plants. 210 Pb and 210 Po, decay products of the uranium series get dissolved in water and are first transported into plants and subsequently to the human being. Also, the uptake of radionuclides into roots from the soils and phosphate fertilizers along with direct deposition of 210 Pb by rainfall represents the principal mechanism of incorporation of 210 Pb and 210 Po into the tobacco plants. Uranium present in soil enters the plants through roots and gets distributed in various parts of the tobacco plants. This phenomenon may cause high intake of uranium and its radioactive decay products leading to harmful effects in human being. In the present work, Gamma spectrometry (HPGe detector of high-resolution gamma spectrometry system) has been used at Inter University Accelerator Center (IUAC), New Delhi, for the measurement of activity concentrations of 238 U, 232 Th and 40 K in some tobacco samples. The alpha radioactivity of the leaves of the tobacco plants was measured using plastic track detectors LR-115 Type-Il manufactured by Kodak. Measurement of track densities (track cm -2 day -1 ) shows variation on the upper face and the bottom face of the leaves for the plants. The track density due to alpha particles is higher at bottom face as compared to top face of the leaves. (author)

  6. Analytical method for solving radioactive transformations

    International Nuclear Information System (INIS)

    Vukadin, Z.

    1999-01-01

    The exact method of solving radioactive transformations is presented. Nonsingular Bateman coefficients, which can be computed using recurrence formulas, greatly reduce computational time and eliminate singularities that often arise in problems involving nuclide transmutations. Depletion function power series expansion enables high accuracy of the performed calculations, specially in a case of a decay constants with closely spaced values. Generality and simplicity of the method make the method useful for many practical applications. (author)

  7. Method for storage of liquid radioactive waste

    International Nuclear Information System (INIS)

    Hesky, H.; Wunderer, A.

    1978-01-01

    When nuclear fuel is reprocessed, apart from liquid radioactive wastes in certain cases also oxyhydrogen, i.e. a mixture of oxygen and hydrogen, is formed by radiolysis. It is proposed to remove the decay heat that will be formed by means of boiling cooling, to condense the steam and to recycle the condensate to the liquid waste store. The oxyhydrogen is to be rarefied by means of the steam and then catalytically recombined. The most advantageous process steps are discussed. (RW) [de

  8. 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)

  9. Radioactive materials production

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    The Radiochemical Processing Plant (RPP) at ORNL has served as the national repository and distribution center for 233 U for > 20 years. Several hundred kilograms of uranium, containing approximately 90 to 98% 233 U, are stored there in the form of metal, oxides, and nitrate solutions. All of these uranium materials contain small, but significant, concentrations of 232 U, ranging from 2 to 225 ppm. Most of the radioactivity associated with the 233 U comes from the decay daughters of 232 U (74-year half-life). The 252 Cf Industrial Sales/Loan Program involves loans of 252 Cf neutron sources to agencies of the US Government and sales of 252 Cf as the bulk oxide and as palladium-californium alloy pellets and wires. The program has been operated since 1968 in temporary facilities at the Savannah River Laboratory (SRL). The obsolete hot-cell facilities at SRL are now being decommissioned, and the program activities are being transferred to ORNL's Californium Facility in Bldg. 7930, which is managed by the staff of the Transuranium Processing Plant

  10. Environmental radioactivity

    International Nuclear Information System (INIS)

    1985-01-01

    Outline summary of a report prepared under contract to the DOE: Research Priorities and UK Estuaries: An Overview identifying Research Requirements. Topics considered include the study of radionuclides released into the NE Irish Sea from BNFL, Sellafields, differences in the isotopic composition of stable lead in various sediments, the concentration and distribution of 'hot particles' derived from BNFL in the Irish Sea and adjacent areas, together with attempts to separate hot particles from sediments, and the composition and properties of marine surfaces in relation to uptake and loss of radionuclides, particularly in relation to the common mussel, Mytilus edulis. The problem of the presence of transuranic radionuclides in the bottom sediments of the NE Irish Sea is considered. Profiles of radioactivity are being developed at the shelf-break in order to determine the transfer of radionuclides from the sea surface to the deep sea and to coastal waters; organisms examined include phytoplankton, zooplankton and crustacea (shrimps). Organisms such as Acantharia have been examined to determine transfer of elements and radionuclides to skeletal structures eg Sr, Ba and Si. (U.K.)

  11. Sigma beta decay

    International Nuclear Information System (INIS)

    Newman, D.E.

    1975-01-01

    Describes an experiment to measure beta decays of the sigma particle. Sigmas produced by stopping a K - beam in a liquid hydrogen target decayed in the following reactions: Kp → Σπ; Σ → Neν. The electron and pion were detected by wire spark chambers in a magnetic spectrometer and by plastic scintillators, and were differentiated by a threshold gas Cherenkov counter. The neutron was detected by liquid scintillation counters. The data (n = 3) shell electrons or the highly excited electrons decay first. Instead, it is suggested that when there are two to five electrons in highly excited states immediately after a heavy ion--atom collision the first transitions to occur will be among highly excited Rydberg states in a cascade down to the 4s, 4p, and 3d-subshells. If one of the long lived states becomes occupied by electrons promoted during the collision or by electrons falling from higher levels, it will not decay until after the valence shell decays. LMM rates calculated to test the methods used are compared to previous works. The mixing coefficients are given in terms of the states 4s4p, 45sp+-, and 5s5p. The applicability of Cooper, Fano, and Prats' discussion of the energies and transition rates of doubly excited states is considered

  12. Disposal options for radioactive waste

    International Nuclear Information System (INIS)

    Olivier, J.P.

    1991-01-01

    On the basis of the radionuclide composition and the relative toxicity of radioactive wastes, a range of different options are available for their disposal. Practically all disposal options rely on confinement of radioactive materials and isolation from the biosphere. Dilution and dispersion into the environment are only used for slightly contaminated gaseous and liquid effluents produced during the routine operation of nuclear facilities, such as power plants. For the bulk of solid radioactive waste, whatever the contamination level and decay of radiotoxicity with time are, isolation from the biosphere is the objective of waste disposal policies. The paper describes disposal approaches and the various techniques used in this respect, such as shallow land burial with minimum engineered barriers, engineered facilities built at/near the surface, rock cavities at great depth and finally deep geologic repositories for long-lived waste. The concept of disposing long-lived waste into seabed sediment layers is also discussed, as well as more remote possibilities, such as disposal in outer space or transmutation. For each of these disposal methods, the measures to be adopted at institutional level to reinforce technical isolation concepts are described. To the extent possible, some comments are made with regard to the applicability of such disposal methods to other hazardous wastes. (au)

  13. 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

  14. Radioactivity of air caused by nuclear bomb tests

    Energy Technology Data Exchange (ETDEWEB)

    Aron, A; Gross, B

    1957-01-01

    Daily checks of radioactive fallout at the above institute (Instituto Nacional de Tecnologia, Rio de Janeiro) gave an activity 10 times as high as the average on June 25, 1957. By applying the decay law for fallout of Way and Wigner the origin could be traced to the British H-bomb test at Christmas Island on May 15, 1957. By autoradiography of the filter it was shown that the high activity was caused by only one highly radioactive particle.

  15. 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

  16. Transport of radioactive substances

    International Nuclear Information System (INIS)

    2014-12-01

    The report on the transport of radioactive substances covers the following topics: facts on radioactive materials transport, safety of the transport of radioactive substances, legal regulations and guidelines: a multiform but consistent system, transport of nuclear fuels, safety during the transport of nuclear fuel, future transport of spent fuel elements and high-level radioactive wastes in Germany.

  17. Fundamental symmetries and astrophysics with radioactive beams

    International Nuclear Information System (INIS)

    Vogt, E.

    1996-04-01

    A major new initiative at TRIUMF pertains to the use of radioactive beams for astrophysics and for fundamental symmetry experiments. Some recent work is described in which the β-decay-followed by alpha particle emission of 16 N was used to find the resonance parameters dominating the alpha particle capture in 12 C and thus to find the astrophysical S-factor of this reaction which is of crucial importance for alpha-particle burning and the subsequent collapse of stars. In some work underway trapped neural atoms of radioactive potassium atoms will be used to study fundamental symmetries of the weak interactions. Trapping has been achieved and soon 38m K decay will be used to search for evidence of scalar interactions and 37 K decay to search for right-handed gauge-bosom interactions. Future experiments are planned to look for parity non-conservation in trapped francium atoms. This program is part of a revitalization for the TRIUMF laboratory accompanied by the construction of the radioactive beam facility (ISAC). (author)

  18. Incremento del índice de dientes permanentes cariados, perdidos por caries y obturados, entre escolares de Loja, España Increasing decayed, missing, and filled teeth index among school children in Loja, Spain

    Directory of Open Access Journals (Sweden)

    Diego Almagro-Nievas

    2001-06-01

    Full Text Available Objetivo. Identificar variables clínicas, socioeconómicas y de hábitos alimentarios e higiénicos, predictoras del incremento del índice (DMFT, por sus siglas en inglés de dientes definitivos que están cariados, ausentes por caries y obturados en la cohorte de escolares de la localidad de Loja, Granada, España, en un trienio (1994-1997. Material y métodos. Estudio de cohorte retrospectivo sobre 812 alumnos a los que se les realizó una exploración dental siguiendo la metodología recomendada por la Organización Mundial de la Salud. Para la construcción de modelos se usa la metodología de regresión logística. Resultado. El índice DMFT de toda la cohorte pasó de 1.86 a 4.5 (en el trienio y en los miembros de la cohorte de 12 años, de 3.71 a 4.47. El DMFT medio está asociado con el incremento del DMFT final. La asistencia al colegio 3 tiene un riesgo relativo (RR de 0.69 (IC 95% 0.60-0.8 frente a la asistencia al colegio 4, y un RR de 0.78 (IC 95% 0.67-0.90 frente a la asistencia al colegio 5. Conclusión. En el modelo final se encontró que el riesgo de incrementar la caries es por el DMFT medio del trienio, y que el factor protector es la asistencia al colegio 3. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.htmlObjective. To identify the clinical, socioeconomic, dietary, and hygienic predictors of the increasing Decayed, Missing, and Filled Teeth (DMFT index, in a cohort of school children in Loja, Granada, Spain, during a three-year period (1994-1997. Material and methods. A retrospective cohort study was conducted in 812 students to measure the DMFT index, using the methods recommended by the World Health Organization. Statistical analysis was conducted using logistic regression models. Results. During the study period, the DMFT index increased from 1.86 to 4.5 for the study cohort as a whole, and from 3.71 to 4.47 among twelve-year olds. The DMFT at mid-period was

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

    Science.gov (United States)

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

    2013-03-01

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

  20. Radioactive waste management

    International Nuclear Information System (INIS)

    Kawakami, Yutaka

    2008-01-01

    Radioactive waste generated from utilization of radioisotopes and each step of the nuclear fuel cycle and decommissioning of nuclear facilities are presented. On the safe management of radioactive waste management, international safety standards are established such as ''The Principles of Radioactive Waste Management (IAEA)'' and T he Joint Convention on the Safety of Radioactive Waste Management . Basic steps of radioactive waste management consist of treatment, conditioning and disposal. Disposal is the final step of radioactive waste management and its safety is confirmed by safety assessment in the licensing process. Safety assessment means evaluation of radiation dose rate caused by radioactive materials contained in disposed radioactive waste. The results of the safety assessment are compared with dose limits. The key issues of radioactive waste disposal are establishment of long term national strategies and regulations for safe management of radioactive waste, siting of repository, continuity of management activities and financial bases for long term, and security of human resources. (Author)

  1. Beta and muon decays

    International Nuclear Information System (INIS)

    Galindo, A.; Pascual, P.

    1967-01-01

    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)

  2. Decay of superdeformed bands

    International Nuclear Information System (INIS)

    Carpenter, M.P.; Khoo, T.L.; Lauritsen, T.

    1995-01-01

    One of the major challenges in the study of superdeformation is to directly connect the large number of superdeformed bands now known to the yrast states. In this way, excitation energies, spins and parities can be assigned to the levels in the second well which is essential to establish the collective and single-particle components of these bands. This paper will review some of the progress which has been made to understand the decay of superdeformed bands using the new arrays including the measurement of the total decay spectrum and the establishment of direct one-step decays from the superdeformed band to the yrast line in 194 Hg. 42 refs., 5 figs

  3. 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)

  4. 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

  5. Weak interactions: muon decay

    International Nuclear Information System (INIS)

    Sachs, A.M.; Sirlin, A.

    1975-01-01

    The traditional theory of the dominant mode of muon decay is presented, a survey of the experiments which have measured the observable features of the decay is given, and those things which can be learned about the parameters and nature of the theory from the experimental results are indicated. The following aspects of the theory of muon decay are presented first: general four-fermion theory, two-component theory of the neutrino, V--A theory, two-component and V--A theories vs general four-fermion theory, intermediate-boson hypothesis, radiative corrections, radiative corrections in the intermediate-boson theory, and endpoint singularities and corrections of order α 2 . Experiments on muon lifetime, isotropic electron spectrum, total asymmetry and energy dependence of asymmetry of electrons from polarized muons, and electron polarization are described, and a summary of experimental results is given. 7 figures, 2 tables, 109 references

  6. 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)

  7. 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.

  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. 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

  10. Sequential decay of Reggeons

    International Nuclear Information System (INIS)

    Yoshida, Toshihiro

    1981-01-01

    Probabilities of meson production in the sequential decay of Reggeons, which are formed from the projectile and the target in the hadron-hadron to Reggeon-Reggeon processes, are investigated. It is assumed that pair creation of heavy quarks and simultaneous creation of two antiquark-quark pairs are negligible. The leading-order terms with respect to ratio of creation probabilities of anti s s to anti u u (anti d d) are calculated. The production cross sections in the target fragmentation region are given in terms of probabilities in the initial decay of the Reggeons and an effect of manyparticle production. (author)

  11. Do protons decay

    International Nuclear Information System (INIS)

    Litchfield, P.J.

    1984-09-01

    The experimental status of proton decay is reviewed after the Leipzig International conference, July 1984. A brief comparative description of the currently active experiments is given. From the overall samples of contained events it can be concluded that the experiments are working well and broadly agree with each other. The candidates for proton decay from each experiment are examined. Although several experiments report candidates at a higher rate than expected from background calculations, the validity of these calculations is still open to doubt. (author)

  12. 103Pd decay

    International Nuclear Information System (INIS)

    Belyavenko, V.S.; Borozenets, G.P.; Vishnevskij, I.N.; Zheltonozhskij, V.A.

    1986-01-01

    103 Pd decay in different chemical states has been investigated. The change of the partial half-life period equal to 0.67±0.15% has been detected. The γ-spectrum has been measured to a high precision. The new data have been obtained on population probabilities of 103 Rh excited states and the total energy of decay for 103 Pd has been determined to a high precision (543.0±0.8). The values of log ft have been determined

  13. Decay of 99Mo

    International Nuclear Information System (INIS)

    Dickens, J.K.; Love, T.A.

    1976-01-01

    Relative intensities for K x-rays and gamma rays emanating from 99 Mo in equilibrium with its 99 Tc* daughter have been measured using several Ge photon detectors. Combining these intensities with an evaluated set of electron-conversion coefficients has provided a set of absolute intensities for the observed gamma rays. The absolute intensity for the dominant 140.5-keV gamma ray in 99 Tc was determined to be 90.7 +- 0.6/100 99 Mo disintegrations for 99 Mo decay in equilibrium with decay of the 99 Tc* daughter

  14. Supersymmetry in Z' decays

    International Nuclear Information System (INIS)

    Corcella, G.

    2014-01-01

    I study the phenomenology of new heavy neutral gauge bosons Z', predicted by Grand Unification Theories-driven U(1)' gauge groups and by the sequential standard model. BSM (Beyond Standard Model) decays into supersymmetric final states are accounted for, besides the SM (Standard Model) modes usually investigated. I give an estimate of the number of supersymmetric events in Z' decays possibly expected at LHC, as well as of the product of the Z' cross section times the branching fraction into electron and muon pairs. (author)

  15. Effective liquid drop description for alpha decay of atomic nuclei

    International Nuclear Information System (INIS)

    Tavares, O.A.P.; Duarte, S.B.; Rodriguez, O.; Guzman, F.; Goncalves, M.; Garcia, F.

    1998-06-01

    Alpha decay half-lives are presented in the framework of an effective liquid drop model for different combination of mass transfer descriptions and inertia coefficients. Calculated half-life-values for ground-state to ground-state favoured alpha transitions are compared with available, updated experimental data. Results have shown that the present model is very suitable to treat the alpha decay process on equal foot as cluster radioactivity and cold fission processes. Better agreement with the data is found when the sub-set of even-even alpha emitters are considered in the calculation. (author)

  16. 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

  17. Radioactive thickness gauge (1962); Jauge d'epaisseur radioactive (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Guizerix, J [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1962-07-01

    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{sub 1}/I{sub 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) [French] L'auteur decrit une jauge d'epaisseur dans laquelle le cristal scintillant detecteur 'voit' alternativement une source radioactive a travers le materiau a mesurer, puis une source de reference de meme nature; la separation des rayonnements est faite dans le temps a l'aide d'un volet absorbeur a secteurs alternativement pleins et creux. Les courants correspondants aux deux sources sont separes apres le tube photomultiplicateur par un detecteur synchrone avec la rotation du volet. On fait ensuite le quotient de ces deux courants a l'aide d'un potientometre enregistreur classique. il resulte de cette disposition que la valeur moyenne de la reponse, qui est de la forme G = f(I{sub 1}/I{sub 2}) n'est pas affectee par la decroissance des sources radioactives, et qu'elle est peu sensible aux variations de haute tension, de temperature ou des proprietes de l'air dans l'intervalle source-detecteur. On donne les performances de cette jauge. (auteur)

  18. Radiating school milk

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    School milk is milk delivered by a separate distribution network to schools and sold there at reduced prices. Radioactivities of these school milk have been sampled and compared to the milk sold in the usual shops. It turns out that the school milk is frequently more active than the ordinary milk: this is critisized. (qui)

  19. MONITORING OF RADIOACTIVITY AT DNURT CAMPUS

    Directory of Open Access Journals (Sweden)

    L. F. Dolina

    2016-06-01

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

  20. Radioactive isotopes in solid-state physics

    CERN Document Server

    Deicher, M

    2002-01-01

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

  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

    Energy Technology Data Exchange (ETDEWEB)

    Emara, A E [National Center for radiation Research and Technology Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    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. 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

  4. 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

  5. A theoretical study of cluster radioactivity in platinum isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, Deepthy Maria; Ashok, Nithu; Joseph, Antony [University of Calicut, Department of Physics, Malappuram, Kerala (India)

    2018-01-15

    The probable cluster decay modes in platinum isotopes are predicted with the help of effective liquid drop model. The calculated half-lives are compared with those of universal decay law model and with the experimental data. The investigation affirms the decisive role of neutron magicity in the phenomenon of cluster radioactivity. It is found that the probability of cluster emission decreases with the increase in the neutron number of parent nucleus. Geiger-Nuttall plots of the probable decay modes show linear behaviour, which in turn leads to the equation for logarithmic half-life for the clusters emitted from Pt isotopes. (orig.)

  6. Triton beta decay

    International Nuclear Information System (INIS)

    Saito, T.Y.; Wu, Y.; Ishikawa, S.; Sasakawa, T.

    1990-01-01

    Triton β-decay has been calculated using wave functions for 3 He and 3 H obtained from (Coulomb-modified) Faddeev equations for various interactions. We get a value for the Gamow-Teller matrix element of √3 (0.962±0.002) without regards to two- or three-nucleon inteactions. This value agrees with the experimental value. (orig.)

  7. Unparticles and muon decay

    International Nuclear Information System (INIS)

    Choudhury, Debajyoti; Ghosh, Dilip Kumar; Mamta

    2008-01-01

    Recently Georgi has discussed the possible existence of 'Unparticles' describable by operators having non-integral scaling dimensions. With the interaction of these with the Standard Model particles being constrained only by gauge and Lorentz symmetries, it affords a new source for lepton flavour violation. Current and future muon decay experiments are shown to be very sensitive to such scenarios

  8. Unparticles and muon decay

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, Debajyoti [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India); Ghosh, Dilip Kumar [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India)], E-mail: dkghosh@physics.du.ac.in; Mamta [Department of Physics, S.G.T.B. Khalsa College, University of Delhi, Delhi 110 007 (India)

    2008-01-03

    Recently Georgi has discussed the possible existence of 'Unparticles' describable by operators having non-integral scaling dimensions. With the interaction of these with the Standard Model particles being constrained only by gauge and Lorentz symmetries, it affords a new source for lepton flavour violation. Current and future muon decay experiments are shown to be very sensitive to such scenarios.

  9. Gluons in quarkonium decay

    International Nuclear Information System (INIS)

    Koller, K.; Walsh, T.

    1978-03-01

    We discuss what can be learned of the 3 S 1 quarkonium decay QantiQ → 3 gluoans QantiQ → γ + 2 gluons. The former is a way to find gluon jets and test QCD. The latter also allows us to measure gluoan + gluon → hadrons and look for pure gluonic resonances (glueballs). (orig.) [de

  10. Symmetry violating kaon decays

    International Nuclear Information System (INIS)

    Herczeg, P.

    1979-01-01

    An analysis of the muon number violating decay modes of the K-mesons is given. Subsequently, some new developments in the field of CP-violation are reviewed and the question of time-reversal invariance and the status of CPT-invariance are briefly considered. 42 references

  11. Double Beta Decay Experiments

    International Nuclear Information System (INIS)

    Piepke, A.

    2005-01-01

    The experimental observation of neutrino oscillations and thus neutrino mass and mixing gives a first hint at new particle physics. The absolute values of the neutrino mass and the properties of neutrinos under CP-conjugation remain unknown. The experimental investigation of the nuclear double beta decay is one of the key techniques for solving these open problems

  12. On the proton decay

    International Nuclear Information System (INIS)

    Fonda, L.; Ghirardi, G.C.; Weber, T.

    1983-07-01

    The problem of the proton decay is considered taking into account that in actual experiments there is an interaction of the proton with its environment which could imply an increase of its theoretical lifetime. It is seen that, by application of the time-energy uncertainty relation, no prolongation of the lifetime is obtained in this case. (author)

  13. Cosmology with decaying particles

    International Nuclear Information System (INIS)

    Turner, M.S.

    1984-09-01

    We consider a cosmological model in which an unstable massive relic particle species (denoted by X) has an initial mass density relative to baryons β -1 identically equal rho/sub X//rho/sub B/ >> 1, and then decays recently (redshift z less than or equal to 1000) into particles which are still relativistic today (denoted by R). We write down and solve the coupled equations for the cosmic scale factor a(t), the energy density in the various components (rho/sub X/, rho/sub R/, rho/sub B/), and the growth of linear density perturbations (delta rho/rho). The solutions form a one parameter (β) family of solutions; physically β -1 approx. = (Ω/sub R//Ω/sub NR/) x (1 + z/sub D/) = (ratio today of energy density of relativistic to nonrelativistic particles) x (1 + redshift of (decay)). We discuss the observational implications of such a cosmological model and compare our results to earlier results computed in the simultaneous decay approximation. In an appendix we briefly consider the case where one of the decay products of the X is massive and becomes nonrelativistic by the present epoch. 21 references

  14. Cosmology with decaying particles

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.S.

    1984-09-01

    We consider a cosmological model in which an unstable massive relic particle species (denoted by X) has an initial mass density relative to baryons ..beta../sup -1/ identically equal rho/sub X//rho/sub B/ >> 1, and then decays recently (redshift z less than or equal to 1000) into particles which are still relativistic today (denoted by R). We write down and solve the coupled equations for the cosmic scale factor a(t), the energy density in the various components (rho/sub X/, rho/sub R/, rho/sub B/), and the growth of linear density perturbations (delta rho/rho). The solutions form a one parameter (..beta..) family of solutions; physically ..beta../sup -1/ approx. = (..cap omega../sub R//..cap omega../sub NR/) x (1 + z/sub D/) = (ratio today of energy density of relativistic to nonrelativistic particles) x (1 + redshift of (decay)). We discuss the observational implications of such a cosmological model and compare our results to earlier results computed in the simultaneous decay approximation. In an appendix we briefly consider the case where one of the decay products of the X is massive and becomes nonrelativistic by the present epoch. 21 references.

  15. 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...

  16. 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

  17. 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

  18. Exhaust gas cleaning system for handling radioactive fission and activation gases

    International Nuclear Information System (INIS)

    Queiser, H.; Schwarz, H.

    1975-01-01

    An exhaust gas cleaning system utilizing the principle of delaying radioactive gases to permit their radioactive decay to a level acceptable for release to the atmosphere, comprising an adsorbent for adsorbing radioactive gas and a container for containing the adsorbent and for constraining gas to flow through the adsorbent, the adsorbent and the container forming simultaneously an adsorptive delay section and a mechanical delay section, by means of a predetermined ratio of volume of voids in the adsorbent to total volume of the container containing the adsorbent, for delaying radioactive gas to permit its radioactive decay to a level acceptable for release to the atmosphere is described. A method of using an adsorbent for cleaning a radioactive gas containing an isotope which is adsorbed by the adsorbent and containing an isotope whose adsorption by the adsorbent is low as compared to the isotope which is adsorbed and which is short-lived as compared to the isotope which is adsorbed, comprising constraining the gas to flow through the adsorbent with the retention time for the isotope which is adsorbed being at least the minimum for permitting radioactive decay to a level acceptable for release to the atmosphere and with the retention time for the isotope of relatively low adsorption and relatively short life being at least the minimum for permitting radioactive decay to a level acceptable for release to the atmosphere is also described. (U.S.)

  19. 2He decay from excited states: the 18Ne case

    International Nuclear Information System (INIS)

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

    2011-01-01

    Two-proton radioactivity studies have been performed on excited states of 18 Ne produced by 20 Ne fragmentation at the FRIBs facility of the Laboratori Nazionali del Sud. The study of the relative-momentum correlations of the two protons allowed to disentangle the diproton, democratic and sequential decay contributions to the 2p emission. In order to extend the study on two-proton decay to other light-masses nuclei, an upgrade of the FRIBs facility is planned. A new configuration of the Fragment Separator would be able to increase the acceptance of the beam line and therefore the yield of the produced radioactive beams. Also the present tagging setup will be modified in view of the gain intensity, in order to sustain the higher foreseen incoming rate. Status and perspectives of the facility will be presented. (author)

  20. Nuclear parameters determination of the {sup 127}Te {beta} {sup -} decay: a proposal for teaching nuclear physics; Determinacao de parametros nucleares do nucleo de {sup 127}Te: uma proposta para o ensino de fisica nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Batista, Wagner Fonseca

    2011-07-01

    A study of the {sup 127}Te {beta}{sup -} decay was carried out by means of gamma spectroscopy measurements using high resolution HPGe detector, in the region from 30 keV to 1.0 MeV, aiming to get a better understanding of the {sup 127}Te nuclear structure. The radioactive sources of {sup 12}7Te were obtained from the {sup 126}Te(n,{gamma}){sup 1}'2{sup 7}Te nuclear reaction produced in the IEA- R1 nuclear reactor at IPEN/CNEN-SP. Five gamma {sup t}ransitions previously attributed to this decay were confirmed with a better precision than previously. The half-life of {sup 127}Te was also studied resulting in data with lower uncertainty. Using a set of data selected from gamma spectroscopy measurements was developed and applied a didactic proposal for high school students using the Excel software. (author)

  1. Natural atmospheric radioactivity

    International Nuclear Information System (INIS)

    Renoux, A.

    1986-01-01

    After having summed up the different old or new units, used in radioactivity and radioprotection, the origins of atmospheric radioactivity are reported. Next the authors deal with the air content in radon, thoron and their radioactive descendants, insisting on the variations of the radon air content and on the radioactive balance between radon and its descendants. Then a few notions concerning the natural radioactive aerosol are developed: electric charge state, granulometric distribution. The possible effects of natural atmospheric radioactivity on man are studied with a distinction between inner irradiation and outer irradiation, an average assessment is shown. Finally the important problem of radon in inhabitations is approached [fr

  2. Rare B decays at LEP

    CERN Document Server

    Kluit, P M

    2001-01-01

    The results of the LEP experiments for rare B decays will be reviewed, covering hadronic final states, radiative and other rare decays and results for the inclusive charmless branching ratio. (8 refs).

  3. Nuclear chemistry research and spectroscopy with radioactive sources. Twenty-second annual progress report, February 1, 1986-January 31, 1987

    International Nuclear Information System (INIS)

    Fink, R.W.

    1986-01-01

    The nuclear chemistry group in the School of Chemistry continues investigations of radioactive decay of nuclei far from stability under this DOE contract. These nuclei are produced with heavy ions from the Holifield Heavy Ion Research Facility (HHIRF) and studied on-line with the University Isotope Separator at Oak Ridge (UNISOR). Radioactive decay represents a unique method for the population of low-energy, low-spin structures in nuclei, and new phenomena which do not occur near stability can be explored. Our research interest encompasses three aspects of nuclear structure: (1) nuclear spectroscopy with detailed γγt, e - γt, Xγt, αγt multiparameter coincidence spectrometry; (2) measurements of single γ-ray angular distributions and magnetic moments of mass separated low-temperature oriented nuclei, using the helium dilution refrigerator ''ORIENT'' being installed on-line to the isotope separator; and (3) on-line laser hyperfine structure (hfs) and isotope shift measurements for determination of nuclear quadrupole moments, nuclear spins, and changes in mean nuclear charge radii as a means of revealing systematic shape changes in nuclei. 35 refs., 8 figs., 1 tab

  4. Nuclear chemistry research and spectroscopy with radioactive sources. Twenty-first annual progress report, February 1, 1985-January 31, 1986

    International Nuclear Information System (INIS)

    Fink, R.W.

    1985-01-01

    The nuclear chemistry group in the School of Chemistry continues investigating the radioactive decay of nuclei far from stability under this DOE contract. These nuclei are produced with heavy ions from the Holifield Heavy Ion Research Facility [HHIRF] and studied on-line with the University Isotope Separator at Oak Ridge [UNISOR]. Radioactive decay represents a unique method for the population of low-energy, low-spin structures in nuclei, and new phenomena which do not occur near stability can be explored. Our research encompasses three aspects of nuclear structure: (1) nuclear spectroscopy with detailed γγt, e - γt, Xγt, etc., multiparameter coincidence spectrometry; (2) on-line laser hyperfine structure [hfs] and isotope shift measurements for the determination of nuclear quadrupole moments, nuclear spins, and changes in mean nuclear charge radii as a means of revealing systematic shape changes in nuclei; and (3) theoretical calculations of predictions of nuclear models for comparison with experimental level structures in nuclei studied at UNISOR. 20 refs., 9 figs., 2 tabs

  5. Mechanism of f-decay - spontaneous emission of fragments by heavy nuclei

    International Nuclear Information System (INIS)

    Rubchenya, V.A.; Ehjsmont, V.P.; Yavshits, S.G.

    1987-01-01

    A new type of model of radioactive decay - spontaneous emission of fragments by heavy nuclei, for which f-decay has been suggested, is formulated. The consideration is based on representation about a disintegrating configuration, for which the probability of f-cluster formation is close to 1. The moments method is used to determine the parameters of the disintegrating configuration. The probability of disintegrating configuration formation is determined by collective properties of a disintegrating nucleus. Effect of nucleon shells of the daughter nucleus and fragment leads to more compact disintegrating configuration and to decay energy increase, that's why at f-decay magic nuclei are formed. Probable spontaneous f-decay values calculated agree satisfactorily with experimental data. The calculational results testify to considerable decrease of f-decay probability at Z≥94

  6. JNDC FP decay data file

    International Nuclear Information System (INIS)

    Yamamoto, Tohru; Akiyama, Masatsugu

    1981-02-01

    The decay data file for fission product nuclides (FP DECAY DATA FILE) has been prepared for summation calculation of the decay heat of fission products. The average energies released in β- and γ-transitions have been calculated with computer code PROFP. The calculated results and necessary information have been arranged in tabular form together with the estimated results for 470 nuclides of which decay data are not available experimentally. (author)

  7. Visible neutrino decay at DUNE

    Energy Technology Data Exchange (ETDEWEB)

    Coloma, Pilar [Fermilab; Peres, Orlando G. [ICTP, Trieste

    2017-05-09

    If the heaviest neutrino mass eigenstate is unstable, its decay modes could include lighter neutrino eigenstates. In this case part of the decay products could be visible, as they would interact at neutrino detectors via mixing. At neutrino oscillation experiments, a characteristic signature of such \\emph{visible neutrino decay} would be an apparent excess of events at low energies. We focus on a simple phenomenological model in which the heaviest neutrino decays as $\

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

    Directory of Open Access Journals (Sweden)

    A. Gottardo

    2017-09-01

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

  9. Reactivity effects of fission product decay in PWRs

    International Nuclear Information System (INIS)

    Aragones, J.M.; Ahnert, C.

    1988-01-01

    The purpose of the work reported in this paper is to analyze the effects of fission product chains with radioactive decay on the reactivity in pressurized water reactor (PWR) cores, calculating their accumulation and absorption rates along fuel burnup at continuous operation and after shutdown periods extending from 1 day to a few months. The authors PWR version of the WIMS-D4 code is first used to obtain the individual number densities, absorption rates, and averaged cross sections for every nuclide of the fission product chains with significant decay rates, as a function of fuel burnup at continuous irradiation. Next, by an auxiliary ad hoc code, these data, have been processed together with the required one for fissile nuclides and boron, also taken from WIMS at each burnup step, to calculate the average or effective values relevant for the analysis and the decay and change in overall absorption after several shutdown times. (1) The reactivity effect of fission product decay changes significantly with the shutdown time. The maximum absorption increase by decay is reached in ∼ 10 days' shutdown. (2) The dependence with fuel type, enrichment, and burnup is slight, but the change with previous power density is nearly linear, which might be significant after coast-down in previous cycles. (3) For long shutdown periods, the overall reactivity effect of decay in the three fission product chains considered is much less than if only the samarium peak due to 149 Nd is considered

  10. Artificial radioactive products in the atmosphere at Paris. [In French

    Energy Technology Data Exchange (ETDEWEB)

    Abribat, M; Pouradier, J; Venet, A M

    1952-01-01

    The radioactivity of solid matter in rain water and air collected near Paris in November 1951, and in April and May 1952, follows the same decay law as that observed for fission products after a nuclear detonation in Nevada in November 1951.

  11. 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)

  12. Experimental study of ion-induced nucleation by radon decay

    International Nuclear Information System (INIS)

    He, F.; Hopke, P.K.

    1993-01-01

    In the environment, the presence of ions from natural radioactivity may increase the rate of new particle formation through ion-induced nucleation. A thermal diffusion cloud chamber (TDCC) has been built to experimentally study ion-induced nucleation where the ions are produced by gaseous radioactive sources. The critical supersaturation values and nucleation rates for methanol, ethanol, 1-propanol, and 1-butanol vapors on ions produced within the volume of the chamber by alpha decay of 222 Rn have been measured quantitatively at various radioactivity concentrations and supersaturations. The presence of ion tracks and the effect of an external electric field were also investigated. The alpha tracks and ion-induced nucleation formed by 222 Rn decay become visible at the critical supersaturation that is below the value needed for homogeneous nucleation. At this supersaturation, the nucleation rates increase substantially with increasing 222 Rn at low activity concentrations, but attain limiting values at higher concentrations. The experimental results indicate that the ionization by radon decay will promote ion-cluster formation and lower the free energy barriers. The formation of visible droplets is strongly dependent on the supersaturation. This study also confirms that the external electric field has a significant effect on the observed rates of nucleation

  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. Character of decay instability

    International Nuclear Information System (INIS)

    Polovin, R.V.; Demutskii, V.P.

    1981-01-01

    If the initial wave is unstable in the upper half plane Im ω>0 and there are no branch points of the quasiwave number, or if waves traveling in the same direction coalesce at a branch point, the instability is convective. On the other hand, if a branch point k(ω) does exist in the upper half-plane Im ω>0, and not all the waves that merge at this point travel in the same direction, the instability is absolute. A Green's function that describes the evolution of the perturbations of the initial wave in space and in time is constructed. The growth rates of the decay instability of the harmonics are determined. The produced waves are richer in harmonics than the initial waves. It is shown that the decay instability of an Alfven wave is absolute

  15. Decay of 57Ni

    International Nuclear Information System (INIS)

    Santos Scardino, A.M. dos.

    1987-01-01

    The decay of 57 Ni to 57 Co was studied by gamma ray spectroscopy using both singles and coincidence spectra. The sources were obtained with the 58 Ni (Y,n) 57 Ni reaction. Natural metallic nickel was irradiated in the bremsstrahluhng beam of the linear accelerator of the Instituto de Fisica da Universidade de Sao Paulo with 30 MeV electrons. The singles espectra were taken with 104 cc HPGe detector and the coincidences espectra with 27 and 53cc Ge(Li) and 104 cc. HPGe detectors. The energies of transitions that follow the 57 Ni decay were measured using 56 Co as standard (which was obtained by (Y,np) reaction in 58 Ni) and taking into account the cascade cross-over relations. (author) [pt

  16. Electroweak penguin B decays

    CERN Document Server

    Nikodem, Thomas

    2016-01-01

    Flavour Changing Neutral Currents (FCNC) are sensitive probes for physics beyond the Standard Model (SM), so-called New Physics. An example of a FCNC is the $b \\to s$ quark transition described by the electroweak penguin Feynman diagram shown in Figure 1. In the SM such FCNC are only allowed with a loop structure (as e:g: shown in the figure) and not by tree level processes. In the loops heavy particles appear virtually and do not need to be on shell. Therefore also not yet discovered heavy particles with up to a mass $\\mathcal{O}$(TeV) could virtually contribute significantly to observables. Several recent measurements of electroweak penguin B decays exhibit interesting tensions with SM predictions, most prominently in the angular observable $P'_5$ 5 of the decay $B^0 \\to K^{*0} \\mu^+ \\mu^1$[1], which triggered a lot of discussion in the theory community [2]-[14].

  17. Decay /sup 133/Ba

    Energy Technology Data Exchange (ETDEWEB)

    Singh, K; Hasiza, M L; Grewal, B S; Sahota, H S

    1982-07-01

    The relative gamma ray intensities of transitions in the decay of /sup 133/Ba have been measured using an intrinsic Ge detector. The electron capture branching ratios have been determined for 81, 161, 384 and 437 keV levels. The attenuation effect of long half-life of 81 keV levels has been studied in solid and liquid media. The electron capture decay has been investigated by changing the concentration of ethylene-diamine-tetraacetic acid (EDTA) environment. The 5/2/sup +/ yields 5/2/sup +/ 79.67 keV transition has an E0 to E2 intensity qsub(k)sup(2) <= 0.31. 10 refs., 4 figures.

  18. 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

  19. 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

  20. 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.

  1. Radioactivity of bone cement

    International Nuclear Information System (INIS)

    Scherer, M.A.; Winkler, R.; Ascherl, R.; Lenz, E.

    1993-01-01

    A total of 14 samples of different types of bone cement from five different manufacturers were examined for their radioactivity. Each of the investigated bone cements showed a low radioactivity level, i.e. between [de

  2. Immersed radioactive wastes

    International Nuclear Information System (INIS)

    2017-03-01

    This document presents a brief overview of immersed radioactive wastes worldwide: historical aspects, geographical localization, type of wastes (liquid, solid), radiological activity of immersed radioactive wastes in the NE Atlantic Ocean, immersion sites and monitoring

  3. Hypernuclear weak decay puzzle

    International Nuclear Information System (INIS)

    Barbero, C.; Horvat, D.; Narancic, Z.; Krmpotic, F.; Kuo, T.T.S.; Tadic, D.

    2002-01-01

    A general shell model formalism for the nonmesonic weak decay of the hypernuclei has been developed. It involves a partial wave expansion of the emitted nucleon waves, preserves naturally the antisymmetrization between the escaping particles and the residual core, and contains as a particular case the weak Λ-core coupling formalism. The extreme particle-hole model and the quasiparticle Tamm-Dancoff approximation are explicitly worked out. It is shown that the nuclear structure manifests itself basically through the Pauli principle, and a very simple expression is derived for the neutron- and proton-induced decays rates Γ n and Γ p , which does not involve the spectroscopic factors. We use the standard strangeness-changing weak ΛN→NN transition potential which comprises the exchange of the complete pseudoscalar and vector meson octets (π,η,K,ρ,ω,K * ), taking into account some important parity-violating transition operators that are systematically omitted in the literature. The interplay between different mesons in the decay of Λ 12 C is carefully analyzed. With the commonly used parametrization in the one-meson-exchange model (OMEM), the calculated rate Γ NM =Γ n +Γ p is of the order of the free Λ decay rate Γ 0 (Γ NM th congruent with Γ 0 ) and is consistent with experiments. Yet the measurements of Γ n/p =Γ n /Γ p and of Γ p are not well accounted for by the theory (Γ n/p th p th > or approx. 0.60Γ 0 ). It is suggested that, unless additional degrees of freedom are incorporated, the OMEM parameters should be radically modified

  4. Meson radiative decays

    International Nuclear Information System (INIS)

    Edwards, B.J.; Kamal, A.N.

    1979-04-01

    The status of decays of the kind V → Pγ and P → Vγviewed with special emphasis on the work done by the authors in this field. The low experimental value of GAMMA(rho → πγ) remains the outstanding problem. The lastest preliminary numbers from a Fermi Laboratory experiment go in the right direction but not far enough. 15 references

  5. Decay of 83Sr

    International Nuclear Information System (INIS)

    Yu Xiaohan; Shi Shuanghui; Gu Jiahui

    1997-01-01

    The decay of 83 Sr was reinvestigated using γ singles and γ-γ-t coincidence measurement. A new level scheme of Rb, which contains 41 excited levels and about 180 transitions, is constructed. 19 new levels were added to the old level scheme and 8 formerly adopted levels were denied. A new data set of branching ratio, log(ft) value and spin parity was obtained

  6. Realization of radioactive equilibrium in the KRISS radon chamber

    International Nuclear Information System (INIS)

    Lee, Mo Sung; Park, Tae Soon; Lee, Jong Man

    2013-01-01

    The maintenance of radioactive equilibrium between radon and its decay products in a radon chamber is necessary to calibrate radon decay product monitors. In this study, the activity concentrations of radon decay products have been measured, and mosquito-repellent incense has been used to produce aerosol particles in the chamber. Filter papers with 8 μm pore size were used to collect aerosol in the chamber. The activity concentrations of radon decay products have been evaluated by the Modified Tsivoglou Method. The correction factors due to the differences in counting time requirements of the Modified Tsivoglou Method and the time delay between consecutive measurements have been determined. Finally, the radioactive equilibrium has been confirmed by applying the Bateman equation. - Highlights: • The activity concentrations of radon decay products are evaluated by the Modified Tsivoglou Method. • Mosquito-repellent incense is used to produce aerosol particles in the radon chamber. • The radioactive equilibrium in the chamber was achieved within 2 days and confirmed by the Bateman equation

  7. Radioactive waste management for a radiologically contaminated hospitalized patient

    International Nuclear Information System (INIS)

    Pina Jomir, G.; Michel, X.; Lecompte, Y.; Chianea, N.; Cazoulat, A.

    2015-01-01

    Radioactive waste management in the post-accidental phase following caring for a radiologically contaminated patient in a hospital decontamination facility must be anticipated at a local level to be truly efficient, as the volume of waste could be substantial. This management must comply with the principles set out for radioactive as well as medical waste. The first step involves identification of radiologically contaminated waste based on radioactivity measurement for volume reduction. Then, the management depends on the longest radioactive half-life of contaminative radionuclides. For a half-life inferior to 100 days, wastes are stored for their radioactivity to decay for at least 10 periods before disposal like conventional medical waste. Long-lived radioactive waste management implies treatment of liquid waste and special handling for sorting and packaging before final elimination at the French National Agency for Radioactive Waste Management (ANDRA). Following this, highly specialized waste management skills, financial responsibility issues and detention of non-medical radioactive sources are questions raised by hospital radioactive waste management in the post-accidental phase. (authors)

  8. MULTIFLUID MAGNETOHYDRODYNAMIC TURBULENT DECAY

    International Nuclear Information System (INIS)

    Downes, T. P.; O'Sullivan, S.

    2011-01-01

    It is generally believed that turbulence has a significant impact on the dynamics and evolution of molecular clouds and the star formation that occurs within them. Non-ideal magnetohydrodynamic (MHD) effects are known to influence the nature of this turbulence. We present the results of a suite of 512 3 resolution simulations of the decay of initially super-Alfvenic and supersonic fully multifluid MHD turbulence. We find that ambipolar diffusion increases the rate of decay of the turbulence while the Hall effect has virtually no impact. The decay of the kinetic energy can be fitted as a power law in time and the exponent is found to be -1.34 for fully multifluid MHD turbulence. The power spectra of density, velocity, and magnetic field are all steepened significantly by the inclusion of non-ideal terms. The dominant reason for this steepening is ambipolar diffusion with the Hall effect again playing a minimal role except at short length scales where it creates extra structure in the magnetic field. Interestingly we find that, at least at these resolutions, the majority of the physics of multifluid turbulence can be captured by simply introducing fixed (in time and space) resistive terms into the induction equation without the need for a full multifluid MHD treatment. The velocity dispersion is also examined and, in common with previously published results, it is found not to be power law in nature.

  9. 152Eu decay

    International Nuclear Information System (INIS)

    Artamonova, K.P.; Vinogradov, V.M.; Grigor'ev, E.P.; Zolotavin, A.V.; Makarov, V.M.; Sergeev, V.O.; Usynko, T.M.

    1978-01-01

    The purpose of this paper is the measurement of the relative intensities of the most intensive conversion lines of 152 Eu, the determination of as reliable as possible magnitudes of the intensities of γ-quanta using all the available data on γ-radiation of 152 Eu, the measurement of the interval conversion coefficients (ICC) for the most intensive γ-transitions, the determination of the probabilities of the 152 Eu β-decays to the 152 Sm and 152 Gd levels. The conversion lines of the most intensive γ-transitions in the 152 Eu decay are studied and the corresponding ICC are measured on the beta-spectrometers of π√2 and UMB type. The balance for the γ-transitions in the 152 Sm and 152 Gd daughter nuclei are presented. This balance is used to determine the absolute intensities of γ-rays (in terms of the percentage of the 152 Eu decays) and the probabilities of β-transitions to the levels of daughter nuclei. More accurate data on γ-rays and conversion electrons obtained can be used for the calibration of gamma and beta spectrometers

  10. Transport of radioactive wastes

    International Nuclear Information System (INIS)

    Stuller, C.

    2003-01-01

    In this article author describes the system of transport and processing of radioactive wastes from nuclear power of Slovenske elektrarne, plc. It is realized the assurance of transport of liquid and solid radioactive wastes to processing links from places of their formation, or of preliminary storage and consistent transports of treated radioactive wastes fixed in cement matrix of fibre-concrete container into Rebublic storage of radioactive wastes in Mochovce

  11. Polarized secondary radioactive beams

    International Nuclear Information System (INIS)

    Zaika, N.I.

    1992-01-01

    Three methods of polarized radioactive nuclei beam production: a) a method nuclear interaction of the non-polarized or polarized charged projectiles with target nuclei; b) a method of polarization of stopped reaction radioactive products in a special polarized ion source with than following acceleration; c) a polarization of radioactive nuclei circulating in a storage ring are considered. Possible life times of the radioactive ions for these methods are determined. General schemes of the polarization method realizations and depolarization problems are discussed

  12. Management of radioactive waste

    International Nuclear Information System (INIS)

    Neerdael, B.; Marivoet, J.; Put, M.; Van Iseghem, P.; Volckaert, G.; Wacquier, W.

    1998-09-01

    The document gives an overview of of different aspects of radioactive waste management in Belgium. The document discusses the radioactive waste inventory in Belgium, the treatment and conditioning of radioactive waste as well as activities related to the characterisation of different waste forms. A separate chapter is dedicated to research and development regarding deep geological disposal of radioactive waste. In the Belgian waste management programme, particular emphasis is on studies for disposal in clay. Main results of these studies are highlighted and discussed

  13. Focus on radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, M

    1989-01-01

    Written for children, this book looks at the nature of radioactive materials, how they were discovered, what they are used for and how they affect the environment around us. The emphasis is on the benefits of radioactive materials, particularly in nuclear power stations, in medical diagnostics and radiotherapy, in industry and in agriculture. Nuclear fission and fusion are explained, how radioactive materials are handled and naturally occurring radioactivity are included. (UK).

  14. 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

  15. 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.)

  16. 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

  17. 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)

  18. Some problems in critical use of nuclear decay data

    International Nuclear Information System (INIS)

    Kawada, Yasushi

    1975-01-01

    A great variety of radionuclides are utilized at present and they have been increasing steadly in number with the development of science and technology. Therefore, the parameters such as their decay patterns, half lives, kinds of radioactive ray, ratio of energy emission, coefficients of internal conversion, fluorescence yields, etc. should be grasped for RI utilization. This report gives the outline of the present status and some problems for arranging nuclear decay data from the viewpoint of utilizing radioisotopes. The compilation and evaluation of nuclear decay data prevailing at present are summarized in ''Table of Isotopes'' and ''Nuclear Data Sheets'', but some gaps are found between them. Conspicuous gaps are recognized in such data as half life, γ-ray intensity, radiation energy, coefficient of internal conversion, etc. Some problems are also found in the data of fluorescence yield,

  19. ZZ RADDECAY, Decay Data Library for Radiological Assessment

    International Nuclear Information System (INIS)

    2000-01-01

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

  20. Teaching about radioactivity and ionising radiation: an alternative approach

    International Nuclear Information System (INIS)

    Millar, R.; Klaassen, K.; Eijkelhof, H.

    1990-01-01

    This article reviews children's ideas about radiation and radioactivity and identifies several common areas of misunderstanding. A new approach to teaching the topic at school level, which seeks specifically to address these known difficulties, is then proposed and outlined. (author)

  1. Radioactive nuclides in the living environment

    International Nuclear Information System (INIS)

    Ueno, Kaoru; Hoshi, Michio.

    1993-09-01

    There are several radioactive nuclides in the living environment, such as those existing since the creation of the earth, those coming from experimental nuclear explosions, and radiations of the cosmic rays. A lesson on these radioactive nuclides was considered useful for understanding the place of nuclear technology, and have been made on the title of 'Radioactive Nuclides in the Living Environment' in the general course of the Nuclear Engineering School of Japan Atomic Energy Research Institute. When the curriculum of the general course was modified in 1993, the lesson was left in a changed form. Thus, the textbook of the lesson is presented in this report. The contents are natural and artificial radioactive nuclides in the living environment and where they have come from etc. (author)

  2. Aspects of radioactive waste management

    International Nuclear Information System (INIS)

    Cutoiu, Dan

    2003-01-01

    The origin and types of radioactive waste, the objective and the fundamental principles of radioactive waste management and the classification of radioactive waste are presented. Problems of the radioactive waste management are analyzed. (authors)

  3. DECSERVIS-2: A tool for natural decay series mass flow simulation

    International Nuclear Information System (INIS)

    Azzam, Saad; Suksi, Juhani; Ammann, Michael

    2009-01-01

    After the publication of 'DECSERVIS: a tool for radioactive decay series visualisation' we have further developed our DECSERVIS software. With the new tool DECSERVIS-2 one can simulate radioactive decay chains in open systems, i.e. when the concentrations of nuclides change also due to mass flows. Decay chains can be simulated under continuous and successive nuclide mass flow events into and out from the system and in freely determined time intervals. Simulation output for the entire decay chain (nuclide activity, mass, number of nuclides, nuclide ratios) can be presented as a function of time with various graphical presentations such as solid curve and column diagrams or animation. In this paper we introduce DECSERVIS-2 and demonstrate its use with simulation examples. DECSERVIS-2 is easy to use and has been designed with an eye on the demands of teaching.

  4. 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.

  5. Understanding radioactive waste

    International Nuclear Information System (INIS)

    Murray, R.L.

    1989-01-01

    This book discusses the sources and health effects of radioactive wastes. It reveals the techniques to concentrate and immobilize radioactivity and examines the merits of various disposal ideas. The book, which is designed for the lay reader, explains the basic science of atoms,nuclear particles,radioactivity, radiation and health effects

  6. Transport of radioactive materials

    International Nuclear Information System (INIS)

    2013-01-01

    This ninth chapter presents de CNEN-NE--5.01 norm 'Transport of radioactive material'; the specifications of the radioactive materials for transport; the tests of the packages; the requests for controlling the transport and the responsibilities during the transport of radioactive material

  7. Radioactivity in the environment

    International Nuclear Information System (INIS)

    2011-01-01

    Illustrated by drawings, this publication briefly describes radioactive exposure modalities (external or internal irradiation), the ways they are measured and assessed (doses, units), the different natural radioactivity origins, the different radioactivity origins related to human activity, the share of each origin in population exposures

  8. Radioactive lightning rods waste treatment

    International Nuclear Information System (INIS)

    Vicente, Roberto; Dellamano, Jose C.; Hiromoto, Goro

    2008-01-01

    Full text: In this paper, we present alternative processes that could be adopted for the management of radioactive waste that arises from the replacement of lightning rods with attached Americium-241 sources. Lightning protectors, with Americium-241 sources attached to the air terminals, were manufactured in Brazil until 1989, when the regulatory authority overthrew the license for fabrication, commerce, and installation of radioactive lightning rods. It is estimated that, during the license period, about 75,000 such devices were set up in public, commercial and industrial buildings, including houses and schools. However, the policy of CNEN in regard to the replacement of the installed radioactive rods, has been to leave the decision to municipal governments under local building regulations, requiring only that the replaced rods be sent immediately to one of its research institutes to be treated as radioactive waste. As a consequence, the program of replacement proceeds in a low pace and until now only about twenty thousand rods have reached the waste treatment facilities The process of management that was adopted is based primarily on the assumption that the Am-241 sources will be disposed of as radioactive sealed sources, probably in a deep borehole repository. The process can be described broadly by the following steps: a) Receive and put the lightning rods in initial storage; b) Disassemble the rods and pull out the sources; c) Decontaminate and release the metal parts to metal recycling; d) Store the sources in intermediate storage; e) Package the sources in final disposal packages; and f) Send the sources for final disposal. Up to now, the disassembled devices gave rise to about 90,000 sources which are kept in storage while the design of the final disposal package is in progress. (author)

  9. RADIATIVE PENGUIN DECAYS FROM BABAR

    Energy Technology Data Exchange (ETDEWEB)

    Eigen, Gerald

    2003-08-28

    Electroweak penguin decays provide a promising hunting ground for Physics beyond the Standard Model (SM). The decay B {yields} X{sub s}{gamma}, which proceeds through an electromagnetic penguin loop, already provides stringent constraints on the supersymmetric (SUSY) parameter space. The present data samples of {approx}1 x 10{sup 8} B{bar B} events allow to explore radiative penguin decays with branching fractions of the order of 10{sup -6} or less. In this brief report they discuss a study of B {yields} K*{ell}{sup +}{ell}{sup -} decay modes and a search for B {yields} {rho}({omega}){gamma} decays.

  10. Shannon entropy and particle decays

    Science.gov (United States)

    Carrasco Millán, Pedro; García-Ferrero, M. Ángeles; Llanes-Estrada, Felipe J.; Porras Riojano, Ana; Sánchez García, Esteban M.

    2018-05-01

    We deploy Shannon's information entropy to the distribution of branching fractions in a particle decay. This serves to quantify how important a given new reported decay channel is, from the point of view of the information that it adds to the already known ones. Because the entropy is additive, one can subdivide the set of channels and discuss, for example, how much information the discovery of a new decay branching would add; or subdivide the decay distribution down to the level of individual quantum states (which can be quickly counted by the phase space). We illustrate the concept with some examples of experimentally known particle decay distributions.

  11. Measurement of artificial radioactivity in the atmosphere at Ottawa, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Terentiuk, F

    1958-01-01

    In recent years there has been considerable interest in the artificial radioactivity in the atmosphere originating from atomic and thermonuclear explosions. For the past year daily measurements of radioactivity have been made at Ottawa. The sampling times corresponded to air volumes of 425 cubic metric and 2000 cubic meters, respectively. Filters were kept for a period of 3 days before measurements were made in order to permit natural activity resulting from daughter products of radon and thoron to decay to a negligible value. Measurements of the gross beta activity from the filters were made directly with end-window Geiger tubes. Filters showing considerable initial radioactivity were measured at intervals of a few days in order to obtain the rate of decay of the activity. It was hoped that the data obtained would make it possible to fix the date of the explosion responsible for the filter activity but the fixing of dates was very uncertain.

  12. Column: Factors Affecting Data Decay

    Directory of Open Access Journals (Sweden)

    Kevin Fairbanks

    2012-06-01

    Full Text Available In nuclear physics, the phrase decay rate is used to denote the rate that atoms and other particles spontaneously decompose. Uranium-235 famously decays into a variety of daughter isotopes including Thorium and Neptunium, which themselves decay to others. Decay rates are widely observed and wildly different depending on many factors, both internal and external. U-235 has a half-life of 703,800,000 years, for example, while free neutrons have a half-life of 611 seconds and neutrons in an atomic nucleus are stable.We posit that data in computer systems also experiences some kind of statistical decay process and thus also has a discernible decay rate. Like atomic decay, data decay fluctuates wildly. But unlike atomic decay, data decay rates are the result of so many different interplaying processes that we currently do not understand them well enough to come up with quantifiable numbers. Nevertheless, we believe that it is useful to discuss some of the factors that impact the data decay rate, for these factors frequently determine whether useful data about a subject can be recovered by forensic investigation.(see PDF for full column

  13. 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.

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

    CERN Document Server

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

    2003-01-01

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

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  16. Rare B decays at LHCb

    CERN Document Server

    Puig Navarro, Albert

    2017-01-01

    Rare decays are flavour changing neutral current processes that allow sensitive searches for phenomena beyond the Standard Model (SM). In the SM, rare decays are loop-suppressed and new particles in SM extensions can give significant contributions. The very rare decay $B^0_s\\to\\mu^+\\mu^-$ in addition helicity suppressed and constitutes a powerful probe for new (pseudo) scalar particles. Of particular interest are furthermore tests of lepton universality in rare $b\\to s\\ell^+\\ell^-$ decays. The LHCb experiment is designed for the study of b-hadron decays and ideally suited for the analysis of rare decays due to its high trigger efficiency, as well as excellent tracking and particle identification performance. Recent results from the LHCb experiment in the area of rare decays are presented, including tests of lepton universality and searches for lepton flavour violation.

  17. B decays to open charm

    CERN Document Server

    AUTHOR|(CDS)2073670

    2016-01-01

    Studies of $B$ meson decays to states involving open charm mesons in data recorded by the LHCb experiment have resulted in first observations of several new decay modes, including $B_s^{0} \\rightarrow D_s^{*\\mp} K^{\\pm}$, $B_s^{0} \\rightarrow \\overline{D}^{0} K_S^{0}$ and $B^{+} \\rightarrow D^{+} K^{+} \\pi^{-}$ decays. An upper limit has been placed on the branching fraction of $B_s^{0} \\rightarrow \\overline{D}^{0} f_0(980)$ decays. Measurements of other branching fractions, such as those of $B_s^{0} \\rightarrow D_s^{(*)+} D_s^{(*)-}$ decays, are the most precise to date. Additionally, amplitude analyses of $B^{0} \\rightarrow \\overline{D}^{0} \\pi^{+} \\pi^{-}$ and $B^{0} \\rightarrow \\overline{D}^{0} K^{+} \\pi^{-}$ decays have been performed, alongside the first $CP$ violation analysis using the Dalitz plot of $B^{0} \\rightarrow D K^{+} \\pi^{-}$ decays.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

  19. 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.

  20. Treating radioactive effluent

    International Nuclear Information System (INIS)

    Kirkham, I.A.

    1981-01-01

    In the treatment of radioactive effluent it is known to produce a floc being a suspension of precipitates carrying radioactive species in a mother liquor containing dissolved non-radioactive salts. It is also known and accepted practice to encapsulate the floc in a solid matrix by treatment with bitumen, cement and the like. In the present invention the floc is washed with water prior to encapsulation in the solid matrix whereby to displace the mother liquor containing the dissolved non-radioactive salts. This serves to reduce the final amount of solidified radioactive waste with consequent advantages in the storage and disposal thereof. (author)

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

    CERN Document Server

    Lynch, Kara Marie

    2015-01-01

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

  2. The stakes in managing radioactive wastes

    International Nuclear Information System (INIS)

    Boissier, F.

    2012-01-01

    Like any human activity, the nuclear industry produces wastes. The wastes containing radioactive substances have to be managed as a function of the related risks. Nowadays, 1.300.000 tons of radioactive wastes have accumulated in France. More than 90% of them have short half-lives and are stored on the ground by ANDRA (national agency for the management of radioactive wastes) on 2 sites in the Aube district. ANDRA also designs solutions for stocking the other wastes. Those with long half-lives and very high activity will be stored deep underground (500 meter deep) at Cigeo in the Meuse and Haute-Marne districts. The wastes with long half-lives but low activity (less than 10 5 decays/s for graphite and less than a few thousands decays/s for radium contaminated wastes) will be disposed in a specific way. Implementing a storage solution for each type of waste is necessary for the nuclear industry's sustainability, but it does not dispense the latter from pursuing its efforts to reduce the quantity and danger of the wastes produced. This holds in particular for the so-called 'fourth generation' of future installations. It is important to take stock of all the issues related to managing nuclear wastes

  3. CHAINS-PC, Decay Chain Atomic Densities

    International Nuclear Information System (INIS)

    1994-01-01

    1 - Description of program or function: CHAINS computes the atom density of members of a single radioactive decay chain. The linearity of the Bateman equations allows tracing of interconnecting chains by manually accumulating results from separate calculations of single chains. Re-entrant loops can be treated as extensions of a single chain. Losses from the chain are also tallied. 2 - Method of solution: The Bateman equations are solved analytically using double-precision arithmetic. Poles are avoided by small alterations of the loss terms. Multigroup fluxes, cross sections, and self-shielding factors entered as input are used to compute the effective specific reaction rates. The atom densities are computed at any specified times. 3 - Restrictions on the complexity of the problem: Maxima of 100 energy groups, 100 time values, 50 members in a chain

  4. Modification of the rate of β-decay by chiral molecular environment

    International Nuclear Information System (INIS)

    Garay, A.S.; Biological Research Center, Szeged

    2000-01-01

    The radioactive isotope 32 P in the form of phosphoric acid (H 3 32 PO 4 ) and 22 Na in the form of sodium chloride ( 22 NaCl), were dissolved in R and S mirror image chiral solvents of 2-phenylbutyric acid (PBA) and diethyltartrate (DET). Then their decay rates were determined and compared to each other, to their decay rates in water and to their decay rates in racemic mixtures. It was found that 32 P decayed significantly faster if dissolved in R-PBA than in S-PBA. Similarly, 22 Na decayed significantly faster if dissolved in R-DET than in S-DET. Evidently the decay rates are sensitive to the right- and left-handed potential fields of the solvent molecules. However, the decay rate of 32 P was insensitive to the chiral senses of the DET solvents. Similarly, the decay rate of 22 Na was insensitive to the chiral senses of the PBA solvents. This can be tentatively explained by the interactions between the solvents and the solutes. It was also observed that in the first ten percent of the half-life time the decay of 32 P and particularly the decay of 22 Na often showed some deviation from the exponential behavior. This effect is chirality-dependent. (author)

  5. A Mixed Message: The School Vending Machine.

    Science.gov (United States)

    Hinkle, Margaret Murray

    1982-01-01

    Dental disease, especially tooth decay, is reaching epidemic proportions among children of school age. Since sugar is a major cause of tooth decay and since many confections are sold in schools, it is recommended that schools remove confections and other nonnutritional food items from vending machines, fund-raising activities, and food services.…

  6. Decay of 36K

    International Nuclear Information System (INIS)

    Fritts, M.J.

    1976-01-01

    36 K was produced via the 36 Ar(p, n) 36 K reaction. Measurement of 27 β + delayed γ rays associated with the decay of 36 K implied 10 new β + branches to energy levels in 36 Ar. Branching ratios and logft values are calculated for the β + branches. Restrictions on spin and parity assignments for the 36 Ar levels are given, as well as branching ratios for γ transitions from these levels. The half-life of 36 K is determined to be 344 +- 3 msec

  7. η decays at Saclay

    International Nuclear Information System (INIS)

    Mayer, B.

    1991-01-01

    A facility dedicated to the production of η mesons has been installed at the Saturne synchrotron with the purpose of investigating rare decays of this meson. The η are produced by the pd → 3 Heη reaction near threshold and tagged by the detection of 3 He in a magnetic spectrometer (SPES2). A rate of 10 5 /s tagged η can be achieved. In the first experiment, η → μ + μ - , the μ will be detected in range telescopes. Magnetic spectrometers for lepton detection are considered for future experiments

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

    Science.gov (United States)

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

    2012-02-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  10. Educational laboratory experiments on chemistry in a nuclear engineering school

    International Nuclear Information System (INIS)

    Akatsu, E.

    1982-01-01

    An educational laboratory experiment on radiochemistry was investigated by students in the general course of the Nuclear Engineering School of Japan Atomic Energy Research Institute. Most of them are not chemical engineers, but electrical and mechanical engineers. Therefore, the educational experiment was designed for them by introducing a ''word experiment'' in the initial stage and by reducing the chemical procedure as far as possible. It began with calculations on a simple solvent extraction process-the ''word experiment''--followed by the chemical separation of 144 Pr from 144 Ce with tri-n-butyl phosphate in a nitric acid system and then measurement of the radioactive decay and growth of the separated 144 Pr and 144 Ce, respectively. The chemical procedure was explained by the phenomenon but not by the mechanism of chelation. Most students thought the experiment was an exercise in solvent extraction or radiochemical separation rather than a radioactive equilibrium experiment. However, a pure chemist considered it as a sort of physical experiment, where the chemical procedure was used only for preparation of measuring samples. Another experiment, where 137 Cs was measured after isolation with ammonium phosphomolybdate, was also investigated. The experiment eliminated the need for students who were not chemists to know how to use radioactive tracers. These students appreciated the realization that they could understand the radioactivity in the environmental samples in a chemical frame of reference even though they were not chemists

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

    International Nuclear Information System (INIS)

    Navarrete, J.M.; Mueller, G.; Zuniga, M.A.; Camacho, M.; Espinosa, G.; Golzarri, J.I.

    2014-01-01

    During a time period little longer than 60 years, it has been created a radioactive pollution background over the natural one, which started in 1945 and it has been growing up since then, due to several nuclear tests, minor nuclear reactors failure and four major accidents: Wind Scale, Three Mile Island, Chernobyl and Fukushima. This radioactive polluting background can be easily detected through 137 Cs fission product, which by the effect of wind, river currents and rain has been accumulated in marine sediments, mainly because sea represents about 80 % of earth's surface. Since energy demand has been growing up with no interruption during last two centuries, and nuclear energy seems to be the largest available source, it is very likely a great expansion of nuclear energy during twenty-first century. So, this paper presents results obtained in strategic points of the two large littorals in Mexico: Gulf and Pacific Ocean, as an attempt to establish there some figure to evaluate the present radioactive pollution. An adequate figure to do it, seems to be the quotient of activity per gram of 137 Cs in marine sediments (Bq 137 Cs/g), divided by activity per gram of 40 K natural radioactivity (Bq 40 K/g). When this result is multiplied by 100 the percentage of polluting radioactivity ( 137 Cs) related to natural radioactivity ( 40 K) is obtained. This percentage seems to be useful to evaluate the importance of radioactive pollution from 4 points of view: a) calculate the extent of already radioactive pollution present in the seas of world; b) avoid the panic in case of nuclear accidents, c) what will be the growing up rate in the future; d) if it is possible to keep one decreasing rate at same decaying rate of 137 Cs (t 1/2 = 30.07 years), since from 1945, starting time of radioactive pollution, it has decayed only about 2.2 half lives. (author)

  12. Rare decays and CP asymmetries in charged B decays

    International Nuclear Information System (INIS)

    Deshpande, N.G.

    1991-01-01

    The theory of loop induced rare decays and the rate asymmetry due to CP violation in charged B Decays in reviewed. After considering b → sγ and b → se + e - decays, the asymmetries for pure penguin process are estimated first. A larger asymmetry can result in those modes where a tree diagram and a penguin diagram interfere, however these estimates are necessarily model dependent. Estimates of Cabbibo suppressed penguins are also considered

  13. Pulsed radiation decay logging

    International Nuclear Information System (INIS)

    Mills, W.R. Jr.

    1983-01-01

    There are provided new and improved well logging processes and systems wherein the detection of secondary radiation is accomplished during a plurality of time windows in a manner to accurately characterize the decay rate of the secondary radiation. The system comprises a well logging tool having a primary pulsed radiation source which emits repetitive time-spaced bursts of primary radiation and detector means for detecting secondary radiation resulting from the primary radiation and producing output signals in response to the detected radiation. A plurality of measuring channels are provided, each of which produces a count rate function representative of signals received from the detector means during successive time windows occurring between the primary radiation bursts. The logging system further comprises means responsive to the measuring channels for producing a plurality of functions representative of the ratios of the radiation count rates measured during adjacent pairs of the time windows. Comparator means function to compare the ratio functions and select at least one of the ratio functions to generate a signal representative of the decay rate of the secondary radiation

  14. 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)

  15. Decay Heat Calculations for Reactors: Development of a Computer Code ADWITA

    International Nuclear Information System (INIS)

    Raj, Devesh

    2015-01-01

    Estimation of release of energy (decay heat) over an extended period of time after termination of neutron induced fission is necessary for determining the heat removal requirements when the reactor is shutdown, and for fuel storage and transport facilities as well as for accident studies. A Fuel Cycle Analysis Code, ADWITA (Activation, Decay, Waste Incineration and Transmutation Analysis) which can generate inventory based on irradiation history and calculate radioactivity and decay heat for extended period of cooling, has been written. The method and data involved in Fuel Cycle Analysis Code ADWITA and some results obtained shall also be presented. (author)

  16. Two-proton decays from light to heavy nuclei - Comparison of theory and experiment

    International Nuclear Information System (INIS)

    Grigorenko, L. V.; Zhukov, M. V.

    2009-01-01

    Two-proton (2p) radioactivity was predicted by V.I. Goldansky in 1960 [1] as an exclusively quantum-mechanical phenomenon. True three-body decay, in his terms, is a situation where the sequential emission of the particles is energetically prohibited from the ground state of a nucleus and all the final-state fragments are emitted simultaneously. Since the experimental discovery of the 4 6F e two-proton radioactivity in 2002 [2,3], this field has made fast progress. New cases of 2p radioactivity were found for 6 4Z n [4], 1 9M g [5], and, maybe, 4 8N i [6]. The 2p correlations were recently measured for the ground state decays of 4 6F e [7], 1 9M g [5,8], 1 6N e [8], and 6 B e [9]. All these decays exhibit complex correlation patterns. These correlation patterns are well described within the three-cluster theory of two-proton radioactivity (see Ref. [9] and Refs. therein); the example of the 6 B e ground state decay is provided in Fig. 1. The correlations are shown to be sensitive to the details of structure and nuclear interactions. Thus experimental studies of correlations can provide important information about the structure of decaying nuclei. With lifetimes and correlations well described by the theory in a broad range of nuclear masses (6 B e, 1 9M g, and 4 6F e belong to p, s-d, and p-f shells respectively) understanding of the nature of 2p radioactivity is getting now a solid empirical support. This is specially important in the view of astrophysical implementations of the three-body decay theory for the inverse processes of the three-body radiative capture in astrophysics, which seem to be not completely understood so far.(author)

  17. Search for proton decay: introduction

    International Nuclear Information System (INIS)

    Goldhaber, M.

    1984-01-01

    In interpreting contained events observed in various proton decay detectors one can sometimes postulate, though usually not unambiguously, a potential decay mode of the proton, called a candidate. It is called a candidate, because for any individual event it is not possible to exclude the possibility that it is instead due to cosmic ray background, chiefly atmospheric neutrinos. Some consistency checks are proposed which could help establish proton decay, if it does occur in the presently accessible lifetime window

  18. Rare beauty and charm decays

    International Nuclear Information System (INIS)

    Blake, T.

    2016-01-01

    Rare beauty and charm decays can provide powerful probes of physics beyond the Standard Model. These proceedings summarise the latest measurements of rare beauty and charm decays from the LHCb experiment at the end of Run 1 of the LHC. Whilst the majority of the measurements are consistent with SM predictions, small differences are seen in the rate and angular distribution of b → sℓ"+ℓ"− decay processes.

  19. Germanium detectors and natural radioactivity in food

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  20. The first underground low radioactivity bolometric system

    International Nuclear Information System (INIS)

    Alessandrello, A.; Brofferio, C.; Camin, D.V.; Cremonesi, O.; Fiorini, E.; Giuliani, A.; Pessina, G.; Previtali, E.

    1990-01-01

    A dilution refrigerator was installed in an underground location for the first time. The cryostat is made of as clean as possible material from the radioactivity point of view, with the aim to measure rare events like double beta decay or 'dark matter' interactions via coherent nuclear scattering. It is also planned to surround all the cryostat frame with lead and with a specially built Faraday cage. All the experimental apparatus involved have to be tested to obtain a very good background rejection. An 11g Ge bolometer, already tested on surface coupled with a 4.2 K GaAs preamplifier was built to measure the effective bolometer background in this new experimental area and to check the experimental set-up for double beta decay experiment. The present performance of the underground bolometric system is reported. (R.P.) 8 refs.; 7 figs

  1. Weak decays of heavy quarks

    International Nuclear Information System (INIS)

    Gaillard, M.K.

    1978-08-01

    The properties that may help to identify the two additional quark flavors that are expected to be discovered. These properties are lifetime, branching ratios, selection rules, and lepton decay spectra. It is also noted that CP violation may manifest itself more strongly in heavy particle decays than elsewhere providing a new probe of its origin. The theoretical progress in the understanding of nonleptonic transitions among lighter quarks, nonleptonic K and hyperon decay amplitudes, omega minus and charmed particle decay predictions, and lastly the Kobayashi--Maskawa model for the weak coupling of heavy quarks together with the details of its implications for topology and bottomology are treated. 48 references

  2. Statistical decay of giant resonances

    International Nuclear Information System (INIS)

    Dias, H.; Teruya, N.; Wolynec, E.

    1986-01-01

    Statistical calculations to predict the neutron spectrum resulting from the decay of Giant Resonances are discussed. The dependence of the resutls on the optical potential parametrization and on the level density of the residual nucleus is assessed. A Hauser-Feshbach calculation is performed for the decay of the monople giant resonance in 208 Pb using the experimental levels of 207 Pb from a recent compilation. The calculated statistical decay is in excelent agreement with recent experimental data, showing that the decay of this resonance is dominantly statistical, as predicted by continuum RPA calculations. (Author) [pt

  3. Statistical decay of giant resonances

    International Nuclear Information System (INIS)

    Dias, H.; Teruya, N.; Wolynec, E.

    1986-02-01

    Statistical calculations to predict the neutron spectrum resulting from the decay of Giant Resonances are discussed. The dependence of the results on the optical potential parametrization and on the level density of the residual nucleus is assessed. A Hauser-Feshbach calculation is performed for the decay of the monopole giant resonance in 208 Pb using the experimental levels of 207 Pb from a recent compilation. The calculated statistical decay is in excellent agreement with recent experimental data, showing that decay of this resonance is dominantly statistical, as predicted by continuum RPA calculations. (Author) [pt

  4. The management of hospital radioactive wastes

    International Nuclear Information System (INIS)

    Peyrin, J.O.

    1992-01-01

    Enquiries performed by nuclear medicine services together with ANDRA in order to characterize the radioactive wastes from hospital origin have led to suggest some improvements in the management of these products: improved screening on the production site by rationalized collection, planning of a local storage installation for decay of 125 I-containing products, systematic education of concerned hospital staff, in particular to prevent infectious risks, obtaining legislatively a change of class for tritiated and carbonated hospital radioactive wastes, which will be then considered as common wastes. The practical application of these arrangements in hospital by the 'radiation protection competent person' would liberate hospital departments from systematic appeal to ANDRA and thus result in money saving

  5. Keeping Sealed Radioactive Sources Safe and Secure

    International Nuclear Information System (INIS)

    Potterton, Louise

    2013-01-01

    Radioactive sources are used in a wide variety of devices in medical, industrial, agricultural and research facilities worldwide. These sources, such as cobalt-60 and caesium-137, emit high levels of ionizing radiation, which can treat cancer, measure materials used in industry and sterilize food and medical appliances. Problems may arise when these sources are no longer needed, or if they are damaged or decayed. If these sources are not properly stored they can be a threat to human health and the environment and pose a security risk. Procedures to secure these spent or 'disused' sources are often highly expensive and need specialized assistance. The IAEA helps its States find long term solutions for the safe and secure storage of disused sealed radioactive sources (DSRSs)

  6. Radioactivity and food

    International Nuclear Information System (INIS)

    Olszyna-Marzys, A.E.

    1990-01-01

    Two topics relating to radioactivity and food are discussed: food irradiation for preservation purposes, and food contamination from radioactive substances. Food irradiation involves the use of electromagnetic energy (x and gamma rays) emitted by radioactive substances or produced by machine in order to destroy the insects and microorganisms present and prevent germination. The sanitary and economic advantages of treating food in this way are discussed. Numerous studies have confirmed that under strictly controlled conditions no undesirable changes take place in food that has been irradiated nor is radioactivity induced. Reference is made to the accident at the Chernobyl nuclear power station, which aroused public concern about irradiated food. The events surrounding the accident are reviewed, and its consequences with regard to contamination of different foods with radioactive substances, particularly iodine-131 and cesium-137, are described. Also discussed are the steps that have been taken by different international organizations to set limits on acceptable radioactivity in food.15 references

  7. Radioactive air sampling methods

    CERN Document Server

    Maiello, Mark L

    2010-01-01

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

  8. ORNL radioactive waste operations

    International Nuclear Information System (INIS)

    Sease, J.D.; King, E.M.; Coobs, J.H.; Row, T.H.

    1982-01-01

    Since its beginning in 1943, ORNL has generated large amounts of solid, liquid, and gaseous radioactive waste material as a by-product of the basic research and development work carried out at the laboratory. The waste system at ORNL has been continually modified and updated to keep pace with the changing release requirements for radioactive wastes. Major upgrading projects are currently in progress. The operating record of ORNL waste operation has been excellent over many years. Recent surveillance of radioactivity in the Oak Ridge environs indicates that atmospheric concentrations of radioactivity were not significantly different from other areas in East Tennesseee. Concentrations of radioactivity in the Clinch River and in fish collected from the river were less than 4% of the permissible concentration and intake guides for individuals in the offsite environment. While some radioactivity was released to the environment from plant operations, the concentrations in all of the media sampled were well below established standards

  9. Radioactive waste disposal via electric propulsion

    Science.gov (United States)

    Burns, R. E.

    1975-01-01

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

  10. 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)

  11. Drainage of radioactive areas

    International Nuclear Information System (INIS)

    1981-04-01

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

  12. Radioactivity and its measurement

    CERN Document Server

    Mann, W B; Garfinkel, S B

    1980-01-01

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

  13. Radioactive wastes and discharges

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

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

  14. Learning more about radioactivity

    International Nuclear Information System (INIS)

    2008-01-01

    This digest brochure explains what radioactivity is, where it comes from, how it is measured, what are its effects on the body and the way to protect it against these effects, the uses of radioactivity (In the medical field, In industry, In the food industry, and In the cultural world). It ends with some examples of irradiation levels, of natural radioactivity and with the distribution in France of various sources of exposure. (J.S.)

  15. Radioactive waste management

    International Nuclear Information System (INIS)

    2003-01-01

    Almost all IAEA Member States use radioactive sources in medicine, industry, agriculture and scientific research, and countries remain responsible for the safe handling and storage of all radioactively contaminated waste that result from such activities. In some cases, waste must be specially treated or conditioned before storage and/or disposal. The Department of Technical Co-operation is sponsoring a programme with the support of the Nuclear Energy Department aimed at establishing appropriate technologies and procedures for managing radioactive wastes. (IAEA)

  16. 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)

  17. Radioactive wastes and discharges

    International Nuclear Information System (INIS)

    2000-01-01

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

  18. CP violation in K decays and rare decays

    International Nuclear Information System (INIS)

    Buchalla, G.

    1996-12-01

    The present status of CP violation in decays of neutral kaons is reviewed. In addition selected rare decays of both K and B mesons are discussed. The emphasis is in particular on observables that can be reliably calculated and thus offer the possibility of clean tests of standard model flavor physics. 105 refs

  19. Determination of radioactivity levels from some Egyptian building materials

    International Nuclear Information System (INIS)

    Abd EL Sattar, M.; Morsy, A.A.

    2007-01-01

    Our world is radioactive and has been, since it was created. Over 60 radionuclides (radioactive elements) can be found in nature. Radon is naturally occurring radioactive gas, that is produced by the radioactive decay of radium. Breathing high concentration of radon can cause lung cancer. A set of experiments were carried out using Cr-39 as solid state nuclear track detectors with the optimum etching conditions, 6.25 N Na OH at 70 o C for 8 hours. The radon-222 activity in this survey was found to be in the range of 0.303 kBq/m 3 to 5.04 KBq/m 3 for different building materials in Egypt

  20. Relation between local landform and radioactive geopollution. Part 2

    International Nuclear Information System (INIS)

    Kimura, Kazuya; Nirei, Hisashi; Nakadai, Hiroki; Hiyama, Tomoyo; Yoshida, Takeshi

    2013-01-01

    A lot of radioactive materials were emitted by the Fukushima Daiichi nuclear disaster in March, 2011. Those of them; Cs-134 and Cs-137 have comparatively long half-life have cause the radioactivity geo pollution in the east Japan. In fact, it is not explained completely how to spread, move and absorb cesium. However, it seems that there is a certain law of nature. That is to say, we should measure radioactive materials according to the law of generation (decay), movement, deposition and take necessary actions under the Katori-Narita-Itako Declaration of IUGS GEM (IUGS-GEM, 2011). We followed this declaration and have continued measurement by use of RT-30 (made by GEORADIS). And it becomes clear that radioactivity geo pollution is strongly subject to the influence of land form, in the result carrying out diffusion and movement. In addition to the new data, this paper shows detail examples. (author)