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

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

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

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

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.)

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

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

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.

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

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

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)

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

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)

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

Electroplating method for producing ultralow-mass fissionable deposits

International Nuclear Information System (INIS)

Ruddy, F.H.

1989-01-01

A method for producing ultralow-mass fissionable deposits for nuclear reactor dosimetry is described, including the steps of holding a radioactive parent until the radioactive parent reaches secular equilibrium with a daughter isotope, chemically separating the daughter from the parent, electroplating the daughter on a suitable substrate, and holding the electroplated daughter until the daughter decays to the fissionable deposit

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.

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)

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.

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.

Radioactive waste disposal in deep geologic deposits. Associated research problems

International Nuclear Information System (INIS)

Rousset, G.

1992-01-01

This paper describes the research associated problems for radioactive waste disposal in deep geologic deposits such granites, clays or salt deposits. After a brief description of the underground disposal, the author studies the rheology of sedimentary media and proposes rheological models applied to radioactive wastes repositories. Waste-rock interactions, particularly thermal effects and temperature distribution versus time. 17 refs., 14 figs

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)

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

Science.gov (United States)

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

2015-01-01

Soil deposition density maps of gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant (NPP) accident were constructed on the basis of results from large-scale soil sampling. In total 10,915 soil samples were collected at 2168 locations. Gamma rays emitted from the samples were measured by Ge detectors and analyzed using a reliable unified method. The determined radioactivity was corrected to that of June 14, 2011 by considering the intrinsic decay constant of each nuclide. Finally the deposition maps were created for (134)Cs, (137)Cs, (131)I, (129m)Te and (110m)Ag. The radioactivity ratio of (134)Cs-(137)Cs was almost constant at 0.91 regardless of the locations of soil sampling. The radioactivity ratios of (131)I and (129m)Te-(137)Cs were relatively high in the regions south of the Fukushima NPP site. Effective doses for 50 y after the accident were evaluated for external and inhalation exposures due to the observed radioactive nuclides. The radiation doses from radioactive cesium were found to be much higher than those from the other radioactive nuclides. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

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.

Reconnaissance for radioactive deposits in Alaska, 1953

Science.gov (United States)

Matzko, John J.; Bates, Robert G.

1955-01-01

During the summer of 1953 the areas investigated for radioactive deposits in Alaska were on Nikolai Creek near Tyonek and on Likes Creek near Seward in south-central Alaska where carnotite-type minerals had been reported; in the headwaters of the Peace River in the eastern part of the Seward Peninsula and at Gold Bench on the South Fork of the Koyukuk River in east-central Alaska, where uranothorianite occurs in places associated with base metal sulfides and hematite; in the vicinity of Port Malmesbury in southeastern Alaska to check a reported occurrence of pitchblende; and, in the Miller House-Circle Hot Springs area of east-central Alaska where geochemical studies were made. No significant lode deposits of radioactive materials were found. However, the placer uranothorianite in the headwaters of the Peace River yet remains as an important lead to bedrock radioactive source materials in Alaska. Tundra cover prevents satisfactory radiometric reconnaissance of the area, and methods of geochemical prospecting such as soil and vegetation sampling may ultimately prove more fruitful in the search for the uranothorianite-sulfide lode source than geophysical methods.

Thorium deposit of Morro do Ferro in Pocos de Caldas, Brazil: an analogue of a radioactive waste repository

International Nuclear Information System (INIS)

Franca, E.P.; Carlos, M.T.; Sachett, I.A.; Campos, M.J.M.T. de; Lei, W.; Eisenbud, M.; New York Univ., NY

1986-01-01

A highly weathered deposit of thorium and rare earth elements located near the summit of a hill (Morro do Ferro) in Pocos de Caldas M.G., is being studied as an analogue for a radioactive waste repository that, sometime in the distant future, may be eroded to the surface or intruded by groundwater. Th - serves as an analogue for Pu 4+ and La 3+ as an analogue for Cm 3+ and Am 3+ . The mobilization rates of the analogue elements by groundwater are so slow (10 -7 to 10 -9 per year), as to suggest that essentially complete radioactive decay of transuranic actinides would occur in place, even under the unfavorable conditions that exist at a site such as this. (Author) [pt

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.

RETADD-II: a long-range atmospheric trajectory model with consistent treatment of deposition loss and species growth and decay

International Nuclear Information System (INIS)

Murphy, B.D.; Ohr, S.Y.; Begovich, C.L.

1984-08-01

A versatile model is described which estimates long-range atmospheric dispersion based on plume trajectories. This model allows the treatment of the dispersal from a source at an arbitrary height while taking account of plume depletion by dry and wet deposition together with the decay of material to successor species. The plume depletion, decay and growth equations are solved in an efficient manner which can accommodate up to eight pollutants (i.e., a parent and seven serial decay products). The code is particularly suitable for applications involving radioactive chain decay or for cases involving chemical species with successor decay products. Arbitrary emission rates can be specified for the members of the chain or, as is commonly the case, a sole emission rate can be specified for the first member. The code uses readily available upper-air wind data for the North American continent and it is therefore intended for the estimation of regional or continental scale dispersion patterns. This code is one of a group of codes, the Computerized Radiological Risk Investigation System (Baes and Miller, 1981), designed to simulate the transport of radionuclides through environmental pathways. 24 references, 5 figures

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

Directory of Open Access Journals (Sweden)

Gavrilin Yu.l.

2013-12-01

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

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)

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

International Nuclear Information System (INIS)

Fallis, S.M.

1973-12-01

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

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

Surface deposition from radioactive plumes

International Nuclear Information System (INIS)

Garland, J.A.

1980-01-01

Accidents involving nuclear plants may release radioactive particles and gases to the atmosphere. Dry deposition of particles has been investigated mainly in the laboratory and a general understanding of the transfer mechanisms has been established. However there is apparently a substantial discrepancy between the few field observations of dry deposition of particles and laboratory measurements, particularly for 0.1 - 1 μm particles for which laboratory work shows very small deposition rates. In addition there are few estimates of deposition rates for forest and some other kinds of terrain. The most important gas in the context of a nuclear accident is I-131 and the behaviour of this gas at grass surfaces has received much attention. However smaller quantities of other gases and vapours may be released and the surface absorption of these species may require further investigation. In addition there is little knowledge of the behaviour of gases over many types of surface. The rate of deposition of particles and gases is influenced by many parameters including wind speed and the temperature stratification of the lower atmosphere. Conditions which give poor atmospheric dispersion usually give lower deposition velocities. Transfer to man depends on the availability of deposited materials on crops and grass. A wide range of isotopes including iodine and several metallic fission products are lost with a half life for residence on grass ranging from a few days to a few tens days, depending on climatic conditions

Radioactive sedimentary deposits concerning the coasts of the Camargue

International Nuclear Information System (INIS)

2000-01-01

CRII-RAD has detected abnormal levels of radioactivity on some beaches situated near the Espiguette lighthouse in the south-east coast of France. This document presents the in-situ measurements performed by IPSN. These results confirm a relevant increase of gamma radiation in sedimentary deposits. Chemical analyses have shown that this radioactivity is due to potassium 40 and radionuclides from thorium and uranium series. There is no doubt about the natural origin of this radioactivity but thorough geo-chemical studies are necessary to see whether these radioactive sands are a consequence of nearby industrial activities concerning ore dressing. (A.C.)

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.)

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.)

Deposition of aerosols formed by HCDA due to decay heat transport in inner containment atmospheres

International Nuclear Information System (INIS)

Vate, J.F. van de

1976-01-01

Coupling of decay heat transfer by aerosol-laden inner containment atmospheres with aerosol deposition from such atmospheres leads to useful and simple models for calculation of the time dependence of the aerosol mass concentration. Special attention is given to thermophoretic deposition (dry case) and condensation followed by gravitational deposition (wet case). Attractive features of the models are: 1) coagulation can be omitted and therefore complicated and doubtful calculations on coagulation are avoided, 2) material and particle size of the aerosol are not important for the aerosol decay rate, 3) the aerosol decay rate is related to the decay heat production which is known function of time, and the relevant part of it must be assessed usually for other purposes as well. (orig.) [de

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

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.)

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

Energy Technology Data Exchange (ETDEWEB)

Fallis, S.M.

1973-12-01

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

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.)

Radioactive cesium deposition on rice, wheat, peach tree and soil after nuclear accident in Fukushima

International Nuclear Information System (INIS)

Nakanishi, T.M.; Kobayashi, N.I.; Tanoi, K.

2013-01-01

We present how radioactive Cs was deposited on wheat, rice, peach tree and soil after nuclear accident in Fukushima. The deposition of radioactive Cs was found as spots at the surface of the leaves, branch or trunk of the trees, as well as in soil using one of the imaging method, autoradiography. The deposited radioactive Cs was not easily washed out, even with the treatment of acid solution. When the wheat was harvested 2 months after the accident, high radioactivity of Cs was found only on the leaves developed and expanded at the time of the accident. In the case of the rice grain, most of the radioactivity was found in bran and the radioactivity was drastically reduced in milled rice. Most of the radioactive Cs accumulation in rice plants was estimated from the absorption of the Cs ion dissolved in water, rather than Cs adsorbed in soil. (author)

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

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

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

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.

A radon progeny deposition model

International Nuclear Information System (INIS)

Rielage, Keith; Elliott, Steven R.; Hime, Andrew; Guiseppe, Vincent E.; Westerdale, S.

2010-01-01

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

A Radon Progeny Deposition Model

International Nuclear Information System (INIS)

Guiseppe, V. E.; Elliott, S. R.; Hime, A.; Rielage, K.; Westerdale, S.

2011-01-01

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

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)

Financial compensation due to municipalities that host radioactive waste deposits

International Nuclear Information System (INIS)

Silva, Renata A. da; Simoes, Francisco Fernando L.; Martins, Vivian B.

2013-01-01

This work aims to perform calculation about the financial compensation due to municipalities where there is viability for construction of radioactive waste deposits from low and medium activity. Were used like base structure de Resolution No. 96 of August, 10, 2010, entitled 'Model of Calculation For Financial Compensation to Municipalities' where are determinate those principal characteristics by the waste and deposits, such as the half-life, activity level, type of deposits (initial, intermediate or final), costs for construction and maintenance of deposits, demography, between others. The calculation was made according to the temporally or definitive storage for solids waste like personal protection equipment (gloves, shoes, masks, etc) resins and filters used in wastewater treatment, between others, from of nuclear and radioactivity facilities. There are presented some countries that do the compensation, financial or not, for some municipalities for the construction of waste deposits and in some cases, the way that occurred the negotiation between the stake holders, in other words, the local population and the companies. Also are presented others forms of financial compensation in Brazil in consequence of activities in large scale which result in potential risk for the surrounding population and for the environment, like compensation for oil and natural gas, hydropower plants and mining. Were used on methodology the inventory of waste presented on RMBN project (Repository of Waste of Low and Medium Activity) developed by the CDTN which present the implementation of a repository for final storage to radioactive waste. With this was possible to develop a case study with the creation of four scenarios. Values were found which initially range from R$2,6 thousand to R$79,8 thousand for month. Finally are analyzed the possible influences which that values may have on the municipality budget revenue and some divergent points about the resolution. (author)

Financial compensation due to municipalities that host radioactive waste deposits

Energy Technology Data Exchange (ETDEWEB)

Silva, Renata A. da; Simoes, Francisco Fernando L.; Martins, Vivian B., E-mail: renata.amaral@ufrj.br, E-mail: flamego@ien.gov.br, E-mail: vbmartins@gmail.com [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2013-07-01

This work aims to perform calculation about the financial compensation due to municipalities where there is viability for construction of radioactive waste deposits from low and medium activity. Were used like base structure de Resolution No. 96 of August, 10, 2010, entitled 'Model of Calculation For Financial Compensation to Municipalities' where are determinate those principal characteristics by the waste and deposits, such as the half-life, activity level, type of deposits (initial, intermediate or final), costs for construction and maintenance of deposits, demography, between others. The calculation was made according to the temporally or definitive storage for solids waste like personal protection equipment (gloves, shoes, masks, etc) resins and filters used in wastewater treatment, between others, from of nuclear and radioactivity facilities. There are presented some countries that do the compensation, financial or not, for some municipalities for the construction of waste deposits and in some cases, the way that occurred the negotiation between the stake holders, in other words, the local population and the companies. Also are presented others forms of financial compensation in Brazil in consequence of activities in large scale which result in potential risk for the surrounding population and for the environment, like compensation for oil and natural gas, hydropower plants and mining. Were used on methodology the inventory of waste presented on RMBN project (Repository of Waste of Low and Medium Activity) developed by the CDTN which present the implementation of a repository for final storage to radioactive waste. With this was possible to develop a case study with the creation of four scenarios. Values were found which initially range from R$2,6 thousand to R$79,8 thousand for month. Finally are analyzed the possible influences which that values may have on the municipality budget revenue and some divergent points about the resolution. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-12-15

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

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

International Nuclear Information System (INIS)

Zhang, Qiong; Guo, RuiPing; Zhang, ChunMing; Chen, XiaoQiu; Wang, Bo

2014-01-01

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

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.)

Radioactive waste disposal and study of mineral deposit of uranium

International Nuclear Information System (INIS)

Doi, Kazumi

2003-01-01

To realize high level radioactive waste disposal, it is need to guarantee with high reliability safety of isolation of radioactive waste during some ten thousand years. There are two important factors related to geophysics such as ground water and diastrophism. The problems to be solved in the present point are followings; 1) increasing data of characteristics of radionuclide within high level radioactive waste, 2) development of undisruptive exploration technologies of lithosphere, especially formal fabric of pore and 3) improvement of protection technologies of diastrophism. Our country has to make efforts to realize the safety of isolation of radioactive waste on the basis of researches, by means of keeping them in the strong facilities without disposal. The formation of concentrated uranium in the mineral deposit was explained in relation with high level radioactive waste disposal. (S.Y.)

Radioactive mineral deposits of the Pembroke-Renfrew area

International Nuclear Information System (INIS)

Masson, S.L.; Gordon, J.B.

1981-01-01

This report deals with the geological features of all the reported uranium and thorium occurrences in the Pembroke-Renfrew area of southeastern Ontario. There are 118 radioactive occurrences within the study area of which 102 were examined by the authors during the summers of 1977 and 1978. The report consists of a comprehensive description of the geological association and mineral content of the deposits which were examined. In addition, an attempt has been made to determine their mode of origin in order to assess the potential for discovery of additional deposits and to provide guidelines for exploration

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.

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.)

Deposition of radon decay products on the skin of balneotherapy patients in Gastein

International Nuclear Information System (INIS)

Tempfer, H.; Schober, A.; Lettner, H.; Hofmann, W.; Foisner, W.; Steger, F.

2001-01-01

In Bad Gastein and Bad Hofgastein, radon-rich thermal water is used for the treatment of various diseases, especially for Morbus Bechterew, a degenerative illness of the spinal column. One of the therapeutic applications of the thermal water is the exposition of patients in 450 1 bathtubs (''Best'sche Wanne''). To check the hypothesis that the radon decay products contribute to the therapeutic effect, the adsorption behaviour of radon decay products was examined. A group of patients was exposed to the thermal water for 20 minutes. Immediately after leaving the bathtub, the activities were measured at several locations of the human body (forearms, belly, lower legs) by alpha spectrometry. The activities of the decay products 218 Po, 214 Pb and 214 Bi/ 214 Po were determined from the measured spectra and decay curves. In order to study the time dependence of the decay product adsorption, one test person was exposed for 10, 20, to 30, 40 and 60 minutes; afterwards the decay curves were recorded again over a period of 30 minutes. The results showed that the activities of the decay products on the skin can differ appreciably. On the one hand, the distribution on the body surface seems to be quite inhomogeneous, on the other hand, the deposition varies considerably from person to person. As a result of this, skin activities varied between 1.2 and 4.1 Bq/cm 2 . The exposition and measurement of copper and PVC plates confirmed earlier results, that the deposition of radon decay products in water on artificial surfaces is much less than that on living surfaces. In conclusion, the remarkably high decay product activities on the skin does indeed suggest a positive correlation with the observed therapeutic effects. (orig.) [de

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)

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).

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.

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)

Surface deposition of 222Rn decay products with and without enhanced air motion

International Nuclear Information System (INIS)

Rudnick, S.N.; Maher, E.F.

1986-01-01

The effectiveness of fan-induced air motion in reducing airborne activities of short-lived 222 Rn decay products was evaluated in a 78.5-m3 chamber. Observed reductions were as high as 50% for 218Po (RaA), 79% for 214 Pb (RaB), and 86% for 214 Bi (RaC). Activity measurements of these nuclides on chamber and fan surfaces, along with airborne activities, were used to calculate material balances. Greater than about 90% of deposited activity was found on chamber surfaces, although areal activity densities were higher on fan surfaces. Deposition velocities for decay products not attached to particles were 2.3 mm s-1 when no fans were in operation and 9.2 to 13 mm s-1 when fans were used. Mean boundary layer thicknesses for unattached decay products were estimated to be about four times the recoil distance of a 214 Pb atom when no fans were used and about equal to the recoil distance when fans were used

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

Biological response of Tradescantia stamen-hairs in Brazilian radioactive waste deposits

International Nuclear Information System (INIS)

Gomes, Heliana A.; Macacini, Jose Flavio

2005-01-01

The objective of the present study was to apply a highly sensitive botanical test of mutagenicity (the Tradescantia stamen-hair mutation bioassay), to assess in situ the biological responses induced by occurring radiation in Brazilian radioactive waste deposits (waste deposits from the Mineral Treatment Unit/Brazilian Nuclear Industries (UTM/INB), from the Centro de Desenvolvimento de Tecnologia Nuclear (CDTN) and from the Instituto de Pesquisas Energeticas e Nucleares (IPEN). The mutagenesis was evaluated in environments presenting gamma radiation exposure rates ranging from 1.6 μR.min -1 up to 3300.0 μR.min -1 . It was detected a significant increase in the mutation rate for pink Tradescantia stamen-hair only for the local presenting the highest exposition rate within UTM/INB which had a radiation exposition rate of 750 μR.min -1 . The Tradescantia plants exposed to the radioactive waste deposits from CDTN and IPEN presented an insufficient number of flowers for the statistical evaluation of mutagenicity. (author)

Occupational monitoring at radioactive waste deposit

Energy Technology Data Exchange (ETDEWEB)

Pereira, Wagner S.; Cunha, Franklin S. [Indústrias Nucleares do Brasil (COMAP.N/FCN/INB), Resende, RJ (Brazil). Fábrica de Combustível Nuclear. Coordenação de Meio Ambiente e Proteção Radiológica Ambiental; Kelecom, Alphonse [Universidade Federal Fluminense (LARARA-PLS/UFF), Niterói, RJ (Brazil). Lab. de Radiobiologia e Radiometria Pedro Lopes dos Santos; Silva, Ademir X., E-mail: pereiraws@gmail.com, E-mail: wspereira@inb.gov.br, E-mail: franklincunha@inb.gov.br, E-mail: lararapls@hotmail.com, E-mail: Ademir@nuclear.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

2017-07-01

The Initial Deposit of Low Activity Radioactive Waste - DIRBA is an ancillary facility to the Nuclear Fuel Factory - FCN for the initial storage of low activity radioactive waste generated in the nuclear fuel cycle under the responsibility of the FCN. Currently approximately 460 200-liter drums containing Class 2.3 waste are stored: Waste containing Natural Radionuclides (RBMN-RN). As part of the nuclear licensing of the facility, an area radiological monitoring program was developed with monthly monitoring of 17 exposure points, 3 direct long-distance air sampling points with CAM alpha-7 monitors, monitored in January and 9 points where smears of alpha long half-life emitters were monitored in January. The mean exposure rate between points was 0.5 μSv∙h{sup -1}, with a maximum of 1.27 μSv∙h{sup -1} varying, on average, between 0.98 μSv∙h{sup -1} at point P1 to 0.23 μSv∙h{sup -1} at P11. The monthly average was the same, 0.50 μSv∙h-1, ranging from 0.46 μSv∙h{sup -1} (November) to 0.57 μSv∙h{sup -1} (August). The half-life long-lived alpha sampling were all below the MDA as well as the 9 smears. Regarding the requirements of monitored areas, the deposit must be considered as supervised area, from the point of view of radioprotection. The possibility of tipping the drums or other accidents with spillage of material contained into them caused, in a proactive way, the area to be considered a controlled area. (author)

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

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.)

MESOI Version 2.0: an interactive mesoscale Lagrangian puff dispersion model with deposition and decay

International Nuclear Information System (INIS)

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

1983-11-01

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

Virtual reality in simulation of operational procedures in radioactive waste deposits

International Nuclear Information System (INIS)

Freitas, Victor Goncalves Gloria

2016-01-01

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

Gold and radioactive elements in the bauxite deposits of Shevaroy hills, Tamil Nadu

Energy Technology Data Exchange (ETDEWEB)

Mukherjee, B K; Sengupta, D K

1982-11-01

The presence of gold and radioactive elements in the bauxite deposits of Shevaroy Hills has been determined by neutron activation technique. The behaviour of uranium supports the theoretical findings. The higher concentration of gold (<10/sup 3/%) indicates that the deposits are auriferous.

Gold and radioactive elements in the bauxite deposits of Shevaroy hills, Tamil Nadu

International Nuclear Information System (INIS)

Mukherjee, B.K.; Sengupta, D.K.

1982-01-01

The presence of gold and radioactive elements in the bauxite deposits of Shevaroy Hills has been determined by neutron activation technique. The behaviour of uranium supports the theoretical findings. The higher concentration of gold ( -3 %) indicates that the deposits are auriferous. (author)

Simulation of Rn-222 decay products concentration deposited on a filter. Description of radon1.pas computer program

International Nuclear Information System (INIS)

Machaj, B.

1996-01-01

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

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

Influence of radioactive contamination to agricultural products due to dry and wet deposition processes during a nuclear emergency

International Nuclear Information System (INIS)

Hwang, Won Tae; Kim, Eun Han; Suh, Kyung Suk; Han, Moon Hee; Choi, Yong Ho; Lee, Chang Woo

2002-01-01

Combined with deposition model onto the ground of radionuclides, the influence of radioactive contamination to agricultural products was analyzed due to wet deposition as well as dry deposition from radioactive air concentration during a nuclear emergency. The previous dynamic food chain model, in which initial input parameter is only radionuclide concentrations on the ground, was improved for the evaluating of radioactive contamination to agricultural products from either radionuclide concentrations in air or radionuclide concentrations on the ground. As the results, in case of deposition onto the ground, wet deposition was more dominant process than dry deposition. While the contamination levels of agricultural products were dependent on the a variety of factors such as radionuclides and rainfall rate. It means that the contamination levels of agricultural products are determined from which is more dominant process between deposition on the ground and interception onto agricultural plants

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

Air concentration and ground deposition following radioactive airborne releases

International Nuclear Information System (INIS)

Brofferio, C.; Cagnetti, P.; Ferrara, V.

1985-01-01

The fundamental aim of this report is to provide the mathematical and physical operational basis for the evaluation of air concentration and ground deposition, following radioactive airborne releases from a nuclear power plant, both during normal operations and in accidental conditions. As far as accidental releases are concerned, the basical assumptions on meteorological and diffusive situation are considered from a safety point of view: namely those pessimistic but realistically representative situation are taken into account which lead to maximum air concentration and ground deposition values, even if characterized by low recurrence probability. Those elements are the inputs for many environmental transfer models of maximum consequence evaluations up to man. As far as routine releases are concerned, it is shown, together with the usual models based on long term averaged meteorological conditions, also models studied to estimate atmospheric diffusion and deposition in low wind situations and in fog conditions, being those latter very frequent in the Po valley. Finally, the main operations and modalities of collecting and elaborating meteorological data for for radioprotection evaluations are also shown. It is to be pointed out that the methods and the models developed and considered in this work are of a more general validity, and can be also used for applications concerning non-radioactive releases, as it is the case when dealing with conventional power plants

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

Dose estimation from residual and fallout radioactivity, 1

International Nuclear Information System (INIS)

Takeshita, Kenji

1975-01-01

External dose rates and cumulative doses for early entrants from areal surveys and simulated experiments are reviewed. The average cumulative doses to infinity at the hypocenters were 101 rad in Hiroshima and 32 rad in Nagasaki, with a variation of about 60 percent. Radioactive fallout areas nearly matched the ''black rain'' areas in Nagasaki and in Hiroshima. Radioactivity in the fallout areas was affected by radioactive decay and by the leaching and dissipation by rains. Considering these factors, the cumulative dose to infinity in the fallout area of Hiroshima was estimated to be 13 rad, excluding internal radiation doses from inhaled and ingested radionuclides. Attempts to estimate radiation dose from internally deposited radionuclides are also described. (auth.)

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.

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

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)

Resuspension. Decadal monitoring time series of the anthropogenic radioactivity deposition in Japan

International Nuclear Information System (INIS)

Igarashi, Yasuhito; Aoyama, Michio; Hirose, Katsumi; Miyao, Takashi; Nemoto, Kazuhiro; Tomita, Masatoshi; Fujikawa, Takashi

2003-01-01

Monthly atmospheric depositions of 90 Sr and 137 Cs have been observed at the Meteorological Research Institute (MRI), Tsukuba, Japan. This study reports temporal trends and levels of 90 Sr and 137 Cs depositions in the 1990s. Although the current 90 Sr and 137 Cs concentrations declined dramatically, they have been found continuously in the deposition samples throughout the 1990s. During this period, the annual 90 Sr ( 137 Cs) deposits at MRI ranged from 70-180 (140-350) mBq/m 2 /year. With a sufficiently long time series, the decreasing trend of the deposition evidently differs from the past stratospheric fallout; it is far slower. Thus, reservoirs other than the stratosphere provide small amounts of 90 Sr and 137 Cs to the atmosphere. A simple calculation clearly refutes the significance of the ocean as a potential source of airborne anthropogenic radioactivity. We will demonstrate that these radionuclides in the deposited materials originate from resuspension processes (soil dust suspension processes). The temporal trends of the time series monitoring reveal differences from those in the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) Report 2000, which were predicted by a model that disregarded resuspension. The specific activity of 90 Sr ( 137 Cs) in the annual depositions exhibited a 10-year (20-year) half-life. Those data were comparable with values reported in the literature for the half-residence time (HRT) of 90 Sr and 137 Cs in Japanese surface soils. They were also comparable to those calculated from nationwide data of 90 Sr and 137 Cs concentrations in the surface soil (0-10 cm) obtained from the Ministry of Education, Culture, Sports, Science and Technology Environmental Radiation Database (the MEXT Database). Regarding the activity ratio of 137 Cs/ 90 Sr, the Japanese nationwide surface soil data collected during the 1990s in the MEXT Database (median: 5.3, n=584) did not accord with that in the deposition samples

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

Power Deposition due to Muon Decay Losses in a Neutrino Factory

CERN Document Server

Keil, Eberhard

2000-01-01

The power in the charged muon decay products, deposited per unit distance, depends on the muon energy only through the relativistic factor beta. For a typical neutrino factory it is about one Watt/m, multiplied by the number of passes through a particular component. The power is highest in the muon decay ring, where the muon lifetime cooresponds to about 150 turns. The electrons or positrons from muon decay in the long straight section may remain inside the vacuum chamber, until they are lost at the beginning of the arcs, because of their large energy errors, that are enhanced by synchrotron radiation losses. The power losses along the straight section and the arcs are studied by computer simulation, and the results are presented. About two thirds of the power ends up in the straight section, the remainder in the matching section and in the first half of the dispersion suppressor.

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

Analysis of water content in salt deposits: its application to radioactive waste storage

International Nuclear Information System (INIS)

Cuevas Muller, C. de la.

1993-01-01

The salt deposits as radioactive storage medium are analyzed. This report studies the physical-chemical characteristics of water into salts deposits, its implications for the safety of the repository, and the transport water release mechanism. The last part analyzes the geochemical numerical data of correlation analysis, geostatistics analysis and interpretation of statistical data

Theoretical modeling of fine-particle deposition in 3-dimensional bronchial bifurcations

International Nuclear Information System (INIS)

Shaw, D.T.; Rajendran, N.; Liao, N.S.

1978-01-01

A theoretical model is developed for the prediction of the peak to average particle deposition flux in the human bronchial airways. The model involves the determination of the peak flux by a round-nose 2-dimensional bifurcation channel and the average deposition flux by a curved-tube model. The ''hot-spot'' effect for all generations in the human respiratory system is estimated. Hot spots are usually associated with the sites of bronchoconstriction or even chronic bronchitis and lung cancer. Recent studies indicate that lung cancer in smokers may be caused by the deposition of radioactive particles produced by the burning of tobacco leaves. High local concentrations of Po-210 have been measured in epithelium from bronchial bifurcations of smokes. This Po-210 is the radioactive daughter of Pb-210 which is produced from a long chain of radioactive decay starting from uranium in the fertilizer-enriched soil. It is found that the peak deposition flux is higher than the average deposition flux by a factor ranging between 5 and 30, depending on the generation number. The importance of this peak to average deposition flux ratio on consideration of environmental safety studies is discussed

Minimization of radioactive material deposition in water-cooled nuclear reactors

International Nuclear Information System (INIS)

Ruiz, C.P.; Blaies, D.M.

1988-01-01

This patent describes the method for inhibiting the deposition of radioactive cobalt in a water-bearing vessel of a water-cooled nuclear reactor which comprises adding zinc ion to water entering the water-bearing vessel. The improvement contains a substantially lower proportion of the /sup 64/Zn isotope than naturally occurring zinc

Uav-Based Detection of Unknown Radioactive Biomass Deposits in Chernobyl's Exclusion Zone

Science.gov (United States)

Briechle, S.; Sizov, A.; Tretyak, O.; Antropov, V.; Molitor, N.; Krzystek, P.

2018-05-01

Shortly after the explosion of the Chernobyl nuclear power plant (ChNPP) in 1986, radioactive fall-out and contaminated trees (socalled Red Forest) were buried in the Chernobyl Exclusion Zone (ChEZ). These days, exact locations of the buried contaminated material are needed. Moreover, 3D vegetation maps are necessary to simulate the impact of tornados and forest fire. After 30 years, some of the so-called trenches and clamps are visible. However, some of them are overgrown and have slightly settled in the centimeter and decimeter range. This paper presents a pipeline that comprises 3D vegetation mapping and machine learning methods to precisely map trenches and clamps from remote sensing data. The dataset for our experiments consists of UAV-based LiDAR data, multi-spectral data, and aerial gamma-spectrometry data. Depending on the study areas overall accuracies ranging from 95.6 % to 99.0 % were reached for the classification of radioactive deposits. Our first results demonstrate an accurate and reliable UAV-based detection of unknown radioactive biomass deposits in the ChEZ.

Spatio-temporal variability of the deposited radioactive materials in forest environments after the Fukushima Daiichi NPP accident

Science.gov (United States)

Kato, H.; Onda, Y.; Komatsu, Y.; Yoda, H.

2012-12-01

Soil, vegetation and other ecological compartments are expected to be highly contaminated by the deposited radionuclides after the Fukushima Daiichi nuclear power plant (NPP) accident triggered by a magnitude 9.1 earthquake and the resulting tsunami on Marchi 11, 2011. Study site have been established in Yamakiya district, Kawamata Town, Fukushima prefecture, located about 35 km from Fukushima power plant, and designated as the evacuated zone. The total deposition of radioactive materials at the study site ranged from 0.02to >10 M Bq/m2 for Cs-137. The mature cedar, young cedar, and broad-leaf stands were selected as experimental site for the monitoring of spatio-temporal variability of the deposited radionuclides after the accidental release of radioactive materials. In order to measure the vertical distribution of radioactivity in forest, a tower with the same height of tree have been established at each experimental site. The measurement of radioactivity by using a portable Ge gamma-ray detector (Detective-DX-100, Ortec) and radionuclide analysis of leaf samples at different height revealed that a large proportion of radionuclides which deposited on forest were trapped by canopies of the cedar forests. In contrast, in the broad-leaf forest highest radioactivity was found at the forest floor. Furthermore, spatio-temporal variability of radioactivity at the forest floor indicated that huge amount of caesium still remains on the canopy of coniferous forest, and subsequently transfers to forest floor in association with throughfall, stemflow, and litter fall.

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)

Radioactive waste disposal in the Gorleben salt deposit

International Nuclear Information System (INIS)

Gizycki, P. von

1985-01-01

In the opinion of five experts, the protective function of the overlying rock as a barrier has turned out to be questionable after borings and measurements carried through at Gorleben. Moreover, the results have also raised doubts about the geological safety of the salt deposit as a barrier in the long run. The geological multibarrier concept must be discarded. Not only critics, but also 3 advocates from the field of official research on radioactive waste disposal state their opinion. (DG) [de

Hydrothermal convection and uranium deposits in abnormally radioactive plutons

International Nuclear Information System (INIS)

1978-09-01

Hydrothermal uranium deposits are often closely associated with granites of abnormally high uranium content. We have studied the question whether the heat generated within such granites can cause fluid convection of sufficient magnitude to develop hydrothermal uranium deposits. Numerical models of flow through porous media were used to calculate temperatures and fluid flow in and around plutons similar to the Conway Granite, New Hampshire, i.e. with a halfwidth of 17 km, a thickness of 6.25 km, and with a uniform internal heat generation rate of 20 x 10 -13 cal/cm 3 -sec. Fluid convection was computed for plutons with permeabilities between 0.01 and 5 millidarcies (1 x10 -13 cm 2 to 5 x 10 -11 cm 2 . Flow rates and the size and location of convection cells in and around radioactive plutons like the Conway Granite were found to depend critically on the permeability distribution within the pluton and in adjacent country rocks. The depth of burial, the distribution of heat sources within the pluton, and small rates of heat generation in the country rock are only of minor importance. Topographic relief is unlikely to effect flow rates significantly, but can have a major influence on the distribution of recharge and discharge areas. Within a few million years, the mass of water transported by steady state convection through such radioactive plutons can equal the mass of water which can convect through them during initial cooling from magmatic temperatures. If the permeability in a Conway-type pluton is on the order of 0.5 millidarcies, the rate of fluid convection is probably sufficient to develop a hydrothermal ore deposit containing 10,000 tons of uranium in a period of two million years. Such a uranium deposit is most likely to develop in an area of strong upwelling or strong downwelling flow

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

Directory of Open Access Journals (Sweden)

Jozef Slavkovský

2007-01-01

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

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)

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)

Natural radioactivity at CBPP waste pile

International Nuclear Information System (INIS)

Kovac, Jadranka; Marovic, Gordana

2008-01-01

Electrical power requirements will necessitate doubling the present generating capacity in Croatia in the future. As a result, environmental discharges associated with the coal power industry will considerably increase. Burning of coal is one source of enhanced radiation exposure to naturally occurring elements, particularly members of uranium and thorium decay chains. By coal burning (in CBPP at about 1700 C degrees) the activity originating from uranium and thorium is redistributed from underground (where the impact on humanity is nil) and liberated into the environment. Most of the radioactive substances are concentrated in the ash and slag, which are heavy and drop to the bottom of a furnace, lately transported to deposit pile, from where some activity may leach into aquifer, or be dispersed by wind. Lighter fly ash, however, is carried up the chimney and into the atmosphere and irradiates people and contaminates food crops. Also, 222 Rn escapes into the atmosphere during incineration, while the non-gaseous members of the uranium decay series remain in the ash and slag. Extensive investigations have been performed in the coal burning power plant (CBPP) Plomin in Croatia and at deposit pile. A network of radon escalation measurements, in-situ gamma-spectrometric measurements and monitoring of waste pile were organized. The results of the measurements confirm that the ash/slag deposite site are well monitored and involve all the necessary protective measures. All obtained data can be used as a valuable database for future estimations and modeling of the impact of radioactive pollution to the marine environment. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-10-15

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

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

International Nuclear Information System (INIS)

Lee, Cheol Ho; Son, Jaebum; Lee, Sangmin; Kim, Tae Hoon; Kim, Yong-Kyun

2016-01-01

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

Long-term evolution of radio-active waste storage in geological formations: analogy with the weathering of mineral deposits

International Nuclear Information System (INIS)

Cantinolle, P.; Griffault, L.; Jebrak, M.

1986-01-01

The aim of this study was to select examples of mineral deposits and their weathering environment, showing the long-term behaviour, in geological time, measuring (area, volume) some constituent elements of radio-active waste storage subject to the hazards of hydrogeochemical weathering. Initially, a feasibility study was made to collate data available within the BRGM (mining group and public service) and from literature dealing with weathering of deposits. It was thus discovered that the analogy between radio-active waste storage and mineral deposits could be approached in two different yet complementary ways: - one approach is to observe the behaviour of a mineral deposit in relation to the country rocks. For this a bibliographic metallogenic study was made. The other approach is to observe the behaviour of chemical elements during deposition of a mineral deposit whose genesis is similar to the spatial and thermal environment of a deposit of radio-active waste in a geological formation. For this two sites were selected corresponding to hydrothermal systems showing strong analogies to those expected in the neighbourhood of the storage sites. These two sites, Langenberg in the Vosges and La Telhaie in Brittany, were the subject of complementary analytical work [fr

Investigation On Natural Background Radioactivity At TanLong, Lagi, BinhThuan Residential Area On Ilmenite Deposit Location

International Nuclear Information System (INIS)

Pham Thi Kim Loan; Tran Van Luyen; Thai Khac Dinh

2008-01-01

An Ilmenite deposit zone located at TanLong, Lagi, Binh Thuan province. After the year of 2000, a new village of population has set up at this place. To estimate the effect on the human health of radioactivity accompanying with the deposit, the sand samples were collected and natural radioactive analyzed at center for nuclear techniques. The average year doses D annual , hazard radiation exposed index H ex and Radium equivalence Ra eq were calculated based on the natural radioactivities. The results show that these factors are overcome the international average as well as southern Vietnam values. (author)

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.

Natural decay series radionuclide studies at the Needle's Eye natural analogue site

International Nuclear Information System (INIS)

MacKenzie, A.B.; Scott, R.D.; Houston, C.M.; Hooker, P.J.

1991-01-01

This report covers work on a natural radioactive geochemical system and has been carried out with the aim of improving confidence in using predictive models of radionuclide migration in the geosphere. It is one of a series being produced and is concerned with the U/Th decay series characterization of the hydrothermal mineral veins and the movement of these radionuclides into post-glacial flood plain deposits

UAV-BASED DETECTION OF UNKNOWN RADIOACTIVE BIOMASS DEPOSITS IN CHERNOBYL’S EXCLUSION ZONE

Directory of Open Access Journals (Sweden)

S. Briechle

2018-05-01

Full Text Available Shortly after the explosion of the Chernobyl nuclear power plant (ChNPP in 1986, radioactive fall-out and contaminated trees (socalled Red Forest were buried in the Chernobyl Exclusion Zone (ChEZ. These days, exact locations of the buried contaminated material are needed. Moreover, 3D vegetation maps are necessary to simulate the impact of tornados and forest fire. After 30 years, some of the so-called trenches and clamps are visible. However, some of them are overgrown and have slightly settled in the centimeter and decimeter range. This paper presents a pipeline that comprises 3D vegetation mapping and machine learning methods to precisely map trenches and clamps from remote sensing data. The dataset for our experiments consists of UAV-based LiDAR data, multi-spectral data, and aerial gamma-spectrometry data. Depending on the study areas overall accuracies ranging from 95.6 % to 99.0 % were reached for the classification of radioactive deposits. Our first results demonstrate an accurate and reliable UAV-based detection of unknown radioactive biomass deposits in the ChEZ.

Nuclear power plant providing a function of suppressing the deposition of radioactive substance

International Nuclear Information System (INIS)

Honda, T.; Kawakami, T.; Izumiya, M.; Minato, A.; Ohsumi, K.

1988-01-01

In a nuclear power plant having a cooling system and radioactive coolant in the cooling system, the cooling system is described including ferrous structural material in contact with the radioactive coolant, wherein the ferrous structural material has a preliminary oxide film formed thereon, by oxidation of the bare surface portion thereof, by contacting bare surfaces of the structural material with flowing water containing an oxidizing agent and no metallic ions. The preliminary oxide film is formed at those portions of the ferrous structural material to be in contact with the radioactive coolant. The preliminary oxide film is formed prior to the structural material contacting the radioactive coolant. The preliminary oxide film consists essentially of Fe/sub 2/O/sub 3/ and having a thickness of at least 300 A, whereby later formation of new oxide film while the structural material is in contact with the radioactive coolant is suppressed to thereby suppress deposition of the radioactive substances on the ferrous structural material

Temporal and spatial variation in radioactivity deposition in Japan-influence of the Asian dust-Kosa

International Nuclear Information System (INIS)

Igarashi, Yasuhito; Aoyama, Michio; Hirose, Katsumi; Shinoda, Yoshihiro

2007-01-01

The possible effect of Asian dust-Kosa in radioactivity deposition, recorded during the recent years, is addressed. The Kosa events were remarkable during 2000 to 2002 in the Far East region, however no significant change was admitted in the MRI radioactivity deposition time series for 90 Sr and 137 Cs. Therefore, we looked at the nationwide distribution and seasonal trends in 90 Sr and 137 Cs depositions by using the data from the Environmental Radioactivity and Radiation Database available on the web. It was found that 137 Cs deposition was larger in northern Japan along the Japan Sea side during spring. The 137 Cs/ 90 Sr activity ratio as well as the 137 Cs specific activity tended to be larger at the high 137 Cs deposition sites. The influence of the Kosa during 2000 to 2002 had larger in northern Japan/Sea of Japan side and the source of the Kosa may be different from the conventional type of the Kosa. The high 137 Cs/ 90 Sr activity ratio and the high 137 Cs specific activity suggest the source area had higher precipitation rate (higher fallout), where the fractionation between the 137 Cs and 90 Sr proceeded. Such area may become new source area for the aeolian dust due possibly to the recent global climate change. This accords with the literature on the source statistics of the Asian dust during the 1990s and the early 2000s. (author)

HARAD, Decay Isotope Concentration from Atmospheric Noble-Gas Release

International Nuclear Information System (INIS)

Moore, R.E.

1986-01-01

1 - Description of problem or function: HARAD calculates concentrations of radioactive daughters in air following the atmospheric release of a parent radionuclide for a variety of release heights and meteorological conditions. It can be applied most profitably to the assessment of doses to man from the noble gases such as Rn-222, Rn-220, and Xe and Kr isotopes. These gases can produce significant quantities of short-lived particulate daughters in an airborne plume, which are the major contributors to dose. The simultaneous processes of radioactive decay, buildup and environmental loss due to wet and dry deposition on ground surfaces are calculated for a daughter chain in an airborne plume as it is dispersed downwind from a point of release of a parent. 2 - Method of solution: The code evaluates the analytic solution to the set of coupled first order differential equations describing time variation of the concentration of a chain of radionuclides. The analytic solutions assume that the coefficient describing the fractional rate of dry deposition is constant with time. To account for the variation the time coordinate is automatically divided into intervals and a set of average values are used. 3 - Restrictions on the complexity of the problem: - The maximum length of decay chain is 10 nuclides; calculations can be made at a maximum of 24 downwind distances

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

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.)

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

Directory of Open Access Journals (Sweden)

Najat K. Mohammed

2013-01-01

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

Problems concerning food production, supply and use caused by radioactive deposition: A study directed towards needs for early decision making after radioactive fallout

International Nuclear Information System (INIS)

Bergman, R.

1995-12-01

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

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)

Methodology of testing environmental samples from the area surrounding radioactive waste deposits

International Nuclear Information System (INIS)

Kropikova, S.; Pastuchova, D.

1979-01-01

Methods are described of environmental sample investigation in the area surrounding radioactive waste deposits, namely monitoring ground water, surface water, sediments, water flows and catchments, vegetation and soil. Methods of sample preparation, and methods of radionuclides determination in mixtures are also discussed, as are spot activity measurement methods. (author)

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

Nuclear chemistry research and spectroscopy with radioactive sources. Nineteenth annual progress report

International Nuclear Information System (INIS)

Fink, R.W.

1983-01-01

Our effort is centered on radioactive decay studies of far-from-stable nuclides produced with heavy ions from the Holifield Heavy Ion Research Facility (HHIRF) and studied on-line with the University Isotope Separator at Oak Ridge (UNISOR). Progress is reported on the following studies: lifetime of the g/sub 7/2/ level in 109 Ag; halflife of the h/sub 9/2/ level in 187 Au; decay of 8.4 min 187 Au → 187 Pt; orbital EC probabilities and decay energy of 207 Bi; decay of 9 min /sup 201m/Po and 16 min /sup 201g/Po; decay of 2.5 min 125 Ba; decay of 7.4 min 203 At; exploration of neutron-deficient Sm, Pm, and Nd nuclides; preparation of thoron active deposit conversion electron sources; inception of nuclear laser spectroscopy at UNISOR; and nuclear structure calculations with nuclear models. Publications are listed

Derivation of ingestion dose conversion factors for the U-238 decay series

International Nuclear Information System (INIS)

Jenkins, P.H.; Nicoll, R.M.; Doty, R.L.

1978-01-01

Dose conversion factors (DCF's) for the U-238 decay series were derived for use in the assessment of potential doses to man, through several ingestion pathways, by radionuclide deposition from radioactive airborne effluents. The methodology used, although similar to that outlined in the U.S. Nuclear Regulatory Commission's Regulatory Guide 1.109, is complicated by consideration of the ingrowth of decay products. Eight ingestion pathways were considered: (1) fresh vegetables, (2) stored vegetables, (3) milk from cows that eat pasture grass, (4) milk from cows that eat stored feed, (5) goat milk - pasture grass, (6) goat milk - stored feed, (7) beef - pasture grass, and (8) beef - stored feed. Radionuclide deposition was assumed to occur for the entire operational lifetime of the facility. Because the expected operational lifetime may vary from facility to facility, DCF's were calculated for six lifetimes: 10, 15, 20, 25, 30, and 35 years. DCF's were calculated for each of 13 'parent' nuclides in the decay series, with each DCF considering the ingrowth of all subsequent nuclides in the series. The methodology used to derive the DCF's is detailed, and DCF's normalized to a deposition rate of the parent nuclide of 1 μCi m -2 s -1 are reported. (author)

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

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)

Estimation of radioactive effluents concentrations in the vicinity of nuclear power plant

International Nuclear Information System (INIS)

Arsov, Lj.

1977-01-01

This paper deals with the problem of mathematical prediction of radioactive effluent concentrations around nuclear power plants. This mathematical model which describes the behaviour of the effluent in the atmosphere here in after is expanded and adapted for radioactive effluent treatment. In this way the mathematical model includes the description of the following effects: the rise of plume caused by its vertical momentum and its heat content, wind velocity profile and vertical growth of the coefficient of diffusion, fallout under gravity, ground deposition, precipitation scavenging, and radioactive decay. The advanced computer program DIFFUS has been applied to evaluate the ground concentration of the nuclides of I, which constitute the greatest risk for population.(author)

Aerosol properties of indoor radon decay products

International Nuclear Information System (INIS)

Martell, E.A.

1984-01-01

Lung cancer risks attributable to indoor radon are highly dependent on the properties of radon progeny aerosols which, in turn, are dependent on the nature and concentration of small particles in indoor air. In clean filtered air, radon progeny are attached to small hygroscopic particles of high mobility which are rapidly deposited on surfaces. By contrast, radon progeny attached to cigarette smoke are on large particles of low mobility which persist in air. Radon progeny ingaled by smokers are largely associated with smoke particles from 0.5 to 4.0 μm diameter. Such particles are selectively deposited at bronchial bifurcations and are highly resistant to dissolution. The attached radon progeny undergo a substantial degree of radioactive decay at deposition sites before clearance which gives rise to large alpha radiation doses in small volumes of bronchial epithelium. These processes provide new insights on mechanisms of bronchial cancer induction and on relative risks of lung cancer in smokers, passive smokers, and other non-smokers. (Author)

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.

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

New depositing method of Langmuir-Blodgett film of fatty acid soap as a radioactive source

Energy Technology Data Exchange (ETDEWEB)

Iwahashi, Makio; Watanabe, Norifumi; Seimiya, Tsutomu; Naito, Fujio

1985-02-01

A stable radioactive source in vacuo was obtained by a new depositing method of Langmuir-Blodgett (L/B) film. In spite of the slight consumption of the substrate solution (only 2-2.5 ml) for preparing a 15 mm x 25 mm sized L/B film containing four molecular layers of /sup 109/Cd-eicosanoate, the deposition of the film was complete. (author).

Deposits of naturally occurring radioactivity in production of oil and natural gas

International Nuclear Information System (INIS)

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

1997-01-01

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

Results of environmental radioactivity measurements in the Member States of the European Community for air - deposition - water - milk. 1981

International Nuclear Information System (INIS)

1983-01-01

This is the 21st report on ambient radioactivity published by the Health and Safety Directorate of the Commission of the European Communities. It was drawn up using the data collected by stations responsible for environmental radioactivity monitoring in Member States. The results are extracts from the data sent to the Commission under Article 36 of the Treaty of Rome establishing the European Atomic Energy Community. The results presented in this report deal with radioactivity of the air, deposition, surface water and milk during 1981 in the ten Member States of the European Community, viz. Belgium, Denmark, Federal Republic of Germany, Greece, France, Ireland, Italy, Luxembourg, the Netherlands and the United Kingdom. The results are presented under four main headings: artificial radioactivity in the air at ground level; artificial radioactivity in deposition; radioactivity of water; radioactivity of milk. The report also contains the list of sampling stations and laboratories, together with a list of publications by Member States in this field. This report places special emphasis on the measurement results for specific radionuclides, but it also contains data on total beta activity so as to ensure continuity vis-a-vis previous and provide comparative values

Consistent treatment of ground deposition together with species growth and decay during atmospheric transport

International Nuclear Information System (INIS)

Murphy, B.D.; Nelson, C.B.; Ohr, S.Y.

1981-01-01

We discuss the adaptation of a trajectory model to an initial pollutant species and a series of successor species at mesoscale distances. The effect of source height is discussed since it is important in determining close-in ground level concentration, which influences plume depletion due to dry deposition. A scheme is outlined which handles deposition and species decay in a consistent manner and which does so for an arbitrary number of successor pollutant species. This scheme is discussed in terms of a Lagrangian trajectory model which accounts for initial source height and which calculates ground-level concentrations out to mesoscale distances

RESRAD-BUILD: A computer model for analyzing the radiological doses resulting from the remediation and occupancy of buildings contaminated with radioactive material

International Nuclear Information System (INIS)

Yu, C.; LePoire, D.J.; Jones, L.G.

1994-11-01

The RESRAD-BUILD computer code is a pathway analysis model designed to evaluate the potential radiological dose incurred by an individual who works or lives in a building contaminated with radioactive material. The transport of radioactive material inside the building from one compartment to another is calculated with an indoor air quality model. The air quality model considers the transport of radioactive dust particulates and radon progeny due to air exchange, deposition and resuspension, and radioactive decay and ingrowth. A single run of the RESRAD-BUILD code can model a building with up to: three compartments, 10 distinct source geometries, and 10 receptor locations. A shielding material can be specified between each source-receptor pair for external gamma dose calculations. Six exposure pathways are considered in the RESRAD-BUILD code: (1) external exposure directly from the source; (2) external exposure to materials deposited on the floor; (3) external exposure due to air submersion; (4) inhalation of airborne radioactive particulates; (5) inhalation of aerosol indoor radon progeny; and (6) inadvertent ingestion of radioactive material, either directly from the sources or from materials deposited on the surfaces of the building compartments

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.

Conditions of sedimentation of deposits of the lower section of the productive strata and their natural radioactivity

International Nuclear Information System (INIS)

Alieva, E.G.; Aliev, Ch.S.; Huseynov, D.A.

2008-01-01

In this article for the time for sedimentary deposits of the southern Caspian basin is an attempt use of the data of natural radioactivity of sediments in order to reconstruct their conditions sedimentation. The results obtained show a good comparability of the nature of the distribution of radioactive elements with the conditions of sedimentation. Clear contents of dependency is detected radioactive elements from the source of sedimentary material that can be successfully used in conducting the paleo facial and paleogeographic building.

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

International Nuclear Information System (INIS)

Fei, Lin.

1996-04-01

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

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

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

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.

Diffusion of disintegration products of radioactive gases in circular and flat channels

International Nuclear Information System (INIS)

Ingham, D.B.

1975-01-01

The problem of steady state diffusion of the decaying products resulting from the disintegration of a radioactive gas flowing through circular and flat channels is presented. Axial diffusion is neglected and a small diffusion parameter is assumed. Results are obtained for the axial displacement and density distribution of atoms deposited on the walls when the laminar flow is Poiseuille and plug. These results can be used to determine diffusion coefficients of disintegration products. (author)

Atmospheric behavior, deposition, and budget of radioactive materials from the Fukushima Daiichi nuclear power plant in March 2011

Science.gov (United States)

Morino, Y.; Ohara, T.; Nishizawa, M.

2011-12-01

To understand the atmospheric behavior of radioactive materials emitted from the Fukushima Daiichi nuclear power plant after the nuclear accident that accompanied the great Tohoku earthquake and tsunami on 11 March 2011, we simulated the transport and deposition of iodine-131 and cesium-137 using a chemical transport model. The model roughly reproduced the observed temporal and spatial variations of deposition rates over 15 Japanese prefectures (60-400 km from the plant), including Tokyo, although there were some discrepancies between the simulated and observed rates. These discrepancies were likely due to uncertainties in the simulation of emission, transport, and deposition processes in the model. A budget analysis indicated that approximately 13% of iodine-131 and 22% of cesium-137 were deposited over land in Japan, and the rest was deposited over the ocean or transported out of the model domain (700 × 700 km2). Radioactivity budgets are sensitive to temporal emission patterns. Accurate estimation of emissions to the air is important for estimation of the atmospheric behavior of radionuclides and their subsequent behavior in land water, soil, vegetation, and the ocean.

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

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)

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.

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...

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.

Dynamics of radioactive lead isotopes in the global environmental atmosphere

International Nuclear Information System (INIS)

Koike, Yuya; Kosako, Toshiso

2006-01-01

Fundamental information of radioactive lead isotopes, which used as the atmospheric tracer in the global environmental atmosphere, is reviewed. Emanation and exhalation of Rn and Tn, parent nuclide, is stated. Some reports on measurement and application of short-lived lead isotopes are reported. Transfer of radioactive lead isotopes in the atmosphere, vertical profiles of radon, thoron, and short-lived lead isotopes for different turbulent mixing conditions, deposition to aerosol, basic processes of Rn decay product behavior in air defining 'unattached' and 'aerosol-attached' activities, seasonal variation of atmospheric 210 Pb concentration at Beijing and Chengdu, seasonal variation of atmospheric 212 Pb concentration at several observation sites in Japan Islands, and variation in the atmospheric concentration of 212 Pb along with SO 2 are shown. (S.Y.)

Airborne and deposited radioactivity in Finland in 1987

International Nuclear Information System (INIS)

Aaltonen, H.; Saxen, R.; Ikaeheimonen, T.K.

1990-04-01

In the air surveillance programme concentrations of artificial radionuclides are monitored in the air close to the ground. In 1987, air dust samples were collected in Nurmijaervi, 40 km north of Helsinki and in Rovaniemi. When necessary, sampling was also launched in Helsinki. Several radionuclides originating from the accident in Chernobyl in 1987 could still be detected in air dust samples. A sharp decrease in the amounts of radioactive subtances deposited was noted at all the 18 sampling stations as against 1986. The total annual amounts of deposited 137 Cs varied at different stations in 1987 from 7.7 Bq/m 2 (Rovaniemi) to 1500 Bq/m 2 (Kauhava) and those of 90 Sr in 1986 from 4.7 Bq/m 2 (Taivalkoski) to 590 Bq/m 2 (Kuhmo) and in 1987 from 1.4 Bq/m 2 (Ivalo) to 38 Bq/m 2 (Kuhmo). The total annual amounts of 238 Pu and 239 , 240 Pu were 3.1 and 12 mBq/m 2 in Nurmijaervi and 3.4 and 14 mBq/m 2 and Lappeenranta in 1987, respectively. In 1987, resuspension of radionuclides was characteristic of the depostion situation. Due to this phenomenon, unexpectedly high contents of deposited radiocesium occurred occasionally in the samples, though the discharge caused by the Chernobyl accident lasted for only a short period in spring 1986. The proportion of 137 Cs originating from Chernobyl in 1987 varied from 3% to about 40% of the corresponding amounts in 1986 at different stations. The corresponding percentages for 90 Sr varied from 1.6% to 34%

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

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

Lung Deposition Calculations for Radioactive Aerosol Particles Originating from Caves and Uranium Mines

International Nuclear Information System (INIS)

Alfoldy, B.; Torok, Sz.; Winkler, R.

2001-01-01

Full text: The present study simulates lung deposition of radioactive aerosol particles originating from the atmosphere of a therapeutic cave (Szemlohegyi cave, Budapest) and several uranium mines. Particle deposition patterns and surface densities have been calculated by the stochastic lung model of Koblinger and Hofmann. In the model, deposition can be caused by the simultaneous effects of Brownian motion, inertial impaction and gravitational settling. The calculations were carried out by considering the aerosol particle size distribution and radon concentration of the atmosphere of the cave and mines. The deposition was computed in the whole lung, in characteristic parts of the respiratory system such as extrathoracic, tracheobronchial, acinar and alveolar regions and in the singe airway generations at different flow rates for adults. The adverse health effects of inhaled radionuclides strongly depend from the local deposition density values in cellular dimensions. Thus we will built in the results to a cellular effects model of Balashazy and Hofmann for the simulation of the pathological effects of inhaled radionuclides for risk assessment. (author)

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)

PABLM, Doses from Radioactive Releases to Atmosphere and Food Chain

International Nuclear Information System (INIS)

Napier, B.A.; Kennedy, W.E. Jr.; Soldat, J.K.

1983-01-01

1 - Description of problem or function: PABLM calculates internal radiation doses to man from radionuclides in food products and external radiation doses from radionuclides in the environment. Radiation doses from radionuclides in the environment may be calculated from deposition on the soil or plants during an atmospheric or liquid release, or from exposure to residual radionuclides after the releases have ended. Radioactive decay is considered during the release, after deposition, and during holdup of food after harvest. The radiation dose models consider exposure to radionuclides deposited on the ground or crops from contaminated air or irrigation water, radionuclides in contaminated drinking water, aquatic foods raised in contaminated water, and radionuclides in bodies of water and sediments where people might fish, boat, or swim. For vegetation, the radiation dose model considers both direct deposition and uptake through roots. Doses may be calculated for either a maximum-exposed individual or for a population group. The program is designed to calculate accumulated radiation doses from the chronic ingestion of food products that contain radionuclides and doses from the external exposure to radionuclides in the environment. A first-year committed dose is calculated as well as an integrated dose for a selected number of years. 2 - Method of solution: A chain decay scheme including branching for transitions to and from isomeric states is used for radioactive decay. The equations for calculating internal radiation doses are derived from those given by the International Commission on Radio- logical Protection (ICRP) for body burdens and the maximum possible concentration (MPC) for each radionuclide. These doses are calculated as a function of radionuclide concentration in food products, ingestion rates, and a radionuclide-specific dose- commitment factor. Radiation doses from external exposure to contaminated water and soil are calculated using the basic assumption

Tritium in the underground waters of the Karazheera coal deposit

International Nuclear Information System (INIS)

Panin, M.S.; Artamonova, H.N.

2001-01-01

Full text: The Karazheera coal deposit is the unique geological object due to it's location on the Balapan site of the former Semipalatinsk nuclear polygon (SNP) with its wide range of underground nuclear tests fulfilled here (more than 130 explosions). That is why some radiological problems may appear with the geological ones which take place in the open mining work of the deposit. The radio-active pollution of SNP has been actively discussed in scientific literature for a long time. The present report evaluates the radio-active tritium pollution ( 3 H) of the deposit's underground waters. That very component of nature is subjected to radiation pollution in large extent after underground nuclear tests. 3 H radio-active isotope with 12-13 year period of half-decay. 3 H is generated in the result of nuclear reactions caused by cosmic radiation and nuclear reactions of explosions. The total number of 3 H on the globe comes to 12 kg. The content of 3 H has been studied in underground waters of self-pouring wells number 76, 82, springs and dipholes of the deposit. It has been fixed that concentration of 3 H in the deposit is fluctuating within 0.4-37.9 tritium units (TU) while the average content 10.3 TU (1 TU - 3.2x10 -12 Curie/liter). The analysis of 3 H decay shows that its maximum concenliaiion has been fixed in the deposit 82 (37.9 TU) and in diphole (32.3 TU). The background content of 3 H in water was evaluated on the level of 1-8 TU till 1945. In the result of nuclear weapon tests the background has been considerably increased and according to First data (1994) it is corresponded to 23 TU. The average content of the 3 H in underground waters of Karazheera is half the size of this index (10.3 TU). It comprises 3.3x10 -11 and it is more lower than quota 4x10 -6 Ci/l. It is considered that the content of more than 10 TU in waters is caused by thermal nuclear test. Precipitations fallen after 1961 are presented in subsoil waters containing of 20 TU or more

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.

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.

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1998-07-01

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

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-07-01

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

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

International Nuclear Information System (INIS)

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

1979-01-01

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

Atmospheric deposition of radioactive cesium (137Cs) associated with dust events in East Asia

International Nuclear Information System (INIS)

Fujiwara, H.

2010-01-01

Since the cessation of atmospheric nuclear testing in 1980, there has been no known serious atmospheric contamination by radioactive cesium (sup(137)Cs) apart from the Chernobyl nuclear reactor accident in 1986. There now remain only small amounts of anthropogenic radionuclides in the atmosphere that can be directly related to past testing. However, sup(137)Cs is still regularly found in atmospheric deposition samples in Japan. In this study, we analyzed sup(137)Cs monitoring data, meteorological data, and field survey results to investigate the recent transport and deposition of sup(137)Cs associated with dust phenomena. Monthly records of nationwide sup(137)Cs deposition in Japan during the 1990s show a consistent seasonal variation, with higher levels of deposition occurring in spring. In March 2002, an unexpectedly high amount of sup(137)Cs was deposited in the northwestern coastal area of Japan at the same time as an Asian dust event was observed. Analysis of land-based weather data showed that sandstorms and other dust-raising phenomena also occurred in March 2002 over areas of Mongolia and northeastern China where grassland and shrubs predominated. Furthermore, radioactivity measurements showed sup(137)Cs enrichment in the surface layer of grassland soils in the areas affected by these sandstorms. These results suggest that grasslands are potential sources of sup(137)Cs-bearing dust. Continued desertification of the East Asian continent in response to recent climate change can be expected to result in an increase in sup(137)Cs-bearing soil particles in the atmosphere, and their subsequent re-deposition in Japan. However, soil dust is also raised around Japanese monitoring sites by the strong winds that are common in Japan in spring, and this local dust might also contribute to sup(137)Cs deposition in Japan. To estimate the relative contributions of local and distant dust events to the total sup(137)Cs deposition, we monitored deposition of mineral particles

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)

Modeling ground water flow and radioactive transport in a fractured aquifer

International Nuclear Information System (INIS)

Pohll, G.; Hassan, A.E.; Chapman, J.B.; Papelis, C.; Andricevic, R.

1999-01-01

Three-dimensional numerical modeling is used to characterize ground water flow and contaminant transport at the Shoal nuclear test site in north-central Nevada. The fractured rock aquifer at the site is modeled using an equivalent porous medium approach. Field data are used to characterize the fracture system into classes: large, medium, and no/small fracture zones. Hydraulic conductivities are assigned based on discrete interval measurements. Contaminants from the Shoal test are assumed to all be located within the cavity. Several challenging issues are addressed in this study. Radionuclides are apportioned between surface deposits and volume deposits in nuclear melt glass, based on their volatility and previous observations. Surface-deposited radionuclides are released hydraulically after equilibration of the cavity with the surrounding ground water system, and as a function of ground water flow through the higher-porosity cavity into the low-porosity surrounding aquifer. Processes that are modeled include the release functions, retardation, radioactive decay, prompt injection, and in growth of daughter products. Prompt injection of radionuclides away from the cavity is found to increase the arrival of mass at the control plane but is not found to significantly impact calculated concentrations due to increased spreading. Behavior of the other radionuclides is affected by the slow chemical release and retardation behavior. The transport calculations are sensitive to many flow and transport parameters. Most important are the heterogeneity of the flow field and effective porosity. The effect of porosity in radioactive decay is crucial and has not been adequately addressed in the literature. For reactive solutes, retardation and the glass dissolution rate are also critical

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)

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

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.

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.)

Consequences of radioactive deposition on aquatic environments

International Nuclear Information System (INIS)

Suolanen, V.

1994-12-01

The publication concentrates on the analyses of the main effects of radioactive deposition on Nordic aquatic environments. A modelling approach is applied for predicting the temporal behaviour of concentrations in fish of inland freshwater ecosystems. The observed values are considered in parallel with the calculations. The time-integrated consequences, the radiation doses are estimated for the relatively significant dose pathways. After a preliminary study of various lake environments in Nordic countries, three representative examples of lake systems were selected for closer consideration: small forest lake, medium-sized forest lake and mountain lake. The effects of changes in the trophic levels of lakes are also tentatively accounted for. The results of the analyses indicate that the radiological consequences of shallow forest lakes are greater than those of mountain lakes which usually have shorter turnover times compared to forest lakes. In long-term consideration, the fish ingestion pathway may in general become important and, in addition to the external exposure, has a high contribution to the expected doses. (orig.) (8 refs., 11 figs., 9 tabs.)

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.

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)

Emanations and 'induced' radioactivity: from mystery to (mis)use

International Nuclear Information System (INIS)

Kolar, Z.I.

1999-01-01

The natural Rn isotopes were discovered within the period 1899-1902 and at that time referred to as emanations because they came out (emanated) of sources/materials containing actinium, thorium and radium, respectively. The (somewhat mysterious) emanations appeared to disintegrate into radioactive decay products which by depositing at solid surfaces gave rise to 'induced' radioactivity i.e. radioactive substances with various half-lives. Following the discovery of the emanations the volume of the research involving them and their disintegration products grew steeply. The identity of a number of these radioactive products was soon established. Radium emanation was soon used as a source of RaD ( 210 Pb) to be applied as an 'indicator' (radiotracer) for lead in a study on the solubility of lead sulphide and lead chromate. Moreover, radium and its emanation were introduced into the medical practice. Inhaling radon and drinking radon-containing water became an accepted medicinal use (or misuse?) of that gas. Shortly after the turn of the century, the healing (?) action of natural springs (spas) was attributed to their radium emanation, i.e. radon. Bathing in radioactive spring water and drinking it became very popular. Even today, bathing in radon-containing water is still a common medical treatment in Jachymov, Czech Republic. (author)

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)

Radioactive mineral deposits

Energy Technology Data Exchange (ETDEWEB)

1948-01-01

This publication was designed as a guide for uranium and thorium prospectors in Australia. Physical properties, such as color, streak, luster, hardness, fracture, and specific gravity of the uranium and thorium-bearing minerals are summarized and the various methods suitable for detecting radioactivity in minerals are described. Two colored plates show samples of pitchblende (uraninite), autunite, carnotite, monazite, and others of the most important minerals sources of uranium and thorium.

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

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.)

Entrapment of krypton in sputter deposited metals: a storage medium for radioactive gases

International Nuclear Information System (INIS)

Tingey, G.L.; McClanahan, E.D.; Bayne, M.A.; Moss, R.W.

1979-04-01

Sputter deposition of metals with a negative substrate bias results in a deposit containing relatively large concentrations of the sputtering gas. This phenomenon has been applied as a technique for storage of the radioactive gas, 85 Kr, which is generated in nuclear fuels for power production. Alloys which sputter to yield an amorphous product have been shown to contain up to 12 atom % Kr [42 cm 3 of Kr(STP)/g of deposit; concentration equivalent to a gas at 4380 psi pressure]. Release from these metals occurs at so low a rate that extrapolation to long times yields a 85 Kr release at 300 0 C of about 0.06% in 100 years. A preliminary evaluation of the engineering feasibility and economics of the sputtering process indicates that 85 Kr can be effectively trapped in a solid matrix with currently available techniques on a scale required for handling DOE-generated waste or commercial reprocessed fuels and that the cost should not be a limiting factor

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

Analytical approximations for the long-term decay behavior of spent fuel and high-level waste

International Nuclear Information System (INIS)

Malbrain, C.M.; Deutch, J.M.; Lester, R.K.

1982-01-01

Simple analytical approximations are presented that describe the radioactivity and radiogenic decay heat behavior of high-level wastes (HLWs) from various nuclear fuel cycles during the first 100,000 years of waste life. The correlations are based on detailed computations of HLW properties carried out with the isotope generation and depletion code ORIGEN 2. The ambiguities encountered in using simple comparisons of the hazards posed by HLWs and naturally occurring mineral deposits to establish the longevity requirements for geologic waste disposal schemes are discussed

Radioactive mineral occurrences in the Bancroft area

Energy Technology Data Exchange (ETDEWEB)

Satterly, J

1958-12-31

The report summarizes three years of field work conducted in the Bancroft area investigating occurrences of radioactive minerals, and also includes accounts of properties in the area for which drill logs and survey reports have been filed. It begins with a history of exploration and development of radioactive mineral deposits in the area, a review of the area`s general geology (Grenville metasediments, plutonic rocks), and general descriptions of the types of radioactive mineral deposits found in the area (deposits in granitic and syenitic bodies, metasomatic deposits in limy rocks, hydrothermal deposits). It also describes the mineralogy of radioactive minerals found in the area and the Geiger counter technique used in the investigation. The bulk of the report consists of descriptions of radioactive mineral properties and mine workings, containing (where available) information on exploration history, general and economic geology, and production.

Radioactive cesium isotope ratios as a tool for determining dispersal and re-dispersal mechanisms downwind from the Nevada Nuclear Security Site.

Science.gov (United States)

Snyder, Darin C; Delmore, James E; Tranter, Troy; Mann, Nick R; Abbott, Michael L; Olson, John E

2012-08-01

Fractionation of the two longer-lived radioactive cesium isotopes ((135)Cs and (137)Cs) produced by above ground nuclear tests have been measured and used to clarify the dispersal mechanisms of cesium deposited in the area between the Nevada Nuclear Security Site and Lake Mead in the southwestern United States. Fractionation of these isotopes is due to the 135-decay chain requiring several days to completely decay to (135)Cs, and the 137-decay chain less than one hour decay to (137)Cs. Since the Cs precursors are gases, iodine and xenon, the (135)Cs plume was deposited farther downwind than the (137)Cs plume. Sediment core samples were obtained from the Las Vegas arm of Lake Mead, sub-sampled and analyzed for (135)Cs/(137)Cs ratios by thermal ionization mass spectrometry. The layers proved to have nearly identical highly fractionated isotope ratios. This information is consistent with a model where the cesium was initially deposited onto the land area draining into Lake Mead and the composite from all of the above ground shots subsequently washed onto Lake Mead by high intensity rain and wind storms producing a layering of Cs activity, where each layer is a portion of the composite. Copyright © 2012 Elsevier Ltd. All rights reserved.

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.

Deposition of radioactive corrosion products on the internal surfaces of tube elements in gaseous phase of dissociating system N2O4 reversible 2NO2 reversible 2NO+O2

International Nuclear Information System (INIS)

Gol'tsev, V.P.; Dolgov, V.M.; Katanaev, A.O.

1979-01-01

Analysis of experimental data, obtained as a result of γ-scanning of tube element samples of loop assembling with dissociating coolant contacting with N 2 O 4 gaseous phase is presented. Radioactive depositions are differentiated on fixed and unfixed ones by the method of radiochemical analysis. The data obtained have made it possible to establish the analytical form of radioactive element distribution functions along the piping length. It is noted, that relative quantities of radioactive isotopes, existing in fixed and unfixed depositions vary with temperature. The fraction of soluble forms of corrosion radioactive products in unfixed depositions increases both with the decrease of temperature and after passing of radioactive impurity through the zone of liquid coolant

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.

Surface deposition of radon decay products with and without enhanced air motion

International Nuclear Information System (INIS)

Rudnick, S.N.; Maher, E.F.; Hinds, W.C.; First, M.W.

1983-01-01

The effectiveness of fan-induced air motion in reducing airborne activity of short-lived radon decay products was evaluated in a 78-m 3 chamber. Observed reductions were as high as 50% for RaA ( 218 Po), 79% for RaB ( 214 Pb), and 86% for RaC ( 214 Bi). Activity Measurements of these nuclides on chamber and fan surfaces, along with airborne activity, were used to calculate material balances. Greater than about 90% of deposited activity was found on chamber surfaces, although areal activity density was higher on fan surfaces. Deposition velocity and diffusional boundary thickness were also determined. When no fans were used, boundary layer thickness was estimated to be 25 times the recoil distance of a RaB atom and, with fans, about 4 times the recoil distance, suggesting that recoiling of RaB atoms probably do not play a significant role in the relationship between surface and airborne activity. The results of this study have relevance for all habitable spaces having excessive radon concentration

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...

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

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

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.)

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.

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.

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

Radioactivity in the Calcasieu River/Lake Complex

International Nuclear Information System (INIS)

Broussard, M.; Beck, J.N.

1987-01-01

Concentrations of natural and manmade radionuclides including 40 K, 137 Cs, 226 Ra, 228 Ac, and their decay products were measured in sediment and water samples. Gross alpha and gross beta activities were also determined in water samples. The levels of radioactivity were found to be low in all water samples, with a general increase of activity toward the brackish waters of the southern portion of the study area. The concentrations of uranium and thorium daughters found in sediment samples were found to be relatively constant across the study area. The concentration of 40 K was found to vary in a regular manner, with the lowest values found in the northern portion of the river/lake complex and highest values found at the southern stations. This suggests transport and deposition of potassium into the organic-rich sediments. The only manmade radionuclide found was 137 Cs which was deposited only in the top 15 to 20 cm of sediment and was uniformly distributed across the sample area

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

The IRSN publishes an assessment of doses received in Japan by external irradiation due to radioactive deposits caused by the Fukushima-Daiichi power plant accident

International Nuclear Information System (INIS)

2011-01-01

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

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

The uranium mine Key Lake, Canada, as an example of final deposition of radioactive tailings

International Nuclear Information System (INIS)

Schmitz, T.

1984-01-01

The main part of that waste handling system is tailing storage. The other parts include the water storage reservoirs and monitoring ponds. Soil conditions and design features of the tailings pond are described in detail as well as the method of tailings disposal. Finally the method of deposition results in a laminated radioactive tailings deposit and the tailings reach a degree of compactness comparable to concrete. The Key Lake Mining Corporation and its consultants have developed a tailings handling program in order to minimize environmental impact and to take advantage of the natural topography and soil materials in the project area. (orig./HP) [de

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.

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

Simulation of fire in a deposit of radioactive waste and the radiological risk associated to this scenario

International Nuclear Information System (INIS)

Domingos, Érica Nascimento; Lima, Zelmo Rodrigues de; Aguiar, Laís Alencar de

2017-01-01

A fire at radioactive waste deposit can result in significant damage as well as serious risks to the environment and the health of the general public. The CNEN (National Commission of Nuclear Energy) norms have fire protection regulations criteria and requirements to prevent the occurrence, neutralize the action and minimize the effects of the fire on the radioactive material present on the plant. These norms it is for to avoid or limit to the lowest possible levels the effects of ionizing radiation or toxic substances on humans and the environment. Before a possible fire containing radioactive material is necessary information that can estimate the dose in which the population will be submitted. In this work the proposal is to simulate a fire scenario containing radioactive material using Hotspot Health Physics simulation code and to identify the radiological risk of cancer in the respiratory system associated with this scenario using the BEIR V model. (author)

Simulation of fire in a deposit of radioactive waste and the radiological risk associated to this scenario

Energy Technology Data Exchange (ETDEWEB)

Domingos, Érica Nascimento; Lima, Zelmo Rodrigues de, E-mail: erica.ndomingos@gmail.com, E-mail: zrlima@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Aguiar, Laís Alencar de, E-mail: laguiars@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2017-07-01

A fire at radioactive waste deposit can result in significant damage as well as serious risks to the environment and the health of the general public. The CNEN (National Commission of Nuclear Energy) norms have fire protection regulations criteria and requirements to prevent the occurrence, neutralize the action and minimize the effects of the fire on the radioactive material present on the plant. These norms it is for to avoid or limit to the lowest possible levels the effects of ionizing radiation or toxic substances on humans and the environment. Before a possible fire containing radioactive material is necessary information that can estimate the dose in which the population will be submitted. In this work the proposal is to simulate a fire scenario containing radioactive material using Hotspot Health Physics simulation code and to identify the radiological risk of cancer in the respiratory system associated with this scenario using the BEIR V model. (author)

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

Investigation of produced waters radioactivity of oil and gas deposits in the Dnieper-Donets province

Directory of Open Access Journals (Sweden)

Plyatsuk L. D.

2017-12-01

Full Text Available The process of radioactive pollution of produced waters, oilfield equipment, oil-contaminated soils and sludge is widely spread and differs within the various oil and gas regions. Formation waters contained radioactive element isotopes become the significant source and cause of elevated level of equivalent dose power and as a consequence, an increase in the incidence among the population. The author's idea is formulation of specific recommendations on the decontamination of the investigated objects by conducting the necessary appropriate experimental studies. The purpose of the article is to determine the content of radionuclides, γ- and α-emitters in technogenic objects of Bugruvate oil and gas fields, and to reveal the relationship with the features of mineralogical composition, geological structure and technological process. The γ-spectrometric analysis was used to determine the radionuclide composition of the natural radiators of the 238U (226Ra, 214Pо, 214Bi and 232Th (228Ac, 212Pb, 212Вi series in samples of technological sludge, oil, individual soil samples and water. The content of radionuclides of α-emitters was determined using separate radiochemical techniques. It was investigated that the radioactivity of the formation water is mainly determined by 226Ra and 228Ra and the products of their decay.

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

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.))

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.)

Uranium isotopes as radioactive pollutants in groundwaters of the Morro do Ferro thorium deposit, Brazil

International Nuclear Information System (INIS)

Bonotto, D.M.

1991-01-01

Groundwater and surface water samples were collected at Morro do Ferro, a thorium and rare earth deposit located on the Pocos de Caldas Plateau, Minas Gerais State, Brazil, to evaluate if the mechanisms related to the migration of 238 U and 234 U isotopes can generate concentrations greater than the gross-alpha activity contaminant limit. The 238 U content range was 0.003-0.24 pCi/1 and the 234 U content range was 0.004-0.25 pCi/1, showing that the studied hydrologic environment doesn't indicate pollution by radioactivity due to these nuclides. However, 226 Ra and 228 Ra isotopes can be considered as radioactive pollutants in groundwaters but not in surface waters of the Morro do Ferro. (author)

Estimation of natural radioactivity in different fertilizers

International Nuclear Information System (INIS)

Gupta, Monika; Chauhan, Pooja; Chauhan, R.P.; Sonkawade, R.G.; Kant, K.

2011-01-01

Fertilizers have become essential to the agricultural field all over the world. The natural radionuclides of fertilizers consist mainly of 226 Ra, 232 Th, isotopes with their decay products. The level of activity concentration of radionuclides in phosphate fertilizers provides useful information in the monitoring of environmental contamination. The concepts of natural radiation are essential for radiation protection purpose. Radionuclides present in fertilizers affect the common people and farmers immensely. They are produced and used worldwide in increasing quantities to replenish natural nutrients depleted from soils because of forming and erosion. However, the mining, processing and use of fertilizer materials in massive quantities redistribute radioactive trace elements throughout the environment, principally uranium, radium, radium decay products. The agricultural phosphate fertilizer industries use raw materials that consist of phosphate rocks, phosphoric acid, ammonium phosphate. The level of activity concentration of radionuclides in different fertilizers provides useful information in the monitoring of environmental contamination. Radiological impacts of phosphate rocks mining and manufacture could be significant due to the elevated radioactivity contents of the naturally occurring radioactive materials (NORM), such as 238 U series, 232 Th series and 40 K, in some phosphate deposits. The concepts of natural radiation are essential for radiation protection purpose. This paper emphasis on the public risk assessment in an integrated manner assessing doses to members of the public via the atmospheric aquatic and secondary pathways. In the present study radioactivity in different fertilizer samples, which are widely used in Indian fields, was determined. The experimental work includes the measurements of 226 Ra, 232 Th and 40 K using gamma spectrometry and radon concentration and exhalation rates measurement using solid state nuclear track detectors to asses a

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.)

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

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

Estimation of radioactive effluents concentrations in the vicinity of nuclear power plant; Predviduvanje na koncentraciite na radioaktivni aerozagaduvaci vo okolinata na nuklearni energetski postrojni

Energy Technology Data Exchange (ETDEWEB)

Arsov, Lj [Elektrostopanstvo, Skopje (Yugoslavia)

1977-07-01

This paper deals with the problem of mathematical prediction of radioactive effluent concentrations around nuclear power plants. This mathematical model which describes the behaviour of the effluent in the atmosphere here in after is expanded and adapted for radioactive effluent treatment. In this way the mathematical model includes the description of the following effects: the rise of plume caused by its vertical momentum and its heat content, wind velocity profile and vertical growth of the coefficient of diffusion, fallout under gravity, ground deposition, precipitation scavenging, and radioactive decay. The advanced computer program DIFFUS has been applied to evaluate the ground concentration of the nuclides of I, which constitute the greatest risk for population.(author)

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.

Quantitative evaluation of inhaled radioactive aerosol deposition patterns in the lungs in obstructive airways disease

Energy Technology Data Exchange (ETDEWEB)

Teshima, Takeo; Isawa, Toyoharu; Hirano, Tomio; Ebina, Akio; Shiraishi, Koichiro; Konno, Kiyoshi

1985-12-01

Uneven distribution of inhaled aerosol in the lungs is the characteristics of obstructive airways disease such as chronic bronchitis and pulmonary emphysema, and has been classified typically into peripheral and central deposition patterns, respectively by visual inspection, whereas in the normal the distribution is homogeneous throughout the lungs. The purpose of the present study was to analyse the distribution of inhaled radioactivity in the lungs by way of matrixes by a computer. The seemingly homogeneous distribution pattern in normal subjects has been found to indicate a gradual change in count profile between the neighboring matrixes. The peripheral pattern indicates the patchy presence of small number of matrixes with excessive radioactivity throughout the lungs, and the central pattern, the presence of matrixes of excessive radioactivity along the major central airways forming a comma-like configuration superimposed on the peripheral pattern. Our computer analysis has a potentiality to characterize obstructive airways disease for a better understanding of their pathophysiology, which is not feasible by a simple visual inspection of images on a polaroid picture.

Pretreatment method for radioactive iodine-containing liquid wastes and pretreatment device

International Nuclear Information System (INIS)

Wakaida, Yasuo.

1996-01-01

Heretofore, radioactive iodine-containing liquid wastes have been discharged directly to a storing and decaying storage vessel to conduct a water draining treatment. In the present invention, the radioactive iodine-containing liquid wastes to be discharged are not discharged to the storage vessel directly but injected to a filling tank, as a pretreatment, to distinguish whether proteins are mixed in the liquid wastes or not. When proteins are mixed, miscellaneous materials such as proteins are recovered and removed by a protein processing system. When proteins are not mixed, radioactive iodine is recovered and removed directly by an iodine processing system. With such procedures, water draining treatment in the storing and decaying storage vessel is mitigated, and even when the amount of the radioactive iodine-containing liquid wastes is increased, the existent maintaining and decaying storage vessel can be used as it is. Accordingly, a safe water draining treatment with good efficiency can be conducted relative to radioactive iodine-containing liquid wastes at a reduced cost. (T.M.)

Radioactivity measurements in Europe after the Chernobyl accident. Part II: Fallout and deposition

International Nuclear Information System (INIS)

De Cort, M.; Graziani, G.; Raes, F.; Stanners, D.; Grippa, G.; Ricapito, I.

1990-01-01

The collection of deposition measurements, presented in this report and included in the floppy disk in the back cover has been put together as part of the REM programme (Radioactivity environmental Monitoring). This follows the compilation of air measurements (part 1) published previously (Raes, 1989). The objective of these compilations is to promote the integration of Chernobyl data on a European-wide basis to make them widely available in a coherent form for scientific study. Deposition measurements come in many forms (fallout, rain, soil) but all reflect the phenomena by which radionuclides in the air reach the surface. Depending on the manner of sampling, measurements can reflect integral values (e.g. from surface soil) or some fraction of the deposition (e.g. daily deposition using fallout or rain collectors). The latter can also be expressed as wet or dry according to the sampling apparatus used. The original sources of information from which this compilation was made vary widely : some of the data were obtained directly from floppy disks or tapes; others were copied manually from tables found in reports or papers in the scientific literature. The sets of measurements presented in this report were selected from this large patrimony of data in the REM data bank. Specific criteria were used to make this selection. Overall, only those data were used which had fully defined records. For daily deposition data actually sampled over 24 hourly periods were selected. With cumulative deposition care was taken to select data which covered the whole period of deposition marked by the passage of the cloud. The resulting data are presented on a unified format and as far as possible keep to individual measured values. In this manner the greatest flexibility is given to the user of this data

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

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 ...

Study of materials for use in final deposits of radioactive waste

International Nuclear Information System (INIS)

Amaral, A.F.; Tello, C.C.O.

2011-01-01

Clays are used in repositories (final deposits of radioactive waste) due to their radionuclide sorption and soil waterproofing capacities. The objectives of this work are to research and develop tests of characterization relevant to the use of clays in repositories, to characterize national clays and to assemble a database with information on the suppliers and the tests that were done. Results are shown for the mineral identification test, for the determination of the normal Proctor compaction curve, size distribution, cationic exchange capacity, specific surface, and others, for two materials. Such information will allow the selection of the best among these materials for use in the backfill and in other applications, besides indicating the most reliable test for estimating characteristics of different materials. (author)

Ge deposition on Si(1 0 0) in the conditions close to dynamic equilibrium between islands growth and their decay

International Nuclear Information System (INIS)

Shklyaev, A.A.; Budazhapova, A.E.

2016-01-01

Graphical abstract: - Highlights: • Solid source MBE is used for island growth by Ge deposition on Si(1 0 0) at 700–900 °C. • Islands acquire a monomodal size distribution at temperatures above 800 °C. • Islands form ordered arrays during Ge deposition at 900 °C. • Conditions close to dynamic equilibrium are realized for growth and decay of islands at 900 °C. • Shape of ordered islands is cone with shallow sidewalls. - Abstract: The formation of islands arrays during Ge deposition on Si(1 0 0) at high temperatures is studied using scanning tunneling and electron microscopies. It is found that the island size and shape distributions, which are known to be bimodal at growth temperatures below 700 °C, become monomodal at temperatures above 800 °C. The obtained data suggest that the processes such as island nucleation and Ostwald ripening become less significant in the surface morphology formation, giving the advantage to selective attachment of deposited Ge atoms to island sidewalls and spatially inhomogeneous Si-Ge intermixing, as the temperature increases. At 900 °C, the islands exhibit a tendency to form laterally ordered arrays when the growth conditions approach the dynamic equilibrium between the growth of islands and their decay by means of Si-Ge intermixing. The islands ordering is accompanied by their shape transformation into the cone with shallow sidewalls inclined from (1 0 0) by angles of around 10°.

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

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)

Radiometric survey of radioactive minerals in the Matias Romero dam, in Oaxaca

International Nuclear Information System (INIS)

Flores, J.H.; Pena, P.; Balcazar, M.; Lopez, A.M.; Juarez, S.F.; Cabrera, M.O.; Huizar, R.

2006-01-01

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

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

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.

Radioactive fallout in the South Pacific : a history. Part 3: strontium-90 and caesium-137 deposition in New Zealand and resulting contamination of milk

International Nuclear Information System (INIS)

Matthews, K.M.

1993-12-01

The report provides a comprehensive analysis of milk radioactivity data, principally pertaining to 90 Sr and 137 Cs, collected in nine regions of New Zealand. Fallout deposition data are also reviewed and relationships between deposition and resulting milk contamination described. This report provides further information on 90 Sr deposition in New Zealand and summarises period from 1961 to 1990. Trends in levels of 90 Sr and 137 Cs in milk over long periods and also annual trends are described, together with variations between regions, modelled relationships between fallout deposition and milk contamination levels, measurements of 131 I and 89 Sr in milk, and estimates of resulting dietary radiation exposure in New Zealand. A major aim of the present report was to summarise as much of the information contained in the deposition and dairy product databases as possible through the description of trends and derivation of relationships in order to improve understanding of the behaviour of artificial radioactive contaminants in the environment and their passage through food-chains. 34 refs., 29 tabs., 50 figs., 1 ill

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

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)

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

PATHWAY: a dynamic foodchain model to predict radionuclide ingestion after fallout deposition. Final report, September 17, 1979-December 31, 1985

International Nuclear Information System (INIS)

Whicker, F.W.; Kirchner, T.B.

1986-01-01

This paper describes the structure and basis for parameter values of a computerized foodchain transport model for radionuclides. The model, called ''PATHWAY,'' estimates the time-integrated intake by humans of twenty radionuclides after a single deposition of radioactive material from the atmosphere to the landscape. The model solves a set of differential equations to estimate the inventories and concentrations of radionuclides in three soil layers and numerous types of vegetation, animal tissues and animal products as a function of time following a deposition event. Dynamic processes considered in the model include foliar interception, weathering and absorption; plant growth, uptake, harvest and senescence; soil resuspension, percolation, leaching and tillage; radioactive decay; livestock ingestion, absorption, excretion; and etc. An age- and sex-specific human diet is embodied in the model to permit calculation of time-dependent radionuclide ingestion rates, which are then numerically integrated. 3 figs., 10 tabs

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)

Dry interim storage of radioactive material in Germany

International Nuclear Information System (INIS)

Drobniewski, Christian; Palmes, Julia

2013-01-01

In accordance with the waste management concept in Germany, spent fuel is stored in interim storage facilities for a period of up to 40 years until deposition in a geological repository. In twelve on-site interim storages in the vicinity or directly on the sites of the nuclear power plants, spent fuel elements from reactor operation are stored after the necessary period of decay in wet storage basins inside the reactors. Additionally, three central interim storage facilities for storage of spent fuel of different origin are in operation. The German facilities realize the concept of dry interim storage in metallic transport and storage casks. The confinement of the radioactive material is ensured by the double lid system of the casks, of which the leak tightness is monitored constantly. The casks are constructed to provide adequate heat removal and shielding of gamma and neutron radiation. Usually the storage facilities are halls of thick concrete structures, which ensure the removal of the decay heat by natural convection. The main safety goal of the storage concept is to prevent unnecessary exposure of persons, material goods and environment to ionizing radiation. Moreover any exposure should be kept as low as reasonable achievable. To reach this goal the containment of the radioactive materials, the disposal of decay heat, the sub criticality and the shielding of ionizing radiation has to be demonstrated by the applicant and verified by the licensing authority. In particular accidents, incidents and disasters have to be considered in the facility and cask design. This includes mechanical impacts onto the cask, internal and external fire, and environmental effects like wind, rain, snowfall, flood, earthquakes and landslides. In addition civilizatoric influences like plane crashes and explosions have to be taken into account. In all mentioned cases the secure confinement of the radioactive materials has to be ensured. On-site storage facilities have to consider the

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.

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

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

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

Energy Technology Data Exchange (ETDEWEB)

Venhart, M., E-mail: martin.venhart@savba.sk [Institute of Physics, Slovak Academy of Sciences, SK-84511 Bratislava (Slovakia); Wood, J.L. [Department of Physics, Georgia Institute of Technology, Atlanta GA 30332 (United States); Boston, A.J. [Institute of Physics, Slovak Academy of Sciences, SK-84511 Bratislava (Slovakia); Cocolios, T.E. [School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); KU Leuven, Instituut voor Kern, en Stralingsfysica, B-3001 Leuven (Belgium); Harkness-Brennan, L.J.; Herzberg, R.-D.; Joss, D.T.; Judson, D.S. [Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Kliman, J.; Matoušek, V. [Institute of Physics, Slovak Academy of Sciences, SK-84511 Bratislava (Slovakia); Motyčák, Š. [Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, SK-812 19 Bratislava (Slovakia); Page, R.D.; Patel, A. [Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Petrík, K.; Sedlák, M.; Veselský, M. [Institute of Physics, Slovak Academy of Sciences, SK-84511 Bratislava (Slovakia)

2017-03-21

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-01-01

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

Global deposition and transport efficiencies of radioactive species with respect to modelling credibility after Fukushima (Japan, 2011)

International Nuclear Information System (INIS)

Evangeliou, Nikolaos; Balkanski, Yves; Florou, Heleni; Eleftheriadis, Konstantinos; Cozic, Anne; Kritidis, Panayotis

2015-01-01

In this study we conduct a detailed comparison of the modelling response of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident with global and local observations. We use five different model versions characterized by different horizontal and vertical resolutions of the same General Circulation Model (GCM). Transport efficiencies of 137 Cs across the world are presented as an indication of the expected radioactive impact. Activity concentrations were well represented showing lower Normalized Mean Biases (NMBs) when the better resolved versions of the GCM were used. About 95% of the results using the zoom configuration over Europe (zEur) remained within a factor of 10 from the observations. Close to Japan, the model reproduced well 137 Cs concentrations using the zoom version over Asia (zAsia) showing high correlations, while more than 64% of the modelling results were found within a factor of two from the observations and more than 92% within a factor of 10. Labile and refractory rare radionuclides calculated indirectly showed larger deviations, with about 60% of the simulated concentrations within a factor of 10 from the observations. We estimate that around 23% of the released 137 Cs remained into Japan, while 76% deposited in the oceans. Around 163 TBq deposited over North America, among which 95 TBq over USA, 40 TBq over Canada and 5 TBq over Greenland). About 14 TBq deposited over Europe (mostly in the European part of Russia, Sweden and Norway) and 47 TBq over Asia (mostly in the Asian part of Russia, Philippines and South Korea), while traces were observed over Africa, Oceania and Antarctica. Since the radioactive plume followed a northward direction before its arrival to USA and then to Europe, a significant amount of about 69 TBq deposited in the Arctic, as well. These patterns of deposition are fully consistent with the most recent reports for the accident. - Highlights: • 5 versions of an Eulerian model were used to simulate the Fukushima

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

OpenAIRE

Evrard, Olivier; Chartin, Caroline; Onda, Yuichi; Patin, Jeremy; Lepage, Hugo; Lef?vre, Ir?ne; Ayrault, Sophie; Ottl?, Catherine; Bont?, Philippe

2013-01-01

Measurement of radioactive dose rates in fine sediment that has recently deposited on channel bed-sand provides a solution to address the lack of continuous river monitoring in Fukushima Prefecture after Fukushima Dai-ichi nuclear power plant (FDNPP) accident. We show that coastal rivers of Eastern Fukushima Prefecture were rapidly supplied with sediment contaminated by radionuclides originating from inland mountain ranges, and that this contaminated material was partly exported by typhoons t...

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.

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-11-30

CUORICINO was a cryogenic bolometer experiment designed to search for neutrinoless double beta decay and other rare processes, including double beta decay with two neutrinos (2vββ). The experiment was located at Laboratori Nazionali del Gran Sasso and ran for a period of about 5 years, from 2003 to 2008. The detector consisted of an array of 62 TeO₂ crystals arranged in a tower and operated at a temperature of 10 mK. Events depositing energy in the detectors, such as radioactive decays or impinging particles, produced thermal pulses in the crystals which were read out using sensitive thermistors. The experiment included 4 enriched crystals, 2 enriched with ¹³⁰Te and 2 with ¹²⁸Te, in order to aid in the measurement of the 2vββ rate. The enriched crystals contained a total of 350 g ¹³⁰Te. The 128-enriched (130-depleted) crystals were used as background monitors, so that the shared backgrounds could be subtracted from the energy spectrum of the 130- enriched crystals. Residual backgrounds in the subtracted spectrum were fit using spectra generated by Monte-Carlo simulations of natural radioactive contaminants located in and on the crystals. The 2vββ half-life was measured to be T^2v_1/2 = [9.81± 0.96(stat)± 0.49(syst)] x10²⁰ y.

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.

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

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)

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

International Nuclear Information System (INIS)

Imanaka, Tetsuji; Hayashi, Gohei; Endo, Satoru

2015-01-01

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

A survey of radioactive caesium in British soils

International Nuclear Information System (INIS)

Cawse, P.A.; Baker, S.J.

1990-08-01

The accumulation of radioactive caesium-137 in soils under permanent grassland was measured by Harwell Laboratory in 1977. The objective was to provide at selected locations in Great Britain a reference of background radioactivity in soil resulting from depositions of nuclear weapons fallout over some thirty years. Following the Chernobyl reactor accident in April 1986, the Department of the Environment requested further measurements at the reference sites in 1987 to record changes and regional differences in the amounts present in soil caused by radioactive fallout. Results from the 1987 survey generally showed the highest accumulations of Cs-137 derived from both nuclear weapons and Chernobyl fallout in western and northern regions of Great Britain, owing to the effectiveness of rainfall on scavenging of radioactivity from the atmosphere. Thus the reference sites in south-west and central Scotland had the maximum accumulation of 26kBq Cs-137/m 2 to 30cm soil depth, at Burrow Head and Rannoch; at these locations the soil concentrations attained 256Bq/kg whereas at all sites in England levels were 2 . To 30cm depth, an average soil concentration in Scotland of ∼ 100Bq/kg was derived, which is 11% of the generalised derived limit (GDL). Comparison of 1987 results with decay-corrected 1977 data showed that nine locations in England receiving negligible Chernobyl fallout had a net loss of Cs-137 by soil erosion and/or leaching over the ten-years interval. At other locations in England a minimum of 6-40% of Cs-137 to 30cm depth was Chernobyl-derived, but this increased to 50-95% in Scotland where substantial accumulations of Cs-134 were also recorded. At the two peat sites in north-east Scotland the accumulated deposition of Cs-137 in 1987 was two and five-fold greater than in 1977. In peatland vegetation the concentrations of Cs-137 followed the order sphagnum mosses > heather > g

Research on the reliability of measurement of natural radioactive nuclide concentration of U-238

Energy Technology Data Exchange (ETDEWEB)

Cha, Seok Ki; Kim, Gee Hyun [Dept. of Nuclear engineering, Univ. of SeJong, Seoul (Korea, Republic of); Joo, Sun Dong; Lee, Hoon [KoFONS, Seongnam (Korea, Republic of)

2016-12-15

Naturally occurred radioactive materials (NORM) can be found all around us and people are exposed to this no matter what they do or where they live. In this study, two indirect measurement methods of NORM U-238 has been reviewed; one that has used HPGe on the basis of the maintenance, and the other is disequilibrium theory of radioactive equilibrium relationships of mother and daughter nuclide at Decay-chain of NORM U-238. For this review, complicated pre-processing process (Breaking->Fusion->Chromatography->Electron deposit) has been used , and then carried out a comparative research with direct measurement method that makes use of and measures Alpha spectrometer. Through the experiment as above, we could infer the daughter nuclide whose radioactive equilibrium has been maintained with U-238. Therefore, we could find out that the daughter nuclide suitable to be applied to Gamma indirect measurement method was Th-234. Due to Pearson Correlation statistics, we could find out the reliability of the result value that has been analyzed by using Th-234.

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

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

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

Using of natural radioactivity for determination of phosphorus content in phosphate rocks, apatites and superphosphates

Energy Technology Data Exchange (ETDEWEB)

Magas, S; Kasprzak, K S; Gorski, Z [Politechnika Poznanska (Poland). Inst. Chemii Podstawowej

1980-01-01

A quick radiometric method of determination of phosphorus content in natural phosphate rocks, apatites and phosphorus fertilizers, obtained from them has been developed on the basis of uranium and the products of its radioactive decay contained in these materials. The uranium content in these materials amounts to 0.01/0.02%, and is for a given deposit proportional to the phosphorus content. The method is well fitted for laboratory quick determination of phosphorus content in raw-materials and products in factories producing phosphorus fertilizers and makes possible the automation of process and proportioning of sulphuric acid in production of superphosphates.

Method of determining paper-deposited materials, eg. lead, by their reaction with radioactive krypton

International Nuclear Information System (INIS)

Tolgyessy, J.; Pruzinec, J.

1976-01-01

The invention claims a method of determining substances on a paper carrier based on the substance reaction with 85 Kr gas and the measurement of radioactivity of the kryptonate formed. Lead is shown as an example. Different amounts of lead acetate were deposited on Whatman 2 chromatographic paper as was an unknown sample of Pb salt. The paper was exposed to a 2.5 mCi 85 Kr atmosphere for 48 hours. The activity of the individual spots was then measured, a calibration curve established and the amount of lead in the analyzed sample read-out. (Ha)

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)

Environmental radioactivity 1996

International Nuclear Information System (INIS)

1997-01-01

Environmental Radioactivity in New Zealand and Rarotonga : annual report 1996 was published in May this year. The 1996 environmental radioactivity monitoring programme included, as usual, measurements in New Zealand and the Cook Islands of atmospheric, deposited and dairy product radioactivity. The environment in the New Zealand and Cook Island regions has now virtually returned to the situation in the 'pre-nuclear' era. The contination of monitoring, although at a reduced level of intensity, is basically to ensure that any change from the present state, due to any source of radioactivity does not go undetected or unquestioned. (author)

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.

Complete decay of radionuclides: Implications for low-level waste disposal in municipal landfills

International Nuclear Information System (INIS)

Meck, R.A.

1996-01-01

The time required for the complete decay of a radioactive source can be quantified by specifying an acceptable probability and using an original derivation. The physical phenomenon of complete decay may be used as the technical basis to change regulations and permit, with public acceptance, the inexpensive disposal of short half-lived radioactive waste into municipal landfills. Current regulations require isolation of trash form the biosphere for 30 years during the post-closure control period for municipal landfills. Thirty years is sufficient time for complete decay of significant quantities of short-lived radionuclides, and there is a large decay capacity in the nation's landfills. As the major generators of low-level radioactive waste with relatively short half-lives, the academic, medical, and research communities likely would benefit most from such regulatory relief. Disposal of such waste is prohibited or costly. The waste must be specially packaged, stored, transported, and disposed in designated repositories. Regulatory relief can be initiated by citizens since the Administrative Procedures Act gives citizens the right to petition for regulatory change. 10 refs., 2 tabs

Underground storage of radioactive wastes

International Nuclear Information System (INIS)

Dietz, D.N.

1977-01-01

An introductory survey of the underground disposal of radioactive wastes is given. Attention is paid to various types of radioactive wastes varying from low to highly active materials, as well as mining techniques and salt deposits

Contribution to the study of tracheobronchial and pulmonary deposits in 52 subjects after inhalation of radioactive particles

International Nuclear Information System (INIS)

Lange, Pierre.

1980-03-01

Particle deposits in the bronchopulmonary system can lead to three main types of disorder: pneumoconioses, bronchial cancers and most chronic bronchopulmonary diseases. The study of deposition is useful for the prevention, diagnosis and treatment of these illnesses. The air-borne contaminants laid down are cleared by different mechanisms corresponding roughly to distinct anatomical regions. Short-term clearance, known as tracheobronchial (TB) takes place in a few hours, while long-term clearance from the deep lung is much slower: according to the International Radiological Protection Commission, 60% of particles deposited in the bronchiolo-alveolar region take more than 500 days to eliminate. It is useful therefore to known in what proportions the particles are fixed in the tracheobronchial region and on the deep lung. This was the purpose of the present work. The distribution of the deposit between these two regions was measured in 52 subjects having breathed in radioactive particles (indium 111). A functional respiratory study was conducted at the same time to find out whether the two sets of experimental data are related in any way [fr

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

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.

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

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.

[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.

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

Energy Technology Data Exchange (ETDEWEB)

Freitas, Victor Goncalves Gloria

2016-07-01

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

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.

Exogenous deposits

International Nuclear Information System (INIS)

Khasanov, A.Kh.

1988-01-01

Exogenous deposits forming as a result of complex exogenous processes, passed under the influence of outside forces on the Earth surface. To them relate physical and chemical weathering, decomposition and decay of mineral masses, redistribution and transportation of material, forming and deposit of new minerals and ores steady on the earth surface conditions

Possibility of Radioactive and Toxic WasteDisposal in a Rock Ssalt Deposits in Slovakia Combining Wells and Cavities

Directory of Open Access Journals (Sweden)

Škvareková Erika

2004-09-01

Full Text Available Disposal of radioactive and toxic waste in rock salt can be performed in two ways – disposal in the salt mine repository or disposal in the deep wells connected with salt cavity. Presented article deals with the option of the disposal in a salt cavity at medium depths. The article also cover partially salt deposits in Slovakia and their potential suitability for waste disposal..

The model of atmospheric diffusion and deposition adopted for the German reactor risk study (phase A)

International Nuclear Information System (INIS)

Huebschmann, W.G.; Vogt, S.

1980-01-01

The consequence model of the German reactor risk study comprises the release of radioactivity and thermal energy from the containment, the atmospheric diffusion, and the deposition of activity on the ground, the calculation of dose equivalents induced via the main exposure pathways, and the calculation of early and late health effects to the population, taking into account emergency actions for the protection of the public. The following exposure pathways are included in the model: external irradiation from the passing cloud and from the activity deposited on the ground, inhalation of the cloud activity and of resuspended material, and ingestion of contaminated food. Account is taken of the following effects: building wake, plume rise to thermal energy release, dynamic change of diffusion parameters, and plume depletion due to radioactive decay, dry and wet deposition. The calculations are performed for 115 weather sequences with starting times evenly distributed over one year. It is shown that such a choice of weather sequences reflects the total variety of meteorological situations, including precipitation, in a statistically adequate way. The area of the Federal Republic of Germany is divided into four meteorological site-regions, each with typical meteorological characteristics. Each power reactor site is assigned to one of the meteorological site-regions

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.

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.)

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

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.

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.

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

Investigation on radioactivity of deposition

International Nuclear Information System (INIS)

Vaas, L.H.; Smetsers, R.C.G.M.; Mattern, F.C.M.; Drost, R.M.S. van; Ockhuizen, A.; Glastra, P.; Koolwijk, A.C.

1990-04-01

This report of the Dutch National Institute of Public Health and Environmental Protection (RIVM) summarizes the results of measurements of radionuclides deposited in the Netherlands in 1988. The samples of deposition were taken at Bilthoven, located near the center of the country. In 1988 measurements were carried out to determine the activities of γ-emitters, where 7 Be, 40 K, 134 Cs and 137 Cs were identified, and those of 3 H, 210 Pb and 210 Po. Also the gross α-, gross β- and gross γ-activities were determined. (author). 10 refs.; 7 figs.; 6 tabs

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

Energy Technology Data Exchange (ETDEWEB)

Bergman, R

1995-12-01

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

An automated system for selective fission product separations; decays of 113-115Pd

International Nuclear Information System (INIS)

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

1981-01-01

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

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.

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.

Sampling methods for pasture, soil and deposition for radioactivity emergency preparedness in the Nordic countries

International Nuclear Information System (INIS)

Isaksson, M.

2002-01-01

The aim of this work was to compare sampling techniques for pasture, soil and deposition, planned for radioactivity surveillance in emergency situations in the Nordic countries. The basis of the survey was a questionnaire, sent to radiation protection authorities and laboratories. Sampling of pasture is performed with a cutting height between 1 and 5 cm above the ground from an area of about 1 m 2 . The sampling plots are usually randomly positioned. Soil samples, 3 to 20 cores in various patterns, are generally taken by a corer of varying diameter. For deposition sampling, precipitation collectors of different sizes are used. When comparing results, the differences between laboratories should be borne in mind so that proper corrections can be made. It is, however, important to consider that, especially in an emergency situation, the use of standardised methods may worsen the results if these methods are not part of the daily work. (orig.)

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.)

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)

Natural Radioactivity in Abu-Tartor Phosphate Deposits and the Surrounding Region, New Valley, Egypt

International Nuclear Information System (INIS)

Khater, A.E.; Higgy, R.H.; Pimpl, M.

1999-01-01

Abu-Tartor phosphate mine. New Valley district, is one of the biggest phosphate mines in Egypt which will start full production soon. The planned ore rocks (24.8%P 2 O 5 ) annual production is 4 million tons. The aim of this study is to estimate the natural radioactivity levels in Abu-Tartor phosphate deposits and the surrounding region. The environmental radioactivity levels in the surrounding region will be considered as pre-operational levels which are essential to determine the radiological impacts of phosphate mining later on. Phosphate samples (ore rocks, wet rocks and beneficiation wastes) and environmental samples (soil, water and plant)were collected. The specific activities of Ra-226 (U-238) series, Th-232 series and K-40 were measured using gamma-ray spectrometry based on Hyper pure Germanium detectors. The specific activities of uranium isotopes (U-238, U-235 and U-234) were measured using alpha spectrometry based on surface barrier detectors after radiochemical separation. The specific activity of Pb-210 was measured using low background proportional gas counting system after radiochemical separation . The results were discussed and compared with national and international values

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-10-26

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

Handling of natural occurring radioactive deposits in the oil and gas industry in Norway, United Kingdom and the Netherlands

International Nuclear Information System (INIS)

Lysebo, I.; Tufto, P.

1999-03-01

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

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.

Genetic effects from internally deposited radionuclides

International Nuclear Information System (INIS)

Anon.

1987-01-01

It was learned in the late 1920's that ionizing radiation could produce genetic effects such as gene mutations and chromosome aberrations. However, at least until 1945, the focus on interest in radiation protection was primarily on somatic effects manifested in the individual exposed. Studies of the genetic effects of radiation using drosophila, however, refocused attention on effects transmitted to the exposed individuals offspring and concern over fallout in the 1950's resulted in efforts to estimate the genetic effects from exposure of human populations to internally deposited radionuclides. No human populations have been identified with burdens of internally deposited radioactive materials which have been shown to produce evidence of transmissible genetic damage. As a result, the research approach has been one in which macromolecular, cellular, and whole animal genetic studies have been combined to estimate genetic effects on humans following the deposition of radioactive materials in the body. The purpose of this report is to update the information available from animal and cellular experiments that relates genetic effects to deposited activity and dose from internally deposited radioactive materials

Radioactivity in fossils at the Hagerman Fossil Beds National Monument.

Science.gov (United States)

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

2008-08-01

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

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)

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

Energy Technology Data Exchange (ETDEWEB)

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

1990-01-01

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

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

International Nuclear Information System (INIS)

Dillman, L.T.

1980-01-01

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

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

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)

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.

Estimation of alpha radioactivity in some fertilizers and plants

International Nuclear Information System (INIS)

Nain, Mahabir; Chauhan, Pooja; Chauhan, R.P.; Chakarvarti, S.K.

2012-01-01

The uptake of radio nuclides 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 some plants. Uranium and its decay products present in soil enter the plants through roots and get distributed in various parts of the 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 the variation in alpha radioactivity of the leaves of some plants was measured using plastic track detectors LR-115 Type-II manufactured by Kodak. The healthy leaves from different samples of plants at regular interval of were plucked, dried and then sandwiched between two plastic track detectors each of same size (1 cm x 1 cm) by wrapping a cello tape tightly to record the tracks for alpha radiations emitted from both upper and bottom faces of the leaves The radon exhalation rates in different fertilizer samples have also been measured using Canister Technique. At the end of exposure time, the detectors were removed and subjected to a chemical etching process. The detectors were washed, dried and after that, the tracks caused by alpha radiations were counted using an optical Olympus microscope. Measurement of track densities (track cm -2 day -1 ) shows a variation on the upper face and the bottom face of the leaves for the plants. The variation in track density has also been observed with use of different fertilizers with some higher levels in phosphate fertilizers compared with other cases under study. (author)

Acceptance criteria for radioactive waste deposition

International Nuclear Information System (INIS)

Rzyski, B.M.

1989-01-01

The disposal of low-and intermediate level radioactive waste in either shallow ground or rock cavities must be subjected to special guidelines which are used by national authorities and implementing bodies when establishing and regulating respositories. These informations are given by the acceptance criteria and will depend on specific site conditions and optmized procedures. (author) [pt

Measuring the scintillation decay time for different energy deposited by γ-rays and neutrons in a Cs{sub 2}LiYCl{sub 6}:Ce{sup 3+} detector

Energy Technology Data Exchange (ETDEWEB)

Wen, Xianfei, E-mail: wenxianfei@ufl.edu; Enqvist, Andreas

2017-05-01

In nuclear safeguards and homeland security applications, it is greatly beneficial to simultaneously detect γ-rays, thermal neutrons, and fast neutrons using a single detector with reasonable pulse shape discrimination capability, energy resolution comparable with or even better than NaI(Tl) detectors, and high detection efficiency. Cs{sub 2}LiYCl{sub 6}:Ce{sup 3+}(CLYC) scintillation detectors have been proven to be one promising candidate to meet these requirements. In this work, the decay time and fraction of each scintillation component for different energy deposition and incident particle type (γ-ray, thermal neutron, and fast neutron) were investigated based on fitting the PMT anode output with exponential functions. For γ-rays, four components were determined with ultrafast decay time of less than one nanosecond and slow time in the order of magnitude of microsecond. It was found that the dependence on the energy deposited by γ-rays of the fraction as well as the decay time of the three slow components was small. However, significant dependence was observed for the ultrafast component. Two or three components were determined for thermal neutrons and fast neutrons without observing a component with fast decay time. To verify the approach used it was first applied to scintillation pulses induced by γ-rays in a NaI(Tl) detector. The results were consistent with well-known data already published in the literature.

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)

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

Method and apparatus for removing radioactive gases from a nuclear reactor

International Nuclear Information System (INIS)

Frumerman, R.; Brown, W.W.

1975-01-01

A description is given of a method for removing radioactive gases from a nuclear reactor including the steps of draining coolant from a nuclear reactor to a level just below the coolant inlet and outlet nozzles to form a vapor space and then charging the space with an inert gas, circulating coolant through the reactor to assist the release of radioactive gases from the coolant into the vapor space, withdrawing the radioactive gases from the vapor space by a vacuum pump which then condenses and separates water from gases carried forward by the vacuum pump, discharging the water to a storage tank and supplying the separated gases to a gas compressor which pumps the gases to gas decay tanks. After the gases in the decay tanks lose their radioactive characteristics, the gases may be discharged to the atmosphere or returned to the reactor for further use

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

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.

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

Natural radioactivity of Loire river sediments: relations with the lithology

International Nuclear Information System (INIS)

Patryl, L.

2000-01-01

This study has been carried out on request of the Loire-Bretagne water agency by the Laboratory of geology of Tours univ. (EA2100 GeEAC) in collaboration with CEA-Le Ripault. The main objective was the study of the nature and distribution of natural radioactivity in the Loire river alluvial deposits, its origin in the rocks of the surrounding basins and its links with the alluvial petrography. The radioactive flux linked with the sediments of the bottom of the river has been also determined. The Loire river and its main affluents have been the object of radiological and petrographic analyses (grain size, sands and clays mineralogy, organic matter content). The average radioactivities of 40 K, 238 U and 228 Ac in the alluvial deposits are 934.3 ± 164.7 Bq.kg -1 , 50.6 ± 30.8 Bq.kg -1 and 28.8 ± 18.1 Bq.kg -1 , respectively. The average radioactivity of 238 U, 228 Ac and their daughter products is statistically higher in Loire superieure (Massif Central mounts) than in Loire moyenne (Paris basin). The activities of 238 U and 228 Ac are mainly influenced by the grain size of the alluvial deposits and by the mineralogical composition of the sand fraction. The alluvial deposits are mainly sandy and the coarse fraction is the most abundant. The primary radioactivity is carried by the few zircons of the sediments. The activity of the uranium and thorium families increase with the feldspars content. The fixation of radioactivity seems to be linked with the presence of clay minerals inside the weathered feldspar grains which are abundant in the sands. The radioactivity of the Loire river alluvial deposits shows no important changes with respect to the substratums because of a smoothing due to the predominance of longitudinal fluxes with respect to the lateral ones. The impact of an old uranium mine on the alluvial deposits of the Besbre river is detectable along about a tenth of km s downstream only. Because of the strong variations of radioactivity with granularity, a

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)

Forensic microanalysis of Manhattan Project legacy radioactive wastes in St. Louis, MO.

Science.gov (United States)

Kaltofen, Marco; Alvarez, Robert; Hixson, Lucas W

2018-06-01

Radioactive particulate matter (RPM) in St Louis, MO, area surface soils, house dusts and sediments was examined by scanning electron microscopy with energy dispersive X-ray analysis. Analyses found RPM containing 238 U and decay products (up to 46 wt%), and a distinct second form of RPM containing 230 Th and decay products (up to 15.6 wt%). The SEM-EDS analyses found similar RPM in Manhattan Project-era radioactive wastes and indoor dusts in surrounding homes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Correlation of gravestone decay and air quality 1960-2010

Science.gov (United States)

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

2017-03-01

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

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.

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

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)

Role of shell corrections in the phenomenon of cluster radioactivity

Science.gov (United States)

Kaur, Mandeep; Singh, Bir Bikram; Sharma, Manoj K.

2018-05-01

The detailed investigation has been carried out to explore the role of shell corrections in the decay of various radioactive parent nuclei in trans-lead region, specifically, which lead to doubly magic 208Pb daughter nucleus through emission of clusters such as 14C, 18,20O, 22,24,26Ne, 28,30 Mg and 34S i. The fragmentation potential comprises of binding energies (BE), Coulomb potential (Vc) and nuclear or proximity potential (VP) of the decaying fragments (or clusters). It is relevant to mention here that the contributions of VLDM (T=0) and δU (T=0) in the BE have been analysed within the Strutinsky renormanlization procedure. In the framework of quantum mechanical fragmentation theory (QMFT), we have investigated the above mentioned cluster decays with and without inclusion of shell corrections in the fragmentation potential for spherical as well as non-compact oriented nuclei. We find that the experimentally observed clusters 14C, 18,20O, 22,24,26 Ne, 28,30 Mg and 34Si having doubly magic 208 Pb daughter nucleus are not strongly minimized, they do so only after the inclusion of shell corrections in the fragmentation potential. The nuclear structure information carried by the shell corrections have been explored via these calculations, within the collective clusterisation process of QMFT, in the study of ground state decay of radioactive nuclei. The role of different parts of fragmentation potentials such as VLDM, δU, Vc and Vp is dually analysed for better understanding of radioactive cluster decay.

Water pollution by radioactive materials

International Nuclear Information System (INIS)

Bovard, P.

1976-01-01

Within the frame of the definition of a philosophy and politics of waste disposal and site selection, an analysis is made of the main elements of radioactive pollution of waters: sources of radioactivity, radionuclides classified according to their hazard, waste processing, disposal criteria and transfer processes in the compartments: water, suspended sediments, deposited sediments, biomass [fr

A natural analogy of high-level radioactive waste disposal. A case study of the groundwater from a uranium deposit

International Nuclear Information System (INIS)

Li Xinchun; Zhang Zhanshi; Ouyang Hegen

2009-01-01

Radionuclide migration is one of the key effects of high-level radioactive waste disposal. The groundwater is considered the primary means of radionuclide migration. Uranium and rare earth element(REE) in groundwater from a uranium deposit were used as a chemical analogue to study the migration of radionuclides. The results show that REE and its chemical analogue might migrate under the uranium deposit condition, but uranium and its analogue do not migrate obviously. According to the results, we might infer that after the groundwater penetrates into the HLW repository, REE and its analogue might migrate with the groundwater; but there is no obvious migration of uranium and its chemical analogue,which might increase our confidence to built a safe HLW repository. (authors)

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

Radioactive waste today - an asset tomorrow

Energy Technology Data Exchange (ETDEWEB)

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

2014-07-01

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

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

On the influence of infiltration of radioactive beds by flushing fluid on γ-ray logging results obtained from uranium deposit No. 387

International Nuclear Information System (INIS)

Ren Bingxiang; Zhang Yuechun; Ai Shuyi.

1985-01-01

A large number of field logging data obtained during the course of exploration on uranium deposit No. 387 show when the radioactive beds are encountered by drill holes and the drilling continues the γ-ray intensity decreases. It is considered that the escape of emanation does not considerably influence the logging results. Therefore, based upon the experiment of immerseing ores in fluid and geological and hydrogeological data of the deposit, the hypotheses that the γ-ray intensity in drill hole is closely related with the infiltration of flushing fluid is suggested. The ore bodies are strictly controlled by faults. Most of the uranium and thorium are absorbed by pelitic-carbonaceous cements or fill the porous spaces in structural breccia and cataclasite. They are easy to dissolve in water. Moreover, the ore-bearing structures are the unique water aquifers which is under pressure. As the level of flushing fluid is higher than the pressure head so it continuously pours into the ore-bearing beds, resulting in the infiltration of U and Ra. Consequently, the radioactivity detected is low

Fertilizer consumption in Norway and the natural radioactivity in the raw materials

International Nuclear Information System (INIS)

Ormberg, S.

1988-01-01

The principal radionuclides contained in fertilizers are various members of the uranium and thorium decay series and K-40. The radionuclides from the uranium and thorium decay series originate mainly from the phosphorus component of fertilizers, whereas the K-40 originates from the potash component. This paper discusses the radioactivity content of fertilizers used in the Norwegian market and the radioactivity uptake through crops from the use of fertilizers in Norway. It is emphasized that the natural balance of potash in the environment is very little influenced by fertilizers

Analytic solutions to linear, time-dependent fission product deposition models for isothermal laminar, slug, or multiregion flow conditions

International Nuclear Information System (INIS)

Durkee, J.W. Jr.

1983-01-01

The time-dependent convective-diffusion equation with radioactive decay is solved analytically in axisymmetric cylindrical geometry for laminar and slug velocity profiles under isothermal conditions. Concentration dependent diffusion is neglected. The laminar flow solution is derived using the method of separation of variables and Frobenius' technique for constructing a series expansion about a regular singular point. The slug flow multiregion solution is obtained using the method of separation of variables. The Davidon Variable Metric Minimization algorithm is used to compute the coupling coefficients. These solutions, which describe the transport of fission products in a flowing stream, are then used to determine the concentration of radioactive material deposited on a conduit wall using a standard mass transfer model. Fission product deposition measurements for five diffusion tubes in a Fort St. Vrain High-Temperature Gas-Cooled reactor plateout probe are analyzed. Using single region slug and laminar models, the wall mass transfer coefficients, diffusion coefficients, and inlet concentrations are determined using least squares analysis. The diffusion coefficients and inlet concentrations are consistent between tubes. The derived diffusion coefficients and wall mass transfer coefficients are in relative agreement with known literature values

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

Radioactivity monitoring in Ireland of air, deposition and water 1982-1987

International Nuclear Information System (INIS)

Sequeira, S.; McRandall, M.; Hayden, E.; Cunningham, J.D.

1989-02-01

The Nuclear Energy Board in conjunction with the Meteorological Service undertakes an environmental radioactivity monitoring programme with the objective of determining levels of artificially produced radioactivity in the Irish environment. The levels of radioactivity in airbourne dust, total fallout samples, precipitation and drinking water are presented for 1982, 1983, 1984, 1985, 1986 and 1987

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

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

Science.gov (United States)

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

2014-05-01

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

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)

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

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

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

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

Treatment and disposal of radioactive wastes from nuclear power plants. Program for encapsulation, deep geologic deposition and research, development and demonstration

International Nuclear Information System (INIS)

1995-09-01

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

Decommissioning Strategies Selection for Facilities Using Radioactive Material

International Nuclear Information System (INIS)

Husen Zamroni; Jaka Rachmadetin

2008-01-01

The facilities using radioactive material that have been stopped operation will require some form of the decommissioning for public and environment safety. The approaches are identified by three decommissioning strategies: immediate dismantling, deferred dismantling and entombment. If a facility undergoes immediate dismantling, most radio nuclides will have no such sufficient time to decay and therefore this strategy may not provide reduction in the worker exposure. A facility that undergoes deferred dismantling may advantage from the radioactive decay of residual radio nuclides during the long term storage period and entombment could be a viable option for other nuclear facilities containing only short lived or limited concentrations of long lived radionuclides. Mostly, only two types of the decommissioning used to be done in the world, immediate and deferred dismantling. (author)

Folding model analysis of alpha radioactivity

International Nuclear Information System (INIS)

Basu, D N

2003-01-01

Radioactive decay of nuclei via emission of α-particles has been studied theoretically in the framework of a superasymmetric fission model using the double folding (DF) procedure for obtaining the α-nucleus interaction potential. The DF nuclear potential has been obtained by folding in the density distribution functions of the α nucleus and the daughter nucleus with a realistic effective interaction. The M3Y effective interaction has been used for calculating the nuclear interaction potential which has been supplemented by a zero-range pseudo-potential for exchange along with the density dependence. The nuclear microscopic α-nucleus potential thus obtained has been used along with the Coulomb interaction potential to calculate the action integral within the WKB approximation. This subsequently yields calculations for the half-lives of α decays of nuclei. The density dependence and the exchange effects have not been found to be very significant. These calculations provide reasonable estimates for the lifetimes of α-radioactivity of nuclei

Method of decontaminating radioactive-contaminated instruments

Energy Technology Data Exchange (ETDEWEB)

Urata, M; Fujii, M; Kitaguchi, H

1982-03-29

Purpose: To enable safety processing of liquid wastes by recovering radioactive metal ions remaining in the electrolytes after the decontamination procedure thereby decreasing the radioactivity. Method: In a decontamination tank containing electrolytes consisting of diluted hydrochloric acid and diluted sulfuric acid, are provided a radioactive contaminated instrument connected to an anode and a collector electrode made of stainless steel connected to a cathode respectively. Upon applying electrical current, the portion of the mother material to be decontaminated is polished electrolytically into metal ions and they are deposited as metal on the collection electrode. After completion of the decontamination, an ultrasonic wave generator is operated to strip and remove the oxide films. Thereafter, the anode is replaced with the carbon electrode and electrical current is supplied continuously, whereby the remaining metal ions are deposited and recovered as the metal on the collection electrode.

Amount, disposal and relative toxicity of long-lived fission products and actinides in the radioactive wastes of the nuclear fuel cycles

International Nuclear Information System (INIS)

Haug, H.O.

1975-11-01

A review is presented on the magnitude of the long-term problems of radioactive wastes from the nuclear power industry of the FRG (and Western Europe). The production of long-lived fission products and actinides has been calculated for several fuel types of the uranium-plutonium and thorium-uranium fuel cycles and related to a prediction of the development and share of LWR, FBR and HTGR. The quantities and concentrations of actinides, the radioactivity and relative toxicity index of the wastes of reprocessing (and fuel refabrication) and their changes by radioactive decay are presented. The radiotoxicity of the nuclide inventory of the solidified high-level wastes have been compared with naturally occuring uranium ores. On the long term (>10 3 years) the radiotoxicity level of the total area of the final repository in deep geological formation does not result in a significantly higher radiotoxicity level than an uranium ore deposit of low uranium content. Also discussed have been the chemical separation of the actinides from high-level wastes and recycling in fission reactors. (orig.) [de

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

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)

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.)

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.)

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

CERN Multimedia

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

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

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

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

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

Chernobyl accident. The ground deposition of radionuclides in Padana plain and in Alps Valleys and the radioactive contamination of the Como lake

Energy Technology Data Exchange (ETDEWEB)

Capra, D; Facchini, U; Gianelle, V; Ravasini, G; Ravera, O; Volta, L; Pizzola, A; Bacci, P

1988-01-01

The radioactive cloud released during the Chernobyl accident reached the Padana plain and Lombardy in the night of April 30th 1986; the cloud remained in the northern Italian skies for a few days and then disappeared either dispersed by winds and washed by rains. The evidence in atmosphere of radionuclides as Tellurium, Iodine, Cesium, was promptly observed. The intense rain, in first week of may, washed the radioactivity and fall-out contamined the land, soil, grass. The present work concerns the overall contamination of the Northern Italy territory and in particular the radioactive fall-out in the Lakes region. Samples of soil have been measured at the gamma spectroscope; a correlation is found between the radionuclides concentration in soil samples and the rain intensity, when appropriate deposition models are considered. A number of measurements has been done on the Como'lake ecosystem: sediments, plankton, fishes and the overall fall-out in the area has been investigated.

Radioactivity in New Zealand meat products

Energy Technology Data Exchange (ETDEWEB)

NONE

1986-07-01

Full text: New Zealand has no nuclear power programme of radioactive waste disposal programme. The only artificial radioactivity detectable in the New Zealand environment is global fallout from nuclear weapons tests conducted mainly in the northern hemisphere before 1964. This fallout in New Zealand is currently at its lowest level since environmental monitoring began in 1960. The total beta activity deposited in rain during 1985, for example, averaged 76 MBQ/km{sup 2}, with most of that being due to naturally occurring radionuclides, principally lead-210/Bismuth-210. Levels of artificial radioactivity in New Zealand dairy products reflect this very low deposition rate. During 1985, for example, Strontium-90 and Caesium-137 levels in cow's milk averaged 0.035 BG/GCA and 0.27BQ/QK respectively. Those levels were similar to, or less than, levels reported in northern hemisphere countries during 1985. No change in environmental contamination levels has been recorded in New Zealand during 1985. The very low deposition rate and milk contamination levels indicate that fallout contamination levels generally are insignificant in New Zealand and monitoring of other foodstuffs such as meat products is not warranted. (author)

Radioactivity in New Zealand meat products

International Nuclear Information System (INIS)

1986-01-01

Full text: New Zealand has no nuclear power programme of radioactive waste disposal programme. The only artificial radioactivity detectable in the New Zealand environment is global fallout from nuclear weapons tests conducted mainly in the northern hemisphere before 1964. This fallout in New Zealand is currently at its lowest level since environmental monitoring began in 1960. The total beta activity deposited in rain during 1985, for example, averaged 76 MBQ/km 2 , with most of that being due to naturally occurring radionuclides, principally lead-210/Bismuth-210. Levels of artificial radioactivity in New Zealand dairy products reflect this very low deposition rate. During 1985, for example, Strontium-90 and Caesium-137 levels in cow's milk averaged 0.035 BG/GCA and 0.27BQ/QK respectively. Those levels were similar to, or less than, levels reported in northern hemisphere countries during 1985. No change in environmental contamination levels has been recorded in New Zealand during 1985. The very low deposition rate and milk contamination levels indicate that fallout contamination levels generally are insignificant in New Zealand and monitoring of other foodstuffs such as meat products is not warranted. (author)

Reconnaissance for radioactive materials in northeastern United States during 1952

Science.gov (United States)

McKeown, Francis A.; Klemic, Harry

1953-01-01

Reconnaissance for radioactive materials was made in parts of Maine, New York, New Jersey, and Pennsylvania. The primary objective was to examine the iron ore deposits and associated rocks in the Adirondack Mountains of New York and the Highlands of New Jersey. In addition, several deposits known or reported to contain radioactive minerals were examined to delimit their extent. Most of the deposits examined are not significant as possible sources of radioactive elements and the data pertaining to them are summarized in table form. Deposits that do warrant more description than can be given in table form are: Benson Mines, St. Lawrence County, N. Y.; Rutgers mine, Clinton County, N. Y.; Mineville Mines, Essex County, N. Y.l Canfield phosphate mine, Morris County, N. J.; Mullgan quarry, Hunterdon County, N. J.; and the Chestnut Hill-Marble Mountain area, Pennsylvania and New Jersey. The Old Bed in the Mineville district is the only deposit that may be economically significant. Apatite from Old Bed ore contains as much as 4.9 percent total rare earth. 0.04 percent thorium, and 0.018 percent uranium. Magnetite ore at the Rutgers mine contains radioactive zircon and apatite. Radioactivity measurements of outcrops and dump material show that the ore contains from 0.005 to 0.010 percent equivalent uranium. One sample of lean magnetite ore contains 0.006 percent equivalent uranium. Garnet-rich zones in the Benson Mines magnetite deposit contain as much as 0.017 equivalent uranium. Most of the rock and ore, however, contains about 0.005 percent equivalent uranium. Available data indicate that the garnet-rich zones are enriched in radioactive allanite. A shear zone in the Kittatinny limestone of Cambrian age at the Mulligan quarry contains uraniferous material. Radioactivity anomalies elsewhere in the quarry and in adjacent fields indicate that there may be other uraniferous shear zones. Assays of samples and measurements of outcrop radioactivity indicate that the uranium

Contribution to Radioactive Waste Management in Croatia

International Nuclear Information System (INIS)

Hudec, M.; Frgic, L.; Sunjerga, S.

2002-01-01

The problem of dangerous waste disposal in Croatia is not more only technical problem; it grew over to political one of the first degree. Nobody likes to have the repository in own courtyard. Some five hundred institutions and factories produce in Croatia low, intermediate or high level radioactive waste. Till now all the dangerous waste is keeping in basements of the institute Rudjer Boskovic in Zagreb, just one kilometre form the city centre. This temporary solution is working fore some fifty years, but cannot be conserved forever. In the paper are presented some of the solutions for radioactive waste deposition, known from the references. The deep, impermeable layers in Panonian area have conserved petroleum and gas under pressure of more hundred bars for few dozens millions of years. Therefore, we propose the underground deposition of radioactive waste in deep boreholes. The liquid waste can be injected in deep isolated layers. In USA and Russia, for many years such solutions are realised. In USA exist special regulations for this kind of waste management. In the paper is described the procedure of designing, execution and verification of deposition in Russia. In northern part of Croatia exist thousand boreholes with known geological data. The boreholes were executed for investigation and exploitation of oil and gas fields. This data can make good use to define safe deep layers capable to be used for repositories of liquid waste. For the high level radioactive waste we propose the deep boreholes of greater diameter, filled with containers. One borehole with 50 cm diameter and 1000 m deep can be safe deposition for c/a 50 m3 of solid high level radioactive waste. Croatia has not big quantity of waste and some boreholes can satisfy all the quantities of waste in Croatia. This is not the cheapest solution, but it can satisfy the strongest conditions of safety. (author)

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)

Assessment of natural radionuclide content in deposits from drinking water purification station and excess lifetime cancer risk due to gamma radioactivity

International Nuclear Information System (INIS)

Issa, S.A.M.; Uosif, M.A.M.; Tammam, M.; Elsaman, R.

2012-01-01

The concentrations of natural radionuclide in deposits samples taken from Thirty-six drinking water purification stations have been measured and determined using gamma-ray spectrometry system using (sodium iodide NaI (Tl) detector). Knowledge of radioactivity present in deposits of drinking water purification station enables one to assess any possible radiological hazard to humankind by the use of such materials. The natural radionuclide ( 226 Ra, 232 Th and 40 K) contents have been analyzed for the deposits samples with an aim of evaluating the radiation hazard nature. The Absorbed dose rate, The annual effective dose equivalent, Radium equivalent activities, Hazard indices (H ex and H in ), Gamma index, Excess lifetime cancer risk and Annual gonadal dose equivalent were calculated for investigated area. Results of the study could serve as an important baseline radiometric data for future epidemiological studies and monitoring initiatives in the study area.

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

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.

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.

Natural radioactivity measurements and dose calculations to the public: Case of the uranium-bearing region of Poli in Cameroon

International Nuclear Information System (INIS)

Saidou; Bochud, Francois O.; Baechler, Sebastien; Moise, Kwato Njock; Merlin, Ngachin; Froidevaux, Pascal

2011-01-01

The objective of this work is to carry out a baseline study of the uranium-bearing region of Poli in which lies the uranium deposit of Kitongo, prior to its impending exploitation. This study required sampling soil, water and foodstuffs representative of the radioactivity exposure and food consumption patterns of the population of Poli. After sampling and radioactivity measurements were taken, our results indicated that the activities of natural series in soil and water samples are low. However, high levels of 210 Po and 210 Pb in foodstuffs (vegetables) were discovered and elevated activities of 40 K were observed in some soil samples. All components of the total dose were assessed and lead to an average value of 5.2 mSv/year, slightly higher than the average worldwide value of 2.4 mSv/year. Most of this dose is attributable to the ingestion dose caused by the high levels of 210 Po and 210 Pb contained in vegetables, food items which constitute an important part of the diet in Northern Cameroon. Consequently, bringing uranium ore from underground to the surface might lead to an increased dose for the population of Poli through a higher deposition of 222 Rn decay products on leafy vegetables.

Method of decontaminating radioactive-contaminated instruments

International Nuclear Information System (INIS)

Urata, Megumu; Fujii, Masaaki; Kitaguchi, Hiroshi.

1982-01-01

Purpose: To enable safety processing of liquid wastes by recovering radioactive metal ions remaining in the electrolytes after the decontamination procedure thereby decreasing the radioactivity. Method: In a decontamination tank containing electrolytes consisting of diluted hydrochloric acid and diluted sulfuric acid, are provided a radioactive contaminated instrument connected to an anode and a collector electrode made of stainless steel connected to a cathode respectively. Upon applying electrical current, the portion of the mother material to be decontaminated is polished electrolytically into metal ions and they are deposited as metal on the collection electrode. After completion of the decontamination, an ultrasonic wave generator is operated to strip and remove the oxide films. Thereafter, the anode is replaced with the carbon electrode and electrical current is supplied continuously, whereby the remaining metal ions are deposited and recovered as the metal on the collection electrode. (Yoshino, Y.)

Predicting the radioactive contamination of the surroundings near a nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Khristova, M; Paskalev, Z

1975-01-01

Predicting the radioactive contamination requires determining the concentration of radioactive material emitted from the stack of a nuclear power plant into the air and deposited on the earth's surface. The main factors determining the degree of contamination are the distance from the stack, the wind velocity and air turbulence. Formulas are presented for predicting the amount of radioactivity as a function of the initial concentration of activity, the distance from the stack and the meteorological condition. Formulas are given for the maximum deposition of radioactive aerosols at a distance R from the stack under wet and dry condtions. 2 refs. (SJR)

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)

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.)

Reassessment of the Goiânia radioactive waste repository in Brazil using HYDRUS-1D

Directory of Open Access Journals (Sweden)

Pontedeiro Elizabeth M.

2018-06-01

Full Text Available In September 1987 an accident occurred with a cesium chloride (CsCl teletherapy source taken from a cancer therapy institute in Goiânia, Brazil. Misuse of the abandoned source caused widespread contamination of radioactive material (about 50 TBq of 137Cs in the town of Goiânia. Decontamination of affected areas did lead to about 3,500 m3 of solid radioactive wastes, which were disposed in two near-surface repositories built in concrete in 1995. This paper documents a safety assessment of one of the low-level radioactive waste deposits containing 137Cs over a time period of 600 years. Using HYDRUS-1D, we first obtained estimates of water infiltrating through the soil cover on top of the repository into and through the waste and its concrete liners and the underlying vadose zone towards groundwater. Calculations accounted for local precipitation and evapotranspiration rates, including root water uptake by the grass cover, as well as for the effects of concrete degradation on the hydraulic properties of the concrete liners. We next simulated long-term water fluxes and 137Cs transport from the repository towards groundwater. Simulations accounted for the effects of 137Cs sorption and radioactive decay on radionuclide transport from the waste to groundwater, thus permitting an evaluation of potential consequences to the environment and long-term exposure to the public. Consistent with previous assessments, our calculations indicate that very little if any radioactive material will reach the water table during the lifespan of the repository, also when accounting for preferential flow through the waste.

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.

Final report: Accelerated beta decay for disposal of fission fragment wastes

International Nuclear Information System (INIS)

Reiss, Howard R.

2000-01-01

The fundamental theory of the interaction of intense, low-frequency electromagnetic fields with certain radioactive nuclei has been fully formulated. The nuclei are of the type that exists in high-level radioactive wastes that are end products of the production of energy from nuclear fission. The basic physical mechanisms that underlie the coupling of the applied field to the nucleus have been identified. Both the basic theory and numerical predictions that stem from it support the conclusion that high-level radioactive wastes can be disposed of by substantially accelerating the rate of radioactive decay. Some old experiments on the acceleration of this type of radioactivity, with results that were not understood at the time, have been re-examined. Their interpretation is now clear, and the experiments are found to be in agreement with the theory

Bulletin of the radioactivity. No. 83. January-December, 1999

International Nuclear Information System (INIS)

2001-01-01

This report contains the result of observations by the Japan Meteorological Agency (JMA) of atmospheric and seawater radioactivity for the year 1999. The sampling, measurement methods and results of gross beta-radioactivity in precipitation, radioactivity in airborne dust, monthly mean 90 Sr concentration in airborne dust, gross beta-radioactivity in seawater, deposition of 89 Sr, 90 Sr and 137 Cs, natural background radioactivity and vertical distribution of atmospheric radioactivity are described. The results of special observations on the criticality accident at an uranium processing plant, Tokai-mura, Japan showed that gamma-ray spectrum analysis in airborne dust indicated Cs-137 ND (lower than detection limit) and I-131 ND in Sendai and Tokyo at sampling at 99/10/1. 09h-99/10/1,14h and in Tsukuba at sampling 99/09/30, 09h-99/10/01, 09h. Gross beta-radioactivity in precipitation showed 40 MBq/km 2 deposition in Hachijo-jima at sampling 99/09/30,09h-99/10/01, 09h, but no precipitation in Sendai, Akita, Tokyo and Wajima. Mean gamma-radiation dose rate in Wajima indicated 9.8 cps at monitoring 99/09/30-99/10/01,15h. (S.Y.)

AKTIS Nr. 12: To better understand radioactive aerosol deposit in order to better measure it; Radio-induced lesions: a new step towards healing; Modelling the collapse of an immersed grain column; To better model soot deposit; Towards the prediction of the leakage rate of containment enclosures

International Nuclear Information System (INIS)

Benderitter, Marc; Perales, Frederic; Monerie, Yann; Maro, Denis; Boyer, Patrick; Lemaitre, Pascal; Porcheron, Emmanuel; Depuydt, Guillaume; Masson, Olivier; Gensdarmes, Francois

2013-04-01

This publication presents the main results of researches undertaken by the IRSN in the field of radiation protection, nuclear safety and security. The topics herein addressed are: radio-induced lesions as a new step towards healing (case of injection mesenchymal stem cells for the treatment of induced severe colorectal lesions), the modelling of the collapse of an immersed grain column (to study the nuclear fuel behaviour in an accidental situation through a modelling of fluid-grain interactions), a better understanding of radioactive aerosol deposit (to study particle or aerosol deposits after radioactive releases in the atmosphere in case of accident), a better modelling of soot deposits (in case of fire), the prediction of leakage rates of containment enclosures (ageing phenomena of installations, systems and equipment, with the case of cracks due to material ageing and resulting in confinement losses which could thus be quantified)

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.

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.)

Geochemistry of radioactive elements in bituminous sands and sandstones of Permian bitumen deposits of Tatarstan (east of the Russian plate)

Science.gov (United States)

Mullakaev, A. I.; Khasanov, R. R.; Badrutdinov, O. R.; Kamaletdinov, I. R.

2018-05-01

The article investigates geochemical features of Permian (Cisuralian, Ufimian Stage and Biarmian, Kazanian Stage of the General Stratigraphic Scale of Russia) bituminous sands and sandstones located on the territory of the Volga-Ural oil and gas province (Republic of Tatarstan). Natural bitumens are extracted using thermal methods as deposits of high-viscosity oils. In the samples studied, the specific activity of natural radionuclides from the 238U (226Ra), 232Th, and 40K series was measured using gamma spectrometry. As a result of the precipitation of uranium and thorium and their subsequent decay, the accumulation of radium (226Ra and 228Ra) has been shown to occur in the bituminous substance. In the process of exploitation of bitumen-bearing rock deposits (as an oil fields) radium in the composition of a water-oil mixture can be extracted to the surface or deposited on sulfate barriers, while being concentrated on the walls of pipes and other equipment. This process requires increased attention to monitoring and inspection the environmental safety of the exploitation procedure.

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

Radioactive waste management in Brazil: a realistic view

International Nuclear Information System (INIS)

Heilbron Filho, Paulo Fernando Lavalle; Perez Guerrero, Jesus Salvador; Xavier, Ana Maria

2014-01-01

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

Radioactive waste management in Brazil: a realistic view

Energy Technology Data Exchange (ETDEWEB)

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

2014-07-01

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

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)

Environmental radioactivity in Caithness and Sutherland. Pt. 1: Food-chain model validation and the attribution of radionuclide sources to deposition

International Nuclear Information System (INIS)

Rose, C.L.; Halliwell, C.M.

1995-01-01

This study is part of a continuing programme investigating the behaviour of environmental radioactivity in the vicinity of the AEA Technology establishment at Dounreay, Caithness and Sutherland. The study aims were to assess the applicability of a National Radiological Protection Board (NRPB) food-chain model to the Caithness and Sutherland area, and to determine the contribution of different radionuclide sources to activities in measured total deposition in the same region. The NRPB model predicts the movement of radionuclides through the food-chain, and in this study was validated by comparing model outputs with measured crop data (ryegrass and clover). Five radionuclides ( 137 Cs, 90 Sr, 239+240 Pu, 238 Pu, 241 Am) were considered. The contribution of different radionuclide sources to activities in total deposition were divided into three categories: Dounreay stack inputs, sea-to-land transfer, and the combined contribution from nuclear weapons testing and Chernobyl fallout. The analyses indicated that the contribution of the Dounreay stack to total deposition was very small for the radionuclides studied. The Chernobyl accident made a large impact on the total deposition of 137 Cs in the study area, and 90 Sr deposition was also affected by this, but to a much lesser extent. The Chernobyl accident appeared to have no effect on total Pu deposition in the region. The cessation of nuclear weapons testing and the length of time since Chernobyl meant that actual 137 Cs and 90 Sr deposition as a result of weapons/Chernobyl inputs had reached a low level by the end of the study period (summer 1987). It became evident that a contribution to total deposition was being made by additional factors, thought to be local resuspension of large particles for 137 Cs, and possibly deposition of plant material for 90 Sr. For Pu, sea-to-land transfer was probably an important contributor at coastal sites. (Author)

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.)

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.)

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-07-01

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

Table of nuclear reactions and subsequent radioactive dacays induced by 14-MeV neutrons

International Nuclear Information System (INIS)

Tsukada, Kineo

1977-09-01

Compilation of the data on nuclear reactions and subsequent radioactive decays induced by 14-MeV neutrons is presented in tabular form for most of the isotopes available in nature and for some of the artificially-produced isotopes, including the following items: Nuclide (isotopic abundance), type of nuclear reaction, reaction Q-value, reaction product, type of decay, decay Q-value, half-life of reaction product, decay product, maximum reaction cross section, neutron energy for maximum cross section, reaction cross section for 14 MeV neutrons, saturated radioactivity induced by irradiation of a neutron flux of 1 n/cm 2 sec for a mol of atoms, and reference for the cross section. The mass number dependence of (n, γ), (n, 2n), (n, p), (n, d), (n, t), (n, 3 He) and (n, α) reaction cross sections for 14-MeV neutrons is given in figures to show general trends of the cross sections

Study of radio-active ions in the atmosphere

International Nuclear Information System (INIS)

Renoux, A.

1965-01-01

A comparative study is made of active, deposits of radon and thoron in suspension in the atmosphere by means of α radiation counting, using ZELENY tubes, scattering equipment, filter papers or membranes. It has been possible to show the existence of small and large ions which are negative and positive, as well as of neutral radio-active nuclei; their properties are studied. A theoretical interpretation of the results is presented. The average content of radon (using the Ra A concentration) and of Th B in the air has been determined. The radioactive equilibrium between radon and its daughter products in atmospheric air are examined. The techniques developed for active radon and thoron deposits are applied to the study of artificial radio-activity, the analyses being carried out by means of γ spectrometry. (author) [fr

Wipe sampling for characterization of noncompactable radioactive waste

International Nuclear Information System (INIS)

Barbieri, Aline E.O.; Ferreira, Robson J.; Vicente, Roberto

2009-01-01

Wipe sampling is a method of monitoring radioactive surface contamination on working area and on radioactive, non-compactable wastes, constituted of large pieces of replaced parts of equipment in nuclear and radioactive installations. In this method, sampling is executed by rubbing a disc of filter paper on the contaminated surface in such a way as to collect entirely or partially the deposited material. The target radioisotopes are subsequently measured directly on the wipe or extracted by appropriate radio analytical methods and then qualitatively and quantitatively determined. The collection factor, or the efficiency with which the material is removed from the surface and deposited on the smear, is the main source of error in quantitative measurements. The determination of the collection efficiency is the object of this communication. (author)

NRI's research on radioactive wastes

International Nuclear Information System (INIS)

Alexa, J.; Dlouhy, Z.; Kepak, F.; Kourim, V.; Napravnik, J.; Razga, J.; Ralkova, J.; Uher, E.; Vojtech, O.

1976-01-01

A survey is given (including 41 references) of work carried out at the Nuclear Research Institute. Discussed are sorption processes (a selective sorbent for 90 Sr based on BaSO 4 , etc.), sorption on inorganic ion exchangers (heteropolyacid salts, ferrocyanides for 137 Cs capture), on organic cation exchangers (separation of lanthanides), electrocoagulation. The process is described of vitrification of highly radioactive wastes, the arrest of emissions, the deposition of radioactive wastes and surface decontamination. (M.K.)

Radioactivity assessment of the waste deposited in Candonga's lake after the FundÃO Dam's collapse

Energy Technology Data Exchange (ETDEWEB)

Freire, Carolina Braccini; Cuccia, Valeria; Lameiras, Fernando Soares; Rocha, Zildete, E-mail: cbf@cdtn.br, E-mail: vc@cdtn.br, E-mail: fsl@cdtn.br, E-mail: rochaz@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Santos, Talita Oliveira, E-mail: talitaolsantos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Anatomia e Imagem; Sales, Gabriel Lopes, E-mail: gabriellopessales@hotmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Dept. de Engenharia Química

2017-07-01

The collapse of the Fundão dam on November 5{sup th} 2015 caused impacts along the hydrographic basin of Rio Doce. Renova Foundation has the mission to repair, restore and reconstruct the regions affected by this disaster. After the collapse, a huge amount of waste was deposited in Risoleta Neves Hydroelectric Power Plant’s lake (Candonga). This waste has been dredged out from the lake and deposited in a nearby pile. The use of the waste from this pile is being considered for civil construction. Samples of this waste pile were collected and they were characterized by X-rays diffraction and EDS analyses, which showed that it consists of 80% quartz, 11% hematite, 8% goethite and 1% clays, mainly kaolinite. There is also organic matter consisting of branches, roots and leaves of trees and plants. Previous radiological analyses made before the collapse showed that the radionuclide content of the waste deposited in Fundão dam was very low. However, the waste deposited in Candonga's lake has a new composition and it is important to evaluate its radioactivity assessment. The analyses results of the Candonda's waste samples will be presented and compared to the results obtained in the Fundão dam samples, before its collapse. (author)

Radioactivity assessment of the waste deposited in Candonga's lake after the FundÃO Dam's collapse

International Nuclear Information System (INIS)

Freire, Carolina Braccini; Cuccia, Valeria; Lameiras, Fernando Soares; Rocha, Zildete; Santos, Talita Oliveira; Sales, Gabriel Lopes

2017-01-01

The collapse of the Fundão dam on November 5 th 2015 caused impacts along the hydrographic basin of Rio Doce. Renova Foundation has the mission to repair, restore and reconstruct the regions affected by this disaster. After the collapse, a huge amount of waste was deposited in Risoleta Neves Hydroelectric Power Plant’s lake (Candonga). This waste has been dredged out from the lake and deposited in a nearby pile. The use of the waste from this pile is being considered for civil construction. Samples of this waste pile were collected and they were characterized by X-rays diffraction and EDS analyses, which showed that it consists of 80% quartz, 11% hematite, 8% goethite and 1% clays, mainly kaolinite. There is also organic matter consisting of branches, roots and leaves of trees and plants. Previous radiological analyses made before the collapse showed that the radionuclide content of the waste deposited in Fundão dam was very low. However, the waste deposited in Candonga's lake has a new composition and it is important to evaluate its radioactivity assessment. The analyses results of the Candonda's waste samples will be presented and compared to the results obtained in the Fundão dam samples, before its collapse. (author)

Radioactivity in groundwater along the borders of Oman and UAE

International Nuclear Information System (INIS)

Murad, A.; Alshamsi, D.; Al Shidi, F.; Al Kendi, R.; Aldahan, A.; Uppsala University, Uppsala

2014-01-01

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

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.

Deposition and interception of radionuclides. Current knowledge and future requirements

International Nuclear Information System (INIS)

1998-12-01

Following an accidental or routine release of radionuclides into the environment, a good knowledge of deposition processes is necessary in order to accurately predict the radiation dose to members of the public. In order to understand the environmental impact of released radionuclides and their transfer through the environment, including the food chain to man, there have been numerous studies on deposition of radionuclides to a range of surfaces such as bare soil, crops, forests, water bodies and urban surfaces. The RADREM committee provides a forum for liaison on UK research and monitoring in the areas of radioactive substances and radioactive waste management. RADREM has set up four sub-committees to cover issues related to radioactivity in the atmospheric, terrestrial and aquatic environments as well as those related radioactive waste management. One of the sub-committee tasks is to organise seminars and workshops on specific topics of interest. The first of these was the workshop on 'Deposition and Interception of Radionuclides: Current knowledge and future requirements' organised last year by the Ministry of Agriculture, Fisheries and Food (MAFF), acting as secretariat for the Terrestrial Environment Sub-Committee (TESC) of RADREM. The intent of this workshop was to provide an opportunity to exchange information on deposition-related aspects between representatives from various interested parties including government, regulatory bodies, industry and research organisations. Through presentations and discussions, this workshop addressed current developments in the areas of deposition and interception of radionuclides by various surfaces and served to identify areas which need further research. Papers were presented on various aspects of deposition and interception of radionuclides including deposition into grass, fruits and other crops as well as deposition into urban areas and forests

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

High-level radioactive waste isolation by incorporation in silicate rock

International Nuclear Information System (INIS)

Schwartz, L.L.; Cohen, J.J.; Lewis, A.E.; Braun, R.L.

1978-01-01

A number of technical possibilities for isolating high-level radioactive materials have been theoretically investigated at various times and places. Isolating such wastes deep underground to ensure long term removal from the biosphere is one such possibility. The present concept involves as a first step creating the necessary void space at considerable depth, say 2 to 5 km, in a very-low-permeability silicate medium such as shale. Waste in dry, calcined or vitrified form is then lowered into the void space, and the access hole or shaft sealed. Energy released by the radioactive decay raises the temperature to a point where the surrounding rock begins to melt. The waste is then dissolved in it. The extent of this melt region grows until the heat generated is balanced by conduction away from the molten zone. Resolidification then begins, and ends when the radioactive decay has progressed to the point that the temperature falls below the melting point of the rock-waste solution. Calculations are presented showing the growth and resolidification process. A nuclear explosion is one way of creating the void space. (author)

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

Science.gov (United States)

Smerajec, M.; Vaupotič, J.

2012-04-01

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

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

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)

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

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

Directory of Open Access Journals (Sweden)

Rolf Bielecki

2007-01-01

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

On the contents of some radionuclides in precipitation (deposits) of Yerevan city, Armenia

International Nuclear Information System (INIS)

Ananyan, V.; Appleby, P.; Danagulyan, A.; Nalbandyan, A.

2004-01-01

Biosphere is exposed to cosmic and α -, β -, γ -radiation of numerous radionuclides dispersed in rocks, groundwater, terrestrial water of rivers, seas and oceans, air and biota. The main components of natural radiation are 40 K, 238 U, 232 Th and radioactive products of their decay. The goal of this investigation was to determine radionuclide composition of atmospheric precipitation (deposits) of Yerevan city. For sample collection we used sedimentation method, which covers all deposits on 1 m 2: admixtures, dust and sand fractions during wind (precipitation deposits). The dish made of neutral material (50 x 50 cm) was positioned at a height 1,5 m in a selected sampling site. The bottom of the dish was underlain by filtering paper. The samples were taken monthly. After deposit evaporation and ashing at 450 degree C the deposits were weighed. Total weight of such samples made 41 g for 2000 (12 months). For measurements one sample per season was selected (totally 4 samples). Radionuclide measurements were done on a low-background gamma-spectrometer with Hp Ge semiconductor detector. The exposures of sample measurement and background made 117,34 h each. The sample was positioned close to the detector. After removal of background, radionuclide concentrations were determined. Concentrations of all isotopes of uranium family (234 Th,214 Pb, 214 Bi), except 210 Pb in sample are similar (within the limits of error), so in natural environment they stay in equilibrium. The same is relevant also to radionuclides of thorium family. Concentrations of 210 Pb are almost threefold higher, this deserving further detailed research. Among the remaining isotopes, contents of 40 K are the highest as it greatly contributes to natural radioactive background (N RB). Concentrations of 137 Cs were minimal, as this radionuclide derives only from global man-made environmental pollution. Thus, the results have revealed the radionuclide composition of the sample of atmospheric deposits in

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)

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.

Evaluation of thermal hydraulics characteristics of natural cooling low level radioactive waste storage system

International Nuclear Information System (INIS)

Yoshii, Toshihiro; Iwaki, Chikako; Ikeda, Tatsumi; Ikeda, Hiroshi; Koyama, Tomonori; Usui, Nobuhiko; Watanabe, Hisao; Masaki, Yoshikazu

2012-01-01

It is necessary to design a low level radioactive waste storage system so that the decay heat of radioactive waste does not breach the structural safety limit. Currently, this waste storage system is designed as a natural cooling system, which continuously cools the radioactive waste without an active device. It consists simply of a storage pit for radioactive waste and air inlet and outlet ducts. The radioactive waste is cooled by natural convective air flow, which is generated by the buoyancy of heated air due to the decay heat of radioactive waste. It is important to clarify the flow characteristics in the systems in order to evaluate the cooling performance. The air mass flow rate through the system is determined by the balance between the natural convective flow force and pressure loss within the system. Therefore, the pressure drop and flow pattern in the waste storage pit are important flow characteristics. In this study, the pressure drop and air temperature distribution, greatly influenced by the flow pattern in the pit, were measured using a 1/5 scale model and compared with the results obtained from CFD. Flow network analysis, which is a simple model that simulates the flow by nodes and junctions, was conducted and its validity was confirmed by experimental results and CFD. (author)

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

Reactor safety study. An assessment of accident risks in U. S. commercial nuclear power plants. Appendix VI. Calculation of reactor accident consequences. [PWR and BWR

Energy Technology Data Exchange (ETDEWEB)

1975-10-01

Information is presented concerning the radioactive releases from the containment following accidents; radioactive inventory of the reactor core; atmospheric dispersion; reactor sites and meteorological data; radioactive decay and deposition from plumes; finite distance of plume travel; dosimetric models; health effects; demographic data; mitigation of radiation exposure; economic model; and calculated results with consequence model.

Reactor safety study. An assessment of accident risks in U.S. commercial nuclear power plants. Appendix VI. Calculation of reactor accident consequences

International Nuclear Information System (INIS)

1975-10-01

Information is presented concerning the radioactive releases from the containment following accidents; radioactive inventory of the reactor core; atmospheric dispersion; reactor sites and meteorological data; radioactive decay and deposition from plumes; finite distance of plume travel; dosimetric models; health effects; demographic data; mitigation of radiation exposure; economic model; and calculated results with consequence model

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.

Simulation of radon short lived decay daughters' inhalation using the lung compartmental model

International Nuclear Information System (INIS)

Tomulescu, Vlad C.

2002-01-01

Radon and its short-lived decay daughters are the main source of radiation on natural ways for population. The radon gas, released from soil, water or construction materials is producing by radioactive decay the following solid daughters: Po-218, Bi-214, Pb-214, and Po-214, which can attach to aerosols, and consequently penetrate the organism by inhalation. The human respiratory tract can be approximated by aid of a compartment model that takes into account the different anatomical structures exposed to contamination and irradiation, as well as the respective physiological processes. This model is associated to a mathematical equation system that describes the behavior of the radioactive material inside the body. The results represent the dose equivalent on different organs and tissues, as a function of subject and the activity performed in contaminating environment. (author)

Study on radioactive corrosion products behaviour in primary circuits of JOYO

International Nuclear Information System (INIS)

Iizawa, Katsuyuki; Suzuki, Soju; Tamura, Masaaki; Seki, Seiichi; Hikichi, Takayoshi

1987-01-01

Radioactive CP deposition and distribution, and the resulting radiation fields along the JOYO primary circuit piping have been measured. The measurement results have been compared with calculations for estimating radioactive CP behaviour and the resulting radiation fields in an LMFBR primary circuit using a computer code which is named PSYCHE. The deposited radioactivity of CPs calculated by using PSYCHE agreed well with the measured results within a factor of 0.5-2. The gamma dose rate distribution calculated from the PSYCHE results reproduced measured values within a factor of 0.6-2 over the piping system, using the JOANDARC modification of the QAD-CG code. Using these verified codes, a prediction of radiation levels for future plant operation, and an evaluation of methods for the reduction of radioactive CPs have been conducted. (orig./DG)

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

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

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

Influence of weather conditions on natural radioactivity

International Nuclear Information System (INIS)

Simion, Florin; Simion, Elena; Cuculeanu, Vasile; Mihalcea, Ion

2011-01-01

This paper presents the dependence of the natural radioactivity on atmospheric weather conditions: air temperature, atmospheric pressure, wind speed, atmospherical precipitations and relative humidity. The values used in the paper were taken from the environmental radioactivity monitoring in Botosani city, Romania, as measured by the Environmental Radioactivity Surveillance Station. Daily global measurements of atmospheric deposition beta and atmospheric aerosols as well were carried out, including the indirect determination of radon and thoron, and the absorbed gamma dose rate in air, as well. Sampling and measurement frequency depended on the type of sample analyzed as follows: atmospheric deposition were taken daily, atmospheric aerosols were collected 4 times/day, with a sampling interval of 5 hours while the air absorbed dose rate was determined at a hourly rate. The coefficient of multiple correlation between the type of analysis and weather conditions, was determined. By using multiple linear regression it was highlighted the natural radioactivity dependence on the atmospheric conditions and meteorological parameters by a mathematical expression that can be used to determine missing values in a time series of measured data. By predicting the measured values our procedure can be considered as a validation process of the measurement accuracy

The effect of fog on radionuclide deposition velocities

International Nuclear Information System (INIS)

Gibb, R.; Carson, P.; Thompson, W.

1997-01-01

Current nuclear power station release models do not evaluate deposition under foggy atmospheric conditions. Deposition velocities and scavenging coefficients of radioactive particles entrained in fog are presented for the Point Lepreau area of the Bay of Fundy coast. It is recommended to calculate deposition based on fog deposition velocities. The deposition velocities can be calculated from common meteorological data. The range of deposition velocities is approximately 1 - 100 cm/s. Fog deposition is surface roughness dependent with forests having larger deposition and deposition velocities than soil or grasses. (author)

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

Control of radioactive material transport in sodium-cooled reactors

International Nuclear Information System (INIS)

Brehm, W.F.

1980-03-01

The Radioactivity Control Technology (RCT) program was established by the Department of Energy to develop and demonstrate methods to control radionuclide transport to ex-core regions of sodium-cooled reactors. This radioactive material is contained within the reactor heat transport system with any release to the environment well below limits established by regulations. However, maintenance, repair, decontamination, and disposal operations potentially expose plant workers to radiation fields arising from radionuclides transported to primary system components. This paper deals with radioactive material generated and transported during steady-state operation, which remains after 24 Na decay. Potential release of radioactivity during postulated accident conditions is not discussed. The control methods for radionuclide transport, with emphasis on new information obtained since the last Environmental Control Symposium, are described. Development of control methods is an achievable goal

Results of environmental radioactivity measurements in the Member States of European Community for air-deposition-water 1973-1974, milk 1972-1973-1974

International Nuclear Information System (INIS)

1977-01-01

The present document is the fifteenth report published by the Health and Safety Directorate of the Commission of the European Communities concerning ambient radioactivity and using the data collected by the stations in charge of the surveillance of the environmental radioactivity in Member States. The results are compiled and extracted from the data sent to the Commission in application of Article 36 of the Treaty of Rome instituting the European Atomic Energy Community. It is the first document in which data from Denmark, Ireland and the United Kingdom which joined the European Community on 1 January 1973 are included in addition to data from Belgium, the Federal Republic of Germany, France, Italy, Luxembourg and the Netherlands. The results presented in this report cover the years 1973 and 1974 for air deposition and surface water and the years 1972, 1973 and 1974 for milk

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

Age, genesis and exploration for mineral deposits: the possibilities offered by lead isotopes

International Nuclear Information System (INIS)

Marcoux, E.; Calvez, J.Y.

1985-01-01

After a brief theoretical survey of the subject, the paper discusses the assistance that lead isotopes can bring to solving problems of metallogenesis and mineral exploration. Lead isotopes act as a true geologic clock when radioactive decay of lead takes place in a closed U-Th-Pb system, or when these conditions have been recreated by homogenization of a large crustal segment. The lead clock is thus reliable for deposits whose process of formation was part of a hydrothermal event that affected a significant part of the crust, most importantly in island-arc volcanosedimentary deposits, much less so for deposits formed by spatially restricted hydrothermal activity such as the emplacement of veins. Very interesting possibilities are also to be found in the capacity of lead isotopes to act as geochemical tracers. In conjunction with paragenetic and gitologic studies, determination of the isotopic composition of lead allows the sources of metals to be identified and permits an approach to the understanding of inheritance phenomena in a mineral deposit or province. This information also assists in unravelling the successive metallogenic processes in a region, thus contributing to refinement of the concept of a metallogenic province. Lastly lead isotopes provide an additional factor in assessing the economic potential of a deposit undergoing exploration. The method is based on a comparison of the isotopic signature of the deposit with that of economic mineralization occuring elsewhere in the circa. Examples of stratiform deposits and the gold-bearing veins of Limousin are described. The application of this method to gossans can provide additional information to standard geochemistry and thus assist in grading of targets [fr

Environmental radioactivity in Caithness and Sutherland. Part 1

International Nuclear Information System (INIS)

Cawse, P.A.

1988-01-01

A network of soil sampling sites on permanent grassland was selected and sampled in 1979, covering an area of about 2200 km 2 in Caithness and Sutherland, in northern Scotland. In autumn 1978, agricultural crops and arable soils were sampled at two farms, near to and distant from the Dounreay Nuclear Power Development Establishment. In autumn 1978 and in the summer of 1979, peat profiles were sampled to a depth of 2 m at eight sites. Finally, litter from coniferous woodland was sampled at seven locations. The objective of the study was to provide information on the integrated local deposition of 137 Cs, 239+240 Pu and 90 Sr to soil and peat, and the concentrations of these radionuclides in crop plants. Thus it was necessary to determine the distribution of possible emissions from the nuclear establishment at Dounreay in the presence of radioactivity deposited from nuclear weapons fallout, that is superimposed on the natural background of radioactivity in soil. Results from soil and peat samples collected in Caithness and Sutherland are compared with the average integrated deposition in British soils from nuclear fallout. The observed deposition of radioactivity has little radioligical significance, based on assessment of risk by inhalation of soil dust that contains plutonium, and by concentrations of 137 Cs and plutonium in crops. (author)

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)

Exposure of the Public from Large Deposits of Mineral Residues

International Nuclear Information System (INIS)

2011-06-01

All minerals and raw materials contain radionuclides of natural origin. In most situations, the exposure of humans to such radionuclides is considered to be part of the normal natural radiation background and is not generally of concern. In some cases, however, the radionuclide concentrations are elevated above normal levels or become elevated as a result of mineral processing activities, and measures for protecting against exposure to the material involved may need to be considered. The mineral or raw material is then treated as radioactive material for the purposes of radiation protection and falls within the definition of naturally occurring radioactive material (NORM). The IAEA has developed criteria for determining which materials need to be considered for regulatory control. For materials containing only radionuclides of natural origin, the criteria are an activity concentration of 1 Bq/g for 238 U, 235 U, 232 Th and their decay progeny and an activity concentration of 10 Bq/g for 40 K. These values were determined on the basis of the activity concentrations of these radionuclides in normal rocks and soil, and represent the (rounded) upper bounds of the ranges of such concentrations as determined by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The values are intended to apply to all solid materials except foodstuffs, material in transport and radioactive residues in the environment (for which separate criteria apply) and 40 K in the body (which is excluded entirely from regulatory requirements). While the radiation dose was not a consideration in the determination of the above-mentioned regulatory criteria, the IAEA has noted that doses received by individuals as a consequence of the use of these criteria are unlikely to exceed about 1 mSv in a year, excluding the emanation of radon. However, in the case of bulk volumes of material contaminating water pathways, such as large deposits of NORM residues from mining and

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)

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.

First design for the optics of the decay ring for the beta-beams

International Nuclear Information System (INIS)

Chance, A.; Payet, J.

2006-03-01

The aim of the beta-beams is to produce pure electronic neutrino and anti-neutrino highly energetic beams, coming from beta radioactive disintegration decay of the 18 Ne 10+ and 6 He 2+ , directed to experiment situated in the Frejus tunnel. The high ion intensities are stored in a ring, until the ions decay. The losses due to the decay of the radioactive ions are compensated with regular injections. These should be done in presence of the circulating beam. The new ions are injected at a different energy from the stored beam energy, the design of the ring must enable this type of injection and accept the injected and stored beams. In this note, we will focus on the study of the design of such a ring at the first and second orders. We have reached the constraint on the dispersion in the injection section: a horizontal dispersion superior to 10 m with β x = 20 m. We have put sextupoles in the arcs to correct the chromaticity. In the same time, we have compensated the third order resonances to have a large enough dynamic aperture. So the decay ring accepts injected and stored beams. In a top-down approach, the high stored intensities impose to take into account the space charge effects. However, due to the merging, the beam blows up after each injection in the longitudinal space charge, which imposes to include a momentum collimation section in the decay ring

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

Science.gov (United States)

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

2009-12-20

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

Cluster radioactivity and very asymmetric fission through quasi-molecular shapes

International Nuclear Information System (INIS)

Royer, G.

1997-01-01

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

Airborne concentrations of radioactive materials in severe accidents

International Nuclear Information System (INIS)

Ross, D.F. Jr.; Denning, R.S.

1989-01-01

Radioactive materials would be released to the containment building of a commercial nuclear reactor during each of the stages of a severe accident. Results of analyses of two accident sequences are used to illustrate the magnitudes of these sources of radioactive materials, the resulting airborne mass concentrations, the characteristics of the airborne aerosols, the potential for vapor forms of radioactive materials, the effectiveness of engineered safety features in reducing airborne concentrations, and the release of radioactive materials to the environment. Ability to predict transport and deposition of radioactive materials is important to assessing the performance of containment safety features in severe accidents and in the development of accident management procedures to reduce the consequences of severe accidents

Method of monitoring volume activity of natural radioactive aerosol

International Nuclear Information System (INIS)

Dvorak, V.

1980-01-01

The method of monitoring radioactivity of a aerosol trapped, eg., with a filter is based on counting quasi-coincidences of the RaC-RaC' and ThC-ThC' decay. The first electronic unit counts quasi-coincidences at a time interval proportional to the ThC' half-life while the second electronic unit counts quasi-coincidences at a time interval proportional to the RaC' half-life, reduced by the time interval of the first electronic unit. The quasi-coincidences are evaluated of the RaC-RaC' decay independently of the ThC-ThC' quasi-coincidences and the decay products of the trapped radon and thoron gases are thus offset separately. (J.P.)

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...

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

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,

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

Environmental radioactivity of radon daughter's radionuclides 210Pb-210Bi-210Po

International Nuclear Information System (INIS)

Momoshima, N.

2003-01-01

Radionuclide, 210 Pb(22.3 y)- 210 Bi(5.013 d)- 210 Po(138.4 d) belongs to the uranium decay chain and widely distributed in the environment. 222 Rn escaped from the earth surface is a major source of atmospheric 210 Pb. These nuclides attach with atmospheric aerosols and are removed to the ground as wet and dry depositions. The residence time of the atmospheric aerosol, thus, was obtained by activity ratios of 210 Bi/ 210 Pb and 210 Po/ 210 Pb, showing different values. The discrepancy on the residence times are explained with inputs of 210 Po to the atmosphere other than 222 Rn emanated from the earth surface. The removal of aerosol as wet deposition occupies a significant fraction, which reaches 72% on 210 Pb and 89% on 7 Be. In the ocean, the radionuclides are used as tracer to examine dynamic processes occurring in the ocean, such as removal of particulate matter from seawater column to bottom. The 210 Pb and 210 Po concentrations in the ocean water collected off continent decreased from surface toward bottom, and the shortage on 210 Po content relative to that of 210 Po was observed at shallow ocean layers, however, the 210 Po/ 210 Pb activity ratio closed to the radioactive equilibrium at deeper layers. The 210 Pb is a very good tracer to evaluate an accumulation rate of bottom sediment in ocean, lake and river. This is called as 210 Pb dating and is successfully applicable to accumulation circumstances that bottom sediment deposits at constant rate. Most of the actual cases, simultaneous 137 Cs dating is carried out, which uses 137 Cs peak in the core as originated from radioactive fallout of nuclear tests, showing the maximum in 1963. Recently new findings on source of atmospheric 210 Po are report by laboratory experiments and environmental measurements, which proves biologically supported emission of volatile Po compounds to the atmosphere. (author)

Modeling of radionuclide migration and a temperature dynamics in underground disposal of liquid radioactive waste

International Nuclear Information System (INIS)

Larin, V.K.; Zubkov, A.A.; Balakhonov, V.G.; Sukhorukov, V.A.; Zhiganov, A.N.; Noskov, M.D.; Istomin, A.D.; Kesler, A.G.

2002-01-01

Mathematical model of radionuclide migration and temperature field dynamics during underground disposal of liquid radioactive wastes is presented. The model involves the description of filtration, convective-dispersion mass transfer, sorption and desorption of radionuclides, radioactive decay, convective heat transport and hear transfer. Software making possible to conduct prognosis calculations of changing state of stratum-collector of radioactive wastes was made. Results of the simulation of temperature field dynamics and behaviour of radionuclides on underground disposal of liquid radioactive wastes of the Siberian chemical plant are performed [ru

Monitoring dissolved radioactive cesium in Abukuma River in Fukushima Prefecture

International Nuclear Information System (INIS)

Yasutaka, Tetsuo; Kawabe, Yoshishige; Kurosawa, Akihiko; Komai, Takeshi

2013-01-01

Radioactive materials were released into the atmosphere and deposited over wide areas of farmland, forests, and cities; elevated levels of "1"3"1I, "1"3"4Cs, and "1"3"7Cs have been detected in these areas due to the accident at the Tokyo Power Fukushima Daiichi Nuclear Power Plant caused by the April 2011 earthquake and tsunami in eastern Japan. Radioactive Cs deposited on farmland and forests gradually leaches into water bodies such as mountain streams and rivers adsorbed onto particles or in a dissolved state. It is important to calrify the level of dissolved and total radioactive Cs in environmental water for forecasting the of discharge of radioactive Cs from forest and watersheds, assessing on the effect of dissolved and total radioactive Cs on not only irrigation water but also rice and other crops, and evaluating the transport of radioactive Cs from rivers to costal areas. Therefore, it is important to monitor their levels in Fukushima Prefecture over time. In this research, we monitored the levels of dissolved and total radioactive Cs in Abukuma River using a conventional evaporative concentration method. By monitoring the river waters since September 2012, it was estimated that the levels of dissolved radioactive Cs were less than 0.128 Bq/L and those of total radioactive Cs were less than 0.274 Bq/L in the main stream and branches of Abukuma River in the low suspended solid condition. (author)