Chart of nuclides relating to neutron activation

International Nuclear Information System (INIS)

Okada, Minoru

1981-09-01

This chart is for frequent use in the prediction of the product species of neutron activation. The first edition of the chart has been made in 1976 after the repeated trial preparation. It has the following good points. (1) Any letter in chart is as large as one can read easily. [This condition has been obtained by the selection of items to be shown in chart. They are the name (the symbol of element, mass number, and half-life) of nuclide or of isomer, and the type of decay.]. (2) Decay product has been shown indirectly for branchings with two-step decay via short-lived daughter in an excited state. [This matter has been realized by use of the new mode of indication.] (3) Nuclides shown in chart are (a) naturally occurring nuclides and (b) nuclides formed from naturally occurring nuclides through one of the following reactions: (n, γ), (n, n'), (n, p), (n, α), (n, 2n), (n, pn), (n, 3n), (n, αn), (n, t), (n, 3 He), (n, 2p), and (n, γ)(n, γ). In the revision of the first edition, some modes of indication have become a little simpler, and the isomers of shorter half-lives (0.1 - 1 μs) have been added. (author)

WWW chart of the nuclides

International Nuclear Information System (INIS)

Huang Xiaolong; Zhou Chunmei; Zhuang Youxiang; Zhao Zhixiang; Golashvili, T.V.; Chechev, V.P.

2000-01-01

WWW chart of the nuclides was established on the basis of the latest evaluations of nuclear structure and decay data. By viewing WWW chart of the nuclides, one can retrieve the fundamental data of nuclide such as atomic mass, abundance, spin and parity; the decay mode, branching ratio, half-life and Q-value of radioactive nuclide, energy and intensity of strong γ-ray, etc. The URL (Uniform Resource Locator) of WWW chart of the nuclides is: http://myhome.py.gd.cn/chart/index,asp

The oceanic chemistry of the U- and Th-series nuclides

International Nuclear Information System (INIS)

Cochran, J.K.

1982-01-01

The subject is discussed under the headings: input and removal of U- and Th-series nuclides in the oceans; uranium (input to the oceans; in the coastal ocean; in the open ocean; in sediment pore water; removal from the oceans; sources and sinks of 234 U in the oceans); thorium (scavenging in the deep sea; 230 Th and 231 Pa balance; removal from the coastal and surface ocean); Ra-226 and Ra-228; radon (in surface waters; near bottom 222 Rn as a tracer for vertical mixing); lead-210; polonium-210. (U.K.)

Apparatus for eliminating electrodeposition of radioactive nuclide

International Nuclear Information System (INIS)

Inomata, Ichiro; Ishibe, Tadao; Matsunaga, Masaaki; Konuki, Ryoichi; Suzuki, Kazunori; Watanabe, Minoru; Tomoshige, Shozo; Kondo, Kozo.

1990-01-01

In a conventional device for eliminating by radioactive nuclides electrodeposition, a liquid containing radioactive nuclides is electrolyzed under a presence of non-radioactive heavy metals and removing radioactive nuclides by electrodepositing them together with the heavy metals. Two anode plates are opposed in an electrolysis vessel of this device. A plurality (4 to 6) of cathode plates are arranged between the anodes in parallel with them and the cathode surfaces opposed to the anodes are insulated. Further, such a plurality of cathode plates are grouped into respective units. Alternatively, the anode plate is made of platinum-plated titanium material and the cathode plate is made of stainless steel. In the thus constituted electrodeposition eliminating device, since the cathode surface directed to the anodes on both ends are insulated, all of electric current from the anode reach the core cathode after flowing around the cathodes at both ends. As a result, there is no substantial difference in the flowing length of the electrolyzing current to each of the cathodes and these is neither difference in the electrodeposition amount. The electrodeposited products are adhered uniformly and densely to the electrodes and, simultaneously, Co-60 and Mn-54, etc. are also electrodeposited. (I.S.)

Nuclide separation by hydrothermal treatment and ion exchange: a highly effective method for treatment of liquid effluents - 59217

International Nuclear Information System (INIS)

Braehler, Georg; Rieck, Ronald; Avramenko, V.A.; Sergienko, V.I.; Antonov, E.A.

2012-01-01

Liquid low level radioactive effluents, when solidified in e.g. cement matrix, contribute to a significant extent to the waste amount to be disposed of in final repositories. Accordingly, since many years scientists and engineers investigate processes to remove the radioactive nuclides selectively from the effluents, to split the raw solution into two separate fractions: a large fraction with activity concentrations below the limits for free release; and a small fraction, containing the activity in concentrated form on e. g. ion exchanger materials (ion exchange has proven to be the most promising method for such 'nuclide separation'). The challenge to be taken up is: When (and this is most often the case) the effluent contains organic materials and complexing agents, the formation of e. g. the 60-Co-EDTA complex prohibits its fixation to the ion exchangers. Accordingly the complexing agent needs to be removed or destroyed. The Institute for Chemistry of the Russian Academy of Sciences has applied the method of hydrothermal treatment (at elevated temperature and pressure, 200 deg. C, 200 bar), supported by Hydrogen Peroxide oxidation, to allow virtually complete removal of radioactive nuclides on inorganic ion exchangers. Pilot plants have been operated successfully in Russian power stations, and an operational plant has been designed. The method is being extended for an interesting and promising application: spent organic ion exchange resins, loaded up to the medium activity level, represent a serious disposal problem. With the hydrothermal process, in a process cycle, the activity can be stripped from the resins, the organic content is destroyed, and the activity is fixed on an inorganic absorber, well suited for final disposal. (authors)

A computer program to calculate nuclide yields in complex decay chain for selection of optimum irradiation and cooling condition

International Nuclear Information System (INIS)

Takeda, Tsuneo

1977-11-01

This report is prepared as a user's input manual for a computer code CODAC-No.5 and provides a general description of the code and instructions for its use. The code represents a modified version of the CODAC-No.4 code. The code developed is capable of calculating radioactive nuclide yields in an any given complex decay and activation chain independent of irradiation history. In this code, eighteen kinds of valuable tables and graphs can be prepared for output. They are available for selection of optimum irradiation and cooling conditions and for other intentions in accordance with irradiation and cooling. For a example, the ratio of a nuclide yield to total nuclide yield depending on irradiation and cooling times is obtained. In these outputs, several kinds of complex and intricate equations and others are included. This code has almost the same input forms as that of CODAC-No.4 code excepting input of irradiation history data. Input method and formats used for this code are very simple for any kinds of nuclear data. List of FORTRAN statements, examples of input data and output results and list of input parameters and its definitions are given in this report. (auth.)

The nuclide inventory in SFR-1

International Nuclear Information System (INIS)

Ingemansson, Tor

2001-10-01

This report is an account for a project carried out on behalf of the Swedish Radiation Protection Authority (SSI): 'Nuclide inventory in SFR-1' (The Swedish underground disposal facility for low and intermediate level reactor waste). The project comprises the following five sub-projects: 1) Measuring methods for nuclides, difficult to measure, 2) The nuclide inventory in SFR-1, 3) Proposal for nuclide library for SFR-1 and ground disposal, 4) Nuclide library for exemption, and 5) Characterising of the nuclide inventory and documentation for SFL waste. In all five sub-projects long-lived activity, including Cl-36, has been considered

Uptake of nuclides by plants

International Nuclear Information System (INIS)

Greger, Maria

2004-04-01

This review on plant uptake of elements has been prepared to demonstrate how plants take up different elements. The work discusses the nutrient elements, as well as the general uptake and translocation in plants, both via roots and by foliar absorption. Knowledge of the uptake by the various elements within the periodic system is then reviewed. The work also discusses transfer factors (TF) as well as difficulties using TF to understand the uptake by plants. The review also focuses on species differences. Knowledge necessary to understand and calculate plant influence on radionuclide recirculation in the environment is discussed, in which the plant uptake of a specific nuclide and the fate of that nuclide in the plant must be understood. Plants themselves determine the uptake, the soil/sediment determines the availability of the nuclides and the nuclides themselves can interact with each other, which also influences the uptake. Consequently, it is not possible to predict the nuclide uptake in plants by only analysing the nuclide concentration of the soil/substrate

Uptake of nuclides by plants

Energy Technology Data Exchange (ETDEWEB)

Greger, Maria [Stockholm Univ. (Sweden). Dept. of Botany

2004-04-01

This review on plant uptake of elements has been prepared to demonstrate how plants take up different elements. The work discusses the nutrient elements, as well as the general uptake and translocation in plants, both via roots and by foliar absorption. Knowledge of the uptake by the various elements within the periodic system is then reviewed. The work also discusses transfer factors (TF) as well as difficulties using TF to understand the uptake by plants. The review also focuses on species differences. Knowledge necessary to understand and calculate plant influence on radionuclide recirculation in the environment is discussed, in which the plant uptake of a specific nuclide and the fate of that nuclide in the plant must be understood. Plants themselves determine the uptake, the soil/sediment determines the availability of the nuclides and the nuclides themselves can interact with each other, which also influences the uptake. Consequently, it is not possible to predict the nuclide uptake in plants by only analysing the nuclide concentration of the soil/substrate.

Karlsruhe nuclide chart - new 9. edition 2015

Energy Technology Data Exchange (ETDEWEB)

Soti, Zsolt [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, DE-76125 Karlsruhe, (Germany); Magill, Joseph; Pfennig, Gerda; Derher, Raymond [Nucleonica GmbH, c/o European Commission, Postfach 2340, DE-76125 Karlsruhe, (Germany)

2015-07-01

Following the success of the 8. Edition of the Karlsruhe Nuclide Chart 2012, a new edition is planned for 2015. Since the 2012 edition, more than 100 nuclides have been discovered and about 1400 nuclides have been updated. In summary, the new 9. edition contains decay and radiation data on approximately 3230 ground state nuclides and 740 isomers from 118 chemical elements. The accompanying booklet provides a detailed explanation of the nuclide box structure used in the Chart. An expanded section contains many additional nuclide decay schemes to aid the user to interpret the highly condensed information in the nuclide boxes. The booklet contains - in addition to the latest values of the physical constants and physical properties - a periodic table of the elements, tables of new and updated nuclides, and a difference chart showing the main changes in the Chart graphically. (authors)

Karlsruhe nuclide chart - new 9. edition 2015

International Nuclear Information System (INIS)

Soti, Zsolt; Magill, Joseph; Pfennig, Gerda; Derher, Raymond

2015-01-01

Following the success of the 8. Edition of the Karlsruhe Nuclide Chart 2012, a new edition is planned for 2015. Since the 2012 edition, more than 100 nuclides have been discovered and about 1400 nuclides have been updated. In summary, the new 9. edition contains decay and radiation data on approximately 3230 ground state nuclides and 740 isomers from 118 chemical elements. The accompanying booklet provides a detailed explanation of the nuclide box structure used in the Chart. An expanded section contains many additional nuclide decay schemes to aid the user to interpret the highly condensed information in the nuclide boxes. The booklet contains - in addition to the latest values of the physical constants and physical properties - a periodic table of the elements, tables of new and updated nuclides, and a difference chart showing the main changes in the Chart graphically. (authors)

Chart of the nuclides

International Nuclear Information System (INIS)

Yoshizawa, Y.; Horiguchi, T.; Yamada, M.

1980-01-01

In this chart, four colors are use to classify nuclides according to their half-lives. The different symbols are also to show the decay modes and their percentage in each nuclide. Four tables are provided on the back of the chart. Table 1 is the ordinary periodic Table. Table 2 provides fundamental constants used for nuclear physics. Tables 3 lists the physical constants (mean density, ionization potential, melting point, and boiling point) of all elements. Table 4 provides the gamma-ray intensity standards. Half-lives, energy, relative intensity, and intensity per decay are list for 33 nuclides. (J.P.N.)

International chart of the nuclides. 2001

International Nuclear Information System (INIS)

Golashvili, T.V.; Kupriyanov, V.M.; Lbov, A.A.

2002-01-01

The International Chart of Nuclides - 2001 has been developed taking into account the data obtained in 1998-2001. Unlike widespread nuclide charts the present Chart of Nuclides contains EVALUATED values of the main characteristics. These values are supplied with the standard deviations. (author)

Removal of Radioactive Nuclides by Multi-Functional Microcapsules Enclosing Inorganic Ion-Exchangers and Organic Extractants

Energy Technology Data Exchange (ETDEWEB)

Mimura, H.; Akiba, K.; Onodera, Y.

2002-02-26

The microcapsules enclosing two kinds of functional materials, inorganic ion-exchangers and organic extractants, were prepared by taking advantage of the high immobilization ability of alginate gel polymer. The fine powders of inorganic ion-exchanger and oil drops of extractant were kneaded with sodium alginate (NaALG) solution and the kneaded sol readily gelled in a salt solution of CaCl2, BaCl2 or HCl to form spherical gel particles. The uptake properties of various nuclides, 137Cs, 85Sr, 60Co, 88Y, 152Eu and 241Am, for thirty-four specimens of microcapsules in the presence of 10-1-10-4 M HNO3 were evaluated by the batch method. The distribution coefficient (Kd) of Cs+ above 103 cm3/g was obtained for the microcapsules enclosing CuFC or AMP. The Kd of Sr2+ around 102 cm3/g was obtained for the microcapsules containing clinoptilolite, antimonic acid, zeolite A, zeolite X or titanic acid. The microcapsules enclosing DEHPA exhibited relatively large Kd values of trivalent metal ions above 103 cm3/g; for example, the Kd values of Cs+, Sr2+, Co2+, Y3+, Eu3+ and Am3+ for a favorable microcapsule (CuFC/clinoptilolite/DEHPA/CaALG) were 1.1x104, 7.5x10, 1.1x10, 1.0x104, 1.4x104, 3.4x103 cm3/g, respectively. The uptake rates of Cs+, Y3+, Eu3+ and Am3+ for this microcapsule were rather fast; the uptake percentage above 90% was obtained after 19 h-shaking and the uptake equilibrium was attained within 1 d. The AMP/CaALG exhibited high uptake ability for Cs+ even after irradiation of 188 kGy, and DEHPA/CaALG microcapsule had similar Kd values of Cs+, Sr2+, Co2+, Y3+, Eu3+ and Am3+ ions before and after irradiation. The microcapsules with various shapes such as spherical, columnar, fibrous and filmy forms were easily prepared by changing the way of dipping kneaded sol into gelling salt solution. The microcapsules enclosing inorganic ion-exchangers and extractants have a potential possibility for the simultaneous removal of various radioactive nuclides from waste solutions.

Efficiency Of Transuranium Nuclides Transmutation

International Nuclear Information System (INIS)

Kazansky, Yu.A.; Klinov, D.A.; Semenov, E.V.

2002-01-01

One of the ways to create a wasteless nuclear power is based on transmutation of spent fuel nuclides. In particular, it is considered that the radioactivity of the nuclear power wastes should be the same (or smaller), than radioactivity of the uranium and the thorium extracted from entrails of the Earth. The problem of fission fragments transmutation efficiency was considered in article, where, in particular, the concepts of transmutation factor and the ''generalised'' index of biological hazard of the radioactive nuclides were entered. The transmutation efficiency has appeared to be a function of time and, naturally, dependent on nuclear power activity scenario, from neutron flux, absorption cross-sections of the nuclides under transmutation and on the rate of their formation in reactors. In the present paper the efficiency of the transmutation of transuranium nuclides is considered

NON-CONVENTIONAL PET NUCLIDES: PRODUCTION AND IMAGING

OpenAIRE

Laforest, Richard

2015-01-01

Abstract Medical cyclotrons are now commonly used for the production of PET nuclides by the (pn) reaction. These devices are typically capable of delivering 10-15 MeV protons beams at sufficiently high intensity for timely production of β+ decaying nuclides. Non-conventional PET nuclides have emerged recently and offers new opportunities for diagnostic and therapy drug discovery. In this paper, we will review the production capabilities for such nuclides at Washington University Medical Schoo...

An introduction to in-situ produced cosmogenic nuclides

International Nuclear Information System (INIS)

Norton, K.P.

2012-01-01

Cosmogenic nuclides are produced through interactions between cosmic rays and target nuclei in Earth's atmosphere and surface materials. Those which are produced in Earth's atmosphere are termed 'meteoric' while the nuclides produced in surface material are known as in-situ cosmogenic nuclides. The past two decades have seen a proliferation of applications for cosmogenic nuclides. This is primarily due to a revolution in accelerator mass spectrometry, AMS, measurement techniques which has allowed the measurement of very small amounts of nuclides. The following is a brief introduction to the theory and application of in-situ produced cosmogenic nuclide methods. (author). 17 refs., figs., 1 tab.

Cementification for radioactive waste including high-concentration sodium sulfate and high-concentration radioactive nuclide

International Nuclear Information System (INIS)

Miyamoto, Shinya; Sato, Tatsuaki; Sasoh, Michitaka; Sakurai, Jiro; Takada, Takao

2005-01-01

For the cementification of radioactive waste that has large concentrations of sodium sulfate and radioactive nuclide, a way of fixation for sulfate ion was studied comprising the pH control of water in contact with the cement solid, and the removal of the excess water from the cement matrix to prevent hydrogen gas generation with radiolysis. It was confirmed that the sulfate ion concentration in the contacted water with the cement solid is decreased with the formation of ettringite or barium sulfate before solidification, the pH value of the pore water in the cement solid can control less than 12.5 by the application of zeolite and a low-alkali cement such as alumina cement or fly ash mixed cement, and removal of the excess water from the cement matrix by heating is possible with aggregate addition. Consequently, radioactive waste including high-concentration sodium sulfate and high-concentration radioactive nuclide can be solidified with cementitious materials. (author)

Selection of exception limits for all actinide nuclides based on revised criteria for safe international transport

International Nuclear Information System (INIS)

Lavarenne, C.; Rouyer, V.; Sert, G.; Mennerdahl, D.; Dean, C.; Barton, N.; Jean, F.

2003-01-01

Since 1998, there have been some speculations about future transport of significant quantities and concentrations of other actinide nuclides than the four currently listed in the regulation for the safe transport of the radioactive material. Therefore, it raised a need to specify exception limits for such actinides. Additionally, the total fissile nuclide mass per consignment of excepted packages was limited in the 1996 edition of the regulations (a conveyance limit is preliminary supported in the 2003 revision). The proposed changes of the rules have to take this new control into account. The European Community (DGTREN) decided to fund a project related to this subject. In order to define credible exception limits, it was necessary to have reasonably accurate data for all actinide nuclides. Then the authors of the study decided to perform calculations with different codes (MONK, MCNP, CRISTAL, SCALE) and different cross-section libraries (JEF2.2, ENDFB, JENDL, etc.). This article presents the work achieved and gives propositions of modification for the IAEA requirements for the Safe Transport of Radioactive Material related to, firstly, the list of the fissile materials, and secondly, the rule to determine the quantities of actinide nuclides that can be excepted from the requirements for the packages containing fissile materials. The participants acknowledge the DGTREN who made this work possible due to its support. (author)

GAUSS VIII: a computer program for the nuclide activity analysis of γ-ray spectra from GE semiconductor spectrometers

International Nuclear Information System (INIS)

Putman, M.H.; Helmer, R.G.; McCullagh, C.M.

1985-12-01

A description is given of a computer program, GAUSS VII, which has been written to determine nuclide or isotopic activities from γ-ray spectra from GE semiconductor spectrometers. The preliminary portion of the program can determine the energy- and width-calibration equations, locate individual peaks and define ''peak regions'' that are significantly above the local spectral background. The user may edit these lists of peaks and regions. Each peak region is fitted with one or more components in which the peaks are represented by a Gaussian function or a Gaussian with one or two additive exponential tails on the low-energy side and one on the high-energy side. A step-like background function can be used with each component. The program will automatically recycle to add one or more components to a region if needed to improve the fit. The γ-ray energies and intensities are computed from the resulting Gaussian positions and peak areas. From a comparison of these peak energies and the γ-ray energies for various nuclides in a nuclide library, the nuclides that may be present are identified. The user may edit this nuclide list. The program identifies secondary γ rays that should be present for these nuclides and obtains peak areas for them, if the areas are not already available. All of the peak areas are then analyzed to obtain the best nuclidic activities. The peak areas for any one nuclide and those for nuclides that have interfering lines are analyzed in one least-squares ft. Nuclides whose activities are essentially 0, and peaks which cannot be accounted for are removed from the analysis. Besides the nuclidic activities, a peak-by-peak summary is provided. This program is intended to analyze large groups of spectra as well as an individual spectrum

Radioactive nuclides in the living environment

International Nuclear Information System (INIS)

Ueno, Kaoru; Hoshi, Michio.

1993-09-01

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

Decay and Transmutation of Nuclides

CERN Document Server

Aarnio, Pertti A

1999-01-01

We present a computer code DeTra which solves analytically the Bateman equations governing the decay, build-up and transmutation of radionuclides. The complexity of the chains and the number of nuclides are not limited. The nuclide production terms considered include transmutation of the nuclides inside the chain, external production, and fission. Time dependent calculations are possible since all the production terms can be re-defined for each irradiation step. The number of irradiation steps and output times is unlimited. DeTra is thus able to solve any decay and transmutation problem as long as the nuclear data i.e. decay data and production rates, or cross sections, are known.

Method for the transmutation of nuclides

International Nuclear Information System (INIS)

1984-01-01

The invention relates to a method for the systematic and optimal manufacture of nuclides with beneficial properties as well as for the transmutation of noxious nuclides into innocuous ones, e.g. radioactive wastes. For that purpose, use is made of the periodic system of atoms and of the so-called twin-subshell model of nuclear structure, in order to trace the possible transformations of the nuclide through irradiation with appropriate particles or radiation. (G.J.P.)

Natural radio-nuclides in drinking water

International Nuclear Information System (INIS)

Deflorin, O.

2003-01-01

This article discusses the presence of radio-nuclides in Switzerland's drinking water. The article describes research done into the natural radioactivity to be found in various drinking water samples taken from the public water supply in the Canton of Grisons in eastern Switzerland. The various natural nuclides to be expected are listed and the methods used to take the samples are described. The results of the analysis are presented in the form of sketches showing the geographical distribution of the nuclide samples. Diagrams of the cumulative frequency of the quantities of nuclides found are presented, as are such diagrams for the yearly radioactive doses that the population is exposed to. The results and their consequences for the water supply are discussed in detail and further investigations to be made in the region are proposed

The MacNuclide nuclear data environment

International Nuclear Information System (INIS)

Stone, C.A.

1992-01-01

Advance in technology have produced intriguing tools that can be applied to problems in nuclear science. Information management in nuclear science is an example of how technology is not quickly exploited. The U.S. Department of Energy supports an extensive program to evaluate published nuclear properties and store them in an electronic data base. Much of the evaluation effort has focused on producing the journal Nuclear Data Sheets and the publication Table of Isotopes. Although the electronic data base can itself be a valuable source of information, the software used to access is was designed using decades-old technologies. The authors of this paper have developed a novel data-base management system for nuclear properties. The application is known as MacNuclide. It is a nuclear data-base environment that uses the highly interactive and intuitive windowing environmentsof desk-top computers. The environment is designed around that image of the chart of nuclides. Questions are posed to the data base by placing constraints on properties and defining collections of nuclides to be used in data-base seraches. Results are displayed either as a simple list of nuclides that meet the imposed constraints or as a color chart of nuclides

Alpha-emitting nuclides in the marine environment

Science.gov (United States)

Pentreath, R. J.

1984-06-01

The occurrence of alpha-emitting nuclides and their daughter products in the marine environment continues to be a subject of study for many reasons. Those nuclides which occur naturally, in the uranium, thorium and actinium series, are of interest because of their value in determining the rates of geological and geochemical processes in the oceans. Studies of them address such problems as the determination of rates of transfer of particulate matter, deposition rates, bioturbation rates, and so on. Two of the natural alpha-series nuclides in which a different interest has been expressed are 210Po and 226Ra, because their concentrations in marine organisms are such that they contribute to a significant fraction of the background dose rates sustained both by the organisms themselves and by consumers of marine fish and shellfish. To this pool of naturally-occurring nuclides, human activities have added the transuranium nuclides, both from the atmospheric testing of nuclear devices and from the authorized discharges of radioactive wastes into coastal waters and the deep sea. Studies have therefore been made to understand the chemistry of these radionuclides in sea water, their association with sedimentary materials, and their accumulation by marine organisms, the last of these being of particular interest because the transuranics are essentially "novel" elements to the marine fauna and flora. The need to predict the long-term behaviour of these nuclides has, in turn, stimulated research on those naturally-occurring nuclides which may behave in a similar manner.

Removal of Sr from radioactive waste solutions by polymer enhanced ultra filtration: study of selectivity and mechanism of the process

International Nuclear Information System (INIS)

Kedari, C.S.; Yadav, J.S.; Gandhi, P.M.; Banerjee, K.

2016-01-01

The removal of 90 Sr in liquid radioactive wastes is an important issue for waste disposal. Because of the physical and biological half-life of 90 Sr, it is one of the most hazardous radionuclides for internal exposure. Accumulation in bones tissues and high-energy beta particles from its daughter nuclide, 90 Y (half-life: 64.1 h), cause the damage to bone marrow. These characteristics are forcing the implementation of monitoring 90 Sr activities and its elimination from the industrial waste solutions. Filtration through semi permeable membrane with the potential of selective retention is a well-established commercial technique, which also has great applicability in nuclear waste processing. The UF based separation is a solute fractionation using appropriate pore size membrane as a sieve. The advantage of working with UF is: high throughput can be achieved as compared to RO while using low driving pressure and temperature. The objective of this research was to determine the effectiveness of separation of divalent strontium by complexing with water soluble cation exchange polymer and its removal by ultra filtration

Lake-0: A model for the simulation of nuclides transfer in lake scenarios

International Nuclear Information System (INIS)

Garcia-Olivares, A.; Aguero, A.; Pinedo, P.

1994-01-01

This report presents documentation and a user's manual for the program LAKE-0, a mathematical model of nuclides transfer in lake scenarios. Mathematical equations and physical principles used to develop the code are presented in section 2. The program use is presented in section 3 including input data sets and output data. Section 4 presents two example problems, and some results. The complete program listing including comments is presented in Appendix A. Nuclides are assumed to enter the lake via atmospheric deposition and carried by the water runoff and the dragged sediments from the adjacent catchment. The dynamics of the nuclides inside the lake is based in the model proposed by Codell (11) as modified in (5). The removal of concentration from the lake water is due to outflow from the lake and to the transfer of activity to the bottom sediments. The model has been applied to the Esthwaite Water (54 degree 21 minute N, 03 degree 00 minute W at 65 m. asl.) in the frame of the VAMP Aquatic Working Group (8) and to Devoke Water (54 degree 21 minute 5'N, 03 degree, 18 minute W at 230 m. asl.)

LAKE-0: a model for the simulation of nuclides transfer in lake scenarios

International Nuclear Information System (INIS)

Garcia-Olivares, A.; Aguero, A.; Pinedo, P.

1994-01-01

This report presents documentation and a user's manual for the program LAKE-0, a mathematical model of nuclides transfer in lake scenarios. Mathematical equations and physical principles used to develop the code are presented in section 2. The program use is presented in section 3 including input data sets and output data. Section 4 presents two example problems, and some results. The complete program listing including comments is presented in Appendix A. Nuclides are assumed to center the lake via atmospheric deposition and carried by the water runoff and the dragged sediments from the adjacent catchment. The dynamics of the nuclides inside the lake is based in the model proposed by Codell (11) as modified in (5). The removal of concentration from the lake water is due to out flow from the lake and to the transfer of activity to the button sediments. The model has been applied to the Esthwaite Water (54 degree celsius 2 l'N, 03 degree celsius 00'W at 65 m. asi.) in the frame of the VAMP Aquatic Working Group (8) and to Devoke Water (5 21.5'N, 03H8'W at 230 m. asi.). (Author). 13 refs

Radioactive nuclide adsorption

International Nuclear Information System (INIS)

Fukushima, Kimichika.

1982-01-01

Purpose: To improve the efficiency of a radioactive nuclide adsorption device by applying a nickel plating on a nickel plate to render the surface active. Constitution: A capturing device for radioactive nuclide such as manganese 54, cobalt 60, 58 and the like is disposed to the inside of a pipeway provided on the upper portion of fuel assemblies through which liquid sodium as the coolant for LMFBR type reactor is passed. The device comprises a cylindrical adsorption body and spacers. The adsorption body is made of nickel and applied with a nickel plating on the surface thereof. The surface of the adsorption body is unevened to result in disturbance in the coolant and thereby improve the adsorptive efficiency. (Kawakami, Y.)

On the measurement of cosmogenic nuclides in cometary materials

International Nuclear Information System (INIS)

Herzog, G.F.; Englert, P.A.J.; Reedy, R.C.; Nishiizumi, K.; Kohl, C.P.; Arnold, J.R.

1989-01-01

Determinations of the cosmogenic nuclide concentrations in cometary material will help to define the recent surface history of the comet and its exposure to cosmic rays. In particular, the rates for the removal or mixing of surface material could be studied, and any variations in cosmic-ray intensity implied by the data could be used to infer orbital changes during the last few million years. The measurement of the shorter-lived isotopes poses technical challenges that should be addressed now. The measurement of longer-lived isotopes will be straightforward provided that rates of mass loss are not too high. 46 refs., 2 figs

The nuclide inventory in SFR-1; Nuklidinventariet i SFR-1

Energy Technology Data Exchange (ETDEWEB)

Ingemansson, Tor [ALARA Engineering, Skultuna (Sweden)

2001-10-01

This report is an account for a project carried out on behalf of the Swedish Radiation Protection Authority (SSI): 'Nuclide inventory in SFR-1' (The Swedish underground disposal facility for low and intermediate level reactor waste). The project comprises the following five sub-projects: 1) Measuring methods for nuclides, difficult to measure, 2) The nuclide inventory in SFR-1, 3) Proposal for nuclide library for SFR-1 and ground disposal, 4) Nuclide library for exemption, and 5) Characterising of the nuclide inventory and documentation for SFL waste. In all five sub-projects long-lived activity, including Cl-36, has been considered.

Decontamination Experiments on Intact Pig Skin Contaminated with Beta-Gamma- Emitting Nuclides

Energy Technology Data Exchange (ETDEWEB)

Edvardsson, K A; Hagsgaard, S [AB Atomenergi, Nykoeping (Sweden); Swensson, A [Dept. of Occupational Medicine, Karolinska Sjukhuset, Stockholm (Sweden)

1966-11-15

A number of decontamination experiments have been performed on intact pig skin. In most of the experiments NaI-131 in water solution has been utilized because this nuclide is widely used within the Studsvik research establishment, is easy to detect and relatively harmless, and is practical to use in these experiments. Among the {beta} {gamma}-nuclides studied 1-131 has furthermore proved to be the one most difficult to remove from the skin. The following conclusions and recommendations regarding the decontamination of skin are therefore valid primarily for iodine in the form of Nal, but are probably also applicable to many other {beta} {gamma}-nuclides. a) A prolonged interval between contamination and decontamination has a negative effect on the result of the decontamination. Therefore start decontamination as soon as possible after the contamination. b) Soap and water has proved to be the most suitable decontamination agent. A number of other agents have appeared to be harmful to the skin. Therefore, first of all use only soap and water in connection with gentle rubbing. c) No clear connection between the temperature of the water for washing and the result of the decontamination has been demonstrated. d) Skin not degreased before the contamination seems to be somewhat easier to decontaminate than degreased skin, particularly if the activity has been on the skin for a long time. Therefore do not remove the sebum of the skin when engaged on radioactive work involving contamination risks. e) Irrigation of the contaminated surface with a solution containing the corresponding inactive ions or ordinary water in large quantities may considerably decrease the skin contamination. f) In radioactive work of long duration involving high risks of contamination prophylactic measures in the form of a protective substance ('invisible glove'), type Kerodex, may make decontamination easier.

Decontamination Experiments on Intact Pig Skin Contaminated with Beta-Gamma- Emitting Nuclides

International Nuclear Information System (INIS)

Edvardsson, K.A.; Hagsgaard, S.; Swensson, A.

1966-11-01

A number of decontamination experiments have been performed on intact pig skin. In most of the experiments NaI-131 in water solution has been utilized because this nuclide is widely used within the Studsvik research establishment, is easy to detect and relatively harmless, and is practical to use in these experiments. Among the β γ-nuclides studied 1-131 has furthermore proved to be the one most difficult to remove from the skin. The following conclusions and recommendations regarding the decontamination of skin are therefore valid primarily for iodine in the form of Nal, but are probably also applicable to many other β γ-nuclides. a) A prolonged interval between contamination and decontamination has a negative effect on the result of the decontamination. Therefore start decontamination as soon as possible after the contamination. b) Soap and water has proved to be the most suitable decontamination agent. A number of other agents have appeared to be harmful to the skin. Therefore, first of all use only soap and water in connection with gentle rubbing. c) No clear connection between the temperature of the water for washing and the result of the decontamination has been demonstrated. d) Skin not degreased before the contamination seems to be somewhat easier to decontaminate than degreased skin, particularly if the activity has been on the skin for a long time. Therefore do not remove the sebum of the skin when engaged on radioactive work involving contamination risks. e) Irrigation of the contaminated surface with a solution containing the corresponding inactive ions or ordinary water in large quantities may considerably decrease the skin contamination. f) In radioactive work of long duration involving high risks of contamination prophylactic measures in the form of a protective substance ('invisible glove'), type Kerodex, may make decontamination easier

Selective cesium and strontium removal for TRU-liquid waste including fission products and concentrated nitric acids

International Nuclear Information System (INIS)

Mimori, T.; Miyajima, K.; Kozeki, M.; Kubota, T.; Tusa, E.; Keskinen, A.

1996-01-01

A nuclide removal system was designed for treatment of liquid radioactive waste at the Japan Atomic Energy Research Institute (JAERI) Tokai site. Total system will include removal of plutonium, cesium and strontium. Removal of plutonium will be carried out by a method developed by JAERI. Removal of cesium and strontium will be carried out by the methods developed in Finland. The whole project will be implemented for JAERI in cooperation between Mitsui Engineering and Shipbuilding and IVO International. This project has been carried out under the Science and Technology Agency (STA) of Japan. The liquid to be treated includes 7.4x10 9 Bq/L of cesium and 7.4x10 9 Bq/L of strontium. The amount of alpha nuclides is 3.7x10 6 Bq/L. Nitric acid concentration is 1.74 mol/L. The volume of 11,000 liters had to be treated in 200 batches of operation. Removal of cesium and strontium is based on the use of new ion exchange materials developed in Finland. These inorganic ion exchange materials have extremely good properties to separate cesium and strontium from even very difficult liquids. Ion exchange material will be used in columns, where there are materials both for cesium and strontium. According to column tests with simulated waste, one 2 liter column will effectively reach the required DF during 10 batches of operation. Purified liquid can be led to further liquid treatment at the site. After treatment of liquids, both used particle filters and used ion exchange columns will be drained and stored to wait for final treatment and disposal. The designed treatment system has a special beneficial feature as it does not produce secondary waste. Final waste is in the form of particle filters or ion exchange columns with material. Used ion exchange columns and filters will be replaced with new ones by means of remote handling. Construction of the treatment system will be scheduled to commence in FY1995 and assemblying at the site in FY1996. (J.P.N.)

Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

Directory of Open Access Journals (Sweden)

Byung-Sik Lee

2015-12-01

Full Text Available The aim of this work is to investigate the transport mechanism of radioactive nuclides through the reverse osmosis (RO membrane and to estimate its effectiveness for nuclide separation from radioactive liquid waste. An analytical model is developed to simulate the RO separation, and a series of experiments are set up to confirm its estimated separation behavior. The model is based on the extended Nernst–Plank equation, which handles the convective flux, diffusive flux, and electromigration flux under electroneutrality and zero electric current conditions. The distribution coefficient which arises due to ion interactions with the membrane material and the electric potential jump at the membrane interface are included as boundary conditions in solving the equation. A high Peclet approximation is adopted to simplify the calculation, but the effect of concentration polarization is included for a more accurate prediction of separation. Cobalt and cesium are specifically selected for the experiments in order to check the separation mechanism from liquid waste composed of various radioactive nuclides and nonradioactive substances, and the results are compared with the estimated cobalt and cesium rejections of the RO membrane using the model. Experimental and calculated results are shown to be in excellent agreement. The proposed model will be very useful for the prediction of separation behavior of various radioactive nuclides by the RO membrane.

Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Sik [KEPCO Engineering and Construction, Gimcheon (Korea, Republic of)

2015-12-15

The aim of this work is to investigate the transport mechanism of radioactive nuclides through the reverse osmosis (RO) membrane and to estimate its effectiveness for nuclide separation from radioactive liquid waste. An analytical model is developed to simulate the RO separation, and a series of experiments are set up to confirm its estimated separation behavior. The model is based on the extended Nernst-Plank equation, which handles the convective flux, diffusive flux, and electromigration flux under electroneutrality and zero electric current conditions. The distribution coefficient which arises due to ion interactions with the membrane material and the electric potential jump at the membrane interface are included as boundary conditions in solving the equation. A high Peclet approximation is adopted to simplify the calculation, but the effect of concentration polarization is included for a more accurate prediction of separation. Cobalt and cesium are specifically selected for the experiments in order to check the separation mechanism from liquid waste composed of various radioactive nuclides and nonradioactive substances, and the results are compared with the estimated cobalt and cesium rejections of the RO membrane using the model. Experimental and calculated results are shown to be in excellent agreement. The proposed model will be very useful for the prediction of separation behavior of various radioactive nuclides by the RO membrane.

Plant for removing radioactive rare gases

International Nuclear Information System (INIS)

An, Buzai; Kanazawa, Toshio

1977-01-01

The outline of the pilot plant to remove and recover radioactive rare gases generated from nuclear power plants, reprocessing installations for nuclear fuel, nuclear research installations, etc. is described below. Among the studies of various processes such as liquefaction and distillation, absorption into solvents, active carbon adsorption, diaphragm method, etc., the liquefaction and distillation process by rectification at low temperature has been positively developed. It is in the stage of practical application for removing rare gases in waste gases from reprocessing and nuclear power plants. This is the process with high safety and excellent rare gas removing capability. Further research and development have been also made for selective adsorption and desorption method at low temperature which is very efficient as there is no release of long life nuclides such as Krypton-85. Rare gases recovered by the above mentioned removal systems must be stored safely for a long time as their half lives are long and specific radioactivities are high. The study has been made continuously on the storage methods including adsorption in cylinders and remotely automatically sealing storing system. (Kobatake, H.)

Radioactive nuclides in the marine environment

International Nuclear Information System (INIS)

Yamato, Aiji; Miyagawa, Naoto; Miyanaga, Naotake

1984-01-01

To investigate behaviour of 95 Zr, 95 Nb in the marine environment, various samples have been collected and measured by means of Ge(Li) γ-ray spectrometry and/or radiochemical analysis during a period from 1974 to 1982 at coastal area of Tokai-mura, Ibaraki prefecture. Concentration of the nuclides in seaweeds increased remarkably after atmospheric nuclear detonation by P.R. of China, and the activity ratio between the nuclides changed by time was not fit well by the transient decay equation. Concentration variation in sea water was smaller than that in sea weeds, and the minimum change in sea sediment. Increase of concentration in these environmental samples was observed in chronological order of sea water, sea weeds then sediment after detonations, suggesting that the uptake of the nuclides by these sea weeds from sea water is faster than that via root. Observed concentration factors on the nuclides by sea weeds were calculated from the observed concentrations in sea water and sea weeds. Maximum values on 95 Zr and 95 Nb were 2110, 2150, respectively for Ecklonia cava and Eisenia bicyclis. (author)

Algorithm improvement program nuclide identification algorithm scoring criteria and scoring application.

Energy Technology Data Exchange (ETDEWEB)

Enghauser, Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-02-01

The goal of the Domestic Nuclear Detection Office (DNDO) Algorithm Improvement Program (AIP) is to facilitate gamma-radiation detector nuclide identification algorithm development, improvement, and validation. Accordingly, scoring criteria have been developed to objectively assess the performance of nuclide identification algorithms. In addition, a Microsoft Excel spreadsheet application for automated nuclide identification scoring has been developed. This report provides an overview of the equations, nuclide weighting factors, nuclide equivalencies, and configuration weighting factors used by the application for scoring nuclide identification algorithm performance. Furthermore, this report presents a general overview of the nuclide identification algorithm scoring application including illustrative examples.

NNDC Chart of Nuclides

International Nuclear Information System (INIS)

Sonzogni, A.

2008-01-01

The National Nuclear Data Center has recently developed an interactive chart of nuclides, http://www.nndc.bnl.gov/chart/, that provides nuclear structure and decay data. Since its implementation, it has proven to be one of the most popular web products. The information presented is derived from the ENSDF and Nuclear Wallet Card databases. Experimentally known nuclides are represented by a cell in chart with the number of neutrons on the horizontal axis and the number of protons on the vertical axis. The color of the cell is used to indicate the ground state half-life or the ground state predominant decay mode. (author)

Selective Redundancy Removal: A Framework for Data Hiding

Directory of Open Access Journals (Sweden)

Ugo Fiore

2010-02-01

Full Text Available Data hiding techniques have so far concentrated on adding or modifying irrelevant information in order to hide a message. However, files in widespread use, such as HTML documents, usually exhibit high redundancy levels, caused by code-generation programs. Such redundancy may be removed by means of optimization software. Redundancy removal, if applied selectively, enables information hiding. This work introduces Selective Redundancy Removal (SRR as a framework for hiding data. An example application of the framework is given in terms of hiding information in HTML documents. Non-uniformity across documents may raise alarms. Nevertheless, selective application of optimization techniques might be due to the legitimate use of optimization software not supporting all the optimization methods, or configured to not use all of them.

LAKE-0: a model for the simulation of nuclides transfer in lake scenarios

Energy Technology Data Exchange (ETDEWEB)

Garcia-Olivares, A.; Aguero, A.; Pinedo, P.

1994-07-01

This report presents documentation and a user's manual for the program LAKE-0, a mathematical model of nuclides transfer in lake scenarios. Mathematical equations and physical principles used to develop the code are presented in section 2. The program use is presented in section 3 including input data sets and output data. Section 4 presents two example problems, and some results. The complete program listing including comments is presented in Appendix A. Nuclides are assumed to center the lake via atmospheric deposition and carried by the water runoff and the dragged sediments from the adjacent catchment. The dynamics of the nuclides inside the lake is based in the model proposed by Codell (11) as modified in (5). The removal of concentration from the lake water is due to out flow from the lake and to the transfer of activity to the button sediments. The model has been applied to the Esthwaite Water (54 degree celsius 2 l'N, 03 degree celsius 00'W at 65 m. asi.) in the frame of the VAMP Aquatic Working Group (8) and to Devoke Water (5 21.5'N, 03H8'W at 230 m. asi.). (Author). 13 refs.

Nuclide content in reactor waste

International Nuclear Information System (INIS)

1981-11-01

Certain corrosion and fission products of importance in reactor waste management cannot be measured by gammaspectrometric techniques. In this study, a method is suggested by which the occurence of such nuclides can be quantitatively related to suitable gamma-emitters of similar origin. The method is tested by statistical analysis on the waste data recorded from two Swedish nuclear power plants. As this method is not applicable for Carbon-14, this nuclide was measured directly in spent ion exchange resins from three Finnish and Swedish power plants. (author)

Local tissue distribution of fissile nuclides

International Nuclear Information System (INIS)

Smith, J.M.

1981-01-01

Conventional tissue-section autoradiography of alpha-emitting actinide elements may require prohibitively long exposure times. Neutron-induced or fission-track autoradiography can be used for fissile nuclides such as 233 U, 235 U, and 239 Pu to circumvent this difficulty. The detection limit for these nuclides is about 4 x 10 -13 (weight fraction). This paper describes a specific technique for determining their microdistribution with histologically stained tissue sections

Vertical oceanic transport of alpha-radioactive nuclides by zooplankton fecal pellets

International Nuclear Information System (INIS)

Higgo, J.J.W.; Cherry, R.D.; Heyraud, M.; Fowler, S.W.; Beasley, T.M.

1980-01-01

This paper gives the results of research to explain the role played by marine plankton metabolism in the vertical oceanic transport of the alpha-emitting nuclides. The common Mediterranean euphausiid, Meganyctiphanes norvegica, was selected as the typical zooplanktonic species that is the focus of this work. Measurements of 239 240 Pu, 238 U, 232 Th, and 210 Po are reported in whole euphausiids and in euphausiid fecal pellets and molts. The resulting data are inserted into a simple model that describes the flux of an element through a zooplanktonic animal. Concentrations of the nuclides concerned are high in fecal pellets, at levels which are typical of geological rather than biological material. It is suggested that zooplanktonic fecal pellets play a significant role in the vertical oceanic transport of plutonium, thorium, and polonium

Square chart of nuclides with the best coordinates

International Nuclear Information System (INIS)

Wang Yuying

2001-01-01

It analyzes upper limiting feature of even Z=60-82 in different charts of nuclides. It has illustrated that the break line of upper limiting Z=60-82 in the chart of nucleus with proton number Z and neutron number N, parameters Z and H (=N-Z), two new parameters S(=2Z-N) and H, and parameters K (=S-H) and H, in proper order, it shows that the break line trends from the left lower to the right upper, the line alternates with horizontal and vertical, and the line trends from the right lower to the left upper. Here it finds that the square chart of nuclides places the middle among these charts. It shows that nuclei distribution is concentrated, so are scope of whole region of nuclides in the different charts of nuclides

Special actinide nuclides: Fuel or waste?

International Nuclear Information System (INIS)

Srinivasan, M.; Rao, K.S.; Dingankar, M.V.

1989-01-01

The special actinide nuclides such as Np, Cm, etc. which are produced as byproducts during the operation of fission reactors are presently looked upon as 'nuclear waste' and are proposed to be disposed of as part of high level waste in deep geological repositories. The potential hazard posed to future generations over periods of thousands of years by these long lived nuclides has been a persistent source of concern to critics of nuclear power. However, the authors have recently shown that each and every one of the special actinide nuclides is a better nuclear fuel than the isotopes of plutonium. This finding suggests that one does not have to resort to exotic neutron sources for transmuting/incinerating them as proposed by some researchers. Recovery of the special actinide elements from the waste stream and recycling them back into conventional fission reactors would eliminate one of the stigmas attached to nuclear energy

Nuclide Importance and the Steady-State Burnup Equation

International Nuclear Information System (INIS)

Sekimoto, Hiroshi; Nemoto, Atsushi

2000-01-01

Conventional methods for evaluating some characteristic values of nuclides relating to burnup in a given neutron spectrum are reviewed in a mathematically systematic way, and a new method based on the importance theory is proposed. In this method, these characteristic values of a nuclide are equivalent to the importances of the nuclide. By solving the equation adjoint to the steady-state burnup equation with a properly chosen source term, the importances for all nuclides are obtained simultaneously.The fission number importance, net neutron importance, fission neutron importance, and absorbed neutron importance are evaluated and discussed. The net neutron importance is a measure directly estimating neutron economy, and it can be evaluated simply by calculating the fission neutron importance minus the absorbed neutron importance, where only the absorbed neutron importance depends on the fission product. The fission neutron importance and absorbed neutron importance are analyzed separately, and detailed discussions of the fission product effects are given for the absorbed neutron importance

Finite medium Green's function solutions to nuclide transport in porous media

International Nuclear Information System (INIS)

Oston, S.G.

1979-01-01

Current analytical techniques for predicting the transport of nuclides in porous materials center on the Green's function approach - i.e., determining the response characteristics of a geologic pathway to an impulse function input. To data, the analyses all have set the boundary conditions needed to solve the 1-D transport equation as though each pathway were infinite in length. The purpose of this work is to critically examine the effect that this infinite pathway assumption has on Green's function models of nuclide transport in porous media. The work described herein has directly attacked the more difficult problem of obtaining suitable Green's functions for finite pathways whose dimensions, in fact, may not be much greater than the diffusion length. Two different finite media Green's functions describing the nuclide mass flux have been determined, depending on whether the pathway is terminated by a high or a low flow resistance at the outlet end. Pulse shapes and peak amplitudes have been computed for each Green's function over a wide range of geohydrologic parameters. These results have been compared to both infinite and semi-infinite medium solutions. It was found that predicted pulse shapes are quite sensitive to selection of a Green's function model for short pathways only. For long pathways all models tend toward a symmetric Gaussian flux-time history at the outlet. Thus, the results of our previous waste transport studies using the infinite pathway assumption are still generally valid because they always included at least one long pathway. It was also found that finite medium models offer some unique computational advantages for evaluating nuclide transport in a series of connecting pathways

Improvement of WWW chart of the nuclides interface

International Nuclear Information System (INIS)

Okamoto, Tsutomu; Minato, Futoshi; Iwamoto, Osamu; Koura, Hiroyuki

2016-03-01

The booklet 'chart of the nuclides' is issued every 4 years since 1976 from Nuclear Data Center, Japan Atomic Energy Agency. The chart of the nuclides for WWW (World Wide Web) was developed in 1999 in order to be available from the Internet browser. The Internet connection speeds, browser functions and JavaScript libraries has, however, progressed at present compared with the Internet technology in those days. In connection with the release of the 2014 edition of the chart of the nuclides, the interface of the WWW chart of the nuclides has been improved by introducing new Internet technologies aiming at enhancing convenience on accessibilities via browsers. We introduced a scrolling screen that would make capabilities of easy screen movement on a map with the addition of the drag scrolling function. Considering smart phone access, the light-weight edition which introduced automatic switch was prepared. The new system results in reduction in access time and usefulness in mobile environment. The method of making figures of the chart was reconsidered due to addition of new decay schemes to the 2014 edition. SVG (Scalable Vector Graphics) was adopted so as to make figures easily. It is concluded that the accessibilities of WWW chart of the nuclides are substantially improved from the previous version by introducing the new technologies. (author)

Process for selected gas oxide removal by radiofrequency catalysts

Science.gov (United States)

Cha, Chang Y.

1993-01-01

This process to remove gas oxides from flue gas utilizes adsorption on a char bed subsequently followed by radiofrequency catalysis enhancing such removal through selected reactions. Common gas oxides include SO.sub.2 and NO.sub.x.

Multi-pathway model of nuclide transport in fractured media and its application

International Nuclear Information System (INIS)

Li Xun; Yang Zeping; Li Jinxuan

2010-01-01

In order to know the law of nuclide transport in fracture system, the basic differential equations of nuclide transport in fracture and matrix were obtained based on the dual media theory, and the general analytic solutions of nuclide transport in single fractured media with exponential attenuation source in fracture were deduced by Laplace transform, and one-dimensional multi-pathway model of nuclide transport was proposed based on dual media theory and stochastic distribution of fracture parameters. The transport of Th-229, Cs-135 and Se-79 were simulated with this model, the relative concentration of these nuclides in fracture system were predicted. Further more, it was deduced that aperture and velocity can distinctly influence transport of nuclide by comparing with the results which were simulated by single fracture model. (authors)

Nuclides and isotopes. Twelfth edition

International Nuclear Information System (INIS)

Anon.

1977-01-01

This explanatory booklet was designed to be used with the Chart of the Nuclides. It contains a brief history of the atomic theory of matter: ancient speculations, periodic properties of elements (Mendeleev table), radioactivity, early models of atomic structure, the Bohr atom, quantum numbers, nature of isotopes, artificial radioactivity, and neutron fission. Information on the pre-Fermi (natural) nuclear reactor at Oklo and the search for superheavy elements is given. The booklet also discusses information presented on the Chart and its coding: stable nuclides, metastable states, data display and color, isotopic abundances, neutron cross sections, spins and parities, fission yields, half-life variability, radioisotope power and production data, radioactive decay chains, and elements without names. The Periodic Table of the Elements is appended. 3 figures, 3 tables

Nuclide release from the near-field of a L/ILW repository

International Nuclear Information System (INIS)

Karlsson, L.G.; Hoeglund, L.O.; Pers, K.

1986-12-01

For Project Gewaehr 1985, the release of nuclides from a repository for low- and intermediate-level radioactive waste is calculated. The calculations are made for a reference design repository located in the marl host rock at the Oberbauen Stock reference site. The results are limited to the release of the nuclides from the waste through the engineered barriers into the surrounding host rock and will, therefore, constitute a source term for the far-field and biosphere calculations. The most probable nuclide transport mechanism is diffusion and releases are thus influenced by the nuclide diffusivities in the barriers, nuclide sorption and nuclide solubility limits. Degradation of the engineered concrete barriers is taken into account. The effects of convective flow through the barriers are described elsewhere. A near-field release model is presented. It consists of a set of computer programs suited to handel different repository designs, solubility limitations and the different waste categories. The release calculations were made for a base case in which best estimates of the parameters were used. Sensitivity to the choice of the most important parameters was tested by parameter variations. The numerical models used were checked by comparative calculations with different codes and similar data. The results of the base calculations show that near-field barriers will cause both a delay of the release to the far-field and a reduced rate of release. The sorbed nuclides, comprising the actinides and some activation and fission products, will be delayed by 10'000 years and have a maximum release rate of less than 10 -3 Ci/a each. The non-sorbed nuclides are delayed by only about 100 years and the maximum release rate is less than 10 -2 Ci per year and nuclide. The parameter variations and the design model tests gave only limited deviations from the base case results. (author)

The stochastic nuclide transport model for buffer/backfill materials

International Nuclear Information System (INIS)

Ma Liping; Han Yongguo

2014-01-01

Currently, study on nuclide migration law in geological disposal repository of high level waste is assumed buffer/backfill layer to be continuous medium, utilized the continuity equation, equation of state, the equations of motion, etc, formed a set of theory and method to estimate nuclide concentration distribution in buffer/backfill layer, and provided an important basis for nuclide migration rules of repository. However, it is necessary to study the buffer/backfill layer microstructure and subtly describe the pore structure and fracture system of the buffer/backfill layer, and reflect the changes in connectivity and in different directions of the buffer/backfill layer. Through using random field theory, the nuclide transport for the buffer/backfill layer in geological disposal repository of nuclear waste is described in the paper. This paper mainly includes that, t represents the time, ξ t ⊂ Z d = d represents the integer lattice, Z represents collectivity integers, d = l, 2, 3, for instance, d = 2, Z d = {(m, n) : m, n ∈ Z} the state point of ξ t is typically considered to be occupied by the nuclide concentration values of the buffer/backfill layer, ξ t also represents random set in the diagram of two dimensional integer lattice, namely, t ∈ [0, T], {ξ t ,0 ≤ t ≤ ⊂ T} Consequently, according to the stochastic process obtained above, the changes of the nuclide concentration values of the buffer/backfill layer or the buffer/backfill laboratory materials in the repository with the time can be known. (authors)

Water hyacinth : the suitable aquatic weed for radioactive nuclide absorption in water

International Nuclear Information System (INIS)

Chalermsuk, Somporn; Jungpattanawadee, Komgrid; Tongrong, Thanachai

2003-06-01

The experiment was set up to determine the quantities of radioactive nuclides which were absorbed by aquatic weeds in Khon Kaen Province. The best aquatic weed would be used to be sampled for study of radioactive nuclide quantities in natural water resources. Seven kinds of aquatic weeds in the same site were corrected and pretreated by ovening to be ash at 450 οC. Gamma-ray spectra of the samples were detected and analyzed for comparing the quantities of radioactive nuclides. Gamma-ray spectrometry with a HPGe detector was set up to detect radioactive nuclides and their quantities in ashes of aquatic weeds. According to this study, water hyacinth, from seven aquatic weeds, had the most quantities of radioactive nuclides. The water hyacinth with 30 cm leaves in length can absorb the most quantities of radioactive nuclides

Development of a new nuclide generation and depletion code using a topological solver based on graph theory

International Nuclear Information System (INIS)

Kasselmann, S.; Scholthaus, S.; Rössel, C.; Allelein, H.-J.

2014-01-01

The problem of calculating the amounts of a coupled nuclide system varying with time especially when exposed to a neutron flux is a well-known problem and has been addressed by a number of computer codes. These codes cover a broad spectrum of applications, are based on comprehensive validation work and are therefore justifiably renowned among their users. However, due to their long development history, they are lacking a modern interface, which impedes a fast and robust internal coupling to other codes applied in the field of nuclear reactor physics. Therefore a project has been initiated to develop a new object-oriented nuclide transmutation code. It comprises an innovative solver based on graph theory, which exploits the topology of nuclide chains. This allows to always deal with the smallest nuclide system for the problem of interest. Highest priority has been given to the existence of a generic software interfaces well as an easy handling by making use of XML files for input and output. In this paper we report on the status of the code development and present first benchmark results, which prove the applicability of the selected approach. (author)

Distribution of transuranic nuclides in soils: a review

International Nuclear Information System (INIS)

Essington, E.H.; Fowler, E.B.

1976-01-01

The literature is reviewed to ascertain the degree of movement and the distribution patterns for transuranic and uranium nuclides in soils. Typical plutonium and uranium profiles are presented and an attempt is made to identify unique characteristics causing deviation from an ideal distribution pattern. By far most of the distribution observations are with plutonium and little is reported for uranium and other transuranic nuclides

Mass measurements on short-lived Cd and Ag nuclides at the online mass spectrometer ISOLTRAP

International Nuclear Information System (INIS)

Breitenfeldt, Martin

2009-01-01

ISOLDE side, e.g., by improving the selectivity of the transfer line or on the ISOLTRAP setup by implementing an electrostatic ion beam trap for a fast and efficient isobaric selection. Nevertheless the obtained results contribute to the knowledge of nuclear structure. The trends in the two-neutron separation-energy S2n and the interaction between the last neutrons and last protons δV pn were corrected to more smooth evolutions, as already seen in other regions of the nuclear chart. The strongest corrections have been observed for even-N nuclides, were more new experimental data are available. Thus, new measurements on odd-N nuclides are suggested. This also is underlined by the trends observed in the Garvey-Kelson relations for the neutron-rich Cd nuclides. Furthermore, it has been shown, that the prominent structure of the δV pn for an entire chain of nuclides including inflexion points can be reproduced by using simple relations between quantum numbers of the occupied orbits. This approach connects ten values for each nuclide with only one adjusted parameter. This has been investigated for 63 δV pn values of even-even nuclides in the vicinity of Z = 50 and 50 ≤ N ≤ 82. The simple model works remarkably well for the elements Cd, Sn, and Te. Small deviation have been observed for the Xe and Pd nuclides which were explained with the limitations of the model to the vicinity of the close shells, where the nuclides have only few valence protons and neutrons. Thus, it would be interesting to study the overlap model in the vicinity of the doubly magic nuclide 208 Pb and also for more neutron-rich nuclides in the region of 132 Sn. (orig.)

Mutagenic effects induced by accumulating rare earths nuclides with different ionic radius in fission fragments

International Nuclear Information System (INIS)

Zhu Shoupeng; Wang Liuyi; Cao Genfa; Sun Baofu

1991-05-01

The purpose of the present study was to ascertain the correlation between the different ionic radius of rare earths nuclides such as 170 Tm, 152 Eu, 147 Pm and its accumulation peculiarity as well as induction of mutagenic effect on bone marrow cells. The study showed that the accumulation peculiarity of rare earths nuclides will vary with the ionic radius. The results indicated that large ionic radius of 147 Pm was selectively localized in liver in early stage, while small ionic radius of 170 Tm and 152 Eu were deposited in bone predominantly. There was a positive relationship between the incidence of chromosome aberration rates and the absorption dose in skeleton by 170 Tm, 152 Eu, or 147 Pm. Studies indicated that the chromosome aberration rates were elevated when the absorption dose in skeleton was increased. Among the type of chromosome aberrations induced by rare earths nuclides with different ionic radius, chromatid breakage was predominant, accompanied with a few chromosome breakage and translocation. At the same time mitosis index of metaphase cells was depressed. Internal contamination of 170 Tm, 152 Eu, or 147 Pm can be induced by some aberrations in one cell. This phenomenon might be due in part to nonuniform irradiation of bone marrow cell with local deposition of these rare earths nuclides with different ionic radius

Nuclide identifier and grat data reader application for ORIGEN output file

International Nuclear Information System (INIS)

Arif Isnaeni

2011-01-01

ORIGEN is a one-group depletion and radioactive decay computer code developed at the Oak Ridge National Laboratory (ORNL). ORIGEN takes one-group neutronics calculation providing various nuclear material characteristics (the buildup, decay and processing of radioactive materials). ORIGEN output is a text-based file, ORIGEN output file contains only numbers in the form of group data nuclide, nuclide identifier and grat. This application was created to facilitate data collection nuclide identifier and grat, this application also has a function to acquire mass number data and calculate mass (gram) for each nuclide. Output from these applications can be used for computer code data input for neutronic calculations such as MCNP. (author)

Nuclides.net: An integrated environment for computations on radionuclides and their radiation

International Nuclear Information System (INIS)

Galy, J.; Magill, J.

2002-01-01

Full text: The Nuclides.net computational package is of direct interest in the fields of environment monitoring and nuclear forensics. The 'integrated environment' is a suite of computer programs ranging from a powerful user-friendly interface, which allows the user to navigate the nuclide chart and explore the properties of nuclides, to various computational modules for decay calculations, dosimetry and shielding calculations, etc. The main emphasis in Nuclides.net is on nuclear science applications, such as health physics, radioprotection and radiochemistry, rather than nuclear data for which excellent sources already exist. In contrast to the CD-based Nuclides 2000 predecessor, Nuclides.net applications run over the internet on a web server. The user interface to these applications is via a web browser. Information submitted by the user is sent to the appropriate applications resident on the web server. The results of the calculations are returned to the user, again via the browser. The product is aimed at both students and professionals for reference data on radionuclides and computations based on this data using the latest internet technology. It is particularly suitable for educational purposes in the nuclear industry, health physics and radiation protection, nuclear and radiochemistry, nuclear physics, astrophysics, etc. The Nuclides.net software suite contains the following modules/features: a) A new user interface to view the nuclide charts (with zoom features). Additional nuclide charts are based on spin, parity, binding energy etc. b) There are five main applications: (1) 'Decay Engine' for decay calculations of numbers, masses, activities, dose rates, etc. of parent and daughters. (2) 'Dosimetry and Shielding' module allows the calculation of dose rates from both unshielded and shielded point sources. A choice of 10 shield materials is available. (3) 'Virtual Nuclides' allows the user to do decay and dosimetry and shielding calculations on mixtures of

Selection of exception limits for all actinide nuclides based on revised criteria for safe international transport and including storage delay

International Nuclear Information System (INIS)

Lavarenne, C.; Rouyer, V.; Mennerdahl, D.; Dean, C.; Barton, N.; Jean, F.

2004-01-01

Since 1998, there have been some speculations about future transport of significant quantities and concentrations of other actinide nuclides than the four currently listed in the regulation for the safe transport of the radioactive material. Therefore, it raised a need to specify exception limits for such actinides. In order to define credible exception limits, it was necessary to have reasonably accurate data for all actinide nuclides. Then the DGTREN/participants decided to perform calculations with different codes (MONK, MCNP, CRISTAL and SCALE) and different cross-section libraries (JEF2.2, ENDFB, etc.). The parameters of interest (such as k-infinite, critical masses) were determined. This article presents the work achieved and the questions raised, e.g. related to the effect of the radioactive decay of the isotopes on the criticality risks. It also points out the need for an evolution of the regulation of the safe transport of radioactive materials and gives a proposition of modification for the IAEA requirements related to, firstly, the list of the fissile materials, secondly, the rule to determine the quantities of actinide nuclides that can be excepted from the requirements for the packages containing fissile materials

Calculation device for amount of heavy element nuclide in reactor fuels and calculation method therefor

International Nuclear Information System (INIS)

Naka, Takafumi; Yamamoto, Munenari.

1995-01-01

When there are two or more origins of deuterium nuclides in reactor fuels, there are disposed a memory device for an amount of deuterium nuclides for every origin in a noted fuel segment at a certain time point, a device for calculating the amount of nuclides for every origin and current neutron fluxes in the noted fuel segment, and a device for separating and then displaying the amount of deuterium nuclides for every origin. Equations for combustion are dissolved for every origin of the deuterium nuclides based on the amount of the deuterium nuclides for every origin and neutron fluxes, to calculate the current amount of deuterium nuclides for every origin. The amount of deuterium nuclides originated from uranium is calculated ignoring α-decay of curium, while the amount of deuterium nuclides originated from plutonium is calculated ignoring the generation of plutonium formed from neptunium. Deuterium nuclides can be measured and controlled accurately for every origin of the reactor fuels. Even when nuclear fuel materials have two or more nationalities, the measurement and control thereof can be conducted for every country. (N.H.)

Separation of mobile long-lived nuclides in a simplified reprocessing

International Nuclear Information System (INIS)

Fujine, Sachio; Uchiyama, Gunzo; Kihara, Takehiro; Asakura, Toshihide; Sakurai, Tsutomu

1997-01-01

Enhancing confinement efficiency of long-lived nuclides in a simplified Purex process is the primary subject of our PARC (Partitioning Conundrum Key) R and D project. Nuclides focused here are all susceptible to diffuse into the environment and highly concerned as potential hazard among the long-lived nuclides in spent fuels. New functions in PARC concept are designed to mitigate the environmental impacts of reprocessing wastes and also to improve the economy of reprocessing in the future. Experimental work has been conducted to demonstrate the feasibility of the concept. (author)

A Study on the Nuclide Migration and Retardation Using Natural Barrier

International Nuclear Information System (INIS)

Baik, Min Hoon; Park, Chung Kyun; Kim, Seung Soo

2010-02-01

In this study, we investigated the properties of geochemical reactions and sorption of high-level radionuclides (U, Th, Am, and Np), constructed databases for the geochemical reactions and sorption of the high-level radionuclides, and developed application methodologies of the databases. For the investigation on the nuclide migration and retardation through fractured rocks in KURT, in-situ solute migration system and on-line monitoring system were installed. The migration and retardation behaviors of nuclides were investigated annually for non-sorbing, simply sorbing and multi-valent sorbing nuclides, respectively, and interactions with fracture-filling materials were also analyzed. Besides, researches difficult to perform in KURT were carried out in foreign underground research facilities as joint studies for nuclide and colloid migration. The results from domestic and foreign underground facilities were compared each other and the reliability of the domestic results were assured from this. Diffusion depths of high-level radionuclides into rock matrix were measured in KURT conditions and their diffusion properties were analyzed and evaluated. In addition, the effects of bio-mineralization and redox reactions of a nuclide and microbe on nuclide behaviors were carried out to study the effects of combined interactions between minerals and microbes on the radionuclide migration and retardation

The determination of critical nuclides in PWR waste streams

International Nuclear Information System (INIS)

Centner, B.

1993-01-01

A current method for the determination of critical nuclides in the waste streams produced by a nuclear power reactor consists in applying correlation factors or scaling factors between those critical nuclides and so called key radionuclides, which can be easily measured and are representatives for the occurrence of activation products (Co-60) and fission products (Cs-137) in the waste streams. BELGATOM (BA) has developed a code (low level waste Activity Assessment-LLWAA code). The use of the code can clarify the analytical technique lower detection level that has to be achieved for each critical nuclide, in order to accurately measure it's activity in the different types of waste. (1 tab., 1 fig.)

Nuclide migration from a bedrock repository for spent fuel

International Nuclear Information System (INIS)

Grundfelt, B.

1978-08-01

A study of the migration of radionuclides from a repository for spent, unprocessed fuel is presented. The study makes use of a unidimensional dispersion model developed at BNWL. The results show that a number of nuclides decay significantly during the migration. The doses to future man was calculated in a separate study performed at Studsvik. The dose calculations are based on the activity in-flows, presented in this report, and show that the predominant dose contribution comes from the nuclide radium-226. This nuclide is formed mainly by the decay of uranium-238 which means that the main part of the dose would arise even from a repository for non-irradiated fuel

[The fate of nuclides in natural water systems

International Nuclear Information System (INIS)

Turekian, K.K.

1989-01-01

Our research at Yale on the fate of nuclides in natural water systems has three components to it: the study of the atmospheric precipitation of radionuclides and other chemical species; the study of the behavior of natural radionuclides in groundwater and hydrothermal systems; and understanding the controls on the distribution of radionuclides and stable nuclides in the marine realm. In this section a review of our progress in each of these areas is presented

Contribution of short-lived nuclides to decay heat

International Nuclear Information System (INIS)

Katakura, Jun-ichi

1987-01-01

Comments are made on the calculation of decay heat, centering on evaluation of average decay energy. It is difficult to obtain sufficiently useful decay diagrams of short lived nucleides. High-energy levels are often missing in inferior decay diagrams, leading to an overestimation of the intensity of beta-rays at low-energy levels. Such an overestimation or underestimation due to the inferiority of a decay diagram is referred to as pandemonium effect. The pandemonium effect can be assessed by means of the ratio of the measured energy of the highest level of the daughter nuclide to the Q β -value of the beta-decay. When a satisfactory decay diagram cannot be obtained, the average decay energy has to be estimated by theoretical calculation. The gross theory for beta-decay proposed by Yamada and Takahashi is employed for the calculation. To carry out the calculation according to this theory, it is required to determine the value for the parameter Q 00 , the lowest energy of the daughter nuclide that meets the selection rule for beta-decay. Currently, Q 00 to be used for this purpose is estimated from data on the energy of the lowest level found in a decay diagram, even if it is inferior. Some examples of calculation of decay heat using the average beta- or gamma-ray energy are shown and compared with measurements. (author)

I-129, Kr-85, C-14 and NO/sub x/ removal from spent fuel dissolver off-gas at atmospheric pressure and at reduced off-gas flow

International Nuclear Information System (INIS)

Henrich, E.; Huefner, R.

1981-01-01

A dissolver off-gas (DOG) system suitable for a LWR, FBR or HTR spent fuel reprocessing plant is described, incorporating the following features: (1) the DOG flow is reduced to a reasonably small volume, using fumeless dissolution conditions, by maintaining high concentrations, the retention procedures are simplified and accompanied by an economic reduction of the equipment size; (2) all process operations are conducted at atmospheric or subatmospheric pressure, including noble gas removal by selective absorption, without using high temperature processes; (3) all processes, except HEPA filtering, are continuous and do not accumulate large amounts of waste nuclides, the DOG process sequence is mutually compatible with itself and with processing in the headend, showing on-line redundancy for the removal of the most radiotoxic nuclides; and (4) the DOG system only deviates slightly from proven technology. The stage of development and relevant results are given both for a lab. scale and a pilot plant scale

Mass measurements on short-lived Cd and Ag nuclides at the online mass spectrometer ISOLTRAP

Energy Technology Data Exchange (ETDEWEB)

Breitenfeldt, Martin

2009-07-03

, the r process has not yet been reached. Further technical development on suppression of contaminants are required. This includes improvements on the ISOLDE side, e.g., by improving the selectivity of the transfer line or on the ISOLTRAP setup by implementing an electrostatic ion beam trap for a fast and efficient isobaric selection. Nevertheless the obtained results contribute to the knowledge of nuclear structure. The trends in the two-neutron separation-energy S2n and the interaction between the last neutrons and last protons {delta}V{sub pn} were corrected to more smooth evolutions, as already seen in other regions of the nuclear chart. The strongest corrections have been observed for even-N nuclides, were more new experimental data are available. Thus, new measurements on odd-N nuclides are suggested. This also is underlined by the trends observed in the Garvey-Kelson relations for the neutron-rich Cd nuclides. Furthermore, it has been shown, that the prominent structure of the {delta}V{sub pn} for an entire chain of nuclides including inflexion points can be reproduced by using simple relations between quantum numbers of the occupied orbits. This approach connects ten values for each nuclide with only one adjusted parameter. This has been investigated for 63 {delta}V{sub pn} values of even-even nuclides in the vicinity of Z = 50 and 50 {<=} N {<=} 82. The simple model works remarkably well for the elements Cd, Sn, and Te. Small deviation have been observed for the Xe and Pd nuclides which were explained with the limitations of the model to the vicinity of the close shells, where the nuclides have only few valence protons and neutrons. Thus, it would be interesting to study the overlap model in the vicinity of the doubly magic nuclide {sup 208}Pb and also for more neutron-rich nuclides in the region of {sup 132}Sn. (orig.)

The mechanism of selective corrugation removal by KOH anisotropic wet etching

International Nuclear Information System (INIS)

Shikida, M; Inagaki, N; Sasaki, H; Amakawa, H; Fukuzawa, K; Sato, K

2010-01-01

The mechanism of selective corrugation removal by anisotropic wet etching—which reduces a periodic corrugation, called 'scalloping', formed on the sidewalls of microstructures by the Bosch process in deep reactive-ion etching (D-RIE)—was investigated. In particular, the corrugation-removal mechanism was analyzed by using the etching rate distribution pattern, and two equations for predicting the corrugation-removal time by the etching were derived. A Si{1 0 0} wafer was first etched by D-RIE at a depth of 29.4 µm (60 cycles) to form the corrugation on the sidewall surface. The height and pitch of the corrugation were 196 and 494 nm, respectively. Selective removal of the corrugation by using 50% KOH (40 °C) was experimentally tried. The corrugation formed on Si{1 0 0} sidewall surfaces was gradually reduced in size as the etching progressed, and it was completely removed after 5 min of etching. Similarly, the corrugation formed on a Si{1 1 0} sidewall surface was also selectively removed by KOH etching (etching time: 3 min). The roughness value of the sidewall surface was reduced from 17.6 nm to a few nanometers by the etching. These results confirm that the corrugation-removal mechanism using anisotropic wet etching can be explained in terms of the distribution pattern of etching rate

Behaviour of transuranic nuclides in coastal environment

International Nuclear Information System (INIS)

Pillai, K.C.; Mathew, E.; Matkar, V.M.; Dey, N.N.; Abani, M.C.; Chhapgar, B.F.; Mullay, C.D.

1982-01-01

In view of the nuclear technological developments, the potential for contamination of marine environment with transuranic nuclides has increased. In this context it is necessary to know not only the current levels of these artificial nuclides but there is also a need to understand the physico-chemical, biological and geochemical behaviour of transuranics to evaluate their significance in the marine environment. Studies on these aspects have been carried out in the coastal environment of the west coast of India, near Bombay. The results obtained and conclusions drawn from the various investigations carried out are given in this document

Nuclide inventories of spent fuels from light water reactors

International Nuclear Information System (INIS)

Okumura, Keisuke; Okamoto, Tsutomu

2012-02-01

Accurate information on nuclide inventories of spent fuels from Light Water Reactors (LWRs) is important for evaluations of criticality, decay heat, radioactivity, toxicity, and so on, in the safety assessments of storage, transportation, reprocessing and waste disposal of the spent fuels. So, a lot of lattice burn-up calculations were carried out for the possible fuel specifications and irradiation conditions in Japanese commercial LWRs by using the latest nuclear data library JENDL-4.0 and a sophisticated lattice burn-up calculation code MOSRA-SRAC. As a result, burn-up changes of nuclide inventories and their possible ranges were clarified for 21 heavy nuclides and 118 fission products, which are important from the viewpoint of impacts to nuclear characteristics and nuclear fuel cycle and environment. (author)

Retardation of escaping nuclides from a final depository

International Nuclear Information System (INIS)

Neretnieks, I.

1977-09-01

study has been made on retardation of radionuclides in various materials, which could be suited for use in the final repository. A literature survey has shown that except for Cs and Sr very little is known on ion exchange equilibria in ground water surroundings. Measurements were made to determine equilibrium data for Cs, Sr, Eu and U in five natural zeolites, which could be used as filling material. Diffusivities in zeolite particles and bbeds as well as clay beds were also determined. With the aid of these data the function of the ion exchange barrier was investigated. The barrier is so short that the nuclide transport is by diffusion. An 0.2 m barrier of a zeolite will delay Cs and Sr so long that they will decay totally. Am 241 will also be considerably delayed. An 0.2 m clay-quartz barrier will have very little effect on these nuclides. A 1 m clay-quartz barrier will have about the same effect as an 0.2 m zeolite barrier. Most other nuclides have so long lives that they will only be delayed, but not sufficiently long to decay. He rock itself interacts with many of the radionuclides. A simple model has been made to describe the nuclide retardation and dispersion in fissured rock. With the aid of this, tracer experiments in actual underground rock have been analysed

Migration studies of fission product nuclides in rocks. Pt.5: Diffusion and permeability of nuclide 125I in marble

International Nuclear Information System (INIS)

Wen Ruiyuan; Gao Hongcheng; Wang Xiangyun

1996-01-01

The migration behaviour of nuclide 125 I, as a simulation of the long lived fission product 129 I, in marble is studied in self-designed cells. A series of the most important parameters of diffusion and permeability (e.g., intrinsic diffusion coefficient, dispersion coefficient and interstitial flow velocity, etc.) are determined. Based on the differential equation of the nuclide migration, the distribution function and numerical solution of 125 I in marble are presented. The results show that the migration velocity of 125 I in marble is fast, indicating that it is not suitable to dispose nuclear waste in marble

The role of marine zooplankton in the vertical oceanic transport of alpha-emitting nuclides

International Nuclear Information System (INIS)

Cherry, R.D.; Heyraud, M.; Higgo, J.J.W.; Fowler, S.W.; LaRosa, J.

1976-01-01

This project aims at studying, in quantitative detail, the role played by marine plankton in the vertical oceanic transport of alpha-emitting nuclides. The common Mediterranean euphausiid, Meganyotiphanes norvegica, for which the necessary quantitative biological data are available as a result of previous work in the Monaco Laboratory, has been selected as the typical macrozooplanktonic species which is the focus of this work

Measurement of soluble nuclide dissolution rates from spent fuel

International Nuclear Information System (INIS)

Wilson, C.N.; Gray, W.J.

1990-01-01

Gaining a better understanding of the potential release behavior of water-soluble radionuclides is the focus of new laboratory spent fuel dissolution studies being planned in support of the Yucca Mountain Project. Previous studies have suggested that maximum release rates for actinide nuclides, which account for most of the long-term radioactivity in spent fuel, should be solubility-limited and should not depend on the characteristics or durability of the spent fuel waste form. Maximum actinide concentrations should be sufficiently low to meet the NRC (Nuclear Regulatory Commission) annual release limits. Potential release rates for soluble nuclides such as 99 Tc, 135 Cs, 14 C and 129 I, which account for about 1-2% of the activity in spent fuel at 1,000 years, are less certain and may depend on processes such as oxidation of the fuel in the repository air environment. Dissolution rates for several soluble nuclides have been measured from spent fuel specimens using static and semi-static methods. However, such tests do not provide a direct measurement of fuel matrix dissolution rates that may ultimately control soluble-nuclide release rates. Flow-through tests are being developed as a potential supplemental method for determining the matrix component of soluble-nuclide dissolution. Advantages and disadvantages of both semi-static and flow-through methods are discussed. Tests with fuel specimens representing a range of potential fuel states that may occur in the repository, including oxidized fuel, are proposed. Preliminary results from flow-through tests with unirradiated UO 2 suggesting that matrix dissolution rates are very sensitive to water composition are also presented

Catalogue of gamma rays from radionuclides ordered by nuclide

International Nuclear Information System (INIS)

Ekstroem, L.P.; Andersson, P.; Sheppard, H.M.

1984-01-01

A catalogue of about 28500 gamma-ray energies from 2338 radionuclides is presented. The nuclides are listed in order of increasing (A,Z) of the daughter nuclide. In addition the gamma-ray intensity per 100 decays of the parent (if known) and the decay half-life are given. All data are from a computer processing of a recent ENSDF (Evaluated Nuclear Structure Data File) file. (authors)

Selective removal of esthetic composite restorations with spectral guided laser ablation

Science.gov (United States)

Yi, Ivana; Chan, Kenneth H.; Tsuji, Grant H.; Staninec, Michal; Darling, Cynthia L.; Fried, Daniel

2016-02-01

Dental composites are used for a wide range of applications such as fillings for cavities, adhesives for orthodontic brackets, and closure of gaps (diastemas) between teeth by esthetic bonding. Anterior restorations are used to replace missing, diseased and unsightly tooth structure for both appearance and function. When these restorations must be replaced, they are difficult to remove mechanically without causing excessive removal or damage to enamel because dental composites are color matched to teeth. Previous studies have shown that CO2 lasers have high ablation selectivity and are well suited for removal of composite on occlusal surfaces while minimizing healthy tissue loss. A spectral feedback guidance system may be used to discriminate between dental composite and dental hard tissue for selective ablation of composite material. The removal of composite restorations filling diastemas is more challenging due to the esthetic concern for anterior teeth. The objective of this study is to determine if composite spanning a diastema between anterior teeth can be removed by spectral guided laser ablation at clinically relevant rates with minimal damage to peripheral healthy tissue and with higher selectivity than a high speed dental handpiece.

Neutron cross sections of 28 fission product nuclides adopted in JENDL-1

International Nuclear Information System (INIS)

Kikuchi, Yasuyuki; Nakagawa, Tsuneo; Igarasi, Sin-iti; Matsunobu, Hiroyuki; Kawai, Masayoshi; Iijima, Shungo.

1981-02-01

This is the final report concerning the evaluated neutron cross sections of 28 fission product nuclides adopted in the first version of Japanese Evaluated Nuclear Data Library (JENDL-1). These 28 nuclides were selected as being most important for fast reactor calculations, and are 90 Sr, 93 Zr, 95 Mo, 97 Mo, 99 Tc, 101 Ru, 102 Ru, 103 Rh, 104 Ru, 105 Pd, 106 Ru, 107 Pd, 109 Ag, 129 I, 131 Xe, 133 Cs, 135 Cs, 137 Cs, 143 Nd, 144 Ce, 144 Nd, 145 Nd, 147 Pm, 147 Sm, 149 Sm, 151 Sm, 153 Eu and 155 Eu. The status of the experimental data was reviewed over the whole energy range. The present evaluation was performed on the basis of the measured data with the aid of theoretical calculations. The optical and statical models were used for evaluation of the smooth cross sections. An improved method was developed in treating the multilevel Breit-Wigner formula for the resonance region. Various physical parameters and the level schemes, adopted in the present work are discussed by comparing with those used in the other evaluations such as ENDF/B-IV, CEA, CNEN-2 and RCN-2. Furthermore, the evaluation method and results are described in detail for each nuclide. The evaluated total, capture and inelastic scattering cross sections are compared with the other evaluated data and some recent measured data. Some problems of the present work are pointed out and ways of their improvement are suggested. (author)

Measurement of radioactive nuclides in the `Mayak` region

Energy Technology Data Exchange (ETDEWEB)

Myasoedov, B F [V.I. Vernadsky Inst. of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation); Novikov, A P [V.I. Vernadsky Inst. of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation)

1997-03-01

The study of environmental contamination caused by anthropogenic impact and, primarily, by radioactive nuclides is one of the main scientific problems facing contemporary science. Radioecological monitoring, decision making on remediation of polluted areas need detailed information about distribution of radioactive nuclides in the terrestrial and aquatic ecosystems, knowledge about radioactive nuclide occurrence forms and migration patterns. Experimental tests of nuclear and thermonuclear weapon in atmosphere and underground, nuclear power engineering and numerous accidents that took place at the nuclear power plants (NPP), unauthorized dump of radioactive materials in various places of the ocean and pouring off the strongly dump of radioactive wastes from ships and submarine equipped with nuclear power engines made artificial radionuclides a constant and unretrievable component of the modern biosphere, becoming an additional unfavorable ecological factor. As regards Former Sovient Union (FSU) the most unfavorable regions are Southern Ural, zones suffered from Chernobyl Accident, Altay, Novaya Zemlya, some part of West Siberia near Seversk (Tomsk-7) and Zheleznogorsk (Krasnoyarsk-26). (orig.)

Measurement of radioactive nuclides in the 'Mayak' region

International Nuclear Information System (INIS)

Myasoedov, B.F.; Novikov, A.P.

1997-01-01

The study of environmental contamination caused by anthropogenic impact and, primarily, by radioactive nuclides is one of the main scientific problems facing contemporary science. Radioecological monitoring, decision making on remediation of polluted areas need detailed information about distribution of radioactive nuclides in the terrestrial and aquatic ecosystems, knowledge about radioactive nuclide occurrence forms and migration patterns. Experimental tests of nuclear and thermonuclear weapon in atmosphere and underground, nuclear power engineering and numerous accidents that took place at the nuclear power plants (NPP), unauthorized dump of radioactive materials in various places of the ocean and pouring off the strongly dump of radioactive wastes from ships and submarine equipped with nuclear power engines made artificial radionuclides a constant and unretrievable component of the modern biosphere, becoming an additional unfavorable ecological factor. As regards Former Sovient Union (FSU) the most unfavorable regions are Southern Ural, zones suffered from Chernobyl Accident, Altay, Novaya Zemlya, some part of West Siberia near Seversk (Tomsk-7) and Zheleznogorsk (Krasnoyarsk-26). (orig.)

Cosmic-ray interactions and dating of meteorite stranding surfaces with cosmogenic nuclides

International Nuclear Information System (INIS)

Reedy, R.C.

1988-01-01

A wide variety of products from cosmic-ray interactions have been measured in terrestrial or extraterrestrial samples. These ''cosmogenic'' products include radiation damage tracks and rare nuclides that are made by nuclear reactions. They often have been used to determine the fluxes and composition of cosmic-ray particles in the past, but they are usually used to study the history of the ''target'' (such as the time period that it was exposed to cosmic-ray particles). Products made by both the high-energy galactic cosmic rays and energetic particles emitted irregularly from the Sun have been extensively studied. Some of these cosmogenic products, especially nuclides, have been or can be applied to studies of Antarctic meteorite stranding surfaces, the ice surfaces in Antarctica where meteorites have been found. Cosmogenic nuclides studied in samples from Antarctica and reported by others elsewhere in this volume include those in meteorites, especially radionuclides used to determine terrestrial ages, and those made in situ in terrestrial rocks. Cosmogenic nuclides made in the Earth's atmosphere or brought in with cosmic dust have also been studied in polar ice, and it should also be possible to measure nuclides made in situ in ice. As an introduction to cosmogenic nuclides and their applications, cosmic rays and their interactions will be presented below and production systematics of cosmogenic nuclides in these various media will be discussed later. 20 refs., 2 tabs

Cosmic-ray interactions and dating of meteorite stranding surfaces with cosmogenic nuclides

Energy Technology Data Exchange (ETDEWEB)

Reedy, R.C.

1988-01-01

A wide variety of products from cosmic-ray interactions have been measured in terrestrial or extraterrestrial samples. These ''cosmogenic'' products include radiation damage tracks and rare nuclides that are made by nuclear reactions. They often have been used to determine the fluxes and composition of cosmic-ray particles in the past, but they are usually used to study the history of the ''target'' (such as the time period that it was exposed to cosmic-ray particles). Products made by both the high-energy galactic cosmic rays and energetic particles emitted irregularly from the Sun have been extensively studied. Some of these cosmogenic products, especially nuclides, have been or can be applied to studies of Antarctic meteorite stranding surfaces, the ice surfaces in Antarctica where meteorites have been found. Cosmogenic nuclides studied in samples from Antarctica and reported by others elsewhere in this volume include those in meteorites, especially radionuclides used to determine terrestrial ages, and those made in situ in terrestrial rocks. Cosmogenic nuclides made in the Earth's atmosphere or brought in with cosmic dust have also been studied in polar ice, and it should also be possible to measure nuclides made in situ in ice. As an introduction to cosmogenic nuclides and their applications, cosmic rays and their interactions will be presented below and production systematics of cosmogenic nuclides in these various media will be discussed later. 20 refs., 2 tabs.

A nuclide transfer model for barriers of the seabed repository using response function

International Nuclear Information System (INIS)

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

1996-01-01

A nuclide transfer by utilizing mass transfer coefficient and barrier response function defined for each barrier is proposed, by which the final nuclide transfer rate into the sea water can be evaluated. When simple and immediate quantification of the nuclide release is necessary in the conservative aspect, using this kind of approach may be advantageous since each layered barrier can be treated separately from other media in series in the repository system, making it possible to apply separate solutions in succession to other various media. Although one disadvantage is that while flux continuity can be maintained at the interface by using the exit nuclide flux from the first medium as the source flux for the next one, there may be no guarantee for concentration continuity, this problem could be eliminated assuming that there is no boundary resistance to mass transfer across the interface. Mass transfer coefficient can be determined by the assumption that the nuclide concentration gradient at the interface between adjacent barriers remains constant and barrier response function is obtained from an analytical expression for nuclide flow rate out of each barrier in response to a unit impulse into the barrier multiplied by mass transfer coefficient. Total time-dependent nuclide transfer rate from the barrier can then be obtained by convoluting the response function for the barrier with a previously calculated set of time-varying input of nuclide flow rate for the previous barrier. 18 refs., 5 figs. (author)

Nuclides.net: A computational environment for nuclear data and applications in radioprotection and radioecology

International Nuclear Information System (INIS)

Berthou, V.; Galy, J.; Leutzenkirchen, K.

2004-01-01

An interactive multimedia tool, Nuclides.net, has been developed at the Institute for Transuranium Elements. The Nuclides.net 'integrated environment' is a suite of computer programs ranging from a powerful user-friendly interface, which allows the user to navigate the nuclides chart and explore the properties of nuclides, to various computational modules for decay calculations, dosimetry and shielding calculations, etc. The product is particularly suitable for environmental radioprotection and radioecology. (authors)

Method of processing radioactive nuclide-containing liquids

International Nuclear Information System (INIS)

Hirai, Masahide; Tomoshige, Shozo; Kondo, Kozo; Suzuki, Kazunori; Todo, Fukuzo; Yamanaka, Akihiro.

1985-01-01

Purpose: To solidify radioactive nuclides in to a much compact state and facilitate the storage. Method: Liquid wastes such as drain liquids generated from a nuclear power plant at a low density of 1 x 10 -6 - 10 -4 μCi/ml are previously brought into contact with a chelate type ion exchange resin such as of phenolic resin or ion exchange resin to adsorb the radioactive nuclides on the resin and the nuclides are eluted with sulfuric acid or the like to obtain liquid concentrates. The liquid concentrates are electrolyzed in an ordinary electrolytic facility using platinum or the like as the anode, Al or the like as the cathode, under the presence of 1 - 20 g/l of non-radioactive heavy metals such as Co and Ni in the liquid and while adjusting pH to 2 - 8. The electrolysis liquid residue is returned again to the electrolysis tank as it is or in the form of precipitates coagulated with a polymeric floculant. The supernatant liquid upon floculating treatment is processed with the chelate type ion exchange resin into hazardless liquid. (Sekiya, K.)

Status of determining transuranic nuclides speciation in aqueous solution with laser spectrometry

International Nuclear Information System (INIS)

Wang Bo; Liu Dejun; Yao Jun; Chen Xi; Long Haoqi; Zeng Jishu; Su Xiguang; Fan Xianhua

2007-01-01

The knowledge about speciation of transuranic nuclides in aqueous solution is a basis for understanding the chemical and migration behavior of transuranic nuclides in aqueous solution. The speciation of transuranic nuclides with trace concentration is complicated in near neutral aqueous solutions, including change of oxidation state, complexation and colloid generation, etc. The concentrations of transuranium in near neutral aqueous solution usually below the sensitivity range of method such as conventional absorption spectroscopy. The radioactive analysis method has a very low detection limits for radionuclides, however, it wouldn' t allow the direct measurement of the transuranic species. In contrast with these methods, laser spectroscopy is an ideal method with high sensitivity, and non-contact and non-destructive for determining the speciation of transuranic nuclides. This paper summarizes the status and application of LIPAS (Laser-induced Photoacoustic Spectrometry), LIBD (Laser-induced Breakdown Detection) and TRLFS (Time-resolved Laser Fluorescence Spectrometry) to determine the speciation of transuranic nuclides with trace concentration in aqueous solutions. (authors)

The method study for nuclide analysis of waste drum

International Nuclear Information System (INIS)

Ruan Guanglin; Huang Xianguo; Xing Shixiong

2001-01-01

The principle of waste drum nuclide analysis system and the principle of the detector chosen are introduced. The linear attenuation coefficient and mass attenuation coefficient of five environmental medium (water, soil, red brick, concrete and sands) have been measured with γ transmission method simulative equipment. The absorption coefficient and nuclide activity of three measuring conditions (collimation-columnar source, un-collimation-columnar source, and un-collimation-rotation-drum source) have been calculated

ZZ REAC-2, Nuclide Activation and Transmutation

International Nuclear Information System (INIS)

Mann, F.M.

2002-01-01

1 - Description of program or function: Flux library: Format: special format, Number Of Groups: 63 group fluxes, Nuclides: H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Br, Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Xe, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po. Origin: Fred Mann (Westinghouse, Hanford). Cross Section library: Format: special format, Number Of Groups: 63 group cross section, Nuclides: H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Br, Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Xe, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po. Origin: Fred Mann (Westinghouse, Hanford). Decay Data library: Format: special format, Nuclides: H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Br, Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Xe, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po. Origin: Fred Mann (Westinghouse, Hanford). REAC2 calculates the change in composition of materials in a radiation field and related activation quantities. It is best suited to problems where many variables (e.g. materials, facilities or locations within facilities, power histories) are to be investigated. Where very accurate results are needed, the user must access the accuracy of the cross section base (e.g. source, flux weighting) as in the use of any neutronics code. REAC2 consists of three programs - SREAC, SLSTCOM, and SLIB. SREAC calculates the transmutation of nuclides in a radiation field. SLSTCOM reads the output file produced by SREAC and produces listings of

Development of a new nuclide generation and depletion code using a topological solver based on graph theory

Energy Technology Data Exchange (ETDEWEB)

Kasselmann, S., E-mail: s.kasselmann@fz-juelich.de [Forschungszentrum Jülich, 52425 Jülich (Germany); Schitthelm, O. [Forschungszentrum Jülich, 52425 Jülich (Germany); Tantillo, F. [Forschungszentrum Jülich, 52425 Jülich (Germany); Institute for Reactor Safety and Reactor Technology, RWTH-Aachen, 52064 Aachen (Germany); Scholthaus, S.; Rössel, C. [Forschungszentrum Jülich, 52425 Jülich (Germany); Allelein, H.-J. [Forschungszentrum Jülich, 52425 Jülich (Germany); Institute for Reactor Safety and Reactor Technology, RWTH-Aachen, 52064 Aachen (Germany)

2016-09-15

The problem of calculating the amounts of a coupled nuclide system varying with time especially when exposed to a neutron flux is a well-known problem and has been addressed by a number of computer codes. These codes cover a broad spectrum of applications, are based on comprehensive validation work and are therefore justifiably renowned among their users. However, due to their long development history, they are lacking a modern interface, which impedes a fast and robust internal coupling to other codes applied in the field of nuclear reactor physics. Therefore a project has been initiated to develop a new object-oriented nuclide transmutation code. It comprises an innovative solver based on graph theory, which exploits the topology of nuclide chains and therefore speeds up the calculation scheme. Highest priority has been given to the existence of a generic software interface well as an easy handling by making use of XML files for the user input. In this paper we report on the status of the code development and present first benchmark results, which prove the applicability of the selected approach.

Variable temperature effects on release rates of readily soluble nuclides

International Nuclear Information System (INIS)

Kim, C.-L.; Light, W.B.; Lee, W.W.-L.; Chambre, P.L.; Pigford, T.H.

1988-09-01

In this paper we study the effect of temperature on the release rate of readily soluble nuclides, as affected by a time-temperature dependent diffusion coefficient. In this analysis ground water fills the voids in the waste package at t = 0 and one percent of the inventories of cesium and iodine are immediately dissolved into the void water. Mass transfer resistance of partly failed container and cladding is conservatively neglected. The nuclides move through the void space into the surrounding rock under a concentration gradient. We use an analytic solution to compute the nuclide concentration in the gap or void, and the mass flux rate into the porous rock. 8 refs., 4 figs

Preparation of tracing source layer in simulation test of nuclide migration

International Nuclear Information System (INIS)

Zhao Yingjie; Ni Shiwei; Li Weijuan; Yamamoto, T.; Tanaka, T.; Komiya, T.

1993-01-01

In cooperative research between CIRP and JAERI on safety assessment for shallow land disposal of low level radioactive waste, a laboratory simulation test of nuclide migration was carried out, in which the undisturbed loess soil column sampled from CIRP' s field test site was used as testing material, three nuclides, Sr-85, Cs-137 and Co-60 were used as tracers. Special experiment on tracing method was carried out, which included measuring pH value of quartz sand in HCl solution, determining the eligible water content of quartz sand as tracer carrier, measuring distribution uniformity of nuclides in the tracing quartz sand, determining elution rate of nuclides from the tracing quartz sand and detecting activity uniformity of tracing source layer. The experiment results showed that the tracing source layer, in which fine quartz sand was used as tracer carrier, satisfied expected requirement. (1 fig.)

Mechanism of fission of neutron-deficient actinoids nuclides

International Nuclear Information System (INIS)

Sueki, Keisuke; Nakahara, Hiromichi; Tanase, Masakazu; Nagame, Yuichiro; Shinohara, Nobuo; Tsukada, Kazuaki.

1996-01-01

A heavy ion reaction ( 19 F+ 209 Bi) is selected. The reaction produces neutron-deficient 228 U which is compound nucleus with a pair of Rb(z=37) and Cs(Z=55). Energy dissipation problem of nucleus was studied by measuring the isotope distribution of two fissile nuclides. Bismuth metal evaporated on aluminium foil was irradiated by 19 F with the incident energy of 105-128 MeV. We concluded from the results that the excess energy of reaction system obtained with increasing the incident energy is consumed by (1) light Rb much more than Cs and (2) about 60% of energy is given to two fission fragments and the rest 40% to the translational kinetic energy or unknown anomalous γ-ray irradiation. (S.Y.)

Production, study and use of short-lived nuclides in pure and applied nuclear research

International Nuclear Information System (INIS)

Bjoernstad, T.

1986-01-01

The thesis which is based on 17 published papers, reports on the on-line performance of the fast radiochemical separation system SISAK, technical devlopment in the preparation of sources for beta-particles and neutrons, and on important SISAK system improvements concerning liquid hold-up time. It further reports on the development of new production targets at ISOLDE for 600 MeV proton and 910 MeV 3 He-particle irradiations, on tests with a heavy ion beam of 1 GeV 12 C-particles, and on the present availability of mass-separated beams of the halogen elements through new ion source development. Some results from nuclear spectroscopic studies of nuclides in selected mass regions when using such new or improved techniques are given. Examples of techniques for practical application of short-lived nuclides in radiochemical analysis and for radiochemical production for medical purposes are presented

Soil nuclide distribution coefficients and their statistical distributions

International Nuclear Information System (INIS)

Sheppard, M.I.; Beals, D.I.; Thibault, D.H.; O'Connor, P.

1984-12-01

Environmental assessments of the disposal of nuclear fuel waste in plutonic rock formations require analysis of the migration of nuclides from the disposal vault to the biosphere. Analyses of nuclide migration via groundwater through the disposal vault, the buffer and backfill, the plutonic rock, and the consolidated and unconsolidated overburden use models requiring distribution coefficients (Ksub(d)) to describe the interaction of the nuclides with the geological and man-made materials. This report presents element-specific soil distribution coefficients and their statistical distributions, based on a detailed survey of the literature. Radioactive elements considered were actinium, americium, bismuth, calcium, carbon, cerium, cesium, iodine, lead, molybdenum, neptunium, nickel, niobium, palladium, plutonium, polonium, protactinium, radium, samarium, selenium, silver, strontium, technetium, terbium, thorium, tin, uranium and zirconium. Stable elements considered were antimony, boron, cadmium, tellurium and zinc. Where sufficient data were available, distribution coefficients and their distributions are given for sand, silt, clay and organic soils. Our values are recommended for use in assessments for the Canadian Nuclear Fuel Waste Management Program

Field tests on migration of TRU-nuclide, (1). General introduction

International Nuclear Information System (INIS)

Ogawa, Hiromichi; Tanaka, Tadao; Mukai, Masayuki

2003-01-01

The field migration test using TRU nuclide was carried out as a cooperative research project between JAERI (Japan Atomic Energy Research Institute) and CIRP (China Institute for Radiation Protection). This report introduced the out-line of the field migration test and described the outline of the series of 'Field Test on Migration of TRU-nuclide' and main results as a summary report. (author)

Method of separating radioactive nuclides from ion exchange resins

International Nuclear Information System (INIS)

Suzuki, Kazunori; Saikoku, Masami; Taneta, Daisuke; Yagi, Takuro.

1987-01-01

Purpose: To enable to safely process radioactive nuclides from spent ion exchange resins by using existent processing facilities. Method: Ion exchange resins in aqueous medium are at first placed to the ultrasonic wave irradiation site and put into such a state where clads and resins are easily separatable from each other by weakening the bonding force between them. Since the clads are magnetic material such as Fe 3 O 4 or NiFe 2 O 4 , the clads can be collected in the direction of the magnetic force by exerting the magnetic field simultaneously. The collected clads are transported by means of the aqueous medium to a collecting tank by removing the effect of magnetic field, for example, by interrupting the current supply to the electromagnet. Finally, they were subjected to stabilization and fixation into inorganic hardening agent such as cement hardener. Thus, processions can be made safely by using existent facilities. (Takahashi, M.)

Radioactive-nuclide decay data in science and technology

International Nuclear Information System (INIS)

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

1975-01-01

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

Radioactive-nuclide decay data in science and technology

International Nuclear Information System (INIS)

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

1975-01-01

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

Validation of spent nuclear fuel nuclide composition data using percentage differences and detailed analysis

Energy Technology Data Exchange (ETDEWEB)

Kim, Man Cheol [Chung-Ang Univ., Seoul (Korea, Republic of). School of Energy Systems Engineering

2017-06-15

Nuclide composition data of spent nuclear fuels are important in many nuclear engineering applications. In reactor physics, nuclear reactor design requires the nuclide composition and the corresponding cross sections. In analyzing the radiological health effects of a severe accident on the public and the environment, the nuclide composition in the reactor inventory is among the important input data. Nuclide composition data need to be provided to analyze the possible environmental effects of a spent nuclear fuel repository. They will also be the basis for identifying the origin of unidentified spent nuclear fuels or radioactive materials.

Chemical concentration of a new natural spontaneously fissionable nuclide from solutions with low salt background

International Nuclear Information System (INIS)

Korotkin, Yu.S.; Ter-Akop'yan, G.M.; Popeko, A.G.; Drobina, T.P.; Zhuravleva, E.L.

1982-01-01

The results of experiments on further concentration of a new natural spontaneously fissionable nuclide, the concentrates of which form the Cheleken geothermal brines have been obtained, are presented. The conclusions are drown about the chemical nature of a new spontaneously fissionable nuclide. It is a chalcophile element which copreipitates with sulphides of copper, lead, arsenic and mercury from weakly acid solutions. The behaviour of the new nuclide in sulphide systems in many respects is similar to the behaviour of polonium, astatine and probably of bismuth. The most probable stable valence of the new nuclide varies from +1 up to +3. The data available on the chemical behaviour of the new nuclide as well as the analysis over contamination by spontaneously fissionable isotopes permit to state that the new natural spontaneously fissionable nuclide does not relate to the known isotopes

Evaluation of nuclides with closely spaced values of depletion constants in transmutation chains

International Nuclear Information System (INIS)

Vukadin, Z.S.

1977-01-01

New method of calculating nuclide concentrations in a transmutation chain is developed in this thesis. Method is based on originally derived recurrence formulas for expansion series of depletion functions and on originally obtained, nonsingular, Bateman coefficients. Explicit expression for the nuclide concentrations in a transmutation chain is obtained. This expression can be used as it stands for arbitrary values of nuclides depletion constants. By computing hypothetical transmutation chains and neptunium series, method is compared with the Bateman analytical solution, with the approximate solutions and with the matrix exponential method. It comes out that the method presented in this thesis is suitable for calculating very long depletion chains even in the case of some closely spaced and/or equal values of nuclide depletion constants. Though, presented method is of great practical applicability in a number of nuclear physics problems that are dealing with the nuclide transmutations: starting from the studies of the stellar evolution up to the design of nuclear reactors (author) [sr

Nuclides Economy

International Nuclear Information System (INIS)

Ivanov, Evgeny; Subbotin, Stanislav

2007-01-01

Traditionally the subject of discussion about the nuclear technology development is focused on the conditions that facilitate the nuclear power deployment. The main objective of this work is seeking of methodological basis for analysis of the coupling consequences of nuclear development. Nuclide economy is the term, which defines a new kind of society relations, dependent on nuclear technology development. It is rather closed to the setting of problems then to the solving of them. Last year Dr. Jonathan Tennenbaum published in Executive Intelligence Review Vol. 33 no 40 the article entitled as 'The Isotope Economy' where main interconnections for nuclear energy technologies and their infrastructure had been explained on the popular level. There he has given several answers and, therefore, just here we will try to expand this concept. We were interested by this publication because of similarity of our vision of resource base of technologies development. The main paradigm of 'Isotope economy' was expresses by Lyndon H. LaRouche: 'Instead of viewing the relevant resources of the planet as if they were a fixed totality, we must now assume responsibility of man's creating the new resources which will be more than adequate to sustain a growing world population at a constantly improved standard of physical per-capita output, and personal consumption'. We also consider the needed resources as a dynamic category. Nuclide economy and nuclide logistics both are needed for identifying of the future development of nuclear power as far we follow the holistic analysis approach 'from cave to grave'. Thus here we try to reasoning of decision making procedures and factors required for it in frame of innovative proposals development and deployment. The nuclear power development is needed in humanitarian scientific support with maximally deep consideration of all inter-disciplinary aspects of the nuclear power and nuclear technologies implementation. The main objectives for such

Corrosion Tests of LWR Fuels - Nuclide Release

International Nuclear Information System (INIS)

P.A. Finn; Y. Tsai; J.C. Cunnane

2001-01-01

Two BWR fuels [64 and 71 (MWd)/kgU], one of which contained 2% Gd, and two PWR fuels [30 and 45 (MWd)/kgU], are tested by dripping groundwater on the fuels under oxidizing and hydrologically unsaturated conditions for times ranging from 2.4 to 8.2 yr at 90 C. The 99 Tc, 129 I, 137 Cs, 97 Mo, and 90 Sr releases are presented to show the effects of long reaction times and of gadolinium on nuclide release. This investigation showed that the five nuclides at long reaction times have similar fractional release rates and that the presence of 2% Gd reduced the 99 Tc cumulative release fraction by about an order of magnitude over that of a fuel with a similar burnup

Residual Nuclides Induced in Cu Target by a 250 MeV Proton Beam

International Nuclear Information System (INIS)

Zhang Hong-Bin; Zhang Xue-Ying; Ma Fei; Ju Yong-Qin; Ge Hong-Lin; Chen Liang; Zhang Yan-Bin; Li Yan-Yan; Luo Peng; Wang Jian-Guo; Wan Bo; Xu Xiao-Wei; Wei Ji-Fang; Zhou Bin

2015-01-01

Residual nuclide production is studied experimentally by bombarding a Cu target with a 250 MeV proton beam. The data are measured by the off-line γ-spectroscopy method. Six nuclides are identified and their cross sections are determined. The corresponding calculated results by the MCNPX and GEANT4 codes are compared with the experimental data to check the validity of the codes. A comparison shows that the MCNPX simulation has a better agreement with the experiment. The energy dependence of residual nuclide production is studied with the aid of MCNPX simulation, and it is found that the mass yields for the nuclides in the light mass region increase significantly with the proton energy. (paper)

Modelling the reactive-path between pyrite and radioactive nuclides

International Nuclear Information System (INIS)

Kang Mingliang; Wu Shijun; Dou Shunmei; Chen Fanrong; Yang Yongqiang

2008-01-01

The mobility of redox sensitive nuclides is largely dependent on their valence state. The radionuclides that make the dominant contributions to final dose calculations are redox sensitive. Almost all the radionuclides (except 129 I) have higher mobility at high valence state, and correspond to immobilization at low valence state due to the much lower solubility. Pyrite is an ubiquitous and stable mineral in geological environment, and would be used as a low-cost long time reductant for the immobilization of radionuclides. However, pyrite oxidation is supposed to generate acid, which will enhance the mobility of nuclides. In this paper, the reaction path of the reactions between radionuclides (U, Se and Tc) and pyrite in the groundwater from Wuyi well in Beishan area of China has been simulated using geochemical modeling software. According to the results, pyrite can reduce high valence nuclides to a dinky-level effectively, with the pH slightly increasing under anaerobic condition that is common in deep nuclear waste repositories. (authors)

Phase II Nuclide Partition Laboratory Study Influence of Cellulose Degradation Products on the Transport of Nuclides from SRS Shallow Land Burial Facilities; FINAL

International Nuclear Information System (INIS)

Serkiz, S.M.

1999-01-01

Degradation products of cellulosic materials (e.g., paper and wood products) can significantly influence the subsurface transport of metals and radionuclides. Codisposal of radionuclides with cellulosic materials in the E-Area slit trenches at the Savannah River Site (SRS) is, therefore, expected to influence nuclide fate and transport in the subsurface. Due to the complexities of these systems and the scarcity of site-specific data, the effects of cellulose waste loading and its subsequent influence on nuclide transport are not well established

Mechanism of fission of neutron-deficient actinoids nuclides

Energy Technology Data Exchange (ETDEWEB)

Sueki, Keisuke; Nakahara, Hiromichi [Tokyo Metropolitan Univ., Hachioji (Japan). Faculty of Science; Tanase, Masakazu; Nagame, Yuichiro; Shinohara, Nobuo; Tsukada, Kazuaki

1996-01-01

A heavy ion reaction ({sup 19}F+{sup 209}Bi) is selected. The reaction produces neutron-deficient {sup 228}U which is compound nucleus with a pair of Rb(z=37) and Cs(Z=55). Energy dissipation problem of nucleus was studied by measuring the isotope distribution of two fissile nuclides. Bismuth metal evaporated on aluminium foil was irradiated by {sup 19}F with the incident energy of 105-128 MeV. We concluded from the results that the excess energy of reaction system obtained with increasing the incident energy is consumed by (1) light Rb much more than Cs and (2) about 60% of energy is given to two fission fragments and the rest 40% to the translational kinetic energy or unknown anomalous {gamma}-ray irradiation. (S.Y.)

Chart of the nuclides - Strasbourg 1990

International Nuclear Information System (INIS)

Antony, M.S.

1991-01-01

Data were compiled for a nuclide chart over the last two years. The compilation is complete to the end of September 1990. The chart includes about 30000 data. Decay modes are represented by colours. Announcement capabilities and prices are given. (G.P.) 3 refs

An innovative method for determining the diffusion coefficient of product nuclide

Energy Technology Data Exchange (ETDEWEB)

Chen, Chih Lung [Dept. of Nuclear Back-end Management, Taiwan Power Company, Taipei (China); Wang, Tsing Hai [Dept. Biomedical Engineering and Environment Sciences, National Tsing Hua University, Hsinchu (China)

2017-08-15

Diffusion is a crucial mechanism that regulates the migration of radioactive nuclides. In this study, an innovative numerical method was developed to simultaneously calculate the diffusion coefficient of both parent and, afterward, series daughter nuclides in a sequentially reactive through-diffusion model. Two constructed scenarios, a serial reaction (RN{sub 1} → RN{sub 2} → RN{sub 3}) and a parallel reaction (RN{sub 1} → RN{sub 2}A + RN{sub 2}B), were proposed and calculated for verification. First, the accuracy of the proposed three-member reaction equations was validated using several default numerical experiments. Second, by applying the validated numerical experimental concentration variation data, the as-determined diffusion coefficient of the product nuclide was observed to be identical to the default data. The results demonstrate the validity of the proposed method. The significance of the proposed numerical method will be particularly powerful in determining the diffusion coefficients of systems with extremely thin specimens, long periods of diffusion time, and parent nuclides with fast decay constants.

The protection of radioactive nuclide and nursing management in DSA room

International Nuclear Information System (INIS)

Zhang Guimin

2009-01-01

Objective: To discuss the protection of radioactive nuclide and nursing management in DSA room. Methods: The clinical state of the protection of radioactive 131 I nuclide and nursing management in DSA room was retrospectively summarized. Results: The standard management for the protection of radioactive nuclide in DSA room was established. The main management schemas included the management of personnel, the management of professional skills and, specialty, the management of radioactive drugs and abandoned odds and ends, preoperative health education, etc. Conclusion: The standard management can ensure that the patients get a good radionuclide therapy in DSA room, and, at the same time, the working environment can be effectively protected and the professional nursing staff can be well trained. (authors)

Accelerator produced nuclides for use in biology and medicine. A bibliography: January 1974--June 1976

International Nuclear Information System (INIS)

Karlstrom, K.I.; Christman, D.R.

1978-01-01

This bibliography (Volume II) follows the format of the first bibliography. Nuclides used therapeutically have not been included. References to medical application of the various nuclides of iodine, gallium, and indium have been excluded as being beyond the scope of this bibliography (and to keep its size to manageable proportions). For nuclides having fifteen or fewer references there is no breakdown into subcategories. For the others they have been subdivided as follows: (1) Production methods, (2) Compound syntheses, and (3) Medical uses. The first part of the bibliography contains references of general interest of various types. Where specific nuclides are involved, these references are also cross-indexed to each nuclide. The original reference number is always used for cross-indexing. The nuclide section is arranged in alphabetical order, and within each section alphabetically by first author. The author index lists each reference once for each author, with no indication of cross-referencing given

Evaluation of Nuclide Release Scenarios for a Hypothetical LILW Repository

International Nuclear Information System (INIS)

Lee, Youn Myoung; Jeong, Jong Tae

2010-11-01

A program for the safety assessment and performance evaluation of a low- and intermediate-level radioactive waste (LILW) repository system has been developed. Utilizing GoldSim (GoldSim, 2006), the program evaluates nuclide release and transport into the geosphere and biosphere under various disruptive natural and manmade events and scenarios that can occur after a waste package failure. We envisaged and illustrated these events and scenarios as occurring after the closure of a hypothetical LILW repository, and they included the degradation of various manmade barriers, pumping well drilling, and natural disruptions such as the sudden formation of a preferential flow pathway in the far-field area of the repository. Possible enhancement of nuclide transport facilitated by colloids or chelating agents is also dealt with. We used the newly-developed GoldSim template program, which is capable of various nuclide release scenarios and is greatly suited for simulating a potential repository given the geological circumstances in Korea, to create the detailed source term and near-field release scheme, various nuclide transport modes in the far-field geosphere area, and the biosphere transfer. Even though all parameter values applied to the hypothetical repository were assumed, the illustrative results, particularly the probabilistic calculations and sensitivity studies, may be informative under various scenarios

Cosmic-ray produced nuclides in ground level air and in precipitation

Energy Technology Data Exchange (ETDEWEB)

Schumann, G.; Roedel, W.; Stoeppler, M.

1963-11-15

There are mainly three kinds of radioactive substances in the atmosphere: emanations from the ground and their daughters, nuclides produced in the atmosphere by cosmic rays, and artificial products originating from nuclear weapon tests (and in a very small amount from other nuclear technical applications). This paper deals in particular with some of the cosmic-ray produced nuclides.

Adsorptive removal of selected pharmaceuticals by mesoporous silica SBA-15

International Nuclear Information System (INIS)

Bui, Tung Xuan; Choi, Heechul

2009-01-01

The removal of five selected pharmaceuticals, viz., carbamazepine, clofibric acid, diclofenac, ibuprofen, and ketoprofen was examined by batch sorption experiments onto a synthesized mesoporous silica SBA-15. SBA-15 was synthesized and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N 2 adsorption-desorption measurement, and point of zero charge (PZC) measurement. Pharmaceutical adsorption kinetics was rapid and occurred on a scale of minutes, following a pseudo-second-order rate expression. Adsorption isotherms were best fitted by the Freundlich isotherm model. High removal rates of individual pharmaceuticals were achieved in acidic media (pH 3-5) and reached 85.2% for carbamazepine, 88.3% for diclofenac, 93.0% for ibuprofen, 94.3% for ketoprofen, and 49.0% for clofibric acid at pH 3 but decreased with increase in pH. SBA-15 also showed high efficiency for removal of a mixture of 5 pharmaceuticals. Except for clofibric acid (35.6%), the removal of pharmaceuticals in the mixture ranged from 75.2 to 89.3%. Based on adsorption and desorption results, the mechanism of the selected pharmaceuticals was found to be a hydrophilic interaction, providing valuable information for further studies to design materials for the purpose. The results of this study suggest that mesoporous-silica-based materials are promising adsorbents for removing pharmaceuticals from not only surface water but also wastewater of pharmaceutical industrial manufactures.

Adsorptive removal of selected pharmaceuticals by mesoporous silica SBA-15

Energy Technology Data Exchange (ETDEWEB)

Bui, Tung Xuan, E-mail: bxtung@gist.ac.kr [Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of); Choi, Heechul, E-mail: hcchoi@gist.ac.kr [Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of)

2009-09-15

The removal of five selected pharmaceuticals, viz., carbamazepine, clofibric acid, diclofenac, ibuprofen, and ketoprofen was examined by batch sorption experiments onto a synthesized mesoporous silica SBA-15. SBA-15 was synthesized and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N{sub 2} adsorption-desorption measurement, and point of zero charge (PZC) measurement. Pharmaceutical adsorption kinetics was rapid and occurred on a scale of minutes, following a pseudo-second-order rate expression. Adsorption isotherms were best fitted by the Freundlich isotherm model. High removal rates of individual pharmaceuticals were achieved in acidic media (pH 3-5) and reached 85.2% for carbamazepine, 88.3% for diclofenac, 93.0% for ibuprofen, 94.3% for ketoprofen, and 49.0% for clofibric acid at pH 3 but decreased with increase in pH. SBA-15 also showed high efficiency for removal of a mixture of 5 pharmaceuticals. Except for clofibric acid (35.6%), the removal of pharmaceuticals in the mixture ranged from 75.2 to 89.3%. Based on adsorption and desorption results, the mechanism of the selected pharmaceuticals was found to be a hydrophilic interaction, providing valuable information for further studies to design materials for the purpose. The results of this study suggest that mesoporous-silica-based materials are promising adsorbents for removing pharmaceuticals from not only surface water but also wastewater of pharmaceutical industrial manufactures.

Determination of k0-factors of short-lived nuclides and application of k0-NAA to selected trace elements

International Nuclear Information System (INIS)

Acharya, R.; Holzbecher, J.; Chatt, A.

2012-01-01

As part of the standardization program of k 0 -based NAA (k 0 -NAA) methods at the Dalhousie University SLOWPOKE-2 reactor (DUSR) facility, the k 0 -factors of 15 analytically important short-lived nuclides (half-life 197 Au). The elemental standards used were prepared mostly from their primary standard solutions. The samples were irradiated in both inner and outer pneumatic sites of the DUSR facility and counted using an HPGe-detector coupled to an ORTEC’s digital gamma-ray spectrometer. The k 0 -factors determined using both inner and outer irradiation sites were found to be within ±5% with respect to either recommended or literature values in most cases. The Z-score values at 95% confidence level were found to be in the range of ±0.03–1.6. The k 0 -NAA method was applied to three different NIST standard reference materials (SRMs) and concentrations of six elements, namely Ag, F, Hf, Rb, Sc, and Se were determined using their short-lived nuclides. The concentrations of these elements were also determined by relative NAA method for comparison purposes.

A model on valence state evaluation of TRU nuclides in reprocessing solutions

International Nuclear Information System (INIS)

Uchiyama, Gunzo; Fujine, Sachio; Yoshida, Zenko; Maeda, Mitsuru; Motoyama, Satoshi.

1998-02-01

A mathematical model was developed to evaluate the valence state of TRU nuclides in reprocessing process solutions. The model consists of mass balance equations, Nernst equations, reaction rate equations and electrically neutrality equations. The model is applicable for the valence state evaluation of TRU nuclides in both steady state and transient state conditions in redox equilibrium. The valence state which is difficult to measure under high radiation and multi component conditions is calculated by the model using experimentally measured data for the TRU nuclide concentrations, nitric acid and redox reagent concentrations, electrode potential and solution temperature. (author)

Study on sorption capacity of synthetic zeolite for simulated nuclide Cs+

International Nuclear Information System (INIS)

Wang Jinming; Yi Facheng

2006-01-01

For the sake of understanding the functionary order of simulated nuclide Cs + and Synthetic Zeolite (ZF), the sorption equilibrium time and sorption capacity of simulated nuclide Cs + on ZF are studied with the intermittence method. The difference of temperature, pH value, Cs + concentration and medium on sorption capacity and sorption ratio are investigated. The results show that the sorption complexion of simulated nuclide Cs + on ZF in the same concentration solution are sorption equilibrium quantity in range of 155-190 mg/g in different temperatures and that in range of 165-190 mg/g in different pH values and that in range of 120-210 mg/g in different media; and changing order of equilibrium adsorption ratio is the same to that of sorption equilibrium quantity, but their changing range are wider than that of sorption equilibrium quantity; equilibrium adsorption quantity in range of 180-380 mg/g in different concentration solutions, and changing order of equilibrium adsorption ratio is opposite to that of sorption equilibrium quantity, and more-over, their changing range are wider than that of the sorption equilibrium quantity. Sorption equilibrium time of simulated nuclide Cs + on ZF is about ten to fifteen days. So the changing range of sorption capacity of simulated nuclide Cs + on ZF with conditions effects is smaller and the sorption equilibrium time is also less and ZF preferably absorbs Cs in radiation wastes and thus consumedly reduces the effect of radwaste on the environment. (authors)

Modeling for Colloid and Chelator Facilitated Nuclide Transport in Radioactive Waste Disposal System

International Nuclear Information System (INIS)

Lee, Youn Myoung; Jeong, Jong Tae

2010-08-01

A modeling study and development of a total system performance assessment (TSPA) program template, by which assessment of safety and performance for a radioactive waste repository with normal and/or abnormal nuclide release cases can be made has been developed. Colloid and chelator facilitated transport that is believed to result for faster nuclide transport in various mediabothinthegeosphereandbiospherehas been evaluated deterministically and probabilistically to demonstrate the capability of the template developed through this study. To this end colloid and chelator facilitated nuclide transport has been modeled rather strainghtforwardly with assumed data through this study by utilizing some powerful function offered by GoldSim. An evaluation in view of apparent influence of colloid and chelator on the nuclide transport in the various media in and around a repository system with data assumed are illustrated

News from the Library: The 8th edition Karlsruhe nuclide chart has been released

CERN Multimedia

CERN Library

2012-01-01

The 8th edition of the Karlsruhe Nuclide Chart contains new data not found in the 7th edition.   Since 1958, the well-known Karlsruhe Nuclide Chart has provided scientists with structured, valuable information on the half-lives, decay modes and energies of radioactive nuclides. The chart is used in many disciplines in physics (health physics, radiation protection, nuclear and radiochemistry, astrophysics, etc.) but also in the life and earth sciences (biology, medicine, agriculture, geology, etc.). The 8th edition of the Karlsruhe Nuclide Chart contains new data on 737 nuclides not found in the 7th edition. In total, nuclear data on 3847 experimentally observed ground states and isomers are presented. A new web-based version of this chart is in the final stages of development for use within the Nucleonica Nuclear Science Portal - a portal for which CERN has an institutional license. The chart is also available in paper format.   If you want to buy a paper version of the chart, ple...

The review of separation technology for fission nuclides 90Sr and 137Cs

International Nuclear Information System (INIS)

Zhang Huaming; Li Xingliang; Luo Shunzhong; Peng Shuming; Lei Jiarong

2010-01-01

The progress of separation technologies for fission nuclides 90 Sr and 137 Cs, including precipitation method, liquid-liquid extraction process and ion exchanging operation, are mainly reviewed. Crown ether (DtBuCH18C6) and calixarene-crown ether (BOBCalixC6) can be highly selective for 90 Sr and 137 Cs respectively in acidic waste; Ionic liquids extraction and supercritical fluid extraction can be applied for separation 90 Sr and 137 Cs from high level waste. Crystalline silicotitiate (CST) and metal sulfide (KMS-1) have highly selectivity for 90 Sr and 137 Cs separately in basic condition. The prospects of disposal technology for high level waste are also discussed in this review. (authors)

Decontamination of contaminated oils with radio nuclides using magnetic fields

International Nuclear Information System (INIS)

Gutierrez R, C. E.

2011-01-01

The present work is focused in to find a solution to the wastes treatment that are generated during the maintenance to the nuclear power industry, the specify case of the contaminated oils with radio nuclides, for this purpose was necessary to make a meticulous characterization of the oils before the treatment proposal using advanced techniques, being determined the activity of them, as well as their physical-chemical characteristics. By means of the developed procedure that combines the use of magnetic fields and filtration to remove the contaminated material with radioactive particles, is possible to diminish the activity of the oils from values that oscillate between 6,00 and 10,00 up to 0,00 to 0,0003 Bq/ml. The decontamination factor of the process is of 99.00%. The proposal of the necessary technology for to decontaminate the oils is also made and is carried out the economic analysis based on the reuse of these, as well as the calculation of the avoided damages. (Author)

Modeling study on nuclide transport in ocean - an ocean compartment method

International Nuclear Information System (INIS)

Lee, Youn Myoung; Suh, Kyung Suk; Han, Kyoung Won

1991-01-01

An ocean compartment model simulating transport of nuclides by advection due to ocean circulation and interaction with suspended sediments is developed, by which concentration breakthrough curves of nuclides can be calculated as a function of time. Dividing ocean into arbitrary number of characteristic compartments and performing a balance of mass of nuclides in each ocean compartment, the governing equation for the concentration in the ocean is obtained and a solution by the numerical integration is obtained. The integration method is specially useful for general stiff systems. For transfer coefficients describing advective transport between adjacent compartments by ocean circulation, the ocean turnover time is calculated by a two-dimensional numerical ocean method. To exemplify the compartment model, a reference case calculation for breakthrough curves of three nuclides in low-level radioactive wastes, Tc-99, Cs-137, and Pu-238 released from hypothetical repository under the seabed is carried out with five ocean compartments. Sensitivity analysis studies for some parameters to the concentration breakthrough curves are also made, which indicates that parameters such as ocean turnover time and ocean water volume of compartments have an important effect on the breakthrough curves. (Author)

A new estimation method for nuclide number densities in equilibrium cycle

International Nuclear Information System (INIS)

Seino, Takeshi; Sekimoto, Hiroshi; Ando, Yoshihira.

1997-01-01

A new method is proposed for estimating nuclide number densities of LWR equilibrium cycle by multi-recycling calculation. Conventionally, it is necessary to spend a large computation time for attaining the ultimate equilibrium state. Hence, the cycle in nearly constant fuel composition has been considered as an equilibrium state which can be achieved by a few of recycling calculations on a simulated cycle operation under a specific fuel core design. The present method uses steady state fuel nuclide number densities as the initial guess for multi-recycling burnup calculation obtained by a continuously fuel supplied core model. The number densities are modified to be the initial number densities for nuclides of a batch supplied fuel. It was found that the calculated number densities could attain to more precise equilibrium state than that of a conventional multi-recycling calculation with a small number of recyclings. In particular, the present method could give the ultimate equilibrium number densities of the nuclides with the higher mass number than 245 Cm and 244 Pu which were not able to attain to the ultimate equilibrium state within a reasonable number of iterations using a conventional method. (author)

Preparation of SiO2-KCoFC composite ion-exchanger for removal of Cs in the soil decontamination waste solution

International Nuclear Information System (INIS)

Lee, Jung Joon; Moon, Jei kwon; Lee, Kune Woo

2009-01-01

The soil decontamination process has been developed for remediate the soil wastes excavated from the TRIGA research reactor sites. Even though the process was proven to be very effective for decontaminate the radioactive nuclides such as cesium and cobalt, the secondary spent solution should be treated with an appropriate method to minimize the waste volume. There are mainly two components in the spent decontamination solution of Cs and Co. The Co in the waste solution can be removed easily by precipitation under a basic condition. However, since the Cs is hardly removed by precipitation, an appropriate selective removal method should be employed. In this study, an inorganic composite ion exchanger of SiO 2 -KCoFC was prepared by sol-gel method for a removal of Cs in the decontamination waste solution. An optimum condition for a preparation of the composite ion exchanger and the adsorption performances of the prepared composite ion exchangers were evaluated

Transmutation of long-lived nuclides

International Nuclear Information System (INIS)

Liang Tongxiang; Tang Chunhe

2003-01-01

Partitioning and transmutation of long-lived nuclides have profound benefits for economic development, global political stability and the environment. This technology would reduce nuclear waste disposal requirements, prevent proliferation and eliminate a major hurdle to the development of nuclear power. This paper reviews the advanced fuel cycle process and development of ATW in the world, and some suggestions about the R and D of nuclear power in China are proposed

Study of the acceleration of nuclide burnup calculation using GPU with CUDA

International Nuclear Information System (INIS)

Okui, S.; Ohoka, Y.; Tatsumi, M.

2009-01-01

The computation costs of neutronics calculation code become higher as physics models and methods are complicated. The degree of them in neutronics calculation tends to be limited due to available computing power. In order to open a door to the new world, use of GPU for general purpose computing, called GPGPU, has been studied [1]. GPU has multi-threads computing mechanism enabled with multi-processors which realize mush higher performance than CPUs. NVIDIA recently released the CUDA language for general purpose computation which is a C-like programming language. It is relatively easy to learn compared to the conventional ones used for GPGPU, such as OpenGL or CG. Therefore application of GPU to the numerical calculation became much easier. In this paper, we tried to accelerate nuclide burnup calculation, which is important to predict nuclides time dependence in the core, using GPU with CUDA. We chose the 4.-order Runge-Kutta method to solve the nuclide burnup equation. The nuclide burnup calculation and the 4.-order Runge-Kutta method were suitable to the first step of introduction CUDA into numerical calculation because these consist of simple operations of matrices and vectors of single precision where actual codes were written in the C++ language. Our experimental results showed that nuclide burnup calculations with GPU have possibility of speedup by factor of 100 compared to that with CPU. (authors)

Selective removal of mercury from aqueous solutions using thiolated cross-linked polyethylenimine

Science.gov (United States)

Saad, Dalia M.; Cukrowska, Ewa M.; Tutu, Hlanganani

2013-06-01

A successful approach to develop an insoluble form of polyethylenimine with a thiol-based functional group for selective removal of Hg(II) from aqueous solutions is reported. The selectivity of the modified polymer for Hg(II) as well as its ability to be regenerated for re-use has been studied. The synthesised polymer exhibited high selectivity for Hg(II) with high removal efficiency of up to 97 %, even in the presence of competing ions. The Freundlich isotherm was found to best fit and describe the experimental data. The pseudo-second-order equation explains the adsorption kinetics most effectively implying chemisorption. The thermodynamic study of the adsorption process revealed high activation energies >41 kJ mol-1, further confirming chemisorption as the mechanism of interaction between mercury ions and the polymer surface. The polymer exhibited good potential for re-use after many cycles of regeneration, giving good removal efficiency up to the fifth cycle.

Inorganic sorbents for radiostrontium removal from waste solutions: selectivity and role of calixarenes

International Nuclear Information System (INIS)

Vijayan, S.; Belikov, K.; Drapailo, A.

2011-01-01

The challenge in the remediation of 90 Sr-contaminated waters arises from the need to achieve very high removal efficiencies to meet discharge targets from waste effluents containing relatively high concentrations of non-radioactive cations. Low-cost natural zeolites are not selective for strontium over other divalent cations, notably such ions as calcium; and produce low 90 Sr removal performance, and large volumes of spent sorbent waste. The synthesis and use of selective, synthetic inorganic sorbents could prove to be a feasible approach for high 90 Sr removal efficiencies, and much smaller volumes of secondary solid waste generation. The essential advantages of inorganic sorbents include their stability and resistance to radiation, and the potential for producing stable waste forms such as vitrified glass or ceramics for disposal. However, the cost of strontium-specific sorbents is prohibitive for large-scale applications at present. This paper is a review of the reported information on removal mechanisms and performance of Sr-specific inorganic sorbents. The analysis has revealed promising performance, efficiency and selectivity for strontium removal from solutions containing low and high concentrations of salts. The leading sorbents are crystalline silicotitanate and oxides of metals such as titanium. An initial assessment has also been made of the performance of calixarene-based macrocyclic compounds. These are known for their selectivity for strontium in solvent extraction processes. From the initial strontium removal results in bench-scale tests using different solid substrates, impregnated with calixarene derivatives, only sodium-mordenite impregnated with calyx[8]arene octamide gave an overall strontium removal efficiency in the range of 90 to 95% in the presence of 3.5 ppm calcium. There was no improvement observed for strontium-removal efficiency or selectivity over calcium in the calixarene-impregnated inorganic sorbent matrix. In several tests, the

Recalculation of measured fuel nuclide concentrations

International Nuclear Information System (INIS)

Moeller, W.

1984-01-01

The concentrations and concentration ratios of heavy fuel nuclides determined in the Central Institute for Nuclear Research Rossendorf on the basis of destructive burnup measurements are compared with the results of microburnup calculations. The possibility is discussed to improve the results by taking into account the spectral characteristics at the positions of the measuring samples. (author)

Transient nuclide release through the bentonite barrier -SKB 91

International Nuclear Information System (INIS)

Bengtsson, A.; Widen, H.

1991-05-01

A study of near-field radionuclide migration is presented. The study has been performed in the context of the SKB91 study which is a comprehensive performance assessment of disposal of spent fuel. The objective of the present study has been to enable the assessment of which nuclides can be screened out because they decay to insignificant levels already in the near-field of the repository. A numerical model has been used which describes the transient transport of radionuclides through a small hole in a HLW canister imbedded in bentonite clay into a fracture in the rock outside the bentonite. Calculations for more than twenty nuclides, nuclides with both high and low solubility have been made. The effect of sorption in the bentonite backfill is included. The size of the penetration hole was assumed to be constant up to time when the calculations were terminated, 500000 year after the deposition. The mass transport rate is controlled by diffusion. The model is three dimensional. The report describes the geometry of the modelled system, the assumptions concerning the transport resistances at the boundary conditions, the handling of the source term and obtained release curves. (au)

Attempt to enrich of a new spontaneous fissioning nuclide by evaporation of natural brine

International Nuclear Information System (INIS)

Adamek, A.; Zhuravleva, E.L.; Constantinescu, M.; Constantinescu, o.; Chuburkov, Yu.T.

1983-01-01

The enrichment of the new spontaneous fissioning nuclide discovered in the Cheleken brine, was made by evaporation. The purpose of this work was the comparison of behaviour of the new spontaneous fissioning nuclide with that of the known elements in the formation processes of the high concentration brines. Spontaneous fission of the nuclide was measured by means of the counters for multiple emission of neutrons. It is shown that the new spontaneous fissioning nuclide was enriched as well as other trace elements (Hg, Tl, Bi and Pb) in a solution remained after the evaporation of the initial solution. The conclusion is drawn that from the sea water brines could be obtained by evaporation which are enriched in trace elements with an enrichment degree higher than the natural brines

Radioactivity nuclide identification based on BP and LM algorithm neural network

International Nuclear Information System (INIS)

Wang Jihong; Sun Jian; Wang Lianghou

2012-01-01

The paper provides the method which can identify radioactive nuclide based on the BP and LM algorithm neural network. Then, this paper compares the above-mentioned method with FR algorithm. Through the result of the Matlab simulation, the method of radioactivity nuclide identification based on the BP and LM algorithm neural network is superior to the FR algorithm. With the better effect and the higher accuracy, it will be the best choice. (authors)

Cosmogenic nuclide production within the atmosphere and long period comets

Science.gov (United States)

Overholt, Andrew C.

The Earth is constantly bombarded by cosmic rays. These high energy particles collide with target nuclei, producing a shower of secondary particles. These secondaries contribute significantly to the radiation background at sea level and in the atmosphere, as well as producing rare cosmogenic nuclides. This contribution is variable over long time scales as astrophysical events change the cosmic ray flux incident on the Earth. Our work re-examines a previously proposed climate effect of increased cosmic ray flux due to galactic location. Although our work does not support this effect, cosmic ray secondaries remain a threat to terrestrial biota. We calculate the cosmogenic neutron flux within the atmosphere as a function of primary spectrum. This work is pivotal in determining the radiation dose due to any arbitrary astrophysical event where the primary spectrum is known. Additionally, this work can be used to determine the cosmogenic nuclide production from such an event. These neutrons are the fundamental source of cosmogenic nuclides within our atmosphere and extraterrestrial matter. We explore the idea that excursions in 14C and 10Be abundances in the atmosphere may arise from direct deposition by long-period comet impacts, and those in 26Al from any bolide. We find that the amount of nuclide mass on large long-period comets entering the Earth's atmosphere may be sufficient for creating anomalies in the records of 14C and 10Be from past impacts. In particular, the estimated mass of the proposed Younger Dryas comet is consistent with its having deposited sufficient isotopes to account for recorded nuclide increases at that time. The 26Al/10Be ratio is much larger in extraterrestrial objects than in the atmosphere, and so, we note that measuring this ratio in ice cores is a suitable further test for the Younger Dryas impact hypothesis. This portion of our work may be used to find possible impact events in the geologic record as well as determination of a large

Capability of minor nuclide confinement in fuel reprocessing

International Nuclear Information System (INIS)

Fujine, Sachio; Uchiyama, Gunzo; Mineo, Hideaki; Kihara, Takehiro; Asakura, Toshihide

1999-01-01

Experiment with spent fuels has started with the small scale reprocessing facility in NUCEF-BECKY αγ cell. Primary purpose of the experiment is to study the capability of long-lived nuclide confinement both in the PUREX flow sheet applied to the large scale reprocessing plant and also in the PARC (Partitioning Conundrum key process) flow sheet which is our proposal as a simplified reprocessing of one cycle extraction system. Our interests in the experiment are the behaviors of minor long-lived nuclides and the behaviors of the heterogeneous substances, such as sedimentation in the dissolver, organic cruds in the extraction banks. The significance of those behaviors will be assessed from the standpoint of the process safety of reprocessing for high burn-up fuels and MOX fuels. (author)

Selective removal of diclofenac from contaminated water using molecularly imprinted polymer microspheres

International Nuclear Information System (INIS)

Dai Chaomeng; Geissen, Sven-Uwe; Zhang Yalei; Zhang Yongjun; Zhou Xuefei

2011-01-01

A molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using diclofenac (DFC) as a template. Binding characteristics of the MIP were evaluated using equilibrium binding experiments. Compared to the non-imprinted polymer (NIP), the MIP showed an outstanding affinity towards DFC in an aqueous solution with a binding site capacity (Q max ) of 324.8 mg/g and a dissociation constant (K d ) of 3.99 mg/L. The feasibility of removing DFC from natural water by the MIP was demonstrated by using river water spiked with DFC. Effects of pH and humic acid on the selectivity and adsorption capacity of MIP were evaluated in detail. MIP had better selectivity and higher adsorption efficiency for DFC as compared to that of powdered activated carbon (PAC). In addition, MIP reusability was demonstrated for at least 12 repeated cycles without significant loss in performance, which is a definite advantage over single-use activated carbon. - Highlights: → A MIP was synthesized by precipitation polymerization using DFC as template. → The MIP had better selectivity and higher adsorption efficiency for DFC. → The MIP is an effective method for selective removal of DFC from complex water. → MIP reusability is a definite advantage over single-use activated carbon. - A diclofenac molecularly imprinted polymer synthesized by precipitation polymerization was used for the selective removal of diclofenac from contaminated water.

Selective removal of diclofenac from contaminated water using molecularly imprinted polymer microspheres

Energy Technology Data Exchange (ETDEWEB)

Dai Chaomeng [State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092 (China); Department of Environmental Technology, Chair of Environmental Process Engineering, Technical University of Berlin, Berlin (Germany); Geissen, Sven-Uwe, E-mail: sven.geissen@tu-berlin.de [Department of Environmental Technology, Chair of Environmental Process Engineering, Technical University of Berlin, Berlin (Germany); Zhang Yalei, E-mail: zhangyalei@tongji.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092 (China); Zhang Yongjun [Department of Environmental Technology, Chair of Environmental Process Engineering, Technical University of Berlin, Berlin (Germany); Zhou Xuefei [State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092 (China)

2011-06-15

A molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using diclofenac (DFC) as a template. Binding characteristics of the MIP were evaluated using equilibrium binding experiments. Compared to the non-imprinted polymer (NIP), the MIP showed an outstanding affinity towards DFC in an aqueous solution with a binding site capacity (Q{sub max}) of 324.8 mg/g and a dissociation constant (K{sub d}) of 3.99 mg/L. The feasibility of removing DFC from natural water by the MIP was demonstrated by using river water spiked with DFC. Effects of pH and humic acid on the selectivity and adsorption capacity of MIP were evaluated in detail. MIP had better selectivity and higher adsorption efficiency for DFC as compared to that of powdered activated carbon (PAC). In addition, MIP reusability was demonstrated for at least 12 repeated cycles without significant loss in performance, which is a definite advantage over single-use activated carbon. - Highlights: > A MIP was synthesized by precipitation polymerization using DFC as template. > The MIP had better selectivity and higher adsorption efficiency for DFC. > The MIP is an effective method for selective removal of DFC from complex water. > MIP reusability is a definite advantage over single-use activated carbon. - A diclofenac molecularly imprinted polymer synthesized by precipitation polymerization was used for the selective removal of diclofenac from contaminated water.

Removal of selected pollutants from aqueous media by hardwood mulch

International Nuclear Information System (INIS)

Ray, Asim B.; Selvakumar, Ariamalar; Tafuri, Anthony N.

2006-01-01

Generic hardwood mulch, usually used for landscaping, was utilized to remove several selected pollutants (heavy metals and toxic organic compounds) typically found in urban stormwater (SW) runoff. The hardwood mulch sorbed all the selected pollutants from a spiked stormwater mixture, including copper (Cu 2+ ), cadmium (Cd 2+ ), chromium (Cr 6+ ), lead (Pb 2+ ), zinc (Zn 2+ ), 1,3 dichlorobenzene (DCB), naphthalene (NP), fluoranthene (FA), butylbenzylphthalate (BBP), and benzo(a)pyrene (B[a]P). Masses of the pollutants sorbed depended upon the pollutant species, contact time, and initial concentration which varied from 20 to 100%. Sorption rates of the metals, in general, were more rapid than those of the organics; however, mass removals (percent) of the organics, in contrast to those of the metals, were independent of their initial concentrations. With the exception of Cd, percentages (weight) of the metals removed declined as their initial concentrations decreased. None of the sorbed pollutants desorbed to any significant extent upon extended washing with water. It is quite feasible that in the presence of mulch the uptake of these pollutants by the aquatic species will be reduced significantly

Model for GCR-particle fluxes in stony meteorites and production rates of cosmogenic nuclides

International Nuclear Information System (INIS)

Reedy, R.C.

1984-01-01

A model is presented for the differential fluxes of galactic-cosmic-ray (GCR) particles with energies above 1 MeV inside any spherical stony meteorite as a function of the meteorite's radius and the sample's depth. This model is based on the Reedy-Arnold equations for the energy-dependent fluxes of GCR particles in the moon and is an extension of flux parameters that were derived for several meteorites of various sizes. This flux is used to calculate the production rates of many cosmogenic nuclides as a function of radius and depth. The peak production rates for most nuclides made by the reactions of energetic GCR particles occur near the centers of meteorites with radii of 40 to 70 g cm -2 . Although the model has some limitations, it reproduces well the basic trends for the depth-dependent production of cosmogenic nuclides in stony meteorites of various radii. These production profiles agree fairly well with measurements of cosmogenic nuclides in meteorites. Some of these production profiles are different than those calculated by others. The chemical dependence of the production rates for several nuclides varies with size and depth. 25 references, 8 figures

Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

OpenAIRE

Lee, Byung-Sik

2015-01-01

The aim of this work is to investigate the transport mechanism of radioactive nuclides through the reverse osmosis (RO) membrane and to estimate its effectiveness for nuclide separation from radioactive liquid waste. An analytical model is developed to simulate the RO separation, and a series of experiments are set up to confirm its estimated separation behavior. The model is based on the extended Nernst–Plank equation, which handles the convective flux, diffusive flux, and electromigration f...

Effect of selective removal of organic matter and iron oxides on the ...

African Journals Online (AJOL)

The effect of selective removal of organic matter and amorphous and crystalline iron oxides on N2-BET specific surface areas of some soil clays was evaluated. Clay fractions from 10 kaolinitic tropical soils were successively treated to remove organic matter by oxidation with Na hypochlorite, amorphous Fe oxide with acid ...

Sequential selective same-day suture removal in the management of post-keratoplasty astigmatism.

Science.gov (United States)

Fares, U; Mokashi, A A; Elalfy, M S; Dua, H S

2013-09-01

In a previous study, we proposed that corneal topography performed 30-40 min after the initial suture removal can identify the next set of sutures requiring removal, for the treatment of post-keratoplasty astigmatism. The aim of this study was to evaluate the effect of removing subsequent sets of sutures at the same sitting. 10/0 nylon interrupted sutures were placed, to secure the graft-host junction, at the time of keratoplasty. Topography was performed using Pentacam (Oculus) before suture removal. The sutures to be removed in the steep semi-meridians were identified and removed at the slit-lamp biomicroscope. Topography was repeated 30-40 min post suture removal, the new steep semi-meridians determined, and the next set of sutures to be removed were identified and removed accordingly. Topography was repeated 4-6 weeks later and the magnitude of topographic astigmatism was recorded. A paired-samples t-test was used to evaluate the impact of selective suture removal on reducing the magnitude of topographic and refractive astigmatism. Twenty eyes of 20 patients underwent sequential selective same-day suture removal (SSSS) after corneal transplantation. This study showed that the topographic astigmatism decreased by about 46.7% (3.68 D) and the refractive astigmatism decreased by about 37.7% (2.61 D) following SSSS. Vector calculations also show a significant reduction of both topographic and refractive astigmatism (P<0.001). SSSS may help patients to achieve satisfactory vision more quickly and reduce the number of follow-up visits required post keratoplasty.

Calculated nuclide production yields in relativistic collisions of fissile nuclei

Energy Technology Data Exchange (ETDEWEB)

Benlliure, J.; Schmidt, K.H. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Grewe, A.; Jong, M. de [Technische Univ. Darmstadt (Germany). Inst. fuer Kernphysik; Zhdanov, S. [AN Kazakhskoj SSR, Alma-Ata (USSR). Inst. Yadernoj Fiziki

1997-11-01

A model calculation is presented which predicts the complex nuclide distribution resulting from peripheral relativistic heavy-ion collisions involving fissile nuclei. The model is based on a modern version of the abrasion-ablation model which describes the formation of excited prefragments due to the nuclear collisions and their consecutive decay. The competition between the evaporation of different light particles and fission is computed with an evaporation code which takes dissipative effects and the emission of intermediate-mass fragments into account. The nuclide distribution resulting from fission processes is treated by a semiempirical description which includes the excitation-energy dependent influence of nuclear shell effects and pairing correlations. The calculations of collisions between {sup 238}U and different reaction partners reveal that a huge number of isotopes of all elements up to uranium is produced. The complex nuclide distribution shows the characteristics of fragmentation, mass-asymmetric low-energy fission and mass-symmetric high-energy fission. The yields of the different components for different reaction partners are studied. Consequences for technical applications are discussed. (orig.)

Measurements of neutron cross sections of radioactive waste nuclides

Energy Technology Data Exchange (ETDEWEB)

Katoh, Toshio [Gifu College of Medical Technology, Seki, Gifu (Japan); Harada, Hideo; Nakamura, Shoji; Tanase, Masakazu; Hatsukawa, Yuichi

1998-01-01

Accurate nuclear reaction cross sections of radioactive fission products and transuranic elements are required for research on nuclear transmutation methods in nuclear waste management. Important fission products in the nuclear waste management are {sup 137}Cs, {sup 135}Cs, {sup 90}Sr, {sup 99}Tc and {sup 129}I because of their large fission yields and long half-lives. The present authors have measured the neutron capture cross sections and resonance integrals of {sup 137}Cs, {sup 90}Sr and {sup 99}Tc. The purpose of this study is to measure the neutron capture cross sections and resonance integrals of nuclides, {sup 129}I and {sup 135}Cs accurately. Preliminary experiments were performed by using Rikkyo University Reactor and JRR-3 reactor at Japan Atomic Energy Research Institute (JAERI). Then, it was decided to measure the cross section and resonance integral of {sup 135}Cs by using the JRR-3 Reactor because this measurement required a high flux reactor. On the other hand, those of {sup 129}I were measured at the Rikkyo Reactor because the product nuclides, {sup 130}I and {sup 130m}I, have short half-lives and this reactor is suitable for the study of short lived nuclide. In this report, the measurements of the cross section and resonance integral of {sup 135}Cs are described. To obtain reliable values of the cross section and resonance integral of {sup 135}Cs(n, {gamma}){sup 136}Cs reaction, a quadrupole mass spectrometer was used for the mass analysis of nuclide in the sample. A progress report on the cross section of {sup 134}Cs, a neighbour of {sup 135}Cs, is included in this report. A report on {sup 129}I will be presented in the Report on the Joint-Use of Rikkyo University Reactor. (author)

Nuclide transfer test device in soil

International Nuclear Information System (INIS)

Sakata, Yoshiyuki.

1994-01-01

The device comprises a pressure-proof vessel having a perforated port, a compression vessel having a sample-containing chamber with circumferential walls having a plurality of small holes being gastightly engaged to the perforated port, a mechanically pressurizing means for vertically compressing the compression chamber, a pressurizing gas supply system for supplying a pressurizing gas to compress the soil specimen in a lateral direction and a sample water-supply system for supplying sample water to the sample containing chamber. The soil sample is pressurized so that the sample water is caused to permeate by isotropic pressure due to equilibrium of vertical compression by mechanical force and lateral compression by the pressurizing gas. The transfer state of radioactive nuclides in the soil can be tested easily in a state where the sample water is caused to permeate in a vertical direction in parallel, to simulate an actual processing circumstance. Namely, since the sample water is caused to permeate to the soil sample in the pressure-proof vessel, a desired test can easily be conducted in a restricted space without undergoing influences of the kind and the dose rate of the radioactive nuclides. (N.H.)

IDGAM. A PC code and database to help nuclide identification in activation analysis

International Nuclear Information System (INIS)

Paviotti Corcuera, R.; Moraes Cunha, M. de; Jayanthi, K.A.

1994-01-01

The document describes a PC diskette containing a code and database which helps researchers to identify the nuclides in a radioactive sample. Data can be retrieved by gamma-ray energy, nuclide or element. The PC diskette is available, costfree, from the IAEA Nuclear Data Section, upon request. (author). 6 refs, 5 figs

Accelerator produced nuclides for use in biology and medicine. A bibliography, 1939--1973

International Nuclear Information System (INIS)

Christman, D.R.; Karlstrom, K.I.; Fowler, J.; Lambrecht, R.; Wolf, A.P.

1975-04-01

A bibliography of more than 1300 references on accelerator-produced nuclides for use in biology and medicine is presented. The information is arranged by subject and by specific nuclide. An author index is included. Appendices are provided of medical uses of specific elements and of radioisotopes not included in the main bibliography. (U.S.)

The efficacy of selective calculus ablation at 400 nm: comparison to conventional calculus removal methods

Science.gov (United States)

Schoenly, Joshua E.; Seka, Wolf; Romanos, Georgios; Rechmann, Peter

A desired outcome of scaling and root planing is the complete removal of calculus and infected root tissue and preservation of healthy cementum for rapid healing of periodontal tissues. Conventional periodontal treatments for calculus removal, such as hand instrument scaling and ultrasonic scaling, often deeply scrape the surface of the underlying hard tissue and may leave behind a smear layer. Pulsed lasers emitting at violet wavelengths (specifically, 380 to 400 nm) are a potential alternative treatment since they can selectively ablate dental calculus without ablating pristine hard tissue (i.e., enamel, cementum, and dentin). In this study, light and scanning electron microscopy are used to compare and contrast the efficacy of in vitro calculus removal for several conventional periodontal treatments (hand instruments, ultrasonic scaler, and Er:YAG laser) to calculus removal with a frequency-doubled Ti:sapphire (λ = 400 nm). After calculus removal, enamel and cementum surfaces are investigated for calculus debris and damage to the underlying hard tissue surface. Compared to the smear layer, grooves, and unintentional hard tissue removal typically found using these conventional treatments, calculus removal using the 400-nm laser is complete and selective without any removal of pristine dental hard tissue. Based on these results, selective ablation from the 400-nm laser appears to produce a root surface that would be more suitable for successful healing of periodontal tissues.

Bio-active glass air-abrasion has the potential to remove resin composite restorative material selectively

International Nuclear Information System (INIS)

Milly, Hussam; Andiappan, Manoharan; Thompson, Ian; Banerjee, Avijit

2014-01-01

The aims of this study were to assess: (a) the chemistry, morphology and bioactivity of bio-active glass (BAG) air-abrasive powder, (b) the effect of three air-abrasion operating parameters: air pressure, powder flow rate (PFR) and the abrasive powder itself, on the selective removal of resin composite and (c) the required “time taken”. BAG abrasive particles were characterised using scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). Standardised resin composite restorations created within an enamel analogue block (Macor™) in vitro, were removed using air-abrasion undersimulated clinical conditions. 90 standardised cavities were scanned before and after resin composite removal using laser profilometry and the volume of the resulting 3D images calculated. Multilevel linear model was used to identify the significant factors affecting Macor™ removal. BAG powder removed resin composite more selectively than conventional air-abrasion alumina powder using the same operating parameters (p < 0.001) and the effect of altering the unit's operating parameters was significant (p < 0.001). In conclusion, BAG powder is more efficient than alumina in the selective removal of resin composite particularly under specific operating parameters, and therefore may be recommended clinically as a method of preserving sound enamel structure when repairing and removing defective resin composite restorations.

Some notes on experiments measuring diffusion of sorbed nuclides through porous media

International Nuclear Information System (INIS)

Lever, D.A.

1986-11-01

Various experimental techniques for measuring the important parameters governing diffusion of sorbed nuclides through water-saturated porous media are described, and the particular parameters obtained from each technique are discussed. Recent experiments in which diffusive transport takes place more rapidly than expected are reviewed. The author recommends that through-transport diffusion experiments are the most satisfactory method of determining whether this arises from surface diffusion of sorbed nuclides. (author)

Selective sodium removal from lithium chloride brine with novel ...

African Journals Online (AJOL)

Natrium superionic conductor (NASICON) ceramics present interesting sensitive and selective properties against alkaline cations due to their structure. The powder of Li1.4La0.4Zr1.6(PO4)3 has been synthesized by a solid phase reaction. The removal of sodium was studied in an extensive series of tests involving different ...

Transmutation of long-lived nuclides in the fuel cycle of Brest-type reactors

International Nuclear Information System (INIS)

Lopatkin, A.V.; Orlov, V.V.; Filin, A.I.

2001-01-01

Transmutation of long-lived nuclides produced as a result of nuclear generation, should be set up proceeding from the principle of reasonable sufficiency, expressed as radiation equivalence between the radwaste sent to disposal and source natural uranium. In this case, introduction of fast reactors of new generation (such as BREST or other reactors based on similar philosophy) will resolve transmutation problems even with the thermal-to-fast reactor capacity ratio of 2:1. The authors of the 'Strategy of nuclear power development in Russia' foresee, and substantiate their prediction, that fast reactors of the new generation will account for no less than 2/3 of nuclear capacity in future large-scale nuclear power sector. Fast reactors will be the basis of a transmutation fuel cycle, which will remove the need of creating additional transmutation facilities. (author)

A GoldSim Model for Colloid Facilitated Nuclide Transport

International Nuclear Information System (INIS)

Lee, Youn Myoung; Jeong, Jong Tae

2010-01-01

Recently several total system performance assessment (TSPA) programs, called 'template' programs, ready for the safety assessment of radioactive waste repository systems which are conceptually modeled have been developed by utilizing GoldSim and AMBER at KAERI. It is generally believed that chelating agents (chelators) that could be disposed of together with radioactive wastes in the repository and natural colloids available in the geological media affect on nuclides by enhancing their transport in the geological media. A simple GoldSim module to evaluate such quantitative effects, by which colloid and chelator-facilitated nuclide release cases could be modeled and evaluated is introduced. Effects of the chelators alone are illustrated with the case associated with well pumping scenario in a hypothetical repository system

An Evaluation Method for Activation Analysis using Pre-evaluated Contribution of Nuclides with Impurity

Energy Technology Data Exchange (ETDEWEB)

Woo, Myeong Hyeon; Kim, Song Hyun; Kim, Do Hyun; Shin, Chang Ho [Hanyang University, Seoul (Korea, Republic of); Kim, Gee Suck [KAERI, Daejeon (Korea, Republic of)

2016-05-15

Nuclides in radiation facilities become unstable from nuclear reaction. It emits residual radiation to be stable. Some unstable nuclides remain after operation in the material. It continuously emits the radiation, which has a harmful effect to worker when they try maintenance and plant decommissioning. It is known that residual radiation from impurity occupies a large portion of the radiation dose. If impurity concentration is higher than expectation, the effects of residual radiation could be underestimated. Therefore, estimation of residual radiation is repeatedly calculated according to impurity concentration. In this study, an approach estimating the activation was proposed using pre-evaluated nuclide's contribution to reduce the calculation time and effort of worker. In this study, in order to reduce the calculation time and effort of worker, activation analysis method based on pre-evaluated nuclide contribution was proposed. This method was verified using concreate activation problem, which is located in nuclear power plant. The results show that our proposed method has good agreement with Bateman equation.

Metrological aspects of radiochemical methods for determining activity of gamma-emitting nuclides

International Nuclear Information System (INIS)

Shcherbakov, B.Y.

1986-01-01

The author considers the problem of metrological compatibility of the two stages in the radiochemical method of determining the activity of a gamma-emitting nuclide: chemical isolation of the nuclide and radiometric measurement of its activity. The authors show that preparation of the specimen in liquid form provides for important advantages compared with the traditional application of the solid residue onto a flat substate. The work here is of interest for analytical chemists who are involved with determination of the activity of gamma emitting nuclides such as Ru 103, Rh 106, Sn 113, Cs 134, Cs 137, La 140, Ce 141, Ce 144, Hg 203, Na 24, Mn 54, Fe 59, Co 60, Zn 65, Zr 95, and Nb 95, for example, in waste water or in emissions to the atmosphere, with the goal of protecting the environment

Runoff and sediment yield model for predicting nuclide transport in watersheds using BIOTRAN

Energy Technology Data Exchange (ETDEWEB)

Gallegos, A.F.; Wenzel, W.J.

1990-09-01

The environmental risk simulation model BIOTRAN was interfaced with a series of new subroutines (RUNOFF, GEOFLX, EROSON, and AQUIFER) to predict the movement of nuclides, elements, and pertinent chemical compounds in association with sediments through lateral and channel flow of runoff water. In addition, the movement of water into and out of segmented portions of runoff channels was modeled to simulate the dynamics of moisture flow through specified aquifers within the watershed. The BIOTRAN soil water flux subroutine, WATFLX, was modified to interface the relationships found in the SPUR model for runoff and sediment transport into channels with the particle sorting relationships to predict radionuclide enrichment and movement in watersheds. The new subroutines were applied specifically to Mortandad Canyon within Los Alamos National Laboratory by simultaneous simulation of eight surface vegetational subdivisions and associated channel and aquifer segments of this watershed. This report focuses on descriptions of the construction and rationale for the new subroutines and on discussing both input characteristics and output relationships to known runoff events from Mortandad Canyon. Limitations of the simplified input on model behavior are also discussed. Uranium-238 was selected as the nuclide for demonstration of the model because it could be assumed to be homogeneously distributed over the watershed surface. 22 refs., 18 figs., 9 tabs.

Impact of high-risk conjunctions on Active Debris Removal target selection

OpenAIRE

Lidtke, Aleksander A.; Lewis, Hugh G.; Armellin, Roberto

2015-01-01

All rights reserved.Space debris simulations show that if current space launches continue unchanged, spacecraft operations might become difficult in the congested space environment. It has been suggested that Active Debris Removal (ADR) might be necessary in order to prevent such a situation. Selection of objects to be targeted by ADR is considered important because removal of non-relevant objects will unnecessarily increase the cost of ADR. One of the factors to be used in this ADR target se...

Evaluation of improved technologies for the removal of 90Sr and 137Cs from process wastewater and groundwater: FY 1995 status

International Nuclear Information System (INIS)

Bostick, D.T.; Arnold, W.D. Jr.; Burgess, M.W.; McTaggart, D.R.; Taylor, P.A.; Guo, B.

1996-03-01

A number of new sorbents are currently being developed for the removal of 90 Sr and 137 Cs from contaminated, caustic low-level liquid waste (LLLW). These sorbents are potentially promising for use in the cleanup of contaminated groundwater and process wastewater containing the two radionuclides. The goal of this subtask is to evaluate the new sorbents to determine whether their associated treatment technology is more selective for the decontamination of wastewater streams than that of currently available processes. Activities during fiscal year 1995 have included completing the characterization of the standard treatment technology, ion exchange on chabazite zeolite. Strontium and cesium sorption on sodium-modified zeolite was observed in the presence of elevated concentrations of wastewater components: sodium, potassium, magnesium, and calcium. The most significant loss of nuclide sorption was noted in the first 0- to 4-meq/L addition of the cations to a wastewater simulant. Radionuclide sorption on the pretreated zeolite was also determined under dynamic flow conditions. Resorcinol-formaldehyde (R-F) resin, which was developed at the Savannah River Site, was selected as the first new sorbent to be evaluated for wastewater treatment. Nuclide sorption on this resin was greater when the resin had been washed with ultrapure water and air dried prior to use

Synchrotron radiation based Mössbauer absorption spectroscopy of various nuclides

Energy Technology Data Exchange (ETDEWEB)

Masuda, Ryo, E-mail: masudar@rri.kyoto-u.ac.jp; Kobayashi, Yasuhiro; Kitao, Shinji; Kurokuzu, Masayuki; Saito, Makina [Kyoto University, Research Reactor Institute (Japan); Yoda, Yoshitaka [Japan Synchrotron Radiation Research Institute, Resarch and Utilization Division (Japan); Mitsui, Takaya [Japan Atomic Energy Agency, Condensed Matter Science Division, Sector of Nuclear Science Research (Japan); Seto, Makoto [Kyoto University, Research Reactor Institute (Japan)

2016-12-15

Synchrotron-radiation (SR) based Mössbauer absorption spectroscopy of various nuclides is reviewed. The details of the measuring system and analysis method are described. Especially, the following two advantages of the current system are described: the detection of internal conversion electrons and the close distance between the energy standard scatterer and the detector. Both of these advantages yield the enhancement of the counting rate and reduction of the measuring time. Furthermore, SR-based Mössbauer absorption spectroscopy of {sup 40}K, {sup 151}Eu, and {sup 174}Yb is introduced to show the wide applicability of this method. In addition to these three nuclides, SR-based Mössbauer absorption spectroscopy of {sup 61}Ni, {sup 73}Ge, {sup 119}Sn, {sup 125}Te, {sup 127}I, {sup 149}Sm, and {sup 189}Os has been performed. We continue to develop the method to increase available nuclides and to increase its ease of use. The complementary relation between the time-domain method using SR, such as nuclear forward scattering and the energy-domain methods such as SR-based Mössbauer absorption spectroscopy is also noted.

The Development of Magnetic Molecules for the Selective Removal of Contaminants

International Nuclear Information System (INIS)

Bushart, S.P.; Bradbury, D.; Elder, G.; Duffield, J.; Pascual, I.; Ratcliffe, N.

2006-01-01

'Magnetic molecules' are a new type of decontaminant for removing dilute dissolved contaminants from solution. Magnetic molecules have a specific ion exchange function to selectively react with a particular type of ionic contamination in a liquid solution. The magnetic molecules also have a very small magnetic ferritin core (ferritin is an iron-III mammalian storage protein having about 10 nm diameter), which enables the magnetic molecule to be removed from solution by magnetic filtration. The ion exchange function is attached to the magnetic ferritin core by organic reaction sequences. The ion exchange function selectively bonds to a specific type of contaminant ion. For example, ion exchange functions can selectively target radioactive contaminant ions such as cobalt, cesium and plutonium. The procedure for decontamination is that the appropriate magnetic molecule (which targets the contaminant which it is desired to remove) is added to the solution and the solution is then passed through a magnetic filter. The contaminant binds to the magnetic molecule and is then removed by the magnetic filter. The magnetic molecule/contaminant can then be recovered from the magnetic filter by back-washing. Work has been undertaken towards the development of magnetic molecules for use as radioactive decontaminants for radioactive waste management purposes. Previously we have reported on the functionalization of ferritin with the chelating agent DTPA and have shown that this can be used to bind Ca(II) in solution and separate it from Na(I) ions by the process of equilibrium dialysis. Approximately 100 DTPA molecules could be bound to the surface of the ferritin molecule. Synthetic conditions have been optimised, and which will be reported here, ferritin has been functionalized with approximately 1200 DTPA molecules per mole of ferritin and used successfully to achieve a quantitative separation of Co(II) from Cs(I) ions by equilibrium dialysis. This separation has been carried

Accelerator based production of fissile nuclides, threshold uranium price and perspectives

International Nuclear Information System (INIS)

Djordjevic, D.; Knapp, V.

1988-01-01

Accelerator breeder system characteristics are considered in this work. One such system which produces fissile nuclides can supply several thermal reactors with fissile fuel, so this system becomes analogous to an uranium enrichment facility with difference that fissile nuclides are produced by conversion of U-238 rather than by separation from natural uranium. This concept, with other long-term perspective for fission technology on the basis of development only one simpler technology. The influence of basic system characteristics on threshold uranium price is examined. Conditions for economically acceptable production are established. (author)

Bio-active glass air-abrasion has the potential to remove resin composite restorative material selectively

Energy Technology Data Exchange (ETDEWEB)

Milly, Hussam [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Andiappan, Manoharan [Unit of Dental Public Health, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Thompson, Ian [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Banerjee, Avijit, E-mail: avijit.banerjee@kcl.ac.uk [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Unit of Conservative Dentistry, King' s College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom)

2014-06-01

The aims of this study were to assess: (a) the chemistry, morphology and bioactivity of bio-active glass (BAG) air-abrasive powder, (b) the effect of three air-abrasion operating parameters: air pressure, powder flow rate (PFR) and the abrasive powder itself, on the selective removal of resin composite and (c) the required “time taken”. BAG abrasive particles were characterised using scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). Standardised resin composite restorations created within an enamel analogue block (Macor™) in vitro, were removed using air-abrasion undersimulated clinical conditions. 90 standardised cavities were scanned before and after resin composite removal using laser profilometry and the volume of the resulting 3D images calculated. Multilevel linear model was used to identify the significant factors affecting Macor™ removal. BAG powder removed resin composite more selectively than conventional air-abrasion alumina powder using the same operating parameters (p < 0.001) and the effect of altering the unit's operating parameters was significant (p < 0.001). In conclusion, BAG powder is more efficient than alumina in the selective removal of resin composite particularly under specific operating parameters, and therefore may be recommended clinically as a method of preserving sound enamel structure when repairing and removing defective resin composite restorations.

Selective removal of phosphate for analysis of organic acids in complex samples.

Science.gov (United States)

Deshmukh, Sandeep; Frolov, Andrej; Marcillo, Andrea; Birkemeyer, Claudia

2015-04-03

Accurate quantitation of compounds in samples of biological origin is often hampered by matrix interferences one of which occurs in GC-MS analysis from the presence of highly abundant phosphate. Consequently, high concentrations of phosphate need to be removed before sample analysis. Within this context, we screened 17 anion exchange solid-phase extraction (SPE) materials for selective phosphate removal using different protocols to meet the challenge of simultaneous recovery of six common organic acids in aqueous samples prior to derivatization for GC-MS analysis. Up to 75% recovery was achieved for the most organic acids, only the low pKa tartaric and citric acids were badly recovered. Compared to the traditional approach of phosphate removal by precipitation, SPE had a broader compatibility with common detection methods and performed more selectively among the organic acids under investigation. Based on the results of this study, it is recommended that phosphate removal strategies during the analysis of biologically relevant small molecular weight organic acids consider the respective pKa of the anticipated analytes and the detection method of choice. Copyright © 2015 Elsevier B.V. All rights reserved.

Memory Outcomes Following Selective versus Nonselective Temporal Lobe Removal: A Systematic Review

Science.gov (United States)

Girgis, Fady

2012-01-01

The surgical removal of brain tissue for the treatment of temporal lobe epilepsy can be either nonselective, as with an anterior temporal lobectomy (ATL), or selective, as with a selective amygdalohippocampectomy (SAH). Although seizure outcomes are similar with both procedures, cognitive and memory outcomes remain a matter of debate. This study…

WebCN: A web-based computation tool for in situ-produced cosmogenic nuclides

Energy Technology Data Exchange (ETDEWEB)

Ma Xiuzeng [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States)]. E-mail: hongju@purdue.edu; Li Yingkui [Department of Geography, University of Missouri-Columbia, Columbia, MO 65211 (United States); Bourgeois, Mike [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Caffee, Marc [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Elmore, David [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Granger, Darryl [Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette, IN 47907 (United States); Muzikar, Paul [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Smith, Preston [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States)

2007-06-15

Cosmogenic nuclide techniques are increasingly being utilized in geoscience research. For this it is critical to establish an effective, easily accessible and well defined tool for cosmogenic nuclide computations. We have been developing a web-based tool (WebCN) to calculate surface exposure ages and erosion rates based on the nuclide concentrations measured by the accelerator mass spectrometry. WebCN for {sup 10}Be and {sup 26}Al has been finished and published at http://www.physics.purdue.edu/primelab/for{sub u}sers/rockage.html. WebCN for {sup 36}Cl is under construction. WebCN is designed as a three-tier client/server model and uses the open source PostgreSQL for the database management and PHP for the interface design and calculations. On the client side, an internet browser and Microsoft Access are used as application interfaces to access the system. Open Database Connectivity is used to link PostgreSQL and Microsoft Access. WebCN accounts for both spatial and temporal distributions of the cosmic ray flux to calculate the production rates of in situ-produced cosmogenic nuclides at the Earth's surface.

Light nuclides produced in the proton-induced spallation of {sup 238}U at 1 GeV

Energy Technology Data Exchange (ETDEWEB)

Ricciardi, M.V.; Armbruster, P. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Benlliure, J. [Universidad de Santiago de Compostela (ES)] [and others

2005-09-01

The production of light and intermediate-mass nuclides formed in the reaction {sup 1}H+{sup 238}U at 1 GeV was measured at the fragment separator (FRS) at GSI, Darmstadt. The experiment was performed in inverse kinematics, shooting a 1 A GeV {sup 238}U beam on a thin liquid-hydrogen target. 254 isotopes of all elements in the range 7{<=}Z{<=}37 were unambiguously identified, and the velocity distributions of the produced nuclides were determined with high precision. The results show that the nuclides are produced in a very asymmetric binary decay of heavy nuclei originating from the spallation of uranium. All the features of the produced nuclides merge with the characteristics of the fission products as their mass increases. (orig.)

Bioremediation system on-line for removal radionuclides in radioactive waters

International Nuclear Information System (INIS)

Belinchon, J. A.; Garcia, A. M.; Ruibal, C.; Moreno, D. A.

2010-01-01

In previous studies developed in Cofrentes Nuclear Power Plant (Valencia, Spain), has been observed that the microorganisms in the radioactive waters of the spent nuclear fuel pool are capable of colonizing the metallic surfaces of the walls and pipes and perform biofilm. These biofilm retain the nuclides contributing to decontaminate the water. In this project, carried out in Cofrentes Nuclear Power Plant, a pilot plant has been designed for the bio decontamination of the radioactive water. At present, the radioactive water coming from the spent nuclear fuel pools, pass through ionic exchange resins. After, these resins are managed as radioactive waste. In this project, the water passes through a bioreactor with stainless steel balls capable of being colonized by the microorganisms in the water. Inside the bioreactor the water gets in contact with the material of the balls, and a biofilm, which retains the nuclides in the water, is developed. The biofilm is easily removed by any conventional procedure of radiochemical decontamination of materials and the nuclides can be collected in a small volume for recovery final disposition or containment. Later, the material of the bioreactor could be managed as not radioactive material. (Author) 9 refs.

The extraction behavior of some noticeable nuclides in the Tokai reprocessing plant

International Nuclear Information System (INIS)

Yamanouchi, T.; Sasao, N.; Ozawa, M.; Yamana, H.

1987-01-01

The extraction behavior of some TRU nuclides and Ru-106 were investigated on the basis of the process analytical data obtained during this decade of the hot operation in the Tokai Reprocessing Plant. Some characteristics of their extraction behavior under Tokai-flowsheet became clear. They were explainable by the chemical features of these nuclides in conjunction with the chemical conditions of the process. Some extraction-simulation calculations were performed to supplement the understanding of their characteristic behaviors

Method selection for mercury removal from hard coal

Directory of Open Access Journals (Sweden)

Dziok Tadeusz

2017-01-01

Full Text Available Mercury is commonly found in coal and the coal utilization processes constitute one of the main sources of mercury emission to the environment. This issue is particularly important for Poland, because the Polish energy production sector is based on brown and hard coal. The forecasts show that this trend in energy production will continue in the coming years. At the time of the emission limits introduction, methods of reducing the mercury emission will have to be implemented in Poland. Mercury emission can be reduced as a result of using coal with a relatively low mercury content. In the case of the absence of such coals, the methods of mercury removal from coal can be implemented. The currently used and developing methods include the coal cleaning process (both the coal washing and the dry deshaling as well as the thermal pretreatment of coal (mild pyrolysis. The effectiveness of these methods various for different coals, which is caused by the diversity of coal origin, various characteristics of coal and, especially, by the various modes of mercury occurrence in coal. It should be mentioned that the coal cleaning process allows for the removal of mercury occurring in mineral matter, mainly in pyrite. The thermal pretreatment of coal allows for the removal of mercury occurring in organic matter as well as in the inorganic constituents characterized by a low temperature of mercury release. In this paper, the guidelines for the selection of mercury removal method from hard coal were presented. The guidelines were developed taking into consideration: the effectiveness of mercury removal from coal in the process of coal cleaning and thermal pretreatment, the synergy effect resulting from the combination of these processes, the direction of coal utilization as well as the influence of these processes on coal properties.

Decay of neutron-rich Mn nuclides and deformation of heavy Fe isotopes

CERN Document Server

Hannawald, M; Wöhr, A; Walters, W B; Kratz, K L; Fedosseev, V; Mishin, V I; Böhmer, W; Pfeiffer, B; Sebastian, V; Jading, Y; Köster, U; Lettry, Jacques; Ravn, H L

1999-01-01

The use of chemically selective laser ionization combined with beta-delayed neutron counting at CERN/ISOLDE has permitted identification and half-life measurements for 623-ms Mn-61 up through 14-ms Mn-69. The measured half-lives are found to be significantly longer near N=40 than the values calculated with a QRPA shell model using ground-state deformations from the FRDM and ETFSI models. Gamma-ray singles and coincidence spectroscopy has been performed for Mn-64 and Mn-66 decays to levels of Fe-64 and Fe-66, revealing a significant drop in the energy of the first 2+ state in these nuclides that suggests an unanticipated increase in collectivity near N=40.

Considerations on the activity concentration determination method for low-level waste packages and nuclide data comparison between different countries

International Nuclear Information System (INIS)

Kashiwagi, M.; Mueller, W.

2000-01-01

In low-level waste disposal, acceptable activity concentration limits are regulated for individual nuclides and groups of nuclides according to the conditions of each disposal site. Such regulated limits principally concern total alpha and beta /gamma activity as well as nuclides such as C-14, Ni-63, and Pu-238 which are long-lived and difficult to measure (hereinafter referred to as difficult-to-measure nuclides). Before waste packages are transported to the disposal site, the activities or activity concentrations of the regulated nuclides and groups of nuclides in the waste packages must be assessed and declared. A generally applicable theoretical method to determine these activities is lacking at present. Therefore, to meet this requirement, for NPP waste each country independently samples actual waste and carries out radiochemical analyses on these samples. The activity concentrations of difficult-to-measure nuclides are then determined by statistical correlation of the measured data between difficult-to-measure nuclides and Co-60 and Cs-137 which are measurable from outside the waste packages (hereinafter referred to as key nuclides). This method is called 'Scaling Factor Method'. It is widely adopted as a method for determining the activity concentrations of the limited nuclides in low-level waste packages from NPP, and it is also approved by responsible authorities in the respective country. In the past, each country independently determined scaling factors based on measurements on samples from the local NPPs. In the first part of this study, the possibility of an international scaling factor assessment using a database integrating data from different countries was studied by comparing radiochemical analysis data between Germany, Japan, and the United States. These countries have accumulated a large number of those nuclide data required to determine scaling factors. Statistical values such as correlation coefficients change with an accumulation of data. In

Sampling soils for transuranic nuclides: a review

International Nuclear Information System (INIS)

Fowler, E.B.; Essington, E.H.

1976-01-01

A review of the literature pertinent to the sampling of soils for radionuclides is presented; emphasis is placed on transuranic nuclides. Sampling of soils is discussed relative to systems of heterogeneous distributions and varied particle sizes encountered in certain environments. Sampling methods that have been used for two different sources of contamination, global fallout, and accidental or operational releases, are included

FISPIN - a computer code for nuclide inventory calculations

International Nuclear Information System (INIS)

Burstall, R.F.

1979-10-01

The code is used for assessment of three groups of nuclides, the actinides, the fission products, and structural materials. The methods of calculation are described, together with the input and output of the code and examples of both. Recommendations are given for the best use of the code. (author)

Removal of radionuclides from partitioning waste solutions by adsorption and catalytic oxidation methods

Energy Technology Data Exchange (ETDEWEB)

Yamagishi, Isao; Yamaguchi, Isoo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kubota, Masumitsu [Research Organization for Information Science and Technology (RIST), Tokai, Ibaraki (Japan)

2000-09-01

Adsorption of radionuclides with inorganic ion exchangers and catalytic oxidation of a complexant were studied for the decontamination of waste solutions generated in past partitioning tests with high-level liquid waste. Granulated ferrocyanide and titanic acid were used for adsorption of Cs and Sr, respectively, from an alkaline solution resulting from direct neutralization of an acidic waste solution. Both Na and Ba inhibited adsorption of Sr but Na did not that of Cs. These exchangers adsorbed Cs and Sr at low concentration with distribution coefficients of more than 10{sup 4}ml/g from 2M Na solution of pH11. Overall decontamination factors (DFs) of Cs and total {beta} nuclides exceeded 10{sup 5} and 10{sup 3}, respectively, at the neutralization-adsorption step of actual waste solutions free from a complexant. The DF of total {alpha} nuclides was less than 10{sup 3} for a waste solution containing diethylenetriaminepentaacetic acid (DTPA). DTPA was rapidly oxidized by nitric acid in the presence of a platinum catalyst, and radionuclides were removed as precipitates by neutralization of the resultant solution. The DF of {alpha} nuclides increased to 8x10{sup 4} by addition of the oxidation step. The DFs of Sb and Co were quite low through the adsorption step. A synthesized Ti-base exchanger (PTC) could remove Sb with the DF of more than 4x10{sup 3}. (author)

Selective cesium removal from radioactive liquid waste by crown ether immobilized new class conjugate adsorbent

OpenAIRE

Awual, M. R.; 矢板 毅; 田口 富嗣; 塩飽 秀啓; 鈴木 伸一; 岡本 芳浩

2014-01-01

Conjugate materials can provide chemical functionality, enabling an assembly of the ligand complexation ability to metal ions that are important for applications, such as separation and removal devices. In this study, we developed ligand immobilized conjugate adsorbent for selective cesium (Cs) removal from wastewater. The adsorbent was synthesized by direct immobilization of DB24C8 onto inorganic mesoporous silica. The obtained results revealed that adsorbent had higher selectivity towards C...

A study on nuclide migration in buffer materials and rocks for geological disposal of radioactive waste

International Nuclear Information System (INIS)

Sato, Haruo

1998-01-01

This thesis summarizes the results investigated in order to establish a basic theory on the predictive method of diffusion coefficients of nuclides in compacted sodium bentonite which is a candidate buffer material and in representative rocks for the geological disposal of radioactive waste by measuring the pore structural factors of the compacted bentonite and rocks such as porosity and tortuosity, measuring diffusion coefficients of nuclides in the bentonite and rocks, acquiring basic data on diffusion and developing diffusion models which can quantitatively predict nuclide migration in long-term. (J.P.N.). 117 refs

Overview of Task 4 nuclide transport data

International Nuclear Information System (INIS)

Serne, R.J.

1977-01-01

A multi-year program plan is presented to collect the necessary data on nuclide sorption-desorption interactions with geologic media. Detailed activities which need to be performed in each of the six subtasks are described. The general areas in which each subcontractor performed work in FY 77 were presented in the overview. Detailed technical discussions of each subcontractor's work will be presented in ensuing presentations

Comparative uptake of gamma-emitting fission product nuclides by plants

International Nuclear Information System (INIS)

D'souza, T.J.; Mistry, K.B.

1974-01-01

The comparative uptake of long-lived gamma-emitting fission product nuclides 106 Ru, 125 Sb, 137 Cs and 144 Ce, present in global fallout from nuclear explosions, by maize (Zea mays L) plants was examined in water culture experiments. Over identical duration of plant growth, the extent of accumulation of the radionuclides in aerial tissues was in the following decreasing order: 137 Cs >, 125 Sb >, 106 Ru > and 144 Ce. In roots, however, the retention of 144 Ce and 106 Ru was greater than that of 137 Cs and 125 Sb. Complementary studies with maize and rice (Oryza sativa L) grown on two contrasting soil types, namely, laterite and black clay loam indicated that 137 Cs uptake by plants was markedly greater than that of the other radionuclides in both soil types. Plant uptake of 106 Ru and 125 Sb was significantly higher than that of 144 Ce in the black soil. In the laterite, however, 144 Ce uptake far exceeded that of 106 Ru and 125 Sb. In general, maize removed higher amounts of the radionuclides than rice from both soil types. (author)

Therapeutic result of radioactive nuclide 90Sr/90Y treatment in patients with benign prostatic hypertrophy (BPH)

International Nuclear Information System (INIS)

Chen Hanchao; Li Yuying

2008-01-01

Objective: To study the effect of radioactive nuclide 90 Sr/ 90 Y treatment in patients with benign prostatic hypertrophy (BPH). Methods: Sixty patients with BPH were treated with a course of transurethral radioactive nuclide 90 Sr/ 90 Y therapy. Results: The severity of BPH was assessed with four parameters: maximal flow rate (MFR), volume of residual urine (VRU), international prostatic symptom score (IPSS) and volume (size) of prostate. In this series, the total effective rate was 93.33% with no treatment- related mortality. Favorable changes of the parameters after a course of radioactive nuclide therapy were significant. Conclusion: Radioactive nuclide 90 Sr/ 90 Y therapy for patients with BPH was safe, easily performed and quite effective. This procedure is worth popularizing in appropriate patients. (authors)

Radiometric dating by alpha spectrometry on uranium series nuclides

NARCIS (Netherlands)

Wijk, Albert van der

1987-01-01

De Engelse titel van dit proegschrift \\"Radiometric Dating by Alpha Spectometry on Uranium Series Nuclides\\" kan in het Nederlands wellicht het best worden weergegeven door \\"ouderdomsdbepalingen door stralingsmeting aan kernen uit de uraniumreeks met behulp van alfaspectometrie\\". In dit laatste

Selective removal of cesium by ammonium molybdophosphate – polyacrylonitrile bead and membrane

Energy Technology Data Exchange (ETDEWEB)

Ding, Dahu, E-mail: ddh@njau.edu.cn [College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Graduate School of Life and Environmental Science, University of Tsukuba, Tsukuba, Ibaraki 305-8572 (Japan); Zhang, Zhenya [Graduate School of Life and Environmental Science, University of Tsukuba, Tsukuba, Ibaraki 305-8572 (Japan); Chen, Rongzhi [College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100044 (China); Cai, Tianming, E-mail: ctm@njau.edu.cn [College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China)

2017-02-15

Highlights: • AMP-PAN membrane was prepared for the first time through a simple way. • AMP-PAN bead performed high adsorption capacity and selectivity towards Cs{sup +}. • Liquid film diffusion was the rate-limiting step during the batch adsorption process. • AMP-PAN membrane could eliminate Cs{sup +} effectively from water through rapid filtration. - Abstract: The selective removal of radionuclides with extremely low concentrations from environmental medium remains a big challenge. Ammonium molybdophosphate possess considerable selectivity towards cesium ion (Cs{sup +}) due to the specific ion exchange between Cs{sup +} and NH{sub 4}{sup +}. Ammonium molybdophosphate – polyacrylonitrile (AMP-PAN) membrane was successfully prepared for the first time in this study. Efficient removal of Cs{sup +} (95.7%, 94.1% and 91.3% of 1 mg L{sup −1}) from solutions with high ionic strength (400 mg L{sup −1} of Na{sup +}, Ca{sup 2+} or K{sup +}) was achieved by AMP-PAN composite. Multilayer chemical adsorption process was testified through kinetic and isotherm studies. The estimated maximum adsorption capacities even reached 138.9 ± 21.3 mg g{sup −1}. Specifically, the liquid film diffusion was identified as the rate-limiting step throughout the removal process. Finally, AMP-PAN membrane could eliminate Cs{sup +} from water effectively through the filtration adsorption process.

Aircraft-borne spectrometry - a fast method for nuclide-specific measurement of soil contamination

International Nuclear Information System (INIS)

Winkelmann, I.; Schweiger, M.; Thomas, M.; Endrulat, H.J.

1991-01-01

An airworthy gamma spectrometer system for fast and large-area, nuclide-specific measurement of the soil contamination is described. The system encompasses an ultrapure germanium detector combined with a computer-controlled multichannel analyser system. The development from the laboratory system to an industrial-scale measuring system is explained. The practical testing is explained and first results are reported, obtained from measuring flights for the nuclide-specific determination of the soil contamination in the free State of Bavaria. (orig.) [de

The future implications of some long-lived fission product nuclides discharged to the environment in fuel reprocessing wastes

International Nuclear Information System (INIS)

Bryant, P.M.; Jones, J.A.

1972-12-01

Current reprocessing practice leads to the discharge to the environment of virtually all the krypton-85 and tritium, and a large fraction of the iodine-129, formed as fission products in reactor fuel. As nuclear power programmes expand the global inventory of these long-lived nuclides is increasing. The radiological significance of these discharges is assessed in terms of radiation exposure of various population groups during the next few decades. The results of this assessment show that krypton-85 will give higher dose rates than tritium or iodine-129, but that on conventional radiological protection criteria these do not justify taking action to remove krypton-85 from reprocessing plant effluents before the 21st century. (author)

WIS decontamination factor demonstration test with radioactive nuclides

International Nuclear Information System (INIS)

Kanbe, Hiromi; Mayuzumi, Masami; Ono, Tetsuo; Nagae, Madoka; Sekiguchi, Ryosaku; Takaoku, Yoshinobu.

1987-01-01

A radioactive Waste Incineration System (WIS) with suspension combustion is noticed as effective volume reduction technology of low level radiactive wastes that are increasing every year. In order to demonstrate the decontamination efficiency of ceramic filter used on WIS, this test has been carried out with the test facilities as joint research of Central Research Institute of Electric Power Industry (CRIEPI) and Sumitomo Heavy Industries, Ltd. Miscellaneous combustible waste and power resin, to which 5 nuclides (Mn-54, Fe-59, Co-60, Zn-65, Cs-137) were added, were used as samples for incineration. As the result of the test, it was verified that Decontamination Factor (DF) of the single stage ceramic filter was usually kept over 10 5 for every nuclide, and from the results of above DF, over 10 8 is expected for real commercial plant as a total system. Therefore, it is realized that the off-gas clean up system of the WIS composed of only single stage of ceramic filter is capable of sufficiently efficient decontamination of exhaust gas to be released to stack. (author)

Comparative test on nuclide migration in aerated zone

International Nuclear Information System (INIS)

Li Shushen; Zhao Yingjie; Wu Qinghua; Wang Zhiming; Hao Janzhong; Ji Shaowei; Guo Liangtian; Guo Zhiming

2002-01-01

In order to study the influence of different tracer source layer material on nuclide migration behavior, the comparative test on stable elements Sr, Nd and Ce migration in aerated loess zone was carried out using loess and arenaceous quartz as the tracer source layer materials respectively. The test lasted 470 days. During the test, four times of sampling were done. The testing results indicate that under artificial sprinkling of 5 mm/h and 3 h/d, Nd and Ce not only in loess tracer source layer but also in arenaceous quartz tracer source layer did not obviously downwards migrated. Concentration peak of Sr for loess layer migrated down about 15 cm in 470 d (mass center moved down about 10 cm) but for arenaceous quartz layer the concentration peak of Sr did not obviously migrated down (mass center moved down about 2.7 cm). The test results show that very thin arenaceous quartz layer with thickness of 7 mm is also able to shield unsaturated water flow obviously. This is the main reason why the nuclides in arenaceous quartz layer migrate down slowly

Nuclide transport of decay chain in the fractured rock medium: a model using continuous time Markov process

International Nuclear Information System (INIS)

Younmyoung Lee; Kunjai Lee

1995-01-01

A model using continuous time Markov process for nuclide transport of decay chain of arbitrary length in the fractured rock medium has been developed. Considering the fracture in the rock matrix as a finite number of compartments, the transition probability for nuclide from the transition intensity between and out of the compartments is represented utilizing Chapman-Kolmogorov equation, with which the expectation and the variance of nuclide distribution for the fractured rock medium could be obtained. A comparison between continuous time Markov process model and available analytical solutions for the nuclide transport of three decay chains without rock matrix diffusion has been made showing comparatively good agreement. Fittings with experimental breakthrough curves obtained with nonsorbing materials such as NaLS and uranine in the artificial fractured rock are also made. (author)

Notre Dame Nuclear Database: A New Chart of Nuclides

Science.gov (United States)

Lee, Kevin; Khouw, Timothy; Fasano, Patrick; Mumpower, Matthew; Aprahamian, Ani

2014-09-01

Nuclear data is critical to research fields from medicine to astrophysics. We are creating a database, the Notre Dame Nuclear Database, which can store theoretical and experimental datasets. We place emphasis on storing metadata and user interaction with the database. Users are able to search in addition to the specific nuclear datum, the author(s), the facility where the measurements were made, the institution of the facility, and device or method/technique used. We also allow users to interact with the database by providing online search, an interactive nuclide chart, and a command line interface. The nuclide chart is a more descriptive version of the periodic table that can be used to visualize nuclear properties such as half-lives and mass. We achieve this by using D3 (Data Driven Documents), HTML, and CSS3 to plot the nuclides and color them accordingly. Search capabilities can be applied dynamically to the chart by using Python to communicate with MySQL, allowing for customization. Users can save the customized chart they create to any image format. These features provide a unique approach for researchers to interface with nuclear data. We report on the current progress of this project and will present a working demo that highlights each aspect of the aforementioned features. This is the first time that all available technologies are put to use to make nuclear data more accessible than ever before in a manner that is much easier and fully detailed. This is a first and we will make it available as open source ware.

Contribution of some food categories on intakes of U, Th and other nuclides

International Nuclear Information System (INIS)

Shiraishi, Kunio

1999-01-01

The assessment of radiation dose in human from radioactive 232 Th, 238 U, 137 Cs, and 90 Sr are important because those nuclides are the largest contributors to committed internal doses. A market basket study was conducted to clarify the food pathways of the nuclides in Japanese subjects. Foodstuffs of 336 were purchased from markets in the vicinity of Mito-City during 1994-1995. Statistical consumption data were used for collection of the food samples. Thorium-232, 238 U, and stable isotope ( 133 Cs) in eighteen food groups were determined by inductively coupled mass spectrometry (ICP-MS). Radioisotopes ( 137 Cs) was analyzed by γ-spectrometry. Stable strontium ( 88 Sr) was also analyzed by inductively coupled atomic emission spectrometry (ICP-AES). Big contributors to the nuclide intakes in Japanese were as follows: 232 Th fishes and shellfishes (44%) and green vegetables (11%); 238 U seaweeds (50%) and fishes and shellfishes (26%); 88 Sr seaweeds (53%) and fishes and shellfishes (14%); 137 Cs mushrooms (17%), fishes and shell fishes (15%), milk products (11%), meats (9%), and potatoes (7%). The food categories of oil and fats, eggs and cooked meals were minor contributors in those nuclides. Dietary intake studies by using eighteen or more food categories should be effective procedure to resolve critical food and critical pathway for Japanese. Furthermore, critical pathways of radionuclides could be estimated by the analyses of stable isotopes. (author)

Mass measurement of halo nuclides and beam cooling with the mass spectrometer Mistral

International Nuclear Information System (INIS)

Bachelet, C.

2004-12-01

Halo nuclides are a spectacular drip-line phenomenon and their description pushes nuclear theories to their limits. The most critical input parameter is the nuclear binding energy; a quantity that requires excellent measurement precision, since the two-neutron separation energy is small at the drip-line by definition. Moreover halo nuclides are typically very short-lived. Thus, a high accuracy instrument using a quick method of measurement is necessary. MISTRAL is such an instrument; it is a radiofrequency transmission mass spectrometer located at ISOLDE/CERN. In July 2003 we measured the mass of the Li 11 , a two-neutron halo nuclide. Our measurement improves the precision by a factor 6, with an error of 5 keV. Moreover the measurement gives a two-neutron separation energy 20% higher than the previous value. This measurement has an impact on the radius of the nucleus, and on the state of the two valence neutrons. At the same time, a measurement of the Be 11 was performed with an uncertainty of 4 keV, in excellent agreement with previous measurements. In order to measure the mass of the two-neutron halo nuclide Be 14 , an ion beam cooling system is presently under development which will increase the sensitivity of the spectrometer. The second part of this work presents the development of this beam cooler using a gas-filled Paul trap. (author)

Details of modelling HTR core physics: the use of pseudo nuclide traces

International Nuclear Information System (INIS)

Kuijper, J.C.; Oppe, J.; Haas, J.B.M. de; Da Cruz, D.F.

2003-01-01

At present most combined neutronic and thermal hydraulic analyses of reactors, and the HTR is no exception, are being performed by codes employing few-group (typically 2-group) neutronics on the basis of parametrized few-group macroscopic (and microscopic) cross sections for homogenized areas, depending on quantities like irradiation (fuel only), 135 Xe concentration, temperature, etc. The irradiation parameter (time-integrated power per unit initial heavy metal mass) is sufficient for keeping track of the evolution of areas containing fuel. However, the use of the same parameter in areas without fuel, e.g. containing burnable poison, requires some special provisions. This can be met by the introduction of pseudo nuclides, with very specific cross sections and reaction chains, in the procedure to generate the parametrized few-group cross sections. It is shown that the time-evolution of a non-fuelled burnable poison area, as calculated by the 2-group (HTR) reactor code PANTHERMIX employing pseudo nuclides, compares well to the time-evolution obtained from an explicit burnup calculation by the WIMS8A/SNAP code. Examples are also shown using the pseudo nuclide method to keep track of the fast fluence (time-integrated flux above 0.1 MeV) in a continuous reload pebble-bed HTR reactor calculation by PANTHERMIX. Although the present implementation of the pseudo nuclide method exhibits some peculiarities connected to the specific codes in use (WIMS8A and PANTHERMIX) it is considered to be sufficiently general to be applicable in other code suites, requiring only limited modifications. (authors)

Details of modelling HTR core physics: the use of pseudo nuclide traces

Energy Technology Data Exchange (ETDEWEB)

Kuijper, J.C.; Oppe, J.; Haas, J.B.M. de; Da Cruz, D.F. [Nuclear Research and consultancy Group (NRG), Petten (Netherlands)

2003-07-01

At present most combined neutronic and thermal hydraulic analyses of reactors, and the HTR is no exception, are being performed by codes employing few-group (typically 2-group) neutronics on the basis of parametrized few-group macroscopic (and microscopic) cross sections for homogenized areas, depending on quantities like irradiation (fuel only), {sup 135}Xe concentration, temperature, etc. The irradiation parameter (time-integrated power per unit initial heavy metal mass) is sufficient for keeping track of the evolution of areas containing fuel. However, the use of the same parameter in areas without fuel, e.g. containing burnable poison, requires some special provisions. This can be met by the introduction of pseudo nuclides, with very specific cross sections and reaction chains, in the procedure to generate the parametrized few-group cross sections. It is shown that the time-evolution of a non-fuelled burnable poison area, as calculated by the 2-group (HTR) reactor code PANTHERMIX employing pseudo nuclides, compares well to the time-evolution obtained from an explicit burnup calculation by the WIMS8A/SNAP code. Examples are also shown using the pseudo nuclide method to keep track of the fast fluence (time-integrated flux above 0.1 MeV) in a continuous reload pebble-bed HTR reactor calculation by PANTHERMIX. Although the present implementation of the pseudo nuclide method exhibits some peculiarities connected to the specific codes in use (WIMS8A and PANTHERMIX) it is considered to be sufficiently general to be applicable in other code suites, requiring only limited modifications. (authors)

Nuclide Inventory Calculation Using MCNPX for Wolsung Unit 1 Reactor Decommissioning

Energy Technology Data Exchange (ETDEWEB)

Rabir, Mohamad Hairie; Noh, Kyoung Ho; Hah, Chang Joo [KEPCO International Nuclear Graduate School, Daejeon (Korea, Republic of)

2014-05-15

The CINDER90 computation process involves utilizing linear Markovian chains to determine the time dependent nuclide densities. The CINDER90 depletion algorithm is implemented the MCNPX code package. The coupled depletion process involves a Monte-Carlo steady-state reaction rate calculation linked to a deterministic depletion calculation. The process is shown in Fig.1. MCNPX runs a steady state calculation to determine the system eigenvalue collision densities, recoverable energies from fission and neutrons per fission events. In order to generate number densities for the next time step, the CINDER90 code takes the MCNPX generated values and performs a depletion calculation. MCNPX then takes the new number densities and caries out a new steady-stated calculation. The process repeats itself until the final time step. This paper describe the preliminary source term and nuclide inventory calculation of Candu single fuel channel using MCNPX, as a part of the activities to support the equilibrium core model development and decommissioning evaluation process of a Candu reactor. The aim of this study was to apply the MCNPX code for source term and nuclide inventory calculation of Candu single fuel channel. Nuclide inventories as a function of burnup will be used to model an equilibrium core for Candu reactor. The core lifetime neutron fluence obtained from the model is used to estimate radioactivity at the stage of decommisioning. In general, as expected, the actinides and fission products build up increase with increasing burnup. Despite the fact that the MCNPX code is still in development we can conclude that the code is capable of obtaining relevant results in burnup and source term calculation. It is recommended that in the future work, the calculation has to be verified on the basis of experimental data or comparison with other codes.

Device for determining the gross weight, dose rate, surface contamination and/or nuclide inventory

International Nuclear Information System (INIS)

1987-01-01

Barrels with low nuclide inventories (about 1E6 Bq) and with high inventories (1E13 Bq) are inspected with the barrel inspection system. The system provides a rotating plate, which is part of some scales and a measuring sensor arrangement for this purpose. The surface contamination and nuclide inventories of the 200 litre barrels can be calculated from the weight and radiation detector values. (DG) [de

Numerical solution of stiff burnup equation with short half lived nuclides by the Krylov subspace method

International Nuclear Information System (INIS)

Yamamoto, Akio; Tatsumi, Masahiro; Sugimura, Naoki

2007-01-01

The Krylov subspace method is applied to solve nuclide burnup equations used for lattice physics calculations. The Krylov method is an efficient approach for solving ordinary differential equations with stiff nature such as the nuclide burnup with short lived nuclides. Some mathematical fundamentals of the Krylov subspace method and its application to burnup equations are discussed. Verification calculations are carried out in a PWR pin-cell geometry with UO 2 fuel. A detailed burnup chain that includes 193 fission products and 28 heavy nuclides is used in the verification calculations. Shortest half life found in the present burnup chain is approximately 30 s ( 106 Rh). Therefore, conventional methods (e.g., the Taylor series expansion with scaling and squaring) tend to require longer computation time due to numerical stiffness. Comparison with other numerical methods (e.g., the 4-th order Runge-Kutta-Gill) reveals that the Krylov subspace method can provide accurate solution for a detailed burnup chain used in the present study with short computation time. (author)

Sensitivity and uncertainty analysis for functionals of the time-dependent nuclide density field

International Nuclear Information System (INIS)

Williams, M.L.; Weisbin, C.R.

1978-04-01

An approach to extend the present ORNL sensitivity program to include functionals of the time-dependent nuclide density field is developed. An adjoint equation for the nuclide field was derived previously by using generalized perturbation theory; the present derivation makes use of a variational principle and results in the same equation. The physical significance of this equation is discussed and compared to that of the time-dependent neutron adjoint equation. Computational requirements for determining sensitivity profiles and uncertainties for functionals of the time-dependent nuclide density vector are developed within the framework of the existing FORSS system; in this way the current capability is significantly extended. The development, testing, and use of an adjoint version of the ORIGEN isotope generation and depletion code are documented. Finally, a sample calculation is given which estimates the uncertainty in the plutonium inventory at shutdown of a PWR due to assumed uncertainties in uranium and plutonium cross sections. 8 figures, 4 tables

Light nuclides observed in the fission and fragmentation of 238U

International Nuclear Information System (INIS)

Ricciardi, M.V.; Schmidt, K.H.; Benlliure, J.

2001-05-01

Light nuclides produced in collisions of 1 A.GeV 238 U with protons and titanium have been fully identified with a high-resolution forward magnetic spectrometer, the fragment separator (FRS), at GSI, and for each nuclide an extremely precise determination of the velocity has been performed. The so-obtained information on the velocity shows that the very asymmetric fission of uranium, in the 238 U + p reaction, produces neutron-rich isotopes of elements down to around charge 10. New important features of the fragmentation of 238 U, concerning the velocity and the N/Z-ratio of these light fragments, and a peculiar even-odd structure in N=Z nuclei, have also been observed. (orig.)

Instant detection of incorporated radio-nuclides

International Nuclear Information System (INIS)

Dolgirev, E.I.; Porozov, N.V.

1978-01-01

A method is described for rapid estimation of radionuclides both in the whole human body and in individual human organs beginning from levels equal to 0.1-0.01 of the maxium permissible value of annual absorption by personnel. In post-accident radiation exposure surveys, the whole-body content of gamma-emitting nuclides is monitored by measuring the flow of gamma quanta by use of a gas-discharge counter cassette placed at a distance of 0.5 m from the subject. Relationships for determining radionuclides in the human body are presented

Sensitivity Analysis of Nuclide Importance to One-Group Neutron Cross Sections

International Nuclear Information System (INIS)

Sekimoto, Hiroshi; Nemoto, Atsushi; Yoshimura, Yoshikane

2001-01-01

The importance of nuclides is useful when investigating nuclide characteristics in a given neutron spectrum. However, it is derived using one-group microscopic cross sections, which may contain large errors or uncertainties. The sensitivity coefficient shows the effect of these errors or uncertainties on the importance.The equations for calculating sensitivity coefficients of importance to one-group nuclear constants are derived using the perturbation method. Numerical values are also evaluated for some important cases for fast and thermal reactor systems.Many characteristics of the sensitivity coefficients are derived from the derived equations and numerical results. The matrix of sensitivity coefficients seems diagonally dominant. However, it is not always satisfied in a detailed structure. The detailed structure of the matrix and the characteristics of coefficients are given.By using the obtained sensitivity coefficients, some demonstration calculations have been performed. The effects of error and uncertainty of nuclear data and of the change of one-group cross-section input caused by fuel design changes through the neutron spectrum are investigated. These calculations show that the sensitivity coefficient is useful when evaluating error or uncertainty of nuclide importance caused by the cross-section data error or uncertainty and when checking effectiveness of fuel cell or core design change for improving neutron economy

Systematics of criticality data of special actinide nuclides deduced through the Trombay criticality formula

International Nuclear Information System (INIS)

Srinivasan, M.; SubbaRao, K.; Garg, S.B.; Acharya, G.V.

1989-01-01

The authors describe a number of interesting systematics and correlations deduced by analyzing the criticality data of special actinide nuclides using concepts embodied in the Trombay critically formula (TCF). The κ ∞ of fast metal actinide nuclides gives a remarkable linear correlation with the fissility parameter Z 2 /A. The neutron leakage probability of all fast metal cores characterized using a constant parameter σ std enables computation of the critical mass value of any unknown fissile nuclide knowing only its Z 2 /A value. Since the neutron leakage probability from dilute fissile solutions is primarily governed by the scattering/slowing down properties of the hydrogen present in water, critical masses and subcritical limits can be predicted for any water-reflected system at any specified hydrogen-to-actinide atomic ratio knowing only the κ ∞ value of the given fissile solution

Sampling of soils for transuranic nuclides: a review

International Nuclear Information System (INIS)

Fowler, E.B.; Essington, E.H.

1977-01-01

A review of the literature pertinent to the sampling of soils for radionuclides is presented; emphasis is placed on transuranic nuclides. Sampling of soils is discussed relative to systems of heterogeneous distributions and varied particle sizes encountered in certain environments. Sampling methods that have been used for two different sources of contamination, global fallout, and accidental or operational releases, are included

Analytical basis for neutron-activation analysis measuring nuclides with a half-life of second order

International Nuclear Information System (INIS)

Yonezawa, Chushiro; Ichimura, Shigeju; Matsue, Hideaki; Kurosawa, Tatsuya

1998-01-01

An analytical basis for a neutron-activation analysis (NAA) for measuring nuclides of second-order half-lives produced by the (n, γ) reaction has been studied using a neutron-activation analysis facility (PN-3) of JRR-3M. The NAA facility, comprising a fast pneumatic irradiation system and a high count-rate gamma-ray spectrometer, is able to automatically conduct NAA with short-lived nuclides. Basic experimental conditions, such as a high count-rate gamma-ray measurement, the effects of irradiation-capsule material and the stability of the neutron flux, were examined. The analytical sensitivities and detection limits for 20 elements of which activated radionuclide having half-lives from 0.7 to 100 s were obtained. Scandium, In, Dy and Hf were elements having the highest analytical sensitivity, with detection limits down to 4.2 to 14 ng. Fluorine, which is difficult to determine by other methods, can be detected at above 530 ng. Analytical applications of NAA with short-lived nuclides have been carried out for F, Se, Sc, Hf, In and Dy in various materials, including reference materials. The accuracy, precision and detection limits of NAA with short-lived nuclides have been evaluated. (author)

Efficacy of Substance Removal by Immunoadsorption With a Selective Plasma Separator.

Science.gov (United States)

Hanafusa, Norio; Yamamoto, Hiroko; Tamachi, Masaki; Torato, Toshihiro; Sakurai, Satoko; Tsuchiya, Ken; Nitta, Kosaku; Nangaku, Masaomi

2017-06-01

Immunoadsorption with a tryptophan-conjugated column has a limited capacity and reduces fibrinogen. We speculated that immunoadsorption with a selective plasma separator has higher efficiency in removing immunoglobulins than ordinary immunoadsorption without affecting coagulation factors. This study investigated the efficacy of immunoadsorption with a selective plasma separator in vitro. The sieving coefficients, the pool concentration, and the adsorbed amount were investigated serially with up to 5 L of processed plasma. The sieving coefficients of the selective plasma separator were 0.8, 0.5, and 0.1 for albumin, immunoglobulin G (IgG), and factor 13, respectively. The trend of concentrations for the ordinary plasma separator in the pool reached its nadir at 1.5 L and 3.5 L of plasma processed for IgG, IgG1, or IgG2, and IgG3, respectively. However, the volume was doubled for the selective plasma separator. The trends of fibrinogen and factor 13 concentrations differed significantly between two plasma separators. The trends of the absorbed amount were mirror images of the concentration in the pool. Comparison of the peak amount absorbed indicated that the amounts were almost identical between the two separators for IgG, IgG1, and IgG2. On the other hand, the peak amounts were less for albumin, fibrinogen, and IgG3 with the selective plasma separator than with the ordinary separator. Although further investigations about bradykinin are required, immunoadsorption with the selective plasma separator supports the administration of more frequent and intensive treatments to remove IgG1 or IgG2 without affecting coagulation factors. © 2017 International Society for Apheresis, Japanese Society for Apheresis, and Japanese Society for Dialysis Therapy.

A redundancy-removing feature selection algorithm for nominal data

Directory of Open Access Journals (Sweden)

Zhihua Li

2015-10-01

Full Text Available No order correlation or similarity metric exists in nominal data, and there will always be more redundancy in a nominal dataset, which means that an efficient mutual information-based nominal-data feature selection method is relatively difficult to find. In this paper, a nominal-data feature selection method based on mutual information without data transformation, called the redundancy-removing more relevance less redundancy algorithm, is proposed. By forming several new information-related definitions and the corresponding computational methods, the proposed method can compute the information-related amount of nominal data directly. Furthermore, by creating a new evaluation function that considers both the relevance and the redundancy globally, the new feature selection method can evaluate the importance of each nominal-data feature. Although the presented feature selection method takes commonly used MIFS-like forms, it is capable of handling high-dimensional datasets without expensive computations. We perform extensive experimental comparisons of the proposed algorithm and other methods using three benchmarking nominal datasets with two different classifiers. The experimental results demonstrate the average advantage of the presented algorithm over the well-known NMIFS algorithm in terms of the feature selection and classification accuracy, which indicates that the proposed method has a promising performance.

Determination and declaration of critical nuclide inventories in Belgian NPP radwaste streams

International Nuclear Information System (INIS)

Lemmens, A.; Centner, B.; Beguin, P.; Mannaerts, K.

2001-01-01

The nuclear power plants (NPPs) managed by ELECTRABEL are located at the Doel (4 units) and the Tihange (3 units) sites and have a total capacity of 5700 MW(e). All the units are of the PWR type. Taking into account the need for retrievability and reliability of all requested waste data, the operator ELECTRABEL has subcontracted a complete study to the engineering company TRACTEBEL ENERGY ENGINEERING (TEE) in order to elaborate a computer code for the determination of critical nuclides in the different waste streams. This program should guarantee retrievability and reliability of all information related to the waste packages produced at the NPP. Two computer codes, LLWAA and DECL, have therefore been developed by TEE. The first code (LLWAA: low level waste activity assessment code), enables to predict the global inventories and/or the scaling factors of the critical nuclides in the conditioned and in the non-conditioned waste generated by the operation of a PWR. This code is site-specific as it takes into account the plant design characteristics and operating conditions. A version for BWR plants is under development. The second code 'DECL', deals mainly with the complete database management of each waste package produced in order to guarantee full retrievability. LLWAA and DECL are implemented as an integrated software package called 'DECLARE' at the sites of Doel and Tihange. Furthermore, the LLWAA-code has been extended for the determination of the critical nuclides activities in ashes produced by incineration (LLWAA-Ashes) and for the assessment of the critical nuclides activities deposited on equipment of the nuclear auxiliary systems (LLWAA-Decom). (author)

A Probabilistic Consideration on Nuclide Releases from a Pyro-processed Waste Repository

Energy Technology Data Exchange (ETDEWEB)

Lee, Youn Myoung; Jeong, Jong Tae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

Very recently, a GoldSim template program, GSTSPA, for a safety assessment of a conceptual hybrid-typed repository system, called 'A-KRS,' in which two kinds of pyroprocessed radioactive wastes, low-level metal wastes and ceramic high-level wastes that arise from the pyroprocessing of PWR nuclear spent fuels, has been developed and is to be disposed of by 'separate disposal' strategies. The A-KRS is considered to be constructed at two different depths in geological media: at a 200m depth, at which a possible human intrusion is considered to be limited after closure, for the pyroprocessed metal wastes with lower or no decay heat producing nuclides, and at a 500m depth, believed to be the reducing condition for nuclides with a rather higher radioactivity and heat generation rate. This program is ready for a probabilistic total system performance assessment (TSPA) which is able to evaluate nuclide release from the repository and farther transport into the geosphere and biosphere under various normal, disruptive natural and manmade events, and scenarios that can occur after a failure of a waste package and canister with associated uncertainty. To quantify the nuclide release and transport through the various possible pathways in the near- and far-fields of the A-KRS repository system under a normal groundwater flow scenario, some illustrative evaluations have been made through this study. Even though all parameter values associated with the A-KRS were assumed for the time being, the illustrative results should be informative since the evaluation of such releases is very important not only in view of the safety assessment of the repository, but also for design feedback of its performance

A Probabilistic Consideration on Nuclide Releases from a Pyro-processed Waste Repository

International Nuclear Information System (INIS)

Lee, Youn Myoung; Jeong, Jong Tae

2012-01-01

Very recently, a GoldSim template program, GSTSPA, for a safety assessment of a conceptual hybrid-typed repository system, called 'A-KRS,' in which two kinds of pyroprocessed radioactive wastes, low-level metal wastes and ceramic high-level wastes that arise from the pyroprocessing of PWR nuclear spent fuels, has been developed and is to be disposed of by 'separate disposal' strategies. The A-KRS is considered to be constructed at two different depths in geological media: at a 200m depth, at which a possible human intrusion is considered to be limited after closure, for the pyroprocessed metal wastes with lower or no decay heat producing nuclides, and at a 500m depth, believed to be the reducing condition for nuclides with a rather higher radioactivity and heat generation rate. This program is ready for a probabilistic total system performance assessment (TSPA) which is able to evaluate nuclide release from the repository and farther transport into the geosphere and biosphere under various normal, disruptive natural and manmade events, and scenarios that can occur after a failure of a waste package and canister with associated uncertainty. To quantify the nuclide release and transport through the various possible pathways in the near- and far-fields of the A-KRS repository system under a normal groundwater flow scenario, some illustrative evaluations have been made through this study. Even though all parameter values associated with the A-KRS were assumed for the time being, the illustrative results should be informative since the evaluation of such releases is very important not only in view of the safety assessment of the repository, but also for design feedback of its performance

Cosmogenic nuclides in the Martian surface: constraints for sample recovery and transport

International Nuclear Information System (INIS)

Englert, P.A.J.

1988-01-01

Stable and radioactive cosmogenic nuclides and radiation damage effects such as cosmic ray tracks can provide information on the surface history of Mars. A recent overview on developments in cosmogenic nuclide research for historical studies of predominantly extraterrestrial materials was published previously. The information content of cosmogenic nuclides and radiation damage effects produced in the Martian surface is based on the different ways of interaction of the primary galactic and solar cosmic radiation (GCR, SCR) and the secondary particle cascade. Generally the kind and extent of interactions as seen in the products depend on the following factors: (1) composition, energy and intensity of the primary SCR and GCR; (2) composition, energy and intensity of the GCR-induced cascade of secondary particles; (3) the target geometry, i.e., the spatial parameters of Martian surface features with respect to the primary radiation source; (4) the target chemistry, i.e., the chemical composition of the Martian surface at the sampling location down to the minor element level or lower; and (5) duration of the exposure. These factors are not independent of each other and have a major influence on sample taking strategies and techniques

U-Th series nuclides in the Gulf of Mexico

International Nuclear Information System (INIS)

Scott, M.R.

1981-01-01

A study of U and Th series nuclides is being conducted on sediments from the Gulf of Mexico. Uranium concentrations as a function of depth have been determined, as well as changes in the 234 U/ 238 U activity ratio. The geochemical behavior of uranium in shelf sediments is discussed

Membrane Characteristics for Removing Particulates in PFC Wastes

International Nuclear Information System (INIS)

Kim, Gye Nam; Lee, Sung Yeol; Won, Hui Jun; Jung, Chong Hun; Oh, Won Zin; Park, Jin Ho

2005-01-01

Pc (Per fluorocarbon) decontamination process is one of best methods to remove hot particulate adhered at inside surface of hot cell and surface of equipment in hot cell. It was necessary to develop a particulate filtration equipment to reuse Pc solution used on Pc decontamination due to its high cost and to minimize the volume of second wastewater. Contamination characteristics of hot particulate were investigated and then a filtration process was presented to remove hot particulate in Pc solution generated through Pc decontamination process. The removal efficiency of Pvdf (Poly vinylidene fluoride), Pp (Polypropylene), Ceramic (Al 2 O 3 ) filter showed more than 95%. The removal efficiency of Pvdf filter was a little lower than those of other kiters at same pressure (3 psi). A ceramic filter showed a higher removal efficiency with other filters, while a little lower flux rate than other filters. Due to inorganic composition, a ceramic filter was highly stable against radio nuclides in comparison with Pvdf and Pp membrane, which generate H 2 gas in α-radioactivity atmosphere. Therefore, the adoption of ceramic filter is estimated to be suitable for the real nitration process.

40 CFR 761.247 - Sample site selection for pipe segment removal.

Science.gov (United States)

2010-07-01

... end of the pipe segment. (3) If the pipe segment is cut with a saw or other mechanical device, take..., take samples from a total of seven segments. (A) Sample the first and last segments removed. (B) Select... total length for purposes of disposal, take samples of each segment that is 1/2 mile distant from the...

Development of a novel bioactive glass for air-abrasion to selectively remove orthodontic adhesives.

Science.gov (United States)

Taha, Ayam A; Hill, Robert G; Fleming, Padhraig S; Patel, Mangala P

2018-05-01

To develop a novel, bioactive glass for removing residual orthodontic adhesive via air-abrasion, following bracket debonding, and to evaluate its effectiveness against a proprietary bioactive glass 45S5(Sylc™)-air-abrasion, and a slow-speed tungsten carbide (TC) bur. Three glasses were prepared and their bioactivity was proved. One novel glass (QMAT3) was selected due to its appropriate hardness, lower than that of enamel/45S5(Sylc™). Sixty extracted human premolars were randomly assigned to adhesive removal using: (a) QMAT3-air-abrasion, (b) 45S5(Sylc™)-air-abrasion, and (c) TC bur, which were further subdivided (n = 10) based on the adhesive used (Transbond XT™ or Fuji Ortho LC™). Enamel roughness was assessed using scanning electron microscopy (SEM) and non-contact profilometry before bracket bonding, after removing residual adhesive following bracket debonding and after polishing. QMAT3 formed apatite faster (6 h) than 45S5(Sylc™) (24 h) in Tris solution. QMAT3-air-abrasion gave the lowest enamel roughness (Ra) after removing the adhesives. SEM images showed a pitted, roughened enamel surface in the TC bur group and to a lesser extent with 45S5(Sylc™), while a virtually smooth surface without any damage was observed in the QMAT3-air-abrasion group. The time taken for adhesive removal with QMAT3 was comparable to 45S5(Sylc™) but was twice as long with the TC bur. QMAT3-air-abrasion is a promising technique for selective removal of adhesives without inducing tangible enamel damage. A novel bioactive glass has been developed as an alternative to the use of TC burs for orthodontic adhesive removal.

Selective removal of arsenic and monovalent ions from brackish water reverse osmosis concentrate.

Science.gov (United States)

Xu, Pei; Capito, Marissa; Cath, Tzahi Y

2013-09-15

Concentrate disposal and management is a considerable challenge for the implementation of desalination technologies, especially for inland applications where concentrate disposal options are limited. This study has focused on selective removal of arsenic and monovalent ions from brackish groundwater reverse osmosis (RO) concentrate for beneficial use and safe environmental disposal using in situ and pre-formed hydrous ferric oxides/hydroxides adsorption, and electrodialysis (ED) with monovalent permselective membranes. Coagulation with ferric salts is highly efficient at removing arsenic from RO concentrate to meet a drinking water standard of 10 μg/L. The chemical demand for ferric chloride however is much lower than ferric sulfate as coagulant. An alternative method using ferric sludge from surface water treatment plant is demonstrated as an efficient adsorbent to remove arsenic from RO concentrate, providing a promising low cost, "waste treat waste" approach. The monovalent permselective anion exchange membranes exhibit high selectivity in removing monovalent anions over di- and multi-valent anions. The transport of sulfate and phosphate through the anion exchange membranes was negligible over a broad range of electrical current density. However, the transport of divalent cations such as calcium and magnesium increases through monovalent permselective cation exchange membranes with increasing current density. Higher overall salt concentration reduction is achieved around limiting current density while higher normalized salt removal rate in terms of mass of salt per membrane area and applied energy is attained at lower current density because the energy unitization efficiency decreases at higher current density. Copyright © 2013 Elsevier B.V. All rights reserved.

Selective near-UV ablation of subgingival dental calculus: measurement of removal rates

Science.gov (United States)

Schoenly, J. E.; Seka, W.; Rechmann, P.

2010-02-01

A noncontact profilometer (laser triangulation) was used to measure the removal rates of subgingival dental calculus irradiated with a frequency-doubled Ti:sapphire laser (60-ns pulse duration, 400-nm wavelength, 10-Hz repetition rate, 7-mJ pulse energy). Profilometer traces before and after irradiation were used to create a removal map with 4-μm axial and 15-μm transverse resolution. Twenty-three teeth (15 with calculus and 8 pristine) were irradiated at 90° and 45° under a cooling water spray with a super-Gaussian beam (~300-μm diameter). Subgingival calculus was selectively removed at 5.6 and 4.0 J/cm2 for 90° and 45°, respecetively, within a range of rates, between 2 to 9 μm/pulse. These ablation rates were constant during these exposures. For comparison, pristine cementum irradiated for 10 min at the same peak fluence and pulse repetition rate showed only craters, 15 to 50 μm deep, corresponding to an equivalent removal rate three orders of magnitude smaller than that obtained for calculus. Pristine enamel was not removed under the same irradiation conditions.

Novel reprocessing methods with nuclide separation for volume reduction of high level radioactive waste

International Nuclear Information System (INIS)

Suzuki, Tatsuya

2015-01-01

We have proposed the reprocessing system with nuclide separation processes based on the chromatographic technique in the hydrochloric acid solution system. Our proposing system consists of the dissolution process, the reprocessing process, the MA separation process, and nuclide separation processes. In our proposing processes, the pyridine resin is used as a main separation media. We expect that our proposing will contribute to that volume reduction of high level radioactive waste by combining the transmutation techniques, usage of valuable elements, and so on. (author)

Influence of Selective Edge Removal and Refractory Period in a Self-Organized Critical Neuron Model

International Nuclear Information System (INIS)

Lin Min; Gang, Zhao; Chen Tianlun

2009-01-01

A simple model for a set of integrate-and-fire neurons based on the weighted network is introduced. By considering the neurobiological phenomenon in brain development and the difference of the synaptic strength, we construct weighted networks develop with link additions and followed by selective edge removal. The network exhibits the small-world and scale-free properties with high network efficiency. The model displays an avalanche activity on a power-law distribution. We investigate the effect of selective edge removal and the neuron refractory period on the self-organized criticality of the system. (condensed matter: structural, mechanical, and thermal properties)

The recovery and study of heavy nuclides produced in a nuclear explosion - the Hutch event

International Nuclear Information System (INIS)

Hoff, R.W.; Hulet, E.K.

1970-01-01

During the explosion of the Hutch device, the target ( 238 U and 232 Th) was subjected to a very high neutron exposure, 2.4 x 10 25 neutrons /cm 2 . Multiple neutron capture reactions resulted in the production of heavy nuclides, up to and including 257Fm. Results of the search for species with A > 257 were negative. The recovery and chemical processing of kilograms of Hutch debris has resulted in the isolation of 10 10 atoms of 257Fm, which is 10 2 times more material than has been available for experimentation in the past. Experimentally significant amounts of other rare nuclides, e.g., : 254 Cf, 251 Cf, 255 -Es, and 250 Cm, have also been separated from the Hutch debris. The production of these nuclides in thermonuclear explosions is shown to be a valuable supplement to the AEC program for reactor production of transplutonium elements. The neutron flux achieved in Hutch was insufficient to even approach production of nuclides in the region of 298 114. A much more intense neutron flux is required. In future experiments, considerable attention must be given to the problem of adequate sample recovery, in order to properly use the ability to subject targets to an exceedingly intense time-integrated neutron flux. (author)

SOURCES OF COPPER IONS AND SELECTED METHODS OF THEIR REMOVAL FROM WASTEWATER FROM THE PRINTED CIRCUITS BOARD PRODUCTION

Directory of Open Access Journals (Sweden)

Maciej Thomas

2014-10-01

Full Text Available This paper presents the issues related to the presence and removal of copper compounds from industrial effluents with including wastewater from plants involved in the production of printed circuit boards. Characterized the toxicological properties of selected copper compounds, described the applicable technological processes, sources of copper ions in the effluents and selected methods for their removal.

Parameters for several plutonium nuclides and 252Cf of safeguards interest

International Nuclear Information System (INIS)

Zucker, M.S.; Holden, N.E.

1984-01-01

Sets of the neutron emission multiplicity distribution gleaned from the literature for plutonium nuclides and 252 Cf are considered. A methodology for rendering the different sets comparable is presented and used to convert the sets to a common basis such that the differences can be evaluated objectively and that allows realistic estimate of the uncertainties. This in turn permits development of a canonical consensus set in certain instances. Evaluated data on the average neutron multiplicity, the total half-lives, and the half-lives for spontaneous fission are also given. A careful search of the literature reveals that the data on neutron multiplicity distributions for many nuclides is surprisingly sparse, considering that almost thirty years has elapsed since the original pioneering work, which in some cases, yield the only reported value. 93 references, 26 tables

Some nuclear chemical aspects of medical generator nuclide production at the Los Alamos hot cell facility

CERN Document Server

Fassbender, M; Heaton, R C; Jamriska, D J; Kitten, J J; Nortier, F M; Peterson, E J; Phillips, D R; Pitt, L R; Salazar, L L; Valdez, F O; 10.1524/ract.92.4.237.35596

2004-01-01

Generator nuclides constitute a convenient tool for applications in nuclear medicine. In this paper, some radiochemical aspects of generator nuclide parents regularly processed at Los Alamos are introduced. The bulk production of the parent nuclides /sup 68/Ge, /sup 82/Sr, /sup 109/Cd and /sup 88/Zr using charged particle beams is discussed. Production nuclear reactions for these radioisotopes, and chemical separation procedures are presented. Experimental processing yields correspond to 80%-98% of the theoretical thick target yield. Reaction cross sections are modeled using the code ALICE-IPPE; it is observed that the model largely disagrees with experimental values for the nuclear processes treated. Radionuclide production batches are prepared 1-6 times yearly for sales. Batch activities range from 40MBq to 75 GBq.

Some nuclear chemical aspects of medical generator nuclide production at the Los Alamos hot cell facility

International Nuclear Information System (INIS)

Fassbender, M.; Nortier, F.M.; Phillips, D.R.; Hamilton, V.T.; Heaton, R.C.; Jamriska, D.J.; Kitten, J.J.; Pitt, L.R.; Salazar, L.L.; Valdez, F.O.; Peterson, E.J.

2004-01-01

Generator nuclides constitute a convenient tool for applications in nuclear medicine. In this paper, some radiochemical aspects of generator nuclide parents regularly processed at Los Alamos are introduced. The bulk production of the parent nuclides 68 Ge, 82 Sr, 109 Cd and 88 Zr using charged particle beams is discussed. Production nuclear reactions for these radioisotopes, and chemical separation procedures are presented. Experimental processing yields correspond to 80%-98% of the theoretical thick target yield. Reaction cross sections are modeled using the code ALICE-IPPE; it is observed that the model largely disagrees with experimental values for the nuclear processes treated. Radionuclide production batches are prepared 1-6 times yearly for sales. Batch activities range from 40 MBq to 75 GBq. (orig.)

Radium removal from Canadian uranium mining effluents by a radium-selective ion exchange complexer

International Nuclear Information System (INIS)

1984-07-01

A laboratory test program was initiated by the Department of Energy, Mines and Resources as part of the National Uranium Tailings Program to investigate the applicability of a radium-selective ion exchange complexer for removing radium from Canadian uranium mining effluents. The ion exchange complexer was shown to be efficient in removing radium from contaminated water of uranium mining operations, with the ultimate loading capacity of the resin on one type of water treated being determined as approximately 1,600 Bq/cm 3 of new resin. The results showed that the resin was effective in removing radium but not any other contaminants

The clinical application of nuclide bone imaging in malignant lymphomas

International Nuclear Information System (INIS)

Jin Xing; Tang Mingdeng; Lin Duanyu; Ni Leichun

2006-01-01

Objective: To evaluate the clinical application value of nuclide bone imaging in malignant lymphoma. Methods: 71 cases of patients were diagnosed by pathology as malignant lymphoma, among whom there were 8 cases of Hodgkin disease (HL) and 63 cases of non-Hodgkin disease (NHL). The examinations were performed from 2.5 to 6 hours later after the intravenous injection of 99m Tc-MDP (555-925 MBq). Results: 31 cases were bone-infiltrating lesions, including 3 cases of HL and 28 cases of NHL. The total number of the focus was 103, except 2 cases of bone lack, including 35 foci in vertebral column (34.65%), 30 foci in limb and joint (29.70%), 14 foci in rib (13.86%), 13 foci in elvis (12.0%), 5 foci in skull (4.95%) and 4 foci in sternum (3.96%). Conclusion: The nuclide bone imaging has a high value in the clinical stage, therapeutic observation and prognosis of bone-infiltrating malignant lymphoma. (authors)

Programme of research into the management and storage of radioactive waste, nuclide migration studies, and mathematical modelling

International Nuclear Information System (INIS)

1982-01-01

The progress of the work is reported under the headings: nuclide migration studies (nuclide-rock interactions; physico-chemical effects; field experiments; groundwater dating); mathematical modelling (calculation of steady groundwater flow using NAMMU; comparison of thermally and naturally driven flows near a radioactive waste repository; diffusion of radionuclides into a rock matrix; radionuclide migration). (U.K.)

[Radioactive nuclides in the marine environment--distribution and behaviour of 95Zr, 95Nb originated from fallout].

Science.gov (United States)

Yamato, A; Miyagawa, N; Miyanaga, N

1984-07-01

To investigate behaviour of 95Zr, 95Nb in the marine environment, various samples have been collected and measured by means of Ge(Li) gamma-ray spectrometry and/or radiochemical analysis during a period from 1974 to 1982 at coastal area of Tokai-mura, Ibaraki prefecture. Concentration of the nuclides in seaweeds increased remarkably after atmospheric nuclear detonation by P.R. of China, and the activity ratio between the nuclides changed by time was not fit well by the transient decay equation. Concentration variation in sea water was smaller than that in sea weeds, and the minimum change in sea sediment. Increase of concentration in these environmental samples was observed in chronological order of sea water, sea weeds then sediment after detonations, suggesting that the uptake of the nuclides by these sea weeds from sea water is faster than that via root. Observed concentration factors on the nuclides by sea weeds were calculated from the observed concentrations in sea water and sea weeds. Maximum values on 95Zr and 95Nb were 2110, 2150, respectively for Ecklonia cava and Eisenia bicyclis.

Nuclide-specific monitoring of airborne radioactivity

International Nuclear Information System (INIS)

Aures, R.; Neu, A.

1996-01-01

Since the end of the seventies the Landesanstalt fuer Umweltschutz Baden-Wuerttemberg ist operating two radioaerosol monitoring stations at the border in the opposite of foreign nuclear power plants. Since the end of the eighties six similar monitoring stations were built up for measuring activity in breathing air in the common environment in Baden-Wuerttemberg. A special filtersystem allows measuring the activity concentration of up to 99 nuclides. The measuring system was optimized by advanced PC-technology, a multitasking operating system and a special software for users and gamma-spectroscopy. These increased the average availability of all monitoring stations to 96% in 1996. (orig.) [de

Applications of short lived nuclides in activation analysis, problems and progress

Energy Technology Data Exchange (ETDEWEB)

Grass, F [Atominstitut, Vienna (Austria)

1976-07-01

Short lived nuclides or isomeric transitions, respectively would have some advantages over long lived ones. Although we published a paper concerning a germanium-determination in iron meteorites some years ago, only few laboratories use this technique, the main reason being that the high matrix activity disturbs the measurement of energy-spectra. A multichannel analyzer in the time sequence mode enables Li-8 determination by a purely instrumental method which is therefore used more frequently. In the time sequence mode much higher counting rates up to 10 - 50 MHz are processed then by taking energy-spectra. This is the reason why activation analysis with short lived isomeric states is seldom applied when counting rate and pulse height are to be detected simultaneously. Exceptional difficulties are encountered in measurement of samples activated by a reactor pulse. Further difficulties arise from the fact that an optimal expelling time depends on the half life of the nuclide, and is more critical if the half life is short and the full width half maximum of the reactor pulse is small. Commercial Ge-Li-detectors can be used only at low counting rates, so that samples with high matrix activities cannot be measured. Modifying the electronic system enables registration of samples with high matrix activities. For short lived nuclides emitting hard beta-rays, e.g. B-12 or Li-8, a Cerenkov-detector is optimal. These problems are discussed in examples. (author)

Analytical approach to the evaluation of nuclide transmutations

International Nuclear Information System (INIS)

Vukadin, Z.; Osmokrovic, P.

1995-01-01

Analytical approach to the evaluation of nuclide concentrations in a transmutation chain is presented. Non singular Bateman coefficients and depletion functions are used to overcome numerical difficulties when applying well-known Bateman solution of a simple radioactive decay. Method enables evaluation of complete decay chains without elimination of short lived radionuclides. It is efficient and accurate. Practical application of the method is demonstrated by computing the neptunium series inventory in used Candu TM fuel. (author)

Utilizing Monte-Carlo radiation transport and spallation cross sections to estimate nuclide dependent scaling with altitude

Science.gov (United States)

Argento, D.; Reedy, R. C.; Stone, J.

2010-12-01

Cosmogenic Nuclides (CNs) are a critical new tool for geomorphology, allowing researchers to date Earth surface events and measure process rates [1]. Prior to CNs, many of these events and processes had no absolute method for measurement and relied entirely on relative methods [2]. Continued improvements in CN methods are necessary for expanding analytic capability in geomorphology. In the last two decades, significant progress has been made in refining these methods and reducing analytic uncertainties [1,3]. Calibration data and scaling methods are being developed to provide a self consistent platform for use in interpreting nuclide concentration values into geologic data [4]. However, nuclide dependent scaling has been difficult to address due to analytic uncertainty and sparseness in altitude transects. Artificial target experiments are underway, but these experiments take considerable time for nuclide buildup in lower altitudes. In this study, a Monte Carlo method radiation transport code, MCNPX, is used to model the galactic cosmic-ray radiation impinging on the upper atmosphere and track the resulting secondary particles through a model of the Earth’s atmosphere and lithosphere. To address the issue of nuclide dependent scaling, the neutron flux values determined by the MCNPX simulation are folded in with estimated cross-section values [5,6]. Preliminary calculations indicate that scaling of nuclide production potential in free air seems to be a function of both altitude and nuclide production pathway. At 0 g/cm2 (sea-level) all neutron spallation pathways have attenuation lengths within 1% of 130 g/cm2. However, the differences in attenuation length are exacerbated with increasing altitude. At 530 g/cm2 atmospheric height (~5,500 m), the apparent attenuation lengths for aggregate SiO2(n,x)10Be, aggregate SiO2(n,x)14C and K(n,x)36Cl become 149.5 g/cm2, 151 g/cm2 and 148 g/cm2 respectively. At 700 g/cm2 atmospheric height (~8,400m - close to the highest

Survey of reference materials for trace elements, nuclides and organic microcontaminants

International Nuclear Information System (INIS)

Parr, R.M.; Stone, S.F.; Bel-Amakeletch, T.; Zeisler, R.

1998-01-01

The International Atomic Energy Agency (IAEA), in co-operation with the United Nations Environment Programme (UNEP), has recently prepared a survey on internationally available analytical reference materials for trace elements, nuclides and organic contaminants in biological, environmental and related matrices. The purpose is to help analysts to select reference materials for quality assurance that match as closely as possible, with respect to matrix type and concentrations of the measurands of interest, the ''real'' samples that are to be measured. The present version of the survey, which is available in the form of two cost-free printed volumes [1], contains over 10,000 certified and information values in 650 reference materials from 27 different producers. The 455 measurands listed include trace elements, major and minor elements, organic contaminants, organometallic compounds, radionuclides and stable isotopes. Currently, the database from which the survey has been produced is being modified and extended so as to make the data available in electronic form via the Internet. (orig.)

Nuclide-related exemption limits for radioactive materials

International Nuclear Information System (INIS)

Przyborowski, S.; Scheler, R.

1984-01-01

A procedure has been proposed for setting nuclide-related exemption limits for radioactive materials. It consists in grading the radionuclides into 4 groups of radiotoxicity and assigning only one activity limit to each of them. Examples are given for about 200 radionuclides. The radiation exposures resulting from a continuous steady release of activity fractions or from short-period release of the entire activity were assessed to remain below 0.1 ALI in both of these borderline cases, thus justifying the license-free utilization of radioactive materials below the exemption limits. (author)

The recovery and study of heavy nuclides produced in a nuclear explosion - the Hutch event

Energy Technology Data Exchange (ETDEWEB)

Hoff, R W; Hulet, E K [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

1970-05-15

During the explosion of the Hutch device, the target ({sup 238}U and {sup 232}Th) was subjected to a very high neutron exposure, 2.4 x 10{sup 25} neutrons /cm{sup 2}. Multiple neutron capture reactions resulted in the production of heavy nuclides, up to and including 257Fm. Results of the search for species with A > 257 were negative. The recovery and chemical processing of kilograms of Hutch debris has resulted in the isolation of 10{sup 10} atoms of 257Fm, which is 10{sup 2} times more material than has been available for experimentation in the past. Experimentally significant amounts of other rare nuclides, e.g., :{sup 254}Cf, {sup 251}Cf, {sup 255}-Es, and {sup 250}Cm, have also been separated from the Hutch debris. The production of these nuclides in thermonuclear explosions is shown to be a valuable supplement to the AEC program for reactor production of transplutonium elements. The neutron flux achieved in Hutch was insufficient to even approach production of nuclides in the region of {sup 298}114. A much more intense neutron flux is required. In future experiments, considerable attention must be given to the problem of adequate sample recovery, in order to properly use the ability to subject targets to an exceedingly intense time-integrated neutron flux. (author)

A compartment model for nuclide release calculation in the near-and far-field of a HLW repository

International Nuclear Information System (INIS)

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

2004-01-01

The HLW-relevant R and D program for disposal of high-level radioactive waste has been carried out at Korea Atomic Energy Research Institute (KAERI) since early 1997, from which a conceptual Korea Reference Repository System for direct disposal of nuclear spent fuel is to be introduced by the end of 2007. A preliminary reference geologic repository concept considering such established criteria and requirements as spent fuel and generic site characteristics in Korea was roughly envisaged in 2003. Not only to demonstrate how much a reference repository is safe in the generic point of view with several possible scenarios and cases associated with a preliminary repository concept by conducting calculations for nuclide release and transport in the near - and far - field components of the repository, even though sufficient information has not been available that much yet, but also to show a appropriate methodology by which both a generic and site - specific safety assessment could be performed for further in - depth development of Korea reference repository concept, nuclide release calculation study for various nuclide release cases is mandatory. To this end a similar study done and yet limited for the near - field release case has been extended to the case including far - field system by introducing some more geosphere compartments. Advective and longitudinal dispersive nuclide transports along the fracture with matrix diffusion as well as several retention mechanisms and nuclide ingrowth has been added

A Potential Waste to be Selected as Media for Metal and Nutrient Removal

Science.gov (United States)

Zayadi, N.; Othman, N.; Hamdan, R.

2016-07-01

This study describes the potential of application of cassava peel, banana peel, coconut shell, and coconut coir to be selected as metal removal while limestone and steel slag for nutrient removal. The media were characterized by X-Ray Fluorescence (XRF), Fourier Transform Infrared (FTIR), Field Emission Scanning Electron Microscopy-Energy Dispersive X-Ray (FESEM-EDX), and X-Ray Powder Diffraction (XRD). The results of XRF analysis medias show the present of calcium oxide, CaO which confirm the high efficiency in adsorbing metal ions and nutrient which is in agreement with the result of XRD. The characteristics of medias by FTIR analysis also confirmed the involvement of alcohol, carboxylic, alkanes, amines and ethers which play important role to reduce ions while FESEM-EDX indicates the porous structures of study medias. The characterization analysis highlight that cassava peel and steel slag were selected as a potential media in this study.

Radio nuclides in mineral rocks and beach sand minerals in south east coast, Odisha

International Nuclear Information System (INIS)

Vidya Sagar, D.; Sahoo, S.K.; Essakki, Chinna; Tripathy, S.K.; Ravi, P.M.; Tripathi, R.M.; Mohanty, D.

2014-01-01

The primordial and metamorphic mineral rocks of the Eastern Ghats host minerals such as rutile, ilmenite, Silmenite, zircon, garnet and monazite in quartz matrix. The weathered material is transported down to the sea by run-off through Rivers and deposited back in coastal beach as heavy mineral concentrates. The minerals are mined by M/S Indian Rare Earths Ltd at the Chatrapur plant in Odisha coast to separate the individual minerals. Some of these minerals have low level radioactivity and may pose external and internal radiation hazard. The present paper deals with natural Thorium and Uranium in the source rocks with those observed in the coastal deposits. The study correlates the nuclide activity ratios in environmental samples in an attempt to understand the ecology of the natural radio nuclides of 238 U, 232 Th, 40 K and 226 Ra in environmental context. Further work is in progress to understand the geological process associated with the migration and reconcentration of natural radio-nuclides in the natural high background radiation areas

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.

Simultaneous determination of actinide and strontium nuclides by extraction chromatography

International Nuclear Information System (INIS)

Vajda, N.; Molnar, Zs.

1999-01-01

A relatively fast and simple separation procedure has been developed for the simultaneous determination of thorium, uranium, neptunium, plutonium, americium, curium and strontium radionuclides. Most of the isotopes of these elements are long-lived, pure alpha and beta emitters regarded as 'difficult to determine' ones in the literature. Our major goal was to develop a combined procedure capable for the analysis of all these nuclides in the same sample aliquot so that correlations can be revealed without the errors arising due to inhomogeneity of samples when the radionuclides are determined from different sub-samples. The combined procedure has the advantage that sample destruction becomes simpler and faster, too. The chemical procedure consists of co-precipitations for the pre-concentration of groups of chemically similar elements and extraction chromatographic separations for the purification of individual elements. By means of pre-concentration relatively big samples can be treated offering the possibility of low activity measurements that cannot be performed by analysing small sample amounts. Pre-concentration techniques were always chosen in order to improve the selectivity of the following separation steps. (authors)

The analyses of measured nuclide concentration in project ISTC 2670

International Nuclear Information System (INIS)

Chrapciak, V.

2006-01-01

In this article are analyzed experiments for WWER-440 fuel and compared with theoretical results by new version of the SCALE 5 code: nuclide compositions - measurement in Kurchatov institute for 3.6% - measurement in Dimitrovgrad for 3.6% (project ISTC 2670) The focus is on modules TRITON and ORIGEN-S (Authors)

600 MeV Simulation of the Production of Cosmogenic Nuclides in Meteorites by Galactic Protons

CERN Multimedia

2002-01-01

A large variety of stable and radioactive nuclides is produced by the interaction of solar and galactic cosmic rays with extraterrestrial matter. Measurements of such cosmogenic nuclides provide information about the constancy of cosmic ray fluxes in space and time and about the irradiation history of individual extraterrestrial objects provided that there exist reliable models describing the production process. For the calculation of the depth dependent production of cosmogenic nuclides in meteorites no satisfactory Therefore, the irradiation of small stony meteorites (radii~$<$~40~cm) by galactic protons is simulated in a series of thick target irradiation experiments at the 600~MeV proton beam of the SC. \\\\ \\\\ The thick targets are spheres (R = 5, 15, 25 cm) and are made out of diorite because of its low water content, its high density (3.0~g/cm|3) and because it provides a good approximation of the chemical composition of some common meteorite clas These spheres will also contain a wide variety of pure...

Exact error estimation for solutions of nuclide chain equations

International Nuclear Information System (INIS)

Tachihara, Hidekazu; Sekimoto, Hiroshi

1999-01-01

The exact solution of nuclide chain equations within arbitrary figures is obtained for a linear chain by employing the Bateman method in the multiple-precision arithmetic. The exact error estimation of major calculation methods for a nuclide chain equation is done by using this exact solution as a standard. The Bateman, finite difference, Runge-Kutta and matrix exponential methods are investigated. The present study confirms the following. The original Bateman method has very low accuracy in some cases, because of large-scale cancellations. The revised Bateman method by Siewers reduces the occurrence of cancellations and thereby shows high accuracy. In the time difference method as the finite difference and Runge-Kutta methods, the solutions are mainly affected by the truncation errors in the early decay time, and afterward by the round-off errors. Even though the variable time mesh is employed to suppress the accumulation of round-off errors, it appears to be nonpractical. Judging from these estimations, the matrix exponential method is the best among all the methods except the Bateman method whose calculation process for a linear chain is not identical with that for a general one. (author)

Progress on multi-nuclide AMS of JAEA-AMS-TONO

Science.gov (United States)

Saito-Kokubu, Yoko; Matsubara, Akihiro; Miyake, Masayasu; Nishizawa, Akimitsu; Ohwaki, Yoshio; Nishio, Tomohiro; Sanada, Katsuki; Hanaki, Tatsumi

2015-10-01

The JAEA-AMS-TONO (Japan Atomic Energy Agency's Accelerator Mass Spectrometer established at the Tono Geoscience Center) facility has been used for the dating of geological samples. The AMS system is versatile, based on a 5 MV tandem Pelletron-type accelerator. Since its establishment in 1997, the AMS system has been used for measurement of carbon-14 (14C) mainly for 14C dating studies in neotectonics and hydrogeology, in support of JAEA's research on geosphere stability applicable to the long-term isolation of high-level radioactive waste. Results of the measurement of 14C in soils and plants has been applied to the dating of fault activity and volcanism. Development of beryllium-10 (10Be) and aluminum-26 (26Al) AMS systems are now underway to enhance the capability of the multi-nuclide AMS in studies of dating by cosmogenic nuclides. The 10Be-AMS system has already been used for routine measurements in applied studies and improvements of the measurement technique have been made. Now we plan to fine tune the system and perform test measurements to develop the 26Al-AMS system.

Progress on multi-nuclide AMS of JAEA-AMS-TONO

Energy Technology Data Exchange (ETDEWEB)

Saito-Kokubu, Yoko, E-mail: kokubu.yoko@jaea.go.jp [Japan Atomic Energy Agency, Toki, Gifu 509-5102 (Japan); Matsubara, Akihiro [Japan Atomic Energy Agency, Toki, Gifu 509-5102 (Japan); Miyake, Masayasu; Nishizawa, Akimitsu; Ohwaki, Yoshio; Nishio, Tomohiro; Sanada, Katsuki [Pesco Corp., Ltd., Toki, Gifu 509-5123 (Japan); Hanaki, Tatsumi [Japan Atomic Energy Agency, Toki, Gifu 509-5102 (Japan)

2015-10-15

The JAEA-AMS-TONO (Japan Atomic Energy Agency’s Accelerator Mass Spectrometer established at the Tono Geoscience Center) facility has been used for the dating of geological samples. The AMS system is versatile, based on a 5 MV tandem Pelletron-type accelerator. Since its establishment in 1997, the AMS system has been used for measurement of carbon-14 ({sup 14}C) mainly for {sup 14}C dating studies in neotectonics and hydrogeology, in support of JAEA’s research on geosphere stability applicable to the long-term isolation of high-level radioactive waste. Results of the measurement of {sup 14}C in soils and plants has been applied to the dating of fault activity and volcanism. Development of beryllium-10 ({sup 10}Be) and aluminum-26 ({sup 26}Al) AMS systems are now underway to enhance the capability of the multi-nuclide AMS in studies of dating by cosmogenic nuclides. The {sup 10}Be-AMS system has already been used for routine measurements in applied studies and improvements of the measurement technique have been made. Now we plan to fine tune the system and perform test measurements to develop the {sup 26}Al-AMS system.

Some problems in utilization system of FP nuclides and actinides in the high level liquid wastes

International Nuclear Information System (INIS)

Ichiyanagi, Katsuaki; Emura, Satoru

1974-01-01

There are three nuclides of sup(134/137)Cs for irradiation sources, 90 Sr for radioisotope thermoelectric generators, and 238 Pu for cardiac pacemakers, as the nuclides for which considerable demand is expected in near future among those contained in reprocessed high level liquid wastes. Technical problems are first described from the viewpoint of utilization system. Then the control system of reprocessed high level wastes is expained. Finally, economic possibility and problems in their utilization are discussed. Being in competition with 60 Co, the price of sup(134/137)Cs will be lower than that of 60 Co after a decade. The annual demand in 1985 may be 6.1 x 10 6 Ci. The conclusive factor of 90 Sr market price is hard to get because it finds no strong competitive nuclides. It may be about 20 yen/Ci after ten years. Demand is expected to be approximately 1.2 x 10 7 Ci/year. However it is pretty hard to pay the cost of group separation and solidification, storage and conversion to products with such gain. It is estimated that the balance of income and outgo would be almost profitable, if the utilization of FP nuclides would progress and the demand three times as large as this assumption would be developed. (Wakatsuki, Y.)

Level of natural radiation nuclides in food and water in Hubei Province

International Nuclear Information System (INIS)

Chen Keling; Sun Bangyin; Zhang Xiaozhen; Li Guangming

1990-01-01

This paper reports the level of natural radiation nuclides in Hubei Province, China. 10 spots were selected in Wuhan, Jiangling etc., 171 samples in 14 kinds of food such as rice, cabbage and tap water, water in Yangtze River and other rivers were analysed.The results show that the values of U, Th, 226 Ra were n x 10 -2 Bq.kg -1 and that of 40 K was n x 10 Bq.kg -1 in food. The values of U, Th, 226 Ra, 40 K were n x 10 -2 Bq.L -1 , and that of 3 H was nBq.L -1 in drinking water. The data investigated indicates that Hubei Province belongs to the region of normal natural radiation. It is found that 226 Ra value in food is higher in general in the county of Tongcheng, and this problem needs further study

Development and application of the generator for the short-living nuclides production

International Nuclear Information System (INIS)

Tsejner, A.

1979-01-01

The results are stated of investigations by means of radioisotopes on the substance transfer in technological equipment. For these purposes, in most cases, nuclides with high gamma-activity are used and, if possible, having short half-life because the short half-life gives certain advantages in the cases when it is impossible to store radioactive substances in the technological equipment for a long time. It is noted that in connection with short half-life of the nucludes used for labelling and for the economic and radiation safety reasons, activity of these nuclides can not be high. It has been established that the most suitable nuclide for the labelling purpose is lanthanum-140 produced either in a nuclear reactor, or by means of separation from barium=-140 transforming into lanthanum-140 in an isotopic generator. Some methods of lanthanum separation from barium are described, in particular, in the isotopic generator described, barium is adsorbed on the cation-exchanger KPS-200 having high enough stability with respect to the ionozing radiations. As an eluent the 10 -2 M solution of the complexone (Na 2 - EDTA) was used. The complexone solution can be easely obtained and, because of the hydrolysis, it serves as a buffer solution. The data are given for radiation purity and yield of lanthanum-=140 [ru

Selection and identification of fungi isolated from sugarcane bagasse and their application for phenanthrene removal from soil.

Science.gov (United States)

Cortés-Espinosa, D V; Fernández-Perrino, F J; Arana-Cuenca, A; Esparza-García, F; Loera, O; Rodríguez-Vázquez, R

2006-01-01

This work investigated the identification and selection of fungi isolated from sugarcane bagasse and their application for phenanthrene (Phe) removal from soil. Fungi were identified by PCR amplification of ITS regions as Aspergillus terrus, Aspergillus fumigatus and Aspergillus niger, Penicillium glabrum and Cladosporium cladosporioides. A primary selection of fungi was accomplished in plate, considering Phe tolerance of every strain in two different media: potato dextrose agar (PDA) and mineral medium (MM). The radial extension rate (r(r)) in PDA exhibited significant differences (p<0.05) at 200 and 400 ppm of Phe. A secondary selection of A. niger, C. cladosporoides, and P. glabrum sp. was achieved based on their tolerance to 200, 400, 600 and 800 ppm of Phe, in solid culture at a sugarcane bagasse/contaminated soil ratio of 95:5, in Toyamas, Czapeck and Wunder media. Under these conditions, a maximum (70%) Phe removal by A. niger was obtained. In addition C. cladosporioides and A. niger were able to remove high (800 ppm) Phe concentrations.

Nuclide analysis at domestic Nuclear Power Plant with CZT Detector during the overhaul

International Nuclear Information System (INIS)

Kang, Seokon; Yoon, Kanghwa; Soo, Moonjin; Lee, Byoungil; Kim, Jeongin

2013-01-01

AEP (American Electric Power) also introduced another type CZT detector to perform source term monitoring and they had announced the results through the ISOE (Information System on Occupational Exposure). A CZT semiconductor detector is good to monitor source terms at a NPP in that it is possible to make a portable type because it does not need any cooling system at room temperature and it has good energy resolution. To follow up global atmosphere, KHNP (Korea Hydro and Nuclear Power) has been trying to use CZT monitoring system at a domestic NPP. This study shows a result of the kinds of nuclides between Before H 2 O 2 and After Clean-Up process for primary reactor coolant system nearby a steam generator during the overhaul for the first time. The detected source terms were the same for all measurement conditions, but the measurement was not quantitative analysis. It needs Spectrum Analysis Program to acquire quantitative analysis and we are developing the system. If the system is set-up in the CZT monitoring system, we will be able to know detail information of nuclides more. The result of spectra was the same regardless of measurement conditions and the intensity of the major nuclides is different obviously according to the measurement points. Even though the results only give US the information of the kinds of nuclides without any other information, the meaning is very significant to US, because the measurement is performed for the first time all over country. Especially, the result of both Red Plot and Blue Plot is very interesting in that the primary coolant is (Red plot) inside the pipe whereas it is not (Blue plot) inside the steam generator. Our study will be continued to find the reasons

Nuclide analysis at domestic Nuclear Power Plant with CZT Detector during the overhaul

Energy Technology Data Exchange (ETDEWEB)

Kang, Seokon; Yoon, Kanghwa; Soo, Moonjin; Lee, Byoungil; Kim, Jeongin [Radiation Health Research Institute, Seoul (Korea, Republic of)

2013-05-15

AEP (American Electric Power) also introduced another type CZT detector to perform source term monitoring and they had announced the results through the ISOE (Information System on Occupational Exposure). A CZT semiconductor detector is good to monitor source terms at a NPP in that it is possible to make a portable type because it does not need any cooling system at room temperature and it has good energy resolution. To follow up global atmosphere, KHNP (Korea Hydro and Nuclear Power) has been trying to use CZT monitoring system at a domestic NPP. This study shows a result of the kinds of nuclides between Before H{sub 2}O{sub 2} and After Clean-Up process for primary reactor coolant system nearby a steam generator during the overhaul for the first time. The detected source terms were the same for all measurement conditions, but the measurement was not quantitative analysis. It needs Spectrum Analysis Program to acquire quantitative analysis and we are developing the system. If the system is set-up in the CZT monitoring system, we will be able to know detail information of nuclides more. The result of spectra was the same regardless of measurement conditions and the intensity of the major nuclides is different obviously according to the measurement points. Even though the results only give US the information of the kinds of nuclides without any other information, the meaning is very significant to US, because the measurement is performed for the first time all over country. Especially, the result of both Red Plot and Blue Plot is very interesting in that the primary coolant is (Red plot) inside the pipe whereas it is not (Blue plot) inside the steam generator. Our study will be continued to find the reasons.

Influence of Groundwater Flow Rate on Nuclide Releases from Pyro-processed Waste Repository

International Nuclear Information System (INIS)

Lee, Youn Myoung; Jeong, Jong Tae

2011-01-01

Since the early 2000s several template programs for the safety assessment of a high-level radioactive waste repository as well as a low- and intermediate level radioactive waste repository systems have been developed by utilizing GoldSim and AMBER at KAERI. Very recently, another template program for a conceptual hybrid-typed repository system, called 'A-KRS' in which two kinds of pyroprocessed radioactive wastes, low-level metal wastes and ceramic high-level wastes that arise from pyroprocessing of PWR nuclear spent fuels has been developed and are to be disposed of by separate disposal strategies. The A-KRS is considered to be constructed at two different depths in geological media: 200m depth, at which a possible human intrusion is considered to be limited after closure, for the pyroprocessed metal wastes with lower or no decay heat producing nuclides, and 500m depth, believed to be in the reducing condition for nuclides with a rather higher radioactivity and heat generation rate. This program is ready for total system performance assessment which is able to evaluate nuclide release from the repository and farther transport into the geosphere and biosphere under various normal, disruptive natural and manmade events, and scenarios that can occur after a failure of waste package and canister. To quantify a nuclide release and transport through the possible various pathways especially in the near-fields of the A-KRS repository system, some illustrative evaluations have been made through the study. Even though all parameter values associated with the A-KRS were assumed for the time being, the illustrative results should be informative since the evaluation of such releases is very important not only in view of the safety assessment of the repository, but also for design feedback of its performance

Treatment of liquid waste containing alpha nuclides by adsorption

International Nuclear Information System (INIS)

Zeng Jishu; Su Xiguang; Xia Dejing; Fan Sianhua

1997-01-01

In this paper, experimental investigations on the removal of actinides from a decontaminating waste stream by using adsorption technique following the cementation of a resultant absorbent sludge are described. One kind of apatites was selected as an actinide absorbent from a number of indigenous materials by batch equilibrium tests. The influence of contact time, temperature, particle size and pH variables on the adsorption of actinides is given. The removal of total alpha activity is higher tan 97% by absorbent precipitation process when the absorbent addition percentage of the liquid waste is more than 3.25 wt%, making alpha-activity level of the primary waste stream below 3.7 x 10 3 Bq/L, which can meet the acceptance requirements of the Low Level Radwaste Treatment Plant. The studies on the cementation of the absorbent sludge included the selection of cements used for solidification, formulation and characterization of the selected cemented waste forms. The results obtained have shown that both 525 type Portland cement and 325 type Portland pozzolana cement were compatible with the absorbent sludge. The selected cemented waste forms meet the requirements of the Chinese National Standard (GB 14569.1-93): Characteristic Requirements for Solidified Waste of Low and Intermediate Level Radioactive Waste - Cement Solidified Waste. (author). 9 refs, 3 figs, 14 tabs

Cosmogenic nuclides principles, concepts and applications in the earth surface sciences

CERN Document Server

Dunai, Tibor J

2010-01-01

This is the first book to provide a comprehensive and state-of-the-art introduction to the novel and fast-evolving topic of in-situ produced cosmogenic nuclides. It presents an accessible introduction to the theoretical foundations, with explanations of relevant concepts starting at a basic level and building in sophistication. It incorporates, and draws on, methodological discussions and advances achieved within the international CRONUS (Cosmic-Ray Produced Nuclide Systematics) networks. Practical aspects such as sampling, analytical methods and data-interpretation are discussed in detail and an essential sampling checklist is provided. The full range of cosmogenic isotopes is covered and a wide spectrum of in-situ applications are described and illustrated with specific and generic examples of exposure dating, burial dating, erosion and uplift rates and process model verification. Graduate students and experienced practitioners will find this book a vital source of information on the background concepts and...

Long-term behaviour of radioactive nuclides in the environment

International Nuclear Information System (INIS)

Brechignac, F.; Moberg, L.; Suomela, M.

1999-01-01

Report of recent advances in Europe, regarding the long-term development of radioactive nuclides in the environment. The corresponding scientific findings from three projects - Peace, Landscape and Epora (involving 18 European laboratories) - have been collected together. These projects were managed by the IPSN for the European Commission (DG XII) in the framework of the programme 'Surete de la fission nucleaire' (Nuclear fission safety programme). (author)

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).

Capture and Solidification of Rare Earth Nuclide (Nd) in LiCl-KCl Eutectic Salt Using a Synthetic Inorganic Composite

Energy Technology Data Exchange (ETDEWEB)

Kim, Na-Young; Eun, Hee-Chul; Park, Hwan-Seo; Ahn, Do-Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2017-06-15

In this study, neodymium (Nd) nuclides in LiCl-KCl eutectic salts were captured and solidified using a synthetic inorganic composite (Li{sub 2}O-SiO{sub 2}-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}), a process that allows the selective capture of Nd and fabrication of a composite with Nd captured from waste, without additional additives or mixing. The Nd nuclides in the LiCl-KCl eutectic salt were mainly captured in the form of LiNdSiO{sub 4}, and it was confirmed that NdSiO{sub 3} can be formed in the composite with captured Nd when the content of Nd in the composite is increased. The capture efficiency was higher than about 98 wt%. It was thought that the salt recovered from the Nd capture test was a renewable form could be reused in the pyroprocessing of used nuclear fuel, because the composite has high chemical durability in a LiCl-KCl eutectic salt at 900 ℃. The composite captured Nd was fabricated into a homogeneous glass form and a stable ceramic form.

Librarian driven analysis with graphic user interface for nuclides quantification by gamma spectra

Energy Technology Data Exchange (ETDEWEB)

Kondrashov, V.S. E-mail: vlkondra@cdrewu.edu; Rothenberg, S.J.; Petersone, I

2001-09-11

For a set of a priori given radionuclides extracted from a general nuclide data library, the authors use median estimates of the gamma-peak areas and estimates to produce a list of possible radionuclides matching gamma-ray line(s). An a priori determined list of nuclides is obtained by searching for a match with the energy information of the database. This procedure is performed in an interactive graphic mode by markers that superimpose, on the spectral data, the energy information and yields provided by a general gamma-ray data library. This library of experimental data includes approximately 17,000 gamma-energy lines related to 756 known gamma emitter radionuclides listed by ICRP.

A rational approximation to Reich-Moore collision matrix of non-fissile nuclides

International Nuclear Information System (INIS)

Devan, K.; Keshavamurthy, R.S.

1999-01-01

The cross sections of many important nuclides are represented in Reich-Moore (RM) formalism in the recent American Evaluated Nuclear Data file, ENDF/B-VI. Processing of cross sections with RM resonance parameters is much more difficult than the other multilevel formalisms such as MLBW and Adler-Adler. In this paper, we derive a rational approximation to the RM collision matrix in the vicinity of a resonance. This simplifies the cross section processing. The energy range of the validity of this approximation in the vicinity of a resonance is also derived. Choosing Ni 58 as an example, results of our approximation for a non-fissile nuclide are given for two typical s-wave resonances. Our rational approximation method is found to work with good accuracies in the vicinity of resonances

Measurement of cosmogenic nuclides in extraterrestrial material

International Nuclear Information System (INIS)

Nishiizumi, K.; Arnold, J.R.

1981-01-01

Meteorites are rocks and pieces of iron-nickel alloy which fall to earth from time to time. They were formed about 4.6 billion years ago when our solar system was started. Thus it has been said that meteorites are the Rosetta stones of our solar system. We use the long-lived radioactive nuclides produced by cosmic ray bombardment, to study the history of the meteorites and also the history of the cosmic rays. When we have these historical facts in our hads, we hope we will be able to understand better how the solar system works, and how it got started. We can also learn more about the nature and origin of the cosmic rays. The accelerator mass spectrometry method helps not only reduce sample size, in most cases by two or three orders of magnitude, but opens another set of cosmogenic nuclides which have not been measured yet. Already 10 Be (t/sub 1/2 = 1.6 x 10 6 y), 36 Cl (3.0 x 10 5 y) and 129 I (1.6 x 10 7 y) in meteorites have been measured by accelerator mass spectrometry [3, 4, 7, 10]. Possible new candidates for measurement in extraterrestrial materials are 26 Al (7.2 x 10 5 y), 41 Ca (1.3 x 10 5 y), 60 Fe (approx. 10 5 y) and 59 Ni (7.6 x 10 4 y). We hope also to measure 146 Sm (1.0 x 10 8 y) and 92 Nb

Scaling in situ cosmogenic nuclide production rates using analytical approximations to atmospheric cosmic-ray fluxes

Science.gov (United States)

Lifton, Nathaniel; Sato, Tatsuhiko; Dunai, Tibor J.

2014-01-01

Several models have been proposed for scaling in situ cosmogenic nuclide production rates from the relatively few sites where they have been measured to other sites of interest. Two main types of models are recognized: (1) those based on data from nuclear disintegrations in photographic emulsions combined with various neutron detectors, and (2) those based largely on neutron monitor data. However, stubborn discrepancies between these model types have led to frequent confusion when calculating surface exposure ages from production rates derived from the models. To help resolve these discrepancies and identify the sources of potential biases in each model, we have developed a new scaling model based on analytical approximations to modeled fluxes of the main atmospheric cosmic-ray particles responsible for in situ cosmogenic nuclide production. Both the analytical formulations and the Monte Carlo model fluxes on which they are based agree well with measured atmospheric fluxes of neutrons, protons, and muons, indicating they can serve as a robust estimate of the atmospheric cosmic-ray flux based on first principles. We are also using updated records for quantifying temporal and spatial variability in geomagnetic and solar modulation effects on the fluxes. A key advantage of this new model (herein termed LSD) over previous Monte Carlo models of cosmogenic nuclide production is that it allows for faster estimation of scaling factors based on time-varying geomagnetic and solar inputs. Comparing scaling predictions derived from the LSD model with those of previously published models suggest potential sources of bias in the latter can be largely attributed to two factors: different energy responses of the secondary neutron detectors used in developing the models, and different geomagnetic parameterizations. Given that the LSD model generates flux spectra for each cosmic-ray particle of interest, it is also relatively straightforward to generate nuclide-specific scaling

Nanofluids and chemical highly retentive hydrogels for controlled and selective removal of overpaintings and undesired graffiti from street art.

Science.gov (United States)

Giorgi, Rodorico; Baglioni, Michele; Baglioni, Piero

2017-06-01

One of the main problems connected to the conservation of street art is the selective removal of overlying undesired graffiti, i.e., drawings and tags. Unfortunately, selective and controlled removal of graffiti and overpaintings from street art is almost unachievable using traditional methodologies. Recently, the use of nanofluids confined in highly retentive pHEMA/PVP semi-interpenetrated polymer networks was proposed. Here, we report on the selective removal of acrylic overpaintings from a layer of acrylic paint on mortar mockups in laboratory tests. The results of the cleaning tests were characterized by visual and photographic observation, optical microscopy, and FT-IR microreflectance investigation. It was shown that this methodology represents a major advancement with respect to the use of nonconfined neat solvents.

Selective Removal of Residual Orthodontic Composite Using a Rapidly Scanned Carbon Dioxide Laser with Spectral Feedback

Science.gov (United States)

Hirasuna, Krista

Background and Objective: Excessive heat accumulation within the tooth, incomplete removal of composite, and variable damage to the enamel are shortcomings of using conventional burs to remove residual orthodontic composite after debonding fixed appliances. The objective of this study was to determine if composite could be selectively removed from the enamel surface using a rapidly scanned carbon dioxide laser controlled by spectral feedback. Materials and Methods: A carbon dioxide laser operating at a wavelength of 9.3 microm with a pulse duration of 10-15 micros and a pulse repetition rate of ˜ 200 Hz was used to selectively remove composite from the buccal surfaces of 21 extracted teeth. GrenGloo(TM) composite was used to better visualize residual composite and the amount of enamel lost was measured with optical microscopy. A spectral feedback system utilizing a miniature spectrometer was used to control the laser scanning system. Pulpal temperature measurements were performed during composite removal to determine if there was excessive heat accumulation. Results: The amount of enamel lost averaged 22.7microm +/- 8.9 and 25.3 microm +/- 9.4 for removal at 3.8 and 4.2 J/cm2, respectively. An average maximum temperature rise of 1.9°C +/- 1.5 was recorded, with no teeth approaching the critical value of 5.5°C. The average time of composite removal was 19.3 +/- 4.1 seconds. Conclusions: Residual orthodontic composite can be rapidly removed from the tooth surface using a rapidly scanned CO2 laser with spectral feedback, with minimal temperature rise within the pulp and with minimal damage to the underlying enamel surface.

Removal of cesium and strontium from low active waste solutions by zeolites

International Nuclear Information System (INIS)

Jain, Savita; Ramaswamy, M.; Theyyunni, T.K.

1994-01-01

Ion exchange, crystallographic and thermal characteristics of sodium, cesium and strontium forms of locally available synthetic zeolites have been investigated. X-ray and differential thermal analyses have confirmed that the synthetic materials AR1 and 4A belonged to the mordenite and A type families of zeolites respectively. Equilibrium uptake of cesium and strontium ions by sodium forms of zeolite was studied as a function of time, pH and sodium concentration. It was found that the rate of sorption by AR1 was higher than that by 4A. In regard to pH, distribution of nuclides on zeolites was found to pass through maxima at a pH value of around 9. Sodium ion interfered with the sorption of cesium and strontium by zeolites. However, at sodium concentration ≤ 0.01 M, distribution coefficient values for these nuclides were sufficiently high to merit consideration of these zeolites for low level waste treatment. Lab-scale column runs using 5 ml beds of materials showed that the zeolites AR1 and 4A were very effective in removing cesium and strontium nuclides respectively from large volumes (a decontamination factor of 50 for a throughput of 6000 bed volumes) of actual low level waste solutions. Thus, the zeolite system has a potential future for large scale application in the treatment of low level wastes. (author). 6 refs., 5 figs., 6 tabs

Removal of fission products from waste solutions using 16 different soil samples

International Nuclear Information System (INIS)

Bangash, M.A.; Hanif, J.

1997-01-01

Most of the nuclear sites use pits in the surrounding soils for the storage/disposal of low active waste (LAW) solutions. The characteristics of the soil if not suitable for the fixation or adsorption of the radioactive nuclides, may cause migration of these nuclides to hydrosphere. The phenomenon has the risk of radio toxic pollution for the living bodies therefore minerals composing the soil and their adsorption properties need to be investigated. For this purpose 16 different soil samples were collected from all over Pakistan. Mineralogical composition of the soils was determined by X-ray diffraction analysis. It was found that most of the samples contained clay minerals, illite, kaolinite and montmorillonite. Studies for the removal of fission products like, /sup 137/Cs. /sup 60/Sr and activation product /sup 60/CO from solution were carried out on these samples. The sorption experiments were performed by batch technique using radioactive as tracers. Distribution co-efficient were determined by mixing he element solution at pH 3 with the soil at soil solution ratios of 1 to 20. It is revealed from the experimental data that efficient removal of fission products from solutions is achieved by soil samples containing clay mineral montmorillonite, followed by little and kaolinite. These soils thus can be effectively used for the disposal of low level radioactive waste solutions without causing any environmental hazard. (author)

Role of Core-collapse Supernovae in Explaining Solar System Abundances of p Nuclides

Science.gov (United States)

Travaglio, C.; Rauscher, T.; Heger, A.; Pignatari, M.; West, C.

2018-02-01

The production of the heavy stable proton-rich isotopes between 74Se and 196Hg—the p nuclides—is due to the contribution from different nucleosynthesis processes, activated in different types of stars. Whereas these processes have been subject to various studies, their relative contributions to Galactic chemical evolution (GCE) are still a matter of debate. Here we investigate for the first time the nucleosynthesis of p nuclides in GCE by including metallicity and progenitor mass-dependent yields of core-collapse supernovae (ccSNe) into a chemical evolution model. We used a grid of metallicities and progenitor masses from two different sets of stellar yields and followed the contribution of ccSNe to the Galactic abundances as a function of time. In combination with previous studies on p-nucleus production in thermonuclear supernovae (SNIa), and using the same GCE description, this allows us to compare the respective roles of SNeIa and ccSNe in the production of p-nuclei in the Galaxy. The γ process in ccSN is very efficient for a wide range of progenitor masses (13 M ⊙–25 M ⊙) at solar metallicity. Since it is a secondary process with its efficiency depending on the initial abundance of heavy elements, its contribution is strongly reduced below solar metallicity. This makes it challenging to explain the inventory of the p nuclides in the solar system by the contribution from ccSNe alone. In particular, we find that ccSNe contribute less than 10% of the solar p nuclide abundances, with only a few exceptions. Due to the uncertain contribution from other nucleosynthesis sites in ccSNe, such as neutrino winds or α-rich freeze out, we conclude that the light p-nuclides 74Se, 78Kr, 84Sr, and 92Mo may either still be completely or only partially produced in ccSNe. The γ-process accounts for up to twice the relative solar abundances for 74Se in one set of stellar models and 196Hg in the other set. The solar abundance of the heaviest p nucleus 196Hg is

Standards of compounds labeled with positron nuclides approved as established techniques for medical use (2001 revision)

International Nuclear Information System (INIS)

2001-01-01

The subcommittee on Medical Application of Cyclotron-Produced Radionuclides, Medical Science and Pharmaceutical Committee, Japan Radioisotope Association, revised the Standards in the title for their manufacturing, quality, manufacturing work environment etc. The facilities must have the individual committee for the organization and its responsibility is for the control and hygiene in manufacturing the nuclides, for the quality control and for the medical use. Based on this, the Standard defined such pharmaceutical items as the general rule; gas agents and injection formulations; test methods involving γ-ray measurement including spectrometry and derived determination, determination with well-type scintillation counter and ionization chamber, method to measure half-time and determination of the nuclide purity; individual definition of [ 18 F]2-deoxy-2-fluoro-D-glucose, 15 O gas and 15 O-carbon monoxide and 15 O-carbon dioxide; and guideline of manufacturing the nuclides and its environment involving monitoring and records. (K.H.)

Selective removal of cesium from aqueous solutions with nickel (II) hexacyanoferrate (III) functionalized agricultural residue-walnut shell.

Science.gov (United States)

Ding, Dahu; Lei, Zhongfang; Yang, Yingnan; Feng, Chuanping; Zhang, Zhenya

2014-04-15

A novel nickel (II) hexacyanoferrate (III) functionalized agricultural residue-walnut shell (Ni(II)HCF(III)-WS) was developed to selectively remove cesium ion (Cs(+)) from aqueous solutions. This paper showed the first integral study on Cs(+) removal behavior and waste reduction analysis by using biomass adsorption material. The results indicated that the removal process was rapid and reached saturation within 2h. As a special characteristic of Ni(II)HCF(III)-WS, acidic condition was preferred for Cs(+) removal, which was useful for extending the application scope of the prepared biomass material in treating acidic radioactive liquid waste. The newly developed Ni(II)HCF(III)-WS could selectively remove Cs(+) though the coexisting ions (Na(+) and K(+) in this study) exhibited negative effects. In addition, approximately 99.8% (in volume) of the liquid waste was reduced by using Ni(II)HCF(III)-WS and furthermore 91.9% (in volume) of the spent biomass material (Cs-Ni(II)HCF(III)-WS) was reduced after incineration (at 500°C for 2h). Due to its relatively high distribution coefficient and significant volume reduction, Ni(II)HCF(III)-WS is expected to be a promising material for Cs(+) removal in practice. Copyright © 2014 Elsevier B.V. All rights reserved.

Apparatus and method for quantitatively evaluating total fissile and total fertile nuclide content in samples

International Nuclear Information System (INIS)

Caldwell, J.T.; Cates, M.R.; Franks, L.A.; Kunz, W.E.

1985-01-01

Simultaneous photon and neutron interrogation of samples for the quantitative determination of total fissile nuclide and total fertile nuclide material present is made possible by the use of an electron accelerator. Prompt and delayed neutrons produced from resulting induced fissions are counted using a single detection system and allow the resolution of the contributions from each interrogating flux leading in turn to the quantitative determination sought. Detection limits for 239 Pu are estimated to be about 3 mg using prompt fission neutrons and about 6 mg using delayed delayed neutrons

Rapid and selective removal of composite from tooth surfaces with a 9.3 µm CO2 laser using spectral feedback.

Science.gov (United States)

Chan, Kenneth H; Hirasuna, Krista; Fried, Daniel

2011-09-01

Dental composite restorative materials are color matched to the tooth and are difficult to remove by mechanical means without excessive removal or damage to peripheral enamel and dentin. Lasers are ideally suited for selective ablation to minimize healthy tissue loss when replacing existing restorations, sealants, or removing composite adhesives such as residual composite left after debonding orthodontic brackets. In this study, a carbon dioxide laser operating at 9.3-µm with a pulse duration of 10-20-microsecond and a pulse repetition rate of ∼200 Hz was integrated with a galvanometer based scanner and used to selectively remove composite from tooth surfaces. Spectra of the plume emission were acquired after each laser pulse and used to differentiate between the ablation of dental enamel or composite. Microthermocouples were used to monitor the temperature rise in the pulp chamber during composite removal. The composite was placed on tooth buccal and occlusal surfaces and the carbon dioxide laser beam was scanned across the surface to selectively remove the composite without excessive damage to the underlying sound enamel. The residual composite and the damage to the underlying enamel was evaluated using optical microscopy. The laser was able to rapidly remove composite from tooth buccal and occlusal surfaces with minimal damage to the underlying sound enamel and without excessive heat accumulation in the tooth. This study demonstrated that composite can be selectively removed from tooth surfaces at clinically relevant rates using a CO(2) laser operating at 9.3-µm with high pulse repetition rates with minimal heat deposition and damage to the underlying enamel. Copyright © 2011 Wiley-Liss, Inc.

Validation of corrections for errors in collimation during measurement of gastric emptying of nuclide-labeled meals

Energy Technology Data Exchange (ETDEWEB)

Van Deventer, G.; Thomson, J.; Graham, L.S.; Thomasson, D.; Meyer, J.H.

1983-03-01

The study was undertaken to validate phantom-derived corrections for errors in collimation due to septal penetration or scatter, which vary with the size of the gastric region of interest (ROI). Six volunteers received 495 ml of 20% glucose labeled with both In-113m DTPA and Tc-99m DTPA. Gastric emptying of each nuclide was monitored by gamma camera as well as by periodic removal and reinstillation of the meal through a gastric tube. Serial aspirates from the gastric tube confirmed parallel emptying of In-113m and Tc-99m, but analyses of gamma-camera data yielded parallel emptying only when adequate corrections were made for errors in collimation. Analyses of ratios of gastric counts from anterior to posterior, as well as analyses of peak-to-scatter ratios, revealed only small, insignificant anteroposterior movement of the tracers within the stomach during emptying. Accordingly, there was no significant improvement in the camera data when corrections were made for attenuation with intragastric depth.

Zirconium-based metal organic frameworks: Highly selective adsorbents for removal of phosphate from water and urine

Energy Technology Data Exchange (ETDEWEB)

Lin, Kun-Yi Andrew, E-mail: linky@nchu.edu.tw [Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan (China); Chen, Shen-Yi [Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan (China); Jochems, Andrew P. [New Mexico Bureau of Geology & Mineral Resources and New Mexico Institute of Mining & Technology, Socorro, NM (United States)

2015-06-15

Phosphate is one of the most concerning compounds in wastewater streams and a main nutrient that causes eutrophication. To eliminate the phosphate pollution, Metal Organic Frameworks (MOFs) are proposed in this study as adsorbents to remove phosphate from water. The zirconium-based MOF, UiO-66, was selected as representative MOF given its exceptional stability in water. To investigate the effect of an amine functional group, UiO-66-NH2 was also prepared using an amine-substituted ligand. The adsorption kinetics and isotherm reveal that UiO-66-NH2 exhibited higher adsorption capacities than UiO-66 possibly due to the amine group. However, the interaction between phosphate and zirconium sites of UiO MOFs might be the primary factor accounting for the phosphate adsorption to UiO MOFs. UiO MOFs also exhibited a high selectivity towards phosphate over other anions such as bromate, nitrite and nitrate. Furthermore, UiO MOFs were found to adsorb phosphate and to completely remove diluted phosphate in urine. We also found that UiO MOFs could be easily regenerated and re-used for phosphate adsorption. These findings suggest that UiO MOFs can be effective and selective adsorbents to remove phosphate from water as well as urine. - Highlights: • UiO-66 as the first type of MOFs was used to remove phosphate from water and urine. • The amine group in UiO MOFs was found to enhance the phosphate adsorption. • UiO-66 exhibited a high adsorption selectivity towards phosphate over other anions. • UiO-66 could be easily regenerated and re-used with 85% regeneration efficiency.

A study on the stochastic model for nuclide transport in the fractured porous rock using continuous time Markov process

International Nuclear Information System (INIS)

Lee, Youn Myoung

1995-02-01

As a newly approaching model, a stochastic model using continuous time Markov process for nuclide decay chain transport of arbitrary length in the fractured porous rock medium has been proposed, by which the need for solving a set of partial differential equations corresponding to various sets of side conditions can be avoided. Once the single planar fracture in the rock matrix is represented by a series of finite number of compartments having region wise constant parameter values in them, the medium is continuous in view of various processes associated with nuclide transport but discrete in medium space and such geologic system is assumed to have Markov property, since the Markov process requires that only the present value of the time dependent random variable be known to determine the future value of random variable, nuclide transport in the medium can then be modeled as a continuous time Markov process. Processes that are involved in nuclide transport are advective transport due to groundwater flow, diffusion into the rock matrix, adsorption onto the wall of the fracture and within the pores in the rock matrix, and radioactive decay chain. The transition probabilities for nuclide from the transition intensities between and out of the compartments are represented utilizing Chapman-Kolmogorov equation, through which the expectation and the variance of nuclide distribution for each compartment or the fractured rock medium can be obtained. Some comparisons between Markov process model developed in this work and available analytical solutions for one-dimensional layered porous medium, fractured medium with rock matrix diffusion, and porous medium considering three member nuclide decay chain without rock matrix diffusion have been made showing comparatively good agreement for all cases. To verify the model developed in this work another comparative study was also made by fitting the experimental data obtained with NaLS and uranine running in the artificial fractured

Cosmogenic nuclide shielding corrections determined via MCNPX radiation transport and spallation cross sections

Science.gov (United States)

Argento, D.; Reedy, R. C.; Stone, J. O.

2011-12-01

Cosmogenic Nuclides (CNs) are a critical new tool for geomorphology, allowing researchers to date Earth surface events and measure process rates [1]. Prior to CNs, many of these events and processes had no absolute method for measurement and relied entirely on relative methods. Reliable absolute measurement methods impact research constraining ice age extents and provide important climatic data via well constrained erosion rates, etc. [2]. Continuing to improve CN methods is critical for these sciences. Significant progress has been made in the last two decades in refining the method and reducing analytic uncertainties [1,3]. CRONUS-Earth, a collaboration of cosmogenic nuclide researchers, has been developing calibration data and scaling methods to provide a self-consistent platform for use in interpreting nuclide concentration values into geologic data. However, several aspects of the radiation cascade have been exceedingly difficult to measure empirically with either accuracy or spatial extent. One such aspect is the angular distribution of secondary cosmic rays that are energetic enough to produce cosmogenic nuclides via spallation. Researchers studying the angular distribution of such cosmic rays have usually described the distribution as (cos(Θ))^m. Currently, the standard corrections, assume an m of 2.3, which is based on very sparse data sets with very limited spatial and altitude variation [1,4,5]. Researchers using CNs must know the production rate at the sample location, and then make corrections for the portion of the sky that is blocked by nearby topography. If the shielding correction model currently used is too simplistic, this introduces error into the final results. In this study, a Monte Carlo method radiation transport code, MCNPX is used to model the Galactic Cosmic Ray (GCR) radiation impinging on the upper atmosphere and tracks the resulting secondary particles through a model of the Earth's atmosphere. Angle and energy distributions are

Selective removal of cesium and strontium using porous frameworks from high level nuclear waste.

Science.gov (United States)

Aguila, Briana; Banerjee, Debasis; Nie, Zimin; Shin, Yongsoon; Ma, Shengqian; Thallapally, Praveen K

2016-05-01

Efficient and cost-effective removal of radioactive (137)Cs and (90)Sr found in spent fuel is an important step for safe, long-term storage of nuclear waste. Solid-state materials such as resins and titanosilicate zeolites have been assessed for the removal of Cs and Sr from aqueous solutions, but there is room for improvement in terms of capacity and selectivity. Herein, we report the Cs(+) and Sr(2+) exchange potential of an ultra stable MOF, namely, MIL-101-SO3H, as a function of different contact times, concentrations, pH levels, and in the presence of competing ions. Our preliminary results suggest that MOFs with suitable ion exchange groups can be promising alternate materials for cesium and strontium removal.

Off-Gas Treatment: Evaluation of Nano-structured Sorbents for Selective Removal of Contaminants

Energy Technology Data Exchange (ETDEWEB)

Utgikar, Vivek; Aston, D. Eric; Sabharwall, Piyush

2018-03-30

Reprocessing of used nuclear fuel (UNF) is expected to play an important role for sustainable development of nuclear energy by increasing the energy extracted from the fuel and reducing the generation of the high level waste (HLW). However, aqueous reprocessing of UNF is accompanied by emission of off-gas streams containing radioactive nuclides including iodine, krypton, xenon, carbon, and tritium. Volatile iodine (129I), and krypton (85Kr) are long lived isotopes which have adverse effects on the environment as well as human health. Development of methods for the capture and long-term storage of radioactive gases is of crucial importance in order to manage their emissions that are anticipated to increase significantly with the growth of nuclear energy. For more than 70 years, porous solid sorbents have been in the forefront of radioactive contaminant removal due to promising results and their advantages such as high removal efficiency, low maintenance cost, simple equipment design and operation over other techniques. The research conducted in this project has focused on development of a novel nanostructured sorbent and its application for the capture of the above two contaminants of interest. Nanostructured carbon polyhedrons supported on Engelhard Titanosilicate-10 sorbent was synthesized using hydrothermal methods and subjected to structural and compositional characterization using various techniques including electron microscopy, Raman, x-ray diffraction and BET surface area analysis. Dynamic sorption experiments conducted using a flow-through column setup yielded information on the thermodynamics and kinetics of sorption in single-contaminant and multi-contaminant streams. Parameters varied in the study included carbon loading, temperature, contact time, contaminant concentration and humidity. The behavior of the system was modeled using models available in literature as well as development of a mass-transfer model from fundamental principles. Experimental

Selective removal of methyl mercaptan in coffee aroma using oxidized microporous carbon

Energy Technology Data Exchange (ETDEWEB)

Sakano, T. [Ajinomoto General Foods Inc., Tokyo (Japan). Central Research Laboratoties; Tamon, H.; Okazaki, M. [Kyoto University, Kyoto (Japan). Dept. of Chemical Engineering

1999-10-01

Coffee aroma recovered from the extraction process of roasted coffee beans is used to improve the quality of soluble coffee products. Coffee aroma often has an irritating sulfurous odor. In the present work, it is experimentally elucidated that methyl mercaptan could be selectively removed from the coffee aroma-containing gas by the oxidized microporous carbon. Breakthrough curves of coffee aroma-containing gas on zeolite 5A, microporous carbon (MSC 5A), and MSC 5A oxidized with 13.2N HNO{sub 3} aqueous solution revealed that the adsorption capacity of methyl mercaptan on the oxidized carbon was 4.2 times of that on the zeolite. The loss of desired coffee aroma was decreased using the oxidized carbon in the removal of methyl mercaptan. (author)

Development of detection method for individual environmental particles containing alpha radioactive nuclides

International Nuclear Information System (INIS)

Esaka, Konomi; Yasuda, Kenichiro; Esaka, Fumitaka; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu; Nakayama, Shinichi

2006-01-01

Artificial radioactive nuclides have been emitted from various sources and have fallen on the surface of the earth as fine particles. Although the characterization of the individual fallout particles is very important, their analysis is difficult. The purpose of this study is to develop a new detection method for individual objective particles containing radioactive nuclides in the environment. The soil or sediment sample was confined in a plastic film and the locations of objective particles were identified with alpha tracks created in a solid-state detectors (BARYOTRAK, Fukuvi Chemical, Ltd) stuck to the both sides of the plastic film. A piece of the film containing the objective particle was cut with a nitrogen laser for following individual particle analysis. This procedure allowed us to detect the objective particle from innumerable number of particles in the environment and characterize the individual particles. (author)

Retention of simulated fallout nuclides in agricultural crops. 1. Experiments on leys

International Nuclear Information System (INIS)

Eriksson, Aake; Rosen, K.; Haak, E.

1998-01-01

Experiments with artificial wet depositions of 134 Cs and 85 Sr during the growth period were carried out. The studies are complementary to the experiences after the Chernobyl fallout. The aim was to get a description of the relative transfer to the harvest products of new clover-grass leys and old grass leys after initial depositions of tracer nuclides at different times during the growth period. The reduction in transfer with time, from deposition to sampling, depends partly on dilution by growth and partly on fall-off to the ground. The reduction half-time for the nuclide content showed a range 10 - 14 days. The data obtained in the experiments can extend the basis for prediction of the consequences of fallout events at different times to new as well as to old leys in the field

Treatment of liquid waste containing alpha nuclides by adsorption

Energy Technology Data Exchange (ETDEWEB)

Jishu, Zeng; Xiguang, Su; Dejing, Xia; Sianhua, Fan [China Inst. of Atomic Energy, Beijing (China). Radiochemistry Dept.

1997-02-01

In this paper, experimental investigations on the removal of actinides from a decontaminating waste stream by using adsorption technique following the cementation of a resultant absorbent sludge are described. One kind of apatites was selected as an actinide absorbent from a number of indigenous materials by batch equilibrium tests. The influence of contact time, temperature, particle size and pH variables on the adsorption of actinides is given. The removal of total alpha activity is higher tan 97% by absorbent precipitation process when the absorbent addition percentage of the liquid waste is more than 3.25 wt%, making alpha-activity level of the primary waste stream below 3.7 x 10{sup 3} Bq/L, which can meet the acceptance requirements of the Low Level Radwaste Treatment Plant. The studies on the cementation of the absorbent sludge included the selection of cements used for solidification, formulation and characterization of the selected cemented waste forms. The results obtained have shown that both 525 type Portland cement and 325 type Portland pozzolana cement were compatible with the absorbent sludge. The selected cemented waste forms meet the requirements of the Chinese National Standard (GB 14569.1-93): Characteristic Requirements for Solidified Waste of Low and Intermediate Level Radioactive Waste - Cement Solidified Waste. (author). 9 refs, 3 figs, 14 tabs.

Calculation of the minimum critical mass of fissile nuclides

International Nuclear Information System (INIS)

Wright, R.Q.; Hopper, Calvin Mitchell

2008-01-01

The OB-1 method for the calculation of the minimum critical mass of fissile actinides in metal/water systems was described in a previous paper. A fit to the calculated minimum critical mass data using the extended criticality parameter is the basis of the revised method. The solution density (grams/liter) for the minimum critical mass is also obtained by a fit to calculated values. Input to the calculation consists of the Maxwellian averaged fission and absorption cross sections and the thermal values of nubar. The revised method gives more accurate values than the original method does for both the minimum critical mass and the solution densities. The OB-1 method has been extended to calculate the uncertainties in the minimum critical mass for 12 different fissile nuclides. The uncertainties for the fission and capture cross sections and the estimated nubar uncertainties are used to determine the uncertainties in the minimum critical mass, either in percent or grams. Results have been obtained for U-233, U-235, Pu-236, Pu-239, Pu-241, Am-242m, Cm-243, Cm-245, Cf-249, Cf-251, Cf-253, and Es-254. Eight of these 12 nuclides are included in the ANS-8.15 standard.

Pyrochemical extraction for selective removal of transuranium elements from molten LiCl-KCl

International Nuclear Information System (INIS)

Ackermann, J.P.; Johnson, T.R.

1993-01-01

Recent determinations of separation factors that describe partition of the actinide and rare earth elements between liquid cadmium and LiCl-KCl eutectic allowed identification of a process for selective removal of the transuranium (TRU) element chlorides from the electrolyte used for electrofining of metal fuel from the Integral Fast Reactor. It is periodically necessary to remove rare earth elements from the electrolyte to limit heat generation from radioactive decay. Countercurrent extraction of electrolyte with uranium in cadmium solution allows retention of valuable TRU elements in the reprocessed fuel, and results in a rare earth waste stream that is essentially free of TRU elements and their concomitant long-term hazards

Selective removal of cesium from aqueous solutions with nickel (II) hexacyanoferrate (III) functionalized agricultural residue–walnut shell

International Nuclear Information System (INIS)

Ding, Dahu; Lei, Zhongfang; Yang, Yingnan; Feng, Chuanping; Zhang, Zhenya

2014-01-01

Highlights: • Novel biosorbent for cesium removal was derived from agricultural residue. • It could remove cesium effectively from aqueous solution. • Large size of granules makes it easy to be separated from solutions. • The volume of used biosorbent could be significantly reduced after incineration. • Incinerated biosorbent has a low volume and a low cost final disposal. - Abstract: A novel nickel (II) hexacyanoferrate (III) functionalized agricultural residue-walnut shell (Ni II HCF III -WS) was developed to selectively remove cesium ion (Cs + ) from aqueous solutions. This paper showed the first integral study on Cs + removal behavior and waste reduction analysis by using biomass adsorption material. The results indicated that the removal process was rapid and reached saturation within 2 h. As a special characteristic of Ni II HCF III -WS, acidic condition was preferred for Cs + removal, which was useful for extending the application scope of the prepared biomass material in treating acidic radioactive liquid waste. The newly developed Ni II HCF III -WS could selectively remove Cs + though the coexisting ions (Na + and K + in this study) exhibited negative effects. In addition, approximately 99.8% (in volume) of the liquid waste was reduced by using Ni II HCF III -WS and furthermore 91.9% (in volume) of the spent biomass material (Cs-Ni II HCF III -WS) was reduced after incineration (at 500 °C for 2 h). Due to its relatively high distribution coefficient and significant volume reduction, Ni II HCF III -WS is expected to be a promising material for Cs + removal in practice

VRF ("Visual RobFit") — nuclear spectral analysis with non-linear full-spectrum nuclide shape fitting

Science.gov (United States)

Lasche, George; Coldwell, Robert; Metzger, Robert

2017-09-01

A new application (known as "VRF", or "Visual RobFit") for analysis of high-resolution gamma-ray spectra has been developed using non-linear fitting techniques to fit full-spectrum nuclide shapes. In contrast to conventional methods based on the results of an initial peak-search, the VRF analysis method forms, at each of many automated iterations, a spectrum-wide shape for each nuclide and, also at each iteration, it adjusts the activities of each nuclide, as well as user-enabled parameters of energy calibration, attenuation by up to three intervening or self-absorbing materials, peak width as a function of energy, full-energy peak efficiency, and coincidence summing until no better fit to the data can be obtained. This approach, which employs a new and significantly advanced underlying fitting engine especially adapted to nuclear spectra, allows identification of minor peaks that are masked by larger, overlapping peaks that would not otherwise be possible. The application and method are briefly described and two examples are presented.

Statistical effects in beta-delayed neutron emission from fission product nuclides

International Nuclear Information System (INIS)

McElroy, R.D. Jr.

1986-01-01

The delayed neutron spectra for the precursors Rb-93, 94, 95, 96, 97 and Cs-145 were measured by use of the on-line isotope separator facility TRISTAN and a time-of-flight (TOF) spectrometer. Flight paths were used that provided, for energies below 70 keV, a FWHM energy resolution between 2 and 4 percent. Each spectrum showed discrete neutron peaks below 156 keV, with as many as 26 in the Rb-95 spectra. Level densities near the neutron binding energy in the neutron-emitting nuclide were deduced using a missing-level indicator based on a Porter-Thomas distribution of neutron peak intensities. The resulting level density data were compared to the predictions of the Gilbert and Cameron formulism and to those of Dilg, Schantl, Vonach and Uhl. Comparisons were made between the empirically-based level parameter a and the values predicted by each model for Sr-93, 94, 95, 97 and Ba-145. The two models appear, within the uncertainties, to be equally capable of describing these neutron-rich nuclides and equally as capable for them as they are for nuclides in the valley of beta stability. Measurements of the neutron strength function are sometimes possible with the present TOF system for neutron decays with competing neutron branches to levels in the grandchild nucleus. A value for the d-wave strength function of Sr-96 is found to be (4.2 +- 1.1)/10 4 . Improvements in the TOF system, allowing the measurement of the neutron strength function for the more general case, are discussed. 72 refs., 56 figs., 16 tabs

Removing the interview for medical school selection is associated with gender bias among enrolled students.

Science.gov (United States)

Wilkinson, David; Casey, Mavourneen G; Eley, Diann S

2014-02-03

To report, and determine reasons for, a change in the gender ratio observed among enrolled medical students after removal of the interview from the selection process. Cross-sectional study of 4051 students admitted to the medical program at the University of Queensland between 2004 and 2012. Students are enrolled either directly as graduates or via a school-leaver pathway. Change in proportions of male and female students over time, and gender-specific scores in the three sections of the GAMSAT (Graduate Medical School Admissions Test). Between 2004 and 2008 (when an interview was part of the selection process), 891 enrolled students (51.4%) were male, whereas between 2009 and 2012 (no interview), 1134 (57.7%; P interview was removed to 64.0% (514 students; P interview (reaching 73.8% in 2012). Between 2004 and 2012, male students consistently performed better than female students on GAMSAT section III (mean score, 71.5 v 68.5; P interview from the selection process. This change is limited to domestic direct graduate-entry students, and seems to be due to higher scores by male students in section III of the GAMSAT. The interview may play an important role in ensuring gender equity in selection, and medical schools should carefully monitor the consequences of changes to selection policy.

Investigation on natural radioactive nuclide contents of rock products in Xi'an construction materials market

International Nuclear Information System (INIS)

Zhou Chunlin; Han Feng; Shang Aiguo; Li Tiantuo; Guo Huiping; Yie Lichao; Li Guifang

2001-01-01

The author reports the investigation results on natural radioactive nuclide contents of rock products from Xi'an construction materials market. The products were classified according to the national standard. The results show that natural radioactive nuclide contents in sampled rock products are in normal radioactive background levels. The radio-activity ranges of 238 U, 226 Ra, 232 Th and 40 K are 2.7 - 181.8, 0.92 - 271.0, 0.63 - 148.0, 1.8 - 1245 Bq·kg -1 , respectively. According to the national standard (JC 518-93), the application of some rock products must be limited

Fukushima-derived fission nuclides monitored around Taiwan: Free tropospheric versus boundary layer transport

Science.gov (United States)

Huh, Chih-An; Hsu, Shih-Chieh; Lin, Chuan-Yao

2012-02-01

The 2011 Fukushima nuclear accident in Japan was the worst nuclear disaster following the 1986 Chernobyl accident. Fission products (nuclides) released from the Fukushima plant site since March 12, 2011 had been detected around the northern hemisphere in about two weeks and also in the southern hemisphere about one month later. We report here detailed time series of radioiodine and radiocesium isotopes monitored in a regional network around Taiwan, including one high-mountain and three ground-level sites. Our results show several pulses of emission from a sequence of accidents in the Fukushima facility, with the more volatile 131I released preferentially over 134Cs and 137Cs at the beginning. In the middle of the time series, there was a pronounced peak of radiocesium observed in northern Taiwan, with activity concentrations of 134Cs and 137Cs far exceeding that of 131I during that episode. From the first arrival time of these fission nuclides and their spatial and temporal variations at our sampling sites and elsewhere, we suggest that Fukushima-derived radioactive nuclides were transported to Taiwan and its vicinity via two pathways at different altitudes. One was transported in the free troposphere by the prevailing westerly winds around the globe; the other was transported in the planetary boundary layer by the northeast monsoon wind directly toward Taiwan.

Modelling indoor exposure to natural radioactive nuclides

International Nuclear Information System (INIS)

Hofmann, W.; Daschil, F.

1986-01-01

Radon enters buildings from several sources primarily from building materials and from the soil or rocks that underlie or surround building fundaments. A multicompartment model was developed which describes the fate of radon and attached or free radon decay products in a model room by a set of linear time-dependent differential equations. Time-dependent coefficients allow to model temporal parameter changes, e.g. the opening of windows, or a sudden pressure drop leading to enhanced exhalation. While steady-state models were used to study the effect of parameter changes on steady state nuclide concentrations, the time-dependent models provided additional information on the time scale of these changes. (author)

Selective cesium removal from radioactive liquid waste by crown ether immobilized new class conjugate adsorbent.

Science.gov (United States)

Awual, Md Rabiul; Yaita, Tsuyoshi; Taguchi, Tomitsugu; Shiwaku, Hideaki; Suzuki, Shinichi; Okamoto, Yoshihiro

2014-08-15

Conjugate materials can provide chemical functionality, enabling an assembly of the ligand complexation ability to metal ions that are important for applications, such as separation and removal devices. In this study, we developed ligand immobilized conjugate adsorbent for selective cesium (Cs) removal from wastewater. The adsorbent was synthesized by direct immobilization of dibenzo-24-crown-8 ether onto inorganic mesoporous silica. The effective parameters such as solution pH, contact time, initial Cs concentration and ionic strength of Na and K ion concentrations were evaluated and optimized systematically. This adsorbent was exhibited the high surface area-to-volume ratios and uniformly shaped pores in case cavities, and its active sites kept open functionality to taking up Cs. The obtained results revealed that adsorbent had higher selectivity toward Cs even in the presence of a high concentration of Na and K and this is probably due to the Cs-π interaction of the benzene ring. The proposed adsorbent was successfully applied for radioactive Cs removal to be used as the potential candidate in Fukushima nuclear wastewater treatment. The adsorbed Cs was eluted with suitable eluent and simultaneously regenerated into the initial form for the next removal operation after rinsing with water. The adsorbent retained functionality despite several cycles during sorption-elution-regeneration operations. Copyright © 2014 Elsevier B.V. All rights reserved.

Nanofluids confined in chemical hydrogels for the selective removal of graffiti from street art

DEFF Research Database (Denmark)

Baglioni, Michele; Alterni, Margherita; Giorgi, Rodorico

2017-01-01

The main challenge in the conservation of street art is the selective removal of graffiti (i.e. tags, writings and overpaintings) from the original artwork. Nowadays, the effective methods available for this intervention involve risking damage to the original. The novel combination of nanofluids ...

Production of residual nuclides by proton-induced reactions on target W at the energy of 72 MeV

Energy Technology Data Exchange (ETDEWEB)

Miah, Moazzem Hossain [Univ. of Chittagong, Dept. of Physics, Chittagong (Bangladesh); Kuhnhenn, Jochen; Herpers, Ulrich [Univ. of Cologne, Dept. of Nuclear Chemistry, Cologne (Germany); Michel, Rolf [University of Hannover, Centre for Radiation Protection and Radioecology (Germany); Kubik, Peter [Paul Scherrer Inst., c/o Institute for Particle Physics, ETH Hoenggerberg, Zuerich (Switzerland)

2002-08-01

Investigations of cross-sections for residual nuclide production on the target element W by proton-induced reactions were performed by irradiating the target with 72 MeV protons using the cyclotron facilities at Paul-Scherrer Institute, Zurich, Switzerland. Residual nuclides were measured by gamma-spectrometry of HpGe detectors calibrated with standard gamma sources. The measured data contains 104 individual cross-sections for 20 identified nuclides in the proton energies between 52.5 - 68.9 MeV. These nuclear data is important in the study of spallation neutron source and in accelerator driven technologies such as waste transmutation and energy amplification. The present data are compared with the shape of the excitation functions of earlier only one measurement at higher energies and they are in good agreement to each other. (author)

An Ilustrative Nuclide Release Behavior from an HLW Repository due to an Earthquake Event

International Nuclear Information System (INIS)

Lee, Youn-Myoung; Hwang, Yong-Soo; Choi, Jong-Won

2008-01-01

Program for the evaluation of a high-level waste repository which is conceptually modeled. During the last few years, programs developed with the aid of AMBER and GoldSim by which nuclide transports in the near- and far-field of a repository as well as transport through the biosphere under various normal and disruptive release scenarios could be modeled and evaluated, have been continuously demonstrated. To show its usability, as similarly done for the natural groundwater flow scheme, influence of a possible disruptive event on a nuclide release behavior from an HLW repository system caused naturally due to an earthquake has been investigated and illustrated with the newly developed GoldSim program

Selective removal of cesium from aqueous solutions with nickel (II) hexacyanoferrate (III) functionalized agricultural residue–walnut shell

Energy Technology Data Exchange (ETDEWEB)

Ding, Dahu, E-mail: dingdahu@gmail.com [Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 (Japan); Lei, Zhongfang; Yang, Yingnan [Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 (Japan); Feng, Chuanping [School of Water Resources and Environment, China University of Geosciences (Beijing), Key Laboratory of Groundwater Circulation and Evolution, Ministry of Education, Beijing 100083 (China); Zhang, Zhenya, E-mail: zhang.zhenya.fu@u.tsukuba.ac.jp [Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 (Japan)

2014-04-01

Highlights: • Novel biosorbent for cesium removal was derived from agricultural residue. • It could remove cesium effectively from aqueous solution. • Large size of granules makes it easy to be separated from solutions. • The volume of used biosorbent could be significantly reduced after incineration. • Incinerated biosorbent has a low volume and a low cost final disposal. - Abstract: A novel nickel (II) hexacyanoferrate (III) functionalized agricultural residue-walnut shell (Ni{sup II}HCF{sup III}-WS) was developed to selectively remove cesium ion (Cs{sup +}) from aqueous solutions. This paper showed the first integral study on Cs{sup +} removal behavior and waste reduction analysis by using biomass adsorption material. The results indicated that the removal process was rapid and reached saturation within 2 h. As a special characteristic of Ni{sup II}HCF{sup III}-WS, acidic condition was preferred for Cs{sup +} removal, which was useful for extending the application scope of the prepared biomass material in treating acidic radioactive liquid waste. The newly developed Ni{sup II}HCF{sup III}-WS could selectively remove Cs{sup +} though the coexisting ions (Na{sup +} and K{sup +} in this study) exhibited negative effects. In addition, approximately 99.8% (in volume) of the liquid waste was reduced by using Ni{sup II}HCF{sup III}-WS and furthermore 91.9% (in volume) of the spent biomass material (Cs-Ni{sup II}HCF{sup III}-WS) was reduced after incineration (at 500 °C for 2 h). Due to its relatively high distribution coefficient and significant volume reduction, Ni{sup II}HCF{sup III}-WS is expected to be a promising material for Cs{sup +} removal in practice.

Transuranium nuclides in the environment

International Nuclear Information System (INIS)

Sakanoue, Masanobu

1987-01-01

Many countries are presently concerned with problems relating to the safe disposal of nuclear waste containing various levels of transuranium nuclides. In this context, a review on the distribution and behaviour of transuranium elements in the environment studied at Kanazawa University in Japan is presented. About 17 years ago, a high degree of accumulation of 239 Pu in the surface soil of Nagasaki was found in the Nishiyama area, where 'black rain' occured just after the nuclear bomb explosion. The introduction of newly developed radiochemical methods and instrumentation has enabled studies to be carried out on environmental plutonium isotopes, americium-241 and more recently neptunium-237 with respect to distribution depth profile, variation with time and relationship with organic materials. Valuable information has been obtained on the basis of samples collected from various locations in Japan, including surface soil, sea and lake sediments, atmospheric aerosol, water from the Japan Sea and the Pacific Ocean, and from material related with the 'Bikini Event' of 1954. (orig.)

Geographical distribution of radioactive nuclides released from the Fukushima Daiichi Nuclear Power Station accident in eastern Japan

International Nuclear Information System (INIS)

Ishida, Masanobu; Umetsu, Kohei; Sugimoto, Miyabi; Yamaguchi, Yuta; Yamazaki, Hideo; Nakagawa, Ryota

2013-01-01

The geographical distribution of radioactive nuclides released from the Fukushima Daiichi Nuclear Power Station accident in metropolitan areas located in eastern Japan was investigated. The radioactive contamination of environmental samples, including soil and biological materials, was analyzed. The concentrations of 131 I, 134 Cs, and 137 Cs in the soil samples collected from Fukushima City were 122000, 11500 and 14000 Bq/kg on 19th March 2011 and 129000, 11000 and 13700 Bq/kg on 26th March 2011, for the three nuclides respectively. The concentrations of 131 I, 134 Cs and 137 Cs in the soil samples collected from March-June 2011 from study sites ranged from 240 to 101000, 28 to 26200, and 14 to 33700 Bq/kg, respectively. In Higashiosaka City, it began to detect those radioactive nuclides in the atmospheric airborne dust from 25th March. Radioactive fission products 95 Zr- 95 Nb were detected on 18th April 2011. Biological samples collected from Tokyo Bay were studied. The maximum concentrations of 134 Cs and 137 Cs detected in the biological samples were 12.2 and 19.2 Bq/kg, which were measured in goby. 131 I was not detected in the biological samples however, trace amounts of the short half-life nuclide 110m Ag were found in the shellfish samples. (author)

DRENA: A model for the transport of nuclides in drainage slopes

International Nuclear Information System (INIS)

Garcia-Olivares, A.; Aguero, A.; Pinedo, P.

1994-01-01

This report presents documentation and a user's manual for program DRENA, a mathematical model of nuclides transfer in simple slopes and sections of a drainage catchment. Mathematical equations and physical principles utilized to develop the code are presented in section 2. The flowchart and some mathematic and numerical details are presented in Section 3. Section 4 presents an overview of how problems should be set up to properly use the code as well as the detailed input instructions and output results formats. One example problem, including sample input data sets and output data, are presented in Section 5. The complete program listings including comments are presented in the Appendices. Nuclides are assumed to enter the catchment via atmospheric deposition and then carried by the water runoff and the dragged sediments. The desorption/adsorption dynamics between water and sediments are considered to be in the equilibrium given by a Kd parameter, a distribution coefficient. Codell's and Einstein expressions for the caudal and concentration of dragged sediments are utilized. (Author)

DRENA: A model for the transport of nuclides in drainage slopes

International Nuclear Information System (INIS)

Garcia-Olivares, A.; Aguero, A.; Pinedo, P.

1994-01-01

This report presents documentation and a user's manual for program DRENA, a mathematical model of nuclides transfer in simple slopes and sections of a drainage catchment. Mathematical equations and physical principles utilized to develop the code are presented in section 2. The flowchart and some mathematic and numerical details are presented in Section 3. Section 4 presents an overview of how problems should be set up to properly use the code as well as the detailed input instructions and output results formats. One example problem, including sample input data sets and output data, are presented in Section 5. The complete program listings including comments are presented in the Appendices. Nuclides are assumed to enter the catchment via atmospheric deposition and then carried by the water runoff and the dragged sediments. The desorption/adsorption dynamics between water and sediments are considered to be in the equilibrium given by a Kd parameter, a distribution coefficient. Codell's and Einstein expressions for the caudal and concentration of dragged sediments are utilized. (Author) 36 refs

DRENA: A model for the transport of nuclides in drainage slopes

Energy Technology Data Exchange (ETDEWEB)

Garcia-Olivares, A.; Aguero, A.; Pinedo, P.

1994-07-01

This report presents documentation and a user's manual for program DRENA, a mathematical model of nuclides transfer in simple slopes and sections of a drainage catchment. Mathematical equations and physical principles utilized to develop the code are presented in section 2. The flowchart and some mathematic and numerical details are presented in Section 3. Section 4 presents an overview of how problems should be set up to properly use the code as well as the detailed input instructions and output results formats. One example problem, including sample input data sets and output data, are presented in Section 5. The complete program listings including comments are presented in the Appendices. Nuclides are assumed to enter the catchment via atmospheric deposition and then carried by the water runoff and the dragged sediments. The desorption/adsorption dynamics between water and sediments are considered to be in the equilibrium given by a Kd parameter, a distribution coefficient. Codell's and Einstein expressions for the caudal and concentration of dragged sediments are utilized. (Author) 36 refs.

DRENA: A model for the transport of nuclides in drainage slopes

Energy Technology Data Exchange (ETDEWEB)

Garcia-Olivares, A; Aguero, A; Pinedo, P

1994-07-01

This report presents documentation and a user's manual for program DRENA, a mathematical model of nuclides transfer in simple slopes and sections of a drainage catchment. Mathematical equations and physical principles utilized to develop the code are presented in section 2. The flowchart and some mathematic and numerical details are presented in Section 3. Section 4 presents an overview of how problems should be set up to properly use the code as well as the detailed input instructions and output results formats. One example problem, including sample input data sets and output data, are presented in Section 5. The complete program listings including comments are presented in the Appendices. Nuclides are assumed to enter the catchment via atmospheric deposition and then carried by the water runoff and the dragged sediments. The desorption/adsorption dynamics between water and sediments are considered to be in the equilibrium given by a Kd parameter, a distribution coefficient. Codell's and Einstein expressions for the caudal and concentration of dragged sediments are utilized. (Author) 36 refs.

Removal of PCR inhibitors using dielectrophoresis as a selective filter in a microsystem

DEFF Research Database (Denmark)

Perch-Nielsen, Ivan Ryberg; Bang, Dang Duong; Poulsen, Claus Riber

2003-01-01

, the removal of PCR inhibitors in sample preparation steps is essential and several methods have been published. The methods are either chemical or based on filtering. Conventional ways of filtering include mechanical filters or washing e. g. by centrifugation. Another way of filtering is the use of electric...... to manipulate cells in many microstructures. In this study, we used DEP as a selective filter for holding cells in a microsystem while the PCR inhibitors were flushed out of the system. Haemoglobin and heparin-natural components of blood-were selected as PCR inhibitors, since the inhibitory effects...

Selective removal of chromium from sulphuric acid leach liquor of ilmenite ore by solvent extraction with trioctylamine

Directory of Open Access Journals (Sweden)

E.O. Olanipekun

2000-12-01

Full Text Available The selective removal of chromium, a trace impurity that degrades the whiteness of titanium(IV oxide pigments, from sulphuric acid leach liquor of ilmenite, was investigated by solvent extraction with xylene solutions of trioctylamine. Important factors of commercial significance affecting the extraction operation have been examined. More than 99% of the chromium was selectively removed in multiple batch extractions from the leach liquor and titanium losses were minimal (< 1%. The chromium content of extracted solutions was reduced to less than 1 ppm and thermal hydrolysis of these solutions yielded white titanium(IV oxide pigments that are suitable for use in the coatings pigment industry.

Enhanced selective removal of Cu(II) from aqueous solution by novel polyethylenimine-functionalized ion imprinted hydrogel: Behaviors and mechanisms

Energy Technology Data Exchange (ETDEWEB)

Wang, Jingjing [State Key Laboratory of Pollutant Control and Resource Reuse, Nanjing 210023 (China); School of the Environment, Nanjing University, Nanjing 210023 (China); Li, Zhengkui, E-mail: zhkuili@nju.edu.cn [State Key Laboratory of Pollutant Control and Resource Reuse, Nanjing 210023 (China); School of the Environment, Nanjing University, Nanjing 210023 (China)

2015-12-30

Highlights: • A novel ion-imprinted poly(polyethylenimine/hydroxyethyl acrylate) hydrogel was synthesized. • The prepared hydrogel enhanced the selectivity of Cu(II) removal. • The material had high adsorption capacity and excellent regeneration property for copper. • The adsorption mechanism was the chelate interaction between functional groups and Cu(II) ions. - Abstract: A novel polyethylenimine-functionalized ion-imprinted hydrogel (Cu(II)-p(PEI/HEA)) was newly synthesized by {sup 60}Co-γ-induced polymerization for the selective removal of Cu(II) from aqueous solution. The adsorption performances including the adsorption capacity and selectivity of the novel hydrogel were much better than those of similar adsorbents reported. The hydrogel was characterized via scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectra, thermal gravimetric analysis and X-ray photoelectron spectroscopy to determine the structure and mechanisms. The adsorption process was pH and temperature sensitive, better fitted to pseudo-second-order equation, and was Langmuir monolayer adsorption. The maximum adsorption capacity for Cu(II) was 40.00 mg/g. The selectivity coefficients of ion-imprinted hydrogel for Cu(II)/Pb(II), Cu(II)/Cd(II) and Cu(II)/Ni(II) were 55.09, 107.47 and 63.12, respectively, which were 3.93, 4.25 and 3.53 times greater than those of non-imprinted hydrogel, respectively. Moreover, the adsorption capacity of Cu(II)-p(PEI/HEA) could still keep more than 85% after four adsorption–desorption cycles. Because of such enhanced selective removal performance and excellent regeneration property, Cu(II)-p(PEI/HEA) is a promising adsorbent for the selective removal of copper ions from wastewater.

Alpha-emitting nuclides in commercial fish species caught in the vicinity of Windscale, United Kingdom, and their radiological significance to man

International Nuclear Information System (INIS)

Pentreath, R.J.; Lovett, M.B.; Harvey, B.R.; Ibbett, R.D.

1979-01-01

The concentrations of a number of alpha-emitting nuclides have been determined in the tissues of several commercial fish species caught in the vicinity of the fuel reprocessing plant at Windscale. All tissues analysed were found to contain 238 Pu, sup(239+240)Pu and 241 Am, but 242 Cm and 244 Cm could only be reliably detected in the liver samples of some fish. Fish of the same species, but taken from the North Sea, have also been analysed for some naturally occurring alpha-emitting nuclides. Whereas uranium ( 238 U) and thorium ( 232 Th) could be detected in bone samples of fish, neither could be reliably detected in samples of muscle: in contrast, 210 Po was readily detected in samples of liver, muscle and bone. Commercial fish fillets from the Irish Sea, including the Windscale area, are also routinely monitored for alpha-emitting nuclides, and their radiological significance to man is briefly discussed. Comments are also made on the significance of the naturally occurring nuclides. (author)

Zirconium-modified materials for selective adsorption and removal of aqueous arsenic

Science.gov (United States)

Zhao, Hongting; Moore, Robert C.

2004-11-30

A method, composition, and apparatus for removing contaminant species from an aqueous medium comprising: providing a material to which zirconium has been added, the material selected from one or more of zeolites, cation-exchangeable clay minerals, fly ash, mesostructured materials, activated carbons, cellulose acetate, and like porous and/or fibrous materials; and contacting the aqueous medium with the material to which zirconium has been added. The invention operates on all arsenic species in the form of arsenate, arsenite and organometallic arsenic, with no pretreatment necessary (e.g., oxidative conversion of arsenite to arsenate).

High Accuracy mass Measurement of the very Short-Lived Halo Nuclide $^{11}$Li

CERN Multimedia

Le scornet, G

2002-01-01

The archetypal halo nuclide $^{11}$Li has now attracted a wealth of experimental and theoretical attention. The most outstanding property of this nuclide, its extended radius that makes it as big as $^{48}$Ca, is highly dependent on the binding energy of the two neutrons forming the halo. New generation experiments using radioactive beams with elastic proton scattering, knock-out and transfer reactions, together with $\\textit{ab initio}$ calculations require the tightening of the constraint on the binding energy. Good metrology also requires confirmation of the sole existing precision result to guard against a possible systematic deviation (or mistake). We propose a high accuracy mass determintation of $^{11}$Li, a particularly challenging task due to its very short half-life of 8.6 ms, but one perfectly suiting the MISTRAL spectrometer, now commissioned at ISOLDE. We request 15 shifts of beam time.

Estimating cumulative soil accumulation rates with in situ-produced cosmogenic nuclide depth profiles

International Nuclear Information System (INIS)

Phillips, William M.

2000-01-01

A numerical model relating spatially averaged rates of cumulative soil accumulation and hillslope erosion to cosmogenic nuclide distribution in depth profiles is presented. Model predictions are compared with cosmogenic 21 Ne and AMS radiocarbon data from soils of the Pajarito Plateau, New Mexico. Rates of soil accumulation and hillslope erosion estimated by cosmogenic 21 Ne are significantly lower than rates indicated by radiocarbon and regional soil-geomorphic studies. The low apparent cosmogenic erosion rates are artifacts of high nuclide inheritance in cumulative soil parent material produced from erosion of old soils on hillslopes. In addition, 21 Ne profiles produced under conditions of rapid accumulation (>0.1 cm/a) are difficult to distinguish from bioturbated soil profiles. Modeling indicates that while 10 Be profiles will share this problem, both bioturbation and anomalous inheritance can be identified with measurement of in situ-produced 14 C

Selection of controlled variables in bioprocesses. Application to a SHARON-Anammox process for autotrophic nitrogen removal

DEFF Research Database (Denmark)

Mauricio Iglesias, Miguel; Valverde Perez, Borja; Sin, Gürkan

Selecting the right controlled variables in a bioprocess is challenging since the objectives of the process (yields, product or substrate concentration) are difficult to relate with a given actuator. We apply here process control tools that can be used to assist in the selection of controlled var...... variables to the case of the SHARON-Anammox process for autotrophic nitrogen removal....

Development of a method to determine the nuclide inventory in bituminized waste packages; Entwicklung eines Verfahrens zur Bestimmung des Nuklidinventars in bituminierten Abfallgebinden

Energy Technology Data Exchange (ETDEWEB)

Mesalic, E.; Kortman, F.; Lierse von Gostomski, C. [Technische Univ. Muenchen, Garching (Germany). Zentrale Technisch-Wissenschaftliche Betriebseinheit Radiochemie Muenchen (RCM)

2014-01-15

Until the 1980s, bitumen was used as a conditioning agent for weak to medium radioactive liquid waste. Its use can be ascribed mainly to the properties that indicated that the matrix was optimal. However, fires broke out repeatedly during the conditioning process, so that the method is meanwhile no longer permitted in Germany. There are an estimated 100 waste packages held by the public authorities in Germany that require a supplementary declaration. In contrast to the common matrices, such as for example resins or sludges, there is still no standardized technology for taking samples and subsequently determining the radio-nuclide for bitumen. Aspects, such as the thermoplastic behaviour, make determining the nuclide inventory more difficult in bituminized waste packages. The development of a standardized technology to take samples with a subsequent determination of the radio-nuclide analysis is the objective of a project funded by the BMBF. Known, new methods, specially developed for the project, are examined on inactive bitumen samples and then transferred to active samples. At first non-destructive methods are used. The resulting information forms an important basis to work out and apply destructive strategy for sampling and analysis. Since the project is on-going, this report can only address the development of the sampling process. By developing a sampling system, it will be possible to take samples from an arbitrary selected location of the package across the entire matrix level and thus gain representative analysis material. The process is currently being optimized. (orig.)

Interlaboratory comparison of environmental relevant nuclides with spinach powder as sample medium; Vergleichspruefung mit Spinatpulver als Probenart fuer umweltrelevante Nuklide

Energy Technology Data Exchange (ETDEWEB)

Roos, N.; Tait, D. [Max Rubner-Institut, Kiel (Germany). Leitstelle fuer Boden, Bewuchs, Futtermittel und Nahrungsmittel pflanzlicher und tierischer Herkunft

2014-01-20

Spinach is cited as a representative medium for leafy vegetables in the Integrated Measurement and Information System for the surveillance of environmental radioactivity (IMIS) in Germany. Fresh spinach, however, is not suitable in interlaboratory comparisons on the determination of spiked radionuclides because of the difficulties in homogeneously distributing the radionuclides and attaining a known specific activity in the samples. In contrast, spinach powder is finely milled, so that homogeneous distribution and known specific activities of the nuclides are more readily achievable. For this interlaboratory comparison spinach powder was mixed with the pure beta emitter Sr-90 and the gamma-emitting nuclides I-131, Cs-134 and Cs-137. After homogenization samples were dispatched to 77 laboratories from Germany and other European countries (59 in Germany, 5 in Switzerland, 4 each in the UK and Austria, and one each in France, Italy, the Netherlands, Ireland and Luxembourg). In addition to the added nuclides participants had to determine the natural radionuclide K-40. The participants were instructed to use a fast method for the determination of dry matter (DM). To check the homogeneity of the nuclide distribution 14 samples of the labeled spinach powder were randomly selected and analyzed in the Coordinating Laboratory for the Surveillance of Radioactivity in the Environment of the Max Rubner-Institute (MRI). According to DIN 13528:2005 the samples showed sufficient homogeneity of the added nuclides. For the evaluation of the interlaboratory comparison the Physikalisch-Technische Bundesanstalt (PTB) determined reference values for the the specific activities (Bq per kg DM) of the gamma emitters. The values with the expanded uncertainties (k = 2) were as follows: I-131: 181 ± 6 Bq/kg; Cs-134: 34.4 ± 1.1 Bq/kg; Cs-137: 11.1 ± 0.4 Bq/kg; K-40: 1240 ± 40 Bq/kg. Since a reference value of the PTB for the specific activity of Sr-90 was not available the general average

Biological effect on removal of Th-234, Po-210 and Pb-210 from surface water in Funka Bay, Japan

Energy Technology Data Exchange (ETDEWEB)

Tanaka, N; Takeda, Y; Tsunogai, S [Hokkaido Univ., Hakodate (Japan). Dept. of Chemistry

1983-10-01

Vertical and temporal variations in the radioactivities of Th-234, Pb-210 and Po-210 were measured at a station in Funka Bay from April 1979 to February 1980. The inventory of Th-234 showed a minimum in early spring, when a spring bloom of phytoplankton was observed, then a steady increase to a maximum value in late summer, just before open sea water invaded the bay and a secondary phytoplankton bloom started. The inventories of Pb-210 and Po-210 also showed minima in early spring. These results suggest that the removal of these nuclides from sea water is accelerated by biological activity. The concentration of Th-234 decreased with depth, but those of Po-210 and Pb-210 were higher in the bottom water in August 1979 when the bay water was strongly stratified. This may be due to the supply of Pb-210 and Po-210 from the bottom. However, if the supply of these nuclides is expected in sediment particles, the concentrations of these nuclides in suspended matter were not sufficient to explain their increments in the bottom water. Residence times of Th, Pb and Po were estimated.

Use of Chelex-100 for selectively removing Y-90 from its parent Sr-90

International Nuclear Information System (INIS)

Huntley, M.W.

1996-01-01

A method for selectively removing yttrium-90 from its parent strontium-90 contained in an environmental sample includes loading the sample onto a column containing a chelating ion-exchange resin capable of retaining yttrium-90; washing the column with a solution capable of removing strontium, calcium, and other contaminants from the yttrium-90 fraction retained on the column; removing excess acetate salts from the column; eluting yttrium-90 solution from the column and adjusting the pH of this solution to about 2.7; filtering the yttrium-90 solution and weighing this solution for gravimetric yield; and, counting the yttrium-90 containing solution with a radiological counter for a time sufficient to achieve the statistical accuracy desired. It is preferred that the chelating ion-exchange resin is a ligand having the chemical name iminodiacetic acid mounted on a divinyl benzene substrate, converted from sodium form to ammonia form

A multi-nuclide approach to quantify long-term erosion rates and exposure history through multiple glacial-interglacial cycles

DEFF Research Database (Denmark)

Strunk, Astrid; Larsen, Nicolaj Krog; Knudsen, Mads Faurschou

Cosmogenic nuclides are traditionally used to either determine the glaciation history or the denudation history of the most recent exposure period. A few studies use the cosmogenic nuclides to determine the cumulative exposure and burial durations of a sample. However, until now it has not been...... possible to resolve the complex pattern of exposure history under a fluctuating ice sheet. In this study, we quantify long-term erosion rates along with durations of multiple exposure periods in West Greenland by applying a novel Markov Chain Monte Carlo (MCMC) inversion approach to existing 10Be and 26Al....... The new MCMC approach allows us to constrain the most likely landscape history based on comparisons between simulated and measured cosmogenic nuclide concentrations. It is a fundamental assumption of the model that the exposure history at the site/location can be divided into two distinct regimes: i...

DOSEmanPRO - active electronic online personal air sampler for detection of radon progeny long lived alpha nuclides

International Nuclear Information System (INIS)

Streil, T.; Oeser, V.

2002-01-01

Full text: Using the micro system - technology we developed a online personal air sampler not bigger than a mobile phone, to open a new dimension in personal dosimetry of inhaled radioactive aerosols. The DOSEman PRO containing an internal pump with a continuous air flow of 0.15 I/min sample the radon progeny or other nuclides on a millipore filter with excellent spectroscopic resolution. A 1.5 cm 2 light protected ion-implanted silicon detector analyses the alpha radiation at the filter. This small detector head contains also the pre amplification and pulse processing. The alpha radiation of the radon progeny and the long lived alpha nuclides is analyzed by a 60 channel spectrometer. The energy resolution of the online analyzed filter spectra is in the order of 150 keV. Mechanical and electronic design enables one to distinguish the long lived alpha nuclides from the radon and thoron progeny very easily. Using a special algorithm we correct the influence of the tailing of the radon progeny to the long lived alpha nuclides and take into consideration possible interference in determining the long lived alpha nuclides. Because of the air sampling volume of nearly 10 I/h, the system has a high efficiency. The detection limit by 2 hours sampling time is 0.05 Bq/m 3 alpha nuclide concentration. In a modified device for air sampling especially of long-lived alpha nuclides like uranium, radium or plutonium, the flow rate is increased to 0,3 1/min e.g. during a 10 h sampling period we can detect 0.005 Bq/m 3 in a low radon atmosphere. Assuming increased radon progeny concentration, the statistical error for the long lived alpha nuclides will be higher, but in most of the cases for use in nuclear facilities low radon concentrations are ambient conditions. This concept of an electronic personal air sampler with an alpha spectroscopy offers some outstanding advantages compared to passive dosimeters or off-line alpha air filters: The dose value and the nuclide concentration is

Applications of in situ cosmogenic nuclides in the geologic site characterization of Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Gosse, J.C.; Harrington, C.D.

1995-01-01

The gradual buildup of rare isotopes from interactions between cosmic rays and atoms in an exposed rock provides a new method of directly determining the exposure age of rock surfaces. The cosmogenic nuclide method can also provide constraints on erosion rates and the length of time surface exposure was interrupted by burial. Numerous successful applications of the technique have been imperative to the complete surface geologic characterization of Yucca Mountain, Nevada, a potential high level nuclear waste repository. In this short paper, we summarize the cosmogenic nuclide method and describe with examples some the utility of the technique in geologic site characterization. We report preliminary results from our ongoing work at Yucca Mountain

Use of the bleeding sap for investigation of radionuclide transfer to crops through root and translocation of the nuclide in the crops

International Nuclear Information System (INIS)

Uchida, Shigeo; Sumiya, Misako; Yanagisawa, Kei; Ohmomo, Yoichiro.

1991-01-01

Adsorption and translocation characteristics of radionuclides in the root of tomato plant were investigated. Mature tomato plant was transplanted to culture solution containing 85 Sr, 137 Cs, 131 I, 54 Mn, 60 Co and 65 Zn. Immediately after transplantation, the tomato plant was cut at 10 cm above the surface of the culture solution in order to collect bleeding sap solution (Experiment-1). Another mature tomato plant was cultured for 3 days in culture solution containing radionuclides as mentioned above and then transplanted to fresh culture solution. Bleeding sap solution was also collected in the same way as shown in Experiment-1 (Experiment-2). Activity ratios of bleeding sap to culture solution were measured for several hours. Adsorption and removement of those radionuclides in tomato plant were summarized as follows; 137 Cs was taken up by the root almost at the same speed as that of water and accumulated in the lowest among the six nuclides used in the experiments. The concentrations of 85 Sr, 54 Mn and 65 Zn in the bleeding sap of 3 days' uptake experiment were higher than the initial concentrations of the culture solution for several hours even after the tomato plant was transplanted to fresh culture solution. 131 I and 60 Co were accumulated much in the root and found extremely low in the bleeding sap during the experiment, suggesting that the nuclide were absorbed on the surface of the roots and scarcely moved. (author)

A method of alpha-radiating nuclide activity measuring in aerosol filters

International Nuclear Information System (INIS)

Ignatov, V.P.; Galkina, V.N.

1992-01-01

Scintillation method of determination of alpha-radiating nuclide activity in aerosol filters was suggested. The method involves dissolution of the filter in organic solvent, introduction of luminophore into solution prepared, drying of the preparation and measurement of radionuclide activity. Dependences of alpha-radiation detection efficiency on the content of luminophore, filter material, colourless and coloured substances in preparations analyzed were considered

Sampling art for ground-water monitoring wells in nuclide migration

International Nuclear Information System (INIS)

Liu Wenyuan; Tu Guorong; Dang Haijun; Wang Xuhui; Ke Changfeng

2010-01-01

Ground-Water sampling is one of the key parts in field nuclide migration. The objective of ground-water sampling program is to obtain samples that are representative of formation-quality water. In this paper, the ground-water sampling standards and the developments of sampling devices are reviewed. We also designed the sampling study projects which include the sampling methods, sampling parameters and the elementary devise of two types of ground-Water sampling devices. (authors)

Selective binding behavior of humic acid removal by aluminum coagulation.

Science.gov (United States)

Jin, Pengkang; Song, Jina; Yang, Lei; Jin, Xin; Wang, Xiaochang C

2018-02-01

The reactivity characteristics of humic acid (HA) with aluminium coagulants at different pH values was investigated. It revealed that the linear complexation reaction occurred between aluminum and humic acid at pH aluminum existed in the form of free aluminum and remained unreacted in the presence of HA until the concentration reached to trigger Al(OH) 3(s) formation. Differentiating the change of functional groups of HA by 1 H nuclear magnetic resonance spectroscopy and X-ray photoelectron spectra analysis, it elucidated that there was a selective complexation between HA and Al with lower Al dosage at pH 5, which was probably due to coordination of the activated functional groups onto aluminium. While almost all components were removed proportionally by sweep adsorption without selectivity at pH 7, as well as that with higher Al dosage at pH 5. This study provided a promising pathway to analyse the mechanism of the interaction between HA and metal coagulants in future. Copyright © 2017 Elsevier Ltd. All rights reserved.

Iodine removing means

International Nuclear Information System (INIS)

Takeshima, Masaki.

1975-01-01

Object: To employ exhaust gas from an incinerator to effect regeneration of an adsorbent such as active carbon which has adsorbed a radioactive gas such as iodine contained in the ventilating system exhaust gas of a boiling water reactor power plant. Structure: Radioactive exhaust gas such as iodine, xenon and krypton is led to an active carbon adsorbing means for removal through adsorption. When the adsorbing function of the active carbon adsorption means is reduced, the exhaust gas discharged from the incinerator is cooled down to 300 0 C and then caused to flow into the active carbon layer, and after depriving it of sulfur dioxide gas, oxides of nitrogen, daughter nuclides resulting from attenuation of radioactive gas and so forth, these being adsorbed by the carbon active layer, it is led again to the incinerator, whereby the radioactivity accompanying the regenerated gas is sealed as ash within the incinerator. Further, similarly accompanying fine active carbon particles and the like are utilized as a heat source for the incinerator. (Kamimura, M.)

Investigation on the movements and the distributions of radon, thoron and their decay nuclides on the life circumstances

International Nuclear Information System (INIS)

Morishima, Hiroshige; Koga, Taeko

2001-03-01

UNSCEAR (2000) reported that the effective doses due to the inhalation of radon and its decay nuclides account on average of the all world for about one-half of all natural sources of radiation. These have great influences on various forms as the sources of terrecial environmental γ radiation and of radon on our life circumstances. Radon and thoron, which are natural gaseous radioactive nuclides released out of rocks and soil etc. are chemical inert and electrically uncharged, but they in the air can spontaneously decay to other metal atoms. And they made a wide fluctuation seasonally and spatially on the environment, but these are not uniformly. We have selected and observed on Misasa spa district, Tottori pref., Kawanishi-shi, Hyogo pref. and Masutomi spa, Yamanashi pref., for HBRA, and Higashi-osaka-shi, Osaka pref., for CA. We have carried out the study on the environmental movement and distribution of natural radioactive nuclides containing radon, thoron and their decay nuclides, and reported these results on following; (1) Radon measurements have been carried using a small pico-rad detector and many sampling points and Pilon scintillation-cell with 300 ml volume by grub sampling. Mean radon concentrations of get briefly for 24 hours are measured to be available on draw of the concentration distribution map. (2) We continued time cource variation of mean radon concentrations on same private house of Misasa spa district. Mean radon concentrations in air for 6 years were fluctuated 6.7-50 Bq/m 3 and 23-170 Bq/m 3 indoor. The mean concentrations on summer and rain season is low level at open-door situation and that on winter is high, as same as these on Kawanishi Hyogo pref.. It was shown that radon outdoor concentrations variation in time course almost have a similar tendency with indoor and the life situation of air ventilation and conditioning are more influenced than variation on area condition. (3) Radon concentrations on Masutomi spa districts, Yamanashi

Enhanced selective removal of Cu(II) from aqueous solution by novel polyethylenimine-functionalized ion imprinted hydrogel: Behaviors and mechanisms.

Science.gov (United States)

Wang, Jingjing; Li, Zhengkui

2015-12-30

A novel polyethylenimine-functionalized ion-imprinted hydrogel (Cu(II)-p(PEI/HEA)) was newly synthesized by (60)Co-γ-induced polymerization for the selective removal of Cu(II) from aqueous solution. The adsorption performances including the adsorption capacity and selectivity of the novel hydrogel were much better than those of similar adsorbents reported. The hydrogel was characterized via scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectra, thermal gravimetric analysis and X-ray photoelectron spectroscopy to determine the structure and mechanisms. The adsorption process was pH and temperature sensitive, better fitted to pseudo-second-order equation, and was Langmuir monolayer adsorption. The maximum adsorption capacity for Cu(II) was 40.00 mg/g. The selectivity coefficients of ion-imprinted hydrogel for Cu(II)/Pb(II), Cu(II)/Cd(II) and Cu(II)/Ni(II) were 55.09, 107.47 and 63.12, respectively, which were 3.93, 4.25 and 3.53 times greater than those of non-imprinted hydrogel, respectively. Moreover, the adsorption capacity of Cu(II)-p(PEI/HEA) could still keep more than 85% after four adsorption-desorption cycles. Because of such enhanced selective removal performance and excellent regeneration property, Cu(II)-p(PEI/HEA) is a promising adsorbent for the selective removal of copper ions from wastewater. Copyright © 2015 Elsevier B.V. All rights reserved.

How patient-selected colors for removable appliances are reflected in electronically tracked compliance (wear times and wear behavior).

Science.gov (United States)

Schott, Timm C; Menne, Dieter

2018-03-27

A broad spectrum of colors for removable appliances, intended to optimize acceptance of treatment and patient cooperation, have been available on the dental market for years. This is the first study to analyze how patient-selected colors are reflected in wear times and wear behavior of removable appliances. The study included 117 children (55 girls and 62 boys) who were treated with active removable plate or functional appliances. All patients were offered to choose from 11 different colors, which were pooled into six groups (black, blue, green, yellow, pink, red) for analysis, or to combine any two to four colors ("multicolored" group) for their appliances. All appliances featured a built-in microsensor (TheraMon; MC Technology, Hargelsberg, Austria) for objective wear-time tracking. Differences between wear times were analyzed using pairwise t tests and Tukey correction. The longest median wear times were recorded in the blue and green groups (≈11 h/d) and the shortest ones in the red and pink groups (≈9 h/d), but they were not significantly influenced by the patient-selected colors. The median wear times involved an age-related decrease by 0.56 h/y that was statistically significant ( P = .00005). No gender-specific patterns of wear behavior were observed. Patient-selected colors for removable appliances can presumably improve acceptance of treatment, but they are not associated with statistically significant improvements in wear time or wear behavior.

Sequential multi-nuclide emission rate estimation method based on gamma dose rate measurement for nuclear emergency management

International Nuclear Information System (INIS)

Zhang, Xiaole; Raskob, Wolfgang; Landman, Claudia; Trybushnyi, Dmytro; Li, Yu

2017-01-01

Highlights: • Sequentially reconstruct multi-nuclide emission using gamma dose rate measurements. • Incorporate a priori ratio of nuclides into the background error covariance matrix. • Sequentially augment and update the estimation and the background error covariance. • Suppress the generation of negative estimations for the sequential method. • Evaluate the new method with twin experiments based on the JRODOS system. - Abstract: In case of a nuclear accident, the source term is typically not known but extremely important for the assessment of the consequences to the affected population. Therefore the assessment of the potential source term is of uppermost importance for emergency response. A fully sequential method, derived from a regularized weighted least square problem, is proposed to reconstruct the emission and composition of a multiple-nuclide release using gamma dose rate measurement. The a priori nuclide ratios are incorporated into the background error covariance (BEC) matrix, which is dynamically augmented and sequentially updated. The negative estimations in the mathematical algorithm are suppressed by utilizing artificial zero-observations (with large uncertainties) to simultaneously update the state vector and BEC. The method is evaluated by twin experiments based on the JRodos system. The results indicate that the new method successfully reconstructs the emission and its uncertainties. Accurate a priori ratio accelerates the analysis process, which obtains satisfactory results with only limited number of measurements, otherwise it needs more measurements to generate reasonable estimations. The suppression of negative estimation effectively improves the performance, especially for the situation with poor a priori information, where it is more prone to the generation of negative values.

Sequential multi-nuclide emission rate estimation method based on gamma dose rate measurement for nuclear emergency management

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xiaole, E-mail: zhangxiaole10@outlook.com [Institute for Nuclear and Energy Technologies, Karlsruhe Institute of Technology, Karlsruhe, D-76021 (Germany); Institute of Public Safety Research, Department of Engineering Physics, Tsinghua University, Beijing, 100084 (China); Raskob, Wolfgang; Landman, Claudia; Trybushnyi, Dmytro; Li, Yu [Institute for Nuclear and Energy Technologies, Karlsruhe Institute of Technology, Karlsruhe, D-76021 (Germany)

2017-03-05

Highlights: • Sequentially reconstruct multi-nuclide emission using gamma dose rate measurements. • Incorporate a priori ratio of nuclides into the background error covariance matrix. • Sequentially augment and update the estimation and the background error covariance. • Suppress the generation of negative estimations for the sequential method. • Evaluate the new method with twin experiments based on the JRODOS system. - Abstract: In case of a nuclear accident, the source term is typically not known but extremely important for the assessment of the consequences to the affected population. Therefore the assessment of the potential source term is of uppermost importance for emergency response. A fully sequential method, derived from a regularized weighted least square problem, is proposed to reconstruct the emission and composition of a multiple-nuclide release using gamma dose rate measurement. The a priori nuclide ratios are incorporated into the background error covariance (BEC) matrix, which is dynamically augmented and sequentially updated. The negative estimations in the mathematical algorithm are suppressed by utilizing artificial zero-observations (with large uncertainties) to simultaneously update the state vector and BEC. The method is evaluated by twin experiments based on the JRodos system. The results indicate that the new method successfully reconstructs the emission and its uncertainties. Accurate a priori ratio accelerates the analysis process, which obtains satisfactory results with only limited number of measurements, otherwise it needs more measurements to generate reasonable estimations. The suppression of negative estimation effectively improves the performance, especially for the situation with poor a priori information, where it is more prone to the generation of negative values.

Modeling the nuclide migration and dose estimating using GoldSim

International Nuclear Information System (INIS)

Xiong Xiaowei

2010-01-01

Nuclide migration of the high-level waste (HLW) repository in the near-and far-field as well as a transport through a biosphere under reference scenario has been modeled by utilizing GoldSim. The concept design of engineered barrier system (EBS), geosphere and biosphere characteristics are derived from H12 in Japan. The calculated results are consistent with H12 report, which can be considered as technical basis for the safety assessment of China HLW disposal. (authors)

Isomers in neutron-rich A ∼ 190 nuclides from 208Pb fragmentation

International Nuclear Information System (INIS)

Rykaczewski, Krzysztof Piotr; Caamano, M.; Banu, A.; Walker, P.M.; Morton, N.H.; Regan, P. H.; Regan, Patrick H; Pfutzner, M.; Podolyak, Zs.; Gerl, J.; Hellstrom, M.; Mayet, P.; Miernik, K.; Mineva, M.N.; Aprahamian, A.; Benlliure, J.; Bruce, A.M.; Butler, P.A.; Cortina Gil, D.; Cullen, D.M.; Doring, J.; Enqvist, T.; Fox, C.; Garces Narro, J.; Geissel, H.; Gelletly, W.; Giovinazzo, J.; Gorska, M.; Grawe, H.; Grzywacz, R.; Kleinbohl, A.; Korten, W.; Lewitowicz, M.; Lucas, R.; Mach, H.; O'Leary, C.D.; De Oliveira, F.; Pearson, C.J.; Rejmund, F.

2004-01-01

Relativistic projectile fragmentation of 208 Pb has been used to produce isomers in neutron-rich, A ∼ 190 nuclides. A forward-focusing spectrometer provided ion-by-ion mass and charge identification. The detection of gamma-rays emitted by stopped ions has led to the assignment of isomers in 188 Ta, 190 W, 192 Re, 193 Re, 195 Os, 197 Ir, 198 Ir, 200 Pt, 201 Pt, 202 Pt and 203 Au, with half-lives ranging from approximately 10 ns to 1 ms. Tentative isomer information has been found also for 174 Er, 175 Er, 185 Hf, 191 Re, 194 Re and 199 Ir. In most cases, time-correlated, singles gamma-ray events provided the first spectroscopic data on excited states for each nuclide. In 200 Pt and 201 Pt, the assignments are supported by gamma-gamma coincidences. Isomeric ratios provide additional information, such as half-life and transition energy constraints in particular cases. The level structures of the platinum isotopes are discussed, and comparisons are made with isomer systematics

The production of residual nuclides in Pb irradiated by 400 MeV/u carbon ions

Energy Technology Data Exchange (ETDEWEB)

Ge, H.L. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Ma, F., E-mail: mf@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zhang, X.Y.; Ju, Y.Q.; Zhang, H.B.; Chen, L.; Luo, P. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zhou, B. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Y.B.; Li, J.Y.; Xu, J.K. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Liang, T.J. [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wang, S.L. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Yang, Y.W.; Yang, L. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

2014-10-15

The experiment was performed by irradiating a Pb foil with 400 MeV/u carbon beam at the HIRFL-CSR in Lanzhou, China. The experimental data was acquired by the off-line γ-spectroscopy method. 32 radioactive residual nuclides had been observed and their cross sections were determined. The measured results were compared with the results simulated by Monte Carlo code MCNPX2.7.0. The comparison shows that the simulated cross sections were underestimated for the fragments from A = 20 to 41 and A = 110 to 175. By fitting the measured and simulated cross sections to Rudstams semi-empirical formula, it was found that the charge distribution of products was asymmetric for the residual nuclides with a high mass number.

Performance of a nuclide identification of HYPERGAM on the IAEA 2002 test spectra

International Nuclear Information System (INIS)

Park, B. G.; Jung, N. S.; Kim, J. H.; Choi, H. D.; Park, C. S.

2010-01-01

An important part of the γ-ray spectrum analysis software is the ability to identify radionuclides on the spectrum, and to determine activity of each radionuclide. Rapid determination and a low number of missing and false hit are required to the γ-ray spectrum analysis software to be useful. HyperGam has been developed to analyze an HPGe γ-ray spectrum by Applied Nuclear Physics Group in Seoul National University. Through a series of subsequent studies, the on-line analysis as well as the off-line analysis was possible. In addition, the automatic algorithm of nuclide identification has been developed to identify the peaks on the spectrum considering with yield, efficiency, energy and peak area of the γ-ray line from radionuclide. In this study, the performance of the nuclide identification of HyperGam is tested by using the IAEA 2002 set of test spectra and is compared to the well-known γ-ray spectrum analysis software

An accuracy estimation on neutron penetration calculation through concrete shield with PALLAS codes using bunched component nuclides of concrete

International Nuclear Information System (INIS)

Sasamoto, Nobuo; Kotegawa, Hiroshi

1984-11-01

In order to improve computational efficiency of PALLAS code, an accuracy is estimated on the neutron penetration calculation through a concrete shield, using bunched component nuclides of concrete. The calculated fast neutron flux is observed to depend weakly on how the nuclides are bunched. Contrary to this, the calculated thermal neutron fluxes are strongly dependent on the manner of bunching, mainly due to the fact that iron cross section has exceptionally large negative sensitivity to thermal neutron flux. (author)

Improving the Quality of Recycled Fine Aggregate by Selective Removal of Brittle Defects

OpenAIRE

Ogawa, Hideo; Nawa, Toyoharu

2012-01-01

Crushed recycled aggregate contains particles with brittle defects such as cracks, pores, and voids. This study presents a method for improving the quality of recycled fine aggregate by selectively removing these defects. Fourteen recycled fine aggregates were manufactured by three types of processors including a jaw crusher, ball mill, and granulator. The influence of the recycled fine aggregate on the flowability and strength of the mortar was evaluated by multivariate analysis. The results...

Selection of electrogenic bacteria for microbial fuel cell in removing Victoria blue R from wastewater.

Science.gov (United States)

Chen, Chih-Yu; Tsai, Teh-Hua; Wu, Pei-Ssu; Tsao, Shuo-En; Huang, Yu-Shan; Chung, Ying-Chien

2018-01-28

This study was conducted to select electrogenic bacteria from wastewater sludge. Phylogenetic analysis revealed that Proteobacteria was the dominant phylum in the microbial fuel cell (MFC) during the decomposition process of organic pollutants. Five culturable bacteria strains - namely, Bacillus subtilis, Flavobacterium sp., Aeromonas hydrophila, Citrobacter freundii, and Stenotrophomonas sp. - have a double potential in dye removal and electricity generation. We inoculated the mixed electrogenic bacteria at a specific ratio and treated them with a triphenylmethane dye, Victoria blue R (VBR), to evaluate their electricity generation ability for the artificial and real wastewater. The results of the VBR shock-loading experiment indicated that the inoculated MFC could adapt to shock loading in 1-2 days and exhibited high removal efficiency (95-100%) for 100-800 mg L -1 VBR with a power density of 8.62 ± 0.10 to 34.81 ± 0.25 mW m -2 . The selected electrogenic bacteria in the MFC could use VBR as only electron donor for power generation. The matrix effects of the real wastewater on VBR removal and electricity generation of MFC were insignificant. VBR degradation by the electrogenic bacteria involves a stepwise demethylation process to yield partially dealkylated VBR species. In addition, these results demonstrate the feasibility of inoculating culturable bacteria strains to develop an efficient MFC for purifying wastewater.

Effect of local burn-up variation on computed mean nuclide concentrations

International Nuclear Information System (INIS)

Moeller, W.

1982-01-01

Mean concentrations of U-235, U-236, U-238, Pu-239, Pu-240, Pu-241 and Pu-242 in some volume areas of WWER-440 fuel assemblies have been calculated from corresponding burn-up microdistribution data and compared with those calculated from burn-up mean values. Differences occurring were below 3% for the uranium nuclides but, at low burn-ups, considerable for Pu-241 and Pu-242. (author)

Geochemical behaviour of natural uranium-series nuclides in geological formation

International Nuclear Information System (INIS)

Yamakawa, Minoru

1991-01-01

Recent research and investigation show that the Tono uranium deposit and its natural uranium-series nuclides have been preserved, without any significant changes like re-migration or reconcentration, throughout geological events such as upheaval-submergence, marine transgression-regression, and faulting which can readily change geological, hydrogeological, and geochemical conditions. This situation might have come about as a result of being kept in a geometrical closure system, with reducing and milk alkalic geochemical conditions, from the hydrogeological and geochemical point of view. (author)

Selective removal of heavy metal ions by disulfide linked polymer networks

Energy Technology Data Exchange (ETDEWEB)

Ko, Dongah [Department of Environmental Engineering, Technical University of Denmark, Miljøvej 113, 2800 Kgs. Lyngby (Denmark); Lee, Joo Sung [Graduate School of EEWS, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141 (Korea, Republic of); Patel, Hasmukh A. [Department of Chemistry, Northwestern University, Evanston, IL 60208 (United States); Jakobsen, Mogens H. [Department of Micro and Nano technology, Technical University of Denmark, Ørsteds Plads, 345B, 2800 Kgs. Lyngby (Denmark); Hwang, Yuhoon [Department of Environmental Engineering, Seoul National University of Science and Technology, 232 Gongreung-ro, Nowon-gu, Seoul 01811 (Korea, Republic of); Yavuz, Cafer T. [Graduate School of EEWS, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141 (Korea, Republic of); Hansen, Hans Chr. Bruun [Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Andersen, Henrik R., E-mail: henrik@ndersen.net [Department of Environmental Engineering, Technical University of Denmark, Miljøvej 113, 2800 Kgs. Lyngby (Denmark)

2017-06-15

Highlights: • Disulfide/thiol polymer networks are promising as sorbent for heavy metals. • Rapid sorption and high Langmuir affinity constant (a{sub L}) for stormwater treatment. • Selective sorption for copper, cadmium, and zinc in the presence of calcium. • Reusability likely due to structure stability of disulfide linked polymer networks. - Abstract: Heavy metal contaminated surface water is one of the oldest pollution problems, which is critical to ecosystems and human health. We devised disulfide linked polymer networks and employed as a sorbent for removing heavy metal ions from contaminated water. Although the polymer network material has a moderate surface area, it demonstrated cadmium removal efficiency equivalent to highly porous activated carbon while it showed 16 times faster sorption kinetics compared to activated carbon, owing to the high affinity of cadmium towards disulfide and thiol functionality in the polymer network. The metal sorption mechanism on polymer network was studied by sorption kinetics, effect of pH, and metal complexation. We observed that the metal ions–copper, cadmium, and zinc showed high binding affinity in polymer network, even in the presence of competing cations like calcium in water.

Development of a method for determining 93Zr, 107Pd and 135Cs nuclides in UP2 800/UP3 hulls

International Nuclear Information System (INIS)

Excoffier, E.; Bienvenu, Ph.; Combes, C.; Delteil, N.; Ferrini, R.

2000-01-01

A CEA and COGEMA joint project was established for the determination of the activity of three long-lived radionuclides, Zirconium 93, Palladium 107 and Cesium 135 in zircaloy hulls recovered from reprocessing operations. These isotopes are pure β- emitters with half-lives in the range of 10 6 years. It is difficult to measure such nuclides using routine radiochemical methods because of their low specific activity and the presence of many interfering radionuclides in irradiated hulls. The procedure described in this paper involves a mass spectrometry technique, Inductively Coupled Plasma - Mass Spectrometry (ICP - MS) applied after dissolution of the samples and selective extraction of each nuclide studied from the matrix. Theoretical contents of 93 Zr, 107 Pd and 135 Cs in hulls can be estimated by computer codes relative to fission and activation reactions. From the CESAR code, the contents are expected to be in the range of 1 to 10 2 ppm zircaloy, i.e. around 8.10 -5 to 5.10 -3 g.l -1 after dissolution of the hulls. While such values are much higher than the detection limits achievable by ICP-MS in simple matrices, the measurement of 93 Zr, 107 Pd and 135 Cs is unfeasible in irradiated zircaloy solutions unless chemical separations are performed prior to analysis. In fact, the high zirconium content (40 g.l -1 ), the radioactivity of the solution (1010 Bq.I -1 ), the nature of acids (HNO 3 , HF) and above all, the presence of interfering isotopes prevent the direct determination of these radionuclides in zircaloy solutions. To overcome these difficulties, a procedure was developed to extract each nuclide from the original matrix and to separate it from interfering nuclide. The procedure was carried out on a synthetic solution containing the studied elements (Zr, Pd, Cs), the interfering elements (Nb, Ag, Ba) and the elements with major * emitting isotopes (Co, Sr, Ru, Rh, Sb, Ce, Eu) in hulls. The first stage of the procedure is a reverse phase chromatography

Analysis of nuclide transport under natural convection and time dependent boundary condition using TOUGH2

Energy Technology Data Exchange (ETDEWEB)

Javeri, V. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Koeln (Germany)

1995-03-01

After implementation of TOUGH2 at GRS in summer 91, it was first used to analyse the gas transport in a repository for the nuclear waste with negligible heat generation and to verify the results obtained with ECLIPSE/JAV 92/. Since the original version of TOUGH2 does not directly simulate the decay of radionuclide and the time dependent boundary conditions, it is not a appropriate tool to study the nuclide transport in a porous medium/PRU 87, PRU 91/. Hence, in this paper some modifications are proposed to study the nuclide transport under combined influence of natural convection diffusion, dispersion and time dependent boundary condition. Here, a single phase fluid with two liquid components is considered as in equation of state model for water and brine/PRU 91A/.

Short-lived radioactive nuclides in meteorites and early solar system processes

International Nuclear Information System (INIS)

Chaussidon, M.; Gounelle, M.

2007-01-01

Now extinct, short-lived radioactive nuclides, such as 7 Be (T 1/2 = 53 days), 10 Be (T 1/2 = 1.5 Ma), 26 Al (T 1/2 = 0.74 Ma), 36 Cl (T 1/2 = 0.3 Ma), 41 Ca (T 1/2 = 0.1 Ma), 53 Mn (T 1/2 = 3.7 Ma) and 60 Fe (T 1/2 = 1.5 Ma), were present in the proto-solar nebula when the various components of meteorites formed. The presence of these radioactive isotopes requires a 'last-minute' origin, either nucleosynthesis in a massive star dying close in space and time to the nascent solar system or production by local irradiation of part of the proto-solar disk by high-energy solar cosmic rays. In this review, we list: (i) the different observations indicating the existence of multiple origins for short-lived radioactive nuclides, namely 7 Be, 10 Be and 36 Cl for irradiation scenario and 60 Fe for injection scenario; (ii) the constraints that exist on their distribution (homogeneous or heterogeneous) in the accretion disk; (iii) the constraints they brought on the timescales of nebular processes (from Ca-Al-rich inclusions to chondrules) and of the accretion and differentiation of planetesimals. (authors)

Radioactive nuclides formed by irradiation of the natural elements with thermal neutrons

Energy Technology Data Exchange (ETDEWEB)

Ekberg, Kim

1959-05-15

For each natural element up to Bi this report gives: the 2200 m/sec neutron absorption cross section; the nuclides formed by thermal neutron activation; the saturation activity per gram natural element for a certain flux; half life and 'tenth life' of the activity; {beta}-energy and/or type of decay; mean {gamma} energy per disintegration; energy and abundance of {gamma} quanta.

Measurements of transuranium nuclides in the environment at the Institute for Radiation Protection of the Gessellschaft fuer Strehlen-und Umweltforschung mbH, Munich

International Nuclear Information System (INIS)

Rosner, G.; Hoetzl, H.; Winkler, R.

1978-01-01

Work on environmental transuranium nuclides at the Institute for Radiation Protection of the Gesellschaft fur Strahlen-und Umweltforschung mbH, Munich, is briefly described and standard needs are discussed. Fallout plutonium measurements in air dust and precipitation samples started in 1970/1971. The procedure is outlined and results are presented as annual mean and sum values, respectively. Since 1973, transuranium nuclides in primary coolant, stack effluent air and waste-water samples from nuclear power stations are measured. Nuclides detected are 239 240 Pu, 238 Pu and/or 241 Am, 242 Cm and 244 Cm. Examples of alpha particle spectra are given. Needs for standards in environmental transuranium analysis are discussed. (author)

Selective Removal of Uranium from the Washing Solution of Uranium-Contaminated Soil

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Soo; Han, G. S.; Kim, G. N.; Koo, D. S.; Jeong, J. W.; Choi, J. W. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

This study examined selective removal methods of uranium from the waste solution by ion exchange resins or solvent extraction methods to reduce amount of the 2{sup nd} waste. Alamine-336, known as an excellent extraction reagent of uranium from the leaching solution of uranium ore, did not remove uranium from the acidic washing solution of soil. Uranyl ions in the acidic waste solution were sorbed on ampholyte resin with a high sorption efficiency, and desorbed from the resin by a washing with 0.5 M Na{sub 2}CO{sub 3} solution at 60 .deg. C. However, the uranium dissolved in the sulfuric acid solution was not sorbed onto the strong anion exchanger resins. A great amount of uranium-contaminated (U-contaminated) soil had been generated from the decommissioning of a uranium conversion plant. Our group has developed a decontamination process with washing and electrokinetic methods to decrease the amount of waste to be disposed of. However, this process generates a large amount of waste solution containing various metal ions.

Rapid and selective removal of preservative from ophthalmic formulations during eyedrops instillation.

Science.gov (United States)

Hsu, Kuan-Hui; Chauhan, Anuj

2015-11-01

About 70% of eyedrops contain benzalkonium chloride (BAK) as a preservative to prevent the growth of microorganisms. While preservatives are mandated to maintain sterility, many patients exhibit irritation and toxicity to such compounds. We propose to mitigate the ocular toxicity in the ocular formulations without compromising sterility by designing a device that can be incorporated into an eyedrops bottle to selectively remove the preservatives during the process of drop instillation. Here, we specifically focus on macroporous poly(2-hydroxyethyl methacrylate) (pHEMA) gel due to its excellent biocompatibility and high partition coefficient for BAK. In addition to specific selectivity for BAK, the device also requires high hydraulic permeability to allow drop dispensing without excessive pressure drop. The pHEMA monolith can remove nearly 100% of contained BAK from a 25 ml, 0.012% BAK solution with negligible uptake of the hydrophilic drugs such as timolol and dorzolamide. The filter, however, had to be pre-equilibrated with hydrophobic drugs to reach a high separation of BAK without reducing the concentration of the active drug. The average hydraulic permeability of the filter was 0.025 Darcy, which is about 5-fold lower than the ideal value. Incorporation of a pHEMA macroporous gel into an eyedrops bottle can virtually eliminate the exposure of the eyes to the preservatives without compromising the sterility. Our novel design can eliminate the preservative induced toxicity from eyedrops thereby impacting hundreds of millions of patients with chronic ophthalmic diseases such as glaucoma and dry eyes. Copyright © 2015 Elsevier B.V. All rights reserved.

Bioremediation system on-line for removal radionuclides in radioactive waters; Sistema de biorremediation on-line pra la eliminacion de radionuclidos en aguas radiactivas

Energy Technology Data Exchange (ETDEWEB)

Belinchon, J. A.; Garcia, A. M.; Ruibal, C.; Moreno, D. A.

2010-07-01

In previous studies developed in Cofrentes Nuclear Power Plant (Valencia, Spain), has been observed that the microorganisms in the radioactive waters of the spent nuclear fuel pool are capable of colonizing the metallic surfaces of the walls and pipes and perform biofilm. These biofilm retain the nuclides contributing to decontaminate the water. In this project, carried out in Cofrentes Nuclear Power Plant, a pilot plant has been designed for the bio decontamination of the radioactive water. At present, the radioactive water coming from the spent nuclear fuel pools, pass through ionic exchange resins. After, these resins are managed as radioactive waste. In this project, the water passes through a bioreactor with stainless steel balls capable of being colonized by the microorganisms in the water. Inside the bioreactor the water gets in contact with the material of the balls, and a biofilm, which retains the nuclides in the water, is developed. The biofilm is easily removed by any conventional procedure of radiochemical decontamination of materials and the nuclides can be collected in a small volume for recovery final disposition or containment. Later, the material of the bioreactor could be managed as not radioactive material. (Author) 9 refs.

Removal of Selected Pharmaceutical and Personal Care Products by the Green Alga Nannochloris sp.

Science.gov (United States)

Bai, X.; Acharya, K.

2016-12-01

Emerging contaminants have become an increasing concern in the environment due to their ubiquitous distribution and potential adverse effects on wildlife and humans. Municipal wastewater is a major source of pharmaceutical and personal care products (PPCPs) in the Las Vegas metropolitan area. The ecotoxic impacts of PPCPs on aquatic organisms include development of antimicrobial resistance, decreases in plankton diversity, and endocrine disruption. Freshwater algae can be responsible for the uptake and transfer of the contaminants because they are a major food source for most aquatic organisms. This research applied laboratory-based incubation studies to evaluate the removal efficiency and uptake mechanisms of the selected PPCPs (trimethoprim, sulfamethoxazole, and triclosan) by the green alga Nannochloris sp. The results showed that trimethoprim and sulfamethoxazole remained in the algal culture at 100% and 68%, respectively, after 14 days of incubation, and therefore were not significantly removed from the medium. However, the antimicrobial triclosan was significantly removed from the medium. Immediately after incubation began, 74% of triclosan dissipated and 100% of triclosan was removed after 7 days of incubation. Additionally, over 42% of triclosan was found associated with the algal cells throughout the incubation. The results demonstrate that the presence of Nannochloris sp. eliminated triclosan in the aquatic system, but could not significantly remove the antibiotics trimethoprim and sulfamethoxazole. This study provided crucial information that toxicity of triclosan in aquatic organisms is a critical concern because of its high uptake by phytoplankton. The resistance of trimethoprim and sulfamethoxazole to uptake by phytoplankton may threaten water quality.

Specific gamma-ray dose constants for nuclides important to dosimetry and radiological assessment

International Nuclear Information System (INIS)

Unger, L.M.; Trubey, D.K.

1982-05-01

Tables of specific gamma-ray dose constants (the unshielded gamma-ray dose equivalent rate at 1 m from a point source) have been computed for approximately 500 nuclides important to dosimetry and radiological assessment. The half life, the mean attenuation coefficient, and thickness for a lead shield providing 95% dose equivalent attenuation are also listed

Tributyl phosphate removal from reprocessing off-gas streams using a selected sorbent

International Nuclear Information System (INIS)

Parker, G.B.

1980-01-01

Laboratory experiments used small laboratory-scale columns packed with selected sorbent materials to remove tributyl phosphate (TBP) and iodine at conditions approaching those in actual reprocessing off-gas streams. The sorbent materials for TBP removal were placed upstream of iodine sorbent materials to protect the iodine sorbent from the deleterious effects of TBP. Methyl iodide in an airstream containing 30% TBP in normal paraffin hydrocarbons (NPH) and water vapor was metered to two packed columns of sorbents simultaneously (in parallel). One column contained a segment of 8-in. x 14-in. mesh alumina sorbent for TBP removal, the other did not. The measure of the effectiveness of TBP sorbent materials for TBP removal was determined by comparing the iodine retention of the iodine sorbent materials in the two parallel columns. Results from an 18 wt % Ag substituted mordenite iodine sorbent indicated that the iodine retention capacity of the sorbent was reduced 60% by the TBP and that the column containing iodine sorbent material protected by the alumina TBP sorbent retained 30 times more iodine than the column without TBP sorbent. TBP concentration was up to 500 mg/m 3 . Similar experiments using a 7 wt % Ag impregnated silica gel indicated that the TBP vapor had little effect on the iodine retention of the silica gel material. The stoichiometric maximum amount of iodine was retained by the silica gel material. Further experiments were conducted assessing the effects of NO 2 on iodine retention of this 7 wt % Ag sorbent. After the two columns were loaded with iodine in the presence of TBP (in NPH), one column was subjected to 2 vol % NO 2 in air. From visual comparison of the two columns, it appeared that the NO 2 regenerated the silica gel iodine sorbent and that iodine was washed off the silica gel iodine sorbent leaving the sorbent in the original state

Radioactive nuclides formed by irradiation of the natural elements with thermal neutrons

Energy Technology Data Exchange (ETDEWEB)

Ekberg, Kim

1959-05-15

For each natural element up to Bi this report gives: the 2200 m/sec neutron absorption cross section; the nuclides formed by thermal neutron activation; the saturation activity per gram natural element for a certain flux; half life and 'tenth life' of the activity; {beta}-energy and/or type of decay; mean {gamma} energy per disintegration; energy and abundance of {gamma} quanta.

Total and spontaneous fission half-lives of the americium and curium nuclides

International Nuclear Information System (INIS)

Holden, N.E.

1984-01-01

The total half-life and the half-life for spontaneous fission are evaluated for the various long-lived nuclides of interest. Recommended values are presented for 241 Am, /sup 242m/Am, 243 Am, 242 Cm, 243 Cm, 244 Cm, 245 Cm, 246 Cm, 247 Cm, 248 Cm, and 250 Cm. The uncertainties are provided at the 95% confidence limit for each of the recommended values

HETC-3STEP calculations of proton induced nuclide production cross sections at incident energies between 20 MeV and 5 GeV

International Nuclear Information System (INIS)

Takada, Hiroshi; Yoshizawa, Nobuaki; Ishibashi, Kenji.

1996-08-01

For the OECD/NEA code intercomparison, nuclide production cross sections of 16 O, 27 Al, nat Fe, 59 Co, nat Zr and 197 Au for the proton incidence with energies of 20 MeV to 5 GeV are calculated with the HETC-3STEP code based on the intranuclear cascade evaporation model including the preequilibrium and high energy fission processes. In the code, the level density parameter derived by Ignatyuk, the atomic mass table of Audi and Wapstra and the mass formula derived by Tachibana et al. are newly employed in the evaporation calculation part. The calculated results are compared with the experimental ones. It is confirmed that HETC-3STEP reproduces the production of the nuclides having the mass number close to that of the target nucleus with an accuracy of a factor of two to three at incident proton energies above 100 MeV for nat Zr and 197 Au. However, the HETC-3STEP code has poor accuracy on the nuclide production at low incident energies and the light nuclide production through the fragmentation process induced by protons with energies above hundreds of MeV. Therefore, further improvement is required. (author)

Fuel burn-up distribution and transuranic nuclide contents produced at the first cycle operation of AP1000

International Nuclear Information System (INIS)

Jati Susilo; Jupiter Sitorus Pane

2016-01-01

AP1000 reactor core was designed with nominal power of 1154 MWe (3415 MWth), operated within life time of 60 years and cycle length of 18 months. For the first cycle, the AP1000 core uses three kinds of UO 2 enrichment, they are 2.35 w/o, 3.40 w/o and 4.45 w/o. Absorber materials such as ZrB 2 , Pyrex and Boron solution are used to compensate the excess reactivity at the beginning of cycle. In the core, U-235 fuels are burned by fission reaction and produce energy, fission products and new neutron. Because of the U-238 neutron absorption reaction, the high level radioactive waste of heavy nuclide transuranic such as Pu, Am, Cm and Np are also generated. They have a very long half life. The purpose of this study is to evaluate the result of fuel burn-up distribution and heavy nuclide transuranic contents produced by AP1000 at the end of first cycle operation (EOFC). Calculation of ¼ part of the AP1000 core in the 2 dimensional model has been done using SRAC2006 code with the module of COREBN/HIST. The input data called the table of macroscopic cross section, is calculated using module of PIJ. The result shows that the maximum fuel assembly (FA) burn-up is 27.04 GWD/MTU, that is still lower than allowed maximum burn-up of 62 GWD/MTU. Fuel loading position at the center/middle of the core will produce bigger burn-up and transuranic nuclide than one at the edges the of the core. The use of IFBA fuel just give a small effect to lessen the fuel burn-up and transuranic nuclide production. (author)

Removal of clay by stingless bees: load size and moisture selection.

Science.gov (United States)

Costa-Pereira, Raul

2014-09-01

Some organisms disperse energy, associated with the transportation of resource, which is not necessarily food. Stingless bees of Central Amazonia (Melipona flavolineata and M. lateralis) collect clay in banks along streams for nest building. The moisture of the clay varies along the bank, and bees collect clay from specific location, indicating that there is some sort of preference regarding their selection. This study aims at identifying: if larger bees carry more clay; if there is a preference for moisture of substrates; and if bees are less efficient accumulating and transporting clay when it is wet. In order to do so, I measured the size of the bees and of the pellets of clay found in the corbicula. I set up a field experiment to test substrate preferences. The amount of clay transported, increased exponentially in accordance to the size of the bee, and the preferred substrate was the driest clay. The amount and the efficiency of removal of clay were not affected by the moisture of the substrate. Despite the wet clay being denser, it does not reduce the efficiency of exploitation of the resource, but suggests that bees spend more energy to carry the same quantity of wet clay, which may be the underlying mechanism explaining their preference for removing drier clay.

Analysis of Residual Nuclide in a ACM and ACCT of 100-MeV proton beamline By measurement X-ray Spectrum

Energy Technology Data Exchange (ETDEWEB)

Park, Jeong-Min; Yun, Sang-Pil; Kim, Han-Sung; Kwon, Hyeok-Jung; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Gyeongju (Korea, Republic of)

2015-10-15

The proton beam is provides to users as various energy range from 20 MeV to 100 MeV. After protons generated from the ion source are accelerated to 100 MeV and irradiated to target through bending magnet and AC magnet. At this time, relatively high dose X-ray is emitted due to collision of proton and components of beamline. The generated X-ray is remaining after the accelerator is turned off and analyzing residual nuclides through the measurement of X-ray spectrum. Then identify the components that are the primary cause of residual nuclides are detected form the AC magnet(ACM) and associated components (ACCT). Analysis of the X-ray spectrum generated form the AC magnet(ACM) and AC current transformer(ACCT) of 100 MeV beamline according to the proton beam irradiation, most of the residual nuclides are identified it can be seen that emission in the stainless steel by beam loss.

Study on the environmental movements and distributions of natural radioactive nuclides on the granite area (II)

International Nuclear Information System (INIS)

Morishima, Hiroshige; Koga, Taeko

1999-03-01

The natural radionuclides as K-40, uranium decay series and thorium decay series etc. are widely distributed on environment, but are not uniformly. These have various forms as the sources of terrestrial environmental γ radiation and of radon and make wide fluctuation seasonal and spatially on the environment. We have selected Ikeda mineral spring district, Shimane pref., Misasa spa district, Tottori pref., Muro district, Hachibuse district, Nara pref. and Arima spa district, Hyogo-pref. for HBRA, and Kawanishi-shi, Hyogo pref. and Higashi-osaka-shi, Osaka pref. as CA. We have carried out the study on the environmental movement and distribution of natural radioactive nuclides containing radon and decay nuclides. Radon measurements have been carried using cup typed radon and thoron monitors, pico-rad method by active charcoal sampling and Pilon scintillation-cell by grub sampling. Accumulated radon monitors have been used with cellulose nitrate as solid state track detector. Rn-222 concentrations in air at Misasa spa ranged 2 - 150 Bq/m 3 outdoor and 8 - 194 Bq/m 3 indoor. Rn-222 concentrations on Misasa district, Asahi district and Takeda district geologically formed from granite strata are high, and those on Osika district and Mitoku district formed from volcanic rocks (Andesite and Basalt) are low level. Rn-222 concentration variations in well water used as drinking water were 2 - 138 Bq/l (mean value 31 Bq/l) and those in ground waters varied from non detectable to 4620 Bq/l (mean 875 Bq/l) on sampling time and places. Mean Rn-222 concentration in the spring water at Arima spa area, Hyogo prefecture is 26 Bq/l at Tansan spring source and the other spring sources are comparatively low level. (J.P.N.)

Selective noble gases monitoring

International Nuclear Information System (INIS)

Janecka, S.; Jancik, O.; Kapisovsky, V.; Kubik, I.; Sevecka, S.

1995-01-01

The monitoring of leak releases from ventilation stack of NPP requires a system by several orders more sensitive then currently used radiometer Kalina, designed to cover the range up to a design-based accident. To reach this goal a noble gases monitor with a germanium detector (MPVG) has been developed. It enables nuclide selective monitoring of current value of volume activity of particular nuclides in ventilation stack and daily releases of noble gases (balancing). MPVG can be viewed as a system build of three levels of subsystem: measuring level; control level; presentation level. Measuring level consists of gamma-spectroscopy system and operational parameters monitoring unit (flow rate, temperature, humidity). Control level provides communication between presentation and measuring level, acquisition of operational parameters and power supply. The presentation level of MPVG enables: 1) the measured data storage in predetermined time intervals; 2) the presentation of measured and evaluated values of radiation characteristics. The monitored radionuclides - default set: argon-41, krypton-85m, krypton-87, krypton-88, krypton-89, xenon-131m, xenon-133, xenon-133m, xenon-135, xenon-135m, xenon-137 and xenon-138. The values of volume activities observed at maximum releases have been approximately ten times higher. In that case in balancing some other nuclides exceed corresponding detection limits: 88 Kr(67; 22) Bq/m 3 ; 85m Kr(17; 7) Bq/m 3 ; 135m Xe(7.1; 0.5) Bq/m 3 ; 138 Xe(5.9; 0.9) Bq/m 3 . (J.K.)

Selective noble gases monitoring

Energy Technology Data Exchange (ETDEWEB)

Janecka, S; Jancik, O; Kapisovsky, V; Kubik, I; Sevecka, S [Nuclear Power Plants Research Institute, a.s., Trnava (Slovakia)

1996-12-31

The monitoring of leak releases from ventilation stack of NPP requires a system by several orders more sensitive then currently used radiometer Kalina, designed to cover the range up to a design-based accident. To reach this goal a noble gases monitor with a germanium detector (MPVG) has been developed. It enables nuclide selective monitoring of current value of volume activity of particular nuclides in ventilation stack and daily releases of noble gases (balancing). MPVG can be viewed as a system build of three levels of subsystem: measuring level; control level; presentation level. Measuring level consists of gamma-spectroscopy system and operational parameters monitoring unit (flow rate, temperature, humidity). Control level provides communication between presentation and measuring level, acquisition of operational parameters and power supply. The presentation level of MPVG enables: 1) the measured data storage in predetermined time intervals; 2) the presentation of measured and evaluated values of radiation characteristics. The monitored radionuclides - default set: argon-41, krypton-85m, krypton-87, krypton-88, krypton-89, xenon-131m, xenon-133, xenon-133m, xenon-135, xenon-135m, xenon-137 and xenon-138. The values of volume activities observed at maximum releases have been approximately ten times higher. In that case in balancing some other nuclides exceed corresponding detection limits: {sup 88}Kr(67; 22) Bq/m{sup 3}; {sup 85m}Kr(17; 7) Bq/m{sup 3}; {sup 135m}Xe(7.1; 0.5) Bq/m{sup 3}; {sup 138}Xe(5.9; 0.9) Bq/m{sup 3}. (J.K.).

Atmospheric dust contribution to budget of U-series nuclides in weathering profiles. The Mount Cameroon volcano

Science.gov (United States)

Pelt, E.; Chabaux, F. J.; Innocent, C.; Ghaleb, B.

2009-12-01

Analysis of U-series nuclides in weathering profiles is developed today for constraining time scale of soil and weathering profile formation (e.g., Chabaux et al., 2008). These studies require the understanding of U-series nuclides sources and fractionation in weathering systems. For most of these studies the impact of aeolian inputs on U-series nuclides in soils is usually neglected. Here, we propose to discuss such an assumption, i.e., to evaluate the impact of dust deposition on U-series nuclides in soils, by working on present and paleo-soils collected on the Mount Cameroon volcano. Recent Sr, Nd, Pb isotopic analyses performed on these samples have indeed documented significant inputs of Saharan dusts in these soils (Dia et al., 2006). We have therefore analyzed 238U-234U-230Th nuclides in the same samples. Comparison of U-Th isotopic data with Sr-Nd-Pb isotopic data indicates a significant impact of the dust input on the U and Th budget of the soils, around 10% for both U and Th. Using Sr-Nd-Pb isotopic data of Saharan dusts given by Dia et al. (2006) we estimate U-Th concentrations and U-Th isotope ratios of dusts compatible with U-Th data obtained on Saharan dusts collected in Barbados (Rydell H.S. and Prospero J.M., 1972). However, the variations of U/Th ratios along the weathering profiles cannot be explained by a simple mixing scenario between material from basalt and from the defined atmospheric dust pool. A secondary uranium migration associated with chemical weathering has affected the weathering profiles. Mass balance calculation suggests that U in soils from Mount Cameroon is affected at the same order of magnitude by both chemical migration and dust accretion. Nevertheless, the Mount Cameroon is a limit case were large dust inputs from continental crust of Sahara contaminate basaltic terrain from Mount Cameroon volcano. Therefore, this study suggests that in other contexts were dust inputs are lower, or the bedrocks more concentrated in U and Th

Removal of radium from drinking water

International Nuclear Information System (INIS)

Lauch, R.P.

1992-08-01

The report summarizes processes for removal of radium from drinking water. Ion exchange, including strong acid and weak acid resin, is discussed. Both processes remove better than 95 percent of the radium from the water. Weak acid ion exchange does not add sodium to the water. Calcium cation exchange removes radium and can be used when hardness removal is not necessary. Iron removal processes are discussed in relation to radium removal. Iron oxides remove much less than 20 percent of the radium from water under typical conditions. Manganese dioxide removes radium from water when competition for sorption sites and clogging of sites is reduced. Filter sand that is rinsed daily with dilute acid will remove radium from water. Manganese dioxide coated filter sorption removes radium but more capacity would be desirable. The radium selective complexer selectively removes radium with significant capacity if iron fouling is eliminated

Fate of nuclides in natural water systems. Annual progress report, April 1, 1983-March 31, 1984

International Nuclear Information System (INIS)

Turekian, K.K.

1983-01-01

This study of the behavior of nuclides in natural water systems is divided into studies of atmospheric aerosols, soils, groundwater, rivers, estuaries and coastal zones, the carbon cycle and the growth rates of marine organisms

ENDF/B-IV fission-product files: summary of major nuclide data

International Nuclear Information System (INIS)

England, T.R.; Schenter, R.E.

1975-09-01

The major fission-product parameters [sigma/sub th/, RI, tau/sub 1/2/, E-bar/sub β/, E-bar/sub γ/, E-bar/sub α/, decay and (n,γ) branching, Q, and AWR] abstracted from ENDF/B-IV files for 824 nuclides are summarized. These data are most often requested by users concerned with reactor design, reactor safety, dose, and other sundry studies. The few known file errors are corrected to date. Tabular data are listed by increasing mass number

Performance of polydimethylsiloxane membrane contactor process for selective hydrogen sulfide removal from biogas.

Science.gov (United States)

Tilahun, Ebrahim; Bayrakdar, Alper; Sahinkaya, Erkan; Çalli, Bariş

2017-03-01

H 2 S in biogas affects the co-generation performance adversely by corroding some critical components within the engine and it has to be removed in order to improve the biogas quality. This work presents the use of polydimethylsiloxane (PDMS) membrane contactor for selective removal of H 2 S from the biogas. Experiments were carried out to evaluate the effects of different pH of absorption liquid, biogas flowrate and temperature on the absorption performances. The results revealed that at the lowest loading rate (91mg H 2 S/m 2 ·h) more than 98% H 2 S and 59% CO 2 absorption efficiencies were achieved. The CH 4 content in the treated gas increased from 60 to 80% with nearly 5% CH 4 loss. Increasing the pH (7-10) and loading rate (91-355mg H 2 S/m 2 ·h) enhanced the H 2 S absorption capacity, and the maximum H 2 S/CO 2 and H 2 S/CH 4 selectivity factors were 2.5 and 58, respectively. Temperature played a key role in the process and lower temperature was beneficial for intensifying H 2 S absorption performance. The highest H 2 S fluxes at pH 10 and 7 were 3.4g/m 2 ·d and 1.8g/m 2 ·d with overall mass transfer coefficients of 6.91×10 -6 and 4.99×10 -6 m/s, respectively. The results showed that moderately high H 2 S fluxes with low CH 4 loss may be achieved by using a robust and cost-effective membrane based absorption process for desulfurization of biogas. A tubular PDMS membrane contactor was tested for the first time to remove H 2 S from biogas under slightly alkaline conditions and the suggested process could be a promising for real scale applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Uncertainties in the production of p nuclides in thermonuclear supernovae determined by Monte Carlo variations

Science.gov (United States)

Nishimura, N.; Rauscher, T.; Hirschi, R.; Murphy, A. St J.; Cescutti, G.; Travaglio, C.

2018-03-01

Thermonuclear supernovae originating from the explosion of a white dwarf accreting mass from a companion star have been suggested as a site for the production of p nuclides. Such nuclei are produced during the explosion, in layers enriched with seed nuclei coming from prior strong s processing. These seeds are transformed into proton-richer isotopes mainly by photodisintegration reactions. Several thousand trajectories from a 2D explosion model were used in a Monte Carlo approach. Temperature-dependent uncertainties were assigned individually to thousands of rates varied simultaneously in post-processing in an extended nuclear reaction network. The uncertainties in the final nuclear abundances originating from uncertainties in the astrophysical reaction rates were determined. In addition to the 35 classical p nuclides, abundance uncertainties were also determined for the radioactive nuclides 92Nb, 97, 98Tc, 146Sm, and for the abundance ratios Y(92Mo)/Y(94Mo), Y(92Nb)/Y(92Mo), Y(97Tc)/Y(98Ru), Y(98Tc)/Y(98Ru), and Y(146Sm)/Y(144Sm), important for Galactic Chemical Evolution studies. Uncertainties found were generally lower than a factor of 2, although most nucleosynthesis flows mainly involve predicted rates with larger uncertainties. The main contribution to the total uncertainties comes from a group of trajectories with high peak density originating from the interior of the exploding white dwarf. The distinction between low-density and high-density trajectories allows more general conclusions to be drawn, also applicable to other simulations of white dwarf explosions.

Combination of selected enzymes with cetyltrimethylammonium bromide in biofilm inactivation, removal and regrowth

KAUST Repository

Araujo, Paula Alexandra Da Silva; Machado, Idalina; Meireles, Ana; Leiknes, TorOve; Mergulhã o, Filipe; Melo, Luí s F.; Simõ es, Manuel

2017-01-01

Enzymes are considered an innovative and environmentally friendly approach for biofilm control due to their lytic and dispersal activities. In this study, four enzymes (β-glucanase, α-amylase, lipase and protease) were tested separately and in combination with the quaternary ammonium compound cetyltrimethylammonium bromide (CTAB) to control flow-generated biofilms of Pseudomonas fluorescens. The four enzymes caused modest reduction of biofilm colony forming units (CFU). Protease, β-glucanase and α-amylase also caused modest biofilm removal. CTAB combined with either β-glucanase or α-amylase increased biofilm removal. Its combination with either β-glucanase or protease increased CFU reduction. However, CTAB−protease combination was antagonist in biofilm removal. Long-term effects in biofilm mass reduction were observed after protease exposure. In contrast, biofilms treated with β-glucanase were able to regrowth significantly after exposure. Moreover, short-term respirometry tests with planktonic cells were performed to understand the effects of enzymes and their combination with CTAB on P. fluorescens viability. Protease and lipase demonstrated antimicrobial action, while α-amylase increased bacterial metabolic activity. The combination of CTAB with either protease or α-amylase was antagonistic, decreasing the antimicrobial action of CTAB. The overall results demonstrate a modest effect of the selected enzymes in biofilm control, either when applied alone or each one in combination with CTAB. Total biofilm removal or CFU reduction was not achieved and, in some cases, the use of enzymes antagonized the effects of CTAB. The results also propose that complementary tests, to characterize biofilm integrity and microbial viability, are required when someone is trying to assess the role of novel biocide - enzyme mixtures for effective biofilm control.

Combination of selected enzymes with cetyltrimethylammonium bromide in biofilm inactivation, removal and regrowth

KAUST Repository

Araujo, Paula Alexandra Da Silva

2017-03-01

Enzymes are considered an innovative and environmentally friendly approach for biofilm control due to their lytic and dispersal activities. In this study, four enzymes (β-glucanase, α-amylase, lipase and protease) were tested separately and in combination with the quaternary ammonium compound cetyltrimethylammonium bromide (CTAB) to control flow-generated biofilms of Pseudomonas fluorescens. The four enzymes caused modest reduction of biofilm colony forming units (CFU). Protease, β-glucanase and α-amylase also caused modest biofilm removal. CTAB combined with either β-glucanase or α-amylase increased biofilm removal. Its combination with either β-glucanase or protease increased CFU reduction. However, CTAB−protease combination was antagonist in biofilm removal. Long-term effects in biofilm mass reduction were observed after protease exposure. In contrast, biofilms treated with β-glucanase were able to regrowth significantly after exposure. Moreover, short-term respirometry tests with planktonic cells were performed to understand the effects of enzymes and their combination with CTAB on P. fluorescens viability. Protease and lipase demonstrated antimicrobial action, while α-amylase increased bacterial metabolic activity. The combination of CTAB with either protease or α-amylase was antagonistic, decreasing the antimicrobial action of CTAB. The overall results demonstrate a modest effect of the selected enzymes in biofilm control, either when applied alone or each one in combination with CTAB. Total biofilm removal or CFU reduction was not achieved and, in some cases, the use of enzymes antagonized the effects of CTAB. The results also propose that complementary tests, to characterize biofilm integrity and microbial viability, are required when someone is trying to assess the role of novel biocide - enzyme mixtures for effective biofilm control.

Final results of the 'Benchmark on computer simulation of radioactive nuclides production rate and heat generation rate in a spallation target'

International Nuclear Information System (INIS)

Janczyszyn, J.; Pohorecki, W.; Domanska, G.; Maiorino, R.J.; David, J.C.; Velarde, F.A.

2011-01-01

A benchmark has been organized to assess the computer simulation of nuclide production and heat generation in a spallation lead target. The physical models applied for the calculation of thick lead target activation do not produce satisfactory results for the majority of analysed nuclides, however one can observe better or worse quantitative compliance with the experimental results. Analysis of the quality of calculated results show the best performance for heavy nuclides (A: 170 - 190). For intermediate nuclides (A: 60 - 130) almost all are underestimated while for A: 130 - 170 mainly overestimated. The shape of the activity distribution in the target is well reproduced in calculations by all models but the numerical comparison shows similar performance as for the whole target. The Isabel model yields best results. As for the whole target heating rate, the results from all participants are consistent. Only small differences are observed between results from physical models. As for the heating distribution in the target it looks not quite similar. The quantitative comparison of the distributions yielded by different spallation reaction models shows for the major part of the target no serious differences - generally below 10%. However, in the most outside parts of the target front layers and the part of the target at its end behind the primary protons range, a spread higher than 40 % is obtained

HETC-3STEP calculations of proton induced nuclide production cross sections at incident energies between 20 MeV and 5 GeV

Energy Technology Data Exchange (ETDEWEB)

Takada, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yoshizawa, Nobuaki; Ishibashi, Kenji

1996-08-01

For the OECD/NEA code intercomparison, nuclide production cross sections of {sup 16}O, {sup 27}Al, {sup nat}Fe, {sup 59}Co, {sup nat}Zr and {sup 197}Au for the proton incidence with energies of 20 MeV to 5 GeV are calculated with the HETC-3STEP code based on the intranuclear cascade evaporation model including the preequilibrium and high energy fission processes. In the code, the level density parameter derived by Ignatyuk, the atomic mass table of Audi and Wapstra and the mass formula derived by Tachibana et al. are newly employed in the evaporation calculation part. The calculated results are compared with the experimental ones. It is confirmed that HETC-3STEP reproduces the production of the nuclides having the mass number close to that of the target nucleus with an accuracy of a factor of two to three at incident proton energies above 100 MeV for {sup nat}Zr and {sup 197}Au. However, the HETC-3STEP code has poor accuracy on the nuclide production at low incident energies and the light nuclide production through the fragmentation process induced by protons with energies above hundreds of MeV. Therefore, further improvement is required. (author)

Cross Sections for the Production of Residual Nuclides by Proton-Induced Reactions with Uranium at Medium Energies

International Nuclear Information System (INIS)

Issa, S.A.M.; Michel, R.; Uosif, M.A.M.; Issa, S.A.M.; Flamentc, J.L.; David, J.C.; Leray, S.

2009-01-01

The production of residual nuclides by proton-induced reactions on uranium is investigated using activated targets from irradiation experiments at Saturne II synchrocyclotron at the Laboratory National Saturne/Saclay. These investigations contribute to the European research project NUDATRA within the IP EUROTRANS in which the feasibility of accelerator-driven transmutation of nuclear waste is evaluated. Experimental cross sections are derived from gamma-spectrometric measurements. A total of 1894 cross-section was deter-mined covering 44 residual nuclides in the energy range from 211 MeV to 2530 MeV. The experimental data together with those of earlier work of our group are discussed in the context of theoretical excitation functions calculated by the newly developed INCL4 + ABLA and the TALYS codes

Accelerator based production of fissile nuclides, threshold uranium price and perspectives; Akceleratorska proizvodnja fisibilnih nuklida, granicna cijena urana i perspektive

Energy Technology Data Exchange (ETDEWEB)

Djordjevic, D [INIS-Inzenjering, Sarajevo (Yugoslavia); Knapp, V [Elektrotehnicki fakultet, zagreb (Yugoslavia)

1988-07-01

Accelerator breeder system characteristics are considered in this work. One such system which produces fissile nuclides can supply several thermal reactors with fissile fuel, so this system becomes analogous to an uranium enrichment facility with difference that fissile nuclides are produced by conversion of U-238 rather than by separation from natural uranium. This concept, with other long-term perspective for fission technology on the basis of development only one simpler technology. The influence of basic system characteristics on threshold uranium price is examined. Conditions for economically acceptable production are established. (author)

Application of bacteriophages to selectively remove Pseudomonas aeruginosa in water and wastewater filtration systems.

Science.gov (United States)

Zhang, Yanyan; Hunt, Heather K; Hu, Zhiqiang

2013-09-01

Water and wastewater filtration systems often house pathogenic bacteria, which must be removed to ensure clean, safe water. Here, we determine the persistence of the model bacterium Pseudomonas aeruginosa in two types of filtration systems, and use P. aeruginosa bacteriophages to determine their ability to selectively remove P. aeruginosa. These systems used beds of either anthracite or granular activated carbon (GAC), which were operated at an empty bed contact time (EBCT) of 45 min. The clean bed filtration systems were loaded with an instantaneous dose of P. aeruginosa at a total cell number of 2.3 (± 0.1 [standard deviation]) × 10(7) cells. An immediate dose of P. aeruginosa phages (1 mL of phage stock at the concentration of 2.7 × 10(7) PFU (Plaque Forming Units)/mL) resulted in a reduction of 50% (± 9%) and >99.9% in the effluent P. aeruginosa concentrations in the clean anthracite and GAC filters, respectively. To further evaluate the effects of P. aeruginosa phages, synthetic stormwater was run through anthracite and GAC biofilters where mixed-culture biofilms were present. Eighty five days after an instantaneous dose of P. aeruginosa (2.3 × 10(7) cells per filter) on day 1, 7.5 (± 2.8) × 10(7) and 1.1 (± 0.5) × 10(7) P. aeruginosa cells/g filter media were detected in the top layer (close to the influent port) of the anthracite and GAC biofilters, respectively, demonstrating the growth and persistence of pathogenic bacteria in the biofilters. A subsequent 1-h dose of phages, at the concentration of 5.1 × 10(6) PFU/mL and flow rate of 1.6 mL/min, removed the P. aeruginosa inside the GAC biofilters and the anthracite biofilters by 70% (± 5%) and 56% (± 1%), respectively, with no P. aeruginosa detected in the effluent, while not affecting ammonia oxidation or the ammonia-oxidizing bacterial community inside the biofilters. These results suggest that phage treatment can selectively remove pathogenic bacteria with minimal impact on beneficial

Radioactive fallout nuclides in a peat-bog ecosystem

International Nuclear Information System (INIS)

Pausch, G.; Hofmann, W.; Steger, F.; Tuerk, R.

1996-01-01

The Province of Salzburg belongs to the regions with the highest contamination from the Chernobyl-fallout outside the former USSR. The peat-bog investigated in this study is situated in Koppl, east of Salzburg. A peat-bog is a special example of an ecosystem, which is generally not disturbed by human activities because it is under strict nature-conservation and whose soil structure is not affected by animal activities from moles and earthworms. Peat-bogs are characterized by acidic soils which are high in organic material and low in clay mineral content. A number of previous studies have demonstrated that especially in peat-bogs and especially in the Koppl-peat-bog very high amounts of radioactive fallout nuclides from the Chernobyl accident and from the bomb-testings could be found

Radioactive material transport in sodium-cooled nuclear reactors

International Nuclear Information System (INIS)

Brehm, W.F.; McGuire, J.C.; Colburn, R.P.; Maffei, H.P.; Olson, W.H.

1980-03-01

Trapping devices which remove nuclides from the sodium stream in pre-selected locations away from maintenance areas have been developed and proven successful in in-reactor testing. The release of corrosion product radionuclides as a function of system temperature and oxygen content has been quantitatively evaluated. Ongoing work concentrates on further in-reactor testing of radionuclide removal devices, and characterization of fission product release and deposition from fuel pins with breached-cladding

New analytical method for fast nuclide identification in mobile in-situ gamma spectrometers; Neue analytische Methode zur schnellen Nuklididentifikation in mobilen in-situ Gammaspektrometern

Energy Technology Data Exchange (ETDEWEB)

Streil, T.; Oeser, V.; Wagner, W. [SARAD GmbH, Dresden (Germany); Doerfel, H.R. [IDEA System GmbH, Karlsruhe (Germany)

2016-07-01

Demolition and accidents of nuclear reactors or terroristic attacks may lead to large-area contamination with radionuclides. A suitable mobile measurement equipment should allow a quick overview about the extent of contamination. Recent methods apply for nuclide identification either time-consuming peak-fitting methods inclusive background correction or the so-called trapezoid method determining so-called regions of interest (ROI). Since the nuclide vector is often known, this information can be used as a starting point for the nuclide identification. The presented method uses dynamic smoothing of the registered energy spectrum in accordance with the detector resolution. In this way, noise is effectively suppressed without substantial degradation of the detector resolution. The statistically prepared spectrum is then two-fold differentiated. This provides the peak positions and the two turning points of the found peaks. Nuclide identification is possible using the peak positions, and with the peak and turning point positions and the corresponding values of the spectrum, on may calculate the area of an assumed Gausz distribution without considering the in any case present continuous background. With a 2 x 2'' NaI-detector, as being used in the NucScout device, one can identify a {sup 137}Cs-activity of 200 Bq/kg at distance of 1 m in 10 s. Combined with adapted calibration methods, the algorithm for nuclide identification implemented in the NucScout is also applicable for other geometries, e. g., using a Marinelli cup in the LabScout device.

Radiometric dating by alpha spectrometry on uranium series nuclides

International Nuclear Information System (INIS)

Wijk, A. van der.

1987-01-01

This thesis describes the analytical and technical procedures that are required for routine application of both the 230 Th/ 234 U disequilibrium dating method for peat and the 210 Pb dating method for lake sediments. Its principal aim is to test, refine and discuss the reliability and validity of these methods. On the other hand, the analytical procedures that were introduced open a wide range of other interesting fields of research that are not necessarily restricted to geological problems only. Chapter 5 reports an obviously not foreseen application: detection of alpha emitting nuclides released in the first weeks of May, 1986 during the accident with the nuclear power plant in Chernobyl, USSR. 128 refs.; 43 figs.; 15 tabs

Denitration of simulated high-level liquid wastes and selective removal of cesium with zeolites

Energy Technology Data Exchange (ETDEWEB)

Mimura, Hitoshi; Kanno, Takuji [Tohoku Univ., Sendai (Japan). Research Inst. of Mineral Dressing and Metallurgy; Kimura, Toshiya

1982-03-01

Denitration of high-level liquid wastes (HLW) from nuclear fuel reprocessing has been studied. Selective removal of Cs has been also examined with various types of zeolites. The following zeolites were used in this study; Na-synthetic mordenite (NaSM), Na-natural mordenite (NaNM), Na-natural clinoptilolite (NaCP) and H-synthetic mordenites (HSM). The effective denitration is found in the simulated HLW (15 components, 2N HNO/sub 3/ soln.) containing platinum group elements in the case of the addition of formic acid, and the pH of the solution shows the value of 5.4 when the excess formic acid ((HCOOH)/(HNO/sub 3/) = 2.0) was added. Platinum group elements may react as a catalyst for the decomposition of nitric acid and the excess formic acid. The break-through properties of NaSM column are poor for the simulated HLW, and the selective removal of Cs appears to be difficult. On the other hand, good results are obtained in the denitrated HLW, i.e., break-through capacity, total capacity and column utilization are 59.4 (meq./100 g zeolite), 147 (meq./100 g zeolite) and 40.4 (%), respectively. The break-through properties of NaSM and NaNM are superior to those of HSM. The break-through capacity and column utilization increase with an increase in column temperature.

Denitration of simulated high-level liquid wastes and selective removal of cesium with zeolites

International Nuclear Information System (INIS)

Mimura, Hitoshi; Kanno, Takuji; Kimura, Toshiya.

1982-01-01

Denitration of high-level liquid wastes (HLW) from nuclear fuel reprocessing has been studied. Selective removal of Cs has been also examined with various types of zeolites. The following zeolites were used in this study; Na-synthetic mordenite (NaSM), Na-natural mordenite (NaNM), Na-natural clinoptilolite (NaCP) and H-synthetic mordenites (HSM). The effective denitration is found in the simulated HLW (15 components, 2N HNO 3 soln.) containing platinum group elements in the case of the addition of formic acid, and the pH of the solution shows the value of 5.4 when the excess formic acid ([HCOOH]/[HNO 3 ] = 2.0) was added. Platinum group elements may react as a catalyst for the decomposition of nitric acid and the excess formic acid. The break-through properties of NaSM column are poor for the simulated HLW, and the selective removal of Cs appears to be difficult. On the other hand, good results are obtained in the denitrated HLW, i.e., break-through capacity, total capacity and column utilization are 59.4 (meq./100 g zeolite), 147 (meq./100 g zeolite) and 40.4 (%), respectively. The break-through properties of NaSM and NaNM are superior to those of HSM. The break-through capacity and column utilization increase with an increase in column temperature. (author)

Performance evaluation of reverse osmosis technology for selected antibiotics removal from synthetic pharmaceutical wastewater

Directory of Open Access Journals (Sweden)

Gholami Mitra

2012-12-01

Full Text Available Abstract This study addresses the possibility for low pressure reverse osmosis membrane (RE 2521, CSM process to serve as an alternative to remove selected antibiotics (ampicillin and amoxicillin from synthetic wastewater by changing operating conditions such as pH = 3, 6.5 and 10; Pressure = 9, 11 and13 (bar; antibiotic concentration = 10, 255 and 500(mg/L, and temperature = 20, 30 and 40°C. The experiment was designed based on Box-benken, which is a Response Surface methodology design (RSM, using Design Expert software. The concentration of antibiotics was measured by applying a UV-spectrophotometer (Cecil, at the wavelength of 254 nm. Results showed a range of rejection percentage from 73.52% to 99.36% and 75.1% to 98.8%, for amoxicillin and ampicillin, respectively. Considering the solute rejections and the membrane porosity show that the prevailing rejection mechanism of the examined antibiotics by the membrane was the size exclusion effect. The permeate flux for both of the antibiotics was 12–18.73 L/m2.h. Although the permeate flux and antibiotic rejection are influenced by operating pressure, pH, and temperature individually, the interaction between operating parameters did not have noticeable effects. According to the results obtained in this study, the application of RO membrane is recommended for the selected antibiotics to be removed to a considerable degree (up to 95%.

Rapid, Selective Heavy Metal Removal from Water by a Metal-Organic Framework/Polydopamine Composite.

Science.gov (United States)

Sun, Daniel T; Peng, Li; Reeder, Washington S; Moosavi, Seyed Mohamad; Tiana, Davide; Britt, David K; Oveisi, Emad; Queen, Wendy L

2018-03-28

Drinking water contamination with heavy metals, particularly lead, is a persistent problem worldwide with grave public health consequences. Existing purification methods often cannot address this problem quickly and economically. Here we report a cheap, water stable metal-organic framework/polymer composite, Fe-BTC/PDA, that exhibits rapid, selective removal of large quantities of heavy metals, such as Pb 2+ and Hg 2+ , from real world water samples. In this work, Fe-BTC is treated with dopamine, which undergoes a spontaneous polymerization to polydopamine (PDA) within its pores via the Fe 3+ open metal sites. The PDA, pinned on the internal MOF surface, gains extrinsic porosity, resulting in a composite that binds up to 1634 mg of Hg 2+ and 394 mg of Pb 2+ per gram of composite and removes more than 99.8% of these ions from a 1 ppm solution, yielding drinkable levels in seconds. Further, the composite properties are well-maintained in river and seawater samples spiked with only trace amounts of lead, illustrating unprecedented selectivity. Remarkably, no significant uptake of competing metal ions is observed even when interferents, such as Na + , are present at concentrations up to 14 000 times that of Pb 2+ . The material is further shown to be resistant to fouling when tested in high concentrations of common organic interferents, like humic acid, and is fully regenerable over many cycles.

Radon and its short-lived decay nuclides in the living environment

International Nuclear Information System (INIS)

Abe, Siro

1988-01-01

The problem about radon and its shortlived decay nuclides in the living environment has been frequently closed-up. The problem is focused on the exposure of human being due to radon and its progeny. This paper reports the reason to the occurrence of the problem. Radon source as well as its pathway into our rooms are outlined here. The behavior of radon and its progeny indoors is also shown in this paper in comparison with outdoor situation and from the persons' activity's point of view. (author)

Removal of clay by stingless bees: load size and moisture selection

Directory of Open Access Journals (Sweden)

RAUL COSTA-PEREIRA

2014-09-01

Full Text Available Some organisms disperse energy, associated with the transportation of resource, which is not necessarily food. Stingless bees of Central Amazonia (Melipona flavolineata and M. lateralis collect clay in banks along streams for nest building. The moisture of the clay varies along the bank, and bees collect clay from specific location, indicating that there is some sort of preference regarding their selection. This study aims at identifying: if larger bees carry more clay; if there is a preference for moisture of substrates; and if bees are less efficient accumulating and transporting clay when it is wet. In order to do so, I measured the size of the bees and of the pellets of clay found in the corbicula. I set up a field experiment to test substrate preferences. The amount of clay transported, increased exponentially in accordance to the size of the bee, and the preferred substrate was the driest clay. The amount and the efficiency of removal of clay were not affected by the moisture of the substrate. Despite the wet clay being denser, it does not reduce the efficiency of exploitation of the resource, but suggests that bees spend more energy to carry the same quantity of wet clay, which may be the underlying mechanism explaining their preference for removing drier clay.

Demonstration of nuclide migration phenomena in rock on high level irradiation waste geological disposal

International Nuclear Information System (INIS)

Kanazawa, Yasuo; Okuyama, Yasuko; Takahashi, Manabu

1997-01-01

We have studied on main three theme. From study of material movement in rock-groundwater system in the area of high concentration of irradiative elements, the results proved that minerals with Fe 3+ and clay mineral were very important as mineral held nuclide, the existence of pyrite suggested uranium nuclei enrichment and the latter reduced circumstances, and nuclei movement and accumulation could be estimated from oxidation-reduction potential, kinds of dissolved ions and activity ratio. By study of evaluation of permeability in deep rock fissure system, each measurement method of transmissivity in the Transient Pulse method, the Oscillation test and the Flow Pump method was established. The effect of principle stress, confining pressure, pore water pressure and axial pressure on transmissivity could be determined in the limited level of stress. By study of nuclide migration phenomena and change of rock depend on fissure system, the relation between the degree of change and fissure system was investigated and alternation mineral was identified and it's formation conditions estimated. (S.Y.)

Timing of Expansions of the Quelccaya Ice Cap, Peru, and Implications for Cosmogenic Nuclide Production Rate Calibration

Science.gov (United States)

Lowell, T. V.; Kelly, M. A.; Applegate, P. J.; Smith, C. A.; Phillips, F. M.; Hudson, A. M.

2010-12-01

We calibrate the production rate of the cosmogenic nuclide beryllium-10 (10Be) at a low-latitude, high-elevation site, using nuclide concentrations measured in moraine boulders and an independent chronology determined with bracketing radiocarbon dates. The measurement of terrestrial cosmogenic nuclide (TCN) concentrations in earth surface materials has been an important development for understanding a host of earth surface processes. Uncertainty in cosmogenic nuclide production rates has hampered application of this method. Here, we contribute to the estimation of 10Be production rates by reporting both preliminary 10Be concentrations and independent radiocarbon dates from a low latitude, high elevation site. Our study site in the southeastern Peruvian Andes (~13.9°S, 70.9°W, 4850 m asl) is centered on a moraine set, known as the Huancané II moraines, that represents a ~4 km expansion of Quelccaya Ice Cap during late glacial time. At this location, organic material situated both stratigraphically below and above moraines in two adjacent valleys provide material for radiocarbon dating. Based on geomorphic arguments, we correlate results from the two valleys. The timing of ice cap margin advance is bracketed by 13 radiocarbon ages on organic material within the outermost Huancané II moraines that range from 13.6 to 12.5 ka. Two stratigraphic sections upvalley from the moraines yield 6 radiocarbon ages from 11.3 to 12.4 ka, indicating the time of retreat . We computed the probability density function that lies between these two sets of dates, and assign an age of 12.4 ka (+/-???) for the formation of the Huancané II moraines. Calculating beryllium-10 exposure dates from the measured concentrations yield exposure dates that significantly underestimate the independently determined age of the moraine (~8-30%), if existing production rate estimates are used. We suggest that the radiocarbon age for the moraines can be used as a robust independent calibration for 10Be

The selective and non-selective cyclooxygenase inhibitors valdecoxib and piroxicam induce the same postoperative analgesia and control of trismus and swelling after lower third molar removal

Directory of Open Access Journals (Sweden)

V. Benetello

2007-08-01

Full Text Available We compared the clinical efficacy of orally administered valdecoxib and piroxicam for the prevention of pain, trismus and swelling after removal of horizontally and totally intrabony impacted lower third molars. Twenty-five patients were scheduled to undergo removal of symmetrically positioned lower third molars in two separate appointments. Valdecoxib (40 mg or piroxicam (20 mg was administered in a double-blind, randomized and crossed manner for 4 days after the surgical procedures. Objective and subjective parameters were recorded for comparison of postoperative courses. Both agents were effective for postoperative pain relief (N = 19. There was a similar mouth opening at suture removal compared with the preoperative values (86.14 ± 4.36 and 93.12 ± 3.70% of the initial measure for valdecoxib and piroxicam, respectively; ANOVA. There was no significant difference regarding the total amount of rescue medication taken by the patients treated with valdecoxib or piroxicam (173.08 ± 91.21 and 461.54 ± 199.85 mg, respectively; Wilcoxon test. There were no significant differences concerning the swelling observed on the second postoperative day compared to baseline measures (6.15 ± 1.84 and 8.46 ± 2.04 mm for valdecoxib and piroxicam, respectively; ANOVA or on the seventh postoperative day (1.69 ± 1.61 and 2.23 ± 2.09 mm for valdecoxib and piroxicam, respectively; ANOVA. The cyclooxygenase-2 selective inhibitor valdecoxib is as effective as the non-selective cyclooxygenase inhibitor piroxicam for pain, trismus and swelling control after removal of horizontally and totally intrabony impacted lower third molars.

Impact of burnable absorber Gd on nuclide composition for VVER-440 fuel (Gd-2)

International Nuclear Information System (INIS)

Zajac, R.; Chrapciak, V.

2010-01-01

The latest version of Russian fuel VVER-440 includes burnable absorber in 6 pins. In this article is impact of burnable absorber on nuclide composition and criticality analyzed. In part 1 was analyzed whole burnup interval 0-50 MWd/kgU. In present part 2 are detailed analysis only for first cycle (burnup 0-10 MWd/kgU). (Authors)

Production and Separation of T = 1/2 Nuclides for {beta}--{nu} angular correlation measurements

Energy Technology Data Exchange (ETDEWEB)

Delahaye, P.; Bajeat, O.; Saint Laurent, M. G.; Thomas, J. C.; Traykov, E. [GANIL, CEA/DSM-CNRS/IN2P3, Bd. Becquerel, BP 55027, 14076 CAEN Cedex 05 (France); Couratin, C. [GANIL, CEA/DSM-CNRS/IN2P3, Bd. Becquerel, BP 55027, 14076 CAEN Cedex 05 (France); LPC Caen, 6 bd Marechal Juin, 14050 CAEN Cedex (France); Lienard, E.; Ban, G.; Durand, D.; Flechard, X. [LPC Caen, 6 bd Marechal Juin, 14050 CAEN Cedex (France); Naviliat-Cuncic, O. [NSCL, Michigan State University, 1 Cyclotron, East Lansing, Michigan 48824-1321 (United States); Stora, T. [ISOLDE, CERN, 1211 Geneva 23 (Switzerland); Collaboration: GANISOL Group

2011-11-30

The SPIRAL facility at GANIL, which uses the so-called ISOL method to produce radioactive ion beams, is being upgraded to extend its production capabilities to the metallic beams of neutron deficient isotopes. We discuss here the potentialities offered by this upgrade for the measurement of the {beta}--{nu} angular correlation in the {beta}--decay of mirror nuclides.

Performance of water filters towards the removal of selected ...

African Journals Online (AJOL)

Organic matter removal was found to be 47%, 43%, 53%, 43.4% for bio-sand, slow sand, ceramic and membrane purifier respectively, while, fluoride removal was found to be 95.5% for bone char filter. Furthermore, filters were also assessed in terms of media availability, buying costs, operation, benefits/ effectiveness ...

Difficulty in the usage of nuclides in hospitals

International Nuclear Information System (INIS)

Ueda, Hideo

1980-01-01

In Japan, the uses of radioisotopes in hospitals are increasing year after year. Therefore, the problems of the treatment and disposal of radioactive wastes are important. The liquid and gaseous wastes with radioactivity concentrations below the maximum permissible levels are allowed to be disposed of on the sites by the law. However, high-level liquid wastes and solid wastes cannot be disposed of on the sites. These wastes stored in steel drums are collected by Japan Radioisotope Association, and finally treated and disposed of on the site of Japan Atomic Energy Research Institute. The nuclides used in hospitals are principally Tc-99m, and also 131 I, 198 Au, 125 I and 3 H. The following matters are described: the present situation, radioactive wastes from medical treatments, and the management of radioactive solid, liquid and gaseous wastes from hospitals. (J.P.N.)

Transuranium nuclides in the environment

International Nuclear Information System (INIS)

1976-01-01

Projected development of nuclear power up to the year 2000 entails a substantial increase in the number of nuclear power reactors, of irradiated fuel reprocessing plants and of various other supporting facilities in the nuclear fuel cycle. In this period, transuranium elements, especially plutonium, will be produced in substantial quantities as by-products of the fission process and for use as fuel in present and future nuclear power reactors; these elements will have other peaceful applications as well. Growing world-wide interest and a natural desire to protect man and his environment have led to increasing concern in public, scientific and governmental sectors about the, release of such radionuclides into the environment. Although releases of transuranium nuclides from existing nuclear facilities can be controlled to very low levels, it is essential, in view of their long half-lives and high relative radiotoxicities, that their fate in the environment be understood well enough to permit associated potential impacts to be assessed and hence effective control to be provided. Extensive studies for many years have investigated the distribution and behaviour of these elements and potential detriments resulting from their release to the environment. More recently, scientists have begun to make projections for evaluating the degree of control necessary if such materials are to enter the complex chain of commercial activities associated with nuclear power production

Evaluation of selected ion exchangers for the removal of cesium from MVST W-25 supernate

International Nuclear Information System (INIS)

Collins, J.L.; Egan, B.Z.; Anderson, K.K.; Chase, C.W.; Mrochek, J.E.; Bell, J.T.; Jernigan, G.E.

1995-04-01

The goal of this batch-test equilibration study was to evaluate the effectiveness of certain ion exchangers for removing cesium from supernate taken from tank W-25 of the Melton Valley Storage Tank (MVST) Facility located at the Oak Ridge National Laboratory (ORNL). These exchangers were selective for removing cesium from alkaline supernatant solutions with high salt concentrations. Since the supernates of evaporator concentrates stored in tanks at the MVST facility have compositions similar to some of those stored in tanks at Hanford, the data generated in this study should prove useful in the overall evaluation of the ion exchangers for applications to Hanford and other US Department of Energy (USDOE) sites. A goal of the waste processing effort at Hanford is to remove enough cesium to ensure that the resulting LLW will meet the Nuclear Regulatory Commission (NRC) 10 CFR 61 class A limit for 137 Cs (1 Ci/m 3 or 1 μCi/mL). The separated cesium may be concentrated and vitrified for disposal in the high-level waste repository. The decontaminated effluent would be solidified for near-surface disposal

Four shells atomic model to computer the counting efficiency of electron-capture nuclides

International Nuclear Information System (INIS)

Grau Malonda, A.; Fernandez Martinez, A.

1985-01-01

The present paper develops a four-shells atomic model in order to obtain the efficiency of detection in liquid scintillation courting, Mathematical expressions are given to calculate the probabilities of the 229 different atomic rearrangements so as the corresponding effective energies. This new model will permit the study of the influence of the different parameters upon the counting efficiency for nuclides of high atomic number. (Author) 7 refs

Atomic and nuclear parameters of single electron capture decaying nuclides

International Nuclear Information System (INIS)

Grau, A.

1981-01-01

Atomic and nuclear parameters of the following nuclides which decay by electron capture have been calculated: 37 A r, 41 C a, 49 V , 53 M n, 55 F e,59 N i, 68Ge,82 S r, 97 T c, 118 T e, 131 C s, 137 L a, 140 N d, 157 T b, 165 E r, 193 p t, 194 H g, and 205 P h The evaluation rules are included in the first part of the paper. The values and the associated uncertainties of the following parameters have been tabulated: decay energy, electron capture probabilities, fluorescence yield, electron emission and X-ray emission. (Author) 27 refs

Isoreticular rare earth fcu-MOFs for the selective removal of H 2 S from CO 2 containing gases

KAUST Repository

Bhatt, Prashant

2017-05-04

In this work, we present the implementation of reticular chemistry and the molecular building block approach to unveil the appropriateness of Rare Earth (RE) based Metal-Organic Frameworks (MOFs) with fcu topology for H2S removal applications. Markedly, RE-fcu-MOFs, having different pore apertures sizes in the range of 4.7-6.0 Å and different functionalities, showed excellent properties for the removal of H2S from CO2 and CH4 containing gases such as natural gas, biogas and landfill gas. A series of cyclic mixed gas breakthrough experiments were carried out on three isoreticular fcu-MOFs, containing linkers of different lengths (between 8.4 and 5 Å), by using simulated natural gas mixture containing CO2/H2S/CH4 (5%/5%/90%) under different adsorption and regeneration conditions. The fcu-MOF platform has good H2S removal capacity with a high H2S/CO2 selectivity, outperforming benchmark materials like activated carbon and Zeolites in many aspects. The comparison of H2S removal performance with the related structures of the RE-fcu-MOFs provides insightful information to shed light on the relationship between the structural features of the MOF and its associated H2S separation properties. The excellent H2S/CO2 and H2S/CH4 selectivity of these materials offer great prospective for the production of pure H2S, with acceptable levels of CO2for Claus process to produce elemental sulfur.

Uranium, thorium and potassium contents and radioactive equilibrium states of the uranium and thorium series nuclides in phosphate rocks and phosphate fertilizers

Energy Technology Data Exchange (ETDEWEB)

Komura, K; Yanagisawa, M; Sakurai, J; Sakanoue, M

1985-10-01

Uranium, thorium and potassium contents and radioactive equilibrium states of the uranium and thorium series nuclides have been studied for 2 phosphate rocks and 7 phosphate fertilizers. Uranium contents were found to be rather high (39-117 ppm) except for phosphate rock from Kola. The uranium series nuclides were found to be in various equilibration states, which can be grouped into following three categories. Almost in the equilibrium state, 238U approximately 230Th greater than 210Pb greater than 226Ra and 238U greater than 230Th greater than 210Pb greater than 226Ra. Thorium contents were found to be, in general, low and appreciable disequilibrium of the thorium series nuclides was not observed except one sample. Potassium contents were also very low (less than 0.3% K2O) except for complex fertilizers. Based on the present data, discussions were made for the radiation exposure due to phosphate fertilizers.

A methodology for selective removal of orbital debris

Science.gov (United States)

Ash, R. L.; Odonoghue, P. J.; Chambers, E. J.; Raney, J. P.

1992-01-01

Earth-orbiting objects, large enough to be tracked, were surveyed for possible systematic debris removal. Based upon the statistical collision studies of others, it was determined that objects in orbits approximately 1000 km above the Earth's surface are at greatest collisional risk. Russian C-1B boosters were identified as the most important target of opportunity for debris removal. Currently, more than 100 in tact boosters are orbiting the Earth with apogees between 950 km and 1050 km. Using data provided by Energia USA, specific information on the C-1B booster, in terms of rendezvous and capture strategies, was discussed.

Importance of individual fission nuclide to incontainment radioactive reading during PWR accidents

International Nuclear Information System (INIS)

Li Junfeng; Shi Zhongqi

2004-01-01

Containment radiation level is one of the most important base for core damage assessment and protective actions recommendation during accidents. Incontainment radioactive reading calculations is the precondition of using this kind of method. Importance of individual nuclides were compared during normal coolant release, gap release and core melt. Conclusions are deduced that when the spray is off, the radioactive reading in containment is mainly from iodine and noble gas, and the spray is on, the radioactive reading is mainly from noble gas. (authors)

Selective flotation for the removal of radionuclides from contaminated soil

International Nuclear Information System (INIS)

Miller, J.D.; Yu, Q.; Lu, Y.Q.

1995-01-01

Low-level radioactive contaminated soils (10--500 pci/gm) created by defense-related activities at certain Superfund sites, such as Nevada Test Site (NTS), is a current environmental concern. Many of these contaminated sites may require appropriate cleanup and restoration, which could cost billions of dollars and put tremendous pressure on limited financial resources. Therefore, the development of a selective flotation process to separate such radionuclides from contaminated soils should be considered. In this study, both a pure depleted UO 2 sample and three synthetic UO 2 /soil mixtures were used to evaluate surface chemistry features and to examine the possibility for the flotation of fine UO 2 particles from selected soils. It was intended that this model system would be a reasonable representation of contaminated soils such as those found the Nevada Test Site which are reported to be contaminated by PuO 2 fallout. The effect of reagent schedule, particle size distribution, and surface charge are discussed with respect to the flotation separation of the UO 2 /soil mixtures. It was found that both commercial fatty acids and reagent grade sodium oleate are effective collectors for UO 2 flotation provided the pH is adjusted to the range of pH 8--9. The bench-scale flotation results successfully demonstrated that froth flotation technology can be used to remove UO 2 from such model contaminated soils with appropriate flotation chemistry conditions which depend on the soil characteristics and other pretreatment procedures

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.

Neogene basin infilling from cosmogenic nuclides (10Be and 21Ne) in Atacama, Chile

Science.gov (United States)

Sanchez, Caroline; Regard, Vincent; Carretier, Sébastien; Riquelme, Rodrigo; Blard, Pierre-Henri; Campos, Eduardo; Brichau, Stéphanie; Lupker, Marteen; Hérail, Gérard

2017-04-01

In the hyperarid Atacama Desert, northern Chile, Neogene sediments host copper rich layers (exotic supergene mineralization). Current mines are excavated into relatively thin (production (quickly decreasing with depth) and disintegration (not for 21Ne). Sampling depths are at ˜100 m and at ˜50 m below the desert surface. First, 21Ne gives lower boundaries for upstream erosion rates or local sedimentation rate. These bounds are between 2 and 10 m/Ma, which is quite important for the area. The ratio between the two cosmogenic nuclides indicate a maximum burial age of 12 Ma (minimal erosion rate of 15 m/Ma) and is surprisingly similar from bottom to top, indicating a probable rapid infilling. We finally processed a Monte-Carlo inversion. This inversion helps taking into account the post-deposition muonic production of cosmogenic nuclides. Inversion results is dependent on the muonic production scheme. Interestingly, the similarity in concentrations from bottom to top pleads for quite low production at depth. Our data finally indicates a quick infilling between 12.5 and 10 Ma BP accounting for ˜100 m of deposition (minimum sedimentation rate of 40 m/Ma).

Study on fitness functions of genetic algorithm for dynamically correcting nuclide atmospheric diffusion model

International Nuclear Information System (INIS)

Ji Zhilong; Ma Yuanwei; Wang Dezhong

2014-01-01

Background: In radioactive nuclides atmospheric diffusion models, the empirical dispersion coefficients were deduced under certain experiment conditions, whose difference with nuclear accident conditions is a source of deviation. A better estimation of the radioactive nuclide's actual dispersion process could be done by correcting dispersion coefficients with observation data, and Genetic Algorithm (GA) is an appropriate method for this correction procedure. Purpose: This study is to analyze the fitness functions' influence on the correction procedure and the forecast ability of diffusion model. Methods: GA, coupled with Lagrange dispersion model, was used in a numerical simulation to compare 4 fitness functions' impact on the correction result. Results: In the numerical simulation, the fitness function with observation deviation taken into consideration stands out when significant deviation exists in the observed data. After performing the correction procedure on the Kincaid experiment data, a significant boost was observed in the diffusion model's forecast ability. Conclusion: As the result shows, in order to improve dispersion models' forecast ability using GA, observation data should be given different weight in the fitness function corresponding to their error. (authors)

An analysis of the correlation between dust storms in Korea and 137Cs nuclide concentration

International Nuclear Information System (INIS)

Choi, Soo-won; Kim, Jeong-hun; Shin, Sang-hwa; Hwang, Joo-ho

2008-01-01

Dust storms occur in Korea during spring time when fine dust is blown in from the far western regions of western China and Mongolia. A fine powdery dust is blown up into the sky and enters the upper reaches of the atmosphere where it is carried easterly across China then slowly falls to the ground on the Korean peninsula and Japan. The dust originates mostly in the Gobi dessert of China, as well as the yellow earth regions in the middle and upper streams of the Yellow river in China. Previous studies on dust storms have been limited to following or estimating their courses, distribution and frequency, or distribution of the heavy metals they transmit. However, since radionuclides exist in the dust, they must also exist in the dust storms. In this study, we analyzed the correlation of :1 37 Cs nuclide concentration based on a count of annual dust storm occurrence in the city of Suwon, South Korea and assessed seasonal differences of 137 Cs nuclide concentration

Distribution of transuranic nuclides in Mediterranean ecosystems

International Nuclear Information System (INIS)

Ballestra, S.; Thein, M.; Fukai, R.

1982-01-01

For the comprehensive understanding of the behaviour of transuranic elements in the marine environment, the knowledge on the distribution of these elements in various components of marine ecosystems is essential. Since the Mediterranean Sea is considered a sufficiently self-contained system, our approach for studying the processes controlling the transuranic cycling in the sea has been to follow, step by step, the redistribution of plutonium and americium in different components of the marine environment, taking Mediterranean ecosystems as examples. While the studies in the past years have supplied quantitative information on the inputs of plutonium and americium into the Mediterranean from atmospheric fallout and rivers as well as on their behaviour in the Mediterranean water column, only scattered data have been made available so far on the occurrence of the transuranic nuclides in the Mediterranean marine biota or sediments. In order to fill up this information gap, biological and sediment samples were collected from the northwestern Mediterranean region during 1975-1978 for the transuranic measurements. The results of these determinations are given in the present report

Complex nuclear-structure phenomena revealed from the nuclide production in fragmentation reactions

International Nuclear Information System (INIS)

Ricciardi, M.V.; Kelic, A.; Napolitani, P.; Schmidt, K.H.; Yordanov, O.; Ignatyuk, A.V.; Rejmund, F.

2003-12-01

Complex structural effects in the nuclide production from the projectile fragmentation of 1 A GeV 238 U nuclei in a titanium target are reported. The structure seems to be insensitive to the excitation energy induced in the reaction. This is in contrast to the prominent structural features found in nuclear fission and in transfer reactions, which gradually disappear with increasing excitation energy. Using the statistical model of nuclear reactions, relations to structural effects in nuclear binding and in the nuclear level density are demonstrated. (orig.)

The behavior of U- and Th-series nuclides in groundwater

Science.gov (United States)

Porcelli, D.; Swarzenski, P.W.

2003-01-01

Groundwater has long been an active area of research driven by its importance both as a societal resource and as a component in the global hydrological cycle. Key issues in groundwater research include inferring rates of transport of chemical constituents, determining the ages of groundwater, and tracing water masses using chemical fingerprints. While information on the trace elements pertinent to these topics can be obtained from aquifer tests using experimentally introduced tracers, and from laboratory experiments on aquifer materials, these studies are necessarily limited in time and space. Regional studies of aquifers can focus on greater scales and time periods, but must contend with greater complexities and variations. In this regard, the isotopic systematics of the naturally occurring radionuclides in the U- and Th- decay series have been invaluable in investigating aquifer behavior of U, Th, and Ra. These nuclides are present in all groundwaters and are each represented by several isotopes with very different half-lives, so that processes occurring over a range of time-scales can be studied (Table 1⇓). Within the host aquifer minerals, the radionuclides in each decay series are generally expected to be in secular equilibrium and so have equal activities (see Bourdon et al. 2003). In contrast, these nuclides exhibit strong relative fractionations within the surrounding groundwaters that reflect contrasting behavior during release into the water and during interaction with the surrounding host aquifer rocks. Radionuclide data can be used, within the framework of models of the processes involved, to obtain quantitative assessments of radionuclide release from aquifer rocks and groundwater migration rates. The isotopic variations that are generated also have the potential for providing fingerprints for groundwaters from specific aquifer environments, and have even been explored as a means for calculating groundwater ages.

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)

Selective Magnetic Removal of Pb(II from Aqueous Solution by Porphyrin Linked-Magnetic Nanoparticles

Directory of Open Access Journals (Sweden)

H. Ghanbarnejad

2012-12-01

Full Text Available The discharge of lead containing effluents into the environment and water bodies is harmful for the human, animals, aquatic flora and fauna. Herein, a novel surface engineered magnetic nanoparticle for removing Pb2+  ions was studied. After surface modification of the magnetite by 3-amino-propyltriethoxysilane (APTES magnetic nanoparticles with covalently linked porphyrins were synthesized. Two atropisomers of  meso-tetrakis(2-carboxy-4-nonylphenyl porphyrin (TCNP were tested to analyze the atropisomeric effect on lead uptake. For characterize the synthesized nanosorbents methods like: Transform Infrared Spectroscopy, X-ray diffraction, Transmission Electron Microscopy and Thermo-Gravimetric Analysis were used. The effects of pH, contact time, sorbent dosage and some co-existing cations were investigated. Regeneration of lead adsorbed material could be possible and the modified magnetic nanoparticles exhibited good reusability. The use of such a system can provide fast and efficient removal of the lead ion by using an external magnetic field. The competitive adsorption tests showed good adsorption selectivity for lead ion.

Nuclide release calculation in the near-field of a reference HLW repository

International Nuclear Information System (INIS)

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

2004-01-01

The HLW-relevant R and D program for disposal of high-level radioactive waste has been carried out at Korea Atomic Energy Research Institute (KAERI) since early 1997 in order to develop a conceptual Korea Reference Repository System for direct disposal of nuclear spent fuel by the end of 2007. A preliminary reference geologic repository concept considering such established criteria and requirements as waste and generic site characteristics in Korea was roughly envisaged in 2003 focusing on the near-field components of the repository system. According to above basic repository concept, which is similar to that of Swedish KBS-3 repository, the spent fuel is first encapsulated in corrosion resistant canisters, even though the material has not yet been determined, and then emplaced into the deposition holes surrounded by high density bentonite clay in tunnels constructed at a depth of about 500 m in a stable plutonic rock body. Not only to demonstrate how much a reference repository is safe in the generic point of view with several possible scenarios and cases associated with a preliminary repository concept by conducting calculations for nuclide release and transport in the near-field components of the repository, even though enough information has not been available that much yet, but also to show a methodology by which a generic safety assessment could be performed for further development of Korea reference repository concept, nuclide release calculation study strongly seems to be necessary

Development of in-situ laser cutting technique for removal of single selected coolant channel from pressurized heavy water reactor

International Nuclear Information System (INIS)

Vishwakarma, S.C.; Upadhyaya, B.N.

2016-01-01

We report on the development of a pulsed Nd:YAG laser based cutting technique for removal of single coolant channel from pressurized heavy water reactor (PHWR). It includes development of special tools/manipulators and optimization of laser cutting process parameters for cutting of liner tube, end fitting, bellow lip weld joint, and pressure tube stubs. For each cutting operation, a special tool with precision motion control is utilized. These manipulators/tools hold and move the laser cutting nozzle in the required manner and are fixed on the same coolant channel, which has to be removed. This laser cutting technique has been successfully deployed for removal of selected coolant channels Q-16, Q-15 and N-6 of KAPS-2 reactor with minimum radiation dose consumption and in short time. (author)

International program to improve decay data for transactinium nuclides

International Nuclear Information System (INIS)

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

1985-01-01

To help meet an identified need for precise decay data, in 1977 the IAEA organized an international Coordinated Research Program (CRP) to measure and evaluate half-lives and γ - and α - emission probabilities for selected transactinium nuclides of importance for reactor technology. The CRP goals were (1) to determine a list of data that needed improvement, (2) to encourage new measurements, and (3) to evaluate the available data. All three phases of this work are now complete. Our participation in this effort has involved the measurement of γ-ray emission probabilities for /sup 232, 233, 235/U, /sup 238, 239, 240, 241/Pu, 229 Th and 233 Pa, as well as participating in the data evaluation. The γ-emission probabilities were determined from the measurement of γ-emission rates with the goal of obtaining uncertainties of less than or equal to 1%. γ measurements were made on calibrated Ge detectors. These calibrations were done by standard methods, generally involving measurements at approx. 60 γ-ray energies from 14 to 2700 keV. The efficiency-calibration functions were assigned uncertainties ranging from 2% below 50 keV to 0.50% from 400 to 1400 keV. The determination of the decay rates of the various sources involved several techniques. The 238 Pu, 239 Pu and 240 Pu samples were calibrated by gross α-emission-rate measurements at NBS. The 235 U sample was taken from an NBS-calibrated spike solution. The 241 Pu and 233 U samples were calibrated by isotope-dilution mass spectrometry based on spikes of the calibrated 239 Pu, 240 Pu and 235 U materials. Some of our results are given, together with a comparison of some present and previous results. 20 refs

Trace elements and radionuclides in the Connecticut River and Amazon River estuary

International Nuclear Information System (INIS)

Dion, E.P.

1983-01-01

The Connecticut River, its estuary and the Amazon River plume were studied to elucidate processes which control the flux of nuclides to the sea. Major ions (Ca, Mg, Na, Cl, Bicarbonate) and selected trace elements (Ra, Ba, Cu, Si) are introduced to the Connecticut River in proportion to the total dissolved load of various groundwaters. Si, Ra, and Ba are subject to removal from solution by seasonal diatom productivity; whereas the other groundwater-derived elements are found in proportion to TDS both time and space. These nuclides are released in the estuary when a portion of the Ra, Ba, and Si in riverine biogenic detritus is trapped in salt marshes and coves bordering the estuary where it redissolves and is exported to the main river channel at ebb tide. In the Amazon River estuary, the Ra and Ba are released in mid-salinity waters. Ra and Ba together with Si are subsequently removed by diatom productivity as reflected in increased Ra and Ba in the suspended particles and depleted dissolved nuclide concentrations in samples from the high productivity zone. In both the Connecticut River system and the Amazon River plume, Cu behaves conservatively; whereas the fates of Fe and Al are linked to soil-derived humic acids. Trace elements in Amazon plume sediments are found simply in proportion to the percentage of fine-grained size materials, despite low Th-228/Ra-228 mean residence times in the plume and the presence of Cs-137 in the sediment column. Estimates of the total flux of nuclides to the oceans can best be calculated on a mass balance basis using groundwater inputs. Unless significant repositories for nuclides exist in the river-estuarine system, the groundwater flux of dissolved nuclides is net flux to the ocean despite the reactions which occur in both rivers and estuaries

Methods of Increasing the Performance of Radionuclide Generators Used in Nuclear Medicine: Daughter Nuclide Build-Up Optimisation, Elution-Purification-Concentration Integration, and Effective Control of Radionuclidic Purity

Directory of Open Access Journals (Sweden)

Van So Le

2014-06-01

Full Text Available Methods of increasing the performance of radionuclide generators used in nuclear medicine radiotherapy and SPECT/PET imaging were developed and detailed for 99Mo/99mTc and 68Ge/68Ga radionuclide generators as the cases. Optimisation methods of the daughter nuclide build-up versus stand-by time and/or specific activity using mean progress functions were developed for increasing the performance of radionuclide generators. As a result of this optimisation, the separation of the daughter nuclide from its parent one should be performed at a defined optimal time to avoid the deterioration in specific activity of the daughter nuclide and wasting stand-by time of the generator, while the daughter nuclide yield is maintained to a reasonably high extent. A new characteristic parameter of the formation-decay kinetics of parent/daughter nuclide system was found and effectively used in the practice of the generator production and utilisation. A method of “early elution schedule” was also developed for increasing the daughter nuclide production yield and specific radioactivity, thus saving the cost of the generator and improving the quality of the daughter radionuclide solution. These newly developed optimisation methods in combination with an integrated elution-purification-concentration system of radionuclide generators recently developed is the most suitable way to operate the generator effectively on the basis of economic use and improvement of purposely suitable quality and specific activity of the produced daughter radionuclides. All these features benefit the economic use of the generator, the improved quality of labelling/scan, and the lowered cost of nuclear medicine procedure. Besides, a new method of quality control protocol set-up for post-delivery test of radionuclidic purity has been developed based on the relationship between gamma ray spectrometric detection limit, required limit of impure radionuclide activity and its measurement

APTES Functionalized Iron Oxide-Silver Magnetic Hetero-Nanocomposites for Selective Capture and Rapid Removal of Salmonella enteritidis from Aqueous Solution

Science.gov (United States)

Trang, Vu Thi; Dinh, Ngo Xuan; Lan, Hoang; Tam, Le Thi; Huy, Tran Quang; Tuan, Pham Anh; Phan, Vu Ngoc; Le, Anh-Tuan

2018-02-01

Magnetic nanomaterials, as a promising platform for the fast and sensitive detection of bacterial pathogens, have attracted increasing interest from researchers in recent years. In this work, by utilizing a two-step synthetic technique consisting of co-precipitation and subsequent hydrothermal reaction, followed by functionalization steps with (3-aminopropyl)triethoxysilane (APTES) and the antibody against Salmonella enteritidis, antibody-conjugated Fe3O4-Ag@APTES hetero-nanocomposites were successfully prepared. Due to the specific antibody, the developed Fe3O4-Ag@APTES@SE-Ab conjugates are capable of selectively capturing S. enteritidis at a low concentration of about 101 CFU/mL. Moreover, the prepared magnetic conjugates also revealed that the S. enteritidis could be rapidly removed from water solution in 20 min by using an external magnetic field with a removal efficiency obtained of ˜ 91.36%. These results indicated that the Fe3O4-Ag@APTES@SE-Ab conjugates are promising for the rapid selective capture and removal of bacterial pathogens from aqueous environments, and can be used for improving the detection quality of pathogens in water samples using immunosensor-based diagnostic tests.

Nuclide transport models for HLW repository safety assessment in Finland, Japan, Sweden, and Canada

Energy Technology Data Exchange (ETDEWEB)

Lee, Young Myoung; Kang, Chul Hyung; Hwang, Yong Soo; Choi, Jong Won; Kim, Sung Gi; Koh, Won Il

1997-10-01

Disposal and design concepts in such countries as Sweden, Finland, Canada and Japan which have already published safety assessment reports for the HLW repositories have been reviewed mainly in view of nuclide transport models used in their assessment. This kind of review would be very helpful in doing similar research in Korea where research program regarding HLW has been just started. (author). 44 refs., 2 tabs., 30 figs

Technical factors in the site selection for a radioactive wastes storage of low and intermediate level

International Nuclear Information System (INIS)

Badillo A, V. E.; Ramirez S, J. R.; Palacios H, J. C.

2009-10-01

The storage on surface or near surface it is viable for wastes of low and intermediate level which contain radio nuclides of short half life that would decay at insignificant levels of radioactivity in some decades and also radio nuclides of long half life but in very low concentrations. The sites selection, for the construction of radioactive waste storages, that present an appropriate stability at long term, a foreseeable behavior to future and a capacity to fulfill other operational requirements, is one of the great tasks that confront the waste disposal agencies. In the selection of potential sites for the construction of a radioactive wastes storage of low and intermediate level, several basic judgments should be satisfied that concern to physiography, climatology, geologic, geo-hydrology, tectonic and seismic aspects; as well as factors like the population density, socioeconomic develops and existent infrastructure. the necessary technician-scientific investigations for the selection of a site for the construction of radioactive waste storages are presented in this work and they are compared with the pre-selection factors realized in specify areas in previous studies in different regions of the Mexican Republic. (Author)

Development of gas-jet transport systems for fission products and coupling these with methods for continuous separation of short-lived product nuclides

International Nuclear Information System (INIS)

Stender, E.

1979-01-01

The development of gas-jet transport systems for fission products as well as the coupling of these with continuous separation methods from aqueous solutions (SISAK) and with a mass separator for on-line separation of neutron-rich nuclides are described in this work. Nuclides from the fission of 235 U or other fission materials can be transported using gas-jet systems with thermal neutrons over larger distances (100 m and over). Aerosols (clusters) of either organic (e.g. ethylene) or inorganic nature (e.g. potassium chloride) serve as carrier for the nuclides. The clusters are passed through 1 mm capillaries with a transport gas (nitrogen, helium etc.) under laminar flow conditions. The diameter of the cluster fluctuates between 10 -7 and 10 -6 m. The time required from the production of a nuclide to its detection at the end of a 8 m long capillary tube is 0.8 s for the ethylene/nitrogen and potassium chloride/helium gas-jet systems. By coupling various gas-jet systems with the continuous extraction technique SISAK working with H centrifuges, the elements lanthanum, cerium, praseodymium, zirconium, niobium and technetium can be separated out of the complex fission product mixtures. The on-line technetium chemistry was used with neutron-rich 106 Tc (36 s), 107 Tc (21 s) and 108 Tc (5 s) for γγ(t) measurements. The coupling of a potassium chloride/helium gas jet with a mass separator equiped with a plasma ion source is described. The dependence of the transmission rate of various test parameters is investigated to optimize the system. (orig.) [de

Stable evaluation methods of neutron-physical characteristics of nuclides on the basis of experimental data

International Nuclear Information System (INIS)

Volkov, N.G.; Kryanev, A.V.

1984-01-01

Technique for obtaining estimations of neutron-physical characteristics of nuclides on the basis of stable estimation methods is set forth. The technique presupposes correction of incorrectly determined errors of measurements and disclosure of systematic errors with their succeeding accountancy. A system of orthogonal polynomials is used as approximating functional dependence. The technique is also generalized at the presence of correlation between measurements

Method of estimating the sensitivity of a calculated nuclide vector to deviations in initial data

International Nuclear Information System (INIS)

Ivanov, E.A.

1998-12-01

The application of perturbation theory algorithms in modelling of nuclides transmutation is considered. The perturbation theory is used to construct the analytical technique of sensitivity analysis. It is shown that such algorithms have to be used in modelling of lifetime performance of nuclear power installations with the Monte Carlo method. The present approach differs from others by consistent use of analytical methods. (author)

Innovative Highly Selective Removal of Cesium and Strontium Utilizing a Newly Developed Class of Inorganic Ion Specific Media - 16221

International Nuclear Information System (INIS)

Denton, Mark S.; Kanatzidis, Mercouri G.

2009-01-01

Highly selective removal of Cesium and Strontium is critical for waste treatment and environmental remediation. Cesium-137 is a beta-gamma emitter and Strontium-90 is a beta emitter with respective half-lives of 30 and 29 years. Both elements are present at many nuclear sites. Cesium and Strontium can be found in wastewaters at Washington State's Hanford Site, as well as in waste streams of many Magnox reactor sites. Cesium and Strontium are found in the Reactor Coolant System of light water reactors at nuclear power plants. Both elements are also found in spent nuclear fuel and in high-level waste (HLW) at DOE sites. Cesium and Strontium are further major contributors to the activity and the heat load. Therefore, technologies to extract Cesium and Strontium are critical for environmental remediation waste treatment and dose minimization. Radionuclides such as Cesium-137 and Strontium-90 are key drivers of liquid waste classification at light water reactors and within the DOE tank farm complexes. The treatment, storage, and disposal of these wastes represents a major cost for nuclear power plant operators, and comprises one of the most challenging technology-driven projects for the DOE Environmental Management (EM) program. Extraction technologies to remove Cesium and Strontium have been an active field of research. Four notable extraction technologies have been developed so far for HLW: solvent extraction, prussian blue, crystalline silico-titanate (CST) and organic ion-exchangers (e.g., resorcinol formaldehyde and SuperLig). The use of one technology over another depends on the specific application. For example, the waste treatment plant (WTP) at Hanford is planning on using a highly-selective organic ion-exchange resin to remove Cesium and Strontium. Such organic ion-exchangers use molecular recognition to selectively bind to Cesium and Strontium. However, these organic ion-exchangers are synthesized using multi-step organic synthesis. The associated cost to

Field methods for determining contents of alpha-radiating nuclides on the areas contaminated with depositions after the Chernobyl nuclear power station failure

International Nuclear Information System (INIS)

Pitkevich, V.A.; Duba, V.V.

1992-01-01

The work is aimed at creating field methods for estimating contents of alpha-radiating nuclides on the areas contaminated with depositions after the Chernobyl' station failure and for measuring the density of alpha-particles flux at various depths of soil. The methods make it possible to estimate the character of migration of isotopes Pu in depth. Instrumental and physical grounding of the methods are given. One can find the results of field measurements of α-active nuclides content in depositions. The results of measurement prove theoretical and practical feasibility of the suggested methods. 2 refs.; 4 figs.; 1 tabs

Application of on-line HPLC-ICP-MS for the determination of the nuclide abundances of lanthanides produced via spallation reactions in an irradiated tantalum target of a spallation neutron source

International Nuclear Information System (INIS)

Kerl, W.; Becker, J.S.; Dietze, H.J.

1998-01-01

An analytical procedure has been developed for the determination of spallation nuclides in an irradiated tantalum target using HPLC coupled on-line to ICP-MS after dissolution and separation of the tantalum matrix. Pieces of tantalum were taken from different locations of the irradiated tantalum target which had been used as the target material in a spallation neutron source. Tantalum was dissolved in a HNO 3 /HF mixture and the tantalum matrix was separated by liquid-liquid extraction so that only the spallation nuclides were left in the sample solutions. The major fraction of the spallation nuclides in the tantalum target are lanthanide metals in the μg g -1 concentration range determined in the present study. Additional reaction products are formed by the irradiation of trace impurities in the original tantalum target. The nuclide abundances of the lanthanide metals measured in the tantalum target differ significantly from the natural isotopic composition so that a lot of isobaric interferences of long-lived radionuclides and stable isotopes in the mass spectrum are to be expected. Therefore, all the lanthanide metals had to be separated chemically prior to their mass spectrometric determination. The separation of all rare earth elements was performed by ion chromatography on-line to ICP-MS. The nuclide abundances of each lanthanide were determined using a sensitive double-focusing sector field inductively coupled plasma mass spectrometer. The nuclide abundances of the lanthanides in the irradiated tantalum target calculated theoretically and the experimental results obtained by on-line HPLC-ICP-MS proved to be in good agreement. (orig.)

Stable nuclide tracer studies and human amino acid requirements. A summary

International Nuclear Information System (INIS)

Young, V.R.

1994-01-01

The nutritional requirements for proteins have been estimated for various age groups. The current status of knowledge concerning the quantitative needs for specific indispensable amino acids was reviewed and it was concluded that, except for infants, current values for pre-school children, school age children and healthy adults are based on limited experimental data and/or on results from nitrogen balance determinations which are open to serious question regarding their nutritional significance. A review of 13 C-labelled tracer studies carried out in MIT laboratories was undertaken to demonstrate the applicability of stable nuclide tracer studies for purposes of determining the amino acid requirements of humans. 5 refs

Tackling the challenge of selective analytical clean-up of complex natural extracts: the curious case of chlorophyll removal.

Science.gov (United States)

Bijttebier, Sebastiaan; D'Hondt, Els; Noten, Bart; Hermans, Nina; Apers, Sandra; Voorspoels, Stefan

2014-11-15

Alkaline saponification is often used to remove interfering chlorophylls and lipids during carotenoids analysis. However, saponification also hydrolyses esterified carotenoids and is known to induce artifacts. To avoid carotenoid artifact formation during saponification, Larsen and Christensen (2005) developed a gentler and simpler analytical clean-up procedure involving the use of a strong basic resin (Ambersep 900 OH). They hypothesised a saponification mechanism based on their Liquid Chromatography-Photodiode Array (LC-PDA) data. In the present study, we show with LC-PDA-accurate mass-Mass Spectrometry that the main chlorophyll removal mechanism is not based on saponification, apolar adsorption or anion exchange, but most probably an adsorption mechanism caused by H-bonds and dipole-dipole interactions. We showed experimentally that esterified carotenoids and glycerolipids were not removed, indicating a much more selective mechanism than initially hypothesised. This opens new research opportunities towards a much wider scope of applications (e.g. the refinement of oils rich in phytochemical content). Copyright © 2014 Elsevier Ltd. All rights reserved.

RICKI, Interactive Gamma Spectra Unfolding with Isotope Identification

International Nuclear Information System (INIS)

Proctor, A.E.

1990-01-01

1 - Description of program or function: RICKI is an interactive program for analysis of gamma spectra containing one or more peaks with possible multiplets. Algorithms are incorporated for peak fitting, analysis, and nuclide identification. Comprehensive output keeps the user informed of the analysis as it proceeds and presents the results. User-selectable options for plotting and neutron activation analysis are available to control this analysis. RICKI was developed to analyze spectra from examinations of severe fuel damage specimens. Two features included to streamline the analysis of Three Mile Island (TMI) core bore data are the edit of averaged activities and the output file created for generating a spreadsheet. Activity editing allows the user to select which gamma lines are used for a specific nuclide in average activity calculations. Contributions from peak areas which result from overlapping lines of two or more nuclides may be removed. For each averaged activity an edited activity file record is written containing the nuclide name, averaged activity, activity standard deviation, scan start position, and scan end position. 2 - Method of solution: The peak search algorithm utilizes an optimized second derivative filter for efficient and reliable determination of peak location. A linear Gaussian fitting technique, which is a modified version of Mukoyama's linear least squares fitting method in which the centroid, sigma, and peak height are free parameters, is used to calculate peak areas. An estimated background is computed for each peak using Gunnink's method. Nuclide activities are computed by matching centroids with nuclide library entries and averaging the activity calculated for each matching peak. 3 - Restrictions on the complexity of the problem - Maxima of: 500 gamma library entries, 80 peaks/spectrum

Transfer of nuclides from the water phase to the sediments during normal and extraordinary hydrological cycles

International Nuclear Information System (INIS)

1985-07-01

Atucha I and Atucha II nuclear power plants are located on the right margin of the Parana de las Palmas river. This river belongs to the Cuenca del Plata, whose 1982-1983 hydrologic cycle registered the greatest freshets of the century. Works and studies previously fixed had to be altered and investigations were adapted to the possibilities and the particular hydric conditions verified. Considerations on the transfer of nuclides between water and sediments are presented. The floods reduce the water-sediments contact time on the bed of the river. In outer areas, the waters labelled by the nuclear power plant effluent discharge favor the infiltration in alluvial soils, as well as the exchange with the sediments. The investigations carried out for the phase near to the discharge of liquid effluents (related to the critical group) made possible to prove the characteristics of the path of the liquid wastes released, the distribution coefficient and the fixation or penetrability of some nuclides in soils of the floody valley. In this manner, a balance of radioactive nuclides incorporated to soils and sediments from the neighbourhood of Atucha and the water-course of Parana de las Palmas river is obtained. The presence of 60 Co and 137 Cs in the floody soils on the right margin of this river was detected and measured during the greatest flood of the century. On the other hand, 144 Ce, 51 Cr, 106 Ru and 90 Sr have not been detected. The detection of artificial radioisotopes turns out to be impossible in normal hydrological years, even in the sorroundings of the nuclear power plant or the critical group (from the point of view of the surface waters, The Fishing Club, 3 km down stream). (M.E.L.) [es

Batch test equilibration studies examining the removal of Cs, Sr, and Tc from supernatants from ORNL underground storage tanks by selected ion exchangers

International Nuclear Information System (INIS)

Collins, J.L.; Egan, B.Z.; Anderson, K.K.; Chase, C.W.; Bell, J.T.

1995-01-01

Bench-scale batch equilibration tests have been conducted with supernatants from two underground tanks at the Melton Valley Storage Tank (MVST) Facility at Oak Ridge National Laboratory (ORNL) to determine the effectiveness of selected ion exchangers in removing cesium, strontium, and technetium. Seven sorbents were evaluated for cesium removal, nine for strontium removal, and four for technetium removal. The results indicate that granular potassium cobalt hexacyanoferrate was the most effective of the exchangers evaluated for removing cesium from the supernatants. The powdered forms of sodium titanate (NaTiO) and cystalline silicotitanate (CST) were superior in removing the strontium; however, for the sorbents of suitable particle size for column use, titanium monohydrogen phosphate (TiHP φ), sodium titanate/polyacrylonitrile (NaTiO-PAN), and titanium monohydrogen phosphate/polyacrylonitrile (TiP-PAN) gave the best results and were about equally effective. Reillex trademark 402 was the most effective exchanger in removing the technetium; however, it was only slightly more satisfactory than Reillex trademark HPQ

Nuclear power technology system with molten salt reactor for transuranium nuclides burning in closed fuel cycle

International Nuclear Information System (INIS)

Alekseev, P.N.; Dudnikov, A.A.; Ignatiev, V.V.; Prusakov, V.N.; Ponomarev-Stepnoy, N.N.; Subbotin, S.A.

2000-01-01

A concept of nuclear power technology system with homogeneous molten salt reactors for burning and transmutation of long-lived radioactive toxic nuclides is considered in the paper. Disposition of such reactors in enterprises of fuel cycle allows to provide them with power and facilitate solution of problems with rad waste with minimal losses. (Authors)

Do cosmogenic nuclides (10Be, 14C , 21Ne, 26Al) track late Quaternary climate changes on the Altiplano?

Science.gov (United States)

Hippe, K.; Kober, F.; Zeilinger, G.; Ivy-Ochs, S.; Kubik, P.; Maden, C.; Wieler, R.

2010-12-01

The high Altiplano plateau is the most prominent element of the Central Andes, separating the Andean Cordilleras between 15° to 22° S. It represents a tectonically quiet, intramontane basin with arid to semi-arid climate, low relief and internal drainage. Throughout the late Quaternary regional climate on the Altiplano repeatedly changed between wet and dry conditions [1]. The influence of climate on the plateau evolution during the Pleistocene/Holocene is unclear, however, as data on erosion processes and rates on the Altiplano are sparse. Here, we present a multiple-nuclide study investigating surface denudation at the eastern Altiplano of Bolivia (16°-17° S) on millennial and longer timescales. The aim is a better understanding of the complex feedback between climate, tectonics and geomorphology on the topographic evolution of the Andes. Catchment-wide denudation (CWD) rates are provided for a 150 km NW-SE transect along the Altiplano edge based on the analyses of cosmogenic 10Be, 26Al, 21Ne and in-situ 14C in river-borne sediment. Single nuclide CWD rates obtained for 10Be, 26Al and 21Ne are similar for all three nuclides and on the order of 3-37 mm/ka. Thus, the calculated denudation rates provide an averaged denudation history dating back at least to the middle Pleistocene. Denudation rates correlate positively with the mean basin hillslope, which is mainly controlled by basin lithology. For most catchments both, the 26Al/10Be ratios and the 21Ne/10Be ratios indicate a complex erosion/exposure history with probably several periods of sediment storage and burial/shielding totalling ~0.5 - 1.2 Ma. Local geomorphology featuring low slopes and low relief, small terraces and local floodplains also suggests that sediment transport might have been periodically ineffective. Concentrations of in-situ produced short-lived 14C are significantly lower than expected from the concentrations of the long-lived and stable cosmogenic nuclides. This would indicate a 30

Study on Selective Removal of Impurity Iron from Leached Copper-Bearing Solution Using a Chelating Resin

Directory of Open Access Journals (Sweden)

Yubiao Li

2016-10-01

Full Text Available In order to selectively remove iron from copper laden solution after leaching but prior to electrowinning, equilibrium, kinetic, and thermodynamic studies have been conducted on an a chelating resin of Rexp-501 at pH 1.0 and at various temperatures. Both Langmuir and Freundlich models were investigated, with the Langmuir model proving to be more suitable for fitting iron removal performance, with little influence from copper concentration. Compared with the pseudo first order kinetic model, the pseudo second order kinetic model fitted the dynamic adsorption process better, indicating a chemisorption mechanism. Fourier transform infrared spectroscopy (FT-IR results indicated that C=O from carbonyl group played a key role in combining with iron and can be regenerated and reused. However, the C=O of the acylamino group combining with iron was not able to be released after oxalic acid was applied.

Application and evolution of several therapy nuclides labelled antibody in tumour therapy

International Nuclear Information System (INIS)

He Jiaheng; Luo Shunzhong; Wang Guanquan

2004-12-01

Radiolabeled Monoclonal antibody had a lot of merits, such as decreasing the lesion because of the external exposure to normal tissue and the whole body, destroying cancer cells which McAb could not reach, and little ornamentation effect by Antigen. Therefor, it gradually became a kind of guiding therapy method which endowed with practical value. Up to now, the radionuclides which be used for tumour radioimmunotherapy included mostly 131 I, 90 Y, 188 Re, 186 Re, 153 Sm, 211 At, et al. The application and evolution of several therapy nuclides labelled antibody in tumour therapy are in troduced. (authors)

Scoping calculation of nuclides migration in engineering barrier system for effect of volume expansion due to overpack corrosion and intrusion of the buffer material

International Nuclear Information System (INIS)

Yoshita, Takashi; Ishihara, Yoshinao; Ishiguro, Katsuhiko; Ohi, Takao; Nakajima, Kunihiko

1999-11-01

Corrosion of the carbon steel overpack leads to a volume expansion since the specific gravity of corrosion products is smaller than carbon steel. The buffer material is compressed due to the corrosive swelling, reducing its thickness and porosity. On the other hand, buffer material may be extruded into fractures of the surrounding rock and this may lead to a deterioration of the planned functions of the buffer, including retardation of nuclides migration and colloid filtration. In this study, the sensitivity analyses for the effect of volume expansion and intrusion of the buffer material on nuclide migration in the engineering barrier system are carried out. The sensitivity analyses were performed on the decrease in the thickness of the buffer material in the radial direction caused by the corrosive swelling, and the change in the porosity and dry density of the buffer caused by both compacting due to corrosive swelling and intrusion of buffer material. As results, it was found the maximum release rates of relatively shorter half-life nuclides from the outside of the buffer material decreased for taking into account of a volume expansion due to overpack corrosion. On the other hand, the maximum release rates increased when the intrusion of buffer material was also taking into account. It was, however, the maximum release rates of longer half-life nuclides, such as Cs-137 and Np-237, were insensitive to the change of buffer material thickness, and porosity and dry density of buffer. (author)

Boiling water reactors with Uranium-Plutonium mixed oxide fuel. Report 1: Accuracy of the nuclide concentrations calculated by CASMO-4

International Nuclear Information System (INIS)

Demaziere, C.

1999-01-01

This report is a part of the project titled 'Boiling Water Reactors With Uranium-Plutonium Mixed Oxide (MOx) Fuel'. The aim of this study is to model the impact of a core loading pattern containing MOx bundles upon the main characteristics of a BWR (reactivity coefficients, stability, etc.). The tools that are available to perform a modeling in the Department of Reactor Physics in Chalmers are CASMO-4/TABLES-3/SIMULATE-3 from Studsvik of America. These CMS (Core Management System) programs have been extensively compared with both measurements and reference codes. Nevertheless some data are proprietary in particular the comparison of the calculated nuclide concentrations versus experiments (because of the cost of this kind of experimental study). This is why this report describes such a comparative investigation carried out with a General Electric 7x7 BWR bundle. Unfortunately, since some core history parameters were unknown, a lot of hypotheses have been adopted. This invokes sometimes a significant discrepancy in the results without being able to determine the origin of the differences between calculations and experiments. Yet one can assess that, except for four nuclides - Plutonium-238, Curium-243, Curium-244 and Cesium-135 - for which the approximate power history (history effect) can be invoked, the accuracy of the calculated nuclide concentrations is rather good if one takes the numerous approximations into account

Nuclide creation and annealing reactor waste in neutron fields

International Nuclear Information System (INIS)

Kondrat'ev, V.N.; Kadenko, I.M.

2007-01-01

We consider chemical elements in the Universe (their properties and transmutations) as a fuel powering an evolution of stars, galaxies, etc. The nuclear fusion reactions represent an energy source of stars and, in particular, the Sun fitting the life on the Earth. This brings a question on an origin and conditions for creation of life. We discuss some specific features of nuclear reaction chains at the hydrostatic burning of nuclides in stars and treaties for development of thermonuclear fusion reactors at the Earth based environment. The nova and supernova give promising astrophysical site candidates for synthesis of heavy atomic nuclei and renewing other nuclear components. Such an explosive nucleosynthesis yields the actinides containing basic fuel for nuclear fission reactors, among others. We briefly outline the e-, s-, and r-processes while accounting for ultra-strong stellar magnetization, and discuss some ideas for annealing the radioactive toxic nuclear waste

Application of Micro-coprecipitation Method to Alpha Source Preparation for Measuring Alpha Nuclides

International Nuclear Information System (INIS)

Lee, Myung Ho; Park, Jong Ho; Oh, Se Jin; Song, Byung Chul; Song, Kyuseok

2011-01-01

Among the source preparations, an electrodeposition is a commonly used method for the preparation of sources for an alpha spectrometry, because this technique is simple and produces a very thin deposit, which is essential for a high resolution of the alpha peak. Recently, micro-coprecipitation with rare earths have been used to yield sources for -spectrometry. In this work, the Pu, Am and Cm isotopes were purified from hindrance nuclides and elements with an a TRU resin in radioactive waste samples, and the activity concentrations of the Pu, Am and Cm isotopes were determined by radiation counting methods after alpha source preparation like micro coprecipitation. After the Pu isotopes in the radioactive waste samples were separated from the other nuclides with an anion exchange resin, the Am isotopes were purified with a TRU resin and an anion exchange resin or a TRU resin. Activity concentrations and chemical recoveries of 241 Am purified with the TRU resin were similar to those with the TRU resin and anion exchange resin. In this study, to save on the analytical time and cost, the Am isotopes were purified with the TRU resin without using an additional anion exchange resin. After comparing the electrodeposition method with the micro-coprecipitation method, the micro-coprecipitation method was used for the alpha source preparation, because the micro-coprecipitation method is simple and more reliable for source preparation of the Pu, Am and Cm isotopes

A novel method of selective removal of human DNA improves PCR sensitivity for detection of Salmonella Typhi in blood samples.

Science.gov (United States)

Zhou, Liqing; Pollard, Andrew J

2012-07-27

Enteric fever is a major public health problem, causing an estimated 21million new cases and 216,000 or more deaths every year. Current diagnosis of the disease is inadequate. Blood culture only identifies 45 to 70% of the cases and is time-consuming. Serological tests have very low sensitivity and specificity. Clinical samples obtained for diagnosis of enteric fever in the field generally have blood, so that even PCR-based methods, widely used for detection of other infectious diseases, are not a straightforward option in typhoid diagnosis. We developed a novel method to enrich target bacterial DNA by selective removal of human DNA from blood samples, enhancing the sensitivity of PCR tests. This method offers the possibility of improving PCR assays directly using clinical specimens for diagnosis of this globally important infectious disease. Blood samples were mixed with ox bile for selective lysis of human blood cells and the released human DNA was then digested with addition of bile resistant micrococcal nuclease. The intact Salmonella Typhi bacteria were collected from the specimen by centrifugation and the DNA extracted with QIAamp DNA mini kit. The presence of Salmonella Typhi bacteria in blood samples was detected by PCR with the fliC-d gene of Salmonella Typhi as the target. Micrococcal nuclease retained activity against human blood DNA in the presence of up to 9% ox bile. Background human DNA was dramatically removed from blood samples through the use of ox bile lysis and micrococcal nuclease for removal of mammalian DNA. Consequently target Salmonella Typhi DNA was enriched in DNA preparations and the PCR sensitivity for detection of Salmonella Typhi in spiked blood samples was enhanced by 1,000 fold. Use of a combination of selective ox-bile blood cell lysis and removal of human DNA with micrococcal nuclease significantly improves PCR sensitivity and offers a better option for improved typhoid PCR assays directly using clinical specimens in diagnosis of

Mechanism study of selective heavy metal ion removal with polypyrrole-functionalized polyacrylonitrile nanofiber mats

International Nuclear Information System (INIS)

Wang, Jianqiang; Luo, Chao; Qi, Genggeng; Pan, Kai; Cao, Bing

2014-01-01

Graphical abstract: - Highlights: • PAN/PPy core/shell nanofiber used for Cr(VI) removal. • Adsorption mechanisms were investigated. • Selective adsorption performances were investigated. - Abstract: Polyacrylonitrile/polypyrrole (PAN/PPy) core/shell nanofiber mat was prepared through electrospinning followed by a simple chemical oxidation method. The polypyrrole-functionalized nanofiber mats showed selective adsorption performance for anions. The interaction between heavy metal anions and polypyrrole (especially the interaction between Cr 2 O 7 2− and polypyrrole) during the adsorption process was studied. The results showed that the adsorption process included two steps: one was the anion exchange process between the Cl − and Cr(VI), and the other was the redox process for the Cr(VI) ions. The adsorption amount was related to the protonation time of the PAN/PPy nanofiber mat and increased as protonation time increased. Meanwhile, the Cr(VI) ions were reduced to Cr(III) through the reaction with amino groups of polypyrrole (from secondary amines to tertiary amines). PAN/PPy nanofiber mat showed high selectivity for Cr(VI), and the adsorption performance was nearly unaffected by other co-existing anions (Cl − , NO 3 − , and SO 4 2− ) except for PO 4 3− for the pH change

The selective removal of 90Sr and 137Cs from liquid low-level waste at Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Bostick, D.T.; Arnold, W.D.; Burgess, M.W.; Taylor, P.A.; Kent, T.E.

1995-01-01

Methods are being developed for the selective removal of the two principal radioactive contaminants, 90 Sr and 137 Cs, from liquid low-level waste generated and/or stored at Oak Ridge National Laboratory. These methods are to be used in a future centralized treatment facility at ORNL. Removal of 90 Sr in the proposed treatment flashed is based on coprecipitation from strongly alkaline waste by adding stable strontium to the waste solution. Ferric sulfate, added with the stable strontium, improves the 90 Sr removal and aids in the flocculation of the strontium carbonate (SrCO 3 ) precipitate. After separation of the solids, the resultant supernate is adjusted to pH 8 for the cesium removal treatment. Upon pH adjustment, aluminum originally present in the untreated alkaline waste precipitates and sorbs an additional amount of 90 Sr. Cesium is removed from the neutralized waste by two sequential treatments with potassium cobalt hexacyanoferrate (KCCF) slurry formed by the addition of potassium ferrocyanide (K 4 Fe(CN) 6 ) and cobalt nitrate (Co(NO 3 ) 2 ) solutions. The cumulative decontamination factors (DFs) for 90 Sr and 137 Cs in benchscale studies are 4900 and 1 x 10 6 , respectively, if high speed centrifugation is used for the liquid/solid separations. Efforts are now underway to evaluate process-scale techniques to perform the liquid/solid separations required for removal of SrCO 3 and 137 Cs-bearing hexacyanoferrate solids from the treated waste solution

Which trees should be removed in thinning?

Directory of Open Access Journals (Sweden)

Timo Pukkala

2015-12-01

Full Text Available Background: In economically optimal management, trees that are removed in a thinning treatment should be selected on the basis of their value, relative value increment and the effect of removal on the growth of remaining trees. Large valuable trees with decreased value increment should be removed, especially when they overtop smaller trees. Methods: This study optimized the tree selection rule in the thinning treatments of continuous cover management when the aim is to maximize the profitability of forest management. The weights of three criteria (stem value, relative value increment and effect of removal on the competition of remaining trees were optimized together with thinning intervals. Results and conclusions: The results confirmed the hypothesis that optimal thinning involves removing predominantly large trees. Increasing stumpage value, decreasing relative value increment, and increasing competitive influence increased the likelihood that removal is optimal decision. However, if the spatial distribution of trees is irregular, it is optimal to leave large trees in sparse places and remove somewhat smaller trees from dense places. However, the benefit of optimal thinning, as compared to diameter limit cutting is not usually large in pure one-species stands. On the contrary, removing the smallest trees from the stand may lead to significant (30–40 % reductions in the net present value of harvest incomes. Keywords: Continuous cover forestry, Tree selection, High thinning, Optimal management, Spatial distribution, Spatial growth model

Organically functionalized mesoporous SBA-15 as sorbents for removal of selected pharmaceuticals from water

Energy Technology Data Exchange (ETDEWEB)

Bui, Tung Xuan [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of); Kang, Seo-Young [International Environmental Research Center (IERC), Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of); Lee, Sang-Hyup [Water Environment Center, Korea Institute of Science and Technology, Cheongryang, Seoul 130-650 (Korea, Republic of); Choi, Heechul, E-mail: hcchoi@gist.ac.kr [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of)

2011-10-15

Highlights: {yields} SBA-15 grafted with aminopropyl, hydroxymethyl, and trimethylsilyl groups as sorbents. {yields} Sorbents for removal of a mixture of 12 pharmaceuticals from water. {yields} Hydroxymethyl-SBA-15 shows similar adsorption efficiency like SBA-15. {yields} Aminopropyl-SBA-15 makes increase for clofibric acid, diclofenac, decrease for atenolol, estrone, trimethoprim. {yields} Trimethylsilyl-SBA-15 makes increase for 9 compounds; 7 compounds from 70.6% to 98.9%. - Abstract: Mesoporous silica SBA-15 and its postfunctionalized counterparts with hydroxymethyl (HM-SBA-15), aminopropyl (AP-SBA-15), and trimethylsilyl (TMS-SBA-15) were prepared and characterized by powder X-ray diffraction, N{sub 2} adsorption-desorption measurement, Fourier-transform infrared spectroscopy, and elemental analysis. The removal of a mixture of 12 selected pharmaceuticals was investigated by batch adsorption experiments onto SBA-15 and the grafted materials. SBA-15 showed to have moderate adsorption affinity with amino-containing (atenolol, trimethoprim) and hydrophobic pharmaceuticals, but it displayed minimal adsorption affinity toward hydrophilic compounds. HM-SBA-15 was analogous with SBA-15 in terms of the adsorption efficiency toward all pharmaceuticals. AP-SBA-15 exhibited an increase in the adsorption of two acidic compounds (clofibric acid, diclofenac) but a decrease in the adsorption of estrone and the two amino-containing compounds. Among the grafted materials, TMS-SBA-15 had the highest adsorption affinity toward most pharmaceuticals. Moreover, the adsorption of nine pharmaceuticals to TMS-SBA-15 was significantly higher than that to SBA-15; seven of which showed the removal percentages from 70.6% to 98.9% onto TMS-SBA-15. The number of pharmaceuticals showing high adsorption efficiency onto TMS-SBA-15 did not alter significantly as the pH changed in the range of 5.5-7.6. The results suggest that TMS-SBA-15 is a promising material for the removal of pharmaceuticals

Organically functionalized mesoporous SBA-15 as sorbents for removal of selected pharmaceuticals from water

International Nuclear Information System (INIS)

Bui, Tung Xuan; Kang, Seo-Young; Lee, Sang-Hyup; Choi, Heechul

2011-01-01

Highlights: → SBA-15 grafted with aminopropyl, hydroxymethyl, and trimethylsilyl groups as sorbents. → Sorbents for removal of a mixture of 12 pharmaceuticals from water. → Hydroxymethyl-SBA-15 shows similar adsorption efficiency like SBA-15. → Aminopropyl-SBA-15 makes increase for clofibric acid, diclofenac, decrease for atenolol, estrone, trimethoprim. → Trimethylsilyl-SBA-15 makes increase for 9 compounds; 7 compounds from 70.6% to 98.9%. - Abstract: Mesoporous silica SBA-15 and its postfunctionalized counterparts with hydroxymethyl (HM-SBA-15), aminopropyl (AP-SBA-15), and trimethylsilyl (TMS-SBA-15) were prepared and characterized by powder X-ray diffraction, N 2 adsorption-desorption measurement, Fourier-transform infrared spectroscopy, and elemental analysis. The removal of a mixture of 12 selected pharmaceuticals was investigated by batch adsorption experiments onto SBA-15 and the grafted materials. SBA-15 showed to have moderate adsorption affinity with amino-containing (atenolol, trimethoprim) and hydrophobic pharmaceuticals, but it displayed minimal adsorption affinity toward hydrophilic compounds. HM-SBA-15 was analogous with SBA-15 in terms of the adsorption efficiency toward all pharmaceuticals. AP-SBA-15 exhibited an increase in the adsorption of two acidic compounds (clofibric acid, diclofenac) but a decrease in the adsorption of estrone and the two amino-containing compounds. Among the grafted materials, TMS-SBA-15 had the highest adsorption affinity toward most pharmaceuticals. Moreover, the adsorption of nine pharmaceuticals to TMS-SBA-15 was significantly higher than that to SBA-15; seven of which showed the removal percentages from 70.6% to 98.9% onto TMS-SBA-15. The number of pharmaceuticals showing high adsorption efficiency onto TMS-SBA-15 did not alter significantly as the pH changed in the range of 5.5-7.6. The results suggest that TMS-SBA-15 is a promising material for the removal of pharmaceuticals from aqueous phase

Application of Cyclone to Removal of Hot Particulate in Hot Cell

International Nuclear Information System (INIS)

Kim, Gye Nam; Lee, Sung Yeol; Won, Hui Jun; Jung, Chong Hun; Oh, Won Zin

2005-01-01

The size and main ingredient of hot particulate generated during the nuclide experiment in hot cells of nuclear facilities were 0.5300 μm and UO 2 . A cyclone filter equipment which consists of a cyclone and Bag/HEPA filter was devised to remove hot particulate generated during the nuclide experiment in hot cells of nuclear facilities. The experimental conditions to maximize the collection efficiency of hot particulate were suggested through experiments done with the cyclone filter equipment. With the large size of simulated particulate, the collection efficiency of the particulate was high. When the size of simulated particulate was more than 5 μm, the collection efficiency of the particulate was more than 80% and when the size of simulated particulate was less than 1.0 μm, the collection efficiency decreased by less than. If the inflow velocity of simulated particulate was increased, the collection efficiency of the particulate was also increased. When the inflow velocity of simulated particulate was more than 12 m/sec, the collection efficiency was higher than , but after 17 m/sec inflow velocity, no change observed. The collection efficiency of the simulated particulate can be enhanced with the length of vortex finder inside the chamber. With the length of vortex finder, 7.2 cm, the observed collection efficiency of the particulate was the maximum. Moreover, when the sub-cone was attached under the cyclone, the collection efficiency of cyclone increased 2%. It was found that effect by attachment of sub-cone was not serious.

The preparation and application of carbon-11 nuclide and its PET imaging agent

International Nuclear Information System (INIS)

Wang Mingfang

2002-01-01

Carbon-11 is a valuable positron nuclide, for it can be used to replace carbon atom at specific position inside the organic molecules and not change the molecular biochemistry character. Carbon-11 has wide application in the labeling of amino acids, fatty acids, receptor-ligand and neurotransmitter molecular etc, which are used for detecting the blood flow, metabolism, the synthesis of protein and the neurotransmitter function in brain by PET imaging. It is very important in basic science and clinical research to understand and master the preparation of carbon-11 and its labeled compounds

The Performance Assessment of the Detector for the Portable Environmental Radiation Distribution Monitoring System with Rapid Nuclide Recognition

International Nuclear Information System (INIS)

Lee, Uk Jae; Kim, Hee Reyoung

2015-01-01

The environment radiation distribution monitoring system measures the radiation using a portable detector and display the overall radiation distribution. Bluetooth and RS-232 communications are used for constructing monitoring system. However RS-232 serial communication is known to be more stable than Bluetooth and also it can use the detector's raw data which will be used for getting the activity of each artificial nuclide. In the present study, the detection and communication performance of the developed detector with RS-232 method is assessed by using standard sources for the real application to the urban or rural environment. Assessment of the detector for the portable environmental radiation distribution monitoring system with rapid nuclide recognition was carried out. It was understood that the raw data of detector could be effectively treated by using RS-232 method and the measurement showed a good agreement with the calculation within the relative error of 0.4 % in maximum

The Performance Assessment of the Detector for the Portable Environmental Radiation Distribution Monitoring System with Rapid Nuclide Recognition

Energy Technology Data Exchange (ETDEWEB)

Lee, Uk Jae; Kim, Hee Reyoung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

2015-05-15

The environment radiation distribution monitoring system measures the radiation using a portable detector and display the overall radiation distribution. Bluetooth and RS-232 communications are used for constructing monitoring system. However RS-232 serial communication is known to be more stable than Bluetooth and also it can use the detector's raw data which will be used for getting the activity of each artificial nuclide. In the present study, the detection and communication performance of the developed detector with RS-232 method is assessed by using standard sources for the real application to the urban or rural environment. Assessment of the detector for the portable environmental radiation distribution monitoring system with rapid nuclide recognition was carried out. It was understood that the raw data of detector could be effectively treated by using RS-232 method and the measurement showed a good agreement with the calculation within the relative error of 0.4 % in maximum.

Effect of error propagation of nuclide number densities on Monte Carlo burn-up calculations

International Nuclear Information System (INIS)

Tohjoh, Masayuki; Endo, Tomohiro; Watanabe, Masato; Yamamoto, Akio

2006-01-01

As a result of improvements in computer technology, the continuous energy Monte Carlo burn-up calculation has received attention as a good candidate for an assembly calculation method. However, the results of Monte Carlo calculations contain the statistical errors. The results of Monte Carlo burn-up calculations, in particular, include propagated statistical errors through the variance of the nuclide number densities. Therefore, if statistical error alone is evaluated, the errors in Monte Carlo burn-up calculations may be underestimated. To make clear this effect of error propagation on Monte Carlo burn-up calculations, we here proposed an equation that can predict the variance of nuclide number densities after burn-up calculations, and we verified this equation using enormous numbers of the Monte Carlo burn-up calculations by changing only the initial random numbers. We also verified the effect of the number of burn-up calculation points on Monte Carlo burn-up calculations. From these verifications, we estimated the errors in Monte Carlo burn-up calculations including both statistical and propagated errors. Finally, we made clear the effects of error propagation on Monte Carlo burn-up calculations by comparing statistical errors alone versus both statistical and propagated errors. The results revealed that the effects of error propagation on the Monte Carlo burn-up calculations of 8 x 8 BWR fuel assembly are low up to 60 GWd/t

Determination of the nuclide vector for decommissioning projects at PSI (Paul Scherrer Institute, Switzerland)

Energy Technology Data Exchange (ETDEWEB)

Jaeggi, Maya; Eikenberg, J. [Paul Scherrer Inst. (PSI), Villigen (Switzerland). Labor fuer Radioanalytik; Ehrlicher, U. [Paul Scherrer Inst. (PSI), Villigen (Switzerland). Sektion Rueckbau und Entsorgung

2012-06-15

In the context of two reactor decommissioning projects, radioactive slurry from concrete cutting was collected in the retention pond (RHB) at the Paul Scherrer Institute, along with radioactive drain outlets. Additionally, there are active residues from former operations. The task was to determine the nuclide vector of the radioactive slurry before final disposal. Due to the slurry from neutron-activated concrete, activation products, like {sup 55}Fe, {sup 60}Co, {sup 63}Ni, {sup 133}Ba, {sup 152}Eu, {sup 154}Eu and {sup 155}Eu can be expected. Accumulated drain outlets from laboratories, where work with radioactive substances is being done, were expected to contain {sup 22}Na, {sup 60}Co, {sup 134}Cs, {sup 137}Cs, {sup 133}Ba, {sup 152}Eu, {sup 154}Eu, {sup 155}Eu, {sup 241}Am, {sup 239/240}Pu, {sup 241}Pu, {sup 244}Cm, {sup 234}U, {sup 235}U, {sup 238}U, {sup 230}Th, {sup 232}Th and {sup 90}Sr. For further clarification, {sup 3}H and {sup 14}C in the water and in the organic phase had to be measured as well. This work gives an overview about the slurry dissolution techniques, the radiochemical separation methods and activity concentrations of the nuclide vector. Further processing of the slurry is also discussed. (orig.)

Fabrication of a tissue-equivalent torso phantom for intercalibration of in-vivo transuranic-nuclide counting facilities

International Nuclear Information System (INIS)

Griffith, R.V.; Dean, P.N.; Anderson, A.L.; Fisher, J.C.

1978-01-01

A tissue-equivalent human-torso phantom has been constructed for calibration of the counting systems used for in-vivo measurement of transuranic nuclides. The phantom contains a human male rib cage, removable model organs, and includes tissue-equivalent chest plates that can be placed over the torso to simulate people with a wide range of statures. The organs included are lungs, heart, liver, kidneys, spleen, and tracheo-bronchial lymph nodes. Polyurethane with different concentrations of calcium carbonate was used to simulate the linear photon-attenuation properties of various human tissues--lean muscle, adipose-muscle mixtures, and cartilage. Foamed polyurethane with calcium carbonate simulates lung tissue. Transuranic isotopes can be incorporated uniformly in the phantom's lungs and other polyurethane-based organs by dissolution of the nitrate form in acetone with lanthanum nitrate carrier. Organs have now been labelled with highly pure 238 Pu, 239 Pu, and 241 Am for calibration measurements. This phantom is the first of three that will be used in a U.S. Department of Energy program of intercomparisons involving more than ten laboratories. The results of the intercomparison will allow participating laboratories to prepare sets of transmission curves that can be used to predict the performance of their counting systems for a wide range of subject builds and organ depositions. The intercomparison will also provide valuable information on the relative performance of a variety of detector systems and counting techniques

23-gauge vitrectomy with intraocular foreign body removal via the limbus: An alternative approach for select cases

Directory of Open Access Journals (Sweden)

Ramandeep Singh

2014-01-01

Full Text Available Purpose: To study the outcome of removal of retained intraocular foreign bodies (RIOFBs via limbus using 23-gauge transconjunctival sutureless vitrectomy (TSV. Materials and Methods: In this prospective, non-comparative interventional case series, fourteen eyes of 14 patients fulfilling the inclusion criteria were enrolled. They underwent 23-gauge TSV for management of posterior segment RIOFB and reviewed at 1 day, 7 days, 6 weeks, 3, 6 and 12 months. Eyes with penetrating eye injury involving cornea or limbus (corneal injury not so severe to hinder vitrectomy, cataract associated with anterior and/or posterior capsular tear requiring cataract surgery and posterior segment RIOFB with minimal posterior segment involvement were included. Main outcome measures include success in removal of RIOFB without enlarging sclerotomy, ability to preserve capsular support, improvement in visual acuity and complications, if any. Results: All eyes underwent the successful RIOFB removal through limbal port without enlarging scleral ports. None of the eyes required suturing of the sclera, cornea or conjunctiva. Anterior capsular rim could be preserved in all eyes except one. Postoperatively follow up ranged from one year in 8, 6 months in 4 and 3 months in 2 eyes. The mean logMAR visual acuity at 3, 6, and 12 months showed significant improvement. There were no intraoperative complications. Postoperative complications include microscopic hyphema and loose blood in vitreous cavity in one eye. Conclusion: The advantages of 23-gauge TSV for removal of RIOFB may be passed on to select cases. RIOFB removal through limbal route obviated the need for scleral port enlargement and preserved capsular support for early visual rehabilitation.

Preliminary study on the establishment of the radionuclide declaration methods for radionuclides in LILW radioactive waste

International Nuclear Information System (INIS)

Hwang, K. H.; Lee, K. J.; Jung, C. W.

2003-01-01

The preliminary study on declaration methods has been done for each radionuclide in LILW radwaste drum in Korean NPPs. View from the preliminary establishment of radio nuclide declaration methods, The selection of assessment target nuclide through the qualitative method and preliminary criteria for routine declaration methods in each radio nuclide was derived. First of all, selection criteria and preliminary assessment method for each target radionuclide was surveyed and investigated. And, the selection criteria and selected the target radio nuclides from the basis on criteria was derived. And the preliminary suggestion about the declaration methods for each target radio nuclide was established

Flowsheet development studies for the decontamination of high-activity-level water at Three Mile Island Unit 2

International Nuclear Information System (INIS)

Collins, E.D.; Bigelow, J.E.; Campbell, D.O.; King, L.J.; Knauer, J.B.

1980-01-01

Several chemical processing flowsheets were considered for the decontamination of high-activity-level water at the Three Mile Island (TMI) Unit 2. A zeolite ion exchange process was evaluated and recommended for absorption of the bulk of the highly radioactive cesium and strontium. Standard organic ion-exchange resins were selected to remove the remaining traces of radioactive nuclides (except tritium which cannot be removed by any practical process). Process conditions were evaluated using both synthetic, tracer-level solutions and samples of actual, high-activity level water from TMI Unit 2

Spent Nuclear Fuel (SNF) Removal Campaign Plan

International Nuclear Information System (INIS)

PAJUNEN, A.L.

2000-01-01

The overall operation of the Spent Nuclear Fuel Project will include fuel removal, sludge removal, debris removal, and deactivation transition activities. Figure 1-1 provides an overview of the current baseline operating schedule for project sub-systems, indicating that a majority of fuel removal activities are performed over an approximately three-and-one-half year time period. The purpose of this document is to describe the strategy for operating the fuel removal process systems. The campaign plan scope includes: (1) identifying a fuel selection sequence during fuel removal activities, (2) identifying MCOs that are subjected to extra testing (process validation) and monitoring, and (3) discussion of initial MCO loading and monitoring in the Canister Storage Building (CSB). The campaign plan is intended to integrate fuel selection requirements for handling special groups of fuel within the basin (e.g., single pass reactor fuel), process validation activities identified for process systems, and monitoring activities during storage

Selective removal of 2,4-dichlorophenol from contaminated water using non-covalent imprinted microspheres

International Nuclear Information System (INIS)

Li Ying; Li Xin; Li Yuqi; Qi Jingyao; Bian Jiang; Yuan Yixing

2009-01-01

A molecularly imprinted polymer (MIP) for selective removal of 2,4-dichlorophenol (2,4-DCP) in water was prepared as microspheres by the reverse microemulsion polymerization method based on the non-covalent interactions between 2,4-DCP, oleic acid, and divinylbenzene in acetonitrile. Microspheres have been characterized by Fourier transform infrared spectrometer (FTIR) and energy dispersive X-ray spectrometer (EDS) studies with evidence of 2,4-DCP linkage in polymer particles and scanning electron microscopy (SEM) to study their morphological properties. The proper adsorption and selective recognition ability of the MIP were studied by an equilibrium-adsorption method. The MIP showed outstanding affinity towards 2,4-DCP in aqueous solution and the optimum pH value for binding has been found around the neutral range. The molecular recognition of 2,4-DCP was analyzed in detail by using molecular modeling software. In addition, by investigating the variation in the adsorption ability of the MIP, it clearly showed excellent reproducibility. - Molecular imprinting has potential as a remediation technology in water treatment.

Transfer Factors of Nuclides for Five Fish Species Inhabiting the Sea near the Yonggwang Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Lim, Kwangmuk; Choi, Yongho; Jun, In; Kim, Byungho; Keum, Dongkwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-05-15

The IAEA is going to publish a handbook of the TF values of various radionuclides for a number of plant and animal species. However, it is recommended that they be used in case there is no site-specific data. This is because TF values can vary considerably with wild-life species and environmental conditions. Therefore, it is necessary to urgently establish our own database of wild-life transfer factors for use in the wild-life dose assessment probably in the near future. In the present study, TF values of various radionuclides were investigated for several marine fish species living around the Younggwang NPP. It was done by measuring the concentrations of stable isotopes in fish and seawater samples. TF values of 21 nuclides were measured for five fish species inhabiting the sea near the Younggwang NPP. They showed considerable variations with the nuclides and fish species. Determination of TF values needs to be extended to various kinds of domestic wild lives so as to establish an input data file for a Korean assessment model such as K-BIOTA.

Discussion on effective utilization of nuclear fuel based on peculiar property of the fifth unstable nuclide series

International Nuclear Information System (INIS)

Zhang Jiahua

2000-01-01

Based on a peculiar property of the Fifth Unstable Nuclide Series (FUNS) in developing stage, namely the transformation rate of parent fuel- 238 U consumption to fission production being increased with the fuel's reactor core life, it was shown that the used fuel taken out from the reactor core of PWR could be used again as PWR fuel, and the post processing for the used fuel needed only to de-contaminate the fission products from the used fuel and then to rebuild it into its normal form. Scheme A discussed the condition of using such rebuilt used fuel in PWR. Another peculiar property of FUNS is characterized by the fact that the equilibrium saturate concentrations of the derived nuclides in FUNS are different for different types of reactor. It is well known that the saturate concentration of 239 Pu in PWR is much larger than that in HWR. Scheme B i.e. a method of using the rebuilt used fuel from PWR to replace the natural uranium fuel for HWR was discussed

Natural and artificial nuclides in Salesópolis reservoir by gamma spectrometry

Energy Technology Data Exchange (ETDEWEB)

Silva, Paulo S.C.; Semmler, Renato; Zahn, Guilherme S.; Rocha, Flávio R.; Damatto, Sandra R.; Fávaro, Déborah I.T., E-mail: pscsilva@ipen.br, E-mail: rsemmler@ipen.br, E-mail: gzahn@ipen.br, E-mail: flavio@baquara.com, E-mail: damatto@ipen.br, E-mail: defavaro@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

Natural radioactivity is ubiquitous in the environment mainly due to the presence of the nuclides from the uranium and thorium series and {sup 40}K. Although in the South Hemisphere nuclear tests have been fewer in number than that in the North, artificial radionuclides can also be found spread at ground level. In this study, the activity concentrations of natural nuclides from the uranium and thorium series, {sup 40}K and the artificial {sup 137}Cs were determined in a sediment core with 42 cm depth collected in the middle of the Salesópolis reservoir, located in the Metropolitan Region of São Paulo city (SPMR). The Usina Parque Rio Tietê reservoir belongs to the Alto do Tietê system for the capture, storage and treatment of water for SPMR. Therefore, the quality of the water and sediments of this dam is of great importance. The activity concentrations were measured by gamma spectrometry. Samples were measured and saved at regular intervals at a maximum of 160 000 seconds. The gross area were determined for each peak and plotted against time and the counting rate was obtained by the slope of the curve. Background and reference materials were also counted and treated in the same way. Results showed that {sup 226}Ra varied from 45 to 116 Bq kg{sup -1}; {sup 228}Ra, from 80 to 165 Bq kg{sup -1}; {sup 40}K, from 155 to 1 187 Bq kg{sup -1} and {sup 137}Cs varied from 0.3 to 7 Bq kg{sup -1}. The methodology applied for determining low levels of {sup 137}Cs in sediment proved to be efficient and reproducible. (author)

Natural and artificial nuclides in Salesópolis reservoir by gamma spectrometry

International Nuclear Information System (INIS)

Silva, Paulo S.C.; Semmler, Renato; Zahn, Guilherme S.; Rocha, Flávio R.; Damatto, Sandra R.; Fávaro, Déborah I.T.

2017-01-01

Natural radioactivity is ubiquitous in the environment mainly due to the presence of the nuclides from the uranium and thorium series and 40 K. Although in the South Hemisphere nuclear tests have been fewer in number than that in the North, artificial radionuclides can also be found spread at ground level. In this study, the activity concentrations of natural nuclides from the uranium and thorium series, 40 K and the artificial 137 Cs were determined in a sediment core with 42 cm depth collected in the middle of the Salesópolis reservoir, located in the Metropolitan Region of São Paulo city (SPMR). The Usina Parque Rio Tietê reservoir belongs to the Alto do Tietê system for the capture, storage and treatment of water for SPMR. Therefore, the quality of the water and sediments of this dam is of great importance. The activity concentrations were measured by gamma spectrometry. Samples were measured and saved at regular intervals at a maximum of 160 000 seconds. The gross area were determined for each peak and plotted against time and the counting rate was obtained by the slope of the curve. Background and reference materials were also counted and treated in the same way. Results showed that 226 Ra varied from 45 to 116 Bq kg -1 ; 228 Ra, from 80 to 165 Bq kg -1 ; 40 K, from 155 to 1 187 Bq kg -1 and 137 Cs varied from 0.3 to 7 Bq kg -1 . The methodology applied for determining low levels of 137 Cs in sediment proved to be efficient and reproducible. (author)

Progress of nuclide tracing technique in the study of soil erosion in recent decade

International Nuclear Information System (INIS)

Liu Gang; Yang Mingyi; Liu Puling; Tian Junliang

2007-01-01

In the last decade nuclide tracing technique has been widely employed in the investigation of soil erosion, which makes the studies of soil erosion into a new and rapid development period. This paper tried to review the recent progress of using 137 Cs, 210 Pb ex , 7 Be, composite tracers and REE-INAA in soil erosion rate, sedimentation rate, sediment source and soil erosion processes study, and also the existing research results. The trends for future development and questions are also discussed. (authors)

Probabilities and energies to obtain the counting efficiency of electron-capture nuclides, KLMN model

International Nuclear Information System (INIS)

Casas Galiano, G.; Grau Malonda, A.

1994-01-01

An intelligent computer program has been developed to obtain the mathematical formulae to compute the probabilities and reduced energies of the different atomic rearrangement pathways following electron-capture decay. Creation and annihilation operators for Auger and X processes have been introduced. Taking into account the symmetries associated with each process, 262 different pathways were obtained. This model allows us to obtain the influence of the M-electron-capture in the counting efficiency when the atomic number of the nuclide is high

Probabilities and energies to obtain the counting efficiency of electron-capture nuclides. KLMN model

International Nuclear Information System (INIS)

Galiano, G.; Grau, A.

1994-01-01

An intelligent computer program has been developed to obtain the mathematical formulae to compute the probabilities and reduced energies of the different atomic rearrangement pathways following electron-capture decay. Creation and annihilation operators for Auger and X processes have been introduced. Taking into account the symmetries associated with each process, 262 different pathways were obtained. This model allows us to obtain the influence of the M-electro capture in the counting efficiency when the atomic number of the nuclide is high. (Author)

Research and Development of Technologies for Partitioning and Transmutation of Long-lived Nuclides in Japan - Status and Evaluation

International Nuclear Information System (INIS)

Sanae Aoki

2003-01-01

Japanese basic policy regarding disposal of high-level radioactive waste (HLW) is to solidify it into stabilized form, to store it for 30-50 years to be cooled, and to dispose of it deep to the underground (geological disposal). In Japan, reference to P and T technology for long-lived and other nuclides first appeared in the Long-term Programme for Nuclear Research, Development and Utilisation (or 'long-term nuclear programme') back in 1972. That programme noted the need for research and development in order to ensure effective processing of radioactive waste. The long-term nuclear programme issued in 1987 stated that P and T technology was very important from the viewpoint of recycling HLW and enhancing disposal efficiency. It also stated that systematic R and D would be carried out jointly by JAERI, the Power Reactor and Nuclear Fuel Development Corp. (PNC, now JNC) and others. The long-term nuclear programme issued in 1994 stated that each research institute would carry out basic studies on P and T technologies and evaluate each technology at some time in the mid- 1990's to determine how to proceed thereafter. Based on the evaluation schedule stated in this program, the AEC's Advisory Committee on Nuclear Fuel Cycle Back-end Policy investigated and considered matters concerning P and T technology for long-lived and other nuclides. In March 2000, the Committee issued a report entitled 'Research and Development of Technologies for Partitioning and Transmutation of Long-lived Nuclide Status and Evaluation Report'. A brief summary of this report is presented

Database on nuclide content of coal and gangue in Chinese coal mines

International Nuclear Information System (INIS)

Liu Fudong; Liao Haitao; Wang Chunhong; Chen Ling; Liu Senlin

2006-01-01

The designing ides, structure, interface and basic function of a database are introduced of nuclide content of coal or gangue in Chinese coal mine. The design of the database adopts Sybase database system, and the database has the functions of making inquiries of keyword, classification and statistics, printing, data input which are achieved by using Power builder Language program. At the present, in this database, the data are collected on the radioactivity of natural radionuclide of 2043 coal, gangue and the other relative samples from various coal miners of all over the country. The database will provide the basic data for the environmental impact assessment of Chinese coal energy. (authors)

Process and device for monitoring active and highly active liquids for specific nuclides, particularly in the primary coolant of boiling water and pressurized water reactors

International Nuclear Information System (INIS)

Paffrath; Haag; Hanstein, W.

1986-01-01

The invention provides for a direct continuous measurement of amounts of activity or concentration and the automatic execution of analysis cycles for specific nuclides, which occur depending on the continuously determined total gamma value. The continuously determined total gamma values in a first measuring circuit are used to decide the frequency of sampling, the volume of samples, the measuring times, the doses of separating chemicals and the sample remnants. These parameters are provided for the control of the execution of an analysis cycle for specific nuclides occurring in a second measuring circuit. (orig./HP) [de

New perspectives for the petroleum industry. Bioprocesses for the selective removal of sulphur, nitrogen and metals

International Nuclear Information System (INIS)

Zerlia, T.

2000-01-01

Fuel biocatalytic conversion is a process that removes, through selective enzyme-catalyzed reactions, sulphur, nitrogen and metals. The mild operating conditions, the specificity of reactions and the quality of coproducts (particularly the organo sulphur compounds, a source for the petrochemical industry) are just a few of the attractive aspects of this new technology which could open a new world of possibilities in the technology and in the environmental impact of fuels. The paper shows the state-of-the-art of the research and applications of bioprocesses to the petroleum field [it

Table of specific activities of selected isotopes

International Nuclear Information System (INIS)

Shipley, G.

The bulk of this publication consists of a table of the half-lives, decay modes, and specific activities of isotopes selected for their particular interest to the Environmental Health and Safety Department, LBL. The specific activities were calculated with a PDP 9/15 computer. Also included in the report is a table of stable isotopes, the Th and U decay chains, a chart of the nuclides for elements 101 through 106, the heavy element region of the periodic table, and a specific activity monograph. 5 figures, 2 tables

Removal of radium from drinking water

International Nuclear Information System (INIS)

Clifford, D.A.

1990-01-01

The traditional, proven process for radium removal are sodium ion exchange softening, lime softening, and reverse osmosis. The newer, radium-specific column processes include adsorption onto the Dow RSC and BaSO 4 -impregnated alumina. The most promising new radium-specific treatment process for large-scale use is adsorption onto preformed manganese dioxide followed by multimedia or diatomaceous earth filtration The disposal of radium-contaminated wastewaters and sludges from processes under consideration will be a major factor in process selection. The processes of choice for municipal water supply treatment to remove radium are sodium ion exchange softening, lime softening, manganese dioxide adsorption-filtration, and selective adsorption onto the Dow RSC or BaSO 4 -impregnated alumina. Where the water is brackish, reverse osmosis hyperfiltration should also be considered. The radium removal process of choice for whole-house or point-of-entry treatment is sodium ion exchange softening. For point-of-use radium removal, a standard reverse osmosis system including cartridge filtration, activated carbon adsorption, and reverse osmosis hyperfiltration is recommended. Although no cost estimates have been made, the relative costs from most expensive to least expansive, for radium removal in small community water supplies are reverse osmosis, sodium ion exchange softening, lime soda softening, manganese dioxide adsorption-filtration, and the radium-selective adsorbents. 34 refs., 7 figs., 2 tabs

Transuranium and other alpha-emitting nuclides in the marine environment

International Nuclear Information System (INIS)

Pentreath, R.J.

1980-01-01

Marine environment contains naturally occurring alpha-emitting transuranium nuclides which are discharged from nuclear fuel reprocessing plants into the marine environment. Calculation of their potential of both the inhalation pathway and ingestion pathway to man, their residence time in the oceans, their loss to sediments, the chemical state in which they exist in sea water, their oxidation states in sea water, and their biological availability to sea organisms are discussed. The areas where data are lacking are indicated. Studies on the Windscale Site (U.K.) are extensively referred to in the discussion of above-mentioned aspects. It is brought out that the study of the naturally occurring actinides can be useful in the understanding of behaviour of man-made radionuclides in the marine environment, because many of the former are good analogues of the latter. (M.G.B.)

Mechanism study of selective heavy metal ion removal with polypyrrole-functionalized polyacrylonitrile nanofiber mats

Energy Technology Data Exchange (ETDEWEB)

Wang, Jianqiang; Luo, Chao [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Qi, Genggeng [Department of Materials Science and Engineering, Cornell University, Ithaca, NY (United States); Pan, Kai, E-mail: pankai@mail.buct.edu.cn [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Department of Materials Science and Engineering, Cornell University, Ithaca, NY (United States); Cao, Bing, E-mail: bcao@mail.buct.edu.cn [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China)

2014-10-15

Graphical abstract: - Highlights: • PAN/PPy core/shell nanofiber used for Cr(VI) removal. • Adsorption mechanisms were investigated. • Selective adsorption performances were investigated. - Abstract: Polyacrylonitrile/polypyrrole (PAN/PPy) core/shell nanofiber mat was prepared through electrospinning followed by a simple chemical oxidation method. The polypyrrole-functionalized nanofiber mats showed selective adsorption performance for anions. The interaction between heavy metal anions and polypyrrole (especially the interaction between Cr{sub 2}O{sub 7}{sup 2−} and polypyrrole) during the adsorption process was studied. The results showed that the adsorption process included two steps: one was the anion exchange process between the Cl{sup −} and Cr(VI), and the other was the redox process for the Cr(VI) ions. The adsorption amount was related to the protonation time of the PAN/PPy nanofiber mat and increased as protonation time increased. Meanwhile, the Cr(VI) ions were reduced to Cr(III) through the reaction with amino groups of polypyrrole (from secondary amines to tertiary amines). PAN/PPy nanofiber mat showed high selectivity for Cr(VI), and the adsorption performance was nearly unaffected by other co-existing anions (Cl{sup −}, NO{sub 3}{sup −}, and SO{sub 4}{sup 2−}) except for PO{sub 4}{sup 3−} for the pH change.

Preparation of ferrocyanide molybdate and their selective uptake properties for palladium and cesium ions

Energy Technology Data Exchange (ETDEWEB)

Hitoshi, Mimura; Ayumi, Asakura; Yan, Wu; Yuichi, Niibori; Masaki, Ozawa [Tohoku Univ., Dept. of Quantum Science and Engineering Graduate School of Engineering (Japan)

2007-07-01

The selective separation of heat-generating nuclide (Cs) and platinum group metal (Pd) containing in high-level liquid wastes (HLLW) is an important subject for the advancement of nuclear fuel cycle. Selective uptake of these nuclides was accomplished by using insoluble ferrocyanide molybdates (FeMo-[1-4]). The uptake properties of Pd{sup 2+} and Cs{sup +} for MoFe-[1-4] in the presence of 1 M HNO{sub 3} were examined by batch method. Relatively high uptake percentages of Pd{sup 2+} and Cs{sup +} above 90% were obtained within 30 min. The uptake percentage above 90% was kept in the presence of 0.1-3 M HNO{sub 3}. The uptake selectivity of Pd{sup 2+} was higher than that of Cs{sup +}; the separation factor of Pd{sup 2+} to Cs{sup +} increased with coexisting HNO{sub 3} concentration and was estimated to be 15 at 3 M HNO{sub 3}. The uptake of Pd{sup 2+} and Cs{sup +} on FeMo-[1-4] followed a Langmuir-type adsorption equation, and the uptake capacities of Pd{sup 2+} and Cs{sup +} were estimated to be [0.17-0.28] and [1.68-2.24] mmol/g, respectively. The uptake is mainly governed by the ion-exchange reaction between exchangeable cations (Na{sup +} and K{sup +}) and target cations (Pd{sup 2+} and Cs{sup +}). Further, the selective uptake of Pd{sup 2+} and Cs{sup +} was confirmed by using simulated HLLW (28 components, SW-11, JAEA); the uptake equilibrium attained within 30 min and the uptake percentages of Pd{sup 2+} and Cs{sup +} were 99 and 85 %, respectively. In order to granulate the fine powders of FeMo exchangers, the alginate gel polymer was used as an immobilizing matrix for the micro-encapsulation. The uptake percentages of Pd{sup 2+} and Cs{sup +} for FeMo-3 micro-capsule were above 80% even in the presence of 3 M HNO{sub 3}. Thus the molybdate can be converted to the ion-exchanger having high selectivity towards Pd{sup 2+} and Cs{sup +} in HLLW. This conversion method leads to the volume reduction of wastes and the utilization of useful nuclides. (authors)

Calculation of nuclide inventory, decay power, activity and dose rates for spent nuclear fuel

International Nuclear Information System (INIS)

Haakansson, Rune

2000-03-01

The nuclide inventory was calculated for a BWR and a PWR fuel element, with burnups of 38 and 55 MWd/kg uranium for the BWR fuel, and 42 and 60 MWd/kg uranium for the PWR fuel. The calculations were performed for decay times of up to 300,000 years. Gamma and neutron dose rates have been calculated at a distance of 1 m from a bare fuel element and outside the spent fuel canister. The calculations were performed using the CASMO-4 code

Prompt neutron fission spectrum mean energies for the fissile nuclides and 252Cf

International Nuclear Information System (INIS)

Holden, N.E.

1985-01-01

The international standard for a neutron spectrum is that produced from the spontaneous fission of 252 Cf, while the thermal neutron induced fission neutron spectra for the four fissile nuclides, 233 U, 235 U, 239 Pu, and 241 Pu are of interest from the standpoint of nuclear reactors. The average neutron energies of these spectra are tabulated. The individual measurements are recorded with the neutron energy range measured, the method of detection as well as the average neutron energy for each author. Also tabulated are the measurements of the ratio of mean energies for pairs of fission neutron spectra. 75 refs., 9 tabs

Thiacrown polymers for removal of mercury from waste streams

Science.gov (United States)

Baumann, Theodore F.; Reynolds, John G.; Fox, Glenn A.

2004-02-24

Thiacrown polymers immobilized to a polystyrene-divinylbenzene matrix react with Hg.sup.2+ under a variety of conditions to efficiently and selectively remove Hg.sup.2+ ions from acidic aqueous solutions, even in the presence of a variety of other metal ions. The mercury can be recovered and the polymer regenerated. This mercury removal method has utility in the treatment of industrial wastewater, where a selective and cost-effective removal process is required.

performance of water filters towards the removal of selected

African Journals Online (AJOL)

Morohani Merinyo

sand, ceramic and membrane purifier respectively, while, fluoride removal was found to be 95.5% ... associated diseases in developing countries ... The main drinking water risks in developing ... Tanzania Demographic and Health Survey.

Performance of Universal Adhesive in Primary Molars After Selective Removal of Carious Tissue: An 18-Month Randomized Clinical Trial.

Science.gov (United States)

Lenzi, Tathiane Larissa; Pires, Carine Weber; Soares, Fabio Zovico Maxnuck; Raggio, Daniela Prócida; Ardenghi, Thiago Machado; de Oliveira Rocha, Rachel

2017-09-15

To evaluate the 18-month clinical performance of a universal adhesive, applied under different adhesion strategies, after selective carious tissue removal in primary molars. Forty-four subjects (five to 10 years old) contributed with 90 primary molars presenting moderately deep dentin carious lesions on occlusal or occluso-proximal surfaces, which were randomly assigned following either self-etch or etch-and-rinse protocol of Scotchbond Universal Adhesive (3M ESPE). Resin composite was incrementally inserted for all restorations. Restorations were evaluated at one, six, 12, and 18 months using the modified United States Public Health Service criteria. Survival estimates for restorations' longevity were evaluated using the Kaplan-Meier method. Multivariate Cox regression analysis with shared frailty to assess the factors associated with failures (Padhesion strategy did not influence the restorations' longevity (P=0.06; 72.2 percent and 89.7 percent with etch-and-rinse and self-etch mode, respectively). Self-etch and etch-and-rinse strategies did not influence the clinical behavior of universal adhesive used in primary molars after selective carious tissue removal; although there was a tendency for better outcome of the self-etch strategy.

Production of ultrapure D-T gas by removal of molecular tritium by selective adsorption

International Nuclear Information System (INIS)

Maienschein, J.L.; Hudson, R.S.; Tsugawa, R.T.; Fearon, E.M.; Souers, P.C.; Collins, G.W.

1991-07-01

The application of selective adsorption to purification of D-T gas by removal of T 2 has been demonstrated for small quantities of gas typical in research applications. This represents a variation on the production of pure spin isomers of deuterium and hydrogen. The use of an adsorption column offers several advantages over conventional separation techniques, such as low tritium inventory, rapid delivery to prevent radiation damage of the accumulated product, compact size, simplicity of design, construction, and operation, and operation without carrier gas. Because a column can have several thousand equilibrium stages, the purity of the product can be very high. The adsorption column has been shown to be an attractive separation tool for small quantities of hydrogen isotopes

Production of ultrapure D-T gas by removal of molecular tritium by selective adsorption

International Nuclear Information System (INIS)

Maienschein, J.L.; Hudson, R.S.; Tsugawa, R.T.; Fearon, E.M.; Souers, P.C.; Collins, G.W.

1992-01-01

Production of molecular deuterium-tritium (D-T) with very low molecular tritium (T 2 ) is necessary for application as a nuclear spin polarized fuel. Selective adsorption of hydrogen isotopes on zeolites or alumina can provide the separation needed to produce D-T with very low T 2 . Use of an absorption column at 20-25 K offers low inventory, compact size, and rapid operation, in comparison with conventional separation techniques such as cryogenic distillation or thermal diffusion. In this paper, the authors discuss principles of absorption, and describe a calculational model of the absorption column and operational implications revealed by it. The authors show experimental proof-of-principle data for removal of T 2 from D-T with an adsorption column operated at 23 K

Influence of Decontamination

International Nuclear Information System (INIS)

Knaack, Michael

2016-01-01

This paper describes the influence of several decontamination techniques on the decommissioning of nuclear facilities. There are different kinds of decontamination methods like mechanical and chemical processes. The techniques specified, and their potential to change measured characteristics like the isotope vector of the contamination is demonstrated. It is common for all these processes, that the contamination is removed from the surface. Slightly adhered nuclides can be removed more effectively than strongly sticking nuclides. Usually a mixture of these nuclides forms the contamination. Problematically any kind of decontamination will influence the nuclide distribution and the isotope vector. On the one hand it is helpful to know the nuclide distribution and the isotope vector for the radiological characterization of the nuclear facility and on the other hand this information will be changed in the decontamination process. This is important especially for free release procedures, radiation protection and waste management. Some questions on the need of decontamination have been discussed. (authors)

10Be concentrations and the long-term fate of particle-reactive nuclides in five soil profiles from California

International Nuclear Information System (INIS)

Monaghan, M.C.; Krishnaswami, S.; Thomas, J.H.

1983-01-01

Concentration-depth profiles of cosmic-ray-produced 10 Be(tsub(1/2)=1.5 m.y.) have been measured by accelerator-mass spectrometry in five soil profiles. These measurements were made in an effort (1) to understand the retentivity of soil surfaces for particle-reactive tracers depositing from the atmosphere on time scales of 10 4 -10 6 years, and (2) to explore the application of 10 Be as a chronometer of geomorphic surface age. The profiles sampled are from two wave-cut terraces located near Mendocino, California, a table mountain top and an alluvial fan, both located near Friant, California. The ages of the Mendocino terraces are inferred to be (1-5) x 10 5 years based on amino-stratigraphic correlations and models of terrace evolution; those of the table mountain top and alluvial fan are 9.5 x 10 6 years and 6.0 x 10 5 years, respectively, based on K-Ar analyses. All the surfaces sampled are nearly flat and exhibit few erosional features. In addition to 10 Be we measured 210 Pb, sup(239,) 240 Pu and 7 Be to ascertain the retentivity of the soils for particle-reactive nuclides and to assess the present-day delivery rate of nuclides from the atmosphere. The 7 Be inventory is 4.0 dpm/cm 2 similar to those observed at nearby locations. The inventories of 210 Pb and Pu isotopes conform to those predicted from model calculations and suggest that the soil surfaces sampled retain the entire burden of particle-reactive nuclides delivered to them over short time scales, approx.= 100 years. The 10 Be concentrations in the sample range between (0.2 and 7) x 10 8 atoms/g soil and show strong correlations with leachable Fe and/or Al. (orig./WL)

Hazards of radioactive nuclide and their migration and repair research status in the environment

International Nuclear Information System (INIS)

Shi Yuting

2014-01-01

This paper gives a systematic and comprehensive introduction of the source of the radionuclides in the environment and the harm it brings to human and ecological environment. Furthermore, It summarizes the basic nature and environmental characteristics of three typical nuclides, which are 235 U, 131 I, 90 Sr respectively. In the end, a review of the migration and repairmen of the radionuclides in the environment is given. This paper provides a reference for further study of the radionuclide migration and the phytoremediation of low level radionuclide contamination. (author)

Analysis of neonicotinoids by gas chromatography coupled to nuclide 63Ni - Electron Capture Detector - GC/ECD

International Nuclear Information System (INIS)

Amaral, Priscila O.; Leao, Claudio; Redigolo, Marcelo M.; Crepaldi, Caike; Bustillos, Oscar V.

2015-01-01

Recently, several reports have been published discussing reduction in bee population which polymerizes cultures around the world this phenomenon is known as Colony Collapse Disorder (CCD). The phenomenon describes the lack of worker honeybees in the colony despite having pups and food. The causes of this problem are unknown but there are studies that claim that reduction of population of bees is linked to poisoning through insecticides specifically neonicotinoids. Among this type of pesticide are imidacloprid (C 9 H 10 ClN 5 O 2 ), clothianidin (C 6 H 8 ClN 5 O 2 S) and thiamethoxam (C 8 H 10 ClN 5 O 3 S). This paper presents the analysis of neonicotinoids - clothianidin, imidacloprid and thiamethoxam - by the technique of gas chromatography coupled to nuclide 63 Ni electron capture detector (GC/ECD). The electron capture detector (ECD) is a gas chromatography detector that has been used for the detection of organic halogens, nitriles, nitrates and organometallic compounds. The ECD detector ionizes the analytes by the beta particles from the nuclide sources 63 Ni within carrier gas N 2 . The electrons produced in this process are collected and create a current that are amplified and generates a chromatographic peak. Methodology and details of the analysis are present in this work. (author)

Cosmic-ray-produced stable nuclides: various production rates and their implications

International Nuclear Information System (INIS)

Reedy, R.C.

1981-01-01

The rates for a number of reactions producing certain stable nuclides, such as 3 He and 4 He, and fission in the moon are calculated for galactic-cosmic-ray particles and for solar protons. Solar-proton-induced reactions with bromine usually are not an important source of cosmogenic Kr isotopes. The 130 Ba(n,p) reaction cannot account for the undercalculation of 130 Xe production rates. Calculated production rates of 15 N, 13 C, and 2 H agree fairly well with rates inferred from measured excesses of these isotopes in samples with long exposure ages. Cosmic-ray-induced fission of U and Th can produce significant amounts of fission tracks and of 86 Kr, 134 Xe, and 136 Xe, especially in samples with long exposures to cosmic-ray particles

Application of the activation analysis using the method of retarded fission neutrons counting for the determination of some fissionable nuclides

International Nuclear Information System (INIS)

Armelin, M.J.A.

1984-01-01

A system for the detection and counting of delayed neutrons which allows the analysis of some fissile and fertile nuclides, in samples of milligram size, was developed. This was applied for the analysis of natural uranium and thorium and also for determining the 235 U/ 238 U ratio in non-irradiated samples which contain uranium with different degrees of enrichment in 235 U. The spectrum of activated neutrons was varied in order to discriminate the nuclides, by covering or not the sample with a material (cadmium or boron) able to absorb low energy neutrons. Determination of 235 U/ 238 U ratios, through the number of delayed neutrons, was made by drawing a calibration curve using standards ranging from 0.5% to 93% on 235 U; the accuracy of the method was also examined. In a first step, conditions for a simultaneous and non-destructive analysis of uranium and thorium were developed. The interference between these two nuclides was studied, using simulated samples. Real samples were provided by Nuclemon and IAEA. For samples with uranium concentration in the range of percentages and thorium concentration of some ppm, uranium interferes in the determination of thorium through the non-destructive analytical method. For this case, a fast and quantitative chemical method was studied which allows for the separation of thorium from uranium before the determination of throrium concentration by counting the delayed fission neutrons. It was found that the results obtained by both destructive and non-destructive methods are very consistent and can be considered statistically equivalent within a confidence level of 95%. (Author) [pt

Potential of vetiver (vetiveria zizanioides l.) grass in removing selected pahs from diesel contaminated soil

International Nuclear Information System (INIS)

Nisa, W.U.; Rashid, A.

2015-01-01

Phytoremediation has been renowned as an encouraging technology for the remediation of polycyclic aromatic hydrocarbon (PAH)-contaminated soils, little is known about how plant species behave during the process of PAH phytoremediation. Therefore, the aim of this study was to investigate the effectiveness of vetiver (Vetiveria zizanioides L.) plant in PAH phytoremediation and extraction potential of Vetiveria zizanioides for selected PAHs from the diesel contaminated soil. The field soil samples were spiked with varying concentrations (0.5% and 1%) of diesel and used for pot experiment which was conducted in greenhouse. Vetiver grass was used as experimental plant. Physico-chemical analysis of soil was performed before and after the experiment. Concentration of selected PAHs i.e. phenanthrene, pyrene and benzo(a)pyrene in soil was determined using HPLC. Plant parameters such as root/shoot length and dry mass were compared after harvest. Concentrations of PAHs were also determined in plant material and in soils after harvesting. Result showed that initial concentration of phenanthrene was significantly different from final concentration in treatments in which soil was spiked with diesel. Initial and final concentration of pyrene in soil was also significantly different from each other in two treatments in which soil was spiked with 1% diesel. Pyrene concentration was significantly different in roots and shoots of plants while benzo(a)pyrene concentration in treatments in which soil was spiked with diesel was also significantly different from roots and shoots. Phenanthrene was less extracted by the plant in all the treatments and it was present in higher concentration in soil as compared to plant. Our results indicate that vetiver grass has effectively removed PAHs from soil consequently a significantly higher root and shoot uptake of PAHs was observed than control treatments. Study concludes Vetiveria zizanioides as potentially promising plant specie for the removal