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Sample records for thulium-170 isotope power

  1. Infrastructure for thulium-170 isotope power systems for autonomous underwater vehicle fleets

    International Nuclear Information System (INIS)

    Walter, C.E.

    1991-07-01

    The radioisotope thulium-170 is a safe and environmentally benign heat source for providing the high endurance and energy densities needed by advanced power systems for autonomous underwater vehicles (AUV). Thulium Isotope Power (TIP) systems have an endurance of ∼3000 h, and gravimetric and volumetric energy densities of 3 x 10 4 Wh/kg and 3 x 10 8 Wh/m 3 , respectively. These energy densities are more than 200 times higher than those currently provided by Ag-Zn battery technology. In order to capitalize on these performance levels with about one hundred AUVs in continuous use, it will be necessary to establish an infrastructure for isotope production and heat-source refurbishment. The infrastructure cost is not trivial, and studies are needed to determine its optimum configuration. The major component of the projected infrastructure is the nuclear reactor used to produce Tm- 170 by neutron absorption in Tm-169. The reactor design should ideally be optimized for TM-170 production. Using the byproduct ''waste'' heat beneficially would help defray the cost of isotope production. However, generating electric power with the reactor would compromise both the cost of electricity and the isotope production capacity. A coastal location for the reactor would be most convenient from end-use considerations, and the ''waste'' heat could be used to desalinate seawater in water-thirsty states. 13 refs., 6 figs., 2 tabs

  2. Thulium-170 heat source

    Science.gov (United States)

    Walter, Carl E.; Van Konynenburg, Richard; VanSant, James H.

    1992-01-01

    An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

  3. Thulium-170-labeled microparticles for local radiotherapy: preliminary studies.

    Science.gov (United States)

    Polyak, Andras; Das, Tapas; Chakraborty, Sudipta; Kiraly, Reka; Dabasi, Gabriella; Joba, Robert Peter; Jakab, Csaba; Thuroczy, Julianna; Postenyi, Zita; Haasz, Veronika; Janoki, Gergely; Janoki, Gyozo A; Pillai, Maroor R A; Balogh, Lajos

    2014-10-01

    The present article describes the preparation, characterization, and biological evaluation of Thulium-170 ((170)Tm) [T1/2 = 128.4 days; Eβmax = 968 keV; Eγ = 84 keV (3.26%)] labeled tin oxide microparticles for its possible use in radiation synovectomy (RSV) of medium-sized joints. (170)Tm was produced by irradiation of natural thulium oxide target. 170Tm-labeled microparticles were synthesized with high yield and radionuclidic purity (> 99%) along with excellent in vitro stability by following a simple process. Particle sizes and morphology of the radiolabeled particles were examined by light microscope, dynamic light scattering, and transmission electron microscope and found to be of stable spherical morphology within the range of 1.4-3.2 μm. The preparation was injected into the knee joints of healthy Beagle dogs intraarticularly for biological studies. Serial whole-body and regional images were taken by single-photon-emission computed tomography (SPECT) and SPECT-CT cameras up to 9 months postadministration, which showed very low leakage (compound did not show any possible radiotoxicological effect. These preliminary studies showed that 170Tm-labeled microparticles could be a promising nontoxic and effective radiopharmaceutical for RSV applications or later local antitumor therapy.

  4. Thulium-170 oxide heat source experimental and analytical radiation and shielding study

    International Nuclear Information System (INIS)

    Tse, A.; Nelson, C.A.

    1970-05-01

    Radiation dose rates from three thulium-170 oxide sources (20.7, 10.0 and 5.0 thermal watts) were measured through three thicknesses (1/4, 1/2 and 1 inch) of absorber by thermoluminescent dosimetry techniques. Absorber materials used were aluminium, stainless steel, lead, tungsten and depleted uranium. Resultant radiation doses were measured at 19 and 100 cm. Comparison of theoretical dose rates calculated by computer with measured dose rates validated the calculation technique for lead, tungsten and uranium absorbers but not for aluminum and stainless steel. Use of infinite medium build-up factors (B/sub ∞/) was thus validated in computation of dose rates for lead, tungsten and uranium absorbers; use of B/sub ∞/ in computation of dose rates for aluminum and stainless steel absorbers overestimated dose rates vis-a-vis experimentally determined dose rates by an approximate factor of 2

  5. Thulium oxide fuel characterization study (thulium-170 fueled capsule parametric design)

    Energy Technology Data Exchange (ETDEWEB)

    DesChamps, N.H.

    1968-10-01

    A doubly encapsulated thulia wafer, i.e., individually lined wafers stacked one upon another inside a fuel capsule was studied. The temperature profiles were determined for thulia power densities ranging from 8 to 24 W/cc and fuel capsule surface temperatures ranging from 1000/sup 0/F (538/sup 0/C) to 2000/sup 0/F (1093/sup 0/C). Parametric studies were also carried out on a singly encapsulated configuration in which the thulia wafers were stacked face to face in an infinitely long, lined cylinder. The doubly encapsulated wafer configuration yielded a lower centerline temperature than the singly encapsulated capsule. Only in extreme cases of a large wafer diameter in combination with a high thulia power density did the fuel capsule centerline temperature exceed the thulia melt temperature of 4172/sup 0/F (2300/sup 0/C). Results are also given for the maximum radius attainable without having centerline melting when using a thulia microsphere fuel form.

  6. Thulium heat source for high-endurance and high-energy density power systems

    International Nuclear Information System (INIS)

    Walter, C.E.; Kammeraad, J.E.; Van Konynenburg, R.; VanSant, J.H.

    1991-05-01

    We are studying the performance characteristics of radioisotope heat source designs for high-endurance and high-energy-density power systems that use thulium-170. Heat sources in the power range of 5--50 kW th coupled with a power conversion efficiency of ∼30%, can easily satisfy current missions for autonomous underwater vehicles. New naval missions will be possible because thulium isotope power systems have a factor of one-to-two hundred higher endurance and energy density than chemical and electrochemical systems. Thulium-170 also has several other attractive features, including the fact that it decays to stable ytterbium-170 with a half-life of four months. For terrestrial applications, refueling on that time scale should be acceptable in view of the advantage of its benign decay. The heat source designs we are studying account for the requirements of isotope production, shielding, and integration with power conversion components. These requirements are driven by environmental and safety considerations. Thulium is present in the form of thin refractory thulia disks that allow power conversion at high peak temperature. We give estimates of power system state points, performance, mass, and volume characteristics. Monte Carlo radiation analysis provides a detailed assessment of shield requirements and heat transfer under normal and distressed conditions is also considered. 11 refs., 7 figs., 4 tabs

  7. Controlled power supply for isotopes separator

    International Nuclear Information System (INIS)

    Lavaitte, A.; Pottier, J.

    1953-01-01

    This equipment is destined to equip the separator of isotopes who is the subject of the CEA report n 138. It includes: - a controlled power supply in voltage. - a controlled power supply in current. The spectra of fluctuations of these assembly is different in the two cases. (authors) [fr

  8. Special Application Thermoelectric Micro Isotope Power Sources

    International Nuclear Information System (INIS)

    Heshmatpour, Ben; Lieberman, Al; Khayat, Mo; Leanna, Andrew; Dobry, Ted

    2008-01-01

    Promising design concepts for milliwatt (mW) size micro isotope power sources (MIPS) are being sought for use in various space and terrestrial applications, including a multitude of future NASA scientific missions and a range of military applications. To date, the radioisotope power sources (RPS) used on various space and terrestrial programs have provided power levels ranging from one-half to several hundred watts. In recent years, the increased use of smaller spacecraft and planned new scientific space missions by NASA, special terrestrial and military applications suggest the need for lower power, including mW level, radioisotope power sources. These power sources have the potential to enable such applications as long-lived meteorological or seismological stations distributed across planetary surfaces, surface probes, deep space micro-spacecraft and sub-satellites, terrestrial sensors, transmitters, and micro-electromechanical systems. The power requirements are in the range of 1 mW to several hundred mW. The primary technical requirements for space applications are long life, high reliability, high specific power, and high power density, and those for some special military uses are very high power density, specific power, reliability, low radiological induced degradation, and very low radiation leakage. Thermoelectric conversion is of particular interest because of its technological maturity and proven reliability. This paper summarizes the thermoelectric, thermal, and radioisotope heat source designs and presents the corresponding performance for a number of mW size thermoelectric micro isotope power sources

  9. Brayton Isotope Power System (BIPS) facility specification

    International Nuclear Information System (INIS)

    1976-01-01

    General requirements for the Brayton Isotope Power System (BIPS)/Ground Demonstration System (GDS) assembly and test facility are defined. The facility will include provisions for a complete test laboratory for GDS checkout, performance, and endurance testing, and a contamination-controlled area for assembly, fabrication, storage, and storage preparation of GDS components. Specifications, schedules, and drawings are included

  10. Brayton Isotope Power System (BIPS) facility specification

    Energy Technology Data Exchange (ETDEWEB)

    1976-05-31

    General requirements for the Brayton Isotope Power System (BIPS)/Ground Demonstration System (GDS) assembly and test facility are defined. The facility will include provisions for a complete test laboratory for GDS checkout, performance, and endurance testing, and a contamination-controlled area for assembly, fabrication, storage, and storage preparation of GDS components. Specifications, schedules, and drawings are included.

  11. High Flux Isotope Reactor power upgrade status

    International Nuclear Information System (INIS)

    Rothrock, R.B.; Hale, R.E.; Cheverton, R.D.

    1997-01-01

    A return to 100-MW operation is being planned for the High Flux Isotope Reactor (HFIR). Recent improvements in fuel element manufacturing procedures and inspection equipment will be exploited to reduce hot spot and hot streak factors sufficiently to permit the power upgrade without an increase in primary coolant pressure. Fresh fuel elements already fabricated for future use are being evaluated individually for power upgrade potential based on their measured coolant channel dimensions

  12. Brayton dynamic isotope power systems update

    International Nuclear Information System (INIS)

    Davis, K.A.; Pietsch, A.; Casagrande, R.D.

    1986-01-01

    Brayton dynamic power systems are uniquely suited for space applications. They are compact and highly efficient, offer inherent reliability due to only one moving part, and utilize a single phase and inert working fluid. Additional features include gas bearings, constant speed, and operation at essentially constant temperature. The design, utilizing an inert gas working fluid and gas bearing, is unaffected by zero gravity and can be easily started and restarted in space at low temperatures. This paper describes the salient features of the BIPS as a Dynamic Isotope Power System (DIPS), summarizes the development work to date, establishes the maturity of the design, provides an update on materials technology, and reviews systems integration considerations

  13. Radio-isotope powered light source

    International Nuclear Information System (INIS)

    Spottiswoode, N.L.; Ryden, D.J.

    1979-01-01

    The light source described comprises a radioisotope fuel source, thermal insulation against heat loss, a biological shield against the escape of ionizing radiation and a material having a surface which attains incandescence when subject to isotope decay heat. There is then a means for transferring this heat to produce incandescence of the surface and thus emit light. A filter associated with the surface permits a relatively high transmission of visible radiation but has a relatively high reflectance in the infra red spectrum. Such light sources require the minimum of attention and servicing and are therefore suitable for use in navigational aids such as lighthouses and lighted buoys. The isotope fuel sources and thus the insulation and shielding and the incandescent material can be chosen for the use required and several sources, materials, means of housing etc. are detailed. Operation and efficiency are discussed. (U.K.)

  14. Controlled power supply for isotopes separator; Alimentations regulees pour separateur d'isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Lavaitte, A; Pottier, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1953-07-01

    This equipment is destined to equip the separator of isotopes who is the subject of the CEA report n 138. It includes: - a controlled power supply in voltage. - a controlled power supply in current. The spectra of fluctuations of these assembly is different in the two cases. (authors) [French] Cet equipement est destine a equiper le separateur d'isotopes qui fait l'objet du rapport C.E.A. n 138. Il comprend: - une alimentation regulee en tension. - une alimentation regulee en courant. Le spectre de fluctuations de ces ensembles est different dans les deux cas. (auteurs)

  15. Hydrogen isotope separation for fusion power applications

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R., E-mail: robert.smith@ccfe.ac.uk [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); JET-EFDA, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Whittaker, D.A.J.; Butler, B.; Hollingsworth, A.; Lawless, R.E.; Lefebvre, X.; Medley, S.A.; Parracho, A.I.; Wakeling, B. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); JET-EFDA, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

    2015-10-05

    Highlights: • Summary of the tritium plant, the Active Gas Handling System (AGHS), at JET. • Review of the Water Detritiation System (WDS) under construction. • Design of the new Material Detritiation Facility (MDF). • Review of problems in fusion related to metal/hydrogen system. - Abstract: The invited talk given at MH2014 in Salford ranged over many issues associated with hydrogen isotope separation, fusion machines and the hydrogen/metal systems found in the Joint European Torus (JET) machine located near Oxford. As this sort of talk does not lend itself well to a paper below I have attempted to highlight some of the more pertinent information. After a description of the Active Gas Handling System (AGHS) a brief summary of isotope separation systems is described followed by descriptions of three major projects currently being undertaken by the Tritium Engineering and Science Group (TESG), the upgrade to the Analytical Systems (AN-GC) at the AGH, the construction of a Water Detritiation System (WDS) and a Material Detritiation Facility (MDF). Finally, a review of some of the challenges facing fusion with respect to metal/hydrogen systems is presented.

  16. Organic Rankine Kilowatt Isotope Power System. Final phase I report

    International Nuclear Information System (INIS)

    1978-01-01

    On 1 August 1975 under Department of Energy Contract EN-77-C-02-4299, Sundstrand Energy Systems commenced development of a Kilowatt Isotope Power System (KIPS) directed toward satisfying the higher power requirements of satellites of the 1980s and beyond. The KIPS is a 238 PuO 2 fueled organic Rankine cycle turbine power system which will provide design output power in the range of 500 to 2000 W/sub (e)/ with a minimum of system changes. The principal objectives of the Phase 1 development effort were to: conceptually design a flight system; design a Ground Demonstration System (GDS) that is prototypic of the flight system in order to prove the feasibility of the flight system design; fabricate and assemble the GDS; and performance and endurance test the GDS using electric heaters in lieu of the isotope heat source. Results of the work performed under the Phase 1 contract to 1 July 1978 are presented

  17. Isotope powered Stirling generator for terrestrial applications

    International Nuclear Information System (INIS)

    Tingey, G.L.; Sorensen, G.C.; Ross, B.A.

    1995-01-01

    An electric power supply, small enough to be man-portable, is being developed for remote, terrestrial applications. This system is designed for an operating lifetime of five years without maintenance or refueling. A small Radioisotope Stirling Generator (RSG) has been developed. The energy source of the generator is a 60 watt plutonium-238 fuel clad used in the General Purpose Heat Sources (GPHS) developed for space applications. A free piston Stirling Engine drives a linear alternator to convert the heat to power. The system weighs about 7.5 kg and produces 11 watts AC power with a conversion efficiency of 18.5%. Two engine models have been designed, fabricated, and tested to date: (a) a developmental model instrumented to confirm and test parameters, and (b) an electrically heated model with an electrical heater equipped power input leads. Critical components have been tested for 10,000 to 20,000 hours. One complete generator has been operating for over 11,000 hours. Radioisotope heated prototypes are expected to be fabricated and tested in late 1995

  18. Quality assurance program for isotopic power systems

    Energy Technology Data Exchange (ETDEWEB)

    Hannigan, R.L.; Harnar, R.R.

    1982-12-01

    This report summarizes the Sandia National Laboratories Quality Assurance Program that applies to non-weapon (reimbursable) Radioisotopic Thermoelectric Generators. The program has been implemented over the past 16 years on power supplies used in various space and terrestrial systems. The quality assurance (QA) activity of the program is in support of the Department of Energy, Office of Space Nuclear Projects. Basic elements of the program are described in the report and examples of program decumentation are presented.

  19. Quality assurance program for isotopic power systems

    International Nuclear Information System (INIS)

    Hannigan, R.L.; Harnar, R.R.

    1982-12-01

    This report summarizes the Sandia National Laboratories Quality Assurance Program that applies to non-weapon (reimbursable) Radioisotopic Thermoelectric Generators. The program has been implemented over the past 16 years on power supplies used in various space and terrestrial systems. The quality assurance (QA) activity of the program is in support of the Department of Energy, Office of Space Nuclear Projects. Basic elements of the program are described in the report and examples of program decumentation are presented

  20. Solid state isotopic power source for computer chips

    International Nuclear Information System (INIS)

    Brown, P.M.

    1992-01-01

    This paper reports that recent developments in materials technology now make it possible to fabricate nonthermal thin-film isotopic energy converters (REC) with a specific power of 24 W/kg and 5 to 10 year working life at 5 to 10 Watts. This creates applications never before possible, such as placing the power supply directly on integrated circuit chips. The efficiency of the REC is about 25% which is two to three times greater than the 6 to 8% capabilities of current thermoelectric systems

  1. Program plan for the Brayton Isotope Power System. Phase I. Design, fabrication and test of the Brayton Isotope Power System

    International Nuclear Information System (INIS)

    1975-01-01

    Phase I of an overall program for the development of a 500 to 2000 W(e) (EOM), 7-y life, power system for space vehicles is discussed. The system uses a closed Brayton dynamic system to convert energy from an isotope heat source at a net efficiency greater than 25 percent. This first phase, a 35-month effort, is for the conceptual design of a 1300 W(e), 450 lb flight system and the design, fabrication, and test of a ground demonstration system. The flight system will use, for the baseline design, two of the multihundred-watt (MHW) heat sources being developed. The Ground Demonstration System will simulate, as closely as possible, the Brayton Isotope Power Flight System and will utilize components and technology being developed for the Mini-Brayton rotating unit, recuperator and heat source assembly, respectively. The Ground Demonstration System includes a performance test and a 1000-h endurance test

  2. High-Voltage Power Supply System for Laser Isotope Separation

    Energy Technology Data Exchange (ETDEWEB)

    Ketaily, E.C.; Buckner, R.P.; Uhrik, R.L.

    1979-06-26

    This report presents several concepts for Laser High-Voltage Power Supply (HVPS) Systems for a Laser Isotope Separation facility. Selection of equipments and their arrangement into operational systems is based on proven designs and on application concepts now being developed. This report has identified a number of alternative system arrangements and has provided preliminary cost estimates for each. The report includes a recommendation for follow-on studies that will further define the optimum Laser HVPS Systems. Brief descriptions are given of Modulator/Regulator circuit trade-offs, system control interfaces, and their impact on costs.

  3. High-Voltage Power Supply System for Laser Isotope Separation

    International Nuclear Information System (INIS)

    Ketaily, E.C.; Buckner, R.P.; Uhrik, R.L.

    1979-01-01

    This report presents several concepts for Laser High-Voltage Power Supply (HVPS) Systems for a Laser Isotope Separation facility. Selection of equipments and their arrangement into operational systems is based on proven designs and on application concepts now being developed. This report has identified a number of alternative system arrangements and has provided preliminary cost estimates for each. The report includes a recommendation for follow-on studies that will further define the optimum Laser HVPS Systems. Brief descriptions are given of Modulator/Regulator circuit trade-offs, system control interfaces, and their impact on costs

  4. Technology verification phase. Dynamic isotope power system. Final report

    International Nuclear Information System (INIS)

    Halsey, D.G.

    1982-01-01

    The Phase I requirements of the Kilowatt Isotope Power System (KIPS) program were to make a detailed Flight System Conceptual Design (FSCD) for an isotope fueled organic Rankine cycle power system and to build and test a Ground Demonstration System (GDS) which simulated as closely as possible the operational characteristics of the FSCD. The activities and results of Phase II, the Technology Verification Phase, of the program are reported. The objectives of this phase were to increase system efficiency to 18.1% by component development, to demonstrate system reliability by a 5000 h endurance test and to update the flight system design. During Phase II, system performance was improved from 15.1% to 16.6%, an endurance test of 2000 h was performed while the flight design analysis was limited to a study of the General Purpose Heat Source, a study of the regenerator manufacturing technique and analysis of the hardness of the system to a laser threat. It was concluded from these tests that the GDS is basically prototypic of a flight design; all components necessary for satisfactory operation were demonstrated successfully at the system level; over 11,000 total h of operation without any component failure attested to the inherent reliability of this type of system; and some further development is required, specifically in the area of performance

  5. Technology verification phase. Dynamic isotope power system. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Halsey, D.G.

    1982-03-10

    The Phase I requirements of the Kilowatt Isotope Power System (KIPS) program were to make a detailed Flight System Conceptual Design (FSCD) for an isotope fueled organic Rankine cycle power system and to build and test a Ground Demonstration System (GDS) which simulated as closely as possible the operational characteristics of the FSCD. The activities and results of Phase II, the Technology Verification Phase, of the program are reported. The objectives of this phase were to increase system efficiency to 18.1% by component development, to demonstrate system reliability by a 5000 h endurance test and to update the flight system design. During Phase II, system performance was improved from 15.1% to 16.6%, an endurance test of 2000 h was performed while the flight design analysis was limited to a study of the General Purpose Heat Source, a study of the regenerator manufacturing technique and analysis of the hardness of the system to a laser threat. It was concluded from these tests that the GDS is basically prototypic of a flight design; all components necessary for satisfactory operation were demonstrated successfully at the system level; over 11,000 total h of operation without any component failure attested to the inherent reliability of this type of system; and some further development is required, specifically in the area of performance. (LCL)

  6. Small Stirling dynamic isotope power system for robotic space missions

    International Nuclear Information System (INIS)

    Bents, D.J.

    1992-08-01

    The design of a multihundred-watt Dynamic Isotope Power System (DIPS), based on the US Department of Energy (DOE) General Purpose Heat Source (GPHS) and small (multihundred-watt) free-piston Stirling engine (FPSE), is being pursued as a potential lower cost alternative to radioisotope thermoelectric generators (RTG's). The design is targeted at the power needs of future unmanned deep space and planetary surface exploration missions ranging from scientific probes to Space Exploration Initiative precursor missions. Power level for these missions is less than a kilowatt. The incentive for any dynamic system is that it can save fuel and reduce costs and radiological hazard. Unlike DIPS based on turbomachinery conversion (e.g. Brayton), this small Stirling DIPS can be advantageously scaled to multihundred-watt unit size while preserving size and mass competitiveness with RTG's. Stirling conversion extends the competitive range for dynamic systems down to a few hundred watts--a power level not previously considered for dynamic systems. The challenge for Stirling conversion will be to demonstrate reliability and life similar to RTG experience. Since the competitive potential of FPSE as an isotope converter was first identified, work has focused on feasibility of directly integrating GPHS with the Stirling heater head. Thermal modeling of various radiatively coupled heat source/heater head geometries has been performed using data furnished by the developers of FPSE and GPHS. The analysis indicates that, for the 1050 K heater head configurations considered, GPHS fuel clad temperatures remain within acceptable operating limits. Based on these results, preliminary characterizations of multihundred-watt units have been established

  7. Brayton Isotope Power System, Design Integrity Checklist (BIPS-DIC)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, L.G.

    1976-06-10

    A preliminary Failure Modes, Effects and Criticality Analysis (FMECA) for the BIPS Flight System (FS) was published as AiResearch Report 76-311709 dated January 12, 1976. The FMECA presented a thorough review of the conceptual BIPS FS to identify areas of concern and activities necessary to avoid premature failures. In order to assure that the actions recommended by the FMECA are effected in both the FS and the Ground Demonstration System (GDS), a checklist (the BIPS-DIC) was prepared for the probability of occurrence of those failure modes that rated highest in criticality ranking. This checklist was circulated as an attachment to AiResearch Coordination Memo No. BIPS-GDS-A0106 dated January 23, 1976. The Brayton Isotope Power System-Design Integrity Checklist (BIPS-DIC) has been revised and is presented. Additional entries have been added that reference failure modes determined to rank highest in criticality ranking. The checklist will be updated periodically.

  8. Kilowatt Isotope Power System: component report for the Ground Demonstration System Accumulator

    International Nuclear Information System (INIS)

    Brainard, E.L.

    1978-01-01

    The Model Number ORC1A3A01 System Accumulator for the Kilowatt Isotope Power System was expulsion tested and demonstrated to be in compliance with the requirements of Sundstrand Explusion Test Procedure, TP 400. Test requirements of TP 400 were extracted from the Kilowatt Isotope Power System, Ground Demonstration System Test Plan

  9. System design specification Brayton Isotope Power System (BIPS) Flight System (FS), and Ground Demonstration System (GDS)

    International Nuclear Information System (INIS)

    1976-01-01

    The system design specification for ground demonstration, development, and flight qualification of a Brayton Isotope Power System (BIPS) is presented. The requirements for both a BIPS conceptual Flight System (FS) and a Ground Demonstration System (GDS) are defined

  10. Kilowatt isotope power system phase II plan. Volume II: flight System Conceptual Design (FSCD)

    International Nuclear Information System (INIS)

    1978-03-01

    The Kilowatt Isotope Power System (KIPS) Flight System Conceptual Design (FSCD) is described. Included are a background, a description of the flight system conceptual design, configuration of components, flight system performance, Ground Demonstration System test results, and advanced development tests

  11. Dynamic Isotope Power System: technology verification phase, program plan, 1 October 1978

    International Nuclear Information System (INIS)

    1979-01-01

    The technology verification phase program plan of the Dynamic Isotope Power System (DIPS) project is presented. DIPS is a project to develop a 0.5 to 2.0 kW power system for spacecraft using an isotope heat source and a closed-cycle Rankine power-system with an organic working fluid. The technology verification phase's purposes are to increase the system efficiency to over 18%, to demonstrate system reliability, and to provide an estimate for flight test scheduling. Progress toward these goals is reported

  12. Isotopic Tracing of Thallium Contamination in Soils Affected by Emissions from Coal-Fired Power Plants.

    Science.gov (United States)

    Vaněk, Aleš; Grösslová, Zuzana; Mihaljevič, Martin; Trubač, Jakub; Ettler, Vojtěch; Teper, Leslaw; Cabala, Jerzy; Rohovec, Jan; Zádorová, Tereza; Penížek, Vít; Pavlů, Lenka; Holubík, Ondřej; Němeček, Karel; Houška, Jakub; Drábek, Ondřej; Ash, Christopher

    2016-09-20

    Here, for the first time, we report the thallium (Tl) isotope record in moderately contaminated soils with contrasting land management (forest and meadow soils), which have been affected by emissions from coal-fired power plants. Our findings clearly demonstrate that Tl of anthropogenic (high-temperature) origin with light isotope composition was deposited onto the studied soils, where heavier Tl (ε(205)Tl ∼ -1) naturally occurs. The results show a positive linear relationship (R(2) = 0.71) between 1/Tl and the isotope record, as determined for all the soils and bedrocks, also indicative of binary Tl mixing between two dominant reservoirs. We also identified significant Tl isotope variations within the products from coal combustion and thermo-desorption experiments with local Tl-rich coal pyrite. Bottom ash exhibited the heaviest Tl isotope composition (ε(205)Tl ∼ 0), followed by fly ash (ε(205)Tl between -2.5 and -2.8) and volatile Tl fractions (ε(205)Tl between -6.2 and -10.3), suggesting partial Tl isotope fractionations. Despite the evident role of soil processes in the isotope redistributions, we demonstrate that Tl contamination can be traced in soils and propose that the isotope data represent a possible tool to aid our understanding of postdepositional Tl dynamics in surface environments for the future.

  13. Basic separative power of multi-component isotopes separation in a gas centrifuge

    International Nuclear Information System (INIS)

    Jiang, Hongmin; Lei, Zengguang; Zhuge, Fu

    2008-01-01

    On condition that the overall separation factor per unit exists in centrifuge for multi-component isotopes separation, the relations between separative power of each component and molecular weight have been investigated in the paper while the value function and the separative power of binary-component separation are adopted. The separative power of each component is proportional to the square of the molecular weight difference between its molecular weight and the average molecular weight of other remnant components. In addition, these relations are independent on the number of the components and feed concentrations. The basic separative power and related expressions, suggested in the paper, can be used for estimating the separative power of each component and analyzing the separation characteristics. The most valuable application of the basic separative power is to evaluate the separative capacity of centrifuge for multi-component isotopes. (author)

  14. Reliability program plan for the Kilowatt Isotope Power System (KIPS) technology verification phase

    International Nuclear Information System (INIS)

    1978-01-01

    Ths document is an integral part of the Kilowatt Isotope Power System (KIPS) Program Plan. This document defines the KIPS Reliability Program Plan for the Technology Verification Phase. This document delineates the reliability assurance tasks that are to be accomplished by Sundstrand and its suppliers during the design, fabrication and testing of the KIPS

  15. Kilowatt isotope power system, Phase II Plan. Volume IV. Teledyne FSCD vs GDS

    Energy Technology Data Exchange (ETDEWEB)

    1978-03-15

    This Volume contains Teledyne's input to the Kilowatt Isotope Power System Phase II Plan. Included is a description of the Flight System Heat Generation System, Flight System Radiator, Thermal Insulation Stability, GDS Heat Generation System and GDS Radiator.

  16. Uranium-isotope enrichment: application bounds of the separative power and separation work concepts

    Energy Technology Data Exchange (ETDEWEB)

    Novelli, P.

    1981-05-01

    The aim of this paper is a critical re-examination of the concepts of separative power, separation work and value function in order to understand if their extension to the new enrichment processes such as Laser Isotope Separation is possible.

  17. Band head spin assignment of superdeformed bands in Hg isotopes through power index formula

    Science.gov (United States)

    Sharma, Honey; Mittal, H. M.

    2018-05-01

    The power index formula has been used to obtain the band head spin (I 0) of all the superdeformed (SD) bands in Hg isotopes. A least squares fitting approach is used. The root mean square deviations between the determined and the observed transition energies are calculated by extracting the model parameters using the power index formula. Whenever definite spins are available, the determined and the observed transition energies are in accordance with each other. The computed values of dynamic moment of inertia J (2) obtained by using the power index formula and its deviation with the rotational frequency is also studied. Excellent agreement is shown between the calculated and the experimental results for J (2) versus the rotational frequency. Hence, the power index formula works very well for all the SD bands in Hg isotopes expect for 195Hg(2, 3, 4).

  18. Brayton isotope power system, phase I. Final report

    International Nuclear Information System (INIS)

    1978-01-01

    The Phase I program resulted in the development and ground demonstration of a dynamic power conversion system. The two key contractual objectives of 25% conversion efficiency and 1000 h of endurance testing were successfully met. As a result of the Phase I effort, the BIPS is a viable candidate for further development into a flight system capable of sustained operation in space. It represents the only known dynamic space power system to demonstrate the performance and endurance coupled with the simplicity necessary for reliable operation. This final report follows thirty-five monthly reports. For expediency, it makes liberal use of referenced documents which have been submitted to DOE during the course of the program

  19. Kilowatt isotope power system. Phase II plan. Volume V. Safety, quality assurance and reliability

    International Nuclear Information System (INIS)

    1978-01-01

    The development of a Kilowatt Isotope Power System (KIPS) was begun in 1975 for the purpose of satisfying the power requirements of satellites in the 1980's. The KIPS is a 238 PuO 2 -fueled organic Rankine cycle turbine power system to provide a design output of 500 to 2000 W. Included in this volume are: launch and flight safety considerations; quality assurance techniques and procedures to be followed through system fabrication, assembly and inspection; and the reliability program made up of reliability prediction analysis, failure mode analysis and criticality analysis

  20. Small Stirling dynamic isotope power system for multihundred-watt robotic missions

    International Nuclear Information System (INIS)

    Bents, D.J.

    1991-01-01

    Free Piston Stirling Engine (FPSE) and linear alternator (LA) technology is combined with radioisotope heat sources to produce a compact dynamic isotope power system (DIPS) suitable for multihundred watt space application which appears competitive with advance radioisotope thermoelectric generators (RTGs). The small Stirling DIPS is scalable to multihundred watt power levels or lower. The FPSE/LA is a high efficiency convertor in sizes ranging from tens of kilowatts down to only a few watts. At multihundred watt unit size, the FPSE can be directly integrated with the General Purpose Heat Source (GPHS) via radiative coupling; the resulting dynamic isotope power system has a size and weight that compares favorably with the advanced modular (Mod) RTG, but requires less than a third the amount of isotope fuel. Thus the FPSE extends the high efficiency advantage of dynamic systems into a power range never previously considered competitive for DIPS. This results in lower fuel cost and reduced radiological hazard per delivered electrical watt. 33 refs

  1. Importance of resonance parameters of fertile nuclei and of 239Pu isotope for fast power reactors

    International Nuclear Information System (INIS)

    Barre, J.Y.; Khairallah, A.

    1975-01-01

    The importance of resonance parameters of fertile nuclei and of 239 Pu isotope for fast power reactors will be restricted, in this presentation, to mixed oxide-uranium-plutonium fuelled sodium-cooled and uranium-oxide-sodium reflected fast reactors. The power range lies between 200 and 2000 MWe. Among the topics of this specialist meeting, the isotopes to be considered are, primarly 239 Pu then 238 U and 240 Pu. Resonance parameters are mainly used in fast power reactor calculations through the well-known concept of self shielding factors. After a short description of the determination and the use of these self-shielding factors, their sensitivities to resonance parameters are characterized from some specific examples: those sensitivities are small. Then, the main design parameters sensitive to the amplitude of self-shielding factors are considered: critical enrichment, global breeding gain. The relative importance of isotope, reaction rate and energy range are mentionned. In a third part, the Doppler effect, sensitive to the temperature variation of self-shielding factors, is considered in the same way. Finally, it is concluded that the present knowledge of resonance parameters for 238 U, 239 Pu and 240 Pu is sufficient for fast power reactors from a designer point of view [fr

  2. High-power CO laser with RF discharge for isotope separation employing condensation repression

    Science.gov (United States)

    Baranov, I. Ya.; Koptev, A. V.

    2008-10-01

    High-power CO laser can be the effective tool in such applications as isotope separation using the free-jet CRISLA method. The way of transfer from CO small-scale experimental installation to industrial high-power CO lasers is proposed through the use of a low-current radio-frequency (RF) electric discharge in a supersonic stream without an electron gun. The calculation model of scaling CO laser with RF discharge in supersonic stream was developed. The developed model allows to calculate parameters of laser installation and optimize them with the purpose of reception of high efficiency and low cost of installation as a whole. The technical decision of industrial CO laser for isotope separation employing condensation repression is considered. The estimated cost of laser is some hundred thousand dollars USA and small sizes of laser head give possibility to install it in any place.

  3. Preliminary Failure Modes, Effects and Criticality Analysis (FMECA) of the conceptual Brayton Isotope Power System (BIPS) Flight System

    International Nuclear Information System (INIS)

    Miller, L.G.

    1976-01-01

    A failure modes, effects and criticality analysis (FMECA) was made of the Brayton Isotope Power System Flight System (BIPS-FS) as presently conceived. The components analyzed include: Mini-BRU; Heat Source Assembly (HSA); Mini-Brayton Recuperator (MBR); Space Radiator; Ducts and Bellows, Insulation System; Controls; and Isotope Heat Source (IHS)

  4. Loop containment (joint integrity) assessment Brayton Isotope Power System flight system

    International Nuclear Information System (INIS)

    1976-01-01

    The Brayton Isotope Power System (BIPS) contains a large number of joints. Since the failure of a joint would result in loss of the working fluid and consequential failure of the BIPS, the integrity of the joints is of paramount importance. The reliability of the ERDA BIPS loop containment (joint integrity) is evaluated. The conceptual flight system as presently configured is depicted. A brief description of the flight system is given

  5. Kilowatt isotope power system. Phase II plan. Volume I. Phase II program plan

    International Nuclear Information System (INIS)

    1978-01-01

    The development of a Kilowatt Isotope Power System (KIPS) was begun in 1975 for the purpose of satisfying the power requirements of satellites in the 1980's. The KIPS is a 238 PuO 2 -fueled organic Rankine cycle turbine power system to provide a design output of 500 to 2000 W. Phase II of the overall 3-phase KIPS program is described. This volume presents a program plan for qualifying the organic Rankine power system for flight test in 1982. The program plan calls for the design and fabrication of the proposed flight power system; conducting a development and a qualification program including both environmental and endurance testing, using an electrical and a radioisotope heat source; planning for flight test and spacecraft integration; and continuing ground demonstration system testing to act as a flight system breadboard and to accumulate life data

  6. Comparison of dynamic isotope power systems for distributed planet surface applications

    Science.gov (United States)

    Bents, David J.; Mckissock, Barbara I.; Hanlon, James C.; Schmitz, Paul C.; Rodriguez, Carlos D.; Withrow, Colleen A.

    1991-01-01

    Dynamic isotope power system (DIPS) alternatives were investigated and characterized for the surface mission elements associated with a lunar base and subsequent manned Mars expedition. System designs based on two convertor types were studied. These systems were characterized parametrically and compared over the steady-state electrical output power range 0.2 to 20 kWe. Three methods of thermally integrating the heat source and the Stirling heater head were considered, depending on unit size. Figures of merit were derived from the characterizations and compared over the parametric range. Design impacts of mission environmental factors are discussed and quantitatively assessed.

  7. Considerations in the design of a high power medical isotope production reactor

    International Nuclear Information System (INIS)

    Ball, Russell M.; Nordyke, William H.; Brown, Roy

    2002-01-01

    For the low enriched aqueous homogeneous reactor to be economic in the production of medical isotopes, such as Mo-99 and Sr-89, the power level should be of the order of 100 kWth. This is double the earlier designs and this paper discusses the design changes which must be considered to meet this goal. The topics considered are: 1. Heat removal from the reactor solution; 2. Recombination of radiolytic gases; 3. Adequate radiation shielding; 4. Stability of reactor power with fluctuating reactivity; 5. Adequate cooling of the reflector; 6. Independent shutdown mechanisms; 7. Required volume of the reactor; 8. Economic implementation. (author)

  8. Brayton Isotope Power System. Phase I. (Ground demonstration system) Configuration Control Document (CCD)

    International Nuclear Information System (INIS)

    1976-01-01

    The configuration control document (CCD) defines the BIPS-GDS configuration. The GDS configuration is similar to a conceptual flight system design, referred to as the BIPS-FS, which is discussed in App. I. The BIPS is being developed by ERDA as a 500 to 2000 W(e), 7-y life, space power system utilizing a closed Brayton cycle gas turbine engine to convert thermal energy (from an isotope heat source) to electrical energy at a net efficiency exceeding 25 percent. The CCD relates to Phase I of an ERDA Program to qualify a dynamic system for launch in the early 1980's. Phase I is a 35-month effort to provide an FS conceptual design and GDS design, fabrication, and test. The baseline is a 7-year life, 450-pound, 4800 W(t), 1300 W(e) system which will use two multihundred watt (MHW) isotope heat sources being developed

  9. Computer study of isotope production for medical and industrial applications in high power accelerators

    Science.gov (United States)

    Mashnik, S. G.; Wilson, W. B.; Van Riper, K. A.

    2001-07-01

    Methods for radionuclide production calculation in a high power proton accelerator have been developed and applied to study production of 22 isotopes. These methods are readily applicable both to accelerator and reactor environments and to the production of other radioactive and stable isotopes. We have also developed methods for evaluating cross sections from a wide variety of sources into a single cross section set and have produced an evaluated library covering about a third of all natural elements that may be expanded to other reactions. A 684 page detailed report on this study, with 37 tables and 264 color figures, is available on the Web at http://t2.lanl.gov/publications/.

  10. FABGEN, a transient power-generation and isotope birth rate calculator

    International Nuclear Information System (INIS)

    Roland, H.C.

    1975-04-01

    A description is given of the FABGEN program, a fast-running program for calculating fuel element power-generation rates and selected fission product birth rates in a known neutron flux as functions of time. A first forward difference calculation is used, and the time step is one day. Provisions are made for including various fuel element lengths, variation of thermal flux with time, and use of different fertile isotopes. Five different fission products may be specified for birth-rate calculations. A daily summary may be output, or totals by days may be accumulated for final output. (U.S.)

  11. In-situ Isotopic Analysis at Nanoscale using Parallel Ion Electron Spectrometry: A Powerful New Paradigm for Correlative Microscopy

    Science.gov (United States)

    Yedra, Lluís; Eswara, Santhana; Dowsett, David; Wirtz, Tom

    2016-01-01

    Isotopic analysis is of paramount importance across the entire gamut of scientific research. To advance the frontiers of knowledge, a technique for nanoscale isotopic analysis is indispensable. Secondary Ion Mass Spectrometry (SIMS) is a well-established technique for analyzing isotopes, but its spatial-resolution is fundamentally limited. Transmission Electron Microscopy (TEM) is a well-known method for high-resolution imaging down to the atomic scale. However, isotopic analysis in TEM is not possible. Here, we introduce a powerful new paradigm for in-situ correlative microscopy called the Parallel Ion Electron Spectrometry by synergizing SIMS with TEM. We demonstrate this technique by distinguishing lithium carbonate nanoparticles according to the isotopic label of lithium, viz. 6Li and 7Li and imaging them at high-resolution by TEM, adding a new dimension to correlative microscopy. PMID:27350565

  12. A dynamic isotope power system for Space Exploration Initiative surface transport systems

    International Nuclear Information System (INIS)

    Hunt, M.E.; Harty, R.B.; Cataldo, R.

    1992-03-01

    The Dynamic Isotope Power System (DIPS) Demonstration Program, sponsored by the U.S. Department of Energy with support funding from NASA, is currently focused on the development of a standardized 2.5-kWe portable generator for multiple applications on the lunar or Martian surface. A variety of remote and mobile potential applications have been identified by NASA, including surface rovers for both short- and extended-duration missions, remote power to science packages, and backup to central base power. Recent work focused on refining the 2.5-kWe design and emphasizing the compatibility of the system with potential surface transport systems. Work included an evaluation of the design to ensure compatibility with the Martian atmosphere while imposing only a minor mass penalty on lunar operations. Additional work included a study performed to compare the DIPS with regenerative fuel cell systems for lunar mobile and remote power systems. Power requirements were reviewed and a modular system chosen for the comparison. 4 refs

  13. A dynamic isotope power system portable generator for the Moon or Mars

    International Nuclear Information System (INIS)

    Johnson, R.A.; Hunt, M.E.; Mason, L.S.

    1991-01-01

    The Dynamic Isotope Power Systems (DIPS) Demonstration Program is focused on a standardized 2.5 kWe portable generator for multipole uses on the Lunar or Martian surface. A variety of potential remote or mobile applications has been identified by the National Aeronautics and Space Administration (NASA). These applications include remote power to science packages, surface rovers for both short and extended duration missions, and back up to central base power. In this paper, reviews conducted on alternative power sources for these applications are described. These include the comparison of DIPS to regenerative fuel cells (RFCs) related to such things as mass, complexity, and life cycle costs, and concluded that each power source has application. Recent work is presented refining the 2.5 kWe design to assure compatibility with the Martian environment while imposing only a minor mass penalty on Lunar operations. This was accomplished by limiting temperatures, except in the heat source unit (HSU), to the nonrefractory materials regime and protecting the necessary refractories in the HSU from the environment. Design changes to the HSU are described. Finally, work related to recent concerns regarding astronaut radiation doses is described. This work includes the bases for the calculations to determine the necessary shielding or operational limitations

  14. Organic Rankine kilowatt isotope power system. First annual summary report, August 1, 1975--August 1, 1976

    International Nuclear Information System (INIS)

    1976-01-01

    Sundstrand Energy Systems is developing a Kilowatt Isotope Power System (KIPS) directed toward satisfying the higher power requirements of satellites of the 1980's. The KIPS is a plutonium oxide fueled organic Rankine cycle turbine power system which will provide design output power in the range of 500 to 2000 W(e) with a minimum of system changes. Research progress is reported on Phase I comprising: (1) flight system conceptual design and ground demonstration; (2) flight system design and ground qualification; and (3) flight system production, acceptance testing and delivery. The principal objectives of Phase I are to: (1) conceptually design the flight system, (2) based on the flight system concept, design and build the ground demonstration system (GDS), (3) conduct performance and endurance testing using electric heaters to simulate the radioisotope heat source, (4) identify and initiate long lead development efforts required to achieve the initial flight qualification hardware availability date of April 1981, and (5) finalize the flight concept design and prepare the program plan for the Phase II effort

  15. Features of adsorbed chemical elements and their isotopes distribution in iodine air filters AU-1500 of nuclear power plant

    International Nuclear Information System (INIS)

    Neklyudov, I.M.; Dovbnya, A.N.; Dikiy, N.P.; Ledenyov, O.P.; Lyashko, Yu.V.

    2013-01-01

    The main aim of research is to investigate the physical features of spatial distribution of the adsorbed chemical elements and their isotopes in the granular filtering medium in the iodine air filters of the type of AU-1500 in the forced-exhaust ventilation at the nuclear power plant. The ?-activation analysis method is applied to accurately characterize the distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the AU-1500 iodine air filter after its long term operation at the nuclear power plant. The typical spectrum of the detected chemical elements and their isotopes in the AU-1500 iodine air filter, which was exposed by the irradiation of bremsstrahlung gamma-quantum producing by the accelerating electrons in the tantalum target, are obtained. The spatial distributions of the detected chemical element 127 I and some other chemical elements and their isotopes in the layer of absorber, which was made of the cylindrical coal granules of the type of SKT-3, in the AU-1500 iodine air filter are also researched. The possible influences by the standing wave of air pressure in the iodine air filter on the spatial distribution of the chemical elements and their isotopes in the iodine air filter are discussed. The comprehensive analysis of obtained research results on the distribution of the adsorbed chemical elements and their isotopes in the absorber of iodine air filter is performed.

  16. Rhodium self-powered detector for monitoring neutron fluence, energy production, and isotopic composition of fuel

    International Nuclear Information System (INIS)

    Sokolov, A.P.; Pochivalin, G.P.; Shipovskikh, Yu.M.; Garusov, Yu.V.; Chernikov, O.G.; Shevchenko, V.G.

    1993-01-01

    The use of self-powered detectors (SPDs) with a rhodium emitter customarily involves monitoring of neutron fields in the core of a nuclear reactor. Since current in an SPD is generated primarily because of the neutron flux, which is responsible for the dynamics of particular nuclear transformations, including fission reactions of heavy isotopes, the detector signal can be attributed unambiguously to energy release at the location of the detector. Computation modeling performed with the KOMDPS package of programs of the current formation in a rhodium SPD along with the neutron-physical processes that occur in the reactor core makes it possible to take account of the effect of the principal factors characterizing the operating conditions and the design features of the fuel channel and the detector, reveal quantitative relations between the generated signal and individual physical parameters, and determine the metrological parameters of the detector. The formation and transport of changed particles in the sensitive part of the SPC is calculated by the Monte Carlo method. The emitter activation, neutron transport, and dynamics of the isotopic composition in the fuel channel containing the SPD are determined by solving the kinetic equation in the multigroup representation of the neutron spectrum, using the discrete ordinate method. In this work the authors consider the operation of a rhodium SPD in a bundle of 49 fuel channels of the RBMK-1000 reactor with a fuel enrichment of 2.4% from the time it is inserted into a fresh channel

  17. Preliminary design study of an alternate heat source assembly for a Brayton isotope power system

    Science.gov (United States)

    Strumpf, H. J.

    1978-01-01

    Results are presented for a study of the preliminary design of an alternate heat source assembly (HSA) intended for use in the Brayton isotope power system (BIPS). The BIPS converts thermal energy emitted by a radioactive heat source into electrical energy by means of a closed Brayton cycle. A heat source heat exchanger configuration was selected and optimized. The design consists of a 10 turn helically wound Hastelloy X tube. Thermal analyses were performed for various operating conditions to ensure that post impact containment shell (PICS) temperatures remain within specified limits. These limits are essentially satisfied for all modes of operation except for the emergency cooling system for which the PICS temperatures are too high. Neon was found to be the best choice for a fill gas for auxiliary cooling system operation. Low cycle fatigue life, natural frequency, and dynamic loading requirements can be met with minor modifications to the existing HSA.

  18. The determination of minor isotope abundances in naturally occurring uranium materials. The tracing power of isotopic signatures for uranium

    Energy Technology Data Exchange (ETDEWEB)

    Ovaskainen, R

    1999-11-01

    The mass spectrometric determination of minor abundant isotopes, {sup 234}U and {sup 236}U in naturally occurring uranium materials requires instruments of high abundance sensitivity and the use of highly sensitive detection systems. In this study the thermal ionisation mass spectrometer Finnigan MAT 262RPQ was used. It was equipped with 6 Faraday cups and a Secondary Electron Multiplier (SEM), which was operated in pulse counting mode for the detection of extremely low ion currents. The dynamic measurement range was increased considerably combining these two different detectors. The instrument calibration was performed carefully. The linearity of each detector, the deadtime of the ion counting detector, the detector normalisation factor, the baseline of each detector and the mass discrimination in the ion source were checked and optimised. A measurement technique based on the combination of a Gas Source Mass Spectrometry (GSMS) and a Thermal Ionisation Mass Spectrometry (TIMS) was developed for the accurate determination of isotopic composition in naturally occurring uranium materials. Because the expected ratio of n({sup 234}U)/n({sup 238}U) exceeded the dynamic measurement range of the Faraday detectors of the TIMS instrument, an experimental design using a combination of two detectors was developed. The n({sup 234}U)/n({sup 235}U) and n({sup 236}U)/n({sup 235}U) ratios were determined using ion counting in combination with the decelerating device. The n({sup 235}U)/n({sup 238}U) ratio was determined by the Faraday detector. This experimental design allowed the detector cross calibration to be circumvented. Precisions of less than 1 percent for the n({sup 234}U)/n({sup 235}U) ratios and 5-25 percent for the n({sup 236}U)/n({sup 235}U) ratios were achieved. The purpose of the study was to establish a register of isotopic signatures for natural uranium materials. The amount ratio, and isotopic composition of 18 ore concentrates, collected by the International

  19. The determination of minor isotope abundances in naturally occurring uranium materials. The tracing power of isotopic signatures for uranium

    International Nuclear Information System (INIS)

    Ovaskainen, R.

    1999-01-01

    The mass spectrometric determination of minor abundant isotopes, 234 U and 236 U in naturally occurring uranium materials requires instruments of high abundance sensitivity and the use of highly sensitive detection systems. In this study the thermal ionisation mass spectrometer Finnigan MAT 262RPQ was used. It was equipped with 6 Faraday cups and a Secondary Electron Multiplier (SEM), which was operated in pulse counting mode for the detection of extremely low ion currents. The dynamic measurement range was increased considerably combining these two different detectors. The instrument calibration was performed carefully. The linearity of each detector, the deadtime of the ion counting detector, the detector normalisation factor, the baseline of each detector and the mass discrimination in the ion source were checked and optimised. A measurement technique based on the combination of a Gas Source Mass Spectrometry (GSMS) and a Thermal Ionisation Mass Spectrometry (TIMS) was developed for the accurate determination of isotopic composition in naturally occurring uranium materials. Because the expected ratio of n( 234 U)/n( 238 U) exceeded the dynamic measurement range of the Faraday detectors of the TIMS instrument, an experimental design using a combination of two detectors was developed. The n( 234 U)/n( 235 U) and n( 236 U)/n( 235 U) ratios were determined using ion counting in combination with the decelerating device. The n( 235 U)/n( 238 U) ratio was determined by the Faraday detector. This experimental design allowed the detector cross calibration to be circumvented. Precisions of less than 1 percent for the n( 234 U)/n( 235 U) ratios and 5-25 percent for the n( 236 U)/n( 235 U) ratios were achieved. The purpose of the study was to establish a register of isotopic signatures for natural uranium materials. The amount ratio, and isotopic composition of 18 ore concentrates, collected by the International Atomic Energy Agency (IAEA) from uranium milling and mining

  20. Almost twenty years' search of transuranium isotopes in effluents discharged to air from nuclear power plants with VVER reactors.

    Science.gov (United States)

    Hölgye, Z; Filgas, R

    2006-04-01

    Airborne effluents of 5 stacks (stacks 1-5) of three nuclear power plants, with 9 pressurized water reactors VVER of 4,520 MWe total power, were searched for transuranium isotopes in different time periods. The search started in 1985. The subject of this work is a presentation of discharge data for the period of 1998-2003 and a final evaluation. It was found that 238Pu, 239,240Pu, 241Am, 242Cm, and 244Cm can be present in airborne effluents. Transuranium isotope contents in most of the quarterly effluent samples from stacks 2, 4 and 5 were not measurable. Transuranium isotopes were present in the effluents from stack l during all 9 years of the study and from stack 3 since the 3rd quarter of 1996 as a result of a defect in the fuel cladding. A relatively high increase of transuranium isotopes in effluents from stack 3 occurred in the 3rd quarter of 1999, and a smaller increase occurred in the 3rd quarter of 2003. In each instance 242Cm prevailed in the transuranium isotope mixtures. 238Pu/239,240Pu, 241Am/239,240Pu, 242Cm/239,240Pu, and 244Cm/239,240Pu ratios in fuel for different burn-up were calculated, and comparison of these ratios in fuel and effluents was performed.

  1. Stable isotope composition of mercury forms in flue gases from a typical coal-fired power plant, Inner Mongolia, northern China

    International Nuclear Information System (INIS)

    Tang, Shunlin; Feng, Chaohui; Feng, Xinbin; Zhu, Jianming; Sun, Ruoyu; Fan, Huipeng; Wang, Lina; Li, Ruiyang; Mao, Tonghua; Zhou, Ting

    2017-01-01

    Highlights: • The first speciated Hg isotope ratios in coal combustion flue gases are presented. • Significant Hg isotope kinetic MDF was observed during Hg forms transformation. • Emitted gaseous Hg highly enriches in heavy Hg isotopes relative to feed coal. - Abstract: Mercury forms emitted from coal combustion via air pollution control devices are speculated to carry different Hg isotope signatures. Yet, their Hg isotope composition is still not reported. Here, we present the first onsite Hg isotope data for gaseous elemental Hg (GEM) and gaseous oxidized Hg (GOM) of flue gases from a typical lignite-fired power plant (CFPP). Significant mass dependent fractionation (MDF) and insignificant mass independent fractionation (MIF) are observed between feed coal and coal combustion products. As compared to feed coal (δ 202 Hg = −2.04 ± 0.25‰), bottom ash, GEM and GOM in flue gases before and after wet flue gas desulfurization system significantly enrich heavy Hg isotopes by 0.7–2.6‰ in δ 202 Hg, while fly ash, desulfurization gypsum and waste water show slight but insignificant enrichment of light Hg isotopes. GEM is significantly enriched heavy Hg isotopes compared to GOM and Hg in fly ash. Our observations verify the previous speculation on Hg isotope fractionation mechanism in CFPPs, and suggest a kinetically-controlled mass dependent Hg isotope fractionation during transformation of Hg forms in flue gases. Finally, our data are compared to Hg isotope compositions of atmospheric Hg pools, suggesting that coal combustion Hg emission is likely an important atmospheric Hg contributor.

  2. Stable isotope composition of mercury forms in flue gases from a typical coal-fired power plant, Inner Mongolia, northern China

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Shunlin, E-mail: tangshunlin@hpu.edu.cn [Institute of Resources and Environment, Henan Polytechnic University, Jiaozuo, Henan Province, 454000 (China); Feng, Chaohui [Institute of Resources and Environment, Henan Polytechnic University, Jiaozuo, Henan Province, 454000 (China); Feng, Xinbin [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002 (China); Zhu, Jianming [Institute of Resources and Environment, Henan Polytechnic University, Jiaozuo, Henan Province, 454000 (China); State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing, 100086 (China); Sun, Ruoyu, E-mail: ruoyu.sun@tju.edu.cn [CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026 (China); Fan, Huipeng; Wang, Lina; Li, Ruiyang; Mao, Tonghua [Institute of Resources and Environment, Henan Polytechnic University, Jiaozuo, Henan Province, 454000 (China); Zhou, Ting [State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002 (China)

    2017-04-15

    Highlights: • The first speciated Hg isotope ratios in coal combustion flue gases are presented. • Significant Hg isotope kinetic MDF was observed during Hg forms transformation. • Emitted gaseous Hg highly enriches in heavy Hg isotopes relative to feed coal. - Abstract: Mercury forms emitted from coal combustion via air pollution control devices are speculated to carry different Hg isotope signatures. Yet, their Hg isotope composition is still not reported. Here, we present the first onsite Hg isotope data for gaseous elemental Hg (GEM) and gaseous oxidized Hg (GOM) of flue gases from a typical lignite-fired power plant (CFPP). Significant mass dependent fractionation (MDF) and insignificant mass independent fractionation (MIF) are observed between feed coal and coal combustion products. As compared to feed coal (δ{sup 202}Hg = −2.04 ± 0.25‰), bottom ash, GEM and GOM in flue gases before and after wet flue gas desulfurization system significantly enrich heavy Hg isotopes by 0.7–2.6‰ in δ{sup 202}Hg, while fly ash, desulfurization gypsum and waste water show slight but insignificant enrichment of light Hg isotopes. GEM is significantly enriched heavy Hg isotopes compared to GOM and Hg in fly ash. Our observations verify the previous speculation on Hg isotope fractionation mechanism in CFPPs, and suggest a kinetically-controlled mass dependent Hg isotope fractionation during transformation of Hg forms in flue gases. Finally, our data are compared to Hg isotope compositions of atmospheric Hg pools, suggesting that coal combustion Hg emission is likely an important atmospheric Hg contributor.

  3. Isotopic power materials development. Quarterly progress report for period ending March 31, 1976

    International Nuclear Information System (INIS)

    Schaffhauser, A.C.

    1976-06-01

    The second in a series of quarterly reports for Technology and Space Applications materials programs conducted by the Metals and Ceramics Division of Oak Ridge National Laboratory for the Nuclear Research and Applications Division of ERDA is presented. These quarterly reports replace the monthly and annual reports previously issued on this work. The areas of research covered include high-temperature alloys for space isotopic heat sources, physical and mechanical metallurgy of heat source containment materials, isotope Brayton system materials support, and space nuclear flight systems hardware

  4. Isotopic Tracing of Thallium Contamination in Soils Affected by Emissions from Coal-Fired Power Plants

    Czech Academy of Sciences Publication Activity Database

    Vaněk, A.; Grösslová, Z.; Mihaljevič, M.; Trubač, J.; Ettler, V.; Teper, L.; Cabala, J.; Rohovec, Jan; Zádorová, T.; Penížek, V.; Pavlů, L.; Holubík, O.; Němeček, K.; Houška, J.; Drábek, O.; Ash, C.

    2016-01-01

    Roč. 50, č. 18 (2016), s. 9864-9871 ISSN 0013-936X Institutional support: RVO:67985831 Keywords : environmental implications * isotope * fractionation * combustion * utility * health * oxides * silver * lead Subject RIV: DD - Geochemistry Impact factor: 6.198, year: 2016

  5. Sulphur isotopes as tracers of the influence of a coal-fired power plant on a Scots pine forest in Catalonia (NE Spain)

    Science.gov (United States)

    Puig, R.; Àvila, A.; Soler, A.

    Stable sulphur isotopes and major ionic composition were analysed in precipitation and throughfall samples from a Scots pine ( Pinus sylvestris, L.) forest near the Cercs coal-fired power plant (Catalonia, NE Spain). The purpose of the study was to determine the main sources of sulphur deposition on this pine forest. Sulphur isotope measurements from the SO 2 power plant stack emissions were used to identify the isotopic signature of this source. Net throughfall fluxes of sulphur (26.1 kg S ha 1 yr -1) and nitrogen (16.3 kg N ha -1 yr -1) were higher—5-25 times higher for S and 5-15 times for N—at this site than in other forests in Catalonia. Sulphur isotope analysis confirmed that the net throughfall fluxes of sulphur were mostly due to the dry deposition of the SO 2 power plant emissions onto the pine canopies. Two potential atmospheric end-members were distinguished: regional background rainwater (δ 34S=+7.2‰) and power plant emissions (δ 34S=-2.8‰). By applying a two-component sulphur isotope mixing model, we found that during periods of low power plant activity (⩽10 emission h day -1), 62% of the throughfall sulphate could be attributed to the power plant emissions. At higher activity periods (⩾14 emission h day -1), this contribution rose to 73%. Although power plant contribution to bulk deposition was lower in both cases (34% and 45%), the possible influence of sulphate coming with long-range transport events from the polluted areas in the Mediterranean basin (δ 34S≈0‰) was not discarded.

  6. Kilowatt Isotope Power System. Phase I. System test report. 78-KIPS-33

    International Nuclear Information System (INIS)

    1978-01-01

    The KIPS Ground Demonstration System (GDS) was designed to simulate, as closely as possible, a Flight System Conceptual Design (FSCD). No radiator was incorporated and electric heat sources were used in place of isotope heat sources. To minimize air in-leakage and to simulate heat losses associated with space operation, the system was operated in a vacuum chamber. Initial testing was performed on the development system which did not incorporate a high performance turbine or non-condensing configuration of the cold liquid passages in certain regenerator vapor regions. After testing of the development system and retrofit to the GDS configuration, which included improvements in the above two items, the GDS was installed in the test chamber. Testing to date showed the GDS configuration has demonstrated a system efficiency of greater than 15%. Satisfactory heat balances have been calculated on most system components, permitting evaluation of component performance. Certain performance deficiencies currently exist which prevented the 18% efficiency goal being attained. These can be corrected with further development

  7. Radium-based estimates of cesium isotope transport and total direct ocean discharges from the Fukushima Nuclear Power Plant accident

    Energy Technology Data Exchange (ETDEWEB)

    Charette, M.A.; Breier, C.F.; Henderson, P.B.; Pike, S.M.; Buesseler, K.O. [Woods Hole Oceanographic Institution, Woods Hole, MA (United States). Dept. of Marine Chemistry and Geochemistry; Rypina, I.I.; Jayne, S.R. [Woods Hole Oceanographic Institution, Woods Hole, MA (United States). Dept. of Physical Oceanography

    2013-07-01

    Radium has four naturally occurring isotopes that have proven useful in constraining water mass source, age, and mixing rates in the coastal and open ocean. In this study, we used radium isotopes to determine the fate and flux of runoff-derived cesium from the Fukushima Dai-ichi Nuclear Power Plant (FNPP). During a June 2011 cruise, the highest cesium (Cs) concentrations were found along the eastern shelf of northern Japan, from Fukushima south, to the edge of the Kuroshio Current, and in an eddy ∝ 130 km from the FNPP site. Locations with the highest cesium also had some of the highest radium activities, suggesting much of the direct ocean discharges of Cs remained in the coastal zone 2-3 months after the accident. We used a short-lived Ra isotope ({sup 223}Ra, t{sub 1/2} = 11.4 d) to derive an average water mass age (T{sub r}) in the coastal zone of 32 days. To ground-truth the Ra age model, we conducted a direct, station-by-station comparison of water mass ages with a numerical oceanographic model and found them to be in excellent agreement (model avg. T{sub r} = 27 days). From these independent T{sub r} values and the inventory of Cs within the water column at the time of our cruise, we were able to calculate an offshore {sup 134}Cs flux of 3.9-4.6 x 10{sup 13} Bq d{sup -1}. Radium-228 (t{sub 1/2} = 5.75 yr) was used to derive a vertical eddy diffusivity (K{sub z}) of 0.7 m{sup 2} d{sup -1} (0.1 cm{sup 2} s{sup -1}); from this K{sub z} and {sup 134}Cs inventory, we estimated a {sup 134}Cs flux across the pycnocline of 1.8 x 10{sup 4} Bq d{sup -1} for the same time period. On average, our results show that horizontal mixing loss of Cs from the coastal zone was ∝ 10{sup 9} greater than vertical exchange below the surface mixed layer. Finally, a mixing/dilution model that utilized our Ra-based and oceanographic model water mass ages produced a direct ocean discharge of {sup 134}Cs from the FNPP of 11-16 PBq at the time of the peak release in early April 2011

  8. The isotopic composition and content of sulphur in soils of Kansk-Achinsk fuel power generation complex

    International Nuclear Information System (INIS)

    Grinenko, L.N.; Grinenko, V.A.

    1991-01-01

    In the 1970s the first phase of a large coal-burning power complex was brought into operation in the Kansk-Achinsk region of the Soviet Union. The target consumption for this complex is 50 x 10 6 tonnes yr -1 and most of this is supplied from local open-pit mines. The emission of SO 2 from this plant caused concern as to its impact on the local environment and prompted a study of the sulphurous depositions. Monitoring the areal extent and distribution of the deposited S and its fate in the environment can be a mammoth task involving continual measurement of many biological and physical factors including atmospheric concentrations, wind speed, emission rates, and forms of S in soil, plants, and animals. A possible alternative for evaluating the amount, distribution, and fate of the emitted S in the ecosystem is stable sulphur isotope analyses since different coals and SO 2 from their combustion often have δ 34 S values differing from those of soils and plants in the region. The study reported here was initiated to see if the δ 34 S values for emissions differed significantly from the natural environment. Assuming that the difference was sufficient, a second objective was to document changes that have occurred in the sulphur isotope compositions of the environmental receptors over time. Soil samples from 23 sites were collected and analysed for S content and δ 34 S values. Coal, cinder and ash collected from furnaces and SO 2 from the combustion products were similarly analysed. Figs and tabs

  9. Isotope production

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Dewi M.

    1995-07-15

    Some 2 0% of patients using radiopharmaceuticals receive injections of materials produced by cyclotrons. There are over 200 cyclotrons worldwide; around 35 are operated by commercial companies solely for the production of radio-pharmaceuticals with another 25 accelerators producing medically useful isotopes. These neutron-deficient isotopes are usually produced by proton bombardment. All commonly used medical isotopes can be generated by 'compact' cyclotrons with energies up to 40 MeV and beam intensities in the range 50 to 400 microamps. Specially designed target systems contain gram-quantities of highly enriched stable isotopes as starting materials. The targets can accommodate the high power densities of the proton beams and are designed for automated remote handling. The complete manufacturing cycle includes large-scale target production, isotope generation by cyclotron beam bombardment, radio-chemical extraction, pharmaceutical dispensing, raw material recovery, and labelling/packaging prior to the rapid delivery of these short-lived products. All these manufacturing steps adhere to the pharmaceutical industry standards of Good Manufacturing Practice (GMP). Unlike research accelerators, commercial cyclotrons are customized 'compact' machines usually supplied by specialist companies such as IBA (Belgium), EBCO (Canada) or Scanditronix (Sweden). The design criteria for these commercial cyclotrons are - small magnet dimensions, power-efficient operation of magnet and radiofrequency systems, high intensity extracted proton beams, well defined beam size and automated computer control. Performance requirements include rapid startup and shutdown, high reliability to support the daily production of short-lived isotopes and low maintenance to minimize the radiation dose to personnel. In 1987 a major step forward in meeting these exacting industrial requirements came when IBA, together with the University of Louvain-La-Neuve in Belgium, developed the Cyclone-30

  10. Assessment of groundwater pollution from ash ponds using stable and unstable isotopes around the Koradi and Khaperkheda thermal power plants (Maharashtra, India)

    Energy Technology Data Exchange (ETDEWEB)

    Voltaggio, M.; Spadoni, M. [CNR — Istituto di Geologia Ambientale e Geoingegneria, Via Salaria km. 29.300, 00010 Montelibretti, Roma (Italy); Sacchi, E. [Dept. of Earth and Environmental Sciences, University of Pavia and CNR-IGG, Via Ferrata 1, 27100 Pavia (Italy); Sanam, R.; Pujari, P.R.; Labhasetwar, P.K. [CSIR-National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440020 (India)

    2015-06-15

    The impact on local water resources due to fly ash produced in the Koradi and Khaperkheda thermal power plants (district of Nagpur, Maharashtra — India) and disposed in large ponds at the surface was assessed through the study of environmental variation of ratios of stable and unstable isotopes. Analyses of oxygen and hydrogen isotopes suggest scarce interaction between the water temporarily stored in the ponds and the groundwater in the study area. Data also highlight that the high salinity of groundwater measured in the polluted wells is not due to evaporation, but to subsequent infiltration of stream waters draining from the ponds to the local aquifer. {sup 87}Sr/{sup 86}Sr values, when associated with Sr/Ca ratios, demonstrate the dominant role of waste waters coming from tens of brick kilns surrounding the pond sulfate pollution. Uranium isotopic analyses clearly show evidence of the interaction between groundwater and aquifer rocks, and confirm again the low influence of ash ponds. A new conceptual model based on the study of the isotopes of radium is also proposed and used to estimate residence times of groundwater in the area. This model highlights that high salinity cannot be in any case attributed to a prolonged water–rock interaction, but is due to the influence of untreated waste water of domestic or brick kiln origin on the shallow and vulnerable aquifers. - Highlights: • Ash ponds have wide environmental and social impact in India. • Isotope ratios can be used as tracers for possible pollution of groundwater. • Isotopes of O, H, Sr, U and Ra have been used to investigate the area of Koradi. • Salinity of groundwater is not due to fly ash but linked to local brick kilns. • A model for the residence time of water based on Ra isotopes is described.

  11. Actinides record, power calculations and activity for present isotopes in the spent fuel of a BWR

    International Nuclear Information System (INIS)

    Enriquez C, P.; Ramirez S, J. R.; Lucatero, M. A.

    2012-10-01

    The administration of spent fuel is one of the more important stages of the nuclear fuel cycle, and this has become a problem of supreme importance in countries that possess nuclear reactors. Due to this in this work, the study on the actinides record and present fission products to the discharge of the irradiated fuel in a light water reactor type BWR is shown, to quantify the power and activity that emit to the discharge and during the cooling time. The analysis was realized on a fuel assembly type 10 x 10 with an enrichment average of 3.69 wt % in U-235 and the assembly simulation assumes four cycles of operation of 18 months each one and presents an exposition of 47 G Wd/Tm to the discharge. The module OrigenArp of the Scale 6 code is the computation tool used for the assembly simulation and to obtain the results on the actinides record presents to the fuel discharge. The study covers the following points: a) Obtaining of the plutonium vector used in the fuel production of mixed oxides, and b) Power calculation and activity for present actinides to the discharge. The results presented in this work, correspond at the same time immediate of discharge (0 years) and to a cooling stage in the irradiated fuel pool (5 years). (Author)

  12. Analyzing powers and isotope ratios for the natAg(rvec p, intermediate-mass fragment) reaction at 200 MeV

    International Nuclear Information System (INIS)

    Renshaw, E.; Yennello, S.J.; Kwiatkowski, K.; Planeta, R.; Woo, L.W.; Viola, V.E.

    1991-01-01

    Analyzing powers and isotope ratios have been measured for ejectiles with Z≤7 emitted at forward angles in the 200-MeV rvec p+ nat Ag reaction. The observed analyzing powers are consistent with zero, and thus do not provide evidence for a significant contribution from cluster knockout, or similar direct formation mechanisms. Fragment kinetic-energy spectra above the Coulomb peak are compared with a coalescence calculation. The isotopic composition of the elemental kinetic-energy spectra is found to favor N/Z≥1 nuclei for fragment energies near the exit-channel Coulomb energy, whereas species with N/Z≤1 are more abundant in the high-energy spectral tails. This behavior is consistent with the predictions of an accreting source calculation

  13. Various analytical techniques used for the measurement of isotopic purity of heavy water at Madras Atomic Power Station

    International Nuclear Information System (INIS)

    Satyanarayanan, V.; Umapathy, P.; Bhaskaran, R.; Nagarajan, J.; Pradeep, Jeena; Ayyar, S.R.

    2008-01-01

    The paper deals with the various techniques used for the measurement of isotopic purity of heavy water samples received from different sources viz. reactor systems, heavy water upgrading plant and fresh consignment from heavy water production plants. Heavy water is used in PHWRs as moderator and primary coolant. Isotopic Purity is an important parameter to be monitored/analysed regularly for both the systems. There is a minimum isotopic purity level to be maintained in the moderator system due to neutron economy/fuel burnup and in the case of coolant system the measurement is of paramount importance due to its safety considerations. The selection of the method of analysis depends on the isotopic range. The techniques used to measure the isotopic purity of heavy water are a) Infrared Spectrophotometry b) Refractometry c) Densitometry. Infrared spectrometer uses the property of molecular absorption of IR radiation by HOD species and the absorbance is the measure of isotopic purity. This technique is generally used for measuring high isotopic (80-99.98%) and low isotopic samples. Refractometer uses the property of refractive index of heavy water. The difference in refractive indices of light water and heavy water is 0.0048. A 1 % change in D 2 O concentration would thus equal to 0.000048 refractive index units. This method is used for determining the approximate isotopic value of a sample. Density meter uses the property of difference in densities of light and heavy water. The difference in density of 99.999% D 2 O and light water is 0.107540 which covers the whole range of interest. The experience gained with these techniques in the measurements of isotopic purity of various samples are presented in this paper. (author)

  14. Mercury isotope signatures of seawater discharged from a coal-fired power plant equipped with a seawater flue gas desulfurization system.

    Science.gov (United States)

    Lin, Haiying; Peng, Jingji; Yuan, Dongxing; Lu, Bingyan; Lin, Kunning; Huang, Shuyuan

    2016-07-01

    Seawater flue gas desulfurization (SFGD) systems are commonly used to remove acidic SO2 from the flue gas with alkaline seawater in many coastal coal-fired power plants in China. However, large amount of mercury (Hg) originated from coal is also transferred into seawater during the desulfurization (De-SO2) process. This research investigated Hg isotopes in seawater discharged from a coastal plant equipped with a SFGD system for the first time. Suspended particles of inorganic minerals, carbon residuals and sulfides are enriched in heavy Hg isotopes during the De-SO2 process. δ(202)Hg of particulate mercury (PHg) gradually decreased from -0.30‰ to -1.53‰ in study sea area as the distance from the point of discharge increased. The results revealed that physical mixing of contaminated De-SO2 seawater and uncontaminated fresh seawater caused a change in isotopic composition of PHg isotopes in the discharging area; and suggested that both De-SO2 seawater and local background contributed to PHg. The impacted sea area predicted with isotopic tracing technique was much larger than that resulted from a simple comparison of pollutant concentration. It was the first attempt to apply mercury isotopic composition signatures with two-component mixing model to trace the mercury pollution and its influence in seawater. The results could be beneficial to the coal-fired plants with SFGD systems to assess and control Hg pollution in sea area. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Assessment of groundwater pollution from ash ponds using stable and unstable isotopes around the Koradi and Khaperkheda thermal power plants (Maharashtra, India).

    Science.gov (United States)

    Voltaggio, M; Spadoni, M; Sacchi, E; Sanam, R; Pujari, P R; Labhasetwar, P K

    2015-06-15

    The impact on local water resources due to fly ash produced in the Koradi and Khaperkheda thermal power plants (district of Nagpur, Maharashtra - India) and disposed in large ponds at the surface was assessed through the study of environmental variation of ratios of stable and unstable isotopes. Analyses of oxygen and hydrogen isotopes suggest scarce interaction between the water temporarily stored in the ponds and the groundwater in the study area. Data also highlight that the high salinity of groundwater measured in the polluted wells is not due to evaporation, but to subsequent infiltration of stream waters draining from the ponds to the local aquifer. (87)Sr/(86)Sr values, when associated with Sr/Ca ratios, demonstrate the dominant role of waste waters coming from tens of brick kilns surrounding the pond sulfate pollution. Uranium isotopic analyses clearly show evidence of the interaction between groundwater and aquifer rocks, and confirm again the low influence of ash ponds. A new conceptual model based on the study of the isotopes of radium is also proposed and used to estimate residence times of groundwater in the area. This model highlights that high salinity cannot be in any case attributed to a prolonged water-rock interaction, but is due to the influence of untreated waste water of domestic or brick kiln origin on the shallow and vulnerable aquifers. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Pu isotopes in the western North Pacific Ocean before the accident at Fukushima Dai-ichi Nuclear Power Station

    Science.gov (United States)

    Yamada, M.; Zheng, J.; Aono, T.

    2011-12-01

    Anthropogenic radionuclides such as Pu-239 (half-life: 24100 yr), Pu-240 (half-life: 6560 yr) and Pu-241 (half-life: 14.325 yr) mainly have been released into the environment as the result of atmospheric nuclear weapons testing. In the North Pacific Ocean, two distinct sources of Pu isotopes can be identified; i.e., the global stratospheric fallout and close-in tropospheric fallout from nuclear weapons testing at the Pacific Proving Grounds in the Marshall Islands. The atom ratio of Pu-240/Pu-239 is a powerful fingerprint to identify the sources of Pu in the ocean. The Pu-240/Pu-239 atom ratios in seawater and marine sediment samples collected in the western North Pacific before the accident at Fukushima Dai-ichi Nuclear Power Station will provide useful background data for understanding the process controlling Pu transport and for distinguishing future Pu sources. The atom ratios of Pu-240/Pu-239 in water columns from the Yamato and Tsushima Basins in the Japan Sea were significantly higher than the mean global fallout ratio of 0.18; however, there were no temporal variation of atom ratios during the period from 1984 to 1993 in the Japan Sea. The total Pu-239+240 inventories in the whole water columns were approximately doubled during the period from 1984 to 1993 in the two basins. The atom ratio of Pu-240/Pu-239 in surface water from Sagami Bay, western North Pacific Ocean, was 0.224 and showed no notable variation from the surface to the bottom with the mean atom ratio being 0.234. The atom ratios for the Pacific coast, near the Rokkasho nuclear fuel reprocessing plant, were approximately the same as the 0.224 ratio obtained from Sagami Bay, western North Pacific margin. The atom ratios in the surficial sediments from Sagami Bay ranged from 0.229 to 0.247. The mean atom ratio in the sediment columns in the East China Sea ranged from 0.248 for the Changjiang estuary to 0.268 for the shelf edge. The observed atom ratios were significantly higher than the mean

  17. The study of the dynamics of migration main radiologically significant isotopes in the near and far field Chernobyl nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Bondarkov, M.; Bondarkov, D.; Maksymenko, A. [Chornobyl Center for Nuclear Safety, Radioactive Waste and Radioecology (Ukraine); Zheltonozhskaya, M.; Zheltonozhsky, V. [Institute for nuclear research (Ukraine)

    2014-07-01

    The study of the migration of {sup 90}Sr, {sup 137}Cs, {sup 241}Am and Pu isotopes in soil near Chernobyl nuclear power plant area, as well as the Chernigov region, Ukraine is described. Experiments were conducted using a semiconductor spectrometry and radiochemical separation of isotopes needed. The experimental data obtained were processed using a mathematical model that takes into account in convective component (fit parameter V-- linear velocity of radionuclide movement dependent upon soil moisture) and diffusive one (fit parameter D- diffusion coefficient) migration of isotopes. The parameter values in V and D of migration, in turn, allow us to estimate halftime of decontamination top five-centimeter layer of soil. The results obtained in this paper halftime of decontamination for the various isotopes and their comparison with those obtained by us and by other authors in the past 10-20 years, confirms the trend previously noticed by a significant speeding migration Radiostrontium compared with Radiocesium. It is shown that for all the types studied soils in the late phase of Chernobyl accident halftime of decontamination of the top 5 - cm soil layer for radiostrontium, and for radioactive cesium in the order of magnitude or more greater than the period of the physical half-life of the radionuclide that is, matching in the late phase of the accident change the exposure dose of radiation is mainly determined by the physical decay of the radionuclide. According to the estimated periods decontamination upper soil horizons of different migration mobility of radionuclides in soils exclusion zone reduced in number: {sup 90}Sr> {sup 137}Cs> {sup 241}Am ≥ {sup 238-240}Pu, migration mobility of isotopes of transuranic elements is very low. Document available in abstract form only. (authors)

  18. Preliminary Failure Modes, Effects and Criticality Analysis (FMECA) of the Brayton Isotope Power System (BIPS) Ground Demonstration System. Report 76-311965

    International Nuclear Information System (INIS)

    Miller, L.G.

    1976-01-01

    A Failure Modes, Effects and Criticality Analysis (FMECA) has been made of the Brayton Isotope Power System Ground Demonstration System (BIPS-GDS). Details of the analysis are discussed. The BIPS Flight System was recently analyzed in an AIRPHX report. Since the results of the Flight System FMECA are directly applicable to the BIPS to be tested in the GDS mode, the contents of the earlier FMECA have not been repeated in this current analysis. The BIPS-FS FMECA has been reviewed and determined to be essentially current

  19. Natural stable isotopic compositions of mercury in aerosols and wet precipitations around a coal-fired power plant in Xiamen, southeast China

    Science.gov (United States)

    Huang, Shuyuan; Sun, Lumin; Zhou, Tingjin; Yuan, Dongxing; Du, Bing; Sun, Xiuwu

    2018-01-01

    In this study, samples of 18 wet precipitations (WPs) and 38 aerosols were collected around a coal-fired power plant (CFPP) located in Xiamen, southeast China, which was equipped with a seawater flue gas desulfurization system. Total particulate mercury (TPM) in aerosol samples, and total mercury (WP-TM), dissolved mercury (WP-DM) and particulate mercury (WP-PM) in WP samples were analyzed for the natural isotopic compositions of mercury. For the first time, both mass dependent fractionation (MDF) and mass independent fractionation of odd (odd-MIF) and even (even-MIF) isotopes of WP-DM and WP-PM were reported and discussed. Both WP-TM and TPM displayed negative MDF and slightly positive even-MIF. Negative odd-MIF was observed in TPM and WP-PM, whereas positive odd-MIF was observed in WP-TM and WP-DM. It was found that the mercury budget in WP-PM samples was mainly controlled by atmospheric particles. Potential sources of mercury in samples were identified via analysis of mercury isotopic signatures and meteorological data with the NOAA HYSPLIT model. The results showed that TPM and WP-PM in solid samples were homologous and the isotopic compositions of WP-TM depended on those of WP-DM. The ratios of Δ199Hg/Δ201Hg resulting from photochemical reactions and positive Δ200Hg values (from -0.06‰ to 0.27‰) in all samples indicated that the mercury coming from local emission of the CFPP together with long-distance transportation were the two main contributing sources.

  20. Inventory of programs. Calculation of the isotope inventory after a hypothetical accident at the Cofrentes Nuclear power

    International Nuclear Information System (INIS)

    Albendea, M.

    2014-01-01

    Iberdrola is developing a new application to calculate the inventory of radiological material, then of a hypothetical accident, with the name of inventory. This application allows you to calculate the inventory isotopic, analysers and accurate thermal of all or part of the nucleus of the plant of Cofrentes, even of any single element, based on its history of irradiation and specific periods of decay, since the reactor at any time after the shutdown. (Author)

  1. Fundamentals for the development of a low-activation lead coolant with isotopic enrichment for advanced nuclear power facilities

    International Nuclear Information System (INIS)

    Khorasanov, G.L.; Blokhin, A.I.

    2002-01-01

    The purpose of this paper is to study the prospects of new coolants for fast reactors and accelerator driven systems. The main focus is on their improvement using the isotopic tailoring technique to reduce post-irradiation activity. Calculations using the FISPACT-3 code show that irradiating natural lead (Pb-nat) for 30 years leads to the accumulation of long-lived toxic radionuclides, 207 Bi, 208 Bi and 210 Pb, which extends the cooling down period to the clearance level. This time can be shortened by using the lead isotope 206 Pb instead of Pb-nat. This substantially decreases the concentration of the most toxic polonium isotope, 210 Po. Calculations for lead activation in the hard proton-neutron ADS spectrum were performed using the CASCADE/SNT code. The time-dependent activity of the 207 Bi produced in Pb-nat and 206 Pb after irradiation for one year with a proton beam having an energy of 0.8 GeV and a current of 30 mA is given. The activity of 207 Bi is decreased by four orders of magnitude when 206 Pb is used instead of natural lead as a coolant for ADS targets. The production of such radiotoxic nuclides as 210 Po is also substantially diminished. (author)

  2. Electron linac for medical isotope production with improved energy efficiency and isotope recovery

    Science.gov (United States)

    Noonan, John; Walters, Dean; Virgo, Matt; Lewellen, John

    2015-09-08

    A method and isotope linac system are provided for producing radio-isotopes and for recovering isotopes. The isotope linac is an energy recovery linac (ERL) with an electron beam being transmitted through an isotope-producing target. The electron beam energy is recollected and re-injected into an accelerating structure. The ERL provides improved efficiency with reduced power requirements and provides improved thermal management of an isotope target and an electron-to-x-ray converter.

  3. Power of isotopic fine structure for unambiguous determination of metabolite elemental compositions: In silico evaluation and metabolomic application

    International Nuclear Information System (INIS)

    Nagao, Tatsuhiko; Yukihira, Daichi; Fujimura, Yoshinori; Saito, Kazunori; Takahashi, Katsutoshi; Miura, Daisuke; Wariishi, Hiroyuki

    2014-01-01

    Graphical abstract: - Highlights: • We developed a method to determine elemental composition of metabolites. • The method was based on mass spectral data and empirical constraints. • In the validation study, the method succeeded for 70% of detected peaks. - Abstract: In mass spectrometry (MS)-based metabolomics studies, reference-free identification of metabolites is still a challenging issue. Previously, we demonstrated that the elemental composition (EC) of metabolites could be unambiguously determined using isotopic fine structure, observed by ultrahigh resolution MS, which provided the relative isotopic abundance (RIA) of 13 C, 15 N, 18 O, and 34 S. Herein, we evaluated the efficacy of the RIA for determining ECs based on the MS peaks of 20,258 known metabolites. The metabolites were simulated with a ≤25% error in the isotopic peak area to investigate how the error size effect affected the rate of unambiguous determination of the ECs. The simulation indicated that, in combination with reported constraint rules, the RIA led to unambiguous determination of the ECs for more than 90% of the tested metabolites. It was noteworthy that, in positive ion mode, the process could distinguish alkali metal-adduct ions ([M + Na] + and [M + K] + ). However, a significant degradation of the EC determination performance was observed when the method was applied to real metabolomic data (mouse liver extracts analyzed by infusion ESI), because of the influence of noise and bias on the RIA. To achieve ideal performance, as indicated in the simulation, we developed an additional method to compensate for bias on the measured ion intensities. The method improved the performance of the calculation, permitting determination of ECs for 72% of the observed peaks. The proposed method is considered a useful starting point for high-throughput identification of metabolites in metabolomic research

  4. Calculation and analysis of neutron and radiation characteristics of lead coolants with isotopic tailoring for future nuclear power facilities

    Energy Technology Data Exchange (ETDEWEB)

    Blokhin, A.I.; Ivanov, A.P.; Korobeinikov, V.V.; Lunev, V.P.; Manokhin, V.N.; Khorasanov, G.L. [SSC RF A. I. Leypunsky Institute for Physics and Power Engineering, Obninsk, Kaluga Region (Russian Federation)

    2000-03-01

    A new type of safe fast reactor with lead coolant was proposed in Russia. The use of coolants with low moderating properties is one of the ways to get a hard neutron spectrum and an increase in the burning of Np-237, Am-243 and other miner actinides(MA) fissionable preferentially in the fast reactor. The stable lead isotope, Pb-208, is proposed as the one of such coolants. The neutron inelastic scattering cross-section of Pb-208 is 3.0-3.5 times less than the one of other lead isotopes. Calculation of the MA transmutation rates in the standard BN-type fast reactor with different coolants is performed by Monte-Carlo method using Code MMKFK. Six various models are simulated for the fast reactor blanket with different kinds of fuel and coolant. The fast reactor with natural-lead coolant practically does not differ from the reactor with sodium coolant relative to MA incineration. The use of Pb-208 as a coolant in the fast reactor results in increasing incineration of MA from 18 to 26% in comparison with a usual fast reactor. Calculation of induced radioactivity was performed using the FISPACT-3 inventory code, also. The results include total induced radioactivity and dose rate for initial material composition and selected long-lived radionuclides. The calculations show that the coolant consisting of lead isotope, Pb-206, or Pb-207, can be considered as the low-activation one because it does not practically contain long-lived toxic radionuclides. (M. Suetake)

  5. Isotopic signature and nano-texture of cesium-rich micro-particles: Release of uranium and fission products from the Fukushima Daiichi Nuclear Power Plant.

    Science.gov (United States)

    Imoto, Junpei; Ochiai, Asumi; Furuki, Genki; Suetake, Mizuki; Ikehara, Ryohei; Horie, Kenji; Takehara, Mami; Yamasaki, Shinya; Nanba, Kenji; Ohnuki, Toshihiko; Law, Gareth T W; Grambow, Bernd; Ewing, Rodney C; Utsunomiya, Satoshi

    2017-07-14

    Highly radioactive cesium-rich microparticles (CsMPs) released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) provide nano-scale chemical fingerprints of the 2011 tragedy. U, Cs, Ba, Rb, K, and Ca isotopic ratios were determined on three CsMPs (3.79-780 Bq) collected within ~10 km from the FDNPP to determine the CsMPs' origin and mechanism of formation. Apart from crystalline Fe-pollucite, CsFeSi 2 O 6  · nH 2 O, CsMPs are comprised mainly of Zn-Fe-oxide nanoparticles in a SiO 2 glass matrix (up to ~30 wt% of Cs and ~1 wt% of U mainly associated with Zn-Fe-oxide). The 235 U/ 238 U values in two CsMPs: 0.030 (±0.005) and 0.029 (±0.003), are consistent with that of enriched nuclear fuel. The values are higher than the average burnup estimated by the ORIGEN code and lower than non-irradiated fuel, suggesting non-uniform volatilization of U from melted fuels with different levels of burnup, followed by sorption onto Zn-Fe-oxides. The nano-scale texture and isotopic analyses provide a partial record of the chemical reactions that occurred in the fuel during meltdown. Also, the CsMPs were an important medium of transport for the released radionuclides in a respirable form.

  6. Isotopic clusters

    International Nuclear Information System (INIS)

    Geraedts, J.M.P.

    1983-01-01

    Spectra of isotopically mixed clusters (dimers of SF 6 ) are calculated as well as transition frequencies. The result leads to speculations about the suitability of the laser-cluster fragmentation process for isotope separation. (Auth.)

  7. Natural Radium Isotopes in Particulate and Dissolved Phases of Seawater and Rainwater at the West Coast Peninsular Malaysia Caused by Coal-Fired Power Plant

    Directory of Open Access Journals (Sweden)

    Nik Azlin Nik Ariffin

    2010-07-01

    Full Text Available The concentration levels of natural radium isotopes such as 226Ra and 228Ra were measured in the atmospheric samples including rainwater, total suspended solids (TSSrw and marine environment samples collected around the Kapar coal-fired power plant from September 2006 to February 2008. Activity concentration of 228Ra and 226Ra in rainwater showed the higher concentrations compared to the seawater. The mean activities of 226Ra and 228Ra in rainwater at Kapar were 20.45±4.50 mBq/L and 74.82±25.38 mBq/L, respectively. Meanwhile the levels in total suspended solids (TSSrw of rainwater showed 226.99±52.57 Bq/kg for 226Ra and 439.92±186.17 Bq/kg for 228Ra. The measurements of radium isotopes concentration in rainwater at coal-fired power plant in Kapar are found in relation to their sources and application as tracers in lower atmosphere. The mean value of pH in rainwater during this study is pH 5.51 slightly acidic as lowest value for the standard of clean rainwater. Radium in seawater also strong adsorption onto total suspended solids with the distribution coefficient, Kd values of 228Ra and 226Ra ranged from 0.054 × 104 to 163.90 × 104 L/g and between 0.49 × 104 to 191.54 × 104 L/g, respectively.

  8. Stable isotopes

    International Nuclear Information System (INIS)

    Evans, D.K.

    1986-01-01

    Seventy-five percent of the world's stable isotope supply comes from one producer, Oak Ridge Nuclear Laboratory (ORNL) in the US. Canadian concern is that foreign needs will be met only after domestic needs, thus creating a shortage of stable isotopes in Canada. This article describes the present situation in Canada (availability and cost) of stable isotopes, the isotope enrichment techniques, and related research programs at Chalk River Nuclear Laboratories (CRNL)

  9. Fully portable blood irradiator

    International Nuclear Information System (INIS)

    Hungate, F.P.; Riemath, W.F.; Bunnell, L.R.

    1980-01-01

    A fully portable blood irradiator was developed using the beta emitter thulium-170 as the radiation source and vitreous carbon as the body of the irradiator, matrix for isotope encapsulation, and blood interface material. These units were placed in exteriorized arteriovenous shunts in goats, sheep, and dogs and the effects on circulating lymphocytes and on skin allograft retention times measured. The present work extends these studies by establishing baseline data for skin graft rejection times in untreated animals

  10. Isotope separation

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1979-01-01

    A method of isotope separation is described which involves the use of a laser photon beam to selectively induce energy level transitions of an isotope molecule containing the isotope to be separated. The use of the technique for 235 U enrichment is demonstrated. (UK)

  11. Solid state NMR of isotope labelled murine fur: a powerful tool to study atomic level keratin structure and treatment effects

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Wai Ching Veronica; Narkevicius, Aurimas; Chow, Wing Ying; Reid, David G.; Rajan, Rakesh [University of Cambridge, Department of Chemistry (United Kingdom); Brooks, Roger A. [University of Cambridge, Department of Trauma and Orthopaedic Surgery, Addenbrooke’s Hospital (United Kingdom); Green, Maggie [University of Cambridge, Central Biomedical Resources, School of Clinical Medicine (United Kingdom); Duer, Melinda J., E-mail: mjd13@cam.ac.uk [University of Cambridge, Department of Chemistry (United Kingdom)

    2016-10-15

    We have prepared mouse fur extensively {sup 13}C,{sup 15}N-labelled in all amino acid types enabling application of 2D solid state NMR techniques which establish covalent and spatial proximities within, and in favorable cases between, residues. {sup 13}C double quantum–single quantum correlation and proton driven spin diffusion techniques are particularly useful for resolving certain amino acid types. Unlike 1D experiments on isotopically normal material, the 2D methods allow the chemical shifts of entire spin systems of numerous residue types to be determined, particularly those with one or more distinctively shifted atoms such as Gly, Ser, Thr, Tyr, Phe, Val, Leu, Ile and Pro. Also the partial resolution of the amide signals into two signal envelopes comprising of α-helical, and β-sheet/random coil components, enables resolution of otherwise overlapped α-carbon signals into two distinct cross peak families corresponding to these respective secondary structural regions. The increase in resolution conferred by extensive labelling offers new opportunities to study the chemical fate and structural environments of specific atom and amino acid types under the influence of commercial processes, and therapeutic or cosmetic treatments.

  12. Estimation of uranium isotopes in soil affected by Fukushima nuclear power plant accident and its mobility based on distribution coefficient and soil properties

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, S.K. [National Institute of Radiological Sciences (Japan); Mishra, S. [Bhabha Atomic Research Centre (India); Sorimachi, A.; Hosoda, M.; Tokonami, S. [Hirosaki University (Japan); Kritsananuwat, R. [Tokyo Metropolitan University (Japan); Ishikawa, T. [Fukushima Medical University (Japan)

    2014-07-01

    An extraordinary earthquake of magnitude 9.0 followed by Tsunami on 11 March 2011 caused serious nuclear accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) about 250 km north to Tokyo, capital of Japan. This resulted in radioactive contamination due to deposition of long-lived radionuclides. Contaminated soil can cause an enhanced radiation exposure even after many years. Depending upon environmental conditions radionuclides can be mobilized to aquatic systems. Therefore, the fate and transfer of these radionuclides in the soil water system is very important for radiation protection and dose assessment. In the present study, emphasis has been given on isotope ratio measurement of uranium that may give some idea about its contamination during accident. Soil and water samples were collected from contaminated areas around FDNPP. Inductively coupled plasma mass spectrometry (ICPMS) is used for total uranium concentration and thermal ionization mass spectrometry (TIMS) has been used for uranium isotopes measurement. Extraction chromatography has been used for the separation of uranium. We have observed, isotope ratio {sup 235}U/{sup 238}U is of natural origin, however in a few soil samples {sup 236}U has been detected. For the migration behavior, its distribution coefficient (K{sub d}) has been determined using laboratory batch method. Depleted uranium is used as tracer for uranium K{sub d} estimation. Chemical characterization of soil with respect to different parameters has been carried out. The effect of these soil parameters on distribution coefficient of uranium has been studied in order to explain the radionuclide mobility in this particular area. The distribution coefficient values for uranium are found to vary from 30-35679 L/Kg. A large variation in the distribution coefficient values shows the retention or mobility of uranium is highly dependent on soil characteristics in the particular area. This variation is explained with respect to pH, Fe, Mn

  13. Isotope enrichment

    International Nuclear Information System (INIS)

    Garbuny, M.

    1979-01-01

    The invention discloses a method for deriving, from a starting material including an element having a plurality of isotopes, derived material enriched in one isotope of the element. The starting material is deposited on a substrate at less than a critical submonatomic surface density, typically less than 10 16 atoms per square centimeter. The deposit is then selectively irradiated by a laser (maser or electronic oscillator) beam with monochromatic coherent radiation resonant with the one isotope causing the material including the one istope to escape from the substrate. The escaping enriched material is then collected. Where the element has two isotopes, one of which is to be collected, the deposit may be irradiated with radiation resonant with the other isotope and the residual material enriched in the one isotope may be evaporated from the substrate and collected

  14. Stable isotopes

    International Nuclear Information System (INIS)

    Brazier, J.L.; Guinamant, J.L.

    1995-01-01

    According to the progress which has been realised in the technology of separating and measuring isotopes, the stable isotopes are used as preferable 'labelling elements' for big number of applications. The isotopic composition of natural products shows significant variations as a result of different reasons like the climate, the seasons, or their geographic origins. So, it was proved that the same product has a different isotopic composition of alimentary and agriculture products. It is also important in detecting the pharmacological and medical chemicals. This review article deals with the technology, like chromatography and spectrophotometry, adapted to this aim, and some important applications. 17 refs. 6 figs

  15. Isotope separation

    International Nuclear Information System (INIS)

    Bartlett, R.J.; Morrey, J.R.

    1978-01-01

    A method and apparatus is described for separating gas molecules containing one isotope of an element from gas molecules containing other isotopes of the same element in which all of the molecules of the gas are at the same electronic state in their ground state. Gas molecules in a gas stream containing one of the isotopes are selectively excited to a different electronic state while leaving the other gas molecules in their original ground state. Gas molecules containing one of the isotopes are then deflected from the other gas molecules in the stream and thus physically separated

  16. Isotopic ratio and vertical distribution of radionuclides in soil affected by the accident of Fukushima Dai-ichi nuclear power plants

    International Nuclear Information System (INIS)

    Fujiwara, Takeshi; Saito, Takumi; Muroya, Yusa; Sawahata, Hiroyuki; Yamashita, Yuji; Nagasaki, Shinya; Okamoto, Koji; Takahashi, Hiroyuki; Uesaka, Mitsuru; Katsumura, Yosuke; Tanaka, Satoru

    2012-01-01

    The results of γ analyses of soil samples obtained from 50 locations in Fukushima prefecture on April 20, 2011, revealed the presence of a spectrum of radionuclides resulted from the accident of the Fukushima Dai-ichi nuclear power plant (FDNPP). The sum γ radioactivity concentration ranged in more than 3 orders of magnitude, depending on the sampling locations. The contamination of soils in the northwest of the FDNPP was considerable. The 131 I/ 137 Cs activity ratios of the soil samples plotted as a function of the distance from the F1 NPPs exhibited three distinctive patterns. Such patterns would reflect not only the different deposition behaviors of these radionuclides, but also on the conditions of associated release events such as temperature and compositions and physicochemical forms of released radionuclides. The 136 Cs/ 137 Cs activity ratio, on the other hand, was considered to only reflect the difference in isotopic compositions of source materials. Two locations close to the NPP in the northwest direction were found to be depleted in short-lived 136 Cs. This likely suggested the presence of distinct sources with different 136 Cs/ 137 Cs isotopic ratios, although their details were unknown at present. Vertical γ activity profiles of 131 I and 137 Cs were also investigated, using 20–30 cm soil cores in several locations. About 70% or more of the radionuclides were present in the uppermost 2-cm regions. It was found that the profiles of 131 I/ 137 Cs activity ratios showed maxima in the 2–4 cm regions, suggesting slightly larger migration of the former nuclide. - Highlights: ► We report the results of γ analyses of soil samples around Fukushima Dai-ichi NPPs. ► The contamination of soils in the northwest of the power plant was considerable. ► The 131 I/ 137 Cs activity ratios exhibited three distinctive patterns. ► Most of 131 I and 137 Cs were present in the uppermost 2-cm regions of soil.

  17. Isotopes in action

    International Nuclear Information System (INIS)

    1987-01-01

    For most people the obvious application of nuclear technology is in power generation. But there are many other uses for radioactive materials or for products made with their help. They are found in our factories, hospitals, offices and homes. ''Isotopes in Action'' looks at the many applications of radioisotopes in our society. (author)

  18. ISOTOPE METHODS IN HOMOGENEOUS CATALYSIS.

    Energy Technology Data Exchange (ETDEWEB)

    BULLOCK,R.M.; BENDER,B.R.

    2000-12-01

    The use of isotope labels has had a fundamentally important role in the determination of mechanisms of homogeneously catalyzed reactions. Mechanistic data is valuable since it can assist in the design and rational improvement of homogeneous catalysts. There are several ways to use isotopes in mechanistic chemistry. Isotopes can be introduced into controlled experiments and followed where they go or don't go; in this way, Libby, Calvin, Taube and others used isotopes to elucidate mechanistic pathways for very different, yet important chemistries. Another important isotope method is the study of kinetic isotope effects (KIEs) and equilibrium isotope effect (EIEs). Here the mere observation of where a label winds up is no longer enough - what matters is how much slower (or faster) a labeled molecule reacts than the unlabeled material. The most careti studies essentially involve the measurement of isotope fractionation between a reference ground state and the transition state. Thus kinetic isotope effects provide unique data unavailable from other methods, since information about the transition state of a reaction is obtained. Because getting an experimental glimpse of transition states is really tantamount to understanding catalysis, kinetic isotope effects are very powerful.

  19. Isotopic separation

    International Nuclear Information System (INIS)

    Castle, P.M.

    1979-01-01

    This invention relates to molecular and atomic isotope separation and is particularly applicable to the separation of 235 U from other uranium isotopes including 238 U. In the method described a desired isotope is separated mechanically from an atomic or molecular beam formed from an isotope mixture utilising the isotropic recoil momenta resulting from selective excitation of the desired isotope species by radiation, followed by ionization or dissociation by radiation or electron attachment. By forming a matrix of UF 6 molecules in HBr molecules so as to collapse the V 3 vibrational mode of the UF 6 molecule the 235 UF 6 molecules are selectively excited to promote reduction of UF 6 molecules containing 235 U and facilitate separation. (UK)

  20. Isotopic separation

    International Nuclear Information System (INIS)

    Chen, C.L.

    1979-01-01

    Isotopic species in an isotopic mixture including a first species having a first isotope and a second species having a second isotope are separated by selectively exciting the first species in preference to the second species and then reacting the selectively excited first species with an additional preselected radiation, an electron or another chemical species so as to form a product having a mass different from the original species and separating the product from the balance of the mixture in a centrifugal separating device such as centrifuge or aerodynamic nozzle. In the centrifuge the isotopic mixture is passed into a rotor where it is irradiated through a window. Heavier and lighter components can be withdrawn. The irradiated mixture experiences a large centrifugal force and is separated in a deflection area into lighter and heavier components. (UK)

  1. Isotope angiocardiography

    International Nuclear Information System (INIS)

    Stepinska, J.; Ruzyllo, W.; Konieczny, W.

    1979-01-01

    Method of technetium isotope 99 m pass through the heart recording with the aid of radioisotope scanner connected with seriograph and computer is being presented. Preliminary tests were carried out in 26 patients with coronary disease without or with previous myocardial infarction, cardiomyopathy, ventricular septal defect and in patients with artificial mitral and aortic valves. The obtained scans were evaluated qualitatively and compared with performed later contrast X-rays of the heart. Size of the right ventricle, volume and rate of left atrial evacuation, size and contractability of left ventricle were evaluated. Similarity of direct and isotope angiocardiographs, non-invasional character and repeatability of isotope angiocardiography advocate its usefulness. (author)

  2. Leatherback Isotopes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC is currently working on a project identifying global marine isotopes using leatherback turtles (Dermochelys coriacea) as the indicator species. We currently...

  3. Isotope Identification

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-18

    The objective of this training modules is to examine the process of using gamma spectroscopy for radionuclide identification; apply pattern recognition to gamma spectra; identify methods of verifying energy calibration; and discuss potential causes of isotope misidentification.

  4. Isotope laboratories

    International Nuclear Information System (INIS)

    1978-01-01

    This report from the Dutch Ministry of Health is an advisory document concerned with isotope laboratories in hospitals, in connection with the Dutch laws for hospitals. It discusses which hospitals should have isotope laboratories and concludes that as many hospitals as possible should have small laboratories so that emergency cases can be dealt with. It divides the Netherlands into regions and suggests which hospitals should have these facilities. The questions of how big each lab. is to be, what equipment each has, how each lab. is organised, what therapeutic and diagnostic work should be carried out by each, etc. are discussed. The answers are provided by reports from working groups for in vivo diagnostics, in vitro diagnostics, therapy, and safety and their results form the criteria for the licences of isotope labs. The results of a questionnaire for isotope labs. already in the Netherlands are presented, and their activities outlined. (C.F.)

  5. Isotopic chirality

    Energy Technology Data Exchange (ETDEWEB)

    Floss, H.G. [Univ. of Washington, Seattle, WA (United States)

    1994-12-01

    This paper deals with compounds that are chiral-at least in part, due to isotope substitution-and their use in tracing the steric course of enzyme reaction in vitro and in vivo. There are other applications of isotopically chiral compounds (for example, in analyzing the steric course of nonenzymatic reactions and in probing the conformation of biomolecules) that are important but they will not be discussed in this context.

  6. Isotopic separation

    International Nuclear Information System (INIS)

    Chen, C.L.

    1982-01-01

    A method is described for separating isotopes in which photo-excitation of selected isotope species is used together with the reaction of the excited species with postive ions of predetermined ionization energy, other excited species, or free electrons to produce ions or ion fragments of the selected species. Ions and electrons are produced by an electrical discharge, and separation is achieved through radial ambipolar diffusion, electrostatic techniques, or magnetohydrodynamic methods

  7. Isotope enrichment

    International Nuclear Information System (INIS)

    Lydtin, H-J.; Wilden, R.J.; Severin, P.J.W.

    1978-01-01

    The isotope enrichment method described is based on the recognition that, owing to mass diffusion and thermal diffusion in the conversion of substances at a heated substrate while depositing an element or compound onto the substrate, enrichment of the element, or a compound of the element, with a lighter isotope will occur. The cycle is repeated for as many times as is necessary to obtain the degree of enrichment required

  8. Actinide isotopic analysis systems

    International Nuclear Information System (INIS)

    Koenig, Z.M.; Ruhter, W.D.; Gunnink, R.

    1990-01-01

    This manual provides instructions and procedures for using the Lawrence Livermore National Laboratory's two-detector actinide isotope analysis system to measure plutonium samples with other possible actinides (including uranium, americium, and neptunium) by gamma-ray spectrometry. The computer program that controls the system and analyzes the gamma-ray spectral data is driven by a menu of one-, two-, or three-letter options chosen by the operator. Provided in this manual are descriptions of these options and their functions, plus detailed instructions (operator dialog) for choosing among the options. Also provided are general instructions for calibrating the actinide isotropic analysis system and for monitoring its performance. The inventory measurement of a sample's total plutonium and other actinides content is determined by two nondestructive measurements. One is a calorimetry measurement of the sample's heat or power output, and the other is a gamma-ray spectrometry measurement of its relative isotopic abundances. The isotopic measurements needed to interpret the observed calorimetric power measurement are the relative abundances of various plutonium and uranium isotopes and americium-241. The actinide analysis system carries out these measurements. 8 figs

  9. Isotope Exchange in Oxide Catalyst

    Science.gov (United States)

    Hess, Robert V.; Miller, Irvin M.; Schryer, David R.; Sidney, Barry D.; Wood, George M., Jr.; Hoyt, Ronald F.; Upchurch, Billy T.; Brown, Kenneth G.

    1987-01-01

    Replacement technique maintains level of CO2/18 in closed-cycle CO2 lasers. High-energy, pulsed CO2 lasers using rare chemical isotopes must be operated in closed cycles to conserve gas. Rare isotopes operated in closed cycles to conserve gas. Rare isotopes as CO2/18 used for improved transmission of laser beam in atmosphere. To maintain laser power, CO2 must be regenerated, and O2 concentration kept below few tenths of percent. Conditions achieved by recombining CO and O2.

  10. Power

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård; Fogsgaard, Morten

    2016-01-01

    and creativity suggests that when managers give people the opportunity to gain power and explicate that there is reason to be more creative, people will show a boost in creative behaviour. Moreover, this process works best in unstable power hierarchies, which implies that power is treated as a negotiable....... It is thus a central point that power is not necessarily something that breaks down and represses. On the contrary, an explicit focus on the dynamics of power in relation to creativity can be productive for the organisation. Our main focus is to elaborate the implications of this for practice and theory...

  11. Isotopes Project

    International Nuclear Information System (INIS)

    Dairiki, J.M.; Browne, E.; Firestone, R.B.; Lederer, C.M.; Shirley, V.S.

    1984-01-01

    The Isotopes Project compiles and evaluates nuclear structure and decay data and disseminates these data to the scientific community. From 1940-1978 the Project had as its main objective the production of the Table of Isotopes. Since publication of the seventh (and last) edition in 1978, the group now coordinates its nuclear data evaluation efforts with those of other data centers via national and international nuclear data networks. The group is currently responsible for the evaluation of mass chains A = 167-194. All evaluated data are entered into the International Evaluated Nuclear Structure Data File (ENSDF) and are published in Nuclear Data Sheets. In addition to the evaluation effort, the Isotopes Project is responsible for production of the Radioactivity Handbook

  12. Cold regions isotope applications

    International Nuclear Information System (INIS)

    Perrigo, L.D.; Divine, T.E.

    1976-04-01

    Pacific Northwest Laboratories (PNL) started the Cold Regions Isotope Applications Program in FY-1975 to identify special conditions in the Arctic and similar geographic areas (Cold Regions) where radioisotope power, heater, or sterilization systems would be desirable and economically viable. Significant progress was made in the first year of this program and all objectives for this initial 12-month period were achieved. The major conclusions and recommendations resulting for this effort are described below. The areas of interest covered include: radiosterilization of sewage; heating of septic tanks; and radioisotope thermoelectric generators as power sources for meteorological instruments and navigational aids

  13. Isotopic Thermionic Generator

    International Nuclear Information System (INIS)

    Clemot, M.; Devin, B.; Durand, J.P.

    1967-01-01

    This report describes the general design of a thermionic direct conversion space generator. The power source used is a radioisotope. Two radioisotopes are considered: Pu 238 and Cm 244. The system is made up of a heat pipe concentrating the thermal flux from the isotope to the emitter, and of a second heat pipe evacuating the waste heat from the collector to the outer wall used as radiating panel. Calculations are given in the particular case of a 100 electrical watts output power. (authors) [fr

  14. Calculation of absorbed dose for skin contamination imparted by beta radiation through the VARSKIN modified code for 122 interesting isotopes for nuclear medicine, nuclear power plants and research

    International Nuclear Information System (INIS)

    Alvarez R, J.T.

    1991-01-01

    In this work the implementation of a modification of the VARSKIN code for calculation of absorbed dose for contamination in skin imparted by external radiation fields generated by Beta emitting is presented. The modification consists on the inclusion of 47 isotopes of interest even Nuclear Plants for the dose evaluation in skin generated by 'hot particles'. The approach for to add these isotopes is the correlation parameter F and the average energy of the Beta particle, with relationship to those 75 isotopes of the original code. The methodology of the dose calculation of the VARSKIN code is based on the interpolation, (and integration of the interest geometries: punctual or plane sources), of the distribution functions scaled doses in water for beta and electrons punctual sources, tabulated by Berger. Finally a brief discussion of the results for their interpretation and use with purposes of radiological protection (dose insurance in relation to the considered biological effects) is presented

  15. Isotopically modified compounds

    International Nuclear Information System (INIS)

    Kuruc, J.

    2009-01-01

    In this chapter the nomenclature of isotopically modified compounds in Slovak language is described. This chapter consists of following parts: (1) Isotopically substituted compounds; (2) Specifically isotopically labelled compounds; (3) Selectively isotopically labelled compounds; (4) Non-selectively isotopically labelled compounds; (5) Isotopically deficient compounds.

  16. Isotope generator

    International Nuclear Information System (INIS)

    1979-01-01

    The patent describes an isotope generator incorporating the possibility of stopping elution before the elution vessel is completely full. Sterile ventilation of the whole system can then occur, including of both generator reservoir and elution vessel. A sterile, and therefore pharmaceutically acceptable, elution fluid is thus obtained and the interior of the generator is not polluted with non-sterile air. (T.P.)

  17. A multidisciplinary approach to the identification and evaluation of novel concepts for deeply buried hardened target defeat

    Science.gov (United States)

    Branscome, Ewell Caleb

    of RIPTP components in available volume; close-contact melting in a medium with nonlinear thermodynamic properties; radiation shielding; radiation health physics; point source plume dispersal calculations; alternative technologies for production of radioisotopes; chemical and physical properties of isotope compounds; nuclear reactor characteristics; high temperature material stability and inter-material compatibility; weapon and delivery system integration; a variety of heat transfer regimes including radiation, conduction, convection, nucleate boiling, and film boiling; thermal/mechanical stress analysis (steady-state and transient); rock physical and thermodynamic properties as a function of temperature; detection/mapping of deeply buried facility spaces; and more. The following disciplinary analyses were composed into a multidisciplinary analysis code for a RIPTP: packing of RIPTP components in available volume; close-contact melting analysis; transmutation of isotope species by neutron activation; reactor neutron economy; radioisotope power generation through decay; metamodelled radiation shielding calculations for a RIPTP; and steady state thermal analyses for a RIPTP in various scenarios. Filtering of radioisotopes for potential suitability, their possible production mechanisms, state of technological development, and multidisciplinary analysis code predicted performance lead to the identification of Thulium-170 as the best isotope for powering a RIPTP using present-day technology and technical data. Ytterbium-169 was identified as an alternative isotope offering the potential for significant potential improvements over Thulium-170 in radiological safety as well as RIPTP performance and producibility. Production, however, was determined to require identification of a cost effective technology for highly enriching Ytterbium-168 from its low natural abundance. Performance analysis of the identified baseline Thulium-170 RIPTP suggested that the predicted low

  18. Methodology of conversion of plutonium of various isotopic compositions to the equivalent plutonium as applied to system studies in nuclear power

    International Nuclear Information System (INIS)

    Yatsenko, E.M.; Chebeskov, A.N.; Kagramanyan, V.S.; Kalashnikov, A.G.

    2012-01-01

    It is shown that the developed methodology, possessing comprehensible accuracy, allows not only to correct enrichment, but also to lower uncertainty degree at carrying out the system researches of atomic engineering taking into account dynamics of change of fuel isotopic composition at its multiple recycle in fast reactors [ru

  19. Isotope separation process

    International Nuclear Information System (INIS)

    Kaldor, A.; Rabinowitz, P.

    1979-01-01

    A method of separating the isotopes of an element is described, which comprises the steps of (i) subjecting molecules of a gaseous compound of the element simultaneously to two infrared radiations of different wavelengths, the first radiation having a wavelength which corresponds to an absorption band of the compound, which in turn corresponds to a mode of molecular motion in which there is participation by atoms of the element, and the second radiation having a power density greater than 10 6 watts per cm 2 , thereby exciting molecules of the compound in an isotopically selective manner, this step being conducted in such manner that the excited molecules either receive a level of energy sufficient to cause them to undergo conversion by unimolecular decomposition or receive a level of energy sufficient to cause them to undergo conversion by reaction with molecules of another gas present for that purpose; and (ii) separating and recovering converted molecules from unconverted molecules. (author)

  20. Isotope hydrology

    International Nuclear Information System (INIS)

    Drost, W.

    1978-01-01

    The International Symposium on Isotope Hydrology was jointly organized by the IAEA and UNESCO, in co-operation with the National Committee of the Federal Republic of Germany for the International Hydrological Programme (IHP) and the Gesellschaft fuer Strahlen- und Umweltforschung mbH (GSF). Upon the invitation of the Federal Republic of Germany the Symposium was held from 19-23 June 1978 in Neuherberg on the GSF campus. The Symposium was officially opened by Mr. S. Eklund, Director General of the IAEA. The symposium - the fifth meeting held on isotope hydrology - was attended by over 160 participants from 44 countries and four international organizations and by about 30 observers from the Federal Republic of Germany. Due to the absence of scientists from the USSR five papers were cancelled and therefore only 46 papers of the original programme were presented in ten sessions

  1. Optimization of the operational parameters in isotopic exchange installations. ROMAG PROD plant production of heavy water for the nuclear power plant

    International Nuclear Information System (INIS)

    Pop, A.

    2002-01-01

    The ROMAG PROD heavy water plant at Drobeta Turnu Severin together with SN Nuclearelectrica Company and Nuclear Fuel Plant at Pitesti are the most important pillars the National Nuclear Program is based on. The plant became operational on 17th July 1988, was later modernized and now reached in the field a leading position known world wide. There are described the modifications adopted to the two stages of the isotopic exchange installation besides some refurbishment measures of general character. The increase of discharge flow rate in cool columns vs hot columns resulted in a rise of technological regime stability and the feeding rate. Also in the first stage the stripping vapor injection in the hot columns was modified to avoid vacuum excursion in the columns. In the second stage two isotopic exchange trays were replaced with dry trays to obtain drop separation at the cool column top. All the trays from the isotopic exchange section of the cool column were replaced by trays from the hot column. The thermal exchange zone in the cool column was modified by introducing trays with number of holes. The gas flow rate of the stage two compressor was adapted to the design requirements. By these changes of the parameters in the original design were substantially improved, the operation became easier, more secure and safer for the environment while the production of the heavy water doubled between 1995 and 2001 reaching a value of 163 t/y in 2001

  2. Possible application of laser isotope separation

    International Nuclear Information System (INIS)

    Delionback, L.M.

    1975-05-01

    The laser isotope separation process is described and its special economic features discussed. These features are its low cost electric power operation, capital investment costs, and the costs of process materials. (Author)

  3. A new infiltration method for coating highly permeable matrices with compound materials for high-power isotope-separator-on-line production target applications

    International Nuclear Information System (INIS)

    Kawai, Y.; Bilheux, Jean-Christophe; Stracener, Daniel W; Alton, Gerald D

    2005-01-01

    A new infiltration coating method has been conceived for uniform and controlled thickness deposition of target materials onto highly permeable, complex-structure matrices to form short-diffusion-length isotope-separator-on-line (ISOL) production targets for radioactive ion beam research applications. In this report, the infiltration technique is described in detail and the universal character of the technique illustrated in the form of SEMs of several metal-carbide, metal-oxide and metal-sulfide targets for potential use at present or future radioactive ion beam research facilities

  4. Natural isotopes

    International Nuclear Information System (INIS)

    Vogel, J.C.

    1986-01-01

    14 C dates between 600 and 900 AD were obtained for early Iron Age sites in Natal, and from 1300 to 1450 AD for rock engraving sites in Bushmanland. Palaeoenvironmental data derived from the dating of samples related to sedimentary and geomorphic features in the central and northern Namib Desert enabled the production of a tentative graph for the changes in humidity in the region over the past 40000 years. These results suggest that relatively humid conditions came to an end in the Namib at ±25000 BP (before present). The increased precision of the SIRA mass spectrometer enabled the remeasurement of 13 C and 18 O in the Cango stalagmite. This data confirmed that the environmental temperatures in the Southern Cape remained constant to within ±1 o C during the past 5500 years. Techniques and applications for environmental isotopes in hydrology were developed to determine the origin and movement of ground water. Isotopic fractionation effects in light elements in nature were investigated. The 15 N/ 14 N ratio in bones of animals and humans increases in proportion to the aridity of the environment. This suggests that 15 N in bone from dated archaeological sites could be used to detect changes in past climatic conditions as naturally formed nitrate minerals are higly soluble and are only preserved in special, very dry environments. The sources and sinks of CO 2 on the South African subcontinent were also determined. The 13 C/ 12 C ratios of air CO 2 obtained suggest that the vegetation provides the major proportion of respired CO 2 . 9 refs., 1 fig

  5. The application of an isotopic ratio technique to a study of the atmospheric oxidation of sulfur dioxide in the plume from a coal fired power plant

    International Nuclear Information System (INIS)

    Newman, L.; Forrest, J.; Manowitz, B.

    1975-01-01

    The extent of oxidation of sulfur dioxide to sulfate in the plume of a coal fired plant has been studied by using sampling with a single engine aircraft. A technique employing isotopic ratio measurements was utilized in conjunction with simultaneous concentration measurements of sulfur dioxide and sulfate. The use of sulfur hexafluroide as a conservative tracer was explored. The heterogeneous mechanism postulated in an oil fired plume study appears to pertain to the coal fired plume. However, the extent of oxidation seldom exceeded 5% and is limited by the relatively low particulate content of the coal fired plume. Evidence is presented for the apparent dropping out of sulfate from the plume. Implications pertaining to the ambient oxidation of sulfur dioxide are presented. (author)

  6. Stable isotope studies

    International Nuclear Information System (INIS)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  7. Method for separating isotopes

    International Nuclear Information System (INIS)

    Jepson, B.E.

    1975-01-01

    Isotopes are separated by contacting a feed solution containing the isotopes with a cyclic polyether wherein a complex of one isotope is formed with the cyclic polyether, the cyclic polyether complex is extracted from the feed solution, and the isotope is thereafter separated from the cyclic polyether

  8. Handbook of environmental isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Baskaran, Mark (ed.) [Wayne State Univ., Detroit, MI (United States). Dept. Geology

    2011-07-01

    Applications of radioactive and stable isotopes have revolutionized our understanding of the Earth and near-earth surface processes. The utility of the isotopes are ever-increasing and our sole focus is to bring out the applications of these isotopes as tracers and chronometers to a wider audience so that they can be used as powerful tools to solve environmental problems. New developments in this field remain mostly in peer-reviewed journal articles and hence our goal is to synthesize these findings for easy reference for students, faculty, regulators in governmental and non-governmental agencies, and environmental companies. While this volume maintains its rigor in terms of its depth of knowledge and quantitative information, it contains the breadth needed for wide variety problems and applications in the environmental sciences. This volume presents all of the newer and older applications of isotopes pertaining to the environmental problems in one place that is readily accessible to readers. This book not only has the depth and rigor that is needed for academia, but it has the breadth and case studies to illustrate the utility of the isotopes in a wide variety of environments (atmosphere, oceans, lakes, rivers and streams, terrestrial environments, and sub-surface environments) and serves a large audience, from students and researchers, regulators in federal, state and local governments, and environmental companies. (orig.)

  9. Isotopes a very short introduction

    CERN Document Server

    Ellam, Rob

    2016-01-01

    An isotope is a variant form of a chemical element, containing a different number of neutrons in its nucleus. Most elements exist as several isotopes. Many are stable while others are radioactive, and some may only exist fleetingly before decaying into other elements. In this Very Short Introduction, Rob Ellam explains how isotopes have proved enormously important across all the sciences and in archaeology. Radioactive isotopes may be familiar from their use in nuclear weapons, nuclear power, and in medicine, as well as in carbon dating. They have been central to establishing the age of the Earth and the origins of the solar system. Combining previous and new research, Ellam provides an overview of the nature of stable and radioactive isotopes, and considers their wide range of modern applications. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subjec...

  10. Method for separating isotopes

    International Nuclear Information System (INIS)

    Jepson, B.E.

    1976-01-01

    The invention comprises a method for separating different isotopes of elements from each other by contacting a feed solution containing the different isotopes with a macrocyclic polyether to preferentially form a macrocyclic polyether complex with the lighter of the different isotopes. The macrocyclic polyether complex is then separated from the lighter isotope depleted feed solution. A chemical separation of isotopes is carried out in which a constant refluxing system permits a continuous countercurrent liquid-liquid extraction. (LL)

  11. Method for separating isotopes

    International Nuclear Information System (INIS)

    Schlenker, R.F.

    1978-01-01

    A vortex tube for separating isotopes is described. A gas mixture containing the isotopic molecules enters the vortex tube under pressure and is separated into a hot discharge flow stream and a cold discharge flow stream. The hot discharge is enriched in lighter isotopic molecules whereas the cold discharge flow stream is enriched in the heavier isotopic molecules. The vortex tube can be used in a single stage or multistage isotope separation apparatus

  12. Development of nuclear battery using isotope sources

    International Nuclear Information System (INIS)

    Chang, Won Jun

    2004-02-01

    Until now, the development of the useful micro electromechanical systems has the problems because previous batteries (solar, chemical, etc) did not satisfy the requirements related to power supply. At this point of time, nuclear battery using isotope sources is rising the solution of this problem. Nuclear battery can provide superior out-put power and lifetime. So a new type of micro power source (nuclear battery) for micro electromechanical systems has been designed and analyzed. In this work, I designed the three parts, isotope source, conversion device, and shielding. I chose suitable sources, and designed semiconductor using the chosen isotope sources. Power is generated by radiation exciting electrons in the semiconductor depletion region. The efficiency of the nuclear battery depends upon the pn-junction. In this study the several conceptual nuclear batteries using radioactive materials are described with pn-junction. And for the safety, I designed the shielding to protect the environment by reducing the kinetic energy of beta particles

  13. Method of isotope separation

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, R K

    1975-05-22

    Isotopes of a gaseous compound can be separated by multi-infrared photoabsorption which follows a selective dissociation of the excited molecules by single photon absorption of photons of visible or UV radiation. The process involves three steps. Firstly, the molecules to be separated are irradiated with a high-energy IR laser, whereby the molecules of the compound containing the lighter isotopes are preferably excited. They are then irradiated by a second laser with UV or visible light whose frequency of radiation brings the excited molecules into a form in which they can be separated from the non-excited molecules. The third step is the reformation of the substances according to known methods. A power density of at least 10/sup 4/ watt/cm/sup 2/ per torr gas pressure with an irradiation time of 10/sup -10/ to 5 x 10/sup -5/ seconds in the presence of a second gas with at least 5 times higher partial pressure is necessary for the IR radiation. The method may be used for UF/sub 6/ for which an example is given here.

  14. Kinetic coefficients in isotopically disordered crystals

    International Nuclear Information System (INIS)

    Zhernov, Arkadii P; Inyushkin, Alexander V

    2002-01-01

    Peculiarities of the behavior of kinetic coefficients, like thermal conductivity, electric conductivity, and thermoelectric power, in isotopically disordered materials are reviewed in detail. New experimental and theoretical results on the isotope effects in the thermal conductivity of diamond, Ge, and Si semiconductors are presented. The suppression effect of phonon-drag thermopower in the isotopically disordered Ge crystals is discussed. The influence of dynamic and static crystal lattice deformations on the electric conductivity of metals as well as on the ordinary phonon spectrum deformations is considered. (reviews of topical problems)

  15. Rapid analysis of U isotopes in vegetables using ICP-MS. Application to the emergency U monitoring after the nuclear accident at TEPCO's Fukushima Dai-ichi power station

    International Nuclear Information System (INIS)

    Jian Zheng; Keiko Tagami; Shigeo Uchida

    2012-01-01

    After the nuclear accident at TEPCO's Fukushima Dai-ichi power station in March, hydrogen explosions and reactor building explosion resulted in releases of radionuclides in the environment. Severe radioactive cesium and iodine contaminations have been observed in fallout deposition samples and soils in the East Japan. Radioactive cesium, iodine, uranium, and transuranic radionuclides were set as the monitoring targets in food safety tests. However, so far, only radioactive cesium and iodine were daily measured and reported by the Ministry of Health, Labour, and Welfare. The tedious and time consuming conventional alpha spectrometric method hampered the emergency monitoring U contamination in foods. In this work, we propose a simple and rapid analytical method for 238 U and 235 U/ 238 U isotope ratio analysis in fresh vegetables. This method was applied to the emergency monitoring of radioactive contamination after the nuclear accident at TEPCO's Fukushima Dai-ichi power station. The results showed no U contamination in fresh vegetables collected in Chiba and Ibaraki prefectures in April and May, 2011. (author)

  16. Isotope puzzle in sputtering

    International Nuclear Information System (INIS)

    Zheng Liping

    1998-01-01

    Mechanisms affecting multicomponent material sputtering are complex. Isotope sputtering is the simplest in the multicomponent materials sputtering. Although only mass effect plays a dominant role in the isotope sputtering, there is still an isotope puzzle in sputtering by ion bombardment. The major arguments are as follows: (1) At the zero fluence, is the isotope enrichment ejection-angle-independent or ejection-angle-dependent? (2) Is the isotope angular effect the primary or the secondary sputter effect? (3) How to understand the action of momentum asymmetry in collision cascade on the isotope sputtering?

  17. Mobile nuclear power systems

    International Nuclear Information System (INIS)

    Andersson, B.

    1988-11-01

    This report is meant to present a general survey of the mobile nuclear power systems and not a detailed review of their technical accomplishments. It is based in published material mainly up to 1987. Mobile nuclear power systems are of two fundamentally different kinds: nuclear reactors and isotopic generators. In the reactors the energy comes from nuclear fission and in the isotopic generators from the radioactive decay of suitable isotopes. The reactors are primarily used as power sourves on board nuclear submarines and other warships but have also been used in the space and in remote places. Their thermal power has ranged from 30 kWth (in a satellite) to 175 MWth (on board an aircraft carrier). Isotopic generators are suitable only for small power demands and have been used on board satellites and spaceprobes, automatic weatherstations, lighthouses and marine installations for navigation and observation. (author)

  18. Isotopically exchangeable phosphorus

    International Nuclear Information System (INIS)

    Barbaro, N.O.

    1984-01-01

    A critique revision of isotope dilution is presented. The concepts and use of exchangeable phosphorus, the phosphate adsorption, the kinetics of isotopic exchange and the equilibrium time in soils are discussed. (M.A.C.) [pt

  19. Optical isotope shifts for unstable samarium isotopes

    International Nuclear Information System (INIS)

    Eastham, D.A.; Walker, P.M.; Griffith, J.A.R.; Evans, D.E.; Grant, I.S.; England, J.G.; Fawcett, M.J.

    1984-01-01

    Using a tunable dye laser beam intersecting a thermal atomic beam, optical isotope shifts and hyperfine splittings have been measured for the four unstable samarium isotopes between 144 Sm and 154 Sm, covering the well known transition region from spherical to deformed shapes. (orig.)

  20. Isotope hydrology: Investigating groundwater contamination

    International Nuclear Information System (INIS)

    Dubinchuk, V.; Froehlich, K.; Gonfiantini, R.

    1989-01-01

    Groundwater quality has worsened in many regions, with sometimes serious consequences. Decontaminating groundwater is an extremely slow process, and sometimes impossible, because of the generally long residence time of the water in most geological formations. Major causes of contamination are poor groundwater management (often dictated by immediate social needs) and the lack of regulations and control over the use and disposal of contaminants. These types of problems have prompted an increasing demand for investigations directed at gaining insight into the behaviour of contaminants in the hydrological cycle. Major objectives are to prevent pollution and degradation of groundwater resources, or, if contamination already has occurred, to identify its origin so that remedies can be proposed. Environmental isotopes have proved to be a powerful tool for groundwater pollution studies. The IAEA has had a co-ordinated research programme since 1987 on the application of nuclear techniques to determine the transport of contaminants in groundwater. An isotope hydrology project is being launched within the framework of the IAEA's regional co-operative programme in Latin America (known as ARCAL). Main objectives are the application of environmental isotopes to problems of groundwater assessment and contamination in Latin America. In 1989, another co-ordinated research programme is planned under which isotopic and other tracers will be used for the validation of mathematical models in groundwater transport studies

  1. Oxygen isotopic fractionation during bacterial sulfate reduction

    Science.gov (United States)

    Balci, N.; Turchyn, A. V.; Lyons, T.; Bruchert, V.; Schrag, D. P.; Wall, J.

    2006-12-01

    Sulfur isotope fractionation during bacterial sulfate reduction (BSR) is understood to depend on a variety of environmental parameters, such as sulfate concentration, temperature, cell specific sulfate reduction rates, and the carbon substrate. What controls oxygen isotope fractionation during BSR is less well understood. Some studies have suggested that carbon substrate is important, whereas others concluded that there is a stoichiometric relationship between the fractionations of sulfur and oxygen during BSR. Studies of oxygen fractionation are complicated by isotopic equilibration between sulfur intermediates, particularly sulfite, and water. This process can modify the isotopic composition of the extracellular sulfate pool (δ18OSO4 ). Given this, the challenge is to distinguish between this isotopic equilibration and fractionations linked to the kinetic effects of the intercellular enzymes and the incorporation of sulfate into the bacterial cell. The δ18OSO4 , in concert with the sulfur isotope composition of sulfate (δ34SSO4), could be a powerful tool for understanding the pathways and environmental controls of BSR in natural systems. We will present δ18OSO4 data measured from batch culture growth of 14 different species of sulfate reducing bacteria for which sulfur isotope data were previously published. A general observation is that δ18OSO4 shows little isotopic change (kinetic effect during BSR and/or equilibration between sulfur intermediates and the isotopically light water (~-5‰) of the growth medium. Our present batch culture data do not allow us to convincingly isolate the magnitude and the controlling parameters of the kinetic isotope effect for oxygen. However, ongoing growth of mutant bacteria missing enzymes critical in the different steps of BSR may assist in this mission.

  2. Isotopes in heterogeneous catalysis

    CERN Document Server

    Hargreaves, Justin SJ

    2006-01-01

    The purpose of this book is to review the current, state-of-the-art application of isotopic methods to the field of heterogeneous catalysis. Isotopic studies are arguably the ultimate technique in in situ methods for heterogeneous catalysis. In this review volume, chapters have been contributed by experts in the field and the coverage includes both the application of specific isotopes - Deuterium, Tritium, Carbon-14, Sulfur-35 and Oxygen-18 - as well as isotopic techniques - determination of surface mobility, steady state transient isotope kinetic analysis, and positron emission profiling.

  3. Geochemistry of silicon isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Tiping; Li, Yanhe; Gao, Jianfei; Hu, Bin [Chinese Academy of Geological Science, Beijing (China). Inst. of Mineral Resources; Jiang, Shaoyong [China Univ. of Geosciences, Wuhan (China).

    2018-04-01

    Silicon is one of the most abundant elements in the Earth and silicon isotope geochemistry is important in identifying the silicon source for various geological bodies and in studying the behavior of silicon in different geological processes. This book starts with an introduction on the development of silicon isotope geochemistry. Various analytical methods are described and compared with each other in detail. The mechanisms of silicon isotope fractionation are discussed, and silicon isotope distributions in various extraterrestrial and terrestrial reservoirs are updated. Besides, the applications of silicon isotopes in several important fields are presented.

  4. Applications of stable isotopes

    International Nuclear Information System (INIS)

    Letolle, R.; Mariotti, A.; Bariac, T.

    1991-06-01

    This report reviews the historical background and the properties of stable isotopes, the methods used for their measurement (mass spectrometry and others), the present technics for isotope enrichment and separation, and at last the various present and foreseeable application (in nuclear energy, physical and chemical research, materials industry and research; tracing in industrial, medical and agronomical tests; the use of natural isotope variations for environmental studies, agronomy, natural resources appraising: water, minerals, energy). Some new possibilities in the use of stable isotope are offered. A last chapter gives the present state and forecast development of stable isotope uses in France and Europe

  5. Laser Isotope Enrichment for Medical and Industrial Applications

    Energy Technology Data Exchange (ETDEWEB)

    Leonard Bond

    2006-07-01

    Laser Isotope Enrichment for Medical and Industrial Applications by Jeff Eerkens (University of Missouri), Jay Kunze (Idaho State University), and Leonard Bond (Idaho National Laboratory) The principal isotope enrichment business in the world is the enrichment of uranium for commercial power reactor fuels. However, there are a number of other needs for separated isotopes. Some examples are: 1) Pure isotopic targets for irradiation to produce medical radioisotopes. 2) Pure isotopes for semiconductors. 3) Low neutron capture isotopes for various uses in nuclear reactors. 4) Isotopes for industrial tracer/identification applications. Examples of interest to medicine are targets to produce radio-isotopes such as S-33, Mo-98, Mo-100, W-186, Sn-112; while for MRI diagnostics, the non-radioactive Xe-129 isotope is wanted. For super-semiconductor applications some desired industrial isotopes are Si-28, Ga-69, Ge-74, Se-80, Te-128, etc. An example of a low cross section isotope for use in reactors is Zn-68 as a corrosion inhibitor material in nuclear reactor primary systems. Neutron activation of Ar isotopes is of interest in industrial tracer and diagnostic applications (e.g. oil-logging). . In the past few years there has been a sufficient supply of isotopes in common demand, because of huge Russian stockpiles produced with old electromagnetic and centrifuge separators previously used for uranium enrichment. Production of specialized isotopes in the USA has been largely accomplished using old ”calutrons” (electromagnetic separators) at Oak Ridge National Laboratory. These methods of separating isotopes are rather energy inefficient. Use of lasers for isotope separation has been considered for many decades. None of the proposed methods have attained sufficient proof of principal status to be economically attractive to pursue commercially. Some of the authors have succeeded in separating sulfur isotopes using a rather new and different method, known as condensation

  6. Laser Isotope Enrichment for Medical and Industrial Applications

    International Nuclear Information System (INIS)

    Leonard Bond

    2006-01-01

    Laser Isotope Enrichment for Medical and Industrial Applications by Jeff Eerkens (University of Missouri), Jay Kunze (Idaho State University), and Leonard Bond (Idaho National Laboratory) The principal isotope enrichment business in the world is the enrichment of uranium for commercial power reactor fuels. However, there are a number of other needs for separated isotopes. Some examples are: (1) Pure isotopic targets for irradiation to produce medical radioisotopes. (2) Pure isotopes for semiconductors. (3) Low neutron capture isotopes for various uses in nuclear reactors. (4) Isotopes for industrial tracer/identification applications. Examples of interest to medicine are targets to produce radio-isotopes such as S-33, Mo-98, Mo-100, W-186, Sn-112; while for MRI diagnostics, the non-radioactive Xe-129 isotope is wanted. For super-semiconductor applications some desired industrial isotopes are Si-28, Ga-69, Ge-74, Se-80, Te-128, etc. An example of a low cross section isotope for use in reactors is Zn-68 as a corrosion inhibitor material in nuclear reactor primary systems. Neutron activation of Ar isotopes is of interest in industrial tracer and diagnostic applications (e.g. oil-logging). . In the past few years there has been a sufficient supply of isotopes in common demand, because of huge Russian stockpiles produced with old electromagnetic and centrifuge separators previously used for uranium enrichment. Production of specialized isotopes in the USA has been largely accomplished using old ''calutrons'' (electromagnetic separators) at Oak Ridge National Laboratory. These methods of separating isotopes are rather energy inefficient. Use of lasers for isotope separation has been considered for many decades. None of the proposed methods have attained sufficient proof of principal status to be economically attractive to pursue commercially. Some of the authors have succeeded in separating sulfur isotopes using a rather new and different method, known as condensation

  7. 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

  8. Isotopic exchange reactions. Kinetics and efficiency of the reactors using them in isotopic separation

    International Nuclear Information System (INIS)

    Ravoire, Jean

    1979-11-01

    In the first part, some definitions and the thermodynamic and kinetic isotopic effect concepts are recalled. In the second part the kinetic laws are established, in homogeneous and heterogeneous medium (one component being on occasions present in both phases), without and with isotopic effects. Emphasis is put on application to separation of isotopes, the separation factor α being close to 1, one isotope being in large excess with respect to the other one. Isotopic transfer is then given by: J = Ka (x - y/α) where x and y are the (isotopic) mole fractions in both phases, Ka may be either the rate of exchange or a transfer coefficient which can be considered as the 'same in both ways' if α-1 is small compared to the relative error on the measure of Ka. The third part is devoted to isotopic exchange reactors. Relationships between their efficiency and kinetics are established in some simple cases: plug cocurrent flow reactors, perfectly mixed reactors, countercurrent reactors without axial mixing. We treat only cases where α and the up flow to down flow ratio is close to 1 so that Murphee efficiency approximately overall efficiency (discrete stage contactors). HTU (phase 1) approximately HTU (phase 2) approximately HETP (columns). In a fourth part, an expression of the isotopic separative power of reactors is proposed and discussed [fr

  9. Can a sponge fractionate isotopes?

    Science.gov (United States)

    Patel, B; Patel, S; Balani, M C

    1985-03-22

    The study has unequivocally demonstrated that siliceous sponges Spirastrella cuspidifera and Prostylyssa foetida from the same microecological niche exhibit a high degree of species specificity, while accumulating a host of heavy metal ions (Ni, Cr, Cd, Sn, Ti, Mo, Zr). S. cuspidifera accumulated, in addition, 60Co and 63Ni, showing discrimination against other radionuclides, 137Cs and 131I, present in the ambient waters receiving controlled low level waste discharges from a B.W.R. nuclear power station. P. foetida, on the other hand, accumulated only 131I and showed discrimination against other radionuclides including 60Co, although the stable iodine concentrations in both the sponges were the same. The specific activity of 60Co (in becquerels per gram of 59Co) in S. cuspidifera and 131I (in becquerels per gram of 127I) in P. foetida were at least two orders of magnitude greater than in the ambient sea water. That of 63Ni (in becquerels per gram of 62Ni) in S. cuspidifera, on the other hand, was lower by two orders of magnitude than in either abiotic matrices from the same environment. Thus, not only did both the species show bioaccumulation of a specific element, but also preferential uptake of isotopes of the same element, though they were equally available for intake. Such differential uptake of isotopes can possibly be explained in terms of two quite different mechanisms operating, each applicable in a particular case. One is that the xenobiotic isotope enters the environment in a physicochemical form or as a complex different from that of its natural counterpart. If equilibration with the latter is slow, so that the organism acquires the xenobiotic in an unfamiliar chemical context, it may treat it as a chemically distinct entity so that its concentration factor differs from that of stable isotope, thus changing the specific activity. Alternatively, if the xenobiotic is present in the same chemical form as the stable isotope, the only way in which specific

  10. Combined electrolysis catalytic exchange (CECE) process for hydrogen isotope separation

    International Nuclear Information System (INIS)

    Hammerli, M.; Stevens, W.H.; Butler, J.P.

    1978-01-01

    Hydrogen isotopes can be separated efficiently by a process which combines an electrolysis cell with a trickle bed column packed with a hydrophobic platinum catalyst. The column effects isotopic exchange between countercurrent streams of electrolytic hydrogen and liquid water while the electrolysis cell contributes to isotope separation by virtue of the kinetic isotope effect inherent in the hydrogen evolution reaction. The main features of the CECE process for heavy water production are presented as well as a discussion of the inherent positive synergistic effects, and other advantages and disadvantages of the process. Several potential applications of the process in the nuclear power industry are discussed. 3 figures, 2 tables

  11. Process for isotope separation

    International Nuclear Information System (INIS)

    Emile, B.F.M.

    1983-11-01

    A process is claimed for isotopic separation applied to isotopes of elements that can be placed in at least a physicochemical form in which the isotopic atoms or the molecules containing these atoms can be easily displaced and for which there are selective radiations preferentially absorbed by the isotopes of a certain type or by the molecules containing them, said absorption substantially increasing the probability of ionization of said atoms or molecules relative to the atoms or molecules that did not absorb the radiation. The process consists of placing the isotopic mixture in such a form, subjecting it in a separation zone to selective radiations and to an electrical field that produces migration of positive ions toward the negative electrodes and negative ions toward the positive electrodes, and withdrawing from certain such zones the fractions thus enriched in certain isotopes

  12. Isotopic marking and tracers

    International Nuclear Information System (INIS)

    Morel, F.

    1997-01-01

    The use of radioactive isotopes as tracers in biology has been developed thanks to the economic generation of the required isotopes in accelerators and nuclear reactors, and to the multiple applications of tracers in the life domain; the most usual isotopes employed in biology are carbon, hydrogen, phosphorus and sulfur isotopes, because these elements are present in most of organic molecules. Most of the life science knowledge appears to be dependent to the extensive use of nuclear tools and radioactive tracers; the example of the utilization of radioactive phosphorus marked ATP to study the multiple reactions with proteins, nucleic acids, etc., is given

  13. Isotopes in oxidation reactions

    International Nuclear Information System (INIS)

    Stewart, R.

    1976-01-01

    The use of isotopes in the study of organic oxidation mechanisms is discussed. The help provided by tracer studies to demonstrate the two-equivalent path - hydride transfer, is illustrated by the examples of carbonium oxidants and the Wacker reaction. The role of kinetic isotope effects in the study of the scission of carbon-hydrogen bonds is illustrated by hydride abstraction, hydrogen atom abstraction, proton abstraction and quantum mechanical tunnelling. Isotopic studies on the oxidation of alcohols, carbonyl compounds, amines and hydrocarbons are discussed. The role of isotopes in the study of biochemical oxidation is illustrated with a discussion on nicotinamide and flavin coenzymes. (B.R.H.)

  14. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.

    1976-01-01

    The instant invention relates to a process for separating a material into two or more parts in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same material in said material. In one embodiment, the invention relates to a method for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption followed by selective dissociation of said excited molecules by the absorption of a single photon of visible or ultraviolet light. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium. 11 Claims, 2 Drawing Figures

  15. New aspects of uranium isotope separation

    International Nuclear Information System (INIS)

    Leonhardt, W.; Mueller, G.

    1979-01-01

    The need of 235 U enrichment capacity is discussed on the basis of the requirements for nuclear power in the next 10 ... 20 years. In this connection, the performance of gas diffusion, of the gas centrifuge and of the separation nozzle method are compared with each other, and an evaluation of the optical methods of isotope separation is given. (author)

  16. Field experimentation in isotope-aided studies

    International Nuclear Information System (INIS)

    Zapata, F.

    1990-01-01

    Isotopic-aided studies involve the application of isotopically labelled fertilizer as tracers for the quantitative and precise determination of the fate of specific nutrient elements in the soil/plant system. The planning of isotopic-aided studies requires a different approach from that followed in the design of normal fertilizer trials because of the cost and supply of isotopically labelled materials, the use of highly specialized equipment and the need for skillful trained staff in the use of isotope techniques both in the field/greenhouse and the laboratory. This report is intended to highlight the main points to be considered while applying those techniques in the field or greenhouse. It has been well established that nuclear techniques are a powerful tool in agricultural research. One should take advantage of the use of such techniques if the following criteria are met: The isotope method is the only way to solve a particular question or to obtain a specific piece of information. There are other methods available for such a purpose but the nuclear method provides a direct and quick means to obtain the needed information resulting in higher economic return

  17. Li Isotope Studies of Olivine in Mantle Xenoliths by SIMS

    Science.gov (United States)

    Bell, D. R.; Hervig, R. L.; Buseck, P. R.

    2005-01-01

    Variations in the ratio of the stable isotopes of Li are a potentially powerful tracer of processes in planetary and nebular environments [1]. Large differences in the 7Li/6Li ratio between the terrestrial upper mantle and various crustal materials make Li isotope composition a potentially powerful tracer of crustal recycling processes on Earth [2]. Recent SIMS studies of terrestrial mantle and Martian meteorite samples report intra-mineral Li isotope zoning [3-5]. Substantial Li isotope heterogeneity also exists within and between the components of chondritic meteorites [6,7]. Experimental studies of Li diffusion suggest the potential for rapid isotope exchange at elevated temperatures [8]. Large variations in 7Li, exceeding the range of unaltered basalts, occur in terrestrial mantle-derived xenoliths from individual localities [9]. The origins of these variations are not fully understood.

  18. Intracellular Cadmium Isotope Fractionation

    Science.gov (United States)

    Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

    2011-12-01

    Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

  19. Discovery of the iron isotopes

    International Nuclear Information System (INIS)

    Schuh, A.; Fritsch, A.; Heim, M.; Shore, A.; Thoennessen, M.

    2010-01-01

    Twenty-eight iron isotopes have been observed so far and the discovery of these isotopes is discussed here. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  20. Discovery of the silver isotopes

    International Nuclear Information System (INIS)

    Schuh, A.; Fritsch, A.; Ginepro, J.Q.; Heim, M.; Shore, A.; Thoennessen, M.

    2010-01-01

    Thirty-eight silver isotopes have been observed so far and the discovery of these isotopes is discussed here. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  1. Discovery of the cadmium isotopes

    International Nuclear Information System (INIS)

    Amos, S.; Thoennessen, M.

    2010-01-01

    Thirty-seven cadmium isotopes have been observed so far and the discovery of these isotopes is discussed here. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  2. Isotopic research in Antarctica

    International Nuclear Information System (INIS)

    Schuetze, H.

    1983-01-01

    Since 1978 scientists of the Central Institute of Isotope- and Radiation Research of the Academy of Sciences of the GDR have participated in antarctic research. Substantial results have been achieved in research on isotope ratios, on the dynamics of water resources, on concentration of deuterium in lichens, and on age determination of a mummified seal and a penguin colony

  3. Uses of stable isotopes

    International Nuclear Information System (INIS)

    Axente, Damian

    1998-01-01

    The most important fields of stable isotope use with examples are presented. These are: 1. Isotope dilution analysis: trace analysis, measurements of volumes and masses; 2. Stable isotopes as tracers: transport phenomena, environmental studies, agricultural research, authentication of products and objects, archaeometry, studies of reaction mechanisms, structure and function determination of complex biological entities, studies of metabolism, breath test for diagnostic; 3. Isotope equilibrium effects: measurement of equilibrium effects, investigation of equilibrium conditions, mechanism of drug action, study of natural processes, water cycle, temperature measurements; 4. Stable isotope for advanced nuclear reactors: uranium nitride with 15 N as nuclear fuel, 157 Gd for reactor control. In spite of some difficulties of stable isotope use, particularly related to the analytical techniques, which are slow and expensive, the number of papers reporting on this subject is steadily growing as well as the number of scientific meetings organized by International Isotope Section and IAEA, Gordon Conferences, and regional meeting in Germany, France, etc. Stable isotope application development on large scale is determined by improving their production technologies as well as those of labeled compound and the analytical techniques. (author)

  4. Detecting isotopic ratio outliers

    International Nuclear Information System (INIS)

    Bayne, C.K.; Smith, D.H.

    1985-01-01

    An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers. 6 refs., 3 figs., 3 tabs

  5. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    1982-09-01

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  6. ICT: isotope correction toolbox.

    Science.gov (United States)

    Jungreuthmayer, Christian; Neubauer, Stefan; Mairinger, Teresa; Zanghellini, Jürgen; Hann, Stephan

    2016-01-01

    Isotope tracer experiments are an invaluable technique to analyze and study the metabolism of biological systems. However, isotope labeling experiments are often affected by naturally abundant isotopes especially in cases where mass spectrometric methods make use of derivatization. The correction of these additive interferences--in particular for complex isotopic systems--is numerically challenging and still an emerging field of research. When positional information is generated via collision-induced dissociation, even more complex calculations for isotopic interference correction are necessary. So far, no freely available tools can handle tandem mass spectrometry data. We present isotope correction toolbox, a program that corrects tandem mass isotopomer data from tandem mass spectrometry experiments. Isotope correction toolbox is written in the multi-platform programming language Perl and, therefore, can be used on all commonly available computer platforms. Source code and documentation can be freely obtained under the Artistic License or the GNU General Public License from: https://github.com/jungreuc/isotope_correction_toolbox/ {christian.jungreuthmayer@boku.ac.at,juergen.zanghellini@boku.ac.at} Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  7. Separation of uranium isotopes

    International Nuclear Information System (INIS)

    Porter, J.T.

    1980-01-01

    Methods and apparatus are disclosed for separation of uranium isotopes by selective isotopic excitation of photochemically reactive uranyl salt source material at cryogenic temperatures, followed by chemical separation of selectively photochemically reduced U+4 thereby produced from remaining uranyl source material

  8. Isotope research materials

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Preparation of research isotope materials is described. Topics covered include: separation of tritium from aqueous effluents by bipolar electrolysis; stable isotope targets and research materials; radioisotope targets and research materials; preparation of an 241 Am metallurgical specimen; reactor dosimeters; ceramic and cermet development; fission-fragment-generating targets of 235 UO 2 ; and wire dosimeters for Westinghouse--Bettis

  9. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.

    1979-01-01

    A method is described for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption after which more of the excited molecules than nonexcited molecules are converted to a chemically different form which may be separated by means known in the art. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium

  10. Superdeformation in Pb isotopes

    International Nuclear Information System (INIS)

    Naz, Tabassum; Ahmad, Shakeb

    2017-01-01

    The Relatvistic Hartree-Bogoliubov (RHB) theory is used to explore the structure of superdeformed (SD) 190,212 Pb isotopes using the non-linear NL3* and density dependent (DD-ME2, DD-PC1) interactions. We have studied the the excitation energy, the potential depth and the deformation of these Pb isotopes

  11. Detecting isotopic ratio outliers

    Science.gov (United States)

    Bayne, C. K.; Smith, D. H.

    An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers.

  12. Detecting isotopic ratio outliers

    International Nuclear Information System (INIS)

    Bayne, C.K.; Smith, D.H.

    1986-01-01

    An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers

  13. Isotope dilution analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fudge, A.

    1978-12-15

    The following aspects of isotope dilution analysis are covered in this report: fundamental aspects of the technique; elements of interest in the nuclear field, choice and standardization of spike nuclide; pre-treatment to achieve isotopic exchange and chemical separation; sensitivity; selectivity; and accuracy.

  14. Wide angle isotope separator

    International Nuclear Information System (INIS)

    Kantrowitz, A.

    1976-01-01

    A method and apparatus is described for particle separation. The method uses a wide angle radially expanding vapor of a particle mixture. In particular, selective ionization of one isotope type in the particle mixture is produced in a multichamber separator and the ionized isotope type is accelerated out of the path of the vapor expansion for separate collection

  15. Environmental isotope hydrology

    International Nuclear Information System (INIS)

    1973-01-01

    Environmental isotope hydrology is a relatively new field of investigation based on isotopic variations observed in natural waters. These isotopic characteristics have been established over a broad space and time scale. They cannot be controlled by man, but can be observed and interpreted to gain valuable regional information on the origin, turnover and transit time of water in the system which often cannot be obtained by other techniques. The cost of such investigations is usually relatively small in comparison with the cost of classical hydrological studies. The main environmental isotopes of hydrological interest are the stable isotopes deuterium (hydrogen-2), carbon-13, oxygen-18, and the radioactive isotopes tritium (hydrogen-3) and carbon-14. Isotopes of hydrogen and oxygen are ideal geochemical tracers of water because their concentrations are usually not subject to change by interaction with the aquifer material. On the other hand, carbon compounds in groundwater may interact with the aquifer material, complicating the interpretation of carbon-14 data. A few other environmental isotopes such as 32 Si and 238 U/ 234 U have been proposed recently for hydrological purposes but their use has been quite limited until now and they will not be discussed here. (author)

  16. Laser assisted aerodynamic isotope separation

    International Nuclear Information System (INIS)

    Berg, H. van den

    1985-01-01

    It is shown that the efficiency of conventional aerodynamic isotope seperation can be improved by two orders of magnitude with the aid of a relatively weak cw infrared laser which is used to induce isotopically selective condensation. Overall isotope enrichment factors in excess of 2 are obtained as compared to about 1.02 in the conventional seperation. Sulphur isotopes in SF 6 as well as Silicon isotopes in SiF 4 and Bromine isotopes in CF 3 Br are seperated on a laboratory scale. Infrared vibrational predissociation by itself and in combination with isotopically selective condensation are also shown to be effective new ways of isotope separation. (orig.) [de

  17. Isotopes in Greenland Precipitation

    DEFF Research Database (Denmark)

    Faber, Anne-Katrine

    Greenland ice cores offer a unique opportunity to investigate the climate system behaviour. The objective of this PhD project is to investigate isotope modelling of present- day conditions and conduct model-data comparison using Greenland ice cores. Thus this thesis investigates how the integration...... of model and data can be used to improve the understanding of climate changes. This is done through analysis of isotope modelling, observations and ice core measurements. This dissertation comprises three projects: (1) Modelling the isotopic response to changes in Arctic sea surface conditions, (2......) Constructing a new Greenland database of observations and present-day ice core measurements, and (3) Performance test of isotope-enabled CAM5 for Greenland. The recent decades of rapid Arctic sea ice decline are used as a basis for an observational-based model experiment using the isotope-enabled CAM model 3...

  18. Applications of isotopes

    International Nuclear Information System (INIS)

    Kirby-Smith, J.S.

    1976-01-01

    Current and potential applications of stable isotopes as tracers in a number of biomedical and environmental areas are discussed. It is pointed out that a wide variety of problems exist in these fields whose solutions in principle are amenable to the isotopic approach. The number and diversity of these problems as well as the unique role stable isotopes can play in their solution illustrate the importance of achieving and maintaining a broad inventory of isotopic species. Experience has demonstrated unequivocally an additional overriding requirement for widespread exploration of stable isotopes by the scientific and technical community, i.e., the need for low cost availability of the materials in quantity. Some representative applications of 12 C, 13 C, 14 N, 15 N, 16 O, 17 O, and 18 O are discussed

  19. Preliminary design review: Brayton Isotope Power System

    International Nuclear Information System (INIS)

    The design aspects covered include flight system design, design criteria/margins/reliability, GDS design, system analysis, materials, system assembly procedure, and government furnished equipment-BTPS

  20. Atomic vapor laser isotope separation

    International Nuclear Information System (INIS)

    Stern, R.C.; Paisner, J.A.

    1985-01-01

    Atomic vapor laser isotope separation (AVLIS) is a general and powerful technique. A major present application to the enrichment of uranium for light-water power reactor fuel has been under development for over 10 years. In June 1985 the Department of Energy announced the selection of AVLIS as the technology to meet the nation's future need for the internationally competitive production of uranium separative work. The economic basis for this decision is considered, with an indicated of the constraints placed on the process figures of merit and the process laser system. We then trace an atom through a generic AVLIS separator and give examples of the physical steps encountered, the models used to describe the process physics, the fundamental parameters involved, and the role of diagnostic laser measurements

  1. Chromium isotope variations

    DEFF Research Database (Denmark)

    D'Arcy, Joan Mary

    the δ53Cr value of continental runoff into the ocean. The major findings were that river water is characterised by heavy δ53Cr values (+0.1‰ to +1.6‰), while soils are characterised by light δ53Cr values (-0.3‰), relative to the catchment bedrock (-0.17‰ to -0.21‰), indicating that Cr isotopes......, and the quantification the Cr isotope composition of major Cr fluxes into and out of ocean. This thesis adds to the current knowledge of the Cr isotope system and is divided into two studies. The focus of the first study was to determine what processes control the Cr isotopic compositionof river water and to quantify......Chromium (Cr) stable isotopes are a useful tracer of changes in redox conditions because changes in its oxidation state are accompanied by an isotopic fractionation. For this reason the Cr isotope system is being developed as a potential tool for paleo-redox reconstruction. Dissolved Cr in seawater...

  2. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Eugene E.

    2006-06-19

    The following article is an edited transcript based on the Turnbull Lecture given by Eugene E. Haller at the 2005 Materials Research Society Fall Meeting in Boston on November 29, 2005. The David Turnbull Lectureship is awarded to recognize the career of a scientist who has made outstanding contributions to understanding materials phenomena and properties through research, writing, and lecturing, as exemplified by the life work of David Turnbull. Haller was named the 2005 David Turnbull Lecturer for his 'pioneering achievements and leadership in establishing the field of isotopically engineered semiconductors; for outstanding contributions to materials growth, doping and diffusion; and for excellence in lecturing, writing, and fostering international collaborations'. The scientific interest, increased availability, and technological promise of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor crystals. This article reviews results obtained with isotopically controlled semiconductor bulk and thin-film heterostructures. Isotopic composition affects several properties such as phonon energies, band structure, and lattice constant in subtle, but, for their physical understanding, significant ways. Large isotope-related effects are observed for thermal conductivity in local vibrational modes of impurities and after neutron transmutation doping. Spectacularly sharp photoluminescence lines have been observed in ultrapure, isotopically enriched silicon crystals. Isotope multilayer structures are especially well suited for simultaneous self- and dopant-diffusion studies. The absence of any chemical, mechanical, or electrical driving forces makes possible the study of an ideal random-walk problem. Isotopically controlled semiconductors may find applications in quantum computing, nanoscience, and spintronics.

  3. Isotope separation process

    International Nuclear Information System (INIS)

    1976-01-01

    The invention relates to a process for separating a given material into two or more parts, in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same material in the said material. More particularly, the invention relates to a method for the isotopically selective excitation of gas phase UF 6 by infrared photon absorption followed by selective reaction of said excited UF 6 with atomic chlorine, bromine, or iodine to form a product which may be separated by means known in the art

  4. Radiation gradient isotope separator

    International Nuclear Information System (INIS)

    Hughes, J.L.

    1980-01-01

    A system is described for transporting, separating and storing charged particles, charged antiparticles and fully or partially ionized isotopes of any element comprising a laser beam generator, laser beam intensity profiler, a laser beam variable intensity attenuator, and means for injecting charged particles, charged antiparticles and ionized isotopes into the beam and extracting them from the system as required. The invention is particularly useful for channelling electrons and ions used for fuel pellet compression in inertial fusion systems, for separating the isotopes of elements and for the confinement of charged antiparticles and particle/antiparticle plasmas

  5. Atomic and molecular isotope separation

    International Nuclear Information System (INIS)

    Melamed, N.T.

    1979-01-01

    A method for differentially exciting a selected isotopic species in a mixture of isotopic species is described characterized in that almost the entire isotopic mixture is placed in an excited gaseous state; and a preselected isotopic species is then selectively de-excited through stimulated emission

  6. The US national isotope program: Current status and strategy for future success

    International Nuclear Information System (INIS)

    Rivard, Mark J.; Bobek, Leo M.; Butler, Ralph A.; Garland, Marc A.; Hill, David J.; Krieger, Jeanne K.; Muckerheide, James B.; Patton, Brad D.; Silberstein, Edward B.

    2005-01-01

    Since their introduction in the 1940s, peaceful use of stable isotopes and radioisotopes in the United States has expanded continuously. Today, new isotopes for diagnostic and therapeutic uses are not being developed, critical isotopes for national security are in short supply, and demand for isotopes critical to homeland security exceeds supply. While commercial suppliers, both domestic and foreign, can only meet specific needs, the nation needs a consistent, reliable supply of radioactive and stable isotopes for research, medical, security, and space power applications. The national isotope infrastructure, defined as both facilities and trained staff at national laboratories and universities, is in danger of being lost due to chronic underfunding. With the specific recommendations given herein, the US Department of Energy may realign and refocus its Isotope Program to provide a framework for a successful National Isotope Program

  7. Isotope Production Facility (IPF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Los Alamos National Laboratory has produced radioactive isotopes for medicine and research since the mid 1970s, when targets were first irradiated using the 800...

  8. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  9. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.

    1977-01-01

    The instant invention relates to a process for separating a material into two or more parts in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same material in said material. More particularly, the invention relates to a method for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption followed by a step wherein more of the excited molecules than nonexcited molecules are converted to a chemically different form which may be separated by means known in the art. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium. 15 claims, 1 figure

  10. Isotope separation process

    International Nuclear Information System (INIS)

    Thomas, W.R.L.

    1979-01-01

    The instant invention relates to an improved process for separating a material into two or more parts in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same element in said material. More particularly, the invention relates to a method for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption followed by a step wherein more of the excited molecules than non-excited molecules are converted to a chemically different form which may be separated by means known in the art. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium

  11. Calcium stable isotope geochemistry

    International Nuclear Information System (INIS)

    Gausonne, Nikolaus; Schmitt, Anne-Desiree; Heuser, Alexander; Wombacher, Frank; Dietzel, Martin; Tipper, Edward; Schiller, Martin

    2016-01-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  12. Laser separation of uranium isotopes

    International Nuclear Information System (INIS)

    Porter, J.T.

    1981-01-01

    Method and apparatus for separating uranium isotopes are claimed. The method comprises the steps of irradiating a uranyl source material at a wavelength selective to a desired isotope and at an effective temperature for isotope spectral line splitting below about 77 deg.K., further irradiating the source material within the fluorescent lifetime of the source material to selectively photochemically reduce the excited isotopic species, and chemically separating the reduced isotope species from the remaining uranyl salt compound

  13. High mass isotope separation arrangement

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1980-01-01

    This invention relates to the isotope separation art and, more particularly, to a selectively photon-induced energy level transition of an isotopic molecule containing the isotope to be separated and a chemical reaction with a chemically reactive agent to provide a chemical compound containing atoms of the isotope desired. In particular a description is given of a method of laser isotope separation applied to the separation of 235 UF 6 from 238 UF 6 . (U.K.)

  14. Emission spectrometric isotope analyzer

    International Nuclear Information System (INIS)

    Mauersberger, K.; Meier, G.; Nitschke, W.; Rose, W.; Schmidt, G.; Rahm, N.; Andrae, G.; Krieg, D.; Kuefner, W.; Tamme, G.; Wichlacz, D.

    1982-01-01

    An emission spectrometric isotope analyzer has been designed for determining relative abundances of stable isotopes in gaseous samples in discharge tubes, in liquid samples, and in flowing gaseous samples. It consists of a high-frequency generator, a device for defined positioning of discharge tubes, a grating monochromator with oscillating slit and signal converter, signal generator, window discriminator, AND connection, read-out display, oscillograph, gas dosing device and chemical conversion system with carrier gas source and vacuum pump

  15. Isotope toolbox turns 10

    DEFF Research Database (Denmark)

    Wenander, Fredrik; Riisager, Karsten

    2012-01-01

    REX-ISOLDE, one of CERN’s most compact accelerators, has just celebrated its 10th anniversary. The machine’s versatility provides radioactive ion beams across the range of nuclear isotopes.......REX-ISOLDE, one of CERN’s most compact accelerators, has just celebrated its 10th anniversary. The machine’s versatility provides radioactive ion beams across the range of nuclear isotopes....

  16. Laser isotope separation

    International Nuclear Information System (INIS)

    1976-01-01

    The claimed invention is a method of isotope separation based on the unimolecular decomposition of vibrationally excited negative ions which are produced in the reaction of thermal electrons and molecules which have been vibrationally excited in an isotope selective manner. This method is especially applicable to molecules represented by the formula MF 6 wherein M is selected from the group consisting of U, S, W, Se, Te, Mo, Re and Tc

  17. UWIS isotope separator

    Energy Technology Data Exchange (ETDEWEB)

    Wojtasiewicz, A. [Warsaw Univ., Inst. of Experimental Physics, Nuclear Physics Div., Warsaw (Poland)

    1997-12-31

    Since 1995 the University of Warsaw Isotope Separator group has participated in the ISOL/IGISOL project at the Heavy Ion Cyclotron. This project consists in installation of an isotope separator (on line with cyclotron heavy ion beam) with a hot plasma ion source (ISOL system) and/or with an ion guide source (IGISOL system). In the report the short description of the present status of the project is presented. 2 figs, 10 refs.

  18. Laser isotope separation process

    International Nuclear Information System (INIS)

    Kaldor, A.

    1976-01-01

    The claimed invention is a method of isotope separation based on the unimolecular decomposition of vibrationally excited negative ions which are produced in the reaction of thermal electrons and molecules which have been vibrationally excited in an isotope selective manner. This method is especially applicable to molecules represented by the formula MF 6 wherein M is selected from the group consisting of U, S, W, Se, Te, Mo, Re, and Tc. 9 claims, 1 drawing figure

  19. Isotopes in environmental research

    International Nuclear Information System (INIS)

    Bowen, G.; Rozanski, K.; Vose, P.

    1990-01-01

    Radioactive and stable isotopes have long been considered a very efficient tool for studying physical and biological aspects of how the global ecosystem functions. Their applications in environmental research are numerous, embracing research at all levels. This article looks at only a few of the approaches to environmental problems that involve the use of isotopes. Special attention is given to studies of the Amazon Basin. Environmental isotopes are very efficient tools in water cycle studies. Tritium, a radioactive tracer, is especially useful in studying dynamics of water movement in different compartments of the hydrosphere, both on the local and global scales. Heavy stable isotopes of hydrogen and oxygen (deuterium and oxygen-18) provide information about steady-state characteristics of the water cycle. Isotope methods, some relatively new, have a major role in site-specific studies. Some indicative examples include: Studying turnover of organic matter. Changes in the carbon-13/carbon-12 isotopic ratio of organic matter were used to determine the respective contributions of organic carbon derived from forest and pasture. Studying biological nitrogen fixation. One of the ways nitrogen levels in soil can be maintained for productivity is by biological nitrogen fixation. Studying nitrogen availability and losses. The experimental use of nitrogen-15 is invaluable for defining losses of soil nitrogen to the atmosphere and to groundwater. Studies can similarly be done with stable and radioactive sulphur isotopes. This article indicates some potential uses of isotopes in environmental research. While the major problem of global climate change has not been specifically addressed here, the clearing of the Amazon forest, one focus of the IAEA's environmental programme, may have serious consequences for the global climate. These include substantial reduction of the amount of latent heat transported to the regions outside the tropics and acceleration of the greenhouse

  20. Isotopes in everyday life

    International Nuclear Information System (INIS)

    Seligman, H.; Gillen, V.A.

    1990-12-01

    Isotopes represent a tool which can do certain jobs better, easier, quicker, more simply and cheaper than competitive methods. Some measurements could not be done at all without the use of isotopes as there are no alternative methods available. A short review of these tools of science in their different fields is given: food and agriculture, human health applications, industry, hydrology, geology, geochemistry, geophysics and dating, environment, basic scientific research

  1. Isotope separation process

    International Nuclear Information System (INIS)

    Cabicar, J.; Stamberg, K.; Katzer, J.

    1983-01-01

    A process for separating isotopes by the method of controlled distribution is claimed. A first phase is either a solution of isotopic components and a ligand (from 10 - 6 M to a saturated solution), or a gaseous mixture of isotopic components, or a gaseous mixture of isotopic components and an inert gas. The isotopes are in the starting mixture in molar ratio from 1:10 5 to 1:10 - 5 . The second phase is a solid sorbent such as styrene-divinylbenzene ion exchangers, or bio-sorbents on the basis of mycelium of lower fungi and sorbents on the basis of cellulose, or an extraction agent such as tributyl phosphate and trioctyl amine, if need be, kept by a carrier such as teflon, silica gel and cellulose. The two-phase system exhibits non-linear equilibrium isotherm for sorption and/or desorption or for extraction and/or re-extraction. After bringing both phases into contact the rate of transport of isotopic components from one phase into another is not equal. Retardation of isotopic exchange takes place by complexation of isotopes with ligands such as cabonate, sulphate, citrate, chloride and ethylenediamine tetraacetate ions, or by using sorbents and extraction agents with chelating functional groups such as carboxyl and hyroxyl groups, groups on the basis of phosphorus, nitrogen and sulphur and/or by operating in darkness, or in the light having wave length between 2.5x10 2 and 10 9 nm. The contact time is between 10 - 2 and 10 6 s, temperature between 10 2 and 10 3 K, the number of stirrer revolutions between 10 - 2 and 10 4 revolutions per s, flow rate at column arrangement between 10 - 6 and 10 - 1 m/s and the size of particles of sorbent between 10 - 6 and 10 - 2 m

  2. Isotope separation apparatus

    International Nuclear Information System (INIS)

    Lyon, R.K.; Eisner, P.N.; Thomas, W.R.I.

    1983-01-01

    This application discloses a method for and an apparatus in which isotopes of an element in a compared are separated from each other while that compound, i.e., including a mixture of such isotopes, flows along a predetermined path. The apparatus includes a flow tube having a beginning and an end. The mixture of isotopes is introduced into the flow tube at a first introduction point between the beginning and the end thereof to flow the mixture toward the end thereof. A laser irradiates the flow tube dissociating compounds of a preselected one of said isotopes thereby converting the mixture in an isotopically selective manner. The dissociation products are removed from the tube at a first removal point between the first introduction point and the end. The dissociation product removed at the the first removal point are reconverted back into the comound thereby providing a first stage enriched compound. This first stage enriched compound is reintroduced into the flow tube at a second introduction point between the beginning thereof and the first introduction point. Further product is removed from the flow tube at a second removal point between the second introduction point and the first introduction point. The second introduction point is chosen so that the isotope composition of the first stage enriched compound is approximately the same as that of the compound in the flow tube

  3. International Isotopes Markets

    Directory of Open Access Journals (Sweden)

    Stanislaw Z. Zhiznin

    2016-01-01

    Full Text Available The paper studies world markets of stable and radioactive isotopes. Isotopes have found various applications in science, industry, agriculture and other sectors of the economy, but especially - in medicine. Nuclear medicine is developing intensively all over the world thanks to the success in the treatment of various diseases with the help of radioactive pharmaceuticals (radiopharmaceuticals. The article uses empirical data from a forecast study of the global radiopharmaceuticals market made in 2015 by a research company «Markets and Markets» for the European, North American and global markets. The paper also analyzes the statistical data on the global export and import of natural uranium, enriched and depleted uranium, plutonium, thorium and some stable isotopes of non-medical purposes, presented by a company «Trend economy» in 2014. Despite a unique industrial base for the production of isotopes created in the Soviet Union Russia occupies a modest position on the world market of nuclear medicine except for certain areas. More than 80% of isotopes, produced in USSR were consumed domestically, the export of the stable and radioactive isotopes was in equal proportions. Now the country's domestic radiopharmaceuticals market is poorly developed. To radically change the situation, it is necessary to carry out reforms that stimulate the development of nuclear medicine.

  4. Beneficial use of isotopes

    International Nuclear Information System (INIS)

    Bertel, E.; Stevens, G.H.

    1998-01-01

    The paper gives an outlook on the main isotopes currently used for beneficial applications, provides an overview on geographic distribution of isotope production capabilities and identifies the main suppliers world-wide. It analyses trends in different countries and regions, including the refurbishment and/or replacement of ageing facilities and the implementation of new capabilities. Issues related to adequate supply of isotopes and potential under or over capacity of production for some key products are discussed. The evolution of the isotope production sector is analysed. Issues such as lowering of governmental support to production facilities, emergence of international co-operation and agreements on production capabilities, and developments in non-OECD/NEA countries are addressed. The paper offers some concluding remarks on the importance of maintaining and enhancing beneficial uses of isotopes, the role of government policies, the need for co-operation between countries and between the private and public sectors. The paper addresses the role of international cooperation in making efficient use of existing isotope production capacity and investigates ways for reducing the need for investment in additional capacity. (author)

  5. Hydrology of Bishop Creek, California: An Isotopic Analysis

    Science.gov (United States)

    Michael L. Space; John W. Hess; Stanley D. Smith

    1989-01-01

    Five power generation plants along an eleven kilometer stretch divert Bishop Creek water for hydro-electric power. Stream diversion may be adversely affecting the riparian vegetation. Stable isotopic analysis is employed to determine surface water/ground-water interactions along the creek. surface water originates primarily from three headwater lakes. Discharge into...

  6. Ion detectors for isotopic measurements

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, A.

    1978-12-15

    Detector development over the past two decades has been such that this is now the least likely part of the mass spectrometry equipment to give rise to the sort of measurement errors to cause concern. It is now possible to choose from a number of different types of device which can provide more or less 100% efficiency in ion beam detection under all conceivable experimental conditions required for isotopic analysis, from measurement of large samples using the traditional Faraday cage to measurement of exceedingly small ion currents by ion counting techniques. There are even methods of distinguishing one type of ionic species from another in the detector, thus improving the accuracy when unwanted isobaric species might otherwise grossly distort the measurement. Notable contributions to detector development for nuclear measurements have been made by Dietz at the Knolls Atomic Power Laboratory, by Barnett at Oak Ridge and by Daly at Atomic Weapons Research Establishment (AWRE), Aldermaston. This paper describes the detection methods which are currently in use at AWRE for isotopic analysis of solid samples for routine applications as well as non-routine applications. Other methods are merely mentioned as a stimulus for discussion.

  7. Tin isotope fractionation during magmatic processes and the isotope composition of the bulk silicate Earth

    Science.gov (United States)

    Wang, Xueying; Amet, Quentin; Fitoussi, Caroline; Bourdon, Bernard

    2018-05-01

    Tin is a moderately volatile element whose isotope composition can be used to investigate Earth and planet differentiation and the early history of the Solar System. Although the Sn stable isotope composition of several geological and archaeological samples has been reported, there is currently scarce information about the effect of igneous processes on Sn isotopes. In this study, high-precision Sn isotope measurements of peridotites and basalts were obtained by MC-ICP-MS with a double-spike technique. The basalt samples display small variations in δ124/116Sn ranging from -0.01 ± 0.11 to 0.27 ± 0.11‰ (2 s.d.) relative to NIST SRM 3161a standard solution, while peridotites have more dispersed and more negative δ124Sn values ranging from -1.04 ± 0.11 to -0.07 ± 0.11‰ (2 s.d.). Overall, basalts are enriched in heavy Sn isotopes relative to peridotites. In addition, δ124Sn in peridotites become more negative with increasing degrees of melt depletion. These results can be explained by different partitioning behavior of Sn4+ and Sn2+ during partial melting. Sn4+ is overall more incompatible than Sn2+ during partial melting, resulting in Sn4+-rich silicate melt and Sn2+-rich residue. As Sn4+ has been shown experimentally to be enriched in heavy isotopes relative to Sn2+, the effect of melting is to enrich residual peridotites in relatively more compatible Sn2+, which results in isotopically lighter peridotites and isotopically heavier mantle-derived melts. This picture can be disturbed partly by the effect of refertilization. Similarly, the presence of enriched components such as recycled oceanic crust or sediments could explain part of the variations in Sn isotopes in oceanic basalts. The most primitive peridotite analyzed in this study was used for estimating the Sn isotope composition of the BSE, with δ124Sn = -0.08 ± 0.11‰ (2 s.d.) relative to the Sn NIST SRM 3161a standard solution. Altogether, this suggests that Sn isotopes may be a powerful probe of

  8. Methods for removing radioactive isotopes from contaminated streams

    International Nuclear Information System (INIS)

    Hoy, D.R.; Hickey, T.N.; Spulgis, I.S.; Parish, H.C.

    1979-01-01

    Methods for removing radioactive isotopes from contaminated gas streams for use in atmospheric containment and cleanup systems in nuclear power plants are provided. The methods provide for removal of radioactive isotopes from a first portion of the contaminated stream, separated from the remaining portion of the stream, so that adsorbent used to purify the first portion of the contaminated stream by adsorption of the radioactive isotopes therefrom can be tested to determine the adsorbing efficacy of the generally larger portion of adsorbent used to purify the remaining portion of the stream

  9. Isotopic quantum correction to liquid methanol at -30 C

    CERN Document Server

    Benmore, C J; Egelstaff, P A; Neuefeind, J

    2002-01-01

    Hydrogen/deuterium (H/D) substitution of molecular liquids in neutron diffraction is a powerful tool for structure determination. However, recent high-energy X-ray studies have found observable differences in the structures of many H and D liquids at the same temperature. In some cases this isotopic quantum effect can be corrected for by measuring the D sample at a slightly different temperature to the H sample. The example of hydroxyl isotopic substitution in liquid methanol at -30 C is presented. The magnitude of the quantum effect is shown to be significant when compared to the size of the first-order isotopic neutron-difference function. (orig.)

  10. Isotope hydrology and its impact in the developing world

    International Nuclear Information System (INIS)

    Verhagen, B.Th.

    2003-01-01

    Ground water has increasingly taken its place in the provision of safe, potable supply in the developing world. Large investments have been made in infrastructural development for rural ground water supply schemes, but far too little attention has been given to assess the sustainability of these supplies. Overexploitation of aquifers, evident in failing boreholes and deteriorating water quality, has become a world-wide concern. Developments in physics half a century ago established the basis of isotope hydrology. Radioactive isotopes give information on ground water dynamics and recharge rates whilst non-radioactive - or stable - isotopes indicate origins of ground water and delineate ground water bodies. Environmental isotope hydrology is increasingly seen as a powerful discipline in assessing ground water systems. This is particularly important in developing environments, where historical data is rarely available. Brief examples are presented of isotope applications to collaborative ground water studies conducted at the University of the Witwatersrand. Recharge estimates based on isotope 'snapshot' data conform well with results from subsequent long-term water level observations in the Kalahari of Botswana. The importance is demonstrated of irrigation return flow and pollution hazard to the Lomagundi dolomite of Zimbabwe. Isotopes suggest the source of high nitrate concentrations to an important ground water supply in Tanzania. Mechanisms of the release of arsenic into millions of tube wells in Bangladesh are put into perspective. Isotope hydrology as appropriate technology is highlighted in terms of its cost-effectiveness and the investigative empowerment of local investigators. (author)

  11. Transportation of medical isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, D.L.

    1997-11-19

    A Draft Technical Information Document (HNF-1855) is being prepared to evaluate proposed interim tritium and medical isotope production at the Fast Flux Test Facility (FFTF). This assessment examines the potential health and safety impacts of transportation operations associated with the production of medical isotopes. Incident-free and accidental impacts are assessed using bounding source terms for the shipment of nonradiological target materials to the Hanford Site, the shipment of irradiated targets from the FFTF to the 325 Building, and the shipment of medical isotope products from the 325 Building to medical distributors. The health and safety consequences to workers and the public from the incident-free transportation of targets and isotope products would be within acceptable levels. For transportation accidents, risks to works and the public also would be within acceptable levels. This assessment is based on best information available at this time. As the medical isotope program matures, this analysis will be revised, if necessary, to support development of a final revision to the Technical Information Document.

  12. Isotope separation process

    International Nuclear Information System (INIS)

    Wexler, Sol; Young, C.E.

    1976-01-01

    Description is given of method for separating a specific isotope from a mixture of isotopes of an actinide element present as MF 6 , wherein M is the actinide element. It comprises: preparing a feed gas mixture of MF 6 in a propellant gas; passing the feed gas mixture under pressure through an expansion nozzle while heating the mixture to about 600 0 C; releasing the heated gas mixture from the nozzle into an exhaust chamber having a reduced pressure, whereby a gas jet of MF 6 molecules, MF 6 molecular clusters and propellant gas molecules is formed, the MF 6 molecules having a translational energy of about 3 eV; converting the MF 6 molecules to MF 6 ions by passing the jet through a cross jet of electron donor atoms so that an electron transfer takes place between the MF 6 - molecules and the electron donor atoms whereby the jet is now quasi-neutral, containing negative MF 6 - ions and positive donor ions; passing the quasi-neutral jet through a radiofrequency mass filter tuned to separate the MF 6 ions containing the specific isotope from the MF 6 - ions of the other isotopes and neutralizing and collecting the MF 6 molecules of the specific isotope [fr

  13. Noncovalent Hydrogen Isotope Effects

    Science.gov (United States)

    Buchachenko, A. L.; Breslavskaya, N. N.

    2018-02-01

    Zero-point energies (ZPE) and isotope effects, induced by intermolecular, noncovalent vibrations, are computed and tested by experimental data. The ZPE differences of H- and D-complexes of water with hydrogen, methane, and water molecules are about 100-300 cal/mol; they result to isotope effects IE of 1.20-1.70. Semi-ionic bonds between metal ions and water ligands in M(H2O) 6 2+ complexes are much stronger; their ZPEs are about 12-14 kcal/mol per molecule and result to IE of 1.9-2.1 at 300 K. Protonated (deuterated) water and biwater exhibit the largest ZPE differences and isotope effects; the latter are 25-28 and 12-13 for water and biwater, respectively. Noncovalent IEs contribute markedly into the experimentally measured effects and explain many anomalous and even magic properties of the effects, such as the dependence of IE on the solvents and on the presence of the third substances, enormously large isotope effects at the mild conditions, the difference between IEs measured in the reactions of individual protiated and deuterated compounds and those measured in their mixture. Noncovalent IEs are not negligible and should be taken into account to make correct and substantiated conclusions on the reaction mechanisms. The kinetic equations are derived for the total isotope effects, which include noncovalent IEs as additive factors.

  14. Transportation of medical isotopes

    International Nuclear Information System (INIS)

    Nielsen, D.L.

    1997-01-01

    A Draft Technical Information Document (HNF-1855) is being prepared to evaluate proposed interim tritium and medical isotope production at the Fast Flux Test Facility (FFTF). This assessment examines the potential health and safety impacts of transportation operations associated with the production of medical isotopes. Incident-free and accidental impacts are assessed using bounding source terms for the shipment of nonradiological target materials to the Hanford Site, the shipment of irradiated targets from the FFTF to the 325 Building, and the shipment of medical isotope products from the 325 Building to medical distributors. The health and safety consequences to workers and the public from the incident-free transportation of targets and isotope products would be within acceptable levels. For transportation accidents, risks to works and the public also would be within acceptable levels. This assessment is based on best information available at this time. As the medical isotope program matures, this analysis will be revised, if necessary, to support development of a final revision to the Technical Information Document

  15. Isotope methods in hydrology

    International Nuclear Information System (INIS)

    Moser, H.; Rauert, W.

    1980-01-01

    Of the investigation methods used in hydrology, tracer methods hold a special place as they are the only ones which give direct insight into the movement and distribution processes taking place in surface and ground waters. Besides the labelling of water with salts and dyes, as in the past, in recent years the use of isotopes in hydrology, in water research and use, in ground-water protection and in hydraulic engineering has increased. This by no means replaces proven methods of hydrological investigation but tends rather to complement and expand them through inter-disciplinary cooperation. The book offers a general introduction to the application of various isotope methods to specific hydrogeological and hydrological problems. The idea is to place the hydrogeologist and the hydrologist in the position to recognize which isotope method will help him solve his particular problem or indeed, make a solution possible at all. He should also be able to recognize what the prerequisites are and what work and expenditure the use of such methods involves. May the book contribute to promoting cooperation between hydrogeologists, hydrologists, hydraulic engineers and isotope specialists, and thus supplement proven methods of investigation in hydrological research and water utilization and protection wherever the use of isotope methods proves to be of advantage. (orig./HP) [de

  16. Separation of uranium isotopes by accelerated isotope exchange reactions

    International Nuclear Information System (INIS)

    Seko, M.; Miyake, T.; Inada, K.; Ochi, K.; Sakamoto, T.

    1977-01-01

    A novel catalyst for isotope exchange reaction between uranium(IV) and uranium(VI) compounds enables acceleration of the reaction rate as much as 3000 times to make industrial separation of uranium isotopes economically possible

  17. New processes for uranium isotope separation

    International Nuclear Information System (INIS)

    Vanstrum, P.R.; Levin, S.A.

    1977-01-01

    An overview of the status and prospects for processes other than gaseous diffusion, gas centrifuge, and separation nozzle for uranium isotope separation is presented. The incentive for the development of these processes is the increasing requirements for enriched uranium as fuel for nuclear power plants and the potential for reducing the high costs of enrichment. The latest nuclear power projections are converted to uranium enrichment requirements. The size and timing of the market for new enrichment processes are then determined by subtracting the existing and planned uranium enrichment capacities. It is estimated that to supply this market would require the construction of a large new enrichment plant of 9,000,000 SWU per year capacity, costing about $3 billion each (in 1976 dollars) about every year till the year 2000. A very comprehensive review of uranium isotope separation processes was made in 1971 by the Uranium Isotope Separation Review Ad Hoc Committee of the USAEC. Many of the processes discussed in that review are of little current interest. However, because of new approaches or remaining uncertainties about potential, there is considerable effort or continuing interest in a number of alternative processes. The status and prospects for attaining the requirements for competitive economics are presented for these processes, which include laser, chemical exchange, aerodynamic other than separation nozzle, and plasma processes. A qualitative summary comparison of these processes is made with the gaseous diffusion, gas centrifuge, and separation nozzle processes. In order to complete the overview of new processes for uranium isotope separation, a generic program schedule of typical steps beyond the basic process determination which are required, such as subsystem, module, pilot plant, and finally plant construction, before large-scale production can be attained is presented. Also the present value savings through the year 2000 is shown for various

  18. Retention of gaseous isotopes

    International Nuclear Information System (INIS)

    Yarbro, O.O.; Mailen, J.C.; Stephenson, M.J.

    1977-01-01

    Retention of gaseous fission products during fuel reprocessing has, in the past, been limited to a modest retention of 131 I when processing fuels decayed less than about 180 days. The projected rapid growth of the nuclear power industry along with a desire to minimize environmental effects is leading to the reassessment of requirements for retention of gaseous fission products, including 131 I, 129 I, 85 Kr, 3 H, and 14 C. Starting in the late 1960s, a significant part of the LMFBR reprocessing development program has been devoted to understanding the behavior of gaseous fission products in plant process and effluent streams and the development of advanced systems for their removal. Systems for iodine control include methods for evolving up to 99% of the iodine from dissolver solutions to minimize its introduction and distribution throughout downstream equipment. An aqueous scrubbing system (Iodox) using 20 M HNO 3 as the scrubbing media effectively removes all significant iodine forms from off-gas streams while handling the kilogram quantities of iodine present in head-end and dissolver off-gas streams. Silver zeolite is very effective for removing iodine forms at low concentration from the larger-volume plant off-gas streams. Removal of iodine from plant liquid effluents by solid sorbents either prior to or following final vaporization appears feasible. Krypton is effectively released during dissolution and can be removed from the relatively small volume head-end and dissolver off-gas stream. Two methods appear applicable for removal and concentration of krypton: (1) selective absorption in fluorocarbons, and (2) cryogenic absorption in liquid nitrogen. The fluorocarbon absorption process appears to be rather tolerant of the normal contaminants (H 2 O, CO 2 , NOsub(x), and organics) present in typical reprocessing plant off-gas whereas the cryogenic system requires an extensive feed gas pretreatment system. Retention of tritium in a reprocessing plant is

  19. Temporal and spatial distribution of isotopes in river water in Central Europe: 50 years experience with the Austrian network of isotopes in rivers.

    Science.gov (United States)

    Rank, Dieter; Wyhlidal, Stefan; Schott, Katharina; Weigand, Silvia; Oblin, Armin

    2018-05-01

    The Austrian network of isotopes in rivers comprises about 15 sampling locations and has been operated since 1976. The Danube isotope time series goes back to 1963. The isotopic composition of river water in Central Europe is mainly governed by the isotopic composition of precipitation in the catchment area; evaporation effects play only a minor role. Short-term and long-term isotope signals in precipitation are thus transmitted through the whole catchment. The influence of climatic changes has become observable in the long-term stable isotope time series of precipitation and surface waters. Environmental 3 H values were around 8 TU in 2015, short-term 3 H pulses up to about 80 TU in the rivers Danube and March were a consequence of releases from nuclear power plants. The complete isotope data series of this network will be included in the Global Network of Isotopes in Rivers database of the International Atomic Energy Agency (IAEA) in 2017. This article comprises a review of 50 years isotope monitoring on rivers and is also intended to provide base information on the (isotope-)hydrological conditions in Central Europe specifically for the end-users of these data, e.g. for modelling hydrological processes. Furthermore, this paper includes the 2006-2015 supplement adding to the Danube isotope set published earlier.

  20. Stable Isotope Group 1982 progress report

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1983-06-01

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences during 1982, in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and mass spectrometer instrumentation, is described

  1. Stable Isotope Group 1983 progress report

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1984-06-01

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and related fields, and mass spectrometer instrumentation, during 1983, is described

  2. Isotope separation system

    International Nuclear Information System (INIS)

    Lehmann, J.-C.

    1975-01-01

    A description is given of an isotope separation device comprising a system for converting into gaseous form a first and second isotope to be separated, a monochromatic excitation light source to excite the gaseous molecules of these two isotopes in a distinct manner, a first and second receiver to collect selectively the molecules of the first and second distinctly excited isotopes. The frequency FL of the excitation light is selected between a lower limit and a higher limit F2 + 1/2 LD, depending on the frequences F1 and F2 of two absorption lines near this first and second isotope. The difference DF between these two frequencies F1 and F2 is less than the Doppler width LD of each one of these lines and greater than the natural width LN of each of these two lines and also the width of line LR of the excitation light source. The probability that the molecules will be excited by this light depends on the direction of their displacement to a major and different extent for both isotopes. An ionising light source LI is set up to irradiate the seat of interaction between the excitation light and the gaseous molecules with an ionisation light able to ionise the excited molecules without ionising the molecules that are not excited. The receivers are able to collect selectively the ionised molecules. A sufficiently low gas pressure is selected for the distance between the place of interaction and the first receiver to be less than double the free mean travel of the molecules in the gas [fr

  3. Quantitative imaging of subcellular metabolism with stable isotopes and multi-isotope imaging mass spectrometry

    Science.gov (United States)

    Steinhauser, Matthew L.; Lechene, Claude P.

    2014-01-01

    Multi-isotope imaging mass spectrometry (MIMS) is the quantitative imaging of stable isotope labels in cells with a new type of secondary ion mass spectrometer (NanoSIMS). The power of the methodology is attributable to (i) the immense advantage of using non-toxic stable isotope labels, (ii) high resolution imaging that approaches the resolution of usual transmission electron microscopy and (iii) the precise quantification of label down to 1 part-per-million and spanning several orders of magnitude. Here we review the basic elements of MIMS and describe new applications of MIMS to the quantitative study of metabolic processes including protein and nucleic acid synthesis in model organisms ranging from microbes to humans. PMID:23660233

  4. Inventory of programs. Calculation of the isotope inventory after a hypothetical accident at the Cofrentes Nuclear power; Calculo del inventario isotopico despues de un hipotetico accidente en la Central Nuclear de Cofrentes

    Energy Technology Data Exchange (ETDEWEB)

    Albendea, M.

    2014-07-01

    Iberdrola is developing a new application to calculate the inventory of radiological material, then of a hypothetical accident, with the name of inventory. This application allows you to calculate the inventory isotopic, analysers and accurate thermal of all or part of the nucleus of the plant of Cofrentes, even of any single element, based on its history of irradiation and specific periods of decay, since the reactor at any time after the shutdown. (Author)

  5. Climate and isotopic tracers

    International Nuclear Information System (INIS)

    Jean-Baptiste, Ph.

    1997-01-01

    The applications of natural radioactivity and isotopic measurements in the sciences concerning Earth and its atmosphere, are numerous: carbon 14 dating with the Tandetron apparatus at the Cea, measurement of oxygen 18 in coral or sediment limestone for the determination of ocean temperature and salinity, carbon 14 dating of corals for the determination of sea level variations, deuterium content in polar ice-cap leads to temperature variations determination; isotopic measurements also enable the determination of present climate features such as global warming, oceanic general circulation

  6. Method to separate isotopes

    International Nuclear Information System (INIS)

    Coenen, H.; Neuschuetz, D.

    1980-01-01

    An extraction by means of supercritical pure gases (e.g. CD 2 ) or gas mixtures is proposed to separate isotopes, especially H/D, Li-6/Li-7, and U-235/U-238, and water or benzol is used as entrainer. The extraction shall be carried out at pressure rates of about 350 bar above the critical pressure with the temperature being by up to 100 0 C above the critical temperature. A NaCl-solution and the change of the isotopic ratio Cl-35/Cl-37 are investigated for example purpose. (UWI) [de

  7. Environmental isotope survey

    International Nuclear Information System (INIS)

    Jacovides, J.S.

    1979-03-01

    Work was initiated on the 1st of September 1971 with the objective of finding out how best to use environmental isotopes in the interpretation of the hydrology, particularly subsurface hydrology, of Cyprus through a sparse reconnaissance sampling of all the major aquifers and springs covering the whole island. The distribution of sampling was such that the survey in itself could assist in clarifying particular hydrogeologic problems, provide a better understanding of the water systems of the island, establish a general environmental isotope - framework of the hydrologic regimen of Cyprus as well as to provide the basis for specific, more detailed, studies to be undertaken subsequently

  8. Lectures in isotope geology

    International Nuclear Information System (INIS)

    Jaeger, E.; Hunziker, J.C.

    1979-01-01

    Designed for a introductory course in geochronology and the geochemistry of stable isotopes, this text has been written by recognized experts in the field. Emphasis is on the interpretation and on applications, and examples of these are offered along with each technique. Extraterrestrial applications have been avoided and the treatment of pure experimentation has been kept at a minimum. This text will be appreciated by geologists who want to learn more about methods used in isotope geology, how they can be applied, and how to gauge their usefulness. (orig.) [de

  9. High mass isotope separation arrangement

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1976-01-01

    An isotope separation arrangement for separating a preselected isotope from a mixture of chemically-identical but isotopically-different molecules by either photon-induced pure revibrational or vibronic selective excitation of the molecules containing the atoms of the isotope to be separated from a lower to a higher energy state, and a chemical reaction of the higher energy state molecules with a chemically-reactive agent to form a chemical compound containing primarily the atoms of the isotope to be separated in a physicochemical state different from the physicochemical state of the mixture of chemically-identical but isotopically-different molecules. The chemical compound containing the atoms of the isotope to be separated may be subsequently processed to obtain the isotope. The laser configuration used to generate the photon beam is fully described

  10. Isotope separation method and apparatus

    International Nuclear Information System (INIS)

    Lyon, R.K.; Eisner, P.N.; Thomas, W.R.L.

    1980-01-01

    A method and apparatus are specified for separating a mixture of isotopes present in a compound, preferably a gaseous compound, into two or more parts in each of which the abundances of the isotopes differ from the natural abundances of the isotopes in the compound. The invention particularly relates to carrying out a laser induced, isotopically selective conversion of gaseous molecules in such a manner as to achieve more than one stage of isotope separation along the length of the laser beam. As an example, the invention is applied to the separation of the isotopes of uranium in UF 6 , in which either the U-235 or U-238 isotope is selectively excited by means of irradiation from an infrared laser, and the selectively excited isotope converted into a product that can be recovered from UF 6 by one of a variety of methods that are described. (U.K.)

  11. Dynamic simulation of hydrogen isotope distillation unit

    International Nuclear Information System (INIS)

    Le Lann, J.M.; Latge, C.; Joulia, X.; Sere-Peyrigain, P.

    1995-01-01

    Dynamic simulation of hydrogen isotope distillation unit involved in the complex environment of a fusion power plant can be a powerful technique in view to analyze the tritium hazard potential. In this paper, issues related to the development of such a dynamic simulator with model formulation and the numerical treatment of the resulting Differential-Algebraic equation (DAE) system are properly adressed. The typical dynamic characteristics of such columns are quantitatively and qualitatively enlighted on case study with very large disturbances. The developed system has proven to be beneficial for understanding the dynamic behaviour and further for developing control schemes. (orig.)

  12. Dynamic simulation of hydrogen isotope distillation unit

    International Nuclear Information System (INIS)

    Le Lann, J.M.; Joulia, X.; Sere-Peyrigain, P.

    1994-01-01

    Dynamic simulation of hydrogen isotope distillation unit involved in the complex environment of a fusion power plant can be a powerful technique in view to analyze the tritium hazard potential. Issues related to the development of such a dynamic simulator with model formulation and the numerical treatment of the resulting Differential-Algebraic equation (DAE) system are properly addressed. The typical dynamic characteristics of such columns are quantitatively and qualitatively enlightened on case study with very large disturbances. The developed system has proven to be beneficial for understanding the dynamic behaviour and further for developing control schemes. (author) 12 refs.; 4 figs

  13. Techniques for preparing isotopic targets

    International Nuclear Information System (INIS)

    Xu Guoji; Guan Shouren; Luo Xinghua; Sun Shuhua

    1987-12-01

    The techniques of making isotopic targets for nuclear physics experiments are introduced. Vacuum evaporation, electroplating, centrifugal precipitation, rolling and focused heavy-ion beam sputtering used to prepare various isotopic targets at IAE are described. Reduction-distillation with active metals and electrolytic reduction for converting isotope oxides to metals are mentioned. The stripping processes of producing self-supporting isotopic targets are summarized. The store methods of metallic targets are given

  14. Stable isotope ratio measurements in hydrogen, nitrogen, and oxygen using Raman scattering

    International Nuclear Information System (INIS)

    Harney, R.C.; Bloom, S.D.; Milanovich, F.P.

    1975-01-01

    A method for measuring stable isotope ratios using laser Raman scattering was developed which may prove of significant utility and benefit in stable isotope tracer studies. Crude isotope ratio measurements obtained with a low-power laser indicate that with current technology it should be possible to construct an isotope ratio measurement system using laser Raman scattering that is capable of performing 0.1 percent accuracy isotope ratio measurements of 16 O/ 18 O in natural abundance oxygen gas or 14 N/ 15 N in natural abundance nitrogen gas in times less than two minutes per sample. Theory pertinent to the technique, designs of specific isotope ratio spectrometer systems, and data relating to isotope ratio measurements in hydrogen, nitrogen, and oxygen are presented. In addition, the current status of several studies utilizing this technique is discussed. (auth)

  15. Broadband non-selective excitation of plutonium isotopes for isotope ratio measurements in resonance ionization mass spectrometry: a theoretical study.

    Science.gov (United States)

    Sankari, M

    2012-10-15

    Making isotope ratio measurements with minimum isotope bias has always been a challenging task to mass spectrometrists, especially for the specific case of plutonium, owing to the strategic importance of the element. In order to use resonance ionization mass spectrometry (RIMS) as a tool for isotope ratio measurements, optimization of the various laser parameters and other atomic and system parameters is critical to minimize isotopic biases. Broadband simultaneous non-selective excitation of the isotopes of plutonium in the triple resonance excitation scheme with λ(1) = 420.77 nm, λ(2) = 847.28 nm, and λ(3) = 767.53 nm based on density matrix formalism has been theoretically computed for the determination of isotope ratios. The effects of the various laser parameters and other factors such as the atomization temperature and the dimensions of the atomic beam on the estimation of isotope ratios were studied. The effects of Doppler broadening, and time-dependent excitation parameters such as Rabi frequencies, ionization rate and the effect of non-Lorenztian lineshape have all been incorporated. The average laser powers and bandwidths for the three-excitation steps were evaluated for non-selective excitation. The laser intensity required to saturate the three-excitation steps were studied. The two-dimensional lineshape contour and its features were investigated, while the reversal of peak asymmetry of two-step and two-photon excitation peaks under these conditions is discussed. Optimized powers for the non-selective ionization of the three transitions were calculated as 545 mW, 150 mW and 545 mW and the laser bandwidth for all the three steps was ~20 GHz. The isotopic bias between the resonant and off-resonant isotope under the optimized conditions was no more than 9%, which is better than an earlier reported value. These optimized laser power and bandwidth conditions are better than in the earlier experimental work since these comprehensive calculations yield

  16. Isotope separation using tunable lasers

    International Nuclear Information System (INIS)

    Snavely, B.B.

    1975-01-01

    Various processes for laser isotope separation based upon the use of the spectroscopic isotope effect in atomic and molecular vapors are discussed. Emphasis is placed upon processes which are suitable for uranium enrichment. A demonstration process for the separation of uranium isotopes using selective photoionization is described. (U.S.)

  17. Isotope effects on nuclear shielding

    International Nuclear Information System (INIS)

    Hansen, P.E.

    1983-01-01

    This review concentrates upon empirical trends and practical uses of mostly secondary isotope effects, both of the intrinsic and equilibrium types. The text and the tables are arranged in the following fashion. The most 'popular' isotope effect is treated first, deuterium isotope effects on 13 C nuclear shielding, followed by deuterium on 1 H nuclear shieldings, etc. Focus is thus on the isotopes producing the effect rather than on the nuclei suffering the effect. After a brief treatment of each type of isotope effect, general trends are dealt with. Basic trends of intrinsic isotope effects such as additivity, solvent effects, temperature effects, steric effects, substituent effects and hyperconjugation are discussed. Uses of isotope effects for assignment purposes, in stereochemical studies, in hydrogen bonding and in isotopic tracer studies are dealt with. Kinetic studies, especially of phosphates, are frequently performed by utilizing isotope effects. In addition, equilibrium isotope effects are treated in great detail as these are felt to be new and very important and may lead to new uses of isotope effects. Techniques used to obtain isotope effects are briefly surveyed at the end of the chapter. (author)

  18. Isotope shifting capacity of rock

    International Nuclear Information System (INIS)

    Blattner, P.; Department of Scientific and Industrial Research, Lower Hutt

    1980-01-01

    Any oxygen isotope shifted rock volume exactly defines a past throughput of water. An expression is derived that relates the throughput of an open system to the isotope shift of reservoir rock and present-day output. The small isotope shift of Ngawha reservoir rock and the small, high delta oxygen-18 output are best accounted for by a magmatic water source

  19. Uranium Isotopic Analysis with the FRAM Isotopic Analysis Code

    International Nuclear Information System (INIS)

    Vo, D.T.; Sampson, T.E.

    1999-01-01

    FRAM is the acronym for Fixed-Energy Response-Function Analysis with Multiple efficiency. This software was developed at Los Alamos National Laboratory originally for plutonium isotopic analysis. Later, it was adapted for uranium isotopic analysis in addition to plutonium. It is a code based on a self-calibration using several gamma-ray peaks for determining the isotopic ratios. The versatile-parameter database structure governs all facets of the data analysis. User editing of the parameter sets allows great flexibility in handling data with different isotopic distributions, interfering isotopes, and different acquisition parameters such as energy calibration and detector type

  20. Isotopes in aquaculture research

    International Nuclear Information System (INIS)

    Ayyappan, S.; Dash, B.; Ghosh, A.S.

    1996-01-01

    The applications of isotopes in aquaculture research include areas like aquatic production process, nutrient cycles and food chain dynamics, fish nutrition, fish physiology, genetics and immunology. The radioisotopes commonly used are beta emitters. The use of different radioisotopes in aquaculture research are presented. 2 tabs

  1. Process for isotope separation

    International Nuclear Information System (INIS)

    Schuster, E.; Kersting, A.; Gebauhr, W.

    1980-01-01

    Isotope separation in UF 6 gas takes place on the principle of selective excitation by laser irradiation and separation by chemical conversion with a partner in a reaction. Atomic H, N or O or the CH 3 or CHO radicals are suitable partners in the reaction. The recombination takes place by catalytic acceleration on leaving the reaction area. (DG) [de

  2. SHELL ISOTOPE GEOCHEMISTRY

    African Journals Online (AJOL)

    ABSTRACT: The land snail Limicolaria kambeul chudeaui Germain was collected ... Key words/phrases: Ethiopia, isotope geochemistry, Lake Tilo, Limicolaria .... 1984), (c) 6'80 values of precipitation at Addis Ababa, with i 1 S.D. bars for the .... (breakfast cereal), deionised water and cuttlefish bone, the carbon and oxygen.

  3. Isotope separation process

    International Nuclear Information System (INIS)

    Cox, D.M.; Maas, E.T.

    1982-01-01

    Processes are disclosed for the separation of isotopes of an element comprising vaporizing uranyl compounds having the formula (UO2a2)n, where a is a monovalent anion and n in an integer from 2 to 4, the compounds having an isotopically shifted infrared absorption spectrum associated with uranyl ions containing said element which is to be separated, and then irradiating the uranyl compound with infrared radiation which is preferentially absorbed by a molecular vibration of uranyl ions of the compound containing a predetermined isotope of that element so that excited molecules of the compound are provided which are enriched in the molecules of the compound containing that predetermined isotope, thus enabling separation of these excited molecules. The processes disclosed include separation of the excited molecules by irradiating under conditions such that the excited molecules dissociate, and also separating the excited molecules by a discrete separation step. The latter includes irradiating the excited molecules by a second infrared laser in order to convert the excited molecules into a separable product, or also by chemically converting the excited molecules, preferably by reaction with a gaseous reactant

  4. Isotopic effect giant resonances

    International Nuclear Information System (INIS)

    Buenerd, M.; Lebrun, D.; Martin, P.; Perrin, G.; Saintignon, P. de; Chauvin, J.; Duhamel, G.

    1981-10-01

    The systematics of the excitation energy of the giant dipole, monopole, and quadrupole resonances are shown to exhibit an isotopic effect. For a given element, the excitation energy of the transition decreases faster with the increasing neutron number than the empirical laws fitting the overall data. This effect is discussed in terms of the available models

  5. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  6. Isotopes and atomic weights

    International Nuclear Information System (INIS)

    Zhang Qinglian

    1990-01-01

    A review of the chemical and mass spectrometric methods of determining the atomic weights of elements is presented. A, special discussion is devoted to the calibration of the mass spectrometer with highly enriched isotopes. It is illustrated by the recent work on europium. How to choose the candidate element for new atomic weight determination forms the last section of the article

  7. Application of the isotopic index in isotope geochemical investigation

    International Nuclear Information System (INIS)

    Schuetze, H.

    1982-06-01

    A method is described which allows to calculate approximately isotope exchange equilibria between different crystalline silicates. The algorithm uses a newly introduced isotopic index. It is defined using isotopic increments of the variant types of silicatic bonds. This isotopic index gives a quantitative measure of the ability to enrich 18 O or 30 Si, respectively. The dependence of isotopic fractionations on temperature can be calculated approximately by means of the isotopic index, too. On this theoretical base some problems of magmatism and two varieties of an isotope geochemical model of the evolution of the Earth's crust are treated. Finally, the possibility is demonstrated to give prognostic statements about the likelihood of ore bearing of different granites. (author)

  8. Comparison of three gamma ray isotopic determination codes: FRAM, MGA, and TRIFID

    International Nuclear Information System (INIS)

    Cremers, T.L.; Malcom, J.E.; Bonner, C.A.

    1994-01-01

    The determination of the isotopic distribution of plutonium and the americium concentration is required for the assay of nuclear material by calorimetry or neutron coincidence counting. The isotopic information is used in calorimetric assay to compute the effective specific power from the measured isotopic fractions and the known specific power of each isotope. The effective specific power is combined with the heat measurement to obtain the mass of plutonium in the assayed nuclear material. The response of neutron coincidence counters is determined by the 240 Pu isotopic fraction with contributions from the other even plutonium isotopes. The effect of the 240 Pu isotopic fraction and the other neutron contributing isotopes are combined as 240 Pu effective. This is used to calculate the mass of nuclear material from the neutron counting data in a manner analogous to the effective specific power in calorimeter. Comparisons of the precision and accuracy of calorimetric assay and neutron coincidence counting often focus only on the precision and accuracy of the heat measurement (calorimetry) compared to the precision and accuracy of the neutron coincidence counting statistics. The major source of uncertainty for both calorimetric assay and neutron coincidence counting often lies in the determination of the plutonium isotopic distribution ad determined by gamma ray spectroscopy. Thus, the selection of the appropriate isotopic distribution code is of paramount importance to good calorimetric assay and neutron coincidence counting. Three gamma ray isotopic distribution codes, FRAM, MGA, and TRIFID have been compared at the Los Alamos Plutonium Facility under carefully controlled conditions of similar count rates, count times, and 240 Pu isotopic fraction

  9. Isotopic separation by ion chromatography

    International Nuclear Information System (INIS)

    Albert, M.G.; Barre, Y.; Neige, R.

    1994-01-01

    The isotopic exchange reaction and the isotopic separation factor are first recalled; the principles of ion chromatography applied to lithium isotope separation are then reviewed (displacement chromatography) and the process is modelled in the view of dimensioning and optimizing the industrial process; the various dimensioning parameters are the isotopic separation factor, the isotopic exchange kinetics and the material flow rate. Effects of the resin type and structure are presented. Dimensioning is also affected by physico-chemical and hydraulic parameters. Industrial implementation features are also discussed. 1 fig., 1 tab., 5 refs

  10. Physics with isotopically controlled semiconductors

    International Nuclear Information System (INIS)

    Haller, E.E.

    1994-08-01

    Control of the isotopic composition of semiconductors offers a wide range of new scientific opportunities. In this paper a number of recent results obtained with isotopically pure as well as deliberately mixed diamond and Ge bulk single crystals and Ge isotope superlattices will be reviewed. Isotopic composition affects several properties such as phonon energies, bandstructure and lattice constant in subtle but theoretically well understood ways. Large effects are observed for thermal conductivity, local vibrational modes of impurities and after neutron transmutation doping (NTD). Several experiments which could profit greatly from isotope control are proposed

  11. Low energy methods of molecular laser isotope separation

    International Nuclear Information System (INIS)

    Makarov, G N

    2015-01-01

    Of the many proposals to date for laser-assisted isotope separation methods, isotope-selective infrared (IR) multiphoton dissociation (MPD) of molecules has been the most fully developed. This concept served as the basis for the development and operation of the carbon isotope separation facility in Kaliningrad, Russia. The extension of this method to heavy elements, including uranium, is hindered by, among other factors, the high power consumption and the lack of high-efficiency high-power laser systems. In this connection, research and development covering low energy methods for the laser separation of isotopes (including those of heavy atoms) is currently in high demand. This paper reviews approaches to the realization of IR-laser-induced isotope-selective processes, some of which are potentially the basis on which low-energy methods for molecular laser isotope separation can be developed. The basic physics and chemistry, application potential, and strengths and weaknesses of these approaches are discussed. Potentially promising alternatives to the title methods are examined. (reviews of topical problems)

  12. Stable isotope measurement techniques for atmospheric greenhouse gases

    International Nuclear Information System (INIS)

    2002-01-01

    The technical requirements to perform useful measurements of atmospheric greenhouse gas concentrations and of their isotope ratios are of direct relevance for all laboratories engaged in this field. A meaningful interpretation of isotopes in global models on sources and sinks of CO 2 and other greenhouse gases depends on strict laboratory protocols and data quality control measures ensuring comparable data in time and space. Only with this precondition met, the isotope techniques can serve as a potentially powerful method for reducing uncertainties in the global CO 2 budgets and for tracing pathways and interaction of terrestrial, oceanic, and atmospheric pools of carbon. This publication provides four contributions describing methods for the determination of the isotopic composition of trace gases in atmospheric air and in ice cores. These contributions have been indexed separately

  13. Room temperature Sieving of Hydrogen Isotopes Using 2-D Materials

    Energy Technology Data Exchange (ETDEWEB)

    Hitchcock, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Colon-Mercado, H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Krentz, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Serkiz, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Velten, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Xiao, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-09-28

    Hydrogen isotope separation is critical to the DOE’s mission in environmental remediation and nuclear nonproliferation. Isotope separation is also a critical technology for the NNSA, and the ability to perform the separations at room temperature with a relatively small amount of power and space would be a major advancement for their respective missions. Recent work has shown that 2-D materials such as graphene and hexagonal boron nitride can act as an isotopic sieve at room temperature; efficiently separating hydrogen isotopes in water with reported separation ratios of 10:1 for hydrogen: deuterium separation for a single pass. The work performed here suggests that this technique has merit, and furthermore, we are investigating optimization and scale up of the required 2-D material based membranes.

  14. Isotopic and chemical characterization of coal in Pakistan

    International Nuclear Information System (INIS)

    Qureshi, R.M.; Hasany, S.M.; Javed, T.; Sajjad, M.I.; Shah, Z.; Rehman, H.

    1993-11-01

    Stable carbon isotope ratios (delta/sup 13/C PDB) and toxic/trace element concentration levels are determined for Tertiary coal samples collected from seven coal fields in Pakistan. No systematic isotope effects are found in the process of coal liquefaction from peat to Tertiary lignites and sub bituminous coal. Similarly, no age effects are observed during the Tertiary regime. The observed variations in the carbon isotopic composition of coal obtained from 'Sharigh coal field' and the 'Sor-Range/Degari coal field' in Baluchistan are attributed to the depositional environments. More sampling of stable carbon isotope analysis are required to validate these observations. Significant concentrations of toxic elements such as S, Cr, Cd and Pb in Makarwal coal may pose environmental and engineering/operational problems for thermal power plants. (author)

  15. What can Fe stable isotopes tell us about magmas?

    DEFF Research Database (Denmark)

    Stausberg, Niklas

    the differentiation of magmas from the perspective of Fe stable isotopes, integrated with petrology, by studying igneous rocks and their constituent phases (minerals and glasses) from the Bushveld Complex, South Africa, Thingmuli, Iceland, Pantelleria, Italy, and the Bishop Tuff, USA. The findings are interpreted......The majority of the Earth’s crust is formed by magmas, and understanding their production and differentiation is important to interpret the geologic rock record. A powerful tool to investigate magmatic processes is the distribution of the stable isotopes of the major redox-sensitive element...... in magmas, Fe. Fe isotope compositions of magmatic rocks exhibit systematic differences, where the heaviest compositions are found in rhyolites and granites. Understanding of these systematics is complicated by a lack of constraints on Fe isotope fractionation among minerals and liquids under magmatic...

  16. Separation and preparation of "6"2Ni isotope

    International Nuclear Information System (INIS)

    Ren Xiuyan; Mi Yajing; Zeng Ziqiang; Li Gongliang; Tu Rui

    2014-01-01

    Micro nuclear battery is the perfect power of space craft equipment. "6"3Ni is the core operation material of the "6"3Ni battery. It can produce radioisotope "6"3Ni while high abundance "6"2Ni is irradiated in the reactor. In order to meet the requirements of the abundance and the purity, research of the separation for "6"2Ni isotope was developed. The magnetic field and beam transmission status were simulated. The improvement designs of the ion source and the collector pocket were carried out. The process flow of high abundance "6"2Ni using electromagnetic separation method was established. The experiment of "6"2Ni isotope was developed by using electromagnetism isotope separator. The results show that the enrichment of "6"2Ni isotope is more than 90%. (authors)

  17. Isotopic composition of fission gases in LWR fuel

    International Nuclear Information System (INIS)

    Jonsson, T.

    2000-01-01

    Many fuel rods from power reactors and test reactors have been punctured during past years for determination of fission gas release. In many cases the released gas was also analysed by mass spectrometry. The isotopic composition shows systematic variations between different rods, which are much larger than the uncertainties in the analysis. This paper discusses some possibilities and problems with use of the isotopic composition to decide from which part of the fuel the gas was released. In high burnup fuel from thermal reactors loaded with uranium fuel a significant part of the fissions occur in plutonium isotopes. The ratio Xe/Kr generated in the fuel is strongly dependent on the fissioning species. In addition, the isotopic composition of Kr and Xe shows a well detectable difference between fissions in different fissile nuclides. (author)

  18. Dictionary of nuclear power

    International Nuclear Information System (INIS)

    Koelzer, W.

    2012-06-01

    The actualized version (June 2012) of the dictionary on nuclear power includes all actualizations and new inputs since the last version of 2001. The original publication dates from 1980. The dictionary includes definitions, terms, measuring units and helpful information on the actual knowledge concerning nuclear power, nuclear fuel cycle, nuclear facilities, radioactive waste management, nuclear physics, reactor physics, isotope production, biological radiation effects, and radiation protection.

  19. Direct mass measurements of neutron-deficient xenon isotopes with the ISOLTRAP mass spectrometer

    International Nuclear Information System (INIS)

    Dilling, J.; Audi, G.; Beck, D.; Bollen, G.; Henry, S.; Herfurth, F.; Kellerbauer, A.; Kluge, H.-J.; Lunney, D.; Moore, R.B.; Scheidenberger, C.; Schwarz, S.; Sikler, G.; Szerypo, J.

    2002-01-01

    The masses of Xe isotopes with 124≥A≥114 have been measured using the ISOLTRAP spectrometer at the on-line mass separator ISOLDE/CERN. A mass resolving power of 500 000 was chosen resulting in an accuracy of δm∼12 keV for all isotopes investigated. Conflicts with existing mass data of several standard deviations were found

  20. Determination of lead isotopes in Arctic and Antarctic snow and ice

    International Nuclear Information System (INIS)

    Rosman, K.J.R.; Chisholm, W.

    1994-01-01

    The development of high sensitivity mass spectrometry to measure Pb isotopes in Arctic and Antarctic snow and ice has provided a powerful tool for identifying sources of global Pb pollution. The combination of isotope abundance information with concentration measurements adds another dimension to analytical chemistry. (authors). 11 refs., 4 figs

  1. Decontamination of radioactive isotopes

    International Nuclear Information System (INIS)

    Despotovic, R.; Music, S.; Subotic, B.; Wolf, R.H.H.

    1979-01-01

    Removal of radioactive isotopes under controlled conditions is determined by a number of physical and chemical properties considered radiocontaminating and by the characteristics of the contaminated object. Determination of quantitative and qualitative factors for equilibrium in a contamination-decontamination system provides the basis for rational and successful decontamination. The decontamination of various ''solid/liquid'' systems is interesting from the scientific and technological point of view. These systems are of great importance in radiation protection (decontamination of various surfaces, liquids, drinking water, fixation or collection of radiocontaminants). Different types of decontamination systems are discussed. The dependence of rate and efficiency of the preparation conditions and on the ageing of the scavenger is described. The influence of coagulating electrolyte on radioactive isotope fixation efficiency was also determined. The fixation of fission radionuclide on oxide scavengers has been studied. The connection between fundamental investigations and practical decontamination of the ''solid/liquid'' systems is discussed. (author)

  2. Cyclotrons for isotope production

    International Nuclear Information System (INIS)

    Milton, B.F.; Stevenson, N.R.

    1995-06-01

    Cyclotrons continue to be efficient accelerators for radioisotope production. In recent years, developments in the accelerator technology have greatly increased the practical beam current in these machines while also improving the overall system reliability. These developments combined with the development of new isotopes for medicine and industry, and a retiring of older machines indicates a strong future for commercial cyclotrons. In this paper we will survey recent developments in the areas of cyclotron technology, and isotope production, as they relate to the new generation of commercial cyclotrons. We will also discuss the possibility of systems capable of extracted energies up to 100 MeV and extracted beam currents of up to 2.0 mA. (author). 6 refs., 2 tabs., 3 figs

  3. Rechargeable radioactive isotope generator

    International Nuclear Information System (INIS)

    Thornton, A.K.; Cerone, F.E.

    1978-01-01

    The description is given of a rechargeable radioactive isotope generator having the following features: a box containing a transport shield, a shielded generator including elements for the absorption and holding of the parent isotope, an eluant tank, a first pipe causing this tank to communicate with the transport shield, a second pipe causing this transport shield to communicate with the shielded generator and a third pipe placing the shielded generator in communication with the outside of the unit. It also includes a shelf across the external front part of the unit a part of which is shielded by external components, a shielded elution flask in which the eluate is poured and a filter set at a point between the flask and the third pipe [fr

  4. Equipment for isotope diagnostics

    International Nuclear Information System (INIS)

    Platz, W.

    1976-01-01

    The invention concerns an improvement of equipment for isotope diagnostics allowing to mark special intensity ranges of the recorded measurements by means of different colors. For undisturbed operation it is of advantage to avoid electric circuits between movable and unmovable parts of the color recorder. According to the invention, long gear wheels of glass fiber-reinforced polyamide are used for these connections. (ORU) [de

  5. Stable isotope analysis

    International Nuclear Information System (INIS)

    Tibari, Elghali; Taous, Fouad; Marah, Hamid

    2014-01-01

    This report presents results related to stable isotopes analysis carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 127 samples. These results demonstrate that Oxygen-18 and Deuterium in water analysis were performed by infrared Laser spectroscopy using a LGR / DLT-100 with Autosampler. Also, the results are expressed in δ values (‰) relative to V-SMOW to ± 0.3 ‰ for oxygen-18 and ± 1 ‰ for deuterium.

  6. Stable-isotope studies

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Structures of bacteriochlorophyll b and the Krasnovskii photoreduction products of chlorophyll a are given. All 55 13 C and 4 15 N NMR transitions in chlorophyl a and its magnesium-free derivative pheophytin a were assigned. ESR of triplet states of chlorophylls a, b, c/sub z/, and c 2 and bacteriochlorophyll a are reported. Experiments in the cultivation of 13 C-enriched morning glory plants indicated that the isotope enrichment can produce observable morphological changes. (U.S.)

  7. Protected isotope heat source

    International Nuclear Information System (INIS)

    Burns, R.K.; Shure, L.I.; Katzen, E.D.

    1975-01-01

    A radioactive isotope capsule is disposed in a container (heat shield) which will have a single stable trim attitude when reentering the earth's atmosphere and while falling to earth. The center of gravity of the heat source is located forward of the midpoint between the front face and the rear face of the container. The capsule is insulated from the front face of the container but not from the rear surface of the container. (auth)

  8. Isotopes and agriculture

    International Nuclear Information System (INIS)

    Malavolta, E.

    1988-01-01

    The agriculture is defined as the art of desturbing the ecosystems in economical terms with the minimum of irreversible damage. Man survival in the biosphere will depend on its ability of using four technologies - mechanization, fertilizers, irrigation and pest disease control. The isotopes are usefull to establish means of producing more food and to preserve it; and clains of unbearable damages to the ecosystems caused by fertilizers and pesticides are not true, are presented. (author) [pt

  9. The isotope correlation experiment

    International Nuclear Information System (INIS)

    Koch, L.; Schoof, S.

    1983-01-01

    The ESARDA working group on Isotopic Correlation Techniques, ICT and Reprocessing Input Analysis performed an Isotope Correlation Experiment, ICE with the aim to check the feasibility of the new technique. Ten input batches of the reprocessing of the KWO fuel at the WAK plant were analysed by 4 laboratories. All information to compare ICT with the gravimetric and volumetric methods was available. ICT combined with simplified reactor physics calculation was included. The main objectives of the statistical data evaluation were detection of outliers, the estimation of random errors and of systematic errors of the measurements performed by the 4 laboratories. Different methods for outlier detection, analysis of variances, Grubbs' analysis for the constant-bias model and Jaech's non-constant-bias model were applied. Some of the results of the statistical analysis may seem inconsistent which is due to the following reasons. For the statistical evaluations isotope abundance data (weight percent) as well as nuclear concentration data (atoms/initial metal atoms) were subjected to different outlier criteria before being used for further statistical evaluations. None of the four data evaluation groups performed a complete statistical data analysis which would render possible a comparison of the different methods applied since no commonly agreed statistical evaluation procedure existed. The results prove that ICT is as accurate as conventional techniques which have to rely on costly mass spectrometric isotope dilution analysis. The potential of outlier detection by ICT on the basis of the results from a single laboratory is as good as outlier detection by costly interlaboratory comparison. The application of fission product or Cm-244 correlations would be more timely than remeasurements at safeguards laboratories

  10. Isotopic safeguards statistics

    International Nuclear Information System (INIS)

    Timmerman, C.L.; Stewart, K.B.

    1978-06-01

    The methods and results of our statistical analysis of isotopic data using isotopic safeguards techniques are illustrated using example data from the Yankee Rowe reactor. The statistical methods used in this analysis are the paired comparison and the regression analyses. A paired comparison results when a sample from a batch is analyzed by two different laboratories. Paired comparison techniques can be used with regression analysis to detect and identify outlier batches. The second analysis tool, linear regression, involves comparing various regression approaches. These approaches use two basic types of models: the intercept model (y = α + βx) and the initial point model [y - y 0 = β(x - x 0 )]. The intercept model fits strictly the exposure or burnup values of isotopic functions, while the initial point model utilizes the exposure values plus the initial or fabricator's data values in the regression analysis. Two fitting methods are applied to each of these models. These methods are: (1) the usual least squares fitting approach where x is measured without error, and (2) Deming's approach which uses the variance estimates obtained from the paired comparison results and considers x and y are both measured with error. The Yankee Rowe data were first measured by Nuclear Fuel Services (NFS) and remeasured by Nuclear Audit and Testing Company (NATCO). The ratio of Pu/U versus 235 D (in which 235 D is the amount of depleted 235 U expressed in weight percent) using actual numbers is the isotopic function illustrated. Statistical results using the Yankee Rowe data indicates the attractiveness of Deming's regression model over the usual approach by simple comparison of the given regression variances with the random variance from the paired comparison results

  11. Dual isotope assays

    International Nuclear Information System (INIS)

    Smith, G.F.W.; Stevens, R.A.J.; Jacoby, B.

    1980-01-01

    Dual isotope assays for thyroid function are performed by carrying out a radio-immunoassay for two of thyroxine (T4), tri-iodothyronine (T3), thyroid stimulating hormone (TSH), and thyroxine binding globulin (TBG), by a method wherein a version of one of the thyroid components, preferably T4 or T3 is labelled with Selenium-75 and the version of the other thyroid component is labelled with a different radionuclide, preferably Iodine-125. (author)

  12. Finite mixture models for the computation of isotope ratios in mixed isotopic samples

    Science.gov (United States)

    Koffler, Daniel; Laaha, Gregor; Leisch, Friedrich; Kappel, Stefanie; Prohaska, Thomas

    2013-04-01

    Finite mixture models have been used for more than 100 years, but have seen a real boost in popularity over the last two decades due to the tremendous increase in available computing power. The areas of application of mixture models range from biology and medicine to physics, economics and marketing. These models can be applied to data where observations originate from various groups and where group affiliations are not known, as is the case for multiple isotope ratios present in mixed isotopic samples. Recently, the potential of finite mixture models for the computation of 235U/238U isotope ratios from transient signals measured in individual (sub-)µm-sized particles by laser ablation - multi-collector - inductively coupled plasma mass spectrometry (LA-MC-ICPMS) was demonstrated by Kappel et al. [1]. The particles, which were deposited on the same substrate, were certified with respect to their isotopic compositions. Here, we focus on the statistical model and its application to isotope data in ecogeochemistry. Commonly applied evaluation approaches for mixed isotopic samples are time-consuming and are dependent on the judgement of the analyst. Thus, isotopic compositions may be overlooked due to the presence of more dominant constituents. Evaluation using finite mixture models can be accomplished unsupervised and automatically. The models try to fit several linear models (regression lines) to subgroups of data taking the respective slope as estimation for the isotope ratio. The finite mixture models are parameterised by: • The number of different ratios. • Number of points belonging to each ratio-group. • The ratios (i.e. slopes) of each group. Fitting of the parameters is done by maximising the log-likelihood function using an iterative expectation-maximisation (EM) algorithm. In each iteration step, groups of size smaller than a control parameter are dropped; thereby the number of different ratios is determined. The analyst only influences some control

  13. Electrochemically controlled iron isotope fractionation

    Science.gov (United States)

    Black, Jay R.; Young, Edward D.; Kavner, Abby

    2010-02-01

    Variations in the stable isotope abundances of transition metals have been observed in the geologic record and trying to understand and reconstruct the physical/environmental conditions that produced these signatures is an area of active research. It is clear that changes in oxidation state lead to large fractionations of the stable isotopes of many transition metals such as iron, suggesting that transition metal stable isotope signatures could be used as a paleo-redox proxy. However, the factors contributing to these observed stable isotope variations are poorly understood. Here we investigate how the kinetics of iron redox electrochemistry generates isotope fractionation. Through a combination of electrodeposition experiments and modeling of electrochemical processes including mass-transport, we show that electron transfer reactions are the cause of a large isotope separation, while mass transport-limited supply of reactant to the electrode attenuates the observed isotopic fractionation. Furthermore, the stable isotope composition of electroplated transition metals can be tuned in the laboratory by controlling parameters such as solution chemistry, reaction overpotential, and solution convection. These methods are potentially useful for generating isotopically-marked metal surfaces for tracking and forensic purposes. In addition, our studies will help interpret stable isotope data in terms of identifying underlying electron transfer processes in laboratory and natural samples.

  14. Soil organic matter (SOM) dynamics determined by stable isotope techniques

    International Nuclear Information System (INIS)

    Gerzabek, M. H.

    1998-09-01

    Being aware of limitations and possible bias the 13 C natural abundance technique using the different 13 C enrichments in plants with differing photosynthetic pathways in a powerful tool to quantify turnover processes, both in long-term field studies and short-term laboratory experiments. Special care is needed in choosing reference plots and the proper number of replicate samples. The combination of 13 C and 14 C measurements has a high potential for a further improvement of isotope techniques in SOM studies. Natural abundance of 15 N is less powerful with respect to quantification of SOM processes than the isotope dilution technique. However its usefulness could be distinctly improved by introducing other stable isotopes into the studies.(author)

  15. Improvements in RIMS Isotopic Precision: Application to in situ atom-limited analyses

    International Nuclear Information System (INIS)

    Levine, J.; Stephan, T.; Savina, M.; Pellin, M.

    2009-01-01

    Resonance ionization mass spectrometry offers high sensitivity and elemental selectivity in microanalysis, but the isotopic precision attainable by this technique has been limited. Here we report instrumental modifications to improve the precision of RIMS isotope ratio measurements. Special attention must be paid to eliminating pulse-to-pulse variations in the time-of-flight mass spectrometer through which the photoions travel, and resonant excitation schemes must be chosen such that the resonance transitions can substantially power-broadened to cover the isotope shifts. We report resonance ionization measurements of chromium isotope ratios with statistics-limited precision better than 1%.

  16. Selenide isotope generator for the Galileo mission

    International Nuclear Information System (INIS)

    Goebel, C.J.; Hammel, T.E.

    1978-01-01

    A significantly improved thermoelectric generator has been developed to provide electric power for NASA's Galileo Mission in 1982. Nominal power requirements for Galileo will be about 450 watts at BOL (Beginning of Life), and this will be furnished by two Selenide Isotope Generators (SIG) each powered by a Multi Hundred Watt (MHW) radioisotopic heat source. A Ground Demonstration System (GDS) of a nominal 100 w(e) features a 3M - produced selenide ring module around a shortened MHW-dimensioned electrical heat source, newly developed axially-grooved heat pipes on a disc-shaped radiator, and other innovations which will allow a full-sized generator's weight to be held at about 90 lbs

  17. Isotope effects on chemical equilibria

    International Nuclear Information System (INIS)

    Golding, P.D.

    1974-01-01

    The thermodynamic equilibrium constants of three deuterated substituted acetic acids are reported. The calculation of secondary isotope effects of the second kind for the three isotopic acid pairs has been accomplished by the appropriate comparison of thermodynamic equilibrium constants, and by the comparison of isotopic slopes. The effect of substituent variation on the isotope effects reported here disqualifies the simple inductive model as a legitimate description of secondary isotope effects of the second kind. The correlation of diminishing isotope effect per deuterium atom with increasing acidity is also invalidated by the present results. The syntheses of 9-thia-9,10-dihydrophenanthrene-9-oxide and thioxanthene-10-oxide are described. These compounds have been partially deuterated at their respective methylene positions. Spectral evidence indicates stereoselectivity of the methylene protons in the exchange reactions of both compounds. (author)

  18. Therapeutic use of radioactive isotopes

    CERN Document Server

    Caroline Duc

    2013-01-01

    In December, researchers from ISOLDE-CERN, the Paul Scherrer Institute (PSI) and the Institut Laue-Langevin (ILL) published the results of an in vivo study which successfully proved the effectiveness of four terbium isotopes for diagnosing and treating cancerous tumours.   Four terbium isotopes suitable for clinical purposes. “ISOLDE is the only installation capable of supplying terbium isotopes of such purity and intensity in the case of three out of the four types used in this study,” explains Karl Johnson, a physicist at ISOLDE.  “Producing over a thousand different isotopes, our equipment offers the widest choice of isotopes in the world!” Initially intended for fundamental physics research, ISOLDE has diversified its activities over time to invest in various projects in the materials science, biochemistry and nuclear medicine fields. The proof-of-concept study has confirmed that the four terbium isotopes 149Tb, 152Tb, 155Tb produ...

  19. Dual isotope notch observer for isotope identification, assay and imaging with mono-energetic gamma-ray sources

    Science.gov (United States)

    Barty, Christopher P.J.

    2013-02-05

    A dual isotope notch observer for isotope identification, assay and imaging with mono-energetic gamma-ray sources includes a detector arrangement consists of three detectors downstream from the object under observation. The latter detector, which operates as a beam monitor, is an integrating detector that monitors the total beam power arriving at its surface. The first detector and the middle detector each include an integrating detector surrounding a foil. The foils of these two detectors are made of the same atomic material, but each foil is a different isotope, e.g., the first foil may comprise U235 and second foil may comprise U238. The integrating detectors surrounding these pieces of foil measure the total power scattered from the foil and can be similar in composition to the final beam monitor. Non-resonant photons will, after calibration, scatter equally from both foils.

  20. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1984-03-01

    This report contains a listing of electromagnetically separated stable isotopes which are available at the Oak Ridge National Laboratory for distribution for nondestructive research use on a loan basis. This inventory includes all samples of stable isotopes in the Research Materials Collection and does not designate whether a sample is out on loan or is in reprocessing. For some of the high abundance naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56

  1. French days on stable isotopes

    International Nuclear Information System (INIS)

    2000-01-01

    These first French days on stable isotopes took place in parallel with the 1. French days of environmental chemistry. Both conferences had common plenary sessions. The conference covers all aspects of the use of stable isotopes in the following domains: medicine, biology, environment, tracer techniques, agronomy, food industry, geology, petroleum geochemistry, cosmo-geochemistry, archaeology, bio-geochemistry, hydrology, climatology, nuclear and particle physics, astrophysics, isotope separations etc.. Abstracts available on CD-Rom only. (J.S.)

  2. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1982-01-01

    This report contains a listing of electromagnetically separated stable isotopes which are available for distribution within the United States for nondestructive research use from the Oak Ridge National Laboratory on a loan basis. This inventory includes all samples of stable isotopes in the Material Research Collection and does not designate whether a sample is out on loan or in reprocessing. For some of the high abundance naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56

  3. Innovative lasers for uranium isotope separation

    International Nuclear Information System (INIS)

    Brake, M.L.; Gilgenbach, R.M.

    1993-07-01

    Copper vapor laser have important applications to uranium atomic vapor laser isotope separation (AVLIS). We have investigated two innovative methods of exciting/pumping copper vapor lasers which have the potential to improve the efficiency and scaling of large laser systems used in uranium isotope separation. Experimental research has focused on the laser discharge kinetics of (1) microwave, and (2) electron beam excitation/pumping of large-volume copper vapor lasers. Microwave resonant cavity produced copper vapor plasmas at 2.45 GHz, have been investigated in three separate experimental configurations. The first examined the application of CW (0-500W) power and was found to be an excellent method for producing an atomic copper vapor from copper chloride. The second used a pulsed (5kW, 0.5--5 kHz) signal superimposed on the CW signal to attempt to produce vaporization, dissociation and excitation to the laser states. Enhanced emission of the optical radiation was observed but power densities were found to be too low to achieve lasing. In a third experiment we attempted to increase the applied power by using a high power magnetron to produce 100 kW of pulsed power. Unfortunately, difficulties with the magnetron power supply were encountered leaving inconclusive results. Detailed modeling of the electromagnetics of the system were found to match the diagnostics results well. An electron beam pumped copper vapor system (350 kV, 1.0 kA, 300 ns) was investigated in three separate copper chloride heating systems, external chamber, externally heated chamber and an internally heated chamber. Since atomic copper spectral lines were not observed, it is assumed that a single pulse accelerator is not capable of both dissociating the copper chloride and exciting atomic copper and a repetitively pulsed electron beam generator is needed

  4. Chemical separation of boron isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Palko, A.A.

    1978-06-01

    This is the final report of the research performed at ORNL on the chemical fractionation of boron isotopes between BF/sub 3/ gas and the liquid molecular addition compounds of BF/sub 3/. Thirty compounds were studied, ten of them in detail. Graphs and equations are given for variation of isotopic equilibrium constant, vapor pressure, and BF/sub 3/ solubility as a function of temperature. Rate of isotopic exchange and melting points were determined. Several of the compounds are likely candidates for use in a gas-liquid countercurrent exchange system for large-scale separation of boron isotopes. 23 figs, 53 tables, 39 references.

  5. Melatonin labeled with hydrogen isotopes

    International Nuclear Information System (INIS)

    Dmitrevskaya, L.I.; Smushkevich, Yu.I.; Kurkovskaya, L.N.; Ponomarenko, N.K.; Suvorov, N.N.

    1989-01-01

    A study has been made of isotope exchange between melatonin and deuterium (D 2 O) or tritium (HTO) oxide under different conditions. The ease of isotope exchange for the indole ring hydrogens of melatonin in an acidic medium decreases over the series H 4 > H 2 H 6 >> H 7 , enabling the authors to process a route for production of melatonin labeled with hydrogen isotopes at positions 4,6, and 2 of the indole ring. A method has been suggested for producing melatonin labeled with hydrogen isotopes at position 2 by desulfurization of 2-(2,4-dinitro-phenylsulfenyl)melatonin at Ni(Re) (D)

  6. Melatonin labelled by hydrogen isotopes

    International Nuclear Information System (INIS)

    Dmitrevskaya, L.I.; Smushkevich, Yu.I.; Kurkovskaya, L.N.; Ponomarenko, N.K.; Suvorov, N.N.

    1988-01-01

    Isotope exchange of melatonin with deuterium (D 2 O) and tritium (HTO) oxides under different conditions is studied. Simplicity of isotope exchange of hydrogens of the indole ring of melatonin in the acidic medium decreases in series H 4 >H 2 >H 6 >>H 7 , that permits to suggest the way of melatonin preparation labelled by hydrogen isotopes in positions 4,6 and 2 of the indole ring. The way of melatonin preparation labelled by hydrogen isotopes in position 2 according to the reaction of desulfation 2-(2,4-dinitrophenylsulphenyl) melatonin at catalyst Ni(Re)(D) is suggested

  7. Development of Stable Isotope Technology

    International Nuclear Information System (INIS)

    Jeong, Do Young; Kim, Cheol Jung; Han, Jae Min

    2009-03-01

    KAERI has obtained an advanced technology with singular originality for laser stable isotope separation. Objectives for this project are to get production technology of Tl-203 stable isotope used for medical application and are to establish the foundation of the pilot system, while we are taking aim at 'Laser Isotope Separation Technology to make resistance to the nuclear proliferation'. And we will contribute to ensuring a nuclear transparency in the world society by taking part in a practical group of NSG and being collaboration with various international groups related to stable isotope separation technology

  8. Isotope separation by ion waves

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1978-01-01

    One of the isotopes of an element having several isotopes can be separated from the others in a dense, neutral plasma. Thus initially a neutral plasma is prepared including the element in question. This may consist of positive ions and negative electrons or alternatively of positive and negative ions, or else of a mixture of positive ions, negative ions and electrons. The plasma may then be injected into a magnetic field or may be generated in the field where more energy is imparted to a selected isotope than to the others. Finally, the isotopes are separated from each other on the basis of their differential energies. For example, the selected isotope may be given more energy than the others by stimulating it within the plasma at its resonant frequency which may be close to the cyclotron frequency, either by an electric field or by a magnetic field. In order to excite the other isotope, a different resonant frequency is required which depends on the plasma density, the relative concentration of electrons if the plasma contains electrons, the strength of the magnetic field, the ratio of charge to mass of the isotope, and possibly on the physical parameters of the plasma apparatus itself, such as the ratio of the length of the plasma column to its radius. The more energetic isotope may be separated by energy dependent chemical reactions, it may be collected by a positively biased probe or else the isotopes may be separated from each other by magnetic fields or in various other ways

  9. Chemical separation of boron isotopes

    International Nuclear Information System (INIS)

    Palko, A.A.

    1978-06-01

    This is the final report of the research performed at ORNL on the chemical fractionation of boron isotopes between BF 3 gas and the liquid molecular addition compounds of BF 3 . Thirty compounds were studied, ten of them in detail. Graphs and equations are given for variation of isotopic equilibrium constant, vapor pressure, and BF 3 solubility as a function of temperature. Rate of isotopic exchange and melting points were determined. Several of the compounds are likely candidates for use in a gas-liquid countercurrent exchange system for large-scale separation of boron isotopes. 23 figs, 53 tables, 39 references

  10. Isotope separation by magnetic fields

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1978-01-01

    One of the isotopes of an element having several isotopes can be separated from the others in a dense, neutral plasma. Thus initially a neutral plasma is prepared including the element in question. This may consist of positive ions and negative electrons or alternatively of positive and negative ions, or else of a mixture of positive ions, negative ions and electrons. The plasma may then be injected into a magnetic field or may be generated in the field where more energy is imparted to a selected isotope than to the others. Finally, the isotopes are separated from each other on the basis of their differential energies. For example, the selected isotope may be given more energy than the others by stimulating it within the plasma at its resonant frequency which may be close to the cyclotron frequency, either by an electric field or by a magnetic field. In order to excite the other isotope, a different resonant frequency is required which depends on the plasma density, the relative concentration of electrons if the plasma contains electrons, the strength of the magnetic field, the ratio of charge to mass of the isotope, and possibly on the physical parameters of the plasma apparatus itself, such as the ratio of the length of the plasma column to its radius. The more energetic isotope may be separated by energy dependent chemical reactions, it may be collected by a positively biased probe or else the isotopes may be separated from each other by magnetic fields or in various other ways

  11. Nuclear structure studies of rare francium isotopes using Collinear Resonance Ionization Spectroscopy (CRIS)

    CERN Document Server

    AUTHOR|(CDS)2084441

    It was known for many years that nuclei possessing certain numbers of protons (Z) and neutrons (N), called the magic numbers (8,20,28,50,82,126...), exhibit characteristic behavior and are in general more stable than their neighboring isotopes. As the capabilities of producing isotopes with more extreme values of Z and N increased, it was realized that those spherical nuclei only represent a small fraction of the total number of isotopes and that most isotopes are deformed. In order to study exotic isotopes and their deformation, it was necessary to develop new experimental techniques that would be powerful enough to be able to cope with very small production yields, but precise enough to measure the nuclear properties (such as radii and moments) with relatively small uncertainties. One technique that can measure nuclear properties of scarcely produced isotopes is in-source resonant ionization, but this technique does not allow for sufficient precision to deduce nuclear quadrupole moments. Furthermore, this t...

  12. Pb and Sr isotopic compositions of ancient pottery: a method to discriminate production sites

    International Nuclear Information System (INIS)

    Zhang Xun; Chen Jiangfeng; Ma Lin; He Jianfeng; Wang Changsui; Qiu Ping

    2004-01-01

    The discriminating of production sites of ancient pottery samples using multi-isotopic systematics was described. Previous work has proven that Pb isotopic ratios can be used for discriminating the production sites of ancient pottery under certain conditions. The present work suggests that although Nd isotopic ratios are not sensitive to the production sites of ancient pottery, Sr isotopic ratios are important for the purpose. Pb isotopic ratios are indistinguishable for the pottery excavated from the Jiahu relict, Wuyang, Henan Province and for famous Qin Terra-cotta Figures. But, the 87 Sr/ 86 Sr ratios for the former (about 0.715) are significantly lower than that of the latter (0.717-0.718). The authors concluded that a combined use of Pb and Sr isotopes would be a more powerful method for discriminating the production site of ancient pottery. (authors)

  13. Using MASHA+TIMEPIX Setup for Registration Beta Decay Isotopes Produced in Heavy Ion Induced Reactions

    Science.gov (United States)

    Rodin, A. M.; Belozerov, A. V.; Chernysheva, E. V.; Dmitriev, S. N.; Gulyaev, A. V.; Gulyaeva, A. V.; Itkis, M. G.; Novoselov, A. S.; Oganessian, Yu. Ts.; Salamatin, V. S.; Stepantsov, S. V.; Vedeneev, V. Yu.; Yukhimchuk, S. A.; Krupa, L.; Granja, C.; Pospisil, S.; Kliman, J.; Motycak, S.; Sivacek, I.

    2015-06-01

    Radon and mercury isotopes were produced in multi nucleon transfer (48Ca + 232Th) and complete fusion (48Ca + naturalNd) reactions, respectively. The isotopes with given masses were detected using two detectors: a multi-strip detector of the well-type (made in CANBERRA) and a position-sensitive quantum counting hybrid pixel detector of the TIMEPIX type. The isotopes implanted into the detectors then emit alpha- and betaparticles until reaching the long lived isotopes. The position of the isotopes, the tracks, the time and energy of beta-particles were measured and analyzed. A new software for the particle recognition and data analysis of experimental results was developed and used. It was shown that MASHA+ TIMEPIX setup is a powerful instrument for investigation of neutron-rich isotopes far from stability limits.

  14. Biogeochemistry of selenium isotopes: processes, cycling and paleoenvironmental applications

    NARCIS (Netherlands)

    Mitchell, K.A.

    2012-01-01

    Selenium (Se) is an essential trace element, which, with multiple oxidation states and six stable isotopes, has been suggested as a potentially powerful environmental tracer and paleoenvironmental proxy. Chapter 1 provides a literature review of the Se cycle. While the Se cycle shares some

  15. Stable isotope characteristics of precipitation of Pamba River basin ...

    Indian Academy of Sciences (India)

    highly essential input function for isotope hydro- ... Wind speed in the Pamba River basin varies from 8.5 to. 13.6 km/hr (NWDA 2008). ... ets of low values in the hill stations of the Ghats ... reservoir for the hydroelectric power production in.

  16. Isotope instrument FD-138 for the hydrologic parameter

    Energy Technology Data Exchange (ETDEWEB)

    Rukuan, Zheng; Zengxin, Wu [Instituts of Enviromental Protection, Beijing, BJ (China); Heyi, Huang [Beijing Nuclear Instrument Factory, BJ (China)

    1988-07-01

    In order to determine the hydrologic parameters, such as filtration velocity, flow direction and dispersity, {sup 131}I isotope is used as tracer in the groundwater aquifer. This method has advantages over traditional methods in respect of power saving, and is simple, quick and economical.

  17. Isotope instrument FD-138 for the hydrologic parameter

    International Nuclear Information System (INIS)

    Zheng Rukuan; Wu Zengxin; Huang Heyi

    1988-01-01

    In order to determine the hydrologic paraemters, such as filtration velocity, flow direction and dispersity, 131 I isotope is used as tracer in the groundwater aquifer. This method has advantages over traditional methods in respect of power saving, and is simple, quick and economical

  18. Aerodynamic isotope separation processes for uranium enrichment: process requirements

    International Nuclear Information System (INIS)

    Malling, G.F.; Von Halle, E.

    1976-01-01

    The pressing need for enriched uranium to fuel nuclear power reactors, requiring that as many as ten large uranium isotope separation plants be built during the next twenty years, has inspired an increase of interest in isotope separation processes for uranium enrichment. Aerodynamic isotope separation processes have been prominently mentioned along with the gas centrifuge process and the laser isotope separation methods as alternatives to the gaseous diffusion process, currently in use, for these future plants. Commonly included in the category of aerodynamic isotope separation processes are: (a) the separation nozzle process; (b) opposed gas jets; (c) the gas vortex; (d) the separation probes; (e) interacting molecular beams; (f) jet penetration processes; and (g) time of flight separation processes. A number of these aerodynamic isotope separation processes depend, as does the gas centrifuge process, on pressure diffusion associated with curved streamlines for the basic separation effect. Much can be deduced about the process characteristics and the economic potential of such processes from a simple and elementary process model. In particular, the benefit to be gained from a light carrier gas added to the uranium feed is clearly demonstrated. The model also illustrates the importance of transient effects in this class of processes

  19. Semiempirical method to determine the uranium isotopic compositions

    International Nuclear Information System (INIS)

    Tegas Sutondo

    2008-01-01

    In a nuclear reactor design calculation, some variations of U 235 enrichment are commonly needed. This will affect the isotopic compositions of the 3 main uranium isotopes i.e. U 234 , U 235 and U 238 for the respective enrichment. Due to the limited compositions data available, it is urgent to make an approximate way that can be used to determine the compositions of the 3 isotopes, for the desired enrichments. This paper presents the theoretical background used for constructing a semi empirical formula to estimate the composition of the 3 uranium isotopes as a function of U 235 enrichment, obtained based on the measurement data available. Based on the available data, and the lack of compositions data within the enrichment range between 3.5 % and around 12 %, it is concluded that 2 separate linear equations i.e. for ≤ 3.5 % and ≥ 3.5 % might be needed for U 235 isotope. For the U 234 isotope, a polynomial equation of 4 th order is well suited to be used for the whole range of enrichment between 0.711 % and 20 %, whilst for higher enrichment (> 20 %), a power function seems to give a better approach. The composition of U 238 can then be determined from the U 235 and U 234 composition at the desired enrichment of U 235 . (author)

  20. Separation of uranium isotopes by gas centrifugation

    International Nuclear Information System (INIS)

    Jordan, I.

    1980-05-01

    The uranium isotope enrichment is studied by means of the countercurrent gas centrifuge driven by thermal convection. A description is given of (a) the transfer and purification of the uranium hexafluoride used as process gas in the present investigation; (b) the countercurrent centrifuge ZG3; (c) the system designed for the introduction and extraction of the process gas from the centrifuge; (d) the measurement of the process gas flow rate through the centrifuge; (e) the determination of the uranium isotopic abundance by mass spectrometry; (f) the operation and mechanical behavior of the centrifuge and (g) the isotope separation experiments, performed, respectively, at total reflux and with production of enriched material. The results from the separation experiments at total reflux are discussed in terms of the enrichment factor variation with the magnitude and flow profile of the countercurrent given by the temperature difference between the rotor covers. As far as the separation experiments with production are concerned, the discussion of their results is presented through the variation of the enrichment factor as a function of the flow rate, the observed asymmetry of the process and the calculated separative power of the centrifuge. (Author) [pt

  1. Advanced isotope separation

    International Nuclear Information System (INIS)

    1982-01-01

    The Study Group briefly reviewed the technical status of the three Advanced Isotope Separation (AIS) processes. It also reviewed the evaluation work that has been carried out by DOE's Process Evaluation Board (PEB) and the Union Carbide Corporation-Nuclear Division (UCCND). The Study Group briefly reviewed a recent draft assessment made for DOE staff of the nonproliferation implications of the AIS technologies. The staff also very briefly summarized the status of GCEP and Advanced Centrifuge development. The Study Group concluded that: (1) there has not been sufficient progress to provide a firm scientific, technical or economic basis on which to select one of the three competing AIS processes for full-scale engineering development at this time; and (2) however, should budgetary restraints or other factors force such a selection, we believe that the evaluation process that is being carried out by the PEB provides the best basis available for making a decision. The Study Group recommended that: (1) any decisions on AIS processes should include a comparison with gas centrifuge processes, and should not be made independently from the plutonium isotope program; (2) in evaluating the various enrichment processes, all applicable costs (including R and D and sales overhead) and an appropriate discounting approach should be included in order to make comparisons on a private industry basis; (3) if the three AIS programs continue with limited resources, the work should be reoriented to focus only on the most pressing technical problems; and (4) if a decision is made to develop the Atomic Vapor Laser Isotope Separation process, the solid collector option should be pursued in parallel to alleviate the potential program impact of liquid collector thermal control problems

  2. Characteristics of isotope-selective chemical reactor with gas-separating device

    International Nuclear Information System (INIS)

    Gorshunov, N.M.; Kalitin, S.A.; Laguntsov, N.I.; Neshchimenko, Yu.P.; Sulaberidze, G.A.

    1988-01-01

    A study was made on characteristics of separating stage, composed of isotope-selective chemical (or photochemical) reactor and membrane separating cascade (MSC), designated for separation of isotope-enriched products from lean reagents. MSC represents the counterflow cascade for separation of two-component mixtures. Calculations show that for the process of carton isotope separation the electric power expences for MSC operation are equal to 20 kWxh/g of CO 2 final product at 13 C isotope content in it equal to 75%. Application of the membrane gas-separating cascade at rather small electric power expenses enables to perform cascading of isotope separation in the course of nonequilibrium chemical reactions

  3. Variations of lead isotopes and airborne particulate concentrations from the Kozani basin, West Macedonia, Greece.

    Science.gov (United States)

    Charalampides, G; Manoliadis, O; Triantafyllou, A

    2002-03-01

    The spread and variation in 206Pb/207Pb ratios make Pb isotopes a powerful tool when it comes to detecting trends in airborne particulates originating mainly from power plants. This study was conducted to determine the source of pollution in Kozani area, an affected industrial area. Lead isotopic ratios of air filters under certain meteorological conditions were compared to Pb isotope analyses sampled from lignite mines, but also to Pb isotope analyses of cultivations in soil originating from the reclamation of old abandoned lignite-mines. The particles taken into consideration have an aerodynamic diameter less than 10 microm (PM10). The measurements were carried out in a central part of the town of Kozani, West Macedonia, for one year observation period. The lead isotope values of air filters and of wheat in the Kozani area are between the values of lignite Pb and of Greek gasoline.

  4. Isotope effect and isotope separation. A chemist's view

    International Nuclear Information System (INIS)

    Ishida, Takanobu

    2002-01-01

    What causes the isotope effects (IE)? This presentation will be centered around the equilibrium isotope effects due to the differences in the nuclear masses. The occurrence of the equilibrium constant, K, of isotope exchange reactions which differ from the values predicted by the classical theory of statistical mechanics, K cl , is explored. The non-classical K corresponds to the unit-stage separation factor, α, that is different from unity and forms a basis of an isotope separation process involving the chemical exchange reaction. Here, the word 'chemical exchange' includes not only the isotope exchange chemical reactions between two or more chemical species but also the isotope exchanges involving the equilibria between liquid and vapor phases and liquid-gas, liquid solution-gas, liquid-liquid, and solid-liquid phases. In Section I, origins of the isotope effect phenomena will be explored and, in the process, various quantities used in discussions of isotope effect that have often caused confusions will be unambiguously defined. This Section will also correlate equilibrium constant with separation factor. In Section II, various forms of temperature-dependence of IE and separation factor will be discussed. (author)

  5. Container for hydrogen isotopes

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-12

    A container is described for storage, shipping and and dispensing of hydrogen isotopes such as hydrogen, deuterium, tritium, or mixtures of the same. The container is compact, safe against fracture or accident, and is reusable. It consists of an outer housing with suitable inlet and outlet openings and electrical feed elements, the housing containing an activated sorber material in the form, for example of titanium sponge or an activated zirconium aluminate cartridge. The gas to be stored is introduced into the chamber under conditions of heat and vacuum and is retained in the sorber material. Subsequently, it may be released by heating the unit to drive off the stored gas at desired rates.

  6. Applied isotope hydrogeology

    International Nuclear Information System (INIS)

    Pearson, F.J. jr; Balderer, W.; Gautschi, A.

    1991-01-01

    This volume is a report on the isotopic investigations of ground-water in northern Switzerland and adjacent regions carried out since 1981 by Nagra, the Swiss National Cooperation for the Storage of Radio-active Waste. This study was undertaken to support a programme assessing potential sites for nuclear waste repositories. It includes measurements on a large number of stable- and radioisotopes and noble gases, supported by complete water chemical analyses and many rock and mineral analyses. A synthesis and interpretation of the data, along with the data themselves, are given here. (author). refs.; figs.; tabs

  7. Chromatographic hydrogen isotope separation

    International Nuclear Information System (INIS)

    Aldridge, F.T.

    1983-01-01

    Intermetallic compounds with the CaCu5 type of crystal structure, particularly LaNiCo and CaNi5, exhibit high separation factors and fast equilibrium times and therefore are useful for packing a chromatographic hydrogen isotope separation column. The addition of an inert metal to dilute the hydride improves performance of the column. A large scale multi-stage chromatographic separation process run as a secondary process off a hydrogen feedstream from an industrial plant which uses large volumes of hydrogen can produce large quantities of heavy water at an effective cost for use in heavy water reactors

  8. Chromatographic hydrogen isotope separation

    International Nuclear Information System (INIS)

    Aldridge, F.T.

    1981-01-01

    Intermetallic compounds with the CaCu5 type of crystal structure , particularly LaNiCo and CaNi5, exhibit high separation factors and fast equilibrium times and therefore are useful for packing a chromatographic hydrogen isotope separation colum. The addition of an inert metal to dilute the hydride improves performance of the column. A large scale mutli-stage chromatographic separation process run as a secondary process off a hydrogen feedstream from an industrial plant which uses large volumes of hydrogen can produce large quantities of heavy water at an effective cost for use in heavy water reactors

  9. Isotope diagnostics apparatus

    International Nuclear Information System (INIS)

    Herrschaft, H.

    1976-01-01

    The invention relates to a measuring probe for an isotope diagnostics apparatus to determine the distribution of radioactive substances in a body by measuring the radiation emanating from this body by means of a multiplicity of measuring probes directed simultaneously towards areas of measuring surfae and carried in guidances of a holding block. The measuring results of the individual probes are recorded separately, thus allowing the possibility of being evaluated separately, too. Measuring probes of this kind are used in multi-channel measuring objects and are useful particularly for determining the regional cerebral blood flow. (orig./ORU) [de

  10. Container for hydrogen isotopes

    International Nuclear Information System (INIS)

    1976-01-01

    A container is described for storage, shipping and and dispensing of hydrogen isotopes such as hydrogen, deuterium, tritium, or mixtures of the same. The container is compact, safe against fracture or accident, and is reusable. It consists of an outer housing with suitable inlet and outlet openings and electrical feed elements, the housing containing an activated sorber material in the form, for example of titanium sponge or an activated zirconium aluminate cartridge. The gas to be stored is introduced into the chamber under conditions of heat and vacuum and is retained in the sorber material. Subsequently, it may be released by heating the unit to drive off the stored gas at desired rates

  11. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.; Kaldor, A.

    1977-01-01

    In a method for the separation of isotopes of uranium in UF 6 , the UF 6 is subjected to ir radiation at a predetermined wavelength or set of wavelengths for less than 10 -3 sec in such a manner that at least 0.1% of the 235 UF 6 molecules absorb an energy of more than 2000 cm -1 . The excited UF 6 is then reacted with a gaseous reagent, F 2 , Cl 2 , or Br 2 , to produce a product which is then recovered by means known in the art

  12. The ruthenium isotopic composition of the oceanic mantle

    Science.gov (United States)

    Bermingham, K. R.; Walker, R. J.

    2017-09-01

    The approximately chondritic relative, and comparatively high absolute mantle abundances of the highly siderophile elements (HSE), suggest that their concentrations in the bulk silicate Earth were primarily established during a final ∼0.5 to 1% of ;late accretion; to the mantle, following the cessation of core segregation. Consequently, the isotopic composition of the HSE Ru in the mantle reflects an amalgamation of the isotopic compositions of late accretionary contributions to the silicate portion of the Earth. Among cosmochemical materials, Ru is characterized by considerable mass-independent isotopic variability, making it a powerful genetic tracer of Earth's late accretionary building blocks. To define the Ru isotopic composition of the oceanic mantle, the largest portion of the accessible mantle, we report Ru isotopic data for materials from one Archean and seven Phanerozoic oceanic mantle domains. A sample from a continental lithospheric mantle domain is also examined. All samples have identical Ru isotopic compositions, within analytical uncertainties, indicating that Ru isotopes are well mixed in the oceanic mantle, defining a μ100Ru value of 1.2 ± 7.2 (2SD). The only known meteorites with the same Ru isotopic composition are enstatite chondrites and, when corrected for the effects of cosmic ray exposure, members of the Main Group and sLL subgroup of the IAB iron meteorite complex which have a collective CRE corrected μ100Ru value of 0.9 ± 3.0. This suggests that materials from the region(s) of the solar nebula sampled by these meteorites likely contributed the dominant portion of late accreted materials to Earth's mantle.

  13. Stable isotope mass spectrometry in petroleum exploration

    International Nuclear Information System (INIS)

    Mathur, Manju

    1997-01-01

    The stable isotope mass spectrometry plays an important role to evaluate the stable isotopic composition of hydrocarbons. The isotopic ratios of certain elements in petroleum samples reflect certain characteristics which are useful for petroleum exploration

  14. Isotope anomalies in oxygen isotope exchange equilibrium systems

    International Nuclear Information System (INIS)

    Kotaka, M.

    1997-01-01

    The purpose of the present work is to elucidate the isotope anomalies in oxygen isotope exchange equilibrium systems, according to the calculations of the equilibrium constants for oxygen isotopic exchange reactions, and the calculations of the oxygen isotope separation factors between two phases. The equilibrium constants (K65, K67, K68 and K69) of 16 O- 15 O, 16 O 17 O, 16 O- 18 O, and 16 O- 19 O exchange reactions between diatomic oxides were calculated in a wide temperature range on the basis of quantum statistical mechanics. Many equilibrium constants showed the anomalous mass effects, and then had the crossover temperatures and the mass independent fractionation (MIF) temperatures which held K67 = K65, K67 = K68, or K67 = K69, etc. For example, the equilibrium constants for the reactions between OH and the other diatomic oxides (MO) showed the anomalous mass effects, when M was Li, Na, Mg, K, Fe, Al, Ge, Zr, Pt, etc. The 16 O 15 O, 16 O 17 O, 16 O- 18 O, and 16 O- 19 O oxygen isotope separation factors (S65, S67, S68 and S69) between two phases were calculated, when OH and CO were in the first phase, and SiO was in the second phase. Although the oxygen isotopic exchange equilibria in the two phases had no MIF and crossover temperatures, the separation factors showed the anomalous mass effects and had the temperatures. According to what is called the normal mass effects for the equilibrium constant of isotopic exchange reaction, the value of InK68/InK67 is 1.885. Therefore, the value of InS68/InS67 should be 1.885 too. The value calculated, however, widely changed. It can be concluded from the results obtained in the present work that some oxygen isotopic exchange equilibria cause the anomalous mass effects, the anomalous oxygen isotope separation factors, and then isotope anomalies

  15. Stable isotope ratios in hair and teeth reflect biologic rhythms.

    Directory of Open Access Journals (Sweden)

    Otto Appenzeller

    Full Text Available Biologic rhythms give insight into normal physiology and disease. They can be used as biomarkers for neuronal degenerations. We present a diverse data set to show that hair and teeth contain an extended record of biologic rhythms, and that analysis of these tissues could yield signals of neurodegenerations. We examined hair from mummified humans from South America, extinct mammals and modern animals and people, both healthy and diseased, and teeth of hominins. We also monitored heart-rate variability, a measure of a biologic rhythm, in some living subjects and analyzed it using power spectra. The samples were examined to determine variations in stable isotope ratios along the length of the hair and across growth-lines of the enamel in teeth. We found recurring circa-annual periods of slow and fast rhythms in hydrogen isotope ratios in hair and carbon and oxygen isotope ratios in teeth. The power spectra contained slow and fast frequency power, matching, in terms of normalized frequency, the spectra of heart rate variability found in our living subjects. Analysis of the power spectra of hydrogen isotope ratios in hair from a patient with neurodegeneration revealed the same spectral features seen in the patient's heart-rate variability. Our study shows that spectral analysis of stable isotope ratios in readily available tissues such as hair could become a powerful diagnostic tool when effective treatments and neuroprotective drugs for neurodegenerative diseases become available. It also suggests that similar analyses of archaeological specimens could give insight into the physiology of ancient people and animals.

  16. Zirconium isotope separation process

    International Nuclear Information System (INIS)

    Peterson, S.H.; Lahoda, E.J.

    1988-01-01

    A process is described for reducing the amount of zirconium 91 isotope in zirconium comprising: forming a first solution of (a) a first solvent, (b) a scavenger, and (c) a zirconium compound which is soluble in the first solvent and reacts with the scavenger when exposed to light of a wavelength of 220 to 600 nm; irradiating the first solution with light at the wavelength for a time sufficient to photoreact a disproportionate amount of the zirconium compound containing the zirconium 91 isotope with the scavenger to form a reaction product in the first solution; contacting the first solution, while effecting the irradiation, with a second solvent which is immiscible with the first solvent, which the second solvent is a preferential solvent for the reaction product relative to the first solvent, such that at least a portion of the reaction product is transferred to the second solvent to form a second solution; and separating the second solution from the first solution after the contacting

  17. Isotope techniques for hydrology

    International Nuclear Information System (INIS)

    1964-01-01

    In the body of the Panel's report specific conclusions and recommendations are presented in the context of each subject. The general consensus of the Panel is as follows: by the study of this report, the 1961 Panel report, the Proceedings of the March 1963 Tokyo Symposium and other reports of research and technological advances, isotope-technique applications to hydrologic problems have provided some useful avenues for understanding the nature of the hydrologic cycle and in the solution of specific engineering problems. Some techniques are developed thoroughly enough for fairly routine application as tools for use in the solution of practical problems, but further research and development is needed on other concepts to determined whether or not they can be beneficially applied to either research or engineering problems. A concerted effort is required on the part of both hydrologists and isotope specialists working as teams to assure that proper synthesis of scientific advances in the respective fields and translation of these advances into practical technology is achieved

  18. Isotopes in agriculture

    International Nuclear Information System (INIS)

    1983-01-01

    Part 1: The stable isotope of nitrogen 15N has become widely used as tracer in agriculture, medicine and biology research. The film gives an overview of the sample preparation and analytical procedures followed in the analysis of the nitrogen isotopic composition (14N/15N ratio) by optical emission spectrometry at the Seibersdorf Laboratory. The subsampling of plant material and the several steps of chemical pretreatment such as Kjeldahl digestion, distillation, titration and adjustment of the proper N concentration in the extract are demonstrated. The preparation of the discharge tubes is shown in detail. Final measurement of the 14N/15N ratio is carried out with the NOI-5 and JASCO emission spectrometers. Part 2: This training film deals with the use of 32P-labelled materials in field and greenhouse experimentation in soil-plant relationships studies. All technical aspects, including safe handling and radiation protection procedures to be considered in the layout and harvesting of field experiments are documented in detail. Procedures followed up in the evaluation of P fertilizers such as rock phosphates under greenhouse conditions are described. Several soil injection techniques available for determination of the root activity pattern of trees are shown

  19. Isotope techniques for hydrology

    Energy Technology Data Exchange (ETDEWEB)

    1964-01-01

    In the body of the Panel's report specific conclusions and recommendations are presented in the context of each subject. The general consensus of the Panel is as follows: by the study of this report, the 1961 Panel report, the Proceedings of the March 1963 Tokyo Symposium and other reports of research and technological advances, isotope-technique applications to hydrologic problems have provided some useful avenues for understanding the nature of the hydrologic cycle and in the solution of specific engineering problems. Some techniques are developed thoroughly enough for fairly routine application as tools for use in the solution of practical problems, but further research and development is needed on other concepts to determined whether or not they can be beneficially applied to either research or engineering problems. A concerted effort is required on the part of both hydrologists and isotope specialists working as teams to assure that proper synthesis of scientific advances in the respective fields and translation of these advances into practical technology is achieved.

  20. Isotopic geochemistry at Wairakei

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1985-12-01

    Deuterium measurements on geothermal water at Wairakei are consistent with the water being derived from rainfall which has percolated down from the surface. The oxygen-18 content, however, is enriched compared to average rainfall. This 18 O shift is due to isotopic exchange between water and rock at greater-than-explored depths. The magnitude of the shift implied that the mass ration (W/R) of water that has passed through the system (W) to the rock it has exchanged with (R) is about 1 assuming open (i.e. single-pass) conditions. (The ratio is about 2 if it has been a closed system, but this is thought to be less likely). The residence time of water underground cannot be determined from tritium and carbon-14 measurements at present, but arguments based on the argon isotope and deuterium contents suggest mean residence times of a few tens of thousand years. The water-rock ratio and large natural outflow of thermal water prior to exploitation are consistent with this. The 18 O content of the water has changed only slightly, and the D content not at all, during exploitation at Wairakei (measurements from 1963, 1974 and 1981). An initial tendency for the 18 O to increase because of steam loss (also shown more clearly by chloride), has been followed by decrease of 18 O (and chloride) because of dilution with infiltrating near-surface water in parts of the field

  1. Dielectrophoretic separation of gaseous isotopes

    International Nuclear Information System (INIS)

    McConnell, D.B.

    1975-01-01

    Gaseous isotopes are separated from a mixture in a vertically elongated chamber by subjecting the mixture to a nonuniform transverse electric field. Dielectrophoretic separation of the isotopes is effected, producing a transverse temperature gradient in the chamber, thereby enhancing the separation by convective countercurrent flow. In the example given, the process and apparatus are applied to the production of heavy water from steam

  2. Boron isotopes in geothermal systems

    International Nuclear Information System (INIS)

    Aggarwal, J.

    1997-01-01

    Boron is a highly mobile element and during water-rock reactions, boron is leached out of rocks with no apparent fractionation. In geothermal systems where the water recharging the systems are meteoric in origin, the B isotope ratio of the geothermal fluid reflects the B isotope ratio of the rocks. Seawater has a distinctive B isotope ratio and where seawater recharges the geothermal system, the B isotope ratio of the geothermal system reflects the mixing of rock derived B and seawater derived B. Any deviations of the actual B isotope ratio of a mixture reflects subtle differences in the water-rock ratios in the cold downwelling limb of the hydrothermal system. This paper will present data from a variety of different geothermal systems, including New Zealand; Iceland; Yellowston, USA; Ibusuki, Japan to show the range in B isotope ratios in active geothermal systems. Some of these systems show well defined mixing trends between seawater and the host rocks, whilst others show the boron isotope ratios of the host rock only. In geothermal systems containing high amounts of CO 2 boron isotope ratios from a volatile B source can also be inferred. (auth)

  3. Basic methods of isotope analysis

    International Nuclear Information System (INIS)

    Ochkin, A.V.; Rozenkevich, M.B.

    2000-01-01

    The bases of the most applied methods of the isotope analysis are briefly presented. The possibilities and analytical characteristics of the mass-spectrometric, spectral, radiochemical and special methods of the isotope analysis, including application of the magnetic resonance, chromatography and refractometry, are considered [ru

  4. Lead isotope in mineral exploration

    International Nuclear Information System (INIS)

    Gulson, B.L.

    1986-01-01

    This book provides an up-to-date state-of-the-art review of lead isotopes in mineral exploration. Beginning with an historical review on suggested uses of lead isotopes in mineral exploration, the author then outlines the theoretical aspects of lead isotopes and illustrates that the method is based on well-known principles of radioactive decay, from which isotopic signatures for different styles of mineralization are derived. The varying isotopic signatures are then introduced. The major part of the book details over 40 case histories for base and precious metals, uranium and tin using sampling media such as sulfides, gossans, soils, weathered bedrock, vegetation and groundwaters. Advantages and disadvantages of each are discussed. Examples are given of the use of lead isotopes in testing conceptual models for exploration. The success rate and cost-effectiveness of the method are illustrated by actual exploration examples. Analytical advances which should lower the cost of the method and future uses are outlined. Many of the case histories use recently published or unpublished data, 27 tables of which are given in an appendix. Details of sampling, the methods for obtaining the isotope ratios, and a commercially-available integrated lead isotope service are also provided. (Auth.)

  5. Method for separating krypton isotopes

    International Nuclear Information System (INIS)

    Porter, J.T.

    1980-01-01

    Methods and apparatus for separating krypton isotopes utilizing low temperature selective infrared excitation of 85krypton difluoride in an isotopic compound mixture. Multiphoton ir excitation and uv excitation techniques are used, as well as cryogenic matrix isolation and inert buffer gas isolation techniques

  6. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1980-12-01

    This report contains a listing of electromagnetically separated stable isotopes which are available for distribution within the United States for non-destructive research use from the Oak Ridge National Laboratory on a loan basis. This inventory includes all samples of stable isotopes in the Materials Research Collection and does not designate whether a sample is out on loan or in reprocessing

  7. Calcium isotopes in wine

    Science.gov (United States)

    Holmden, C. E.

    2011-12-01

    The δ 44/40Ca values of bottled wine vary between -0.76% to -1.55% on the seawater scale and correlate weakly with inverse Ca concentration and Mg/Ca ratio, such that the lowest δ 44/40Ca values have the highest Ca concentrations and lowest Mg/Ca ratios. The correlation is notable in the sense that the measured wines include both whites and reds sampled from different wine growing regions of the world, and cover a wide range of quality. Trends among the data yield clues regarding the cause of the observed isotopic fractionation. White wines, and wines generally perceived to be of lower quality, have lower δ 44/40Ca values compared to red wines and wines of generally perceived higher quality. Quality was assessed qualitatively through sensory evaluation, price, and scores assigned by critics. The relationship between δ 44/40Ca and wine quality was most apparent when comparing wines of one varietal from one producer from the same growing region. In the vineyard, wine quality is related to factors such as the tonnage of the crop and the ripeness of the grapes at the time of harvesting, the thickness of the skins for reds, the age of the vines, as well as the place where the grapes were grown (terroir). Quality is also influenced by winemaking practices such as fermentation temperature, duration of skin contact, and barrel ageing. Accordingly, the relationship between δ 44/40Ca and wine quality may originate during grape ripening in the vineyard or during winemaking in the cellar. We tested the grape ripening hypothesis using Merlot grapes sampled from a vineyard in the Okanagan, British Columbia, using sugar content (degrees Brix) as an indicator of ripeness. The grapes were separated into pulp, skin, and pip fractions and were analyzed separately. Thus far, there is no clear evidence for a systematic change in δ 44/40Ca values associated with progressive ripening of grapes in the vineyard. On the day of harvesting, the δ 44/40Ca value of juice squeezed from

  8. Pollution and Climate Effects on Tree-Ring Nitrogen Isotopes

    Science.gov (United States)

    Savard, M. M.; Bégin, C.; Marion, J.; Smirnoff, A.

    2009-04-01

    Georgian Bay reflect deposition of NOx emissions from cars and coal-power plants, with higher proportions from coal burning in Georgian Bay (Savard et al., 2009b). This interpretation is conceivable because recent monitoring indicates that coal-power plant NOx emissions play an important role in the annual N budget in Ontario, but they are negligible on the Quebec side. CONCLUSION Interpretations of long tree-ring N isotopic series in terms of effects generated by airborne N-species have been previously advocated. Here we further propose that the contrasted isotopic trends obtained for wood samples from two regions reflect different regional anthropogenic N deposition combined with variations of climatic conditions. This research suggests that nitrogen tree-ring series may record both regional climatic conditions and anthropogenic perturbations of the N cycle. REFERENCES Savard, M.M., Bégin,C., Marion, J., Aznar, J.-C., Smirnoff, A., 2009a. Changes of Air Quality in an urban region as inferred from tree-ring width and stable isotopes. Chapter 9 in "Relating Atmospheric Source Apportionment to Vegetation Effects: Establishing Cause Effect Relationships" (A. Legge ed.). Elsevier, Amsterdam; doi: 10.1016/S1474-8177(08)00209x. Savard, M.M., Bégin, C., Smirnoff, A., Marion, J., Rioux-Paquette, E., 2009b. Tree-ring nitrogen isotopes reflect climatic effects and anthropogenic NOx emissions. Env. Sci. Tech (doi: 10.1021/es802437k).

  9. Correlated optical and isotopic nanoscopy

    Science.gov (United States)

    Saka, Sinem K.; Vogts, Angela; Kröhnert, Katharina; Hillion, François; Rizzoli, Silvio O.; Wessels, Johannes T.

    2014-04-01

    The isotopic composition of different materials can be imaged by secondary ion mass spectrometry. In biology, this method is mainly used to study cellular metabolism and turnover, by pulsing the cells with marker molecules such as amino acids labelled with stable isotopes (15N, 13C). The incorporation of the markers is then imaged with a lateral resolution that can surpass 100 nm. However, secondary ion mass spectrometry cannot identify specific subcellular structures like organelles, and needs to be correlated with a second technique, such as fluorescence imaging. Here, we present a method based on stimulated emission depletion microscopy that provides correlated optical and isotopic nanoscopy (COIN) images. We use this approach to study the protein turnover in different organelles from cultured hippocampal neurons. Correlated optical and isotopic nanoscopy can be applied to a variety of biological samples, and should therefore enable the investigation of the isotopic composition of many organelles and subcellular structures.

  10. Isotopes in global change science: from isotope analytics to Earth system research

    International Nuclear Information System (INIS)

    Oeschger, H.

    1998-01-01

    The aim of this paper is to emphasize some of the studies of Jean Charles Fontes and his role in our scientific community. Isotopes represent a powerful tool for the understanding of the Earth's past environment and defining the envelope of natural environmental variability within which we can assess anthropogenic impact on the Earth's biosphere, geosphere and atmosphere. The reconstruction impacts of past climatic change on the Earth's system are a basis to validate models of the possible impacts of future climate change. Oceanic sediments, polar ice caps, continental sedimentary sequences and groundwater are archives of past climate. Their quantitative study is developed within the IGBP (International Geosphere-Biosphere Program) - Pages project, which strongly emphasizes an optimum use of isotope tools. (author)

  11. Stable isotope enrichment: Current and future potential

    International Nuclear Information System (INIS)

    Tracy, J.G.; Aaron, W.S.

    1992-01-01

    Oak Ridge National Laboratory (ORNL) operates the Isotope Enrichment Facility for the purpose of providing enriched stable isotopes, selected radioactive isotopes (including the actinides), and isotope-related materials and services for use in various research applications. ORNL is responsible for isotope enrichment and the distribution of approximately 225 nongaseous stable isotopes from 50 multi-isotopic elements. Many enriched isotope products are of prime importance in the fabrication of nuclear targets and the subsequent production of special radionuclides. State-of-the-art techniques to achieve special isotopic, chemical, and physical requirements are performed at ORNL This report describes the status and capabilities of the Isotope Enrichment Facility and the Isotope Research Materials Laboratory as well as emphasizing potential advancements in enrichment capabilities

  12. Stable isotope enrichment - current and future potential

    International Nuclear Information System (INIS)

    Tracy, J.G.; Aaron, W.S.

    1993-01-01

    Oak Ridge National Laboratory (ORNL) operates the Isotope Enrichment Facility for the purpose of providing enriched stable isotopes, selected radioactive isotopes (including the actinides), and isotope-related materials and services for use in various research applications. ORNL is responsible for isotope enrichment and the distribution of approximately 225 nongaseous stable isotopes from 50 multi-isotopic elements. Many enriched isotope products are of prime importance in the fabrication of nuclear targets and the subsequent production of special radionuclides. State-of-the-art techniques to achieve special isotopic, chemical, and physical requirements are performed at ORNL. This report describes the status and capabilities of the Isotope Enrichment Facility and the Isotope Research Materials Laboratory as well as emphasizing potential advancements in enrichment capabilities. (orig.)

  13. Isotopic Thermionic Generator; Generateur thermoionique isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Clemot, M; Devin, B; Durand, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    This report describes the general design of a thermionic direct conversion space generator. The power source used is a radioisotope. Two radioisotopes are considered: Pu 238 and Cm 244. The system is made up of a heat pipe concentrating the thermal flux from the isotope to the emitter, and of a second heat pipe evacuating the waste heat from the collector to the outer wall used as radiating panel. Calculations are given in the particular case of a 100 electrical watts output power. (authors) [French] Ce rapport decrit la structure d'un generateur spatial d'electricite a conversion directe du type thermoionique. La source d'energie est un radioisotope. Deux isotopes sont envisages: le Pu 238 et le Cm 244. Le systeme comporte pour l'emetteur un caloduc concentreur de flux thermique et pour le collecteur, un caloduc evacuateur vers l'enveloppe du generateur utilise, en panneau rayonnant. Les calculs ont ete conduits dans le cas particulier d'une puissance convertie de 100 watts electriques. (auteurs)

  14. Lasers for isotope separation

    International Nuclear Information System (INIS)

    O'Hair, E.A.; Piltch, M.S.

    1976-01-01

    The Los Alamos Scientific Laboratory is conducting research on uranium enrichment. All processes being studied employ uranium molecules and use lasers to provide isotopic selectivity and enrichment. There are four well-defined infrared frequencies and two ultraviolet frequency bands of interest. The infrared frequencies are outside the range of the available lasers and an extensive research and development activity is currently underway. Lasers are available in the uv bands, however, much development work remains. The specification for the commercial uranium enrichment plant lasers will depend upon the results of the current enrichment experiments, the laser capital cost, reliability, and maintenance cost. For the processes under investigation there are specific photon requirements but latitude in how these requirements can be met. The final laser selections for the pilot plant need not be made until the mid-1980's. Between now and that time as extensive as possible a research and development effort will be maintained

  15. Applications of stable isotopes

    International Nuclear Information System (INIS)

    Gregg, C.T.

    1977-01-01

    Clinical applications include the galactose breath test which consists of oral administration of 13 C-labeled galactose and measurement of the 13 C content of respired CO 2 as a function of time in patients with cirrhotic livers for diagnosis of liver dysfunction. Another application was the breath test to study glucose metabolism in children. Respired 13 CO 2 from ingested glucose- 13 C was measured for normal and diabetic children. Studies on mice in which 60 percent of the body carbon was replaced with 13 C failed to show significant effects of the isotope. Studies on biochemical applications include nuclear magnetic resonance studies of 13 C-labeled amino acids from Chlorella pyrenoidosa; studies on 15 N nmr spectra of arginine-guanidino- 13 C-2,3-- 15 N 2 as a function of pH; and isolation of fatty acids from algae

  16. Galilei-isotopic relativities

    International Nuclear Information System (INIS)

    Santilli, R.M.

    1991-09-01

    In this note we further develop the proposal made in preceding works of constructing the infinite family of Lie-isotopic liftings of Galilei's relativity for closed-isolated systems of particles possessing local, potential and selfadjoint, as well as nonlocal, nonhamiltonian and non selfadjoint internal forces. In particular, we show that the nonlinear and nonlocal generalization of the Galilei transformations introduced in a preceding note do indeed represent motion of extended particles within resistive media, but in such a way to coincide with the conventional transformations at the abstract, realization-free level. This allows the preservation of the basic, physical and mathematical axioms of Galilei's relativity under our liftings, and their realization in the most general possible nonlinear, nonlocal and nonhamiltonian way. (author). 18 refs, 1 fig

  17. Stable-isotope paleoclimatology

    International Nuclear Information System (INIS)

    Deuser, W.G.

    1978-01-01

    Seasonal variations of temperature and salinity in the surface waters of large parts of the oceans are well established. Available data on seasonal distributions of planktonic foraminifera show that the abundances of different species groups peak at different times of the year with an apparent succession of abundance peaks through most of the year. This evidence suggests that a measure of seasonal contrast is recorded in the isotope ratios of oxygen, and perhaps carbon, in the tests of different foraminiferal species. The evaluation of this potential paleoclimatologic tool awaits planned experiments with recent foraminifera in well-known settings, but a variety of available data is consistent with the idea that interspecies differences in 18 O content contain a seasonal component.(auth.)

  18. Container for hydrogen isotopes

    International Nuclear Information System (INIS)

    Solomon, D.E.

    1977-01-01

    A container for the storage, shipping and dispensing of hydrogen isotopes such as hydrogen, deuterium, tritium, or mixtures of the same which has compactness, which is safe against fracture or accident, and which is reusable is described. The container consists of an outer housing with suitable inlet and outlet openings and electrical feed elements, the housing containing an activated sorber material in the form, for example, of titanium sponge or an activated zirconium aluminate cartridge. The gas to be stored is introduced into the chamber under conditions of heat and vacuum and will be retained in the sorber material. Subsequently, it may be released by heating the unit to drive off the stored gas at desired rates

  19. Radio-isotopic tracers

    International Nuclear Information System (INIS)

    Wolfangel, R.G.

    1976-01-01

    The invention concerns the dispersions that may be used for preparing radio-isotopic tracers, technetium labelled dispersions, processes for preparing these dispersions and their use as tracers. Technetium 99m sulphur colloids are utilized as scintillation tracers to give a picture of the reticulo-endothelial system, particularly the liver and spleen. A dispersion is provided which only requires the addition of a radioactive nuclide to form a radioactively labelled dispersion that can be injected as a tracer. It is formed of a colloid of tin sulphur dispersed in an aqueous buffer solution. Such a reagent has the advantage of being safe and reliable and is easier to use. The colloid can be prepared more quickly since additions of several different reagents are avoided. There is no need to heat up and no sulphuretted hydrogen, which is a toxic gas, is used [fr

  20. Isotopically labelled benzodiazepines

    International Nuclear Information System (INIS)

    Liebman, A.A.

    1987-01-01

    This paper reports on the benzodiazepines which are a class of therapeutic agents. Improvements in the analytical methodology in the areas of biochemistry and pharmacology were significant, particularly in the application of chromatographic and spectroscopic techniques. In addition, the discovery and subsequent development of tritium and carbon-14 as an analytical tool in the biological sciences were essentially post-world war II phenomena. Thus, as these new chemical entities were found to be biologically active, they could be prepared in labeled form for metabolic study, biological half-life determination (pharmacokinetics), tissue distribution study, etc. This use of tracer methodology has been liberally applied to the benzodiazepines and also more recently to the study of receptor-ligand interactions, in which tritium, carbon-11 or fluorine-18 isotopes have been used. The history of benzodiazepines as medicinal agents is indeed an interesting one; an integral part of that history is their use in just about every conceivable labeled form

  1. Canada's isotope crisis : what next?

    International Nuclear Information System (INIS)

    Nathwani, J.; Wallace, D.

    2010-01-01

    Canada urgently requires a rigorous debate on the strategic options for ensuring a robust, reliable, and affordable supply of radioactive isotopes. Should the debate be confined to how Canada can best develop the necessary technologies solely for our own use or should Canada abandon the idea of producing its own isotope supply and any future aspirations to serve the global market? Canada's Isotope Crisis focuses on the central policy question: do we dare to try to shape the future or do we retreat into silence because we are not prepared to make the necessary investments for the future well-being of Canadians? This volume showcases pointed essays and analysis from members of the academy and individuals who have made contributions to the development of medical isotopes and pioneered their use in medical practice. It also includes commentary from those involved in the production, manufacturing, processing, and distribution of isotopes. Canada's Isotope Crisis is a multi-disciplinary effort that addresses the global dimension of isotope supply and combines expert opinions on the present and past with knowledge of the relevant government agencies and the basis for their decisions at critical junctures.

  2. Isotopically labelled pyrimidines and purines

    International Nuclear Information System (INIS)

    Balaban, A.T.; Bally, I.

    1987-01-01

    Among the three diazines, pyrimidine is by far the most important one because its derivatives uracil, thymine and cytosine are constituents of the ubiquitous deoxynucleic acids (DNA) and ribonucleic acids (RNA). Other derivatives of pyrimidine without condensed rings include barbiturates, alloxan, orotic acid and thiamine or vitamin B 1 . From the polycyclic derivatives of pyrimidine such as pteridine, alloxazine, and purine, the latter, through its derivatives adenine and guanine complete the list of bases which occur in DNA and RNA: in addition, other purine derivatives such as hypoxanthine, xanthine, theobromine, theophylline, caffeine and uric acid are important natural products with biological activity. The paper presents methods for preparing isotopically labeled pyrimidines as well as purine derivatives. For convenience, the authors describe separately carbon-labeled with radioisotopes 11 C (T 1/2 = 20.3 min) and 14 C (T 1/2 = 5736 years) or the stable isotope 13 C (natural abundance 1.1%) and then hydrogen-labeled systems with the radioisotope 3 H ≡ T (T 1/2 = 12.346 years) or with the stable isotope 2 H ≡ D (natural abundance 0.015%). We do not separate stable from radioactive isotopes because the synthetic methods are identical for the same element; however, the introduction of hydrogen isotopes into organic molecules is often performed by reactions such as isotope exchange which cannot take place in the case of carbon isotopes

  3. Mass spectrometric measurement of hydrogen isotope fractionation for the reactions of chloromethane with OH and Cl

    Directory of Open Access Journals (Sweden)

    F. Keppler

    2018-05-01

    Full Text Available Chloromethane (CH3Cl is an important provider of chlorine to the stratosphere but detailed knowledge of its budget is missing. Stable isotope analysis is a potentially powerful tool to constrain CH3Cl flux estimates. The largest degree of isotope fractionation is expected to occur for deuterium in CH3Cl in the hydrogen abstraction reactions with its main sink reactant tropospheric OH and its minor sink reactant Cl atoms. We determined the isotope fractionation by stable hydrogen isotope analysis of the fraction of CH3Cl remaining after reaction with hydroxyl and chlorine radicals in a 3.5 m3 Teflon smog chamber at 293 ± 1 K. We measured the stable hydrogen isotope values of the unreacted CH3Cl using compound-specific thermal conversion isotope ratio mass spectrometry. The isotope fractionations of CH3Cl for the reactions with hydroxyl and chlorine radicals were found to be −264±45 and −280±11 ‰, respectively. For comparison, we performed similar experiments using methane (CH4 as the target compound with OH and obtained a fractionation constant of −205±6 ‰ which is in good agreement with values previously reported. The observed large kinetic isotope effects are helpful when employing isotopic analyses of CH3Cl in the atmosphere to improve our knowledge of its atmospheric budget.

  4. Stable isotope analysis of precipitation samples obtained via crowdsourcing reveals the spatiotemporal evolution of Superstorm Sandy.

    Directory of Open Access Journals (Sweden)

    Stephen P Good

    Full Text Available Extra-tropical cyclones, such as 2012 Superstorm Sandy, pose a significant climatic threat to the northeastern United Sates, yet prediction of hydrologic and thermodynamic processes within such systems is complicated by their interaction with mid-latitude water patterns as they move poleward. Fortunately, the evolution of these systems is also recorded in the stable isotope ratios of storm-associated precipitation and water vapor, and isotopic analysis provides constraints on difficult-to-observe cyclone dynamics. During Superstorm Sandy, a unique crowdsourced approach enabled 685 precipitation samples to be obtained for oxygen and hydrogen isotopic analysis, constituting the largest isotopic sampling of a synoptic-scale system to date. Isotopically, these waters span an enormous range of values (> 21‰ for δ(18O, > 160‰ for δ(2H and exhibit strong spatiotemporal structure. Low isotope ratios occurred predominantly in the west and south quadrants of the storm, indicating robust isotopic distillation that tracked the intensity of the storm's warm core. Elevated values of deuterium-excess (> 25‰ were found primarily in the New England region after Sandy made landfall. Isotope mass balance calculations and Lagrangian back-trajectory analysis suggest that these samples reflect the moistening of dry continental air entrained from a mid-latitude trough. These results demonstrate the power of rapid-response isotope monitoring to elucidate the structure and dynamics of water cycling within synoptic-scale systems and improve our understanding of storm evolution, hydroclimatological impacts, and paleo-storm proxies.

  5. Stable isotope analysis of precipitation samples obtained via crowdsourcing reveals the spatiotemporal evolution of Superstorm Sandy.

    Science.gov (United States)

    Good, Stephen P; Mallia, Derek V; Lin, John C; Bowen, Gabriel J

    2014-01-01

    Extra-tropical cyclones, such as 2012 Superstorm Sandy, pose a significant climatic threat to the northeastern United Sates, yet prediction of hydrologic and thermodynamic processes within such systems is complicated by their interaction with mid-latitude water patterns as they move poleward. Fortunately, the evolution of these systems is also recorded in the stable isotope ratios of storm-associated precipitation and water vapor, and isotopic analysis provides constraints on difficult-to-observe cyclone dynamics. During Superstorm Sandy, a unique crowdsourced approach enabled 685 precipitation samples to be obtained for oxygen and hydrogen isotopic analysis, constituting the largest isotopic sampling of a synoptic-scale system to date. Isotopically, these waters span an enormous range of values (> 21‰ for δ(18)O, > 160‰ for δ(2)H) and exhibit strong spatiotemporal structure. Low isotope ratios occurred predominantly in the west and south quadrants of the storm, indicating robust isotopic distillation that tracked the intensity of the storm's warm core. Elevated values of deuterium-excess (> 25‰) were found primarily in the New England region after Sandy made landfall. Isotope mass balance calculations and Lagrangian back-trajectory analysis suggest that these samples reflect the moistening of dry continental air entrained from a mid-latitude trough. These results demonstrate the power of rapid-response isotope monitoring to elucidate the structure and dynamics of water cycling within synoptic-scale systems and improve our understanding of storm evolution, hydroclimatological impacts, and paleo-storm proxies.

  6. Manipulation of rare isotope beams - from high to low energies

    Energy Technology Data Exchange (ETDEWEB)

    Bollen, G. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI (United States)], E-mail: bollen@nscl.msu.edu; Campbell, C.; Chouhan, S.; Guenaut, C.; Lawton, D.; Marti, F. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Morrissey, D.J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Department of Chemistry, Michigan State University, East Lansing, MI (United States); Ottarson, J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Pang, G. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Department of Chemistry, Michigan State University, East Lansing, MI (United States); Schwarz, S.; Zeller, A.F.; Zavodszky, P. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States)

    2008-10-15

    Projectile fragmentation above 50 MeV/u and in-flight separation is a powerful technique for the production and delivery of rare isotopes. The production is fast and chemistry independent, providing nuclides far away from the valley of beta stability and for a very large range of elements. These benefits can be maximized if the produced rare isotopes are made available also as low-energy beams (<15 MeV/u) and at rest. For this purpose the fast beams need to be slowed down and thermalized before being re-accelerated to the desired energy. This can be achieved with gas stopping techniques. This paper discusses various aspects of stopping fast rare isotope beams, including the development of a 'cyclotron gas stopper' that promises to overcome the limitations of present linear gas stopping schemes.

  7. Isotopic shift in even-even barium isotopes

    International Nuclear Information System (INIS)

    Karim, Afaque; Naz, Tabassum; Ahmad, Shakeb

    2017-01-01

    We have discussed the correlation between a nuclear shape and its matter distribution. Here, we present the root-mean-square radii (r rms ) and rms charge radius (r ch ). We have also discussed the isotopic shift in terms of the observable ‹Δr 2 c › N,82 and its differential ‹Δr 2 c › N-2,N . We present nuclear radii evaluated using different interactions. Neutron radii and charge radii for all the isotopic chains are shown. Neutron radii for Ba isotopes show an increasing trend with the neutron number for all isotopic chains. One can observe a clear kink about magic number N=82

  8. Stable isotope genealogy of meteorites

    International Nuclear Information System (INIS)

    Pillinger, C.T.

    1988-01-01

    One of the oldest problems in meteoritics is that of taxonomically grouping samples. In recent years the use of isotopes, particularly oxygen isotopes has proved very successful in this respect. Other light-element systematics potentially can perform the same function. For example, nitrogen in iron meteorites, and nitrogen and carbon in ureilites and SNC meteorites. These measurements will serve to extend and augment existing classification schemes and provide clues to the nature of meteorite parent bodies. They can also aid in the recognition of the isotopic signatures relating to inaccessible regions of the Earth. (author)

  9. Compelling Research Opportunities using Isotopes

    International Nuclear Information System (INIS)

    2009-01-01

    Isotopes are vital to the science and technology base of the US economy. Isotopes, both stable and radioactive, are essential tools in the growing science, technology, engineering, and health enterprises of the 21st century. The scientific discoveries and associated advances made as a result of the availability of isotopes today span widely from medicine to biology, physics, chemistry, and a broad range of applications in environmental and material sciences. Isotope issues have become crucial aspects of homeland security. Isotopes are utilized in new resource development, in energy from bio-fuels, petrochemical and nuclear fuels, in drug discovery, health care therapies and diagnostics, in nutrition, in agriculture, and in many other areas. The development and production of isotope products unavailable or difficult to get commercially have been most recently the responsibility of the Department of Energy's Nuclear Energy program. The President's FY09 Budget request proposed the transfer of the Isotope Production program to the Department of Energy's Office of Science in Nuclear Physics and to rename it the National Isotope Production and Application program (NIPA). The transfer has now taken place with the signing of the 2009 appropriations bill. In preparation for this, the Nuclear Science Advisory Committee (NSAC) was requested to establish a standing subcommittee, the NSAC Isotope Subcommittee (NSACI), to advise the DOE Office of Nuclear Physics. The request came in the form of two charges: one, on setting research priorities in the short term for the most compelling opportunities from the vast array of disciplines that develop and use isotopes and two, on making a long term strategic plan for the NIPA program. This is the final report to address charge 1. NSACI membership is comprised of experts from the diverse research communities, industry, production, and homeland security. NSACI discussed research opportunities divided into three areas: (1) medicine

  10. Advances in laser isotope separation

    International Nuclear Information System (INIS)

    Herman, I.P.; Bernhardt, A.F.

    1988-01-01

    The physical and chemical concepts required to understand laser isotope separation are presented and discussed. The numerous successful demonstrations of separating isotopes using lasers are reviewed to 1983. Emphasis is placed on the separation of 235-U from 238-U by multi-step selective ioniation of uranium atomic vapor, and on the separation of D and H and of T from D, by pulsed infrared laser multiple-photon dissociation of fluoroform and chloroform, respectively, because they are among the most successful and important examples of laser isotope separation to date. 161 refs.; 7 figs

  11. Stable isotopes - separation and application

    International Nuclear Information System (INIS)

    Lockhart, I.M.

    1980-01-01

    In this review, methods used for the separation of stable isotopes ( 12 C, 13 C, 14 N, 15 N, 16 O, 17 O, 18 O, 34 S) will be described. The synthesis of labelled compounds, techniques for detection and assay, and areas of application will also be discussed. Particular attention will be paid to the isotopes of carbon, nitrogen, and oxygen; to date, sulphur isotopes have only assumed a minor role. The field of deuterium chemistry is too extensive for adequate treatment; it will therefore be essentially excluded. (author)

  12. Iodine isotopes and radiation safety

    International Nuclear Information System (INIS)

    Styro, B.; Nedvekajte, T.; Filistovich, V.

    1992-01-01

    Methods of concentration determination of stable and radioactive iodine isotopes in the Earth's different geospheres are described. Iodine isotopes concentration data, chemical forms and transformations as well as their exchange among separate geospheres of their global biochemical circulation (ocean, atmosphere, lithosphere and biosphere) are presented. Information on iodine isotopes as after-effects of nuclear installations accident (in particular, the Chernobyl accident) is generalized. The book is intended for scientists and practical workers in ecology and radioactivity protection and for a students of physics. 442 refs.; 82 figs.; 36 tabs

  13. Compelling Research Opportunities using Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-04-23

    Isotopes are vital to the science and technology base of the US economy. Isotopes, both stable and radioactive, are essential tools in the growing science, technology, engineering, and health enterprises of the 21st century. The scientific discoveries and associated advances made as a result of the availability of isotopes today span widely from medicine to biology, physics, chemistry, and a broad range of applications in environmental and material sciences. Isotope issues have become crucial aspects of homeland security. Isotopes are utilized in new resource development, in energy from bio-fuels, petrochemical and nuclear fuels, in drug discovery, health care therapies and diagnostics, in nutrition, in agriculture, and in many other areas. The development and production of isotope products unavailable or difficult to get commercially have been most recently the responsibility of the Department of Energy's Nuclear Energy program. The President's FY09 Budget request proposed the transfer of the Isotope Production program to the Department of Energy's Office of Science in Nuclear Physics and to rename it the National Isotope Production and Application program (NIPA). The transfer has now taken place with the signing of the 2009 appropriations bill. In preparation for this, the Nuclear Science Advisory Committee (NSAC) was requested to establish a standing subcommittee, the NSAC Isotope Subcommittee (NSACI), to advise the DOE Office of Nuclear Physics. The request came in the form of two charges: one, on setting research priorities in the short term for the most compelling opportunities from the vast array of disciplines that develop and use isotopes and two, on making a long term strategic plan for the NIPA program. This is the final report to address charge 1. NSACI membership is comprised of experts from the diverse research communities, industry, production, and homeland security. NSACI discussed research opportunities divided into three areas: (1

  14. Neodymium isotopic variations in seawater

    Science.gov (United States)

    Piepgras, D. J.; Wasserburg, G. J.

    1980-01-01

    Direct measurement of the isotopic composition of Nd in the Atlantic agree with the Nd content in ferromanganese sediments and differ from the observed amounts in the Pacific samples. These data indicate the existence of distinctive differences in the isotopic composition of Nd in the waters of major oceans; the average values determined from seawater and ferromanganese sediments are considerably lower than in sources with oceanic mantle affinities showing that the REE in the oceans is dominated by continental sources. The Nd isotopic variations in seawater are applied to relate the residence time of Nd and mixing rates between the oceans.

  15. General physical fundamentals of isotope hydrology

    International Nuclear Information System (INIS)

    Moser, H.; Rauert, W.

    1976-01-01

    A description is given of the measurement and measuring units of stable isotopes, the physical properties, measurement and measuring units of radioactive isotopes, the fundamentals of the tracer technique, the environmental isotope distribution in the hydrosphere and the radiation protection in isotope hydrological investigations. (HK) [de

  16. Raman scattering method and apparatus for measuring isotope ratios and isotopic abundances

    International Nuclear Information System (INIS)

    Harney, R.C.; Bloom, S.D.

    1978-01-01

    Raman scattering is used to measure isotope ratios and/or isotopic abundances. A beam of quasi-monochromatic photons is directed onto the sample to be analyzed, and the resulting Raman-scattered photons are detected and counted for each isotopic species of interest. These photon counts are treated mathematically to yield the desired isotope ratios or isotopic abundances

  17. Design of the Advanced Rare Isotope Separator ARIS at FRIB

    Energy Technology Data Exchange (ETDEWEB)

    Hausmann, M., E-mail: hausmann@frib.msu.edu [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Aaron, A.M. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Amthor, A.M. [Dept. of Physics and Astronomy, Bucknell University, Lewisburg, PA 17837 (United States); Avilov, M.; Bandura, L.; Bennett, R.; Bollen, G.; Borden, T. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Burgess, T.W. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Chouhan, S.S. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Graves, V.B. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Mittig, W. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Morrissey, D.J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Pellemoine, F.; Portillo, M.; Ronningen, R.M.; Schein, M. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Sherrill, B.M. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Zeller, A. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States)

    2013-12-15

    The Facility for Rare Isotopes Beams (FRIB) at Michigan State University will use projectile fragmentation and induced in-flight fission of heavy-ion primary beams at energies of 200 MeV/u and higher and at a beam power of 400 kW to generate rare isotope beams for experiments in nuclear physics, nuclear astrophysics, and fundamental symmetries, as well as for societal needs. The Advanced Rare Isotope Separator (ARIS) has been designed as a three-stage fragment separator for the efficient collection and purification of the rare isotope beams of interest. A vertically bending preseparator (first stage) with production target and beam dump is fully integrated into a production target facility hot cell with remote handling. The new separator compresses the accepted momentum width of up to ±5% of the beam by a factor of three in the standard operational mode. Provisions for alternate operational modes for specific cases are included in the design. This preseparator is followed by two, horizontally-bending separator stages (second and third stages) utilizing the magnets from the existing A1900 fragment separator at the National Superconducting Cyclotron Laboratory (NSCL). These stages can alternatively be coupled to a single high-resolution separator stage, resulting in the flexibility to optimize the operation for different experiments, including momentum tagging and in-flight particle identification of rare isotope beams. The design of ARIS will be presented with an emphasis on beam physics characteristics, and anticipated operational modes will be described.

  18. Discrimination of ginseng cultivation regions using light stable isotope analysis.

    Science.gov (United States)

    Kim, Kiwook; Song, Joo-Hyun; Heo, Sang-Cheol; Lee, Jin-Hee; Jung, In-Woo; Min, Ji-Sook

    2015-10-01

    Korean ginseng is considered to be a precious health food in Asia. Today, thieves frequently compromise ginseng farms by pervasive theft. Thus, studies regarding the characteristics of ginseng according to growth region are required in order to deter ginseng thieves and prevent theft. In this study, 6 regions were selected on the basis of Korea regional criteria (si, gun, gu), and two ginseng-farms were randomly selected from each of the 6 regions. Then 4-6 samples of ginseng were acquired from each ginseng farm. The stable isotopic compositions of H, O, C, and N of the collected ginseng samples were analyzed. As a result, differences in the hydrogen isotope ratios could be used to distinguish regional differences, and differences in the nitrogen isotope ratios yielded characteristic information regarding the farms from which the samples were obtained. Thus, stable isotope values could be used to differentiate samples according to regional differences. Therefore, stable isotope analysis serves as a powerful tool to discriminate the regional origin of Korean ginseng samples from across Korea. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Development of fast-release solid catchers for rare isotopes

    Science.gov (United States)

    Nolen, Jerry; Greene, John; Elam, Jeffrey; Mane, Anil; Sampathkumaran, Uma; Winter, Raymond; Hess, David; Mushfiq, Mohammad; Stracener, Daniel; Wiendenhoever, Ingo

    2015-04-01

    Porous solid catchers of rare isotopes are being developed for use at high power heavy ion accelerator facilities such as RIKEN, FRIB, and RISP. Compact solid catchers are complementary to helium gas catchers for parasitic harvesting of rare isotopes in the in-flight separators. They are useful for short lived isotopes for basic nuclear physics research and longer-lived isotopes for off-line applications. Solid catchers can operate effectively with high intensity secondary beams, e.g. >> 1E10 atoms/s with release times as short as 10-100 milliseconds. A new method using a very sensitive and efficient RGA has been commissioned off-line at Argonne and is currently being shipped to Florida State University for in-beam measurements of the release curves using stable beams. The same porous solid catcher technology is also being evaluated for use in targets for the production of medical isotopes such as 211-At. Research supported by the U.S. DOE Office of Nuclear Physics under the SBIR Program and Contract # DE-AC02-06CH11357 and a University of Chicago Comprehensive Cancer Center/ANL Pilot Project.

  20. Medical Isotope Production Analyses In KIPT Neutron Source Facility

    International Nuclear Information System (INIS)

    Talamo, Alberto; Gohar, Yousry

    2016-01-01

    Medical isotope production analyses in Kharkov Institute of Physics and Technology (KIPT) neutron source facility were performed to include the details of the irradiation cassette and the self-shielding effect. An updated detailed model of the facility was used for the analyses. The facility consists of an accelerator-driven system (ADS), which has a subcritical assembly using low-enriched uranium fuel elements with a beryllium-graphite reflector. The beryllium assemblies of the reflector have the same outer geometry as the fuel elements, which permits loading the subcritical assembly with different number of fuel elements without impacting the reflector performance. The subcritical assembly is driven by an external neutron source generated from the interaction of 100-kW electron beam with a tungsten target. The facility construction was completed at the end of 2015, and it is planned to start the operation during the year of 2016. It is the first ADS in the world, which has a coolant system for removing the generated fission power. Argonne National Laboratory has developed the design concept and performed extensive design analyses for the facility including its utilization for the production of different radioactive medical isotopes. 99 Mo is the parent isotope of 99m Tc, which is the most commonly used medical radioactive isotope. Detailed analyses were performed to define the optimal sample irradiation location and the generated activity, for several radioactive medical isotopes, as a function of the irradiation time.

  1. Medical Isotope Production Analyses In KIPT Neutron Source Facility

    Energy Technology Data Exchange (ETDEWEB)

    Talamo, Alberto [Argonne National Lab. (ANL), Argonne, IL (United States); Gohar, Yousry [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-01

    Medical isotope production analyses in Kharkov Institute of Physics and Technology (KIPT) neutron source facility were performed to include the details of the irradiation cassette and the self-shielding effect. An updated detailed model of the facility was used for the analyses. The facility consists of an accelerator-driven system (ADS), which has a subcritical assembly using low-enriched uranium fuel elements with a beryllium-graphite reflector. The beryllium assemblies of the reflector have the same outer geometry as the fuel elements, which permits loading the subcritical assembly with different number of fuel elements without impacting the reflector performance. The subcritical assembly is driven by an external neutron source generated from the interaction of 100-kW electron beam with a tungsten target. The facility construction was completed at the end of 2015, and it is planned to start the operation during the year of 2016. It is the first ADS in the world, which has a coolant system for removing the generated fission power. Argonne National Laboratory has developed the design concept and performed extensive design analyses for the facility including its utilization for the production of different radioactive medical isotopes. 99Mo is the parent isotope of 99mTc, which is the most commonly used medical radioactive isotope. Detailed analyses were performed to define the optimal sample irradiation location and the generated activity, for several radioactive medical isotopes, as a function of the irradiation time.

  2. Fuel reprocessing data validation using the isotope correlation technique

    International Nuclear Information System (INIS)

    Persiani, P.J.; Bucher, R.G.; Pond, R.B.; Cornella, R.J.

    1990-01-01

    The Isotope Correlation Technique (ICT), in conjunction with the gravimetric (Pu/U ratio) method for mass determination, provides an independent verification of the input accountancy at the dissolver or accountancy stage of the reprocessing plant. The Isotope Correlation Technique has been applied to many classes of domestic and international reactor systems (light-water, heavy-water, and graphite reactors) operating in a variety of modes (power, research, and production reactors), and for a variety of reprocessing fuel cycle management strategies. Analysis of reprocessing operations data based on isotopic correlations derived for assemblies in a PWR environment and fuel management scheme, yielded differences between the measurement-derived and ICT-derived plutonium mass determinations of (- 0.02 ± 0.23)% for the measured U-235 and (+ 0.50 ± 0.31)% for the measured Pu-239, for a core campaign. The ICT analyses has been implemented for the plutonium isotopics in a depleted uranium assembly in a heavy-water, enriched uranium system and for the uranium isotopes in the fuel assemblies in light-water, highly-enriched systems

  3. Isotopic Changes During Digestion: Protein

    Science.gov (United States)

    Tuross, N.

    2013-12-01

    Nutrient and hydrological inputs traverse a complicated route of pH, enzymatic and cellular processes in digestion in higher animals. The end products of digestion are the starting products for biosynthesis that are often used to interpret past life-ways. Using an artificial gut system, the isotopic changes (dD, d18O, d13C and d15N) of protein are documented. Three separate protein sources are subjected to the conditions, chemical and enzymatic, found in the stomach and upper small intestine with only a small shift in the oxygen isotopic composition of the proteins observed. Middle to lower small intestine parameters produced both greater isotopic effects and significantly lower molecular weight products. The role of the gastric enterocyte and the likely involvement of the internal milieu of this cell in the isotopic composition of amino acids that are transported to the liver are reported.

  4. High atomic weight isotope separator

    International Nuclear Information System (INIS)

    Book, D.L.

    1978-01-01

    A continuously operating device is described which separates one isotopic species of a given element from a mixture. The given element is vaporized and formed into a neutral beam containing the isotopes desired to be separated. The plasma is accelerated through a laser beam which is formed by two separate lasers which operate in the continuous wave mode in which the beams are as nearly as possible in the same beam path. The two laser output beams excite and ionize the isotope of interest while leaving the remaining atoms unaffected. The ionized isotopes are then separated from the beam by an electrostatic deflection technique and the unaffected atoms continue on in their path and are directed to a recovery device

  5. Discoveries of isotopes by fission

    Indian Academy of Sciences (India)

    country of discovery as well as the production mechanism used to produce the isotopes. ... the disintegration products of bombarded uranium, as a consequence of a ..... advanced accelerator and newly developed separation and detection ...

  6. Isotope separation by standing waves

    International Nuclear Information System (INIS)

    Altshuler, S.

    1984-01-01

    The separation of isotopes is accomplished by scattering a beam of particles from a standing electromagnetic wave. The particles may consist of either atoms or molecules, the beam having in either case a desired isotope and at least one other. The particle beam is directed so as to impinge on the standing electromagnetic wave, which may be a light wave. The particles, that is, the atomic or molecular quantum-mechanical waves, see basically a diffraction grating corresponding to the troughs and peaks of the electromagnetic wave. The frequency of the standing electromagnetic wave substantially corresponds to an internal energy level-transition of the desired isotope. Accordingly, the desired isotope is spatially separated by being scattered or diffracted. (author)

  7. Isotope analysis in petroleum exploration

    International Nuclear Information System (INIS)

    Rodrigues, R.

    1982-01-01

    The study about isotopic analysis in petroleum exploration performed at Petrobras Research Center is showed. The results of the petroleum recuperation in same Brazilian basin and shelves are comented. (L.H.L.L.) [pt

  8. Isotope-based quantum information

    CERN Document Server

    G Plekhanov, Vladimir

    2012-01-01

    The present book provides to the main ideas and techniques of the rapid progressing field of quantum information and quantum computation using isotope - mixed materials. It starts with an introduction to the isotope physics and then describes of the isotope - based quantum information and quantum computation. The ability to manipulate and control electron and/or nucleus spin in semiconductor devices provides a new route to expand the capabilities of inorganic semiconductor-based electronics and to design innovative devices with potential application in quantum computing. One of the major challenges towards these objectives is to develop semiconductor-based systems and architectures in which the spatial distribution of spins and their properties can be controlled. For instance, to eliminate electron spin decoherence resulting from hyperfine interaction due to nuclear spin background, isotopically controlled devices are needed (i.e., nuclear spin-depleted). In other emerging concepts, the control of the spatial...

  9. Isotope shifts in unstable nuclei

    International Nuclear Information System (INIS)

    Rebel, H.

    1980-05-01

    Current experimental investigations of isotope shifts in atomic spectra of unstable nuclei and the resulting information about size and shape of nuclei far off stability are discussed with reference to some representative examples. (orig.)

  10. Dielectrophoretic separation of gaseous isotopes

    International Nuclear Information System (INIS)

    McConnell, D.B.

    1976-01-01

    This invention relates to a process for the separation of gaseous isotopes by electrophoresis assisted by convective countercurrent flow and to an apparatus for use in the process. The invention is especially applicable to heavy water separation from steam; however, it is to be understood that the invention is broadly applicable to the separation of gaseous isotopes having different dipole moments and/or different molecular weights. (author)

  11. Isotope effects in photochemical rearrangements

    International Nuclear Information System (INIS)

    Sommer, F.

    1983-01-01

    Taking anthracene resp. 9-deuteroanthracene as the initial substance, different substitution products have been prepared. The products originating by direct photolysis have been characterized and their structure has been determined. By comparing the measured kinetic isotope effect and the quantum yield of the nondeuterated and the monodeuterated fluorenes formed it could been demonstrated that the isotope effect mainly is due to the reaction rates and the influence of the deuterium substitution upon the radiationless desactivation against that is small. (HBR) [de

  12. Isotope studies in brain diseases

    Energy Technology Data Exchange (ETDEWEB)

    Silfverskioeld, B [Department of Neurology, Soedersjukhuset, S-100 64 Stockholm (Sweden)

    1978-09-01

    Serial pictures of cerebral isotope flow and accumulation after intravenous injection provide several kinds of valuable diagnostic information. The reliability can be increased by using computer-processed pictures on a TV screen and by numerical analysis in accordance with paritcular programs constructed for our routine work. An isotope study should be done when computerized transmission tomography scans have failed to provide a conclusive diagnosis. It should then be performed with optimal technique in order to reduce the need of angiograms.

  13. Isotopes and radiations in agriculture

    International Nuclear Information System (INIS)

    Sawant, A.G.

    1998-01-01

    Some of the spectacular advances in agriculture in developing nations have stimulated wide interest both in basic as well as adaptive research and in harnessing all the tools that science can offer for progress of agriculture. The nuclear tools are relevant in this respect and also offer particular promise in some areas. Ionising radiations and isotopes have immense applications in agriculture. Both radioisotopes and stable isotopes are being used

  14. Phonon scattering by isotopic impurities

    International Nuclear Information System (INIS)

    Dacol, D.K.

    1974-06-01

    The effects upon vibrations of a perfect crystal lattice due to the replacement of some of its atoms by isotopes of these atoms are studied. The approach consists in considering the isotopic impurities as scattering centres for the quanta of the elastic waves the objective is to obtain the scattering amplitudes. These amplitudes are obtained through a canonical transformation method which was introduced by Chevalier and Rideau in the study of the Wentzel's model in quantum field theory

  15. Pharmaceuticals labelled with stable isotopes

    International Nuclear Information System (INIS)

    Krumbiegel, P.

    1986-11-01

    The relatively new field of pharmaceuticals labelled with stable isotopes is reviewed. Scientific, juridical, and ethical questions are discussed concerning the application of these pharmaceuticals in human medicine. 13 C, 15 N, and 2 H are the stable isotopes mainly utilized in metabolic function tests. Methodical contributions are given to the application of 2 H, 13 C, and 15 N pharmaceuticals showing new aspects and different states of development in the field under discussion. (author)

  16. On the problems of separation work unit for the laser isotope separation

    International Nuclear Information System (INIS)

    Wang, Lijun

    2008-01-01

    The concept of separation power or separation work, which is widely used in Uranium isotope separation industry is introduced historically for the weak separating machine and so-called 'ideal cascade'. Therefore, when this concept is applied to a laser isotope separation facility, which is deeply different from a cascade in structure and in mechanism of separation, some confusions may occur. By comparison the costs of SWU of laser isotope separation facility and an ideal cascade we come to a conclusion: the concept of separation work is not applicable for laser isotope separation. In order to compare the economics of laser isotope separation technique with diffusion or centrifugation techniques an equivalent cost of SWU is suggested in this paper. (author)

  17. Apparatus for isotopic separation using a high-frequency wave and coherent radiation

    International Nuclear Information System (INIS)

    Mourier, G.

    1983-11-01

    The purpose of the present invention is an apparatus for industrial separation of isotopes, using a high-frequency electromagnetic field and coherent radiation such as that from a laser. Separation of isotopes by isotopically selective ionization, followed by entrainment of the ions by means of a magnetic field, is known. The selective ionization operation can be carried out in two consecutive stages: excitation of the chosen isotope, from the ground energy state to a specified excited level, near ionization; the energy required for this first stage can be supplied by means of a laser, the laser radiation being characterized for high power and well-defined frequency; this stage offers the advantage of being easily made isotopically selective; then ionization of the excited atoms by means of supplying relatively weak energy which should be insufficient to ionize the nonexcited ions; this second stage can also be carried out by means of a laser

  18. Isotopic study of Karst water

    International Nuclear Information System (INIS)

    Leskovsek-Sefman, H.

    1985-01-01

    Measurement of the isotopic composition of water formed part of an extended investigation of the water drainage system in the Slovenian Karst. These studies were planned to complement geological and speleological investigations which are already being performed in this area, with the knowledge of the mechanism of changes in the isotopic composition of water in the natural environment on some smaller locations, Planina cave near Postojna where the vertical percolation of meteoric water through the karstified carbonate ceiling was studied and the water catchment areas of some small rivers, Ljubljanica, Rizana and Idrijca. Mass spectrometric investigations of the isotopic composition of some elements ( 18 O, D, 13 C and T) in water and in dissolved carbonates, as well as the isotopic composition of 18 O and 13 C in cave carbonates were performed. The results allow to conclude that the waters in karst aquifers in spite of producing the homogenisation to a great extent, qualitative determination of the retention time and of the prevailing sources for some springs and surface and underground water flows is nevertheless possible. The isotopic composition of 18 O in water and of 18 O and 13 C in dissolved carbonates depends on climatic conditions and on denudation processes. The investigation of cave carbonates revealed that they have different isotopic compositions of 18 O and 13 C because of different locations and also different ages

  19. Isotopic meteoric line for Colombia

    International Nuclear Information System (INIS)

    Rodriguez N, Cesar O

    2004-01-01

    Isotope analyses from representative rainfall samples taken from different areas in Colombia were processed to yield the meteoric line. Stable isotope composition in precipitation reflects the effects of temperature, altitude and of the continental site, being affected by different sources of atmospheric humidity over the Colombian territory. There is a seasonal variation in isotopic composition of precipitation with grater σ deviation during the rainy season and lower values in the dry season. In coastal areas the variation is smaller and is more pronounced than at continental stations. Correlation between altitude and isotope content led to equations, which indicate, on a regional level, a change in isotopic composition with altitude, of about 0.5 σ units per 200 m, for O 18 and 4 σ units per 200 m for H 2 . Such equations may be used to identify the original altitude of precipitation water, in hydrological surface and groundwater studies. Meteoric line and the concepts derived from the resulting equations presented in this paper may be applied to the interpretation of isotope analysis in future hydrological studies, particularly in areas without available data

  20. Isotope-based quantum information

    International Nuclear Information System (INIS)

    Plekhanov, Vladimir G.

    2012-01-01

    The present book provides to the main ideas and techniques of the rapid progressing field of quantum information and quantum computation using isotope - mixed materials. It starts with an introduction to the isotope physics and then describes of the isotope - based quantum information and quantum computation. The ability to manipulate and control electron and/or nucleus spin in semiconductor devices provides a new route to expand the capabilities of inorganic semiconductor-based electronics and to design innovative devices with potential application in quantum computing. One of the major challenges towards these objectives is to develop semiconductor-based systems and architectures in which the spatial distribution of spins and their properties can be controlled. For instance, to eliminate electron spin decoherence resulting from hyperfine interaction due to nuclear spin background, isotopically controlled devices are needed (i.e., nuclear spin-depleted). In other emerging concepts, the control of the spatial distribution of isotopes with nuclear spins is a prerequisite to implement the quantum bits (or qbits). Therefore, stable semiconductor isotopes are important elements in the development of solid-state quantum information. There are not only different algorithms of quantum computation discussed but also the different models of quantum computers are presented. With numerous illustrations this small book is of great interest for undergraduate students taking courses in mesoscopic physics or nanoelectronics as well as quantum information, and academic and industrial researches working in this field.

  1. Isotope separation apparatus and method

    International Nuclear Information System (INIS)

    Feldman, B. J.

    1985-01-01

    The invention relates to an improved method and apparatus for laser isotope separation by photodeflection. A molecular beam comprising at least two isotopes to be separated intersects, preferably substantially perpendicular to one broad side of the molecular beam, with a laser beam traveling in a first direction. The laser beam is reflected back through the molecular beam, preferably in a second direction essentially opposite to the first direction. Because the molecules in the beam occupy various degenerate energy levels, if the laser beam comprises chirped pulses comprising selected wavelengths, the laser beam will very efficiently excite substantially all unexcited molecules and will cause stimulated emission of substantially all excited molecules of a selected one of the isotopes in the beam which such pulses encounter. Excitation caused by first direction chirped pulses moves molecules of the isotope excited thereby in the first direction. Stimulated emission of excited molecules of the isotope is brought about by returning chirped pulses traveling in the second direction. Stimulated emission moves emitting molecules in a direction opposite to the photon emitted. Because emitted photons travel in the second direction, emitting molecules move in the first direction. Substantial molecular movement of essentially all the molecules containing the one isotope is accomplished by a large number of chirped pulse-molecule interactions. A beam corer collects the molecules in the resulting enriched divergent portions of the beam

  2. Separation of uranium isotopes

    International Nuclear Information System (INIS)

    Ehrfeld, W.; Ehrfeld, U.

    1977-01-01

    In the nuclear fuel cycle, uranium enrichment is not a principal problem of technological feasibility. Several processes exist for producing LWR fuel and the enrichment method can be selected in consideration of economical, environmental, and political aspects. To date, the gaseous diffusion process constitutes the major part of enrichment capacity. This process has been well demonstrated for over 30 years and, as a matter of fact, no major technological and economical progress is to be expected in the future. Because of their comparatively high development potential, the centrifuge and the separation nozzle method may become increasingly favorable in economics. The development of the centrifuge process which is superior by its low specific energy consumption aims at technological improvements. In the separation nozzle process which offers the advantage of a comparatively simple technology a further reduction of the specific energy consumption is to be expected because of the thermodynamically favorable separation mechanism of this process. Laser isotope separation methods are still on the laboratory scale, although large financial funds have been spent. (orig.) [de

  3. Insects, isotopes and radiations

    International Nuclear Information System (INIS)

    Lingkvist, D.A.

    1987-01-01

    The IAEA activity on coordinating the IAEA member-state efforts in the field of pest control is considered. A complex program of agricultural pest control (IPM), applied in many parts of the world is developed. The program provides for the use of natural means of control and cases of critical pest numbers-the use of insecticides. When controlling certain types of insects it is advisable to apply the 'large area control' methods which provide for the insect destruction in places of their concentration prior to migration. Methods of pest control over large areas also include radiation sexual sterilization method (SSM), application of insect phoromons (sexual attractants) to prevent mating, other types of chemical attractants, traps, mass cultivation and reproduction of parasite plants and animals, destroying insects, as well as improvement of host-plant resistance. A great attention is paid to isotope and radiation application in pest control (labelling, sexual sterilization using ionising radiation, radiation application in genetic engineering, mutant plant cultivation)

  4. Hydrogen isotope technology

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Hydrogen pumping speeds on panels of molecular sieve types 5A and Na-Y were compared for a variety of sieve (and chevron) temperatures between 10 and 30 K. Although pumping speeds declined with time, probably because of the slow diffusion of hydrogen from the surface of the sieve crystals into the internal regions, the different sieve materials and operating conditions could be compared using time-averaged pump speeds. The (average) pumping speeds declined with increasing temperature. Under some conditions, the Na-Y sieve performed much better than the 5A sieve. Studies of the effect of small concentrations (approx. 4%) of hydrogen on helium pumping indicate that compound cryopumps in fusion reactors will not have to provide complete screening of hydrogen from helium panels. The concentrations of hydrogen did not lower effective helium pumping speeds or shorten the helium operating period between instabilities. Studies of tritium recovery from blankets of liquid lithium focused on design and construction of a flowing-lithium test system and on ultimate removal of tritium from yttrium sorbents. At 505 0 C, tritium release from yttrium behaves as a diffusion-controlled process, but the release rates are very low. Apparently, higher temperatures will be required for effective sorbent regeneration. An innovative technique for separating hydrogen isotopes by using bipolar electrolysis with permeable electrodes was analyzed to determine its potential usefulness in multistage separation

  5. Stable isotope enrichment by thermal diffusion

    International Nuclear Information System (INIS)

    Vasaru, Gheorghe

    2003-01-01

    Thermal diffusion (TD) in both gaseous and liquid phase has been the subject of extensive experimental and theoretical investigations, especially after the invention by K. Clusius and G. Dickel of the thermal diffusion column, sixty years ago. This paper gives a brief overview of the most important applications and developments of this transport phenomenon for enrichment of 13 C and of some noble gases isotopes in our institute. The results of calculations of the transport coefficients H and K for a concentric tube type TD column, operated with methane as process gas, are presented. Static separation factor at equilibrium vs gas pressure has been calculated for various molecular models. The experimental separation factors for different gas pressure were found to be consistent with those calculated for the inverse power repulsion model and the Lennard-Jones model. The most important characteristics of a seven-stage cascade consisting of 19 TD columns of concentric tube type are given. This system has been constructed and successfully operated at a temperature of 673 K and produces an enrichment of methane of natural isotopic 13 C abundance, up to the concentration of 25% 13 CH 4 . Enrichment of the noble gases isotopes implies: - a . Enrichment of 20 Ne and 22 Ne in a eight-stage cascade consisting of 8 TD columns; - b. enrichment of 46 Ar in a seven-stage cascade consisting of TD columns and finally; - c. enrichment of 78 Kr and 86 Kr in a fifteen-stage cascade, consisting of 35 TD columns. For all these installations we have adopted TD columns of hot wire type (4 m in length), operated at a temperature of 1073 K. (author)

  6. Significance of iodine radioactive isotopes in the problem of radiation safety of nuclear fuel cycle

    International Nuclear Information System (INIS)

    Malenchenko, A.F.; Mironov, V.P.

    1979-01-01

    The data on actual wastes of nuclear-power plants, environmental distribution and biological effects of iodine radioactive isotopes have been analyzed. Dose-response relationship is estimated as well as its significance for struma maligna development under ionizing radiation and the contribution of iodine radionuclides resulted from nuclear power engineering to this process

  7. Global Security, Medical Isotopes, and Nuclear Science

    Science.gov (United States)

    Ahle, Larry

    2007-10-01

    Over the past century basic nuclear science research has led to the use of radioactive isotopes into a wide variety of applications that touch our lives everyday. Some are obvious, such as isotopes for medical diagnostics and treatment. Others are less so, such as National/Global security issues. And some we take for granted, like the small amount of 241 Am that is in every smoke detector. At the beginning of this century, we are in a position where the prevalence and importance of some applications of nuclear science are pushing the basic nuclear science community for improved models and nuclear data. Yet, at the same time, the push by the basic nuclear science community to study nuclei that are farther and farther away from stability also offer new opportunities for many applications. This talk will look at several global security applications of nuclear science, summarizing current R&D and need for improved nuclear data It will also look at how applications of nuclear science, such as to medicine, will benefit from the push for more and more powerful radioactive ion beam facilities.

  8. Global Security, Medical Isotopes, and Nuclear Science

    International Nuclear Information System (INIS)

    Ahle, Larry

    2007-01-01

    Over the past century basic nuclear science research has led to the use of radioactive isotopes into a wide variety of applications that touch our lives everyday. Some are obvious, such as isotopes for medical diagnostics and treatment. Others are less so, such as National/Global security issues. And some we take for granted, like the small amount of 241 Am that is in every smoke detector. At the beginning of this century, we are in a position where the prevalence and importance of some applications of nuclear science are pushing the basic nuclear science community for improved models and nuclear data. Yet, at the same time, the push by the basic nuclear science community to study nuclei that are farther and farther away from stability also offer new opportunities for many applications. This talk will look at several global security applications of nuclear science, summarizing current R and D and need for improved nuclear data It will also look at how applications of nuclear science, such as to medicine, will benefit from the push for more and more powerful radioactive ion beam facilities

  9. Calcium Isotope Analysis by Mass Spectrometry

    Science.gov (United States)

    Boulyga, S.; Richter, S.

    2010-12-01

    The variations in the isotopic composition of calcium caused by fractionation in heterogeneous systems and by nuclear reactions can provide insight into numerous biological, geological, and cosmic processes, and therefore isotopic analysis finds a wide spectrum of applications in cosmo- and geochemistry, paleoclimatic, nutritional, and biomedical studies. The measurement of calcium isotopic abundances in natural samples has challenged the analysts for more than three decades. Practically all Ca isotopes suffer from significant isobaric interferences, whereas low-abundant isotopes can be particularly affected by neighboring major isotopes. The extent of natural variations of stable isotopes appears to be relatively limited, and highly precise techniques are required to resolve isotopic effects. Isotope fractionation during sample preparation and measurements and instrumental mass bias can significantly exceed small isotope abundance variations in samples, which have to be investigated. Not surprisingly, a TIMS procedure developed by Russell et al. (Russell et al., 1978. Geochim Cosmochim Acta 42: 1075-1090) for Ca isotope measurements was considered as revolutionary for isotopic measurements in general, and that approach is used nowadays (with small modifications) for practically all isotopic systems and with different mass spectrometric techniques. Nevertheless, despite several decades of calcium research and corresponding development of mass spectrometers, the available precision and accuracy is still not always sufficient to achieve the challenging goals. This presentation discusses figures of merits of presently used analytical methods and instrumentation, and attempts to critically assess their limitations. Additionally, the availability of Ca isotope reference materials will be discussed.

  10. Target-fueled nuclear reactor for medical isotope production

    Science.gov (United States)

    Coats, Richard L.; Parma, Edward J.

    2017-06-27

    A small, low-enriched, passively safe, low-power nuclear reactor comprises a core of target and fuel pins that can be processed to produce the medical isotope .sup.99Mo and other fission product isotopes. The fuel for the reactor and the targets for the .sup.99Mo production are the same. The fuel can be low enriched uranium oxide, enriched to less than 20% .sup.235U. The reactor power level can be 1 to 2 MW. The reactor is passively safe and maintains negative reactivity coefficients. The total radionuclide inventory in the reactor core is minimized since the fuel/target pins are removed and processed after 7 to 21 days.

  11. Pulsed CO laser for isotope separation of uranium

    Energy Technology Data Exchange (ETDEWEB)

    Baranov, Igor Y.; Koptev, Andrey V. [Rocket-Space Technics Department, Baltic State Technical University, 1, 1st Krasnoarmeyskaya st.,St. Petersburg, 190005 (Russian Federation)

    2012-07-30

    This article proposes a technical solution for using a CO laser facility for the industrial separation of uranium used in the production of fuel for nuclear power plants, employing a method of laser isotope separation of uranium with condensation repression in a free jet. The laser operation with nanosecond pulse irradiation can provide an acceptable efficiency in the separating unit and a high efficiency of the laser with the wavelength of 5.3 {mu}m. In the present work we also introduce a calculation model and define the parameters of a mode-locked CO laser with a RF discharge in the supersonic stream. The average pulsed CO laser power of 3 kW is sufficient for efficient industrial isotope separation of uranium in one stage.

  12. ITER isotope separation system

    International Nuclear Information System (INIS)

    Busigin, A.; Sood, S.K.; Kveton, O.K.; Sherman, R.H.; Anderson, J.L.

    1990-09-01

    This document presents the results of a study that examined the technical operating and economic viability of an alternative Isotope Separation System (ISS) design based on the distributed design concept. In the distributed design, the ISS is broken up into local independently operable subsystems matched to local processing requirements. The distributed design accepts the same feeds and produces essentially the same products as the reference design. The distributed design consists of two separate, independent subsystems. The first, called ISS-H, receives only protium-dominated streams and waste water from tritium extraction. It has two cryogenic distillation columns and can produce a 50 percent D, 50 percent T product since it lacks D/T separation capability. A final 80 percent T 2 concentration product can be obtained by blending the 50 percent T 2 stream from ISS-H with the more than 99 percent T 2 stream from the second subsystem, ISS-D. The second subsystem receives only deuterium-dominated feeds, which also contain some protium. ISS-D is as complex as the reference design, but smaller. Although each subsystem has some advantages, such as only two cryogenic distillation columns in ISS-H and better than 99 percent steady state T 2 product in ISS-D, the combined subsystems do not offer any real advantage compared to the reference IISS. The entire distributed ISS design has been simulated using Ontario Hydro's FLOSHEET steady state process simulator. Dynamic analysis has not been done for the distributed design. (10 refs., 3 figs., 8 tabs.)

  13. First stable isotope analysis of Asiatic wild ass tail hair from the Mongolian Gobi.

    Science.gov (United States)

    Horacek, Micha; Sturm, Martina Burnik; Kaczensky, Petra

    Stable isotope analysis has become a powerful tool to study feeding ecology, water use or movement pattern in contemporary, historic and ancient species. Certain hair and teeth grow continuously, and when sampled longitudinally can provide temporally explicit information on dietary regime and movement pattern. In an initial trial, we analysed a tail sample of an Asiatic wild ass ( Equus hemionus ) from the Mongolian Gobi. We found seasonal variations in H, C and N isotope patterns, likely being the result of temporal variations in available feeds, water supply and possibly physiological status. Thus stable isotope analysis shows promise to study the comparative ecology of the three autochthonous equid species in the Mongolian Gobi.

  14. Isotope correlation techniques for verifying input accountability measurements at a reprocessing plant

    International Nuclear Information System (INIS)

    Umezawa, H.; Nakahara, Y.

    1983-01-01

    Isotope correlation techniques were studied to verify input accountability measurements at a reprocessing plant. On the basis of a historical data bank, correlation between plutonium-to-uranium ratio and isotopic variables was derived as a function of burnup. The burnup was determined from the isotopic ratios of uranium and plutonium, too. Data treatment was therefore made in an iterative manner. The isotopic variables were defined to cover a wide spectrum of isotopes of uranium and plutonium. The isotope correlation techniques evaluated important parameters such as the fuel burnup, the most probable ratio of plutonium to uranium, and the amounts of uranium and plutonium in reprocessing batches in connection with fresh fuel fabrication data. In addition, the most probable values of isotope abundance of plutonium and uranium could be estimated from the plutonium-to-uranium ratio determined, being compared with the reported data for verification. A pocket-computer-based system was developed to enable inspectors to collect and evaluate data in a timely fashion at the input accountability measurement point by the isotope correlation techniques. The device is supported by battery power and completely independent of the operator's system. The software of the system was written in BASIC. The data input can be stored in a cassette tape and transferred into a higher level computer. The correlations used for the analysis were given as a form of analytical function. Coefficients for the function were provided relevant to the type of reactor and the initial enrichment of fuel. (author)

  15. Isotopic composition of Danube water in the pre-delta section from the years 2009 - 2012

    Directory of Open Access Journals (Sweden)

    RANK Dieter

    2013-12-01

    Full Text Available The isotopic composition of river water in the Danube Basin is mainly governed by the isotopic composition of precipitation in the catchment area, evaporation effects play only a minor role. Short-term and long-term isotope signals from precipitation are thus transmitted through the whole catchment. The isotopic composition of Danube water in the Delta region so provides an integrated isotope signal for climatic/hydrological conditions and changes in the whole catchment. The aim of this investigation was to establish a representative isotope monitoring near the Danube Delta. The results showed that the Danube River is regarding isotope content fully mixed at the bifurcation of the Danube Delta arms. Therefore routine sampling at only one location in the pre-delta region should be sufficient to obtain a representative isotope record for the whole Danube Basin. The δ 18 O time series from November 2009 to May 2012 (sampling twice a month shows seasonal variations in the range of -9.8 ‰ ± 0.7 ‰ with a minimum in spring and a maximum in autumn. The tritium results exhibit the influence of short term contaminations due to human activities. The expected “environmental” tritium content of river water in Central Europe would be about 10 TU. During this investigation 3 H values up to 100 TU were observed in the pre-delta section. This indicates short terms releases of tritium from local sources such as nuclear power plants in the Danube river system.

  16. LACAN Code for global simulation of SILVA laser isotope separation process

    International Nuclear Information System (INIS)

    Quaegebeur, J.P.; Goldstein, S.

    1991-01-01

    Functions used for the definition of a SILVA separator require quite a lot of dimensional and operating parameters. Sizing a laser isotope separation plant needs the determination of these parameters for optimization. In the LACAN simulation code, each elementary physical process is described by simplified models. An example is given for a uranium isotope separation plant whose separation power is optimized with 6 parameters [fr

  17. Preliminary review on isotope separation of long life fission products. Application research of laser isotope separation to 135Cs

    International Nuclear Information System (INIS)

    Oshita, Hironori; Ozawa, Masaki; Ishikawa, Makoto; Koyama, Shin'ichi; Akatsuka, Hiroshi

    2007-09-01

    Recently establishment of self consistent nuclear fuel cycle has been required with respect to economical efficiency, safety and reduction of the load to the environment. Especially 135 Cs included in spent fuel of nuclear power plants has extremely long half life (3.0x10 6 y) and its water solubility leads to the anxiety of exudation into ground water for geologic disposal. The conventional methods for isotope separation based on the mass difference of isotope could not gain large separation factors, which leads to the requirement of operational repetition and large equipment. Furthermore many elements of which the masses are near to that of the object isotope are included in spent fuel, which makes it difficult to expect high separation factor by the methods merely based on the mass difference. Recent technology development of laser e.g. dye laser or semi-conductor laser has come to make it possible in principle to excite a specific isotope and separate it from other isotopes making use of its intrinsic physical and chemical properties of the excited state. This laser isotope separation (LIS) technique is believed to be suitable for cesium because of its stable properties on light absorption and emission and many studies have come to be made. This document reviews the principle, application to the separation of 135 Cs and current status of LIS and reports the subjects to be solved and suggestions; especially laser induced chemical reactions expected as a low-cost and simple equipment isotope separation method. The resulting extracted subjects are 1) the specification of the excited states of cesium i.e. extra-nuclear electron configuration, life (or duration) and transition probability, 2) the factors that may effect on the isotope shift of cesium; the mean square radius of the nucleus, electric quadrupole moment and extra nuclear electron wave function at the nucleus, 3) the factors that may cause the disturbance of the selectivity; resonant energy transference

  18. An overview of copper-laser development for isotope separation

    International Nuclear Information System (INIS)

    Warner, B.E.

    1987-01-01

    We have developed a copper-laser pumped dye-laser system that addresses all of the requirements for atomic vapor laser isotope separation. The requirement for high average power for the laser system has led to the development of copper-laser chains with injection-locked oscillators and multihundred-watt amplifiers. By continuously operating the Laser Demonstration Facility, we gain valuable data for further upgrade and optimization

  19. Co-deposition of palladium with hydrogen isotopes

    International Nuclear Information System (INIS)

    Dash, J.; Ambadkar, A.

    2006-01-01

    Palladium was co-deposited with hydrogen isotopes on a Pd cathode. This resulted in enhanced production of excess thermal power. After electrolysis the Pd Lβ/ Lα ratio was found to be increased in characteristic X-ray spectra from localized, microscopic areas on the surface of the Pd cathode. This suggests the possibility that appreciable amounts of silver are present in these areas. (authors)

  20. Development of Laser Application Technology for Stable Isotope Production

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Do Young; Ko, Kwang Hoon; Kwon, Duck Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)] (and others)

    2007-04-15

    Tl-203 is used as a source material to produce Tl-201 radioisotope which is produced in a cyclotron by irradiating the enriched Tl-203 target. Tl-201 is a radiopharmaceutical for SPECT (single photon emission computerized tomography) to diagnose heart diseases and tumors. This Project aim to develop laser application technology to product stable isotopes such as Tl-203, Yb-168, and Yb-176. For this, photoion extraction device, atomic beam generator, dye lasers, and high power IR lasers are developed.

  1. Development of Laser Application Technology for Stable Isotope Production

    International Nuclear Information System (INIS)

    Jeong, Do Young; Ko, Kwang Hoon; Kwon, Duck Hee

    2007-04-01

    Tl-203 is used as a source material to produce Tl-201 radioisotope which is produced in a cyclotron by irradiating the enriched Tl-203 target. Tl-201 is a radiopharmaceutical for SPECT (single photon emission computerized tomography) to diagnose heart diseases and tumors. This Project aim to develop laser application technology to product stable isotopes such as Tl-203, Yb-168, and Yb-176. For this, photoion extraction device, atomic beam generator, dye lasers, and high power IR lasers are developed

  2. Detection of counterfeit antiviral drug Heptodin and classification of counterfeits using isotope amount ratio measurements by multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) and isotope ratio mass spectrometry (IRMS).

    Science.gov (United States)

    Santamaria-Fernandez, Rebeca; Hearn, Ruth; Wolff, Jean-Claude

    2009-06-01

    Isotope ratio mass spectrometry (IRMS) and multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) are highly important techniques that can provide forensic evidence that otherwise would not be available. MC-ICP-MS has proved to be a very powerful tool for measuring high precision and accuracy isotope amount ratios. In this work, the potential of combining isotope amount ratio measurements performed by MC-ICP-MS and IRMS for the detection of counterfeit pharmaceutical tablets has been investigated. An extensive study for the antiviral drug Heptodin has been performed for several isotopic ratios combining MC-ICP-MS and an elemental analyser EA-IRMS for stable isotope amount ratio measurements. The study has been carried out for 139 batches of the antiviral drug and analyses have been performed for C, S, N and Mg isotope ratios. Authenticity ranges have been obtained for each isotopic system and combined to generate a unique multi-isotopic pattern only present in the genuine tablets. Counterfeit tablets have then been identified as those tablets with an isotopic fingerprint outside the genuine isotopic range. The combination of those two techniques has therefore great potential for pharmaceutical counterfeit detection. A much greater power of discrimination is obtained when at least three isotopic systems are combined. The data from these studies could be presented as evidence in court and therefore methods need to be validated to support their credibility. It is also crucial to be able to produce uncertainty values associated to the isotope amount ratio measurements so that significant differences can be identified and the genuineness of a sample can be assessed.

  3. Development of isotope hydrology technology in China

    International Nuclear Information System (INIS)

    Li Zhangsu

    1988-01-01

    The development of isotope hydrology technology in China is described. The isotope technology provides an independent approach for solving hydrological problems. Isotope hydrology is applied in three ways: the use of change in environmental isotopic composition of water (especially used in water resources exploitation), the use of artificial radioactive tracers and the use of redioisotope instruments. Many important achievements have been obtained in application of isotopic hydrology technology. For the sake of promoting rapid development of isotope hydrology the topics on management, technology and others are commented

  4. Isotope hydrogeochemistry in exploration for buried and blind mineralization

    International Nuclear Information System (INIS)

    Andrew, A.S.; Carr, G.R.; Giblin, A.M.; Whitford, D.J.

    2000-01-01

    Buried and blind deposits, with no direct geological or geochemical manifestation at the surface, are becoming increasingly important targets in Australia. One of the key exploration challenges relates to assessing and ranking targets established from geophysical and other remotely sensed surveys. Sub-surface geology is reflected in the geochemistry of groundwaters (Giblin, 1996) and hydrogeochemical methods provide a particularly powerful technique in areas of poor surface exposure, deep weathering and where transported overburden obscures the underlying geology (Giblin, 1997). In such areas several hundred samples are used to define locally prospective areas although how these relate to a specific mineralization style may be difficult to determine. The question of proximity to an orebody is fundamental to mineral exploration and isotopic (S, Pb, Sr) methods are uniquely capable of contributing to an answer. The isotopic composition of ores and waters that interact with ores carries important information about the elemental source; S and Pb are direct ore indicators allowing straight-forward interpretation of possible ore associations. The isotopic methods also provide unequivocal evidence for mixing. The isotopic compositions of S, Pb and Sr in rocks are unaffected by weathering and in natural waters are unaffected by precipitation, evaporation or dilution. Isotopic methods provide information that is complementary to that obtainable from major and trace element abundances. The application of integrated isotopic studies to conventional hydrogeochemical interpretations was tested in several areas (Fig. 1); Menninnie Dam (Pb, Zn; Eyre Peninsula SA), Abra (Ag, Pb; Bangemall Basin WA), Benambra (Cu, Zn, Pb: Lachlan Fold Belt Vic), Goonumbla (Cu, Au; Lachlan Fold Belt NSW) and Kanmantoo (Cu, Pb, Zn, Au; Kanmantoo Fold Belt SA). These were chosen to include different deposit types, tectonic regimes, climatic and topographic environments and groundwater chemistry

  5. Ca isotopes in refractory inclusions

    International Nuclear Information System (INIS)

    Niederer, F.R.; Papanastassiou, D.A.

    1984-01-01

    We report measurements of the absolute isotope abundance of Ca in Ca-Al-rich inclusions from the Allende and Leoville meteorites. Improved high precision measurements are reported also for 46 Ca. We find that nonlinear isotope effects in Ca are extremely rare in these inclusions. The absence of nonlinear effects in Ca, except for the effects in FUN inclusions, is in sharp contrast to the endemic effects in Ti. One fine-grained inclusion shows an excess of 46 Ca of (7 +- 1) per mille, which is consistent with addition of only 46 Ca or of an exotic (*) component with 46 Ca* approx. 48 Ca*. FUN inclusion EK-1-4-1 shows a small 46 Ca excess of (3.3 +- 1.0) per mille; this confirms that the exotic Ca components in EK-1-4-1 were even more deficient in 46 Ca relative to 48 Ca than is the case for normal Ca. The Ca in the Ca-Al-rich inclusions shows mass dependent isotope fractionation effects which have a range from -3.8 to +6.7 per mille per mass unit difference. This range is a factor of 20 wider than the range previously established for bulk meteorites and for terrestrial and lunar samples. Ca and Mg isotope fractionation effects in the Ca-Al-rich inclusions are common and attributed to kinetic isotope effects. (author)

  6. Isotope separation apparatus and method

    International Nuclear Information System (INIS)

    Cotter, T.P.

    1982-01-01

    The invention relates to a method and apparatus for laser isotope separation by photodeflection. A molecular beam comprising at least two isotopes to be separated intersects, preferable substantially perpendicular to one broad side of the molecular beam, with a laser beam traveling in a first direction. The laser beam is reflected back through the molecular beam, preferably in a second direction essentially opposite to the first direction. The laser beam comprises pi-pulses of a selected wavelength which excite unexcited molecules, or cause stimulated emission of excited molecules of one of the isotopes. Excitation caused by first direction pi-pulses moves molecules of the isotope excited thereby in the first direction. Stimulated emission of excited molecules of the isotope is brought about by returning pi-pulses traveling in the second direction. Stimulated emission moves emitting molecules in a direction opposite to the photon emitted. Because emitted photons travel in the second direction, emitting molecules move in the first direction. Substantial molecular movement is accomplished by a large number of pi-pulse-molecule interactions. A beam corer collects the molecules in the resulting enriched divergent portions of the beam

  7. Isotope-equipped measuring instruments

    International Nuclear Information System (INIS)

    Miyagawa, Kazuo; Amano, Hiroshi

    1980-01-01

    In the steel industry, though the investment in isotope-equipped measuring instruments is small as compared with that in machinery, they play important role in the moisture measurement in sintering and blast furnaces, the thickness measurement in rolling process and others in automatic control systems. The economic aspect of the isotope-equipped measuring instruments is described on the basis of the practices in Kimitsu Works of Nippon Steel Corporation: distribution of such instruments, evaluation of economic effects, usefulness evaluation in view of raising the accuracy, and usefulness evaluation viewed from the failure of the isotope instruments. The evaluation of economic effects was made under the premise that the isotope-equipped measuring instruments are not employed. Then, the effects of raising the accuracy are evaluated for a γ-ray plate thickness gauge and a neutron moisture gauge for coke in a blast furnace. Finally, the usefulness was evaluated, assuming possible failure of the isotope-equipped measuring instruments. (J.P.N.)

  8. Preservation of Fe Isotope Proxies in the Rock Record

    Science.gov (United States)

    Johnson, C.; Beard, B.; Valley, J.; Valaas, E.

    2005-12-01

    Iron isotope variations provide powerful constraints on redox conditions and pathways involved during biogeochemical cycling of Fe in surface and near-surface environments. The relative isotopic homogeneity of igneous rocks and most bulk weathering products contrasts with the significant isotopic variations (4 per mil in 56Fe/54Fe) that accompany oxidation of Fe(II)aq, precipitation of sulfides, and reduction by bacteria. These isotopic variations often reflect intrinsic (equilibrium) Fe isotope fractionations between minerals and aqueous species whose interactions may be directly or indirectly catalyzed by bacteria. In addition, Fe isotope exchange may be limited between reactive Fe pools in low-temperature aqueous-sediment environments, fundamentally reflecting disequilibrium effects. In the absence of significant sulfide, dissimilatory Fe(III) reduction by bacteria produces relatively low 56Fe/54Fe ratios for Fe(II)aq and associated biogenic minerals such as magnetite and siderite. In contrast, Fe(II)aq that exchanges with Fe sulfides (FeS and pyrite) is relatively enriched in 56Fe/54Fe ratios. In modern and ancient environments, anoxic diagenesis tends to produce products that have low 56Fe/54Fe ratios, whereas oxidation of Fe(II)aq from hydrothermal sources tends to produce ferric Fe products that have high 56Fe/54Fe ratios. Redox cycling by bacteria tends to produce reactive ferric Fe reservoirs that have low 56Fe/54Fe ratios. Application of Fe isotopes as a proxy for redox conditions in the ancient rock record depends upon the preservation potential during metamorphism, given the fact that most Archean sedimentary sequences have been subjected to regional greenschist- to granulite-facies metamorphism. The 1.9 Ga banded iron formations (BIFs) of the Lake Superior region that are intruded by large ~1 Ga intrusions (e.g., Duluth gabbro) provide a test of the preservation potential for primary, low-temperature Fe isotope variations in sedimentary rocks. 56Fe/54

  9. Some characteristics of isotopic separation laser systems

    International Nuclear Information System (INIS)

    Pochon, E.

    1988-01-01

    The principle of Laser Isotope Separation (LIS) is simple and based on either selective electronic photoexcitation and photoionization of atomic vapor, or selective vibrational photoexcitation and photodissociation of molecules in the gas phase. These processes, respectively called SILVA (AVLIS) and SILMO (MLIS) in France, both use specific laser systems with wavelengths spanning from infrared to ultraviolet. This article describes briefly some of the characteristics of a SILVA laser system. Following a three-step process, a SILVA laser system is based on dye copper vapor lasers. The pulse dye lasers provide the tunable laser light and are optically pumped by copper vapor laser operating at high repetition rates. In order to meet plant laser system requirements, the main improvements under way relate to copper vapor laser devices the power capability, efficiency, reliability and lifetime of which have to be increased. 1 fig

  10. Multicomponent isotopic separation and recirculation analysis

    International Nuclear Information System (INIS)

    Misra, B.; Maroni, V.A.

    1976-01-01

    A digital computer program for design of multicomponent distillation columns has been developed based on an exact method of solution of the governing equations. Although this computer program was developed for enrichment of the spent fuels from presently conceived tokamak-type fusion power reactors by cryogenic distillation, the program can be used for the design of any multicomponent distillation column, provided, of course, the necessary thermodynamic and phase equilibrium data are available. To prove the versatility of the computer program, parametric investigations to study the effect of design and operating variables on the composition of the product streams was carried out for the case of separating hydrogen isotopes. The computer program is very efficient; hence, a number of parametric investigations can be carried out with limited resources. The program does, however, require a fairly large computer storage space

  11. Cascade theory in isotopic separation processes

    International Nuclear Information System (INIS)

    Agostini, J.P.

    1994-06-01

    Three main areas are developed within the scope of this work: - the first one is devoted to fundamentals: separative power, value function, ideal cascade and square cascade. Applications to two main cases are carried out, namely: Study of binary isotopic mix, Study of processes with a small enrichment coefficient. - The second one is devoted to cascade coupling -high-flux coupling (more widely used and better known) as well as low-flux coupling are presented and compared to one another. - The third one is an outlook on problems linked to cascade transients. Those problem are somewhat intricate and their interest lies mainly into two areas: economics where the start-up time may have a large influence on the interests paid during the construction and start-up period, military productions where the start-up time has a direct bearing on the production schedule. (author). 50 figs. 3 annexes. 12 refs. 6 tabs

  12. Atomic power in space: A history

    International Nuclear Information System (INIS)

    1987-03-01

    ''Atomic Power in Space,'' a history of the Space Isotope Power Program of the United States, covers the period from the program's inception in the mid-1950s through 1982. Written in non-technical language, the history is addressed to both the general public and those more specialized in nuclear and space technologies. 19 figs., 3 tabs

  13. Determination of isotopic composition of uranium in microparticles by secondary ion mass spectrometry

    International Nuclear Information System (INIS)

    Veniaminov, N.N.; Kolesnikov, O.N.; Stebel'kov, V.A.

    1992-01-01

    Aerosol particles including uranium in their composition are specific atmospheric polutants. Uranium is used as nuclear fuel in atomic power stations and in spacecraft power units, and also as a component of nuclear warheads. In order to monitor the discharge of uranium-containing aerosol particles to the atmosphere, they must first be identified. As an example, one may cite an investigation of the elemental composition and radioactivity of particles formed in the accident at the Chernobyl atomic power station. One of the most informative indicators of the origin of uranium-containing aerosol particles is the isotopic composition of the uranium. Secondary ion mass spectrometry (SIMS) offers unique possibilities for the measurement of isotope ratios in individual microscopic objects. At the same time, a measurement of isotope ratios of sulfur in microsection of galenite PbS 2 has shown that the application of SIMS for these purposes is seriously limited by the difference in yield of secondary ions for isotopes with different masses. These discrimination effects, in the case of light elements such as boron, may result in distortion of the isotope ratios by several percent. In the case of heavy elements, however, the effect is less significant, amounting to about 0.5% for lead isotopes. 13 refs., 3 figs., 1 tab

  14. Particle and radiation simulations for the proposed rare isotope accelerator facility

    Energy Technology Data Exchange (ETDEWEB)

    Remec, Igor [Oak Ridge National Laboratory, Oak Ridge, P. O. Box 2008, TN 37831-6172 (United States)]. E-mail: remeci@ornl.gov; Gabriel, Tony A. [Oak Ridge National Laboratory, Oak Ridge, P. O. Box 2008, TN 37831-6172 (United States); Wendel, Mark W. [Oak Ridge National Laboratory, Oak Ridge, P. O. Box 2008, TN 37831-6172 (United States); Conner, David L. [Oak Ridge National Laboratory, Oak Ridge, P. O. Box 2008, TN 37831-6172 (United States); Burgess, Thomas W. [Oak Ridge National Laboratory, Oak Ridge, P. O. Box 2008, TN 37831-6172 (United States); Ronningen, Reginald M. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Blideanu, Valentin [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Bollen, Georg [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Boles, Jason L. [Lawrence Livermore National Laboratory, P. O. Box 808, L-446, Livermore, CA 94550 (United States); Reyes, Susana [Lawrence Livermore National Laboratory, P. O. Box 808, L-446, Livermore, CA 94550 (United States); Ahle, Larry E. [Lawrence Livermore National Laboratory, P. O. Box 808, L-446, Livermore, CA 94550 (United States); Stein, Werner [Lawrence Livermore National Laboratory, P. O. Box 808, L-446, Livermore, CA 94550 (United States)

    2006-06-23

    The Rare Isotope Accelerator (RIA) facility, planned to be built in the USA, will be capable of delivering diverse beams, from protons to uranium ions, with energies from 1 GeV to at least 400 MeV per nucleon to rare isotope-producing targets. High beam power-400 kW-will allow RIA to become the most powerful rare isotope beam facility in the world; however, it also creates challenges for the design of the isotope-production targets. This paper focuses on the isotope-separator-on-line (ISOL) target work, particularly the radiation transport aspects of the two-step fission target design. Simulations were performed with the PHITS, MCNPX, and MARS15 computer codes. A two-step ISOL target considered here consists of a mercury or tungsten primary target in which primary beam interactions release neutrons, which in turn induce fissions-and produce rare isotopes-in the secondary target filled with fissionable material. Three primary beams were considered: 1-GeV protons, 622-MeV/u deuterons, and 777-MeV/u {sup 3}He ions. The proton and deuterium beams were found to be about equivalent in terms of induced fission rates and heating rates in the target, while the {sup 3}He beam, without optimizing the target geometry, was less favorable, producing about 15% fewer fissions and about 50% higher heating rates than the proton beam at the same beam power.

  15. Isotope correlations for safeguards surveillance and accountancy methods

    International Nuclear Information System (INIS)

    Persiani, P.J.; Kalimullah.

    1983-01-01

    Isotope correlations corroborated by experiments, coupled with measurement methods for nuclear material in the fuel cycle have the potential as a safeguards surveillance and accountancy system. The US/DOE/OSS Isotope Correlations for Surveillance and Accountancy Methods (ICSAM) program has been structured into three phases: (1) the analytical development of Isotope Correlation Technique (ICT) for actual power reactor fuel cycles; (2) the development of a dedicated portable ICT computer system for in-field implementation, and (3) the experimental program for measurement of U, Pu isotopics in representative spent fuel-rods of the initial 3 or 4 burnup cycles of the Commonwealth Edison Zion -1 and -2 PWR power plants. Since any particular correlation could generate different curves depending upon the type and positioning of the fuel assembly, a 3-D reactor model and 2-group cross section depletion calculation for the first cycle of the ZION-2 was performed with each fuel assembly as a depletion block. It is found that for a given PWR all assemblies with a unique combination of enrichment zone and number of burnable poison rods (BPRs) generate one coincident curve. Some correlations are found to generate a single curve for assemblies of all enrichments and number of BPRs. The 8 axial segments of the 3-D calculation generate one coincident curve for each correlation. For some correlations the curve for the full assembly homogenized over core-height deviates from the curve for the 8 axial segments, and for other correlations coincides with the curve for the segments. The former behavior is primarily based on the transmutation lag between the end segment and the middle segments. The experimental implication is that the isotope correlations exhibiting this behavior can be determined by dissolving a full assembly but not by dissolving only an axial segment, or pellets

  16. Oak Ridge National Laboratory's isotope enrichment program

    International Nuclear Information System (INIS)

    Tracy, J.G.; Aaron, W.C.

    1997-01-01

    The Isotope Enrichment Program (IEP) at Oak Ridge National Laboratory (ORNL) is responsible for the production and distribution of ∼225 enriched stable isotopes from 50 multi-isotopic elements. In addition, ORNL distributes enriched actinide isotopes and provides extensive physical- and chemical-form processing of enriched isotopes to meet customer requirements. For more than 50 yr, ORNL has been a major provider of enriched isotopes and isotope-related services to research, medical, and industrial institutions throughout the world. Consolidation of the Isotope Distribution Office (IDO), the Isotope Research Materials Laboratory (IRML), and the stable isotope inventories in the Isotope Enrichment Facility (IEF) have improved operational efficiencies and customer services. Recent changes in the IEP have included adopting policies for long-term contracts, which offer program stability and pricing advantages for the customer, and prorated service charges, which greatly improve pricing to the small research users. The former U.S. Department of Energy (DOE) Loan Program has been converted to a lease program, which makes large-quantity or very expensive isotopes available for nondestructive research at a nominal cost. Current efforts are being pursued to improve and expand the isotope separation capabilities as well as the extensive chemical- and physical-form processing that now exists. The IEF's quality management system is ISO 9002 registered and accredited in the United States, Canada, and Europe

  17. Isotopic depletion with Monte Carlo

    International Nuclear Information System (INIS)

    Martin, W.R.; Rathkopf, J.A.

    1996-06-01

    This work considers a method to deplete isotopes during a time- dependent Monte Carlo simulation of an evolving system. The method is based on explicitly combining a conventional estimator for the scalar flux with the analytical solutions to the isotopic depletion equations. There are no auxiliary calculations; the method is an integral part of the Monte Carlo calculation. The method eliminates negative densities and reduces the variance in the estimates for the isotope densities, compared to existing methods. Moreover, existing methods are shown to be special cases of the general method described in this work, as they can be derived by combining a high variance estimator for the scalar flux with a low-order approximation to the analytical solution to the depletion equation

  18. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1986-08-01

    This report contains a listing of electromagnetically separated stable isotopes which are available at the Oak Ridge National Laboratory for distribution for nondestructive research use on a loan basis. This inventory includes all samples of stable isotopes in the Research Materials Collection and does not designate whether a sample is out on loan or is in reprocessing. For some of the high-abundance, naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56. All requests for the loan of samples should be submitted with a summary of the purpose of the loan to: Iotope Distribution Office, Oak Ridge National Laboratory, P.O. Box X, Oak Ridge, Tennessee 37831. Requests from non-DOE contractors and from foreign institutions require DOE approval

  19. Stable isotopes and the environment

    International Nuclear Information System (INIS)

    Krouse, H.R.

    1990-01-01

    Whereas traditionally, stable isotope research has been directed towards resource exploration and development, it is finding more frequent applications in helping to assess the impacts of resource utilization upon ecosystems. Among the many pursuits, two themes are evident: tracing the transport and conversions of pollutants in the environment and better understanding of the interplay among environmental receptors, e.g. food web studies. Stable isotope data are used primarily to identify the presence of pollutants in the environment and with a few exceptions, the consequence of their presence must be assessed by other techniques. Increasing attention has been given to the isotopic composition of humans with many potential applications in areas such as paleodiets, medicine, and criminology. In this brief overview examples are used from the Pacific Rim to illustrate the above concepts. 26 refs., 1 tab., 3 figs

  20. Lithium isotopic separation: preliminary studies

    International Nuclear Information System (INIS)

    Macedo, Sandra Helena Goulart de

    1998-01-01

    In order to get the separation of natural isotopes of lithium by electrolytic amalgamation, an electrolytic cell with a confined mercury cathode was used to obtain data for the design of a separation stage. The initial work was followed by the design of a moving mercury cathode electrolytic cell and three experiments with six batches stages were performed for the determination of the elementary separation factor. The value obtained, 1.053, was ill agreement: with the specialized literature. It was verified in all experiments that the lithium - 6 isotope concentrated in the amalgam phase and that the lithium - 7 isotope concentrated in the aqueous phase. A stainless-steel cathode for the decomposition of the lithium amalgam and the selective desamalgamation were also studied. In view of the results obtained, a five stages continuous scheme was proposed. (author)

  1. Shielding container for radioactive isotopes

    International Nuclear Information System (INIS)

    Sumi, Tetsuo; Tosa, Masayoshi; Hatogai, Tatsuaki.

    1975-01-01

    Object: To effect opening and closing bidirectional radiation used particularly for a gamma densimeter or the like by one operation. Structure: This device comprises a rotatable shielding body for receiving radioactive isotope in the central portion thereof and having at least two radiation openings through which radiation is taken out of the isotope, and a shielding container having openings corresponding to the first mentioned radiation openings, respectively. The radioactive isotope is secured to a rotational shaft of the shielding body, and the shielding body is rotated to register the openings of the shielding container with the openings of the shielding body or to shield the openings, thereby effecting radiation and cut off of gamma ray in the bidirection by one operation. (Kamimura, M.)

  2. Shape coexistence in selenium isotopes

    International Nuclear Information System (INIS)

    Liu Ying; Cao Zhongbin; Xu Furong

    2010-01-01

    Nuclear shape change and shape coexistence in the Selenium isotopes have been investigated by Total-Routhian-Surface (TRS) calculations. It is found that nuclear shapes vary significantly with increasing neutron number. The TRS calculations for the ground states of 66,72,92,94 Se isotopes show that both neutron-deficient and neutron-dripline Selenium isotopes have oblate and prolate shape coexistence. The cranking shell-model calculations for 72,94 Se give that prolate and oblate shape coexistence in low rotational frequency. However, oblate rotational bands disappear and prolate rotational bands become yrast bands with increasing rotational frequency, which is due to the intrusion of the g 9/2 orbitals. (authors)

  3. Isotopic composition of past precipitation

    International Nuclear Information System (INIS)

    Edwards, T.W.D.

    1998-01-01

    The distribution of stable isotopes in precipitation provides critical quantitative information about the global water cycle. The first PAGES/IAEA ISOMAP workshop was held at the IAEA headquarters in Vienna, 24-26 August 1998, which gathered 32 participants. The presentation and discussions demonstrated that a high level of sophistication already exists in the development of transfer functions between measured parameters and precipitation, as a result of the extensive use of water isotope tracers in paleo-environmental investigations, but a major challenge facing both producers and users of paleo-isotope data is the effective management of data and meta-data, to permit ready retrieval of raw and inferred data for comparison and reinterpretation. This will be in important goal of future ISOMAP activities. The critical need for more paleo-data from low latitudes was clearly recognized

  4. Isotopes in research and industry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1961-01-15

    A comprehensive review of the present state of the use of radioisotopes in the physical sciences and industry was made at a major international conference in Copenhagen from 6 to 16 September 1960. The conference covers the use of radioisotopes in geophysics, metallurgy, solid state physics and nuclear physics, industrial applications of radioisotopes, which were divided into two groups, namely applications based on the tracer function of isotopes and those based on the penetration, absorption or scattering of radiation, use of isotopes in various branches of chemistry - from analysis to determine extremely small amounts of material to a study of the mechanism of various chemical reactions.

  5. Electron scattering off palladium isotopes

    International Nuclear Information System (INIS)

    Laan, J.B. van der.

    1986-01-01

    The low-lying states of the even Pd isotopes are characterized by vibrator-like properties. In this thesis the results of an electron scattering experiment on the Pd isotopes, designed to study the description of such nuclei in the Anharmonic Vibrator Model (AVM) and the Interacting Boson Approximation (IBA), are presented and discussed. Data have been taken at the high-resolution electron scattering facility of NIKHEF-K and covered a momentum-transfer range of 0.4 to 2.5 fm -1 . (Auth.)

  6. Natural fractionation of uranium isotopes

    International Nuclear Information System (INIS)

    Noordmann, Janine

    2015-01-01

    The topic of this thesis was the investigation of U (n( 238 U) / n( 235 U)) isotope variations in nature with a focus on samples (1) that represent the continental crust and its weathering products (i.e. granites, shales and river water) (2) that represent products of hydrothermal alteration on mid-ocean ridges (i.e. altered basalts, carbonate veins and hydrothermal water) and (3) from restricted euxinic basins (i.e. from the water column and respective sediments). The overall goal was to explore the environmental conditions and unravel the mechanisms that fractionate the two most abundant U isotopes, n( 238 U) and n( 235 U), on Earth.

  7. Separation process for boron isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Rockwood, S D

    1975-06-12

    The method according to the invention is characterized by the steps of preparing a gaseous mixture of BCl/sub 3/ containing the isotopes of boron and oxygen as the extractor, irradiating that mixture in the tube of the separator device by means of P- or R-lines of a CO/sub 2/ laser for exciting the molecules containing a given isotope of boron, simultaneously irradiating the mixture with UV for photodissociating the excited BCl/sub 3/ molecules and separating BCl/sub 3/ from the reaction products of photodissociation and from oxygen. Such method is suitable for preparing boron used in nuclear reactors.

  8. Isotopic cisternography. Its clinical value

    International Nuclear Information System (INIS)

    Lemort, J.P.; Bizais, Y.; Herzog, B.

    1976-01-01

    A brief study of isotopic cisternography with a new tracer is performed. After describing the physiological circulation of the cerebrospinal fluid the different tracers used are studied and experience with 111 Indium DTPA which is tending to replace the other tracers is given. The indications and the normal and pathological results are discussed. The different forms of hydrocephalus are described; this examination makes it possible in particular to diagnose cases of hydrocephalus with normal pressure, cysts, or localized, subarachnoid pockets. Cerebrospinal fluid fistulas are detected by this technique. Finally, the place of isotopic cisternography in relation to the other neuroradiological examinations and in relation to tomodensitometric investigations is discussed [fr

  9. Recent development in isotope ratio mass spectrometry

    International Nuclear Information System (INIS)

    Platzner, I.

    1992-01-01

    Within the limited of this review the following topics will be briefly discussed: a) Accuracy, precision, internal relative standard deviation (RISD) and external relative standard deviation (RESD) of isotope ratio measurements. With advanced instrumentation and use of standard reference materials, high accuracy and RESD = 0.002% (or better) may be achieved; b) The advantages of modern automatic isotope ratio mass spectrometer are briefly described. Computer controlled operation and data acquisition, and multiple ion collection are the recent important improvement; c) The isotopic fractionation during the course of isotope ratio measurement is considered as a major source of errors in thermal ionization of metallic elements. The phenomenon in strontium, neodymium, uranium, lead and calcium and methods to correct the measured data are discussed; d) Applications of isotope ratio mass spectrometry in atomic weight determinations, the isotope dilution technique, isotope geology, and isotope effects in biological systems are described together with specific applications in various research and technology area. (author)

  10. Isotope separation using vibrationally excited molecules

    International Nuclear Information System (INIS)

    1979-01-01

    This invention relates to isotope separation employing isotopically selective vibrational excitation and vibration-translation reactions of the excited particles. Uranium enrichment, using uranium hexafluoride, is a particular embodiment. (U.K.)

  11. Isotope applications in the environmental field

    International Nuclear Information System (INIS)

    DeWitt, R.

    1978-01-01

    Established uses of enriched isotopes in the environmental field were surveyed to determine future trends in isotope needs. Based on established isotope uses, on the projected increase in the pollution problem, and on the apparent social and economic pressure for pollution abatement, a significant demand for enriched isotopes appears to be developing for the assessment and control of air, water, and soil pollutants. Isotopic techniques will be used in combination with conventional methods of detection and measurement, such as gas chromatography, x-ray fluorescence, and atomic absorption. Recent advances in economical isotope separation methods, instrumentation, and methodology promise to place isotopic technology within the reach of most research and industrial institutions. Increased application of isotope techniques appears most likely to occur in areas where data are needed to characterize the movement, behavior, and fate of pollutants in the environment

  12. High mass isotope separation process and arrangement

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1978-01-01

    An isotope separation arrangement for separating a preselected isotope from a mixture of chemically identical but isotopically different molecules by either photon-induced pure rovibrational or vibronic selective excitation of the molecules containing the atoms of the isotope to be separated from a lower to a higher energy state, and a chemical reaction of the higher energy state molecules with a chemically reactive agent to form a chemical compound containing primarily the atoms of isotope to be separated in a physicochemical state different from the physicochemical state of the mixture of chemically identical but isotopically different molecules. The chemical compound containing the atoms of the isotope to be separated may be subsequently processed to obtain the isotope

  13. Passive sampling for the isotopic fingerprinting of atmospheric mercury

    Science.gov (United States)

    Bergquist, B. A.; MacLagan, D.; Spoznar, N.; Kaplan, R.; Chandan, P.; Stupple, G.; Zimmerman, L.; Wania, F.; Mitchell, C. P. J.; Steffen, A.; Monaci, F.; Derry, L. A.

    2017-12-01

    Recent studies show that there are variations in the mercury (Hg) isotopic signature of atmospheric Hg, which demonstrates the potential for source tracing and improved understanding of atmospheric cycling of Hg. However, current methods for both measuring atmospheric Hg and collecting enough atmospheric Hg for isotopic analyses require expensive instruments that need power and expertise. Additionally, methods for collecting enough atmospheric Hg for isotopic analysis require pumping air through traps for long periods (weeks and longer). Combining a new passive atmospheric sampler for mercury (Hg) with novel Hg isotopic analyses will allow for the application of stable Hg isotopes to atmospheric studies of Hg. Our group has been testing a new passive sampler for gaseous Hg that relies on the diffusion of Hg through a diffusive barrier and adsorption onto a sulphur-impregnated activated carbon sorbent. The benefit of this passive sampler is that it is low cost, requires no power, and collects gaseous Hg for up to one year with linear, well-defined uptake, which allows for reproducible and accurate measurements of atmospheric gaseous Hg concentrations ( 8% uncertainty). As little as one month of sampling is often adequate to collect sufficient Hg for isotopic analysis at typical background concentrations. Experiments comparing the isotopic Hg signature in activated carbon samples using different approaches (i.e. by passive diffusion, by passive diffusion through diffusive barriers of different thickness, by active pumping) and at different temperatures confirm that the sampling process itself does not impose mass-independent fractionation (MIF). However, sampling does result in a consistent and thus correctable mass-dependent fractionation (MDF) effect. Therefore, the sampler preserves Hg MIF with very high accuracy and precision, which is necessary for atmospheric source tracing, and reasonable MDF can be estimated with some increase in error. In addition to

  14. Developing Potential New Reference Materials for Light Isotopes in Foodstuffs

    Science.gov (United States)

    Frew, Russell; Van Hale, Robert; Clarke, Dianne; Abrahim, Aiman; Resch, Christian; Mayr, Leopold; Cannavan, Andrew; Gröning, Manfred

    2013-04-01

    Measurements of subtle variations in stable isotope ratios provide the means for verifying food integrity in numerous ways. Adulterants usually have different isotopic composition so their presence in a food is readily detectable. Stable isotope measurements can also be used to determine the region of production of the food. In most cases the ability of stable isotope measurements to verify, or otherwise reject, the authenticity of the food is greatly enhanced by comparison of a result to a reference database. The more high-quality data in the database, the more statistical power is afforded by the comparison. A serious weakness at present is the lack of reference materials in food matrices available to the community. Thus researchers have to rely on in-house standards for calibration and quality assurance. The result is that there are numerous datasets published that may be internally consistent but it is exceedingly difficult to combine these datasets into a cohesive database. This is particularly important for measurements of the hydrogen isotopes. Here we present a survey of the stable isotope (^2H, ^13C and ^15N) composition of 12 Reference Materials from the International Atomic Energy Agency catalogue. All but one of these materials are plant matter and have been developed as reference materials for other applications such as radionuclide or trace element measurements. Thus they have been verified as suitable materials in terms of stability and homogeneity for those tests. The purpose of this work is to ascertain if they are similarly suitable as stable isotope reference materials. The results from our survey show that there is a wide range in elemental and isotopic composition among these materials. For example, the ^15N values range from-13.5‰ to +18.6‰ and the nitrogen elemental composition range is from 0.7% to 9.7%. The ^13C values range from -20‰ to -40‰ and the carbon elemental composition ranges from 15% to 47%. We are now in the process of

  15. Method and device for isotope separation

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1976-01-01

    The method works with a converted Q machine. The plasma containing the isotopes to be separated is crossed by a magnetic field running in the direction of the plasma column. More energy is transfered to the chosen isotope by oscillating magnetic and/or electric fields or by sound waves by using the specific resonance frequency for the selected isotope. The isotopes thus heated to different extents can be separated according to various methods given in the patent claims. (GG) [de

  16. Isotope mixtures of hydrogen in vanadium

    International Nuclear Information System (INIS)

    Mecking-Schloetensack, P.

    1982-03-01

    The properties of isotope-mixtures of Protium and Deuterium stored in Vanadium have been studied. Protium and Deuterium are existing as interstitial-atoms on tetrahedral sites as well as on octahedral sites in this system. This feature leads to large isotopic-effects between the two isotopes. The dependence of the thermodynamic functions like heat of solution, nonconfigurational entropy, specific heat and ordering temperatures from the composition of the isotope-mixture has been determined. (orig.)

  17. [Carbon isotope fractionation in plants]: Annual technical progress report

    International Nuclear Information System (INIS)

    O'Leary, M.H.

    1988-01-01

    Plants fractionate carbon isotopes during photosynthesis in ways which reflect photosynthetic pathway and environment. The fractionation is product of contributions from diffusion, carboxylation and other factors which can be understood using models which have been developed in our work. The object of our work is to use this fractionation to learn about the factors which control the efficiency of photosynthesis. Unlike previous studies, we do not rely principally on combustion methods, but instead develop more specific methods with substantially higher resolving power. We have recently developed a new short-term method for studying carbon isotope fractionation which promises to provide a level of detail about temperature, species, and light intensity effects on photosynthesis which has not been available until now. We are studying the isotopic compositions of metabolites (particularly aspartic acid) in C 3 plants in order to determine the role of phosphoenolpyruvate carboxylase in C 3 photosynthesis. We are studying the relative roles of diffusion and carboxylation in nocturnal CO 2 fixation in CAM plants. We are studying the use of isotopic content as an index of water-use efficiency in C 3 plants. We are developing new methods for studying carbon metabolism in plants. 3 refs

  18. An Isotopic view of water and nitrogen transport through the ...

    Science.gov (United States)

    Groundwater nitrate contamination affects thousands of households in Oregon’s southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 due to nitrate levels in the groundwater exceeding the human health standard of 10 mg nitrate-N L-1. Much of the nitrogen inputs to the GWMA comes from agricultural nitrogen use, and thus efforts to reduce N inputs to groundwater are focused upon improving N management. However, the effectiveness of these improvements on groundwater quality is unclear because of the complexity of nutrient transport through the vadose zone and long groundwater residence times. Our objective was to focus on vadose zone transport and understand the dynamics and timing of N and water movement below the rooting zone in relation to N management and water inputs. Stable isotopes are a powerful tool for tracking water movement, and understanding nitrogen transformations within the vadose zone. In partnership with local farmers, and state agencies, we established lysimeters and groundwater wells in multiple agricultural fields in the GWMA, and have monitored nitrate, nitrate isotopes, and water isotopes weekly for multiple years. Our results indicate that vadose zone transport is highly complex, and the residence time of water collected in lysimeters was much longer than expected. While input precipitation water isotopes were highly variab

  19. Shell structure of potassium isotopes deduced from their magnetic moments

    CERN Document Server

    Papuga, J.; Kreim, K; Barbieri, C; Blaum, K; De Rydt, M; Duguet, T; Garcia Ruiz, R F; Heylen, H; Kowalska, M; Neugart, R; Neyens, G; Nortershauser, W; Rajabali, M M; Sanchez, R; Smirnova, N; Soma, V; Yordanov, D T

    2014-09-29

    $\\textbf{Background:}$ Ground-state spins and magnetic moments are sensitive to the nuclear wave function, thus they are powerful probes to study the nuclear structure of isotopes far from stability. \\\\ \\\\ $\\textbf{Purpose:}$ Extend our knowledge about the evolution of the $1/2^+$ and $3/2^+$ states for K isotopes beyond the $N = 28$ shell gap. \\\\ \\\\ $\\textbf{Method:}$ High-resolution collinear laser spectroscopy on bunched atomic beams. \\\\ \\\\ $\\textbf{Results:}$ From measured hyperfine structure spectra of K isotopes, nuclear spins and magnetic moments of the ground states were obtained for isotopes from $N = 19$ up to $N = 32$. In order to draw conclusions about the composition of the wave functions and the occupation of the levels, the experimental data were compared to shell-model calculations using SDPF-NR and SDPF-U effective interactions. In addition, a detailed discussion about the evolution of the gap between proton $1d_{3/2}$ and $2s_{1/2}$ in the shell model and $\\textit{ab initio}$ framework is al...

  20. Do Hf isotopes in magmatic zircons represent those of their host rocks?

    Science.gov (United States)

    Wang, Di; Wang, Xiao-Lei; Cai, Yue; Goldstein, Steven L.; Yang, Tao

    2018-04-01

    Lu-Hf isotopic system in zircon is a powerful and widely used geochemical tracer in studying petrogenesis of magmatic rocks and crustal evolution, assuming that zircon Hf isotopes can represent initial Hf isotopes of their parental whole rock. However, this assumption may not always be valid. Disequilibrium partial melting of continental crust would preferentially melt out non-zircon minerals with high time-integrated Lu/Hf ratios and generate partial melts with Hf isotope compositions that are more radiogenic than those of its magma source. Dissolution experiments (with hotplate, bomb and sintering procedures) of zircon-bearing samples demonstrate this disequilibrium effect where partial dissolution yielded variable and more radiogenic Hf isotope compositions than fully dissolved samples. A case study from the Neoproterozoic Jiuling batholith in southern China shows that about half of the investigated samples show decoupled Hf isotopes between zircons and the bulk rocks. This decoupling could reflect complex and prolonged magmatic processes, such as crustal assimilation, magma mixing, and disequilibrium melting, which are consistent with the wide temperature spectrum from ∼630 °C to ∼900 °C by Ti-in-zircon thermometer. We suggest that magmatic zircons may only record the Hf isotopic composition of their surrounding melt during crystallization and it is uncertain whether their Hf isotopic compositions can represent the primary Hf isotopic compositions of the bulk magmas. In this regard, using zircon Hf isotopic compositions to trace crustal evolution may be biased since most of these could be originally from disequilibrium partial melts.

  1. Partitioning evapotranspiration fluxes with water stable isotopic measurements: from the lab to the field

    Science.gov (United States)

    Quade, M. E.; Brueggemann, N.; Graf, A.; Rothfuss, Y.

    2017-12-01

    Water stable isotopes are powerful tools for partitioning net into raw water fluxes such as evapotranspiration (ET) into soil evaporation (E) and plant transpiration (T). The isotopic methodology for ET partitioning is based on the fact that E and T have distinct water stable isotopic compositions, which in turn relies on the fact that each flux is differently affected by isotopic kinetic effects. An important work to be performed in parallel to field measurements is to better characterize these kinetic effects in the laboratory under controlled conditions. A soil evaporation laboratory experiment was conducted to retrieve characteristic values of the kinetic fractionation factor (αK) under varying soil and atmospheric water conditions. For this we used a combined soil and atmosphere column to monitor the soil and atmospheric water isotopic composition profiles at a high temporal and vertical resolution in a nondestructive manner by combining micro-porous membranes and laser spectroscopy. αK was calculated by using a well-known isotopic evaporation model in an inverse mode with the isotopic composition of E as one input variable, which was determined using a micro-Keeling regression plot. Knowledge on αK was further used in the field (Selhausen, North Rhine-Westphalia, Germany) to partition ET of catch crops and sugar beet (Beta vulgaris) during one growing season. Soil and atmospheric water isotopic profiles were measured automatically across depths and heights following a similar modus operandi as in the laboratory experiment. Additionally, a newly developed continuously moving elevator was used to obtain water vapor isotopic composition profiles with a high vertical resolution between soil surface, plant canopy and atmosphere. Finally, soil and plant samples were collected destructively to provide a comparison with the traditional isotopic methods. Our results illustrate the changing proportions of T and E along the growing season and demonstrate the

  2. Using cosmogenic isotopes to measure basin-scale rates of erosion

    International Nuclear Information System (INIS)

    Bierman, P.R.; Steig, E.

    1992-01-01

    The authors present a new and different approach to interpreting the abundance of in situ-produced cosmogenic nuclides such as 36 Cl, 26 Al, and 10 Be. Unlike most existing models, which are appropriate for evaluating isotope concentrations on bedrock surfaces, this model can be used to interpret isotope concentration in fluvial sediment. Because sediment is a mixture of material derived from the entire drainage basin, measured isotope abundances can be used to estimate spatially-averaged rates of erosion and sediment transport. Their approach has the potential to provide geomorphologists with a relatively simple but powerful means by which to constrain rates of landscape evolution. The model considers the flux of cosmogenic isotopes into and out of various reservoirs. Implicit in model development are the assumptions that a geomorphic steady-state has been reached and that sampled sediment is spatially and temporally representative of all sediment leaving the basin. Each year, the impinging cosmic-ray flux produces a certain quantity of cosmogenic isotopes in the rock and soil of a drainage basin. For a basin in steady state, the outgoing isotope flux is also constant. They solve for the rate of mass loss as a function of isotope abundance in the sediment, the cosmic ray attenuation length, the isotope half life, and the effective isotope production rate. There are only a few published measurements of cosmogenic isotope abundance in sediment. They calculated model denudation rates for sediment samples from Zaire and central Texas. The denudation rates they calculated appear reasonable and are similar to those they have measured directly on granite landforms in Georgia and southeastern California and those calculated for the Appalachian Piedmont

  3. Stable isotopes and biomarkers in microbial ecology

    NARCIS (Netherlands)

    Boschker, H.T.S.; Middelburg, J.J.

    2002-01-01

    The use of biomarkers in combination with stable isotope analysis is a new approach in microbial ecology and a number of papers on a variety of subjects have appeared. We will first discuss the techniques for analysing stable isotopes in biomarkers, primarily gas chromatography-combustion-isotope

  4. Isotope exchange reactions in hydrogen mixtures

    International Nuclear Information System (INIS)

    Czaplinski, W.; Gula, A.; Kravtsov, A.; Mikhailov, A.; Popov, N.

    1990-12-01

    The rates of isotopic exchange for the excited states of muonic hydrogen are calculated as functions of collision energy. Ground state population q 1s for different collision energies, target densities and isotope concentrations is obtained. It is shown that for principal quantum numbers n > 5 the isotopic exchange still considerably influences the value of q 1s . (author)

  5. Dynamical symmetry breaking in barium isotopes

    International Nuclear Information System (INIS)

    Rawat, Bir Singh; Chattopadhyay, P.K.

    1997-01-01

    The isotopes of Xe with mass numbers 124, 126, 128, 130 and the isotopes of barium with mass numbers 128, 130, 132, 134 were shown to correspond to the O(6) dynamical symmetry of IBM. In the investigation of the dynamical symmetry breaking in this region, the barium isotopes for departures from O(6) symmetry have been studied

  6. ICP-MS for isotope ratio measurement

    Science.gov (United States)

    The use of stable isotopes in mineral nutrition research has become a fundamental aspect of conducting this research. A gradual transition has occurred, now virtually complete, from radioactive isotope studies to those using stable isotopes. Although primarily used in human research, mineral stable ...

  7. Isotopes in day to day life

    Science.gov (United States)

    1984-06-01

    Developments are reported in the use of isotopic labeling and isotope irradiation in agriculture, medical science, hydrology, geochemistry, geophysics, environment pollution detection, and industries. Radioisotope instruments are described as well as techniques for gamma radiography, neutron radiography, and autoradiography. Isotope dating in geology and archaeology is covered. Basic scientific research topics in various areas are listed.

  8. Use of Isotopes for Studying Reaction Mechanisms

    Indian Academy of Sciences (India)

    In the first part of this series, we discussed how isotopes can be used as markers to determine the nature of intermediates in chemical reactions. The second part covered the effect of isotopes on equilibria and reactions, in processes where the bond to the isotopic a tom is broken. We showed with specific examples how.

  9. Radioactive isotopes on the Moon

    International Nuclear Information System (INIS)

    Davis, R. Jr.

    1975-01-01

    A limited review of experiments and studies of radioactivity and isotope ratios in lunar materials is given. Observations made on the first few millimeters of the surface where the effects of solar flare particles are important, some measurements on individual rocks, and some studies of radioactivities produced deep in the lunar soil by galactic cosmic rays, are among the experiments discussed

  10. Isotopes in the earth sciences

    Energy Technology Data Exchange (ETDEWEB)

    Bowen, Robert

    1988-01-01

    This book examines significant aspects of isotope applications in geology and geochemistry commencing with basic matters, such as atomic structure, stable nuclides and their fractionation, as well as the various decay modes of unstable nuclides. Modern mass spectrometry techniques including electrostatic tandem accelerators are followed by a review of radioisotope dating technology. The relatively new method using the rare earth elements samarium and neodymium are covered. Other geochronometers, applicable to both rocks and minerals not dateable otherwise, are included. A review is given of isotopes in the atmosphere, hydrosphere and lithosphere of the Earth. Those of oxygen and hydrogen together with the cosmogenic radionuclides tritium and radiocarbon are discussed in relation to the biosphere. The role of isotopes of carbon, nitrogen and sulphur is described and extended to fossil fuels and rocks as well as meteorites. Related themes such as Phanerozoic oceans, oceanic palaeothermometry, snow and ice stratigraphy and geothermal waters are covered. The field of isotopic palaeoecology is discussed. Radioactive wastes, their accumulation, dangers and disposal are investigated with especial reference to their environmental impacts.

  11. Isotopes in the atomic age

    International Nuclear Information System (INIS)

    Arnikar, H.J.

    1989-01-01

    The first accessible, practical account of isotopes separation processes for engineers. This guide gives expert guidance on all the most important methods (including references to the original papers), how to improve their yields, with discussions of theory and application of each technique. Presentation is clear and non-mathematical. Illustrated

  12. Progress in tropical isotope dendroclimatology

    Science.gov (United States)

    Evans, M. N.; Schrag, D. P.; Poussart, P. F.; Anchukaitis, K. J.

    2005-12-01

    The terrestrial tropics remain an important gap in the growing high resolution proxy network used to characterize the mean state and variability of the hydrological cycle. Here we review early efforts to develop a new class of proxy paleorainfall/humidity indicators using intraseasonal to interannual-resolution stable isotope data from tropical trees. The approach invokes a recently published model of oxygen isotopic composition of alpha-cellulose, rapid methods for cellulose extraction from raw wood, and continuous flow isotope ratio mass spectrometry to develop proxy chronological, rainfall and growth rate estimates from tropical trees, even those lacking annual rings. Isotopically-derived age models may be confirmed for modern intervals using trees of known age, radiocarbon measurements, direct measurements of tree diameter, and time series replication. Studies are now underway at a number of laboratories on samples from Costa Rica, northwestern coastal Peru, Indonesia, Thailand, New Guinea, Paraguay, Brazil, India, and the South American Altiplano. Improved sample extraction chemistry and online pyrolysis techniques should increase sample throughput, precision, and time series replication. Statistical calibration together with simple forward modeling based on the well-observed modern period can provide for objective interpretation of the data. Ultimately, replicated data series with well-defined uncertainties can be entered into multiproxy efforts to define aspects of tropical hydrological variability associated with ENSO, the meridional overturning circulation, and the monsoon systems.

  13. Dual temperature isotope exchange system

    International Nuclear Information System (INIS)

    Spevack, J.S.

    1976-01-01

    Improvements in the method for isotope concentration by dual temperature exchange between feed and auxiliary fluids in a multistage system are described. In a preferred embodiment the first is a vaporizable liquid and the auxiliary fluid a gas, comprising steps for improving the heating and/or cooling and/or humidifying and/or dehumidifying operations

  14. Theory of oxygen isotope exchange

    NARCIS (Netherlands)

    den Otter, M.W.; Boukamp, Bernard A.; Bouwmeester, Henricus J.M.

    2001-01-01

    Transients for oxygen molecular mass numbers 32, 34 and 36 are derived which can be used for the interpretation of oxygen isotope exchange data based on measurement of concentrations of 16O2, 16O18O and 18O2 in the gas phase. Key parameters in the theory are the rate at which oxygen molecules are

  15. Reorientation measurements on tungsten isotopes

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, J J; Saladin, J X; Baktash, C; Alessi, J G [Pittsburgh Univ., Pa. (USA)

    1977-11-14

    In a particle-..gamma.. coincidence experiment, a thick tungsten target, of natural isotopic abundance, was bombarded with ..cap alpha.. and /sup 16/O beams. From analysis of the deexcitation ..gamma..-rays following Coulomb excitation, the spectroscopic quadrupole moment of the second 2/sup +/ state (the 2/sup +/' state) was determined for /sup 186/W and /sup 184/W. In a separate Coulomb excitation experiment a thin, isotopically enriched /sup 186/W target was bombarded with /sup 16/O ions. From analysis of projectiles scattered elastically and inelastically the quadrupole moment of the 2/sup +/' state of /sup 186/W was extracted. The results of the two experiments are in good agreement. The quadrupole moment of the 2/sup +/' state is found to be opposite in sign to that of the first 2/sup +/ state for both isotopes studied. However, its magnitude decreases rapidly in going from /sup 186/W to /sup 184/W, in contrast to the predictions of the rotation-vibration of asymmetric rotor models. The microscopic theory of Kumar and Baranger does predict the experimental trend, qualitatively. Thus the present results are interpreted as being evidence of strong coupling between ..beta.. and ..gamma.. degrees of freedom in the tungsten isotopes, which, according to the theory of Kumar and Baranger, is the source of the reduced value of the quadrupole moment.

  16. Triplet states in lead isotopes

    International Nuclear Information System (INIS)

    Naz, Tabassum; Ahmad, Shakeb; Abusara, H.

    2017-01-01

    Axial and triaxial calculations within RHB have been done to study the shape coexistence phenomena in the lead isotopes. Triplet states have been found in the 184-190 Pb which are in accordance with the experimental and other theoretical observations. The energy difference (in MeV) between the first two excited states also gives the evidence for the same

  17. Non-linear Isotope Effects

    DEFF Research Database (Denmark)

    Schmidt, Johan Albrecht

    ’s stratosphere is nearly mass dependent, and only a small fraction of the observed anomalous oxygen-17 excess can be attributed to N2O photolysis. In contrast, stratospheric photolysis produces a significant inverse clumped isotope effect.(ii) Stratospheric OCS photolysis significantly enrich the remaining OCS...

  18. The isotopic dating of crystals

    International Nuclear Information System (INIS)

    Giuliani, G.; Cheilletz, A.

    1995-01-01

    The first part of this work deals with the answer to the question : why are the crystals dated ? Then, some isotopic dating methods are described : U-Th-Pb, K-Ar, 40 Ar/ 39 Ar, Rb-Sr, Sm-Nd, fission traces, carbon 14 methods. Examples concerning emeralds and diamonds are given. (O.L.). 12 refs., 2 figs

  19. PETROCHEMISTRY, Pb ISOTOPE SYSTEMATICS, AND ...

    African Journals Online (AJOL)

    The petrology, geochemistry, geotectonic setting and common Pb isotope model ages for the granite gneisses in Ilesha schist belt have been studied and presented in this paper. These gneisses, apart from the normal rock-forming silicates, contain apatite, monazite, ilmenite and zircon in trace amounts. The occurrence of ...

  20. Plutonium determination by isotope dilution

    International Nuclear Information System (INIS)

    Lucas, M.

    1980-01-01

    The principle is to add to a known amount of the analysed solution a known amount of a spike solution consisting of plutonium 242. The isotopic composition of the resulting mixture is then determined by surface ionization mass spectrometry, and the plutonium concentration in the solution is deduced, from this measurement. For irradiated fuels neutronic studies or for fissile materials balance measurements, requiring the knowledge of the ratio U/Pu or of concentration both uranium and plutonium, it is better to use the double spike isotope dilution method, with a spike solution of known 233 U- 242 Pu ratio. Using this method, the ratio of uranium to plutonium concentration in the irradiated fuel solution can be determined without any accurate measurement of the mixed amounts of sample and spike solutions. For fissile material balance measurements, the uranium concentration is determined by using single isotope dilution, and the plutonium concentration is deduced from the ratio Pu/U and U concentration. The main advantages of isotope dilution are its selectivity, accuracy and very high sensitivity. The recent improvements made to surface ionization mass spectrometers have considerably increased the precision of the measurements; a relative precision of about 0.2% to 0.3% is obtained currently, but it could be reduced to 0.1%, in the future, with a careful control of the experimental procedures. The detection limite is around 0.1 ppb [fr

  1. Paleogene Seawater Osmium Isotope Records

    Science.gov (United States)

    Rolewicz, Z.; Thomas, D. J.; Marcantonio, F.

    2012-12-01

    Paleoceanographic reconstructions of the Late Cretaceous and early Cenozoic require enhanced geographic coverage, particularly in the Pacific, in order to better constrain meridional variations in environmental conditions. The challenge with the existing inventory of Pacific deep-sea cores is that they consist almost exclusively of pelagic clay with little existing age control. Pelagic clay sequences are useful for reconstructions of dust accumulation and water mass composition, but accurate correlation of these records to other sites requires improved age control. Recent work indicates that seawater Os isotope analyses provide useful age control for red clay sequences. The residence time of Os in seawater is relatively long compared to oceanic mixing, therefore the global seawater 187Os/188Os composition is practically homogeneous. A growing body of Late Cretaceous and Cenozoic data has constrained the evolution of the seawater Os isotopic composition and this curve is now a viable stratigraphic tool, employed in dating layers of Fe-Mn crusts (e.g., Klemm et al., 2005). Ravizza (2007) also demonstrated that the seawater Os isotopic composition can be extracted reliably from pelagic red clay sediments by analyzing the leached oxide minerals. The drawback to using seawater Os isotope stratigraphy to date Paleogene age sediments is that the compilation of existing data has some significant temporal gaps, notably between ~38 and 55 Ma. To improve the temporal resolution of the seawater Os isotope curve, we present new data from Ocean Drilling Program (ODP) Site 865 in the equatorial Pacific. Site 865 has excellent biostratigraphic age control over the interval ~38-55Ma. Preliminary data indicate an increase in the seawater composition from 0.427 at 53.4 Ma to 0.499 by 43 Ma, consistent with the apparent trend in the few existing data points. We also analyzed the Os isotopic composition recorded by oxide minerals at Integrated Ocean Drilling Program (IODP) Site U1370

  2. Deformation properties of lead isotopes

    International Nuclear Information System (INIS)

    Tolokonnikov, S. V.; Borzov, I. N.; Lutostansky, Yu. S.; Saperstein, E. E.

    2016-01-01

    The deformation properties of a long lead isotopic chain up to the neutron drip line are analyzed on the basis of the energy density functional (EDF) in the FaNDF 0 Fayans form. The question of whether the ground state of neutron-deficient lead isotopes can have a stable deformation is studied in detail. The prediction of this deformation is contained in the results obtained on the basis of the HFB-17 and HFB-27 Skyrme EDF versions and reported on Internet. The present analysis reveals that this is at odds with experimental data on charge radii and magnetic moments of odd lead isotopes. The Fayans EDF version predicts a spherical ground state for all light lead isotopes, but some of them (for example, 180 Pb and 184 Pb) prove to be very soft—that is, close to the point of a phase transition to a deformed state. Also, the results obtained in our present study are compared with the predictions of some other Skyrme EDF versions, including SKM*, SLy4, SLy6, and UNE1. By and large, their predictions are closer to the results arising upon the application of the Fayans functional. For example, the SLy4 functional predicts, in just the same way as the FaNDF 0 functional, a spherical shape for all nuclei of this region. The remaining three Skyrme EDF versions lead to a deformation of some light lead isotopes, but their number is substantially smaller than that in the case of the HFB-17 and HFB-27 functionals. Moreover, the respective deformation energy is substantially lower, which gives grounds to hope for the restoration of a spherical shape upon going beyond the mean-field approximation, which we use here. Also, the deformation properties of neutron-rich lead isotopes are studied up to the neutron drip line. Here, the results obtained with the FaNDF 0 functional are compared with the predictions of the HFB-17, HFB-27, SKM*, and SLy4 Skyrme EDF versions. All of the EDF versions considered here predict the existence of a region where neutron-rich lead isotopes undergo

  3. Diet-tissue stable isotope13C and Δ15N) discrimination factors for multiple tissues from terrestrial reptiles

    OpenAIRE

    Steinitz, R; Lemm, JM; Pasachnik, SA; Kurle, CM

    2016-01-01

    Copyright © 2015 John Wiley & Sons, Ltd. Rationale Stable isotope analysis is a powerful tool for reconstructing trophic interactions to better understand drivers of community ecology. Taxon-specific stable isotope discrimination factors contribute to the best use of this tool. We determined the first Δ 13 C and Δ 15 N values for Rock Iguanas (Cyclura spp.) to better understand isotopic fractionation and estimate wild reptile foraging ecology. Methods The Δ 13 C and Δ 15 N values between di...

  4. The isotopic contamination in electromagnetic isotope separators; La contagion isotopique dans les separateurs electromagnetiques d'isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Cassignol, Ch [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    In the early years of isotope separation, and in particular electromagnetic isotope separation, needs for rapid results have conducted to empiric research. This paper describes fundamental research on the electromagnetic isotope separation to a better understanding of isotope separators as well as improving the performances. Focus has been made on the study of the principle of isotope contamination and the remedial action on the separator to improve the isotope separation ratio. In a first part, the author come back to the functioning of an electromagnetic separator and generalities on isotope contamination. Secondly, it describes the two stages separation method with two dispersive apparatus, an electromagnetic separation stage followed by an electrostatic separation stage, both separated by a diaphragm. The specifications of the electrostatic stage are given and its different settings and their consequences on isotope separation are investigated. In a third part, mechanisms and contamination factors in the isotope separation are discussed: natural isotope contamination, contamination by rebounding on the collector, contamination because of a low resolution, contamination by chromatism and diffusion effect, breakdown of condenser voltage. Analysis of experimental results shows the diffusion as the most important contamination factor in electromagnetic isotope separation. As contamination factors are dependent on geometric parameters, sector angle, radius of curvature in the magnetic field and clearance height are discussed in a fourth part. The better understanding of the mechanism of the different contamination factors and the study of influential parameters as pressure and geometric parameters lead to define a global scheme of isotope contamination and determinate optima separator design and experimental parameters. Finally, the global scheme of isotope contamination and hypothesis on optima specifications and experimental parameters has been checked during a

  5. The isotopic contamination in electromagnetic isotope separators; La contagion isotopique dans les separateurs electromagnetiques d'isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Cassignol, Ch. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    In the early years of isotope separation, and in particular electromagnetic isotope separation, needs for rapid results have conducted to empiric research. This paper describes fundamental research on the electromagnetic isotope separation to a better understanding of isotope separators as well as improving the performances. Focus has been made on the study of the principle of isotope contamination and the remedial action on the separator to improve the isotope separation ratio. In a first part, the author come back to the functioning of an electromagnetic separator and generalities on isotope contamination. Secondly, it describes the two stages separation method with two dispersive apparatus, an electromagnetic separation stage followed by an electrostatic separation stage, both separated by a diaphragm. The specifications of the electrostatic stage are given and its different settings and their consequences on isotope separation are investigated. In a third part, mechanisms and contamination factors in the isotope separation are discussed: natural isotope contamination, contamination by rebounding on the collector, contamination because of a low resolution, contamination by chromatism and diffusion effect, breakdown of condenser voltage. Analysis of experimental results shows the diffusion as the most important contamination factor in electromagnetic isotope separation. As contamination factors are dependent on geometric parameters, sector angle, radius of curvature in the magnetic field and clearance height are discussed in a fourth part. The better understanding of the mechanism of the different contamination factors and the study of influential parameters as pressure and geometric parameters lead to define a global scheme of isotope contamination and determinate optima separator design and experimental parameters. Finally, the global scheme of isotope contamination and hypothesis on optima specifications and experimental parameters has been checked during a

  6. Separation and Analysis of Boron Isotope in High Plant by Thermal Ionization Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Qingcai Xu

    2015-01-01

    Full Text Available Knowledge of boron and its isotope in plants is useful to better understand the transposition and translocation of boron within plant, the geochemical behavior in the interface between soil and plant, and the biogeochemical cycle of boron. It is critical to develop a useful method to separate boron from the plant for the geochemical application of boron and its isotope. A method was developed for the extraction of boron in plant sample, whose isotope was determined by thermal ionization mass spectrometry. The results indicated that this method of dry ashing coupled with two-step ion-exchange chromatography is powerful for the separation of boron in plant sample with large amounts of organic matters completely. The ratios of boron isotope composition in those plant tissue samples ranged from -19.45‰ to +28.13‰ (total range: 47.58‰ with a mean value of 2.61±11.76‰ SD. The stem and root isotopic compositions were lower than those in flower and leaf. The molecular mechanism of boron isotope may be responsible for the observed variation of boron isotopic composition and are considered as a useful tool for the better understanding of boron cycling process in the environment and for the signature of living systems.

  7. Method for separating gaseous mixtures of isotopes

    International Nuclear Information System (INIS)

    Neimann, H.J.; Schuster, E.; Kersting, A.

    1976-01-01

    A gaseous mixture of isotopes is separated by laser excitation of the isotope mixture with a narrow band of wavelengths, molecularly exciting mainly the isotope to be separated and thereby promoting its reaction with its chemical partner which is excited in a separate chamber. The excited isotopes and the chemical partner are mixed, perhaps in a reaction chamber to which the two excited components are conducted by very short conduits. The improvement of this method is the physical separation of the isotope mixture and its partner during excitation. The reaction between HCl and the mixture of 238 UF 6 and 235 UF 6 is discussed

  8. Isotopic anomalies - chemical memory of Galactic evolution

    International Nuclear Information System (INIS)

    Clayton, D.D.

    1988-01-01

    New mechanisms for the chemical memory of isotopic anomalies are proposed which are based on the temporal change during the chemical evolution of the Galaxy of the isotopic composition of the mean ejecta from stars. Because of the differing temporal evolution of primary and secondary products of nucleosynthesis, the isotopic composition of the bulk interstellar medium changes approximately linearly with time, and thus any dust component having an age different from that of average dust will be isotopically anomalous. Special attention is given to C, O, Mg, Si, and isotopically heavy average-stellar condensates of SiC. 20 references

  9. Uranium isotope separation using styrene cation exchangers

    International Nuclear Information System (INIS)

    Kahovec, J.

    1980-01-01

    The separation of 235 U and 238 U isotopes is carried out either by simple isotope exchange in the system uranium-cation exchanger (sulphonated styrene divinylbenzene resin), or by combination of isotope exchange in a uranium-cation exchanger (Dowex 50, Amberlite IR-120) system and a chemical reaction. A review is presented of elution agents used, the degree of cation exchanger cross-linking, columns length, and 235 U enrichment. The results are described of the isotope effect study in a U(IV)-U(VI)-cation exchanger system conducted by Japanese and Romanian authors (isotope exchange kinetics, frontal analysis, reverse (indirect) frontal analysis). (H.S.)

  10. Isotopic composition of cosmic ray nuclei

    International Nuclear Information System (INIS)

    Enge, W.

    1976-01-01

    A review will be given on the role of cosmic ray isotopes as tracers of the astrophysical nucleo-synthesis. The products of every nuclear burning chain are first of all isotopes and not elements. Thus, it is the study of the isotopes rather than that of the elements that responds to the questions on these nucleo-synthetic reactions. The problems concerning the solar system isotopic abundances and the cosmic ray isotopic abundances as well as a comparison between both will be presented. Furthermore the present stage of the experimental techniques and the latest results will be discussed. (orig.) [de

  11. 2. Workshop 'Isotopes in Nature'. 1

    International Nuclear Information System (INIS)

    1979-11-01

    The workshop was aimed at discussing in detail the following problems: (1) distribution of stable and radioactive isotopes in nature, (2) theoretical and experimental studies of isotopic effects in natural processes, (3) problems of sample preparation and sample measurement in determining the relative abundance of stable isotopes or radioactive isotopes in nature, (4) age estimations of samples from different areas of the geosphere, (5) contributions to the specification of global and regional substance cycles in nature with the aid of isotopic and geochemical studies. 75 summaries are included

  12. Nuclear structure of Uranium isotopes in the frame work of two parameter formula

    International Nuclear Information System (INIS)

    Vidya Devi; Gupta, J.B.

    2017-01-01

    We studied the power law, ab formula and SRF which are applicable for both deformed and soft nuclei. The formula is particularly successful in soft rotor and deformed nuclei with 2:8≤ R 4/2 3:3. The power law gives good fit of the data for b and a derived either from 2 + , 4 + or 6 + , 8 + energy levels. This study help to understand the structure of isotopes of Uranium and useful to find some new energy level of these isotopes theoretically

  13. The centenary of the discovery of isotopes

    International Nuclear Information System (INIS)

    Soulie, Edgar

    2013-01-01

    This article recalls works performed by different scientists (Marckwald and Keetman, Stromholm and Svedberg, Soddy, Thompson, Aston) which resulted in the observation and identification of the existence of isotopes. The author also recalls various works related to mechanisms of production of isotopes, the discovery of uranium fission and the principle of chain reaction. The author notably evokes French scientists involved in the development of mass spectroscopy and in the research and applications on isotopes within the CEA after the Second World War. A bibliography of article and books published by one of them, Etienne Roth, is provided. References deal with nuclear applications of chemical engineering (heavy water and its production, chemical processes in fission reactors, tritium extraction and enrichment), isotopic fractioning and physical-chemical processes, mass spectrometry and isotopic analysis, isotopic geochemistry (on 07;Earth, search for deuterium in moon rocks and their consequences), first dating and the Oklo phenomenon, radioactive dating, water and climate (isotopic hydrology, isotopes and hailstone formation, the atmosphere), and miscellaneous scientific fields (nuclear measurements and radioactivity, isotopic abundances and atomic weight, isotopic separation and use of steady isotopes)

  14. Mass fractionation processes of transition metal isotopes

    Science.gov (United States)

    Zhu, X. K.; Guo, Y.; Williams, R. J. P.; O'Nions, R. K.; Matthews, A.; Belshaw, N. S.; Canters, G. W.; de Waal, E. C.; Weser, U.; Burgess, B. K.; Salvato, B.

    2002-06-01

    Recent advances in mass spectrometry make it possible to utilise isotope variations of transition metals to address some important issues in solar system and biological sciences. Realisation of the potential offered by these new isotope systems however requires an adequate understanding of the factors controlling their isotope fractionation. Here we show the results of a broadly based study on copper and iron isotope fractionation during various inorganic and biological processes. These results demonstrate that: (1) naturally occurring inorganic processes can fractionate Fe isotope to a detectable level even at temperature ˜1000°C, which challenges the previous view that Fe isotope variations in natural system are unique biosignatures; (2) multiple-step equilibrium processes at low temperatures may cause large mass fractionation of transition metal isotopes even when the fractionation per single step is small; (3) oxidation-reduction is an importation controlling factor of isotope fractionation of transition metal elements with multiple valences, which opens a wide range of applications of these new isotope systems, ranging from metal-silicate fractionation in the solar system to uptake pathways of these elements in biological systems; (4) organisms incorporate lighter isotopes of transition metals preferentially, and transition metal isotope fractionation occurs stepwise along their pathways within biological systems during their uptake.

  15. The cobalt radioactive isotopes in environment

    International Nuclear Information System (INIS)

    2007-01-01

    For the year 1993 the total activity released in cobalt is 69 GBq for the whole of nuclear power plants. The part of activity in cobalt for La Hague in 1993 is 8 GBq of 58 Co and 2 GBq of 60 Co. The radioactive isotopes released by nuclear power plants or the reprocessing plant of La Hague under liquid effluents are shared by half between 58 Co and 60 Co. The exposure to sealed sources is the most important risk for the cobalt. The risk of acute exposure can associate a local irradiation of several decades of grays inducing a radiological burns, deep burn to treat in surgery by resection or graft even amputation. A global irradiation of organism for several grays induces an acute irradiation syndrome, often serious. At long term the stochastic effects are represented by leukemia and radio-induced cancers. The increase of probability of their occurrence is 1% by sievert. We must remind that the natural spontaneous probability is 25%. (N.C.)

  16. Electrical power systems for Mars

    Science.gov (United States)

    Giudici, Robert J.

    1986-01-01

    Electrical power system options for Mars Manned Modules and Mars Surface Bases were evaluated for both near-term and advanced performance potential. The power system options investigated for the Mission Modules include photovoltaics, solar thermal, nuclear reactor, and isotope power systems. Options discussed for Mars Bases include the above options with the addition of a brief discussion of open loop energy conversion of Mars resources, including utilization of wind, subsurface thermal gradients, and super oxides. Electrical power requirements for Mission Modules were estimated for three basic approaches: as a function of crew size; as a function of electric propulsion; and as a function of transmission of power from an orbiter to the surface of Mars via laser or radio frequency. Mars Base power requirements were assumed to be determined by production facilities that make resources available for follow-on missions leading to the establishment of a permanently manned Base. Requirements include the production of buffer gas and propellant production plants.

  17. 13C metabolic flux analysis: optimal design of isotopic labeling experiments.

    Science.gov (United States)

    Antoniewicz, Maciek R

    2013-12-01

    Measuring fluxes by 13C metabolic flux analysis (13C-MFA) has become a key activity in chemical and pharmaceutical biotechnology. Optimal design of isotopic labeling experiments is of central importance to 13C-MFA as it determines the precision with which fluxes can be estimated. Traditional methods for selecting isotopic tracers and labeling measurements did not fully utilize the power of 13C-MFA. Recently, new approaches were developed for optimal design of isotopic labeling experiments based on parallel labeling experiments and algorithms for rational selection of tracers. In addition, advanced isotopic labeling measurements were developed based on tandem mass spectrometry. Combined, these approaches can dramatically improve the quality of 13C-MFA results with important applications in metabolic engineering and biotechnology. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Usage of burnt fuel isotopic compositions from engineering codes in Monte-Carlo code calculations

    International Nuclear Information System (INIS)

    Aleshin, Sergey S.; Gorodkov, Sergey S.; Shcherenko, Anna I.

    2015-01-01

    A burn-up calculation of VVER's cores by Monte-Carlo code is complex process and requires large computational costs. This fact makes Monte-Carlo codes usage complicated for project and operating calculations. Previously prepared isotopic compositions are proposed to use for the Monte-Carlo code (MCU) calculations of different states of VVER's core with burnt fuel. Isotopic compositions are proposed to calculate by an approximation method. The approximation method is based on usage of a spectral functionality and reference isotopic compositions, that are calculated by engineering codes (TVS-M, PERMAK-A). The multiplication factors and power distributions of FA and VVER with infinite height are calculated in this work by the Monte-Carlo code MCU using earlier prepared isotopic compositions. The MCU calculation data were compared with the data which were obtained by engineering codes.

  19. Lead (Pb) isotopic fingerprinting and its applications in lead pollution studies in China: a review.

    Science.gov (United States)

    Cheng, Hefa; Hu, Yuanan

    2010-05-01

    As the most widely scattered toxic metal in the world, the sources of lead (Pb) observed in contamination investigation are often difficult to identify. This review presents an overview of the principles, analysis, and applications of Pb isotopic fingerprinting in tracing the origins and transport pathways of Pb in the environment. It also summarizes the history and current status of lead pollution in China, and illustrates the power of Pb isotopic fingerprinting with examples of its recent applications in investigating the effectiveness of leaded gasoline phase-out on atmospheric lead pollution, and the sources of Pb found in various environmental media (plants, sediments, and aquatic organisms) in China. The limitations of Pb isotopic fingerprinting technique are discussed and a perspective on its development is also presented. Further methodological developments and more widespread instrument availability are expected to make isotopic fingerprinting one of the key tools in lead pollution investigation. Copyright 2009 Elsevier Ltd. All rights reserved.

  20. Isotope hydrology of catchment basins: lithogenic and cosmogenic isotopic systems

    Energy Technology Data Exchange (ETDEWEB)

    Nimz, G. J., LLNL

    1998-06-01

    A variety of physical processes affect solute concentrations within catchment waters. The isotopic compositions of the solutes can indicate which processes have determined the observed concentrations. These processes together constitute the physical history of the water. Many solutes in natural waters are derived from the interaction between the water and the rock and/or soil within the system - these are termed `lithogenic` solutes. The isotopic compositions of these solutes provide information regarding rock-water interactions. Many other solutes have their isotopic compositions determined both within and outside of the catchment - i.e., in addition to being derived from catchment rock and soil, they are solutes that are also transported into the catchment. Important members of this group include solutes that have isotopic compositions produced by atomic particle interactions with other nuclides. The source of the atomic particles can be cosmic radiation (producing `cosmogenic` nuclides in the atmosphere and land surface), anthropogenic nuclear reactions (producing `thermonuclear` nuclides), or radioactive and fission decay of naturally-occurring elements, principally {sup 238}U (producing `in-situ` lithogenic nuclides in the deep subsurface). Current language usage often combines all of the atomic particle-produced nuclides under the heading `cosmogenic nuclides`, and for simplicity we will often follow that usage here, although always indicating which variety is being discussed. This paper addresses the processes that affect the lithogenic and cosmogenic solute concentrations in catchment waters, and how the isotopic compositions of the solutes can be used in integrative ways to identify these processes, thereby revealing the physical history of the water within a catchment system. The concept of a `system` is important in catchment hydrology. A catchment is the smallest landscape unit that can both participate in all of the aspects of the hydrologic cycle and

  1. LSDS Development for Isotopic Fissile Assay in Spent Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Deok; Park, Chang Je; Park, Geun Il; Lee, Jung Won; Song, Kee Chan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-07-01

    As an option to reduce a spent fuel and reuse an existing fissile material in spent fuel, sodium fast reactor SFR program linked with pyro-processing is under development in KAERI. A uranium-TRU mixture through a pyro-process is used to fabricate SFR fuel. An assay of isotopic fissile content plays an important role in an optimum design of storage site and reuse of fissile materials of spent fuel. Lead slowing down spectrometer LSDS is being developed in KAERI to analyze isotopic fissile material content. LSDS has several features: direct fissile assay, near real time fissile assay, no influence from radiation background, fissile isotopic assay and applicable to spent fuel and recycled fuel. Based on the designed geometry, neutron energy resolution was investigated. The neutron energy spectrum was analyzed as well. Spent fuel emits large number of neutrons by spontaneous fission. Neutron generator must overcome the neutron background to get the pure fission signals from fissile materials. Neutron generator is planned to have compact system with one section electron linac which is easy maintenance, less cost and high neutron yield. The LSD has the power to resolve the fission characteristics from each fissile material. This feature can analyze the content of isotopic fissile. From 1keV to 0.1eV energy range, the energy resolution is enough to get the individual fissile fission signatures. The dominant fission signature is shown below 1eV for each fissile isotope. The neutron generation system with target was designed to get fission signals by fissile materials. The system was decided to overcome neutron backgrounds and to get good counting statistics. Finally, an accurate fissile material content will contribute to safety of spent fuel reuse in future nuclear energy system and optimum design of spent fuel storage site. Additionally, an accurate fissile material content will increase international transparence and credibility for the reuse of PWR spent fuel.

  2. LSDS Development for Isotopic Fissile Assay in Spent Fuel

    International Nuclear Information System (INIS)

    Lee, Yong Deok; Park, Chang Je; Park, Geun Il; Lee, Jung Won; Song, Kee Chan

    2011-01-01

    As an option to reduce a spent fuel and reuse an existing fissile material in spent fuel, sodium fast reactor SFR program linked with pyro-processing is under development in KAERI. A uranium-TRU mixture through a pyro-process is used to fabricate SFR fuel. An assay of isotopic fissile content plays an important role in an optimum design of storage site and reuse of fissile materials of spent fuel. Lead slowing down spectrometer LSDS is being developed in KAERI to analyze isotopic fissile material content. LSDS has several features: direct fissile assay, near real time fissile assay, no influence from radiation background, fissile isotopic assay and applicable to spent fuel and recycled fuel. Based on the designed geometry, neutron energy resolution was investigated. The neutron energy spectrum was analyzed as well. Spent fuel emits large number of neutrons by spontaneous fission. Neutron generator must overcome the neutron background to get the pure fission signals from fissile materials. Neutron generator is planned to have compact system with one section electron linac which is easy maintenance, less cost and high neutron yield. The LSD has the power to resolve the fission characteristics from each fissile material. This feature can analyze the content of isotopic fissile. From 1keV to 0.1eV energy range, the energy resolution is enough to get the individual fissile fission signatures. The dominant fission signature is shown below 1eV for each fissile isotope. The neutron generation system with target was designed to get fission signals by fissile materials. The system was decided to overcome neutron backgrounds and to get good counting statistics. Finally, an accurate fissile material content will contribute to safety of spent fuel reuse in future nuclear energy system and optimum design of spent fuel storage site. Additionally, an accurate fissile material content will increase international transparence and credibility for the reuse of PWR spent fuel

  3. LSDS Development for Isotopic Fissile Content Assay

    International Nuclear Information System (INIS)

    Lee, Yong Deok; Park, Chang Je; Park, Geun Il; Lee, Jung Won; Song, Kee Chan

    2010-01-01

    Concerning the sustainable energy supply and green house effect, nuclear energy became the most feasible option to meet the energy demand in Korea. However, the production of the spent nuclear fuel is the inevitable situation. Since the first nuclear power plant started to produce the electricity in Korea, the accumulated amount of spent fuels exceeded 10k tomes recently. The accumulation of the spent fuels is the big issue in the society. Therefore, as an option which strengthens the nuclear proliferation resistance and reduces the amount of spent fuels, sodium fast reactor (SFR) program linked with pyro-processing is under development to re-use the PWR spent fuel and produce the energy. In the process, the produced metallic material involves uranium and TRU (transuranic; neptunium, plutonium, and americium). The uranium-TRU is used to fabricate SFR fuel. The burning the recycled fuel in the reactor is to solve the current spent fuel storage problem and to minimize the actinides accumulation having long half-life. Generally, the spent fuel from PWR has unburned ∼1 % U235, produced ∼0.5 % plutonium from decay chain, ∼3 % fission products, ∼ 0.1 % minor actinides (MA) and uranium remainder. About 1.5 % fissile materials still exist in the spent fuel. Therefore, spent fuel is not only waste but energy resource. The direct and isotopic fissile content assay is the crucial technology for the spent fuel reuse. Additionally, the fissile content analysis will contribute to the optimum storage design and safe spent fuel management. Several nondestructive technologies have been developed for the spent fuel assay; gamma ray measurement, passive and active neutron measurements. Spent fuel emits intense gamma rays and neutrons by (a, n) and spontaneous fission. This intense background has the limitation on the direct analysis of fissile materials. Recently, to analyze the individual fissile content, leadslowing down spectrometer (LSDS) has been being developed in Korea

  4. ISOGEN: Interactive isotope generation and depletion code

    International Nuclear Information System (INIS)

    Venkata Subbaiah, Kamatam

    2016-01-01

    ISOGEN is an interactive code for solving first order coupled linear differential equations with constant coefficients for a large number of isotopes, which are produced or depleted by the processes of radioactive decay or through neutron transmutation or fission. These coupled equations can be written in a matrix notation involving radioactive decay constants and transmutation coefficients, and the eigenvalues of thus formed matrix vary widely (several tens of orders), and hence no single method of solution is suitable for obtaining precise estimate of concentrations of isotopes. Therefore, different methods of solutions are followed, namely, matrix exponential method, Bateman series method, and Gauss-Seidel iteration method, as was followed in the ORIGEN-2 code. ISOGEN code is written in a modern computer language, VB.NET version 2013 for Windows operating system version 7, which enables one to provide many interactive features between the user and the program. The output results depend on the input neutron database employed and the time step involved in the calculations. The present program can display the information about the database files, and the user has to select one which suits the current need. The program prints the 'WARNING' information if the time step is too large, which is decided based on the built-in convergence criterion. Other salient interactive features provided are (i) inspection of input data that goes into calculation, (ii) viewing of radioactive decay sequence of isotopes (daughters, precursors, photons emitted) in a graphical format, (iii) solution of parent and daughter products by direct Bateman series solution method, (iv) quick input method and context sensitive prompts for guiding the novice user, (v) view of output tables for any parameter of interest, and (vi) output file can be read to generate new information and can be viewed or printed since the program stores basic nuclide concentration unlike other batch jobs. The sample

  5. Isotopic contamination in electromagnetic isotope separators; La contagion isotopique dans les separateurs electromagnetiques d'isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Cassignol, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The mechanisms producing isotopic contamination in the electromagnetic separation of isotopes are studied with the aid of the Separator of Saclay and an electrostatic analyzer in cascade. After a separate investigation the result of which is that no contamination comes from the spreading of initial energies of ions, two principal mechanisms are emphasized; scattering and instability of the regime of the sources. The characters of each type of contamination arising from both mechanisms are described in some detail. An unique scheme of isotopic contamination is then derived from the partial ones. This scheme is successfully verified in several experimental separations. The applications concern principally the performances of magnetic cascades and more complex apparatus. It is found that the isotopic purities that such machines can deliver are extremely high. (author) [French] On a etudie, a l'aide du separateur de Saclay et d'un analyseur electrostatique en cascade, les mecanismes par lesquels est produite la contamination isotopique dans la separation electromagnetique des isotopes. A la suite d'une deuxieme etude, qui a mene a la conclusion que la contamination ne provient pas d'une dispersion des energies initiales des ions, on propose deux mecanismes comme etant les plus importants; la diffusion et l'instabilite du regime des sources. On decrit en quelques details la nature de la contamination provenant de deux types de mecanisme. On deduit de ces deux mecanismes un seul schema qui a ete ensuite verifie par plusieurs separations experimentales. Les applications interessent surtout les performances des cascades magnetiques et les appareillages plus complexes. On trouve que les puretes isotopiques que peuvent fournir de tels appareils sont tres elevees. (auteur)

  6. Plutonium isotopes/137Cs activity ratios for soil in Montenegro

    International Nuclear Information System (INIS)

    Antovic, N. M.; Vukotic, P.; Svrkota, N.; Andrukhovich, S.K.

    2011-01-01

    Plutonium isotopes/ 137 Cs activity ratios were determined for six soil samples from Montenegro, using the results of alpha-spectrometric measurements of 239+240 Pu and 238 Pu, as well as gamma-spectrometric cesium measurements. An average 239+240 Pu/ 137 Cs activity ratio is found to be 0.02, as the 238 Pu/ 137 Cs and 238 Pu/ 239+240 Pu one - 0.0006 and 0.03, respectively. It follows from the results that the source of plutonium in Montenegro soil is nuclear weapon testing during the fifties and sixties of the twentieth century. On the other hand, there is a contribution of the accident at the Chernobyl nuclear power plant to the soil contamination with 137 Cs isotope. [sr

  7. DNA stable-isotope probing (DNA-SIP).

    Science.gov (United States)

    Dunford, Eric A; Neufeld, Josh D

    2010-08-02

    DNA stable-isotope probing (DNA-SIP) is a powerful technique for identifying active microorganisms that assimilate particular carbon substrates and nutrients into cellular biomass. As such, this cultivation-independent technique has been an important methodology for assigning metabolic function to the diverse communities inhabiting a wide range of terrestrial and aquatic environments. Following the incubation of an environmental sample with stable-isotope labelled compounds, extracted nucleic acid is subjected to density gradient ultracentrifugation and subsequent gradient fractionation to separate nucleic acids of differing densities. Purification of DNA from cesium chloride retrieves labelled and unlabelled DNA for subsequent molecular characterization (e.g. fingerprinting, microarrays, clone libraries, metagenomics). This JoVE video protocol provides visual step-by-step explanations of the protocol for density gradient ultracentrifugation, gradient fractionation and recovery of labelled DNA. The protocol also includes sample SIP data and highlights important tips and cautions that must be considered to ensure a successful DNA-SIP analysis.

  8. Modeling of the global carbon cycle - isotopic data requirements

    International Nuclear Information System (INIS)

    Ciais, P.

    1994-01-01

    Isotopes are powerful tools to constrain carbon cycle models. For example, the combinations of the CO 2 and the 13 C budget allows to calculate the net-carbon fluxes between atmosphere, ocean, and biosphere. Observations of natural and bomb-produced radiocarbon allow to estimate gross carbon exchange fluxes between different reservoirs and to deduce time scales of carbon overturning in important reservoirs. 18 O in CO 2 is potentially a tool to make the deconvolution of C fluxes within the land biosphere (assimilation vs respirations). The scope of this article is to identify gaps in our present knowledge about isotopes in the light of their use as constraint for the global carbon cycle. In the following we will present a list of some future data requirements for carbon cycle models. (authors)

  9. Separative power of an optimised concurrent gas centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Bogovalov, Sergey; Boman, Vladimir [National Research Nuclear University (MEPHI), Moscow (Russian Federation)

    2016-06-15

    The problem of separation of isotopes in a concurrent gas centrifuge is solved analytically for an arbitrary binary mixture of isotopes. The separative power of the optimised concurrent gas centrifuges for the uranium isotopes equals to δU = 12.7 (V/700 m/s)2(300 K/T)(L/1 m) kg·SWU/yr, where L and V are the length and linear velocity of the rotor of the gas centrifuge and T is the temperature. This equation agrees well with the empirically determined separative power of optimised counter-current gas centrifuges.

  10. Methane clumped isotopes: Progress and potential for a new isotopic tracer

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, Peter M. J.; Stolper, Daniel A.; Eiler, John M.; Sessions, Alex L.; Lawson, Michael; Shuai, Yanhua; Bishop, Andrew; Podlaha, Olaf G.; Ferreira, Alexandre A.; Santos Neto, Eugenio V.; Niemann, Martin; Steen, Arne S.; Huang, Ling; Chimiak, Laura; Valentine, David L.; Fiebig, Jens; Luhmann, Andrew J.; Seyfried, William E.; Etiope, Giuseppe; Schoell, Martin; Inskeep, William P.; Moran, James J.; Kitchen, Nami

    2017-11-01

    The isotopic composition of methane is of longstanding geochemical interest, with important implications for understanding hydrocarbon systems, atmospheric greenhouse gas concentrations, the global carbon cycle, and life in extreme environments. Recent analytical developments focusing on multiply substituted isotopologues (‘clumped isotopes’) are opening a potentially valuable new window into methane geochemistry. When methane forms in internal isotopic equilibrium, clumped isotopes can provide a direct record of formation temperature, making this property particularly valuable for identifying different methane origins. However, it has also become clear that in certain settings methane clumped isotope measurements record kinetic rather than equilibrium isotope effects. Here we present a substantially expanded dataset of methane clumped isotope analyses, and provide a synthesis of the current interpretive framework for this parameter. We review different processes affecting methane clumped isotope compositions, describe the relationships between conventional isotope and clumped isotope data, and summarize the types of information that this measurement can provide in different Earth and planetary environments.

  11. Program for analyzing power boost tests

    International Nuclear Information System (INIS)

    Wills, C.A.

    1982-03-01

    A rapid increase of power in a reactor produces a failure in the fuel. Experiments to study the conditions in the NRU reactor after such failures have been planned and carried out. Given the concentrations of specified isotopes at a number of times over the length of an experiment as produced for example, from the program SARGS and the power history of the reactor, this program calculates the release rates, escape rate coefficients, and fractional releases for the isotopes. These values may be optionally printed and plotted. Decay schemes for a limited number of mass numbers are implemented. The program is written in FORTRAN and runs on the CDC 6600 - CYBER 170 system

  12. Experimental study of hydrogen isotopes storage on titanium bed

    International Nuclear Information System (INIS)

    Vasut, Felicia; Zamfirache, Marius; Bornea, Anisia; Pearsica, Claudia; Bidica, Nicolae

    2002-01-01

    As known, the Nuclear Power Plant Cernavoda equipped with a Canadian reactor, of CANDU type, is the most powerful tritium source from Europe. On long term, due to a 6·10 16 Bq/year, Cernavoda area will be contaminated due to the increasing tritium quantity. Also, the continuous contamination of heavy water from the reactor, induces a reduction of moderation's capacity. Therefore, one considers that it is improperly to use heavy water if its activity level is higher than 40 Ci/kg in the moderator and 2 Ci/kg in the cooling fluid. For these reasons, we have developed a detritiation technology, based on catalytic isotopic exchange and cryogenic distillation. Tritium will be removed from the tritiated heavy water, so it appears the necessity of storage of tritium in a special vessel that can provide a high level of protection and safety of environment and personal. There several metals were tested as storage beds for hydrogen isotopes. One of the reference materials used for storage of hydrogen isotopes is uranium, a material with a great storage capacity, but unfortunately it is a radioactive metal and also can react with the impurities from the stored gas. Other metals and alloys as ZrCo, Ti, FeTi are also adequate as storage beds at normal temperature. The paper presents studies about the reaction between hydrogen and titanium used as storage bed for the hydrogen isotopes resulted after the detritiation of tritiated heavy water. The experiments that were carried out used protium and mixture of deuterium and protium at different storage parameters as process gas. (authors)

  13. Natural fractionation of uranium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Noordmann, Janine

    2015-01-24

    The topic of this thesis was the investigation of U (n({sup 238}U) / n({sup 235}U)) isotope variations in nature with a focus on samples (1) that represent the continental crust and its weathering products (i.e. granites, shales and river water) (2) that represent products of hydrothermal alteration on mid-ocean ridges (i.e. altered basalts, carbonate veins and hydrothermal water) and (3) from restricted euxinic basins (i.e. from the water column and respective sediments). The overall goal was to explore the environmental conditions and unravel the mechanisms that fractionate the two most abundant U isotopes, n({sup 238}U) and n({sup 235}U), on Earth.

  14. Commercialization of DOE isotope production

    International Nuclear Information System (INIS)

    Laflin, S.

    1997-01-01

    This paper describes the business structure and operations of MAC Isotopes (MACI) L.L.C., a newly created business resulting from the commercialization of a former U.S. Department of Energy (DOE) mission at the Idaho National Engineering and Environmental Laboratory (INEEL). MACI began its commercial operations on October 1, 1996, and is the first U.S. commercial isotope production business to result from the commercialization of DOE facilities or programs. The commercialization was the culmination of an -2-yr competitive procurement process by the DOE and Lockheed Martin Idaho Technologies Company (LMITCO). MACI was selected from this competitive process as the commercial business of choice on the basis of providing the best value to the DOE/LMITCO and having the greatest potential for commercial success

  15. Radiogenic age and isotopic studies

    International Nuclear Information System (INIS)

    1991-01-01

    This is one of an annual collection of reports presenting data from the Geochronology Section of the Continental Geoscience Division of the Geological Survey of Canada (GSC). The main purpose of this collection is to make geochronological and other radiogenic isotope data produced by the section available promptly to the geological community. Reports make full presentation of the data, relate these to field settings and make comparatively short interpretations. Other geochronological and isotope data produced in the laboratory but published in outside journals or separate GSC publications are summarized at the end of this report. Reports in this issue give U-Pb zircon ages for rocks in Newfoundland, Yukon Territory, Manitoba, Ontario, and the Northwest Territories; present a compilation of K-Ar ages; and discuss Precambrian activity in New Brunswick, the geochronology of rock from the Northwest Territories, and reconnaissance Nd studies of rocks from the Northwest Territories. (figs., tabs., refs.)

  16. Radiogenic age and isotopic studies

    International Nuclear Information System (INIS)

    1992-01-01

    This is one of an annual collection of reports presenting data from the Geochronology Section of the Continental Geoscience Division of the Geological Survey of Canada (GSC). The main purpose of this collection is to make geochronological and other radiogenic isotope data produced by the section available promptly to the geological community. Reports make full presentation of the data, relate these to field settings and make comparatively short interpretations. Other geochronological and isotope data produced in the laboratory but published in outside journals or separate GSC publications are summarized at the end of this report. Report 5 contains 24 papers from most regions of Canada, but particularly from British Columbia. The Geochronology Laboratory has, over the years, provided substantial U-Pb dating for the Cordilleran Division of the Geological Survey of Canada in Vancouver, and the results of a number of these studies are presented this year. A compilation of K-Ar ages is given. (figs., tabs., refs.)

  17. Isotope hydrology in Latin America

    Energy Technology Data Exchange (ETDEWEB)

    Payne, B R [International Atomic Energy Agency, Division of Research and Laboratories, Isotope Hydrology Section, Vienna (Austria)

    1972-07-01

    A wide variety of problems in hydrology have proved susceptible to the use of nuclear techniques. Conclusions may be drawn from the relative abundances of certain 'environmental isotopes', such as heavy stable isotopes of hydrogen and oxygen in water molecules, tritium, carbon-14 and silicon-32, in atmospheric, surface or ground water; origin and rate of flow, for example, may be deduced. Artificial radioisotopes may be used similarly as a logical extension to well-known tracer techniques using dyes and salts. Inherent in the use of such radiotracers are the advantages of very high detection sensitivity (and thus very low required concentrations and the elimination of density effects), and a choice of a variety of nuclides alien to the geohydrological system (and hence unique identification and low background). (author)

  18. Strange Isotope Ratios in Jupiter

    Science.gov (United States)

    Manuel, O.; Ragland, D.; Windler, K.; Zirbel, J.; Johannes, L.; Nolte, A.

    1998-05-01

    At the January AAS meeting, Dr. Daniel Goldin ordered the release of isotopic data from the 1995 Galileo probe into Jupiter. This probe took mass readings for mass numbers 2-150, which includes all of the noble gas isotopes. A certain few noble gas isotopes, specifically those at mass/charge = 21, 40, 78, 124, and 126, are difficult to distinguish from background, while interference causes some variation in signals for noble gas isotopes at mass/charge = 20, 22, 36, 38, 40, 80, 82, 83, 84 and 86. Some contamination was caused by incomplete adsorption of low mass hydrocarbons by Carbosieve, the material used in the concentration cells [Space Sci. Rev. 60, 120 (1992)]. Thus, preliminary results are most reliable in the high mass region that includes xenon. The Galileo Probe provided the first direct measurements from a planet with a chemical composition drastically different from Earth. Our preliminary analyses indicate that Jupiter contains Xe-X [Nature 240, 99 (1972)], which differs significantly from Earth's xenon. Xe-X and primordial He are tightly coupled on the microscopic scale of meteorite minerals [Science 195, 208 (1977); Meteoritics 15, 117 (1980)]. The presence today of Xe-X in the He-rich atmosphere of Jupiter suggests that the primordial linkage of Xe-X with He extended across the protosolar nebula, on a planetary scale [Comments Astrophys. 18, 335 (1997)]. Contamination by hydrocarbons and other gases does not necessarily remove light noble gases from further consideration. Currently, isolation of signals of these elements from interference continues and may result in the presentation of many other interesting observations at the conference.

  19. Titanium isotopic anomalies in meteorites

    International Nuclear Information System (INIS)

    Niemeyer, S.; Lugmair, G.W.

    1984-01-01

    High-precision analyses of Ti are reported for samples from a variety of meteorite classes. The expanded data base for Allende inclusions still shows Ti isotope anomalies in every inclusion. All the coarse-grained inclusions give quite similar patterns, but fine-grained inclusions show more variable, and sometimes larger, anomalies. One inclusion, 3675A, was analyzed because others identified it as a possible 'FUN' inclusion due to its mass-fractionated Mg. This designation is supported by the significantly more complex Ti isotopic pattern for 3675A compared to all our other Allende inclusions. Available data fail to suggest that any particular Allende mineral phase, including a chromite-carbon fraction from an acid residue, is especially rich in anomalous Ti. We also find anomalous Ti in a bulk sample of a C1 chondrite and in matrix separates from C2 chondrites. The excesses of 50 Ti are smaller than for Allende inclusions, and subtle differences in Ti isotopic patterns tentatively suggest that parent materials for C1-C2 matrix and Allende inclusions are not directly related. Analyses of chondrules from unequilibrated ordinary chondrites did not yield clear evidence for anomalous Ti, but some 'larger than usual' deficits at 50/46 give encouragement for future work in this direction. (author)

  20. Isotope exchange process and device

    International Nuclear Information System (INIS)

    Delvalle, Pierre.

    1974-01-01

    A process for enriching uranium in one of its isotopes is described. To do so, cascade isotopic exchanges are made by contact between U(III) and U(IV) in conditions avoiding the oxidation of U(III) in U(IV). A liquid phase containing an uranium compound and free of other group III to VIII metals of the periodic classification, in which uranium is present at a first valence is placed in contact with a second valence uranium compound, protected from any contact with a conducting solid and with an agent bringing free or release oxygen. The second phase is organic. The process includes a counter current isotopic exchange between an aqueous phase containing a U +4 salting-out agent and the uranium as U +3 ions and an organic phase containing the uranium at valence IV. This is followed by the extraction of U(IV) from the organic phase into the previously spent aqueous phase and the reduction of uranium from valence IV to valence III; finally by oxidation of U(III) of the aqueous phase into U(IV) and the transfer of U(IV) into the previously exhausted organic phase [fr