WorldWideScience

Sample records for airborne gamma spectrometry

  1. Airborne gamma-ray spectrometry

    DEFF Research Database (Denmark)

    Hovgaard, Jens

    A new method - Noise Adjusted Singular Value Decomposition, NASVD - for processing gamma-ray spectra has been developed as part of a Ph.D. project. By using this technique one is able to decompose a large set of data - for example from airborne gamma-ray surveys - into a few spectral components. ...

  2. Airborne gamma spectrometry - towards integration of European operational capability

    International Nuclear Information System (INIS)

    Full text: A nuclear threat can take several forms. The fallout from nuclear weapons or from an accident in a nuclear power reactor may contaminate a large area (>>100,000 km2) whereas the dispersion of single sources, either accidentally or deliberately (dirty bomb), contaminates a much smaller area, perhaps only a few thousand square kilometres or less. Airborne gamma spectrometry (AGS) plays an important role in providing detailed information an the dispersion of radioactive materials. AGS using a fixed-wing or a rotary-wing aircraft is at its best in fallout mapping and in searching for orphan sources. Plume tracking could be a third application but is very complex, and there is a risk of vehicle contamination, which would deteriorate mission capability in the later phases of an accident. Because of obvious advantages, unmanned aerial vehicles could be used to monitor the release rate at the site of an accident and perhaps the plume itself. The aim of the present paper is to discuss ways to utilize existing European airborne monitoring capabilities for multilateral assistance in an accident and to give some thoughts to how an integrated system could be developed to take into account various national measuring strategies. In a large-scale accident, it is to be expected that the European countries use their radiological resources to map their own territory. It is realistic to think of assistance by transferring equipment and staff to another country only in accident scenarios where a country or countries with essential AGS capability would not have been affected by the fallout. Various AGS survey results can be fused only if a common platform for data exchange is available. Formats and protocols have been developed for special cases (ECCOMAGS, Nuclear Fission Safety, 4th and 5th Framework Programmes) but there are no universal solutions applicable to different situations and Instruments. The hardware and software among the European AGS teams are tailor

  3. A New Method for Processing Airborne Gamma Ray Spectrometry Data for Mapping Low Level Contaminations

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, Kim;

    1999-01-01

    A new technique for processing airborne gamma ray spectrometry data has been developed. It is based on the noise adjusted singular value decomposition method introduced by Hovgaard in 1997. The new technique opens for mapping of very low contamination levels. It is tested with data from Latvia...

  4. Calibration procedures in airborne gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The various calibration procedures adopted for airborne gamma-ray spectrometric measurements in Atomic Minerals Division are: (1) Over calibration pads for calculating sensitivities, stripping, and reverse stripping coefficients. Sensitivities are essential for converting the count rates into ground concentrations i.e. ppm (parts per million) in case of uranium and thorium and into percentage for potassium. In order to apply inter-channel corrections to radiometric data, stripping coefficients are essential. (2) Over test strip for calculating linear attenuation coefficients. These linear attenuation coefficients are used for applying height correction to the radiometric data. (3) Computation of sensitivities at nominal flying altitude (122 m) from the data obtained over the test strip for gamma-rays of different energies. In this paper computation of linear attenuation coefficients using test strip data and sensitivities, stripping, and reverse stripping coefficients using calibration pads data have been discussed in detail and results have been reported. The accuracy of the results have been ascertained and errors have been reported. (author). 12 refs., 7 tabs., 6 figs

  5. Research on 3-D terrain correction methods of airborne gamma-ray spectrometry survey

    International Nuclear Information System (INIS)

    The general method of height correction is not effectual in complex terrain during the process of explaining airborne gamma-ray spectrometry data, and the 2-D terrain correction method researched in recent years is just available for correction of section measured. A new method of 3-D sector terrain correction is studied. The ground radiator is divided into many small sector radiators by the method, then the irradiation rate is calculated in certain survey distance, and the total value of all small radiate sources is regarded as the irradiation rate of the ground radiator at certain point of aero- survey, and the correction coefficients of every point are calculated which then applied to correct to airborne gamma-ray spectrometry data. The method can achieve the forward calculation, inversion calculation and terrain correction for airborne gamma-ray spectrometry survey in complex topography by dividing the ground radiator into many small sectors. Other factors are considered such as the un- saturated degree of measure scope, uneven-radiator content on ground, and so on. The results of for- ward model and an example analysis show that the 3-D terrain correction method is proper and effectual. (authors)

  6. Environmental radiation monitoring-airborne gamma ray spectrometry over parts of India

    International Nuclear Information System (INIS)

    Airborne gamma-ray spectrometry (AGRS) has been widely accepted as a technique with large applications not for Uranium exploration, geological mapping, mineral exploration, environmental monitoring. The interesting point of AGRS technique is that it provides information of the ground/soil (density 1.40-2.00 gm/cc) about a meter deep in soil and 33 cm in rock types (density 2.5-3.00gm/cc). This information can become quite important consideration for agriculture, environmental scientists and planners in decision making. Gamma ray surveys are broadly based on surface, subsurface and airborne radiometric measurements. Airborne gamma ray spectrometric surveys began in the developed countries and in India during the early 1950's. These methodologies have undergone a great evolution in the development of the system by way of Instrumentation, Calibration and survey techniques, digital signal data processing, interpretation and data management ever since the early 1950's. With proper instrumentation, calibration, airborne gamma ray spectrometers were capable of providing concentrations of naturally occurring radio nuclides such as potassium, uranium and thorium on the area flown. The exposure rates calculated using the radioelemental distributions over various parts of India. The exposure rates vary from 0.4 to 50 microR/hr. In addition to the above variation of the exposure rates, the cosmic background of 3.767 microR/h has also been taken into account while computing the total dose. These exposure rates are found to be well below the maximum permissible rates as approved by the ICRP. In the present paper the studies over the exposure rates (in micro Roentgen units) from various parts of Satpura basin (covering 7000 sq. km), parts of erstwhile Madhya Pradesh, Andhra Pradesh have been presented. (author)

  7. The relevance of airborne and ground gamma ray spectrometry to global geochemical baselines

    International Nuclear Information System (INIS)

    The International Geochemical Mapping (IGM) project is a response to the fact that information about the distribution of radioactive and non-radioactive elements in the earth's surface materials is inconsistent and incomplete. The IGM project is organized under the International Geological Correlation Program, sponsored by UNESCO and IUGS. The IAEA has provided support for that part of the project which relates to radioactive elements. These elements, both natural and man-made, are part of the geochemical environment and subject to the same chemical and physical processes as non-radioactive elements. For many reasons their spatial distribution should be studied and recorded as part of a common database. Phase 1 of the IGM project has been concerned with the establishment of recommendations for the conduce of future work. Phase 2 of the project will be concerned with establishing global geochemical baselines for all elements. Gamma ray spectrometry is an efficient method of identifying and quantifying radioactive elements, either by in situ measurements at fixed sites, or from a moving vehicle or aircraft. All modes of measurement are required to establish reliable global baselines. However, airborne gamma ray spectrometry (AGRS) has a unique advantage because it provides a continuous profile over any land surface, independent of surface terrain. With calibrated systems, quantitative correlation of airborne and ground data can be assured within definable limits. The IGM project involves the acquisition of new data and, where quality is acceptable, incorporation of old. 24 refs, 3 figs

  8. Comparison of airborne and terrestrial gamma spectrometry measurements - evaluation of three areas in southern Sweden

    International Nuclear Information System (INIS)

    The Geological Survey of Sweden (SGU) has been conducting airborne gamma spectrometry measurements of natural radioactivity in Sweden for more than 40 years. Today, the database covers about 80% of the country's land surface. This article explores the first step of putting this data into use in radioactive source search at ground level. However, in order to be able to use the airborne background measurements at ground level, SGU data must be validated against terrestrial data. In this work, we compare the SGU data with data measured by a portable backpack system. This is done for three different areas in southern Sweden. The statistical analysis shows that a linear relationship and a positive correlation exist between the air and ground data. However, this linear relationship could be revealed only when the region possessed large enough variations in areal activity. Furthermore, the activity distributions measured show good agreement to those of SGU. We conclude that the SGU database could be used for terrestrial background assessment, given that a linear transfer function is established. - Highlights: → Correlation between ground and air measurements depends on activity variability. → Linear ground-to-air relationship exist given large enough activity variability. → Ground-to-air comparisons through activity distribution functions feasible. → Airborne data can be part of a prognostic tool in search operations on ground.

  9. Application of airborne gamma-ray spectrometry to geological mapping, mineral exploration and land-use planning

    International Nuclear Information System (INIS)

    Airborne gamma-ray spectrometry data are used to support regional and details bedrock and surficial geological mapping, mineral exploration for a variety of mineral deposit types, environmental radiation monitoring and land-use planning. Recent case histories developed by the Geological Survey of Canada describe the use of airborne gamma-ray spectrometry to map composite igneous intrusions and mixed igneous, metamorphic and sedimentary terranes, with varying proportions of glacial overburden, soil moisture, surface wetness and vegetation cover. Other case histories show that potassium alteration associated with volcanic-hosted massive sulphide, polymetallic, magmatic-hydrothermal vein, and porphyry mineralization can be distinguished, relative to normal lithological radioelement signatures, by characteristic eTh/K ratio lows. These examples show that effective interpretation of airborne gamma-ray spectrometry data must include all airborne variables and incorporate ground spectrometry, superficial and bedrock geochemistry and petrology. This information compliments magnetic, electromagnetic, geological and conventional geochemical data often collected during regional geoscience and mineral exploration programs. (author)

  10. The development of airborne gamma-ray spectrometry: case study in technological innovation and acceptance

    International Nuclear Information System (INIS)

    Airborne γ-ray spectrometry is now accepted as a technique with worldwide applications for geological mapping, mineral exploration and environmental monitoring. The first suggestions to use airborne radiation detectors for uranium exploration were made in 1943. Early results were disappointing; progress resulted from advances in nuclear instrumentation combined with recognition of the need for large detector-crystal arrays. Development of an effective operational system required the integration of geochemical and geological knowledge with nuclear physics, extending over two decades. The establishment of standards and calibration procedures allowed the first maps of surface radioelement concentrations based on quantitative airborne γ-ray spectrometry to be published in 1971. User-acceptance of the method grew from extensive demonstration of its capabilities, made obvious with the introduction of colour map displays. (author)

  11. European coordination of environmental airborne gamma ray spectrometry. Final report 1999

    International Nuclear Information System (INIS)

    This Concerted Action was funded under the EURATOM Nuclear Fission Safety Programme of the Fourth Framework Programme, and was initiated to address transnational issues relating to environmental airborne gamma ray spectrometry (AGS). Significant development of AGS systems and teams has taken place within Europe during the period following the Chernobyl accident. The technique is increasingly recognised as particularly relevant to emergency response. It is also uniquely capable of acquiring data on anthropogenic and natural radionuclides on regional, national and international scales, for reference purposes, ecological studies and epidemiological research. Prior to this EU programme the methodologies and systems used by European AGS teams had undergone rapid and largely uncoordinated development. This raised questions about comparability of systems, applications, and data between teams, duplication of research, the scope for transnational cooperation and standardisation, and future research and development needs in the field. This project, which brought together ten AGS teams from across Europe, was formed to address these issues. The work was conducted in three stages and has largely succeeded in its objectives. An active communication network was developed for collaboration and exchange of information, and to start the process of harmonisation of the different methodologies used by individual AGS teams. Two formal partners' meetings were organised, the first aimed at defining the EU capability in AGS, the second, in the form of an international symposium (RADMAGS), was aimed at reviewing developments on future research needs and the scope for standardisation. This report gives full details of the project and its deliverables together with discussion of the further needs in support of transnational harmonisation of this topic. The European Capability for AGS was defined at an early stage of the project, and monitored throughout. An EU Bibliography on AGS

  12. Area specific stripping of lower energy windows for AGS and CGS NaI systems[Airborne Gamma Spectrometry; Carbone Gamma Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Korsbech, U.; Aage, H.K. [Technical Univ. of Denmark (Denmark); Bystroem, S.; Wedmark, M. [Geological Survey of Sweden (Sweden); Thorshaug, S. [Norwegian Radiation Protection Agency (Norway); Bargholz, K. [Danish Emergency Management Agency (Denmark)

    2005-05-01

    The report describes the results from a NKS (Nordic Nuclear Safety Research) project aiming at examining the possibilities for extracting stripping factors for Airborne Gamma-ray Spectrometry (AGS) data and Carborne Gamma-ray Spectrometry (CGS) data directly from the recorded set of data, i.e. without having to calibrate the detector systems on beforehand. The project 'NKS project ASSb' has been carried out between 1 August 2004 and 31 March 2005 by a research group composed of persons from Technical University of Denmark (DTU), Danish Emergency Management Agency (DEMA), Geological Survey of Sweden (SGU), and Norwegian Radiation Protection Authority (NRPA). The AGS and CGS data sets used for the project were recorded by SGU, DEMA, NGU (Geological Survey of Norway), and SSI (Swedish Radiation Protection Institute). Most of the project effort has been directed towards analysing AGS and CGS data with point source signals recorded at the Barents Rescue 2001 LIVEX exercise at Boden in Sweden. Possibilities and limitations for the method have been identified. (au)

  13. Application of airborne gamma-ray spectrometry in soil/regolith mapping and applied geomorphology

    International Nuclear Information System (INIS)

    Gamma-ray spectrometric surveys are an important source of information for soil, regolith and geomorphological studies, as demonstrated by the interpretation of airborne surveys in Western Australia, central New South Wales and north Queensland. Gamma-rays emitted from the ground surface relate to the primary mineralogy and geochemistry of the bedrock, and the secondary weathered materials. Weathering modifies the distribution and concentration of radioelements from the original bedrock source. Once the radioelement response of bedrock and weathered materials is understood, the gamma-ray data can provide information on geomorphic processes and soil/regolith properties, including their mineralogy, texture, chemistry and style of weathering. This information can contribute significantly to an understanding of the weathering and geomorphic history of a region and, therefore, has the potential to be used in developing more effective land-management strategies and refining geochemical models in support of mineral exploration. Gamma-ray imagery is enhanced when combined with Landsat TM bands and digital elevation models (DEM). This synergy enables geochemical information derived from the gamma-ray data to be interpreted within a geomorphic framework. Draping gamma-ray images over DEMs as 3D landscape perspective views aids interpretation and allows the interpreter to visualise complex relationships between the gamma-ray response and landform features. 44 refs.,1 tab., 11 figs

  14. Handbook on Mobile Gamma-ray Spectrometry

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C

    2003-01-01

    Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing......Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing...

  15. The screening effect of a tropical forest on airborne gamma-ray spectrometry

    International Nuclear Information System (INIS)

    This work estimates the screening effect of a tropical rain forest on airborne γ-ray measurements. The screening effect is expressed as a multiplicative coefficient. The results were obtained using cylindrical sources on the ground. A layered approximation was used to obtain a first approximation for the screening coefficient for the biomass of the forest. However, the layered approach, neglects the strong anisotropy of the absorber. This is particularly conspicuous for the trunks of trees that contribute up to 80% to the total value of the screening coefficient. Due to the anisotropy of the absorbers layered calculations may produce upward biased screening coefficient values. A Monte Carlo simulation was used to calculate the effect of anisotropy on the screening coefficient of the biomass. The situations where the anisotropy can be neglected are shown here. An additional source of bias, the radiation from the biomass itself, is also estimated. With the results of this work it is possible to estimate a lower limit for the accuracy of airborne γ-radiation measurements taken over a tropical forest. (author)

  16. The effects of a tropical rain forest cover on airborne gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Theoretical calculations have been made to estimate the attenuation and the generation of gamma photons by a model of a tropical rain forest environment. For typical flight altitudes of 100 meters, it is shown that a 35 meter high canopy can attenuate from 40% to 60% of the original gamma photons, depending on the energy considered. It is also shown that the 1.46 MeV photopeak of 40-K measured at flight altitudes is completely dominated by the forest generated component, whereas this effect is negligible for the 2.62 MeV of 208-Tl and the 1.76 MeV of 214-Bi. Of major importance are the effects of forest clearings on the gamma-ray spectrum which can lead to serious misinterpretations of aerial profile data if not taken into account. A short review on the biocycles of potassium from the soil to the biomass of the tropical rain forest is included in the article. A simple experiment has also been made to demonstrate the attenuation due to a forest biomass on the gamma radiation emitted by the soil. (Author)

  17. Airborne gamma spectrometry measurements in the context of the exercise ARM02; Aeroradiometrische Messungen im Rahmen der Uebung ARM02

    Energy Technology Data Exchange (ETDEWEB)

    Bucher, B.; Rybach, L. [ETH Zuerich (Switzerland); Schwarz, G. [Swiss Nuclear Safety Authority, Villigen (Switzerland); Baerlocher, C. [ETH Zuerich (Switzerland)

    2003-05-01

    The international exercise under the European Union project ECCOMAGS (European Coordination and Calibration of Mobile and Airborne Gamma Spectrometry) stood in the centre of the yearly airborne gamma spectrometry measurement flights which were carried out in the time of 27 -31 May 2002. The exercise was held in Southwest Scotland in the region of Dumfries and Galloway. Unfortunately due to difficulties with flight approvals for military aircrafts data could be taken in the exercise area only on the flight back to Switzerland. Immediately after returning to Switzerland the regular measurements around the nuclear power plants Beznau (KKB) and Leibstadt (KKL), around the intermediate storage facilities for radioactive waste (ZWILAG) and around the research facility Paul Scherrer Institute were performed. The flights took place in the context of the exercise ARM02 and were lead by the Swiss National Emergency Operations Centre (NAZ). Unfortunately just a few measurements in the common intercalibration areas could be taken on the flight back from the international exercise. Nevertheless comparisons of the results with those of other European teams could be made. These comparisons proved the good calibration of our equipment. On the flight back measurements were also carried out at great altitude above the sea. This data allowed to determine very well the background of the aircraft and the cosmic stripping ratios. In the context of the regular measurements in the environs of the nuclear facilities in Switzerland the areas around the nuclear power plants Beznau and Leibstadt and around the nuclear research facility Paul Scherrer Institute were measured. The results were very similar to the results of earlier measurements in the last years. The nuclear power plant Beznau couldn't be recognised on the activity maps. But the nuclear power plant Leibstadt could be identified by its direct radiation which is specific for this type of reactor (BWR). At the site of the Paul

  18. Development and calibration of a real-time airborne radioactivity monitor using direct gamma-ray spectrometry with two scintillation detectors

    International Nuclear Information System (INIS)

    The implementation of in-situ gamma-ray spectrometry in an automatic real-time environmental radiation surveillance network can help to identify and characterize abnormal radioactivity increases quickly. For this reason, a Real-time Airborne Radioactivity Monitor using direct gamma-ray spectrometry with two scintillation detectors (RARM-D2) was developed. The two scintillation detectors in the RARM-D2 are strategically shielded with Pb to permit the separate measurement of the airborne isotopes with respect to the deposited isotopes.In this paper, we describe the main aspects of the development and calibration of the RARM-D2 when using NaI(Tl) or LaBr3(Ce) detectors. The calibration of the monitor was performed experimentally with the exception of the efficiency curve, which was set using Monte Carlo (MC) simulations with the EGS5 code system. Prior to setting the efficiency curve, the effect of the radioactive source term size on the efficiency calculations was studied for the gamma-rays from 137Cs. Finally, to study the measurement capabilities of the RARM-D2, the minimum detectable activity concentrations for 131I and 137Cs were calculated for typical spectra at different integration times. - Highlights: • A real-time airborne radioactivity monitor was developed. • The monitor is formed using two scintillation detectors for gamma-ray spectrometry. • The detectors are shielded with Pb. One detector is pointing up and the other down. • The monitors were calibrated using experimental data and Monte Carlo simulations. • The efficiency calculations and MDAC values are given

  19. Reactor gamma spectrometry: status

    International Nuclear Information System (INIS)

    Current work is described for Compton Recoil Gamma-Ray Spectrometry including developments in experimental technique as well as recent reactor spectrometry measurements. The current status of the method is described concerning gamma spectromoetry probe design and response characteristics. Emphasis is given to gamma spectrometry work in US LWR and BR programs. Gamma spectrometry in BR environments are outlined by focussing on start-up plans for the Fast Test Reactor (FTR). Gamma spectrometry results are presented for a LWR pressure vessel mockup in the Poolside Critical Assembly (PCA) at Oak Ridge National Laboratory

  20. Radon potential mapping of the Tralee-Castleisland and Cavan areas (Ireland) based on airborne gamma-ray spectrometry and geology.

    Science.gov (United States)

    Appleton, J D; Doyle, E; Fenton, D; Organo, C

    2011-06-01

    The probability of homes in Ireland having high indoor radon concentrations is estimated on the basis of known in-house radon measurements averaged over 10 km × 10 km grid squares. The scope for using airborne gamma-ray spectrometer data for the Tralee-Castleisland area of county Kerry and county Cavan to predict the radon potential (RP) in two distinct areas of Ireland is evaluated in this study. Airborne data are compared statistically with in-house radon measurements in conjunction with geological and ground permeability data to establish linear regression models and produce radon potential maps. The best agreement between the percentage of dwellings exceeding the reference level (RL) for radon concentrations in Ireland (% > RL), estimated from indoor radon data, and modelled RP in the Tralee-Castleisland area is produced using models based on airborne gamma-ray spectrometry equivalent uranium (eU) and ground permeability data. Good agreement was obtained between the % > RL from indoor radon data and RP estimated from eU data in the Cavan area using terrain specific models. In both areas, RP maps derived from eU data are spatially more detailed than the published 10 km grid map. The results show the potential for using airborne radiometric data for producing RP maps. PMID:21617292

  1. Radon potential mapping of the Tralee-Castleisland and Cavan areas (Ireland) based on airborne gamma-ray spectrometry and geology

    Energy Technology Data Exchange (ETDEWEB)

    Appleton, J D [British Geological Survey (BGS), Keyworth, Nottingham NG12 5GG (United Kingdom); Doyle, E [Geological Survey of Ireland (GSI), Beggars Bush, Haddington Road, Dublin 4 (Ireland); Fenton, D; Organo, C, E-mail: jda@bgs.ac.uk [Radiological Protection Institute of Ireland (RPII), 3 Clonskeagh Square, Dublin 14 (Ireland)

    2011-06-01

    The probability of homes in Ireland having high indoor radon concentrations is estimated on the basis of known in-house radon measurements averaged over 10 km x 10 km grid squares. The scope for using airborne gamma-ray spectrometer data for the Tralee-Castleisland area of county Kerry and county Cavan to predict the radon potential (RP) in two distinct areas of Ireland is evaluated in this study. Airborne data are compared statistically with in-house radon measurements in conjunction with geological and ground permeability data to establish linear regression models and produce radon potential maps. The best agreement between the percentage of dwellings exceeding the reference level (RL) for radon concentrations in Ireland (% > RL), estimated from indoor radon data, and modelled RP in the Tralee-Castleisland area is produced using models based on airborne gamma-ray spectrometry equivalent uranium (eU) and ground permeability data. Good agreement was obtained between the % > RL from indoor radon data and RP estimated from eU data in the Cavan area using terrain specific models. In both areas, RP maps derived from eU data are spatially more detailed than the published 10 km grid map. The results show the potential for using airborne radiometric data for producing RP maps.

  2. Mapping the terrestrial air-absorbed gamma dose rate based on the data of airborne gamma-ray spectrometry in southern cities of China

    International Nuclear Information System (INIS)

    An environmental radioactivity survey by Airborne Gamma-ray Spectrometry (AGS) on a large scale was undertaken in Zhuhai Zone (ZZ) and Shenzhen Zone (SZ), which include major cities in southern China, covering areas of 3800 km2 and 4660 km2, respectively. The estimated dose rates by AGS have been compared with observed results by ionization chamber and portable dosemeter. Maps of the terrestrial dose rate at 1m above ground level have been calculated based on the data of AGS. The mean dose rates are 84.37 ± 51.69 and 82.10 ± 32.98 nGy/h in ZZ and SZ, and the maximum rates are 343.11 and 368.36 nGy/h, respectively. Dose rates in some places are above 180 nGy/h; the areas covered where 149 km2 in ZZ and 43 km2 in SZ. The dominant geological conditions that evidently contribute to the radioactive anomalies are outcrops of Middle and Late Jurassic and Cretaceous biotitic-granite. The growth of industrialization and urbanization has dramatically altered radiation background. Stone mining results in the increase of radiation levels with maximum dose rates approaching 368.36 nGy/h in an open pit. The investigation results provide valuable background data and give a good example for mapping nationwide natural radiation terrestrial dose rates in China by AGS. (author)

  3. Evaluating airborne and ground based gamma spectrometry methods for detecting particulate radioactivity in the environment: A case study of Irish Sea beaches

    International Nuclear Information System (INIS)

    In several places, programmes are in place to locate and recover radioactive particles that have the potential to cause detrimental health effects in any member of the public who may encounter them. A model has been developed to evaluate the use of mobile gamma spectrometry systems within such programmes, with particular emphasis on large volume (16 l) NaI(Tl) detectors mounted in low flying helicopters. This model uses a validated Monte Carlo code with assessment of local geochemistry and natural and anthropogenic background radiation concentrations and distributions. The results of the model, applied to the example of particles recovered from beaches in the vicinity of Sellafield, clearly show the ability of rapid airborne surveys conducted at 75 m ground clearance and 120 kph speeds to demonstrate the absence of sources greater than 5 MBq 137Cs within large areas (10–20 km2 h−1), and identify areas requiring further ground based investigation. Lowering ground clearance for airborne surveys to 15 m whilst maintaining speeds covering 1–2 km2 h−1 can detect buried 137Cs sources of 0.5 MBq or greater activity. A survey design to detect 100 kBq 137Cs sources at 10 cm depth has also been defined, requiring surveys at −1 ground speed. The response of airborne systems to the Sellafield particles recovered to date has also been simulated, and the proportion of the existing radiocaesium background in the vicinity of the nuclear site has been established. Finally the rates of area coverage and sensitivities of both airborne and ground based approaches are compared, demonstrating the ability of airborne systems to increase the rate of particle recovery in a cost effective manner. The potential for equipment and methodological developments to improve performance are discussed. -- Highlights: ► Validated Monte Carlo simulations used to model mobile gamma spectrometry response to radioactive particless. ► Detection limits for airborne and ground based surveys

  4. Airborne Gamma-Ray Survey in Latvia 1995/96

    DEFF Research Database (Denmark)

    Bargholz, Kim

    1998-01-01

    Based on Airborne Gamma-Ray Spectrometry measurements performed with the Danish AGS equipment in 1995 and 1996 maps of the natural radioactivity have been produdced for selected areas in Latvia. The calibration of the quipment have been improved by comparisons with soil sample measurements....

  5. Airborne gamma ray spectrometer surveying

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency (IAEA) in its role as collector and disseminator of information on nuclear techniques has long had an interest in gamma ray spectrometer methods and has published a number of Technical Reports on various aspects of the subject. At an Advisory Group Meeting held in Vienna in November 1986 to review appropriate activities the IAEA could take following the Chernobyl accident, it was recommended that preparation begin on a new Technical Report on airborne gamma ray spectrometer surveying, taking into account the use of the technique for environmental monitoring as well as for nuclear emergency response requirements. Shortly thereafter the IAEA became the lead organization in the Radioelement Geochemical Mapping section of the International Geological Correlation Programme/United Nations Educational, Scientific and Cultural Organization (UNESCO) Project on International Geochemical Mapping. These two factors led to the preparation of the present Technical Report. 18 figs, 4 tabs

  6. Environmental monitoring and in situ gamma spectrometry

    International Nuclear Information System (INIS)

    The in-situ gamma ray spectrometry is widely used for monitoring of the natural as well as man-made radionuclides and corresponding gamma fields in the environment or working places. It finds effective application in the operational and accidental monitoring of the nuclear facilities and their vicinity, radioactive contamination measurements, environmental, radiation hygiene and radiation safety studies, etc. Knowledge of the used detection system response function/matrix makes it possible to analyze measured gamma fields characteristics, calculate energy distributions of the dosimetric quantities in these fields and/or calculate the concentrations of radionuclides in the environment (usually in the soil surface layer). Method of the gamma spectrometry data processing, based on the detector response knowledge, can be applied as for scintillation or semiconductor detection systems and ground measurements, as for airborne spectrometry monitoring. Methods for calculation of angular-energy distributions of gamma fields, originated from typical sources (using Monte Carlo simulation) are discussed as well as methods for calculation of detection systems responses and/or response matrixes in such gamma fields. Techniques of the measured spectra deconvolution and calculation of the dosimetric quantities energy distributions are overviewed. Method and results of calculations of the conversion factors for radionuclides concentrations determination from the measured and calculated photon fluencies energy distributions are discussed (including possibility to set a user-defined radionuclide depth distribution for given experimental data processing). Method (based on detection system response matrix Monte Carlo calculation) developed for the processing and analyzing data from airborne spectrometry monitoring and mapping is described. Sensitivity, achievable precision and some factors influencing the interpretation of results and their accuracy using considered methods are

  7. Gamma and X 93 spectrometry

    International Nuclear Information System (INIS)

    The Meetings of Gamma and X 93 Spectrometry were held on 12-14 October 1993. The symposium was organized into six sessions: Instrumentation development, Nuclear matter measurement, Method and calibration, Medical applications, Environment survey (radioactive traces measurement), other applications (spent fuels analysis, various techniques). Separate abstracts were prepared for all the papers in this volume. (TEC)

  8. Automatic gamma spectrometry analytical apparatus

    International Nuclear Information System (INIS)

    This invention falls within the area of quantitative or semi-quantitative analysis by gamma spectrometry and particularly refers to a device for bringing the samples into the counting position. The purpose of this invention is precisely to provide an automatic apparatus specifically adapted to the analysis of hard gamma radiations. To this effect, the invention relates to a gamma spectrometry analytical device comprising a lead containment, a detector of which the sensitive part is located inside the containment and additionally comprising a transfer system for bringing the analyzed samples in succession to a counting position inside the containment above the detector. A feed compartment enables the samples to be brought in turn one by one on to the transfer system through a duct connecting the compartment to the transfer system. Sequential systems for the coordinated forward feed of the samples in the compartment and the transfer system complete this device

  9. Urban gamma spectrometry. Report 2

    Energy Technology Data Exchange (ETDEWEB)

    Aage, H.K. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Kuukankorpi, S.; Moring, M.; Smolander, P.; Toivonen, H. (Radiation and Nuclear Safety Authority, Helsinki (Finland))

    2009-06-15

    Urban gamma spectrometry has been given only minor attention with the focus being on rural gamma spectrometry. However, in recent years the Nordic emergency management authorities have turned focus towards border control and lost or stolen sources. Gamma spectra measured in urban areas are characterized by a wide variety of spectrum shapes and very fast changes in environmental background. In 2004 a Danish CGS (Carborne Gamma Spectrometry) survey took place in Copenhagen. It was found that gamma spectrometry in urban areas is far more complicated to interpret than had previously been thought and a new method 'Fitting with Spectral Components', FSC, based on NASVD, was tested with some success. In Finland, a database 'LINSSI' has been developed for spectral data management. In CGS search mode a 'peak hypothesis test' is applied to the measured spectra. This system was tested during the Helsinki 2005 Athletics World Championship and it provides fast and reliable automated alarms for intermediate and high level signals. In Sweden mobile detector systems are used for border controls and problems are encountered when making measurement in harbour, container areas. The methods for handling data and for interpretation of urban gamma spectrometry measurements were compared and tested on the same data sets from Copenhagen and Helsinki. Software tools were developed for converting data between the Finnish LINSSI database and the binary file formats used in Denmark and Sweden. The Processing methods used at DTU and STUK have different goals. The ASSS and FSC methods are designed to optimize the overall detection capability of the system, while sacrificing speed, usability and to a certain level robustness. These methods cannot always be used for real time analysis. The Peak Significance method is designed to give robust alarms in real time, while sacrificing some of the detection capability. Thus these methods are not interchangeable, but rather

  10. Towards airborne nanoparticle mass spectrometry with nanomechanical string resonators

    DEFF Research Database (Denmark)

    Schmid, Silvan; Kurek, Maksymilian; Boisen, Anja

    2013-01-01

    airborne nanoparticle sensors. Recently, nanomechanical mass spectrometry was established. One of the biggest challenges of nanomechanical sensors is the low efficiency of diffusion-based sampling. We developed an inertial-based sampling method that enables the efficient sampling of airborne nanoparticles...... first bending mode. Mass spectrometry of airborne nanoparticles requires the simultaneous operation in the first and second mode, which can be implemented in the transduction scheme of the resonator. The presented results lay the cornerstone for the realization of a portable airborne nanoparticle mass...

  11. Gamma spectrometry of infinite 4Π geometry

    International Nuclear Information System (INIS)

    Owing to the weak absorption og gamma radiation by matter, gamma-ray spectrometry may be applied to samples of great volume. A very interesting case is that of the gamma-ray spectrometry applied with 4Π geometry around the detector on a sample assumed to be of infinite extension. The determination of suitable efficiencies allows this method to be quantitative. (author)

  12. Airborne gamma-ray spectrometric anomaly characteristics and prospecting model for quaternary salt lake type potash deposit

    International Nuclear Information System (INIS)

    On the basis of the airborne gamma-ray spectrometric data, this paper briefly discusses partial scientific research achievements related to prospecting for potash and the establishment of prospecting model for Quaternary salt lake type potash deposit, and furthermore through the analysis on Bieletan and Mahai Potash deposits, it shows that airborne gamma-ray spectrometry is certainly of evident effect in prospecting for Quaternary salt lake type potash deposit

  13. Guidelines for radioelement mapping using gamma ray spectrometry data

    International Nuclear Information System (INIS)

    The purpose of the report is to provide an up-to-date review on the use of gamma ray spectrometry for radioelement mapping and, where appropriate, provide guidelines on the correct application of the method. It is a useful training guide for those new to the method. It gives a broad coverage of all aspects of the gamma ray method and provides a comprehensive list of references. The report gives an overview of the theoretical background to radioactivity and the gamma ray spectrometric method followed by a review of the application of the method to mapping the radiation environment. A brief outline is presented of the principles of radioactivity, the interaction of gamma rays with matter, instrumentation applied to the measurement of gamma rays, and the quantities and units in contemporary use in gamma ray spectrometry. This is followed by a review of the fundamentals of gamma ray spectrometry, and its application to ground and airborne mapping. Covered are also all aspects of the calibration and data processing procedures required for estimating the ground concentrations of the radioelements. The procedures required for the recovery of older survey data are also presented as well as an overview of data presentation and integration for mapping applications

  14. Digital Logarithmic Airborne Gamma Ray Spectrometer

    CERN Document Server

    Zeng, GuoQiang; Li, Chen; Tan, ChengJun; Ge, LiangQuan; Gu, Yi; Cheng, Feng

    2014-01-01

    A new digital logarithmic airborne gamma ray spectrometer is designed in this study. The spectrometer adopts a high-speed and high-accuracy logarithmic amplifier (LOG114) to amplify the pulse signal logarithmically and to improve the utilization of the ADC dynamic range, because the low-energy pulse signal has a larger gain than the high-energy pulse signal. The spectrometer can clearly distinguish the photopeaks at 239, 352, 583, and 609keV in the low-energy spectral sections after the energy calibration. The photopeak energy resolution of 137Cs improves to 6.75% from the original 7.8%. Furthermore, the energy resolution of three photopeaks, namely, K, U, and Th, is maintained, and the overall stability of the energy spectrum is increased through potassium peak spectrum stabilization. Thus, effectively measuring energy from 20keV to 10MeV is possible.

  15. Airbornesystem for gamma spectrometry and gamma-background mapping

    International Nuclear Information System (INIS)

    -mobile system for the assessment of anthropogenic pollution and/or its potential employment in searching for a missing radioactive source. In Bulgaria, the system described can be used in a number of specific radiological investigations. One of the main applications is the surveying of former uranium mining sites, by the classical method, sites uranium processing industry and polymetallic ore mining sites. The areas surrounding these places are characterized by so-called technogenically increased natural radioactivity – increased surface concentration of isotopes of the uranium and thorium daughter chains.Another potential area for airborne gamma radiation monitoring is Kozloduy NPP, together with its 30 and 100 – kilometer monitored zones. Since Bulgaria is preparing the construction of a national repository for radioactive waste, it is at this stage that it is most suitable to conduct initial air gamma-spectrometric observations of the future site and its surrounding area.The capabilities of the system for air-mobile gamma range spectrometry and gamma mapping are very significant and it can be used in areas where the ultimate goal is not even to establish the radiation status of an area, but also in various applications that use the physical properties of γ-rays for measurement or other activities

  16. Airborne gamma radiation soil moisture measurements over short flight lines

    Science.gov (United States)

    Peck, Eugene L.; Carrol, Thomas R.; Lipinski, Daniel M.

    1990-01-01

    Results are presented on airborne gamma radiation measurements of soil moisture condition, carried out along short flight lines as part of the First International Satellite Land Surface Climatology Project Field Experiment (FIFE). Data were collected over an area in Kansas during the summers of 1987 and 1989. The airborne surveys, together with ground measurements, provide the most comprehensive set of airborne and ground truth data available in the U.S. for calibrating and evaluating airborne gamma flight lines. Analysis showed that, using standard National Weather Service weights for the K, Tl, and Gc radiation windows, the airborne soil moisture estimates for the FIFE lines had a root mean square error of no greater than 3.0 percent soil moisture. The soil moisture estimates for sections having acquisition time of at least 15 sec were found to be reliable.

  17. Airborne gamma spectrometric survey in the Chernobyl exclusion zone based on oktokopter UAV type

    International Nuclear Information System (INIS)

    The results of field studies of radioactive contamination condition of RWTSP ''Red Forest'' and ''Neftebaza'' in the Chernobyl zone, obtained by the authors in June 2015 are represented. The technique of detection of local inhomogeneities on the soil surface without contrasting borders by airborne gamma spectrometry from the board of oktokopter UAV type is worked through. The technique of searching and contouring of hidden burial of radioactive waste is practiced

  18. The airborne survey of natural gamma radiation level in China

    International Nuclear Information System (INIS)

    Airborne survey of natural gamma radiation level is a fast and effective method for evaluating environment radiation. This paper introduces some results about the investigation of gamma radiation level using airborne gamma ray spectrometer and associated NaI(Tl) crystal detector system by Airborne Survey and Remote Sensing Center of Nuclear Industry. The results of the natural radiation level in the regions surrounding Qinshan Nuclear Power Plant and Shanghai City were showed and analyzed emphatically. Air absorbed dose rate belongs to normal to low. The average is 52.6 nGy/h in Qinshan and 52.2 nGy/h in Shanghai. Among, the maximum is up to 72.5 nGy/h in the mountain forest, the second is approximately 68.4 nGy/h in town, 50∼60 nGy/h in cropland, and 25 nGy/h in beach

  19. The airborne survey of natural gamma radiation level in China

    Energy Technology Data Exchange (ETDEWEB)

    Mingkao, Hu; Renkang, Gu; Jiangqi, Fang; Chongtao, Qiu [Airborne Survey and Remote Sensing Center of Nuclear Industry, Shijiazhuang (China)

    2002-07-01

    Airborne survey of natural gamma radiation level is a fast and effective method for evaluating environment radiation. This paper introduces some results about the investigation of gamma radiation level using airborne gamma ray spectrometer and associated NaI(Tl) crystal detector system by Airborne Survey and Remote Sensing Center of Nuclear Industry. The results of the natural radiation level in the regions surrounding Qinshan Nuclear Power Plant and Shanghai City were showed and analyzed emphatically. Air absorbed dose rate belongs to normal to low. The average is 52.6 nGy/h in Qinshan and 52.2 nGy/h in Shanghai. Among, the maximum is up to 72.5 nGy/h in the mountain forest, the second is approximately 68.4 nGy/h in town, 50{approx}60 nGy/h in cropland, and 25 nGy/h in beach.

  20. Urban gamma spectrometry. Report 1

    International Nuclear Information System (INIS)

    This report contains the present status and results for the NKS UGS-project per 1 June 2006 for NKS partners DTU, Denmark, and STUK, Finland. The Danish and Finnish CGS (Carborne Gamma Spectrometry) systems are not of similar types. The Danish CGS system(s) only make use of one NaI(Tl) detector whereas the Finnish CGS system consists of several detectors, NaI(Tl) and HPGe both and as an additional feature the Finnish detectors have position dependent different fields of view. Furthermore, the Finnish system is equipped with an air sampling system. In terms of operation, the Danish detector is located on the rooftop where as the Finnish detectors are located inside the vehicle. The Finnish and the Danish team use different methods for data processing. STUK uses a hypothesis test method to get robust real time alarms (within 10 seconds) when significant peaks from a previously defined set of nuclides are detected. An alarm for a significantly elevated total pulse rate is sent if none of the predefined nuclides is identified. All data are stored to the LINSSI database, which facilitates easy data retrieval for post processing. DEMA/DTU bases their calculations on full spectrum fitting using NASVD and the Danish software NucSpec. Source signals are found from spectrum fitting residuals or from stripping of energy windows - either by the standard 4-windows method or by a measurement based method where stripping factors for any window of interest can be derived from the measurements themselves. A thorough description of the two systems and data processing methods (including mathematics) are described in this report. For the Danish methods of data processing some comparisons have been made, but no final conclusion has been reached yet. Raw urban data has been investigated along with urban data sets to which source signals have been added and searched for. For the Finnish method calibration plots of the minimum detection limits for two different detector types have been

  1. Urban gamma spectrometry. Report 1

    Energy Technology Data Exchange (ETDEWEB)

    Aage, H.K. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Kuukankorpi, S.; Moring, M.; Smolander, P.; Toivonen, H. (Radiation and Nuclear Safety Authority, Helsinki (Finland))

    2009-06-15

    This report contains the present status and results for the NKS UGS-project per 1 June 2006 for NKS partners DTU, Denmark, and STUK, Finland. The Danish and Finnish CGS (Carborne Gamma Spectrometry) systems are not of similar types. The Danish CGS system(s) only make use of one NaI(Tl) detector whereas the Finnish CGS system consists of several detectors, NaI(Tl) and HPGe both and as an additional feature the Finnish detectors have position dependent different fields of view. Furthermore, the Finnish system is equipped with an air sampling system. In terms of operation, the Danish detector is located on the rooftop where as the Finnish detectors are located inside the vehicle. The Finnish and the Danish team use different methods for data processing. STUK uses a hypothesis test method to get robust real time alarms (within 10 seconds) when significant peaks from a previously defined set of nuclides are detected. An alarm for a significantly elevated total pulse rate is sent if none of the predefined nuclides is identified. All data are stored to the LINSSI database, which facilitates easy data retrieval for post processing. DEMA/DTU bases their calculations on full spectrum fitting using NASVD and the Danish software NucSpec. Source signals are found from spectrum fitting residuals or from stripping of energy windows - either by the standard 4-windows method or by a measurement based method where stripping factors for any window of interest can be derived from the measurements themselves. A thorough description of the two systems and data processing methods (including mathematics) are described in this report. For the Danish methods of data processing some comparisons have been made, but no final conclusion has been reached yet. Raw urban data has been investigated along with urban data sets to which source signals have been added and searched for. For the Finnish method calibration plots of the minimum detection limits for two different detector types have been

  2. Mobile gamma spectrometry. Evaluation of the Resume 99 exercise

    International Nuclear Information System (INIS)

    During the RESUME 99 exercise, the radiocaesium (137Cs) activity in the surroundings of Gavle in central Sweden was mapped using car-borne gamma-ray spectrometry (CGS). The CGS data along with airborne gamma-ray spectrometry (AGS) data from the same area have been used to examine possible correlations between the CGS and AGS results, detector type and position, and geographical information, such as land-use and road type. The overall differences between various CGS results are small, while larger differences are found between AGS and CGS results. In general only little correlation was found with land-use and with road-type and width. The differences between AGS and CGS results arise because airborne detectors have a different field of view than a ground-based detector. From an analysis of the depth-dependency of AGS and CGS data for a depth-distributed source, it is found that the mean mass depth may be inferred from the ratio of AGS to CGS spectral count rates. Integration of AGS and CGS data requires a precise definition of quantities and units for reporting activity concentrations in a complicated geometry and care must be taken to translate AGS results into equivalent CGS quantities taking into account the spatial distribution of the radionuclides. (au)

  3. Mobile gamma spectrometry. Evaluation of the Resume 99 exercise

    Energy Technology Data Exchange (ETDEWEB)

    Mellander, H.; Karlsson, S. [Swedish Radiation Protection Authority, Stockholm (Sweden); Aage, H.K.; Korsbech, U. [Technical Univ. of Denmark, Lyngby (Denmark); Lauritzen, B. [Risoe National Laboratory, Roskilde (Denmark); Smethurst, M. [Geological Survey of Norway, Trondheim (Norway)

    2002-06-01

    During the RESUME 99 exercise, the radiocaesium ({sup 137}Cs) activity in the surroundings of Gavle in central Sweden was ma{sup p}ped using car-borne gamma-ray spectrometry (CGS). The CGS data along with airborne gamma-ray spectrometry (AGS) data from the same area have been used to examine possible correlations between the CGS and AGS results, detector type and position, and geographical information, such as land-use and road type. The overall differences between various CGS results are small, while larger differences are found between AGS and CGS results. In general only little correlation was found with land-use and with road-type and width. The differences between AGS and CGS results arise because airborne detectors have a different field of view than a ground-based detector. From an analysis of the depth-dependency of AGS and CGS data for a depth-distributed source, it is found that the mean mass depth may be inferred from the ratio of AGS to CGS spectral count rates. Integration of AGS and CGS data requires a precise definition of quantities and units for reporting activity concentrations in a complicated geometry and care must be taken to translate AGS results into equivalent CGS quantities taking into account the spatial distribution of the radionuclides. (au)

  4. An automatic sample changer for gamma spectrometry

    International Nuclear Information System (INIS)

    An automatic sample changer for gamma spectrometry is described which is designed for large-volume, low radioactivity environmental samples of various sizes up to maximum dimensions 100 mm diameter x 60 mm high. The sample changer is suitable for use with most existing gamma spectrometry systems which utilize GeLi or NaI detectors in vertical mode, in conjunction with a pulse height analyzer having auto-cycle and suitable data output facilities; it is linked to a Nuclear Data ND 6620 computer-based analysis system. (U.K.)

  5. Reducing Statistical Noise in Airborne Gamma-Ray Data

    DEFF Research Database (Denmark)

    Hovgaard, Jens; Grasty, R. L.

    1997-01-01

    By using the Noise Adjusted Singular Value Decomposition (NASVD) technique it is possible to reconstruct the measured airborne gamma-ray spectra with a noise content that is significant smaller than the noise contained in the original measured spectra. The method can be used for improving the out...

  6. Airborne Gamma-Ray Survey RISØ 2004

    DEFF Research Database (Denmark)

    Aage, Helle Karina

    The aim of the described survey was to monitor the gamma radiation originating from the waste disposal deposits and the now closed reactor.......The aim of the described survey was to monitor the gamma radiation originating from the waste disposal deposits and the now closed reactor....

  7. Compton suppression gamma ray spectrometry

    International Nuclear Information System (INIS)

    In the past decade there have been many studies to use Compton suppression methods in routine neutron activation analysis as well as in the traditional role of low level gamma ray counting of environmental samples. On a separate path there have been many new PC based software packages that have been developed to enhance photopeak fitting. Although the newer PC based algorithms have had significant improvements, they still suffer from being effectively used in weak gamma ray lines in natural samples or in neutron activated samples that have very high Compton backgrounds. We have completed a series of experiments to show the usefulness of Compton suppression. As well we have shown the pitfalls when using Compton suppression methods for high counting deadtimes as in the case of neutron activated samples. We have also investigated if counting statistics are the same both suppressed and normal modes. Results are presented in four separate experiments. (author)

  8. Estimation of uranium from multichannel spectra in airborne gamma ray spectrometry using 1.12 MeV and 1.76 MeV photopeaks of 214Bi - an application to Cuddapah basin

    International Nuclear Information System (INIS)

    Present study examines the utility of gamma rays of energies 1.12 MeV and 1.76 MeV of uranium in estimation of uranium in airborne gamma ray spectrometric survey (AGRS) in comparison to the conventional 1.76 MeV alone used world wide. As a case study, the AGRS data of northern part of Cuddapah Basin is considered. Multi-channel processing is applied on this dataset to reduce the spectral noise and use of combined 1.12 MeV and 1.76 MeV has reduced the Poisson's related statistical error. Uranium is estimated using above two energies individually and in combination, using multi-channel processing followed by standard corrections procedure. Result indicates that a combination of both energies has given best estimation due to a reduction in overall noise which helped in demarcating geological entities and litho-contacts. This indicates the efficacy of this technique which improved the radio-geochemistry of study area in understanding the radio-elemental variation. (author)

  9. Gamma spectrometry of TMI-2 debris

    International Nuclear Information System (INIS)

    To obtain the basic information evaluating the radiochemical property of TMI-2 debris sample, gamma spectrometry was performed on 8 debris samples including fuel pellet fragments at JAERI. The present analysis based on the measurement data (without code calculation) showed the burnup of UO2 fuel in debris samples, Cs retention, and UO2 fraction ranged from 3030 to 3600MWd/t, from 0.4 to 6% and from 64.5 to 83.3wt%, respectively. The gamma spectrometry data base obtained at Idaho National Engineering Laboratory was analyzed by the present evaluation method, thereby the Cs retention and burnup distribution of debris samples collected from different origins were evaluated. The evaluation indicated that the characteristics of debris from the molten pool region was similar to the from the lower head region. Heat generation in debris was estimated by combining the decay heat in TMI-2 fuel calculated by ORIGEN code and the gamma spectrometry data. They were 0.186W/(g-debris) at 224min and 0.142W/(g-debris) at 600min after the initiation of the accident when the average burnup 3300MWd/t and the complete release of high volatile elements were assumed. (author)

  10. Demonstration of lightweight gamma spectrometry systems in urban environments

    International Nuclear Information System (INIS)

    Urban areas present highly complex radiation environments; with small scale features resulting from different construction materials, topographic effects and potential anthropogenic inputs from past industrial activity or other sources. Mapping of the radiation fields in urban areas allows a detailed assessment of exposure pathways for the people who live and work there, as well as locating discrete sources of activity that may warrant removal to mitigate dose to the general public. These areas also present access difficulties for radiometric mapping using vehicles or aircraft. A lightweight portable gamma spectrometry system has been used to survey sites in the vicinity of Glasgow to demonstrate the possibilities of radiometric mapping of urban areas, and to investigate the complex radiometric features such areas present. Variations in natural activity due to construction materials have been described, the presence of 137Cs used to identify relatively undisturbed ground, and a previously unknown NORM feature identified. The effect of topographic enclosure on measurements of activity concentration has been quantified. The portable system is compared with the outputs that might be expected from larger vehicular or airborne systems. For large areas airborne surveys are the most cost effective approach, but provide limited spatial resolution, vehicular surveys can provide sparse exploratory data rapidly or detailed mapping of open areas where off-road access is possible. Backpack systems are ideally suited to detailed surveys of small areas, especially where vehicular access is difficult. -- Highlight: • Demonstration of a lightweight portable gamma spectrometry system. • Effect of topography on radiation in urban environments. • Effect of construction materials on radiation in urban environments

  11. Airborne gamma anomalies in the Elbe Valley near Koenigstein, Germany - Origin and variation with time

    International Nuclear Information System (INIS)

    In 1982, an airborne gamma spectrometer survey was undertaken by SDAG WISMUT which was directed at the detection of further uranium mineralization in Saxony and Thuringia. Anomalies outlined along the Elbe river near the existing Koenigstein uranium mine were attributed to one or a combination of the following causes: radioactive residues from uranium processing facilities located upstream, temporary accumulation of Rn-decay products attached to dust particles in the atmosphere at the time of the survey, and radioactive waters emerging from uraniferous rocks along tectonic structures. In 1994, WISMUT GmbH re-evaluated the survey to determine the need for implementing cleanup measures. Subsequent to the verification of the original airborne data, ground surveys were undertaken that included gamma spectrometry, percussion probing and river sediment sampling. The new results did not confirm the magnitude of most of the 1982 airborne anomalies. The general decline of the radioactivity pointed out by the 1994 ground measurements is interpreted to be a result of the partial erosion and dilution of radionuclides in fluvial sediments as well as burial by additional river sediments since. Additional anomalous copper and zinc concentrations are attributed to sources other than mining. The ground follow-up delineated a new anomalous zone that is caused by radionuclides discharged with treated process and mine water. It is the only area, which may require further investigations and possible remedial action. (author)

  12. Laboratory of High resolution gamma spectrometry

    International Nuclear Information System (INIS)

    The Department of Nuclear Experimentation of the Nuclear Systems Management requests the collaboration of the Engineering unit for the supervision of the execution of the work of the High resolution Gamma spectrometry and low bottom laboratory, using the hut of the sub critic reactor of the Nuclear Center of Mexico. This laboratory has the purpose of determining the activity of special materials irradiated in nuclear power plants. In this report the architecture development, concepts, materials and diagrams for the realization of this type of work are presented. (Author)

  13. Gamma spectrometry of TRIGA fuel elements

    International Nuclear Information System (INIS)

    The burnupt of 19 TRIGA fuel elements was determined by gamma spectrometry using a special fuel element holder developed and constructed at the Atom Institute, Vienna. The investigated fuel element is kept in a horizontal position about 4 m below the reactor pool water surface. A collimator tube extends to the reactor platform where an intrinsic Ge-detector is located. With this system each fuel element was investigated at eight equidistant points along its active zone and the Cs 137 activity was evaluated. (orig.)

  14. Dose Rate Determination from Airborne Gamma-ray Spectra

    DEFF Research Database (Denmark)

    Bargholz, Kim

    1996-01-01

    The standard method for determination of ground level dose rates from airborne gamma-ray is the integral count rate which for a constant flying altitude is assumed proportional to the dose rate. The method gives reasonably results for natural radioactivity which almost always has the same energy...... distribution. When manmade radioactivity is present, this is no longer the case. Another method based on giving the counts of different channels a different weighting has been examined. The new method is more robust against varying energy distribution, and for energies above 200 keV it gives excellent results....

  15. Design, calibration, and application of an airborne gamma spectrometer system in Switzerland

    International Nuclear Information System (INIS)

    Airborne radiometric surveys are finding increasingly wider application in environmental mapping and monitoring. They are the most efficient tool to delimit surface contamination and to locate lost radioactive sources. To secure radiometric capability in survey and emergency situations, a new sensitive airborne system has been built that includes an airborne spectrometer with 256 channels and a sodium iodide detector with a total volume of 16.8 liters. A rack-mounted PC with memory cards is used for data acquisition, with a GPS satellite navigation system for positioning. The system was calibrated with point sources using a mathematical correction to take into account the effects of gamma-ray scattering in the ground and in the atmosphere. The calibration was complemented by high precision ground gamma spectrometry and laboratory measurements on rock samples. In Switzerland, two major research programs make use of the capabilities of airborne radiometric measurements. The first one concerns nuclear power-plant monitoring. The five Swiss nuclear installations (four power plants and one research facility) and the surrounding regions of each site are surveyed annually. The project goal is to monitor the dose-rate distribution and to provide a documented baseline database. The measurements show that all sites (with the exception of the Goesgen power plant) can be identified clearly on the maps. No artificial radioactivity that could not be explained by the Chernobyl release or earlier nuclear weapons tests was detected outside of the fenced sites of the nuclear installations. The second program aims at a better evaluation of the natural radiation level in Switzerland. The survey focused on the crystalline rocks of the Central Massifs of the Swiss Alps because of their relatively high natural radioactivity and lithological variability

  16. Airborne magnetic and gamma-ray data acquisition

    International Nuclear Information System (INIS)

    Current aeromagnetic data acquisition has benefited from improvements in measurement precision and compensation systems for removing with closer line spacing than previously, and this has stimulated a demand for lower survey altitudes with flight heights of the order of 60-80 m now common. Radiometric recording of 256 channels of gamma-ray data is now virtually standard and in-flight stabilisation of these systems has improved markedly. Digital acquisition systems are now designed to facilitate both in-flight and post-flight verification of the data. This article briefly outlines he history of the acquisition equipment used in the earlier surveys and details the current sate-of-the-art technology and methodology used in airborne magnetic and gamma-ray surveys. 9 refs., 1 tab., 2 figs

  17. Isotopic analysis of uranium by gamma spectrometry

    International Nuclear Information System (INIS)

    The scope of this work is to study the precision degree of the determination of 235U isotopical concentration, indispensable to the control of nuclear materials under safeguards and in the stages during the enrichment process. The samples of the uranium oxid U3O8, obtained by uranyl nitrate 6-hidrate thermodecomposition at 1073 k, were analised by gamma spectrometry technique. The method essentially consists of measuring the 186 KeV peak, characteristic of the 235U. Several factors that affect the accuracy and precision of measurements were studied, such as thermodecomposition, sample preparation, geometry of the countings, contribution of 234Pa, self-absorption and detection efficiency. The results, submited to a statistical analyse, indicate that the technique is sensitive enough to determine the enrichment variations of 1 % and with adequate precaution it is possible to reach an accuracy of 0,4 %. (author)

  18. Gamma-ray Spectrometry in Geothermal Exploration: State of the Art Techniques

    Directory of Open Access Journals (Sweden)

    Alistair T. McCay

    2014-07-01

    Full Text Available Gamma-ray spectrometry is a surveying technique that allows the calculation of the heat produced during radioactive decay of potassium, uranium, and thorium within rock. Radiogenic heat producing rocks are often targets for geothermal exploration and production. Hence, refinements in gamma-ray spectrometry surveying will allow better constraint of resources estimation and help to target drilling. Gamma-rays have long half-lengths compared to other radiation produced during radiogenic decay. This property allows the gamma-rays to penetrate far enough through media to be detected by airborne or ground based surveying. A recent example of ground-based surveying in Scotland shows the ability of gamma-ray spectrometry to quickly and efficiently categorize granite plutons as low or high heat producing. Some sedimentary rocks (e.g., black shales also have high radiogenic heat production properties and could be future geothermal targets. Topographical, atmospheric and spatial distribution factors (among others can complicate the collection of accurate gamma-ray data in the field. Quantifying and dealing with such inaccuracies represents an area for further improvement of these techniques for geothermal applications.

  19. Measurement of snow water storage in the Lake Saperior basin using aerial gamma-ray spectrometry

    International Nuclear Information System (INIS)

    A pilot project was started in 1977 over the Lake Superior basin to measure water storage on the land area using aerial gamma-ray spectrometry to provide hydrologic information for forecasting inflow to the lake. Two airborne surveys were made, respectively in November 1977 and March 1978 which provided estimates of the increase in snow water equivalent between these surveys. The basin is located on the Canadian Shield and consequently, the gamma radiation count rate is quite variable. The airborne results are compared with ground measurements on selected flight lines and show generally good agreement. Two equipment calibrations in the Ottawa area provided inconsistent parameter values which are consequently also reflected in the results over the Lake Superior basin. The project has demonstrated to-date that the technique can be developed into an operational system for measuring snow cover water equivalent of this vast and remote area by using well calibrated equipment and processing the spectrometric measurements with great care. (Auth.)

  20. Spectra characteristics of airborne gamma-ray spectrometer based on data fusion

    International Nuclear Information System (INIS)

    Background: Airborne gamma-ray spectrometry is made up of multiple NaI (Tl) detector, but the detectors have the different level of noise. Purpose: Aimed at reducing the affection of noise, a weighted least square fusion estimation algorithm is presented to extract the Spectra Characteristics. Methods: The method doesn't need any prior knowledge on the detector, but carries on the variance estimated on-line these data and timely adjust weights of various fusion sensors in order to make the mean-square error of fusion results least all the time. Results: It is used to process the date come from the standard model, the results show that measurement error range of 40K decreased from 17% to 12%. Conclusions: The result has shown that the method can dramatically decrease the error and improve the accuracy. (authors)

  1. Airborne Gamma-Ray Spectrometer Experiments Over the Canadian Shield

    International Nuclear Information System (INIS)

    The Geological Survey of Canada and Atomic Energy of Canada Ltd. have produced a high sensitivity spectrometer for radiometric mapping of the Canadian Shield. During 1967 experiments were undertaken in the Bancroft and Elliot Lake areas of Ontario to determine the system parameters. Ground control was provided by measurements with field gamma-ray spectrometers on a 200-ft grid over 3 square miles. An experimental spectrometer employed three 5 x 5 in. (12.5 x 12.5 cm) diam. Nal (Tl) detectors, in order to record the full gamma - spectrum in real-time on magnetic tape. To provide the highest possible count-rates per unit distance at varying heights the spectrometer was flown in a helicopter at 25 mph (40 kmph). A study of the spectra obtained shows that the optimum spectral window widths for measuring the relative abundance of potassium, uranium and thorium are potassium, 40K 1.35 - 1.58 meV, uranium, 214Bi 1.65 - 1.88 meV; thorium, 208Tl 2.42 - 2.62 meV. The recorded data was subsequently processed through a PDP-9 computer to provide corrections for dead-time, Compton scattering and deviations from constant terrain clearance. Based on this work a much more sensitive airborne system was constructed in 1968 and installed in a twin-engined STOL aircraft. The system employs twelve 9 x 4 in. (23 x 10 cm) Nal (Tl) crystals. This detector volume provides a 10% (1 standard deviation) precision in corrected accumulated count in any of the three spectral windows when the aircraft measures radiation over an elapsed distance of 350 ft at a ground speed of 120 mph and 400 tt terrain clearance. The airborne system includes Doppler navigation, radar altimeter, and TV tracking camera equipment. (author)

  2. Gamma spectrometry for chronology of recent sediments

    International Nuclear Information System (INIS)

    This thesis deals with several aspects of gamma spectrometric analysis of natural and artificial isotopes in sediments and their use as tracers for qualification and quantification of accumulation and mixing processes in different aquatic environments. Sediment cores from three distinct areas including terrigenous sediments deposited on the continental slope off NW Africa, deep sea sediments off Sumba Island and five stations from the Gulf of Eilat in the Red Sea area were measured and interpreted within this dissertation. The main concern in gamma spectrometry of voluminous environmental samples is a reliable efficiency calibration. This is specially relevant for the analysis of low energy gamma emitters (<100 keV). 210Pb, an important isotopic tracer to cover the period of the last century, is one of them. Within this work mathematical efficiency calibration was applied using a commercial software package. A series of validation tests was performed and evaluated for point and voluminous samples. When using 210Pb as a tracer it is necessary to determine its excess portion, which is not supported by ingrowth from the parent nuclide 226Ra. Its analysis is mostly performed via short lived daughter isotopes that follow after the intermediate gaseous member 222Rn. Preventing the escape of radon from the sample is a critical step before analysis due to a negative effect of supported 210Pb underestimation on the chronology, which was also documented in this thesis. Time series registering ingrowth of 214Pb and 214Bi towards radioactive equilibrium with 226Ra in different containers were evaluated for analyses of 226Ra. Direct analyses of 226Ra was compared to its detection via daughter products. A method for aligning parallel radionuclide depth profiles was described and applied successfully in two case studies from the continental slope off NW Africa and off Sumba Island, Indonesia. This is primarily important when combined profiles obtained from short multicorer cores

  3. Gamma spectrometry for chronology of recent sediments

    Energy Technology Data Exchange (ETDEWEB)

    Pittauerova, Daniela

    2013-12-17

    This thesis deals with several aspects of gamma spectrometric analysis of natural and artificial isotopes in sediments and their use as tracers for qualification and quantification of accumulation and mixing processes in different aquatic environments. Sediment cores from three distinct areas including terrigenous sediments deposited on the continental slope off NW Africa, deep sea sediments off Sumba Island and five stations from the Gulf of Eilat in the Red Sea area were measured and interpreted within this dissertation. The main concern in gamma spectrometry of voluminous environmental samples is a reliable efficiency calibration. This is specially relevant for the analysis of low energy gamma emitters (<100 keV). {sup 210}Pb, an important isotopic tracer to cover the period of the last century, is one of them. Within this work mathematical efficiency calibration was applied using a commercial software package. A series of validation tests was performed and evaluated for point and voluminous samples. When using {sup 210}Pb as a tracer it is necessary to determine its excess portion, which is not supported by ingrowth from the parent nuclide {sup 226}Ra. Its analysis is mostly performed via short lived daughter isotopes that follow after the intermediate gaseous member {sup 222}Rn. Preventing the escape of radon from the sample is a critical step before analysis due to a negative effect of supported {sup 210}Pb underestimation on the chronology, which was also documented in this thesis. Time series registering ingrowth of {sup 214}Pb and {sup 214}Bi towards radioactive equilibrium with {sup 226}Ra in different containers were evaluated for analyses of {sup 226}Ra. Direct analyses of {sup 226}Ra was compared to its detection via daughter products. A method for aligning parallel radionuclide depth profiles was described and applied successfully in two case studies from the continental slope off NW Africa and off Sumba Island, Indonesia. This is primarily important

  4. Embedded gamma spectrometry: new algorithms for spectral analysis

    International Nuclear Information System (INIS)

    Airborne gamma spectrometry was first used for mining prospecting. Three main families were looked for: K-40, U-238 and Th-232. The Chernobyl accident acted as a trigger and for the last fifteen years, a lot of new systems have been developed for intervention in case of nuclear accident or environmental purposes. Depending on their uses, new algorithms were developed, mainly for medium or high energy signal extraction. These spectral regions are characteristics of natural emissions (K-40, U-238 and Th-232 decay chains) and fissions products (mainly Cs-137 and Co-60). Below 400 keV, where special nuclear materials emit, these methods can still be used but are greatly imprecise. A new algorithm called 2-windows (extended to 3), was developed. It allows an accurate extraction, taking the flight altitude into account to minimize false detection. Watching radioactive materials traffic appeared with homeland security policy a few years ago. This particular use of dedicated sensors require a new type of algorithms. Before, one algorithm was very efficient for a particular nuclide or spectral region. Now, we need algorithm able to detect an anomaly wherever it is and whatever it is: industrial, medical or SNM. This work identified two families of methods working under these circumstances. Finally, anomalies have to be identified. IAEA recommend to watch around 30 radionuclides. A brand new identification algorithm was developed, using several rays per element and avoiding identifications conflicts. (author)

  5. Contribution of a germanium detector in mobile gamma-ray spectrometry. Spectral analysis and performance

    CERN Document Server

    Gutierrez, S; Bourgeois, C

    2002-01-01

    The sensitivity of the germanium semi-conductor detector is 30 times lower than that of the sodium iodide (NaI) detectors frequently used in airborne spectrometry. Its energy resolution however, is 20 times better, giving more accurate identification of radionuclides, especially when complex spectra are involved. The use of the germanium detector in mobile gamma-ray spectrometry provides a large amount of qualitative and quantitative information. In post-accident situations a germanium detector will be sufficient, and should therefore be used in preference to a NaI detector. An algorithm for detecting the total absorption peaks by studying the variations in the spectral profile of germanium gamma-ray spectra has been developed at the CEA. The use of digital filters that take into account the characteristics of the absorption peaks reduces the statistical fluctuations, making possible detection based on the analysis of the first and second derivatives. The absorption peak is then estimated by subtracting the b...

  6. Some deficiencies and solutions in gamma ray spectrometry

    International Nuclear Information System (INIS)

    A number of problems in high-resolution gamma ray spectrometry as well as some deficiencies of existing computer programs for the quantitative evaluation of spectra are discussed and some practical solutions are proposed. (author)

  7. Gamma ray spectrometry: applications in uranium prospecting and environment

    International Nuclear Information System (INIS)

    The experience in the use of gamma spectrometry for uranium prospecting and for the determination of natural radiation background is described. The basic principles of the techniques are also given. (author)

  8. Conversion of Airborne Gamma ray Spectra to Ground Level Air Kerma Rates

    DEFF Research Database (Denmark)

    Bargholz, Kim; Korsbech, Uffe C C

    A new method for relating airborne gamma-ray spectra to dose rates and kerma rates at ground level is presented. Dependent on flying altitude 50 m to 125 m the method gives correct results for gamma energies above 250 keV respective 350 keV. At lower energies the method underestimate the dose or ...

  9. Bioaerosol Mass Spectrometry for Rapid Detection of Individual Airborne Mycobacterium tuberculosis H37Ra Particles

    OpenAIRE

    Tobias, Herbert J.; Schafer, Millie P.; Pitesky, Maurice; Fergenson, David P.; Horn, Joanne; Frank, Matthias; Gard, Eric E.

    2005-01-01

    Single-particle laser desorption/ionization time-of-flight mass spectrometry, in the form of bioaerosol mass spectrometry (BAMS), was evaluated as a rapid detector for individual airborne, micron-sized, Mycobacterium tuberculosis H37Ra particles, comprised of a single cell or a small number of clumped cells. The BAMS mass spectral signatures for aerosolized M. tuberculosis H37Ra particles were found to be distinct from M. smegmatis, Bacillus atrophaeus, and B. cereus particles, using a distin...

  10. The Danish airborne gamma-ray surveying results

    Energy Technology Data Exchange (ETDEWEB)

    Hovgaard, J. [Danish Emergency Management Agency, Birkeroed (Denmark)

    1997-12-31

    The Danish Emergency Management Agency (DEMA) in co-operation with the Technical University of Denmark (TUD), Department of Automation, participated in the international exercise RESUME-95 arranged in Finland in August 1995. DEMA performed measurement with their airborne gamma-ray surveying system. Surveys were done in the three areas known as AREA I, II, III. Results from AREA II (3 km x 6 km) show that the apparent {sup 137}Cs deposition assuming a deposition profile equal to the profile in AREA I based on soil samples varies from a few 10th kBqm{sup -2} up to 110 kBqm{sup -2}. However, a detailed analysis using a new method, Noise Adjusted Singular Value Decomposition (NASVD), shows that the true variations probably are smaller and that the observed differences to some extend are due to major variations in the depth distribution of the cesium. For example agricultural areas appears to have cesium much deeper deposit than the undisturbed areas. Another interesting result is that the NASVD analysis shows that the ration of {sup 134}Cs to {sup 137}Cs is fixed and approximately 0.03 (August 1995) a number in good agreement with the expected ratio from the Chernobyl accident. No true real-time software for source detection is yet integrated in the Danish system. Results from AREA III, however, show that the implemented software for rapid post processing of data worked excellent for detection of radioactive sources. Post analysis using NASVD demonstrates that all sources except for a small {sup 137}Cs source can be localized. (au).

  11. Detector calibration for in-situ gamma ray spectrometry

    CERN Document Server

    Balea, G

    2002-01-01

    The power in the technique of in-situ spectrometry lies in the fact that a detector placed on ground measures gamma radiation from sources situated over an area of several hundred square meters. The 'field of view' for the detector would be larger for high energy radiation sources and for sources closer to the soil surface. In contrast, a soil sample would represent an area of a few tens of hundreds of square centimeters. In practice, an effective characterization of a site would involve in-situ gamma ray spectrometry in conjunction with soil sampling. As part of an overall program, in-situ gamma ray spectrometry provides a means to assess the degree of contamination in areas during the course of operations in the field, thus guiding the investigator on where to collect samples. It can also substantially reduce the number of samples need to be collected and subsequently analyzed. (author)

  12. GammaSem Proceedings. A Nordic seminar for users of gamma spectrometry

    International Nuclear Information System (INIS)

    The project GammaSem was proposed to the NKS in 2008. The aim of the project was to arrange two seminars for users of gamma spectrometry, in 2009 and 2010. The seminars were meant to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and initiate a network of gamma spectrometry users in the Nordic countries. Such a Nordic network should strengthen the collaboration between laboratories and improve all participants' competence in practical gamma spectrometry. Both seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 65 people signed up for GammaSem 2010; representing 30 different universities, commercial companies, research institutes and authorities. The working group concept as presented at last year's GammaSem, has not worked out as intended. The reason for this is probably because most of the laboratories that signed up to join the working groups, signed up because they wanted to learn more about the different subjects. In combination with the fact that no funding was made available for the working groups, it was difficult to establish goals on what to achieve. None of the working groups applied for funding from the NKS (or elsewhere) to establish separate projects. There is a big need for more cooperation and for training within the field of gamma spectrometry. This fact has been proved through these two seminars, both by the many different topics that have been discussed, but also by the huge interest for participating in the suggested series of workshop. The GammaSem seminars have thus provided a much welcomed starting point for a broader Nordic collaboration. (Author)

  13. GammaSem Proceedings. A Nordic seminar for users of gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Straalberg, E. (ed.) (Institute for Energy Technolgy (Norway)); Berg, K. (National Institute of Radiation Protection (Denmark)); Dowdall, M. (Norwegian Radiation Protection Authority (Norway)) (and others)

    2010-11-15

    The project GammaSem was proposed to the NKS in 2008. The aim of the project was to arrange two seminars for users of gamma spectrometry, in 2009 and 2010. The seminars were meant to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and initiate a network of gamma spectrometry users in the Nordic countries. Such a Nordic network should strengthen the collaboration between laboratories and improve all participants' competence in practical gamma spectrometry. Both seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 65 people signed up for GammaSem 2010; representing 30 different universities, commercial companies, research institutes and authorities. The working group concept as presented at last year's GammaSem, has not worked out as intended. The reason for this is probably because most of the laboratories that signed up to join the working groups, signed up because they wanted to learn more about the different subjects. In combination with the fact that no funding was made available for the working groups, it was difficult to establish goals on what to achieve. None of the working groups applied for funding from the NKS (or elsewhere) to establish separate projects. There is a big need for more cooperation and for training within the field of gamma spectrometry. This fact has been proved through these two seminars, both by the many different topics that have been discussed, but also by the huge interest for participating in the suggested series of workshop. The GammaSem seminars have thus provided a much welcomed starting point for a broader Nordic collaboration. (Author)

  14. Airborne gamma ray measurements conducted during an international trial in Finland

    International Nuclear Information System (INIS)

    The Scottish Universities Research and Reactor Centre (SURRC) contributed to the Resume 95 exercise by developing the calibration site at Vesivehmaa, and by participating in the airborne gamma spectrometry (AGS) part of the study. This paper summarises the airborne survey results from the SURRC team. The AGS tasks included fallout mapping of a 6x3 km area in central Finland with nominal 150 m line spacing, and a time constrained search for an undisclosed number of hidden radioactive sources. Measurements at the calibration site were also taken to provide a basis for traceable cross comparison between each teams' quantification procedures at a single, well characterised, location. A full set of calibrated maps of Chernobyl deposition and natural radionuclides, together with overlays corresponding to topography, roads, rivers and lakes were finished during the survey and displayed at the end of the exercise. The main survey area (Area II) was found to have a mean 137Cs deposition of 64.4±24.4 kBq m-2, based on the calibration appropriate to the Vesivehmaa site. The major point sources in Area III were discovered, although the collimated 137Cs and 60Co sources were not. Retrospective analysis has shown that sources Cs3 and Cs4 were not significantly above local environmental levels in our data set; whereas the low activity 60Co source Co3 was detected. This confirms the improved sensitivity of AGS source searches to nuclides which are not already present as environmental contaminants. The collimated 192Ir was found both using scattered radiation and from full energy lines detected with a Ge detector. The 99mTc was located using a ratio of low energy integrals from the NaI spectra. (EG)

  15. Airborne gamma ray measurements conducted during an international trial in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Sanderson, D.C.W.; Allyson, J.D.; McConville, P.; Murphy, S.; Smith, J. [Scottish Univ. Research and Reactor Centre, Glasgow, Scotland (United Kingdom)

    1997-12-31

    The Scottish Universities Research and Reactor Centre (SURRC) contributed to the Resume 95 exercise by developing the calibration site at Vesivehmaa, and by participating in the airborne gamma spectrometry (AGS) part of the study. This paper summarises the airborne survey results from the SURRC team. The AGS tasks included fallout mapping of a 6x3 km area in central Finland with nominal 150 m line spacing, and a time constrained search for an undisclosed number of hidden radioactive sources. Measurements at the calibration site were also taken to provide a basis for traceable cross comparison between each teams` quantification procedures at a single, well characterised, location. A full set of calibrated maps of Chernobyl deposition and natural radionuclides, together with overlays corresponding to topography, roads, rivers and lakes were finished during the survey and displayed at the end of the exercise. The main survey area (Area II) was found to have a mean {sup 137}Cs deposition of 64.4{+-}24.4 kBq m{sup -2}, based on the calibration appropriate to the Vesivehmaa site. The major point sources in Area III were discovered, although the collimated {sup 137}Cs and {sup 60}Co sources were not. Retrospective analysis has shown that sources Cs3 and Cs4 were not significantly above local environmental levels in our data set; whereas the low activity {sup 60}Co source Co3 was detected. This confirms the improved sensitivity of AGS source searches to nuclides which are not already present as environmental contaminants. The collimated {sup 192}Ir was found both using scattered radiation and from full energy lines detected with a Ge detector. The {sup 99m}Tc was located using a ratio of low energy integrals from the NaI spectra. (EG). 28 refs.

  16. Airborne system for mapping and tracking extended gamma ray sources

    International Nuclear Information System (INIS)

    An airborne system was developed for mapping and tracking extended sources of airborne or terrestrially distributed γ-ray emitters. The system records 300 channel γ-ray spectral data every three seconds on magnetic tape. Computer programs have been written to isolate the contribution from the particular radionuclide of interest. Aircraft position as sensed by a microwave ranging system is recorded every second on magnetic tape. Measurements of airborne stack releases of 41A concentrations versus time or aircraft position agree well with computer code predictions

  17. GammaSem Proceedings - A Nordic seminar for users of gamma spectrometry

    International Nuclear Information System (INIS)

    The project GammaSem was proposed to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and to establish a network of users of gamma spectrometry in the Nordic countries, thereby strengthening the collaboration and improving all participants' competence in practical gamma spectrometry. The seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 75 people participated; representing 34 different universities, commercial companies, research institutes and also all Nordic authorities. During the seminar several key issues for follow-up were identified and working groups for addressing the identified problems were established. The working groups were: 1) Uncertainties and detections of limits 2) True summing coincidence 3) Monte Carlo simulations and efficiency transfer 4) Absorption (density corrections and geometries) 5) Mobile gamma spectrometry systems 6) Nuclear forensics (on special samples and special parts of the spectra). The identified topics will form the basis for the agenda of the next seminar in 2010. There, the different working groups will be invited to present their ideas/solutions to the relevant problems. (author)

  18. GammaSem Proceedings - A Nordic seminar for users of gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Nunez, P. (ed.) (Institute for Energy Technology (IFE) (Norway)); Klemola, S. (Radiation and Nuclear Safety Authority (STUK) (Finland)); Nielsen, Sven P. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy. Roskilde (Denmark)); Palsson, S.E. (Icelandic Radiation Safety Authority (IS)); Israelson, C. (National Institute of Radiation Protection (Denmark))

    2010-03-15

    The project GammaSem was proposed to provide a forum for discussions and sharing of information on practical issues concerning gamma spectrometry and to establish a network of users of gamma spectrometry in the Nordic countries, thereby strengthening the collaboration and improving all participants' competence in practical gamma spectrometry. The seminars' focus was practical challenges met by the users themselves, rather than theoretical matters. Scientists and users of gamma spectrometry from all five Nordic countries were invited to the seminar, as well as scientist from the Baltic countries. A total of 75 people participated; representing 34 different universities, commercial companies, research institutes and also all Nordic authorities. During the seminar several key issues for follow-up were identified and working groups for addressing the identified problems were established. The working groups were: 1) Uncertainties and detections of limits 2) True summing coincidence 3) Monte Carlo simulations and efficiency transfer 4) Absorption (density corrections and geometries) 5) Mobile gamma spectrometry systems 6) Nuclear forensics (on special samples and special parts of the spectra). The identified topics will form the basis for the agenda of the next seminar in 2010. There, the different working groups will be invited to present their ideas/solutions to the relevant problems. (author)

  19. Carborne Gamma-Ray Spectrometry. Calibration and Applications

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, Kim;

    2006-01-01

    Calibration of carborne gamma-ray spectrometry systems for 137Cs is carried out with a source successively placed at 791 positions within an area of 34m  62m. A computer model supplements the measurements. Hereby a sensitivity map for a surface contamination is generated as well as line and area...

  20. Gamma spectrometry analysis of fertilizers used in Costa Rica

    International Nuclear Information System (INIS)

    Using the low level gamma spectrometry technique, the specific activity of natural and artificial isotopes present in national consumption fertilizers, supplied by local dealers, was quantified. The most outstanding isotope found in some of the fertilizers is U235, with an specific activity higher than the expected in this kind of product, which might mean that this isotope comes from imported raw material. (Author)

  1. Further development of IDGS: Isotope dilution gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The isotope dilution gamma-ray spectrometry (IDGS) technique for determining the plutonium concentration and isotopic composition of highly radioactive spent-fuel dissolver solutions has been further developed. Both the sample preparation and the analysis have been improved. The plutonium isotopic analysis is based on high-resolution, low-energy gamma-ray spectrometry. The plutonium concentration in the dissolver solutions then is calculated from the measured isotopic differences among the spike, the dissolver solution, and the spiked dissolver solution. Plutonium concentrations and isotopic compositions of dissolver solutions analyzed from this study agree well with those obtained by traditional isotope dilution mass spectrometry (IDMS) and are consistent with the first IDGS experimental result. With the current detector efficiency, sample size, and a 100-min count time, the estimated precision is ∼0.5% for 239Pu and 240Pu isotopic analyses and ∼1% for the plutonium concentration analysis. 5 refs., 2 figs., 7 tabs

  2. Determining a pre-mining radiological baseline from historic airborne gamma surveys: A case study

    International Nuclear Information System (INIS)

    Knowing the baseline level of radioactivity in areas naturally enriched in radionuclides is important in the uranium mining context to assess radiation doses to humans and the environment both during and after mining. This information is particularly useful in rehabilitation planning and developing closure criteria for uranium mines as only radiation doses additional to the natural background are usually considered ‘controllable’ for radiation protection purposes. In this case study we have tested whether the method of contemporary groundtruthing of a historic airborne gamma survey could be used to determine the pre-mining radiological conditions at the Ranger mine in northern Australia. The airborne gamma survey was flown in 1976 before mining started and groundtruthed using ground gamma dose rate measurements made between 2007 and 2009 at an undisturbed area naturally enriched in uranium (Anomaly 2) located nearby the Ranger mine. Measurements of 226Ra soil activity concentration and 222Rn exhalation flux density at Anomaly 2 were made concurrent with the ground gamma dose rate measurements. Algorithms were developed to upscale the ground gamma data to the same spatial resolution as the historic airborne gamma survey data using a geographic information system, allowing comparison of the datasets. Linear correlation models were developed to estimate the pre-mining gamma dose rates, 226Ra soil activity concentrations, and 222Rn exhalation flux densities at selected areas in the greater Ranger region. The modelled levels agreed with measurements made at the Ranger Orebodies 1 and 3 before mining started, and at environmental sites in the region. The conclusion is that our approach can be used to determine baseline radiation levels, and provide a benchmark for rehabilitation of uranium mines or industrial sites where historical airborne gamma survey data are available and an undisturbed radiological analogue exists to groundtruth the data. - Highlights: • Data

  3. The software quality control for gamma spectrometry

    International Nuclear Information System (INIS)

    One of major problems with wich the quality control program of an environmental measurements laboratory is confronted is the evaluation of the performances of software packages for the analysis of gamma-ray spectra. A program of tests for evaluating the performances of the software package (SPECTRAN-F, Canberra Inc.) used by our laboratory is being carried out. In this first paper the results of a preliminary study concerning the evaluation of the performance of the doublet analysis routine are presented

  4. Airborne time-series measurement of soil moisture using terrestrial gamma radiation

    Science.gov (United States)

    Carroll, Thomas R.; Lipinski, Daniel M.; Peck, Eugene L.

    1988-01-01

    Terrestrial gamma radiation data and independent ground-based core soil moisture data are analyzed. They reveal the possibility of using natural terrestrial gamma radiation collected from a low-flying aircraft to make reliable real-time soil moisture measurements for the upper 20 cm of soil. The airborne data were compared to the crude ground-based soil moisture data set collected at the core sites.

  5. Quality assurance system in gamma spectrometry laboratory

    International Nuclear Information System (INIS)

    On basis of guidelines for development of QUALITY SYSTEM for a testing laboratory (European Standard Series EN 45000) a quality assurance system was implemented in gamma spectroscopy laboratory, where routine measurements of natural (mainly Ra-226, Ra-228, Ra-224, K-40) and artificial (mainly Cs-137 and Cs-134) isotopes are performed. We measure a variety of samples, but mainly coal, vaste rock, ashe, deposits, vegetation and air filters. Laboratory of gamma spectroscopy in Central Mining Institute has three HPGe detectors. There is one coaxial detector with 45% relative efficiency, one detector for low energy region and one detector with extended range). We have also two Ge(Li) detectors from former Czechoslovakia. Shielding is made mainly of steel (40 cm) with the interior covered with lead and copper. The electronics and software (Genie-PC) was bought at 'Canberra' and 'Silena'. The paper describes not only the system of quality assurance but also main problems met by its implementation and results of intercomparison measurements. The QAS has been introduced in 1992. In 1993 the Accreditation Certificate of Testing Laboratory for our Laboratory has been obtained from the Polish Bureau of Research and Certification as a fifth laboratory in Poland. (author)

  6. Lake Mead dynamic test range for calibration of airborne gamma radiation measuring systems

    International Nuclear Information System (INIS)

    Data are presented for calibrating airborne gamma radiation measuring systems for surface concentrations of U, Th, and K. Data are included for six flight paths at altitudes of 200, 400, 600, 800, 1000, and 1200 feet. Lake Mead Dynamic Test Range is described in detail in Volume I of this report

  7. Lake Mead dynamic test range for calibration of airborne gamma radiation measuring systems

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    Data are presented for calibrating airborne gamma radiation measuring systems for surface concentrations of U, Th, and K. Data are included for six flight paths at altitudes of 200, 400, 600, 800, 1000, and 1200 feet. Lake Mead Dynamic Test Range is described in detail in Volume I of this report. (WHK)

  8. GammaLab-software complex to train in practical spectrometry

    International Nuclear Information System (INIS)

    A software complex GammaLab intended to simulate in real time instrument gamma spectrums of semiconductor and scintillation detectors for measurements of wide set of sources with arbitrary spatial configuration and radionuclide composition is presented in the article. The complex can be used as a simulator for training in work with spectrometry devices and software. It can be used also to decide the tasks of instrument calibration, testing of software and measuring methods when the attested radiation sources with the specific properties (sizes, physico-chemical characteristics, radionuclide composition) are unavailable, or their production requires considerable expenses.

  9. The assessment of site contamination using mobile gamma ray spectrometry

    International Nuclear Information System (INIS)

    3,700 measurements were made on a site of area in excess of 10 Ha using 'LARCH', the Large Area Radioactive Characterisation system. LARCH is a mobile system that combines the use of high resolution gamma spectroscopy with automated mapping techniques to generate a radiation contamination map of the surveyed area. The advantages of using high resolution gamma spectrometry, the means of correcting for contributions from radioactive plant, and the interpretation of results are presented. The techniques used permit a rapid and cost-effective location, identification and quantification of radioactive contamination or demonstration of compliance with clearance criteria. Possible applications of LARCH to other situations in site restoration are discussed. (author)

  10. Airborne Gamma-ray Measurements in the Chernobyl Plume

    DEFF Research Database (Denmark)

    Grasty, R. L.; Hovgaard, Jens; Multala, J.

    On 29 April 1986, the Geological Survey of Finland (GSF) survey aircraft with a gamma ray spectrometer flew through a radioactive plume from the Chernobyl nuclear accident. The aircraft became contaminated and the gamma spectrometer measured radioactivity in the plume as well as radioactivity on ...

  11. Airborne Gamma-ray Measurements in the Chernobyl Plume

    DEFF Research Database (Denmark)

    Grasty, R. L.; Hovgaard, Jens; Multala, J.

    1997-01-01

    On 29 April 1986, the Geological Survey of Finland (GSF) survey aircraft with a gamma ray spectrometer flew through a radioactive plume from the Chernobyl nuclear accident. The aircraft became contaminated and the gamma spectrometer measured radioactivity in the plume as well as radioactivity on...

  12. Quantitative gamma scintillometry and spectrometry in uranium exploration

    International Nuclear Information System (INIS)

    This article discusses aspects of quantitative gamma scintillometry and spectrometry in uranium exploration with particular emphasis on field instrument capabilities and the calibration of surface radiometric field instruments. Factors that influence the accuracy of in-situ (surface) radiometric assaying, for example, disequilibrium, geometry, the physico-chemical characteristics of the calibration source, the presence of thorium and potassium and the non-uniform distribution of the source material are also discussed

  13. Self-attenuation correction in the environmental sample gamma spectrometry

    International Nuclear Information System (INIS)

    Self-attenuation corrections were calculated for gamma ray spectrometry of environmental samples with densities from 0.42 g/ml up to 1.59 g/ml, measured in Marinelli beakers and polyethylene flasks. These corrections are to be used when the counting efficiency is calculated for water measured in the same geometry. The model of Debertin for Marinelli beaker, numerical integration and experimental linear attenuation coefficients were used. (author). 3 refs., 4 figs., 6 tabs

  14. Design and fabrication of shielding for gamma spectrometry

    International Nuclear Information System (INIS)

    To have a system of gamma spectrometry in the Radiological Mobile Unit No. 1 (UMOR-1) was designed and manufactured an armor-plating appropriate to this, to make analysis of radioactive samples in place in the event of a radiological emergency, besides being able to give support to the Management of Radiological Safety, and even to give service of sample analysis of other Institutions. (Author)

  15. Gamma ray spectrometry results from core samples collected for resume 95

    International Nuclear Information System (INIS)

    Field sampling of an airfield at Vesivehmaa, near Vaaksy, Finland (Area 1) was carried out between 26-29 May 1995, to establish the radionuclide deposition and inventory of Chernobyl derived 137Cs, and natural radio radionuclides. The objective was to establish a common calibration site for in-situ and airborne gamma spectrometers, for Exercise RESUME 95 conducted in August 1995. The report presents the sampling details, handling and treatment. The analyses are discussed with particular emphasis given to 137Cs, 134Cs, 40K, 214Tl radionuclides, and the quantification of their respective deposition and inventories. The calibration site was based upon a hexagonal sampling pattern developed by The Scottish Universities Research and Reactor Centre (SURRC). This sampling scheme enables ground level deposition to be related to gamma-ray spectrometers at different heights, taking account of differences in fields of view. More than 50 soil cores were collected in May, split vertically, and taken to Sateilyturvakeskus (STUK) for drying prior to gamma spectrometry. Some 160 individual samples were counted between SURRC and STUK, with 5 samples measured in both laboratories and two IAEA reference materials. Results from common samples and reference materials confirm both compatibility between the two laboratories and traceability to recognised standards. (author)

  16. Airborne gamma radiation measurements of soil moisture during FIFE: Activities and results

    Science.gov (United States)

    Peck, Eugene L.

    1992-01-01

    Soil moisture measurements were obtained during the summer of 1987 and 1989 near Manhattan, Kansas, using the National Weather Service (NWS) airborne gamma radiation system. A network of 24 flight lines were established over the research area. Airborne surveys were flown daily during two intensive field campaigns. The data collected was sufficient to modify the NWS standard operational method for estimating soil moisture for the Field Experiment (FIFE) flight lines. The average root mean square error of the soil moisture estimates for shorter FIFE flight lines was found to be 2.5 percent, compared with a reported value of 3.9 percent for NWS flight lines. Techniques were developed to compute soil moisture estimates for portions of the flight lines. Results of comparisons of the airborne gamma radiation soil moisture estimates with those obtained using the NASA Pushbroom Microwave Radiation (PBMR) system and hydrological model are presented. The airborne soil moisture measurements, and real averages computed using all remotely sensed and ground data, have been in support of the research of the many FIFE investigators whose overall goal was the upscale integration of models and the application of satellite remote sensing.

  17. Application of Bayesian decision theory to airborne gamma snow measurement

    Science.gov (United States)

    Bissell, V. C.

    1975-01-01

    Measured values of several variables are incorporated into the calculation of snow water equivalent as measured from an aircraft by snow attenuation of terrestrial gamma radiation. Bayesian decision theory provides a snow water equivalent measurement by taking into account the uncertainties in the individual measurement variables and filtering information about the measurement variables through prior notions of what the calculated variable (water equivalent) should be.

  18. An Airborne and Vehicular Gamma Survey of Greenham Common, Newbury District and Surrounding Areas

    OpenAIRE

    Sanderson, D.C.W; Allyson, J.D.; Cresswell, A.; McConville, P.

    1997-01-01

    The airborne gamma ray survey recorded more than 40,000 scintillation spectra and 20,000 spectra from semiconductor detectors. The vehicular survey produced a further 1346 and 763 spectral sets respectively. The installation, calibration, recording and analysis followed SURRC procedures which have been developed and validated over many years and are fully documented. Pre flight checks on detector performance for energy calibration, energy resolution and sensitivity were performed on a dail...

  19. Radiological maps of outdoor and indoor gamma dose rates in Greek urban areas obtained by in situ gamma spectrometry

    International Nuclear Information System (INIS)

    The results obtained from 259 indoor and outdoor in situ gamma spectrometry measurements with a portable Ge detector and 707 total gamma dose rate measurements with an NaI detector in urban areas of 16 Greek islands are presented. From the in situ gamma spectra, the absorbed dose rate in air due to Uranium series, Thorium series, 40K and 137Cs are derived and discussed. The results obtained from the present work in conjunction with those reported previously were used for the realization of a complete indoor and outdoor gamma radiation map of Greek urban areas using in situ gamma spectrometry with portable Ge detector. (authors)

  20. Investigation of environmental samples by low-level gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, M. [Nuclear Engineering and Analytics Rossendorf, Inc., Dresden (Germany); Niese, S. [Nuclear Engineering and Analytics Rossendorf, Inc., Dresden (Germany)

    1997-03-01

    The average sample number in our laboratory is about 200 per month (12% technical solid state, 30% geological solid state, 6% geological solid state with low mass, 12% biological, 11% water directly, 25% water after chemical separation, 4% others). In 54% of the measurements the background continuum, and though the detection limit, is determined only by the detector himself and not by the compton continuum from high energy lines in the sample. Some examples in the presented work aim to prove the advantages of gamma ray spectrometry in the underground laboratory Felsenkeller. (orig./DG)

  1. Iterative inversion of gamma or alpha spectrometry data

    International Nuclear Information System (INIS)

    Gamma - and alpha ray spectrometry data are processed by an iterative regression method (Wolberg, 1967) to obtain the activities or yields of radionuclides. This method, applied to Nuclear Geophysics Research, permits the use of either selected energy bands or of all the channels one by one. It may be easily programmed in popular microcomputers and offers many advantages such as the use of mixtures of radionuclides for the calibrations and the treatment of the uncertainties on the measurements and results. Several conclusions about the method and options of nuclear data processing are presented. (Author)

  2. Radioactivity Measurement in the Detergent Products by Gamma Spectrometry

    International Nuclear Information System (INIS)

    Our study focuses on the evaluation of the level of radioactivity in the detergents. We have determined the specific activities of gamma emitting radionuclides belonging to the natural families of uranium, thorium and potassium using gamma spectrometry. The activities of radionuclides (235U, 238U, 226Ra, 232Th, 40K) and their descendants are below the minimum detectable activity for dishwasher products, soaps, bleaches and shampoos, whereas they are found to levels considered very low (between 0,2 and 13 Bq/kg on average) in the products washes linens. These values are always lower than those of raw materials, what is explained by the conservation of radioactive material throughout the manufacturing process. The effective dose due to external exposure estimated below the regulatory standard recommended (<1 mSv / year), allows us to show that detergent products are not contaminated by radioactivity, are healthy and do not have harmful radiological impact on the consumer.

  3. Spatial distribution of gamma radiation levels in Yelagiri Hills, Tamilnadu, India by gamma ray spectrometry

    International Nuclear Information System (INIS)

    The concentration of natural radionuclides in surface soil samples around Yelagiri Hills were determined by gamma ray spectrometry using NaI(Tl) detector. The spatial distribution of uranium and thorium was investigated in soils from the cultivated and undisturbed areas in Yelagiri Hills, Tamilnadu, India. The average absorbed dose rate in the study area was estimated to be 88.62 nGyh-1. To establish the level of radioactivity at different areas isodose map is drawn between the different sampling locations of Yelagiri hills and the absorbed gamma dose rate. (author)

  4. In situ gamma-spectrometry intercomparison exercise in Salzburg, Austria

    International Nuclear Information System (INIS)

    In situ gamma-spectrometry has become a useful method of assessing the nuclide concentrations of man-made and natural gamma-emitters in the soil. For the quality assurance of the measurements, periodically conducted intercomparison exercises are essential. Therefore exercises were organized in different European countries since 1990, the last one was conducted in Salzburg, Austria in September 1994. The participation of 27 measurement teams from all over Europe emphasizes the importance of the intercomparison. Salzburg was selected because the Province of Salzburg, Austria was among the most heavily contaminated regions outside the former USSR by the Chernobyl fallout. Two different typical sites were selected for the measurements: Site 1 was inside the urban area of Salzburg on intensively used grassland which had not been tilled since the deposition of the fallout. This site is representative for intensively used agricultural regions in the Province of Salzburg. Site 2 was in the mountainous regions of the Hohe Tauern at an elevated altitude of 1600 m, representing the agricultural soil- and contamination conditions of the Alpine regions in the Tauern. The two sites differ significantly in terms of soil characteristics, a crucial parameter for the evaluation of in situ gamma-spectra. The participants used different approaches for the evaluation of the gamma-spectra in terms of considering the depth distribution. In the paper the results from the 24 European teams are presented. (orig.)

  5. Design and fabrication of shielding for gamma spectrometry; Diseno y fabricacion de blindaje para espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Mariano H, E

    1991-05-15

    To have a system of gamma spectrometry in the Radiological Mobile Unit No. 1 (UMOR-1) was designed and manufactured an armor-plating appropriate to this, to make analysis of radioactive samples in place in the event of a radiological emergency, besides being able to give support to the Management of Radiological Safety, and even to give service of sample analysis of other Institutions. (Author)

  6. Absolute quantification method and validation of airborne snow crab allergen tropomyosin using tandem mass spectrometry

    International Nuclear Information System (INIS)

    Measuring the levels of the major airborne allergens of snow crab in the workplace is very important in studying the prevalence of crab asthma in workers. Previously, snow crab tropomyosin (SCTM) was identified as the major aeroallergen in crab plants and a unique signature peptide was identified for this protein. The present study advances our knowledge on aeroallergens by developing a method of quantification of airborne SCTM by using isotope dilution mass spectrometry. Liquid chromatography tandem mass spectrometry was developed for separation and analysis of the signature peptides. The tryptic digestion conditions were optimized to accomplish complete digestion. The validity of the method was studied using international conference on harmonization protocol, Where 2-9% for CV (precision) and 101-110% for accuracy, at three different levels of quality control. Recovery of the spiked protein from PTFE and TopTip filters was measured to be 99% and 96%, respectively. To further demonstrate the applicability and the validity of the method for real samples, 45 kg of whole snow crab were processed in an enclosed (simulated) crab processing line and air samples were collected. The levels of SCTM ranged between 0.36-3.92 μg m-3 and 1.70-2.31 μg m-3 for butchering and cooking stations, respectively.

  7. Absolute quantification method and validation of airborne snow crab allergen tropomyosin using tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Anas M. Abdel, E-mail: anasar@mun.ca [Department of Chemistry, Memorial University of Newfoundland, St. John' s, Newfoundland A1B 3X7 (Canada); Lopata, Andreas L. [School of Applied Science, Marine Biomedical Sciences and Health Research Group, RMIT University, Bundoora, 3083 Victoria (Australia); Randell, Edward W. [Department of Laboratory Medicine, Memorial University of Newfoundland, Eastern Health, St. John' s, Newfoundland and Labrador A1B 3V6 (Canada); Helleur, Robert J. [Department of Chemistry, Memorial University of Newfoundland, St. John' s, Newfoundland A1B 3X7 (Canada)

    2010-11-29

    Measuring the levels of the major airborne allergens of snow crab in the workplace is very important in studying the prevalence of crab asthma in workers. Previously, snow crab tropomyosin (SCTM) was identified as the major aeroallergen in crab plants and a unique signature peptide was identified for this protein. The present study advances our knowledge on aeroallergens by developing a method of quantification of airborne SCTM by using isotope dilution mass spectrometry. Liquid chromatography tandem mass spectrometry was developed for separation and analysis of the signature peptides. The tryptic digestion conditions were optimized to accomplish complete digestion. The validity of the method was studied using international conference on harmonization protocol, Where 2-9% for CV (precision) and 101-110% for accuracy, at three different levels of quality control. Recovery of the spiked protein from PTFE and TopTip filters was measured to be 99% and 96%, respectively. To further demonstrate the applicability and the validity of the method for real samples, 45 kg of whole snow crab were processed in an enclosed (simulated) crab processing line and air samples were collected. The levels of SCTM ranged between 0.36-3.92 {mu}g m{sup -3} and 1.70-2.31 {mu}g m{sup -3} for butchering and cooking stations, respectively.

  8. Application on Th normalization for basin gamma spectrometry data processing

    International Nuclear Information System (INIS)

    In procedure of using gamma spectrometry data to explore sandstone-type uranium deposits, interference caused by non-mineralization factor should be eliminated as clean as possible, so as to extract information on uranium mineralization. In this paper, the principle and characteristics of Th normalization are introduced by using Th normalization techniques which relate to mineralization with information on element migration. Gamma spectrometry data in the east of the Erlian Basin are also analyzed; the distributive characteristic of radioactive element in the area, geochemical process, later stage migration and enrichment of uranium element are revealed. Based on other geological informations, the forming mechanism of residual potassium anomaly region (the highly positive and negative region) and highly positive residual uranium deviation region is analyzed. At the same time, it is shown that the highly positive residual uranium deviation region obtained by Th normalization can be used as a direct indicator for redox transitional zone, and it is also an important symbol to further exploration of sandstone-type uranium deposits in the area. (authors)

  9. Sodium fast reactor power monitoring using gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Coulon, R.; Normand, S.; Barbot, L.; Domenech, T.; Kondrasovs, V.; Corre, G.; Frelin, A.M. [CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, CEA - Saclay DRT/LIST/DETECS/SSTM, Batiment 516 - P.C. no 72, Gif sur Yvette, F-91191 (France); Montagu, T.; Dautremer, T.; Barat, E. [CEA, LIST, Laboratoire Processus Stochastiques et Spectres (France); Ban, G. [ENSICAEN (France)

    2009-06-15

    This work deals with the use of high flux gamma spectrometry to monitor the fourth generation of sodium fast reactor (SFR) power. The simulation study part of this work has shown that power monitoring in a short time response and with a good accuracy is possible. An experimental test is under preparation at the French SFR Phenix experimental reactor to validate simulation studies. First, physical calculations have been done to correlate gamma activity to the released thermal power. Gamma emitter production rate in the reactor core was calculated with technical and nuclear data as the sodium velocity, the atomic densities, Phenix neutron spectrum and incident neutron cross-sections of reactions producing gamma emitters. A thermal hydraulic transfer function was used for modeling primary sodium flow in our calculations. For the power monitoring problematic, use of a short decay period gamma emitter will allow to have a very fast response system without cumulative effect. We have determined that the best tagging agent is 20F which emits 1634 keV energy photons with a decay period of 11 s. The gamma spectrum was determined by flux point and a pulse high tally MCNP5.1.40 simulation and shown the possibility to measure the signal of this radionuclide. The experiment will be set during the reactor 'end life testing'. The Delayed Neutron Detection (DND) room has been chosen as the best available location on Phenix reactor to measure this kind of radionuclide due to a short transit time from reactor core to measurement sample. This location is optimum for global power measurement because homogenized sampling in the reactor hot pool. The main spectrometer is composed of a coaxial high purity germanium diode (HPGe) coupled with a transistor reset preamplifier. The HPGe diode signal will be processed by the Adonis digital signal processing due to high flux and fast activity measurement. Post-processing softwares will be used to limit statistical problems of the

  10. Sodium fast reactor power monitoring using gamma spectrometry

    International Nuclear Information System (INIS)

    This work deals with the use of high flux gamma spectrometry to monitor the fourth generation of sodium fast reactor (SFR) power. The simulation study part of this work has shown that power monitoring in a short time response and with a good accuracy is possible. An experimental test is under preparation at the French SFR Phenix experimental reactor to validate simulation studies. First, physical calculations have been done to correlate gamma activity to the released thermal power. Gamma emitter production rate in the reactor core was calculated with technical and nuclear data as the sodium velocity, the atomic densities, Phenix neutron spectrum and incident neutron cross-sections of reactions producing gamma emitters. A thermal hydraulic transfer function was used for modeling primary sodium flow in our calculations. For the power monitoring problematic, use of a short decay period gamma emitter will allow to have a very fast response system without cumulative effect. We have determined that the best tagging agent is 20F which emits 1634 keV energy photons with a decay period of 11 s. The gamma spectrum was determined by flux point and a pulse high tally MCNP5.1.40 simulation and shown the possibility to measure the signal of this radionuclide. The experiment will be set during the reactor 'end life testing'. The Delayed Neutron Detection (DND) room has been chosen as the best available location on Phenix reactor to measure this kind of radionuclide due to a short transit time from reactor core to measurement sample. This location is optimum for global power measurement because homogenized sampling in the reactor hot pool. The main spectrometer is composed of a coaxial high purity germanium diode (HPGe) coupled with a transistor reset preamplifier. The HPGe diode signal will be processed by the Adonis digital signal processing due to high flux and fast activity measurement. Post-processing softwares will be used to limit statistical problems of the signal. An

  11. Contribution of a germanium detector in mobile gamma-ray spectrometry. Spectral analysis and performance

    International Nuclear Information System (INIS)

    The sensitivity of the germanium semi-conductor detector is 30 times lower than that of the sodium iodide (NaI) detectors frequently used in airborne spectrometry. Its energy resolution however, is 20 times better, giving more accurate identification of radionuclides, especially when complex spectra are involved. The use of the germanium detector in mobile gamma-ray spectrometry provides a large amount of qualitative and quantitative information. In post-accident situations a germanium detector will be sufficient, and should therefore be used in preference to a NaI detector. An algorithm for detecting the total absorption peaks by studying the variations in the spectral profile of germanium gamma-ray spectra has been developed at the CEA. The use of digital filters that take into account the characteristics of the absorption peaks reduces the statistical fluctuations, making possible detection based on the analysis of the first and second derivatives. The absorption peak is then estimated by subtracting the background noise modelled in the detection window. This method of analysis offers the advantage of not requiring prior knowledge of the number or nature of the radionuclides to be detected. A study has been carried out to assess the specific performances of this detection software in different situations: average background noise in France and detection of artificial sources with varying activity levels. This analysis showed that the performance of our detection algorithm is very close to the theoretical detection limits, for both natural and artificial radionuclides. This algorithm is therefore well suited to the germanium type of spectral profile and to low count rates

  12. Analysis of burnt nuclear fuel elements by gamma-spectrometry

    International Nuclear Information System (INIS)

    Gamma-spectrometry allows a non-destructive determination of the fission and activation product content of spent nuclear fuel. The concentration of some of these products depends significantly on the so-called fuel parameters which describe the irradiation history and the fuel composition. The use of these dependences for deriving ''unknown fuel parameters'' from measured fission product activities is investigated in this work. Relevant application fields are burnup determination, fuel testing and inspections within the nuclear materials safeguards programme. The present thesis investigates how these dependences can be used to derive unknown fuel parameters. The possibilities and basic limitations of deriving information from a measured gamma spectrum are considered on principle. The main conclusion is that only ratios of fission product activities allow the development of an interpretation method which is generally applicable to all types of fuel from different reactors. The dependence of activity ratios on cooling time, irradiation time, integrated and final neutron flux, fuel composition, as well as fission and breeding rates are then investigated and presented graphically in a way suitable for applicaton. These relationships can be used for the analysis of spent fuel, and the detailed procedures, which depend on the applicaton field, are worked out in this work. In order to test the interpretation methods, samples of nuclear fuel have been irradiated and the gamma spectra analysed. The methods developed in this work can be applied successfully to the analysis of burnt fuel in the frame of fuel testing programmes and to safeguards verification purposes. If however, apart from a gamma spectrum, no information on the investigated fuel is available, the above-mentioned parameters can be derived with low accuracy only. (author)

  13. Gamma ray spectrometry results from core samples collected for RESUME 95

    Energy Technology Data Exchange (ETDEWEB)

    Sanderson, D.C.W.; Allyson, J.D. [SURRC, East Kilbride, Scotland (United Kingdom); Toivonen, H.; Honkamaa, T. [STUK, Helsinki (Finland)

    1997-12-31

    Field sampling of an airfield at Vesivehmaa, near Vaeaeksy, Finland (Area I) was carried out between 26-29 May 1995, to establish the radionuclide deposition and inventory of Chernobyl derived {sup 137}Cs, and natural radionuclides. The objective was to establish a common calibration site for in-situ and airborne gamma spectrometers, for Exercise RESUME 95 conducted in August 1995. The report presents the sampling details, handling and treatment. The analyses are discussed with particular emphasis given to {sup 137}Ca, {sup 134}Cs, {sup 40}K, {sup 214}Bi and {sup 208} radionuclides, and the quantification of their respective deposition and inventories. The results have been used to estimate the effective concentrations of nuclides at the calibration site for in-situ and airborne gamma spectrometry, and the depth distribution. For {sup 137}Cs the weighted mean activity per unit area takes on values of 50.7{+-}5.2 kBq m{sup -2} at 1 m ground clearance, 51.1{+-}6.9 kBq m{sup -2} at 50 m height and 47.9{+-}8.5 kBq m{sup -2} at 100 m. The similarity of these values confirms the suitability of the Vesivehmaa site for comparison of in-situ and airborne results despite variations of a factor of two between results from individual cores. The mean {alpha}/{rho} value for {sup 137}Cs in Area I is 0.77{+-}0.10 cm{sup 2}g{sup -1} (relaxation mass per unit area, {beta} 1.31{+-}0.15 gcm{sup -2}). Additional soil sampling across parts of Area II (a 6x3 km area selected for mapping Chernobyl deposition) was carried out. The mean level of {sup 137}Cs activity from these samples was 92.4{+-}63 kBq m{sup -2}, a sample taken near Laihansuo showing the largest value obtained at 172 kBq m{sup -2}. (EG). 17 refs.

  14. Determination of percentage 235U in depleted uranium by combination of gamma spectrometry and potentiometry and comparison with thermal ionisation mass spectrometry

    International Nuclear Information System (INIS)

    A gamma ray spectrometric method has been developed for the determination of percentage 235U in the depleted uranium samples. The concentration of 235U was determined by gamma spectrometry while that of total uranium by potentiometry. The values compared well with those obtained by thermal ionisation mass spectrometry. A value of 0.614± 0.006 and 0.617 ± 005 were obtained by gamma spectrometry and thermal ionisation mass spectrometry respectively for a set of ten measurements. (author)

  15. Characterization of radioactive orphan sources by gamma spectrometry

    International Nuclear Information System (INIS)

    The sealed radioactive sources are widely applicable in industry. They must have a permanent control and must be registered with the Technical Office of the National Authority (OTAN). However, at times it has identified the presence of abandoned sealed sources unknown to the owner. These sources are called 'orphan sources'. Of course these sources represent a high potential risk because accidents can trigger dire consequences depending on your activity and chemical form in which it presents the radioisotope. This paper describes the process and the actions taken to characterize two orphan radioactive sources from the smelter a Aceros Arequipa. For characterization we used a gamma spectrometry system using a detector NaI(Tl) 3″ x 3″ with a multichannel analyzer Nucleus PCA-II. The radioisotope identified was cesium - 137 (137Cs) in both cases. Fortunately, the sources maintained their integrity would otherwise have generated significant pollution considering the chemical form of the radioisotope and easy dispersion. (author)

  16. Determination of Natural Radioactivity in Building Materials with Gamma Spectrometry

    International Nuclear Information System (INIS)

    In the setting of this work, the natural radioactivity of building materials used in Tunisia has been measured by gamma spectrometry. These products have been ground and dried at 100 degree for 12 h. Then, they have been homogenized, weighed and finally conditioned during 23 days in order to reach the radioactive equilibrium. The measures' results proved that all building materials studied except bauxite and the ESC clay, possess doses lower than the acceptable limit (1 mSv.an-1). However, the possibility of reinforcement of the natural radioactivity in some industry of building can exist. To insure that the cement, the most used in the world, don't present any radiological risk on the workers' health, a survey has been made in the factory - les Ciments de Bizerte - about its manufacture's process. The results of this survey showed that this product can be considered like a healthy product.

  17. Control of quality in spectrometry gamma of low level

    CERN Document Server

    Salazar, A

    1997-01-01

    Low level gamma spectrometry is a very precise technique to measure the concentration of nuclides present in different samples in Bq kg sup - sup 1. The quality control of the procedure and method used can be carried out by intercomparison exercises with world recognized institutions. During the last three years the Nuclear Physics Laboratory Of The University of Costa Rica (LAFNA) has been participating in the international quality assessment program (QAP) carried out by the Environmental Measurements Laboratory (EML), department of Energy, USA. The results show a very good agreement with the rest of the participant laboratories. This provides a very objective evaluation of the high precision of the methods used by LAFNA in low level spectroscopy measurements. (Author)

  18. In situ gamma spectrometry intercomparison in Fukushima, Japan

    International Nuclear Information System (INIS)

    Intercomparison of in situ gamma spectrometry was organized at a site contaminated by the radioactive fallout that originated from the Fukushima Dai-ichi Nuclear Power Plant accident. This intercomparison was conducted by eight teams from four different institutions, which have contributed to the government-led project to construct distribution maps of radionuclides deposited on the ground soil. The resultant 134Cs and 137Cs inventories evaluated by the participants agreed within 6% of the coefficient of variation, after correction for inhomogeneous distribution of the dose rate in air. The evaluated 40K inventories agreed within 4% of the coefficient of variation. The authors estimated that these results were in good agreement for creating distribution maps of the radionuclide inventory in the ground soil. (author)

  19. Control of quality in spectrometry gamma of low level

    International Nuclear Information System (INIS)

    Low level gamma spectrometry is a very precise technique to measure the concentration of nuclides present in different samples in Bq kg-1. The quality control of the procedure and method used can be carried out by intercomparison exercises with world recognized institutions. During the last three years the Nuclear Physics Laboratory Of The University of Costa Rica (LAFNA) has been participating in the international quality assessment program (QAP) carried out by the Environmental Measurements Laboratory (EML), department of Energy, USA. The results show a very good agreement with the rest of the participant laboratories. This provides a very objective evaluation of the high precision of the methods used by LAFNA in low level spectroscopy measurements. (Author)

  20. Airborne gamma-ray spectrometer and magnetometer survey: Sleetmute quadrangle (Alaska). Final report

    International Nuclear Information System (INIS)

    During the months of July, August, and September 1979 an airborne high sensitivity gamma-ray spectrometer and magnetometer survey was carried out over ten 30 x 10 NTMS quadrangles of West-Central Alaska. The results obtained over Sleetmute map are discussed. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps, flight path maps, and computer printer maps. The histograms and the multiparameter profiles are presented with the anomaly maps and flight path map in a separate bound volume

  1. Airborne gamma-ray spectrometer and magnetometer survey: Ophir quadrangle (Alaska). Final report

    International Nuclear Information System (INIS)

    During July, August, and September 1979, an airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten 30 x 10 NTMS quadrangles of West-Central Alaska. The results obtained over the Ophir map area. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps, flight path maps; and computer printer maps. The histograms and the multiparameter profiles are presented with the anomaly maps and flight path map in a separate bound volume

  2. Airborne gamma-ray spectrometer and magnetometer survey, Meade River Quadrangle, Alaska. Final report

    International Nuclear Information System (INIS)

    The results obtained from an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over the Meade River map area of Alaska are presented. Based on the criteria outlined in the general section on interpretation, a total of eight uranium anomalies have been outlined on the interpretation map. Most of these are only weakly to moderately anomalous. Zones 3 and 7 are relatively better than the others though none of the anomalies are thought to be of any economic significance. No follow-up work is recommended

  3. Airborne gamma-ray spectrometer and magnetometer survey: north/south tieline. Final report

    International Nuclear Information System (INIS)

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted along the 990 longitude meridian from the Canadian border southward to the Mexican border. A total of 1555 line miles of geophysical data were acquired and, subsequently, compiled. The north-south tieline was flown as part of the National Uranium Resources Evaluation. NURE is a program of the US Department of Energy's Grand Junction, Colorado, office to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  4. Airborne gamma-ray spectrometer and magnetometer survey: McGrath Quadrangle (Alaska). Final report

    International Nuclear Information System (INIS)

    During the months of July, August, and September 1979, an airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten 30 x 10 NTMS quadrangle of West-Central Alaska. The results obtained over the McGrath map area are discussed. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps, flight path maps, and computer printer maps. The histograms and the multiparameter profiles are presented with the anomaly maps and flight path map in a separate volume

  5. Integrated evaluation of the geology, aero gamma spectrometry and aero magnetometry of the Sul-Riograndense Shield, southernmost Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Leo A.; Savian, Jairo F., E-mail: leo.hartmann@ufrgs.br [Universidade Federal do Rio Grande do Sul (UFRS), Porto Alegre, RS (Brazil). Instituto de Geociencias; Lopes, William R. [Servico Geologico do Brasil (CPRM), Porto Alegre, RS (Brazil). Gerencia de Geologia e Mineracao

    2016-03-15

    An integrated evaluation of geology, aero gamma spectrometry and aero magnetometry of the Sul-Riograndense Shield is permitted by the advanced stage of understanding of the geology and geochronology of the southern Brazilian Shield and a 2010 airborne geophysical survey. Gamma rays are registered from the rocks near the surface and thus describe the distribution of major units in the shield, such as the Pelotas batholith, the juvenile São Gabriel terrane, the granulite-amphibolite facies Taquarembo terrane and the numerous granite intrusions in the foreland. Major structures are also observed, e.g., the Dorsal de Cangucu shear. Magnetic signals register near surface crustal compositions (analytic signal) and total crust composition (total magnetic signal), so their variation as measured indicates either shallow or whole crustal structures. The Cacapava shear is outstanding on the images as is the magnetic low along the N-S central portion of the shield. These integrated observations lead to the deepening of the understanding of the largest and even detailed structures of the Sul-Riograndense Shield, some to be correlated to field geology in future studies. Most significant is the presence of different provinces and their limits depending on the method used for data acquisition - geology, aero gamma spectrometry or aero magnetometry. (author)

  6. Integrated evaluation of the geology, aero gamma spectrometry and aero magnetometry of the Sul-Riograndense Shield, southernmost Brazil

    International Nuclear Information System (INIS)

    An integrated evaluation of geology, aero gamma spectrometry and aero magnetometry of the Sul-Riograndense Shield is permitted by the advanced stage of understanding of the geology and geochronology of the southern Brazilian Shield and a 2010 airborne geophysical survey. Gamma rays are registered from the rocks near the surface and thus describe the distribution of major units in the shield, such as the Pelotas batholith, the juvenile São Gabriel terrane, the granulite-amphibolite facies Taquarembo terrane and the numerous granite intrusions in the foreland. Major structures are also observed, e.g., the Dorsal de Cangucu shear. Magnetic signals register near surface crustal compositions (analytic signal) and total crust composition (total magnetic signal), so their variation as measured indicates either shallow or whole crustal structures. The Cacapava shear is outstanding on the images as is the magnetic low along the N-S central portion of the shield. These integrated observations lead to the deepening of the understanding of the largest and even detailed structures of the Sul-Riograndense Shield, some to be correlated to field geology in future studies. Most significant is the presence of different provinces and their limits depending on the method used for data acquisition - geology, aero gamma spectrometry or aero magnetometry. (author)

  7. Radioisotopic characterization of a Cuban peloid by gamma spectrometry

    International Nuclear Information System (INIS)

    Peloids or thermal muds are complex colloidal systems with known therapeutic properties. In Cuba, peloids have been used for more than two centuries in an empiric way. The chemical characterization of these matrixes will help to obtain scientific bases to understand the behavior of bioactive and toxic elements in different human pathologies, as well as, spreading their use in medical treatments. The use of nuclear analytical techniques is suitable to characterize mainly the inorganic (including radioactive isotopes) phase of peloids. The objective of this work was to determine the natural and artificial radionuclides (gamma emitters) in the San Diego de los Banos peloid (Pinar del Rio, Cuba) by means of gamma spectrometry. The spectra show that the most significant radionuclides are 40K, 137Cs, and those from 238U and 232Th decay series. The activity concentrations of these radionuclides are in good agreement with those from regions of normal radioactive background. These results are consistent with references for similar sediments; nevertheless, 137Cs has been reported for the first time in Cuban peloids. (Author)

  8. Burn-up measurements coupling gamma spectrometry and neutron measurement

    International Nuclear Information System (INIS)

    The need to apply for burn-up credit arises with the increase of the initial enrichment of nuclear fuel. When burn-up credit is used in criticality safety studies, it is often necessary to confirm it by measurement. For the last 10 years, CANBERRA has manufactured the PYTHON system for such measurements. However, the method used in the PYTHON itself uses certain reactor data to arrive at burn-up estimates. Based on R and D led by CEA and COGEMA in the framework of burn-up measurement for burn-up credit and safeguards applications, CANBERRA is developing the next generation of burn-up measurement device. This new product, named SMOPY, is able to measure burn-up of any kind of irradiated fuel assembly with a combination of gamma spectrometry and passive neutron measurements. The measurement data is used as input to the CESAR depletion code, which has been developed and qualified by CEA and COGEMA for burn-up credit determinations. In this paper, we explain the complementary nature of the gamma and neutron measurements. In addition, we draw on our previous experience from PYTHON system and from COGEMA La Hague to show what types of evaluations are required to qualify the SMOPY system, to estimate its uncertainties, and to detect discrepancies in the fuel data given by the reactor plant to characterize the irradiated fuel assembly. (authors)

  9. Laboratory of High resolution gamma spectrometry; Laboratorio de espectrometria gamma de alta resolucion

    Energy Technology Data Exchange (ETDEWEB)

    Mendez G, A.; Giber F, J.; Rivas C, I.; Reyes A, B

    1992-01-15

    The Department of Nuclear Experimentation of the Nuclear Systems Management requests the collaboration of the Engineering unit for the supervision of the execution of the work of the High resolution Gamma spectrometry and low bottom laboratory, using the hut of the sub critic reactor of the Nuclear Center of Mexico. This laboratory has the purpose of determining the activity of special materials irradiated in nuclear power plants. In this report the architecture development, concepts, materials and diagrams for the realization of this type of work are presented. (Author)

  10. A multivariate spatial interpolation of airborne {\\gamma}-ray data using the geological constraints

    CERN Document Server

    Guastaldi, E; Bezzon, G P; Broggini, C; Buso, G P; Caciolli, A; L., Carmignani; Callegari, I; Colonna, T; Dule, K; Fiorentini, G; Xhixha, M Kaçeli; Mantovani, F; Massa, G; Menegazzo, R; Mou, L; Alvarez, C Rossi; Strati, V; Xhixha, G; Zanon, A

    2013-01-01

    In this paper we present maps of K, eU, and eTh abundances of Elba Island (Italy) obtained with a multivariate spatial interpolation of airborne {\\gamma}-ray data using the constraints of the geologic map. The radiometric measurements were performed by a module of four NaI(Tl) crystals of 16 L mounted on an autogyro. We applied the collocated cokriging (CCoK) as a multivariate estimation method for interpolating the primary under-sampled airborne {\\gamma}-ray data considering the well-sampled geological information as ancillary variables. A random number has been assigned to each of 73 geological formations identified in the geological map at scale 1:10,000. The non-dependency of the estimated results from the random numbering process has been tested for three distinct models. The experimental cross-semivariograms constructed for radioelement-geology couples show well-defined co-variability structures for both direct and crossed variograms. The high statistical correlations among K, eU, and eTh measurements a...

  11. New approach in add-on multi-channel analyser for gamma ray spectrometry

    International Nuclear Information System (INIS)

    A recently developed add-on card for data acquisition from National Instrument has the possibility of being employed in the field of the gamma ray spectrometry as an industrial and teaching tool. The card's technical capability, the operating program designed for gamma spectrometry and results of the system's reliability, dynamic characteristics, limits in data processing and the quality of the obtainable gamma spectra are given. The advantages and deficiencies as well as important features are emphasised when prompt gamma analysis is of interest in industrial applications and educational issues

  12. Emergency response exercise of laboratories equipped with gamma spectrometry

    International Nuclear Information System (INIS)

    Seven laboratories equipped with semiconductor gamma spectrometry (HPGe detectors) are currently included in the Radiation Monitoring Network (RMN) in the Czech Republic. These laboratories have more than 30 spectrometric chains and approximately 20 'experts' and 70 'users' who would guarantee measurements during the radiological emergency (RE). The emergency exercise was carried out in 5 of them in 2014 (in 4 of them also in 2013). The aim was to test repeatedly their capacity in existing technical facilities and with current staff in the event of a RE and identify problems (bottlenecks) in the whole process from receipt of samples to entering the results into the central database of RMN. Duration of the exercise was 12 hours, due to the shortage of staff; work in one 12-hour shift is presumed during a RE, which the laboratories should be able to provide for 14 days. These exercise samples covered a wide range of commodities that would probably come to the laboratories during the RE (aerosol filters, sorbents for sorption of gaseous forms of iodine, fallout, surface and drinking waters, food chain components and soils). Some of the samples were previously spiked with 85Sr, 88Y and 40K (in the exercise these nuclides represented actual contamination that would occur in RE); liquid samples were spiked with 85Sr and 88Y and bulk materials with 40K.During the exercise almost 800 samples were analysed; in addition, the automatic gamma counter (GA) in Prague laboratory measured other 90 samples automatically during the night (samples were prepared during the day-shift). On the basis of the results the total measuring capacity of the laboratories of RMN CR was estimated at about 1300 samples per day. (authors)

  13. Airborne gamma ray measurements conducted during an international trial in Finland

    International Nuclear Information System (INIS)

    The Scottish Universities Research and Reactor Centre (SURRC) contributed to the RESUME 95 exercise by developing the calibration site at Vesivehmaa, and by participating in the airborne gamma spectrometry (AGS) part of the study. This report provides a full technical description of the AGS results from the SURRC team. The AGS tasks included fallout mapping of a 6x3 km area in central Finland with nominal 150 m line spacing, and a time constrained search for an undisclosed number of hidden radioactive sources. Measurements at the calibration site were also taken to provide a basis for traceable cross comparison between each teams' quantification procedures at a single, well characterised, location. A decision was taken to transport the SURRC AGS system by land and sea, and to utilise a Finnish Twin Star Helicopter chartered from Helijet OY from Rovaniemi and flown by a UK pilot. Prior to departure the SURRC spectrometer, comprising a 16 l. Nal detector and a 50% GMX detector, was checked, and NaI stripping ratios measured using pads, absorbers and active sheets. Installation and CAA approval details were forwarded to Finland, together with the CV of the proposed pilot, to obtain clearances for the operation. Maps of the study area were digitised to form geographical backdrops for the AGS results. The equipment was transported in a single Landrover, via Harwich, north Germany, and Helsinki; a journey taking 2 days and involving 3 overland stages and two ferries. The system was installed at tested in the Helijet aircraft immediately prior to the study. The SURRC team was the first to fly starting at 8.00 am on the day of study. Fallout mapping in Area II was accomplished within the allotted 2 hour period, and the source search conducted in Area III within the allotted hour. Immediately on landing the positions of 3 hidden sources were reported to the organisers, with paper copies of tabular data available within a few minutes of landing, and initial mapping taking

  14. In situ gamma spectrometry development for site mapping

    International Nuclear Information System (INIS)

    The high-resolution gamma spectrometry currently provides a powerful analytical tool for performing environmental measurements. In the context of radiological characterization of a site (natural or artificial radioactivity) and for the dismantling of nuclear installations, mapping of radionuclides is an important asset. The idea is to move a HPGe spectrometer to study the site and from nuclear and position data, to identify, to locate and to quantify the radionuclides present in the soil. The development of this tool follows an intercomparison (ISIS 2007) where an intervention/crisis exercise showed the limits of current tools. The main part of this research project has focused on mapping of nuclear data. Knowledge of the parameters of an in situ spectrum helped to create a simulator, modeling the response of a spectrometer moving over contaminated soil. The simulator itself helped to develop algorithms for mapping and to test them in extreme situations and not realizable. A large part of this research leads to the creation of a viable prototype providing real-time information concerning the identity and locality as possible radionuclides. The work performed on the deconvolution of data can make in post processing a map of the activity of radionuclide soil but also an indication of the depth distribution of the source. The prototype named OSCAR was tested on contaminated sites (Switzerland and Japan) and the results are in agreement with reference measurements. (author)

  15. Fission products control by gamma spectrometry in purex process solutions

    International Nuclear Information System (INIS)

    This paper deals with a radiometric method for fission products analysisby gamma spectrometry. This method will be applied for fission productscontrol at the irradiated material processing facility, under construction inthe Instituto de Pesquisas Energeticas e Nucleares, SP, Brazil. Countinggeometry was defined taking into account the activities of process solutionsto be analysed, the remotely operated aliquotation device of analytical celland the available detection system. Natural and 19,91% enriched uraniumsamples were irradiated at IEAR-1 reactor in order to simulate thecomposition of Purex process solutions. After a short decay time, the sampleswere dissolved with HNO3 and then, conditioned in standard flasks withdefined geometry. The spectra were obtained by a Ge(Li) semiconductordetector and analysed by the GELIGAM software system, losing a floppy-diskconnected to a PDP-11/05 computer. Libraries were prepared and calibrationswere made with standard sources to fit the programs to the analysis offission products in irradiated uranium solutions. It was possible to choosethe best program to be used in routine analysis with the obtained data.(author)

  16. Radon gamma-ray spectrometry with YAP:Ce scintillator

    CERN Document Server

    Plastino, W; De Notaristefani, F

    2002-01-01

    The detection properties of a YAP:Ce scintillator (YAlO sub 3 :Ce crystal) optically coupled to a Hamamatsu H5784 photomultiplier with standard bialkali photocathode have been analyzed. In particular, the application to radon and radon-daughters gamma-ray spectrometry was investigated. The crystal response has been studied under severe extreme conditions to simulate environments of geophysical interest, particularly those found in geothermal and volcanic areas. Tests in water up to a temperature of 100 deg.C and in acids solutions such as HCl (37%), H sub 2 SO sub 4 (48%) and HNO sub 3 (65%) have been performed. The measurements with standard radon sources provided by the National Institute for Metrology of Ionizing Radiations (ENEA) have emphasized the non-hygroscopic properties of the scintillator and a small dependence of the light yield on temperature and HNO sub 3. The data collected in this first step of our research have pointed out that the YAP:Ce scintillator can allow high response stability for rad...

  17. Reliability evaluation studies of aerial gamma spectrometry system

    International Nuclear Information System (INIS)

    The Aerial Gamma Spectrometry System (AGSS) is a field instrument developed in Bhabha Atomic Research Centre for quick qualitative and quantitative assessment of radioactive contamination over large area on ground in case of a major nuclear/radiological emergency. This necessitates the system to be operated for aerial surveys above complex topography and harsh environmental conditions. The AGSS has been designed taking into consideration all operational aspects with allowance for variations in parameters such as current, voltage, temperature, humidity etc. The measures taken at the design stage of the AGSS are intended to ensure the reliability of the system during the survey operations under various environmental conditions. The AGSS has been built around an Industrial Computer and consists of NaI(Tl) Detector, Signal Processing Module and Data Storage and Interface Module, which are PC add-on cards and a Global Positioning System (GPS). The Industrial Computer, GPS and the detector are commercially available and they have undergone reliability assessment by the manufacturer. The reliability assessment studies of the Signal Processing and the Data storage and Interface modules have been done in-house. This paper describes the details of the reliability study carried out on AGSS components. The results of reliability evaluation show that the AGSS will provide reliable service if operated well within the limits of operating conditions during aerial/field surveys. The chances of functional failure of AGSS are found to be less than two times in thousand operations of eight hours duration each. (author)

  18. Neutron activation analysis of lipsticks using gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Neutron activation analysis with gamma-ray spectrometry was used to measure the concentrations of various elements in lipsticks of popular Indian and foreign brands. The aim of the present work was to study the possibility of existence of trace elements in samples of lipsticks (the ingredients of which are mostly organic in nature) and to see whether trace elements could distinguish lipsticks of different Indian and foreign brands from the forensic point of view apart from their inter-se differentiation. In the different samples of lipsticks that were analysed the following elements were detected: Au, Ba, Br, Ca, Cs, Fe, Na, Ru, Sb, Sc, Ta, Yb, Zn, Rb and Se. It was found that inter-se differentiation of lipsticks was possible on the basis of concentrations of trace elements and their profile. Concentration of bromine in samples of lipsticks identified lipsticks of different Indian brands. Samples of lipsticks of Indian and foreign brands could be differentiated on the basis of concentrations of cesium, antimony and scandium which were found to be higher in foreign brands as compared to those in Indian brands. (authors)

  19. Portable Gamma Spectrometry Surveys of Sites in Portugal in Support of the VADOSE Project

    OpenAIRE

    Cresswell, A.; Sanderson, D.; Burbidge, C.

    2012-01-01

    The VADOSE project involves the use of multiple techniques to evaluate dose rate variability on different spatial scales. Several sites in central northern Portugal, mostly in the vicinity of Aveiro, have been investigated. As part of this investigation, portable gamma spectrometry techniques were used to map areas of approximately 100x100m around each sampling location. The SUERC portable gamma spectrometry system used consists of a 3x3” NaI(Tl) spectrometer with integral...

  20. Basic characterization of 233U: Determination of age and 232U content using sector field ICP-MS, gamma spectrometry and alpha spectrometry

    International Nuclear Information System (INIS)

    The possibility to determine the age, i.e. the time since the last chemical separation, of 233U was studied using two fundamentally different measurement techniques: inductively coupled plasma mass spectrometry (ICP-MS) and gamma spectrometry. Moreover, the isotope ratio 232U/233U was measured using both alpha spectrometry and gamma spectrometry. For the two materials analysed, all measurement results were in agreement, i.e. consistent within the combined uncertainties. One of the materials was also measured using gamma spectrometry under field conditions. This measurement was also in agreement with the other results on this material

  1. The 3D inversion of airborne gamma-ray spectrometric data

    Science.gov (United States)

    Minty, Brian; Brodie, Ross

    2016-07-01

    We present a new method for the inversion of airborne gamma-ray spectrometric line data to a regular grid of radioelement concentration estimates on the ground. The method incorporates the height of the aircraft, the 3D terrain within the field of view of the spectrometer, the directional sensitivity of rectangular detectors, and a source model comprising vertical rectangular prisms with the same horizontal dimensions as the required grid cell size. The top of each prism is a plane surface derived from a best-fit plane to the digital elevation model of the earth's surface within each grid cell area. The method is a significant improvement on current methods, and gives superior interpolation between flight lines. It also eliminates terrain effects that would normally remain in the data after the conventional processing of these data assuming a flat-earth model.

  2. The calibration of portable and airborne gamma-ray spectrometers - theory, problems, and facilities

    International Nuclear Information System (INIS)

    A gamma-ray spectrometer for use in geological exploration possesses four stripping ratios and three window sensitivities which must be determined to make the instrumentation applicable for field assay or airborne measurement of potassium, uranium, and thorium contents in the ground. Survey organizations in many parts of the world perform the instrument calibration using large pads of concrete which simulate a plane ground of known radioelement concentration. Calibration and monitoring trials with twelve facilities in ten countries prove that moisture absorption, radon exhalation, and particle-size effects can offset a radiometric grade assigned to concrete whose aggregate contains an embedded radioactive mineral. These and other calibration problems are discussed from a combined theoretical and practical viewpoint. (author)

  3. Methods for the analysis of the overlapped peaks in analytical gamma-spectrometry

    International Nuclear Information System (INIS)

    A new simple method for the quantitative analysis of the doublet peaks in Ge(Li) or HPGe gamma-spectrometry is presented. No assumptions on the shape of the peaks in gamma-ray spectra being measured are required. Special feature of the method proposed is its usefulness for the analysis of closed doublets. 7 refs., 6 figs. (author)

  4. Corrections for self-attenuation in gamma-ray spectrometry of bulk samples

    International Nuclear Information System (INIS)

    On the basis of the measurement of over 70 radioactive standard bulk sources with different matrix density and different shapes, the gamma-ray self-attenuation corrections needed in activity determination by means of gamma-ray spectrometry are evaluated. The full-energy peak efficiency dependence on the density, and the self-attenuation correction dependence on the photon energy are described

  5. Mapping Forest Species Composition Using Imaging Spectrometry and Airborne Laser Scanner Data

    Science.gov (United States)

    Torabzadeh, H.; Morsdorf, F.; Leiterer, R.; Schaepman, M. E.

    2013-09-01

    Accurate mapping of forest species composition is an important aspect of monitoring and management planning related to ecosystem functions and services associated with water refinement, carbon sequestration, biodiversity, and wildlife habitats. Although different vegetation species often have unique spectral signatures, mapping based on spectral reflectance properties alone is often an ill-posed problem, since the spectral signature is as well influenced by age, canopy gaps, shadows and background characteristics. Thus, reducing the unknown variation by knowing the structural parameters of different species should improve determination procedures. In this study we combine imaging spectrometry (IS) and airborne laser scanning (ALS) data of a mixed needle and broadleaf forest to differentiate tree species more accurately as single-instrument data could do. Since forest inventory data in dense forests involve uncertainties, we tried to refine them by using individual tree crowns (ITC) position and shape, which derived from ALS data. Comparison of the extracted spectra from original field data and the modified one shows how ALS-derived shape and position of ITCs can improve separablity of the different species. The spatially explicit information layers containing both the spectral and structural components from the IS and ALS datasets were then combined by using a non-parametric support vector machine (SVM) classifier.

  6. Emergency response exercise of laboratories equipped with gamma spectrometry

    International Nuclear Information System (INIS)

    At present 7 laboratories equipped with semiconductor gamma spectrometry (HPGe detectors) are included in the Radiation Monitoring Network (RMN) in the Czech Republic. These laboratories have 31 spectrometric chains and approximately 20 'experts' and 70 'users' who would guarantee measurements during a radiological emergency (RE). The stress exercise (a load test) was carried out in 4 of them. The aim was to test their measuring capacity in existing technical facilities and staff in the event of a RE and identify problems (bottlenecks) in the whole process from receipt of samples to entering the results into the central database of RMN. Duration of the exercise was 8 to 14 hours. Due to lack of staff, work in one 12-hour shift during a RE is presumed, which the laboratories should be able to provide for 14 days. Exercise samples covered a wide range of commodities that would probably come to the laboratories during RE (aerosol filters, adsorbed gaseous forms of iodine, fallout, surface and drinking waters, food chain components and soils). Some of the samples were previously spiked with 85Sr, 88Y and 40K (these nuclides represented actual nuclides that would occur in RE); soil samples contained higher values of 137Cs activity originating from the Chernobyl accident. Almost 40 employees took part in the exercise and measurements were carried out at 18 spectrometric chains. An automatic gamma counter which allows automatic operation of two HPGe detectors including the analysis of the spectra with a storage for up to 180 sample containers was operating in one of the laboratories involved in the exercise. The procedures in individual laboratories varied slightly depending on the staff and laboratory space available. During the exercise about 700 samples were evaluated; in addition, gamma-automat measured other 80 samples in the 'night shift'. 700 samples, this means 40 samples per a spectrometric chain or, from another point of view, 18 samples per man. The main

  7. Emergency response exercise of laboratories equipped with gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mala, Helena; Rulik, Petr; Jezkova, Tereza; Beckova, Vera [National Radiation Protection Institute (SURO), 140 00 Praha 28 (Czech Republic)

    2014-07-01

    At present 7 laboratories equipped with semiconductor gamma spectrometry (HPGe detectors) are included in the Radiation Monitoring Network (RMN) in the Czech Republic. These laboratories have 31 spectrometric chains and approximately 20 'experts' and 70 'users' who would guarantee measurements during a radiological emergency (RE). The stress exercise (a load test) was carried out in 4 of them. The aim was to test their measuring capacity in existing technical facilities and staff in the event of a RE and identify problems (bottlenecks) in the whole process from receipt of samples to entering the results into the central database of RMN. Duration of the exercise was 8 to 14 hours. Due to lack of staff, work in one 12-hour shift during a RE is presumed, which the laboratories should be able to provide for 14 days. Exercise samples covered a wide range of commodities that would probably come to the laboratories during RE (aerosol filters, adsorbed gaseous forms of iodine, fallout, surface and drinking waters, food chain components and soils). Some of the samples were previously spiked with {sup 85}Sr, {sup 88}Y and {sup 40}K (these nuclides represented actual nuclides that would occur in RE); soil samples contained higher values of {sup 137}Cs activity originating from the Chernobyl accident. Almost 40 employees took part in the exercise and measurements were carried out at 18 spectrometric chains. An automatic gamma counter which allows automatic operation of two HPGe detectors including the analysis of the spectra with a storage for up to 180 sample containers was operating in one of the laboratories involved in the exercise. The procedures in individual laboratories varied slightly depending on the staff and laboratory space available. During the exercise about 700 samples were evaluated; in addition, gamma-automat measured other 80 samples in the 'night shift'. 700 samples, this means 40 samples per a spectrometric chain or, from

  8. Field GE gamma spectrometry for on site measurements of some parameters characterizing radon-222 exhalation rates from soils and covers

    International Nuclear Information System (INIS)

    We describe a new method based on differential gamma spectrometry for on site determination of some of the parameters which are relevant for the production of radon 222 in soil gas and its transfer from soil to indoor and outdoor atmospheres. This method is investigated in the context of a 3-year Slovenian-French cooperation programme, the PROTEUS project. We are currently using a germanium detector of 100 cm3. The height of the 20 deg. C collimated detector above the soil surface is from 1.5 to 3 m when using a tripod. This arrangement provides results which are representative of soil areas ranging from 1 to 4 square metres. Routine measurements would require larger detector volumes. The main objective is to provide technology and methodology for an efficient mapping of zones with potential for being the source of a high level of indoor radon, eliminating the need for soil sampling followed by laboratory analysis. The feasibility of an airborne mapping laboratory flying at low altitude will be investigated. Another objective is the rapid measurement of radon profiles across covers used to reduce exhalation rates from the surface of a pile of tailings, with characterisation of the influence of humidity content of the top layer. Airborne survey would allow for measuring exhalations from surfaces of slurries not otherwise accessible. (author)

  9. Continuous gamma-ray spectrometry in the Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Gamma-ray continua have been measured at startup in the Fast Flux Test Facility (FFTF). A special FFTF insert, called the In-Reactor Thimble (IRT), provided an adequate environment for in-situ operation of the gamma spectrometer. The IRT replaced a fuel assembly near core center (No. 2101) and measurements were conducted at three axial locations, namely midplane, the lower axial shield, and the upper axial reflector. Observations were carried out with Compton Recoil Gamma-Ray Spectrometry at the state-of-the-art. Advantage was thereby taken of the most recent advances, including extension of gamma-ray spectrometry up to roughly 7 MeV with the new in-situ Janus detector probe. On this basis, in-core gamma-ray continua results are presented for FFTF

  10. Determination of uranium in aqueous attenuating samples using gamma-ray spectrometry.

    Science.gov (United States)

    Agarwal, Chhavi; Kalsi, P C; Mhatre, A; Goswami, A

    2007-12-01

    In the present work, a method for determination of uranium concentration in aqueous solution in standard geometry from attenuating samples has been developed based on modification of the empirical approach of Venkataraman and Croft [2003. Determination of plutonium mass using gamma-ray spectrometry. Nucl. Instrum. Methods Phys. Res. A 505, 527-530]. The method makes use of the multiple gamma (gamma)-rays emitted by 235U and depends on the empirical relation between apparent mass of the sample and gamma-ray energy. It was possible to determine uranium concentration in the range of 12-400mg/ml rapidly by this method without applying transmission corrections. PMID:17768057

  11. Characterization of radioactive orphan sources by gamma spectrometry; Caracterizacion de fuentes huerfanas radiactivas por espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Cruz W, H., E-mail: wcruz@ipen.gob.pe [Instituto Peruano de Energia Nuclear (PGRR/IPEN), Lima (Peru). Planta de Gestion de Residuos Radiactivos

    2013-07-01

    The sealed radioactive sources are widely applicable in industry. They must have a permanent control and must be registered with the Technical Office of the National Authority (OTAN). However, at times it has identified the presence of abandoned sealed sources unknown to the owner. These sources are called 'orphan sources'. Of course these sources represent a high potential risk because accidents can trigger dire consequences depending on your activity and chemical form in which it presents the radioisotope. This paper describes the process and the actions taken to characterize two orphan radioactive sources from the smelter a Aceros Arequipa. For characterization we used a gamma spectrometry system using a detector NaI(Tl) 3″ x 3″ with a multichannel analyzer Nucleus PCA-II. The radioisotope identified was cesium - 137 ({sup 137}Cs) in both cases. Fortunately, the sources maintained their integrity would otherwise have generated significant pollution considering the chemical form of the radioisotope and easy dispersion. (author)

  12. Gamma spectrometry inspection of TRIGA MARK II fuel using caesium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Karimzadeh, S., E-mail: sam.karimzadeh@ati.ac.a [Vienna University of Technology, Institute of Atomic and Subatomic Physics (ATI), Stadionallee 2, A-1020 Vienna (Austria); Khan, R.; Boeck, H. [Vienna University of Technology, Institute of Atomic and Subatomic Physics (ATI), Stadionallee 2, A-1020 Vienna (Austria)

    2011-01-15

    Research highlights: Cs isotopes are the best choices for the burn up determination of spent fuel. Gamma spectrometer calibration using MCNP5. Cs-ratio can be applied by relative calibration method. - Abstract: Gamma spectrometry is one of the common methods to inspect the spent fuel from research reactors. This method has been applied to in-pool measurements of the Spent Fuel Elements (SPEs) of the TRIGA Mark II research reactor. Due to mixed nature of the reactor core and complicated irradiation history of the fuel elements (FEs), the gamma spectrometry of the FE establishes improvements in the calculation and measurement of the SPE. In order to inspect the TRIGA SPE from dry storage and cooled fuel from the reactor pool, the selected spend fuels are scanned and measured using the fuel-scanning machine. Gamma spectrometry is performed by HPGe detector for spend fuel inspection and determination of the {sup 137}Cs activity and {sup 134}Cs/{sup 137}Cs ratio. In this work, the steps of the detector calibration and the use of the Monte Carlo radiation transport code (MCNP5) have been described. In addition, the fuel-scanning machine and the gamma spectrometer are modelled by MCNP5 to simulate the gamma transport from fuel to detector. It also simulate the gamma spectrometer calibration for the burn up determination of the spend fuel. The results from MCNP5 simulation are applied to spectroscopic measurements and compared with the theoretical predictions of the neutronics code ORIGEN2 in this research work.

  13. Gamma spectrometry inspection of TRIGA MARK II fuel using caesium isotopes

    International Nuclear Information System (INIS)

    Research highlights: → Cs isotopes are the best choices for the burn up determination of spent fuel. → Gamma spectrometer calibration using MCNP5. → Cs-ratio can be applied by relative calibration method. - Abstract: Gamma spectrometry is one of the common methods to inspect the spent fuel from research reactors. This method has been applied to in-pool measurements of the Spent Fuel Elements (SPEs) of the TRIGA Mark II research reactor. Due to mixed nature of the reactor core and complicated irradiation history of the fuel elements (FEs), the gamma spectrometry of the FE establishes improvements in the calculation and measurement of the SPE. In order to inspect the TRIGA SPE from dry storage and cooled fuel from the reactor pool, the selected spend fuels are scanned and measured using the fuel-scanning machine. Gamma spectrometry is performed by HPGe detector for spend fuel inspection and determination of the 137Cs activity and 134Cs/137Cs ratio. In this work, the steps of the detector calibration and the use of the Monte Carlo radiation transport code (MCNP5) have been described. In addition, the fuel-scanning machine and the gamma spectrometer are modelled by MCNP5 to simulate the gamma transport from fuel to detector. It also simulate the gamma spectrometer calibration for the burn up determination of the spend fuel. The results from MCNP5 simulation are applied to spectroscopic measurements and compared with the theoretical predictions of the neutronics code ORIGEN2 in this research work.

  14. Statistical interpretation of airborne gamma-ray spectrometric data using factor analysis

    International Nuclear Information System (INIS)

    The statistical technique of factor analysis provides a quantitative and non-subjective means of synthesising and correlationg data from gamma-ray spectrometry surveys. Factor analysis was applied to data from an aerial survey of the Freer-Three Rivers area in South Texas. Variables used were corrected count-rates for potassium, uranium, and thorium, total count, and the ratios 214Bi/40K, 214Bi/208Tl, and 208Tl/40K. Analysis showed that three factors were sufficient to represent all seven variables. Statistical groupings correspond reasonably well to the mapped formations in the area, but some patterns suggest geological complexities which do not appear on available maps. The analysis identifies unusual groupings that are unlike surrounding patterns; many of these occur over known oil and gas pools and appear to indicate geochemically abnormal ground. (author)

  15. Determination of chemical composition of individual airborne particles by SEM/EDX and micro-Raman spectrometry: A review

    Science.gov (United States)

    Stefaniak, E. A.; Buczynska, A.; Novakovic, V.; Kuduk, R.; Van Grieken, R.

    2009-04-01

    The strategies for sampling and analysis by SEM/EDX and micro-Raman spectrometry for individual airborne particles analysis as applied at the University of Antwerp (Belgium) by the MITAC group have been reviewed. Microbeam techniques provide detailed information concerning the origin, formation, transport, reactivity, transformation reactions and environmental impact of particulate matter. Moreover, some particles of certain chemical properties have been recognized as a threat for human health and cultural heritage objects. However, the small sizes of particles result in specific problems with respect to single particle analysis. Development of equipment and software for improvement of analysis and quantification are reported.

  16. An airborne gamma ray survey of parts of SW Scotland in February 1993. Final Report

    International Nuclear Information System (INIS)

    An airborne gamma ray survey was conducted for the Scottish Office Environment Department of coastal and inland parts of SW Scotland to define existing background levels, to locate features worthy of further attention, and to demonstrate the emergency response capabilities of radiometric methods. Coastal areas were surveyed with 500 m line spacing. Inland areas were specified to 2 km line spacing, however it was possible to achieve 1 km line spacing in the majority of the inland zone. The radiometric maps show clearly the distributions of each individual nuclide and indicate the contribution which individual localised features make to the overall gamma ray dose rate. Naturally occurring nuclides reflect the underlying geological and geomorphological contexts of the landscapes. The main granite intrusions, most notably at Cairnsmore of Fleet, the Loch Doon Granodiorite, Glencairn of Carsphairn, the Dalbeattie granite, and Criffel Pluton are readily visible in 40K, 214Bi and 208Tl maps, and control their local radiation environments. A number of areas of enhanced 214Bi, which may reflect radon potential, were noted. A transient radon associated 214Bi signal was observed on the west of the Wigtown peninsular during the survey. Examination of spectral data in the vicinity Dundrennan has confirmed that there is no evidence of widespread terrestrial contamination arising from the use of depleted uranium projectiles on the range. The 137Cs map indicates the environmental distribution of this nuclide in considerable detail. Levels of 137Cs range from approximately 2 kBq m-2, a level consistent with global weapons' testing fallout, from 2-40 kBq m-2 on terrestrial sites affected by deposition from the Chernobyl accident, and from 40 kBq m-2 to over 200 kBq m-2 on tide washed pastures which have accumulated marine sediments from the Irish sea. (author)

  17. The Dortmund Low Background Facility - Low-background gamma ray spectrometry with an artificial overburden.

    Science.gov (United States)

    Gastrich, Holger; Gößling, Claus; Klingenberg, Reiner; Kröninger, Kevin; Neddermann, Till; Nitsch, Christian; Quante, Thomas; Zuber, Kai

    2016-06-01

    The Dortmund Low Background Facility is an instrument for low-level gamma ray spectrometry with an artificial overburden of ten meters of water equivalent, an inner shielding, featuring a neutron absorber, and an active muon veto. An integral background count rate between 40keV and 2700keV of (2.528±0.004)counts/(kgmin) enables low-background gamma ray spectrometry with sensitivities in the range of some 10mBq/kg within a week of measurement time. PMID:27082973

  18. TL dating: low background gamma spectrometry as a tool for the determination of the annual dose

    International Nuclear Information System (INIS)

    The analysis of the natural radioactivity of archaeological artefacts for thermoluminescence (TL) dating is now realized in the CRIAA TL laboratory (Bordeaux) by low background gamma spectrometry. An original calibration procedure permits the non-destructive measurement of natural radioelement contents (K, U and Th) and the control of the equilibrium state of the U series (loss of 222Rn, ratio of activities 238U/226Ra). An intercomparison of analytical methods has shown the excellent potentialities of gamma spectrometry. The low detection limits and the easy implementation make this method particularly suitable for determining the annual dose for TL dating. (author)

  19. Computer programs for data reduction and interpretation in plutonium and uranium analysis by gamma ray spectrometry

    International Nuclear Information System (INIS)

    Non destructive gamma ray have been developed for analysis of isotopic abundances and concentrations of plutonium and uranium in the respective product solutions of a reprocessing plant. The method involves analysis of gamma rays emitted from the sample and uses a multichannel analyser system. Data reduction and interpretation of these techniques are tedious and time consuming. In order to make it possible to use them in routine analysis, computer programs have been developed in HP-BASIC language which can be used in HP-9845B desktop computer. A set of programs, for plutonium estimation by high resolution gamma ray spectrometry and for on-line measurement of uranium by gamma ray spectrometry are described in this report. (author) 4 refs., 3 tabs., 6 figs

  20. Gamma spectrometry application for steam generators radiological characterization

    International Nuclear Information System (INIS)

    radioactivity inside the SG should be known. This stage is the radiological characterization step. The radiological characterization and the radioactivity inventory for decommissioning purpose is an evaluation of internal contamination and activation in order to plan the best procedure for decontamination. As part of the decommissioning of Chooz A, after the decontamination of the steam generators, it is planned to classify these equipments as waste of Very Low Activity in accordance with the ANDRA acceptance criteria. In this context, our objective about the calculation of IRAS's (Index Radiological Acceptance in Storage) is double: - Determination of IRAS overall value of the steam generators - Determination of IRAS value of the plugged tubes in the SG (little or no decontamination) Based on a feasibility study for measuring the activity in the SGs thru gamma spectrometry, we developed a specific design of the measuring system and implementation to characterize SGs decontaminated on site. In this paper we present our approach which has been to: - Achieve a faithful model consisting of three term source including specific calculation method - Perform precise measurements thru: - design of 'a ring structure' to perform several measurements simultaneously - definition of the detectors and the measuring electronics We defined the operational procedures of the non-destructive measurements and interpretation of these results has been incorporated into the application for acceptance of ANDRA. (authors)

  1. Airborne gamma-ray spectrometer and magnetometer survey: Ukiah quadrangle, California. Final report

    International Nuclear Information System (INIS)

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 20 x 10 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 10 x 20 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Ukiah, California, map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately eighteen (18) miles apart. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1517 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  2. Airborne gamma-ray spectrometer and magnetometer survey. Volume I. Final report

    International Nuclear Information System (INIS)

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Mariposa, California and Nevada; Fresno, California; and Bakersfield, Caifornia 1:250,000 National Topographic Map Series (NTMS) 10 x 20 quadrangle maps. The survey was a part of DOE's National Aerial Radiometric Reconnaissance (ARR) program, which in turn is a part of the National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer having a large crystal volume, and a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test range. Data quality was ensured throughout the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. These maps were interpreted and an anomaly interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data processing procedures, the data display format, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

  3. Airborne gamma-ray spectrometer and magnetometer survey: Susanville quadrangle, California. Final report

    International Nuclear Information System (INIS)

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 20 x 10 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 10 x 20 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Susanville, California, map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately eighteen (18) miles apart. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1642.8 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  4. Airborne gamma-ray spectrometer and magnetometer survey: Alturas quadrangle, California. Final report

    International Nuclear Information System (INIS)

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 20 x 10 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 10 x 20 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Alturas, California, map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately eighteen (18) miles apart. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1631.6 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  5. Airborne gamma-ray spectrometer and magnetometer survey: Eureka quadrangle, California. Final report

    International Nuclear Information System (INIS)

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 20 x 10 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 10 x 20 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Eureka/Crescent City, California, map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately eighteen (18) miles apart. A total of 16,880.5 line miles of geophysical data were aquired, compiled, and interpreted during the survey, of which 349.5 line miles are in this area. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  6. Airborne gamma-ray spectrometer and magnetometer survey: Huron quadrangle, South Dakota. Final report

    International Nuclear Information System (INIS)

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 20 x 10 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 20 x 10 NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the Huron map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1459 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  7. Airborne gamma-ray spectrometer and magnetometer survey Coos Bay, Oregon. Final report

    International Nuclear Information System (INIS)

    During the months of August, September, and October of 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over ten (10) areas over northern California and southwestern Oregon. These include the 20 x 10 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 10 x 20 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Coos Bay, Oregon, map area. Line spacing was generally six miles for east/west traverses and eighteen miles for north/south tie lines over the northern one-half of the area. Traverses and tie lines were flown at three miles and twelve miles respectively over the southern one-half of the area. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 863.8 line miles are in this quadrangle

  8. Airborne gamma-ray spectrometer and magnetometer survey: Chico quadrangle, California. Final report

    International Nuclear Information System (INIS)

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 20 x 10 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 10 x 20 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Chico, California, map area. Traverse lines were flown in an east-west direction at a line spacing of three. Tie lines were flown north-south approximately twelve miles apart. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 3026.4 line miles are in the quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  9. Airborne gamma-ray spectrometer and magnetometer survey, Medford Quadrangle Oregon. Final report

    International Nuclear Information System (INIS)

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 20 x 10 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 10 x 20 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Medford, Oregon, map area. Traverse lines were flown in an east-west direction at a line spacing of three miles. Tie lines were flown north-south approximately twelve miles apart. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 2925 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  10. Airborne gamma-ray spectrometer and magnetometer survey, Roseburg Quadrangle, Oregon. Final report

    International Nuclear Information System (INIS)

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 20 x 10 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 10 x 20 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Roseburg, Oregon, map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately eighteen (18) miles apart. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1596 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  11. Airborne gamma-ray spectrometer and magnetometer survey Coos Bay, Oregon. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-01

    During the months of August, September, and October of 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over ten (10) areas over northern California and southwestern Oregon. These include the 2/sup 0/ x 1/sup 0/ NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1/sup 0/ x 2/sup 0/ areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Coos Bay, Oregon, map area. Line spacing was generally six miles for east/west traverses and eighteen miles for north/south tie lines over the northern one-half of the area. Traverses and tie lines were flown at three miles and twelve miles respectively over the southern one-half of the area. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 863.8 line miles are in this quadrangle.

  12. Airborne gamma-ray spectrometer and magnetometer survey: Chico quadrangle, California. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 2/sup 0/ x 1/sup 0/ NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1/sup 0/ x 2/sup 0/ areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Chico, California, map area. Traverse lines were flown in an east-west direction at a line spacing of three. Tie lines were flown north-south approximately twelve miles apart. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 3026.4 line miles are in the quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States.

  13. Airborne gamma-ray spectrometer and magnetometer survey: Susanville quadrangle, California. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 2/sup 0/ x 1/sup 0/ NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1/sup 0/ x 2/sup 0/ areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Susanville, California, map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately eighteen (18) miles apart. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1642.8 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States.

  14. Airborne gamma-ray spectrometer and magnetometer survey, Mitchell Quadrangle, South Dakota. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-04-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 2/sup 0/ x 1/sup 0/ NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2/sup 0/ x 1/sup 0/ NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the Mitchell map area. The purpose of this program is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1479 line miles are in this quadrangle.

  15. Airborne gamma-ray spectrometer and magnetometer survey, Mitchell Quadrangle, South Dakota. Final report

    International Nuclear Information System (INIS)

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 20 x 10 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 20 x 10 NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the Mitchell map area. The purpose of this program is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1479 line miles are in this quadrangle

  16. Airborne gamma-ray spectrometer and magnetometer survey: Huron quadrangle, South Dakota. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-04-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 2/sup 0/ x 1/sup 0/ NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2/sup 0/ x 1/sup 0/ NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the Huron map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1459 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States.

  17. Airborne gamma-ray spectrometer and magnetometer survey: Wenatchee, Concrete, quadrangles (Washington). Final report

    International Nuclear Information System (INIS)

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Wenatchee and Concrete, 1:250,000 National Topographic Map Series (NTMS), quadrangle maps. The survey was part of DOE's National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer with a large crystal volume, and with a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test Range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The anomalies were interpreted and an interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data collection procedures, the data processing procedures, the data presentation, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

  18. Airborne gamma-ray spectrometer and magnetometer survey: Iditarod quadrangle (Alaska). Final report

    International Nuclear Information System (INIS)

    During the months of July, August, and September 1979, an airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten 30 x 10 NTMS quadrangles of West-Central Alaska. The results obtained over the Iditarod map area are reported. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps, flight path maps, and computer printer maps. The histograms and the multiparameter profiles are presented with the anomaly maps and flight path map in a separate volume. Anomalous radioactivity levels are encountered in mine locations on the Idatarod quadrangle, on both the uranium and thorium spectral windows. Three of these are relatively restricted, discrete anomalous features. The other six are in two groups of comparatively long intervals variably high in uranium and thorium series radiation, and they are aligned in such a manner as to suggest that their source is in a length zone or formation enriched in uranium and thorium mineralization

  19. Calculation of the decision thresholds in gamma-ray spectrometry

    International Nuclear Information System (INIS)

    A method was developed for calculating the decision thresholds for gamma-ray spectrometric measurements. At the energies where gamma-ray emitters that are present in the nuclide library, but were not identified in the spectrum, radiate, peaks are supposed to appear. The peak areas are calculated by fitting, using the method of least squares, the spectral region of the supposed peaks with a continuous background and the spectrometer response function at the gamma-ray energies where the supposed peaks are positioned. The null measurement uncertainty of a gamma-ray emitter is obtained as the uncertainty of the weighted average of the activities calculated from the areas of the supposed peaks in a spectrum where the specified activity of the gamma-ray emitter is zero. For the calculation of the decision threshold the null measurement uncertainty is used. These decision thresholds overestimate the critical limits calculated with the Currie formula by about 10% in the case of single gamma-ray emitters. For multi-gamma-ray emitters the decision thresholds yield smaller values than the Currie formula. The presence of a peaked background or peaks that are near the supposed peaks increases the decision threshold considerably. - Highlights: • Decision thresholds were calculated for gamma-ray emitters by inducing type-I errors. • Peaks were supposed to appear at energies where the emitters radiate. • In case of a peaked background the peak area was obtained from the background peak area uncertainty. • Decision thresholds were calculated from the uncertainties of the average activities. • The peaked background increases the decision threshold considerably

  20. Results from an interlaboratory exercise on the determination of plutonium isotopic ratios by gamma spectrometry

    International Nuclear Information System (INIS)

    Results form interlaboratory comparison measurements on the determination of plutonium isotopic ratios by gamma spectrometry, organized by the ESARDA Working Group on Techniques and Standards for Nondestructive Analysis, are presented and discussed. Nine laboratories from nine countries or international organizations participated in the intercomparison exercise, which included both laboratories' own measurements on the plutonium isotopic reference materials NBS-SRM 946, 947, 948 and comparison analyses of gamma spectra from these materials distributed to the participating laboratories. Results from the intercomparison analyses have been used to reevaluate some gamma branching intensity ratios required for plutonium isotopic ratio measurements. (orig.)

  1. An optimum analysis sequence for environmental gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    De la Torre, F.; Rios M, C.; Ruvalcaba A, M. G.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J. L., E-mail: fta777@hotmail.co [Universidad Autonoma de Zacatecas, Centro Regional de Estudis Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2010-10-15

    This work aims to obtain an optimum analysis sequence for environmental gamma-ray spectroscopy by means of Genie 2000 (Canberra). Twenty different analysis sequences were customized using different peak area percentages and different algorithms for: 1) peak finding, and 2) peak area determination, and with or without the use of a library -based on evaluated nuclear data- of common gamma-ray emitters in environmental samples. The use of an optimum analysis sequence with certified nuclear information avoids the problems originated by the significant variations in out-of-date nuclear parameters of commercial software libraries. Interference-free gamma ray energies with absolute emission probabilities greater than 3.75% were included in the customized library. The gamma-ray spectroscopy system (based on a Ge Re-3522 Canberra detector) was calibrated both in energy and shape by means of the IAEA-2002 reference spectra for software intercomparison. To test the performance of the analysis sequences, the IAEA-2002 reference spectrum was used. The z-score and the reduced {chi}{sup 2} criteria were used to determine the optimum analysis sequence. The results show an appreciable variation in the peak area determinations and their corresponding uncertainties. Particularly, the combination of second derivative peak locate with simple peak area integration algorithms provides the greater accuracy. Lower accuracy comes from the combination of library directed peak locate algorithm and Genie's Gamma-M peak area determination. (Author)

  2. An optimum analysis sequence for environmental gamma-ray spectrometry

    International Nuclear Information System (INIS)

    This work aims to obtain an optimum analysis sequence for environmental gamma-ray spectroscopy by means of Genie 2000 (Canberra). Twenty different analysis sequences were customized using different peak area percentages and different algorithms for: 1) peak finding, and 2) peak area determination, and with or without the use of a library -based on evaluated nuclear data- of common gamma-ray emitters in environmental samples. The use of an optimum analysis sequence with certified nuclear information avoids the problems originated by the significant variations in out-of-date nuclear parameters of commercial software libraries. Interference-free gamma ray energies with absolute emission probabilities greater than 3.75% were included in the customized library. The gamma-ray spectroscopy system (based on a Ge Re-3522 Canberra detector) was calibrated both in energy and shape by means of the IAEA-2002 reference spectra for software intercomparison. To test the performance of the analysis sequences, the IAEA-2002 reference spectrum was used. The z-score and the reduced χ2 criteria were used to determine the optimum analysis sequence. The results show an appreciable variation in the peak area determinations and their corresponding uncertainties. Particularly, the combination of second derivative peak locate with simple peak area integration algorithms provides the greater accuracy. Lower accuracy comes from the combination of library directed peak locate algorithm and Genie's Gamma-M peak area determination. (Author)

  3. Spectral-ratio radon background correction method in airborne γ-ray spectrometry based on compton scattering deduction

    International Nuclear Information System (INIS)

    γ-ray released by the radon daughter has severe impact on airborne γ-ray spectrometry. The spectral-ratio method is one of the best mathematical methods for radon background deduction in airborne γ-ray spectrometry. In this paper, an advanced spectral-ratio method was proposed which deducts Compton scattering ray by the fast Fourier transform rather than tripping ratios, the relationship between survey height and correction coefficient of the advanced spectral-ratio radon background correction method was studied, the advanced spectral-ratio radon background correction mathematic model was established, and the ground saturation model calibrating technology for correction coefficient was proposed. As for the advanced spectral-ratio radon background correction method, its applicability and correction efficiency are improved, and the application cost is saved. Furthermore, it can prevent the physical meaning lost and avoid the possible errors caused by matrix computation and mathematical fitting based on spectrum shape which is applied in traditional correction coefficient. (authors)

  4. Fission studies by prompt gamma-ray spectrometry

    Directory of Open Access Journals (Sweden)

    Materna T.

    2015-01-01

    Full Text Available The feasibility of retrieving accurate fission observables with a Ge-detector array around a fissile target placed in a cold neutron beam was tested. In three measurement campaigns performed at ILL with the EXILL setup, 235U and 241Pu targets were placed in the high flux cold neutron beam available at the PF1B neutron guide. Gamma-rays following fission were detected by an array of 16 Ge detectors. In the following study, part of data was analyzed as a proof of principle. A set of yields belonging to the Kr-Ba pair were extracted using a gamma-gamma coincidence technique. Preliminary results were compared to the predictions of two phenomenological models: GEF and FIFRELIN.

  5. Pulser injection with subsequent removal for gamma-ray spectrometry

    Science.gov (United States)

    Hartwell, Jack K.; Goodwin, Scott G.; Johnson, Larry O.; Killian, E. Wayne

    1990-01-01

    An improved system for gamma-ray spectroscopy characterized by an interface module that controls the injection of electronic pulses as well as separation logic that enables storage of pulser events in a region of the spectrum of a multichannel analyzer distinct from the region reserved for storage of gamma-ray events. The module accomplishes this by tagging pulser events (high or low) injected into the amplification circuitry, adding an offset to the events so identified at the time the events are at the output of the analog to digital converter, and storing such events in the upper portion of the spectrum stored in the multichannel analyzer. The module can be adapted for use with existing gamma-ray spectroscopy equipment to provide for automatic analyses of radioisotopes.

  6. Fast-ion energy resolution by one-step reaction gamma-ray spectrometry

    DEFF Research Database (Denmark)

    Salewski, Mirko; Nocente, M.; Gorini, G.;

    2016-01-01

    The spectral broadening of γ-rays from fusion plasmas can be measured in high-resolution gamma-ray spectrometry (GRS). We derive weight functions that determine the observable velocity space and quantify the velocity-space sensitivity of one-step reaction high-resolution GRS measurements in magne...

  7. Plutonium isotopic analysis of nondescript samples by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    A gamma-ray spectrometry system has been developed for the Savannah River Plant that when coupled with calorimetry will allow a complete nondestructive assay of various plutonium product and waste materials contained in sealed cans. The computer-based system employs two germanium detectors to obtain spectral information that is analyzed in a unique fashion to obtain plutonium isotopic ratios

  8. Borehole Logging for Uranium by Gamma-Ray Spectrometry

    DEFF Research Database (Denmark)

    Løvborg, Leif; Nyegaard, P.; Christiansen, E. M.;

    1980-01-01

    The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium-iodide, and the...... photomultiplier gain was stabilized electronically using barium-133 (133 Ba) reference gamma rays. The downhole measurements were carried out at depth intervals of 25 cm, and for each stationary position of the borehole probe, counts were accumulated for 100 sec in four energy windows. The calibration constants...

  9. Borehole Logging for Uranium by Gamma-Ray Spectrometry

    DEFF Research Database (Denmark)

    Løvborg, Leif; Nyegaard, P.; Christiansen, E. M.; Nielsen, B. L.

    1980-01-01

    photomultiplier gain was stabilized electronically using barium-133 (133 Ba) reference gamma rays. The downhole measurements were carried out at depth intervals of 25 cm, and for each stationary position of the borehole probe, counts were accumulated for 100 sec in four energy windows. The calibration constants...

  10. Fourier transformation methods in the field of gamma spectrometry

    Indian Academy of Sciences (India)

    A Abdel-Hafiez

    2006-09-01

    The basic principles of a new version of Fourier transformation is presented. This new version was applied to solve some main problems such as smoothing, and denoising in gamma spectroscopy. The mathematical procedures were first tested by simulated data and then by actual experimental data.

  11. On self-attenuation corrections in gamma-ray spectrometry

    International Nuclear Information System (INIS)

    In this paper we discuss and justify the dependence on the sample density and gamma energy of the self-attenuation correction factor, f, in the transmission method for the full energy peak efficiency calibration of Ge detectors. It is suggested as a method for the direct computing of f in the case that the sample composition is known. (Author)

  12. Burnup determination of power reactor fuel elements by gamma spectrometry

    International Nuclear Information System (INIS)

    This report describes a method for determining by γ spectrometry the burn up and the specific power of fuel elements irradiated in power reactors. The energy spectrum of γ rays emitted by fission products is measured by means of a simple equipment using a sodium iodide detector and a multichannel analyzer. In order to extract from the spectrum a quantity proportional to the burn up, it is necessary to: - isolate an activity specific of one emitter,- give the same importance to fissions in uranium and plutonium - take into account the radioactive decay during and after irradiation. One hundred fuel elements were studied and burn up values obtained by γ spectrometry are compared to results given by chemical analyses. Preliminary measurements show that the accuracy of the results is greatly increased by the use of a germanium detector, due to its good resolution. (authors)

  13. Organization of a multichannel analyzer for gamma ray spectrometry

    International Nuclear Information System (INIS)

    This report describes the software organization of a medium scale multichannel analyzer for qualitative and quantitative measurements of the gamma rays emitted by radioactive samples. The first part reminds basis of radioactivity, principle of gamma ray detection, and data processing used for interpretation of a nuclear spectrum. The second part describes first the general organization of the software and then gives some details on interactivity, multidetector capabilites, and integration of complex algorithms for peak search and nuclide identification;problems encountered during the design phase are mentioned and solutions are given. Basic ideas are presented for further developments, such as expert system which should improve interpretation of the results. This present software has been integrated in a manufactured multichannel analyzer named 'POLYGAM NU416'.

  14. Radionuclide distribution in Yadgir district soil samples using gamma spectrometry

    International Nuclear Information System (INIS)

    The activities of the primordial radionuclides 226Ra, 232Th, and 40K are estimated for Yadgir soil samples. The collected soil samples were analyzed using 4'' X 4'' NaI (Tl) detector based gamma spectrometric system. The range of activity of the three radionuclides 226Ra, 232Th, and 40K were found to be 10-174, 13-283 and 99-1768 Bqkg-1 respectively. The range of gamma absorbed dose rate and Indoor Annual effective dose were estimated in the present study and it is found that activity of the radionuclides are moderately higher than the global value except few samples. (author)

  15. Basic characterization of highly enriched uranium by gamma spectrometry

    OpenAIRE

    Nguyen, Cong Tam; Zsigrai, Jozsef

    2005-01-01

    Gamma-spectrometric methods suitable for the characterization of highly enriched uranium samples encountered in illicit trafficking of nuclear materials are presented. In particular, procedures for determining the 234U, 235U, 238U, 232U and 236U contents and the age of highly enriched uranium are described. Consequently, the total uranium content and isotopic composition can be calculated. For determining the 238U and 232U contents a low background chamber was used. In addition, age dating of...

  16. A laboratory exercise on systematic effects in gamma ray spectrometry

    International Nuclear Information System (INIS)

    A laboratory exercise for calculation of true coincidence summing correction factors as well as calculating the effect of deviations between sample and standard source (filling height) was developed. This laboratory exercise was held in a masters course in nuclear chemistry the first time during fall 2013. The aim of the exercise was to high-light the importance of correcting for biases due to different systematic effects in gamma spectrometric measurements. (author)

  17. Digitalized two parametric system for gamma/neutron spectrometry

    OpenAIRE

    Veškrna Martin; Matěj Zdeněk; Mravec Filip; Přenosil Václav; Cvachovec František; Košťál Michal

    2014-01-01

    Many types of detectors like stilbene, NE-213 etc. in conjunction with photomultiplier loaded with low working resistance produce pulses of approximately 100 ns length and contain information about deposited particle in the trailing edge. Using fast analog to digital converters (ADC) and field-programmable gate array (FPGA) it is possible to create a spectrometric system working in mixed gamma and neutron fields which is not loaded dead time. The count rate of processed pulses can reach more ...

  18. Clearances of solid waste uranium by using gamma spectrometry

    International Nuclear Information System (INIS)

    Clearances of contaminated materials arising from desmantling or decommissioning must be provided with the result of measurement of radionuclide content in such materials. In this research, direct measurement of uranium in solid waste for a clearance requirement had been developed by using gamma spectrometric with HPGe detector. The measurement method was developed based on 1001 keV gamma energy of Pa-234m considering a self absorption, detector characteristic, background level factors. For validation purpose, this method was compared with a neutron activation analysis (NAA) techniques. Efficiency for 1001 keV of Pa-234m was 0,0991– 0,1369 cps/Bq on density of 0,51–1,81 g/cm3 with a minimum detectable level of 8–10 Bq/kg. This method was useful for high concentration of U-238 with a precision in acceptance criteria P < 1% and the gamma spectrometer showed a high performance with a value Zscore <1. (author)

  19. Application of PERALS™ alpha spectrometry and gamma spectrometry for analysis and investigation of environmental spills at ISL uranium mining projects.

    Science.gov (United States)

    Borysenko, A; Ostrowski, A; Bellifemine, D; Palmer, G; Haigh, P; Johnston, A

    2014-03-01

    Radiation protection and environmental monitoring in mining requires effective and reliable radionuclide analysis at all stages of the mine project-prior to mining, during operation and through to remediation and decommissioning. The approach presented in this paper was specially developed for the monitoring of radioactive waste resulting from spills during mining and mineral processing operations and uses a combination of high resolution gamma spectrometry, and PERALS™ alpha spectrometry to identify and reliably quantify the activity of the major members of the U-238 decay chain at activities down to 10 mBq g(-1) by direct radionuclide counting and by assessment of the activity of their decay products. This approach has reduced sample preparation and analysis time while providing effective analysis and quantification of naturally occurring radionuclides in environmental samples. It has been successfully applied to several in situ leach (ISL) mining-related projects involving investigations of process material spill impacts and also to routine environmental monitoring. PMID:24270399

  20. Determination of Ra-226 by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    This work deals with the method of determination of 226Ra by low energy photon spectrometry. For this purpose, the interference due to 235U, that emits a photon with a close energy, has to be considered. The contribution of 235U to the 186 KeV photopeak is studied through the 63 KeV 234Th and the 144 KeV 235U emissions. From the minimum detectable activity of 226Ra it is discussed the applicability of this method to several kind of samples. (Author)

  1. Application of in-situ gamma spectrometry in the remediation of radioactively contaminated soil

    International Nuclear Information System (INIS)

    The Fernald Environmental Management Project (FEMP) is a US Department of Energy site that is undergoing total remediation and closure. Most of the remediation effort entails massive excavation of soil for disposal, both offsite and onsite, at an engineered disposal facility. In-situ gamma spectrometry is routinely used to support soil excavation operations to accurately and quickly identify soil areas as being above or below regulatory remediation criteria. Two different in-situ gamma spectrometry systems are used. The first is a sodium iodide (NaI) detector mounted either on a tractor or a jogging stroller, depending on the terrain to be measured. The NaI system allows the collection of a gamma energy spectrum which can be analyzed to identify and quantify radioactive isotopes which are present within the detector's viewing area. Each energy spectrum is tagged by location coordinates provided by an on-board global positioning system (GPS) to precisely locate elevated contamination areas. The second is a tripod-mounted, high purity germanium detector (HPGe) gamma spectrometry system that is functionally similar to the NaI system. The principal advantage of the HPGe is its superior resolution, which allows much more accurate identification and quantification of radionuclide contaminants in soils. In order to effectively utilize the data quality objective process with these systems, three quality assurance (QA) elements had to be performed

  2. Utilization of airborne gamma ray spectrometric data for geological mapping, radioactive mineral exploration and environmental monitoring of southeastern Aswan city, South Eastern Desert, Egypt

    Science.gov (United States)

    Youssef, Mohamed A. S.; Elkhodary, Shadia T.

    2013-12-01

    The present work utilizes airborne gamma ray spectrometric data in a trial to refine surface geology of igneous, metamorphic and sedimentary rocks, detect any radioactive mineralization and monitor environment at southeastern Aswan city, South Eastern Desert, Egypt. This area is mainly covered with igneous rocks (younger granites, older granites, metasediments, metavolcanics, metagabbro, Tertiary basalt and ring complex), metamorphic rocks as well as sedimentary rocks (Um Barmil Formation, Timsah Formation, Abu Aggag Formation and wadi sediments). Airborne gamma ray spectrometry can be very helpful in mapping surface geology. This provides estimates of the apparent surface concentrations of the most common naturally occurring radioactive elements, such as potassium (K), equivalent uranium (eU) and equivalent thorium (eTh). This is based on the assumption that, the absolute and relative concentrations of these radioelements vary measurably and significantly with lithology. The composite image technique is used to display simultaneously three parameters of the three radioelement concentrations and their three binary ratios on one image. The technique offers much in terms of lithological discrimination, based on colour differences and showed efficiency in defining areas, where different lithofacies occur within areas mapped as one continuous lithology. The integration between surface geological information and geophysical data led to detailing the surface geology and the contacts between different rock units. Significant locations or favourable areas for uranium exploration are defined, where the measurements exceed (X + 2S), taking X as the arithmetic mean of eU, eU/eTh and eU/K measurements and S as the standard deviation corresponding to each variables. The study area shows the presence of four relatively high uraniferous zones. These zones cannot be ignored and need further ground follow-up. In addition, the trend analysis based on the three radioelement maps and

  3. Designing and developing of data evaluation and analysis software applied to gamma-ray spectrometry

    International Nuclear Information System (INIS)

    This study is intended to design and develop software for gamma spectral data evaluation and analysis suitable for a variety of gamma-ray spectrometry systems. The software is written in Visual C++. It is designed to run under Microsoft Windows Operating System. The software is capable of covering all the necessary steps for spectral data evaluation and analysis of the collected data. These include peak search, energy calibration, gross and net peak area calculation, peak centroid determination and peak width calculation of the derived gamma-ray peaks. The software offers the ability to report qualitative and quantitative results. The analysis includes: Peak position identification (qualitative analysis) and calculating of its characteristics; Net peak area calculation by subtracting background; Radioactivity estimation (quantitative analysis) using comparison method for gamma peaks from any radioisotopes present during counting; Radioactivity estimation (quantitative analysis) after efficiency calibration; Counting uncertainties calculation; Limit of detection (LOD) estimation. (author)

  4. Comparative study of the gamma spectrometry method performance in different measurement geometries

    International Nuclear Information System (INIS)

    This paper presents the results obtained by gamma spectrometry on aqueous liquid waste sample using different measurement geometries. A liquid waste sample with known gamma emitters content was measured in three different geometries in order to assess the influence of the geometry on the final results. To obtain low measurement errors, gamma spectrometer was calibrated using a calibration standard with the same physical and chemical characteristics as the sample to be measured. Since the calibration was performed with the source at contact with HPGe detector, the waste sample was also measured, for all the three geometries, at the detector contact. The influence of the measurement geometry on the results was evaluated by computing the relative errors. The measurements performed using three different geometries (250 ml plastic vial, Sarpagan box and 24 ml Tricarb vial) showed that all these geometries may be used to quantify the activity of gamma emitters in different type of radioactive waste. (authors)

  5. ATCA data acquisition system for gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The gamma-ray spectrometer JET EP2 (Joint European Torus enhancement project 2) project aims to perform high-resolution gamma spectroscopy at very high count rate (up to few MHz). Traditional analogue electronic has count rate and pulse processing limitations (long dead-time, pile-up challenge). Digital pulse processing (DPP) systems have been shown to have better performance than analogue ones for processing neutrons or/and gamma-ray signals. DPP can synthesize almost any pulse response shape without the signal degradation associated to complex analogue paths. High-speed transient recorders (TR) with auto-trigger functionality are used to digitize and store the detailed shape of pulses. The data acquisition (DAQ) system provides sophisticated analysis/data reduction based on real time algorithms, implemented in field programmable gate arrays (FPGA), for Pulse Height Analysis (PHA) while resolving pulse pile-up of digitized pulses. This paper describes a new DAQ system for real-time pulse analysis. The system is based on the Advanced Telecommunications Computing ArchitectureTM (ATCATM) and contains an ix86-based processor blade with up to 40 GFLOPS and a TR module interconnected through PCI Express (PCIe) links. TR module features: (i) 8 channels of 13 bit resolution with accuracy equal or higher than 11 bit to cope with the expected signal-to-noise ratio (SNR) of the input pulses; (ii) up to 500 MSamples/s sampling rate with the possibility to achieve 1 GSamples/s; and (iii) 2 or 4 GB of local memory. The core of the TR module is two FPGAs able to perform real-time processing algorithms such as PHA and pile-up resolution. This will allow data reduction by a factor of at least 6 and eventually spectra output in real-time

  6. Efficiency calibration and minimum detectable activity concentration of a real-time UAV airborne sensor system with two gamma spectrometers.

    Science.gov (United States)

    Tang, Xiao-Bin; Meng, Jia; Wang, Peng; Cao, Ye; Huang, Xi; Wen, Liang-Sheng; Chen, Da

    2016-04-01

    A small-sized UAV (NH-UAV) airborne system with two gamma spectrometers (LaBr3 detector and HPGe detector) was developed to monitor activity concentration in serious nuclear accidents, such as the Fukushima nuclear accident. The efficiency calibration and determination of minimum detectable activity concentration (MDAC) of the specific system were studied by MC simulations at different flight altitudes, different horizontal distances from the detection position to the source term center and different source term sizes. Both air and ground radiation were considered in the models. The results obtained may provide instructive suggestions for in-situ radioactivity measurements of NH-UAV. PMID:26773821

  7. Measurement of radioactive contamination in the foodstuffs by gamma spectrometry

    International Nuclear Information System (INIS)

    The Chernobyl nuclear reactor accident in 1986, resulted in the increase of radioactive contamination at a global level. To avoid undesirable exposure to public, Pakistan like other countries imposed radioactive contamination levels on food items. Various imported/to be exported and locally purchased food items for human consumption have been analysed for gamma emitting radionuclides. Amongst the food items, special attention was focussed on the imported dry milk. In addition to naturally occurring K-40 radionuclide, small amounts of Cs-137 and Cs-134 fission products have been detected in some of the samples. The concentrations of these two fission radionuclides are presented and compared with the relevant limits. (author)

  8. Real-time airborne gamma-ray background estimation using NASVD with MLE and radiation transport for calibration

    Science.gov (United States)

    Kulisek, J. A.; Schweppe, J. E.; Stave, S. C.; Bernacki, B. E.; Jordan, D. V.; Stewart, T. N.; Seifert, C. E.; Kernan, W. J.

    2015-06-01

    Helicopter-mounted gamma-ray detectors can provide law enforcement officials the means to quickly and accurately detect, identify, and locate radiological threats over a wide geographical area. The ability to accurately distinguish radiological threat-generated gamma-ray signatures from background gamma radiation in real time is essential in order to realize this potential. This problem is non-trivial, especially in urban environments for which the background may change very rapidly during flight. This exacerbates the challenge of estimating background due to the poor counting statistics inherent in real-time airborne gamma-ray spectroscopy measurements. To address this challenge, we have developed a new technique for real-time estimation of background gamma radiation from aerial measurements without the need for human analyst intervention. The method can be calibrated using radiation transport simulations along with data from previous flights over areas for which the isotopic composition need not be known. Over the examined measured and simulated data sets, the method generated accurate background estimates even in the presence of a strong, 60Co source. The potential to track large and abrupt changes in background spectral shape and magnitude was demonstrated. The method can be implemented fairly easily in most modern computing languages and environments.

  9. Real-time airborne gamma-ray background estimation using NASVD with MLE and radiation transport for calibration

    International Nuclear Information System (INIS)

    Helicopter-mounted gamma-ray detectors can provide law enforcement officials the means to quickly and accurately detect, identify, and locate radiological threats over a wide geographical area. The ability to accurately distinguish radiological threat-generated gamma-ray signatures from background gamma radiation in real time is essential in order to realize this potential. This problem is non-trivial, especially in urban environments for which the background may change very rapidly during flight. This exacerbates the challenge of estimating background due to the poor counting statistics inherent in real-time airborne gamma-ray spectroscopy measurements. To address this challenge, we have developed a new technique for real-time estimation of background gamma radiation from aerial measurements without the need for human analyst intervention. The method can be calibrated using radiation transport simulations along with data from previous flights over areas for which the isotopic composition need not be known. Over the examined measured and simulated data sets, the method generated accurate background estimates even in the presence of a strong, 60Co source. The potential to track large and abrupt changes in background spectral shape and magnitude was demonstrated. The method can be implemented fairly easily in most modern computing languages and environments

  10. Gamma ray spectrometry of LDEF samples at SRL

    Science.gov (United States)

    Winn, W. G.

    1991-07-01

    A total of 31 samples from the Long Duration Exposure Facility (LDEF), including materials of aluminum, vanadium, and steel trunnions were analyzed by ultra-low-level gamma spectroscopy. The study quantified particle induced activations of Na-22, Sc-46, Cr-51, Mn-54, Co-56, Co-57, Co-58, and Co-60. The samples of trunnion sections exhibited increasing activity toward the outer end of the trunnion and decreasing activity toward its radial center. The trunnion sections did not include end pieces, which have been reported to collect noticeable Be-7 on their leading surfaces. No significant Be-7 was detected in the samples analyzed. The Underground Counting Facility at Savannah River Laboratory (SRL) was used in this work. The facility is 50 ft. underground, constructed with low-background shielding materials, and operated as a clean room. The most sensitive analyses were performed with a 90 percent efficient HPGe gamma-ray detector, which is enclosed in a purged active/passive shield. Each sample was counted for one to six days in two orientations to yield more representative average activities for the sample. The non-standard geometries of the LDEF samples prompted the development of a novel calibration method, whereby the efficiency about the samples surfaces (measured with point sources) predicted the efficiency for the bulk sample.

  11. Some aspects related to the high performance in gamma spectrometry

    International Nuclear Information System (INIS)

    Full text: Gamma spectroscopy is the science (or art) of identification and/or quantification of radionuclides through gamma-ray energy spectrum analysis. It is a recognized technique, well illustrated by the following examples: environmental radioactivity monitoring, health physics personnel monitoring, reactor corrosion monitoring, nuclear materials safeguards and homeland security, as well as nuclear forensics, materials testing, nuclear medicine and radiopharmaceuticals, and industrial process monitoring. Within the Reliability and Testing Laboratory of INR Pitesti there is now available such a detector of high performance that includes all aspects related to cooling, signal processing (with a high resolution) and the dedicated software applications. At the present time, taking into account the 'nuclear renaissance' the new experimental testing laboratories require complete set-up rather than laboratories having a mixture of the old equipment. The paper presents the mechanically cooled HPGe spectrometers with an undergoing rapid evolution, which eliminate traditional intensive liquid nitrogen management. Also, there are described the digital signal processing virtually by eliminating system drift, and, at the same time, requiring recalibrations much less frequently. Another important aspect presented is related to the software applications, which cover a broad spectrum of nuclear measurement techniques. (authors)

  12. Gamma-spectrometry of extended sources for analysing environmental samples

    International Nuclear Information System (INIS)

    Measurements of the environmental activity concentration by gamma spectrometers require the determination of the full-energy-peak efficiency as a function of photon energy over the detector range. This can be done by experiments or by calculation. For simple cases, experiments are straightforward, but if the decay scheme is complex, cascade effects modify detection efficiency. Also, actual detection efficiency depends on the detection geometry. All these effects are treated as corrections or modifications of the simple value cases which are especially relevant when applied to large volume of environmental samples. In this thesis calculations are made, using the GEANT MC program, for realistic experimental situations that have been performed, and these calculations are validated. The calculational and experimental results have been compared, and if it proves to be satisfactory, the results can be relied on even for cases when no direct experimental observation is possible. The general problems of gamma spectroscopy and correction problems are discussed. The two main tools, the experimental setup and the simulation program are described. A careful checking of the simulation results and the consequences are presented. (R.P.)

  13. Simultaneous estimation of Pu and fission products by gamma spectrometry

    International Nuclear Information System (INIS)

    A gamma spectrometric method is described for the simultaneous estimation of Pu and fission products using a 62cc intrinsic germanium detector coupled to a 4K MCA. The 120 KeV peak of 239Pu was employed for the assay of plutoniu m. The low energy 51 KeV photopeak of 239Pu was not employed due to the interfer ence of the germanium escape peak from 241Am gamma. A nonlinear exponential parame terised function was employed to relate the concentration of 239Pu and the counts obtained from 129 KeV photopeak after subtracting the compton and background. Standard solutions were used for computing the fitting parameters. For fission product analysis, an efficiency versus energy plot was generated using a fission product solution of known individual activities. This was then fitted in a quadratic equation and the fitting parameters were obtained. The inbuilt programme in 4K MCA was used to calculate the 239Pu and the fission products concentration from the respective fitting factors. The isotopic composition was fed externally to obtain the total plutonium concentration. This method was used for the analysis of Pu in the range of 0.5 to 5 g/1. The values when compared with those obtained with coulometric meth od show an agreement within ± 2.5 per cent in the above range. (author). 4 refs., 4 figs., 2 tables

  14. Standard guide for high-resolution gamma-ray spectrometry of soil samples

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2004-01-01

    1.1 This guide covers the identification and quantitative determination of gamma-ray emitting radionuclides in soil samples by means of gamma-ray spectrometry. It is applicable to nuclides emitting gamma rays with an approximate energy range of 20 to 2000 keV. For typical gamma-ray spectrometry systems and sample types, activity levels of about 5 Bq (135 pCi) are measured easily for most nuclides, and activity levels as low as 0.1 Bq (2.7 pCi) can be measured for many nuclides. It is not applicable to radionuclides that emit no gamma rays such as the pure beta-emitting radionuclides hydrogen-3, carbon-14, strontium-90, and becquerel quantities of most transuranics. This guide does not address the in situ measurement techniques, where soil is analyzed in place without sampling. Guidance for in situ techniques can be found in Ref (1) and (2). This guide also does not discuss methods for determining lower limits of detection. Such discussions can be found in Refs (3), (4), (5), and (6). 1.2 This guide can be us...

  15. Non-destructive quantitative analysis of spent fuels by gamma spectrometry

    International Nuclear Information System (INIS)

    This article describes a fast, quantitative and non destructive method for the gamma spectrometric analysis of cylindrical nuclear fuels from pressurized water stations. The efficiency calibration of the gamma spectrometry apparatus set up in a 'high activity' laboratory, carried out with a 226Ra source and a 60Co reference source, and the experimental study of self-attenuation problems give access to the fission product activity. In addition the specific burn-up can be determined to +- 6% by the quantitative measurement of 137Cs and 106Rh

  16. Gamma-ray spectrometry for the measurement of radioactivity in solid and liquid samples

    International Nuclear Information System (INIS)

    Gamma-ray spectrometry is a fast and widespread method used to identify radio nuclides and to determine their radioactivity. Compared to the other methods used to determine radioactivity, sample preparation is relatively easy and the method can even be used in a non-destructive way. The gamma-ray spectrometry laboratory at SCK-CEN was established in 1969 and at that time only NaI(Tl) scintillator detectors are available allowing low-resolution spectroscopy. Later on, these detectors were gradually upgraded by Ge(Li) semiconductor detectors and in the eighties by High Purity Germanium detectors (HPGe) offering the possibility of high-resolution gamma-ray spectroscopy. Currently, measurements of the radioactivity of gamma- or X- rays emitting radio nuclei in the energy region 5 - 2500 keV are carried out. The High-Resolution Gamma-ray Spectrometry Laboratory is engaged with measurements of amounts of gamma or X-ray emitting substances intermixed with non-radioactive material in solid and liquid samples. Calibrated High Purity Germanium detectors are used for all the measurements. The detectors are calibrated for measuring sample volumes ranging from 1mL up to 2.5L (Marinelli beaker) in a close-to-detector measurement configuration. For the very low energy gamma-rays, the radioactivity is deposited on a planchet and measured with a Low Energy Germanium Detector (LEGe). The experimental calibrations can be complemented with numerical calibrations. Numerical calibrations are based on simulation software that is developed in the laboratory. With the aid of numerical calibrations it is possible to easily account for all possible deviations from a reference calibration geometry and hence to account for e.g. differences in apparent density, material composition, filling height, wall thickness etc. In order to setup numerical calibrations, all dimensional parameters and material specifications describing the sample and detector need to be known (see figure below). The

  17. Extended Survey of Indoor and Outdoor Terrestrial Gamma Radiation in Greek Urban Areas by In situ Gamma Spectrometry with Portable Ge Detector

    International Nuclear Information System (INIS)

    The results obtained from more than 1000 indoor and outdoor in situ gamma spectrometry measurements in 41 towns (from all geographic subdivisions) of the Greek mainland (not islands) are presented. From the in situ gamma spectra the absorbed dose rate in air due to uranium series, thorium series, 40K and 137Cs are derived and discussed. (author)

  18. Gamma-ray spectrometry with thick mercuric iodide detectors

    International Nuclear Information System (INIS)

    Gamma-ray spectra with energies up to 1.3 MeV have been detected for the first time with 1-cm-thick HgI2 semiconductor detectors at room temperature. The spectra can be taken using a long, 10 μs, or a short, 0.5 μs, charge collection time. The latter has produced better results with better peak efficiency, higher peak-to-valley ratio, and fewer low energy counts with little sacrifice in resolution. Spectra for energies between 100 keV and 1.3 MeV and descriptions of the techniques for their acquisition are presented. The thick detectors need a conditioning treatment, which is described, prior to showing spectral response

  19. Development of isotope dilution gamma-ray spectrometry for plutonium analysis

    Energy Technology Data Exchange (ETDEWEB)

    Li, T.K.; Parker, J.L. (Los Alamos National Lab., NM (United States)); Kuno, Y.; Sato, S.; Kurosawa, A.; Akiyama, T. (Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan))

    1991-01-01

    We are studying the feasibility of determining the plutonium concentration and isotopic distribution of highly radioactive, spent-fuel dissolver solutions by employing high-resolution gamma-ray spectrometry. The study involves gamma-ray plutonium isotopic analysis for both dissolver and spiked dissolver solution samples, after plutonium is eluted through an ion-exchange column and absorbed in a small resin bead bag. The spike is well characterized, dry plutonium containing {approximately}98% of {sup 239}Pu. By using measured isotopic information, the concentration of elemental plutonium in the dissolver solution can be determined. Both the plutonium concentration and the isotopic composition of the dissolver solution obtained from this study agree well with values obtained by traditional isotope dilution mass spectrometry (IDMS). Because it is rapid, easy to operate and maintain, and costs less, this new technique could be an alternative method to IDMS for input accountability and verification measurements in reprocessing plants. 7 refs., 4 figs., 4 tabs.

  20. Advances in room-temperature solid-state gamma-ray spectrometry

    International Nuclear Information System (INIS)

    This article presents a review and analysis of different concepts of gamma-ray spectrometry using room-temperature solid-state detectors. The classical approach involving the use of a charge-sensitive preamplifier and attempting to collect all the ionization charge produced by the gamma ray is analyzed and discussed in terms of the charge transport parameters of the most promising compound semiconductor materials. It is concluded that compound semiconductor detector materials having a large disparity between the μ tau products for electrons and holes (such as HgI2 and CdTe) will have rather poor energy resolution if the classical method of spectrometry requiring full charge collection is employed. 30 references

  1. Radioactivity measurements in the aquatic environment using in-situ and laboratory gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The in-situ underwater gamma-ray spectrometry method is validated by inter-comparison with laboratory method. Deployments of the spectrometer KATERINA on a submarine spring and laboratory measurements of water samples with HPGe detector were performed. Efficiency calibrations, Monte Carlo simulations and the Minimum Detectable Activity (MDA) estimations were realized. MDAs varied from 0.19 to 10.4 (lab) and 0.05 to 0.35 (in-situ) Bq/L, while activity concentrations differed from 7% (for radon progenies) up to 10% (for 40K), between the two methods. - Highlights: • In-situ underwater gamma-ray spectrometry method is validated by the lab method. • MC simulations using MCNP5 reproduced experimental energy spectra and efficiency. • MDA of the in-situ method was an order of magnitude lower than the lab method. • The in-situ method was sensitive and cost-effective compared to the lab method

  2. Determination of the self-attenuation correction factor for environmental samples analysis in gamma spectrometry

    International Nuclear Information System (INIS)

    Gamma spectrometry technique has been used in order to obtain the activity concentrations of natural and artificial radionuclides in environmental samples of different origins, compositions and densities. These samples characteristics may influence the calibration condition by the self-attenuation effect. The sample density has been considered the most important factor. For reliable results, it is necessary to determine self-attenuation correction factor which has been subject of great interest due to its effect on activity concentration. In this context, the aim of this work is to show the calibration process considering the correction by self-attenuation in the evaluation of the concentration of each radionuclide to a gamma HPGEe detector spectrometry system. (author)

  3. GammaLog Playback 1.0 - mobile gamma ray spectrometry software

    International Nuclear Information System (INIS)

    The Geological Survey of Norway (NGU) operates a mobile gamma ray spectrometer system which can be used in nuclear emergency situations to determine the location and type of orphan sources, or the extent and type of fallout contamination. The system consists of a 20 litre (16 litre downward and 4 litre upward looking) RSX-5 NaI detector and spectrometer, and can be mounted in fixed wing aircraft, helicopters, or vans/cars as appropriate. NGU has developed its own data acquisition and analysis software for this system. GammaLog (Smethurst 2005) controls the acquisition, display, and storage of data from the spectrometer, and performs real-time data analysis including estimation of dose rates and fallout concentrations, and separation of geological and anthropogenic components of the signal. The latter is particularly important where the geological radioisotope signal varies strongly from one place to another, and makes it easier to locate and identify anthropogenic sources which might otherwise be difficult to separate from the geological background signal. A modified version of GammaLog has been developed, GammaLog Playback, which allows the replay of previously acquired GammaLog datasets, while performing similar processing and display as the GammaLog acquisition software. This allows datasets to be reviewed and compared in the field or during post-survey analysis to help plan subsequent measurement strategies.(Au)

  4. GammaLog Playback 1.0 - mobile gamma ray spectrometry software

    Energy Technology Data Exchange (ETDEWEB)

    Watson, R.J.; Smethurst, M.A.

    2011-07-01

    The Geological Survey of Norway (NGU) operates a mobile gamma ray spectrometer system which can be used in nuclear emergency situations to determine the location and type of orphan sources, or the extent and type of fallout contamination. The system consists of a 20 litre (16 litre downward and 4 litre upward looking) RSX-5 NaI detector and spectrometer, and can be mounted in fixed wing aircraft, helicopters, or vans/cars as appropriate. NGU has developed its own data acquisition and analysis software for this system. GammaLog (Smethurst 2005) controls the acquisition, display, and storage of data from the spectrometer, and performs real-time data analysis including estimation of dose rates and fallout concentrations, and separation of geological and anthropogenic components of the signal. The latter is particularly important where the geological radioisotope signal varies strongly from one place to another, and makes it easier to locate and identify anthropogenic sources which might otherwise be difficult to separate from the geological background signal. A modified version of GammaLog has been developed, GammaLog Playback, which allows the replay of previously acquired GammaLog datasets, while performing similar processing and display as the GammaLog acquisition software. This allows datasets to be reviewed and compared in the field or during post-survey analysis to help plan subsequent measurement strategies.(auth)

  5. A first attempt to derive soil erosion rates from 137Cs airborne gamma measurements in two Alpine valleys

    Science.gov (United States)

    Arata, Laura; Meusburger, Katrin; Bucher, Benno; Mabit, Lionel; Alewell, Christine

    2016-04-01

    The application of fallout radionuclides (FRNs) as soil tracers is currently one of the most promising and effective approach for evaluating soil erosion magnitudes in mountainous grasslands. Conventional assessment or measurement methods are laborious and constrained by the topographic and climatic conditions of the Alps. The 137Cs (half-life = 30.2 years) is the most frequently used FRN to study soil redistribution. However the application of 137Cs in alpine grasslands is compromised by the high heterogeneity of the fallout due to the origin of 137Cs fallout in the Alps, which is linked to single rain events occurring just after the Chernobyl accident when most of the Alpine soils were still covered by snow. The aim of this study was to improve our understanding of the 137Cs distribution in two study areas in the Central Swiss Alps: the Ursern valley (Canton Uri), and the Piora valley (Canton Ticino). In June 2015, a helicopter equipped with a NaI gamma detector flew over the two study sites and screened the 137Cs activity of the top soil. The use of airborne gamma measurements is particularly efficient in case of higher 137Cs concentration in the soil. Due to their high altitude and high precipitation rates, the Swiss Alps are expected to be more contaminated by 137Cs fallout than other parts of Switzerland. The airborne gamma measurements have been related to several key parameters which characterize the areas, such as soil properties, slopes, expositions and land uses. The ground truthing of the airborne measurements (i.e. the 137Cs laboratory measurements of the soil samples collected at the same points) returned a good fit. The obtained results offer an overview of the 137Cs concentration in the study areas, which allowed us to identify suitable reference sites, and to analyse the relationship between the 137Cs distribution and the above cited parameters. The authors also derived a preliminary qualitative and a quantitative assessment of soil redistribution

  6. High-z semiconductor nuclear radiation detectors for room-temperature gamma-ray spectrometry

    International Nuclear Information System (INIS)

    A bibliographical review (182 articles of periodicals, conferences, reports, thesis and french patents) is presented, as addendum of the report CEA-BIB-210 (1974) on high-Z semiconductor compounds used as materials for the gamma and X-ray detection and spectrometry. This publication reviews issues from 1974 to 1977. References and summaries (in french) are incorporated into 182 bibliograhical notices. Index for authors, corporate authors, documents and periodicals, and subjects is included

  7. Measurement of plutonium and uranium isotopic abundances by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The isotopic composition of plutonium and uranium is needed for purposes of sample confirmation, or for interpreting results from calorimeters or neutron-coincidence measurement instruments to determine nuclear material mass. The authors have developed measurement methods and computer codes utilizing high-resolution gamma-ray spectrometry to measure the relative isotopic abundances of plutonium and uranium in various forms nondestructively. The computer codes, known as MGA and MGAU, have unique analysis methodologies that the authors briefly describe in this paper

  8. Measurement of plutonium and uranium isotopic abundances by gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ruhter, W.D. [Lawrence Livermore National Lab., CA (United States); Gunnink, R. [Gunnink (Ray), Fremont, CA (United States)

    1996-02-01

    The isotopic composition of plutonium and uranium is needed for purposes of sample confirmation, or for interpreting results from calorimeters or neutron-coincidence measurement instruments to determine nuclear material mass. The authors have developed measurement methods and computer codes utilizing high-resolution gamma-ray spectrometry to measure the relative isotopic abundances of plutonium and uranium in various forms nondestructively. The computer codes, known as MGA and MGAU, have unique analysis methodologies that the authors briefly describe in this paper.

  9. In situ measurements in an immerged environment of ambient gamma radiation activity and associated spectrometry

    International Nuclear Information System (INIS)

    A set of site measurement devices composed of an ictometer, an air ionization chamber and a gamma ray spectrometry chain was modified so that the type of measurements could be carried out in an immerged environment with the equipment lying on the sediments of the prospected area. The different detectors can be controlled-and the data stored in a portable and autonomous 'PC' microcomputer from a light craft

  10. NMIS With Gamma Spectrometry for Attributes of Pu and HEU, Explosives and Chemical Agents

    International Nuclear Information System (INIS)

    The concept for the system described herein is an active/passive Nuclear Materials Identification System2 (NMIS) that incorporates gamma ray spectrometry3. This incorporation of gamma ray spectrometry would add existing capability into this system. This Multiple Attribute System can determine a wide variety of attributes for Pu and highly enriched uranium (HEU) of which a selected subset could be chosen. This system can be built using commercial off the shelf (COTS) components. NMIS systems are at All-Russian Scientific Research Institute of Experimental Physics (VNIIEF) and Russian Federal Nuclear Center Institute of Technical Physics, (VNIITF) and measurements with Pu have been performed at VNIIEF and analyzed successfully for mass and thickness of Pu. NMIS systems are being used successfully for HEU at the Y-12 National Security Complex. The use of active gamma ray spectrometry for high explosive HE and chemical agent detection is a well known activation analysis technique, and it is incorporated here. This report describes the system, explains the attribute determination methods for fissile materials, discusses technical issues to be resolved, discusses additional development needs, presents a schedule for building from COTS components, and assembly with existing components, and discusses implementation issues such as lack of need for facility modification and low radiation exposure

  11. NMIS With Gamma Spectrometry for Attributes of Pu and HEU, Explosives and Chemical Agents

    Energy Technology Data Exchange (ETDEWEB)

    Mihalczo, J. T.; Mattingly, J. K.; Mullens, J. A.; Neal, J. S.

    2002-05-10

    The concept for the system described herein is an active/passive Nuclear Materials Identification System{sup 2} (NMIS) that incorporates gamma ray spectrometry{sup 3}. This incorporation of gamma ray spectrometry would add existing capability into this system. This Multiple Attribute System can determine a wide variety of attributes for Pu and highly enriched uranium (HEU) of which a selected subset could be chosen. This system can be built using commercial off the shelf (COTS) components. NMIS systems are at All-Russian Scientific Research Institute of Experimental Physics (VNIIEF) and Russian Federal Nuclear Center Institute of Technical Physics, (VNIITF) and measurements with Pu have been performed at VNIIEF and analyzed successfully for mass and thickness of Pu. NMIS systems are being used successfully for HEU at the Y-12 National Security Complex. The use of active gamma ray spectrometry for high explosive HE and chemical agent detection is a well known activation analysis technique, and it is incorporated here. This report describes the system, explains the attribute determination methods for fissile materials, discusses technical issues to be resolved, discusses additional development needs, presents a schedule for building from COTS components, and assembly with existing components, and discusses implementation issues such as lack of need for facility modification and low radiation exposure.

  12. Rapid determination of soil contamination by helicopter gamma ray spectrometry

    International Nuclear Information System (INIS)

    The paper describes aerial nuclide specific measurements of surface contamination that were performed after the Chernobyl reactor accident in the southern region of the Federal Republic of Germany in August 1989. For these measurements, a helicopter equipped with a gamma ray spectrometer system including an HPGe detector with a relative efficiency of 50% was used. Soil contamination due to 134Cs and 137Cs was measured during a number of flights covering a total distance of about 300 km. The average flying altitude measured by a laser altimeter was about 70 m above ground level and the speed was about 130 km/h. The measuring time was chosen to be 60 s for each spectrum, corresponding to a flight path distance of about 2.2 km over which the average soil contamination was determined. The measured 137Cs values of up to 25 kBq/m2 are in good agreement with the results of measurements obtained by other methods. The values measured for 134Cs were lower by a factor of 5. (author). 5 refs, 4 figs

  13. Some improvements in low-activity gamma spectrometry

    International Nuclear Information System (INIS)

    In this study the authors have analysed some problems encountered in their experiments. The choice of an optimum geometry is particularly important in the case of low-activity measurements for which the counting rate needs to be maximized; the variations in the radius/height ratio in a Marinelli-type geometry for different detector dimensions are examined, and significant improvements in the counting rate are noted. In addition, two methods of secondary standard preparation are compared: the first, involving a single mixed source (containing a mixture of standards prepared by a primary laboratory), can only cause a shift in the calibration curve; the second, involving several individual (primary) sources, can in addition change the shape of the curve; the consequences of these different deformations were studied with a view to choosing the best method of preparing secondary standards. The measurements apply to various samples: water, milk, crushed vegetable matter, animal tissues, organic sediments, and sand; the gamma absorption in samples of different compositions was compared in order to establish the minimum number of secondary sources to be prepared. (author)

  14. Several experimental applications of gamma ray spectrometry on the analysis of uranium compounds

    International Nuclear Information System (INIS)

    Several experimental applications of gamma ray spectrometry on the analysis of uranium compounds and materials containing it are studied. Special attention is devoted to the correlation between experimental spectra and the decay chains of 235U and 238U contained in the analyzed samples. The following applications are discussed: enrichment determination without using calibration standards, determination of uranium concentration, intensities of the gamma rays emitted by the nuclides present in the decay chains of study and the activity of such nuclides. Because of its importance, detailed discussion about the former one is shown. In addition, preliminary results regarding the emission probabilities of the most important gamma rays of 234mPa are also informed. (author)

  15. Evaluation of TASTEX task H: measurement of plutonium isotopic abundances by gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gunnink, R.; Prindle, A.L.; Asakura, Y.; Masui, J.; Ishiguro, N.; Kawasaki, A.; Kataoka, S.

    1981-10-01

    This report describes a computer-based gamma spectrometer system that was developed for measuring isotopic and total plutonium concentrations in nitric acid solutions. The system was installed at the Tokai reprocessing plant where it is undergoing testing and evaluation as part of the Tokai Advanced Safeguards Exercise (TASTEX). Objectives of TASTEX Task H, High-Resolution Gamma Spectrometer for Plutonium Isotopic Analysis, the methods and equipment used, the installation and calibration of the system, and the measurements obtained from several reprocessing campaigns are discussed and described. In general, we find that measurements for gamma spectroscopy agree well with those of mass spectrometry and of other chemical analysis. The system measures both freshly processed plutonium from the product accountability tank and aged plutonium solutions from storage tanks. 14 figures, 15 tables.

  16. Determination of radon concentration in soil gas by gamma-ray spectrometry of olive oil

    Energy Technology Data Exchange (ETDEWEB)

    Al-Azmi, Darwish [Department of Applied Sciences, College of Technological Studies, Public Authority for Applied Education and Training, Shuwaikh, P.O. Box: 42325, Code 70654 (Kuwait)]. E-mail: dalazmi@paaet.edu.kw; Karunakara, N. [University Science Instrumentation Centre, Mangalore University, Mangalagangotri 574 199, Mangalore (India)]. E-mail: karunakara_n@yahoo.com

    2007-03-15

    Measurements of radon concentration in soil gas have been carried out using a bubbling system in which the soil gas is drawn through an active pumping to bubble a liquid absorber (olive oil) for the deposition of the soil gas in it. After the bubbling process, the absorber is then taken for gamma-ray measurements. Gamma-ray photopeaks from the {sup 214}Pb and the {sup 214}Bi radon progeny are considered for the detection of the {sup 222}Rn gas to study the concentration levels for radon soil gas. Results for some field measurements were obtained and compared with results obtained using AlphaGuard radon gas monitor. The technique provides a possible approach for the measurements of radon soil gas with gamma-ray spectrometry.

  17. Determination of radon concentration in soil gas by gamma-ray spectrometry of olive oil

    International Nuclear Information System (INIS)

    Measurements of radon concentration in soil gas have been carried out using a bubbling system in which the soil gas is drawn through an active pumping to bubble a liquid absorber (olive oil) for the deposition of the soil gas in it. After the bubbling process, the absorber is then taken for gamma-ray measurements. Gamma-ray photopeaks from the 214Pb and the 214Bi radon progeny are considered for the detection of the 222Rn gas to study the concentration levels for radon soil gas. Results for some field measurements were obtained and compared with results obtained using AlphaGuard radon gas monitor. The technique provides a possible approach for the measurements of radon soil gas with gamma-ray spectrometry

  18. An analysis of nuclear fuel burnup in the AGR-1 TRISO fuel experiment using gamma spectrometry, mass spectrometry, and computational simulation techniques

    International Nuclear Information System (INIS)

    Highlights: • The burnup of irradiated AGR-1 TRISO fuel was analyzed using gamma spectrometry. • The burnup of irradiated AGR-1 TRISO fuel was also analyzed using mass spectrometry. • Agreement between experimental results and neutron physics simulations was excellent. - Abstract: AGR-1 was the first in a series of experiments designed to test US TRISO fuel under high temperature gas-cooled reactor irradiation conditions. This experiment was irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) and is currently undergoing post-irradiation examination (PIE) at INL and Oak Ridge National Laboratory. One component of the AGR-1 PIE is the experimental evaluation of the burnup of the fuel by two separate techniques. Gamma spectrometry was used to non-destructively evaluate the burnup of all 72 of the TRISO fuel compacts that comprised the AGR-1 experiment. Two methods for evaluating burnup by gamma spectrometry were developed, one based on the Cs-137 activity and the other based on the ratio of Cs-134 and Cs-137 activities. Burnup values determined from both methods compared well with the values predicted from simulations. The highest measured burnup was 20.1% FIMA (fissions per initial heavy metal atom) for the direct method and 20.0% FIMA for the ratio method (compared to 19.56% FIMA from simulations). An advantage of the ratio method is that the burnup of the cylindrical fuel compacts can be determined in small (2.5 mm) axial increments and an axial burnup profile can be produced. Destructive chemical analysis by inductively coupled mass spectrometry (ICP-MS) was then performed on selected compacts that were representative of the expected range of fuel burnups in the experiment to compare with the burnup values determined by gamma spectrometry. The compacts analyzed by mass spectrometry had a burnup range of 19.3% FIMA to 10.7% FIMA. The mass spectrometry evaluation of burnup for the four compacts agreed well with the gamma

  19. A Case Study Correlating Innovative Gamma Ray Scanning Detection Systems Data to Surface Soil Gamma Spectrometry Results - 13580

    International Nuclear Information System (INIS)

    HydroGeoLogic (HGL), Inc. completed a United States Environmental Protection Agency (USEPA) study to characterize radiological contamination at a site near Canoga Park, California. The characterized area contained 470 acres including the site of a prototype commercial nuclear reactor and other nuclear design, testing, and support operations from the 1950's until 1988 [1]. The site history included radiological releases during operation followed by D and D activities. The characterization was conducted under an accelerated schedule and the results will support the project remediation. The project has a rigorous cleanup to background agenda and does not allow for comparison to risk-based guidelines. To target soil sample locations, multiple lines of evidence were evaluated including a gamma radiation survey, geophysical surveys, historical site assessment, aerial photographs, and former worker interviews. Due to the time since production and decay, the primary gamma emitting radionuclide remaining is cesium-137 (Cs-137). The gamma ray survey covered diverse, rugged terrain using custom designed sodium iodide thallium-activated (NaI(Tl)) scintillation detection systems. The survey goals included attaining 100% ground surface coverage and detecting gamma radiation as sensitively as possible. The effectiveness of innovative gamma ray detection systems was tested by correlating field Cs-137 static count ratios to Cs-137 laboratory gamma spectrometry results. As a case study, the area encompassing the former location of the first nuclear power station in the U. S. was scanned, and second by second global positioning system (GPS)-linked gamma spectral data were evaluated by examining total count rate and nuclide-specific regions of interest. To compensate for Compton scattering from higher energy naturally occurring radionuclides (U-238, Th-232 and their progeny, and K-40), count rate ratios of anthropogenic nuclide-specific regions of interest to the total count rate were

  20. Airborne gamma-ray and magnetic anomaly signatures of serpentinite in relation to soil geochemistry, northern California

    International Nuclear Information System (INIS)

    Serpentinized ultramafic rocks and associated soils in northern California are characterized by high concentrations of Cr and Ni, low levels of radioelements (K, Th, and U) and high amounts of ferrimagnetic minerals (primarily magnetite). Geophysical attributes over ultramafic rocks, which include airborne gamma-ray and magnetic anomaly data, are quantified and provide indirect measurements on the relative abundance of radioelements and magnetic minerals, respectively. Attributes are defined through a statistical modeling approach and the results are portrayed as probabilities in chart and map form. Two predictive models are presented, including one derived from the aeromagnetic anomaly data and one from a combination of the airborne K, Th and U gamma-ray data. Both models distinguish preferential values within the aerogeophysical data that coincide with mapped and potentially unmapped ultramafic rocks. The magnetic predictive model shows positive probabilities associated with magnetic anomaly highs and, to a lesser degree, anomaly lows, which accurately locate many known ultramafic outcrops, but more interestingly, locate potentially unmapped ultramafic rocks, possible extensions of ultramafic bodies that dip into the shallow subsurface, as well as prospective buried ultramafic rocks. The airborne radiometric model shows positive probabilities in association with anomalously low gamma radiation measurements over ultramafic rock, which is similar to that produced by gabbro, metavolcanic rock, and water bodies. All of these features share the characteristic of being depleted in K, Th and U. Gabbro is the only rock type in the study area that shares similar magnetic properties with the ultramafic rock. The aerogeophysical model results are compared to the distribution of ultramafic outcrops and to Cr, Ni, K, Th and U concentrations and magnetic susceptibility measurements from soil samples. Analysis of the soil data indicates high positive correlation between

  1. Airborne gamma-ray and magnetic anomaly signatures of serpentinite in relation to soil geochemistry, northern California

    Science.gov (United States)

    McCafferty, A.E.; Van Gosen, B. S.

    2009-01-01

    Serpentinized ultramafic rocks and associated soils in northern California are characterized by high concentrations of Cr and Ni, low levels of radioelements (K, Th, and U) and high amounts of ferrimagnetic minerals (primarily magnetite). Geophysical attributes over ultramafic rocks, which include airborne gamma-ray and magnetic anomaly data, are quantified and provide indirect measurements on the relative abundance of radioelements and magnetic minerals, respectively. Attributes are defined through a statistical modeling approach and the results are portrayed as probabilities in chart and map form. Two predictive models are presented, including one derived from the aeromagnetic anomaly data and one from a combination of the airborne K, Th and U gamma-ray data. Both models distinguish preferential values within the aerogeophysical data that coincide with mapped and potentially unmapped ultramafic rocks. The magnetic predictive model shows positive probabilities associated with magnetic anomaly highs and, to a lesser degree, anomaly lows, which accurately locate many known ultramafic outcrops, but more interestingly, locate potentially unmapped ultramafic rocks, possible extensions of ultramafic bodies that dip into the shallow subsurface, as well as prospective buried ultramafic rocks. The airborne radiometric model shows positive probabilities in association with anomalously low gamma radiation measurements over ultramafic rock, which is similar to that produced by gabbro, metavolcanic rock, and water bodies. All of these features share the characteristic of being depleted in K, Th and U. Gabbro is the only rock type in the study area that shares similar magnetic properties with the ultramafic rock. The aerogeophysical model results are compared to the distribution of ultramafic outcrops and to Cr, Ni, K, Th and U concentrations and magnetic susceptibility measurements from soil samples. Analysis of the soil data indicates high positive correlation between

  2. Characterization of airborne particulates by pyrolysis/mass spectrometry and carbon-14 analysis

    Energy Technology Data Exchange (ETDEWEB)

    Voorhees, K.J. (Colorado School of Mines, Golden); Durfee, S.L.; Currie, L.A.; Klouda, G.A.

    1981-08-01

    Pyrolysis/mass spectrometry (Py/MS) has been used to characterize the composition of organics in an ambient air particulate sample from the eastern Utah oil shale lands. The procedure involved collection of the individual contributors, pyrolysis of these samples, and finally a least-squares fitting of the individual contributor spectra to the pyrolysis mass spectrum of the ambient sample. The Py/MS results were verified by using /sup 14/C analysis.

  3. Rapid identification and analysis of airborne plutonium using a combination of alpha spectroscopy and inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Farmer, Dennis E; Steed, Amber C; Sobus, Jon; Stetzenbach, Klaus; Lindley, Kaz; Hodge, Vernon F

    2003-10-01

    Recent wildland fires near two U.S. nuclear facilities point to a need to rapidly identify the presence of airborne plutonium during incidents involving the potential release of radioactive materials. Laboratory turn-around times also need to be shortened for critical samples collected in the earliest stages of radiological emergencies. This note discusses preliminary investigations designed to address both these problems. The methods under review are same day high-resolution alpha spectroscopy to screen air filter samples for the presence of plutonium and inductively coupled plasma mass spectrometry to perform sensitive plutonium analyses. Thus far, using modified alpha spectroscopy techniques, it has been possible to reliably identify the approximately 5.2 MeV emission of 239Pu on surrogate samples (air filters artificially spiked with plutonium after collection) even though the primary alpha-particle emissions of plutonium are, as expected, superimposed against a natural alpha radiation background dominated by short-lived radon and thoron progeny (approximately 6-9 MeV). Several processing methods were tested to prepare samples for analysis and shorten laboratory turn-around time. The most promising technique was acid-leaching of air filter samples using a commercial open-vessel microwave digestion system. Samples prepared in this way were analyzed by both alpha spectroscopy (as a thin-layer iron hydroxide co-precipitate) and inductively coupled plasma mass spectrometry. The detection levels achieved for 239Pu--approximately 1 mBq m(-3) for alpha spectroscopy screening, and, < 0.1 mBq m(-3) for inductively coupled plasma mass spectrometry analysis--are consistent with derived emergency response levels based on EPA's Protective Action Guides, and samples can be evaluated in 36 to 72 h. Further, if samples can be returned to a fixed-laboratory and processed immediately, results from mass spectrometry could be available in as little as 24 h. When fully implemented

  4. Comparison of Pu isotopic composition between gamma and mass spectrometry: Experience from IAEA-SAL

    International Nuclear Information System (INIS)

    About 2000 Pu containing samples have been analysed during the last 8 years at SAL using gamma spectrometry (GS) in parallel with mass spectrometry (MS). Four different detectors have been used for the measurement of gamma-ray spectra and several versions of the MGA program have been used for spectra evaluation. The results of Pu isotopic composition obtained by both methods have neem systematically compared. Attempts to improve the agreement between GS and MS are described. This was done by adjustment of the emission probabilities for some gamma energies and the development of a new correlation equation for 242Pu. These improvements have been applied for evaluation of two sets containing 320 and 404 samples, respectively analysed in 1991 and in 1992-93. The mean differences and their standard deviations between MS and GS were calculated, showing mean relative differences for 238-241Pu isotopes in the range from 0.1 to 0.5% with standard deviations within ± 0.4 to ±1%. For 242Pu these values are about 0.5% and ± 5%, respectively. (author)

  5. Evaluation of radioactive environmental hazards in Area-3, Northern Palmyrides, Central Syria using airborne spectrometric gamma technique.

    Science.gov (United States)

    Asfahani, J; Aissa, M; Al-Hent, R

    2016-01-01

    Airborne spectrometric gamma data are used in this paper to estimate the degree of radioactive hazard on humanity in Area-3, Northern Palmyrides, Central Syria. Exposure Rate (ER), Absorbed Dose Rate (ADR), Annual Effective Dose Rate (AEDR), and Heat Production (HP) of the eleven radiometric units included in the established lithological scored map in the study area have been computed to evaluate the radiation background influence in humans. The results obtained indicate that a human body in Area-3 is subjected to radiation hazards in the acceptable limits for long duration exposure. The highest radiogenetic heat production values in Area-3 correspond to the phosphatic locations characterized by relatively high values of uranium and thorium. PMID:26569554

  6. Radioactivity Levels and Gamma-Ray Dose Rate in Soil Samples from Kohistan (Pakistan) Using Gamma-Ray Spectrometry

    Institute of Scientific and Technical Information of China (English)

    Hasan M. Khan; M. Ismail; K. Khan; P. Akhter

    2011-01-01

    The analysis of naturally occurring radionuclides (226Ra, 232Th and 40K) and an anthropogenic radionuclide 137Cs is carried out in some soil samples collected from Kohistan district of N.W.F.P. (Pakistan), using gamma-ray spectrometry. The gamma spectrometry is operated using a high purity Germanium (HPGe) detector coupled with a computer based high resolution multi channel analyzer. The speciSc activity in soil ranges from 24.72 to 78.48Bq·kg-1 for 226Ra, 21.73 to 75.28Bq·kg-1 for 232Th, 7.06 to 14.9Bq·kg-1 for l37Cs and 298.46 to 570.77Bq·kg-1 for 40K with the mean values of 42.11, 43.27, 9.5 and 418.27Bq·kg-1, respectively. The radium equivalent activity in all the soil samples is lower than the safe limit set in the OECD report (370Bq·kg-1). Man-made radionuclide 137Cs is also present in detectable amount in all soil samples. Presence of 137Cs indicates that the samples in this remote area also receive some fallout from nuclear accident in Chernobyl power plant in 1986. The internal and external hazard indices have the mean values of 0.48 and 0.37 respectively. Absorbed dose rates and effective dose equivalents are also determined for the samples. The concentration of radionuclides found in the soil samples during the present study is nominal and does not pose any potential health hazard to the general public.

  7. Defining South Australian Magnesite Resources Using High-Resolution Airborne Spectrometry and Survey-Grade GPS

    International Nuclear Information System (INIS)

    Sedimentary magnesite (MgCO3) as thin interbeds in dolomite are a minor but significant component of the Skillogalee Dolomite of Proterozoic age, a unit widely distributed throughout the Mount Lofty and northern Flinders Ranges of South Australia. Thickness and abundance of magnesite beds are greatest to the north of Leigh Creek, in the western Flinders Ranges, extending 120 km northwest into the Willouran Ranges. These resources are currently under investigation as a potential feedstock for magnesium metal production. Within the study area, Skillogalee Dolomite varies in thickness from 500 to 5000 m with magnesite interbeds more common in the upper 300 m. Individual magnesite lenses are relatively thin, ranging in thickness from <0.5 m to a maximum of around 5 m, but are laterally very extensive and can be traced over distances exceeding 10 km. The region is arid with extensive rocky outcrop predominantly as strike ridges. Airborne spectral survey provides a rapid means of covering the areas of prospective Skillogalee Dolomite, much of which has poor vehicular access. An orientation ground survey using a portable shortwave infrared analyser (PIMA II) confirmed that discrimination of magnesite-rich areas in the dominantly dolomitic sediments was possible. A trial airborne survey over 30 km strike length of the Screechowl deposit was completed in March, 1998 using the Australian manufactured HyMap hyperspectral scanner which operates with 128 bands across the 0.42-2.5 μm spectral region. Flight altitudes were chosen to achieve effective pixel sizes of less than 5 m. Preliminary image processing of the HyMap data aimed to produce data which approximates laboratory HyMap reflectance spectra of pure minerals. Multistage processing using the dark current image, HyMap laboratory spectra of magnesite, dolomite and halon target enabled reduction of the original 128 channels to 12 significant, noise free bands. Using linear spectral unmixing and pure end-members selected

  8. Bibliographical study on the high-purity germanium radiation detectors used in gamma and X spectrometry

    International Nuclear Information System (INIS)

    The germanium or silicon lithium-drifted detectors, Ge(Li) or Si(Li), and high-purity germanium detectors, HP Ge (impurity concentration approximately 1010cm-3), are the most commonly used at the present time as gamma and X-ray spectrometers. The HP Ge detectors for which room temperature storage is the main characteristic can be obtained with a large volume and a thin window, and are used as the Ge(Li) in γ ray spectrometry or the Si(Li) in X-ray spectrometry. This publication reviews issues from 1974 to 1978 on the state of the art and applications of the HP Ge semiconductor detectors. 101 bibliographical notices with French summaries are presented. An index for authors, documents and periodicals, and subjects is included

  9. Investigation of possibilities of application of neutron capture gamma-ray spectrometry for cement manufactures control

    International Nuclear Information System (INIS)

    Full text: Creation of system of Automatic Management of Technological Processes in cement industry still remains an actual problem, solution of which leads to increase in volume and improvement in the quality of the ready product, and also gives opportunity to effective use of electro energy and raw material resources. In preparation of cement acute stands the question of realization of operative control of the content of main technologically important elements: like Ca, Mg, Fe, Si and Al in the initial raw material and different content must be determined on the technological stream. Among existing analytical methods, nuclear physics method based on prompt gamma radiation of neutron capture spectrometry is one of the better possibilities/1,2/. In this work, results of investigation of possibilities of express determination of technological important elements: Ca, Mg, Fe, Si and Al in the initial raw material by the method of neutron capture prompt gamma - ray spectrometry. Laboratory model of low power radionuclide (252Cf) - source of neutrons with the yield of 5x106 neutron/sec. Measuring equipment consists of semiconductor Ge (Li) - detector with volume of sensitive crystal, 40 sm3 and energy resolution of 4 keV on the line of 60Co with the energy of 1333 keV and multichannel pulse analyzers AI-1024-95. Possibility of express determination of concentration of technologically important elements in the initial raw material of Kyzylkum by means of using neutron capture gamma radiation spectrometry with parameters meeting production requirements of cement industry of Uzbekistan

  10. Gamma spectrometry and chemical characterization of bioactive glass seeds with Holmium-166 for oncological implants

    International Nuclear Information System (INIS)

    Bioactive glass seeds synthesized by the sol-gel technique with Si:Ho:Ca composition with natural holmium incorporated were irradiated in the TRIGA type nuclear reactor IPR-R1 at 100kW, in the central thimble where the thermal neutron flux is 2.8x1012 n/cm2.s and the epithermal neutron flux is 2.6 X 1011 n/cm2.s . After an 8 hour irradiation time, with an induced activity close to 110MBq/seed, a set of seeds was submitted to Gamma Spectrometry Analysis in a counting system with an HPGe detector, ORTEC electronic instrumentation and a Camberra Multichannel Analyser, to determine all radionuclides present on the sample as well as its individual activities. Special attention was paid on the discrimination of Si, 40Ca, 44Ca, C and Ho as the other expected elements like 48Ca, 2H and 18O were present in traces or have very short half-lives. The second sample was submitted to Plasma spectrometry to determine the 166Ho concentration in weight. The third sample was submitted to an X-ray spectrometry in a JEOL-JXA-8900RL equipment to determine its qualitative chemical composition, in order to evaluate impurities and nominal composition. It was determined that most of the activity, after decaying of short half-life elements, was due to 166Ho present on the sample, with a well characterized β and gamma spectra. The homogeneity of the seeds was tested on the X-ray spectrometry, and verified that there is no discrepancy in composition from distinct seeds or in a same seed. The results are relevant on the investigation of the viability of producing 166Ho radioactive seeds for oncological implants. (author)

  11. Thorium determination in intercomparison samples and in some Romanian building materials by gamma ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Pantelica, A.; Georgesecu, I.I.; Murariu-Magureanu, M.D.; Margaritescu, I.; Cincu, E

    2001-07-01

    Thorium content in zircon sand, thorium ore and thorium liquid sample (EU Laboratories Network Intercomparison), as well as in some Romanian building materials: sand, wood, tufa, asbestos-cement, cement mill dust, coal fly ash, bricks, and tile (28 samples) were determined by gamma ray spectrometry. For the building materials, {sup 226}Ra, {sup 40}K and {sup 137}Cs specific activities were also measured. The results were compared with the Romanian legal norms concerning the highest admissible levels for {sup 232}Th, {sup 226}Ra, and {sup 40}K radioactivity, and to Th, U, and K concentration values previously determined in our laboratory on similar types of samples. (author)

  12. Thorium determination in intercomparison samples and in some Romanian building materials by gamma ray spectrometry

    International Nuclear Information System (INIS)

    Thorium content in zircon sand, thorium ore and thorium liquid sample (EU Laboratories Network Intercomparison), as well as in some Romanian building materials: sand, wood, tufa, asbestos-cement, cement mill dust, coal fly ash, bricks, and tile (28 samples) were determined by gamma ray spectrometry. For the building materials, 226Ra, 40K and 137Cs specific activities were also measured. The results were compared with the Romanian legal norms concerning the highest admissible levels for 232Th, 226Ra, and 40K radioactivity, and to Th, U, and K concentration values previously determined in our laboratory on similar types of samples. (author)

  13. Evaluation of independent and cumulative fission product yields with gamma spectrometry

    International Nuclear Information System (INIS)

    Fission product yields are critical data for a variety of nuclear science and engineering applications; however, independent yields have not been extensively measured to date. We have previously documented a methodology to measure the cumulative and independent fission product yields using gamma spectrometry and nuclide buildup and decay modeling, and numerical optimization. We have produced fission products by bombarding 235U with 14.1 MeV neutrons and made measurements of fission product yields. In this paper, we summarize our approach, describe initial experiments, and present preliminary results where we have determined nine fission product yields for long-lived nuclides. (author)

  14. Direct gamma-X spectrometry measurements for energies below 100 keV in environmental samples

    International Nuclear Information System (INIS)

    Extending the validity of direct (without radiochemistry) gamma spectrometry measurement below 100 keV is of interest to quantify 234Th, 241Am, 210Pb and 129I. The relative increase of the photoelectric cross-section below 100 keV compared to the Compton one oblige to take into account the self-absorption in the sample. The experimental measurement of the absorption coefficient gives this contribution. Applying to different solid matrices from the environment (soil, sediment, sand, algae, mussels, fishes, terrestrial moss, milk), dried or ashed, results are presented. (authors)

  15. Overview of gamma spectrometry measurement devices developed by ENVINET a.s

    International Nuclear Information System (INIS)

    This paper demonstrates the development and usage of the devices designed for non- destructive radiological characterization of radioactive waste. All ..systems are based on gamma-spectrometry and are divided into two categories - stable and mobile. Stable ones involve only measurement in fixed detector - package configuration. They are used for assessment of packaged waste, mainly in drums. Mobile ones are flexible and allow measurement of a wide range of objects from various positions and can be also transported to arbitrary location. The calibration of such systems is performed by means of appropriate software which allows computation of full-energy peak efficiency in various configurations. (authors)

  16. Source term estimation based on in-situ gamma spectrometry using a high purity germanium detector

    International Nuclear Information System (INIS)

    An alternative method to reconstruct the source term of a nuclear accident is proposed. The technique discussed here involves the use of in-situ gamma spectrometry. The validation of the applied methodology has been possible through the monitoring of routine releases of Ar-41 originating at a Belgian site from an air cooled graphite research reactor. This technique provides a quick nuclide specific decomposition of the source term and therefore will be have an enormous potential if implemented in nuclear emergency preparedness and radiological assessments of nuclear accidents during the early phase

  17. Determination of trace elements and cosmogenic radionuclides in meteorites by neutron activation analysis and gamma spectrometry

    International Nuclear Information System (INIS)

    In the meteorites trace elements have been determined by instrumental and radiochemical N.A.A. and the cosmogenic radioactivity of 22Na, 26Al, 48V, and 54Mn are measured by low-level gamma spectrometry in the two meteorites Hohenlangenbeck and Trebbin fallen November 1985 and March 1988 onto the territory of the GDR. The contents of Rb and Cs in the meteorite Hohenlangenbeck are relatively high indicating a low condensation temperature. Because of the small activity ratio of 22Na/26Al a lower particle flux in its orbit during the last five years is assumed. (author)

  18. Car-borne gamma spectrometry: a virtual exercise in emergency response

    DEFF Research Database (Denmark)

    Dowdall, M.; Smethurst, M.A.; Watson, R.;

    2012-01-01

    In recent years car-borne gamma spectrometry has expanded from its role as a geological survey platform to being a useful asset in searching for orphan sources and for surveying in the aftermath of an incident involving the release of radioactive materials. The opportunities for gaining practical......-borne measurements to a larger group, a virtual exercise was devised. The exercise ORPEX (Orphan Sources and Fresh Fallout Virtual Exercise in Mobile Measurement) featured two typical emergency scenarios: a search for orphan sources and surveying to delineate fallout from a local release point. Synthetic spectral...

  19. Evaluation of radiological data of some saturated fatty acids using gamma ray spectrometry

    Science.gov (United States)

    Kore, Prashant S.; Pawar, Pravina P.; Palani Selvam, T.

    2016-02-01

    Radiological parameters such as mass attenuation coefficients (μm), total attenuation cross section (σtot), molar extinction coefficient (ε), mass energy absorption coefficient (μen/ρ) and effective electronic cross section (σt, el) of saturated fatty acids, namely butyric acid (C4H8O2), caproic acid (C6H12O2), enanthic acid (C7H14O2), caprylic acid (C8H16O2), pelargonic acid (C9H18O2) and valeric acid (C5H10O2) were measured using NaI(Tl)-based gamma spectrometry. Radioactive sources used in the study are 57Co, 133Ba, 137Cs, 54Mn, 60Co and 22Na. Gamma ray transmission method in a narrow beam good geometry set up was used in the study. The measured data were compared against Win-XCOM-based data. The agreement is within 1%.

  20. Method of gamma ray spectrometry for measuring environmental samples around nuclear power plant

    International Nuclear Information System (INIS)

    The authors present the methodology of γ-spectrometry, which has been set up for determining natural and artificial radionuclides in environmental samples around nuclear power plant with germanium detector-spectrometer systems. The following points are described: the preparation of standard samples and calibration of efficient curve (or calibration coefficients); the consideration of coincidence summing correction related to cascade gamma radiations; self-absorption correction of gamma rays in samples; the detection limits of γ-spectrometer in authors' measurement conditions; the calculation methods used in determining net areas of peaks for some nuclides identified in spectrum; the error analysis and estimation, etc.. In order to reduce errors and fully to utilize the spectrum data, the method of calculating the contents of nuclides 226Ra, 228Ra and 228Th in samples is presented

  1. In-Situ Gamma Spectrometry Measurement of Environmental Radioactivity in Israel

    International Nuclear Information System (INIS)

    In-situ, high-resolution gamma spectrometry is a well-established, nondestructive, rapid and efficient method for detection, identification and quantitative determination of radioactivity in the environment, mainly in soils. Measurements were performed in the soils, along selected areas of southern and northern Israel, for the determination of background radiation levels and soil distributions of natural radionuclides and Chernobyl fallout. An independent analytical method was applied to substantiate the in-situ measurements by collecting soil samples from the site and measuring them in the laboratory. Soil sampling was performed also for obtaining information on radioactivity depth distribution and on the uniformity of superficial concentration of top-soil radioactivity. Exposure rate measurement from gamma radiation at the same site were also performed

  2. Accurate determination of the 235U isotope abundance by gamma spectrometry

    International Nuclear Information System (INIS)

    The purpose of this manual is to serve as guide in applications of the Certified Reference Material EC-NRM-171/NBS-SRM-969 for accurate U-235 isotope abundance measurements on bulk uranium samples by means of gamma spectrometry. The manual provides a thorough description of this non-destructive assay technique. Crucial measurement parameters affecting the accuracy of the gamma-spectrometric U-235 isotope abundance determination are discussed in detail and, whereever possible, evaluated quantitatively. The correction terms and tolerance limits given refer both to physical and chemical properties of the samples under assay and to relevant parameters of typical measurement systems such as counting geometry, signal processing, data evaluation and calibration. (orig.)

  3. Standard test method for quantitative determination of americium 241 in plutonium by Gamma-Ray spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1994-01-01

    1.1 This test method covers the quantitative determination of americium 241 by gamma-ray spectrometry in plutonium nitrate solution samples that do not contain significant amounts of radioactive fission products or other high specific activity gamma-ray emitters. 1.2 This test method can be used to determine the americium 241 in samples of plutonium metal, oxide and other solid forms, when the solid is appropriately sampled and dissolved. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  4. Compton suppressed gamma-spectrometry for Comprehensive Nuclear-Test-Ban Treaty samples

    International Nuclear Information System (INIS)

    The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is supported by a network of certified laboratories that perform high-resolution gamma-spectrometry on global air filter samples for the identification of 85 radionuclides. At the UK CTBT Radionuclide Laboratory (GBL15), the use of advanced Compton suppressed systems has been investigated to reduce the Compton continuum and improve detection sensitivity. Samples collected from the Philippines and during the Fukushima incident have been measured, demonstrating Compton continuum reductions of 28-59% with suppression factors of 0.1-147.0. Detection sensitivity has been improved with typically 40% lower MDAs, including 140Ba to meet CTBT requirements. True coincidence summing effects have been considered, including the application to remove interferences by the elimination of gamma-rays in cascade. This has been demonstrated for the removal of 134Cs allowing improved 131I measurement. (author)

  5. In situ gamma-ray spectrometry: A tutorial for environmental radiation scientists

    International Nuclear Information System (INIS)

    This tutorial is intended for those in the environmental field who perform assessments in areas where there is radioactive contamination in the surface soil. Techniques will be introduced for performing on-site quantitative measurements of gamma radiation in the environment using high resolution germanium detectors. A basic understanding of ionizing radiation principles is assumed; however, a detailed knowledge of gamma spectrometry systems is not required. Emphasized is the practical end of operations in the field and the conversion of measured full absorption peak count rates in a collected spectrum to meaningful radiological quantities, such as the concentration of a radionuclide in the soil, activity per unit area, and dose rate in the air. The theory of operation and calibration procedures will be covered in detail to provide the necessary knowledge to adapt the technique to site-specific problems. Example calculations for detector calibration are also provided

  6. The influence of exogenous conditions on mobile measured gamma-ray spectrometry

    Science.gov (United States)

    Dierke, C.; Werban, U.; Dietrich, P.

    2012-12-01

    In the past, gamma ray measurements have been used for geological surveys and exploration using airborne and borehole logging systems. For these applications, the relationships between the measured physical parameter - the concentration of natural gamma emitters 40K, 238U and 232Th - and geological origin or sedimentary developments are well described. Based on these applications and knowledge in combination with adjusted sensor systems, gamma ray measurements are used to derive soil parameters to create detailed soil maps e.g., in digital soil mapping (DSM) and monitoring of soils. Therefore, not only qualitative but also quantitative comparability is necessary. Grain size distribution, type of clay minerals and organic matter content are soil parameters which directly influence the gamma ray emitter concentration. Additionally, the measured concentration is influenced by endogenous processes like soil moisture variation due to raining events, foggy weather conditions, or erosion and deposition of material. A time series of gamma ray measurements was used to observe changes in gamma ray concentration on a floodplain area in Central Germany. The study area is characterised by high variations in grain size distribution and occurrence of flooding events. For the survey, we used a 4l NaI(Tl) detector with GPS connection mounted on a sledge, which is towed across the field sites by a four-wheel-vehicle. The comparison of data from different time steps shows similar structures with minor variation between the data ranges and shape of structures. However, the data measured during different soil moisture contents differ in absolute value. An average increase of soil moisture of 36% leads to a decrease of Th (by 20%), K (by 29%), and U (by 41%). These differences can be explained by higher attenuation of radiation during higher soil moisture content. The different changes in nuclide concentration will also lead to varying ratios. We will present our experiences concerning

  7. Nuclear Materials Identification System (NMIS) with Gamma Spectrometry for Attributes of Pu, HEU, and Detection of HE and Chemical Agents

    International Nuclear Information System (INIS)

    A combined Nuclear Materials Identification System (NMIS)-gamma ray spectrometry system can be used passively to obtain the following attributes of Pu: presence, fissile mass, 240/239 ratio, and metal vs. oxide. This system can also be used with a small, portable, DT neutron generator to measure the attributes of highly enriched uranium (HEU): presence, fissile mass, enrichment, metal vs. oxide; and detect the presence of high explosives (HE). For the passive system, time-dependent coincidence distributions can be used for the presence, fissile mass, metal vs. oxide for Pu, and gamma-ray spectrometry can be used for 239/240 ratio and presence. So presence can be confirmed by two methods. For the active system with a DT neutron generator, all four attributes for both Pu and HEU can be determined from various features of the time-dependent coincidence distribution measurements for both Pu and HEU. Active gamma ray spectrometry would also give presence and 240/239 ratio for Pu, enrichment for HEU, and metal vs. oxide for both. Active gamma ray spectrometry would determine the presence of HE. The various features of time-dependent coincidence distributions and gamma ray spectrometry that determine these attributes are discussed with some examples from previous determinations

  8. Possibilities for applying gamma-spectrometry software ANGLE in isotope hydrology analytical procedures

    International Nuclear Information System (INIS)

    ANGLE software for gamma-spectrometry (semiconductor detector gamma-efficiency calculations, in particular) in its various forms has been in use for 15 years in numerous gamma-spectrometry laboratories all around. ANGLE is basically a semi-empirical model for efficiency calculations, which combines the advantages of both absolute and relative approach, while attempting to minimize their drawbacks. The physical model behind is the concept of the effective solid angle, which is calculated upon the input data on the geometrical and physical characteristics of (1) the source (including the container vessel), (2) the detector and (3) the counting arrangement (including intercepting layers between the latter two). It was shown earlier that only the simultaneous differential treatment of gamma-attenuation, geometry and detector response, as in ANGLE, is essentially justified for this type of calculations. The program can be applied to practically all counting situations encountered in laboratory practice: point, disc, cylindrical or Marinelli sources and any matrix composition. No standards are required, but a so called 'reference efficiency curve' should be obtained ('once for ever') by measuring a set of calibrated point sources. As a summary, ANGLE is characterized by (1) a very broad application range, (2) satisfactory accuracy (of the order of a few percent), (3) easy data manipulation (under WINDOWS), (4) short computation times, (5) flexibility in respect with input parameters and (6) suitability for didactical purposes. Possibilities for applying ANGLE in isotope hydrology analytical procedures (e.g. with radioactive tracers involved), are discussed. Tracer techniques are of particular interest for water resources management in Mediterranean karstic regions, typically abundant with precipitation in winter, but scarce with ground waters in summer - like is the case with east coast of Adriatic, including the coastal part of Montenegro. (author)

  9. Identification of. gamma. -irradiated spices by electron spin resonance (ESR) spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Uchiyama, Sadao; Kawamura, Yoko; Saito, Yukio (National Inst. of Hygienic Sciences, Tokyo (Japan))

    1990-12-01

    The electron spin resonance (ESR) spectrometry spectra of white (WP), black (BP) and red (Capsicum annuum L. var. frutescerns L., RP) peppers each had a principal signal with a g-value of 2.0043, and the intensities of the principal signals were increased not only by {gamma}-irradiation but also by heating. Irradiated RP also showed a minor signal -30G from the principal one, and the intensity of the minor signal increased linearly with increasing dose from 10 to 50 kGy. Since the minor signal was observed in RP irradiated at 10 kGy and stored for one year, but did not appear either after heating or after exposure to this signal is unique to {gamma}-irradiated RP and should therefore be useful for the identification of {gamma}-irradiated spices of Capsicum genus, such as paprika and chili pepper. The computer simulation of the ESR spectra suggested that the minor signal should be assigned to methyl radical and the principal signal mainly to a combination of phenoxyl and peroxyl radicals. Such minor signals were found in {gamma}-irradiated allspice and cinnamon among 10 kinds of other spices. (author).

  10. Rapid determination of 237Np in soil samples by multi-collector inductively-coupled plasma mass spectrometry and gamma spectrometry

    International Nuclear Information System (INIS)

    A radiochemical procedure is developed for the determination of 237Np in soil with multi-collector inductively-coupled plasma mass spectrometry (MC-ICP-MS) and gamma-spectrometry. 239Np (milked from 243Am) was used as an isotopic tracer for chemical yield determination. The neptunium in the soil is separated by thenoyl-trifluoracetone extraction from 1 M HNO3 solution after reducing Np to Np(IV) with ferrous sulfamate, and then purified with Dowex 1 x 2 anion exchange resin. 239Np in the resulting solution is measured with gamma-spectrometry for chemical yield determination while the 237Np is measured with MC-ICP-MS. Measurement results for soil samples are presented together with those for two reference samples. By comparing the determined value with the reference value of the 237Np activity concentration, the feasibility of the procedure was validated. (author)

  11. Insights into the Structure and Surface Geology of Isla Socorro, Mexico, from Airborne Magnetic and Gamma-Ray Surveys

    Science.gov (United States)

    Paoletti, V.; Gruber, S.; Varley, N.; D'Antonio, M.; Supper, R.; Motschka, K.

    2016-05-01

    The island of Socorro is located in the eastern Pacific Ocean, 650 km off the coast of Mexico. It is a rare example of an oceanic volcanic island whose above sea level volume is made up mostly of peralkaline trachytes and rhyolites, with subordinate mafic rocks. Subaerial volcanism started several hundred thousand years ago and continues until recent times. We present an investigation of surface and subsurface geology of the island, based on the first detailed extensive geophysical survey on the island. Acquired airborne magnetic and gamma-ray data were compared to existing geological information and supplemented with field investigations and satellite imagery. Magnetic data show a wide minimum in the central part of the island, possibly connected to a high-temperature zone in the deeper central portion of the volcano, likely to be due to a still hot magma body. The data also depict two parallel edges possibly suggesting the existence of a nested caldera. Analysis on upward continued magnetic data by recent imaging techniques highlighted two deep sources located around 5 km b.s.l., interpreted as feeding structures that are now filled with crystalline rocks. Gamma-ray data have been interpreted through integration with the geological survey results. Several previously known volcanic deposits have been identified based on radioelement distribution, and others have been redefined based on field evidence. A new succession of volcanic members is proposed, to be verified through more detailed geological mapping, geochemical analyses of rock samples and radiometric dating.

  12. Examination of an Irradiated Fuel Pin Segment by Laser Scanning Profilometry, Gamma Spectrometry and Neutron Radiography

    International Nuclear Information System (INIS)

    Paul Scherrer Institute (PSI) conducts post-irradiation examinations (PIE) on fuel pins irradiated in nuclear power plants. During poolside inspections of the nuclear fuel at one of these plants, an intact fuel pin showed a small deviation in diameter along several mm of the axial elevation. The pin was added to the fuel delivery transport to PSI in the frame of a surveillance program. To detect the exact dimensions of the pin section, a laser scanning profilometer was adapted for hot cell use by mirroring the laser beam. The examined length of the found clad necking matched the nominal length of one fuel pellet, indicating a missing or diameter reduced pellet. Axial gamma spectrometry confirmed the match of the neckings's length with the pellet gaps indicated by higher cesium count rates. The azimuthal variation in cladding diameter was confirmed by gamma spectrometry angle dependent mappings. To investigate the pellet integrity without destructive methods, a neutron radiography was decided for. After cutting a segment of the pin, the radiography at the PSI neutron irradiation facility SINQ revealed one pellet with variations in diameter, but without abnormal structural defects. This paper outlines the combination of the three non-destructive methods as well as technical descriptions of the methods and some results of the examinations. (author)

  13. Decision Threshold and Detection Limit in Spectrometric Measurements. Part 1: Application to Gamma Spectrometry

    International Nuclear Information System (INIS)

    This report summarised the author's lecture of the advanced gamma spectrometry course organised by CIEMAT. The characteristic limits determination in gamma spectrometry generally is obtained through the programming that the trade marks offers to the client with the objective of the automatic calculation of the activity concentrations existing in a sample. In this report, the examples shown in the ISO 11929 standard are compared to the programming realised by Genie 2k for determining characteristic limits. The main difference of both is located in the uncertainty calculations due to the efficiency calibration that is considered by ISO and not by Genie 2K. Through implementation in the software developed by trade marks will be possible to introduce this uncertainty and to assimilate to the calculation done by ISO 11929. In the second part of this report will be analyzed the more complicated samples of this application as counting in a whole body counter (following ISO-28218 about Performance Criteria for radio bioassay), multiplet, overlapping, addition of several peaks for obtaining the activity concentration, etc. (Author) 19 refs.

  14. The Dortmund Low Background Facility - Low-Background Gamma Ray Spectrometry with an Artificial Overburden

    CERN Document Server

    Gastrich, Holger; Klingenberg, Reiner; Kröninger, Kevin; Neddermann, Till; Nitsch, Christian; Quante, Thomas; Zuber, Kai

    2015-01-01

    High-purity germanium (HPGe) detectors used for low-background gamma ray spectrometry are usually operated under either a fairly low overburden of the order of one meter of water equivalent (mw.e.) or a high overburden of the order of 100mw.e. or more, e.g. in specialized underground laboratories. The Dortmund Low Background Facility (DLB) combines the advantages of both approaches. The artificial overburden of 10mw.e. already shields the hadronic component of cosmic rays. The inner shielding, featuring a state-of-the-art neutron shielding and an active muon veto, enables low-background gamma ray spectrometry at an easy-accessible location at the campus of the Technische Universit\\"at Dortmund. The integral background count rate between 40keV and 2700keV is 2.528+-0.004counts/kg/minute. This enables activity measurements of primordial radionuclides in the range of some 10mBq/kg within a week of measurement time.

  15. Determination of {sup 7}BE in soil sample by gamma spectrometry for erosion researchs

    Energy Technology Data Exchange (ETDEWEB)

    Esquivel, Alexander D., E-mail: alexander.esquivel@utp.ac.pa [Centro de Investigaciones Hidraulicas e Hidrotecnicas (CIHH/UTP-PA), Universidad Tecnologica de Panama (Panama); Kastner, Geraldo F.; Amaral, Angela M.; Monteiro, Roberto Pellacani G.; Moreira, Rubens M., E-mail: gfk@cdtn.br, E-mail: ama@cdtn.br, E-mail: rpgm@cdtn.br, E-mail: rubens@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    Cosmogenic {sup 7}Be is a natural radiotracer produced in the stratosphere and troposphere and reached to the Earth surface via wet and dry fallout and hence its measurement for research of erosion in soils is very significant. The {sup 7}Be radio analyse based on gamma spectrometry technique has been a routine methodology for decades and although is the reference procedure is not free of analytical interference. {sup 7}Be is a β-γ emitting radionuclide (Eγ = 477.59 keV, T½ = 53.12d) and depending on the chemical profile of the soil its determination is susceptible to {sup 228}Ac (E{sub γ} = 478.40 keV, T½ = 6.15h) interference. The aim of this work was to establish an analytical protocol for the {sup 7}Be determination in soil samples from Juatuba-Mg region in different sampling periods of dry and rainy seasons for erosion studies and to establish some methodologies for evaluating and correcting the interference level of {sup 228}Ac in the {sup 7}Be activity measurements by gamma spectrometry. (author)

  16. Analytic method development to quantify by in-situ gamma spectrometry radionuclides in the ground

    International Nuclear Information System (INIS)

    This research thesis reports the development of an analytic method based on a Monte Carlo simulation to quantify radionuclides present in soils by means of in-situ gamma spectrometry, to understand physical phenomena involved before and after detection, and to improve and complement results after spectrum analysis. The first part describes the evolution of in-situ gamma spectrometry: sensor development, in-situ measurement principle, evolution of the analysis principle. The second part introduces the Monte Carlo simulation and describes the used models (sensor model using the stripping method, development of a new simulation model for the incident flow). The third part discusses the understanding of an in-situ spectrum with the localization of the origin of incident photons and the identification of measurement parameters. Modelling results are then presented, as well as the development of spectrum de-convolution method, and the calculation of dose factors. Finally, the use of the 'Peak-to-Valley' method completed by the Monte Carlo simulation results is explained and used to localize a source depth and to define the exponential distribution of Cs-137 in Orsay

  17. Determination of Pu isotopic composition and 241Am by high resolution gamma spectrometry on solid samples

    International Nuclear Information System (INIS)

    The present report gives a detailed account of the development of non-destructive assay technique using high resolution gamma-ray spectrometry (HRGS) for determination of plutonium (Pu) isotopic composition and the 241Am content in solid Pu samples. Energy range 120-420 keV was used in this study. The methodology involves in situ relative efficiency calibration during the measurement process itself, to reduce the errors and increase the reliability of the method. Twenty solid Pu samples of power reactor and research reactor grade were analyzed by this method and the results were compared with those obtained by thermal ionization mass spectrometry. The accuracy of the final results depends strongly upon the accuracy of the available nuclear data (decay constant, gamma abundance etc.). MATLAB based programme was written to perform the analysis. A counting time of 4 hour was chosen for achieving good statistics on the results for samples having 100-200 mg of Pu. The attainable accuracy is found to be 0.5-1% for the fissile isotopes (239Pu + 241Pu) and 5-10% for 241Am content. (author)

  18. Low-level gamma-ray spectrometry for analysing fusion plasma conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wieslander, J.S. Elisabeth [EU Commission - JRC - IRMM, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Department of Physics, P.O. Box 35 (YFL), FIN-40014 University of Jyvaeskylae (Finland)], E-mail: elisabeth.wieslander@gmail.com; Hult, Mikael [EU Commission - JRC - IRMM, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium)], E-mail: mikael.hult@ec.europa.eu; Bonheure, Georges [Laboratory for Plasma Physics, Association ' Euratom-Belgian State' , Royal Military Academy, Avenue de la Renaissance, 30 Kunstherlevinglaan, B-1000 Brussels (Belgium); Arnold, Dirk; Dombrowski, Harald [Physikalisch-Technische Bundesanstalt, Bundesallee 100, D-38116 Braunschweig (Germany); Gasparro, Joel [EU Commission - JRC - IRMM, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Laubenstein, Matthias [Laboratori Nazionali del Gran Sasso, S.S. 17/bis, km 18-910, I-67010 Assergi (AQ) (Italy); Marissens, Gerd [EU Commission - JRC - IRMM, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Vermaercke, Peter [SCK-CEN, Boeretang, B-2400 Mol (Belgium)

    2008-06-21

    A new method, combining activation by neutrons and charged particles with ultra low-level gamma-ray spectrometry, aimed at obtaining a better understanding and more adequate measurements of MeV particle leaks in magnetic fusion devices was studied here. A total of 36 samples containing Ti, LiF, B{sub 4}C and W were placed in a boron-nitride holder mounted on the ceiling of the JET Tokamak. The samples were activated by 63 pulses from a D-{sup 3}He plasma and were later measured using underground gamma-ray spectrometry. The radionuclides {sup 7}Be, {sup 46}Sc, {sup 54}Mn, {sup 56}Co, {sup 57}Co, {sup 58}Co, {sup 124}Sb, {sup 181}Hf, {sup 182}Ta, {sup 181}W and {sup 185}W were detected in several of the samples, with very low levels of activity of {sup 47}Sc and {sup 48}V found in a few of the samples. The various production channels for the radionuclides in question are discussed.

  19. Prompt gamma-ray spectrometry for measurement of B-10 concentration in brain tissue and blood

    International Nuclear Information System (INIS)

    Boron-10 (B-10) concentration in the brain tissue and blood was measured continuously for 24 hours after injection of the B-10 compound in live rabbits using prompt gamma-ray spectrometry. Following injection of B-10 compound (Na2B12H11SH, 50mg/kg) dissolved in physiological saline, B-10 concentration was continuously measured in the brain tissue. Intermittently the concentration of B-10 in blood and cerebro-spinal fluid (CSF) was also measured. In 10 minutes after the injection of B-10 compound, the level of B-10 concentration reached the peak of 400-500 ppm in blood and 20-30 ppm in the normal brain tissue. In 60 minutes the level of B-10 concentration rapidly decreased and then a gradual decline was observed. The value was 15-30 ppm at 3 hours after injection, 5-10 ppm at 6 hours and 2-5 ppm at 24 hours in the blood. The concentration in the brain tissue was 3-8 ppm at 3 hours, 2-5 ppm at 6 hours and below 1.5 ppm at 24 hours. B-10 concentration in cerebro-spinal fluid was below 1 ppm. B-10 concentration was also measured in the brain tumor and blood in the human cases at boron neutron capture therapy (BNCT). These data studied by prompt gamma-ray spectrometry are very important and useful to decide the irradiation time. (author)

  20. Radioactivity measurements in soils surrounding four coal-fired power plants in Serbia by gamma-ray spectrometry and estimated dose

    Directory of Open Access Journals (Sweden)

    Vukašinović Ivana Ž.

    2014-01-01

    Full Text Available The study of spatial distribution of activity concentration of 238U, 226Ra, 210Pb, 232Th, 40K, and 137Cs radionuclides in the surface soil samples (n = 42 collected in the vicinity of four coal-fired power plants in Serbia is presented. Radioactivity measurements in soils performed by gamma-ray spectrometry showed values [Bqkg-1] in the range: 15-117 for 238U, 21-115 for 226Ra, 33-65 for 210Pb, 20-69 for 232Th, 324-736 for 40K, and 2-59 for 137Cs. Surface soil radio-activity that could have resulted from deposition of radionuclides from airborne discharges or resuspension of ash from disposal sites showed no enhanced levels. It was found that variation of soil textural properties, pH values, and carbonate content influenced activity levels of natural radionuclides while radiocesium activities were associated with soil organic matter content. Modification of some soil properties was observed in the immediate vicinity (<1 km of power plants where the soil was more alkaline with coarser particles (0.2-0.05 mm and carbonates accumulated. Calculated average values of the absorbed gamma dose rate and annual external effective dose originating from the terrestrial radionuclides were 69.4 nGy/h and 0.085 mSv, respectively. [Projekat Ministarstva nauke Republike Srbije, br. 4007: Studying climate change and its influence on the environment: impacts, adaptation and mitigation

  1. Estimating and accounting for 137Cs source burial through in situ gamma spectrometry in salt marsh environments

    International Nuclear Information System (INIS)

    The use of in-situ gamma ray spectrometry provides a means of rapidly estimating environmental radioactivity inventories. However, one of the principal limitations of this technique has been the influence of variations in vertical activity distribution on the observed photon fluence. This paper demonstrates that the quantification of the forward scattered ratio of the spectrum (Q) can be used to: (i) estimate the mean mass depth (β) of the vertical activity distribution within sediment profiles, and (ii) provide a calibration correction coefficient for in-situ gamma spectrometry in environments which exhibit variable and non-exponential activity distributions, such as salt marshes around the Irish Sea

  2. Performance of HPGe gamma spectrometry system for the measurement of low level radioactivity

    International Nuclear Information System (INIS)

    Comprehensive quality assurance/quality control procedure is very much necessary to obtain accurate and precise analytical measurement result. This paper discusses the quality control aspects of the High-Purity Germanium (HPGe) based gamma spectrometry system, which has been used for the measurement of low-level radioactivity in environmental samples. The gamma spectrometry system consisting of coaxial n-type HPGe detector having 50% relative efficiency with respect to 7.62 cm x 7.62 cm NaI (Tl), Nuclear Instrumentation Module (NIM) based pulse processing electronic accessories and 8 k MCA. To reduce the background contribution, 7.5 cm thick lead has been placed surrounding the detector. The minimum detectable activities (MDA) with 95% confidence level (for 300 g soil sample and 100,000 s counting time) for important radionuclides such as 238U, 226Ra, 232Th, 40K, and 137Cs are 10.4, 4.3, 4.1, 16.9 and 0.1 Bq kg-1, respectively. The Quality control (X bar R) charts were plotted using 137Cs and 40K background counts observed periodically, which showed that the fluctuation is well within the confidence limit and confirms the stability of the system. The laboratory has been participating in the proficiency tests (PTs) of the International Atomic Energy Agency (IAEA). In recently concluded PTs, the samples include soil, spiked standard solution, spinach, phosphogypsum and spiked air filter were analysed for the natural, fission and activation products radionuclides. The performance evaluation of the IAEA PTs showed that the laboratory results were in good agreement with the target value, which confirms the reliability and traceability of the gamma spectrometric measurement result of the laboratory. (author)

  3. The design of shielding material for ultra low-background gamma-ray spectrometry

    International Nuclear Information System (INIS)

    A study of gamma and neutron backgrounds has been performed, based on Monte Carlo simulations combined with radio purity data. With reference to other papers and reports, materials of radiation shielding structure was determined. Then, the thickness of each material is determined by the GEANT4 simulation. In the future the gamma and neutron background radiation will be measured with shielded detector and non-shielded detector to calculate the actual TR. It will be compared with the results of the GEANT4 simulation. Also it is planned an active shielding to reduce cosmic muons with an anti-coincidence of a pair of plastic scintillators and a passive shielding with nitrogen gas. Development and performance of an ultra low-background γ-ray spectrometer will be performed at Dongnam Inst. of Radiological and Medical Sciences (DIRAMS) as basic tool for various radioactivity measurements. Gamma-ray spectrometry with a HPGe detector is widely used for the identification and activity measurements of radionuclides in a sample, impurity checks of a standard source, determination of emission probabilities in radioactive decay, and low level counting's. In low-level counting's, a variety of techniques to reduce the background have been employed and makes it possible to radio assay an environmental sample containing a trace of γ-emitting radio nuclides. The application of γ-spectrometry for environmental monitoring of radioactivity requires as low detection limits as practically achievable due to the limited amount of sample provided for measurement and the relatively low concentrations. We present in this paper a study of shielding materials for ultra low-background shielding structure and a calculation of transmission rate (TR) of the shielded structure using the GEANT4 simulation code

  4. Airborne gamma survey of the historic Sleisbeck mine area in the Northern Territory, Australia, and its use for site rehabilitation planning

    International Nuclear Information System (INIS)

    An airborne γ-survey provided information about the extent of radioactive contamination around the historic Sleisbeck mine. Quickbird satellite data were acquired to relate airborne measurements to land cover features. Enhanced equivalent uranium (eU) levels were found to be confined to the mine and low grade waste rock dumps. The average terrestrial background radiation dose rate estimated from the airborne gamma survey data was 0.10-0.14 μGy h-1 while the area around the mine exhibited a maximum of ∼2.3 μGy h-1, but measurements on the ground indicate that this maximum is exceeded in some localized areas. Rehabilitation of the site is likely to result in a threefold reduction in radiation doses to people accessing the area

  5. Determination Performance Of Gamma Spectrometry Co-Axial HPGE Detector In Radiochemistry And Environment Group, Nuclear Malaysia

    International Nuclear Information System (INIS)

    Gamma Spectrometry System is used to measure qualitatively and quantitatively a gamma emitting radionuclide. The accuracy of the measurement very much depends on the performance specifications of the HPGe detectors. From this study it found that all the seven co-axial HPGe detectors in Radiochemistry and Environment Group, Nuclear Malaysia are in good working conditions base on the verification of performance specifications namely Resolution, Peak Shape, Peak-to-Compton ratio and Relative Efficiency against the warranted value from the manufacturers. (author)

  6. The 124Sb activity standardization by gamma spectrometry for medical applications

    International Nuclear Information System (INIS)

    This work describes a metrological activity determination of 124Sb, which can be used as radiotracer, applying gamma spectrometry methods with hyper pure germanium detector and efficiency curves. This isotope with good activity and high radionuclidic purity is employed in the form of meglumine antimoniate (Glucantime) or sodium stibogluconate (Pentostam) to treat leishmaniasis. 124Sb is also applied in animal organ distribution studies to solve some questions in pharmacology. 124Sb decays by β-emission and it produces several photons (X and gamma rays) with energy varying from 27 to 2700 keV. Efficiency curves to measure point 124Sb solid sources were obtained from a 166mHo standard that is a multi-gamma reference source. These curves depend on radiation energy, sample geometry, photon attenuation, dead time and sample-detector position. Results for activity determination of 124Sb samples using efficiency curves and a high purity coaxial germanium detector were consistent in different counting geometries. Also uncertainties of about 2% (k=2) were obtained.

  7. The {sup 124}Sb activity standardization by gamma spectrometry for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, M.C.M. de, E-mail: marcandida@yahoo.com.b [Laboratorio Nacional de Metrologia das Radiacoes Ionizantes, Instituto de Radioprotecao e Dosimetria, Comissao Nacional de Energia Nuclear (SEMRA/LNMRI/IRD/CNEN), Av. Salvador Allende s/n, Recreio, Rio de Janeiro, RJ, CEP 22780-160 (Brazil); Iwahara, A.; Delgado, J.U.; Poledna, R.; Silva, R.L. da [Laboratorio Nacional de Metrologia das Radiacoes Ionizantes, Instituto de Radioprotecao e Dosimetria, Comissao Nacional de Energia Nuclear (SEMRA/LNMRI/IRD/CNEN), Av. Salvador Allende s/n, Recreio, Rio de Janeiro, RJ, CEP 22780-160 (Brazil)

    2010-07-21

    This work describes a metrological activity determination of {sup 124}Sb, which can be used as radiotracer, applying gamma spectrometry methods with hyper pure germanium detector and efficiency curves. This isotope with good activity and high radionuclidic purity is employed in the form of meglumine antimoniate (Glucantime) or sodium stibogluconate (Pentostam) to treat leishmaniasis. {sup 124}Sb is also applied in animal organ distribution studies to solve some questions in pharmacology. {sup 124}Sb decays by {beta}-emission and it produces several photons (X and gamma rays) with energy varying from 27 to 2700 keV. Efficiency curves to measure point {sup 124}Sb solid sources were obtained from a {sup 166m}Ho standard that is a multi-gamma reference source. These curves depend on radiation energy, sample geometry, photon attenuation, dead time and sample-detector position. Results for activity determination of {sup 124}Sb samples using efficiency curves and a high purity coaxial germanium detector were consistent in different counting geometries. Also uncertainties of about 2% (k=2) were obtained.

  8. Cosmic veto gamma-spectrometry for Comprehensive Nuclear-Test-Ban Treaty samples

    Energy Technology Data Exchange (ETDEWEB)

    Burnett, J.L., E-mail: jonathan.burnett@awe.co.uk; Davies, A.V.

    2014-05-21

    The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is supported by a global network of monitoring stations that perform high-resolution gamma-spectrometry on air filter samples for the identification of 85 radionuclides. At the UK CTBT Radionuclide Laboratory (GBL15), a novel cosmic veto gamma-spectrometer has been developed to improve the sensitivity of station measurements, providing a mean background reduction of 80.8% with mean MDA improvements of 45.6%. The CTBT laboratory requirement for a {sup 140}Ba MDA is achievable after 1.5 days counting compared to 5–7 days using conventional systems. The system consists of plastic scintillation plates that detect coincident cosmic-ray interactions within an HPGe gamma-spectrometer using the Canberra Lynx{sup TM} multi-channel analyser. The detector is remotely configurable using a TCP/IP interface and requires no dedicated coincidence electronics. It would be especially useful in preventing false-positives at remote station locations (e.g. Halley, Antarctica) where sample transfer to certified laboratories is logistically difficult. The improved sensitivity has been demonstrated for a CTBT air filter sample collected after the Fukushima incident.

  9. Rapid determination of uranium in uranyl nitrate solutions by gamma spectrometry

    International Nuclear Information System (INIS)

    Uranium-235 emits gamma rays of 185.7 kev with 54% yield. Gamma spectrometry with this gamma ray presents an excellent method for the estimation of sup(235)U and hence the total uranium concentration by knowing the isotopic ratios. This paper deals with a system which uses 3 inches x 2 inches NaI detector and a microprocessor based 4 K multichannel analyser for assaying liquid samples. A software gain correction method was used in the system to eliminate errors due to amplifier gain shift. Three different ranges of concentrations of uranium in natural uranyl nitrate solution have been studied. Using known, standard samples, calibration graphs of cps Vs concentration have been obtained. Linearity has been observed upto the uranium concentration of about 80 gms/litre while non-linearity due to self-absorption was found in the higher range. An exponential relationship ; y=aesup(-bx) was used for fitting the data in the non-linear range. This method can be used to determine the uranium concentration in all the three ranges of concentration which have been studied, in a rapid and non-destructive way. The standard deviation in the concentration range of 50-80 gms of U per litre was found to be ±1% for a 300 secs. counting time. (author). 1 refs., 4 figs

  10. Significance of Airborne Gamma-ray spectrometric data of Umm bisilla Area, central Eastern Desert, Egypt

    International Nuclear Information System (INIS)

    Umm bisilla area, located in the Central Eastern Desert of Egypt, consists mainly of basement rocks. The present investigation of the airborne spectrometric data is to define the meaningful anomalies from the raw data by applying the significance factor techniques, by calculating the significant radioactive provinces. Determination of the gross structural pattern and broad variations in composition of the crystalline basement, to define the relationships between the tectonic features of the area as interpreted from aeromagnetic data, with the significant anomalies revealed from spectrometric data was carried out through the application of different magnetic techniques. Five significant uraniferous zones were detected associated with Umm Bisilla granite, amphibolite, and grey granite. The intersection of the structural lineaments interpreted from aeromagnetic data illustrated good correlation with the significant uranium anomalous zones interpreted from spectrometric data, and indicated that the concentration is structurally. 15 figs

  11. NMIS with Imaging and Gamma Ray Spectrometry for Pu, HEU, HE and Other Materials

    Energy Technology Data Exchange (ETDEWEB)

    Mihalczo, John T [ORNL; Mullens, James Allen [ORNL

    2012-03-01

    The Nuclear Material Identification System (NMIS) has been under development at ORNL and the National Nuclear Security Administration (NNSA) Y-12 National Security Complex since 1984. In the mid-1990s, what is now the US Department of Energy (DOE) Office of Nuclear Verification (ONV) realized that it was a useful technology for future arms control treaty applications and supported further development of the system. In 2004, fast-neutron imaging was incorporated into the system. In 2007, the ONV decided to develop a fieldable version of the system, designated as FNMIS, for potential use in future treaties. The FNMIS is being developed to be compatible with the eventual incorporation of gamma-ray spectrometry and an information barrier. This report addresses how and what attributes could be determined by the FNMIS system with gamma-ray spectrometry. The NMIS is a time-dependent coincidence system that incorporates tomographic imaging (including mapping of the fission sites) and gamma-ray spectrometry. It utilizes a small, lightweight (30 lb), portable deuterium-tritium (DT) neutron (14.1 MeV) generator (4 x 10{sup 7} neutrons/second) for active interrogation and can also perform passive interrogation. A high-purity germanium (HPGe) gamma-ray detector with multichannel analysis can be utilized in conjunction with the source for active interrogation or passively. The system uses proton recoil scintillators: 32 small 2.5 x 2.5 x 10.2-cm-thick plastic scintillators for imaging and at least two 2 x 2 arrays of 27 x 27 x 10-cm-thick plastic scintillators that detect induced fission radiation. The DT generator contains an alpha detector that time and directionally tags a fan beam of some of the neutrons emitted and subdivides it into pixels. A fast (1 GHz) time correlation processor measures the time-dependent coincidence among all detectors in the system. A computer-controlled scanner moves the small detectors and the source appropriately for scanning a target object for

  12. The role of airborne gamma spectrometric data in the radon programme of the Czech Republic

    International Nuclear Information System (INIS)

    During 40 years of uranium prospecting in the Czech Republic the airborne gammaspectrometric mapping has covered about 60% of the state territory in the working scale of 1:25,000. In the 1990s the gammaspectrometric maps occurred to be a very useful tool for environmental applications. The K, U and Th data, reflecting both the natural characteristics of the bedrock and the environmental impact of intensive U-mining were also used as the input data for the radon risk mapping. Due to the prevailing crystalline and granitic basements, the radon problem was highlighted in the Czech Republic since 1989. First indices, obtained by the Hygienic Survey (radiation departments) referred to indoor radon in the houses built from U-contaminated materials (e.g. the special case of Jachymov - the long term use of material from U-waste dumps for centuries of Ag and adjacent U exploitation or the case of START family prefab houses, built in the 1960s and 70's from the slag concrete). In some of these houses, the internal U sources were not so intensive to explain high indoor Rn values. Later the attention was given to the radon potential of geological environment. In 1989 the Czech Geological Survey carried a proposal for radon risk mapping of the state territory. The geological units as well as the rock types were characterized from the soil gas Rn point of view. The radon risk maps were published in the scale of 1:200,000 and widely distributed to the state authorities and private companies dealing with radon problematics. The regional maps were based on the following data: soil gas Rn measurements, grain-size analyses at the testing areas, U-gammaspectrometric data (both airborne and ground measurements), and geological soils and hydrogeological maps. (author). 4 refs, 4 figs

  13. An airborne gamma ray survey of the Duddon Estuary in February 1993

    International Nuclear Information System (INIS)

    An aerial survey of radioactivity of the Duddon estuary (United Kingdom was conducted on 25th February 1993, using an 8 litre NaI detector. Maps of the distribution of 137Cs, 40K, 214Bi, 208Tl and estimated gamma dose rates are presented. The distribution of 137Cs on estuarine and marsh areas is clearly defined, with the greatest concentrations largely following the salt marsh boundaries. The gamma dose rate map indicates that Cs contamination is a controlling dose contributor. Natural radiation shows considerable variations, reflecting the local geological and geomorphological structures. The 214Bi map shows an anomaly in the vicinity of Millom. Since 214Bi is a radon daughter, this signal may have a dynamic component. Alternatively it may originate from industrial or mining wastes in the area. (5 figures). (UK)

  14. Radon alpha and gamma-ray spectrometry with YAP:Ce-scintillator

    International Nuclear Information System (INIS)

    Full text: The detection properties of a YAP:Ce scintillator (YAlO 3:Ce crystal) for radon and radon daughters alpha and gamma-ray spectrometry was investigated. The crystal response has been studied under severe extreme conditions to simulate environments of geophysical interest, particularly those found in geothermal and volcanic areas. Tests in water up to a temperature of 100 deg C and in acids solutions such as HCl (37%), H2SO4 (48%) and HNO3 (65%) have been performed. The experimental array consisted of a bare cylindrical crystal of YAP:Ce optically coupled to a Hamamatsu H5784 photomultiplier with standard bialkali photocatode. The crystal size was 8 mm diameter and 30 mm height. The crystal was positioned at the geometrical center of a 6 l stainless steel light- and gas-tight vessel equipped with gas input/output and a pass-through electrical connectors. Output signals were integrated with a charge preamplifier, shaped with a spectroscopy amplifier (ORTEC-450) and processed by a multichannel analyzer card (ORTEC-Trump). The collected pulse-height spectrum was managed by a suitable MCA emulation software (ORTEC-Maestro32). The device was serially connected to the radon Reference Measurement System (RMS) developed at the National Institute for Metrology of Ionizing Radiations (INMRI-ENEA). The RMS is routinely used for calibration and testing of radon measuring instruments and it provided the reference radon- in-air activity concentration needed for efficiency calibration of the YAP:Ce radon spectrometer. The RMS is based on a cylindrical electrostatic cell with a Si detector. It is used for the alpha spectrometry of the electrostatically collected polonium ions produced in the decay of radon. The radioactive source section consisted in a 35 cm3 glass bulb filled with about 15 kBq radon in air. The internal volume of the whole circuit was about 10 l. The energy calibration curves of the device were obtained irradiating the crystal by means of a set of

  15. Investigation by gamma-ray spectrometry and INAA of radioactivity impact on phosphate fertilizer plant environment

    International Nuclear Information System (INIS)

    The radioactive polluting effect of a phosphate fertilizer plant on the environment was investigated by gamma-ray spectrometry and neutron activation analysis (INAA). The hazards could arise from industrial plants using raw phosphate materials to prepare fertilizers for agricultural purposes due to the phosphate rock which, depending on the type and geographical zone of provenance may contain rather large amounts of uranium. The fertilizer plant under study is situated about 4 km from the town of Turnu Magurele, on the left bank of the Danube River in Romania. The main by-products of the factory are: nitro phosphate type fertilizers (NP, NPK), Ammonia, Nitric acid, Ammonium nitrate, Urea, Sulfuric acid, Phosphoric acid, Sodium fluorosilicate and Aluminum sulfate. Gamma-ray spectrometry was used to determine activity concentrations of naturally occurring radionuclides (226Ra, 235U, 238U, 232Th, and 40K), as well as 137Cs man-made radionuclide in surface soils collected from semicircular areas within radii of 0.5 and 15 km of the plant; in addition, different NPK type fertilizers and phosphate rocks were investigated. The samples (mass of about 100-g each) were kept tightly closed for one month to permit 226Ra to establish radioactive equilibrium with its decay products. This method makes it possible to assess U, Th, and K contents in samples by measuring 238U and 232Th (in equilibrium with their radioactive daughters) and 40K radioactivity, taken into account that 1 g of U, Th and K yield 12358 Bq 238U, 569 Bq 235U, 4057.2 Bq 232Th and 33.11 Bq 40K, respectively. The spectrometrical chain was based on a HPGe (EG and G Ortec) detector of 30 % relative efficiency and 2.1 keV resolution at 1332 keV of 60Co. INAA technique (neutron irradiation at TRIGA reactor of SCN Pitesti) was used to determine macro, micro and trace elements in samples collected from both technological shops of the factory (air dust and drinking tap water) and its surroundings (surface soil, tree

  16. Rapid determination of 237Np in soil samples by multi-collector inductively-coupled plasma mass spectrometry and gamma spectrometry

    OpenAIRE

    Yi, Xiaowei; Shi, Yanmei; Xu, Jiang; He, Xiaobing; ZHANG, HAITAO; Lin, Jianfeng

    2013-01-01

    A radiochemical procedure is developed for the determination of 237Np in soil with multi-collector inductively-coupled plasma mass spectrometry (MC-ICP-MS) and gamma-spectrometry. 239Np (milked from 243Am) was used as an isotopic tracer for chemical yield determination. The neptunium in the soil is separated by thenoyl-trifluoracetone extraction from 1 M HNO3 solution after reducing Np to Np(IV) with ferrous sulfamate, and then purified with Dowex 1 × 2 anion exchange resin. 239Np in the resu...

  17. Study on the natural radioactivity from the region of Presidente Figueiredo (AM), Brazil, using gamma spectrometry

    International Nuclear Information System (INIS)

    A gamma spectrometry profile was carried out along BR174 highway, that crosses some lithostratigraphic units of the North portion of the Sedimentary Basin of Amazon. Measurements in situ were realized in 116 points, 1 km apart, using a GAD-6 gamma-spectrometer and samples of rocks and soils were collected in geologically representative points, for gamma measurements using a shielded detector of NaI(Tl) available in the Nuclear Geophysics Laboratory of IAG/USP. The criterion used for evaluating the reliability degree of the concentration values of eU (ppm), eTh (ppm) and %K was to establish mathematically detection limits, for all measurement points. Every these points had been located using GPS with accuracy of 50 m to become possible a future detailed study. The purpose of matching portable gamma spectrometer and laboratory determinations was to compare the 2 techniques, using the criterion of detectability limits, and to verify the influence of 222 Rn atmospheric radioactive gas in field measurements. In the case of portable detector, it allows fast measurements and the sensor 'sees' a big volume of material (rock, soil...), that makes it more representative. In some situations where atmospheric phenomena of thermal inversion occurs, measurement can be affected by the 222 Rn cosmic background. Presence of radon daughter elements, associated with aerosols, in this tropical environment (high values of temperature and humidity), where the speed of the wind that could exhaust this gas is practically zero. It is observed that the values of concentration in the some points, got with these 2 techniques, have the same trend, and the stretches where peaks of concentration of K also occur and U and Th are associated with the presence of granite out corps, great boulders, and clay soils from weathering of these rocks. (author)

  18. Determination of uranium content of samples in various geometry by gamma ray spectrometry

    International Nuclear Information System (INIS)

    There are certain limitations concerning the usage of standard source method for efficiency calibration of gamma - ray spectrometers measuring in extended geometry. These limitations arise from the great diversity of forms and dimensions of the objects which are to be evaluated by nondestructive gamma-ray spectroscopy assay, in case of seizure of nuclear materials. We developed a gamma ray spectrometry equipment using a portable MCA Canberra INSPECTOR, a HPGe detector and a self made collimator and now we are using a semiempirical method to calibrate the gamma ray spectrometer for such measurements. A portable high purity germanium detector was used together with a compact workstation incorporating a multi-channel analyzer, a spectroscopic amplifier and a high voltage power supply. Spectral data are processed on-line with a SubNote IBM 486 compatible PC using GeniePC, an OS/2 based spectroscopy software from Canberra. A compact, modular lead housing for the detector was designed and manufactured at ICN, using uncontaminated Pb and an inner layer of copper. In front of the detector a lead collimator with cylindrical slit was used to reduce the range of variation for incidence angle. Hence several collimators were manufactured with 10, 20, 40 and 60 mm diameter slits to be able to assure a proper counting rate in a large range of drum's specific activities by simply changing the collimator. For the efficiency calibration of the spectrometric chain a semiempirical method was used, based on effective solid angle determination. Determination of photo-peak total efficiency is based on the separation of intrinsic efficiency of the detector to the geometric efficiency and self-absorption factor

  19. Implementation and application of the gaussian decomposition software for NaI gamma-ray spectrometry data

    International Nuclear Information System (INIS)

    In order to extract the information of peaks in different energy from the data of overlapping peaks in environmental gamma spectrometer, a spectrum data Gaussian decomposition soft is designed based on least- square Gaussian fitting method. The interface of this software is friendly, it can complete the decomposition of overlapping peaks in gamma spectrometer quickly by the way of man-machines interactive. The result that applied gamma spectrometry to data analysis in the field measurement indicates that the Gaussian decomposition soft can efficiently extract 137Cs from overlapping peaks which has significance to assess the human nuclide contamination of environment. (authors)

  20. X-ray fluorescence and gamma-ray spectrometry combined with multivariate analysis for topographic studies in agricultural soil

    International Nuclear Information System (INIS)

    Physical and chemical properties of soils play a major role in the evaluation of different geochemical signature, soil quality, discrimination of land use type, soil provenance and soil degradation. The objectives of the present study are the soil elemental characterization and soil differentiation in topographic sequence and depth, using Energy Dispersive X-Ray Fluorescence (EDXRF) as well as gamma-ray spectrometry data combined with Principal Component Analysis (PCA). The study area is an agricultural region of Boa Vista catchment which is located at Guamiranga municipality, Brazil. PCA analysis was performed with four different data sets: spectral data from EDXRF, spectral data from gamma-ray spectrometry, concentration values from EDXRF measurements and concentration values from gamma-ray spectrometry. All PCAs showed similar results, confirmed by hierarchical cluster analysis, allowing the data grouping into top, bottom and riparian zone samples, i.e. the samples were separated due to its landscape position. The two hillslopes present the same behavior independent of the land use history. There are distinctive and characteristic patterns in the analyzed soil. The methodologies presented are promising and could be used to infer significant information about the region to be studied. - Highlights: • Characterization of topographic sequence of two hillslopes from agricultural soil. • Employment of EDXRF and gamma-ray spectrometry data combined with PCA. • The combination of green analytical methodologies with chemometric studies allowed soil differentiation. • The innovative methodology is promising for direct characterization of agricultural catchments

  1. Implementation of gamma-ray spectrometry in two real-time water monitors using NaI(Tl) scintillation detectors

    International Nuclear Information System (INIS)

    In this study, the implementation of gamma-ray spectrometry in two real-time water monitors using 2 in.×2 in. NaI(Tl) scintillation detectors is described. These monitors collect the water from the river through a pump and it is analyzed in a vessel, which is shielded with Pb. The full calibration of the monitors was performed experimentally, except for the efficiency curve, which was set using validated Monte Carlo simulations with the EGS5 code system. After the calibration, the monitors permitted the identification and quantification of the involved isotopes in a possible radioactive increment and made it possible to discard possible leaks in the nuclear plants. As an example, a radiological increment during rain is used to show the advantages of gamma-ray spectrometry. To study the capabilities of the monitor, the minimum detectable activity concentrations for 131I, 137Cs and 40K are presented for different integration times. - Highlights: • Gamma-ray spectrometry with NaI(Tl) detectors was implemented in two water monitors. • The monitors were calibrated using experimental data and Monte Carlo simulations. • The efficiency calculations and MDAC values are given. • Advantages of using gamma-ray spectrometry are discussed. • The monitors permit the identification and quantification of isotopes in water

  2. Mobile Gamma Spectrometry Survey of the Scottish Enterprise Technology Park, East Kilbride, 17th-19th August 2009

    OpenAIRE

    Cresswell, A.J.; Sanderson, D.C.W; Weir, A.; Mitchell, C.

    2010-01-01

    Environmental radioactivity arises from natural geological sources, the redistribution of natural activity through industrial processes, the nuclear industry including routine and accidental discharges into the environment, and various medical or industrial uses of radioisotopes. Mobile gamma spectrometry provides a powerful means of measuring the distribution of radioactivity in the environment. Data collected by such methods provide measures of environmental quality, references for public h...

  3. Application of the Monte Carlo code DETEFF to efficiency calibrations for in situ gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Carrazana Gonzalez, J.; Cornejo Diaz, N. [Centre for Radiological Protection and Hygiene, P.O. Box 6195, Habana (Cuba); Jurado Vargas, M., E-mail: mjv@unex.es [Departamento de Fisica, Universidad de Extremadura, 06071 Badajoz (Spain)

    2012-05-15

    We studied the applicability of the Monte Carlo code DETEFF for the efficiency calibration of detectors for in situ gamma-ray spectrometry determinations of ground deposition activity levels. For this purpose, the code DETEFF was applied to a study case, and the calculated {sup 137}Cs activity deposition levels at four sites were compared with published values obtained both by soil sampling and by in situ measurements. The {sup 137}Cs ground deposition levels obtained with DETEFF were found to be equivalent to the results of the study case within the uncertainties involved. The code DETEFF could thus be used for the efficiency calibration of in situ gamma-ray spectrometry for the determination of ground deposition activity using the uniform slab model. It has the advantage of requiring far less simulation time than general Monte Carlo codes adapted for efficiency computation, which is essential for in situ gamma-ray spectrometry where the measurement configuration yields low detection efficiency. - Highlights: Black-Right-Pointing-Pointer Application of the code DETEFF to in situ gamma-ray spectrometry. Black-Right-Pointing-Pointer {sup 137}Cs ground deposition levels evaluated assuming a uniform slab model. Black-Right-Pointing-Pointer Code DETEFF allows a rapid efficiency calibration.

  4. Effect of forest biomass on airborne snow water equivalent estimates obtained by measuring terrestrial gamma radiation

    International Nuclear Information System (INIS)

    Estimates of snow water equivalent derived from measurements of the attenuation of terrestrial gamma radiation emitted by potassium are systematically biased downward if substantial amounts of forest biomass exist in the region where the radiation measurements are obtained. The degree of underestimation is a function of the amount and type of biomass. The effects of these factors on the snow water equivalent estimate are examined, and a means of correcting for the downward bias is given. The methodology presented can aid National Weather Service hydrologists in improving river and flood forecasts, water supply forecasts, and spring flood outlooks for large areas of the United States and Canada

  5. Determination of short-lived fission product yields with gamma spectrometry

    International Nuclear Information System (INIS)

    The majority of fission yield measurements to date have examined cumulative yields of long-lived nuclides. We present a method for determining independent as well as cumulative fission yields using gamma spectrometry and a Bayesian inverse analysis. This paper outlines the impetus for new fission product yield measurements, the methodology developed to measure these and other nuclear parameters, and initial experimental results for long-lived nuclides and sensitivity analyses. In initial scoping measurements, the cumulative yield of 140Ba was estimated as 4.9966±0.3309 %, and the independent yield of 140La was estimated to be 0.0045±0.0022 %. These estimated values are commensurate with existing literature values. (author)

  6. Two low-level gamma spectrometry systems of the IAEA Safeguards Analytical Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Parus, J.L. [IAEA, SAL, Vienna (Austria); Raab, W. [IAEA, SAL, Vienna (Austria); Donohue, D. [IAEA, SAL, Vienna (Austria); Jansta, V. [IAEA, SAL, Vienna (Austria); Kierzek, J. [IAEA, SAL, Vienna (Austria)

    1997-03-01

    A gamma spectrometry system designed for the measurement of samples with low and medium radioactivity (activity from a few to about 10{sup 4} Bq in the energy range from 25 to 2700 keV) has been installed at the IAEA Safeguards Analytical Laboratory in Seibersdorf. The system consists of 3 low level detectors: (1) n-type coaxial Ge with 42.4% relative efficiency, 1.85 keV FWHM at 1.33 MeV (2) planar Ge with 2000 mm{sup 2} area and 20 mm thickness, 562 eV FWHM at 122 keV (3) NaI(Tl) annulus of 25.4 cm diameter and 25.4 cm height, hole diameter 90 mm. (orig./DG)

  7. A review of the nationwide proficiency test on natural radioactivity measurements by gamma spectrometry.

    Science.gov (United States)

    Şahin, N K; Yeltepe, E; Yücel, Ü

    2016-03-01

    This study is the review of the first proficiency test on radioactivity measurement organized in Turkey by Sarayköy Nuclear Research and Training Center (SANAEM) of Turkish Atomic Energy Authority (TAEK) in 2013. The objective of the test was to determine (226)Ra, (232)Th and (40)K activity concentrations in natural soil samples using gamma-ray spectrometry. The bulk material consisting of uranium- and thorium-rich soil and sand was milled, mixed thoroughly and sieved. Homogeneity of the final mix was tested with 6 randomly taken samples. 16 proficiency test samples were distributed to 16 participating laboratories. 12 laboratories reported results. The results were evaluated on the accuracy and precision criteria adopted by the IAEA Proficiency Testing Group. The percentage of acceptable scores was 49%. Some recommendations have been provided to the laboratories to improve the quality of their results. It is planned to extend these proficiency tests periodically for various radionuclides in various matrices. PMID:26750585

  8. U and Pu: some nuclear data by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The precise knowledge of nuclear parameters like energy and emission probability for uranium and plutonium radionuclides is very important for the correct determination of the isotopic ratio or activity determinations. By means of gamma-ray spectrometry it is possible to obtain these parameters, but in the region below 300 keV it is more critical. The published values for their main decay data exhibit significant differences. A new methodology was developed using a nonlinear regression program to fit the calibration curves in energy, resolution and efficiency of a HPGe detector. The results obtained by means new curve fitting software appear to be consistent in that region for energy, and the uncertainties exhibit improvements compared the published data. Consistent results were also obtained in an energy region extended to 1100 keV. (author)

  9. The GeMSE Facility for Low-Background {\\gamma}-Ray Spectrometry

    CERN Document Server

    Sivers, M v; Rosén, Å V; Schumann, M

    2016-01-01

    We describe a new high-purity germanium (HPGe) detector setup for low-background {\\gamma}-ray spectrometry. The GeMSE facility is dedicated to material screening for rare event searches in astroparticle physics as well as to the characterization of meteorites. It is installed in a medium depth (~620 m.w.e.) underground laboratory in Switzerland in a multi-layer shielding and is equipped with an active muon veto. We have reached a very competitive integral background rate of (246$\\pm$2) counts/day (100-2700 keV) which allows the measurement of radioactive contaminations in the $\\mathcal{O}$(50){\\mu}Bq/kg range. We describe the data analysis based on Bayesian statistics, background simulations, the efficiency calibration and first sample measurements.

  10. Geochemical interpretation of gamma-ray spectrometry images from the Achala granite (Cordoba, Argentina)

    International Nuclear Information System (INIS)

    Data of an old spectrometry gamma-ray survey carried out in the Sierras Pampeanas Range by the National Atomic Energy Commission (Argentina) were reprocessed to obtain a corrected digital archive. The geochemical interpretation of the 250 x 250 meters spectrometric grids from the Achala batholith area was based on the behaviour of the radioelements in a peraluminous magma. Spectrometric maps of potassium, uranium, thorium and their ratios were used. In particular, the Th grid was very useful to define the primary magmatic evolution of the granitoids. K and U correlate roughly with Th distribution. The observed positive correlation between Th and U is thought to be the result of surficial leaching of U from uraninite. Finally, U/Th ratio allows to determine both, the magmatic evolution of the rocks and the mineral phase responsible for U content. (author)

  11. High-sensitivity HPGe gamma-spectrometry analysis of radionuclides in Martian meteorites

    International Nuclear Information System (INIS)

    Analysis of cosmogenic radionuclides in Martian meteorites is a great radioanalytical challenge because of the high scientific value of these meteorites, and necessity to apply non-destructive methods of analysis, e.g., low-level gamma-ray spectrometry. The measured 54Mn, 22Na, and 26Al levels in two fragments of the Tissint meteorite, a recent fall (18 July 2011), were 0.9, 1.1 and 0.6 Bq/kg in average. The high 22Na/26Al activity ratio (1.89 ± 0.05) measured in the larger sample (908.7 g) indicates an unsaturated production of 26Al in the Tissint meteorite. (author)

  12. The application of computer technique in routine neutron activation analysis using high resolution gamma ray spectrometry

    International Nuclear Information System (INIS)

    A full system of four computer programs for routine - qualitative and quantitative - neutron activation analysis (NAA) using high resolution gamma ray-spectrometry had been elaborated. The structure and possibilities of the ''data flow'' programs i.e. programs DIDPDP and DIDCDC, dedicated for fast and reliable ''off line'' data transfer between the buffer memory of the spectrometric line (9-track magnetic tape) and the fast access memory (disc) of the used computers PDP-11/45 and CYBER-73 had been presented. The structure and organization of the ''data processing'' programs i.e. programs SAWAPS and MAZYG had been presented as well. The utility and reliability of these programs in the case of the large-scale, routine NAA, exampled by analysis of filters with air polutants, had been tested and discussed. Programs are written mainly in FORTRAN. (author)

  13. Characterization of three digital signal processor systems used in gamma ray spectrometry

    International Nuclear Information System (INIS)

    Various manufacturers have recently introduced digital signal processing systems that allow data acquisition in gamma spectrometry at high-input counting rates (several thousand pulses per second). In these systems, the signal digitization is performed immediately following the preamplification stage. This allows digital shaping and filtering of the signal which increases the number of possible combinations in signal shaping and as a consequence, optimizes the resolution as a function of the detector characteristics and the counting rate. Basic characteristic parameters of three digital signal processors that were recently introduced in the market have been studied and compared to those of an analog system. This study is carried out using a hyper-pure coaxial type germanium detector and 57Co, 60Co and 137Cs radioactive sources. Performance parameters such as energy resolution, system throughput, and counting losses that are due to dead time and pile-up effects are presented and discussed

  14. Determination of relative plutonium isotopic abundances by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Plutonium, a fissionable material and, consequently, a special nuclear material (SNM), must be accurately accounted for and safeguarded. Accountability of plutonium usually requires a measurement of the isotopic abundances as well as the elemental weight or concentration. Although mass spectrometers are commonly used to measure isotopic abundances, they require extensive preparation of the sample and destroy the sample during the analysis. The authors have developed techniques and computer programs have been developed to measure plutonium isotopic abundances by gamma-ray spectrometry, they have developed a methodology that is substantially different. The methods have been programmed into a computerized multigroup analysis (MGA) code. They routinely use the MGA program at Lawrence Livermore National Laboratory for analyzing metals, oxides, and solutions that are high in 239Pu content for materials accountability purposes. The program has also been put into routine use by the Euratom Safeguards Directorate and the international Atomic Energy Agency

  15. Determination of uranium and thorium in monazite bearing sand by gamma ray spectrometry

    International Nuclear Information System (INIS)

    Monazite is one of the most important natural geological mineral due to the presence of heavy metals, rare earth and natural radioactive elements. Monazite is also an important ore for thorium, lanthanum, and cerium. It is very important to assess the concentration of uranium and thorium in various monazite samples observed in Indian coasts and their relative abundance. In addition to thorium, availability of uranium in monazite is also of interest because of an alternate source for the uranium fuel cycle operation going on in our country. The relative abundance of uranium in monazite bearing sands can be represented by the activity ratio of uranium to thorium in the samples. In the present study an attempt has been made to estimate the activity ratios of uranium to thorium in some of the monazite bearing beach sands collected from our coastal regions by using high resolution gamma ray spectrometry techniques

  16. Gamma-ray spectrometry laboratory and in situ: developments and environmental applications

    International Nuclear Information System (INIS)

    Gamma-ray spectrometry enables determining all γ-ray emitters in a sample with a single measurement. Self-absorption of γ-rays in samples is manifest by a loss or a gain of pulses that results in a poor estimation of the counting efficiency. To characterize a new counting geometry improvements of the existing set-up were made with MCNPX simulations. With the new geometry we could specify absorbed and annual effective doses as well as dose conversion factors for the natural radioisotopes of several building materials and soil samples. Simulations show the influence of detection limits of γ-radiation on dose conversion factors and the need for updating these factors. γ-ray measurements of soil in situ require different counting efficiencies simulated by MCNPX for a semi-infinite source. Two in-situ soil analyses were made, one around a nuclear power and the other for a private company. (author)

  17. The Sandwich spectrometer for ultra low-level gamma-ray spectrometry.

    Science.gov (United States)

    Wieslander, J S Elisabeth; Hult, Mikael; Gasparro, Joël; Marissens, Gerd; Misiaszek, Marcin; Preusse, Werner

    2009-05-01

    The technical details and performance of the newly developed Sandwich spectrometer for ultra low-level gamma-ray spectrometry are presented. The spectrometer, which consists of two HPGe detectors, an active muon shield and a lead/copper shield with a convenient and rapid opening mechanism, is located in an underground laboratory at a depth of 500 m water equivalent. The data is collected in list mode, which enables off-line data analysis to identify muon-induced events and possible Ge detector crosstalk due to Compton scattering. The background count-rate from 40 to 2700 keV normalised to the mass of the Ge crystals is 220 day(-1)kg(-1). PMID:19246202

  18. Technical factors of quality management in gamma-ray spectrometry of environmental samples

    International Nuclear Information System (INIS)

    The establishment of a quality management system is the best way to comply with international requirements concerning the achievement of confident and traceable analytical results. Some important points dealing with the technical factors of quality management in gamma-ray spectrometry of environmental samples are discussed. The experience obtained from analytical procedure validation is presented. Results of the application of standardized procedures to the analysis of ALMERA intercomparison samples, as well as the outcome of the utilization of certified reference materials for the quality control of measurement are presented. In fact, the implantation of simple technical principles reports reliable results and allows to elevate the quality of the measurements at a cost relatively low according to the real possibilities of the small laboratories, even in developing countries. (author)

  19. Validation of Cs-137 measurement in food samples using gamma spectrometry system

    International Nuclear Information System (INIS)

    Cs-137 was found to be one of major radionuclide contaminant present in foods consumed by human. In some countries, regulations required consumption foods moving in international trade to be scanned for caesium (Cs-134 and Cs-137) to ensure it does not exceeding the maximum permissible level. This is to ensure that the intake of such foods will not accumulate radionuclide until the significant level inside the human body. Gamma Spectrometry System was used to perform the measurement of caesium isotopes, because it was one of the easiest methods to be performed. This measuring method must be validated for several parameters include specificity, precision (repeatability), bias (accuracy), linearity, range, detection limit, robustness and ruggedness in order to ensure it is fit for the purpose. This paper would summarise how these parameters were fulfilled for this analytical method using several types certified reference materials. The same validated method would be considered workable on Cs-134 as well. (Author)

  20. Elemental compositions and ages of lunar samples by nondestructive gamma-ray spectrometry.

    Science.gov (United States)

    O'kelley, G D; Eldridge, J S; Schonfeld, E; Bell, P R

    1970-01-30

    A gamma-ray spectrometry system with low background was used to determine the radioactivity of crystalline rocks, breccias, and fine material. Nuclides identified were (40)K, (232)Th, (238)U, (7)Be, (22)Na (26)A1, (44)Ti, (46)Sc, (48)V, (52)Mn, (54)Mn, and (56)Co. Concentrations of K, Th, and U ranged between 480 and 2550, 1.01 and 3.30, and 0.26 and 0.83 parts per million, respectively. Concentrations of thorium and uranium were those of terrestrial basalts, while the potassium concentrations were near values for chondrites. Products of low-energy nuclear reactions showed pronounced concentration gradients at rock surfaces. Concentrations of K and of (22)Na determined here were combined with concentrations of rare gases to estimate gas-retention ages and cosmic-ray exposure ages with ranges of 2200 to 3200 and 34 to 340 million years, respectively, for three rocks. PMID:17781504

  1. Analysis for naturally occurring radionuclides at environmental concentrations by gamma spectrometry

    International Nuclear Information System (INIS)

    The analytical potential of low level, high resolution gamma-ray spectrometry for naturally occurring radionuclides at environmental levels is described. Comparisons are drawn between the performance of a specially designed low background detector system, and that of standard 'off the shell' devices. Sample characteristics, calibration procedures and checks are described and empirical minimum detection limits of between 0.4 Bqxkg-1 (226Ra, 228Th) and 10 Bqxkg-1 (210Pb) are derived for soil or sediment samples of about 250 g. Representative analyses of a variety of environmental samples, including water, plant material, animal tissue and sediment, are given to illustrate the routine use of the spectrometer. (author) 14 refs.; 8 figs.; 7 tabs

  2. An iterative approach for TRIGA fuel burn-up determination using nondestructive gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Wang Tienko E-mail: tkw@faculty.nthu.edu.tw; Peir Jinnjer

    2000-01-01

    The purpose of this work is to establish a method for evaluating the burn-up values of the rod-type TRIGA spent fuel by using gamma-ray spectrometry of the short-lived fission products {sup 97}Zr/{sup 97}Nb, {sup 132}I, and {sup 140}La. Fuel irradiation history is not needed in this method. Short-lived fission-product activities were established by re irradiating the spent fuels in a nuclear reactor. Based on the measured activities, {sup 235}U burn-up values can be deduced by iterative calculations. The complication caused by {sup 239}Pu production and fission is also discussed in detail. The burn-up values obtained by this method are in good agreement with those deduced from the conventional method based on long-lived fission products {sup 137}Cs, {sup 134}Cs/{sup 137}Cs ratio and {sup 106}Ru/{sup 137}Cs ratio.

  3. An iterative approach for TRIGA fuel burn-up determination using nondestructive gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The purpose of this work is to establish a method for evaluating the burn-up values of the rod-type TRIGA spent fuel by using gamma-ray spectrometry of the short-lived fission products 97Zr/97Nb, 132I, and 140La. Fuel irradiation history is not needed in this method. Short-lived fission-product activities were established by re irradiating the spent fuels in a nuclear reactor. Based on the measured activities, 235U burn-up values can be deduced by iterative calculations. The complication caused by 239Pu production and fission is also discussed in detail. The burn-up values obtained by this method are in good agreement with those deduced from the conventional method based on long-lived fission products 137Cs, 134Cs/137Cs ratio and 106Ru/137Cs ratio

  4. An iterative approach for TRIGA fuel burn-up determination using nondestructive gamma-ray spectrometry.

    Science.gov (United States)

    Wang, T K; Peir, J J

    2000-01-01

    The purpose of this work is to establish a method for evaluating the burn-up values of the rod-type TRIGA spent fuel by using gamma-ray spectrometry of the short-lived fission products 97Zr/97Nb, 132I, and 140La. Fuel irradiation history is not needed in this method. Short-lived fission-product activities were established by reirradiating the spent fuels in a nuclear reactor. Based on the measured activities, 235U burn-up values can be deduced by iterative calculations. The complication caused by 239Pu production and fission is also discussed in detail. The burn-up values obtained by this method are in good agreement with those deduced from the conventional method based on long-lived fission products 137Cs, 134Cs/137Cs ratio and 106Ru/137Cs ratio. PMID:10670930

  5. Low-level gamma spectrometry using beta coincidence and Compton suppression.

    Science.gov (United States)

    Grigorescu, E L; De Felice, P; Razdolescu, Anamaria-Cristina; Luca, A

    2004-01-01

    A low-level gamma-ray spectrometry system was developed using a Ge(Li) detector with 6% relative efficiency coupled to a 2pi beta plastic detector for coincidence selection and a massive NaI(Tl) detector for Compton suppression. The integral background count rate for (50-1500)keV was 0.5 s(-1)kg(-1) (Ge), using only beta coincidences. With Compton suppression, a value of 0.25 s(-1)kg(-1) (Ge) was obtained. Spectra with and without Compton suppression were studied for 60Co, 137Cs and 152Eu point sources. Considerations are made concerning the Compton suppression advantages in different situations. PMID:15177343

  6. ZZ DLC-19 DECAYGAM, Isotope Gamma Energy Library for Spectrometry Evaluation

    International Nuclear Information System (INIS)

    Nature of physical problem solved: Format: data is recorded as Hollerith records on magnetic tape along with data for each radionuclide. Nuclides: H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Br, Kr, Rb, Sr, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Xe, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Ra, Th, Pa, U, Np, Pu. Origin: Oak Ridge National Laboratory Nuclear Data Project. This compilation contains, for those radionuclides tabulated, all necessary data for qualitatively and quantitatively measuring photon emitting radionuclides as well as conducting activation analysis using gamma-ray spectrometry

  7. The use of difference spectra with a filtered rolling average background in mobile gamma spectrometry measurements

    International Nuclear Information System (INIS)

    The use of difference spectra, with a filtering of a rolling average background, as a variation of the more common rainbow plots to aid in the visual identification of radiation anomalies in mobile gamma spectrometry systems is presented. This method requires minimal assumptions about the radiation environment, and is not computationally intensive. Some case studies are presented to illustrate the method. It is shown that difference spectra produced in this manner can improve signal to background, estimate shielding or mass depth using scattered spectral components, and locate point sources. This approach could be a useful addition to the methods available for locating point sources and mapping dispersed activity in real time. Further possible developments of the procedure utilising more intelligent filters and spatial averaging of the background are identified.

  8. Airborne gamma-ray spectrometer and magnetometer survey: San Luis Obispo (California), Santa Maria (California). Final report

    International Nuclear Information System (INIS)

    An airborne combined radiometric and magnetic survey was performed over the area covered by the Santa Maria and San Luis Obispo, California 1:250,000 National Topographic Map Series (NTMS) 10 x 20 quadrangle maps. The survey was a part of DOE's National Aerial Radiometric Reconnaissance program, which is in turn a part of the National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer having a large crystal volume, and a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test range. Data quality was ensured throughout the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted and contoured to produce anomaly maps based on the radiometric response of individual geological units. These maps were interpreted and an anomaly interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data processing procedures, the data display format, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

  9. Airborne gamma-ray spectrometer and magnetometer survey, Copalis Beach, Seattle, Cape Flattery, Victoria, Quadrangles (Washington). Final report

    International Nuclear Information System (INIS)

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Copalis Beach, Seattle, Victoria, and Cape Flattery, 1:250,000 National Topographic Map Series (NTMS), quadrangle maps. The survey was part of DOE's National Uranium Resource Evaluation (NRRE) program. Data were collected by helicopters equipped with gamma-ray spectrometers with large crystal volumes, and with high sensitivity proton precession magnetometers. The radiometric systems were calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test Range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton Scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The anomalies were interpreted and an interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data collection procedure, the data processing procedures, the data presentation; the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

  10. Study of the artificial radioactivity of the marine medium using gamma spectrometry (1962-1966)

    International Nuclear Information System (INIS)

    The results described in this study are relative to the artificial radioactivity of such elements as zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 and praseodymium-144 which were present in the atmospheric fallout between 1962 and 1964, and their incidence in superficial marine waters. Various physical, chemical or biological processes are studied by a high sensitivity gamma ray spectrometry technic, using those radioelements as 'tracers'. The change of state in sea water of an important fraction (about 50 per cent) of the radioactive particles going into the soluble phase - this phenomenon was not expected for those radioelements - controls the processes of accumulation in the planktonic biomass and the diffusion towards deeper waters. On the other hand, an 'in situ' spectrometry method is described. It enables the direct measurement in the sea of very low concentrations of some gamma ray emitters. The application of this method has made possible to carry out numerous observations in the surface waters of the Western Mediterranean sea and in the Bay of Biscay. It is shown that the mixing depth is closely connected to the depth of the thermocline. An accumulation process at this level is observed. The diffusion coefficients are similar to the thermal turbulent coefficient. The existence during several months of 'compartments' is established for the surface waters of the Bay of Biscay. From the establishment of the budget of fall-out, a comparative study shows that the rate of radioactive fallout on the maritime zone considered is always two to three times higher than on the neighbouring continental regions. Several explanations of this phenomenon are discussed. (author)

  11. Low-energy X-ray and gamma spectrometry using silicon photodiodes

    International Nuclear Information System (INIS)

    The use of semiconductor detectors for radiation detection has increased in recent years due to advantages they present in comparison to other types of detectors. As the working principle of commercially available photodiodes is similar to the semiconductor detector, this study was carried out to evaluate the use of Si photodiodes for low energy x-ray and gamma spectrometry. The photodiodes investigated were SFH-205, SFH-206, BPW-34 and XRA-50 which have the following characteristics: active area of 0,07 cm2 and 0,25 cm2, thickness of the depletion ranging from 100 to 200 μm and junction capacitance of 72 pF. The photodiode was polarized with a reverse bias and connected to a charge sensitive pre-amplifier, followed by a amplifier and multichannel pulse analyzer. Standard radiation source used in this experiment were 241 Am, 109 Cd, 57 Co and 133 Ba. The X-ray fluorescence of lead and silver were also measured through K- and L-lines. All the measurements were made with the photodiodes at room temperature.The results show that the responses of the photodiodes very linear by the x-ray energy and that the energy resolution in FWHM varied between 1.9 keV and 4.4 keV for peaks corresponding to 11.9 keV to 59 keV. The BPW-34 showed the best energy resolution and the lower dark current. The full-energy peak efficiency was also determined and it was observed that the peak efficiency decreases rapidly above 50 keV. The resolution and efficiency are similar to the values obtained with other semiconductor detectors, evidencing that the photodiodes used in that study can be used as a good performance detector for low energy X-ray and gamma spectrometry. (author)

  12. Uncertainty of gamma-ray spectrometry measurement of environmental samples due to uncertainties in matrix composition, density and sample geometry

    International Nuclear Information System (INIS)

    This paper is intended to identify the uncertainties of activities in environmental samples measured with gamma-ray spectrometry that result from uncertainties in matrix composition, density and geometrical dimensions of the sample. For that purpose efficiencies were calculated for a wide range of environmental matrices such as fresh and ashed food samples, water samples and soil samples. Compositions were mainly taken from literature. Densities and geometry parameters were varied in a range occurring in practice. Considered energies cover a range from 46.5 keV to 2000 keV. Finally, a couple of recommendations in respect to gamma-ray spectrometric measurements of environmental samples are given. - Highlights: • Uncertainties of gamma-ray spectrometry measurements were assessed. • Efficiencies were calculated for a wide range of environmental matrices. • The effect of matrix compositions and density on efficiency was studied. • The effect of geometry parameters on efficiency was considered

  13. A mobile high resolution gamma ray spectrometry system for radiological surveys. Final report

    International Nuclear Information System (INIS)

    Magnox Electric has developed a mobile large area radiological survey system designed to produce a rapid and cost effective characterization of outdoor land areas. The system combines the technique of high resolution gamma ray spectrometry, which is capable of rapidly identifying and quantifying specific radionuclides at levels well below those normally associated with natural background radiation, with modern automated surveying techniques that facilitate navigation and provide assurance as to the location of contamination. A dedicated software system supports survey operations, providing real time displays detailing spectrometry and navigational data capture, and enabling seamless remote switching between positioning methods. In open areas with an unrestricted line of sight to satellites Differential Global Positioning System (DGPS) technology provides positional data, in areas where a significant portion of the sky is obscured a laser ranging device known as an Automatic Total Station (ATS) is employed and in the most restricted and confined areas manual surveying resorted to. In this report the system is described, its advantages and limitations compared with conventional survey methodologies are discussed, and its perceived role within the wider framework of the site investigation process is detailed, particularly with respect to current and proposed legislation in the US describing conditions for the release of nuclear licensed sites from regulatory controls. Experience at recent termination surveys on large nuclear licensed facilities is considered in detail, along with the principal features of the Magnox system that will enable it to overcome the difficulties and problems encountered

  14. Uranium thorium and potassium contents analysis of rocks in Changwat Narathiwat by gamma spectrometry

    Directory of Open Access Journals (Sweden)

    Kaewtubtim, P.

    2002-04-01

    Full Text Available Quantitative analysis of three radioactive elements (potassium, equivalent uranium, and equivalent thorium in the granite rocks of the Triassic Age at 24 locations in Narathiwat province was carried out by using a gamma counter. It was found that potassium, equivalent uranium and equivalent thorium contents were on the average of 3.63% (in the range of 1.56-5.24%, 8.55 ppm (2.98-15.27 ppm and 18.74 ppm (0.34- 52.14 ppm, respectively. It is worth noting that the radiation detected from the rocks collected in the three areas : the north, the east and the southwest was higher than in the other places. Potassium and equivalent uranium contents were nearly the same as found in the granite rocks of the Triassic Age in the northern part of Thailand, while equivalent thorium was lower. In addition, the contents of the three elements in the same kind of rocks of the same age were almost the same as found elsewhere around the world. However, the contents of the above elements in the rocks of the Triassic Age in Narathiwat were found to be 1-2 times lower than those of the Cretaceous Age in Pattani province next to Narathiwat province. Moreover, the results were consistent with those investigated by the airborne survey of the Department of Mineral Resources. In conclusion, this information helps to confirm that several areas in Narathiwat province may have a high potential for minerals deposit.

  15. HPGe detectors long time behaviour in high-resolution {gamma} spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sajo-Bohus, L., E-mail: sajobohus@gmail.com [Universidad Simon Bolivar, Apartado 89000, Caracas, YV-1080A (Venezuela, Bolivarian Republic of); Rosso, D. [INFN Laboratori Nazionali, Viale dell' Universita 2, Legnaro (Padova), I-35020 (Italy); Sajo Castelli, A.M. [Universidad Simon Bolivar, Apartado 89000, Caracas, YV-1080A (Venezuela, Bolivarian Republic of); Napoli, D.R.; Fioretto, E. [INFN Laboratori Nazionali, Viale dell' Universita 2, Legnaro (Padova), I-35020 (Italy); Menegazzo, R. [INFN Sez. Padova, via F. Mazzolo 8, Padova, I-35131 (Italy); Barros, H. [Universidad Simon Bolivar, Apartado 89000, Caracas, YV-1080A (Venezuela, Bolivarian Republic of); Ur, C.A. [INFN Laboratori Nazionali, Viale dell' Universita 2, Legnaro (Padova), I-35020 (Italy); Palacios, D.; Liendo, J. [Universidad Simon Bolivar, Apartado 89000, Caracas, YV-1080A (Venezuela, Bolivarian Republic of)

    2011-08-21

    A large set of data on long term performance of n-type HPGe detectors used in GASP, EUROBALL and CLARA {gamma} spectrometers, as well as environmental measurements have been collected over two decades. In this paper a detailed statistical analysis of this data is given and detector long term behaviour is provided to the scientific community. We include failure, failure mode, repair frequency, repair outcome and its influence in the energy efficiency and energy resolution. A remarkable result is that the life span distribution is exponential. A detector's failure is a memory-less process, where a previous failure does not influence the upcoming one. Repaired spectrometers result in high reliability with deep implications in the management of large scale high-resolution gamma spectrometry related projects. Findings show that on average, detectors initial counting efficiency is slightly lower ({approx}2%) than that reported by the manufacturers and the repair process (including annealing) does not affect significantly the energy efficiency, even after a long period of use. Repaired detector energy resolution statistics show that the probability, that a repaired detector will be at least as good as it was originally, is more than 3/4.

  16. Determination of the stellar (n,gamma) cross section of 40Ca with accelerator mass spectrometry

    CERN Document Server

    Dillmann, I; Heil, M; Käppeler, F; Wallner, A; Forstner, O; Golser, R; Kutschera, W; Priller, A; Steier, P; Mengoni, A; Gallino, R; Paul, M; Vockenhuber, C; 10.1103/PhysRevC.79.065805

    2009-01-01

    The stellar (n,gamma) cross section of 40Ca at kT=25 keV has been measured with a combination of the activation technique and accelerator mass spectrometry (AMS). This combination is required when direct off-line counting of the produced activity is compromised by the long half-life and/or missing gamma-ray transitions. The neutron activations were performed at the Karlsruhe Van de Graaff accelerator using the quasistellar neutron spectrum of kT=25 keV produced by the 7Li(p,n)7Be reaction. The subsequent AMS measurements were carried out at the Vienna Environmental Research Accelerator (VERA) with a 3 MV tandem accelerator. The doubly magic 40Ca is a bottle-neck isotope in incomplete silicon burning, and its neutron capture cross section determines the amount of leakage, thus impacting on the eventual production of iron group elements. Because of its high abundance, 40Ca can also play a secondary role as "neutron poison" for the s-process. Previous determinations of this value at stellar energies were based o...

  17. Burn up determination of IEAR-1 fuel elements by non destructive gamma ray spectrometry method

    International Nuclear Information System (INIS)

    Measurement of nuclear fuel burn up by non destructive gamma ray spectrometry is discussed, and results of such measurements, made at the Instituto de Energia Atomica (IEA), are given. Specifically, the burn up of an MTR (Material Testing Reactor) fuel element removed from the IEAR-1 swimming pool reactor in 1958 is evaluated from the measured Cs-137 activity, which gives a single 661,6 keV gamma ray. Due to the long decay time of the test element, no other fission decay product activity could be detected. Analysis of measurements, made with a 3'' x 3'' NaI(Tl) detector at 330 distinct points of the element, showed the total burn up to 3.3 +- -+ 0.8 mg. This is in agreement with a calculated value. As the maximum temperature of IEAR-1 fuel elements is of the order of 400C, migration effects of Cs-137 was not considered, this being significant only at fuel temperature in excess of 10000C

  18. Application of gamma-ray spectrometry in a NORM industry for its radiometrical characterization

    Science.gov (United States)

    Mantero, J.; Gázquez, M. J.; Hurtado, S.; Bolívar, J. P.; García-Tenorio, R.

    2015-11-01

    Industrial activities involving Naturally Occurring Radioactive Materials (NORM) are found among the most important industrial sectors worldwide as oil/gas facilities, metal production, phosphate Industry, zircon treatment, etc. being really significant the radioactive characterization of the materials involved in their production processes in order to assess the potential radiological risk for workers or natural environment. High resolution gamma spectrometry is a versatile non-destructive radiometric technique that makes simultaneous determination of several radionuclides possible with little sample preparation. However NORM samples cover a wide variety of densities and composition, as opposed to the standards used in gamma efficiency calibration, which are either water-based solutions or standard/reference sources of similar composition. For that reason self-absorption correction effects (especially in the low energy range) must be considered individually in every sample. In this work an experimental and a semi-empirical methodology of self-absorption correction were applied to NORM samples, and the obtained results compared critically, in order to establish the best practice in relation to the circumstances of an individual laboratory. This methodology was applied in samples coming from a TiO2 factory (NORM industry) located in the south-west of Spain where activity concentration of several radionuclides from the Uranium and Thorium series through the production process was measured. These results will be shown in this work.

  19. Natural radioactivity in extreme south of Bahia, Brazil, using gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The concentrations activity of natural radionuclides in beach sand in extreme south of Bahia-Brazil was measured using gamma-ray spectrometry. The activity concentrations of 226Ra, 232Th and 40K in beach sand ranged from 14.5 to 8,318.4, 20.5 to 18,450.0, 15.4 to 3,109.0 Bq/kg, with a mean value of 1,078.2, 2,429.6, and 417.0 Bq/kg respectively. The values of radiation hazard indexes in sands of Alcobaca, Caraiva and Cumuruxatiba are higher than the limits preconized by Beretka and Mathew. The use of these sands may be not safe in building constructions. The results show that the absorbed dose rates range from 20.4-15,116.6 nGy/h with mean value of 1762.7. The highest value of gamma dose rates among the studied beaches was found in Cumuruxatiba (15,116.6 nGy/h). The annual effective dose varied between 0.028 and 18.539 mSv/year, with a mean of 2.162 mSv/year. Values of Alcobaca, Trancoso, Caraiva and Cumuruxatiba are higher than the worldwide average for outdoor annual effective dose, 0.07 mSv/year. (author)

  20. A comparative study of commonly used software packages for high resolution gamma ray spectrometry

    International Nuclear Information System (INIS)

    With the help of powerful computers and programming languages, the software packages have an important role in nuclear experiments. Software in the nuclear techniques and experiments controls the instrument's operation, performs the data acquisition, storage and their validation and analysis. In particular, because of the wide range of applications of gamma ray spectrometry, software packages in this field are among the most used. There is a vast selection of commercially available open domain software packages that has been designed for the efficient and correct analysis of high resolution gamma ray spectra. It is essential to compare the performance of these softwares for analyzing various parameters of gamma ray spectra. In this present work, gamma ray spectra obtained from commercially available coaxial HPGe detectors of 190 cc and 54 cc volumes were analysed using the softwares, PCMCA, SAMPO, APTEC and Interwinner-4.01. The important features of gamma ray spectra like stability of resolution, count rate in the peak etc. were compared with these softwares. Among these software packages, PCMCA is a locally available commercial software package and the others are imported software packages commonly used for the spectral data analysis. All these software packages considered have got provision for storage of spectral data, spectrum acquisition and basic spectral data analysis like automatic peak search, energy and efficiency calibration etc. For the present work standard spectrum of 133Ba, 137Cs and 60Co sources kept at a distance of 25 cm away from the detector is used. A comparative study is done for the peak channel calculation (peak position), peak range and peak area estimation of each peak using these software packages. It is observed that all these softwares could identify and calculate the peak positions including the doublets precisely. The ROI (Region Of Interest) estimated by different softwares for peak area calculation and unfolding of doublets are

  1. Airborne gamma-ray spectrometer and magnetometer survey: Weed quadrangle, California. Final report

    International Nuclear Information System (INIS)

    Twelve anamolous areas attributable to gamma radiation in the uranium spectral window, and twenty-three in the thorium channel, have been recognized and delineated on the Weed quadrangle. The majority of the uranium anomalies are located in the southwestern part of the map sheet. Most of these are correlated with the pre-Cretaceous metamorphic rock system and the Mesozoic granitic rocks intrusive into it. Of the twenty-three anomalous areas of increased gamma radiation in the thorium spectral window, most are located in the northeast and the east center in a north-south trending belt. However, this apparent alignment is probably fortuitous as the individual anomalies are correlated with several different rock formations. Three are correlated with upper Cretaceous marine sediments, six with Ordovician marine sediments, two with Mesozoic granitic intrusives, and two with Silurian marine sediments. In the northwestern part of the quadrangle, four thorium radiation anomalies are delineated over exposures of upper Jurassic marine rocks. Anomaly 6, in the southwest, warrants attention as it suggests strong radiation in the uranium channel with little or no thorium radiation. The uranium/thorium and uranium/potassium ratio anomalies are also strong, supporting the likelihood of uranium enrichment. The feature is located on line 540, fiducials 7700 to 7720. Anomaly 7, on line 540, fiducials 8390 to 8420, shows similar characteristics although a minor thorium excursion is present. Anomaly 10, on line 3010 fiducials 9820 to 9840, is also characterized by a strong uranium radiation spike, with minor thorium radiation. The uranium/thorium and uranium/potassium ratio anomalies are well defined and relatively intense

  2. Y-Spect: A Multi-Method Gamma Spectrometry Analysis Program

    International Nuclear Information System (INIS)

    To accomplish a more accurate, precise and correct interpretation and analysis of spectrum data collecting from a gamma spectrometry counting system, a fully interactive computer code, named Y-Spect, has been developed by using the Delphi 7.0 programming language. The code combines several popular methods for peak search, i.e.: Mariscotti, Phillips-Marlow, Robertson et al., Routti-Prussin, Black, Sterlinski, Savitzky-Golay and Block et al. Any combinations of those methods can be chosen during a peak searching process, which can be performed in automatic or manual mode. Moving Window Average- and Savitzky-Golay-methods are available for spectrum data smoothing. Peak fitting is done by using a non-linear least square method of Levenberg-Marquardt for either a pure Gaussian peak shape or one with an additional Right/Left Tail function. Other than standard features, such as: peak identification and determination of: continuum, region of interest (ROI), and peak area, etc., Y-Spect has also a special feature which can predict the existence of escape- and/or sum peaks that belong to a certain radioisotope. Aside from displaying the complete spectrum graph, including: singlet or multiplet ROIs and peak identifications, Y-Spect can also display the first- or second-derivative of the spectrum data. Data evaluation is given as: isotope names, peak energy, Net-Count(-Rate), etc. Y-Spect is provided with a complete ENDF/B-VII.0 gamma-ray library file that contains of 16089 gamma energy lines from 1420 different radioisotopes. Other general specifications are: maximum number of: spectrum's channels = 16*1024; ROIs 2*1024; ROI's width = 2*1024 channels; Overlapping peaks (multiplet) = 20; Identified isotopes = 3*1024, and Isotope library's energy lines = 16*1024. (author)

  3. Efficiency transfer using the GEANT4 code of CERN for HPGe gamma spectrometry.

    Science.gov (United States)

    Chagren, S; Ben Tekaya, M; Reguigui, N; Gharbi, F

    2016-01-01

    In this work we apply the GEANT4 code of CERN to calculate the peak efficiency in High Pure Germanium (HPGe) gamma spectrometry using three different procedures. The first is a direct calculation. The second corresponds to the usual case of efficiency transfer between two different configurations at constant emission energy assuming a reference point detection configuration and the third, a new procedure, consists on the transfer of the peak efficiency between two detection configurations emitting the gamma ray in different energies assuming a "virtual" reference point detection configuration. No pre-optimization of the detector geometrical characteristics was performed before the transfer to test the ability of the efficiency transfer to reduce the effect of the ignorance on their real magnitude on the quality of the transferred efficiency. The obtained and measured efficiencies were found in good agreement for the two investigated methods of efficiency transfer. The obtained agreement proves that Monte Carlo method and especially the GEANT4 code constitute an efficient tool to obtain accurate detection efficiency values. The second investigated efficiency transfer procedure is useful to calibrate the HPGe gamma detector for any emission energy value for a voluminous source using one point source detection efficiency emitting in a different energy as a reference efficiency. The calculations preformed in this work were applied to the measurement exercise of the EUROMET428 project. A measurement exercise where an evaluation of the full energy peak efficiencies in the energy range 60-2000 keV for a typical coaxial p-type HpGe detector and several types of source configuration: point sources located at various distances from the detector and a cylindrical box containing three matrices was performed. PMID:26623928

  4. Gamma-ray spectrometry data collection and reduction by simple computing systems.

    Science.gov (United States)

    Op de Beeck, J

    1975-12-01

    The review summarizes the present state of the involvement of relatively small computing devices in the collection and processing of gamma-ray spectrum data. An economic and utilitarian point of view has been chosen with regard to data collection in order to arrive at practically valuable conclusions in terms of feasibility of possible configurations with respect to their eventual application. A unified point of view has been adopted with regard to data processing by developing an information theoretical approach on a more or less intuitive level in an attempt to remove the largest part of the virtual disparity between the several processing methods described in the literature. A synoptical introduction to the most important mathematical methods has been incorporated, together with a detailed theoretical description of the concept gamma-ray spectrum. In accordance with modern requirements, the discussions are mainly oriented towards high-resolution semiconductor detector-type spectra. The critical evaluation of the processing methods reviewed is done with respect to a set of predefined criteria. Smoothing, peak detection, peak intensity determination, overlapping peak resolving and detection and upper limits are discussed in great detail. A preferred spectrum analysis method combining powerful data reduction properties with extreme simplicity and speed of operation is suggested. The general discussion is heavily oriented towards activation analysis application, but other disciplines making use of gamma-ray spectrometry will find the material presented equally useful. Final conclusions are given pointing to future developments and shifting their centre of gravity towards improving the quality of the measurements rather than expanding the use of tedious and sophisticated mathematical techniques requiring the limits of available computational power. PMID:769794

  5. Gamma-ray spectrometry data collection and reduction by simple computing systems

    International Nuclear Information System (INIS)

    The review summarizes the present state of the involvement of relatively small computing devices in the collection and processing of gamma-ray spectrum data. An economic and utilitarian point of view has been chosen with regard to data collection in order to arrive at practically valuable conclusions in terms of feasibility of possible configurations with respect to their eventual application. A unified point of view has been adopted with regard to data processing by developing an information theoretical approach on a more or less intuitive level in an attempt to remove the largest part of the virtual disparity between the several processing methods described in the literature. A synoptical introduction to the most important mathematical methods has been incorporated, together with a detailed theoretical description of the concept gamma-ray spectrum. In accordance with modern requirements, the discussions are mainly oriented towards high-resolution semiconductor detector-type spectra. The critical evaluation of the processing methods reviewed is done with respect to a set of predefined criteria. Smoothing, peak detection, peak intensity determination, overlapping peak resolving and detection and upper limits are discussed in great detail. A preferred spectrum analysis method combining powerful data reduction properties with extreme simplicity and speed of operation is suggested. The general discussion is heavily oriented towards activation analysis application, but other disciplines making use of gamma-ray spectrometry will find the material presented equally useful. Final conclusions are given pointing to future developments and shifting their centre of gravity towards improving the quality of the measurements rather than expanding the use of tedious and sophisticated mathematical techniques requiring the limits of available computational power. (author)

  6. Y-Spect: A Multi-Method Gamma Spectrometry Analysis Program

    Directory of Open Access Journals (Sweden)

    P.I. Yazid

    2013-04-01

    Full Text Available To accomplish a more accurate, precise and correct interpretation and analysis of spectrum data collecting from a gamma spectrometry counting system, a fully interactive computer code, named Y-Spect, has been developed by using the Delphi 7.0 programming language. The code combines several popular methods for peak search, i.e.: Mariscotti, Phillips-Marlow, Robertson et al., Routti-Prussin, Black, Sterlinski, Savitzky-Golay and Block et al. Any combinations of those methods can be chosen during a peak searching process, which can be performed in automatic or manual mode. Moving Window Average- and Savitzky-Golay-methods are available for spectrum data smoothing. Peak fitting is done by using a non-linear least square method of Levenberg-Marquardt for either a pure Gaussian peak shape or one with an additional Right/Left Tail function. Other than standard features, such as: peak identification and determination of: continuum, region of interest (ROI, and peak area, etc., Y-Spect has also a special feature which can predict the existence of escape- and/or sum peaks that belong to a certain radioisotope. Aside from displaying the complete spectrum graph, including: singlet or multiplet ROIs and peak identifications, Y-Spect can also display the first- or second-derivative of the spectrum data. Data evaluation is given as: isotope names, peak energy, Net-Count(-Rate, etc. Y-Spect is provided with a complete ENDF/B-VII.0 gamma-ray library file that contains of 16089 gamma energy lines from 1420 different radioisotopes. Other general specifications are: maximum number of: spectrum's channels = 16*1024; ROIs = 2*1024; ROI’s width = 2*1024 channels; Overlapping peaks (multiplet = 20; Identified isotopes = 3*1024, and Isotope library's energy lines = 16*1024

  7. Car-borne gamma spectrometry: a virtual exercise in emergency response

    International Nuclear Information System (INIS)

    In recent years car-borne gamma spectrometry has expanded from its role as a geological survey platform to being a useful asset in searching for orphan sources and for surveying in the aftermath of an incident involving the release of radioactive materials. The opportunities for gaining practical experience in the field however are limited by cost considerations and practicability. These limitations are exacerbated by the fact that field data can differ significantly from data generated in the laboratory. As a means of exercising existing emergency measuring/surveying capability and introducing car-borne measurements to a larger group, a virtual exercise was devised. The exercise ORPEX (Orphan Sources and Fresh Fallout Virtual Exercise in Mobile Measurement) featured two typical emergency scenarios: a search for orphan sources and surveying to delineate fallout from a local release point. Synthetic spectral data were generated for point sources and inserted into genuine car-borne measurement data. Participants were presented with a typical software tool and data and were asked to report source locations and isotopes within a time limit. In the second scenario, synthetic data representing fallout from a local fire involving radioactive material were added to real car-borne data, participants being asked to produce maps identifying and characterising the regions of contamination. Fourteen individual organisations from seven different countries supplied results which indicated that for strong sources of isotopes with simple spectra featuring high energy peaks, location and identification was not a problem. Problems arose for isotopes with low energy signals or that presented a weak signal even when visible for extended periods. Experienced analysts tended to perform better in identification of sources irrespective of experience with mobile measurements whereas those with experience in such measurements were more confident in providing more precise estimates of

  8. Gamma-ray spectrometry of granitic suites of the Paranaguá Terrane, Southern Brazil

    Science.gov (United States)

    Weihermann, Jessica Derkacz; Ferreira, Francisco José Fonseca; Cury, Leonardo Fadel; da Silveira, Claudinei Taborda

    2016-09-01

    The Paranaguá Terrane, located in the coastal portion of the states of Santa Catarina, Paraná and São Paulo in Southern Brazil is a crustal segment constituted mainly by an igneous complex, with a variety of granitic rocks inserted into the Serra do Mar ridge. The average altitude is approximately 1200 m above sea level, with peaks of up to 1800 m. Due to the difficulty of accessing the area, a shortage of outcrops and the thick weathering mantle, this terrane is understudied. This research aims to evaluate the gamma-ray spectrometry data of the granitic suites of the Paranaguá Terrane, in correspondence with the geological, petrographical, lithogeochemical, relief and mass movement information available in the literature. Aerogeophysical data were acquired along north-south lines spaced at 500 m, with a mean terrain clearance of 100 m. These data cover potassium (K, %), equivalent in thorium (eTh, ppm) and equivalent in uranium (eU, ppm). After performing a critical analysis of the data, basic (K, eU, eTh) and ternary (R-K/G-eTh/B-eU) maps were generated and then superimposed on the digital elevation model (DEM). The investigation of the radionuclide mobility across the relief and weathering mantle consisted of an analysis of the schematic profiles of elevation related with each radionuclide; a comparison of the K, eU and eTh maps with their 3D correspondents; and the study of mass movements registered in the region. A statistical comparison of lithogeochemical (K, U, Th) and geophysical (K, eU, eTh) data showed consistency in all the granitic suites studied (Morro Inglês, Rio do Poço and Canavieiras-Estrela). Through gamma-ray spectrometry, it was possible to establish relationships between scars (from mass movements) and the gamma-ray responses as well as the radionuclide mobility and the relief and to map the granitic bodies.

  9. Association of gamma imaging and spectrometry for on site radiological mapping

    International Nuclear Information System (INIS)

    Satisfactory completion of decommissioning operations requires precise knowledge of the radiological condition of the facilities. Radiological balances are currently based on dose rate measurements. Laboratory analysis on samples are sometimes carried out. Experience has shown that the gamma activity is often localized in discrete zones, called ''hot spots''. Their identification allows them to be quickly eliminated to remove a great part of the activity and to obtain lower irradiation levels. Over the last years, Nuclear Facilities Decommissioning Unit has been developing and implementing radiation imaging prototype devices ''gamma camera'', suitable for site work. Once the source has been localized, spectrometric data on the source may now be obtained by the use of collimated. compact high resolution probes, associated to the camera body. Use of computer codes, based on geometric assumptions, enables the evaluation of the gamma activity from spectrometry results. This association has been validated on a highly irradiating reprocessing cell. The gamma camera uses a double cone collimator to form a gamma image in the same way as in a pinhole camera. The image is formed on a scintillator plate, Cesium Iodine or organic material, depending on the operating conditions. Gamma photons interact in the scintillator to generate luminous photons, forming an image. The image is then amplified by an intensifier tube, collected on a CCD array and transmitted to a video acquisition card in a PC. The article shows examples of images, obtained before and after the first decontamination phase in a reprocessing cell. The elimination of the main hot spot is observed. In its present configuration, the device is capable of localizing a 137Cs point source irradiating a 250 nGyh-1 within 10 minutes, with a signal to noise ratio reaching 11. After a precise calibration, it is possible to roughly evaluate the dose rate generated by a point source of known energy. However, due to the

  10. Specialized software utilities for gamma ray spectrometry. Final report of a co-ordinated research project 1996-2000

    International Nuclear Information System (INIS)

    A Co-ordinated Research Project (CRP) on Software Utilities for Gamma Ray Spectrometry was initiated by the International Atomic Energy Agency in 1996 for a three year period. In the CRP several basic applications of nuclear data handling were assayed which also dealt with the development of PC computer codes for various spectrometric purposes. The CRP produced several software packages: for the analysis of low level NaI spectra; user controlled analysis of gamma ray spectra from HPGe detectors; a set of routines for the definition of the detector resolution function and for the unfolding of experimental annihilation spectra; a program for the generation of gamma ray libraries for specific applications; a program to calculate true coincidence corrections; a program to calculate full-energy peak efficiency calibration curve for homogenous cylindrical sample geometries including self-attenuation correction; and a program for the library driven analysis of gamma ray spectra and for the quantification of radionuclide content in samples. In addition, the CRP addressed problems of the analysis of naturally occurring radioactive soil material gamma ray spectra, questions of quality assurance and quality control in gamma ray spectrometry, and verification of the expert system SHAMAN for the analysis of air filter spectra obtained within the framework of the Comprehensive Nuclear Test Ban Treaty. This TECDOC contains 10 presentations delivered at the meeting with the description of the software developed. Each of the papers has been indexed separately

  11. Development and Building of Radioactive Concrete Pads for calibration of the airborne and ground gamma-ray spectrometers, used in mineral exploration and hydrocarbons

    International Nuclear Information System (INIS)

    Eight transportable calibration pads were built in to be used as concentration standards for portable and airborne gamma-ray spectrometers calibrations. The pads construction procedure is described in full detail. The pads, with dimensions of 1 m x 1 m x 0,30 m and masses between 593 kg and 673 kg were made radioactive by the addition of different amounts of k-feldspar, caldasite and monazitic sand to the concrete masses. The potassium, uranium and thorium concentration vary significantly in the pads, reaching maximum values of 5,7% of K, 45,6 ppm eU and 137 ppm eTh. The distribution of the gamma radiation flux from the pads surfaces and the heterogeneity magnitudes of the radioactive elements concentration were experimentally established. An example of gamma-ray spectrometer calibration is presented. (author)

  12. Statistical signal processing for gamma spectrometry: application for a pileup correction method; Traitement statistique du signal spectrometrique: etude du desempilement de spectre en energie pour la spectrometrie gamma

    Energy Technology Data Exchange (ETDEWEB)

    Trigano, T

    2005-12-15

    The main objective of gamma spectrometry is to characterize the radioactive elements of an unknown source by studying the energy of the emitted photons. When a photon interacts with a detector, its energy is converted into an electrical pulse. The histogram obtained by collecting the energies can be used to identify radioactive elements and measure their activity. However, at high counting rates, perturbations which are due to the stochastic aspect of the temporal signal can cripple the identification of the radioactive elements. More specifically, since the detector has a finite resolution, close arrival times of photons which can be modeled as an homogeneous Poisson process cause pile-ups of individual pulses. This phenomenon distorts energy spectra by introducing multiple fake spikes and prolonging artificially the Compton continuum, which can mask spikes of low intensity. The objective of this thesis is to correct the distortion caused by the pile-up phenomenon in the energy spectra. Since the shape of photonic pulses depends on many physical parameters, we consider this problem in a nonparametric framework. By introducing an adapted model based on two marked point processes, we establish a nonlinear relation between the probability measure associated to the observations and the probability density function we wish to estimate. This relation is derived both for continuous and for discrete time signals, and therefore can be used on a large set of detectors and from an analog or digital point of view. It also provides a framework to this problem, which can be considered as a problem of nonlinear density deconvolution and nonparametric density estimation from indirect measurements. Using these considerations, we propose an estimator obtained by direct inversion. We show that this estimator is consistent and almost achieves the usual rate of convergence obtained in classical nonparametric density estimation in the L{sup 2} sense. We have applied our method to a set

  13. Developments in gamma-ray spectrometry: systems, software, and methods-II. 4. High-Performance Digital Gamma-Ray Spectrometry

    International Nuclear Information System (INIS)

    This paper reviews recent advances in the field of digital spectrometry made by researchers at X-Ray Instrumentation Associates. All XIA spectrometers are based on a core architecture, which employs digitizing the input signal without shaping and applying all basic data processing in real time to the digital data stream coming out of the wave form digitizer. The real-time digital data processing includes filtering, triggering, pileup rejection, and even pulse shape analysis. In this paper we will describe some of those methods that go beyond emulating a conventional analog system in a digital environment. Rather we will concentrate mainly on methods that have no real equivalent in the analog world. In conventional spectrometers pulse pileup recognition is hardwired and serves a single purpose, namely to reject signals that occur too close to each other to allow for a precise measurement of their amplitude. For a digital device, which can also record wave forms, that would be an unfortunate limitation. The study of very short-lived radioactive isotopes is a case in point. If such an isotope is implanted into a detector in which it then decays by charged particle emission, the signature for the sought-after isotope is that of an implant pulse followed by one or more decay pulses from the isotope and its daughters. If the decay products can be absorbed in the same detector channel, as is the case for proton and alpha emitters in a Si-strip detector, then the isotope decay will show up as a pulse train coming from that detector channel. The difficulty usually is to find the few isotopes of interest amongst a huge background of long-lived or stable isotopes. With programmable pileup recognition logic it is possible to trigger specifically on pulse trains, rather than single pulses, thereby picking out very selectively the isotopes of interest. Analyzing the pulse shape of the incoming preamplifier signal proves to be very useful in many applications. The most obvious

  14. Features and comprehensive evaluation of relative fitting anomalies of airborne gamma spectral in the south Hunan-north Guangxi area of China

    International Nuclear Information System (INIS)

    South Hunan-North Guangxi area is a main uranium metallogenetic area in South China, in which the types of uranium mineralization are mostly granite type and carbonate-siliceous-pelitic rock type, and are main types of uranium prospecting in South China. In order to break through the area by much more economically and effectively utilizing available airborne radioactive data, the main features are studied and summarized for relative fitting anomalies of airborne gamma spectral. The fitting anomalies are mostly distributed in granite areas and its exterior zones, and are closely relative to fault zones and uranium mineralization areas. By comprehensive evaluation, the anomalies of grade 1, 2, and 3 are selected according to the significance of uranium metallogenetic prospect. The mineralization zone in which uranium content is larger than 2 ‰ are discovered in the anomaly of grade 1 by trenching. (authors)

  15. Development of a portable pulse-height-recorder system for in-situ gamma-ray spectrometry

    International Nuclear Information System (INIS)

    In-situ gamma-ray spectrometry has recently been performed with a portable Ge detector system in various fields; in-situ measurements of environmental gamma-rays, measurements of inner contained activities, etc. It is necessary that a multichannel pulse height analyzer is portable, for in-situ gamma-ray measurments with a portable Ge detector. For this purpose, a portable pulse-height-recorder system has been developed using an audio cassette tape recorder. In order to make this system portable, the digital signals outed from an analog-to-digital converter (ADC) are converted to FSK (Frequency Shift Keying) modulated serial signals and recorded directly in a cassette tape recorder. By addition of a dead time correction circuit with a timer, high counting rate measurements at 104 cps are realized with an error of 1%. Using this system, pulse-height data are recorded with the live time signal so that gamma-ray measurements in which counting rate changes with the elasped time can be perfored. Moreover, it is attempted to transmit serial signals to a memory system with a FM wireless transmitter. As results of this experiment, it was confirmed that gamma-ray spectrometry can be performed without use of various electronic signal cables. (author)

  16. Measurement of airborne gunshot particles in a ballistics laboratory by sector field inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Diaz, Ernesto; Sarkis, Jorge E Souza; Viebig, Sônia; Saldiva, Paulo

    2012-01-10

    The present study aimed determines lead (Pb), antimony (Sb) and barium (Ba) as the major elements present in GSR in the environmental air of the Ballistics Laboratory of the São Paulo Criminalistics Institute (I.C.-S.P.), São Paulo, SP, Brazil. Micro environmental monitors (mini samplers) were located at selected places. The PM(2.5) fraction of this airborne was collected in, previously weighted filters, and analyzed by sector field inductively coupled plasma mass spectrometer (SF-HR-ICP-MS). The higher values of the airborne lead, antimony and barium, were found at the firing range (lead (Pb): 58.9 μg/m(3); barium (Ba): 6.9 μg/m(3); antimony (Sb): 7.3 μg/m(3)). The mean value of the airborne in this room during 6 monitored days was Pb: 23.1 μg/m(3); Ba: 2.2 μg/m(3); Sb: 1.5 μg/m(3). In the water tank room, the air did not show levels above the limits of concern. In general the airborne lead changed from day to day, but the barium and antimony remained constant. Despite of that, the obtained values suggest that the workers may be exposed to airborne lead concentration that can result in an unhealthy environment and could increase the risk of chronic intoxication. PMID:21831549

  17. Test spectra experimental construction for evaluating gamma-spectrometry computer codes for the 235U determination

    Directory of Open Access Journals (Sweden)

    Karfopoulos Konstantinos L.

    2014-01-01

    Full Text Available The determination of 235U in environmental samples from its 185.72 keV photons may require the deconvolution of the multiplet photopeak at ~186 keV, due to the co-existence of the 186.25 keV photons of 226Ra in the spectrum. Successful deconvolution depends on many parameters, such as the detector characteristics, the activity concentration of the 235U and 226Ra in the sample, the background continuum in the 186 keV energy region and the gamma-spectrometry computer code used. In this work two sets of experimental test spectra were constructed for examining the deconvolution of the multiplet photopeak performed by different codes. For the construction of the test spectra, a high-resolution low energy germanium detector was used. The first series consists of 140 spectra and simulates environmental samples containing various activity concentration levels of 235U and 226Ra. The second series consists of 280 spectra and has been derived by adding 137Cs, corresponding to various activity concentration levels, to specific first series test spectra. As the 137Cs backscatter edge is detected in the energy region of the multiplet photopeak at ~186 keV, this second series of test spectra tests the analysis of the multiplet photopeak in high background continuum conditions. The analysis of the test spectra is performed by two different g-spectrometry analysis codes: (a spectrum unix analysis code, a computer code developed in-house and (b analysis of germanium detector spectra, a program freely available from the IAEA. The results obtained by the two programs are compared in terms of photopeak detection and photopeak area determination.

  18. Optimization of Gamma-Ray Counting and Spectrometry in Biomedical Tracer Studies

    International Nuclear Information System (INIS)

    In biomedical tracer studies, especially in man and even more so in children and pregnant women, it is important to operate at the lowest possible level of administered radioisotope that is commensurate with the required precision and accuracy of the subsequent radioassay measurements. Similarly, with administered stable elements (as specified compounds) or enriched stable isotopes (again, in compound form), followed by radioactivation analysis of resulting samples, it is important from the toxicological standpoint to minimize the amounts of administered element. The problem of optimization of counting of one, two and three gamma-emitting radioisotopes, by Nal(Tl) scintillation counting, single-channel spectrometry and multichannel spectrometry, has been considered in some detail in these laboratories, with particular attention to single-, double-, or triple-tagging tracer studies with radioisotopes frequently used in biomedical studies: 51Cr, 198Au, 75Se, 197Hg, 64Cu, 76As, 82Br, 59Fe, 60Co, 42K, and 24Na. The same considerations apply to the widely-used thermal-neutron activation analysis determinations of the corresponding elements or enriched stable isotopes, so the results of these counting optimization calculations have a double usefulness. The calculations are based on a few reasonable assumptions made on practical biomedical considerations, namely: (1) small samples (≤ 10 ml), (2) moderate counting periods (s 20 minutes), (3) modest allowable decay periods (≤ 3 days) and (4) use of commercially available counting equipment and shielding. On this basis, the most sensitive methods of counting each of the aforementioned radioisotopes, and a number of pairs and trios of them, have been ascertained. The counting variables included in the considerations are: (1) type of Nal(Tl) crystal, i.e., solid or well-type, (2) size of Nal(Tl) crystal, up to a 5 in x 5 in size, (3) type of measuring equipment: simple scalar, single-channel pulse-height analyser, or

  19. The radioactivity measurements in soils and fertilizers using gamma spectrometry technique

    International Nuclear Information System (INIS)

    Because of their mineral content, soils are naturally radioactive and one of the sources of radioactivity other than those of natural origin is mainly due to the extensive use of fertilizers. The main aim of this paper is to evaluate the fluxes of natural radionuclides in local production of phosphate fertilizers to determine the content of radioactivity in several commercial fertilizers produced in Algeria and to estimate their radiological impact in a cultivated soil even for the long-term exposure due to their application. For these purposes, virgin and fertilized soils were collected from outlying Setif region in Algeria and from phosphate fertilizers used in this area. Gamma spectrometry was exploited to determine activity concentration due to naturally occurring 226Ra, 232Th and 40K in five types of samples (two different sorts of fertilizers, virgin and fertilized soils and well water used for irrigation) taken from Setif's areas. The results show that these radionuclides were present in an average concentration of 134.7 ± 24.1, 131.8 ± 16.7, 11644 ± 550 Bq/kg for the first fertilizer NPK and 190.3 ± 30, 117.2 ± 10.3, 5312 ± 249 Bq/kg for the second fertilizer (NPKs). For the virgin and the fertilized soils, the corresponding values were respectively 47.01 ± 7.3, 33 ± 7, 329.4 ± 19.7 Bq/kg and 53.2 ± 10.6, 50.0 ± 7, 311.4 ± 18.7 Bq/kg. For well water, the values were 1.93 and 0.12 Bq/kg; however the third value was below the Minimum Detectable Activity (MDA). The radium equivalent activity (Raeq) and the representative level index Iγr for all samples were also calculated. The data were discussed and compared with those given in the literature. - Highlights: → We analyze radioactivity in Fertilizers and agricultural soils using Gamma spectrometry technique. → The activity concentration of naturally occurring radionuclides in soil samples were within the world average. → The fertilizer samples show much higher concentrations.

  20. Self-absorption corrections of various sample-detector geometries in gamma-ray spectrometry using sample Monte Carlo Simulations

    International Nuclear Information System (INIS)

    Corrections for self-absorption in gamma-ray spectrometry have been developed using a simple Monte Carlo simulation technique. The simulation enables the calculation of gamma-ray path lengths in the sample which, using available data, can be used to calculate self-absorption correction factors. The simulation was carried out on three sample geometries: disk, Marinelli beaker, and cylinder (for well-type detectors). Mathematical models and experimental measurements are used to evaluate the simulations. A good agreement of within a few percents was observed. The simulation results are also in good agreement with those reported in the literature. The simulation code was carried out in FORTRAN 90,

  1. Determination of self-absorption corrections by computation in routine gamma-ray spectrometry for typical environmental samples

    International Nuclear Information System (INIS)

    A simple and practical method has been developed to quickly calculate self-absorption corrections and mass attenuation coefficients, μ/p, in common environmental samples being analyzed by gamma-ray spectrometry. The method involves using a sample computer program and estimates of the elemental compositions of typical environmental samples. The use of this method eliminates the need for gamma-ray-transmission measurements of individual samples, as well as expensive and time consuming elemental analyses of routine samples. The calculated percent attenuation of the beam through various samples, as determined by this method, agrees very well with experimentally measured values of percent attenuation

  2. Determination of difficult-to-measure Niobium-94 in nuclear wastes using extraction chromatography and gamma spectrometry

    International Nuclear Information System (INIS)

    A radiochemical methodology for 94Nb determination in low-level radioactive wastes from nuclear power plant was proposed. Although it is a strong gamma emitter its concentration in radioactive waste samples are usually several orders of magnitude lower than that of other β-γ emitters, whose emissions affect the emission lines of 94Nb. The procedure involves extraction chromatography by using TEVA resin to isolate the Nb nuclide and the gamma spectrometry to its measurement. The chemical yield was around 75%. Samples of evaporator concentrate and spent resin were analyzed. (author)

  3. Rapid and non-destructive determination of uranium and thorium by gamma spectrometry and a comparison with ICP-AES

    International Nuclear Information System (INIS)

    A rapid, simple and non-destructive method was developed for the determination of thorium, uranium by gamma ray spectrometry (high purity Ge detector) in thorium-uranium mixture. Using the calibration curves, thorium and uranium were analyzed in synthetic samples with RSD ∼2 %. Inter element effect suggested that 583 and 185.7 keV gamma lines are more suitable for the determination of Th and U, respectively in a mixture of Th-U. The newly developed method was validated by routinely employed method using synthetic samples. An ICP-AES based method was developed for the determination of uranium and thorium for comparison purpose. (author)

  4. An analysis of the potassium concentrations of soft drinks by HPGe gamma spectrometry

    International Nuclear Information System (INIS)

    Potassium, in a variety of compounds, occurs in abundance in the Earth's crust, and is an essential nutrient for human health. A naturally occurring radioactive isotope of potassium, 40K, is found in the food and water that we consume. This paper presents the results of a gamma spectrometry analysis of the 40K concentrations of a selection of commercial soft drinks. The 40K concentrations are used to calculate the overall potassium concentrations. The analysis was carried out using a hyper-pure germanium (HPGe) detector with OrtecR ASPEC-927 multichannel analyzer module and GammaVisionR software. This system was chosen for its high resolution and automatic data processing. The carbonated soft drinks (sodas) Coca-ColaR, Coca-Cola LightR (sold as Diet CokeR in the USA and other countries), Coca-Cola ZeroR, PepsiR, Pepsi LightR, Pepsi MaxR, Big ColaR, Lulu-ColaR, Manzana LiftR, SpriteR and FantaR and the mineral waters CielR and PenafielR were analyzed. These brands are all international registered trademarks. The products analyzed were manufactured and bottled in Mexico. The results show a great variety of potassium concentrations in the different soft drinks analyzed (from 128.0 to 1113.1 mg/L). The concentration of potassium in the sodas, in conjunction with the amounts drank by one person in a year (180 L/year), are high enough to warrant consideration by public health authorities and by people to whom high potassium intakes pose a risk. (author)

  5. Non-destructive radionuclide characterization methods of radioactive wastes by gamma spectrometry

    International Nuclear Information System (INIS)

    At Post-Irradiation Examination Laboratory (LEPI) of INR Pitesti methods were developed and procedures were worked out for non-destructive radionuclide characterization by gamma spectrometry of the radioactive wastes barrels destined to final disposal. The equipment used, complying to the ISO 9000 standard, consists in a high resolution HPGe portable detector of Ge-25185P type, a portable spectrometric system of type NOMAD PLUSTM, controlled by a portable PC. The software for data acquisition and spectral analysis, background extraction, peaks' identification, nuclide identification and concentration determination was GAMMAVISIONTM and NUCLIDE NAVIGATOR''TM, while for the efficiency calibration and activity calculation of the radioactive waste barrels the ISOTOPIC TM code was used. The correct activity estimation of the barrels, containing the radioactive wastes, implies an as accurate as possible knowledge of the materials entering the waste matrix composition. The measuring method and the results' treatment implies the following steps: - energy and efficiency calibration of the detector; - weighing the barrel to calculate the radioactive waste matrix density; - the gamma spectra of the barrel are determined with the detector placed at 1.2 m distance; - the GAMMAVISIONTM code is applied to get the activity of the radionuclides in the barrel containing the radioactive wastes; - the report generated by this code is introduced as input file into the ISOTOPIC TM code. Finally, a report is obtained listing all the radionuclide activities, the combined activity, as well as, the implied errors for any of the barrels examined. Experimental methods of checking the occurrence of the computation methods are described. In the frame of radioactive waste managing campaign of the year 2000, 30 barrels containing 137 Cs, 134 Cs and 60 Co were measured at the LEPI department

  6. Gamma-ray spectrometry intra- and interlaboratory test of the Dutch protocol

    International Nuclear Information System (INIS)

    This paper presents the results of a test programme to validate the Dutch pre-normative protocol NVN 5623 'Radioactivity measurements: Determination of the activity of gamma-ray emitting nuclides in a counting sample by means of semi-conductor gamma-spectrometry'. Batches of two reference materials, water and sand, both spiked with radionuclides (133Ba, 134Cs, 137Cs, 40K, 57Co and 60Co) were used in an intra- and interlaboratory test. For the water and sand, 10 and 9 laboratories, respectively, agreed to analyse three samples of each reference material strictly according to the pre-normative protocol. The interlaboratory test programme showed that for both reference materials the values for the reproducibility standard deviation were 1.5-6 times larger than those for the repeatability standard deviation. This extra variation is caused by the parameter 'laboratory'. For both reference materials the repeatability standard deviation was found in the range 0.9-2.0% of the mean activity concentration; the reproducibility standard deviation ranged from 2.5-6.0%. Bias of the test method was found for 134Cs (-6.8%) and 133Ba (-2.3%) in case of the spiked water and for 134Cs (-7.8%) in case of the spiked sand. This bias is attributed to no or insufficient correction for coincidence summing. In general, the interlaboratory test showed satisfactory agreement between laboratories. In the light of regulations on radioactivity in materials it is concluded that for measurement of this activity the Dutch protocol may serve as a blueprint for an (European Community) protocol

  7. Analysis of Elements in The Baltic Sea Sediment by Using Gamma Spectrometry

    International Nuclear Information System (INIS)

    We have done analysis of elements in the Baltic sea sediment by using gamma spectrometry in neutron activation analysis Goal of the analysis is to determine the rate of morsel elements which is contained in the Baltic sea sediment. Sample of the Baltic sea Sediment (IAEA-SED-1), Standard of Reference Material (SRM) 1646 Estuarine Sediment and Standard Ce, Fe, Sc, and Co are put into vial of capsule rabbit, then irradiated together for 30 minutes in rabbit facility Multi Purpose Reactor at power of 25 MW and then cooled for one week. Next sample, standard, and SRM which have irradiated, each is cut for 30 minutes using gamma spectrometer. Result of analysis of rate of elements Ce, Fe, Sc and Co in the baltic sea sediment successively equal to 141.20 ppm, 5.91 %, 14.88 ppm, and 19.59 ppm. Result of analysis in SRM Estuarine sediment successively equal to 96.60 ppm, 3.21 %, 10.25 ppm, and 9.63 ppm. Result of this analysis if compared to the value contained in SRM certificate have good accuracy for the elements of Fe, Sc, and Co that are equal to 95.82 %, 94.90 % and 91.71 %, while for the element of Ce, it is less accurate that is equal to 82.82 %. And the precision of analysis successively for the elements of Ce, Fe, Sc, and Co are equal to 0.04 %, 0.12 %, 0.09 % and 0.05 %. (author)

  8. Use of gamma-ray spectrometry for analysis of Uranium isotopic composition in soil of Iran

    International Nuclear Information System (INIS)

    The use of depleted uranium (DU) in various weaponry and ammunition during the Iraq war in April, 2003 caused serious concern in Iran over possible uranium contamination of the Iran environment and consequently long health effect. After a shell explosion, uranium is discharged by the fire in the air in the form of oxidized particles and can be dispersed within a radius of several kilometers. Gamma-ray spectrometry was used to determine uranium concentration in soil samples collected from 8 sites in Iranian sectors of Iraq border. All soil samples were dried ,gently grounded and passed through a 2 mm sieve. Three hundred grams of each sample were placed in plastic container and sealed for at least 20 days to allow equilibrium in uranium, thorium and actinium series. Gamma-ray intensities were measured with 40% HPGe (CANBERRA) detector. The detector was shielded by 10 cm lead on all sides with cadmium-copper in inner sides. The system is equipped with software for data acquisition and analyzing. The counting time was 6x104 seconds and background spectra were also collected for the same period of time. The concentrations of 238U assessed from 63.3 keV and 92.4 keV emission of its first daughter nuclide, 234Th. To assess the isotopic ratio of 238U/235 U, secular equilibrium was ensured and the concentration of 235U under the 186 keV was deduced. The 226Ra was determined through the 295 keV and 352 keV gamma-rays of 214Pb. The concentrations of 238U and activity ratio of 238U/235U is given. The average of measurement activity ratio is 21,very close to the value of 21.5 for natural uranium, while the activity ratio of DU can be as high as 76.9. The 238U activity ranges within typically accepted levels from 14-33 Bq kg-1, while the typical range given by UNSCEAR (1988) for different soil samples is 10 to 50 Bq kg-1. The analysis of eight surface soil samples of Iranian sites of Iraq border, showed that uranium isotopes are in their natural abundances

  9. Gamma-ray spectrometry across the Aalenian-Bajocian boundary in the Lusitanian Basin (Western Portugal)

    Science.gov (United States)

    Santos, Marisa; Henriques, Helena; Pena, Rui

    2016-04-01

    supply, which has enabled the faunal recovery, as well as the raise of deep infaunal foraminifers recorded at the latest part of the Discites Biochron. This could be related to the increase of calcareous nannofossil fluxes that coincide with a positive shift in carbon isotope compositions of bulk carbonate in the earliest Bajocian reported by some authors for the Murtinheira and other Iberian sections. In basin analysis of carbonate platforms the integration of major biotic turnovers and gamma-ray spectrometry data can be a useful tool in the improvement of correlation between wells and outcrops. Moreover, they assist in the interpretation of depositional environment and paleoclimatic constrains assigned to a basin.

  10. Gamma-ray spectrometry of ultra low levels of radioactivity within the material screening program for the GERDA experiment.

    Science.gov (United States)

    Budjás, D; Gangapshev, A M; Gasparro, J; Hampel, W; Heisel, M; Heusser, G; Hult, M; Klimenko, A A; Kuzminov, V V; Laubenstein, M; Maneschg, W; Simgen, H; Smolnikov, A A; Tomei, C; Vasiliev, S I

    2009-05-01

    In present and future experiments in the field of rare events physics a background index of 10(-3) counts/(keV kg a) or better in the region of interest is envisaged. A thorough material screening is mandatory in order to achieve this goal. The results of a systematic study of radioactive trace impurities in selected materials using ultra low-level gamma-ray spectrometry in the framework of the GERDA experiment are reported. PMID:19243966

  11. Gamma-ray spectrometry applied to agricultural soil in the northwest of the State of Rio de Janeiro

    International Nuclear Information System (INIS)

    The present work presents the use of gamma-ray spectrometry applied to precision agriculture in a sub-tropical area. Our dataset comprises measurements both in rock and residual soil. The soil dataset shows a reduction of 20% on U and Th and 10% on K, when compared to rock samples. This difference could be related to K supplementation associated to chemical fertilization. (author)

  12. Computerization of analysis laboratories. Data processing management of the gamma spectrometry

    International Nuclear Information System (INIS)

    The nuclear analysis laboratories dealing with radiological protection problems receive a large number of samples per annum. They employ several measuring techniques on a large stock of equipment. These laboratories have to manage samples, associated information, relations with the persons who requested the analyses, analysis follow-up, processing and validation of results, problems relating to hard-copy versions, problems relating to archiving, etc... They also have to draw up reviews and compile statistics. Gamma-ray spectrometry techniques are very widely used in these laboratories and are the first affected by the computerization of technical management. This is because computerization can be of invaluable assistance in the field of spectrum processing. Whether this evolves reference to specific libraries and previous results or whether it involves the use of specific software. Not to mention the problems associated with insurance quality in the ways in which results and samples are inter-related, calibration operations, maintenance and intervention. The system should be placed at the service of the laboratory and its personnel, allowing each measuring set to operate in stand-alone mode if necessary. (authors)

  13. Development and application of portable mobile gamma spectrometry system (PMGSS) for realtime online radiological assessment

    International Nuclear Information System (INIS)

    A state of art mobile monitoring system is a prime requirement to combat the challenging radiological situations. In the event of any radiological/nuclear Emergencies an effective, realistic methodology of radiological measurements is an asset. In this context, a highly sensitive real-time online mobile monitoring system having features and provision to display the important parameters will be an essential tool in the course of radiological impact assessment. This paper, describes the efforts that has been made towards providing a useful Portable Mobile Gamma Spectrometry System (PMGSS) and developing applications so as to enhance its usefulness in quick radiological impact assessment and to initiate the proper countermeasures during any Nuclear/Radiological emergency situation in public domain. The system uses a NaI(Tl) detector, a global positioning system (GPS) and a laptop PC for storage, analysis and graphical representation of the acquired data. PMGSS is a highly sensitive, portable and reliable radiation monitoring equipment with capability of qualitative and quick estimation of the radioisotopes. The system was used for the mobile radiological mapping of Bangalore and Mumbai city and demonstrated its capability for use in environmental radiation monitoring during any radiological emergency requirement the results of which are presented here. (abstract)

  14. Low level gamma-ray spectrometry at the PTB underground laboratory UDO

    International Nuclear Information System (INIS)

    A new ultra low level background (ULB) gamma-ray spectrometry system has been installed 925 m below ground at the underground laboratory 'UDO' of the Physikalisch-Technische Bundesanstalt, Braunschweig. This new system, consisting of a 95% coaxial HPGe-detector and a passive shielding (20 cm of low-activity lead, 10 cm electrolytic copper and radon suppression by N2-flushing), will be described. Most of the peak count rates are less than 1 count per day and the integral background count rate in the energy range from 40 keV to 2750 keV is about 20 h-1. The background spectrum of the system is shown. Note that there are empty channels in the measured spectrum where no count was measured in 40 days. This system was especially used to determine very small activity concentrations of 60Co in environmental samples from Hiroshima and Tokaymura as well as for the determination of very small concentrations of long-lived radionuclides in meteorites. Results from these applications will be reported

  15. Detection of 210Pb in the lungs of smokers by in-vivo gamma spectrometry

    International Nuclear Information System (INIS)

    Since mainstream smoke is highly enriched in 210Pb, alpha radiation from inhaled cigarette smoke particles has been proposed as a cancer-producing agent in cigarette smokers. 210Po and 210Pb have been observed in tobacco, cigarette smoke and in the lungs of smokers. Since 210Pb is highly enriched in mainstream smoke, there have been estimates of yearly excesses of 210Pb in the lungs of one-pack-a-day smokers of 3 to 10 pCi (0.11 to 0.37 Bq). The ORNL Whole Body Counter was used to verify this estimate by the methodology of high-resolution, in vivo gamma spectrometry. Measurements were made on 113 adult male non-radiation workers who have either smoked at least one pack of cigarettes per day for at least five years, or have never smoked cigarettes. An analysis-of-variance table was generated based on the Pb-ratio for each individual which revealed that there was no statistically significant increase in the amount of 210Pb in the lungs of smokers over those of non-smokers. Sources of error are also discussed

  16. Estimation of natural potassium concentration in Romanian males by in vivo gamma-ray spectrometry measurements

    International Nuclear Information System (INIS)

    At the Whole Body Monitoring Laboratory, from IFIN-HH, Bucharest, Romania, there were performed in vivo gamma-ray spectrometry measurements on 108 Romanian males in order to evaluate the mineral natural potassium content in human body, as total value and concentration. The measurements were performed with a shadow shield whole body counter, tilted chair geometry, based on a shielded NaI(Tl) scintillation detector of 12.5 cm (diameter) x 10 cm (height) crystal size. The results revealed a calculated value of the mean total body potassium (TBK) of 135.03 ± 2.94 g and a value of 1.9 ± 0.022 g of potassium/kg of body weight for the mean body potassium concentration, for the measured males. These values are similar with the values declared for the Reference Man, in ICRP23. Correlations between total body potassium, potassium concentration and age, weight and Body Build Index were investigated and peculiar conclusions were resulted. (author)

  17. Gamma spectrometry analysis of soil and rock samples from the hypothetical complex of the Bosnian pyramids

    International Nuclear Information System (INIS)

    In Europe, officially until now, there have not existed pyramids built by ancient civilisations. In central Bosnia and Herzegovina, about 30 kilometres north from Sarajevo, there are suspected stone pyramids of monumental proportions. The hypothesis that Visocica Hill, having a noticeable pyramidal shape and rising over the town of Visoko, hides inside itself a step pyramid was developed by Semir Osmanagic, a brilliant Bosnian explorer and expert in pyramidal structures which he studied at locations around the world. Aiming to confirm this hypothesis, intensive researches were carried out at the sites of Visoko town and its vicinity in 2005 and 2006, through combination of classic geo-archeological methods and high-technology methods (satellite imagery, thermal analysis, georadar, seismic and electromagnetic methods, 3D topographic and geodetic high-resolution maps). Tens of world experts (including the leading Egyptian archeologists) undoubtedly confirmed that central B and H hides extraordinary important archeological site on a world scale. The idea of the researches shown in this paper is to determine with nuclear measuring methods whether the regular geometric stone blocks, some weighting over 25 tons, which were excavated at this site, originated from natural geologic processes or these are phenomena made by human hands. For that purpose samples were taken for analysis from stone blocks, soil, as well as from soil and stone structures in the network of underground corridors. In this paper we presented results of gamma spectrometry analysis of these samples, obtained with HPGe detectors. (author)

  18. The significance of variations in the angular correction factor in in situ gamma spectrometry

    International Nuclear Information System (INIS)

    In situ gamma spectrometry is a powerful method of assessing radioactive contamination in soil. The most widely adopted calibration methodology relates the overall sensitivity of the detector system to the product of three calibration factors: (a) the flux at the detector per unit activity in the ground φ/SA, (b) the detected count-rate per unit flux incident normally at the detector No/φ and (c) a correction factor to take into account the angular non-uniformity in response of the detector (Nf/No). The dependence of the latter factor on the activity distribution with soil depth is generally neglected despite the lack of published evidence to support this. By (i) modelling and (ii) use of published experimental profiles, this work examines the range of Nf/No values likely to be encountered in the field. It was found that the use of a fixed angular correction factor is justified given that the maximum errors in the derived activity concentration do not exceed 5% and are far outweighed by other uncertainties. (author)

  19. Gamma Spectrometry Analysis of Different Brands of Cement used in Nigeria

    International Nuclear Information System (INIS)

    The natural radionuclide content of common brands of cement consumed in Nigeria is presented in this work. Samples of 9 brands of grey ordinary Portland cement (OPC) and 5 brands of white cement were collected and analyzed for their radiological content by gamma spectrometry using a 7.6 x 7.6 NaI(TI) detector. The total average content of 226Ra, 232Th and 40k for all the cement brand samples were 38.1, 27.9 and 301.1 Bq/kg respectively and are lower when compared to the world average (50, 50 and 500 Bq/Kg) in building materials. The evaluated radium equivalent activities, external and internal indices were lower than the recommended safe limit and are comparable with result from similar studies concluded in other countries. The evaluation mean gonadal dose of equivalents of two cement brand samples were found to be higher than the world average in soil while others are less than the world average in soil.

  20. Calibration of a Gamma Spectrometry System Used for the Determination of Cs-137 in Spanish Soils

    International Nuclear Information System (INIS)

    The document describes the methodology used at CIEMAT in order to determine, by gamma spectrometry, the background levels of the radionuclide Cs-137 in soils of the Spanish peninsular territory. the work is a part of an extensive research project developed jointly by the University of the Basque Country (UPV-EHU) and the CIEMAT, endellite Content and migration of radiocaesium and radiostrontium in Spanish soils, which is funded by the Plan I+D of the Spanish Nuclear Security Council (CSN). The objective of the project is to establish the reference levels of man-made radionuclides in Spanish soils, with respect to which the evaluation of a possible posterior accidental release of radioactive material could be appraised. The activity concentration of the fission products Cs-137 has been determined in 34 soil cores extracted from representative Spanish soils type zones. This publication describes the experimental system employed, its calibration, the particular conditions applied to perform the measurements, as well as the experimental validation of the methodology. The activity profiles and inventories of the radioactive element so obtained are also presented. The estimation of the background Cs-137 reference levels, will provide a basis for later applications as the study of the spatial distribution in the region, the determination of the correlation between the deposited activity and the meteorological conditions, or the calculation of the specific migration parameters of the radioactive elements in Mediterranean conditions. (Author) 15 refs

  1. In situ gamma-ray spectrometry for environmental monitoring: A semi empirical calibration method

    International Nuclear Information System (INIS)

    In situ gamma spectrometry using high-purity germanium (HPGe) detectors is a frequently used method for the determination of radionuclide ground deposition levels. Such measurements do, however, require an efficiency calibration based on detector sensitivity and parameters such as soil density and vertical activity distribution. In this work, a novel expression is used for the detector efficiency, incorporating both the influence of photon energy and incidence angle. Detector-specific efficiency data are determined empirically. For the theoretical calculation of the photon fluence at the detector, a three-layer model of finite thickness is developed for the description of soil density and vertical activity distribution. In order to facilitate the calibration of in situ measurements, a PC program has been developed to enable rapid, on-site calculations of radionuclide ground deposition levels. The semi empirical calibration method was tested on in situ measurements with two different detectors, and the results show good agreement with results obtained from traditional soil sampling. (authors)

  2. New method for summing effect corrections applied to environmental samples using gamma spectrometry

    International Nuclear Information System (INIS)

    The analysis by gamma spectrometry of low-level activity environmental samples requires the sample to be placed closest to the detector. In case of a radionuclide with a complex decay scheme, the summing effects due to photons emitted in cascade can bias drastically the activity calculation (from a few percent up to a few tens percent). The presented method enables the user to take into account the whole decay scheme, whatever the radionuclide under study, its number of energy level and decay mode. Despite the nuclear data related to the scheme, this method requires the knowledge of the full-energy peak efficiency curve as well as the total efficiency curve. Its originality relies on a recursive approach of the calculation. A complex decay scheme such as the one of Bi-214 is treated in less than one hour. The method was validated in the context of an international proficiency test, with correction factors up to 40%. A derived use of the method allows the analysis of a peak issued from the summation of photons for the activity determination of the considered radionuclide, especially in case of a well-type Germanium detector. This possibility can also lead to the validation of a detected radionuclide and even reduce the minimum detectable activity in case of multiple interferences. (author)

  3. Dating of sediments from four Swiss prealpine lakes with 210Pb determined by gamma-spectrometry: progress and problems

    International Nuclear Information System (INIS)

    In this paper the most important problems in dating lake sediments with unsupported 210Pb are summarized and the progress in gamma-spectrometry of the unsupported 210Pb is discussed. The main topics of these studies concern sediment samples preparation for gamma-spectrometry, measurement techniques and data analysis, as well as understanding of accumulation and sedimentation processes in lakes. The vertical distributions of artificial (137Cs, 241Am, 239Pu) and natural radionuclides (40K, 210,214Pb, 214Bi) as well as stable trace elements (Fe, Mn, Pb) in sediment cores from four Swiss lakes were used as examples for the interpretation, inter-comparison and validation of depth–age relations established by three 210Pb-based models (CF-CSR, CRS and SIT). The identification of turbidite layers and the influence of the turbidity flows on the accuracy of sediment dating is demonstrated. Time-dependent mass sedimentation rates in lakes Brienz, Thun, Biel and Lucerne are discussed and compared with published data. - Highlights: • State-of-the-art aspects of gamma-spectrometry of unsupported 210Pb are summarized. • Reduction of 222Rn loss by sealing sediment samples was experimentally quantified. • 210Pb models (CF-CSR, CRS, SIT) are applied on long sediment cores from 4 lakes. • Results for profiles, depth–age relations and sedimentation rates are compared. • 210Pb dating is supported by independent time-markers (7Be, 137Cs, 241Am, 239Pu)

  4. Field measurements of environmental radionuclides 137Cs and 210Pbex inventories using in-situ gamma-ray spectrometry

    International Nuclear Information System (INIS)

    In-situ measurement of environmental radionuclides 137Cs and 210Pbex has a potential to assess soil erosion and sedimentation rapidly. In this study, we measured the inventories of 137Cs and 210Pbex in the soil of Inner Mongolia grassland using an in-situ gamma detector with the 50 mm shield and Collimator mounted on a cart (ISOCS, In-situ Object Counting System). The detector was set up one meter above the ground with 90 degree collimator installed: the counting time is more than 3600s. The field survey data were compared with data from laboratory analysis of section cores. The results showed that the mean deviations of measured values between field and laboratory measurements are less than 8%, indicating a high precision for in-situ gamma spectrometry. The inventories of 210Pbex measured by in-situ γ spectrometry were much higher than the laboratory measurements due to a short measurement time in the field. The results from our pilot study indicated that in-situ gamma-ray spectrometry has the following advantages over traditional laboratory measurements: no time consuming sample collection, prompt availability of the results, averaging radionuclide activity over a large area and high precision. (authors)

  5. Particle-size distribution of fission products in airborne dust collected at Tsukuba from April to June 1986

    International Nuclear Information System (INIS)

    The radioactivity released by the reactor accident at Chernobyl was detected in surface air at Tsukuba, Japan. Gamma-spectrometry of airborne dust collected using aerodynamic separation showed higher concentrations of radionuclides in fine particles. The particle-size distribution of radionuclides changed with time. (author)

  6. In-situ gamma ray spectrometry with the K-A-TE-RINA submersible detector

    International Nuclear Information System (INIS)

    A new detection system, named K-A-TE-RINA (Innovative Sensor for Artificial Radioactivity), has been developed for radioactivity measurements in the marine environment. The system is based on a NaI scintillator housed by special plastic material capable for operation in open sea. The efficiency of the detection system is measured in the laboratory using two reference gamma ray sources: 40K and 137Cs. The developed electronics offer proper adjustment of the maximum detection energy in order to apply the system in different key-environments, focusing to a special requested radionuclide. The low power consumption and the gain stabilization of the output voltage make the developed system reliable for long-term measurements. Many tests were also made in order to check the linearity of electronics in case of long-term measurements. In future, the system will be installed on a specific application buoy together with other detectors (like salinity, rain-gauge, temperature and wind direction), for the correlation of radioactivity variation with those magnitudes. In situ gamma ray spectrometry is widely used for monitoring natural as well as anthropogenic radioactivity in the marine environment. The sensitivity of such detection system has to be very high due to the dilution factor of the sea. Although various spectrometric methods based on scintillation spectrometry and spectrum deconvolution have been used for monitoring of the marine environment, the NaI-detection systems are not capable of measuring low-level volumetric activity (a few Bq/m3). In addition the poor energy resolution makes the deconvolution procedure not applicable when the energy difference of the involved gamma rays is less than 50 keV at 662keV gamma ray energy. In the present work a newly developed system is presented, named KA-TE-RINA. The system was calibrated in a tank for the energy, energy resolution and efficiency. The specifications of the system as well as the improvements for optimal operation

  7. Comparative and Absolute Measurements of 11 Inorganic Constituents of 38 Human Tooth Samples with Gamma-ray Spectrometry

    International Nuclear Information System (INIS)

    The mean concentrations of the following elements have been simultaneously determined in normal human dentine, enamel and dental calculus with gamma-ray spectrometry; Na, P, Cl, Ca, Mn, Cu, Zn, Br, Sr, W and Au. In a typical run one sample each of dentine, enamel and dental calculus were irradiated together with standards of the elements to be determined in a thermal neutron flux of 2 x 1012 n/cm/sec for 20 hours. The chemical elements were separated into nine groups with ion exchange technique before the subsequent gamma spectrometric measurements. One man can manage the chemical separations and take the necessary gamma spectra from a run in one day. In a few samples of dentine, enamel and dental calculus which had been irradiated in a thermal neutron flux of 7 x 1013 n/cm/sec for one week the additional long lived trace elements were qualitatively determined Cr, Fe, Co, Rb, Ag, Sb, Cs and Ba

  8. Committed effective dose determination in cereal flours by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The health impact from radionuclides ingestion of foodstuffs was evaluated by the committed effective doses determined in commercial samples of South-Brazilian cereal flours (soy, wheat, corn, manioc, rye, oat, barley and rice flour). The radioactivity traces of 228Th, 228Ra, 226Ra, 40K, 7Be and 137Cs were measured by gamma-ray spectrometry employing a 66% relative efficiency HPGe detector. The energy resolution for the 1332.46 keV line of 60Co was 2.03 keV. The committed effective doses were calculated with the activities analyzed in the present flour samples, the foodstuff rates of consumption (Brazilian Institute of Geography and Statistics) and the ingestion dose coefficients (International Commission of Radiological Protection). The reliability median activities were verified with χ2 tests, assuring the fittings quality. The highest concentration levels of 228Th and 40K were 3.5 ± 0.4 and 1469 ± 17 Bq.kg-1 for soy flour, respectively, with 95% of confidence level. The lower limit of detection for 137Cs ranged from 0.04 to 0.4 Bq.kg-1. The highest committed effective dose was 0.36 μSv.y-1 for 228Ra in manioc flour (adults). All committed effective doses determined at the present work were lower than the UNSCEAR limits of 140 μSv.y-1 and much lower than the ICRP (1991) limits of 1 mSv.y-1, for general public. There are few literature references for natural and artificial radionuclides in foodstuffs and mainly for committed effective doses. This work brings the barley flour data, which is not present at the literature and 7Be data which is not encountered in foodstuffs at the literature, besides all the other flours data information about activities and committed effective doses. (author)

  9. Self-absorption corrections in gamma-ray spectrometry applied to norm industrial samples

    International Nuclear Information System (INIS)

    High resolution gamma spectrometry is a versatile non-destructive radiometric technique that makes simultaneous determination of several radionuclides possible with little sample preparation. However, application of self-absorption corrections is a must, especially in the low energy range, if one hopes to obtain correct values of activity concentrations. Usually, NORM samples feature a wide variety of densities and composition, as opposed to the standards used in efficiency calibration, which are often water-based solutions. For that reason self-absorption effects must be considered individually in every sample. In this work an experimental and a semi-empirical method of self-absorption correction were applied to NORM samples and compared with each other in order to establish best practice in relation to the circumstances of an individual laboratory. Following the experimental methodology, transmission measurements of absorption factors with point sources were carried out, while the semi-experimental methodology involved the application of the EFFTRAN code, based on the 'efficiency transfer' principle. Both methods were validated by applying them to a set of spiked NORM matrices coming from the TiO2 industry located in the south-west of Spain in order to determine the flow of several radionuclides from the Uranium and Thorium series though the production process. The main advantages and disadvantages of the two approaches used are highlighted, focusing on the low energy range (46-200 keV). EFFTRAN qualities are its ease of use, its short-run time and good performance with samples of a well-known composition, while the transmission technique can be applied almost under any circumstances, providing that a suitable set of point sources covering the energy range of interest is at hand. (authors)

  10. Results from gamma-ray spectrometry measurements obtained within the environmental monitoring program at IPEN

    International Nuclear Information System (INIS)

    IPEN, at Sao Paulo, is the largest institute in the nuclear research field in Brazil, developing activities in areas such as application of nuclear techniques in industry, radioisotopes, nuclear physics, radiochemistry, nuclear engineering and radiation protection. In order to estimate the radiological impact to the environment around IPEN facilities, a monitoring program was established. Samples of ground water, rainwater and filters for air sampling in the influence area of IPEN were measured by using gamma spectrometry. Results from 1997 to 2003 for ground water and rainwater samples, and from 2000 to 2002 for filters used in atmospheric air monitoring, are presented and the concentrations of natural (210Pb, 226Ra, 228Ra, 228Th, and 7Be) and artificial (131I) radionuclides were determined. The highest values obtained for the activity concentrations were: (131 ± 20) mBq L-1 for 226Ra, (298 ± 87) mBq L-1 for 228Ra and (349 ± 22) mBq L-1 for 228Th in the ground water samples; (399 ± 69) mBq L-1 for 7Be in the rainwater samples; (0,37 ± 0,06) mBq m-3 for 210Pb in fiber filters; and (17,7 ± 0,7) mBq m-3 for 131I in charcoal filters. The results obtained for rainwater suggested that there are higher 7Be concentrations during the rainy season and an increase in the 210Pb activities in the fiber filters during the dry season. In some ground water samples, it was detected 226Ra, 228Ra, and 228Th, in agreement with the literature. In the charcoal filters it was found 131I, due to the normal operation of IPEN facilities. (author)

  11. Accurate gamma-ray spectrometry measurements of the half-life of 92Sr.

    Science.gov (United States)

    Leconte, P; Hudelot, J P; Antony, M

    2008-10-01

    Studies of the nuclear fuel cycle require an accurate knowledge of the energy release from the decay of radioactive nuclides produced in a reactor, including precise half-life data for the short-lived radionuclides. Moreover, short-lived fission products are crucial for fission rate distribution measurements performed in low-power facilities, such as EOLE and MINERVE of CEA Cadarache [Fougeras, P., 2005. EOLE, MINERVE and MASURCA facilities and their associated neutron experimental programs. In: 13th International Conference on Nuclear Engineering, Beijing, China, 16-20 May 2005], and their nuclear decay data need to be known to high precision. For these reasons, the half-life of (92)Sr has been measured to solve a recently observed inconsistency identified with the quoted value in the main nuclear applications libraries (including JEFF3.1): T(1/2)=2.71+/-0.01 h [Parsa, B., Ashari, A., Goolvard, L., Nobar, Y.M., 1971. Decay scheme of 2.71 h (92)Sr. Nucl. Phys. A 175, 629-640]. An overestimation of 4.5% has been identified in this work, based on two independent methods. Specific gamma-ray spectrometry measurements on activated fissile foils have been carried out, using two HPGe detectors. Influencing factors such as net area measurements of photopeaks, pulse pile-up accuracy and dead time corrections in the presence of decaying activity are discussed. A new value has been obtained by combining eight series of measurements: T(1/2)=2.594+/-0.006 h. The uncertainty has been reduced by a factor of two with respect to previous evaluations. This measured value also shows good agreement with the most recent studies of T(1/2)=2.627+/-0.009 h [Nir-El, Y., 2003. Private Communications. Soreq Research Centre, Yavne, Israel]. PMID:18456504

  12. Measurement of natural radioactivity in animal feed supplements samples by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The objective of the present work is to determine the radiation levels found in animal feed supplements due to natural radioactivity. Knowledge of the radiation levels in samples of animal and poultry feed supplements is important, because they directly or indirectly form part of the human diet. In order to obtain this data, gamma-ray spectrometry technique was used, employing a p-type HPGe detector of 30% of relative efficiency, with an energy resolution of 1.9 KeV for the 60Co 1332.46 KeV line. The radioactivity due to radionuclides 40K, 226Ra, 238U, 232Th and its respective decay series was measured. The accommodation recipient of the samples was a 250 cc cylindrical plastic container. The 238U series radioactivity was calculated through 214Pb and 214Bi activities, and the 232Th series' activity was calculated through the 228Ac, 212Pb, 212Bi and 208Tl values. The animal feed supplements samples measured in this work were samples received in this laboratory for radioactivity test certification. Among the samples, the radioactivity concentration of Uranium-238, Thorium-232, Radium-226 and Potassium-40 in animal supplement was found to be in the range of 1.4 ± 0.2 to 32.7 ± 5.7 Bq/kg, 1.8 ± 0.2 to 44.5 ± 6.6 Bq/kg, 4.0 ± 1. 2 to 105.2 ± 10.2 Bq/kg and 13.1 ± 3.6 to 397.2 ± 19.9 Bq/kg respectively. (author)

  13. Analysis of 137Cs contamination in soil using in-situ gamma spectrometry

    International Nuclear Information System (INIS)

    Quantification of radioactive contamination in the environment is often desirable so that health implications can be determined and appropriate remedial measures taken. In-situ gamma spectrometry is a potentially powerful technique that has the advantage of speed and spatial averaging over a large area. Calibration, however, is complex not least because the distribution of the activity in the field is generally unknown. To overcome this problem, methods have previously been proposed to derive information about the vertical activity distribution. All of these methods assume a fixed simple activity distribution model, the parameters of which are derived from varying in-situ spectral region ratios. In this work, these methods have been extensively assessed and compared both theoretically and experimentally for the quantification of 137Cs contamination. In all cases, the best method was that which used a lead plate to alter the contributing angular interval. Experimentally, this Lead Plate Method predicted the activity concentration to within a factor of between 1.50 and 1.66 on average. A new method, using collimated detector measurements within a shallow well was developed and theoretically optimised in terms of number and depths of detector positions and type of collimation. This optimised Submerged Detector Method was assessed and compared with the Lead Plate Method both theoretically and experimentally. The latter comparison involved 19 sites across Wales, UK where there is a wide range of 137Cs activity levels and vertical distributions. The Submerged Detector Method was found to be more accurate both in the theoretical modelling assessment and in the experimental comparison, where the method was found to predict the activity concentration to within a factor of 1.35 on average. Distribution profiles predicted by the Submerged Detector Method were also found to be generally closer to the true profiles than those obtained using the Lead Plate Method. (author)

  14. Some considerations on the use of gamma spectrometry for Kr-85 determination at gaseous effluents in the nuclear industry and environmental samples

    International Nuclear Information System (INIS)

    The possibilities of using high resolution gamma ray spectrometry with GeLi semiconductor detector for measured the 0.514 KeV gamma radiation of Kr-B5 la explored, The detection limit of Kr-85 for a measuring time is 4.10-4 μCi with a counting time of 1000 minutes in a GeLi detector with a 20% efficiency relative to the INa (Tl). It is concluded that the use of gamma ray spectrometry for measuring the Kr-85 is not useful for environmental samples, but it can be used for the Kr-85 effluents control in Nuclear Stations. (Author) 26 refs

  15. Experimental determination of nuclear reaction rates (n,γ) by the gamma-rays capture spectrometry technique

    International Nuclear Information System (INIS)

    The technique of the gamma-rays capture spectrometry was used in the experimental determination of nuclear reaction rates of the type (n,γ). This technique consists in the incidence of a thermal neutrons collimated beam upon a sample, detecting the capture spectrum of gamma rays emitted at a solid fixed angle. In the determination of the efficiency curve intrinsic to the detection electronic system the reactions 199Hg(n,γ)200Hg, 56Fe(n,γ)57Fe and 63Cu(n,γ)64Cu were used with the energy of the gamma rays capture of 5.976, 7.635 and 7.915 Mev respectively, through the irradiation of standard samples of Hg(175.3g), Fe(110.4g) and Cu(108.5g) of cylindrical geometry the two former and parallelepiped the latter. The problem concerning the corrections due to the thermal neutrons flux depression, the gammas auto-attenuation, and the geometric factor due to the cylindrical and parallelepiped geometry are involved in the data process. The experimental determination of the reaction 35Cl(n,γ)36Cl rate was made through the observation of the gamma caputre of 6.111 Mev when a sample of CaCl2 of cylindrical geometry was irradiated. This rate can be favorably compared with the reaction rate determined theoretically. (author)

  16. Airborne remote spectrometry support to rescue personnel at Ground Zero after the World Trade Center attack on September 11, 2001

    Science.gov (United States)

    Simi, Christopher G.; Hill, Anthony B.; Kling, Henry; Zadnik, Jerome A.; Sviland, Marc D.; Williams, Mary M.; Lewis, Paul E.

    2002-11-01

    In order to assist Rescue and Recovery personnel after 11 September 2001, Night Vision and Electronic Sensors Directorate was requested to collect a variety of airborne electro-optic data of the WTC site. The immediate objective was to provide FDNY with geo-rectified high-resolution and solar reflective hyperspectral data to help map the debris-field. Later data collections included calibrated MWIR data. This thermal data provided accurate temperature profiles, which could be warped to the high-resolution data. This paper will describe the assets and software used to help provide the FDNY data products, which were incorporated into their GIS database.

  17. Radon fixation for determination of {sup 224}Ra, {sup 226}Ra and {sup 228}Ra via gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, M. [Departamento Ingenieria Nuclear y Mecanica de Fluidos, E. S. Ingenieros de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n, 48013 Bilbao (Spain)]. E-mail: inphesom@bi.ehu.es; Idoeta, R. [Departamento Ingenieria Nuclear y Mecanica de Fluidos, E. S. Ingenieros de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n, 48013 Bilbao (Spain); Abelairas, A. [Departamento Ingenieria Nuclear y Mecanica de Fluidos, E. S. Ingenieros de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n, 48013 Bilbao (Spain); Legarda, F. [Departamento Ingenieria Nuclear y Mecanica de Fluidos, E. S. Ingenieros de Bilbao - Universidad del Pais Vasco (UPV/EHU), Alda. Urquijo s/n, 48013 Bilbao (Spain)

    2006-04-15

    The aim of this work is the improvement of the procedure for the determination of radium isotopes activities in water, which is done through radiochemical separation and subsequent gamma-ray spectrometry. In addition, radon gas retention is studied using different activated carbon materials. The results of the IAEA Proficiency test: 'Determination of radium and uranium radionuclides in water' of December 2002 [IAEA, 2003. Analytical quality control services: determination of radium and uranium radionuclides in water. Preliminary Report, Seibersdorf] are considered for this work.

  18. Application of the Gamma Spectrometry Sourceless Efficiency Calibration Method to the Measurement of Radionuclides in Rare Earth Residues

    International Nuclear Information System (INIS)

    The paper investigates and analyses NORM residues from rare earth smelting and separation plants in Jiangsu Province using the high purity germanium gamma spectrometry sourceless efficiency calibration method which was verified by IAEA reference materials. The results show that in the rare earth residues the radioactive equilibrium of uranium and thorium decay series has been broken and the activity concentrations in the samples have obvious differences. Based on the results, the paper makes some suggestions and proposes some protective measures for the disposal of rare earth residues. (author)

  19. Execution of a cooperative test by means of 'in-situ-gamma spectrometry' using HP-germanium detectors

    International Nuclear Information System (INIS)

    A cooperative test was carried out in Salzburg, Austria, in order to determine the activity of Cs-137 and other radio nuclides from the Tschernobyl fallout 1986 and from tests of nuclear weapons in the 1960s. 24 groups from 9 countries of Europe took part. The measurements were performed by means of gamma spectrometry using HP-germanium detectors. Most of the groups had excellent results. The groups became acquainted with each other. The personal contact makes it possible to get information quickly in case of accidents of nuclear power stations in the neighbourhood of Austria

  20. In-situ gamma spectrometry measurements of time-dependent Xenon-135 inventory in the TRIGA Mark II reactor Vienna

    OpenAIRE

    Riede, Julia; Boeck, Helmuth

    2013-01-01

    In this work, it has been shown that the time dependent Xe-135 inventory in the TRIGA Mark II reactor in Vienna, Austria can be measured via gamma spectrometry even in the presence of strong background radiation. It is focussing on the measurement of (but not limited to) the nuclide Xe-135. The time dependent Xe-135 inventory of the TRIGA Mark II reactor Vienna has been measured using a temporary beam line between one fuel element of the core placed onto the thermal column after shutdown and ...

  1. The energy calibration and precision of a gamma spectrometry unit - Method using the electron annihilation energy as the only standard

    International Nuclear Information System (INIS)

    Spectrometry using Ge(Li) detectors is discussed. The excellent resolution of this type of detector, the mathematical analysis of the spectral lines of the pulses, and the reproducibility of the spectrometer enable highly accurate measurements of the abscises (some 10-5) corresponding to the peaks. A method using the annihilation energy of the electron as the only standard was developed. The method is applied to the measurement of the gamma ray energies of the radioelements: 22Na, 24Na, 56Mn, 56Co, 59Fe, 72Ga, 88Y, 122Sb, 124Sb and 137Cs. (author)

  2. Determination of the natural and artificial radioactivity of a selection of traditional Mexican medicinal herbs by gamma spectrometry

    International Nuclear Information System (INIS)

    This work presents the results of a gamma spectrometry analysis of 30 traditional Mexican medicinal herbs. The analysis was carried out using low level background shielding, a hyper-pure germanium detector, and a multichannel analyzer system. Natural and artificial radioactivity concentration from 226Ra (through 214Pb and 214Bi), 228Th (through 208Tl), 228Ra (through 228Ac), 40K, and 137Cs were determined in this analysis. The results show low concentration levels of natural radioactivity and no artificial radionuclides, and different contents of natural 40K, in the studied medicinal herbs. These low concentration levels of natural radionuclides, cannot be consider a health risk for common consumers. (author)

  3. Test and rules for computer programs used in gamma spectrometry for the determination of the efficiency response

    International Nuclear Information System (INIS)

    Several computer programs used in gamma spectrometry for the calcul of the efficiency responses, operational in different programmable analysis systems, were tested with a test called Lot no.2. One of them APOCODE, was elaborated by CEA, the others were provided by system suppliers. This test includes three ranges of energy and efficiency points with which it is possible: to know the methods used for the efficiency determination, to estimate the results, to precise the limits of the methods. With this test, the portability of the logiciel APOCOPE, was proved

  4. Radon fixation for determination of 224Ra, 226Ra and 228Ra via gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The aim of this work is the improvement of the procedure for the determination of radium isotopes activities in water, which is done through radiochemical separation and subsequent gamma-ray spectrometry. In addition, radon gas retention is studied using different activated carbon materials. The results of the IAEA Proficiency test: 'Determination of radium and uranium radionuclides in water' of December 2002 [IAEA, 2003. Analytical quality control services: determination of radium and uranium radionuclides in water. Preliminary Report, Seibersdorf] are considered for this work

  5. Medium-term experiences with in-situ gamma-spectrometry of the primary loop transport processes at Paks NPP

    International Nuclear Information System (INIS)

    Surface activity of 15 corrosion/erosion and fission products was determined by in-situ gamma-spectrometry for 2-2 locations on the hot and cold legs of each loop, respectively. Gamma-dosimetry in the assay points was performed. Activity profiles of ion exchange columns were analyzed. Combined measurements along the steam generators completed the characterization of the primary circuits. Most of this technique was regularly included into all maintenance periods. Data evaluation was performed for the surface contaminations as well as coolant activities and reactor operation features for years 1985-2001. Trends and tendencies were investigated in the time behavior of the specific activities. Asymmetry in the surface contamination at the primary loop points, cold-leg activity inversion, water chemistry effects, isotope selectivity were observed. Correlations in different parameters have been calculated and analyzed. (R.P.)

  6. A search for double-electron capture in 74Se using coincidence/anticoincidence gamma-ray spectrometry

    CERN Document Server

    Jeskovsky, M; Kovacik, A; Povinec, P P; Puppe, P; Stanicek, J; Sykora, I; Simkovic, F; Thies, J H

    2015-01-01

    Evaluation of single, coincidence and anticoincidence gamma-ray spectrometry methods has been carried out with the aim to search for double-electron capture in 74Se. This process is unique, because there is probability for transition to the 2+ excited state in 74Ge (1204 keV), and de-excitation through two gamma-quanta cascade with energies of 595.9 keV and 608.4 keV. Long-term measurements with anticosmic shielded HPGe spectrometer and the coincidence HPGe-NaI(Tl) spectrometer did not show any evidence for the double-electron capture in 74Se. The best limit for the half-life of the double electron capture in 74Se (both for the neutrinoless and two neutrino processes) was estimated to be >1.5x10E19 years.

  7. Determination of the natural radioactivity in Qatarian building materials using high-resolution gamma-ray spectrometry

    International Nuclear Information System (INIS)

    This study is aimed at the determination of the activity concentrations of naturally occurring and technically enhanced levels of radiation in building materials used across the State of Qatar. Samples from a range of common building materials, including Qatarian cement, Saudi cement, white cement, sand and washed sand, have been analyzed, in addition to other samples of cement's raw materials and additives collected from the main suppliers in Qatar. In order to establish the activity concentrations associated with the 235,8U and 232Th natural decay chains and 40K, the samples have been studied using a high-resolution, low-background gamma-ray spectrometry set-up. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented, together with the preliminary results of the activity concentrations associated with the naturally occurring radionuclide chains for the building materials collected across the Qatarian peninsula.

  8. Determination of the natural radioactivity in Qatarian building materials using high-resolution gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Al-Sulaiti, Huda, E-mail: h.al-sulaiti@surrey.ac.uk [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Radiation Protection and Chemicals Department, Ministry of Environment, P.O. Box: 7634, Doha (Qatar); Alkhomashi, N. [King Abdulaziz University of Science and Technology (KACST), P.O. Box 6086, Riyadh 11442 (Saudi Arabia); Al-Dahan, N. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Department of Physics, College of Science, University of Kerbala, Kerbala (Iraq); Al-Dosari, M. [Radiation Protection and Chemicals Department, Ministry of Environment, P.O. Box: 7634, Doha (Qatar); Bradley, D.A. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Bukhari, S. [Information Systems Management Department, Ministry of Environment, P.O. Box: 7634, Doha (Qatar); Matthews, M. [Centre of Environmental Health Engineering, Department of Civil Engineering, University of Surrey, Guildford, GU2 7XH (United Kingdom); Regan, P.H.; Santawamaitre, T. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom)

    2011-10-01

    This study is aimed at the determination of the activity concentrations of naturally occurring and technically enhanced levels of radiation in building materials used across the State of Qatar. Samples from a range of common building materials, including Qatarian cement, Saudi cement, white cement, sand and washed sand, have been analyzed, in addition to other samples of cement's raw materials and additives collected from the main suppliers in Qatar. In order to establish the activity concentrations associated with the {sup 235,8}U and {sup 232}Th natural decay chains and {sup 40}K, the samples have been studied using a high-resolution, low-background gamma-ray spectrometry set-up. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented, together with the preliminary results of the activity concentrations associated with the naturally occurring radionuclide chains for the building materials collected across the Qatarian peninsula.

  9. Application of neutron-induced and natural gamma-ray spectrometry for evaluation of coal parameters in the laboratory and in-situ

    International Nuclear Information System (INIS)

    Experimental investigations of the three laboratory nuclear techniques (natural gamma-ray, neutron capture gamma-ray and neutron activation analysis) have been applied for quantitative determination of coal parameters. Natural gamma-ray measurements of carboniferous rocks of the Upper Silesian Coal Basin have shown that the specific activity of shale and mudstone is higher than that of bituminous coal. The determination of ash content, calorific value and carbon content by natural gamma-ray spectrometry was feasible. An elemental analysis of principal elements in coal was performed by neutron capture gamma-ray measurements. The major constituents of mineral components of coal were determined by means of neutron activation analysis. Fields experiments of the two neutron induced gamma-ray spectrometric logging methods (neutron-gamma and neutron activation) have been used for quantitative determination of coal quality parameters. 74 refs, 40 figs, 15 tabs

  10. Statistical signal processing for gamma spectrometry: application for a pileup correction method

    International Nuclear Information System (INIS)

    The main objective of gamma spectrometry is to characterize the radioactive elements of an unknown source by studying the energy of the emitted photons. When a photon interacts with a detector, its energy is converted into an electrical pulse. The histogram obtained by collecting the energies can be used to identify radioactive elements and measure their activity. However, at high counting rates, perturbations which are due to the stochastic aspect of the temporal signal can cripple the identification of the radioactive elements. More specifically, since the detector has a finite resolution, close arrival times of photons which can be modeled as an homogeneous Poisson process cause pile-ups of individual pulses. This phenomenon distorts energy spectra by introducing multiple fake spikes and prolonging artificially the Compton continuum, which can mask spikes of low intensity. The objective of this thesis is to correct the distortion caused by the pile-up phenomenon in the energy spectra. Since the shape of photonic pulses depends on many physical parameters, we consider this problem in a nonparametric framework. By introducing an adapted model based on two marked point processes, we establish a nonlinear relation between the probability measure associated to the observations and the probability density function we wish to estimate. This relation is derived both for continuous and for discrete time signals, and therefore can be used on a large set of detectors and from an analog or digital point of view. It also provides a framework to this problem, which can be considered as a problem of nonlinear density deconvolution and nonparametric density estimation from indirect measurements. Using these considerations, we propose an estimator obtained by direct inversion. We show that this estimator is consistent and almost achieves the usual rate of convergence obtained in classical nonparametric density estimation in the L2 sense. We have applied our method to a set of

  11. Thorium determination in intercomparison samples and in some Romanian building materials by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Thorium content in zircon sand, thorium ore and a thorium liquid sample, as well as in some Romanian building materials: sand, wood, tufa, asbestos-cement, cement mill dust, fly coal ash, bricks and tile (28 samples) was determined by gamma-ray spectrometry. For the building materials, 226 Ra, 40 K and 137 Cs specific activities were also measured. All samples were kept tightly closed in the pots for about one month, to allow that the radioactive equilibrium among the gaseous radionuclides 222 Rn (238 U series), 220 Rn (232 Th series) and their daughter products be reached. 232 Th activity concentration was calculated from its daughter products 228 Ac, 212 Pb, 212 Bi and 208 Tl, assuming radioactive equilibrium among all 232Th decay chain isotopes. The activity concentrations of 226 Ra was calculated by 214 Pb and 214 Bi daughter products, assuming radioactive equilibrium among all 226 Ra decay chain isotopes. Zircon sand, thorium ore and a thorium liquid sample were analyzed in the frame of the European Commission Project 'Thematic network on the analysis of thorium and its isotopes in workplace materials', coordinated by the Health and Safety Laboratory HSL, Sheffield, United Kingdom. Thorium nitrate solution containing 232 Th in equilibrium with its daughter products and the two thorium minerals (without any prior treatment) were prepared as test samples by the Centre for Ionizing Radiation Metrology at the UK National Physical Laboratory (NPL), Teddington, England. The obtained 232 Th results are in good agreement with those of NPL for the liquid and ore samples (analyst/NPL ratios of 0.97 and 1.05, respectively) and rather good agreement for zircon sand (analyst/NPL ratio of 1.20). Sand, wood, tufa, asbestos-cement, cement mill dust, fly coal ash, tile, red and autoclaved cellular concrete (ACC) bricks collected from building material factories in different zones of Romania were investigated for natural and artificial radioactivity. The results were compared

  12. Neutron Activation Analysis and High Resolution Gamma-Ray Spectrometry Applied to Areal Elemental Distribution Studies

    International Nuclear Information System (INIS)

    Schuiling (1967) applied both 'metallogenetic province' and continental drift principles to a study of the world-wide distribution of tin. A plot of tin deposit occurrences on the continents reconstituted as 'Pangeae' yielded 'tin belts' joining intercontinentally between the Americas, Africa and Europe. Discussions with Sir John Cockcroft and Sir Edward Bullard, in April 1967, led to this study of the applicability of automated, instrumental thermal neutron activation analysis techniques to large-scale areal elemental distribution determinations related to continental drift and to metallogenesis. The Enchanted Rock batholith, Llano, Texas, was selected as an initial area in which to apply this method on the basis of the availability of independent geochemical information concerning the pluton from Hutchinson (1956), Billings (1963) and Ragland (1968). Rock samples, including points from areas outside the batholith, were obtained at each of 16 sampling sites. One-gram rock samples were irradiated in a thermal neutron flux of ≈2 x 1012 n/cm2 s for 2 hours. Six trace elements (Hf, Ta, Co, Eu, Sc and La), and one minor element (Fe), were determined by gamma-ray spectrometry utilizing a 19 cm3 Ge(Li) detector and a 3200-channel analyser, and were areally mapped. The results indicate continuous trends in each trace element, through various rock types, over a distance of greater than 50 miles. The trace elements of pyrite, chalcopynte and sphalerite obtained from the Philippine Islands were measured in order to apply this procedure to minerals in a location where their areal extent has not previously been extensively studied. The methodology described above was repeated. A set of average element abundances in chalcopynte, pyrite and sphalerite is suggested on which to base the presence or absence of an element province or combined elements provinces. Preliminary results indicate the presence of a gold province in the northwestern part of Luzon Island. This technique

  13. Use of a Shielded High Resolution Gamma Spectrometry System to Segregate LLW from Contact Handleable ILW Containing Plutonium - 13046

    Energy Technology Data Exchange (ETDEWEB)

    Lester, Rosemary; Wilkins, Colin [Canberra UK Ltd, Unit 1 B528.1, Harwell Science Campus, Oxfordshire OX11 0DF (United Kingdom); Chard, Patrick [Canberra UK Ltd, Forss Business and Technology park, Thurso, Caithness KW14 7UZ (United Kingdom); Jaederstroem, Henrik; LeBlanc, Paul; Mowry, Rick [Canberra Industries, Inc., 800 Research Parkway, Meriden, Connecticut, 06450 (United States); MacDonald, Sanders; Gunn, William [Dounreay Site Restoration Limited, Dounreay, Thurso, Caithness, KW14 7TZ (United Kingdom)

    2013-07-01

    Dounreay Site Restoration Limited (DSRL) have a number of drums of solid waste that may contain Plutonium Contaminated Material. These are currently categorised as Contact Handleable Intermediate Level Waste (CHILW). A significant fraction of these drums potentially contain waste that is in the Low Level Waste (LLW) category. A Canberra Q2 shielded high resolution gamma spectrometry system is being used to quantify the total activity of drums that are potentially in the LLW category in order to segregate those that do contain LLW from CHILW drums and thus to minimise the total volume of waste in the higher category. Am-241 is being used as an indicator of the presence of plutonium in the waste from its strong 59.54 keV gamma-ray; a knowledge of the different waste streams from which the material originates allows a pessimistic waste 'fingerprint' to be used in order to determine an upper limit to the activities of the weak and non-gamma-emitting plutonium and associated radionuclides. This paper describes the main features of the high resolution gamma spectrometry system being used by DSRL to perform the segregation of CHILW and LLW and how it was configured and calibrated using the Canberra In-Situ Object Counting System (ISOCS). It also describes how potential LLW drums are selected for assay and how the system uses the existing waste stream fingerprint information to determine a reliable upper limit for the total activity present in each measured drum. Results from the initial on-site commissioning trials and the first measurements of waste drums using the new monitor are presented. (authors)

  14. Use of a Shielded High Resolution Gamma Spectrometry System to Segregate LLW from Contact Handleable ILW Containing Plutonium - 13046

    International Nuclear Information System (INIS)

    Dounreay Site Restoration Limited (DSRL) have a number of drums of solid waste that may contain Plutonium Contaminated Material. These are currently categorised as Contact Handleable Intermediate Level Waste (CHILW). A significant fraction of these drums potentially contain waste that is in the Low Level Waste (LLW) category. A Canberra Q2 shielded high resolution gamma spectrometry system is being used to quantify the total activity of drums that are potentially in the LLW category in order to segregate those that do contain LLW from CHILW drums and thus to minimise the total volume of waste in the higher category. Am-241 is being used as an indicator of the presence of plutonium in the waste from its strong 59.54 keV gamma-ray; a knowledge of the different waste streams from which the material originates allows a pessimistic waste 'fingerprint' to be used in order to determine an upper limit to the activities of the weak and non-gamma-emitting plutonium and associated radionuclides. This paper describes the main features of the high resolution gamma spectrometry system being used by DSRL to perform the segregation of CHILW and LLW and how it was configured and calibrated using the Canberra In-Situ Object Counting System (ISOCS). It also describes how potential LLW drums are selected for assay and how the system uses the existing waste stream fingerprint information to determine a reliable upper limit for the total activity present in each measured drum. Results from the initial on-site commissioning trials and the first measurements of waste drums using the new monitor are presented. (authors)

  15. Application of PERALS™ alpha spectrometry and gamma spectrometry for analysis and investigation of environmental spills at ISL uranium mining projects

    International Nuclear Information System (INIS)

    Radiation protection and environmental monitoring in mining requires effective and reliable radionuclide analysis at all stages of the mine project—prior to mining, during operation and through to remediation and decommissioning. The approach presented in this paper was specially developed for the monitoring of radioactive waste resulting from spills during mining and mineral processing operations and uses a combination of high resolution gamma spectrometry, and PERALS™ alpha spectrometry to identify and reliably quantify the activity of the major members of the U-238 decay chain at activities down to 10 mBq g−1 by direct radionuclide counting and by assessment of the activity of their decay products. This approach has reduced sample preparation and analysis time while providing effective analysis and quantification of naturally occurring radionuclides in environmental samples. It has been successfully applied to several in situ leach (ISL) mining-related projects involving investigations of process material spill impacts and also to routine environmental monitoring. (paper)

  16. Direct gamma-X spectrometry measurement of 129I in environmental samples using experimental self-absorption corrections

    International Nuclear Information System (INIS)

    Direct gamma-X spectrometry is a suitable technique for quantifying low-level 129I activity, down to a few becquerels per kilogram, in environmental samples. Direct gamma-X spectrometry is a non-destructive technique that is rapid, which can be used for measuring several radioisotopes (multielementary) and that is easy to implement. A description is given of an experimental method for determining the self-absorption correction in the low-energy range, below 25 keV, to quantify 129I in different environmental matrices. The method is based on the measurement of the mass energy-attenuation coefficient μm(E) of the sample and the standard used to calibrate the measuring system. The μm(E) data are introduced in a simplified formulation of the correction factor that is validated for several container-detector sets commonly used in low-level activity environmental measurement. The method has also been tested on 125I, 129I and 137Cs, using different energy transitions. For marine algae species with high iodine concentrations (>2x10-3 as a fraction of mass), an original method of determining the 129I/totalI ratio as against the μm(E) determination in the vicinity of the iodine K-absorption edge energy is described

  17. Methodology for determination of activity of radionuclides by gamma spectrometry; Metodologia para determinacao da atividade de radionuclideos por sistema de espectrometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Fragoso, Maria da Conceicao de Farias; Oliveira, Victor Rogerio S. de; Oliveira, Mercia L.; Lima, Fernando Roberto de Andrade, E-mail: mariacc05@gmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-NE), Recife, PE (Brazil)

    2014-07-01

    Due to the growth in the number of procedures that make use of the positron emission tomography (PET), there is a need for standard solutions for the calibration of the systems used for the measurement of the PET radiopharmaceutical (activimeter) in radiopharmacies and in nuclear medicine services. Among the existing alternatives for the standardization of radioactive sources, the method known as gamma spectrometry is widely used for short-lived radionuclides. The purpose of this study was to implement the methodology for standardization of the {sup 18}F solutions by gamma spectrometry at the Regional Center for Nuclear Sciences of the Northeast (CRCN-NE/CNEN-NE), Brazil. (author)

  18. Gamma-ray spectrometry combined with acceptable knowledge (GSAK). A technique for characterization of certain remote-handled transuranic (RH-TRU) wastes. Part 1. Methodology and techniques

    International Nuclear Information System (INIS)

    Gamma-ray spectrometry combined with acceptable knowledge (GSAK) is a technique for the characterization of certain remote-handled transuranic (RH-TRU) wastes. GSAK uses gamma-ray spectrometry to quantify a portion of the fission product inventory of RH-TRU wastes. These fission product results are then coupled with calculated inventories derived from acceptable process knowledge to characterize the radionuclide content of the assayed wastes. GSAK has been evaluated and tested through several test exercises. GSAK approach is described, while test results are presented in Part II. (author)

  19. Gamma-ray spectrometry combined with acceptable knowledge (GSAK). A technique for characterization of certain remote-handled transuranic (RH-TRU) wastes. Part 2. Testing and results

    International Nuclear Information System (INIS)

    Gamma-ray spectrometry combined with acceptable knowledge (GSAK) is a technique for the characterization of certain remote-handled transuranic (RH-TRU) wastes. GSAK uses gamma-ray spectrometry to quantify a portion of the fission product inventory of RH-TRU wastes. These fission product results are then coupled with calculated inventories derived from acceptable process knowledge to characterize the radionuclide content of the assayed wastes. GSAK has been evaluated and tested through several test exercises. These tests and their results are described; while the former paper in this issue presents the methodology, equipment and techniques. (author)

  20. Remote and continuous gamma spectrometry for environmental radiation protection: A review of potential applications

    International Nuclear Information System (INIS)

    The first nuclear metrology tools for surface water surveillance have been designed in the early 80's. The detection systems were based on the use of a NaI(Tl) detector connected to two Single Channel Analyzers (SCA). The detector was placed in a shielded vessel fed with the water to be analysed through a pump. The analysis was rudimentary. The systems were suffering the inherent temperature drift from the detector. For this reasons the system required frequent maintenance for the mechanical parts and the detection system calibration. The sensitivity of the system was about 10-100 Bq/l, which make it useful for monitoring accidental releases from base nuclear installations. Technical evolutions in the fields of computer sciences and telecommunication have allowed the IRE to develop an original instrument able to detect and to quantify very small radioactivity increase in surface water. The system is based on a NaI(Tl) detector connected to a multi-channel analyzer. The detection system is now directly placed in the medium to survey. The analysis is performed using gamma spectrometry technique. In this way the detector temperature drift is compensated thanks to a special algorithm, the spectral analysis permits to discriminate natural and artificial radioactivity and the detection system is much more sensitive. The design of the detection system without pump make feasible to feed it with solar energy and consequently to install it in any aquatic environment (sea, lake ...). The need for regular maintenance is reduced considerably. This system has been successfully implemented in sea and river waters. The system stability is unique for NaI(Tl) based detection system. The detection limit has been considerably lowered - for 137Cs in seawater - containing 12 Bq/l of 40K - it is in the range 0.13-0.22 Bq/l for a 2-hours measurement, while it is in the range 0.65-0.85 Bq/l for a 2-hours counting time in river water. The reported detection limit in river water is higher

  1. Determination of mercury in airborne particulate matter collected on glass fiber filters using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling

    International Nuclear Information System (INIS)

    A study has been undertaken to assess the capability of high-resolution continuum source graphite furnace atomic absorption spectrometry for the determination of mercury in airborne particulate matter (APM) collected on glass fiber filters using direct solid sampling. The main Hg absorption line at 253.652 nm was used for all determinations. The certified reference material NIST SRM 1648 (Urban Particulate Matter) was used to check the accuracy of the method, and good agreement was obtained between published and determined values. The characteristic mass was 22 pg Hg. The limit of detection (3σ), based on ten atomizations of an unexposed filter, was 40 ng g-1, corresponding to 0.12 ng m-3 in the air for a typical air volume of 1440 m3 collected within 24 h. The limit of quantification was 150 ng g-1, equivalent to 0.41 ng m-3 in the air. The repeatability of measurements was better than 17% RSD (n = 5). Mercury concentrations found in filter samples loaded with APM collected in Buenos Aires, Argentina, were between -1 and 381 ± 24 ng g-1. These values correspond to a mercury concentration in the air between -3 and 1.47 ± 0.09 ng m-3. The proposed procedure was found to be simple, fast and reliable, and suitable as a screening procedure for the determination of mercury in APM samples.

  2. In-situ gamma spectrometry measurements of time-dependent Xenon-135 inventory in the TRIGA Mark II reactor Vienna

    CERN Document Server

    Riede, Julia

    2013-01-01

    In this work, it has been shown that the time dependent Xe-135 inventory in the TRIGA Mark II reactor in Vienna, Austria can be measured via gamma spectrometry even in the presence of strong background radiation. It is focussing on the measurement of (but not limited to) the nuclide Xe-135. The time dependent Xe-135 inventory of the TRIGA Mark II reactor Vienna has been measured using a temporary beam line between one fuel element of the core placed onto the thermal column after shutdown and a detector system located just above the water surface of the reactor tank. For the duration of one week, multiple gamma ray spectra were recorded automatically, starting each afternoon after reactor shutdown until the next morning. One measurement series has been recorded over the weekend. The Xe-135 peaks were extracted from a total of 1227 recorded spectra using an automated peak search algorithm and analyzed for their time-dependent properties. Although the background gamma radiation present in the core after shutdown...

  3. A broadband gamma-ray spectrometry using novel unfolding algorithms for characterization of laser wakefield-generated betatron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Jong Ho, E-mail: jhjeon07@ibs.re.kr; Nakajima, Kazuhisa, E-mail: naka115@dia-net.ne.jp; Pathak, Vishwa Bandhu; Cho, Myung Hoon; Yoo, Byung Ju; Shin, Kang Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Kim, Hyung Taek; Sung, Jae Hee; Lee, Seung Ku; Choi, Il Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Advanced Photonics Research Institute, GIST, Gwangju 500-712 (Korea, Republic of); Rhee, Yong Joo [Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Shin, Jung Hun; Jo, Sung Ha [Advanced Photonics Research Institute, GIST, Gwangju 500-712 (Korea, Republic of); Hojbota, Calin; Cho, Byeoung Ick; Nam, Chang Hee [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 500-712 (Korea, Republic of)

    2015-12-15

    We present a high-flux, broadband gamma-ray spectrometry capable of characterizing the betatron radiation spectrum over the photon energy range from 10 keV to 20 MeV with respect to the peak photon energy, spectral bandwidth, and unique discrimination from background radiations, using a differential filtering spectrometer and the unfolding procedure based on the Monte Carlo code GEANT4. These properties are experimentally verified by measuring betatron radiation from a cm-scale laser wakefield accelerator (LWFA) driven by a 1-PW laser, using a differential filtering spectrometer consisting of a 15-filter and image plate stack. The gamma-ray spectra were derived by unfolding the photostimulated luminescence (PSL) values recorded on the image plates, using the spectrometer response matrix modeled with the Monte Carlo code GEANT4. The accuracy of unfolded betatron radiation spectra was assessed by unfolding the test PSL data simulated with GEANT4, showing an ambiguity of less than 20% and clear discrimination from the background radiation with less than 10%. The spectral analysis of betatron radiation from laser wakefield-accelerated electron beams with energies up to 3 GeV revealed radiation spectra characterized by synchrotron radiation with the critical photon energy up to 7 MeV. The gamma-ray spectrometer and unfolding method presented here facilitate an in-depth understanding of betatron radiation from LWFA process and a novel radiation source of high-quality photon beams in the MeV regime.

  4. A broadband gamma-ray spectrometry using novel unfolding algorithms for characterization of laser wakefield-generated betatron radiation

    International Nuclear Information System (INIS)

    We present a high-flux, broadband gamma-ray spectrometry capable of characterizing the betatron radiation spectrum over the photon energy range from 10 keV to 20 MeV with respect to the peak photon energy, spectral bandwidth, and unique discrimination from background radiations, using a differential filtering spectrometer and the unfolding procedure based on the Monte Carlo code GEANT4. These properties are experimentally verified by measuring betatron radiation from a cm-scale laser wakefield accelerator (LWFA) driven by a 1-PW laser, using a differential filtering spectrometer consisting of a 15-filter and image plate stack. The gamma-ray spectra were derived by unfolding the photostimulated luminescence (PSL) values recorded on the image plates, using the spectrometer response matrix modeled with the Monte Carlo code GEANT4. The accuracy of unfolded betatron radiation spectra was assessed by unfolding the test PSL data simulated with GEANT4, showing an ambiguity of less than 20% and clear discrimination from the background radiation with less than 10%. The spectral analysis of betatron radiation from laser wakefield-accelerated electron beams with energies up to 3 GeV revealed radiation spectra characterized by synchrotron radiation with the critical photon energy up to 7 MeV. The gamma-ray spectrometer and unfolding method presented here facilitate an in-depth understanding of betatron radiation from LWFA process and a novel radiation source of high-quality photon beams in the MeV regime

  5. Development of an open source software of quantitative analysis for radionuclide determination by gamma-ray spectrometry using semiconductor detectors

    International Nuclear Information System (INIS)

    Radioactivity quantification of gamma-ray emitter radionuclides in samples measured by HPGe gamma-ray spectrometry relies on the analysis of the photopeaks present in the spectra, especially on the accurate determination of their net areas. Such a task is usually performed with the aid of proprietary software tools. This work presents a methodology, algorithm descriptions and an open source application, called OpenGamma, for the peak search and analysis in order to obtain the relevant peaks parameters and radionuclides activities. The computational implementation is released entirely in open-source license for the main code and with the use of open software packages for interface design and mathematical libraries. The procedure for the peak search is performed on a three step approach. Firstly a preliminary search is done by using the second-difference method, consisting in the generation of a derived spectrum in order to find candidate peaks. In the second step, the experimental peaks widths are assessed and well formed and isolated ones are chosen to obtain a FWHM vs. channel relationship, by application of the Levenberg-Marquardt minimization method for non-linear fitting. Lastly, regions of the spectrum with grouped peaks are marked and a non-linear fit is again applied to each region to obtain baseline and photopeaks terms; from these terms, peaks net areas are then assessed. (author)

  6. Literature survey of chemical analysis by thermal neutron induced capture gamma ray spectrometry

    International Nuclear Information System (INIS)

    A brief discussion of the principles and techniques of chemical analysis by neutron capture gamma radiation is presented, and the widely scattered literature is collected into a single table arranged by element measured

  7. Determination of gamma radioactivity levels and associated dose rates of soil samples of the Akkuyu/Mersin using high-resolution gamma-ray spectrometry

    International Nuclear Information System (INIS)

    In this study several soil samples were collected from the Bueyuekeceli district where Turkey's first nuclear power plant will be built and radioactivity concentrations of 226Ra, 232Th, 40K and 137Cs were determined by gamma spectrometry using a high-purity germanium detector. The measured activity concentrations in soil samples ranged from 9.8 ± 0.7 to 258.6 ± 15.8, 11.7 ± 0.9 to 85.6 ± 5.0, 173.8 ± 2.1 to 1949.5 ± 14.7 and 0.4 ± 0.1 to 72.2 ± 2.2 Bq kg-1 for 226Ra, 232Th, 40K and 137Cs, respectively. Findings are in good agreement with the published results of neighbouring areas. The absorbed gamma dose rate (D) in air and the annual effective dose of soil samples were calculated to be 80.2 nGy h-1 and 98.3 mSv y-1, respectively. The results show that the radiation hazard in the Bueyuekeceli district is insignificant. The data presented in this study would be very useful to determine the future effects of the nuclear power plant to the environment. (authors)

  8. Quantitative nondestructive assay of uranium bearing fuel rods by high resolution gamma spectrometry

    International Nuclear Information System (INIS)

    A gamma spectrometric method is presented for quantitative assay of uranium bearing fuel rods for safeguards purposes. For determination of enrichment the 60 ... 100 keV region and intrinsic calibration method was used. The determination of the total amount of 238U was based on the measurement of 1001 keV gamma-ray and a careful self-attenuation correction. The method works without use of standards. (author)

  9. Elemental quantification of airborne particulate matter by instrumental neutron activation analysis and induced coupled plasma mass spectrometry analysis

    International Nuclear Information System (INIS)

    Airborne particulate were collected using Gent sampler for PM 10 and using high volume sampler for total suspended particulate (TSP). PM 10 sampling was carried out in Bandung during period of January to December 1997. Whereas TSP samples were collected at Serpong (rural area) and Jakarta (urban area) during period of May and July 1995. The concentration of the PM 10 in the air is independent to the level of the rainfall. The levels of the PM 10 and the PM 2.5 are lower than the maximum permissible levels set by the US Environmental Protection Agency in July 1997. The element detected using short lived radioactivity measurement in PM 10 and PM 2.5 were Al, Na, V, Mn, Br and Cl. Bromine concentration in both coarse and fine fractions was high, and the enrichment factor for bromine in these fraction was found between 2,000 - 10,000. The elemental concentrations of particulate matter obtained by ICP-MS was found that the Ag, Al, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, In, K, Mg, Mn, Na, Ni, Pb, Rb, V and Zn in samples from Serpong area, were lower than those in samples taken from Jakarta area. The level of Pb concentrations in TSP samples from Serpong and Jakarta area were lower than Pb concentration proposed Indonesian standard of 2 μg/m3. The data obtained by INAA no significant different to those obtained by ICP-MS. Therefore comparative data can be obtained by these techniques. (author)

  10. Study of the artificial radioactivity of the marine medium using gamma spectrometry (1962-1966); Etude de la radioactivite artificielle du milieu marin par spectrometrie gamma (1962-1966)

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    The results described in this study are relative to the artificial radioactivity of such elements as zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 and praseodymium-144 which were present in the atmospheric fallout between 1962 and 1964, and their incidence in superficial marine waters. Various physical, chemical or biological processes are studied by a high sensitivity gamma ray spectrometry technic, using those radioelements as 'tracers'. The change of state in sea water of an important fraction (about 50 per cent) of the radioactive particles going into the soluble phase - this phenomenon was not expected for those radioelements - controls the processes of accumulation in the planktonic biomass and the diffusion towards deeper waters. On the other hand, an 'in situ' spectrometry method is described. It enables the direct measurement in the sea of very low concentrations of some gamma ray emitters. The application of this method has made possible to carry out numerous observations in the surface waters of the Western Mediterranean sea and in the Bay of Biscay. It is shown that the mixing depth is closely connected to the depth of the thermocline. An accumulation process at this level is observed. The diffusion coefficients are similar to the thermal turbulent coefficient. The existence during several months of 'compartments' is established for the surface waters of the Bay of Biscay. From the establishment of the budget of fall-out, a comparative study shows that the rate of radioactive fallout on the maritime zone considered is always two to three times higher than on the neighbouring continental regions. Several explanations of this phenomenon are discussed. (author) [French] Les resultats decrits dans cette etude concernent la radioactivite artificielle sous forme de zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 et praseodyme-144 apportee par la retombee

  11. BioAerosol Mass Spectrometry: Reagentless Detection of Individual Airborne Spores and Other Bioagent Particles Based on Laser Desorption/Ionization Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Steele, P T

    2004-07-20

    Better devices are needed for the detection of aerosolized biological warfare agents. Advances in the ongoing development of one such device, the BioAerosol Mass Spectrometry (BAMS) system, are described here in detail. The system samples individual, micrometer-sized particles directly from the air and analyzes them in real-time without sample preparation or use of reagents. At the core of the BAMS system is a dual-polarity, single-particle mass spectrometer with a laser based desorption and ionization (DI) system. The mass spectra produced by early proof-of-concept instruments were highly variable and contained limited information to differentiate certain types of similar biological particles. The investigation of this variability and subsequent changes to the DI laser system are described. The modifications have reduced the observed variability and thereby increased the usable information content in the spectra. These improvements would have little value without software to analyze and identify the mass spectra. Important improvements have been made to the algorithms that initially processed and analyzed the data. Single particles can be identified with an impressive level of accuracy, but to obtain significant reductions in the overall false alarm rate of the BAMS instrument, alarm decisions must be made dynamically on the basis of multiple analyzed particles. A statistical model has been developed to make these decisions and the resulting performance of a hypothetical BAMS system is quantitatively predicted. The predictions indicate that a BAMS system, with reasonably attainable characteristics, can operate with a very low false alarm rate (orders of magnitude lower than some currently fielded biodetectors) while still being sensitive to small concentrations of biological particles in a large range of environments. Proof-of-concept instruments, incorporating some of the modifications described here, have already performed well in independent testing.

  12. Determination of activity by gamma spectrometry of radionuclides present in drums of residues generated in nuclear centrals

    International Nuclear Information System (INIS)

    The generation of radioactive residuals in nuclear centrals as CNA I (Atucha I Nuclear Central) and CNE (Embalse Nuclear Central) makes that the measurement of those radionuclides has been a previous stage to the waste management. A method used in those nuclear centrals it is the gamma spectrometry with HPGe detectors, previous to the immobilization of the residual in a cemented matrix, with this the contact with the external agents and its possible dispersion to the atmosphere in the short term is avoided. The ARN (Nuclear Regulatory Authority) of Argentina it carries out periodically intercomparisons and evaluations of the measurement and procedures systems used in the nuclear power stations for the correct measurement and determination of activity of radioactive residuals by gamma spectrometry. In this work an independent method of measurement is exposed to the nuclear power stations. To determine the activity of the residuals by gamma spectrometry deposited in drums, it is required of the precise knowledge of the efficiency curve for such geometry and matrix. Due to the RNA doesn't have a pattern of these characteristics, a mathematical model has been used to obtain this efficiency curve. For it, it is necessary to determine previously: 1) the geometric efficiency or solid angle sustained by the source-detector system (drum-detector) applying a mathematical model described in this work. 2) To estimate the auto-attenuation factor that present the photons in the cemented matrix, these calculations are carried out with a simple equation and its are verified with the Micro Shield 6.10 program. The container commonly used by these nuclear power stations its are drums for 220 liters constructed with SAE 1010 steel and with a thickness of 0.127 cm, with an approximate weight 7.73 Kg., internal diameter of 57.1 cm, and height: 87 cm. The results obtained until the moment register a discrepancy from 5 to 10% with relationship to the measurements carried out by the

  13. A novel approach to the determination of iridium via Ge-coincidence/NaI(Tl)-anticoincidence gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Iridium has proven to be a useful fingerprint of extraterrestrial material, and neutron activation analysis is the method of choice for its determination because of the high thermal cross section (910 b) of 191Ir (37.3% natural abundance) and the favorable decay characteristics of the product nuclide. However, radiochemical separations are frequently required for the determination of iridium at low concentrations (in the ppb range). The present work describes a precise, nondestructive neutron-activation procedure that is capable of analyzing samples of both high (ppm) and low (ppb) Ir content. Advantage is taken of the fact that the principal gamma lines of 73.8-d 192Ir are in various coincidences with one another. Instead of conventional gamma-gamma coincidence spectrometry with two Ge detectors, we utilize the 784.6- and 920.9- keV sum peaks which are generated when an iridium containing sample is placed in the well of a highly-efficient HPGe detector. The well-type detector is positioned centrally in a large annular NaI(Tl) detector which is operated in an anticoincidence mode. This improves the quality of the gamma spectra by suppressing the Compton backgrounds due to nuclides such as 60Co by a factor of 4-6 in the regions of interest without affecting the intensities of the two sum peaks. The sensitivity of this method under our experimental conditions (20-mg sample irradiated at 1.5x1014 n cm-2 s-1 for 5 min and counted 3-4 weeks after irradiation) is ≅ 5 ppb Ir in a relatively unfavorable matrix such as peridotite. (orig.)

  14. Open-source implementation of an algorithm for photopeaks search and analysis in gamma-ray spectrometry with semiconductor detectors

    International Nuclear Information System (INIS)

    Radioactivity quantification of gamma-ray emitter radionuclides in samples measured by HPGe gamma spectrometers relies on the analysis of the photopeaks present in the spectra, especially on the accurate determination of their net areas. This paper presents a methodology and an algorithm description for the peak search and analysis in order to obtain the relevant peaks parameters and their uncertainties. The procedure is performed on a three step approach: a preliminary search is done by using the second-difference method; experimental peaks widths are assessed in order to obtain a width vs. channel relationship and to define regions with single or overlapping peaks; a non-linear fit is applied to each region of the spectrum with candidate peaks. The final target function is in the form G(x) = B(x) + F(x), where B(x) is the baseline composed by a sum of a weighed left-side BL(x) and right-side BR(x) base-line quadratic functions and the photopeaks term F(x) is a sum of Gaussian functions. The computational implementation is released entirely in open-source license. The code was developed in C++ language and the interface was developed with Qt GUI software toolkit. GNU scientific library, GSL, was employed to perform linear and non-linear fitting procedures as needed. Spectra previously generated at our laboratories were analyzed with the presented methodology and with the commercial software package WinnerGamma. Results obtained are consistent with those obtained with the aforementioned package, suggesting that it could be safely used in general-purpose gamma-ray spectrometry. (author)

  15. Alpha and gamma spectrometry applied to the study of U and Th series radioactive disequilibrium in the phosphates from Abrolhos Archipelago (Brazil offshore)

    International Nuclear Information System (INIS)

    This paper presents the results of uranium and thorium measurements made in aluminium and iron phosphates that occur in the Abrolhos Archipelago (offshore Brazil) by instrumental neutron activation analysis. The U concentrations were also indirectly determined from the gamma-ray activity of 234 Th, 214 Pb and 214 Bi, while those of Th were obtained from the 228 Ca, 212 Pb, 212 Bi and 208 T1 gamma-ray emitters. In both cases it was assumed that 238 U and 232 Th series are in radioactive secular equilibrium. The comparison between the results obtained by neutron activation and gamma-ray spectrometry show radioactive secular equilibrium in the analysed samples. (author)

  16. Experimental Measurements and Computer Simulation of Fission Product Gamma-Ray Spectra

    OpenAIRE

    Sanderson, D.C.W; Cresswell, A.; Allyson, J.D.; McConville, P.

    1997-01-01

    Airborne gamma ray spectrometry using high volume scintillation detectors, optionally in conjunction with Ge detectors, has potential for making rapid environmental measurements in response to nuclear accidents. An experimental investigation and computer simulation have been used to characterise the response of such detectors to short lived fission products. Small samples of 235U were irradiated in a research reactor for short periods, to generate fission product sources. Gamma ray spectra w...

  17. Review of Past Nuclear Accidents: Source Terms and Recorded Gamma-Ray Spectra

    OpenAIRE

    Sanderson, D.C.W.; Cresswell, A.; Allyson, J.D.; McConville, P.

    1997-01-01

    Airborne gamma ray spectrometry using high volume scintillation detectors, optionally in conjunction with Ge detectors, has potential for making rapid environmental measurements in response to nuclear accidents. A literature search on past nuclear accidents has been conducted to define the source terms which have been experienced so far. Selected gamma ray spectra recorded after past accidents have also been collated to examine the complexity of observed behaviour.

  18. Contribution to the three-dimensional simulation of semiconductor detectors in gamma rays spectrometry

    International Nuclear Information System (INIS)

    Parallel to the scientific investigations on gamma radioactivity, technological research on gamma ray detectors have rapidly developed. Gamma ray imaging is changing towards systems using room temperature semiconductors, whose principal advantages are compactness and intrinsic materials performances, due to the direct conversion of the gamma rays into electric charges. In the research field, the available solutions are numerous, thus justifying numerical simulation. Modelling presents a double interest for technological improvement and fast development of new techniques. A fully three-dimensional model of a semiconductor gamma ray detector is presented. It takes into account the physical phenomena involved in the detection process and models the readout electronic response and noise. The model successively involves the finite element transient computation of the adjoint transport equation, the Monte Carlo simulation of the photon transport and the electronic signal processing including an accurate noise model. The simulation outputs are pulse height spectra and bi parametric spectra (rise time versus pulse height). The validation carried out on each part of the simulator and also on the whole simulator confirms that the set of chosen models is correct and that our implementation is reliable. (author)

  19. The metrological activity determination of 238 U and 230 Th by gamma spectrometry to industrial fuel-cycle application

    International Nuclear Information System (INIS)

    This work describes the difficulty for determining the activity of 238 U and 230 Th using gamma spectrometry due to the low gamma-ray emission probabilities of 92 and 67 keV, and, mainly, the associated high uncertainties about 13 and 11%, respectively. 230 Th is a 238 U daughter and it is product from uranium mills and refineries. 230 Th decays to 226 Ra and this decay has to be measured because these radionuclides are not in secular equilibrium with their daughter products, besides the gamma-energies have high uncertainties in the emission probabilities. These radionuclides, mostly 238 U, are important in the nuclear fuel-cycle, since the mining of uranium ore, where the nominal isotopic content of natural uranium is 99.27% of 238 U, until the irradiated fuel reprocessing, where this isotope, a fertile material, is recovered to be used again. The uranium and thorium are considered safeguarded nuclear materials and the metrology tries to calibrate and standardize these materials to improve the activity determination techniques applied in different fuel-cycle scopes. The essential characteristics of the safeguarded materials are low gamma energies (less than 100 keV) and emission probabilities but with high uncertainties. In this way, the metrology can contribute to homeland security defense against illicit nuclear trafficking with the identification and quantification of the safeguarded radionuclides such as uranium and thorium, using specific gamma window energy and high resolution planar or coaxial germanium detector. The efficiency curve is obtained from the reference source spectrum considering the photopeak areas corresponding the standard activities. This curve depends on radiation energy, sample geometry, photon attenuation (sample absorption and material absorption between sample-detector), dead time and sample-detector position. The metrological activity determinations of 238 U solid sources, and of 230 Th, in solution (5 ml flask), were performed using

  20. Airborne intercomparison of HOx measurements using laser-induced fluorescence and chemical ionization mass spectrometry during ARCTAS

    Directory of Open Access Journals (Sweden)

    J. H. Crawford

    2012-08-01

    Full Text Available The hydroxyl (OH and hydroperoxyl (HO2 radicals, collectively called HOx, play central roles in tropospheric chemistry. Accurate measurements of OH and HO2 are critical to examine our understanding of atmospheric chemistry. Intercomparisons of different techniques for detecting OH and HO2 are vital to evaluate their measurement capabilities. Three instruments that measured OH and/or HO2 radicals were deployed on the NASA DC-8 aircraft throughout Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS in the spring and summer of 2008. One instrument was the Penn State Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS for OH and HO2 measurements based on Laser-Induced Fluorescence (LIF spectroscopy. A second instrument was the NCAR Selected-Ion Chemical Ionization Mass Spectrometer (SI-CIMS for OH measurement. A third instrument was the NCAR Peroxy Radical Chemical Ionization Mass Spectrometer (PeRCIMS for HO2 measurement. Formal intercomparison of LIF and CIMS was conducted for the first time on a same aircraft platform. The three instruments were calibrated by quantitative photolysis of water vapor by ultraviolet (UV light at 184.9 nm with three different calibration systems. The absolute accuracies were ±32% (2σ for the LIF instrument, ±65% (2σ for the SI-CIMS instrument, and ±50% (2σ for the PeRCIMS instrument. In general, good agreement was obtained between the CIMS and LIF measurements of both OH and HO2 measurements. Linear regression of the entire data set yields [OH]CIMS = 0.89 × [OH]LIF + 2.8 × 104 cm−3 with a correlation coefficient r2 = 0.72 for OH, and [HO2]CIMS = 0.86 × [HO2]LIF + 3.9 parts per trillion by volume (pptv, equivalent to pmol mol−1 with a correlation coefficient r2 = 0.72 for HO2. In general, the difference between CIMS and LIF instruments for OH and HO2 measurements can be explained by their combined measurement uncertainties. Comparison with box model results shows some

  1. Airborne intercomparison of HOx measurements using laser-induced fluorescence and chemical ionization mass spectrometry during ARCTAS

    Directory of Open Access Journals (Sweden)

    G. Chen

    2012-03-01

    Full Text Available The hydroxyl (OH and hydroperoxyl (HO2 radicals, collectively called HOx, play central roles in tropospheric chemistry. Accurate measurements of OH and HO2 are critical to examine our understanding of atmospheric chemistry. Intercomparisons of different techniques for detecting OH and HO2 are vital to evaluate their measurement capabilities. Three instruments that measured OH and/or HO2 radicals were deployed on the NASA DC-8 aircraft throughout Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS, in the spring and summer of 2008. One instrument was the Penn State Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS for OH and HO2 measurements based on Laser-Induced Fluorescence (LIF spectroscopy. A second instrument was the NCAR Selected-Ion Chemical Ionization Mass Spectrometer (SI-CIMS for OH measurement. A third instrument was the NCAR Peroxy Radical Chemical Ionization Mass Spectrometer (PeRCIMS for HO2 measurement. Formal intercomparison of LIF and CIMS was conducted for the first time on a same aircraft platform. The three instruments were calibrated by quantitative photolysis of water vapor by UV light at 184.9 nm with three different calibration systems. The absolute accuracies were ±32% (2σ for the LIF instrument, ±65% (2σ for the SI-CIMS instrument, and ±50% (2σ for the PeRCIMS instrument. In general, good agreement was obtained between the CIMS and LIF measurements of both OH and HO2 measurements. Linear regression of the entire data set yields [OH]CIMS = 0.89 × [OH]LIF + 2.8 × 105 cm−3 with a correlation coefficient, r2 = 0.72 for OH and [HO2]CIMS = 0.86 × [HO2]LIF + 3.9 parts per trillion by volume (pptv, equivalent to pmol mol−1 with a correlation coefficient, r2 = 0.72 for HO2. In general, the difference between CIMS and LIF instruments for OH and HO2 measurements can be explained by their combined measurement uncertainties. Comparison with box model results shows some

  2. Isotopic composition analysis and age dating of uranium samples by high resolution gamma ray spectrometry

    Science.gov (United States)

    Apostol, A. I.; Pantelica, A.; Sima, O.; Fugaru, V.

    2016-09-01

    Non-destructive methods were applied to determine the isotopic composition and the time elapsed since last chemical purification of nine uranium samples. The applied methods are based on measuring gamma and X radiations of uranium samples by high resolution low energy gamma spectrometric system with planar high purity germanium detector and low background gamma spectrometric system with coaxial high purity germanium detector. The "Multigroup γ-ray Analysis Method for Uranium" (MGAU) code was used for the precise determination of samples' isotopic composition. The age of the samples was determined from the isotopic ratio 214Bi/234U. This ratio was calculated from the analyzed spectra of each uranium sample, using relative detection efficiency. Special attention is paid to the coincidence summing corrections that have to be taken into account when performing this type of analysis. In addition, an alternative approach for the age determination using full energy peak efficiencies obtained by Monte Carlo simulations with the GESPECOR code is described.

  3. Determination of protein content in seeds by prompt gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The protein level in seeds can be directly calculated through the determination of the nitrogen content in grains. The authors show here that the radioactive thermal neutron capture prompt gamma-rays technique can be used to determine the nitrogen content in grains without chemical destruction, with good precision and relative rapidity, by detecting the prompt gamma rays emitted by the 14N(n,γ)15N reaction product. The samples were irradiated in the tangential tube of the IEA-R1 research reactor, in Sao Paulo, and a pair spectrometer was used for the detection of the prompt gamma-rays. The nitrogen content was determined in several samples of soybean, common bean, peas and rice and the results compared with typical nitrogen content values for each grain. 33 references, 1 figure, 1 table

  4. Burn-Up Determination by High Resolution Gamma Spectrometry: Axial and Diametral Scanning Experiments

    International Nuclear Information System (INIS)

    In the gamma spectrometric determination of burn-up the use of a single fission product as a monitor of the specimen fission rate is subject to errors caused by activity saturation or, in certain cases, fission product migration. Results are presented of experiments in which all the resolvable gamma peaks in the fission product spectrum have been used to calculate the fission rate; these results form a pattern which reflect errors in the literature values of the gamma branching ratios, fission yields etc., and also represent a series of empirical correction factors. Axial and diametral scanning experiments on a long-irradiated low-enrichment fuel element are also described and demonstrate that it is possible to differentiate between fissions in U-235 and in Pu-239 respectively by means of the ratios of the Ru-106 activity to the activities of the other fission products

  5. Spatially-Dependent Measurements of Surface and Near-Surface Radioactive Material Using In situ Gamma Ray Spectrometry (ISGRS) For Final Status Surveys

    International Nuclear Information System (INIS)

    In-situ, high-resolution gamma-ray spectrometry (ISGRS) measurements were conducted at the Oak Ridge Institute for Science and Education ORISE field laboratory in Oak Ridge, Tennessee. The purpose of these tests was to provide analytical data for assessing how 'fit for use' this technology is for detecting discrete particles in soil

  6. Spatially-Dependent Measurements of Surface and Near-Surface Radioactive Material Using In situ Gamma Ray Spectrometry (ISGRS) For Final Status Surveys

    Energy Technology Data Exchange (ETDEWEB)

    J. A. Chapman, A. J. Boerner, E. W. Abelquist

    2006-11-15

    In-situ, high-resolution gamma-ray spectrometry (ISGRS) measurements were conducted at the Oak Ridge Institute for Science and Education (ORISE) field laboratory in Oak Ridge, Tennessee. The purpose of these tests was to provide analytical data for assessing how “fit for use” this technology is for detecting discrete particles in soil.

  7. Identification of early Llandovery (Silurian) anoxic palaeo-depressions at the western margin of the Murzuq Basin (southwest Libya), based on gamma-ray spectrometry in surface exposures

    Czech Academy of Sciences Publication Activity Database

    Fello, N.; Lüning, S.; Štorch, Petr; Redfern, J.

    2006-01-01

    Roč. 11, č. 3 (2006), s. 101-118. ISSN 1025-6059 R&D Projects: GA ČR GA205/99/1322 Institutional research plan: CEZ:AV0Z30130516 Keywords : postglacial anoxy * early Llandovery * Murzuq Basin * palaeo-depressions * gamma-spectrometry Subject RIV: DB - Geology ; Mineralogy

  8. Determination of radon activity concentration in hot spring and surface water using gamma spectrometry technique

    International Nuclear Information System (INIS)

    Naturally occurring radionuclides in water such as, 222Rn which emit gamma radiation through its decaying process could reach to human. Water samples were chosen to present ground and surface water. The groundwater samples were collected from, Perak, Selangor, Kelantan and Sembilan. The surface water samples were collected from Perak, Kelantan, and Pahang. In this study, the surface doses rate measurements were done in-situ using LUDLUM rate meter, and the radioactivity concentration levels were done by counting the water samples using gamma spectrometer with HPGe detector. The activities are ranged from (0.29-1.41 Bq/ l). (author)

  9. Estimation of americium in cemented waste block using gamma ray spectrometry

    International Nuclear Information System (INIS)

    A method was developed for the estimation of 241Am present in the cemented waste block which was cylindrical in shape. In such large sample, the attenuation of gamma rays increases with size of the sample and density of the material present. Attenuation correction was incorporated using linear attenuation coefficients of 59.54 keV gamma ray of 241Am. Also in such large samples, error due to the distribution of activity is more. Estimation of 241Am in the cemented sample was carried out by applying corrections for attenuation and for the sample geometry. (author)

  10. Measurement of the activity of a remote source by in-situ gamma-ray spectrometry

    International Nuclear Information System (INIS)

    A method for calculation of the attenuation factor for gamma rays passing through a layer of material is presented. The method is based on the measurement of the amount of radiation scattered in the material at small angles and registered in the spectra of a high resolution gamma-ray detector. The method is applied to the calculation of the activity of a remote source. The attenuation factor, the distance between the source and detector as well as the activity of the source were calculated from the spectra and compared to their reference values. (author)

  11. Geochemical and radiometric surveys of Sabkhet Al-Jaboul area by investigating trace elements, radon measurements and gamma spectrometry

    International Nuclear Information System (INIS)

    Radiometric and geochemical surveys were carried out over various geological formations in Sabkhet Al-Jaboul and its surrounding environment for evaluating the levels of radioactivity in the area. Therefore, a number of exploration techniques were used in this study such as gamma ray spectrometry, geochemical exploration and soil radon measurements. Although the results of this survey indicate some slight variations of which might be useful to distinguish between various lithological units, most of the obtained data do not reveal any significant radiometric values that could be considered important from the exploration point of view. However, these data were successfully handled to estimate the natural background of radioactivity throughout the geological units of the region. The results also showed the importance of the sedimentary transition contact zone where the continental fresh and salt favourable geochemical environment for uranium precipitation when other fundamental geological requirements for developing such concentrations are available. (author)

  12. Continuous measurement of boron-10 concentration in rabbit brain tissue and blood using prompt gamma-ray spectrometry

    International Nuclear Information System (INIS)

    One of the important factors which influence the efficacy of boron neutron capture therapy (BNCT) in patients with malignant brain tumor is the boron-10 concentrations in tumors. The boron-10 concentration in normal brain tissue and the tumor/blood concentration in normal brain tissue and the tumor/blood concentration ratio are also valuable factors to decide the irradiation time and protect the normal tissue from radiation injury. Therefore, it is valuable to know the boron-10 concentration in the tumor, normal brain tissue and blood just before and during neutron irradiation. In this study the authors investigated continuously the boron-10 concentrations in the normal brain tissue of living rabbits and blood for 5-24 hours after injection of boron-10 compound using prompt gamma-ray spectrometry

  13. Optimization of a neural network model for signal-to-background prediction in gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The artificial neural network (ANN) model was optimized for the prediction of signal-to-background (SBR) ratio as a function of the measurement time in gamma-ray spectrometry. The network parameters: learning rate (α), momentum (μ), number of epochs (E) and number of nodes in hidden layer (N) were optimized simultaneously employing variable-size simplex method. The most accurate model with the root mean square (RMS) error of 0.073 was obtained using ANN with online backpropagation randomized (OBPR) algorithm with α = 0.27, μ 0.36, E = 14800 and N = 9. Most of the predicted and experimental SBR values for the eight radionuclides (226Ra, 214Bi, 235U, 40K, 232Th, 134Cs, 137Cs and 7Be), studied in this work, reasonably agreed to within 15 %, which was satisfactory accuracy. (author)

  14. Study pf apatite accurrence from Gaviao and Serra de Jacabina gold deposit by scintillometry and gamma spectrometry

    International Nuclear Information System (INIS)

    This work presents the results of radiogeologic reconnaissance in the Cenozoic, Mesozoic and Pre-Cambrian formations, localized between Salvador and Miguel Calmon, and of the radiogeologic detail study from areas of the radioactive anomalies: Gaviao in the Riacho do Lacuipe and Canavieira Mine, in the Jacobina, Bahia States Scintilometry and gamma spectrometry results make possible to conclude by the association, in the Gaviao's apatite mineralization with throrium and the gold of the Serra de Corrego's conglamerate with uranium, make possible in the both case, orient the Search and the mining by scintilometry. The petrographic study and the radiactivity elements dispersion, suggest a sedimentary primary origin to the regional metamorphic rocks. In the Canavieiras mine was evident the stratigraphic control of the gold, associated to uranium and pirite in the conglomerates. (C.D.G.)

  15. Continuous measurement of radiation from radionuclides deposited on the ground using in situ gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Until recently, in situ measurements in a network of radiation-measuring sites at the Deutscher Wetterdienst could only be started if all components had been put up in an instrumentation shelter and the detector had been cooled for ∼6 h. Within a project on partial automation of radioactivity monitoring, it has now become possible to permanently equip the measuring sites, i.e. the instrumentation shelter, with the components for in situ gamma-ray spectrometry. The cooling technology of the detectors changed from liquid nitrogen based to an electric system and the instrumentation shelters could be fixed with air conditioning to minimise the influence of changes in the outside temperature. (authors)

  16. Application of the radiochemical - and the direct gamma ray spectrometry method to the burnup determination of irradiated uranium oxide

    International Nuclear Information System (INIS)

    The burn up of natural U3O8 that occurs by the action of thermal neutrons was determined, using the radioisotopes 144Ce, 137Cs, 103Ru, 106Ru and 95Zr as monitors. The determination of the burn up was made using both destructive and non-destructive methods. In the non-destructive method, the technique of direct gamma-ray spectrometry was used and the radioisotopes mentioned were simultaneously counted in a Ge-Li detector. In the radiochemical method the same radioisotopes were isolated one from the other and from all other fission products before counting. The solvent extraction technique was used for the radiochemical separation of uranium, cerium, cesium and ruthenium. To separate zirconium and niobium, adsorption in silica-gel was used. The extraction agent employed to isolate cesium was dipycrilamine and for the separation of the other radioisotopes Di-(2-Ethyl Hexyl) Phosphoric acid (HDEHP) was used. (Author)

  17. A theoretical comparison of methods of quantification of radioactive contamination in soil using in situ gamma spectrometry

    International Nuclear Information System (INIS)

    In situ gamma-ray spectrometry offers a rapid method of assessing radioactive contamination in soil. For accurate quantification, however, a knowledge of the activity-depth distribution is essential. Three methods, the multiple peak method, the peak to valley method and the lead plate method, for deriving the distribution were compared by evaluating the uncertainty on the derived activity concentration for two types of distribution: an exponential model and a gaussian model. The lead plate method showed the lowest uncertainty for all distributions and, thus, appeared to offer the best method. Of the other two methods, the peak to valley method offered slightly lower uncertainties at low values of the depth parameter but was worse at high values. (author)

  18. In-situ ground gamma spectrometry — an effective tool for geological mapping (the Male Karpaty Mts., Slovakia

    Directory of Open Access Journals (Sweden)

    Mojzeš Andrej

    2016-06-01

    Full Text Available This contribution presents the results of profile in-situ gamma spectrometry measurements that sought to determine the content of natural radionuclides 40K, 238U and 232Th in a near surface horizon of rocks, their weathering cover and soils in the area of the Malé Karpaty Mts. It is widely established that the exploration of radioactivity of bedrocks and cover rocks can be a very effective and useful tool for both geological mapping, for identifying deposits of mineral resources, and even addressing the issues of structural and tectonic geology. This assertion is equally confirmed by the ground gamma spectrometry measurements carried out as part of this case study on larger scales, seeking more detailed geological structure solutions. The results obtained provide a welcome addition to an already existing database, which monitors the content of naturally occurring radionuclides individually for every rock lithotype of the Western Carpathians, by elaborating on the data collected by previous research and by updating this database for any future needs. The presented results confirmed the low to medium radioactivity levels of rocks and soils in the studied area. The highest values were detected in granitoids and metamorfic phyllitic rocks of the Malé Karpaty Mts. core; the lowest values were detected in carbonates, arenaceous sediments and, above all, amphibolite bodies. In this way, the presented results of the interpreted profile (P5 confirm the model of local geological structure as represented on the most up-to-date edition of the geological map of the Male Karpaty Mts. (Polak et al. 2011.

  19. In-situ ground gamma spectrometry — an effective tool for geological mapping (the Male Karpaty Mts., Slovakia)

    Science.gov (United States)

    Mojzeš, Andrej; Porubčanová, Barbara

    2016-06-01

    This contribution presents the results of profile in-situ gamma spectrometry measurements that sought to determine the content of natural radionuclides 40K, 238U and 232Th in a near surface horizon of rocks, their weathering cover and soils in the area of the Malé Karpaty Mts. It is widely established that the exploration of radioactivity of bedrocks and cover rocks can be a very effective and useful tool for both geological mapping, for identifying deposits of mineral resources, and even addressing the issues of structural and tectonic geology. This assertion is equally confirmed by the ground gamma spectrometry measurements carried out as part of this case study on larger scales, seeking more detailed geological structure solutions. The results obtained provide a welcome addition to an already existing database, which monitors the content of naturally occurring radionuclides individually for every rock lithotype of the Western Carpathians, by elaborating on the data collected by previous research and by updating this database for any future needs. The presented results confirmed the low to medium radioactivity levels of rocks and soils in the studied area. The highest values were detected in granitoids and metamorfic phyllitic rocks of the Malé Karpaty Mts. core; the lowest values were detected in carbonates, arenaceous sediments and, above all, amphibolite bodies. In this way, the presented results of the interpreted profile (P5) confirm the model of local geological structure as represented on the most up-to-date edition of the geological map of the Male Karpaty Mts. (Polak et al. 2011).

  20. Radiological Mapping of the Alkaline Intrusive Complex of Jombo, South Coastal Kenya by In-Situ Gamma-Ray Spectrometry

    Science.gov (United States)

    Kaniu, Ian; Darby, Iain G.; Kalambuka Angeyo, Hudson

    2016-04-01

    Carbonatites and alkaline intrusive complexes are rich in a variety of mineral deposits such as rare earth elements (REEs), including Nb, Zr and Mn. These are often associated with U and Th bearing minerals, including monazite, samarskite and pyrochlore. Mining waste resulting from mineral processing activities can be highly radioactive and therefore poses a risk to human health and environment. The Jombo complex located in Kenya's south coastal region is potentially one of the richest sources of Nb and REEs in the world. It consists of the main intrusion at Jombo hill, three associated satellite intrusions at Mrima, Kiruku and Nguluku hills, and several dykes. The complex is highly heterogeneous with regard to its geological formation as it is characterized by alkaline igneous rocks and carbonatites which also influence its radio-ecological dynamics. In-situ gamma spectrometry offers a low-cost, rapid and spatially representative radioactivity estimate across a range of landscapes compared to conventional radiometric techniques. In this work, a wide ranging radiological survey was conducted in the Jombo complex as follow up on previous studies[1,2], to determine radiation exposure levels and source distributions, and perform radiological risk assessments. The in-situ measurements were carried out using a 2.0 l NaI(Tl) PGIS-2 portable detector from Pico Envirotec Inc integrated with GPS, deployed for ground (back-pack) and vehicular gamma-ray spectrometry. Preliminary results of radiological distribution and mapping will be presented. [1] Patel, J. P. (1991). Discovery and Innovation, 3(3): 31-35. [2] Kebwaro, J. M. et. al. (2011). J. Phys. Sci., 6(13): 3105-3110.

  1. Attributes from NMIS Time Coincidence, Fast-Neutron Imaging, Fission Mapping, And Gamma-Ray Spectrometry Data

    International Nuclear Information System (INIS)

    This work tests a systematic procedure for analyzing data acquired by the Nuclear Materials Identification System (NMIS) at Oak Ridge National Laboratory with fast-neutron imaging and high-purity germanium (HPGe) gamma spectrometry capabilities. NMIS has been under development by the US Department of Energy Office of Nuclear Verification since the mid-1990s, and prior to that by the National Nuclear Security Administration Y-12 National Security Complex, with NMIS having been used at Y-12 for template matching to confirm inventory and receipts. In this present work, a complete set of NMIS time coincidence, fast-neutron imaging, fission mapping, and HPGe gamma-ray spectrometry data was obtained from Monte Carlo simulations for a configuration of fissile and nonfissile materials. The data were then presented for analysis to someone who had no prior knowledge of the unknown object to accurately determine the description of the object by applying the previously-mentioned procedure to the simulated data. The best approximation indicated that the unknown object was composed of concentric cylinders: a void inside highly enriched uranium (HEU) (84.7 ± 1.9 wt % 235U), surrounded by depleted uranium, surrounded by polyethylene. The final estimation of the unknown object had the correct materials and geometry, with error in the radius estimates of material regions varying from 1.58% at best and 4.25% at worst; error in the height estimates varied from 2% to 12%. The error in the HEU enrichment estimate was 5.9 wt % (within 2.5σ of the true value). The accuracies of the determinations could be adequate for arms control applications. Future work will apply this iterative reconstructive procedure to other unknown objects to further test and refine it.

  2. A new approach for the high-precision determination of the elemental uranium concentration in uranium ore by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    A new approach for the determination of elemental uranium in uranium bearing ore, using high resolution gamma-ray spectrometry, was applied. Using a variant of the enrichment meter technique an agreement of better than 1% has been obtained between gamma-ray measurement results and the certified value obtained by other analytical methods. For the calibration of the gamma-ray spectrometer uranium reference samples have been used which are made available jointly in Europe and the USA as Certified Reference Materials for Gamma-ray Spectrometry (EC NRM 171 and NBS SRM 969, respectively). The measured ore has been put in a special designed container which ensured in all directions seen from the radiation window a uniform degree of infinite thickness of about 95%. The measurement results can be taken as an example for the applicability of gamma-ray spectrometry when high accuracy is required and under conditions where homogeneous distributed elemental uranium is embedded in a larger amount of matrix material. (author). 8 refs., 10 figs., 2 tabs., 2 appendices

  3. System for continuous real time air monitoring by means of gamma spectrometry with germanium dosimeter

    International Nuclear Information System (INIS)

    Design of automatic system for real time air monitoring of radioactive particulates are relate. Recommendations are made for design and operation of sampling conduits to minimize losses. By means of experimental equipment loss of particles in long sampling conduits, minimum detectable activity and efficiency of gamma radiation detectable are evaluated. (author)

  4. Drill-Core Scanning for Radioelements by Gamma-Ray Spectrometry

    DEFF Research Database (Denmark)

    Løvborg, Leif; Wollenberg, H.; Rose-Hansen, J.; Leth Nielsen, B.

    1972-01-01

    A system has been developed for the continuous and stepwise scanning of rock drill cores for gamma-ray spectrometric determinations of uranium, thorium, and potassium. The apparatus accomodates 3- to 4-cm-diameter core as it passes two opposing 2-inch diameter by 3-inch- thick NaI(Tl) detectors...

  5. Drill-Core Scanning for Radioelements by Gamma-Ray Spectrometry

    DEFF Research Database (Denmark)

    Løvborg, Leif; Wollenberg, H.; Rose-Hansen, J.; Leth Nielsen, B.

    1972-01-01

    A system has been developed for the continuous and stepwise scanning of rock drill cores for gamma-ray spectrometric determinations of uranium, thorium, and potassium. The apparatus accomodates 3- to 4-cm-diameter core as it passes two opposing 2-inch diameter by 3-inch- thick NaI(Tl) detectors, ...

  6. Determination of mercury in airborne particulate matter collected on glass fiber filters using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Rennan G.O., E-mail: rgoa01@terra.com.br [Laboratorio de Quimica Analitica Ambiental, Departamento de Quimica, Universidade Federal de Sergipe, Campus Sao Cristovao, 49.100-000, Sao Cristovao, SE (Brazil); Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Vignola, Fabiola; Castilho, Ivan N.B. [Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Borges, Daniel L.G.; Welz, Bernhard [Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Vale, Maria Goreti R. [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Instituto de Quimica, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, RS (Brazil); Smichowski, Patricia [Comision Nacional de Energia Atomica (CNEA) and Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires (Argentina); Ferreira, Sergio L.C. [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Instituto de Quimica, Universidade Federal da Bahia, 40170-290, Salvador, BA (Brazil); Becker-Ross, Helmut [Leibniz-Institut fuer Analytische Wissenschaften-ISAS-e.V., Department Berlin, 12489 Berlin (Germany)

    2011-05-15

    A study has been undertaken to assess the capability of high-resolution continuum source graphite furnace atomic absorption spectrometry for the determination of mercury in airborne particulate matter (APM) collected on glass fiber filters using direct solid sampling. The main Hg absorption line at 253.652 nm was used for all determinations. The certified reference material NIST SRM 1648 (Urban Particulate Matter) was used to check the accuracy of the method, and good agreement was obtained between published and determined values. The characteristic mass was 22 pg Hg. The limit of detection (3{sigma}), based on ten atomizations of an unexposed filter, was 40 ng g{sup -1}, corresponding to 0.12 ng m{sup -3} in the air for a typical air volume of 1440 m{sup 3} collected within 24 h. The limit of quantification was 150 ng g{sup -1}, equivalent to 0.41 ng m{sup -3} in the air. The repeatability of measurements was better than 17% RSD (n = 5). Mercury concentrations found in filter samples loaded with APM collected in Buenos Aires, Argentina, were between < 40 ng g{sup -1} and 381 {+-} 24 ng g{sup -1}. These values correspond to a mercury concentration in the air between < 0.12 ng m{sup -3} and 1.47 {+-} 0.09 ng m{sup -3}. The proposed procedure was found to be simple, fast and reliable, and suitable as a screening procedure for the determination of mercury in APM samples.

  7. Preliminary Determination of Natural Radioactivity Levels of the State of Qatar using High-Resolution Gamma-ray Spectrometry

    International Nuclear Information System (INIS)

    The State of Qatar is a peninsula with a total area of 11,437 km2 which lies over a geological formation comprising a sequence of limestone, chalk, clay and gypsum. Establishing a baseline for the radioactivity concentration in Qatar's soil is the main purpose behind the present study. The project is focused on obtaining measurements of representative soil samples from various areas in Qatar to establish concentrations of the 235U, 238U and 232Th natural decay chains and also the long-lived naturally occurring radionuclide 40K. The 235U, 238U, 232Th and 40K concentrations have been measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector situated in a low-background environment with a copper inner-plated passive lead shield. A wide range of different gamma-ray energy transitions lines arising from the multiple decay products from the 235U, 238U and 232Th decay chains have been analyzed separately to obtain more statistically significant overall results

  8. Simultaneous Determination of 30 Trace Elements in Cancerous and Noncancerous Human Tissue Samples with Gamma-ray Spectrometry

    International Nuclear Information System (INIS)

    The following trace elements were quantitatively determined by gamma-ray spectrometry in T samples of non-cancerous and 5 samples of cancerous human tissue: P, Ca, Cr, Fe, Co, Cu, Zn, As, Se, Br, Rb, Mo, Ag, Cd, Sb, Cs, La, Au, and Hg. In some of the samples the following elements were qualitatively determined: Ti+Sc, Ga, Sr, In, Ba, Ce, Hf, Os, Pt, and U. Most of the trace elements were found to be present in much higher concentrations in the non-cancerous than in the corresponding cancerous liver samples. In a typical run one sample each of cancerous and non-cancerous tissue was irradiated together with standards of the elements to be determined in a thermal flux of 2.1013 n/cm2/sec. for 24 hours. The radioactive trace elements were separated into 16, and in some cases 18, groups by means of a chemical group separation method. Subsequently, the gamma spectrometric measurements were performed. Two persons can manage the chemical separations and measure the different activities from a run in 1,5 days. A new method of comparing unknown samples with standards was developed

  9. Measurement of 226Ra in IAEA soil-6 using gamma spectrometry system: Comparison between manual and software calculation

    International Nuclear Information System (INIS)

    IAEA Soil-6 is a reference material with a certified value for 226Ra fall between 69.6 - 93.4 Bq/ kg at 95 % confidence level. This material has been used as a sample and performed repeat measurement weekly between years 2006 - 2009 using a same gamma spectrometry system. The activity concentration of this material is calculated automatically using the operational commercial software and compared with activity obtained from the manual calculation. Study found that only 76.9 %, 64.1 %, 56.3 %, and 79.3 % of the results from the software calculation lie within the confidence level for year 2006, 2007, 2008 and 2009, respectively. However, u-score calculation revealed that 94.9 %, 89.7 %, 79.2 % and 84.9 % data set have no significant bias (u < 2.58) for year 2006, 2007, 2008 and 2009, respectively. On the other hand, all manual calculation data were found to be within the 95 % confidence level. Factors suspected to cause differences between these two approaches were discussed here. Manually peak search, marking and calculation still remains as the preferred option for calculating the gamma radionuclides activity unless limitations of the spectrum analysis software, as described in this paper can be resolved/ improved upon. (author)

  10. Experimental and Monte Carlo study of gamma-ray spectrometry: correction of cascade and matrix effects in environmental measurements

    International Nuclear Information System (INIS)

    Precisely measuring weakly radioactive samples by gamma-ray spectrometry requires optimizing the detection geometry and knowledge of the gamma-ray decay scheme. One can thus increase the counting rate and reduce the statistical uncertainty of the spectral peaks used to determine radioisotope activities. However, an increased sample volume requires a correction for the self-absorption of γ-rays in the sample itself, and approaching a sample to the detector gives rise to coincidence summing. MCNPX simulations permitted finding the separate influence of sample density and effective atomic number of the sample in the attenuation of photons with energies less than 100 keV. Peak-summing corrections were obtained with MCNPX, GESPCOR and ETNA. Thus a data base for 244 radionuclides could be established for SG50 and SG500 geometries in contact with a planar detector. In an application of the results to the health physics domain, construction materials were analyzed. Naturally-occurring Uranium-238, Thorium-232 and Potassium-40 activities were identified and corrected for the above-mentioned effects in order to evaluate the risk indexes, the absorbed dose and the annual effective dose received from different dimensions built of these materials. MCNPX simulations corroborated the model used to calculate the absorbed dose and gave its distribution in an enclosed space. The results obtained are within the recommended norms. (author)

  11. Portable gamma spectrometry with cerium-doped lanthanum bromide scintillators: Suitability assessments for luminescence and electron spin resonance dating applications

    International Nuclear Information System (INIS)

    Cerium-doped lanthanum bromide (LaBr3:Ce) crystals offer a range of improved scintillation properties over traditional NaI:Tl crystals for in situ gamma spectrometry. At present, however, it remains unclear whether the internal radioactivity of LaBr3:Ce detectors compromises their suitability for low-level activity radioisotope measurements of natural sedimentary deposits, such as those required in luminescence and electron spin resonance (ESR) dating. In this study we investigate the suitability of a commercial LaBr3:Ce detector for measuring individual concentrations of 40K, 238U and 232Th using predefined ‘energy windows’ from gamma ray spectra. Performance tests have been undertaken using reference materials with well-constrained radioisotope concentrations (the Oxford calibration blocks) and compared with results obtained for a NaI:Tl detector of the same geometry. These tests reveal that the LaBr3:Ce detector has a non-negligible intrinsic activity that needs to be accurately quantified prior to measuring any gamma ray spectra in the field. Compared to the NaI:Tl detector, the energy resolution of the LaBr3:Ce detector is improved by a factor of two, or more, for the main indicator isotope photopeaks in the 40K, 238U and 232Th decay series. Signal-to-noise ratios for the LaBr3:Ce detector show a 25–35% improvement over those of the NaI:Tl detector. In addition, the LaBr3:Ce detector is characterised by suitable energy linearity over the full spectral range of interest for the 40K, 238U and 232Th decay series. Replicate gamma ray measurements made with the LaBr3:Ce and NaI:Tl detectors for 20 natural sedimentary samples from the Lower Tejo River basin, Portugal, and the Duero River basin, Spain, yield consistent radioisotope concentrations and gamma dose rate estimates. These results are encouraging and suggest that LaBr3:Ce detectors can provide suitable estimates of individual radioisotope concentrations in low-level activity (0.5–1.5 Gy

  12. Aerial gamma spectrometry and aerial magnetometry of the occidental tract from Paulista Precambrian

    International Nuclear Information System (INIS)

    This work includes processing and interpretation of airborne spectrometric and magnetometric data of a 20.000 km2 area between the cities of Sao Paulo and Pirassununga (Sao Paulo State, Brazil). Spectrometric maps were produced and interpreted, showing isorad curves for K, U and Th channels, U/Th, K/U and K/Th ratios, and F = K.U/Th. Main results are the following ones: a comparison between spectrometric and geological data at scale 1:50.000 Itu, Sorocaba, Sao Francisco and Morungaba granitoids showed satisfactory individualization of the bodies, discrimination of different sectors and/or mapping units and relations between facies zonality patterns and distribution of radioactivity levels of K, U and Th channels; airborne spectrometric and magnetometric data compared with geological data generally suggests classification for granitoid rocks following main current proposals of international literature; on the basis of magnetometric features of outcropping Precambrian terrains and with the help of filtered maps, it was possible to induce the tectonic framework of the basement complex covered by sediments and lavas of Parana Basin, with the help of filtered maps. Another interesting aspect was the definition of the tectonic border of this basin inside the studied area, which not only controlled the localization of Itu belt granitoids, but also may have affected the sedimentation in the basin by reactivation processes; finally it was shown that used methods are important mapping tools, which may contribute for the knowledge of the granitoids and the tectonic framework and for the study of metallogenic potential. (author)

  13. Neutron-induced gamma spectrometry for on-line compositional analysis in coal conversion and fluidized-bed combustion plants

    International Nuclear Information System (INIS)

    All available methods of analysis of process streams in coal conversion and fluidized-bed combustion systems require the physical removal and conditioning of a sample from the system before the actual analysis. The inherent time lag makes these measurements unsuitable for process control, and the size and conditioning of the sample raise doubts about the similarity of the composition of the analyzed sample to that of the process stream. What is needed is an on-line analysis of the entire stream cross section, preferably by a non-invasive technique. We are evaluating neutron-capture gamma techniques for this application. Both neutrons and gamma rays are sufficiently penetrating that the sampled volume is comparable to the full section of pipe being irradiated, offering the possibility of non-invasive, continuous on-line instrumental monitoring of composition which is representative of the full process stream. Our studies and those of other groups have established the feasibility of using neutron-induced gamma spectrometry to obtain elemental abundances in coal. Several irradiation assemblies utilizing 252Cf neutron sources have been built and used with lithium-drifted germanium detectors and associated electronics. Samples of a variety of independently analyzed coals and simulated coals have been measured. The spectral responses from H, C, Fe, Si, S, Al, Cl, Ca, Ti, and N have been examined. The evidence indicates that quantitative determination of H, Fe, Si, S, Cl, Ca, and Ti will be possible, and that other constituents such as N, K, and Na may be quantitatively determined with further refinement of the technique. We are also working with fast neutrons from a pulsed 14 MeV neutron generator in order to obtain reliable analyses of the carbon and oxygen content of the coal process stream, as well as analyses for additional elements

  14. Measurement of gamma radiation levels in soil samples from Thanjavur using γ-ray spectrometry and estimation of population exposure

    Directory of Open Access Journals (Sweden)

    Senthilkumar B

    2010-01-01

    Full Text Available This study assesses the level of terrestrial gamma radiation and associated dose rates from the naturally occurring radionuclides 232 Th, 238 U and 40 K in 10 soil samples collected from Thanjavur (Tamil Nadu, India using g-ray spectrometry. The activity profile of radionuclides has clearly showed the existence of low level activity in Thanjavur. The geometric mean activity concentrations of 232 Th, 238 U and 40 K is 42.9±9.4 Bq.kg -1 , 14.7±1.7 Bq.kg -1 and 149.5±3.1 Bq.kg -1 respectively are derived from all the soil samples studied. The activity concentration of 232 Th, 238 U and 40 K in soil is due to the presence of metamorphic rocks like shale, hornblende-biotite gneiss and quartzofeldspathic gneiss in these areas. Gamma absorbed dose rates in air outdoors were calculated to be in the range between 32 nGy.h -1 and 59.1 nGy.h -1 with an arithmetic mean of 43.3 ±9 nGy.h -1 . This value is lesser than the population weighted world-averaged of 60 nGy.h -1 . Inhabitants of Thanjavur are subjected to external gamma radiation exposure (effective dose ranging between 39.2 and 72.6 μSv.y -1 with an arithmetic mean of 53.1±11 μSv.y -1 . The values of the external hazard index determined from the soil radioactivity of the study area are less than the recommended safe levels.

  15. Measurement of gamma radiation levels in soil samples from Thanjavur using γ-ray spectrometry and estimation of population exposure

    International Nuclear Information System (INIS)

    This study assesses the level of terrestrial gamma radiation and associated dose rates from the naturally occurring radionuclides 232Th, 238U and 40K in 10 soil samples collected from Thanjavur (Tamil Nadu, India) using γ-ray spectrometry. The activity profile of radionuclides has clearly showed the existence of low level activity in Thanjavur. The geometric mean activity concentrations of 232Th, 238U and 40K is 42.9 ± 9.4 Bq.kg-1, 14.7 ± 1.7 Bq.kg-1 and 149.5 ± 3.1 Bq.kg-1 respectively are derived from all the soil samples studied. The activity concentration of 232Th, 238U and 40K in soil is due to the presence of metamorphic rocks like shale, hornblende-biotite gneiss and quartzofeldspathic gneiss in these areas. Gamma absorbed dose rates in air outdoors were calculated to be in the range between 32 nGy.h-1 and 59.1 nGy.h-1 with an arithmetic mean of 43.3 ± 9 nGy.h-1. This value is lesser than the population weighted world-averaged of 60 nGy.h-1. Inhabitants of Thanjavur are subjected to external gamma radiation exposure (effective dose) ranging between 39.2 and 72.6 μSv.y-1 with an arithmetic mean of 53.1 ± 11 μSv.y-1. The values of the external hazard index determined from the soil radioactivity of the study area are less than the recommended safe levels. (author)

  16. Characterisation of imperial college reactor centre legacy waste using gamma-ray spectrometry

    Science.gov (United States)

    Shuhaimi, Alif Imran Mohd

    2016-01-01

    Waste characterisation is a principal component in waste management strategy. The characterisation includes identification of chemical, physical and radiochemical parameters of radioactive waste. Failure to determine specific waste properties may result in sentencing waste packages which are not compliant with the regulation of long term storage or disposal. This project involved measurement of intensity and energy of gamma photons which may be emitted by radioactive waste generated during decommissioning of Imperial College Reactor Centre (ICRC). The measurement will use High Purity Germanium (HPGe) as Gamma-ray detector and ISOTOPIC-32 V4.1 as analyser. In order to ensure the measurements provide reliable results, two quality control (QC) measurements using difference matrices have been conducted. The results from QC measurements were used to determine the accuracy of the ISOTOPIC software.

  17. Characterisation of imperial college reactor centre legacy waste using gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Shuhaimi, Alif Imran Mohd [Nuclear Energy Department, Regulatory Economics & Planning Division, Tenaga Nasional Berhad (Malaysia)

    2016-01-22

    Waste characterisation is a principal component in waste management strategy. The characterisation includes identification of chemical, physical and radiochemical parameters of radioactive waste. Failure to determine specific waste properties may result in sentencing waste packages which are not compliant with the regulation of long term storage or disposal. This project involved measurement of intensity and energy of gamma photons which may be emitted by radioactive waste generated during decommissioning of Imperial College Reactor Centre (ICRC). The measurement will use High Purity Germanium (HPGe) as Gamma-ray detector and ISOTOPIC-32 V4.1 as analyser. In order to ensure the measurements provide reliable results, two quality control (QC) measurements using difference matrices have been conducted. The results from QC measurements were used to determine the accuracy of the ISOTOPIC software.

  18. Characterisation of imperial college reactor centre legacy waste using gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Waste characterisation is a principal component in waste management strategy. The characterisation includes identification of chemical, physical and radiochemical parameters of radioactive waste. Failure to determine specific waste properties may result in sentencing waste packages which are not compliant with the regulation of long term storage or disposal. This project involved measurement of intensity and energy of gamma photons which may be emitted by radioactive waste generated during decommissioning of Imperial College Reactor Centre (ICRC). The measurement will use High Purity Germanium (HPGe) as Gamma-ray detector and ISOTOPIC-32 V4.1 as analyser. In order to ensure the measurements provide reliable results, two quality control (QC) measurements using difference matrices have been conducted. The results from QC measurements were used to determine the accuracy of the ISOTOPIC software

  19. Gamma ray spectrometry logs as a hydrocarbon indicator for clastic reservoir rocks in Egypt.

    Science.gov (United States)

    Al-Alfy, I M; Nabih, M A; Eysa, E A

    2013-03-01

    Petroleum oil is an important source for the energy in the world. The Gulf of Suez, Nile Delta and South Valley are important regions for studying hydrocarbon potential in Egypt. A thorium normalization technique was applied on the sandstone reservoirs in the three regions to determine the hydrocarbon potentialities zones using the three spectrometric radioactive gamma ray-logs (eU, eTh and K% logs). The conventional well logs (gamma-ray, deep resistivity, shallow resistivity, neutron, density and sonic logs) are analyzed to determine the net pay zones in these wells. Indices derived from thorium normalized spectral logs indicate the hydrocarbon zones in petroleum reservoirs. The results of this technique in the three regions (Gulf of Suez, Nile Delta and South Valley) are in agreement with the results of the conventional well log analyses by ratios of 82%, 78% and 71% respectively. PMID:23306160

  20. Mapping Brazilian radioactive minerals by gamma-ray spectrometry and using a germanium detector

    International Nuclear Information System (INIS)

    This paper has as scope the organization of a catalogue of the main uranium and/or thorium minerals using their gamma-ray spectra registered by their natural radioactivity with a pure germanium detector. The objective is to accumulate data for the radiometric identification for a posterior comparative study of minerals of same procedence or from new uranium and thorium occurrences. On the respective spectra are marked the main peaks, their energies and the correspondent radioisotopes. An estimative of their radioactive equilibrium state is included. As additional information the decay of the descendents of the natural series of 235U, 238U and 232Th, their gamma-ray energies and, finally, a table of the main uranium and thorium ores are presented. (Author)

  1. Methods for the analysis of overlapped peaks in analytical gamma-ray spectrometry

    International Nuclear Information System (INIS)

    A review of critical evaluation of simple methods for the analysis of overlapped peaks from the point of view of their applicability in activation analysis are described. These methods are adopted from other spectroscopic techniques and gas chromatography. The experimental verification has been carried out for gamma-ray spectra in the energy range 120 KeV - 3 MeV. 28 refs., 8 figs., 3 tabs. (author)

  2. Fully automated system for Pu measurement by gamma spectrometry of alpha contaminated solid wastes

    International Nuclear Information System (INIS)

    A description is given of a fully automated system developed at Comb/Mepis Laboratories which is based on the detection of specific gamma signatures of Pu isotopes for monitoring Pu content in 15-25 l containers of low density (0.1 g/cm3) wastes. The methodological approach is discussed; based on experimental data, an evaluation of the achievable performances (detection limit, precision, accuracy, etc.) is also given

  3. The study and development of cadmium telluride detectors for gamma ray spectrometry

    International Nuclear Information System (INIS)

    The purpose of this work is the study of possibility of cadmium telluride's utilisation in gamma ray spectroscopy. This material has some superiorities in comparison with germanium which is utilised in (Ge Li) structures. In a first chapter we study the interaction of rays with matter in the particular case of cadmium telluride. The range of α and β rays in the some way as the effect cross section of gamma ray versus energy are deducted from data tabulated for tin which has a density and an atomic weight very near. The problems related with creation and collection of charges in a cadmium telluride structure are discussed in the same way as the resolution in nuclear spectroscopy, acting the different parameters characterising the detector. In the second chapter, after some indications in the metallurgy of cadmium telluride, we describe the realisation of several structures types, evaporation of a cadmium telluride's layer, diffusion of gold or copper, metal semiconductor contact. Measures of current-voltage characteristics and capacity allow the determination of possibility of nuclear detection with this structures and state precisely some parameters. In the third chapter range's measures of α rays are compared with the first chapter's theoretical results. Results of α ray spectroscopy obtained with three detectors are described and show the possibility of cadmium telluride in this way. Detection of gamma ray at last justify the choice of this material, but the results obtained here show the progress to do in cadmium telluride metallurgy. (author)

  4. Gamma ray spectrometry logs as a hydrocarbon indicator for clastic reservoir rocks in Egypt

    International Nuclear Information System (INIS)

    Petroleum oil is an important source for the energy in the world. The Gulf of Suez, Nile Delta and South Valley are important regions for studying hydrocarbon potential in Egypt. A thorium normalization technique was applied on the sandstone reservoirs in the three regions to determine the hydrocarbon potentialities zones using the three spectrometric radioactive gamma ray-logs (eU, eTh and K% logs). The conventional well logs (gamma-ray, deep resistivity, shallow resistivity, neutron, density and sonic logs) are analyzed to determine the net pay zones in these wells. Indices derived from thorium normalized spectral logs indicate the hydrocarbon zones in petroleum reservoirs. The results of this technique in the three regions (Gulf of Suez, Nile Delta and South Valley) are in agreement with the results of the conventional well log analyses by ratios of 82%, 78% and 71% respectively. - Highlights: ► The positive DRAD values indicate the hydrocarbon zones in petroleum reservoirs. ► Thorium normalization was applied to determine the hydrocarbon potentialities. ► The conventional well logs are analyzed to determine the net pay zones in wells. ► Determining hydrocarbon potentialities zones using spectrometric gamma-ray logs

  5. Measurement principles of quantitative gamma spectrometry used on Cabri and Phebus testing facilities

    International Nuclear Information System (INIS)

    To improve knowledge about nuclear fuel behavior during accidental sequences and to get information about fission product releases during severe accident in a nuclear reactor, IRSN performs in-pile tests at Cadarache, in the PHEBUS and CABRI experimental facilities. In the frame of these research, IRSN/DRS is steering the CSA(1) research program, which simulates reactivity accident in the CABRI facility, and the PHEBUS FP(2) (fission products) program which simulates in the PHEBUS facility severe accidents on a 20 fuel rods test section and studies fission products release. We developed specific tools to examine the fuel test section before and after a test to get information on the degradation state of the fuel at the end of the transient. The developed instrumentation can measure and localize fission products inside a fuel test section, which is degraded, composed of very dense material and contains strong gamma emitters. Three types of examinations are used concomitantly to provide quantitative results on fission products inside the fuel test section. The first one consists in a gamma scanning along the test device, and provides a first qualitative analysis. The second one is tomography examination which provides information on distribution of high density materials. This technique probes sections of the fuel test device with the use of a high energy X ray source of the LINAC type. After calibration of tomography, 2D images are obtained in which pixel values are converted to densities. Our test devices being very severely degraded after a test, a last examination, called emission computerized tomography, is performed. This technique localizes the different gamma emitters in the test section. This is based on transmission tomography. Gamma emitters are measured but not transmission attenuation. Hyper-pure Germanium collimated mobile detector is used to measure only lines of emission and radial evolutions on multiple angles of measure. About 2000 spectra are

  6. Airborne gamma-ray spectrometer and magnetometer survey, Dryden, Texas; Indian Wells, Texas. Volume I. Detail area. Final report

    International Nuclear Information System (INIS)

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the Dryden Detail Area and the Indian Wells Detail Area of southwestern Texas. The Dryden Detail Area is within the coverage of the Sanderson, Dryden, Thurston, Pandale, Dryden Crossing, Malvado, and Langtry 15' map sheets of the National Topographic Map Series (NTMS). The Indian Wells Detail is within the coverage of the Indian Wells 15' map sheets of the NTMS. The survey was part of DOE's National Uranium Evaluation (NURE) program. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, gridded, and contoured to produce maps of the radiometric variables, uranium, potassium, and thorium; their ratios; and the residual magnetic field. These maps have been analyzed in order to produce a multi-variant analysis contour map based on the radiometric response of the individual geological units. A geochemical analysis has been performed, using the radiometric and magnetic contour maps, the multi-variant analysis map, and factor analysis techniques, to produce a geochemical analysis map for the area

  7. Airborne gamma-ray spectrometer and magnetometer survey: Forsyth quadrangle, Round Up quadrangle, Hardin quadrangle (Montana), Sheridan quadrangle, (Wyoming). Final report

    International Nuclear Information System (INIS)

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Forsyth, Hardin, and Sheridan, and Roundup, 1:250,000 National Topographic Map Series (NTMS), quadrangle maps. The survey was part of DOE's National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer with a large crystal volume, and with a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration Pads and the Lake Mead Dynamic Test Range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The anomalies were interpreted and an interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data collection procedures, the data processing procedures, the data presentation, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

  8. Natural radioactivity of sand samples by low-level gamma spectrometry

    International Nuclear Information System (INIS)

    The natural radioactivities of compressed powdered sand samples from different locations along the Qena-Safaga highway were measured in face to face geometry applying a low-level γ-ray spectrometry method. The average measured values of U, Th and K are: 6.3, 6.2 and 1.5 x 104 ppm, respectively. Some samples were found to be free from thorium to the minimum detectable activity of the spectrometer. Results are discussed and compared with other results presented. (author)

  9. Radial distribution of fission products in fuel pins. Experimental results on PWR elements by gamma spectrometry. Destructive testings (ISOPROF code). Direct testings (TOMOGAN Code)

    International Nuclear Information System (INIS)

    In order to know the distribution of fission products in the nuclear fuel of PWR elements, two methods have been developed using gamma spectrometry. The tests are destructive or non-destructive. In sectional gamma spectrometry, the sample moves across the front of a collimator; at each point a gamma spectrum is obtained which is processed by ISOPROF code. This test is destructive. In the tomographic method, a non-destructive test, horizontal scans of fuel slices are made under different angles. A transversal distribution of the nuclides is thus obtained, area by area. This information is processed in the TOMOGAN code which takes into account the effect of the structures and any presence of a central hole. A critical analysis of the isoconcentraton curves obtained by both methods is made. The tomographic method allows for quick on-site studies which can be completed, if necessary, with laboratory examinations by sectional gamma spectrometry which gives a more accurate quantitative analysis of the spectral concentrations of fission products

  10. Assay for uranium and determination of disequilibrium by means of in situ high resolution gamma-ray spectrometry

    Science.gov (United States)

    Tanner, Allan B.; Moxham, Robert M.; Senftle, F.E.

    1977-01-01

    Two sealed sondes, using germanium gamma-ray detectors cooled by melting propane, have been field tested to depths of 79 m in water-filled boreholes at the Pawnee Uranium Mine in Bee Co., Texas. When, used as total-count devices, the sondes are comparable in logging speed and counting rate with conventional scintillation detectors for locating zones of high radioactivity. When used with a multichannel analyzer, the sondes are detectors with such high resolution that individual lines from the complex spectra of the uranium and thorium series can be distinguished. Gamma rays from each group of the uranium series can be measured in ore zones permitting determination of the state of equilibrium at each measurement point. Series of 10-minute spectra taken at 0.3- to 0.5-m intervals in several holes showed zones where maxima from the uranium group and from the 222Rn group were displaced relative to each other. Apparent excesses of 230Th at some locations suggest that uranium-group concentrations at those locations were severalfold greater some tens of kiloyears, ago. At the current state of development a 10-minute count yields a sensitivity of about 80 ppm U308. Data reduction could in practice be accomplished in about 5 minutes. The result is practically unaffected by disequilibrium or radon contamination. In comparison with core assay, high-resolution spectrometry samples a larger volume; avoids problems due to incomplete core recovery, loss of friable material to drilling fluids, and errors in depth and marking; and permits use of less expensive drilling methods. Because gamma rays from the radionuclides are accumulated simultaneously, it also avoids the problems inherent in trying to correlate logs made in separate runs with different equipment. Continuous-motion delayed-gamma activation by a 163-?g 252Cf neutron source attached to the sonde yielded poor sensitivity. A better neutron-activation method, in which the sonde is moved in steps so as to place the detector

  11. Simultaneous measurements of indoor radon, radon-thoron progeny and high-resolution gamma spectrometry in Greek dwellings

    International Nuclear Information System (INIS)

    Simultaneous indoor radon, radon-thoron progeny and high-resolution in situ gamma spectrometry measurements, with portable high-purity Ge detector were performed in 26 dwellings of Thessaloniki, the second largest town of Greece, during March 2003-January 2005. The radon gas was measured with an AlphaGUARD ionisation chamber (in each of the 26 dwellings) every 10 min, for a time period between 7 and 10 d. Most of the values of radon gas concentration are between 20 and 30 Bq m-3, with an arithmetic mean of 34 Bq m-3. The maximum measured value of radon gas concentration is 516 Bq m-3. The comparison between the radon gas measurements, performed with AlphaGUARD and short-term electret ionisation chamber, shows very good agreement, taking into account the relative short time period of the measurement and the relative low radon gas concentration. Radon and thoron progeny were measured with a SILENA (model 4s) instrument. From the radon and radon progeny measurements, the equilibrium factor F could be deduced. Most of the measurements of the equilibrium factor are within the range 0.4-0.5. The mean value of the equilibrium factor F is 0.49 ± 0.10, i.e. close to the typical value of 0.4 adopted by UNSCEAR. The mean equilibrium equivalent thoron concentration measured in the 26 dwellings is EEC thoron = 1.38 ± 0.79 Bq m-3. The mean equilibrium equivalent thoron to radon ratio concentration, measured in the 26 dwellings, is 0.1 0.06. The mean total absorbed dose rate in air, owing to gamma radiation, is 58 ± 12 nGy h-1. The contribution of the different radionuclides to the total indoor gamma dose rate in air is 38% due to 40 K, 36% due to thorium series and 26% due to uranium series. The annual effective dose, due to the different source terms (radon, thoron and external gamma radiation), is 1.05, 0.39 and 0.28 mSv, respectively. (authors)

  12. An axially symmetric gamma-ray backscatter system for DuMond spectrometry

    International Nuclear Information System (INIS)

    An axially symmetric spectrometer is described which evolved from a program of measuring Compton profiles with unusually high geometric efficiency. When fitted with a large-volume Ge detector for combined X-ray and γ-ray spectrometry, such as the 51 mm diameter LO-AX detector from EG and G, it allows Compton profiles to be measured at counting rates in excess of 20000 cps. The axially symmetric configuration is also suited to high-efficiency analyses of thick targets by both XRF and Rayleigh/Compton (R/C) ratios. The same spectra permit a competitive binary-system analysis based on the shape of the Compton profile. Both this new analysis, which we call DuMond spectrometry, and R/C analysis are applied to studies of osteoporosis in the calcaneus with promising results. The combination of high intrinsic and geometric detection efficiency makes it practical to use very weak sources (≅ 100 MBq) and unusually low, localized doses (≅ 1 μGy) per reading. (orig.)

  13. Analysis of boron, samarium and gadolinium in rock samples by neutron capture gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Prompt gamma neutron activation analysis (PGNAA) is useful for determining many of the elements found in sedimentary rocks. It is particularly suitable for the trace elements boron, samarium and gadolinium. The sensitivity of detection can be of the order of 0.1 ppm with an adequate neutron source. Twenty-five sedimentary rock samples were analyzed in the PGNAA facility at the University of Missouri Research Reactor. The materials included Ottawa sand, Berea sandstone, Royer dolomite and several other formations of interest in the petroleum industry. Results of the analyses are presented. Correlations of gadolinium and samarium and of boron with the sum of samarium and gadolinium are given. (author)

  14. Soil gamma ray spectrometry of the Buquira river basin, SP, Brazil

    International Nuclear Information System (INIS)

    Natural radioactivity found in rocks and its evaluation been frequently used for studies of environmental geochemistry, particularly those of detection and control of pollutants and the consequent changes in environment after antropic interferences. In this work natural radioactivity in forty nine soil samples in the basin of Buquira river, at the Northeast region of Sao Paulo State, has been analysed and measured with a Ge-HP gamma ray spectrometer. A table with the most relevant results found in rocks is shown and discussed. (author)

  15. Uranium thorium and potassium contents analysis of rocks in Changwat Narathiwat by gamma spectrometry

    OpenAIRE

    Kaewtubtim, P.; Changkain, S.

    2002-01-01

    Quantitative analysis of three radioactive elements (potassium, equivalent uranium, and equivalent thorium) in the granite rocks of the Triassic Age at 24 locations in Narathiwat province was carried out by using a gamma counter. It was found that potassium, equivalent uranium and equivalent thorium contents were on the average of 3.63% (in the range of 1.56-5.24%), 8.55 ppm (2.98-15.27 ppm) and 18.74 ppm (0.34- 52.14 ppm), respectively. It is worth noting that the radiation detected from the...

  16. On the possibility of the game Aethod application for the pulse superposition elimination in gamma spectrometry

    International Nuclear Information System (INIS)

    A method of superposition pulses elimination in gamma-spectroscopy based on conclusions of the matrix theory of games is described. The optimum solution in mixed strategies is given and probabilities, when the optimum evaluation of the spectrum is realized, have been calculated. Ways of possible realization of the superposition pulses elimination method are discussed. The simplest is the variant when a random number transducer and a logic device are attached to a standard analyzer. Every input signal starts up the logic device and random number transducer which registrate or don't registrate with pre-set probability the given concrete event in the pulse analyzer memory

  17. Study of Naturally Occurring Radioactive Material (NORM) in soil using low background gamma ray spectrometry

    International Nuclear Information System (INIS)

    There has been an increasing concern in the state of Punjab arising due to naturally occurring radioactive material (NORM) after high concentration levels of uranium was observed in ground water besides nails and hair of children. The concentration levels of 238U, 232 Th and 40K in top soil were measured using low background gamma ray spectrometric setup. The concentration of NORM was found to be similar to what is expected as a result of their normal abundance but was found to be lower than what has been observed in the state of Jharkhand. In addition to NORM the fall out radionuclide 137Cs was also observed in soil samples. (author)

  18. Early detection of radioactive fall-out by gamma-spectrometry

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, K.

    2003-01-01

    Radioactive fallout should be detected as early as possible. A new and efficient method for detection of low-level irradiation from manmade radioactivity is developed. Radiation abnormalities are detectable down to air kerma rate, of 0.5 to 1.0 nGy h(-1) for Cs-137 and even lower for I-131...... For multi-gamma energy radioactivity the detection level is 2.6-3.5 nGy h(-1). A standard NaI detector and a 512-channel analyser are used together with noise adjusted singular value decomposition (NASVD). Statistical noise is removed and the measured spectra are reproduced using spectral components...

  19. Semi-Broad-Beam Gamma Spectrometry of Some Mixtures and Solutions

    International Nuclear Information System (INIS)

    The 33- and 662-keV X rays and gamma rays from 137Cs and the 1173- and 1333-keV gamma rays from 60Co have been employed as single and dual beams to study the attenuation of applied materials. These materials are soil containing water, dextrose solutions, and solutions of lithium chloride, sodium chloride, and potassium chloride. In soil the measurements covered water content ranging from saturation to nearly dry points. For dextrose, the content ranged from 0.25 g.cm-3 to zero. For the chloride solutions, the salt mass fraction was varied up to the ratio 0.1667. The setup geometry was arranged with a source-detector angle of 8.63 deg to allow good reception of the 33-keV line. The results were analyzed on the basis of the dependence of the absorption of intensity (intensities) on the content of the added component. The curves are fitted with concentration-dependent expansions, the coefficients of which are tabulated. It is concluded that soft X rays (33 keV) produce the most sensitive responses to concentrations. Correspondingly, a dual energy of 33 and 1250 keV (or 1333 keV) is the preferred combination to detect a desired component in a sample

  20. Ultra low-level gamma ray spectrometry of thorium in human bone samples

    International Nuclear Information System (INIS)

    Following the use of in vivo measurements of 210Pb to estimate retrospectively radon exposure, interest has been expressed in the use of in vivo measurements of 208Tl to estimate thorium intake. To aid with calibration and to determine the optimum part of the body on which in vivo measurements should be made, the distribution of 208Tl and 228Ac amongst different human bones was measured in the underground laboratory HADES. The 208Tl activity was determined by the 2614.5 keV and the 583.2 keV gamma ray lines. The 228Ac activity was determined by the 911.2 keV and 969.0 keV gamma ray lines. The background under those peaks when measured on the 106% relative efficiency coaxial HPGe detector in HADES is of the order of 1 d-1, resulting in detection limits in the order of 1 mBq for both radionuclides for a typical 10 g bone sample and for a measuring time of 1 week. (author)