Multi-disciplinary facilities at the Centre for Nuclear Sciences,U.W.I.

The Centre for Nuclear Sciences was established in 1984 with the mandate to introduce Caribbean scientists to the application of nuclear technology in multi-disciplinary studies, and to carry out research in areas of national and regional importance. This paper describes the pesent facilities and the major programmes being carried out at the Centre.     

Stability monitoring of selected spike isotopic reference materials for isotope dilution mass spectrometry

Journal of Radioanalytical and Nuclear Chemistry - The provision of high quality spike isotopic reference materials is one of the objectives of the Joint Research Centre of the European Commission....     

Standardization of 177Lu by means of 4π(LS)β-γ coincidence and anti-coincidence counting

Journal of Radioanalytical and Nuclear Chemistry - The activity concentration of a 177Lu solution was measured by the Laboratory of Radioactivity Standards in the Radioisotope Centre POLATOM. The...     

Anwendung der Radionuklidtechnik in Chemie und Verfahrenstechnik

The works done by the “Laboratorium für Isotopentechnik” of the Nuclear Research Centre, Karlsruhe, is discussed in the field of the application of radioisotope techniques in chemistry and chemical engineering.      

Anwendung der neutronenaktivierungsanalyse zur bestimmung von chemischen elementen in heilschlamm aus einem österreichischen moorbad

The content of various elements of mud from Neydharting Austria, that is used for Fango therapy, was determined by neutron-activation analysis. ASTRA-reactor of the Research Centre Seibersdorf and the reactor of the Institute of Nuclear Energy of the Bulgarian Academy of Sciences, Sofia, were used. The concentrations of Ca, Cr, Sc, Fe, Zn, Rb and Co found in our laboratory were in good agreement with the results reported by the Institute of Nuclear Research and Nuclear Energy of the Bulgarian Academy of Sciences, Sofia. All investigated elements in mud with exception of the relatively high uranium values are in good agreement with the values obtained for the distribution of elements in different culture soils.     

Compton suppression instrumental neutron activation analysis performance in determining trace- and minor-element contents in foodstuff

In 2003–2004, several food items were purchased from large commercial outlets in Coimbra, Portugal. Such items included meats (chicken, pork, beef), eggs, rice, beans and vegetables (tomato, carrot, potato, cabbage, broccoli, lettuce). Elemental analysis was carried out through INAA at the Technological and Nuclear Institute (ITN, Portugal), the Nuclear Energy Centre for Agriculture (CENA, Brazil), and the Nuclear Engineering Teaching Lab of the University of Texas at Austin (NETL, USA). At the latter two, INAA was also associated to Compton suppression. It can be concluded that by applying Compton suppression (1) the detection limits for arsenic, copper and potassium improved; (2) the counting-statistics error for molybdenum diminished; and (3) the long-lived zinc had its 1115-keV photopeak better defined. In general, the improvement sought by introducing Compton suppression in foodstuff analysis was not significant. Lettuce, cabbage and chicken (liver, stomach, heart) are the richest diets in terms of human nutrients.     

A European network for nuclear medicine and radiotherapy: EMIR

Nuclear medicine and radiotherapy make a vital contribution to the diagnosis and treatment of major disease. This role is likely to expand with new developments including availability of new medical isotopes. A European network (EMIR) was initiated in 2001 by the Joint Research Centre (JRC) of the European Commission, to identify and solve difficulties that constrain nuclear medicine and radiotherapy development in Europe and facilitate closer interdisciplinary collaboration. Participating organisations include the main European associations of medical radiation specialists, radiopharmaceutical/radioisotope producers, nuclear research reactor institutions, research organizations and the JRC. The steering committee established task groups focusing on eight key areas for development. Liaison with non-European organizations will be encouraged.     

The Synergic Extraction of Uranium(VI) with Bis(octylsulfinyl)ethane (BOSE) and Petroleum Sulfoxides (PSO)

The biological standard reference materials Orchard Leaves SRM 1571 and Oyster Tissue SRM 1566a was analysed by instrumental neutron activation analysis (INAA) at the International Centre for Environmental and Nuclear Sciences, Jamaica at (ICEN) and at the Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Brazil. The comparison of the results with those obtained with the more powerful reactor are used to evaluate the possibilities of INAA for the analysis of biological samples at ICENS. The detection limits, the precision and accuracy of the results obtained in both laboratories are compared. The advantages and disadvantages of the different irradiation facilities are discussed. Some results obtained for Jamaican biological samples are also presented.     

Physicochemical behavior of uranium and technetium in some new stages of the nuclear fuel cycle

Recently published results of the cooperative studies executed by the Institute of Physical Chemistry and Electrochemistry of Russian Academy of Sciences (IPCE RAS), Research Center Vallée du Rhone (CEA, France), Institute of Nuclear Physics Orsay and University Bordeaux I [Centre Nationale de Recherches Scientifiques (CNRS), France] are reviewed. The review includes data obtained for the first time on the electrochemical properties and anodic dissolution of uranium monocarbide considered among possible bases of the fuel for the reactors of the IVth generation. The results of the investigations in the field of the synthesis of tetraalkyl ammonium pertechnetates, their physicochemical properties and thermal decomposition with formation of Tc metal and Tc monocarbide are summarized. The electrochemical reactions with participation of Tc ions in various oxidation states and their application in the nuclear fuel cycle are described. The behavior of technetium in natural waters near the locations of the radwastes long-term storage and in the areas surrounding nuclear power plants in RF and France was studied.     

Elemental composition of dental biologic tissues: study by means of different analytical techniques

The present study determined the organic and inorganic composition of human enamel and dentin. The instrumental neutron activation analysis, inductively-coupled plasma spectrometer, thermogravimetric and differential thermal analysis and X-ray diffraction analysis applied were and performed in the Nuclear Technology Development Centre (CDTN) and Elemental Analysis in the Department of Chemistry of the Federal University of Pernambuco, Brazil. The coronal dentin and enamel were separated from dentin mechanically (1) and by wear (2). The analyses were effective and led to the identification of the main elements present in enamel and dentin: Ca, Na, Cl, Zn, P, Mg, N, C, H, O. There was no contamination of samples of enamel or dentin in either separation technique; however, with separation technique 1, lower percentages of mainly Ca (7.25%) and O (15.16%) components were detected in dentin compared with technique 2.     

Implementing quality assurance in an R&D environment at the Belgian Nuclear Research Centre – SCK·CEN

If we agree that quality assurance (QA) in R&;D indeed provides added value, just how do we show the public that such a QA system is operating well? At the Belgian Nuclear Research Centre (SCKÖbullet CEN), where a QA system has been implemented by various laboratories in accordance with the EN 45001 standard within the general framework of ISO 9001 at the institutional level, several laboratories have already been accredited. At the request of one of our customers the Belgian Agency for Radioactive Waste Management (NIRAS/ONDRAF), we implemented a quality system for research projects related to the characterization, treatment and processing of radioactive wastes in view of disposal. We obtained accreditation for this research in 1999. In this paper, we discuss the implementation of our QS and important issues related to the overall management of the QA system, broken down into three parts: organizational, technical and project-specific quality elements such as the QA plan and internal communication.     

Photofission for the detection of actinides

Nuclear waste management cost at CEA is a heavy budget share. Therefore, it is important, in order to minimize that cost, to select the most suitable repository for the waste. Significant cost savings are obtained, for example, whenever a medium activity waste drum initially filed to end up in a geological repository can be measured accurately enough to be accepted by the Centre de Stockage de l’Aube (CSA). Photofission can be used as a non-destructive technique to measure the actinide content embedded in a nuclear waste drum. It can even be applied when the waste is packaged in its heavy concrete shielding. It is equally sensitive to non-fissile nuclear material. However, the present state of art suffers from a lack of sensitivity to be able to help redirecting the waste to the proper repository. A new program called INPHO is proposed at CEA Saclay aiming at enhancing the sensitivity sufficiently to be applicable for waste characterization.     

Gamma dose rate due to natural and manmade radiation sources from a nuclear facility in Mexico

The environmental external gamma dose rate has been determined at the Mexican Nuclear Research Centre and surrounding communities, located in a forest area. Outdoor direct measurements of external gamma exposure and absorbed dose rates in air were performed using passive integrating thermoluminescent dosimeters. Radiological measurements were also carried out with a portable high pressure ionization chamber. The gamma dose rate was evaluated from data obtained along 10 years measurements. The activity concentrations of ⁴⁰K, ²²⁶Ra, ²³²Th, ¹³⁷Cs, and ²³⁵U in surface soil samples at sampling sites are also presented. The radionuclide activity concentrations were determined by low background gamma spectrometry with hyper-pure germanium detectors. A site specific lineal model to describe the relationship between the external gamma dose rate and the ²²⁶Ra concentration values in the soil is proposed.     

The University of Surrey&;#39;s new proton microprobe and the feasibility of PIXE-tomography for trace element analysis of biological tissues

Summary The University of Surrey Ion Beam Centre has recently installed a tandem accelerator with a new proton microprobe and the potential for sub-micron beam-spot size. The facilities for Nuclear Microscopy (NM), combining scanning transmission ion microscopy/tomography (STIM-T) and proton induced X-ray emission tomography (PIXE-T) of biological tissues are being developed. This paper will review developments in ion beam tomography of biological samples and methods in accurately producing trace-elemental maps that are meaningful. Cell composition and integrity can be seriously compromized by the preparation of the sample and by beam-induced damage, causing loss of matrix elements as well as a change in cell size. Beam-induced damage, determination of 3-dimensional X-ray attenuation and secondary fluorescence contribute to the complex nature of the reconstruction and interpretation of PIXE-tomographic data. A PIXE, STIM and Rutherford backscatter analysis of leukocytes is presented in part to test the new microprobe but also to identify areas of improvement in facilities at the university and nuclear microscopy in general, in anticipation of producing maps for more direct biological and medical research.     

Calibration of the B54X channel and implementation of k 0-NAA at the RA3-reactor,Ezeiza, Argentina

The B54X position of the 8 MW RA3 research reactor at the Ezeiza Atomic Centre of the Argentine National Atomic Energy Commission is currently being used for NAA irradiations. The facility with a nominal average fluence of 5 × 10¹³ cm^?2 s^?1 is dedicated to long irradiations of up to 5 h. Samples are being measured after a decay of typically 7 and 30 days. With the aim of implementing the k ₀-NAA method at the Nuclear Analytical Techniques Laboratory of the Centre, the reactor parameters α and f were estimated applying multi monitor methods using the Kayzero for Windows software. After a careful recalibration of the HPGe detector, SMELS III, NIST SRM 1633b and several other matrix RM’s were analyzed using the k ₀ standardization in order to verify the proper implementation of the k ₀-NAA approach. The found accuracy and associated uncertainties are discussed. In general, good agreement was obtained between results of this work and the reference values of the individual reference materials, thus proving successful first implementation of the above method and trueness of the results achieved. The obtained detection limits for several elements were evaluated.     

Longitudinal study of iodine in market milk and infant formula via epiboron neutron activation analysis

A global radionuclide monitoring system is being engineered as part of a multi-technology verification system for the Comprehensive Nuclear Test Ban Treaty. The system detects airborne radioactive aerosols and gases that can indicate nuclear weapons test debris. The backbone of the system is a network of 80 remote detection stations that utilize high-volume air sampling and high-resolution gamma spectrometry to provide in-situ assay and near-real time reporting. These stations are linked to the International Data Centre, which is a central data processing hub where raw spectral data is automatically processed, analyzed, and disseminated to the states parties. Measurements are categorized based on spectral content to determine which contain anomalous anthropogenic radionuclides that require intensive radiochemical analysis at a certified laboratory. The resulting system has the capability to measure microbecquerel concentrations of radionuclides and provide accessible data products within minutes of field measurements. During the past year of international operations, the minimum detectable concentrations and spectroscopy processing statistics were recorded as a function of geographical location and time. The results show that this system is an effective tool for nuclear test monitoring, as well as other applications such as radiological emergency response, public health monitoring, and scientific research.     

DÖME: revitalizing a low-background counting chamber and developing a radon-tight sample holder for gamma-ray spectroscopy measurements

There was an emerging need at the Nuclear Analysis and Radiography Department of the Centre for Energy Research, Hungarian Academy of Sciences, Budapest to be able to perform low level radioactivity measurements of various samples from in-beam activation and from environmental studies. Important aspects of reusing the low-background chamber called DÖME, which had been unused for some years, were the development of an easily reusable radon-tight sample container and the setup of a measurement system capable of counting extended samples in close-in geometry. As a result of our efforts a special sample container made of HDPE (High-density Polyethylene) was developed, and it is proved that the probability of a radon loss larger than the 2 % of its radioactive decay constant is <95 %. Due to the lack of reference samples, containing the same radionuclides as the unknown sample, the absolute method of measuring the activity concentration of nuclides in the sample had to be applied, which implied the reliable determination of the full-energy peak efficiency. A method called efficiency transfer combined with the correction for true coincidence summing effects is proven to be providing appropriate results and applied.     

Validation of the k0_IAEA software using SMELS material at CDTN/CNEN, Brazil

The Laboratory for Neutron Activation Analysis at CDTN/CNEN, Brazil, acquired the k0_IAEA software package during the Workshop on Nuclear Data for Activation Analysis, 2005, held at the Abdus Salam International Centre for Theoretical Physics, Italy. The IAEA distributed the software to several laboratories and has accepted suggestions from the users about the performance of the program. This paper describes the validation procedure carried out aiming at the validation of the software package. The procedure was to analyze the SMELS samples and to compare the results obtained by this software to the commercial KayWin software package, already established at CDTN/CNEN. The results were compared to the values obtained by the Jožef Stefan Institute, Slovenia. The laboratories applied the same software: k0_IAEA and KayWin. The overall results pointed out that the k0_IAEA software set up at CDTN/CNEN, Brazil, is working properly. The u-score test showed that all results, except data in SMELS Type III for Se obtained at the JSI, are within 95% confidence interval once setting up u-score as 1.96 (P = 95% or ±2σ).     

Fourth Collaborative Materials Exercise of the Nuclear Forensics International Technical Working Group

Journal of Radioanalytical and Nuclear Chemistry - The Nuclear Forensics International Technical Working Group is a community of nuclear forensic practitioners who respond to incidents involving...