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Abstract
On 13 September 1987, a severe radiation accident occurred in the city of Goiânia in central Brazil. Approximately 250 people were directly affected by the radiation, receiving slight to very severe external, partial or whole body, irradiation, and presenting internal and external contamination. Fourteen patients developed some degree of marrow failure, eight developed the clinical signs and symptoms of acute radiation syndrome (ARS), and four eventually died of ARS complications. Twenty-eight people showed acute localized radiation injuries ranging from first to third degree. The author describes the circumstances of the event, the first-aid measures taken on the site, and the medical structure organized to triage and treat the casualties. Aspects relating to hospital contamination control, radiation protection and decontamination procedures are also discussed.
Abstract
The Preparatory Commission of Comprehensive Nuclear Test-Ban-Treaty Organization is setting up a global network capable to monitor treaty compliance. Specific monitoring systems and methodologies that match the needs of the International Monitoring System (IMS), namely to clarify the nuclear character of suspect explosions, had to be developed for monitoring purposes during the last decade. Four xenon isotopes, namely 133Xe, 135Xe, 133mXe and 131mXe play a key role here. A complex background from medical isotope production facilities and nuclear power plants, varying over four orders of magnitude, challenges the system’s capability to distinguish these from treaty-relevant events. Available measurement data are compared with model calculations. The importance of atmospheric transport modelling is demonstrated both for completely understanding the civilian background and for explaining peak concentrations and abnormal events. New methodologies for backtracking nuclide detections improved the capability to locate sources and corroborate the role of radioxenon monitoring.
. Noise level testing Noise level test was carried out as per the rules of notification of PESO (Petroleum and Explosives Safety Organisation), formerly known as ‘Department of Explosives’, Govt. of India. The noise level was measured by four
Abstract
A new variant of a technique for determining ion mobilities by means of horizontal zone electrophoresis in free solutions is developed. Setup circuit is presented. Some details of experiment and results of measuring limiting mobilities of131I-and160Tb3+ are given. On these examples the reproductibility was checked.
Abstract
Two improved processes of99Mo production have been developed on laboratory scale. The first one allows to purify Mo of natural isotopic composition from tungsten impurities from 64 to <10 ppm by using preferential adsorption of tungsten on hydrated tin(IV) oxide (SnO2 nH2O) before irradiation in a nuclear reactor. The second process deals with the separation of pure fission product99Mo from235U irradiated in a reactor. Two versions of separation process for production of fission99Mo have been developed. Both versions start with the dissolution of235U oxide target in nitric acid and are based on sequential use of alumina and anion exchange resin AG® 1-X8 columns. The yield of99Mo in both versions is 80–89%.
Abstract
The distribution of half-lives (seconds) expressed as logarithm (base 10) for over three thousand radionuclides is examined. The best fit normal distribution (mean 1.58, standard deviation 2.38) is shown. The fit while good, tends to underestimate the number of radionuclides at both the high and low ends of the distribution. Some implications are noted.
Summary
Measurement of 210Po by alpha-spectrometry and 210Pb by beta-spectrometry provide accurate methods of determination at low levels of activity, however, both techniques are time consuming and provide no scope for “in-line' evaluation. The main objective of this work was to investigate the suitability of liquid scintillation counting (LSC) to provide a fast analytical procedure for the determination of these radionuclides in hydrometallurgical process samples which are typically acidic, coloured and contain many different matrix ions.
Abstract
In April 2007 the new nuclear research reactor, OPAL, was opened at Lucas Heights in Sydney. OPAL is a 20 MW open pool light water reactor with a heavy water reflector vessel and contains a cold neutron source. It is a multi-purpose facility for radioisotope production, irradiation services and neutron beam research. The OPAL design includes purpose-built facilities for instrumental neutron activation analysis (INAA) and delayed neutron activation analysis (DNAA). For INAA there is a short residence time facility in a neutron flux of around 2·1013 cm−2·s−1 and a number of long residence time facilities providing fluxes from 3·1012 to 1·1014 cm−2·s–1. The flux at the short residence time DNAA facility is around 6·1012 cm−2·s−1. The main focus for INAA at OPAL is the research community, meeting the needs of a wide range of disciplines, including mineral processing, geology, the environment, health and archaeology. Both the relative (comparator) method and the k 0-method of standardization for INAA are being established in OPAL. A description of progress, plans and capabilities are presented.
A new version of TLC with a closed adsorbent layer and an electroosmotic pump has been investigated. The electroosmotic pump was placed on the front of the plate and used to induce rapid movement of the mobile phase. Experimental evaluation of the new version of forced-flow TLC suggests further elaboration of this version of TLC is appropriate.
Thermal analyis of hexadecyltrimethylammonium–montmorillonites
Part 1. Thermogravimetry, carbon and hydrogen analysis and thermo-IR spectroscopy analysis
. Help from Nadezhda Bukhanovsky (The Volcani Center, Agricultural Research Organization, Israel) in preparing thermally treated organoclay samples is appreciated. This research was supported by a grant from the Israeli Science Foundation (No 919/08) and
