[en] In 1957 the Windscale-1 reactor (UK), devoted to military nuclear weapon research, was destroyed by fire during an operation of Wigner energy evacuation from the graphite core. This accident was the most serious known before the TMI event in 1979 and the radioactive releases in the atmosphere were highly greater. This paper gives a general description of the Windscale reactors principle with some details about the Wigner effect and the graphite annealing procedure developed to counterbalance this effect. Then, it describes the accident itself and the emergency procedure followed to extinguish the fire. Finally, as a consequence of the accident, several analyses and inquiries were carried out to study the details of the accident and to determine its environmental impact. These studies have led to the creation of the U.K. Nuclear Inspectorate. (J.S). 4 refs

[en] The design of a cylindrically shaped scintillation camera for volume imaging of positron emitters is discussed. The design is based on the detector concepts developed for a single ring scintillation camera, i.e., the Massachusetts General Hospital analog ring camera. Detector characteristics derived from both computer modeling and measurements are presented. 10 references, 8 figures

[en] A detector employing a pseudo-continuous ring of BGO and analog type position sensing has been constructed. It is fabricated using 360 2 x 3 x 0.4 cm BGO detector elements, a light guide 1 x 1.6 x 51 cm ID and 90 2cm diameter PM tubes. The position of a scintillation event is identified using logic based on a maximum likelihood estimator. A stationary high spatial resolution high detection efficiency tomograph is achieved using this approach

[en] Most hydrocarbon producing sedimentary basins as well as many non-petroliferous sedimentary basins will be potential sites for carbon dioxide (CO₂) storage. The degree to which geological storage of CO₂ will be implemented in the future will depend on the geographical and technical relationships between emission sites and storage locations, and the economic drivers that affect the implementation for each source to sink match. Despite many attempts to estimate the world's total storage potential for CO₂ in terms of capacity, there are inherent uncertainties associated with delivering such an output. As such, maps have yet to be published on the global distribution of the most likely areas for CO₂ storage. However, it is possible to make a preliminary estimate of where the world's CO₂ storage potential might be located by comparing detailed assessments that have been done for a few locations with geological data on hydrocarbon potential. The acquired information can provide insight as to which regions will be likely to provide the most technically and economically viable CO₂ storage sites by overlaying this geological data with the locations of the world's current large stationary energy CO₂ emissions point sources. This paper reviewed datasets from the Australian and United States Geological Surveys in terms of matching CO₂ sources with suitable geological provinces. Some regions have significant prospectivity with good source to sink matches, while others may require longer transport distances between sources and sinks, at higher costs. The latter may need to plan for the future and reduce costs by locating new emission sites closer to storage sites, or by potentially considering hub or industrial ecosystem approaches. It was suggested that access to the development of centralized storage locations for a region could become a critical component to any future involving large scale implementation of geological storage of CO₂ technology. 8 refs., 6 figs

[en] The design of a cylindrically shaped scintillation camera for volume imaging of positron emitters is discussed. The design is based on the detector concepts developed for a single ring scintillation camera, i.e., the Massachusetts General Hospital analog ring camera. Detector characteristics derived from both computer modeling and measurements are presented. The detector's expected characteristics have been summarized. The results show that both high sensitivity and resolution are possible. The noise contribution due to prompt scattered events will be small relative to unscattered signal. The results indicate practical detector designs. Both BGO and GSO would be useful detector materials

[en] Monte-Carlo methods have been applied to the design of a detector suitable for use in a SPECT cylindrically shaped scintillation camera. Included in the study are the calculated detection characteristics of two scintillator materials and the optical performance of several geometric configurations. Results include maps of the light distribution for several rectangular crystal-light guide combinations, a comparison of various approaches to specifying the optical properties of detector surfaces, and estimates of relative light output for various geometries

[en] The availability of BGO as a detector material for PET imaging allows a factor of three improvement in both sensitivity and spatial resolution over NaI detector designs. The concept of a scintillation camera ring detector with analog position detection logic offers an opportunity to overcome many of the problems of present designs and to achieve both high sensitivity and resolution with a stationary instrument. Several different position sensitivie detector designs have been evaluated by computer simulation. Detection efficiency, Compton scattering effects, optics, position sensing and reconstruction artifacts have been studied. As a result of these studies, we have developed a position sensitive detector design consisting of an array of very thin crystals viewed through a light guide by an array of PM tubes

[en] A detector employing a pseudo-continuous ring of bismuth germanate crystals and analog type position sensing has been constructed. It is fabricated using 360 2 x 3 x 0.4cm BGO detector elements, a light guide 1 x 1.6 x 51cm ID and 90 2cm diameter PM tubes. The position of a scintillation event is identified using logic based on a maximum likelihood estimator. A stationary high spatial resolution high detection efficiency tomograph is achieved using this approach

[en] Technetium is currently the most widely used radionuclide in diagnostic nuclear medicine. In developing new ligands which may provide improved properties for in vivo diagnostic imaging, a new N₂S₂ ligand with uneven N-H groups was prepared and the radiochemistry of the TcO(III) complexes were investigated. This new ligand system has an unique feature in that the neutral and lipid-soluble complex can be readily and reversible oxidized to a different neutral complex. The corresponding ReO(III) complexes are being prepared and investigated. The biological distribution in rats displayed high initial uptake in the brain

[en] A single ring PET camera has been constructed to demonstrate the use of one dimensional scintillation camera techniques in positron tomographic design. A pseudo-continuous BGO detector is used. The detector is 46 cm ID, 52 cm OD, 2 cm wide and is made using 360 elements. A narrow light guide and 90 PM Tubes are used for the readout. The position of coincident events are found using unique scintillation camera logic