Abstract: The method and apparatus provide a technique for monitoring radioactive source emissions by detecting photons arising from scintillation within the environment of the area or item under monitoring, caused by the passage of emissions from the radioactive source. The technique includes options for excluding ambient light photons through suitable shielding and/or selective in detection of photons from only certain wavelengths or wavebands. The technique enables levels/types and locations of emissions sources to be determined. The technique is applicable to environmental monitoring instruments, scanning instruments and other types.

Abstract: A method of investigating the response of an instrument to gamma emissions using a source package includes providing a source package on one side of a collimator including an aperture and a detector on the other side of the collimator relative to the source package, the collimator and detector positions defining an operating axis for the instrument. The position of the source package is then moved relative to the collimator. The response of the detector is measured for two or more of these different positions of the source package. The aperture in the collimator has a first dimension measured in a first direction perpendicular to the operating axis. The source package includes one or more individual gamma emitting sources provided in a container. During use, the individual source(s) have an overall extent in the first direction, the overall extent, during at least 10 seconds of use, being two or more times the first dimension of the collimator in that first direction.

Abstract: The apparatus and method provide a technique for significantly reducing capacitance effects in detector electrodes arising due to movement of the instrument relative to the item/location being monitored in ion detection based techniques. The capacitance variations are rendered less significant by placing an electrically conducting element between the detector electrodes and the monitored location/item. Improved sensitivity and reduced noise signals arise as a result. The technique also provides apparatus and method suitable for monitoring elongate items which are unsuited to complete enclosure in one go within a chamber. The items are monitored part by part as the pass through the instrument, so increasing the range of items or locations which can be successfully monitored.

Abstract: The invention provides a technique for correcting gamma ray intensities detected to account for variation in attenuation effects with energy. The corrected intensity values enable more accurate isotopic analysis to be conducted and render such techniques applicable to low level emission cases. The technique is particularly useful in investigate waste materials with a gamma emitting content which needs to be determined. The attenuation is corrected for using a bi-modal function to account for the attenuation effects arising from low and high atomic mass components of the material in which the emitters are present.

Abstract: A spent fuel reprocessing method including the steps of partitioning U and Pu(III) in a solvent by solvent extraction and subsequently polishing the solvent in a neptunium rejection operation for removing Np therefrom. The solvent obtained from the neptunium rejection operation (the polished solvent or NpA solvent product) is then recycled to a U/Pu partitioning operation. The method enables a reduction in solvent feed and solvent effluent volumes.

Abstract: Apparatus and methods for measuring activity of radioactivity at a source location within an environment provided. The method in particular includes measuring emissions using an instrument as a measurement location, which instrument includes a detector, the instrument considering a detector field of view of the environment, which field of view includes a source location and providing an indication of detected emissions for that field of view, correcting the detected emissions to give emitted emissions in respect of that field of view, the correction being achieved by using a correction factor specific for that field of view, the correction factor accounting for one or more field of view format and/or the attenuation between the source location and the detector and/or the distance between the source location and the detector, the emitted emissions being indicative of the activity.

Abstract: Metal ions are removed from solid surfaces which may be contaminated with one or more radionuclides by contacting the solid surfaces with the supercritical fluid, as, for instance, carbon dioxide containing both an acidic ligand and organic amine. The metal ions are extracted from the solid surface and the extract is separated from the solid surface.

Abstract: A fuel cell system includes one or more fuel cells, one or more of the fuel cells including an electrolyte material, a first electrode and first electrical conductor on one side of the electrolyte material and a second electrode and second electrical conductor on the other side of the electrolyte material, the electrolyte material of a fuel cell defining a fuel space, the fuel space being connected to a fuel supply, within the system, the one or more fuel cells being provided within an oxidant space, the oxidant space being connected to an oxidant supply, the oxidant space and one or more fuel spaces being provided within a gas impermeable barrier, the gas impermeable barrier defining a heating space outside of the gas impermeable barrier, a source of heat being provided in the heating space.

Abstract: A method and apparatus are provided for determining radiation dose rates at selected locations within an environment. Incident gamma ray energy and count rate are measured at one or more measured locations within the environment to obtain a measured spectrum for those measured locations. The spatial position of the measured locations is also measured. An emitted spectrum is then determined for the measured locations based on the measured spectrum. The emitted spectrum may then be used to determine the dose rate at one or more selected locations (which may be different than the measured locations). In this way the invention provides an accurate solution for the dose rate at any point of interest within the environment based on the measured count and incident energies.

Abstract: According to the present invention there is provided a container for the storage and transport of nuclear fuel elements comprising a plurality of elongate compartments for receiving the nuclear fuel elements, the compartments being defined by a first set of plates intersecting with a second set of plates, the first set of plates extending perpendicularly with respect to the second set of plates to define compartments having a rectangular cross section, wherein the plates include an interlocking joint, the interlocking joint comprising at least one projection provided on one plate and a recess formed in the other plate, and wherein a retaining portion is provided in the recess for engagement by the projection so as to interlock the plates.

Abstract: Apparatus suitable for vitrifying nuclear waste comprises a tunable microwave cavity connected by a first wave guide to a source of microwave energy; cooling coils for cooling the exterior of the cavity; a hopper for loading particulate fusible material to the interior of the cavity; within the cavity a crucible made of melted and re-solidified fusible particulate material; an exit-chamber connected by a second waveguide to a second microwave source; and a pipe for supplying argon gas to the exit chamber so that a plasma torch can be generated. The separating of the crucible form the cavity walls by unmelted material gives significant advantages in case of cleaning and reduced energy consumption.

Abstract: A method of investigating the response of an instrument to gamma emissions using a source package includes providing a source package on one side of a collimator including an aperture and a detector on the other side of the collimator relative to the source package, the collimator and detector positions defining an operating axis for the instrument. The position of the source package is then moved relative to the collimator. The response of the detector is measured for two or more of these different positions of the source package. The aperture in the collimator has a first dimension measured in a first direction perpendicular to the operating axis. The source package includes one or more individual gamma emitting sources provided in a container. During use, the individual source(s) have an overall extent in the first direction, the overall extent, during at least 10 seconds of use, being two or more times the first dimension of the collimator in that first direction.

Abstract: Processes for the treatment of solutions used for the decontamination of radioactively contaminated surfaces wherein the solution contains radioactive metal ions and organic complexing agents are described herein. The processes include treating the solutions with a reagent suitable for the destruction of the complexing agent and contains a metal capable of existing in more than one oxidation state, and raising the pH of the resultant solution to a level at which the metal of the reagent precipitates or flocs out of the solution. Processes in which the contaminated solutions are treated with electromagnetic radiation, treated with UV or visible radiation, and treated at an ambient temperature are also described herein.

Abstract: A method of reacting an aromatic compound with an immiscible reacting agent involves the passage of the reactant along a flow path having a width of from 10 to 1000 &mgr;m in such a way that essentially laminar flow of the reactant takes place. Reaction takes place across the interface between the phases and without substantial mixing of the unreacted aromatic compound and the reacting agents. A preferred reaction is the nitration reaction which involves reaction of a first phase comprising an organic aromatic compound on a second phase comprising a nitrating agent to produce two new phases of different chemical composition to the starting phases. The aqueous and organic phases produced are ideally separated such that minimum contamination occurs. Other examples of this type of reaction include the sulphonation of an aromatic compound using sulphuric acid as the sulphonating agent. The aromatic compound is slowly consumed in the reaction yielding a single aqueous phase.

Abstract: The invention provides apparatus and methods which facilitate movement of an instrument relative to an item or location being monitored and/or the item or location relative to the instrument, whilst successfully excluding extraneous ions from the detection location. Thus, ions generated by emissions from the item or location can successfully be monitored during movement. The technique employs sealing to exclude such ions, for instance, through an electro-field which attracts and discharges the ions prior to their entering the detecting location and/or using a magnetic field configured to repel the ions away from the detecting location.

Abstract: The invention provides a polynuclear compound comprising two or more metal-hapto-3-capped nidocarborane groups. Also provided is the use of such a compound as a catalyst in a chemical reaction such as a hydrogenation or oxidation reaction.

Abstract: The present invention relates to removal of organic pollutants from aqueous effluent streams. The present invention provides a method of destructively oxidising an organic compound present in an aqueous solution, the method comprising oxidising the organic compound in the presence of a catalyst which contains uranium. The catalyst may comprise a uranium oxide. The reaction may be carried out at low temperature, e.g. ambient temperature. The method may be used to treat aqueous effluent streams to remove organic compounds from the stream.

Abstract: The apparatus and method provide a technique for significantly reducing capacitance effects in detector electrodes arising due to movement of the instrument relative to the item/location being monitored in ion detection based techniques. The capacitance variations are rendered less significant by placing an electrically conducting element between the detector electrodes and the monitored location/item. Improved sensitivity and reduced noise signals arise as a result. The technique also provides apparatus and method suitable for monitoring elongate items which are unsuited to complete enclosure in one go within a chamber. The items are monitored part by part as the pass through the instrument, so increasing the range of items or locations which can be successfully monitored.

Abstract: The invention considers the frequency distributions of singles, doubles and triple neutron emission events from a sample under assay. The count rates are equated to mathematical functions related to the spontaneous fission rate, self-induced fission rate, detection efficiency and &agr;,n rate with probability distribution assigned to each of those factors, the value of the product of all the probability distributions being increased to give an optimised solution and so provide a value of the spontaneous fission rate which is linked to the mass of the neutron source. The technique aims to provide increased accuracy and certainty compared with neutron coincidence counting based techniques.

Abstract: The contents of a container 1 are non-intrusively monitored by probing the container with an ultrasonic signal, and measuring changes in the ultrasound signature of the received signal after the signal has passed through the contents of the container.