Abstract: A process for reducing residual tensile stresses in high nickel-chromium alloy nozzle safe-end welds of pressurized water reactor nuclear pressure vessels such as are found at the reactor vessel inlet and outlet nozzles and the pressurizes surge, spray, safety and relief nozzles. The process involves the application of radial compression on the outside surface of the nozzle's safe-end and/or connecting coolant piping, to reduce the outside diameter at the mid-point of the piping element to which the load is applied to between about 0.2% and about 3%. The radially compressive load applied by this process is imparted using a mechanical device that can be employed at the vessel manufacturer's facility or at a nuclear power plant after welding of the nozzle safe-end to the coolant piping or before either after plant commissioning of operation.

Abstract: According to the invention there is provided a radiation source for use in endovascular radiation treatment which comprises one or more and preferably at least two treating elements or seeds comprising a radiation emitting element and means for containment of said radiation emitting element which radiation source is characterized in that said seeds comprised in an elongated container having at least one deflection site. There is further provided an apparatus for endovascular radiation treatment comprising an elongated catheter, optionally a guide wire and the radiation source as defined above.

Abstract: The invention relates to a process for producing a radiation flood source by printing a radioactive solution, and a radioactive printing solution used in this method. The present invention also relates to a flood source for quality testing and assurance of radiation detecting devices obtained by said process.

Abstract: Packaging system for radioactive materials having: a vial with closure for accommodating the radioactive material; a first casing to be opened, enclosing the vial, and essentially made from a transparent material, which has a capture cross-section selected for shielding at least a part of the emitted radiation; and a second casing to be opened, made from a material with a high capture cross-section (Z) for essentially shielding the remaining radiation, the second casing enclosing the first casing.

Abstract: A method and an apparatus raise samples of liquid such as water from a low level to a higher level, for example for obtaining a sample of groundwater from a borehole. The apparatus comprises a pair of tubes (14 and 16) extending alongside each other, which are introduced into the borehole, linked by a connector (20) at their lower end, a valve (22) communicating between the inside and outside of one of the tubes (16) near its lower end, and a pig (46) insertable into the tube (16). By adjusting the pressure in each tube at their upper end, the pig (46) can be moved from one end to the other of the apparatus (10) and used to transfer samples of water.

Abstract: The alignment of railway tracks may be monitored using an accelerometer (36) mounted on a bogie (24) of a railway vehicle to detect lateral accelerations, and a displacement transducer (38) to monitor the lateral displacements of a wheelset (27) relative to the bogie. The acceleration signals are digitised, and processed corresponding to double integration, so as to deduce the lateral displacements of the bogie, and in conjunction with the signals from the displacement transducer hence to determine the effective lateral displacements of the track. This can provide a more useful indication of the lateral positions of the rails than measurements of the gauge faces. Such equipment (16) may be installed in a service vehicle, and operate automatically, downloading resulting data to a remote base station at regular intervals.

Abstract: In a railway line, thermally-induced stresses are a factor for both rail breaks and rail buckling. These stresses are in the longitudinal direction. A nondestructive measuring technique enables the residual stress in a rail to be determined, and hence the thermally-induced stress. An electromagnetic probe is used to measure the stresses in the rail web in the vertical direction, and in the direction parallel to the longitudinal axis. The residual stress in the longitudinal direction can be deduced from the measured stress in the vertical direction; hence the thermally-induced stress can be determined.

Abstract: Impedance of an unknown load is determined by applying a reference signal from a signal generator through a multi-position switch to the unknown load, a first known calibration impedance, and second known impedance, which can be an open circuit, while measuring the complex voltage developed across each load. The source impedance of the signal generator can be determined from the measurements of the known impedances, and then the unknown impedance can be calculated, using complex voltage divider relationships. The reference signal is applied at one or more frequencies of interest and is preferably a sine wave. Impedance is measured accurately at all frequencies and the limitations of prior art frequency dependant directional-coupler methods of impedance measurement are overcome. The impedance measurement device can be incorporated into a handheld device with a keypad and display.

Abstract: The onset of rolling contact fatigue in an object may be detected by measuring the residual stresses in the surface of the object, and monitoring changes in their magnitude or their direction. The values of residual stresses in the surface are those averaged over a depth that may be in the range say 0.1 mm to 8.0 mm, for example about 2.5 mm. For ferromagnetic objects such as rails, the method may utilize an electromagnetic probe. Prior to rolling contact fatigue the surface stresses are compressive, and the onset of rolling contact fatigue may be characterized by a marked decrease of the stress in the generally transverse direction.

Abstract: A gamma radiation source comprising selenium-75 or a precursor therefore, wherein the selenium is provided in the form of one or more thermally stable compounds, alloys, or mixed metal phases.

Abstract: The variation in properties of a ferromagnetic material with depth below the surface is assessed in a nondestructive fashion using a probe that incorporates an electromagnet. An alternating magnetic field is generated in the electromagnet and so in the object, and a magnetic sensor is arranged to sense a magnetic field due to the electromagnet. Signals from the magnetic sensor are analysed into an in-phase component and a quadrature component, and these are mapped directly into material property and lift-off components; this analysis enables accurate measurements of material property (such as stress) to be distinguished from changes in lift-off. The measurements are repeated for at least five different frequencies of the alternating magnetic field; and the measurements at different frequencies are deconvolved assuming a functional form for the variation of material property with depth, the function having no more than five unknown constants. The stress at depths for example in the range 0.5 mm to 5.

Abstract: A radiographic camera has a housing, having first and second ends, that encloses a conduit having a radiographic source. The conduit is in communication with a lock assembly at the back end of the camera and to a connector assembly at the front end of the camera. The radiographic camera can be held within a jacket that has a handle with a reinforcement structure. The conduit is surrounded by a radiation shield that has a shield end attached to an endplate having a port outlet. The connector assembly features a front plate having a hole aligned with the port outlet on the endplate. The front plate features an internal surface to which a rotor is rotatably attached. The rotor provides a first rotor hole that is aligned with the port outlet and includes a port shield for blocking the first rotor hole, and a second rotor hole that is alignable with the port outlet. The rotor may be rotated so that either the first or second rotor hole is aligned with the port outlet to shield or expose the source.

Abstract: A break in a rail, where two rails (12, 13) extend parallel to each other along a railway line, is detected by connecting the two rails together electrically with two electrical connections (16, 18) at opposite ends of a section of the line, causing electrical currents to flow in parallel along the two rails from a current source (22), and detecting (24) the currents flowing in each of the rails (12, 13). From the two values of current one can find it there is a break in one of the rails (12, 13). The currents may be measured in one of the connections (16). The current source (22) may be DC or low frequency AC, or a coded pulse sequence.

Abstract: A flexible, radioactive radiation source in the form of a wire or other elongated shape, comprising a matrix of a ductile and/or plastic binder material and a radioactive and/or activatable material. The elastic binder material is preferably a metal, a metal alloy, or a radiation resistant plastic material, or a mixture of these, and the radioactive material, or activatable material once activated, is a &bgr;-emitter, a &ggr;-emitter, or an x-ray emitter. The source may be contained, for example, within a tube, capsule, or coating. The flexible, radioactive radiation source may be used for intravascular radiation treatment of cancer, tumor, non-malignant cell growth, scar tissue, or to prevent restenosis.

Abstract: A radioactive static eliminator gun has a cartridge (7) connected to a high pressure air supply (8). Within the cartridge (7) a radioactive source (6) which generates alpha particles is located coaxially along the central longituidinal axis. The alpha particles collide with the high pressure air stream passing through the cartridge thereby generating ions. With this arrangement the ion concentration is greatest at the core of the air stream which ensures that the greatest number of ions is delivered to the surface requiring static elimination. The radioactive static eliminator gun provides improved efficiency in removing static an is particularly suited to use in paint spraying of metal surfaces where the electrostatic forces at the surface of the metal may not be strong enough to attract ions in the air stream emerging from the gun.

Abstract: Fluids in a vessel are subjected to a high ultrasonic intensity, by means of several ultrasonic transducers attached to a wall of the vessel, each transducer (14) radiating no more than 3 W/cm2, the transducers being sufficiently close to each other, and the number of transducers being sufficiently high, that the power dissipation within the vessel is at least 25 W/litre. The number of transducers, the power of the transducers, and the volume of the vessel may be such that the power density is between 40 and 80 W/litre. The vessel may be double walled, and the space between the two walls be filled by a low attenuation buffer liquid (36) whose cavitation threshold is above that of the liquid being treated.

Abstract: A radioactive or activatable seed for use in brachytherapy, and a method for producing the seed, the seed comprising a closed and self-supported casing consisting of (a) a radioactive or activatable metallic material selected from the group consisting of a metal, an alloy and a metal composite or mixtures thereof, optionally in combination with (b) a non-radioactive, non-activatable metallic material; wherein (a) comprises a radioactive nuclide selected from the group consisting of Pd-103, Tm-170, Sr-90, Y-90, Yb-169, P-32, Ge-71, Se-75, Cl-36, Ta-182, Tl-204, Re-188, W-188, Ce-144, Pr-144, Sn-123, Ru-106, Rh-106 and mixtures thereof, and/or an activatable precursor nuclide thereof selected from the group consisting of Pd-102, Rh-103, Tm-169, Y-89, Yb-168, P-31, Ge-70, Se-74, Cl-35, Ta-181, Tl-203, W-186, Sn-122 and mixtures thereof, excluding metallic Pd with natural abundance of Pd-102.

Abstract: A random number generator has a random event source, a random event detector, and a counter for counting the number of pulses generated by the detector for a predetermined length of time. Two memories are provided in which are stored successive sets of counts and a controller compares the sets to determine whether one or both of the sets counted one or more events. Where both sets have one or more events, no output is generated, and where both sets have no events, no output is generated. However, where one set has one or more events and the other set has no events, then a binary number is output in dependence on which of the two sets recorded events. This random number generator has the advantage that the probability of counting no events does not have to be exactly equal to the probability of counting one or more events while still ensuring truly random results.

Abstract: For monitoring railway tracks on a frequent basis, instrumentation packages are installed in service vehicles (18), for example in passenger carriages. The instrumentation package (16) comprises sensors (35, 36, 42) mounted on a bogie (24) of the vehicle (18), which provide data to a computer (40). The computer (40) processes the data to characterise the track quality, and stores the results tagged with positional information. At intervals these stored results are automatically transferred by radio to a remote base station (12). An operator at the base station can monitor the track quality daily, and hence advise on cost-effective maintenance schedules.

Abstract: If the wheel/rail adhesion for a railway vehicle is insufficient then the wheels may slip when braking. If slipping is detected, a control system may reduce the brake pressure to permit a controlled level of slip and so to optimize the braking force for the available adhesion. By determining the pressure supplied to the brake cylinder, a signal may be obtained which indicates the value of the adhesion. Alternatively the adhesion may be monitored by detecting any discrepancy between the braking deceleration demanded by the driver and the observed deceleration. The adhesion signal may activate a warning. It may also be used to adjust the rate at which sand is supplied by a sander to the wheel/rail interface. The rate at which sand is supplied may also be adjusted in accordance with other parameters such as the train speed.