Abstract: A procedure having the steps of: weighing a known volume container (4) in order to determine the average density of its content; positioning the container (4) upon a support (1); positioning on respective supports (5) two &ggr; ray detectors (6) set symmetrically to the container; causing vertical movement (F2) of the container, so that its main longitudinal axis coincides with the axis (I—I) connecting the two detectors (6); causing movement (F1) of the two detectors upon their respective supports in order to stop them in a first tentative position; causing movement (F1) of the two detectors in order to stop them in a second symmetrical position that proves to be suited to providing countings of the radiations that are an optimum; measuring the &ggr; radiation and calculating the geometric mean of the counting ratios of the two detectors, such a geometric mean being linked to the intensity (I) of the corresponding &ggr; radiation by a formula (1-2) from which the radiation intensity is calculated.

Abstract: The method and system of discretisation according to the present invention addresses the problems of the different types of prior art grids. In particular, a problem for which a solution is found is that of the rigidity of the spatial distribution of the cells in a structured grid, implying undesired local thickening of cells, thus causing considerable waste in calculation time and memory. A method consistent with the present invention creates a semistructured grid. Further, a numerical solver needs to be adapted to handle the semistructured grid.

Abstract: A probe is conveniently positioned in a flowing aqueous medium. The probe is formed by two electrodes of notable difference in nobility connected by an electric resistance high enough to ensure that the voltage difference between its terminals is sufficiently great to permit accurate and simultaneous determinations of the growth of biofouling and the chlorine concentration by measuring the potential difference variations between the terminals.

Abstract: A nozzle for the injection of solid fuel in dust form into a combustion chamber, to be installed in correspondence with the outlet of a burner coaxially to the longitudinal axis of the burner, comprising a stationary annular part divided into coal ducts of a circumferential width that decreases towards outlet section to form coal-dust-rich air streams, a central duct for a coal-dust-poor air stream sideways delimited by the coal ducts and having an outlet end, a central member that is axially mobile within the central duct, for varying the cross section of a central passage delimited by the stationary annular part at the outlet end. Air ducts for the coal-dust-poor air stream are formed between each pair of adjacent coal ducts in the stationary annular part communicating with the central duct and having a circumferential width increasing toward the outlet end.

Abstract: A low NOx burner comprising ducts for the primary (6), secondary (7) and tertiary air (14), arranged coaxially around its longitudinal axis, for supplying of the primary, secondary and tertiary air, respectively, to a combustion chamber (3), means for accumulation of the air (5), means to give vorticity to the primary, secondary and tertiary air (11, 15, 27) installed in the respective ducts, means for supply of fuel (23, 32, 43) arranged within said ducts to inject the fuel into said combustion chamber. The axial swirler for the secondary air (11) is formed by a plurality of blades each of which is made up of a stationary part (11a) and a mobile part (11b) connected to actuator means capable of moving it in an angular direction to give an air outlet angle of between 30.degree. and 60.degree.. The axial swirler for the tertiary air is conical in shape and has fixed blades. On the tertiary air duct a passage (16) is formed for supply of secondary and tertiary air.

Abstract: The granulometer uses a measuring laser beam (9) to illuminate particulate and, through the measure of the distribution of the light diffused by the examined particulate and gathered by a collecting lens (11), measures the concentration of particulate in the fluid in low concentration standards, the laser beam (9) being a converging one focused on a laser opaque shell (12) that partly covers the same lens.

Abstract: A system (10) for dissipating heat from the interior space (50) of a containment structure (3, 6) for a nuclear reactor (2), for an indefinite time period, comprises a first heat exchanger (15, 15') outside said containment structure (3, 6) which is submerged vertically in a pool (11) associated with the exterior of the top wall (4, 7) of the structure (3, 6), and a second heat exchanger (25) placed in the interior space (50), said first and second heat exchangers (15, 25) being fluid connected to each other in a closed loop circuit (28) with piping (23, 24) containing a thermal carrier fluid. Said pool (11 is provided with a covering (90) defining a first duct (12) in communication with an outside air intake, and a second duct (13) communication with a chimney (14), the interconnection of said ducts (12, 13) being inhibited by the water present in the pool (11) when filled to a predetermined level (9).

Abstract: This invention relates to a method for protecting the integrity of the reactor container base in nuclear power plants, and a device for implementing the method.The proposed method and device are applicable to all reactor types (PWR or pressurized water reactor, BWR or boiling water reactor, HWR or heavy water reactor, etc.) and to all types of containing system (large dry type, steam suppression type, condensation on ice type, subatmospheric type etc.), although for simplicity the present text will describe only their application to a PWR with a steam suppression and large dry containing system.

Abstract: A high-frequency, switching-type protected power supply, in particular for electrostatic precipitators, characterized by the fact of comprising a regulated power supply system for providing direct voltage adjusted at a desired value and at a relatively low voltage; a high efficiency, high-frequency switching system driving a step-up voltage transformer until reaching substantially the desired operating voltage of the precipitator, the secondary circuit of which directly feeds, by means of a rectifier group, the electrostatic precipitator. The high-frequency switching system is controlled in its operation in response to abnormalities indicating an incipient discharge between the electrodes of the electrostatic precipitator to modify the operating conditions in order to avoid the formation of disruptive discharges with consequent possible damage to the entire power supply and/or electrostatic precipitator.