Abstract: Ceramic pellets, which may have, or not, nuclear fuel materials embedded therein, are formed by first preparing a gel by precipitation of metallic salts from solutions of their compounds at a concentration of at least 10 grams per liter, said solutions being added dropwise to a coagulation bath which contains, for example, ammonium or sodium hydroxide, whereafter the precipitated gel are fired, in one or two stages, to precondition them prior to the compaction to form the final pellets which are subsequently sintered at an appropriate temperature.

Abstract: A method and apparatus for the dynamic balancing of a rotating body, wherein driving signals are obtained through processing of signals detected by sensors as a function of the vibrations of the rotating body. A device for varying the mass of the body is maintained in synchronous rotation with respect to the rotating body itself; the driving signals are used to control the phase of rotation phase of the mass varying device with respect to the rotation phase of the rotating body in order to actuate the device.

Abstract: A steam-generator, particularly to be used in nuclear power stations, with easily detachable parts, especially for the substitution of the tube bundle or a part thereof, comprises five separate portions fastened one to another by means of connections or merely abutting with intermediate sealings. In a substantially cylindrical vessel or housing, defined at the lower end by a distributor chest and at the upper end by a top cover, there are disposed, respectively from the bottom upwards: a heat-exchanger with a bundle of tubes on a common tubeplate, a steam-separator, and a drier unit, which are so supported within the vessel to be readily separable from one another and the vessel by relative vertical displacement therebetween with no interference with the inner wall of the vessel itself. In two alternative embodiments, the distributor chest, i.e. the manifold of the heat-carrier primary medium, is integral either to the heat-exchanger or to the housing.

Abstract: An apparatus for the dosimetry of fast neutrons comprises one or more personal detectors in the form of test tubes made of transparent insulating material and a tank with a holder for suspending said test tubes in an upright position within the tank all at the same level. After exposure of said test tubes to radiation of fast neutrons, they are placed in the tank and filled with an electrolyte into which an electrode is immersed. The tank also is filled with the same liquid up to the same level as the test tubes and an electrode is immersed also into the liquid within the tank. The electrodes within the test tubes are collectively connected to one terminal of a high voltage alternating or pulsating function generator of which the other terminal connects with the electrode within the tank. The tracks of damage by said neutrons are thus developed to the required extent and subsequently inspected for evaluating the amount of the traces of damage.Different forms of the test tubes are disclosed.

Abstract: A feeder circuit for the rapid shutdown for safety devices in nuclear reactors comprising a controllable rectifier providing a d.c. output from an a.c. input of network frequency; a number of inverters to invert said d.c. output to an alternating current at a frequency higher than that of the network and to elevate the voltage thereof; and an adder to add the currents exiting from such inverters and rectify the current sum. The exit voltages of the inverters are dephased with respect to each other by 180/n, n being the number of the inverters in the feeder.

Abstract: A solar electric generator comprises a concentrator of the sun radiation consisting of a system of lenses which focalize the sun radiation into a vessel of which the bottom--that is the wall opposite to the radiation inlet--comprises a thermoionic stage, that is a high temperature electron emitter and a collector which are separated by a low pressure gaseous mixture. At thermal contact with the receiver of the thermoionic stage, a thermoelectric stage is provided, that is a plurality of couples of semiconductor material bars, one of the P type and the other of the N type. One of the ends of each couple is in contact with the collector of the thermoionic stage and the other end is in contact with a heat draining means for transferring the heat from the thermoelectric stage to the atmosphere.The electrical output from said two stages is taken out of the generator and suitably transformed to meet the user's requirement.

Abstract: An apparatus for the electrochemical development of damage tracks in dielectric transparent material sheets comprises a first elongated prismatic vessel within which an axial cavity is provided extending over most of the prism length and communicating with a circular transverse cavity which extends from an opening on one face of the prism thereinto for less than one half of the prism thickness; said longitudinal and transverse cavities being so dimensioned that when enough liquid is supplied thereinto for abundantly flooding the transverse cavity with the vessel upright and the transverse cavity lowermost, the same liquid will not reach the bottom of the transverse cavity when the vessel is set horizontally with the transverse cavity opening up.

Abstract: A hollow disk is carried on a wheeled frame or trolley which is moved over the surface being examined. The hollow disk is slidable perpendicularly to its surface within certain limits. The disk is double walled and a certain degree of vacuum is maintained in the space between the walls during the apparatus operation.The disk wall facing the surface being examined is provided with holes and on the outer surface of the same wall a disk of para rubber is spread which is provided with the same array of holes as the hollow disk wall; the holes of the disk wall being aligned with the holes of the para rubber disk.For each sampling operation a fresh smear disk is applied on the para rubber layer which adheres thereon by the action of the dynamic vacuum existing within the hollow disk. The hollow disk is biased outwards of the frame by a calibrated spring inserted between the disk and the frame structure.

Abstract: A method and apparatus for the dynamic balancing of a centrifuge during rotation in which vibration, amplitude, frequency and phrase are sensed within at least two planes and vibration signals produced. The vibration signals are then processed and converted into piloting signals which are used to vary the mass of the centrifuge.

Abstract: A simulator of the aerosol particle disposition in the human respiratory tract comprises a duct along which the following devices are included in the order: an air humidifier comprising a trunk with longitudinal partitions of blotted paper soaked with water, a cyclone, a vibrated bubbler comprising a cylindrical vertical vessel partially filled with water and provided with a pierced horizontal partition at a level lower than the water level within said vessel, a vacuum pump, a flowmeter. The air to be tested is passed through said duct for a predetermined time period and at a predetermined flow rate. Subsequent to said passage, physical, chemical, toxicological, radiometric analyses are carried out either on the water itself or on the solid therein contained or on both.

Abstract: A method and an apparatus for storing in a digital memory the information obtained by comparing by means of a logical operator any information previously stored in said memory with the information originating from a television camera. Specifically a method and an apparatus for storing in a digital memory the plane projection of a trace left by a particle on a transparent medium or the plane projection of the trajectory of an object moving through the space along with the stationary objects with respect to which said object is moving or without said stationary objects.

Abstract: A coupling is provided for holding and releasing a safety and a safety-and-control rod in a nuclear reactor which coupling comprises three pairs of electromagnets, said electromagnets being arranged in a circular row and act upon a single armature attached to the rod; the electromagnets of each pair being disposed at diametrically opposed position with respect the the rod axis. The signal from each sensor of a set of multiple sensors of each relevant parameter of the reactor operation is supplied to a meter of the parameter. The signals from one of each set of meters are conjointly supplied to a logic circuit which is connected to an amplifier. Finally the power from each amplifier is separately supplied to each pair of electromagnets for controlling the hold and release of the rod. The electromagnets of the coupling are arranged in a circular row and act upon a single armature attached to the rod.