Abstract: An apparatus for inspecting fuel assemblies, includes a water container, a receptacle disposed in the container for securing bases of fuel assemblies vertically disposed in said container, a beam, a plurality of fingers engaged by the beam, measuring probes supported on the fingers, and a guiding device disposed in the container and accurately positioned relative to the receptacle for guiding the beam laterally toward the fuel assemblies for inserting the measuring probes in a given direction into spaces between cladding tubes of fuel rods of the fuel assemblies, each of the fingers being movable relative to the given insertion direction after striking an obstacle.

Abstract: To control leaks between the primary and secondary circuits of a pressurized water reactor system, a pressure equalization is brought about by shutting off the live steam line and the feedwater line connected to the secondary circuit of the steam generator and by increasing the pressure prevailing in the resulting isolated secondary circuit by the injection of gas.

Abstract: In a device for the determination of the vibrations occurring at the internals of a reactor pressure vessel, it is possible to perform the maintenance of the vibration detector located in a housing from outside the reactor pressure vessel. One end of a guide tube is fed through a pipe stub to a receptacle cone connected to the core internals. The end of the guide tube facing away from the reactor pressure vessel is cup-shaped and is sealed with a cover. A flexible rod is connected to the housing and its other end extends into the cup-shaped end of the guide tube. The flexible rod and with it the housing connected to it can be inserted into the receptacle cone, providing good transmission of the vibrations prevailing at the internals, which reach an evaluation unit through the cable.

Abstract: The invention relates to a method for testing fuel element tubes by ultrasonic energy. For testing, each tube becomes disposed in the space between a transmit transducer and a receive transducer. The echo signals falling within a predetermined time interval are evaluated. Since the distance between the transducers may vary as the transducers move through the space between fuel element tubes, the transmitted signal reaching the receive transducer without passing through the tube may be confused with the revolving echo signal. Therefore, this invention discloses an arrangement for cyclically controlling the setting of the time gate before each such tube is in position between the transducers. To this end, the ultrasonic transit time of signals between the transmit transducer and the receive transducer is measured in the gap between the last tested tube and the next to be tested tube.

Abstract: A method and apparatus is shown for establishing a predetermined concentration of gas in the reactor core coolant for a pressurized water nuclear power system. Gas is added to core coolant water in a bubble column. The gas-water mixture flows through static mixers in the column to produce the desired gas concentration in the water.

Abstract: An arrangement for the emergency cooling of the steam generator unit is of a pressurized-water nuclear power plant is disclosed. Steam is passed through a blow-off pipe (11) into a closed vessel (14) having a water space (12) and a gas space (13). A nest of heat exchanger tubes (15) extends through the water space (12) in a heat transfer relationship to cool the water space. Steam is dumped under emergency conditions into the vessel via a steam distributor nozzle (18) operatively connected at the end of the blow-off pipe and is condensed in the water space. The steam distributor nozzle is arranged essentially below and to the side of the nest of heat exchanger tubes to enhance mixing heat transfer. The resulting condensate is returned to the steam generator as condensate.

Abstract: A gas charging device injects hydrogen into the pressurized water that cools the core of a nuclear power reactor through nozzles provided in a pressurized water flow pump. Conduit and valve combinations also are provided to permit solid matter to be flushed from the nozzles.

Abstract: A process for transfer by extraction, of at least one species from a fluid phase to a first liquid phase receptive to such species, comprises intimately contacting the fluid phase with an emulsion of the first liquid phase in a second liquid phase which is permeable with respect to such species and substantially immiscible in the first liquid phase. The emulsion is stabilized by the second liquid phase containing at least one substantially insoluble particulate solid which is substantially non-reactive to constituents contained in each of such phases in an amount sufficient to form a stable emulsion. Transfer of the species is from the fluid phase through the second solids-containing liquid phase to the first liquid phase.In one embodiment, the first liquid phase is lean with respect to the species to be extracted. In another embodiment, mass action is utilized to maintain a driving force by counter-transport of a different ion.

Abstract: A hydraulic vibration brake for use in nuclear power plants is shown. The brake has a casing that a piston divides into two chambers. A storage tank in hydraulic fluid communication through appropriate conduits and valves maintains proper pressure in the system. The piston rod penetrates the casing wall and, at this penetration has a seal which arrests fluid leakage. In this manner, no hydraulic fluid is lost at the seals and sufficient fluid always is available to enable the brake to carry out its function, thereby eliminating the need for a number of burdensome inspections.

Abstract: Defects in the fuel rods of nuclear fuel assemblies are ascertained and located by ultrasonic means. The fuel assemblies are subjected to ultrasonic waves. Differences in fuel rod resonance is indicative of defective rods.

Abstract: A heat exchanger including a pressure vessel and a plurality of heat exchanger tubes extending within the vessel. A tube shroud forms an annular passage between the tubes and the pressure vessel wall. A partition wall, comprising a plurality of openings normally closed by closure means, divides the passage into a fluid inlet compartment and a fluid outlet compartment. In the event the fluid pressure differential between the inlet and outlet compartments attains a predetermined value, at least some of the closure means will open to reduce the pressure differential below the predetermined value. In one embodiment of the invention, the closure means comprise flap valves. In an alternate embodiment of the invention, rupture discs are utilized as closure means.

Abstract: A method and apparatus for locating defective fuel rods of a liquid cooled reactor core wherein the rods have end caps and defective rods collect leakage liquid from the core in the end caps, includes heating the end caps of a plurality of rods to evaporate the leakage liquid, measuring the temperatures of the end caps of the plurality of rods, and simultaneously indicating the temperature differences between defective and non-defective rods. The rods are supported in a container filled with a liquid and the upper ends of the rods and end caps are enclosed within the container in a dry heated temperature. The apparatus includes means for heating the end caps, means for measuring the temperatures and means for simultaneously indicating the temperatures and temperature differences.