Abstract: A typical embodiment of the invention provides a nuclear fuel assembly lock structure for control rod guide tubes. Illustratively, a sleeve telescopes over an end portion of a control rod guide tube which bears against an internal shoulder of the tube. The upper end of the sleeve protrudes beyond the control rod guide tube spider and is locked in place by means of a resilient cellular lattice or lock that is seated in a mating groove in the outer surface of the sleeve. A special tool is provided for disengaging the entire lock structure, washer, spider, spring and grill from the end of the fuel assembly in order to enable these components to be removed in an assembled state and subsequently replaced on the fuel assembly after inspection and repair.

Abstract: A typical embodiment of this invention provides a hydraulic mechanism for alleviating the effect of seismic forces and other stresses that are applied to a fuel assembly in a nuclear reactor. Illustratively, hollow guide posts protrude into a fuel assembly end fitting grid from biased spring pads. Plungers that move with the spring pads plug one end of each of the respective guide posts. Plates on the end fitting grid that have individual holes for fluid discharge partially plug the other ends of the respective guide posts, thereby providing a hydraulic means for absorbing the longitudinal component of seismic shocks and other anticipated forces.

Abstract: A typical embodiment of the invention provides a nuclear fuel assembly lock structure for control rod guide tubes. Illustratively, a sleeve telescopes over an end portion of a control rod guide tube which bears against an internal shoulder of the tube. The upper end of the sleeve protrudes beyond the control rod guide tube spider and is locked in place by means of a resilient cellular lattice or lock that is seated in a mating groove in the outer surface of the sleeve. A special tool is provided for disengaging the entire lock structure, washer, spider, spring and grill from the end of the fuel assembly in order to enable these components to be removed in an assembled state and subsequently replaced on the fuel assembly after inspection and repair.

Abstract: Apparatus including a portable manipulator for the axial alignment of an inspection or repair device with a selected tube in a heat exchanger. The manipulator is angularly positionable about a center toward and away from an arbitrarily chosen axis and radially toward and away from the center by remotely controlled servomotors. Incorporated in the manipulator are position feedback devices whereby the manipulator is positioned to the predetermined polar coordinates of the selected tube.

Abstract: An arrangement for inhibiting low temperature gas-side corrosion of an out of service steam generator and its heat exchange and gas clean-up adjuncts. The arrangement provides for circulating pressurized heated air through the steam generator and its adjuncts, controlling the pressurization of the air to maintain positive gas-side pressure, controlling the heating of the air to maintain gas-side surfaces above the dew point, and returning the air which has passed through the steam generator and its adjuncts to the forced draft fan to be repressurized, reheated and reintroduced into the steam generator.

Abstract: A fluidized bed boiler is equipped with a plurality of slidable sleeves circumscribing the vapor generator tubes disposed therein. By selectively extending or retracting the sleeves over the tubes, the heat transfer characteristics of the tubes exposed to the heat generated within the boiler may be altered. As a consequence, steam output quantity and quality may be easily modulated. In addition, by virtue of the design, tube cleaning may be accomplished with each adjustment pass.

Abstract: Apparatus for the in situ inspection of tubes which are submerged in a liquid such as the primary coolant of a nuclear reactor, wherein a sensor is withdrawn from a tube by a cable, including means for removing the liquid from and drying the cable and returning the liquid to the tubes thus preventing the spread of deleterious liquids to otherwise benign environments and the fouling of the drive mechanism used to control cable movements.

Abstract: Apparatus for the in situ inspection of a nuclear reactor vessel to detect the location and character of flaws in the walls of the vessel, in the welds joining the various sections of the vessel, in the welds joining attachments such as nozzles, elbows and the like to the reactor vessel and in such attachments wherein an inspection head carrying one or more ultrasonic transducers follows predetermined paths in scanning the various reactor sections, welds and attachments.

Abstract: An illustrative embodiment of the invention has a group of three concentrically disposed banks of helical steam generator tubes. Shrouds interposed between each of these three tube banks establish liquid barriers between the individual banks that prevent liquid sodium (or other shell side working fluid) from enjoying free communication throughout all of the tube banks. In this way, potentially damaging leakage between the shell side working fluid and the water within one of the tube banks can be isolated through discontinuation of the shell side working fluid and feedwater flow to the leaking bank, thereby permitting the remaining sound tube banks to continue functioning.

Abstract: A nozzle and thermal sleeve arrangement whereby the thermal sleeve maintains sealing contact with component parts of the nozzle during thermal expansion and contraction without giving rise to stress causing restraints.

Abstract: A method of forming a tube by pushing it through a tilted die to form a bend or change circumferential variations in wall thickness.

Abstract: A method and apparatus of forming a tube by pushing it through a die to form high quality tubular fittings.

Abstract: A typical embodiment of the invention provides a fitting for stabilizing the burnable poison rods and the like within a nuclear reactor fuel element. An illustrative orifice rod assembly fitting is assembled inexpensively from stamped metal strips which expose the ends of the fuel rods within the fuel element for inspection and simplify rearrangement of partially used fuel elements within a reactor core.

Abstract: A method of electroslag welding using a blanket of fiberized siliceous material on a stationary consumable guide in a narrow gap welding process.

Abstract: A typical embodiment of the invention has an array of sockets that are welded to the intersections of the plates that form the upper and lower end fittings of a nuclear reactor fuel element. The sockets, which are generally cylindrical in shape, are oriented in directions that enable the longitudinal axes of the sockets to align with the longitudinal axes of the fuel rods that are received in the respective sockets. Detents impressed in the surfaces of the sockets engage mating grooves that are formed in the ends of the fuel rods to provide for the structural integrity of the fuel element.

Abstract: An illustrative embodiment of the invention converts a feed solution stream into three separate streams of concentrated acid, concentrated alkali and deionized liquid, respectively, through a combination of ion exchange and electrodialysis techniques. Typically, feed fluid from the primary coolant loop of a nuclear reactor that contains ionized boric acid and lithium -7 hydroxide flows into a bed of mixed anion and cation exchange resins. Two of the walls of this bed, however, are of anion permeable and cation permeable membranes respectively, to permit the anions to migrate into an anolyte compartment and to permit the cations to migrate into a catholyte compartment. Within the anolyte compartment there is an anion resin bed which purifies the borate ions from other contaminative anions. Within the catholyte compartment there is a cation resin bed which purifies the lithium ions from other contaminative cations.

Abstract: Apparatus for the on-line detection and location of weld flaws wherein the acoustic emissions from a fault are segregated from other acoustic emissions by recognizing those emissions from the weld zone falling within a predetermined band of frequencies and locating the fault by determining the time required for the recognized emissions to travel to two spaced apart predetermined points.

Abstract: In accordance with an embodiment of the invention, an array of apertured flat plates support the tubes in a heat exchanger. Each aperture has at least three bights that provide individual fluid passageways when the associated tube is lodged in place. At least three inwardly protruding members that separate the bights restrain tube movement. Each of these members define arcs of a circle that has a diameter which is only slightly larger than the outside diameter of the respective tube. During heat exchanger assembly, this slightly larger diameter of the circle defined by the inwardly protruding members accommodates departures in the tubing from a perfectly straight condition. In operation, the individual tubes will tend to lay against one or two of the members in each aperture in almost line contact to prevent "crevice corrosion.

Abstract: A low mass thixotropic alumina-silica refractory mix for producing kiln furniture having smooth surfaces combined with low weight and consequent low heat capacity.

Abstract: A typical embodiment of the invention detects leaking fuel rods by means of a radiation detector that measures the concentration of xenon-133 (Xe.sup.133) within each individual rod. A collimated detector that provides signals related to the energy of incident radiation is aligned with one of the ends of a fuel rod. A statistically significant sample of the gamma radiation (.gamma.-rays) that characterize Xe.sup.133 is accumulated through the detector. The data so accumulated indicates the presence of a concentration of Xe.sup.133 appropriate to a sound fuel rod, or a significantly different concentration that reflects a leaking fuel rod.BACKGROUND OF THE INVENTION1. Field of the InventionThis invention relates to inspection techniques, and more particularly, to a radiation detection method and apparatus for identifying leaking fuel rods within a nuclear reactor core, and the like.2.