Abstract: A storage rack for storing nuclear fuel rod assemblies is provided with an array of cell housings having support elements which are preloaded against the adjacent corner of the adjacent cell housing. The support elements are fixed to the outer corner of one cell housing and have pads which are preloaded or biased against the adjacent corner of the adjacent cell housing. The interface between the pads of the support elements and the adjacent cell housing provide a coulomb damping function which is effective in absorbing vibration from rough handling or seismic events. The cell housings can be located in alternating positions in the array and additional cell locations can be formed from the outer walls of the surrounding cell housings. The cell housings are held together in the array by support bars which are affixed to the top and bottom ends of the cell housings. The support bars may include recesses to align the cell housings.

Abstract: An accelerometer is mounted onto the releasable fuel gripper structure of a refueling machine to form a mechanical interconnection between an accelerometer and a nuclear fuel assembly during removal from a core of a nuclear reactor. An electrical signal is received and processed through an analyzer and recorded corresponding to mechanical vibrations occurring due to the passage of a fluid medium through a porous sidewall defect in a fuel rod of the fuel assembly which is induced by a hydrostatic pressure change on the fuel assembly during upward movement from the reactor core.

Abstract: A storage rack for storing nuclear fuel rod assemblies is provided with an array of cell housings having damping elements which are preloaded against the outer walls of the individual cells. The damping elements are slabs which when preloaded against the cell walls provide a coulomb damping function which is highly effective in absorbing vibration from rough handling or seismic events. The cell housings may be located in alternating positions in the array and cells may be formed from the outer walls of the surrounding cell housings. The cell housings are held together in the array by support bars which are affixed to the top and bottom ends of the cell housings. The support bars may include recesses to align the cell housings.

Abstract: A live-load device for applying a compressive force to packing or gasket material in a valve or pipe conduit junction. The device incorporates spring-washers having resilient blades for imparting a spring force. The spring force is transmitted from each blade through a ball-bearing seated at a selected one of a plurality of contact points along the blade tip. The spring constant of the device is selected by positioning the ball-bearing at a particular one of the contact points. This adjustment capability makes the spring device universally adaptable to a wide variety of valves and conduit junctions.

Abstract: A fuel rod directing chamber for compacting an array of fuel rods from an uncompacted array corresponding to the spacing of fuel rods in a fuel rod assembly to a compacted array in which no spacing exists between the individual fuel rods. The chamber is comprised of an elongated funnel containing a plurality of cavities extending longitudinally therethrough. The cavities form a plurality of holes at an entry end of the funnel corresponding in number and array to an array of fuel rods in a fuel rod assembly. The spacing between the cavities decreases along the length of the funnel until no spacing exists between the cavities. By causing fuel rods of a spent nuclear fuel rod assembly to pass through the cavities of the directing chamber, the spacing between the individual rods decreases, thereby reducing the reactivity of the rods, and increasing the density thereof.

Abstract: A method of withdrawing spent fuel rods from a nuclear fuel rod assembly into a different nuclear fuel rod container wherein the spent fuel rods have a higher fuel rod density, whereby a greater number of spent fuel rods can be stored in a water storage pool. The individual rods are drawn upwardly through a transition funnel from the fuel rod assembly into a fuel rod container. Individual wires extend through the fuel rod container, through the transition funnel and are secured to the top ends of the individual fuel rods within a fuel rod assembly. All of the fuel rods are withdrawn concurrently and are merged toward one another into a tighter array within the fuel rod container.

Abstract: A storage system for the storage of nuclear waste material is disclosed. A storage system includes a plurality of storage canisters of dimensions allowing it to hold spent nuclear fuel rods and a rack structure for maintaining the storage canisters in a definite horizontal and vertical array. A storage system is of particular value for use in underwater nuclear waste storage areas. When used underwater, the system includes buoyant chamber positioned above the rack structure and flexibly connected thereto to provide an upper force to reduce the downward load exerted on a floor of the water pool by the storage canisters and the rack structure. The system thereby allows a far greater number of fuel rods to be stored in an underwater nuclear waste storage area than was possible in the past.

Abstract: A method for withdrawing spent fuel rods from a nuclear fuel rod assembly into a different nuclear fuel rod container wherein the spent fuel rods have a higher fuel rod density, whereby a greater number of spent fuel rods can be stored in a water storage pool. The individual rods are drawn upwardly through a transition funnel from the fuel rod assembly into a fuel rod container. Individual wires extend through the fuel rod container, through the transition funnel and are secured to the top ends of the individual fuel rods within a fuel rod assembly. All of the fuel rods are withdrawn concurrently and are merged toward one another into a tighter array within the fuel rod container.

Abstract: A method and apparatus for withdrawing spent fuel rods from a nuclear fuel rod assembly into a different nuclear fuel rod container wherein the spent fuel rods have a higher fuel rod density, whereby a greater number of spent fuel rods can be stored in a water-storage pool. The individual rods are moved from a fuel assembly and through a transition funnel by movable grippers at opposite ends of the funnel. One movable gripper reciprocates between gripping and release positions in a gap between the fuel assembly and the transition funnel. A stationary gripper can be located in the gap at the entry side of the funnel to hold the fuel rods while the movable gripper returns from a release position to the gripping position. Both grippers include members which can be pressed into frictional engagement with the spaced apart array of fuel rods. All of the fuel rods are withdrawn concurrently and are merged toward one another into a tighter array within the transition funnel and emerge as a bundle.

Abstract: A storage rack for spent nuclear fuel rods is provided having multiple parallel tubes of polygon cross-section with their confronting surfaces having embossed buttons in engagement and having at least one pad of neutron poison material interposed between the confronting surfaces. The tube cells are secured together such that the neutron poison material effectively establishes each individual cell as a neutron isolation chamber and further functions to dampen mechanical vibrations which may be applied to the assembled storage rack.

Abstract: An apparatus for withdrawing spent fuel rods from a nuclear fuel rod assembly into a different nuclear fuel rod container wherein the spent fuel rods have a higher fuel rod density, whereby a greater number of spent fuel rods can be stored in a water-storage pool. The individual rods are moved from a fuel assembly and through a transition funnel by movable grippers at opposite ends of the funnel. One movable gripper reciprocates between gripping and release positions in a gap between the fuel assembly and the transition funnel. A stationary gripper can be located in the gap at the entry side of the funnel to hold the fuel rods while the movable gripper returns from a release position to the gripping position. Both grippers include members which can be pressed into frictional engagement with the spaced apart array of fuel rods. All of the fuel rods are withdrawn concurrently and are merged toward one another into a tighter array within the transition funnel and emerge as a bundle.

Abstract: A method and apparatus for withdrawing spent fuel rods from a nuclear fuel rod assembly into a different nuclear fuel rod container wherein the spent fuel rods have a higher fuel rod density, whereby a greater number of spent fuel rods can be stored in a water storage pool. The individual rods are drawn upwardly through a transition funnel from the fuel rod assembly into a fuel rod container. Individual pulling elements extend through the fuel rod container and through the transition funnel. The pulling members each includes a renewable metal cap and an electrode for welding the cap to the top end of an individual fuel rod within a fuel rod assembly. All of the fuel rods are withdrawn concurrently and are merged toward one another into a tighter array within the fuel rod container.

Abstract: A method and apparatus for withdrawing spent fuel rods from a nuclear fuel rod assembly into a different nuclear fuel rod container wherein the spent fuel rods have a higher fuel rod density, whereby a greater number of spent fuel rods can be stored in a water-storage pool. The individual rods are moved from a fuel assembly and through a transition funnel by movable grippers at opposite ends of the funnel. One movable gripper reciprocates between gripping and release positions in a gap between the fuel assembly and the transition funnel. A stationary gripper can be located in the gap at the entry side of the funnel to hold the fuel rods while the movable gripper returns from a release position to the gripping position. Both grippers include members which can be pressed into frictional engagement with the spaced apart array of fuel rods. All of the fuel rods are withdrawn concurrently and are merged toward one another into a tighter array within the transition funnel and emerge as a bundle.

Abstract: A method and apparatus for withdrawing spent fuel rods from a nuclear fuel rod assembly into a different nuclear fuel rod container wherein the spent fuel rods have a higher fuel rod density, whereby a greater number of spent fuel rods can be stored in a water storage pool. The individual rods are drawn upwardly through a transition funnel from the fuel rod assembly into a fuel rod container. Individual wires extend through the fuel rod container, through the transition funnel and are secured to the top ends of the individual fuel rods within a fuel rod assembly. All of the fuel rods are withdrawn concurrently and are merged toward one another into a tighter array within the fuel rod container.

Abstract: Submerged canisters containing compacted spent nuclear fuel rods are connected to buoyant spacer boxes to reduce the apparent weight of the canisters whereby additional canisters may be introduced into existing water pools without exceeding the load-carrying capacity of the water pool floors. The spacer boxes may be integral with the canisters or may be distinct. The spacer boxes may be rigidly or flaccidly connected to the spacer boxes. Buoyancy in the spacer boxes is preferably achieved by filling them with gas, preferably air.

Abstract: A water level indicator for a pressure vessel is provided which employs a plurality of vertically spaced cantilevered mounted spring members. The free end of each spring member is connected to a depending float member. The float member has sufficient mass and density to depress its spring member when the float member is in a gaseous medium. The float member has sufficient buoyancy to elevate its spring member when the float member is in a water medium. One or more strain gauges is secured to each spring member to indicate the instantaneous position of the spring member and thereby provide an indication of the instantaneous water level.

Abstract: A rack is provided for either temporary or permanent storage of spent nuclear fuel assemblies. The rack consists of a checkerboard array of substantially square cells. Alternate cells in each row include neutron-absorbing poison material, either in the cell wall or otherwise, while the other cells are storage cells for the fuel assemblies. For temporary storage, the poison cells also contain a moderator which may be water or which may be a solid hydrogen compound. For permanent storage fuel assemblies that have decayed to a lower level of radioactivity, the moderator is eliminated so that all the cells can contain spent fuel assemblies, and the entire rack structure is encased in concrete for shielding.

Abstract: A system for supporting a bundle of tubes against lateral movement in a heat exchanger, such as a nuclear power plant steam generator, wherein spring collar devices positioned at intervals along the tubes permit lateral movement of the tubes but prevent any relative movement between the tube and its associated spring collar device. Any lateral movement is between adjacent spring collar devices. With this arrangement, fretting and corrosion between the outer surfaces of the tubes and their lateral support members are substantially eliminated.

Abstract: A maximum density storage rack is provided for long term or semipermanent storage of spent nuclear fuel assemblies. The rack consists of storage cells arranged in a regular array, such as a checkerboard array, and intended to be immersed in water. Initially, cap members are placed on alternate cells in such a manner that at least 50% of the cells are left open, some of the caps being removable. Spent fuel assemblies are then placed in the open cells until all of them are filled. The level of reactivity of each of the stored fuel assemblies is then determined by accurate calculation or by measurement, and the removable caps are removed and rearranged so that other cells are opened, permitting the storage of additional fuel assemblies in a pattern based on the actual reactivity such that criticality is prevented.

Abstract: A method and apparatus are provided for the inspection of nuclear fuel rods to detect defects or failures in such rods. Assemblies of fuel rods are immersed in water and means are provided for causing a change in the relative pressures in the water and within the fuel rod such that fluid is expelled from the rod through any defects that may exist. Means are also provided for thereafter vibrating the rods to cause additional internal fluid or other material that may be trapped in the rod to be expelled. Sensors are provided for detecting the emission of bubbles of fluid or other material from the rod and for locating the position of the defective rod in the assembly.