Abstract: A spacer for use in a fuel assembly of a nuclear reactor having thin, full-height divider members, slender spring members and laterally oriented rigid stops and wherein the total amount of spacer material, the amount of high neutron cross section material, the projected area of the spacer structure and changes in cross section area of the spacer structure are minimized whereby neutron absorption by the spacer and coolant flow resistance through the spacer are minimized.

Abstract: An arrangement for crimping a malleable sleeve over a hole in a punctured nuclear fuel rod in order to prevent the escape of fission gases into the external environment. The arrangement operates underwater and includes jaws for crimping the sleeve onto the fuel rod, which are operated by a hydraulic cylinder. The jaws crimp circumferential sealing ridges onto the inner surface of the sleeve, which bear against the fuel rod.

Abstract: An amphibious end plug gauging device and method for determining the axial location of nuclear fuel element end plugs within or without the upper tie plate of a fuel bundle. The gauging device is maneuvered toward an underwater fuel bundle in a reactor service pool and its tip inserted in a preselected tie plate shank hole to engage the end of a fuel element in the bundle. The position of the fuel element relative the upper surface of the tie plate is registered on a dial indicator.

Abstract: A remotely operable device for cutting sample pieces from the walls of an irradiated component while the component is submerged in a pool of water to shield the operator from radiation.

Abstract: An underwater suction device for collecting irradiated materials in a pool of water. The device includes injection and suction tubes and a removable, disposable filter for capturing irradiated materials. Pressurized water is injected into the suction tube through a jet pump nozzle to establish a suction flow through the tube. The suction device is manually positionable by an operator standing at a dry location and extending the device underwater by maneuvering a positioning pole. The pole is pivotally connected to the injection or suction tube by a variably positioning latching mechanism.

Abstract: Remotely manipulatable probe and apparatus for positioning a corrosion thickness sensing transducer over selected areas of the surface of a radioactive component submerged in a pool of water for radiation shielding.BACKGROUNDIn known types of nuclear power reactors, for example as used in the Dresden Nuclear Power Station near Chicago, Ill., the reactor core comprises a plurality of spaced fuel assemblies arranged in an array capable of self-sustained nuclear fission reaction. The core is contained in a pressure vessel wherein it is submerged in a working fluid, such as light water, which serves both as coolant and as a neutron moderator. Each fuel assembly comprises a removable tubular flow channel, typically of approximately square cross section, surrounding an array of elongated, cladded fuel elements or rods containing suitable fuel material, such as uranium or plutonium oxide, supported between upper and lower tie plates.