Abstract: A steam generator wrapper closure and a method of installing the same includes a plug member (108) which includes a large diameter portion (110) and a small diameter portion (112) with an annular shoulder portion (114) defined therebetween. A locking pawl (124) is rotatably mounted upon the plug (108) through means of its shaft (122). A pawl shaft extension rod (154) and a handle (150) are utilized to manipulate the pawl (124) and the plug (108) from a position external to the steam generator outer shell (16). The axis of the pawl shaft (122) is radially offset with repect to the axis of the plug (108), and the diametrical extent of the pawl (124) is less than that of the small diameter portion (112) of the plug (108).

Abstract: An ultrasonic probe for the weld inspection of nuclear reactor vessel nozzles is constructed from a plurality of segments interconnected by means of a flexible joint and protected by bumpers of various shapes. The probe is capable of successfully operating in an underwater and radioactive environment under remote control while maintaining a high degree of control over the placement and movement of the included transducer assembly for performing contact type testing. The transducer assembly, which includes an ultrasonic transmitter and receiver, is mounted within an ultrasonic sensor body which permits insertion of the probe within a nozzle of a reactor vessel while maintaining direct surface to surface contact with the nozzle for weld area examination by contact type testing.

Abstract: A universal tool for the weld inspection of tubular objects such as reactor vessels is disclosed. The tool is constructed from an array of transducers mounted in groups for common inspection of a particular weld volume. The individual transducers, as well as the groups, are arranged in a compact assembly for minimizing the overall dimensions of the tool and its corresponding weight. The transducers are arranged in a manner which permits inspection of tubular objects having different radii of curvature and corresponding different diameters with a single tool without the need of having to individually adjust the orientation angles of the transducers.

Abstract: An improved model steam generator for simulating the conditions within a nuclear steam generator in order to monitor the condition of the heat exchange tubes and tubesheet of the nuclear steam generator is disclosed herein. The improved model steam generator includes a highly effective separator assembly for separating water droplets entrained within the steam flowing out of the outlet of the secondary side of the generator formed from a plurality of separator grids, each of which includes an array of semi-cylindrical deflector members. The grids are vertically stacked with the deflector members transversely disposed to the flow of steam generated by the model steam generator. Each of the parallel arrays of deflector members in each grid is angularly disposed approximately 45.degree. to the deflector members in the grids above it and below in order to provide a tortuous path for the flow of steam ascending therethrough.

Abstract: Apparatus for processing the damaged tubes of a steam generator either to prepare the tubes for insertion of a sleeve, or to insert a sleeve or to treat the sleeve after it is inserted. This apparatus includes a drilling tool for drilling out plugs, a sleeving tool for inserting sleeves in the tubes, a high-roller tool for rolling the sleeves at their upper ends where they have been expanded, and a low-roller tool for rolling the sleeves at their lower ends in the tube sheet. The sleeves are inserted in the tubes and are rolled by rolls driven by a hydraulic motor. For drilling, for sleeve insertion and for high and low rolling, the motor is controlled by a servo control valve.

Abstract: A steam generator tubesheet/channel head/centerstay assembly wherein a threaded centerstay is screw-inserted to connect the tubesheet and the channel head. Seals are installed between the centerstay, the channel head and the tubesheet to prevent leakage.

Abstract: An improved, compact model steam generator having multiple primary systems is described herein. The model steam generator of the invention is capable of simultaneously simulating a plurality of thermo-hydraulic conditions which may exist in various areas of a full-scale nuclear steam generator in order that the effect of these various conditions on the heat exchange tubes within the full-scale generator may be separately monitored. The model steam generator of the invention generally includes a boiler vessel having a primary side which houses a plurality of individually controllable primary systems, a tubesheet, a secondary side, and a plurality of sample heat exchange tubes for transferring heat between each of the individual primary systems and the secondary side of the boiler vessel.

Abstract: In a nuclear steam generating vessel, a baffle plate disposed a slight distance above the tube sheet has a plurality of openings therethrough for respectively receiving the heat exchanger tubes. Each opening has a circular central portion and eight equally spaced peripheral lobe portions alternating with eight lands. The inner end of the lands lie on a circle have a diameter slightly greater than that of the associated tube. The upper and/or lower surface of the baffle plate is mechanically deformed adjacent to each lobe portion of each opening to displace material into the lobe portions and constrict the cross sectional areas thereof to limit liquid flow therethrough. The lands are dimensioned and arranged so that one or two at a time can contact the associated tube, while the constriction of the lobe portion flow areas limits liquid flow therethrough sufficiently to insure proper baffling operation of the baffle plate.

Abstract: A nozzle dam for providing a fluid-tight seal across a primary fluid nozzle in the plenum of a nuclear steam generating vessel includes an elongated shaft coupled at one end thereof to an anchor assembly frictionally engageable with the inner surface of the nozzle to anchor the dam in place and a fluid-impermeable seal apparatus coupled to the shaft and closing the nozzle and frictionally engageable with the inner surface thereof to form a fluid-tight seal. The seal apparatus includes a circular plate disposable in wedging frictional engagement with a frustoconical portion of the nozzle inner surface. The shaft extends through a central aperture in the plate and is threadedly engaged with a nut which holds the plate in place. The anchor assembly includes a foldable tripod arrangement coupled to the shaft in such a way that movement of the shaft toward the seal plate effects an increase in the frictional anchoring force. The seal assembly also includes an inflatable portion.

Abstract: A model steam generator including an improved feedwater system for monitoring the conditions of the heat exchange tubes within a nuclear steam generator is disclosed herein. The feedwater system generally comprises a first conduit fluidly connected between the boiler vessel of the model steam generator and the feedwater of the nuclear steam generator via a first valve, and a second conduit which is fluidly connected between this boiler vessel and a feedwater reservoir by way of a second valve. The feedwater reservoir is in turn connected to a source of demineralized, deaerated water by means of a third conduit having a third valve. This reservoir is further fluidly connected to the feedwater of the nuclear steam generator by means of a fourth conduit having a fourth valve. The improved feedwater system of the invention gives the operator three running options. First, he may run the model steam generator directly off the feedwater used in the nuclear steam generator.

Abstract: A filter for removing debris of a predetermined size from a fluid path has a first face disposed transversely in the fluid path and a second face disposed substantially parallel to the first face and displaced therefrom in the direction of fluid flow. The displacement of the second face from the first face substantially defines the strength of the filter with respect to deformation by the fluid flow. The first and second faces cooperate to define a plurality of apertures extending through the filter. The apertures are of a size to preclude passage of the debris while presenting a predetermined resistance to the fluid flow. That predetermined resistance is substantially independent of the filter's strength.

Abstract: A model steam generator including a system for facilitating the inspection of the sample tubes within the boiler vessel of the model generator is disclosed herein. The system includes means for detachably connecting the tubesheet from the primary and secondary sides of the boiler vessel. In the preferred embodiment, both end of the tubesheet and the abutting ends of the primary and secondary sides of the boiler vessel are circumscribed by tapered flanges. The tubesheet is detachably connected from the primary and secondary sides of the boiler vessel by means of Grayloc.RTM.-type annular clamps which are circumscribed by grooves for receiving the abutting flanges at the tubesheet joints. Additionally, the system includes a frame for suspending the secondary side of the boiler vessel, a wheeled cart having a jack for both laterally and vertically moving the primary side of the boiler vessel and the tubesheet into a clamping position onto the secondary side of the boiler vessel.

Abstract: A modular separating unit for separating a liquid from a gas-liquid mixture, comprising an annular riser tube, a hub coaxial with and located within the riser tube, four curved blades mounted between the hub and the riser tube, an annular downcomer tube surrounding the riser tube, and an orifice ring having an outer diameter smaller than the inner diameter of the riser tube and located adjacent the outlet end of the riser tube. The leading edge and leading surface of each blade, which are disposed adjacent the inlet end of the riser tube, are contained in a plane parallel to the initial direction of flow of the gas-liquid mixture. The trailing edge and trailing surface of each blade are contained in a plane which is at an angle of approximately 37.degree. to a plane perpendicular to the axis of the hub. The projections of the leading edge of one blade and the trailing edge of an adjacent blade onto a plane perpendicular to the axis of the hub form an angle of approximately 22.5.degree..

Abstract: A crimping tool for crimping a locking cap secured to the nut of a new split-pin assembly to the new split-pin to preclude turning of the nut and pin relative to each other. The tool includes a crimping mechanism including crimping jaws having crimping pins face-to-face near one end. The jaws have external cam surfaces. The crimping pins are retracted and brought into crimping engagement with the cap to be crimped by cam followers which traverse the cam surfaces when actuated hydraulically through a C-frame connected to the cam followers. The crimping mechanism is mounted on a support which is moveable by a hydraulic cylinder between a retracted setting, where it is latched generally vertically, and an operating setting where it is positioned generally horizontally. The piston rod of the cylinder has a slotted extension. The slot is engaged by a pin which is connected to the support.

Abstract: A single stage remote center compliance device having a high degree translational and rotational compliance for use in connection with a manipulator device which includes first and second members spaced from each other and interconnected by a pair of crossed interconnected shafts and a plurality of tilted, axially compressible and laterally deformable compression coil springs.

Abstract: A tool for positioning a lower guide tube of a reactor for replacement of old split-pin assemblies by new split-pin assemblies. The lower guide tube has an upper and a lower flange and has a length typically between 124 and 150 inches. The split-pin assemblies are secured in counterbores in the lower flange. The tool includes an upper deck and a lower deck. The LGT is suspended from the upper deck from pins which engage holes in the upper flange. With the LGT so suspended the lower flange extends into the lower deck in position to be processed for the replacement. A rotary hydraulic cylinder is provided in the upper deck to rotate the LGT in positions to be processed by other tools involved in the replacement and also so that both of the old split-pin assemblies which are spaced 180.degree. around the periphery of the LGT may be replaced by a single set of robotic tools. A hydraulic lift cylinder is also provided at the upper level to raise the LGT so that it clears the pins when the LGT is to be rotated.

Abstract: A metal brazing sleeve includes a ceramic flux band formed on the sleeve adjacent an annular recess typically disposed near an open end of the sleeve for receiving a conventional braze preform, by adhering a powder flux to the sleeve by a tacky adhesive and then melting the powder flux in place, by internal heating of the tube. The ceramic flux band is hard and adherent, and resistant to abrasion effects during insertion of the sleeve into a tube, and provides a shadow effect for protecting an optional cemented powder flux band which may be formed on the braze ring.

Abstract: Small portable electrical resistance heated radiant heating unit useful for insertion in tube bores to effect localized high temperature heating. Useful for the internal heating of tubes and tube/sleeve assemblies in steam generators, having bores as small as 0.75 cm. or less, for brazing, stress relieving, and other applications.

Abstract: A process for brazing a sleeve within a tube which is resistant to longitudinal expansion is disclosed herein. In the first step of the process, a thermally induced radial expansion is induced in the tube in a first longitudinal section of the tube which does not include the ring of brazing alloy which circumscribes the sleeve. In the second step of the process, a brazing heat is applied across the longitudinal section of the tube which does include this ring of brazing material. The residual tensile stress created by the thermally induced radial expansion in the tube avoids the creation of gaps in the braze joint between the sleeve and the inner walls of the tube. This process is particularly useful in creating high-quality braze joints in sleeving operations in nuclear steam generators, where the heat exchange tubes which need to be sleeved may be partially or completely prevented from expanding in the longitudinal direction due to sludge deposits in the generator.

Abstract: A rigid peening spindle for rotopeening the inside wall of a tube is disclosed herein. Generally, the peening spindle comprises a rotatable housing insertable within a tube, a mandrel disposed within the housing and having a plurality of peening flappers connected thereto, and a pair of bearings for rotatably mounting the mandrel within the housing in an off-center orientation relative to the longitudinal axis of the housing so that the peening flappers rotate and orbit within the tube when the mandrel and housing are simultaneously rotated. The housing includes a cage formed from an open section and a ligment, and the mandrel is rotatably mounted within the housing so that the peening flappers may engage the inside wall of the tube through the open section of the cage.