Abstract: A control rod guide tube mounting pin for engaging a hole in an upper core plate of a nuclear reactor pressure vessel has a resilient tubular portion with one or more axial crimps which flex allowing for resiliently fitting into a hole in an upper core plate without needing to enlarge or other machine the existing holes or drilling additional holes. Stainless steel mounting pins may be backfit into existing two pin mounting systems of control rod guide tubes adjacent to the outlet nozzles of the pressure vessels by removing the pins mounting the guide tubes adjacent the outlet nozzles to the upper core support plate; and then replacing the removed pins with stainless steel replacement pins.

Abstract: An apparatus and method are provided for replacing the existing lower internal components in a nuclear reactor vessel with new components. The alignment of the new lower internals to the pressure vessel and the existing upper internals is achieved by customizing the new lower internals on-site based on alignment measurements obtained by gages installed on the new core barrel and the existing upper core plate. The gages allow the custom machining of radial support keys on the lower portion of the new core barrel and the custom drilling of upper core plate alignment pin holes in the new core barrel.

Abstract: An apparatus, which reinforces a shroud that is contained within a reactor vessel, is operable for reinforcement of the shroud in the event of cracking in the shroud. The apparatus comprises a reactor wall positioned surrounding the shroud. A beam is attached to and extends generally axially on the shroud for absorbing the forces generated by the cracking in the shroud, and a radial support is positioned between the beam and the wall of the reactor vessel for transmitting any forces absorbed by the beam to the wall.

Abstract: A jet pump assembly for recirculating coolant through a recirculation loop of a boiling water reactor vessel, the jet pump assembly comprises a jet pump in operative association with the recirculation loop for forcing the coolant through the recirculation loop. A beam is positioned adjacent and in operative association with the jet pump for assisting in maintaining the positional relationship of the jet pump. A bolt is inserted in the beam for resisting the hydraulic forces generated in the jet pump, and an insert is disposed in said beam for receiving and surrounding the bolt which, in turn, reduces stress on the beam.

Abstract: Disclosed is a means for increasing coolant flow through the areas adjacent to where the removable top head closure is bolted to the body of pressurized water nuclear reactor. A circumferential plenum for coolant is provided between the upper flange of the core barrel, the inner wall of the pressure vessel body and the upper circular support plate and providing a plurality of orifices for coolant in the upper flange of the core barrel and the upper circular support plate whereby a coolant may be circulated through the core barrel flange, the circumferential plenum and the upper support plate and into the space enclosed by the removable top closure head.

Abstract: A method for shot peening a first tube external to and concentric with a second tube comprising the steps of forming a slot through the second tube; positioning a shot peening device adjacent the notch in the second tube for propelling shot peening balls; propelling the shot peening balls through the slot in the second tube for shot peening the second tube; and rotating the second tube in increments for shot peening an entire circumferential portion of the first tube positioned outwardly and radially from the slot.

Abstract: The guide pin aligning a top nozzle of a nuclear fuel assembly to an upper core plate of a nuclear reactor, is replaced working exclusively from below the upper core plate. The replacement guide pin has a shaft portion engaged with the upper core plate and the clamping nut which held the original guide pin, by threadable connection and/or by an expansion fitting. A shoulder on the pin bears against a lower surface of the upper core plate, and a nose of the pin is received in the top nozzle of the fuel assembly. A preferred expansion fitting has a bushing with ridges on its outer surface and a conical inside surface, and is inserted into the bored out original guide pin shaft. A threaded conical plug is pulled axially with rotation of the replacement pin shaft to expand the bushing. The ridges rigidly lock the replacement pin between the shoulder and the clamping nut.

Abstract: Both an apparatus and a method for simultaneously inspecting the walls of a tube with both ultrasonic and eddy current probes is disclosed herein. The apparatus generally comprises a cylindrical housing assembly insertable within the tube to be inspected, and a probe carrier rotatably mounted within and helically movable with respect to the housing. The probe carrier holds three ultrasonic probes for transmitting ultrasonic beams which are directly oriented radially, chordally, and axially with resepect to the longitudinal axis of the tube, as well as an eddy current probe for simultaneously inspecting the walls of the tube with electromagnetic lines of flux. The apparatus further includes a helical drive train formed from a lead screw assembly having a motor means, a drive shaft, and a drive sleeve for imparting a helical scanning motion to the probe carrier with respect to the housing.

Abstract: Both an apparatus and a method for simultaneously inspecting the walls of a tube with both ultrasonic and eddy current probes is disclosed herein. The apparatus generally comprises a cylindrical housing assembly insertable within the tube to be inspected, and a probe carrier rotatably mounted within and helically movable with respect to the housing. The probe carrier holds three ultrasonic probes for transmitting ultrasonic beams which are directly oriented radially, chordally, an axially with respect to the longitudinal axis of the tube, as well as an eddy current probe for simultaneously inspecting the walls of the tube with electromagnetic lines of flux. The apparatus further includes a helical drive train formed from a lead screw assembly having a motor means, a drive shaft, and a drive sleeve for imparting a helical scanning motion to the probe carrier with respect to the housing.

Abstract: A process for thermally stress-relieving a stressed portion of a metallic tube is disclosed herein. The process generally comprises the steps of inserting a small diameter radiant heater into the open end of the metallic conduit and then positioning it adjacent to the portion to be stress relieved, and heating this portion to a temperature between about 1150.degree. F. to 1500.degree. F. for a time period of between about four and twelve minutes, depending upon wall thickness. In order to determine the proper amount of electrical power to apply to the radiant heater, the emissivity of the stressed portion of the conduit is first measured by heating a portion of the section to incandescence at a known power level, and then determining the temperature of the incandescent tube by means of a pyrometer which compares the intensity of two selected colors or wavelengths of the transmitted light. This process is particularly useful in thermally stress-relieving the U-bends of heat exchanger tubes formed from Inconel.

Abstract: A flexible radiant tube heater is disclosed herein which is particularly useful in thermally stress-relieving the U-bend sections of the heat exchange tubes within nuclear steam generators. The apparatus generally comprises an elongated, flexible mandrel formed from a spring composed of a heat-resistant alloy, a flexible electrical resistance heating element wound around the mandrel spring, and a flexible insulating sleeve formed from braided alumina fibers disposed around the heating element for electrically insulating the heating element from both the metallic spring and the inner walls of the tube. A nosepiece assembly and an endpiece are disposed on the front and back ends of the spring, respectively. A flexible reinforcing member which may be a thin rod of Inconel.TM. is mounted to both the nosepiece assembly and the endpiece and disposed through the windings of the mandrel coil in order to lend more tensile and compressive strength to the mandrel coil.

Abstract: An inspection system and process for inspecting a plurality of conduits mounted in a manifold is disclosed herein. The system generally comprises a probe carrier for driving an eddy current or ultrasonic probe throughout the conduits to be inspected, and a delivery assembly detachably mountable within the manifold for remotely delivering and inserting the probe carrier into the open ends of the conduits. The delivery system includes an insertion and pusher mechanism for selectively inserting and pushing the probe carrier through the open ends of the tubes, a rail assembly which is removably mountable within the manifold, and a carriage slidably mounted on the rail assembly for supporting and axially positioning the insertion and pusher mechanism. Angular and axial electric drive motors are also provided for rotating and moving the insertion and pusher to a selected angle around and point along the longitudinal axis of the manifold.

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.

Abstract: A rotopeening apparatus comprising a plurality of peening spindles, a rotary and orbital drive assembly coupled to the spindles, and an oscillatory drive means for reciprocating the spindles within the interior of an array of tubes is disclosed herein. Each peening spindle includes a rotatable mandrel connected to at least one peening flapper, as well as means for orbiting the mandrel peening flapper around the longitudinal axis of the tube. The rotary and orbital drive assembly includes an orbital driveshaft and a rotary driveshaft which are concentrically disposed with respect to one another and are detachably connectable to the rotatable and orbital mandrel of the peening spindle.

Abstract: An apparatus is disclosed for inspection of tubing, and more particularly, the determination of the extent of erosion in the wall of a heat exchange tube of a nuclear reactor. An ultrasonic transducer assembly is movable axially and rotatably in a helical path for producing both thickness and position signals to provide a map of wall thickness.