Abstract: An extendible flexible electrical conduit with a telescoping section connected between two spiral gooseneck sections and having insulated electrical conductors extending through the conduit. The conductors are helically wound inside the inner tube of the telescoping section so as to allow them to extend and contract to accommodate extension and contraction of the telescoping section. The outer tube of the telescoping section is oval along most of its length and the sliding end of the inner tube is also oval. The length of the telescoping section may be locked by rotating the inner tube with respect to the outer tube.

Abstract: In order to plug a pressure vessel penetration through which a heater was disposed, a stepped diameter hollow cylinder is provided with grafoil seals which are set on an annular shoulder defined by the stepped diameters of the cylinder and compressed against a lower annular edge of a sleeve which is partially machined away. The hollow cylinder is locked in position in the sleeve by a plurality of barb-shaped flanges which are formed at the upper ends of a plurality of flexible finger-like segments defined in the upper end of the hollow cylinder, and which engage the upper end of the sleeve. A rod is disposed in the hollow cylinder and welded in positon to complete the plug.

Abstract: A fluid tight mechanical clamp for creating a compressed graphite seal between a resistance temperature detector nozzle and a NSSS piping hot or cold leg pipe is provided which includes a split graphite seal ring, a peripheral seal back-up ring, a split load sleeve to axially compress and radially expand the split seal ring, a reactor plate and load ring with bolts to drive the load sleeve and compress the seal, and a blowout retainer to prevent the nozzle from blowing out of its seat in the pipe wall in the event of a weld failure. Extensive welding procedures to repair nozzle leaks are thus eliminated.

Abstract: In order to reduce the time and difficulty of disassembling a seal arrangement in a cramped radioactive environment, a nozzle assembly hub is provided with a step bore which receives a seal arrangement, a compression collar, and a retaining nut which presses the seal arrangement into engagement with an inner wall portion of the hub and an outer wall portion of an ICI (in-core instrument) seal plug assembly. The ICI units remain connected to the seal plug assembly during normal disassembly operations. In this manner, the nozzle assembly may be disassembled by merely removing the retaining nut, compression collar, and seal arrangement and lifting the reactor head, along with the nozzle assembly, over the ICI units. The compression collar extends outside the retaining nut such that the collar can be engaged and compressed by an hydraulic loading tool while threading the retaining nut onto the hub.

Abstract: In order to reduce the time and difficulty of disassembling a seal arrangement which includes a Grayloc flange, in a cramped radioactive environment, the Grayloc hub is modified to include a step bore which receives a seal arrangement and a retaining nut which presses the seal into engagement with an inner wall portion of the hub and outer wall portion of an ICI (in core instrument) supporting column. A loading ring is threaded onto a portion of the column. Bolts associated with the ring are screwed down onto a belleville washer which is disposed between the loading ring and the top of the retaining nut for maintaining a desired amount of load on the seals irrespective of thermal variations.

Abstract: A wear-reduction-sleeve for in-core-instrumentation thimbles of a pressurized water nuclear reactor having bottom mounted instrumentation to curtail flow induced excitation and increase support contact area in the region of thimble length which extends through and defines an annulus with the core support plate and extends upwardly to and through the fuel assembly flow distribution plates. The wear-reduction-sleeve includes a hollow shank portion which gives a low wear coefficient when in contact with the chrome-plated thimble and is inserted into the annulus and below where it is radially expanded and secured to a thimble guide tube. An upper portion of the wear-reduction-sleeve between the core support plate and flow distribution plate has a flow collection chamber and radial flow exit slots which divert thimble flow substantially away from the hole in the fuel assembly flow distribution plate through which the thimble extends.

Abstract: A method of repairing leaky compression fitting seal joints between a pressure stub tube (22) projecting from a nuclear reactor head (12) and a cylindrical thermocouple body (24) concentrically mounted in the stub tube (22) for penetration of the reactor pressure boundary. The method includes the steps of loosening and disassembling compression fitting nuts (30,32) and fitting body (34) to expose, and remove by grinding, a cammed ferrule radial compression means (26,28), cleaning the surfaces to be sealed, axially telescoping a split collar (40) between the tube (22) and the thermocouple body (24) and providing split rings (44,46) of brazing material surrounding the thermocouple body adjacent the exposed ends of the tube (22) and the collar (40). Resistance heating the tube and, therefore, the brazing material and repositioning and reassembling the fitting body (22) and fitting nuts (30,32) to complete the repaired seal joint.