Abstract: A nuclear power plant fuel transfer tube quick operating remote closure device (10) comprised of a reducing ring (20) and a cover assembly (60). The reducing ring (20) is bolted to the transfer tube housing flange (12). Rotation of a chuck key advances jaws on the cover assembly (60) which feed closure latches (78) into a groove (40) on the reducing ring (20). The upper surface (80) of each latch (78) has a bevelled surface (82) corresponding to a bevelled surface (42) of the groove (40). As the latches (78) engage the groove bevelled surface (42), the entire cover assembly (60) is uniformly drawn toward the reducing ring (20). Machined seal faces (13, 30, 44, 68) and O rings (36, 74) provide a fluid and air tight seal between the transfer tube housing flange (12) and the sealing ring (20) and between the cover assembly (60) and the sealing ring (20).

Abstract: In order to support a shroud against bending, shear, stress and torsion, straps which are preferably formed of the same material as the shroud, are placed in strategic positions with respect to cracks or the like type of weaknesses which have been detected, and fastened in place using a suitable fastening technique. In the preferred embodiments of the invention holes a formed using an EDM technique and bolt units which have an expanding portion are inserted into the holes, torqued and expanded in a manner which fastens the strap to the shroud. Welding and the like type of fastening techniques are not excluded and may used alternatively or in combination with the bolting technique as required.

Abstract: A fuel assembly for use in a pressurized water nuclear reactor includes an assembly having guide tubes joined at their upper ends to posts having heads against which is biased a holddown plate spaced from a flow plate. The holddown plate is slidably mounted on the posts. The flow plate is fixed to the posts. The joints have one either post or tube member with spring fingers with projecting steps to lock in abutting relation behind the flow plate with a ring projection on the other captured in a recess in the adjacent finger surfaces. This structure provides a quick connect joint between the tube and the post.

Abstract: In order to eliminate the need to weld, drill or otherwise machine a shroud structure which is used to surround a plurality of fuel assemblies in a nuclear reactor, a plurality of upper hanger rods interconnect a structure above the shroud to a support ring which is clamped about the upper periphery of the shroud. Lower hanger rods interconnect a lower edge or shoulder portion of the shroud with the support ring. Thus, through the upper and lower hanger rods and the support ring, the shroud can be supported within the RPV. The upper support ring is arranged to clamp the lower ends of the upper hanger rods against the upper outer peripheral portion of the shroud while the lower ends of the lower hanger rods are clamped against the lower peripheral wall portion of the shroud by a lower support ring.

Abstract: A boiling water reactor control rod drive support system having radiation shields to protect persons working under the reactor vessel from radiation exposure and to limit the travel of a control rod in the event that a control rod housing is ruptured. The radiation shields include radiation shield rings for surrounding the control rod drive housing and radiation shield cups for surrounding the bottom portion of the control rod drive. The radiation shield rings can be used with support systems having radiation shield cups placed on rows of support bars or with existing support systems.

Abstract: An irradiated steel pressurized nuclear reactor pressure vessel 10 is provided with a crack initiation retarding and crack extension retarding reactor vessel integrity girdle 20 or 120 made up of shoes or links 22, with mechanical take up joints (26 to 34a or 126 to 134a). Instead of pivoted shoe links 22, the girdle 120 may be made using constricting roller chain links 122. In any event, crack initiation and crack extension which may result from pressure loading or vessel material embrittled in the beltline region by neutron bombardment is retarded by maintenance of a prestress under the nozzles during all periods of operation of the reactor.

Abstract: A tank (18) forms a chamber having an upper and lower region. The tank (18) is in even elevation with a horizontal pipe (12) having a top region and a bottom region. An upper connecting pipe (14) fluidly connects the top region of the pipe (12) to the upper region of tank (18). A lower connecting pipe (16) fluidly connects the bottom region of pipe (12) to the lower region of the tank (18). Heat junction thermocouples (22) generate a signal indicative of water in the pipe (12). The signal is transmitted to a remote location by line (24).

Abstract: A plug which is inserted into the nozzle of nuclear reactor steam line is provided with a set of inflatable primary seals which resemble a pair of tires. A locking ring which features pads which can be hydraulically driven radially outward into engagement with the nozzle wall, is located adjacent the tire-like inflatable seals. The latter are inflated by a spring loaded piston. A tool which inserts the plug into the nozzle is adapted to tract the piston against the bias of the preloading springs, until such time as the plug is inserted into position. After insertion the piston is released and the seals are inflated.

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 eliminate the need to weld, drill or otherwise machine a shroud structure which is used to surround a plurality of fuel assemblies in a nuclear reactor, a plurality of upper hanger rods interconnect a structure above the shroud to a support ring which is clamped about the upper periphery of the shroud. Lower hanger rods interconnect a lower edge or shoulder portion of the shroud with the support ring. Thus, through the upper and lower hanger rods and the support ring, the shroud can be supported within the RPV. The upper support ring is arranged to clamp the lower ends of the upper hanger rods against the upper outer peripheral portion of the shroud while the lower ends of the lower hanger rods are clamped against the lower peripheral wall portion of the shroud by a lower support ring.

Abstract: A nuclear fuel rod spacer grid is formed of slottedly interlocked sets of flat strips. One set of strips is formed with integral coplanar tab portions which have one or more edge portions bent at angles to form integral mixing vanes.

Abstract: A permanent annular ring seal and refueling deck assembly providing an effective water barrier over the annular space between a nuclear reactor vessel flange and a surrounding annular ledge includes annular platform, a support and a joint seal. The joint seal has an upper cylindrical section and a lower flexible corrugated or arcuate shaped section which accommodates radial, axial and rotational movements of the vessel, and reduces joint stress.

Abstract: In order to eliminate the need to weld, drill or otherwise machine a shroud structure which is used to surround a plurality of fuel assemblies in a nuclear reactor, a support ring which either seats on top of the upper edge of the shroud, or is formed in multiple segments and is clamped to the side wall of the shroud, have hangers which are rigid therewith on which support hooks can be detachably mounted. The hooks are arranged to be engagable with the inner peripheral wall of the RPV in a manner which prevents lateral movement of the shroud within the pressure vessel.

Abstract: A data acquisition system (1) by which environmental parameters proximate to plant installed valves (2) may be monitored, recorded and correlated with other valve operating data. The system includes sensors (8) for sensing environmental parameters such as gas/vapor concentration, temperature or humidity. The system also includes sensors for sensing changes in the actuating variable (34) and sensors for sensing valve stem displacement (58). The sensors (8, 34, 6) generate electrical signals proportional to the value of the sensed parameter. First data interface equipment (32, 42, 43) is provided for digitizing the sensed actuating variable as the actuating variable is changed to displace the stem, preferably a full stroke from the open-to-close-to-open positions or vice versa. Second data interface equipment (7, 45) is provided for digitizing the sensed environmental parameter as the stem is displaced. Third data interface equipment (6, 45) is provided for digitizing the sensed stem displacement.

Abstract: A mechanically actuated plug comprises a pole system to lower a pair of seals into a refueling pool in a Boiling Water Reactor ("BWR") plant. A plug adapter is connected to the end of a pole system and is attached to a scissors jack assembly. The scissors jack assembly is comprised of at least one jack screw shaft, at least a pair of nuts, scissor arms connected between the nuts and the seals, and scissor arms connected between the nuts and a loading pad. The pole and plug adapter have a central shaft assembly which is connected to the jack screw shaft and transfers rotational motion from the top of the pole to the jack screw shaft. By rotating the central shaft assembly, the plug may be opened to seal the recirculation line. Once opened, the pole and plug adapter are preferably detached from the plug so that the plug may remain in position while the pole system is removed from the refueling pool.

Abstract: The manipulator has a base including an elongated bar having a center between first and second opposed ends. Fluidly actuated end effectors at the first and second ends of the base, are extensible for bracing the base against opposed support surfaces on the steam generator, such as locator pins situated within the clamp ring. A rigid arm is connected to the center of the base and extends radially to a free end. A first drive means is provided for remotely rotating the arm around a rotation axis passing through the center perpendicularly to the base. The preferred transducer means include a bracket situated at the free end of the arm, a pair of radially spaced apart mounting posts supported by the bracket and extending in parallel with the rotation axis, and a transducer shoe assembly carried by each post. A transducer element is mounted in each of the shoe assemblies.

Abstract: Coatings for zirconium alloy components of nuclear reactor fuel assemblies are described. The coating consists of a metal silicate binder, particles of burnable-poison particles, such as boron carbide, optional graphite particles and an optional rheology-enhancing component. The coating is deposited from a liquid suspension which also includes a polar solvent.

Abstract: A bellows-like construction which automatically extends upon immersion in water, is used to provide a relatively inexpensive water-tight enclosure for lifting equipment and the like. The lower end of the bellows is connected to the top of a rigid tubular member which extends up from a hook box or like type of structure, in a manner to form a hermetic seal. The upper end of the bellows-like arrangement is provided with a buoyant member which provides sufficient lift that, when the lifting equipment is lowered into the water to a predetermined depth, the buoyant member floats on the surface of the water in a manner which elongates a corrugated tubular portion of the arrangement and prevents radioactive water from spilling over into the box thus preventing contamination of a hook, hook block and associated apparatus which are enclosed therein.

Abstract: A method for detecting pH imbalances and/or achieving pH balance in crevices of a pressurized water reactor steam generator. The method comprises obtaining hideout return concentrations of sodium, chloride, calcium and sulfate ions, and silica from the water in the secondary side of the steam generator, the concentrations being expressed as moles per kilogram of water, and determining whether the following conditions exist:eq (anions)<eq (cations), and (a)[Na.sup.+ ]<[Cl.sup.- ]+2[SO.sub.4.sup.2- ] (b)the crevice pH being balanced when all the conditions of the determining step are satisfied. The method of the invention preferably further includes determining whether the following conditions also exist:[Cl.sup.- ]<[Na.sup.+ ] (c)[SiO.sub.2 ]>[Ca.sup.2+ ]+[Mg.sup.2+ ] (d)[Na.sup.+ ]/[Cl.sup.- ]<1.9. (e)If and when the above conditions are met, it can be expected that crevice pH will be balanced at a generally neutral level.

Abstract: The content of and hierarchical access to three levels of display pages containing information on critical function monitoring and success path monitoring.