Abstract: A frame 10 with downwardly projecting members 52 mounts by means of a pair of hoists 36 and lifting bracket 42 downwardly into upwardly open recesses of complementary mounting members 54 secured to reactor head lifting legs 30. Frame 10 is mounted on the head either with lead wool shielding blankets 40 hanging from it or without. In the latter case, hangers 60 with blankets 40 hanging therefrom and horizontally gravity biased hooks 64 mounted on a curved beam 62, are lowered by hoist 36 until hooks 64 grapple, pivot and hang hanger 60 and the shielding on frame 10 at a location radially inwardly of the head bolt locations 22. The hook of hoist 36 is lowered until it is disengaged from the radially outwardly biased bail 70 of hanger 60.

Abstract: An improved corrosion resistant ductile modified zirconium alloy for extended burnups in water-moderated nuclear reactor core structural components, fuel cladding and analogous corrosive environment uses is provided. It comprises:measurable amounts of niobium in a range up to 0.6 percent by weight, measurable amounts on antimony in a range up to 0.2 percent by weight, measurable amounts of tellurium in a range up to 0.2 percent by weight, tin in the range 0.5 to 1.0 percent by weight, iron in the range 0.18 to 0.24 percent by weight, chromium in the range 0.07 to 0.13 percent by weight, oxygen in the range of from 900 to 2,000 ppm, nickel in an amount less than 70 ppm, carbon in an amount less than 200 ppm and the balance zirconium and minor amounts of impurities.The alloy structure is substantially alpha phase with some precipitated second phase particles which are preferably within the size range of 1200 to 1800 angstroms.

Abstract: Pressurized water reactor fuel bundles (10) have a cast lower end fitting (20) which provides reduced pressure drop because nozzles (24) are of polygonal (rectangular or square) cross-section and the flow entrance wall portion (32) is a parabolic shape which merges into a wall portion (30) parallel to the flow direction. The parabolic shape of portion (32) and fillets (24a) at the nozzle (24) corners also give an improved draft to the casting. Pressure drop reduction was substantially greater than standard calculations indicated would be obtained.

Abstract: A bolt insert 24 with special bolt 50 provides a fastening method to secure hard metal nuclear reactor parts 12, 14, 16 provided with aligned square EDM produced openings 18, 20, 22. The insert is an elongated square internally threaded member with slots 34 defining flexing fingers 36. Fingers 36 have work engaging shoulders 42. Stop means tabs 28 at the bolt head end prevent overinsertion of the square insert 24 during the operation of pushing it into aligned square holes 18, 20, 22. Internal threads 32 of insert 24 mate with bolt threads 60 during torquing on bolt head 52 to advance bolt 50, which has tapered end 56 and pilot portion 58, to cam fingers 36 into holding position. Couterbores 30 receive stop means tabs 28 such that bolt head 52 does not bottom on insert 24. The method of producing fastening 10 removes the need for accurate threading operations on irradiated parts in the remote field.

Abstract: Valve leakage is quantified by measuring a variable that is commensurate with a heat transfer characteristic of the pipe wall (30) and comparing the measurements to data stored in a database (84) which embodies a quantitive relationship between an index commensurate with the heat transfer characteristic variable and a range of valve leakage rates that could occur for the given valve. In a straight forward implementation of the invention, a thermal hydraulic analysis of the specific valve and associated piping are performed a priori to establish a database of pipe wall temperature downstream of the valve as a function of steam flow rate. The wall temperature is simply measured and compared with the database. In another embodiment, an air cooled sleeve (54) is installed around the pipe (48) downstream of the valve (50) and a controlled flow of air is passed through the annulus (62) between the pipe and the sleeve.

Abstract: The system (12',14) includes a target member (78) associated with the stem valve (24) and displaceable therewith, and a camera (68) adapted to be positioned adjacent the stem for generating a video signal of at least a portion of the target member. A marker (80) associated with the valve in the field of view of the camera is provided for defining a reference displacement scale (82) in the video signal. A converter (62) is responsive to the video signal for generating target data commensurate with the absolute displacement of the target. First data interface equipment (42,58,60) is provided for digitizing the sensed pneumatic pressure as the pressure 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 (44,62) is provided for digitizing the target data commensurate with the displacement of the target.

Abstract: A tool having a rotating mast assembly 12 is provided which includes a hollow conductive gas transmitting electrode 14 and a non-hygroscopic ceramic shielding tube 12 which is made of at least 94% by weight Al.sub.2 O.sub.3 and has a tensile strength of at least 20,000 P.S.I. and an ability to withstand temperatures in excess of 1500.degree. C.

Abstract: The magnet filter (10,100) has a frame for supporting a plurality of elongated, non-magnetic tubes (20, 108) in a regular, spaced-apart array. A plurality of magnetic bodies (38,112), which can take a variety of forms, are situated in the spaces between the tubes of the array, for imposing a magnetic field within each tube over substantially the full length of each tube. The upstream end of each tube is adapted for receiving a fluid to be magnetically filtered and the downstream end is adapted for discharging such fluid. As the fluid passes through each tube, the magnetic field imparts a force to the magnetizable particulates, which are drawn toward the magnetized internal structure within the tube where they are deposited, thus filtering the fluid. The magnetic bodies may produce a field that is oriented either substantially parallel to the tube, or transverse to the tube.

Abstract: A cantilevered hold-down spring (68) for a nuclear fuel assembly (10), comprising an elongated metal bar including a substantially straight long leg portion (66) having one end adapted to be mounted (38) to a fuel assembly, an arcuate transition portion (70) at the other end of the long leg, and a straight short leg portion (76) extending from the transition portion at an acute included angle with the long leg portion, and a load transfer means (64) projecting from the straight leg intermediate the transition portion and the long leg first end. As the load on the primary loading point (80) on the transition portion increases, the load is transferred to the projection (64), thereby effectively shortening and stiffening the spring.

Abstract: A multisectioned nozzle dam (30) for use in a steam generator (24) with an integral bolt ring (32) has a body structure of general circular shape. Redundant seals including at least three separate inflatable peripheral seals (48, 50 and 52) with an alarm (A) for indicating a pressure increase between the second and third seals (50 and 52) is provided. Redundant supports including a plurality of independent bars (60, 62, 64 and 66) bolted to the integral bolt ring (36) secure the dam (30) within the nozzle (26) to the appropriate axial position.

Abstract: A stamping device (28) having a stationary base assembly (76), a carriage assembly (52) mounted on the base assembly for stepwise horizontal movement in a first direction relative to the base assembly, and a marker assembly (34) mounted on the carriage assembly for stepwise horizontal movement in a second, perpendicular direction. The marker assembly includes a marking pin (30) vertically actuable by an air cylinder (42) for impacting the tube sheet (14) adjacent a preselected tube (16). A control system (124) sequentially activates stepping motors (60,66) and the air cylinder to produce a dot matrix character (114) on the tube sheet.

Abstract: A solid oxide fuel cell 10 including a plurality of sheet-like components including a fuel electrode, an electrolyte 28, and an air electrode 26, sandwiched between interconnector sheet members 14,16, wherein the improvement comprises one of the components having exteriorly projecting inorganic whiskers 80 interengaged with inorganic whiskers projecting from another component, the interengagement serving to mechanically anchor the one and other components together. The anchored components can be an electrode and an electrolyte, an electrode and the interconnecting support structure, or the triplex layer as a unit and the interconnecting support structure.

Abstract: A system and method for installing a nozzle dam unit (26) in a nuclear steam generator having a head (12) including a head internal surface, a manway (14) penetrating the head, and a nozzle (16) penetrating the head. The system comprises a manipulator (76) adapted to be passed through the manway and having open end (82) adapted to be attached remotely to the head internal surface and a free end including a clamp member (104). A plurality of nozzle dam segments (54, 56, 58) are each sized to pass through the manway and carry means thereon (120) for engaging at least one other segment, the segments when fully engaged to each other forming a dam subassembly sized to pass into and seat against the nozzle. The manipulator is controlled so that the clamp member grasps and supports one of the dam segments within the head until the subassembly is formed within the head, and then is translated within the head until the dam subassembly seats within the nozzle.

Abstract: A fuel assembly has a spring detent spacer grid of intersecting strips for capturing and retaining deleterious debris carried by reactor coolant before it enters the active region of a fuel assembly. A plurality of fuel end caps are peripherally grooved to receive springs projecting from the strips. The end caps are thus captured by springs and debris is wedged and trapped on opposite sides of the strip and against the end caps by pairs of adjacent integral leaves projecting from the stips intermediate and substantially symmetrically arranged about their intersections.

Abstract: A nuclear fuel support grid 10' of egg-crate structure has wave defining strips 12a, 12b, 12c, 12d defined by bends 16' inclined from the vertical and opposing cantilevered springs 18' with inclined spring bases 20' opposing them for support of fuel rods 22 intermediate their ends. The "inclined waves" defined by inclined surfaces formed by bends 16' and spring bases 20' of cantilevered springs 18' provide lateral components to the coolant flow in patterns which enhance DNB and corrosion behavior.

Abstract: A clustered concentric tangential firing system (12) particularly suited for use in fossil fuel-fired furnaces (10) and a method of operating such furnaces (10) equipped with a clustered concentric tangential firing system (12).

Abstract: A tamper-proof closure 10 is inserted by means of positioning tool 20 into a nuclear fuel consolidation storage canister 30. The closure 10 includes a grooved weakened portion 44, which if it exceeds its elastic limit when the base 12 is flexed during removal attempts will indicate any attempts to remove or otherwise tamper with the thus closed canister. Locking tabs 18, on transverse legs 13 and 14 extending from base 12 are engaged in slots 40 in the wall of the opening of canister 30 when the closure 10 is in fuel storage position. Tool 20 has a portion 46 which enters a slot 48 in base 12 at 90.degree. to its working position and then twists to engage spanning portion 42's flanges 43 in slots of flanges 16 on the legs 13 and 14 to retract tabs 18. The base is prevented from flexing on insertion into the container opening by support it receives from portion 46.

Abstract: A pressurized water reactor fuel assembly (10) has a fastener or bolt (40) of stainless steel with a longitudinal groove (48) attaching zircaloy guide tubes (16) to stainless steel lower end fitting (14). The guide tubes have internally threaded zircaloy plugs (52) for mating with the threads (46) of bolt (40) with points (50) created in the threads (46) by groove (48) providing increased friction. The groove (48) acts to accommodate stresses set up by differential thermal expansion of zircaloy and stainless steel. Apertured stainless steel cups (60) receive the plugged ends of guide tubes (16) to capture them and provide connections to lower grid (22) of stainless steel.

Abstract: An apparatus (10) and a method for applying a chromized coating (46,60,62,66) to one or more of the surfaces of an article (44,56,58,64) particularly in those situations in which the article (44,56,58,64) is intended to be employed in an application wherein the article (44,56,58,64) will be subject to corrosion.

Abstract: A fuel element for a nuclear reactor having a zirconium-tin alloy cladding tube, with a thin coating of particles of enriched boron-containing compound burnable poison particles, deposited from a liquid sol-gel which includes a glass binder material.