Abstract: A surgical instrument, has an end effector that includes an ultrasonic blade, and a clamp arm that moves relative to the ultrasonic blade from an opened position toward an intermediate position and a closed position. The clamp arm is offset from the ultrasonic blade to define a predetermined gap in the intermediate position between the opened position and the closed position. A clamp arm actuator connects to the clamp arm and moves from an opened configuration to a closed configuration to direct the clamp arm from the opened position toward the intermediate position and the closed position. A spacer connects with the clamp arm to inhibit movement of the clamp arm from the intermediate position toward the closed position for maintaining the predetermined gap between the clamp arm and the ultrasonic blade.

Abstract: A surgical stapler, or fastening instrument, may generally comprise a layer, such as a tissue thickness compensator, for example, releasably attached to a fastener cartridge and/or anvil by a flowable attachment portion. The flowable attachment portion may be indefinitely flowable. The flowable attachment portion may be flowable from the time that layer is installed to the fastener cartridge to the time in which the layer is implanted to patient tissue. The flowable attachment portion may comprise a pressure sensitive adhesive. The flowable attachment portion may comprise an adhesive laminate comprising a base layer comprising the tissue thickness compensator and an adhesive layer on at least a portion of a surface of the base layer comprising the pressure sensitive adhesive. Articles of manufacture comprising flowable attachment portion and methods of making and using the flowable attachment portion are also described.

Abstract: Hybrid nuclear reactor grey rods are described, wherein geometric combinations of relatively weak neutron absorber materials such as stainless steel, zirconium or INCONEL, and relatively strong neutron absorber materials, such as hafnium, silver-indium cadmium and boron carbide, are used to obtain the reactivity worths required to reach zero boron change load follow. One embodiment includes a grey rod which has combinations of weak and strong neutron absorber pellets in a stainless steel cladding. The respective pellets can be of differing heights. A second embodiment includes a grey rod with a relatively thick stainless steel cladding receiving relatively strong neutron absorber pellets only. A third embodiment includes annular relatively weak netron absorber pellets with a smaller diameter pellet of relatively strong absorber material contained within the aperture of each relatively weak absorber pellet.

Abstract: A vent system for controlling hydraulically actuated drive means for selectively moving pluralities of rod clusters respectively connected to the plurality of drive means between fully inserted positions within the lower barrel assembly of the vessel in telescoping relationship with fuel rod assemblies contained therein, and a fully withdrawn position. Each drive means responds to the reactor coolant fluid pressure and includes a leakage passage and an outlet channel through which a leakage flow may pass under control of the vent system, the latter comprising a valve arrangement, flow restrictors and a common orifice through which the outlet channels are selectively connected to essentially ambient pressure, for establishing a pressure differential within each drive means producing a net force for moving the drive rods and associated clusters to the withdrawn position at which the drive means mechanically latch the fully withdrawn clusters for mechanically supporting same in the fully withdrawn position.

Abstract: A fuel assembly includes top and bottom nozzles, elongated hollow control rod guide thimbles extending longitudinally between and rigidly interconnecting the top and bottom nozzles such that together they form a rigid structural skeleton of the fuel assembly, transverse grids being supported on the guide thimbles at axially spaced locations therealong between the top and bottom nozzles, fuel rods extending through and being supported by the grids between the top and bottom nozzles so as to extend in generally side-by-side spaced relation to one another and to the guide thimbles, and elongated solid tie rods extending longitudinally between the top and bottom nozzles and through and rigidly interconnected with the grids so as to extend in generally side-by-side spaced relation to one another, to the fuel rods and to the guide thimbles so as to bolster the stiffness of the structural skeleton of the fuel assembly.