Abstract: A mixer grid for a nuclear reactor fuel assembly has a plurality of strips arranged in interlocking rows and columns defining a plurality of cells. A stopper is fixed to each corner of each cell for both directing coolant flow, providing coolant mixing and providing a smooth contact surface for the fuel rod. The stopper is either cone-shaped or cylindrical for directing and channeling coolant flow. The stopper also has a smooth, flat chamfered surface for contacting the fuel rod and minimizing damage upon the shifting of the fuel rod. The grid is attached to the nuclear reactor fuel assembly by using guide cells comprising a plurality of support arches for welding to the nuclear reactor fuel assembly.

Abstract: A trigger system for the ignition system of an internal combustion engine having a crankcase with a rotatable crankshaft includes an aluminum disk-shaped hub for connection to the crankshaft and rotatable therewith on the end opposite the flywheel of the engine. The hub has at least one weight formed into the hub and offset from its center of gravity for balancing and reducing vibration of the engine during operation. A plurality of magnets or other magnetically responsive elements are provided in openings in a flange extending around the periphery of the hub. A stationary sensor is mounted adjacent the hub for detecting impulses from the magnetically responsive elements as the hub rotates and utilizing the impulses to trigger the ignition system.

Abstract: A bottom nozzle plate for a fuel assembly in a nuclear reactor. The bottom nozzle plate is formed from a rigid substantially square plate having legs adapted to be positioned on the lower core plate of the reactor for supporting the fuel assembly above coolant inlet openings in the core plate. The rigid square plate has two types of coolant flow holes therethrough. The first flow holes are grouped in clusters of four to define a square pattern relative to the sides of the plate such that the width of the sections of the plate between the flow holes in each cluster is less than the width of the sections of the plate between the clusters of four holes. Each of the second flow holes is formed in an irregular pattern to define a substantially clover leaf shape. The second flow holes are positioned so as to be above the coolant inlet openings in the core plate when the bottom nozzle plate is installed in the reactor.

Abstract: In nuclear reactor fuel assembly of the floating grid type, a spacer grid insert positioned concentrically about the central instrument guide tube prevents damage to instrument guide tube saddles caused by axial load, while permitting limited movement of the spacer grids.

Abstract: A retainer to provide supplemental holddown force for a control component assembly latched into a fuel assembly of a nuclear reactor. Upon failure of latching mechanism the retainer precludes the ejection of the control component assembly from the fuel assembly by the upward coolant flow drage force. The spring loaded retainer is mounted at the top of the control component assembly and engages both the control component assembly and the core grid plate to form a structural blocking of the grid plate hole thereby precluding the ejection of the control component assembly therethrough.