Westinghouse Electric Corporation

Robert W Cantrell

Edmund E DeMario

James A Sparrow

A fuel assembly has a top nozzle which includes a lower adapter plate and a plurality of guide structures thereon. The lower adapter plate has a peripheral edge. The guide structures are attached to and extend upwardly from the lower adapter plate at locations spaced inwardly from the peripheral edge of the lower adapter plate so as to separate the lower adapter plate into an interior portion extending between interior sides of the guide structures and mountable to the guide thimbles and a peripheral portion extending about exterior sides of the guide structures. The guide structures define a plurality of vertical guide slots. The top nozzle also includes a peripheral hold-down assembly disposed along the peripheral portion of the lower adapter plate about the exterior sides of the guide structures and having a plurality of guide tabs movably coupled to the guide slots of the guide structures for permitting vertical movement of the hold-down assembly relative to the lower adapter plate and guide structures in providing a downward biasing force against the peripheral portion of the lower adapter plate of the top nozzle. The peripheral hold-down assembly includes a peripheral arrangement of leaf springs and an annular upper retainer member overlying the peripheral portion of the lower adapter plate and engaging the peripheral arrangement of leaf springs.

Nuclear fuel assembly top nozzle with improved peripheral hold-down

A double enclosure top nozzle subassembly for a nuclear fuel assembly includes an upper structure having a top plate and an outer depending peripheral sidewall enclosure, a lower structure having a lower adapter plate and an inner upstanding peripheral sidewall enclosure disposed below the top plate and within the outer sidewall enclosure. The outer and inner sidewall enclosures are slidably movable relative to one another as the top plate moves toward and away from adapter plate. A plurality of resiliently-yieldable biasing devices, such as leaf springs extend between and engage the top plate and lower adapter plate. Interengagable structure on the lower and upper edges of the respective outer and inner sidewall enclosures limit movement of the top plate and lower adapter plate away from one another so as to retain the outer and inner sidewall enclosures in sliding contacting relationship together. The leaf springs are movable between compressed and expanded states in response respectively to application and removal of a hold-down force on the upper structure in the direction of the lower structure for permitting and causing movement of the top plate toward and away from the adapter plate and thereby the top nozzle subassembly between compressed and expanded conditions.

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Hopkins, SC, United States of America

Robert W Cantrell