Combustion Engineering, Inc.

Westinghouse Electric Company LLC

Michael L Martin

Zeses E Karoutas

Stephen C Hatfield

Richard P Broders

Patrick A Perrotti

Douglas S Porter

Paul F Joffre

Karl Heinz Haslinger

Woodruff H Higgins

Patrick A Perotti

An improved grid for use in a fuel assembly of a nuclear reactor includes a plurality of straps that are interconnected with one another in a lattice fashion to define a plurality of cells, with the straps being configured to include a plurality of relatively more compliant springs and a plurality of relatively less compliant dimples, whereby each cell includes only one pair of springs and one pair of dimples disposed therein. The springs and dimples are contoured to engage a fuel rod or a thimble tube disposed within the cell. Each spring directly confronts one of the dimples to provide confronting pairs of features that engage the fuel rods or thimble tubes, with each cell including two pairs of confronting features. The ligaments of the springs and dimples extend in a direction generally perpendicular to the direction of coolant flow through the reactor in order to minimize pressure drop.

Fuel assembly and associated grid for nuclear reactor

A wear-reduction-sleeve for in-core-instrumentation thimbles of a pressurized water nuclear reactor having bottom mounted instrumentation to curtail flow induced excitation and increase support contact area in the region of thimble length which extends through and defines an annulus with the core support plate and extends upwardly to and through the fuel assembly flow distribution plates. The wear-reduction-sleeve includes a hollow shank portion which gives a low wear coefficient when in contact with the chrome-plated thimble and is inserted into the annulus and below where it is radially expanded and secured to a thimble guide tube. An upper portion of the wear-reduction-sleeve between the core support plate and flow distribution plate has a flow collection chamber and radial flow exit slots which divert thimble flow substantially away from the hole in the fuel assembly flow distribution plate through which the thimble extends.

Wear-reduction-sleeve for thimbles

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Simsbury, CT, United States of America

Michael L Martin