Westinghouse Electric Company LLC

Pbjt Engineering Solutions LLC

Paul M Evans

Joonhyung Choi

Michael Anthony Marzean

Travis Murphy

Jared Jeffcoat

Brent Jeffcoat

Edmund E DeMario

David A Boatwright

Zeses E Karoutas

Quang M Nguyen

Xiaoyan (Jane) Jiang

Xiaoyan Jiang

Michael E Conner

David Douglas Seel

Zeses Karoutas

Phillip L Hazlett

Gary C Crabtree

Yong Lu

Kevin G Guthrie

John C Rue, Jr

Harry A Pearce

Gregory D Livermore

Benjamin T Burnette

Virgil Jamie Vasquez

Yong (Roger) Lu

Michael Thomas Sloop

Hua Jiang

A spacer grid specifically designed for accident tolerant fuel utilizing fuel rods with SiC cladding for implementation in pressurized water reactors. The spacer grid design allows for ease of SiC fuel rod insertion during the fuel assembly fabrication process by providing a smooth contact geometry. The co-planar support allows the fuel rods to be rotated axially more freely at the grid location than a conventional six-point contact geometry used in existing fuel assembly designs. The fuel rod support cells are attached at their corners which are shared between adjacent support cells.

Spacer grid using tubular cells

A popcorn ceiling scraper includes a scraping head with multiple blades, at least one of which is oriented horizontally in the same plane as the scraping head with other blades extending vertically from the scraping head. The ceiling scraper has a funnel arranged below the scraping head, and the funnel and the scraping head are formed to reach to an edge or juncture between a ceiling and a wall.

Vacuum-assisted popcorn ceiling scraper

A spacer grid specifically designed for accident tolerant fuel utilizing fuel rods with SiC cladding for implementation in pressurized water reactors. The spacer grid has a generally square design that allows for ease of SiC fuel rod insertion during the fuel assembly fabrication process by providing a smooth contact geometry. The co-planar support allows the fuel rods to be rotated axially more freely at the grid location than a conventional six-point contact geometry used in existing fuel assembly designs.

Spacer grid using tubular cells with mixing vanes

A method of determining the bow and twist of a nuclear fuel assembly that utilizes fiber optic shape sensing technology enclosed within a flexible sheath that transmits strain on the interior walls of a control rod guide thimble within the fuel assembly to a fiber cable of the shape sensing technology enclosed within the sheath. The sheath conforms to the interior dimensions of the interior walls of the guide thimble.

Method for measuring bow/twist of a fuel assembly

A fuel assembly for a pressurized water reactor that has a protective grid attached to the bottom nozzle through a spacer insert captured between a control rod guide thimble end plug and the bottom nozzle. A thimble screw attaches the bottom nozzle to the control rod guide thimble end plug through a central opening in the spacer insert. The control rod guide thimble end plug is provided with a raised annular boss that encircles the thimble screw shank and rests against the upper surface of the bottom nozzle through the opening in the spacer insert. The opening in the spacer insert is large enough to provide both an axial and radial clearance between the spacer insert and the end plug to accommodate differences in thermal expansion.

Protective grid attachment

A fuel assembly for a nuclear reactor that employs dissimilar materials for the fuel assembly grid and the control rod guide thimbles. The guide thimbles are secured to the grid employing a through grid cell sleeve that is welded to the grid and spot weld rings that are secured over the sleeve and welded directly to the guide tube through windows in the sleeve.

Nuclear reactor fuel assembly

A nuclear fuel assembly support grid formed from an array of a plurality of orthogonally arranged straps in an egg-crate configuration with angled trailing and/or leading edges that are designed to break the correlation of vortices shed from the edges of the grid straps by varying the phase of the vortices to avoid resonant vibration of the straps.

Nuclear fuel assembly support grid

A protector bottom grid for a nuclear fuel assembly that includes three laterally staggered and horizontally oriented protrusions that extend into the fuel rod cell of a support grid below a vertically oriented spring. The three staggered protrusions extend into the cell a distance that maintains a space between the protrusions and the fuel rod. The vertically oriented spring biases the fuel rod against a dimple extending from the opposite cell wall that is at an elevation just above the spring. The protrusions below the spring trap incoming debris in the area of the fuel rod end cap and protect the fuel rod cladding from fretting.

Nuclear fuel assembly protective bottom grid

A method of fabricating a fuel assembly grid that includes providing a plurality of interconnected straps that form a lattice pattern, wherein the lattice pattern of the straps defines a plurality of cells, providing a sleeve that has a cylindrical portion and a flared portion, and inserting the sleeve into at least one of the cells. When inserted, at least a portion of the cylindrical portion of the sleeve will reside inside the cell and the flared portion will extend above the top end of the cell and overhang the perimeter of the cell. The flared portion is melted and flows over and fuses to the straps that define the cell. The straps may include weld tabs over which the melted material flows and to which it fuses. The melting and fusing steps also preferably cause any loose straps surrounding the cell to become attached to the sleeve.

Method of fabricating a nuclear reactor fuel assembly grid

A new spring design for a strap employed in a grid of a nuclear reactor fuel assembly includes a pair of ligaments that each connect with the free portion of the retention plate. The ligaments each are equally spaced a certain distant from the termination of the slots within the strap body. The spring additionally includes a spring contact plate that is wider than the connections of the spring ligaments with the free portion to increase the surface area with which the spring contact plate is in contact with and retains the fuel rod, and thus reduces the contact stresses therebetween. The spring contact plate additionally includes an embossed spring contact member protruding outwardly therefrom reduces the frictional stresses on the fuel rod when it is inserted into and removed from the cell and during vibration of the fuel rod and/or the strap.

Fretting resistant spring design

The adaptor plate of a top nozzle assembly is removably secured to selected thimble tubes in a nuclear fuel assembly by quick release couplings. The openings in the adaptor plate aligned with the selected thimble tubes are counterbored from above to form shoulders with diametrically opposed slots extending downward through the shoulders. The quick release couplings include a sleeve secured to the upper end of the thimble tube. A support plate fixed to the sleeve has a pair of upwardly extending bosses engaging the slots in the adaptor plate. A latch member with a pair of diametrically opposed outwardly projecting latch ears rotates on the sleeve between a first position in which the latch ears are aligned with the slots and are positioned over the bosses so that the adaptor plate may be lifted off, and a second position with the latch ears overlaying the shoulder to latch the adaptor plate to the thimble tube. A spring member with a cylindrical body has a pair of diametrically opposed radially compliant projections formed by bulges in strips defined by circumferential slits spaced from the bottom edge of the cylindrical body which engage detents in the bosses to latch the latch member in the first, unlatched position even with the adaptor plate removed, and which engage detents in the opening in the adaptor plate to latch the latch member in the second, latched position.

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Lexington, SC, United States of America

Paul M Evans