Spacer grid insert

Patent · Tue Jul 07 04:00:00 EDT 1987

OSTI ID:6047825

King, R A; Larson, J G; Walton, L A

This patent describes an improved floating spacer grid in combination with a nuclear fuel assembly of the type having parallel fuel rods and at least one guide tube maintained in a laterally spaced array by axially spaced spacer grids. The fuel rods and guide tube extend through the spacer grids. The guide tube has a uniform circular outer surface, the spacer grids are movably mounted to the guide tube to permit axial displacement of the spacer grids relative the guide tube. Saddles form from and within the spacer grids at top and bottom edges of the grids, a spacer sleeve positioned concentrically about the guide tube intermediate the adjacent ones of the axially-spaced spacer grids for limiting axial displacement of the spacer grids, and the spacer sleeve has opposite ends closely spaced from the edges of the adjacent spacer grids to define a displacement space. The improvement comprises in combination; tubular inserts, each insert mounted to the guide tube within each of the spacer grids. Each insert includes a tubular portion positioned by the saddles to circumscribe the guide tube within the spacer grid and a circular flange portion at one end of the tubular portion. The flange portion is positioned in the displacement space and abutted to the edge of the spacer grid on the saddles, intermediate the spacer grid and spacer sleeve, and the circular flange portion has substantially the same outer diameter as the spacer sleeve thus precluding direct contact of the spacer sleeve with the spacer grid. The inserts carry all axial through-grid loads and prevent a horizontal vector force component applied against the grids.

• Assignee: Babcock and Wilcox Co., New Orleans, LA
• Patent Number(s): US 4678630
• OSTI ID: 6047825
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220300* -- Nuclear Reactor Technology-- Fuel Elements
DESIGN
ELECTRODES
FLANGES
FUEL ASSEMBLIES
FUEL ELEMENTS
FUEL RODS
GRIDS
OPERATION
POSITIONING
POWER REACTORS
REACTOR COMPONENTS
REACTORS
SPACE DEPENDENCE
SPACERS
TUBES