Nuclear Fuel Assembly Spacer Grid Elastic Positioning
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Solution Overview
Problem
Existing nuclear fuel assembly spacer grids face challenges in achieving good lateral positioning of fuel rods within the fuel channel while being cost-effective and easy to manufacture.
Innovation Solution
A nuclear fuel assembly spacer grid with an elastically deformable peripheral band featuring cantilevered springs and rigid contact projections, which are stamped into the band, provides adjustable positioning and minimal resistance, ensuring proper coolant flow and reduced fabrication complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If rigid tabs, lobs or stops are formed in or assembled to the peripheral band, then lateral positioning of the spacer grid is ensured, but manufacturing complexity and cost increase
Solution Approach 1:
The patent replaces rigid positioning tabs with elastic springs that can deform dynamically. The springs are formed in the peripheral band and can bend to accommodate positioning adjustments, allowing the spacer grid to be positioned laterally while reducing manufacturing complexity compared to rigid tab assemblies.
Solution Approach 2:
The patent changes the physical state of the positioning elements from rigid to elastic. By using elastically deformable springs instead of rigid tabs, the system can achieve positioning through elastic deformation, which simplifies manufacturing while maintaining positioning accuracy.
2Manufacturing precision
If rigid tabs, lobs or stops are formed in or assembled to the peripheral band, then lateral positioning of the spacer grid is ensured, but manufacturing cost increases
Solution Approach 1:
The patent merges the positioning function into the peripheral band itself by forming springs directly in the band material. This eliminates the need for separate positioning components that would need to be assembled, reducing manufacturing steps and costs while achieving reliable lateral positioning.
Solution Approach 2:
The springs are formed self-contained within the peripheral band, utilizing the band's own material properties for positioning. This self-service approach eliminates the need for external positioning components and complex assembly processes, reducing manufacturing cost.
3Ease of operation
If elastically deformable springs are formed in the peripheral band, then lateral positioning is achieved with adjustable force, but structural complexity increases
Solution Approach 1:
The patent applies elastic deformation properties locally at the positioning points within the peripheral band, rather than making the entire structure complex. The springs are localized features formed in the band, providing adjustable positioning force only where needed, which minimizes overall structural complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The spacer grid effectively maintains fuel rods' lateral positioning with adjustable force, minimizing flow resistance and fabrication steps, while ensuring adequate coolant flow and reduced operational stress.
Implementation Method 1
at least one spacer grid positioning spring elastically deformable and formed in the peripheral band
Data Source
AI summary
A nuclear fuel assembly spacer grid defining a lattice of cells for receiving fuel rods is provided. The spacer grid includes a peripheral band composed of at least one peripheral strip delimiting a portion of the peripheral contour of the spacer grid, and at least one spacer grid positioning spring elastically deformable and formed in the peripheral band.