Precision Magnets for Fuel Rod Alignment and Retention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional nuclear reactor systems experience coolant pressure drops and fuel rod damage due to mechanical retention and alignment components, which reduce thermal efficiency and increase the risk of fuel rod wear and seismic-related accidents.
Innovation Solution
A magnetic retention and alignment system using precision magnets with customizable polarity configurations to axially and laterally secure fuel rods without physical contact, allowing for adjustable magnetic attraction and repulsion to maintain alignment and reduce pressure drops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical retention and alignment components are used to hold fuel rods in position, then the fuel rods are secured axially and laterally, but the system experiences coolant pressure drops and thermal efficiency is reduced
Solution Approach 1:
The patent replaces mechanical retention components (springs, braces, end plugs) with a magnetic field-based retention system. Magnets are embedded in the fuel rod cladding and grid structures to provide axial and lateral retention forces through magnetic attraction, eliminating the need for physical contact components that cause pressure drops.
Solution Approach 2:
The patent introduces magnetic fields as an intermediary force field between the fuel rod and grid structures. This magnetic field acts as a non-contact mediator that provides retention and alignment forces without requiring direct mechanical contact, thereby avoiding the harmful effects of mechanical components on coolant flow.
2Reliability
If mechanical retention components are used to secure fuel rods, then the fuel rods are retained in position, but wear and damage to fuel rods occurs due to contact between structural features and fuel
Solution Approach 1:
The patent eliminates mechanical contact-based retention by using embedded magnets in the cladding and grid structures. The magnetic force provides retention without physical contact between structural components and the fuel rod, preventing wear and damage that occurs with traditional mechanical springs, braces, and end plugs.
3Stability of the object's composition
If traditional mechanical retention systems are used, then fuel rod alignment is maintained, but the system complexity and number of components increase
Solution Approach 1:
The patent merges the retention and alignment functions into the fuel rod cladding and grid structures by embedding magnets directly within these components. This integration eliminates separate mechanical retention devices and simplifies the overall system architecture while maintaining precise fuel rod alignment through magnetic forces.
4Reliability
If mechanical retention components are used, then axial and lateral retention is achieved, but thermal efficiency is reduced due to pressure drops
Solution Approach 1:
The patent replaces mechanical retention components with a magnetic field-based system that eliminates physical obstructions to coolant flow. The embedded magnets provide retention forces without creating turbulence or pressure drops, thereby maintaining optimal thermal efficiency and heat transfer from fuel rods to coolant.
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 magnetic system eliminates pressure drops, reduces fuel rod wear, and enhances safety by minimizing seismic forces and the risk of coolant loss accidents, while enabling easier component removal and replacement.
Implementation Method 1
The first precision magnet has at least one of a magnetic north or south polarity and the second precision magnet has at least one of a magnetic south or north polarity opposite the polarity of the confronting first precision magnet to effect magnetic attraction between the confronting first and second precision magnets
Implementation Method 2
The third precision magnet has at least one of a magnetic north or south polarity and the fourth precision magnet has at least one of a magnetic north or south polarity the same as the polarity of the confronting third precision magnet to effect magnetic repulsion between the confronting third and fourth precision magnets for maintaining a gap between the fuel rod and the grid strap
Data Source
AI summary
An improved retention and alignment system for nuclear fuel rods includes an upper nozzle plate and a lower nozzle plate, nuclear fuel rods, each having an upper end and a lower end and extending axially between the upper and lower nozzle plates, a first precision magnet incorporated onto the lower end of the fuel rod, and a plurality of second precision magnets incorporated onto the lower nozzle plate in positions confronting the first precision magnets on the fuel rods. Each first precision magnet has at least one of a magnetic north or south polarity and the second precision magnet has at least one of a magnetic south or north polarity opposite the polarity of the confronting first precision magnet to effect magnetic attraction between the confronting first and second precision magnets. Grids between the upper and lower nozzle plates form cells through which the fuel rods pass. Precision magnets of the same polarity may be positioned laterally along the fuel rods and grid walls in positions confronting each other to repel the fuel rods from the grid walls to maintain fuel rod alignment and prevent contact between the fuel rods and the grids.