Nuclear Fuel Guide Tube Connection Device with Elastic Locking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing connection devices for guide tubes in nuclear fuel assemblies are inconvenient during maintenance operations, as they require complete removal and often fail due to cracking and tearing, leading to irradiated scrap material and increased radiation risk for operators.
Innovation Solution
A connection device with an elastic locking member that axially pushes the screw towards an abutment surface, allowing for secure retention and easy removal of the screw without damaging the locking device, using a radially elastic ring or helical spring to prevent self-unscrewing and facilitate reusable operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a locking device with bulging parts is used to prevent self-unscrewing, then the screw is securely locked, but the locking device cannot be reused after one-time use due to cracks and tears
Solution Approach 1:
The locking device is segmented into two separate components: a screw with a locking groove and an independent elastic locking member (ring or spring). This segmentation allows the screw and locking member to be separated - the screw can be removed and reused while the locking member remains in the body, eliminating the damage accumulation problem of integrated locking devices.
Solution Approach 2:
The locking mechanism changes from permanent deformation (bulging) to elastic deformation. The elastic locking member uses reversible elastic deformation to provide locking force, allowing it to be compressed during tightening and expand during removal, then return to its original state for reuse, unlike the irreversible bulging mechanism.
2Ease of operation
If the locking device is completely removed during maintenance, then the lower nozzle can be replaced, but irradiated scrap material is produced and radiation risk increases for operators
Solution Approach 1:
The locking mechanism enables selective discarding and recovering of components. The elastic locking member can be discarded in the irradiated zone (remaining in the body), while the screw is recovered and removed from the irradiated zone for reuse, minimizing radioactive waste and reducing operator radiation exposure.
3Reliability
If the screw is tightly locked during operation, then connection reliability is ensured, but the screw cannot be easily unscrewed during maintenance without damaging the locking device
Solution Approach 1:
The locking mechanism transitions from a static locked state to a dynamic release state. During operation, the elastic locking member is compressed and provides strong locking force. During maintenance, axial extraction force transforms the state by allowing the locking member to expand and disengage from the locking groove, enabling easy unscrewing without damage.
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 connection device enables efficient and safe maintenance by allowing voluntary unscrewing without damaging the locking mechanism, reducing the risk of radiation exposure and enabling reusable components, thus minimizing waste and handling risks.
Implementation Method 1
the locking device comprises an elastic locking member adapted to axially push the screw along the screw axis towards the abutment surface
Implementation Method 2
the elastic locking member is a radially elastic ring mounted in an annular mounting groove provided in the body or the screw
Data Source
AI summary
A connecting device including a nut, a screw, a body having a bore for screwing the screw to the nut through the bore with the screw abutting an abutment surface of the body, a screw locking device for preventing loosening of the screw.According to one aspect of the invention, the locking device is adapted for axially retaining the screw into the body after unscrewing the screw.