Fuel Rod Sleeve Extraction Using Internal Locking Teeth
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Solution Overview
Problem
Existing nuclear fuel rods and cluster rods are difficult to extract when they lose their end plugs, leading to handling difficulties and potential disengagement within the fuel assembly.
Innovation Solution
A device with an attachment portion featuring teeth that forcibly insert into the rod sleeve, engaging with the inner surface to prevent extraction, and a grip portion for pulling the rod out, ensuring reliable and easy removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of repair
If the end plug is removed or lost from the nuclear fuel rod, then the rod can be accessed or repaired, but the rod becomes difficult to extract from the fuel assembly
Solution Approach 1:
The patent introduces an intermediary extraction device with teeth that engage with the inner surface of the fuel rod sleeve. This mediator transfers the extraction force from the external tool to the rod, enabling removal even when the original end plug handling function is lost. The teeth act as a temporary interface between the extraction tool and the rod sleeve.
2Adaptability or versatility
If a cluster rod becomes disengaged from its upper end plug, then the rod may fall into the guide tube, but this creates handling difficulties and potential damage
Solution Approach 1:
The extraction device performs preliminary engagement with the rod sleeve before extraction begins. The teeth are designed to forcibly insert into the sleeve and lock onto the inner surface, establishing a secure connection in advance. This preliminary locking action prevents the rod from falling or becoming misplaced during the extraction process.
3Device complexity
If traditional extraction devices are used without teeth engagement, then the device structure is simpler, but the extraction reliability is reduced
Solution Approach 1:
The extraction device employs asymmetric teeth with specific geometric features that allow easy insertion but resist extraction. The teeth are configured with inclined surfaces and engagement profiles that create a ratcheting effect, enabling the device to be inserted forcibly while preventing backward movement during extraction. This asymmetric design provides reliable locking without requiring complex mechanical systems.
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 device allows for secure and efficient extraction of damaged nuclear fuel rods and cluster rods by locking within the sleeve, overcoming the challenges of lost end plugs and disengagement, with adjustable locking forces for various applications.
Implementation Method 1
the or each tooth being configured to allow forcible insertion of the attachment portion into the cladding axially, and to engage with the inner surface of the sleeve so as to prevent extraction of the attachment portion from the sleeve
Implementation Method 2
The body comprises a bearing portion configured to press against an edge of the end of the sleeve due to the insertion of the attachment portion into the sleeve
Data Source
AI summary
An extraction device for extracting a nuclear fuel rod or a cluster rod comprises an attachment portion configured to be inserted into a sleeve of the rod through an end without an end plug, and a grip portion, the attachment portion comprising an elongated body along a longitudinal axis and at least one tooth projecting from the body, the or each tooth being configured to allow the attachment portion to be forcibly inserted into the sleeve axially, and to engage with the inner surface of the sleeve so as to prevent the attachment portion from being extracted from the sleeve.