Underwater Hole Re-Machining With Suction for Reactor Nozzle Repair
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Solution Overview
Problem
Damaged centering holes in nuclear reactor nozzles can lead to jamming issues during reactor operations, requiring costly and risky nozzle replacements, which can damage other parts and pose radioactive handling challenges.
Innovation Solution
A repair device with a cutting tool having a suction channel and a drive shaft for underwater machining of damaged holes, allowing for re-machining of centering holes to maintain precise dimensions and prevent jamming, while minimizing radioactive exposure and part damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a nozzle is replaced to fix a damaged centering hole, then the assembly compliance is restored, but the operation becomes lengthy and risks damaging other parts
Solution Approach 1:
The patent extracts the damaged centering hole material and replaces it with a new insert (centering hole insert) that fits into the existing nozzle bore. This avoids the need to remove the entire nozzle while restoring the centering hole functionality, thereby reducing operation time and risk to other components.
Solution Approach 2:
Instead of replacing the entire nozzle, the patent applies a localized repair solution by inserting a new centering hole insert only where the damage occurred. This preserves the rest of the nozzle structure and maintains assembly compliance without the time-consuming process of complete nozzle replacement.
2Reliability
If a nozzle is replaced to fix a damaged centering hole, then the assembly compliance is restored, but the risk of damaging other parts increases
Solution Approach 1:
The patent extracts only the damaged centering hole portion and replaces it with an insert, leaving the rest of the nozzle and surrounding components (guide tubes, connections) untouched. This minimizes the risk of damaging other parts compared to complete nozzle removal and replacement.
Solution Approach 2:
The localized insert repair approach confines the intervention to the specific damaged area (centering hole), preserving the integrity of adjacent components such as guide tubes and connections, thereby reducing the harmful effects on other parts of the assembly.
3Ease of repair
If a nozzle is removed for replacement, then the damaged part can be replaced, but specific storage and removal mode outside normal handling cycle is required
Solution Approach 1:
The patent extracts only the damaged centering hole insert and replaces it with a new insert, avoiding the need to remove the entire nozzle from the assembly. This simplifies the handling procedure and eliminates the need for special storage and removal modes outside the normal handling cycle.
Solution Approach 2:
By applying a localized insert replacement rather than complete nozzle removal, the patent reduces the complexity of handling procedures. The repair can be performed using standard handling equipment and procedures, without requiring special storage facilities or complex removal modes.
4Productivity
If centering hole is damaged and left unrepaired, then the assembly can continue to be used, but jamming of centering pin may occur
Solution Approach 1:
The patent performs preliminary repair of the damaged centering hole by inserting a new insert before jamming of the centering pin occurs. This preventive maintenance approach restores the centering hole dimensions and prevents future jamming, ensuring reliable centering pin operation while maintaining assembly usage continuity.
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
Enables quick, reliable, and economical repair of damaged centering holes, extending the life of nuclear reactor components, reducing the risk of further damage and the need for radioactive storage, and ensuring precise machining within predefined dimensions.
Implementation Method 1
a suction channel extending into the cutting tool between at least one inlet opening and at least one outlet opening
Data Source
AI summary
A repair device for underwater repair of a hole in a nuclear reactor part includes a holder (32), a cutting tool (22) held by the holder (32) and having at least one cutting tooth (70) for remachining an inner surface of the hole. The cutting tool (22) has a suction channel (44) extending into the cutting tool (22) between at least one inlet opening (46) and at least one outlet opening (48), a drive shaft (34) for rotating the cutting tool (22), the drive shaft (34) being held by the holder (32), and a suction tube (36) connected to the holder (32) and fluidly connected to the outlet opening (48) of the suction channel (44).