Nuclear Reactor Guide Key Replacement Method
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The guide keys in nuclear reactors wear out due to friction, leading to excessive travel of internal equipment beyond authorized standards, necessitating a method for precise replacement to maintain accurate positioning and functionality.
Innovation Solution
A method for replacing guide keys involves identifying the original key's sound surfaces to simplify positioning, using a multi-axis robot for precise placement, and drilling positioning bores with electroerosion to ensure accurate engagement of replacement keys, which are fixed using screws and pins, allowing for precise circumferential and axial alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If guide keys are used to guide internal equipment, then the internal equipment can move axially relative to the vessel, but the friction between keys and slideways causes wear and excessive displacement over time
Solution Approach 1:
The guide key is divided into two distinct parts: a guide part that engages with the slide for axial guidance, and a fixing part that is secured to the internal equipment. This segmentation allows the guide part to wear while the fixing part remains stable, maintaining positioning accuracy despite friction-induced wear over time.
Solution Approach 2:
Different parts of the guide key are given different functions and properties. The guide part is designed for movement and guidance, while the fixing part is designed for stable attachment. This local differentiation ensures that wear affects only the guide part, which can be replaced independently, while the fixing part maintains its secure attachment function.
2Ease of repair
If traditional methods are used to replace guide keys, then replacement can be performed, but positioning of the replacement key is complex and time-consuming
Solution Approach 1:
Positioning marks are established on the vessel before the guide key is removed. These marks indicate the precise circumferential and axial positions where the replacement key should be installed. By preparing these marks in advance, the replacement operation becomes straightforward and rapid, eliminating complex measurement and positioning procedures.
Solution Approach 2:
The replacement key is positioned by referencing the marks that replicate the original key's position information. Instead of performing complex measurements during replacement, the pre-established marks serve as a copy of the correct positioning data, enabling quick and accurate installation without time-consuming calculations or measurements.
3Ease of operation
If the guide key is engaged in the slide, then guiding function is provided, but the friction causes wear of the key surfaces
Solution Approach 1:
The harmful wear effect is extracted and isolated to the guide part of the key, which is designed to be replaceable. The fixing part is protected from wear and remains in place. This extraction allows the system to maintain its guiding function while managing wear as a localized, replaceable issue rather than a system-wide degradation.
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
This method enables precise replacement of guide keys, ensuring accurate positioning and preventing excessive displacement of internal equipment, thereby maintaining reactor performance and safety standards.
Implementation Method 1
drilling positioning bores with electroerosion to ensure accurate engagement of replacement keys
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
Method for replacing a rail for guiding a piece of equipment inside a nuclear reactor. The method comprises the following steps: creating a fixed coordinate system (68); determining the coordinates of an origin circumferential position of uncontaminated areas (60, 62, 64) of the original rail (26) with respect to the fixed coordinate system (68); and circumferentially positioning a replacement rail (90) using the origin circumferential position of the uncontaminated areas (60, 62, 64).