Combined Blade Guide and Exchange Tool for Boiling Water Reactors
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Solution Overview
Problem
The existing tools for replacing control rods in a boiling water reactor require multiple steps and tools, leading to inefficiencies and increased radiation exposure due to the need for separate blade guide and exchange tools, as well as verification checks that are not easily accessible.
Innovation Solution
A combined blade guide and exchange tool that integrates the functions of a blade guide tool and a blade exchange tool, utilizing a spring-loaded extension rod to actuate air switches and a trolley and hook assembly for lifting and positioning control rods, allowing for simultaneous fuel bundle removal and control rod replacement with reduced tool setup and verification checks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate blade guide tool and blade exchange tool are used, then each tool can perform its specific function, but the number of tools increases and the process becomes more complex
Solution Approach 1:
The patent combines the blade guide tool and blade exchange tool into a single integrated tool assembly. The blade guide portion provides guiding features for control rod insertion, while the blade exchange portion includes a trolley and hook assembly for lifting and positioning control rods. This merging eliminates the need for separate tools and reduces the number of in-core alterations required during control rod replacement operations.
2Reliability
If multiple separate tools are used for control rod replacement, then verification checks can be performed, but the number of steps increases and time is lost
Solution Approach 1:
The integrated tool assembly includes verification checks that can be performed easily and quickly as part of the streamlined process. The spring-loaded extension rod actuates air switches to verify proper seating and alignment of components before control rod replacement is completed, ensuring reliability without adding significant time to the process.
3Ease of operation
If separate tools are used for fuel bundle removal and control rod replacement, then each operation can be performed independently, but radiation exposure increases due to multiple tool insertions
Solution Approach 1:
By combining the blade guide and blade exchange functions into a single tool assembly, the number of separate tool insertions and removals is reduced. The integrated tool can perform both fuel bundle removal and control rod replacement operations in a streamlined sequence, minimizing the time tools are outside the reactor core and reducing radiation exposure to operators.
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 integrated tool streamlines the control rod replacement process, reducing the number of in-core alterations and eliminating the need for a separate grid guide tool, thereby saving time and minimizing radiation exposure while providing easily verifiable verification checks.
Implementation Method 1
The blade guide tool also contains a spring-loaded extension rod, extending the full length of the tool, that is in line with the core support alignment pin commonly called the 315 pin. When the blade guide seats on the fuel support, this extension rod contacts the 315 pin causing the rod to lift.
Implementation Method 2
a trolley and hook assembly attached to a cable guided by the blade exchange tool and adapted for engaging and lifting a control rod
Data Source
AI summary
A combined blade guide and exchange tool, include a blade guide tool having a lower end and an upper end and a plurality of frame rails supporting a pair of lower collet housings at a lower end of the blade guide tool. A pair of fuel support grapple actuating rods are supported between the plurality of frame rails and have a first end engaging a pair of collets within the pair of lower collet housings and a second end disposed at the upper end of the blade guide tool. A blade exchange tool is releasably mounted to the upper end of the blade guide tool and includes a pair of upper collets for engaging the pair of fuel support grapple actuating rods. The blade exchange tool further including a slider and hook assembly attached to a cable guided by the blade exchange tool and adapted for engaging a control rod.