Sensor Positioning Apparatus for Nuclear Reactor Core Shroud Inspection

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Solution Overview

Problem

Nuclear reactor components, especially the core shroud, are difficult to inspect due to limited access and high radioactivity, requiring lengthy manipulator reconfigurations that increase personnel exposure and plant shutdown duration.

Innovation Solution

A robotic apparatus with a precision positioner system that includes a fixed gear rack mechanism and movable bearing system, allowing a sensor, such as an ultrasonic probe, to be remotely positioned vertically and circumferentially along the core shroud, reducing the need for manipulator reconfigurations by enabling simultaneous inspection of multiple welds without repositioning the tool.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual manipulators are used to position inspection tools in limited access areas, then inspection capability is achieved, but installation and reconfiguration time increases significantly

Engineering Contradiction:

Improveinspection capabilityVSAvoidinstallation and reconfiguration time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The manipulator system is divided into modular components including a base unit, extendable arms, and interchangeable sensor modules. Each module can be independently positioned and configured, allowing rapid reassembly without complete disassembly. The sensor module can be detached and replaced without removing the entire manipulator from the limited access area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The manipulator employs dynamic positioning mechanisms with adjustable joint angles and extendable segments that can be reconfigured in-situ. The system includes motorized actuators and position sensors that enable automated adjustment of arm positions and sensor orientations, eliminating manual repositioning operations.

Inventive Principle:

Principle #15Dynamics

2Reliability

If multiple manipulator reconfigurations are performed to inspect different welds, then comprehensive inspection coverage is achieved, but personnel radiation exposure increases

Engineering Contradiction:

Improveinspection coverageVSAvoidpersonnel radiation exposure

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The manipulator system is designed with universal sensor modules that can inspect multiple weld types and orientations without requiring different specialized tools. The sensor assembly includes multi-directional ultrasonic transducers and adjustable positioning mechanisms that accommodate various weld geometries, allowing a single manipulator configuration to perform multiple inspection functions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The manipulator maintains continuous inspection operation through automated in-situ reconfiguration. Positioning mechanisms enable seamless transition between weld inspection points without removing the manipulator from the radiation field. The system continuously scans welds by adjusting sensor angles and positions programmatically, eliminating idle time and repeated personnel interventions.

Inventive Principle:

Principle #20Continuity of useful action

3Adaptability or versatility

If manipulators are frequently installed and removed for reconfiguration, then inspection adaptability is improved, but plant shutdown duration increases

Engineering Contradiction:

Improveinspection adaptabilityVSAvoidplant shutdown duration

Core Design Contradiction:

Adaptability or versatilityVSDuration of action of stationary object

Solution Approach 1:

The manipulator system employs nested modular components where sensor modules are contained within arm assemblies, which are themselves nested within the base structure. This hierarchical nesting allows inner components to be replaced or reconfigured without affecting outer structures, enabling rapid adaptation while maintaining overall system integrity and minimizing disruption to plant operations.

Inventive Principle:

Principle #7Nested doll (Nesting)

4Ease of manufacture

If manual positioning methods are used in limited access areas, then installation simplicity is maintained, but operational complexity increases

Engineering Contradiction:

Improveinstallation simplicityVSAvoidoperational complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

Manual mechanical positioning operations are replaced with automated motorized actuators and computer-controlled positioning systems. Sensors and feedback mechanisms monitor manipulator position and make automatic adjustments, eliminating complex manual manipulation while maintaining installation simplicity through standardized mounting procedures.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP2907139B1Apparatus and method to control sensor position in limited access areas within a nuclear reactor

Publication Date: 2018.02.14 WESTINGHOUSE ELECTRIC CORP

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AI summary

This invention concerns robotic systems and is specifically concerned with an improved apparatus and method for remotely positioning a sensor (204), such as an ultrasonic probe, in limited access areas within a nuclear reactor. The apparatus includes a bottom frame (202) and a top cover (203) which is substantially aligned with and positioned above the bottom frame (202). A sensor (204) is connected to the top cover (203) and linear rails (205a,b) are connected to the bottom frame (202) in a parallel relationship. There is a mechanism (210) movably connected to the first and second linear rails (205a,b) in order to allow horizontal travel of the top cover (203). Further, there is at least one cable connected to the sensor (204) and a power source, signal source or receiver.