Nuclear Fuel Assembly Turning Device with Immobilization Mechanism

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Solution Overview

Problem

Current devices for turning nuclear fuel assemblies require the use of an overhead crane, which monopolizes it and is not available for other operations, and involves time-consuming displacements of fuel assemblies for maintenance and repairs, especially when operations need to be performed underwater.

Innovation Solution

A compact turning device with a movable support member rotatably mounted on a fixed support member, featuring an immobilization mechanism with synchronization gears and a drive mechanism that allows the container to be turned over 360° without requiring an overhead crane, enabling operation underwater.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If an overhead crane is used to suspend the lifter for turning operations, then the container can be turned over, but the crane is monopolized and unavailable for other operations

Engineering Contradiction:
Improveturning operationVSAvoidcrane availability
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The invention extracts the turning function from the overhead crane system by providing a dedicated turning device with its own support members and drive mechanism. This allows the crane to be freed for other operations while the turning device independently performs container turning operations through its self-contained structure including first and second support members, a drive arm, and associated drive mechanisms.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of repair

If maintenance operations are performed in the maintenance pool, then fuel assemblies can be repaired, but temporary storage cells must be emptied which requires time-consuming displacements

Engineering Contradiction:
Improvefuel assembly maintenanceVSAvoidpool displacement time
Core Design Contradiction:
Ease of repairVSLoss of time

Solution Approach 1:

The invention segments the pool operations by providing dedicated turning and maintenance equipment that enables independent operation in specific pool zones. The turning device with its specialized support members and the maintenance device with robotic manipulators allow operations to be performed without requiring the entire pool to be clear, thus eliminating the need to empty temporary storage cells before maintenance can begin.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If a compact turning device is used instead of overhead crane, then the device is more integrated and easier to use, but the device complexity increases

Engineering Contradiction:
Improvedevice integrationVSAvoidturning device structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention merges multiple functions into an integrated turning device structure. The first support member, second support member, drive arm, and drive mechanisms are combined into a single coordinated system that performs container turning operations. This integrated design provides adaptability and ease of use while managing complexity through functional consolidation rather than separate components.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2676278B1Device for turning a container, particularly for nuclear fuel assemblies, turning assembly, and nuclear power plant
Publication Date: 2015.10.14 AREVA NP SAS
  • EP2676278B1 patent drawingFigure 1
  • EP2676278B1 patent drawingFigure 2
  • EP2676278B1 patent drawingFigure 3

AI summary

The invention relates to a device (6) for turning a container (4) about a turning axis (A), including a stationary holding member (18) and two bearing members (14, 16) which are spaced apart along the turning axis (A) on each side of a space for receiving a container (4), and which are capable of being used for bearing on the container (4) while enabling the rotation of the container about the turning axis (A) relative to the bearing members (14, 16). The device includes a movable holding member (20) that is mounted onto the stationary holding member (18) so as to rotate about the turning axis (A), at least one bearing member (14, 16) being supported by the movable holding member (20) while being mounted onto the movable holding member (20) so as to rotate about the drive axis (A), the or each bearing member (14, 16) supported by the movable holding member (20) not rotating about the turning axis (A) relative to the stationary holding member (18) when the movable holding member (20) rotates about the turning axis (A) relative to the stationary holding member (18).