Double-Walled Reactor Irradiation Device with Gas Insulation

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Solution Overview

Problem

Existing devices for irradiating materials in nuclear reactors face challenges in withstanding high temperatures and pressures, particularly above 450°C, where materials like austenitic steels significantly degrade, and it is difficult to find materials that can maintain mechanical strength and safety under these conditions.

Innovation Solution

A double-walled enclosure device with a container filled with a heat transfer fluid, where the interior and exterior are in fluid communication, allowing the container to be made of materials that can withstand high temperatures without high pressure, and using a gas or gas mixture as a thermal insulator to maintain mechanical strength and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single-walled enclosure is used to contain samples at high temperature, then the structure is simple, but the material cannot withstand both high temperature and high pressure simultaneously

Engineering Contradiction:
Improveenclosure structureVSAvoidmaterial strength under irradiation
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The enclosure is divided into two separate walls: an inner wall that contacts the heat transfer fluid and samples at high temperature, and an outer wall that maintains structural integrity. This segmentation allows each wall to be optimized for its specific function - the inner wall for thermal resistance and the outer wall for mechanical strength under pressure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A heat transfer fluid is introduced as an intermediary substance between the samples and the outer enclosure wall. This fluid transfers heat from the samples to the inner wall while the double-walled structure maintains pressure differential, allowing thermal energy transfer without direct mechanical contact between the high-temperature zone and the pressure-bearing structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If materials like austenitic steel are used above 450°C, then the device can withstand high temperature, but the lifespan is significantly reduced

Engineering Contradiction:
Improvesample temperatureVSAvoidenclosure lifespan
Core Design Contradiction:
TemperatureVSDuration of action of stationary object

Solution Approach 1:

The enclosure walls are segmented into distinct functional zones with the inner wall exposed to high temperature and the outer wall maintained at lower temperature through the cooling fluid, allowing different material selections optimized for their respective thermal environments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The thermal parameters of the enclosure system are changed by introducing a cooling fluid that maintains the outer wall temperature below critical thresholds, thereby extending the lifespan of pressure-bearing materials while still allowing the inner wall to withstand high sample temperatures.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If the container is made of high-temperature resistant material, then it can hold high temperature, but it cannot withstand high pressure

Engineering Contradiction:
Improvecontainer temperatureVSAvoidenclosure pressure
Core Design Contradiction:
TemperatureVSStress or pressure

Solution Approach 1:

The pressure-containing function is separated from the temperature-containing function by dividing the enclosure into two walls with a cooling fluid channel between them. The outer wall is designed to withstand high pressure while the inner wall handles high temperature, resolving the contradiction between pressure and temperature resistance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cooling fluid acts as an intermediary that transmits thermal energy from the high-temperature zone to the outer wall while maintaining a temperature gradient that protects the pressure-bearing outer wall from excessive heat, allowing it to withstand high pressure without material degradation.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If a double-walled enclosure with cooling fluid is used, then high temperature and pressure can be withstood, but the device complexity increases

Engineering Contradiction:
Improveenclosure strength under pressure and temperatureVSAvoidenclosure structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The enclosure is segmented into two walls with a cooling fluid channel, creating a modular structure where each component has a specific function. This segmentation, while increasing structural complexity, enables the system to simultaneously withstand high pressure and temperature that would be impossible with a single wall.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cooling fluid channel serves multiple functions: it cools the inner wall to prevent overheating, provides structural support between the two walls, and allows for pressure equalization. This multi-functionality justifies the increased structural complexity by delivering multiple benefits from a single design feature.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 the achievement of high sample temperatures up to 800°C or more while ensuring mechanical strength and safety, allowing for precise temperature control and extended irradiation duration without compromising the enclosure's mechanical properties.

Implementation Method 1

a volume between the interior wall of the enclosure and the container is intended to be filled with a gas or mixture of gases, called sky gas heat carrier

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

a container intended to contain a heat transfer fluid, a sample support penetrating into the container so that the samples are immersed in the heat transfer fluid

Methodology Applied
Scientific EffectHeat transfer: Convection

Data Source

PatentEP2899724B1Device for irradiating samples in the core or periphery of the core of a reactor
Publication Date: 2016.12.14 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP2899724B1 patent drawingFigure 1~2
  • EP2899724B1 patent drawingFigure 3A~3B
  • EP2899724B1 patent drawingFigure 4~5A

AI summary

Device for irradiating a sample in the core or around the core of a nuclear reactor comprising, - a double-walled enclosure (6) delimiting a chamber (7), - a container (4) contained in said chamber (7), said container being kept away from an inner wall (8) of the enclosure, said container (4) being intended to contain a heat transfer fluid, - a sample holder (2) of which a free end is intended to be located in the container, the interior of the container being in fluidic communication with the exterior of the container and a volume between the inner wall (8) of the enclosure (6) and the container (4) being intended to be filled with a gas or mixture of gases, said heat transfer gas.