Spherical Iridium Radiation Source for Nondestructive Inspection
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Solution Overview
Problem
Conventional radiation sources for nondestructive inspection exhibit anisotropy, nonuniform target-by-target source strength, low geometric resolution, and lack of recyclability due to disc-like targets, making it difficult to achieve high-resolution images and efficient resource use.
Innovation Solution
A spherical irradiation target made of iridium metal with a diameter of 0.5 to 1.5 mm is used, which is manufactured by dropping molten iridium into a liquid or machining, and loaded into a rotating capsule within a reactor, where it is rotated by the downward flow of primary coolant to ensure uniform neutron irradiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If disc-like targets are stacked to form a cylindrical radiation source, then the source can be manufactured, but radiation anisotropy occurs and geometric resolution is low
Solution Approach 1:
The patent applies spheroidality by changing the target shape from disc-like cylindrical segments to spherical segments. This spherical geometry eliminates the anisotropic radiation patterns inherent in disc-like structures, providing uniform radiation emission in all directions and thereby improving geometric resolution in nondestructive inspection images.
Solution Approach 2:
The patent addresses asymmetry by ensuring that spherical targets are uniformly distributed throughout the capsule volume. This uniform distribution compensates for the inherent asymmetry in capsule geometry and target positioning, achieving isotropic radiation emission that eliminates directional bias in the inspection images.
2Ease of manufacture
If disc-like targets are stacked to form a cylindrical radiation source, then the source can be manufactured, but target-by-target source strength becomes nonuniform
Solution Approach 1:
The patent applies parameter changes by transitioning from disc-like targets with varying path lengths to spherical targets with uniform diameter. This parameter standardization ensures that each spherical target presents the same effective area and path length for neutron interaction, resulting in uniform source strength across all targets and enabling consistent recyclability.
3Productivity
If conventional disc-like targets are used, then radiation sources can be manufactured, but recyclability is poor due to target-by-target variations
Solution Approach 1:
The patent enables effective recovery and recycling of irradiated targets by ensuring uniform source strength characteristics across all spherical targets. This uniformity allows irradiated targets to be reliably reused in subsequent irradiation cycles, improving productivity and reducing waste of scarce iridium materials.
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 approach enhances geometric resolution, eliminates radiation source anisotropy, and improves recyclability, leading to more uniform and cost-effective radiation sources with reduced material costs, as the capsule is rotated using reactor coolant flow without external power, simplifying the manufacturing process.
Implementation Method 1
rotating an axial flow impeller by a downward flow of a reactor primary coolant, whereby the rotating capsule is rotated
Implementation Method 2
The spherical irradiation target can be manufactured by dropping molten iridium into a liquid
Data Source
AI summary
An irradiation target is formed into a sphere. The spherical irradiation target can be iridium metal containing natural or enriched iridium. The radiation source can be manufactured by manufacturing a spherical irradiation target, accommodating the spherical irradiation target in a rotating capsule, and rotating an axial flow impeller by a downward flow of a reactor primary coolant, whereby the rotating capsule is rotated. This radiation source provides an improved nondestructive inspection image having a high geometric resolution, and has no radiation source anisotropy and also has high target recyclability.