Spent Nuclear Fuel Cask Dose Attenuation Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current spent nuclear fuel casks lack effective gamma radiation shielding, which poses a safety risk during transport and storage, and fail to adequately dissipate the heat generated by decaying nuclear fuel.
Innovation Solution
A radiation dose attenuation device made of high-density, high-thermal-conductivity materials like copper is inserted into the fuel basket storage cells to block gamma radiation and dissipate heat, providing enhanced shielding and heat management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional fuel basket storage cells are used without additional shielding, then the design is simple and heat dissipation is adequate, but gamma radiation shielding is insufficient
Solution Approach 1:
The radiation attenuation insert is nested inside the existing fuel basket storage cell, utilizing the available clearance space. The insert fits within the 6-10mm gap between the fuel assembly and storage cell walls, adding gamma shielding functionality without requiring external structures or major design changes to the storage cell itself.
Solution Approach 2:
The radiation attenuation insert is selectively placed in peripheral storage cells where gamma radiation exposure is most significant. This localized approach provides shielding where it is most needed while maintaining simplicity in the overall system design.
2Object-affected harmful factors
If dense gamma-blocking materials like lead are used, then gamma radiation shielding is effective, but heat dissipation capability is reduced
Solution Approach 1:
The radiation attenuation insert is constructed from copper, which provides a composite solution combining moderate gamma shielding capability with excellent thermal conductivity. This material selection balances the conflicting requirements of radiation attenuation and heat dissipation, allowing the insert to perform both functions simultaneously.
Solution Approach 2:
The invention changes the material parameter from high-density lead (poor thermal conductor) to copper (moderate density, excellent thermal conductor). This parameter change optimizes the balance between gamma radiation shielding effectiveness and heat dissipation capability.
3Object-affected harmful factors
If radiation attenuation inserts are added to peripheral storage cells, then gamma radiation shielding is enhanced, but manufacturing and installation complexity increases
Solution Approach 1:
The shielding solution is segmented into individual radiation attenuation inserts for each peripheral storage cell rather than requiring a monolithic structure. This segmentation allows for simplified manufacturing of individual components and easier installation by placing separate inserts into existing storage cells.
Solution Approach 2:
The radiation attenuation functionality is extracted as a separate, removable insert component rather than being integrated into the fuel basket structure itself. This extraction allows the shielding to be added independently without modifying the original storage cell design or manufacturing process.
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
The solution effectively attenuates gamma radiation and manages heat dissipation, enhancing safety and operational efficiency during the handling, transport, and storage of spent nuclear fuel.
Implementation Method 1
Effective gamma radiation shielding requires very dense materials, such as lead or others
Implementation Method 2
having a composition with high density and preferably a high thermal conductivity to effectively dissipate the substantial heat generated by the decaying nuclear fuel
Data Source
AI summary
A storage apparatus with radiation shielding for spent nuclear fuel includes a fuel basket comprising elongated fuel storage tubes each defining an open cell configured to hold a nuclear fuel assembly. Gamma radiation attenuation inserts are nested inside at least some of the storage tubes. The inserts each comprise elongated open-ended tubular bodies which may have a rectangular cuboid configuration with square cross section. The inserts are composed of a dense metallic material selected for blocking gamma radiation and may have high thermal conductivity for effective heat dissipation from the decaying nuclear fuel. Attenuation inserts can occupy some or all perimeter tubes to provide shielding against gamma radiation emanating in a lateral direction from the fuel basket. The inserts may include upper and lower securement features for detachable fixation to the storage tubes, and air/gas flow cutouts.