Nuclear Fuel Storage Rack Base Plate Seismic Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing storage rack arrangements for nuclear fuel elements in storage pools face challenges during earthquakes, including displacement, collision risks, and potential leaks due to high seismic forces, which existing solutions like fixed anchoring or the 'free sliding' principle fail to adequately address, especially at higher earthquake loads and storage densities.
Innovation Solution
A storage rack arrangement where multiple storage racks are connected to a common base plate that can displace as a unit, providing a stable connection and hydraulic damping to absorb seismic forces, reducing the transmission of vibrations and preventing structural damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If storage racks are fixedly anchored or screwed down to the storage pool walls and bottom, then stability against earthquake forces is improved, but extremely high peak loads occur locally at anchoring points leading to damage and leaks
Solution Approach 1:
The invention divides the storage rack system into multiple independent racks that can move relative to each other, rather than rigidly anchoring a single large structure. Each rack is supported on the pool bottom but can displace independently during earthquakes, distributing seismic forces across multiple contact points rather than concentrating them at a few anchoring locations.
Solution Approach 2:
The invention transitions from a static fixed-anchoring system to a dynamic system where racks can move and absorb seismic energy through controlled displacement. The racks are designed to slide or rock on their supports during earthquakes, converting harmful seismic energy into kinetic energy of movement, then dissipating it through friction and damping mechanisms.
2Strength
If the free sliding principle is used to eliminate high peak loads at anchoring points, then local structural damage is reduced, but storage space is lost due to required clear zones around pedestals
Solution Approach 1:
The invention merges multiple storage racks into a coordinated system where they share common support structures and can move together as a group. By connecting adjacent racks through shared pedestals and support elements, the design eliminates the need for large clear zones around individual racks, maximizing storage density while maintaining the benefits of controlled movement during earthquakes.
3Reliability
If storage racks are allowed to sway freely during earthquakes, then high horizontal forces are absorbed, but storage rack alignment and arrangement become irregular after earthquakes
Solution Approach 1:
The invention incorporates damping elements, friction interfaces, and controlled resistance mechanisms at the support points that provide cushioning during rack movement. These elements allow racks to displace and absorb seismic energy while simultaneously providing restoring forces that guide racks back to their original positions, preventing permanent misalignment and maintaining orderly arrangement after earthquakes.
4Reliability
If retaining clips are used to connect adjacent storage racks, then collision between racks is avoided, but the design cannot absorb larger horizontal forces effectively
Solution Approach 1:
The invention employs composite support structures combining rigid connecting elements with flexible damping components. The support system integrates metal frameworks for structural strength with elastomeric or friction-based damping elements that allow controlled movement and force absorption. This composite approach enables the system to both prevent rack collisions and absorb large horizontal seismic forces through a combination of rigid connection and flexible energy dissipation.
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 solution effectively dampens both horizontal and vertical seismic components, stabilizes the storage racks, and prevents leaks by distributing seismic energy and reducing peak loads on anchoring points, while maintaining storage efficiency and rack alignment post-earthquake.
Implementation Method 1
the base plate or base plates being displaceable on the floor of the storage basin... providing a stable connection and hydraulic damping to absorb seismic forces
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A storage rack arrangement (1) for storing nuclear fuel elements in a storage pool comprises at least two storage racks (1I-IV), each containing several vertical channels arranged side by side for receiving the fuel elements. The storage rack arrangement 1 also comprises one or more base plates (20, 20I-V), wherein adjacent storage racks are connected by at least one common base plate, and wherein the base plates are slidable on the bottom (24) of the storage pool.