Passive Filtration for Nuclear Spent Fuel Pool Boiling Events
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional nuclear reactor designs face challenges in minimizing the release of radioactive particulates into the atmosphere during a spent fuel pool boiling event, as the existing passive safety systems may not adequately filter out radioactive contaminants, potentially exceeding acceptable radiation dose limits.
Innovation Solution
A passive spent fuel cooling and filtration system is introduced, featuring a vent mechanism with temperature-actuated dampers and a high efficiency particulate air (HEPA) filter positioned in the discharge path to filter the steam and air mixture, ensuring that radioactive particulates are removed before discharge into the atmosphere, utilizing natural pressure differentials for filtration without active components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a spent fuel pool cooling system operates without passive filtration during boiling events, then the system complexity is reduced, but radioactive particulates are released into the atmosphere exceeding acceptable radiation dose limits
Solution Approach 1:
The patent extracts the filtration function from the active cooling system and implements it as a separate passive filtration system that only activates during boiling events. The HEPA filter is positioned in the vent path to capture radioactive particulates, while the temperature-actuated damper isolates the filter during normal operation. This extraction approach reduces the burden on the main cooling system while providing targeted filtration when needed.
Solution Approach 2:
The patent introduces a temperature-actuated damper as an intermediary component between the spent fuel pool and the HEPA filter. This damper acts as a mediator that automatically opens during boiling events to allow steam and air passage through the filter, and closes during normal operation to isolate the filter. This intermediary mechanism enables the system to switch between filtration and non-filtration modes without complex control systems.
2Object-affected harmful factors
If a passive HEPA filter is installed in the vent path, then radioactive particulate release is reduced, but the device complexity and potential failure points increase
Solution Approach 1:
The patent positions the HEPA filter upstream of the discharge damper in the vent path, ensuring that filtration is established before any potential release occurs. The temperature-actuated damper is pre-configured to open automatically when boiling conditions are detected, allowing the filter to be in place and ready to capture particulates before they can escape into the environment.
Solution Approach 2:
The patent provides redundancy by including both a temperature-actuated damper and a discharge damper in the vent path. The temperature-actuated damper serves as a primary control mechanism that opens during boiling events, while the discharge damper provides a secondary barrier and can be manually operated if needed. This layered approach cushions against potential failures of individual components.
3Strength
If the vent mechanism remains closed during normal operation, then filter protection is maintained, but pressure relief capability is reduced during boiling events
Solution Approach 1:
The patent makes the vent mechanism dynamic by implementing a temperature-actuated damper that automatically changes its state based on thermal conditions. During normal operation, the damper remains closed to protect the filter and maintain pressure. When boiling events occur and temperature rises, the damper automatically opens to provide pressure relief while directing flow through the HEPA filter. This dynamic response eliminates the need for manual intervention or complex control systems.
Solution Approach 2:
The patent utilizes temperature as a triggering parameter for the damper actuation. The temperature-actuated damper is designed to respond to temperature changes associated with boiling events, automatically transitioning from a closed state during normal operation to an open state during boiling. This parameter-based control ensures the vent mechanism responds appropriately to changing conditions without requiring external control signals.
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 system effectively reduces the release of radioactive particulates into the atmosphere, ensuring that radiation doses remain within acceptable limits, providing an additional layer of safety and assurance during spent fuel pool boiling events by using passive filtration mechanisms.
Implementation Method 1
a high efficiency particulate air (HEPA) filter positioned in the discharge path to filter the steam and air mixture
Implementation Method 2
temperature-actuated dampers
Implementation Method 3
utilizing natural pressure differentials for filtration without active components
Implementation Method 4
filter the steam and air mixture, ensuring that radioactive particulates are removed before discharge into the atmosphere
Data Source
Figure 1
Figure 2
AI summary
The present invention relates to a passive filtration system for a fuel handling area having a spent fuel pool in a nuclear reactor. The passive filtration system reduces a discharge into the atmosphere of particulates, such as radioactive particulates, generated in a spent fuel pool boiling event. The passive filtration system includes a discharge path, a vent mechanism positioned between the fuel handling area and the discharge path. The vent mechanism is structured to release a steam and air mixture from the fuel handling area to the discharge path. The steam and air mixture includes the particulates. The passive filtration system further includes an air filtration unit located in the discharge path and this unit has at least one passive filter. The steam and air mixture is forced through the at least one passive filter due to a differential pressure generated in the fuel handling area.