Catalyst-Integrated PCCS Condenser for Noncondensable Gas Management
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Solution Overview
Problem
Large amounts of reactive noncondensable gases, such as hydrogen and oxygen, can enter passive coolant features in nuclear power plants during accidents, posing a risk of ignition and damage to structures.
Innovation Solution
Positioning catalyst materials, such as palladium or palladium alloys, within structures exposed to noncondensable gases to facilitate their reaction into inert or harmless products, reducing the risk of explosion and gas pressure through continuous, non-destructive recombination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If passive coolant features are used to cool the reactor during accidents, then cooling capability is improved, but the risk of ignition from reactive noncondensable gases increases
Solution Approach 1:
The patent introduces catalyst material that converts the harmful reactive noncondensable gases (hydrogen, oxygen) into beneficial inert products (water) through catalytic recombination. The catalyst material transforms the dangerous gas mixture into harmless water vapor, eliminating the explosion hazard while maintaining the passive cooling function.
Solution Approach 2:
The catalyst material acts as an intermediary substance between the reactive noncondensable gases and the cooling system. It facilitates the chemical reaction that combines hydrogen and oxygen into water, mediating the interaction between the harmful gases and the cooling environment to produce a safe outcome.
2Reliability
If noncondensable gases are allowed to accumulate during operation, then radiation and chemical release are managed, but explosion risk increases during accidents
Solution Approach 1:
The catalyst material is pre-installed in the passive coolant features before any accident occurs. This preliminary placement ensures that when noncondensable gases accumulate during normal operation or accidents, the catalytic recombination can immediately occur without delay, preventing the buildup of explosive concentrations.
Solution Approach 2:
The catalyst material converts the potentially harmful accumulated noncondensable gases into beneficial inert water products through catalytic recombination, transforming the explosion hazard into a safe chemical reaction that eliminates the harmful gases while managing radiation and chemical release.
3Productivity
If active systems are used to manage noncondensable gases, then gas removal efficiency is improved, but system complexity and power requirements increase
Solution Approach 1:
The catalyst material provides self-service gas management by automatically catalyzing the recombination of noncondensable gases without requiring external power, control systems, or active intervention. The passive coolant features with embedded catalyst material autonomously manage the noncondensable gases through natural convection and catalytic action.
Solution Approach 2:
The patent replaces active mechanical gas removal systems with a passive chemical catalysis system. Instead of using powered fans, pumps, or complex control mechanisms to remove noncondensable gases, the system uses catalyst material to chemically recombine the gases into water through passive thermal and mass transfer processes.
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 catalyst systems effectively mitigate the risk of explosion and reduce gas pressure within containment structures by promoting non-explosive reactions of noncondensable gases, enhancing safety during accident scenarios without requiring external power or forced gas flow.
Implementation Method 1
Positioning catalyst materials, such as palladium or palladium alloys, within structures exposed to noncondensable gases to facilitate their reaction into inert or harmless products
Implementation Method 2
the condensed water is driven by gravity and a pressure differential downward through an annular duct
Data Source
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AI summary
Systems (100, 200, 300, 400) passively eliminate noncondensable gasses from facilities susceptible to damage from combustion of built-up noncondensable gasses, such as H2 and O2 in nuclear power plants, without the need for external power and/or moving parts. Systems include catalyst plates (105) installed in a lower header (53) of the Passive Containment Cooling System (PCCS) condenser (50), a catalyst packing member (205), and/or a catalyst coating (305) on an interior surface of a condensation tube (52) of the PCCS condenser (50) or an annular outlet (54) of the PCCS condenser (50). Structures may have surfaces or hydrophobic elements that inhibit water formation and promote contact with the noncondensable gas. Noncondensable gasses in a nuclear power plant are eliminated by installing and using the systems individually or in combination. An operating pressure of the PCCS condenser may be increased to facilitate recombination of noncondensable gasses therein.