Applications of Palladium-Silver Tubes in the Fusion Industry

The Need for High Hydrogen Permeability Materials in Fusion

In fusion research, the ability to selectively transport hydrogen isotopes is paramount for several key processes: 

• Hydrogen Separation and Purification: Removing impurities from hydrogen fuel streams to ensure efficient fusion reactions. 
• Tritium Recovery: Extracting the radioactive tritium bred within the fusion reactor blanket for reuse in the fuel cycle, which is vital for a sustainable fusion energy industry. 
• Tritium Extraction from Breeders: Recovering tritium from liquid metal breeders or gas streams within the reactor. 

Traditional methods for these processes can be complex and may involve multiple stages. Membrane technologies, particularly those utilizing materials with high hydrogen permeability, offer the potential for more efficient and continuous operation. 

Palladium and Palladium-Silver Alloys

Palladium and its alloys, especially Palladium-Silver (Pd-Ag), are the current standard for hydrogen permeability. This is due to palladium's unique ability to selectively allow hydrogen to pass through its crystal lattice while blocking other gases. However, pure palladium can suffer from hydrogen embrittlement, a phenomenon that can degrade its mechanical properties, especially under high hydrogen pressures and temperatures. Alloying palladium with silver offers significant advantages in this regard: 

• Enhanced Mechanical Strength: Silver addition improves the structural integrity of the material. 
• Reduced Embrittlement: Alloying with silver mitigates the susceptibility to hydrogen embrittlement, leading to improved operational stability and longevity. 
• Improved Operational Stability: The combined effect of increased strength and reduced embrittlement makes Pd-Ag alloys more reliable in demanding fusion environments.
• Potentially Higher Hydrogen Permeability: Some studies suggest that Pd-Ag alloys can exhibit higher hydrogen permeability values compared to pure palladium.

Goodfellow's Role in Supplying Pd-Ag Tubes for Fusion Research

Goodfellow recognizes the critical importance of Pd-Ag alloys in fusion technology and leverages its extensive experience to produce premium materials for these applications. We have specific expertise in manufacturing foils and tubes from palladium alloys, including Pd-Ag. Our Pd-Ag tubes are tailored to meet the stringent requirements of fusion research, providing:In fusion research, the ability to selectively transport hydrogen isotopes is paramount for several key processes: 

• High Hydrogen Permeability: Enabling efficient separation and recovery of hydrogen isotopes.
• Excellent Selectivity: Ensuring that only hydrogen isotopes permeate through the tube walls, while other gases are effectively blocked. 
• Resistance to Hydrogen Embrittlement: Providing durability and stability in tritium-containing and high-temperature environments. 
• Standard stocked products: Goodfellow has a stocked range of standard foil and tubes available for immediate delivery. 
• Custom Manufacturing Capabilities: If standard sizes or specifications are insufficient, Goodfellow offers custom manufacturing and materials production to meet specific research needs (wall thicknesses and diameters,  tube forming, foil production, helium leak testing, and product certification).

Applications of Pd-Ag Tubes in Fusion Systems

The unique properties of Pd-Ag tubes make them suitable for various applications within fusion reactors and related facilities: 

• Hydrogen Permeators: Pd-Ag tubes can be used as the core component in permeator systems designed for the efficient extraction and separation of hydrogen isotopes, including tritium recovery from various sources like liquid metal breeders.
• Tritium Processing Systems: In the fuel cycle of a fusion reactor, Pd-Ag membranes in tubular form can be integrated into systems for purifying tritium and recovering it from tritiated water via membrane reactors coupled with catalysts. The continuous removal of hydrogen through the membrane shifts the equilibrium of reactions like the water gas shift reaction towards the desired products.
• Hydrogen Purification: Pd-Ag tubes can be employed to purify hydrogen fuel streams before they are injected into the fusion plasma, ensuring optimal performance.
• Hydrogen Isotope Separation: The selective permeability of Pd-Ag can be utilized to separate different isotopes of hydrogen (deuterium and tritium) based on subtle differences in their permeation rates.

Conclusion

Palladium-Silver alloy tubes are indispensable materials in the ongoing development of fusion energy. Their exceptional hydrogen permeability, coupled with enhanced mechanical properties and resistance to embrittlement, makes them ideal for critical processes such as hydrogen separation, tritium recovery, and fuel purification within fusion reactors and fuel cycle facilities. Goodfellow Cambridge is committed to supporting the fusion research community by providing exceptional Pd-Ag tubes and other advanced materials tailored to the demanding conditions of this transformative energy technology. Our expertise in custom manufacturing ensures that researchers can access the specific material solutions required to advance the field of fusion power. 

Discover how Goodfellow's expertise can provide the precise Pd-Ag tubes required for your research. Get in touch to discuss your needs.