General Atomics (GA) has successfully manufactured the first batch of full-length SiGA silicon carbide composite tubes, specifically designed for pressurized water reactors.
This advancement signifies progress in developing nuclear fuel rods capable of withstanding significantly higher temperatures than currently used materials.
DOE Partnership for Accident Tolerant Fuel
General Atomics Electromagnetic Systems (GA-EMS) is collaborating with the U.S. Department of Energy (DOE) under its Accident Tolerant Fuel Program to advance silicon carbide fuel cladding technology.
The aim is to enhance the efficiency and safety of the U.S. nuclear reactor fleet.
SiGA: A Durable Composite Material for Fuel Rods
SiGA is a silicon carbide composite material renowned for its hardness and ability to endure extreme temperatures.
It has been utilized for various industrial purposes for decades and now serves as the foundation for developing nuclear reactor fuel rods with superior temperature resistance compared to existing materials like zirconium alloy.
Enhanced Safety and Performance with SiGA Cladding
GA-EMS has successfully engineered silicon carbide nuclear fuel cladding tubes. The company’s innovative technology integrates silicon carbide fibers into the cladding, creating an exceptionally strong and durable composite material.
This material can withstand temperatures up to 3800°F (2093°C), roughly 500 degrees hotter than the melting point of zirconium alloy.
Irradiation Testing and Scalability
GA-EMS has already produced 6-inch (15cm) SiGA rodlets and 3-foot (91cm) cladding samples that adhere to rigorous nuclear power reactor-grade standards. These samples will undergo irradiation testing at the DOE’s Idaho National Laboratory.
Recent achievements have demonstrated the scalability of the manufacturing process to produce full-length 12-foot (3.6m) fuel rods.
Milestone Achievement and Future Goals
Scott Forney, President of GA-EMS, highlighted the significance of this manufacturing breakthrough, stating, “This demonstration of manufacturing SiGA cladding at lengths of 12 feet is a notable achievement in our mission to bring this innovative technology to market.”
He emphasized their strategic fabrication and testing program, along with advancements in manufacturing efficiency and scale-up.
Enhanced Reactor Safety and Economics
Christina Back, Vice President of GA-EMS Nuclear Technologies and Materials, emphasized the potential of SiGA cladding to improve the safety and affordability of existing nuclear reactors.
The material’s stability within the reactor core could reduce the frequency of refueling, thereby enhancing the economic viability of nuclear power plants while offering additional fuel protection in the unlikely event of an accident.
Continued Validation and Performance Testing
The successful manufacturing milestone demonstrated excellent property uniformity across the full length of the cladding and consistent quality throughout the production batch.
GA-EMS will continue to validate their scale-up efforts, ensuring that the key performance metrics observed at shorter lengths are maintained at full length.
In addition to scaling fabrication techniques and process improvements, GA-EMS is dedicated to advanced performance testing and the development of modeling tools for SiGA fuel rods.
Origin and Collaborative Efforts
GA initially developed the SiGA composite for its Energy Multiplier Module (EM2) small modular reactor design, a modified version of its Gas-Turbine Modular Helium Reactor (GT-MHR).
In February 2020, Framatome and GA agreed to assess the feasibility of using SiGA in fuel channel applications through thermomechanical and corrosion testing. The long-term goal is to demonstrate the irradiation of a full-length fuel channel to support licensing and commercialization efforts.