Japan-based Kyoto Fusioneering has begun testing a new hydrogen recovery system, a critical step toward solving one of the main challenges for commercial fusion energy: establishing a continuous fuel supply.
Future fusion power plants will rely on hydrogen isotopes, particularly tritium, which is extremely rare in nature. Because it cannot be mined, tritium must be generated, or “bred,” within the fusion reactor itself.
The company’s solution involves breeding tritium inside a “blanket module” by reacting neutrons with a liquid lithium-lead (LiPb) alloy. The challenge, however, is then extracting that fuel from the hot liquid metal.
This is where the company’s new tests at its UNITY-1 facility come in. The trials are validating a proprietary Vacuum Sieve Tray (VST) technology designed specifically for this extraction.
Increasing the surface area of liquid
The VST technology operates by pouring the tritium-rich lithium-lead alloy into a vacuum chamber. Inside, internal sieve trays disperse the liquid into fine droplets.
This action dramatically increases the surface area of the liquid, allowing the trapped tritium gas to be extracted efficiently.
In the current initial test phase, engineers are using deuterium and hydrogen as substitutes to demonstrate the recovery principle.
The path to a full fuel cycle
This VST system is a key component of the company’s larger Fusion Fuel Cycle System. This complete system is being developed to handle the entire fuel supply chain: recovering the bred tritium, and then storing and supplying it back to the plant.
Data from the current UNITY-1 tests will inform the design of the VST for UNITY-2, a follow-up project in Ontario, Canada. That project, a joint venture with Canadian Nuclear Laboratories (CNL), will conduct the final validation of the technology using actual tritium.
“Demonstrating the effectiveness of hydrogen recovery is a critical step towards scalable fusion power,” said Satoshi Konishi, Co-Founder & CEO at Kyoto Fusioneering.
“These tests validate key components of the Fusion Fuel Cycle System, giving our industrial partners confidence in our ability to deliver reliable fuel supply in future commercial deployments.”
Construction begins on full-loop facility in Canada
In a related development, the UNITY-2 project in Canada has officially moved into the construction phase. Fusion Fuel Cycles, the joint venture, has mobilised crews at the Chalk River Laboratories in Ontario.
The teams are now dismantling legacy equipment to prepare the space for the new process systems.
The facility, formally named the Unique Integrated Testing Facility, is set to be the world’s first to demonstrate a complete, “full-loop” tritium fuel cycle.
Designed to bridge the gap from theory to practical application, UNITY-2 will test all components of the fuel cycle together under fusion-relevant conditions. This includes everything from fuel injection and exhaust to impurity removal, isotope separation, and tritium storage.
The facility is engineered to continuously circulate up to 30 grams of tritium in a 24-hour cycle and is licensed to expand operations to 100 grams.