Canada-based General Fusion announced that third-party analysis conducted by the US Savannah River National Laboratory (SRNL) and funded by the US Department of Energy (DOE) supports the company’s approach to fusion fuel sustainability. The results of the study were published in the peer-reviewed scientific journal Fusion Science and Technology.
The SRNL study, which was completed under DOE’s INFUSE programme and is available on the Office of Scientific and Technical Information website, evaluated key parameters of General Fusion’s Magnetised Target Fusion (MTF) approach. It assessed the fuel cycle enabled by the liquid metal wall technology, which inherently addresses major challenges in fusion power plant design. The liquid metal wall, which is proprietary to General Fusion’s MTF design, shields the fusion machine from neutron activation, produces tritium fuel through neutron interactions with lithium, and efficiently captures the energy produced by fusion.
The researchers at SRNL examined the tritium fuel required to start up and operate a General Fusion power plant, as well as the doubling time needed to breed enough tritium to fuel a second plant. When compared with publicly available data for traditional fusion approaches, such as tokamaks and stellarators, the SRNL study found several advantages in General Fusion’s MTF commercial design. They found the design:
- requires less tritium for the start-up of a commercial fusion power plant;
- achieves a significantly shorter doubling time—the amount of time needed to breed enough tritium to fuel a second power plant; and
- indicates an MTF power plant will produce enough tritium to ensure a self-sustaining fuel source based on the higher tritium breeding ratio.
“This study, where it was important for us to collaborate with Savannah River National Laboratory, one of the leading labs in fuel cycle R&D, demonstrates the many advantages of our MTF with a liquid metal wall,” said Mike Donaldson, Senior Vice President of Technology Development at General Fusion. “The liquid metal wall allows us to own the fuel cycle and provide start-up fuel for a broad fleet of General Fusion power plants.”
Associate Laboratory Director Roderick Jackson, who leads the Science, Energy and Innovation Directorate at SRNL, noted: “Partnering with companies like General Fusion – who utilised Savannah River National Laboratory’s world-leading fuel cycle research, expertise and support – contribute to advancing fusion energy from concept to deployment. This collaborative work is bringing us closer to delivering reliable fusion power at commercial scale.”
General Fusion’s MTF is designed to solve significant barriers to commercialising fusion energy. MTF aims to achieve fusion in a practical way, avoiding superconducting magnets and high-powered lasers, while enabling the use of existing materials for durable machines that would produce cost-effective energy.
In early 2025, General Fusion announced that it had designed, built, and begun operating its Lawson Machine 26 (LM26) fusion demonstration machine in under two years. LM26 is the first MTF demonstration machine to be built at a commercially relevant scale. It mechanically compresses plasma with a lithium liner at 50% commercial-scale diameter.
LM26 aims to achieve key fusion technical milestones: plasma heating to 1 keV (10m degrees Celsius), then 10 keV (100m degrees Celsius), and ultimately the Lawson criterion, the combination of fusion parameters that can produce net fusion energy in the plasma.
