The planned power plant with an energy output of over 500MW utilizes dual magnetic mirrors and direct energy conversion.
The Fusion Report has covered a number of commercial fusion power plant design releases since Helion Energy initially releases their plans for their Orion commercial power plant in March 2025. Today there are dozens of planned commercial fusion power plants. Some of the most noteworthy are the Commonwealth Fusion Systems (CFS) ARC plant in Virginia, Helion’s Orion facility that we just mentioned, the Proxima Fusion/RWE plant in Germany, the UK Atomic Energy Authority (UKAEA) fusion plant in the UK, and the TVA/Type One Energy fusion plant in Tennessee. And now Realta Fusion follows this with their Hammir-DT fusion plant.
What is Hammir-DT, and Why Is It Important?
Hammir is an asymmetric tandem magnific mirror pilot plant designed to generate net electricity and supply high temperature heat directly for heavy industrial markets. Hammir-DT is the version of Hammir which is designed to utilize deuterium-tritium (D-T) fuel to commercially produce fusion energy. Hammir-DT is designed to produce a fusion power of approximately 500MW of total energy, with a total thermal output of 538MW. The “extra” 38 MW of power is the exothermic energy released when breeding tritium from lithium-6 (which is a percentage of the total of lithium in the breeder blanket).
The plant utilizes direct electric conversion (DEC) to convert the energy of fusion-produced charged particles into electricity directly, similar to the concept of Helion’s fusion machines. Assuming Realta’s Hammir-DT achieves QSCI of roughly 5.3 and QENG of 1.3, the electric output should be roughly 200MWe (note that these are the design goals, where QENG of >0 denotes net electricity creation).
Interview with Derek Sutherland, VP of R&D, Realta Fusion
We had an opportunity to interview Derek Sutherland, Vice President of Research and Development at Realta Fusion about the Hammir-DT program.
- What makes Hammir-DT unique among fusion machines?
Derek: From our perspective, this preconceptual design of Hammir-DT is the first modern axisymmetric tandem mirror fusion power plant design ever conceived, using several key advances such as HTS magnets, active plasma stabilization, and modern heating systems. We believe we have line of sight to a levelized cost of electricity well below $50/MWh in production which is certainly competitive with other sources of electricity out there. - Is Hammir-DT a pulsed machine like Helion’s various fusion machines?
Derek: Our system is continuous; it is not pulsed. From a power generation perspective, that is certainly more desirable and looks like more like what is already connected to the grid today, allowing for easier adoption at scale. It also means that we don’t have to try to manage/survive pulses of power output, high-energy charge particle and neutron pulses that damage materials, and struggle as much with power coupling efficiencies. We are targeting a system with the average power roughly the same as the peak power, which allows us to optimize the system for longevity and efficiency. - What is the aspect of the design which is most ground-breaking?
Derek: For any magnetic fusion energy (MFE) machine, the real key is plasma stability that is often a requirement for having good enough confinement of plasma to reach net-gain conditions. We are leveraging advances in plasma stabilization to maintain an axisymmetric form factor that is much more simple, modular and scalable. There is not one single enabling technology for our mirrors that make them compelling, there are three: HTS magnets, advanced plasma stabilization, and modern heating systems. - Your website says that Hammir-DT is the lowest capital, least complex fusion reactor. How much would the machine cost in production?
Derek: In general, the capital cost will usually scale with the power output, and this is no different. In our system, the magnets are one of the highest cost items contributing to the capital cost, which we are planning to use rare-earth barium copper oxide (REBCO) high field magnets made by our magnet partner Commonwealth Fusion Systems. We have four of these high-field magnets per tandem mirror power plant (two on each end), and they’re essentially a fixed cost regardless of the power output in the system which is varied by changing the length of the center cell. The magnets for the central cell (which have fields around 1-3 Tesla) where the fusion occurs are significantly cheaper. To generate more power, these central cells modules can be “stacked”, producing cost-competitive outputs anywhere from 100 MW to 500 MW in total output per unit. GW scale outputs can be accessed by building multiple units and stacking them in parallel at a single power plant site. For machines on this scale of power output, we believe the CapEx will be around $1B to $2B with LCOEs below $50/MWh with line of sight on even lower costs as we scale. - When do you think the first instance of Hammir-DT will be completed?
Derek: We like to think that at Realta we have an aggressive roadmap. Our first step will be to utilize deuterium-deuterium (D-D) fusion first, derisking the physics of the system, after which we will go to D-T.
Conclusion: Realta Fusion is Swinging for the Fences (in a good way)
Realta Fusion is one of the smaller fusion companies from a total funds raised standpoint, having raised $54 million so far. To put that in perspective, this is less than 2% of the funds that have been raised by Commonwealth Fusion Systems ($2.939B), or less than 3.6% of what has been raised by Helion Energy ($1.502B). Clearly, Realta will need to undertake some significant fundraising and/or financing to build the first Hammir-DT power plant, even given the (relatively low) $1B-$2B price estimate.
There are $36M Series A fund raise occurring in May 2025, followed by a $9.5M growth capital debt financing in February this year. One could come to the reasonable conclusion that Realta Fusion will have to raise funds again this year to stay on target, and hopefully we will see a $100M+ fund raise here shortly. I will personally keep my fingers crossed for the company 😊!
