⚛️🌟 Our fusion future: A Quick Q&A with … nuclear engineer Michael Ford

'While I would not put a timeline on fusion commercial viability, I would bet on the science of achieving fusion before mid-century.'

This could be another newsy year for the long-awaited promise of nuclear fusion. A recent piece in The Economist highlights two major developments that signal a shift from public to private sector leadership: the planned opening of SPARC, a near-commercial scale fusion reactor by Commonwealth Fusion capable of 140MW output, and the delayed opening of ITER, the international collaboration's flagship project. While ITER's launch has been pushed to 2034, SPARC aims to achieve net-positive energy output by early 2026, potentially marking a historic breakthrough in the private sector's race to harness fusion power.

As it is, the private fusion sector is rapidly expanding, the piece adds, with over 40 companies raising $7.1 billion in funding. While many startups are exploring alternatives to traditional tokamak designs, their diverse technological paths share a common goal: achieving commercial fusion power. With multiple test reactors launching in 2025, the race for fusion energy extends far beyond any single company's success.

But government still has a role to play. In his recent article, A Public Path to Building a Star on Earth, Michael Ford outlines fusion’s incredible potential to meet (and even far exceed) our growing energy needs, as well as detailing the most promising developments in the field. Ford emphasizes the need for continued public support for this complex field of research. I asked Ford a few quick questions about how far we’ve come in the development of fusion technology, and how far we have to go before we see it become a reality.

Ford is the associate laboratory director for engineering at the Princeton Plasma Physics Laboratory. He previously served as strategy development director for the Energy and Global Security Directorate at the Argonne National Laboratory, as well as research roles at the Harvard University Center for the Environment and in the Harvard Kennedy School.

Ford is a retired Captain in the US Navy who served as a member of the Navy Nuclear Propulsion Examining Board during his career. His subspecialties included nuclear engineering, resource management, and operations analysis.

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1/ Do you think people would be more receptive to fusion than they have historically been to fission, since it doesn’t necessarily carry the baggage of disasters like Fukushima or Chernobyl?

There is a working assumption within the fusion community that fusion will not face the same public perception challenges as fission — but also a realization that this is something that must be addressed as fusion is developed. Fear of accidents, concern about proliferation risks, and the cost of development are three challenges fusion may face in terms of public acceptance.

Fusion has tremendous potential as a sustainable energy source and differs significantly from fission from a safety standpoint because it does not rely on a chain reaction process. But that does not mean it has zero accident risk. For example, most fusion energy system designs under consideration by developers use a deuterium/tritium fuel cycle. Tritium is a radioactive isotope of hydrogen and releases of tritium, though vastly less worrisome than a fission product release, has led to significant issues with public perception. This was most recently seen related to controlled releases of tritiated water at Fukushima. So, it will be critical for developers to work with communities and assure the public regarding controls for tritium management and implications for accidental release.

The second risk that most fusion developers know must be addressed is the (very low) potential for illicit use of their systems to produce fissile material that could be used in furthering a nuclear weapons development program. Fortunately, most fusion systems do not require the presence of materials such as uranium or thorium, which would be necessary in producing fissile material. Therefore, the protections/mitigations that would need to be in place to assure the public this is not a risk are straightforward. The fusion industry recognizes this and has been engaged with regulatory agencies to examine how best to ensure this does not impact public acceptance.

Given what should be far lower concerns about accident risk and proliferation for fusion, regulatory processes for fusion development should not be as significant a cost driver as they have been with fission. But there is a non-zero risk that public perception of fusion could lead to higher deployment costs and more challenges in siting these systems. That risk, coupled with what are still uncertainties about development costs for fusion, could end up being even more impactful from a deployment and market viability standpoint.

2/ What exactly allows fusion to avoid the risks associated with fission?

Fission relies on a chain reaction process that can be more difficult to interrupt, especially if cooling is removed and the fuel is compromised. Fusion is inherently a more controllable process that can quickly be interrupted. For fusion to occur, a plasma must be formed and contained, and significant energy must be injected into that plasma to create the conditions for fusion. Removal of the fuel supply (often deuterium and tritium), the necessary injected energy or elimination of the proper containment conditions will eliminate the temperature and density conditions needed to sustain a fusion reaction. In other words, a fusion reaction — and eventual fusion plant — can be shut down at any time.

3/ How far have our reactor designs come since the concept of commercial fusion was first seriously floated?

Some fusion designs have moved to the prototype stage with proposals for commercial demonstrations in the 2030s. Designs include traditional tokamaks as well as stellarators – first conceived at Princeton Plasma Physics Laboratory (PPPL) – and more novel mirror and Z-pinch machines. That said, some of the key subsystems that are required for many of these designs are still immature at best. Significant challenges remain, requiring strong science and engineering before a fusion pilot plant is constructed. For example, for systems that rely on a deuterium/tritium fuel cycle, there are still significant unknowns regarding the ability to develop fuel management systems that will ensure the breeding of sufficient tritium for self-sustaining operations. There have also been limited developments at scale of blanket systems that will ensure the energy produced in the fusion reaction can be efficiently captured as heat leading to a commercially viable energy system. Finally, materials research will be critical given the extraordinary heat and neutron flux that plasma facing materials will experience over their lifetime. This is an area of particular interest at PPPL where liquid metals approaches for plasma facing surfaces are being evaluated.

While I would not put a timeline on fusion commercial viability, I would bet on the science of achieving fusion before mid-century.

4/ How would you respond to critics of investment who say that “fusion has always been 30 years away and always will be?”