Rather than trying to build a full-scale reactor that can produce net energy via a self-sustaining fusion reaction right off the bat, Shine uses a particle accelerator to drive a series of small-scale fusion reactions. When high-energy ions connect with fuels, such as tritium or deuterium, they undergo a fusion reaction that produces high-energy neutrons and specialized isotopes more often generated for use in industry via fission.
Piefer, who has a PhD in nuclear engineering from the University of Wisconsin-Madison, started up his company by making neutrons for materials testing in the aerospace and defense industries. Unlike other forms of radiation, such as X-rays, neutrons can penetrate dense materials such as metals, hydrogen-containing fuels, or ceramics, making it possible to spot hidden flaws. An otherwise invisible crack in a turbine blade, for example, could still block or scatter neutrons, while contamination from water or oil would absorb neutrons — making these faults clear in a radiographic image.
Scientists also use neutrons to test nuclear fission fuel by identifying contamination and verifying uranium enrichment levels. According to Piefer, Shine produces the neutrons used to test half of all fission fuel today. “Fusion actually already enables the production of 50% of the fission fuel in this country,” he told me.
My mind was blown. I didn’t understand how fusion — a famously expensive endeavor — could be an economically viable option for these applications.
Piefer understood. “I’ll sit here in one breath and I’ll tell you fusion is way too expensive to compete making electricity, and in another breath that it’s much cheaper than fission for making isotopes and doing testing,” he said. As Piefer went on to explain, if the goal isn’t net energy, you can strip the fusion reactor of a good deal of complexity — no superconducting magnets, complicated structures to produce tritium fuel, or control systems to keep the burning fusion plasma contained.
With a simplified system, Piefer told me, it’s much easier to produce a fusion reaction than a fission reaction. The latter, he explained, “operates on the razor’s edge of something called criticality” — a self-sustaining reaction that must be precisely balanced. If a fission reaction accelerates too quickly, power surges dangerously and you get a disaster like Chernobyl. If it slows, there’s simply no reaction at all. Plus, even after a fission reactor shuts down, it keeps producing heat, and thus must be actively cooled. But when it comes to fusion, there’s no danger of an out of control power surge, because, unlike fission, it’s not a chain reaction — if the input conditions change, fusion stops immediately. Furthermore, fusion produces no heat after the reaction stops.
Some of Shine’s customers include manufacturers of turbine blades and explosives such as the U.S. Army and GE Hitachi, as well as the biopharmaceutical companies Blue Earth Therapeutics and Telix Pharmaceuticals. Piefer told me that the company is now “on the verge of essentially breakeven” — no fusion pun intended — when it comes to its operating expenses. These days, it’s reinvesting much of its revenue to build out what Piefer says will be the largest isotope production facility in the world in Wisconsin. Isotopes are created when high energy neutrons strike stable elements, causing the nuclei to absorb the neutron and become radioactive. The isotope’s radioactive properties make them useful for targeting particular tissues, cells, or organs in medical imaging or focused therapies..
Shine’s in-progress facility will primarily produce molybdenum‑99, the most commonly used isotope for medical imaging. The company already operates one smaller isotope facility producing lutetium-177, which features in cutting-edge cancer therapies.
Compared to materials testing, producing medical isotopes has required Shine to increase the temperature and thus the efficiency of its fusion target. Subsequent applications will require greater efficiency still. The idea is that as Shine applies its tech to increasingly challenging and energy-intensive tasks, it will also move step by step toward a commercially viable, net-energy-generating fusion reactor. Piefer just doesn’t know what exactly those incremental improvements will look like.
The company hasn’t committed to any specific reactor design for its fusion energy device yet, and Piefer told me that at this stage, he doesn’t think it’s necessary to pick winners. “We don’t have to, and don’t want to,” he said. “We’ve got this flexible manufacturing platform that’s doing all the things you need to do to get really good at making fusion systems, regardless of technology.”
Fusion energy aside, the company doesn’t even know how it’s going to reach the heat and efficiency requirements needed to achieve its next target — recycling spent fission fuel. But Piefer told me that if Shine can get there, scientists do already understand the chemistry. First, Shine would separate out the long-lived, highly radioactive waste products from the spent fuel using much the same approach it uses for isolating medical isotopes, no fusion reaction needed. Then, Piefer told me, “fusion can turn those long-lived wastes into short-lived waste” by using high-energy fusion neutrons to alter the radioactive nuclei in ways that make them decay faster.
If the company pulls that off — a big if indeed — it would then move on to building an energy-generating reactor. Overall, Piefer guesses this final stage will wind up taking the fusion industry “more time and money than most people predict.” Perhaps, he said, investors will prove willing to bankroll buzzy fusion startups far longer than their ambitious timelines currently imply. But perhaps not. And in the meantime, he thinks many companies will end up turning to the very markets that Shine has been exploring for decades now.
“So we’re well positioned to work with them, well positioned to help create mutual success, or well positioned to use our position to move ourselves forward,” Piefer told me, hinting that the company would be interested in making acquisitions.
Indeed, some fusion companies are already following Shine’s lead, eyeing isotopes as an early — or primary — revenue generating opportunity. Microreactor company Avalanche Energy eventually wants to replace diesel generators, but in the meantime plans to produce radioisotopes for medical and energy applications. U.K.-based fusion company Astral Systems is also making desktop-sized reactors, but with the central aim of selling medical isotopes.
If too many companies break their promises or extend their timelines interminably, as Piefer thinks is likely, more and more will come around to the pragmatism of Shine’s approach, he said. “Near term applications are increasingly talked about,” Piefer told me. “They’re not the highlight of the show yet, but I’d say the voice is getting louder.”
So while he still doesn’t have any idea what the final form for Shine’s hypothetical fusion power plant will take, in his mind the company is leading the race. “I believe we’re actually on the fastest path to fusion commercialization for energy of anybody out there,” Piefer told me. “Because commercial is important to us, and it always has been.”
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