New value from fusion neutrons

Above: Neutron radiography is used in the inspection of gas turbine blade cooling channels

Is fusion commercial? When it comes to the production of electrons, right now the answer is an emphatic ‘no’, but for neutrons it is a different story. “Fusion is commercial,” says Greg Piefer, founder and CEO of SHINE Technologies who was inspired by the realisation that while cost- effective fusion power was a perhaps a step too far, fusion nonetheless offered considerable commercial opportunities. “Fusion is going to generate some of the hottest densest states of matter ever created by humans in one of the worst radiation environments created by humans and then we are going to put some of the most fragile, exotic and expensive to manufacture materials in proximity to all that. I didn’t see a way of making fusion energy cost effectively. For me the lesson learned was that maybe there are things that can be done with fusion that can add value to the world and they may allow you to learn how to do fusion more cost effectively going forward. Applying those incremental lessons is perhaps the right path to create cost- effective fusion energy,” he says.

Instead of energy, Piefer settled on an application which focuses on using the neutrons from fusion reactions. And, it turns out those neutrons on a per reaction basis can be far more valuable than the energy produced. “There was a market that I knew we had enough output to be able to address right away. That market is neutron radiography,” he says.

In contrast to X rays, neutrons tend to scatter more off less dense materials but can penetrate materials like steel or lead fairly easily and so they provide a complimentary imaging process known as neutron radiography. “It’s $100- 200 million a year market. That is not huge, but historically needed nuclear reactors as a source of neutrons. There were only a few reactors around the country that were set up to do this and they were very much limiting the growth of neutron radiography because of access issues. We knew right away we could use fusion to play a role in some of these non-destructive testing markets of which neutron radiography is just one,” says Piefer.

The biggest single segment for NDE is imaging manufactured parts and looking for defects. An example where neutron radiography is actively used is in establishing that the small cooling channels in turbine blade tips are patent and not blocked, a relatively common manufacturing defect that could result in a catastrophic failure in service.

SHINE has developed a range of fusion technology-based devices to generate radiography images, as well as serve other markets. “We have deuterium-deuterium devices, some of which we have even sold. Then we have proton- beryllium sources and then we have deuterium-tritium fusion sources, which are our brightest and most potent sources of neutrons,” he says.

Their current fusion device is an ion beam type in which a particle beam of deuterium ions is accelerated to about 320KeV and fired into a gaseous target to generate a scatter of neutrons.

Piefer explains: “Our first-generation technology I would characterise as a particle beam-solid target. The current generation is particle beam-gas target fusion device. Our DT fusion devices don’t generate a lot of power, maybe 150 W, but that’s not nothing and it’s a pretty bright neutron source at that. At full capacity we should be able to generate tens of millions of dollars of revenue. That gives you an idea of just how much more valuable the neutrons are versus the electricity.”

As he says: “Fusion is not all pie in the sky, we have used it and its offshoots to create value already.”

However, while the imaging technology was developed several years ago as SHINE’s first-generation business, operational under its sister company, Phoenix Neutron Imaging, the company is now moving into what at calls phase two. Again, this relies on neutrons from fusion but with greater intensity they are being used to drive an isotope production process.

“In phase one, we were able to generate enough neutrons to take pictures, but not really enough to alter matter in a material way. We needed to increase the fusion output enough to get from phase one to phase two so that we could start to alter small amounts of matter – transmutation. In particular, we’re looking at turning elements that aren’t very valuable into elements that are extremely valuable,” says Piefer.

The mythical transmutation of base metals into gold, alchemy, has long since been surpassed. Says Piefer: “We could spend our time turning lead into gold, but it turns out the cost of that would be far more expensive than the gold but there are materials that are hyper valuable that are worth doing. For example, we can take uranium that we buy for $6 a gramme and turn it into molybdenum-99 which is worth about $150 million per gramme. The value of that material is that it ultimately decays into technetium-99m, which can be injected into the human body to illuminate disease. There are actually about 30 different diagnostic tests performed with that single isotope.”

Recognising the incredible value available from molybdenum 99, SHINE broke ground on a new production facility in 2019. “We’ve built a large-scale production facility here in the United States. It will be the biggest isotope production facility in the world, capable of generating about 20 million doses of molybdenum 99 per year. To put it in perspective, 20 million doses is about 2 grammes,” he says.

“We’re using the neutrons to alter matter, but on a pretty small scale,” notes Piefer, adding that in the longer term the company aims to use fusion neutrons to produce other therapeutic isotopes such as lutetium-177 that is produced by irradiating ytterbium 176. “Lutetium 177 is really useful for cancer therapy. That is worth $1 to $2 billion per gramme today,” he says.

To step up the neutron production from fusion to go from radiography applications to transmutation required the switch from solid target sources to gases target sources. Piefer says: “We’re now using gas target sources for both the isotope plant and for radiation effects testing in the non-destructive testing business. We could do radiography with the solid target sources but making that gaseous target source work was the key innovation that allowed us to expand into transmutation Isotope production. You get about 10 times as many neutrons per unit power with the gas target versus the solid targets”. He adds: “A higher intensity of neutrons also makes the imaging process that much better, you can go to much higher power densities and it’s more efficient.”

The transmutation process is also opening the door to the company’s third phase of development.

Piefer explains that as part of the transmutation process target is irradiated in a fusion neutron field for about 5.5 days. “It’s an aqueous target – uranium salt dissolved in liquid,” he says. A series of radiochemical separations follows to extract medically pure isotopes from that irradiated uranium solution. “We’ve got really good at handling highly-radioactive uranium streams and selectively separating out materials of value from that stream for the medical business and it turns out those are the same skill sets we need for phase three. It is the next scale in our fusion journey, but what we want to do first and foremost is recycle nuclear waste from power plants,” he says, adding: “To recycle nuclear waste, you take the uranium oxide, dissolve it and separate out the highly valuable materials including plutonium, but also precious metals and other isotopes that you could sell. All these things look exactly like what we’re doing in the isotope plant, just at a larger scale.”

Piefer suggests that such a process can remove about 96% of the waste stream that can be recycled and used as new fuel. However, it also ties in with a fusion-derived neutron flux to generate commercial value. “Fusion comes in on the very back end of this. About 96% of the uranium waste stream is recyclable or valuable but there’s a very small amount, about 0.1%, of the waste stream that consists of really long-lived isotopes that have no value and currently have no disposal path,” Piifer explains. “Just like we use transmutation in phase two to turn low value materials into high value materials, we believe we can use fusion to take those long-lived isotopes and make them short-lived isotopes and thus solve the problem of long-lived nuclear waste as well. I find that to be incredibly valuable from a sociological perspective, because one of the biggest challenges nuclear energy faces is the waste problem.”

The SHINE CEO believes that scaling up fusion devices to be able to handle waste management processes also represents an important step on the road to commercial fusion energy. “That’s the next scale-up for fusion in our strategy and the fusion part of it is cool because at the stage where you’re starting to transmute materials at that waste scale, you’re starting to look like a fusion power plant from a physics perspective. The difference between fusion energy and this transmutation process is you actually still get paid a lot more for the transmutation part than your energy, Maybe 10 to 15 times more per reaction than you would for producing energy,” he says.

Piefer outlines the staged timeframe: “All these are things we’re starting to invest in now. Phase one is growing rapidly now at over 50% a year. We think it’s going to continue that for a bit and it’s profitable. For phase two, longer term, we’ll be using our fusion facility to make lutetium-177 and to make more molybdenum, iodine and xenon around 2024. Right now, we’re using fission reactor neutrons, but we’re using our chemical processing expertise and other technologies we’ve developed to give us a competitive advantage there. Phase three, we think is probably five-ish maybe six years for a pilot plant.”

He concludes with a comment on the development of commercial fusion though: “What we’re trying to do is continue to develop new technologies that make fusion more and more efficient. We’re going to get better and better at building fusion devices as the technology improves, but we’re always going to have a commercial mindset, always trying to build products. That’s first and foremost in our mind, we’re not trying to prove the physics, we’re building products. We call it today’s fusion company because we’re actually doing it today and creating value with it today.”

Reflecting on the challenge of fusion energy Piefer observes: “Most people investing in fusion are trying to go straight to energy and so you need to invest so much money to get to a machine that might work and I say might work because I don’t think any of its been proven yet. It’s a bit like if when Steve Jobs was starting building computers in his garage he said, ‘I’m going to set out to build an iPhone on day one’. They wouldn’t have been able to do that, but they did build a product that had value right away.”

By using fusion to look within, we might just see the energy iphone of the future.