The nuclear renaissance doesn’t just need researchers. It also needs engineers, government supporters, operators, educators, and investors.
Luckily for the industry, Rachel Slaybaugh is all of the above. Over the last few decades, she’s published research on computational methods for fusion plants, developed the fission program at DOE’s ARPA-E office, served as a licensed nuclear reactor operator at Penn State, and taught as an associate professor of nuclear engineering at UC Berkeley.
These days, Slaybaugh is a partner at DCVC, where she spends most of her time working on climate and energy investments. Her team recently led Radiant’s $100M Series C, and DCVC has also made an investment in fusion startup Zap Energy.
Ignition caught up with Slaybaugh to talk about the Radiant raise and vision, challenges facing the nuclear sector, and how nuclear policy and programming might unfold under the second Trump presidency.
Note: This interview has been edited for length and clarity.
Ignition: What was it that drew you to the nuclear sector and nuclear technology in the beginning?
I went into nuclear for environmental reasons. I’ve always cared about environmental stuff, and I was before it was this broad of an issue. I was worried about climate change, and so as a freshman, I was like, “You mean, there’s a thing the size and shape of a coal plant that doesn’t emit air pollution, and we have it right now? Why don’t we do more of that, while all these other clean technologies have time to scale up?” Because at that point, solar was like .01% of electricity—I mean, it was negligible.
Is that still the driving factor for you, many years later?
Yeah, it still really is. And it’s excellent that more types of clean energy are scaling up and becoming deployed. Just moving away from fossil fuels alone requires a tremendous amount of new clean energy, let alone meeting load growth in places like the United States, let alone moving people out of energy poverty in countries that don’t have as much energy access right now. So I feel like we still need every clean energy tool in our toolbox, and sure, you could do it without nuclear energy, but it will be way easier to do if you use nuclear energy.
Tell me about where you sit in your role as an investor at DCVC.
I’m a partner at DCVC, and we have two funds. We have a flagship fund that makes seed and Series A investments across a whole variety of sectors, including climate. And so I spend a little bit of my time on early-stage deals out of that fund. We also have a climate-specific fund that is Series B and Series C, and that’s the bulk of my time. So I only focus on climate. I spend probably the most time on energy, because that’s my background. For DCVC as a firm, everything we do is deep tech, and what we mean by that is there is a significant data and compute component that is driving the advantage of the company.
I think it’s fair to say also that you’re a technical expert in the nuclear field as well as an investor. How does that expertise affect how you consider investments in nuclear startups, or in energy more broadly?
In nuclear specifically, I know a lot about the underlying technology drivers—what’s more proven, and what’s less proven, and what are the technical risks that maybe the companies don’t bring forward themselves, so that’s just been really helpful. Just knowing, “Okay, that sounds like a great idea, but aren’t you going to have to do all your reactor’s maintenance at 300°C? Okay? Well, what’s your plan for that?”
Does that come up often? Do you find companies rely on investors being somewhat ignorant about the technical workings of a reactor?
I think so, and it’s because there’s so many problems to solve. They’re like, “That’s a later problem.” Or they figure they’ll solve it later. I mean, fusion has this too. They’ll say, “Oh, those are engineering problems.”
Has DCVC made investments into fusion companies?
We do have one, and technically a different partner led that, but he’s left the firm, so I’ve taken it over. So Zap Energy is our one fusion deal. We invested in Zap in part because they have a more likely path to a lower-cost power plant. I rely on other people for the plasma physics, and I think a lot about what the power plant will look like and what the path to a power plant is in the long run.
What about Zap is more likely to produce a lower-cost power plant?
Because they don’t have magnets, they’ll have less materials close to the plasma. They should have lower capex, and they should have fewer components that need to worry about radiation.
Looking at the different ways companies are looking to build Gen IV reactors—different cooling methods, different fuels, different output of energy and thermal—what do you think are the levers that are likely to make the biggest difference when it comes to actually bringing those products to market?
Some seem sort of obvious. Are you setting yourself up for higher-cost materials, and if you are, are you getting a benefit that outweighs that additional cost? How are you thinking about that? We’ve only invested in reactors that are quite small. With Radiant, they’re going to be in remote locations without a lot of employees attending to the reactor all the time. So TRISO fuel makes a lot of sense there, because TRISO fuel is so robust and durable that that’s really what you would want in a remote location like that. It’s going to be at a higher cost, but that cost makes the most sense for the application, and the market can bear that cost.
There’s also time-to-market. How much experience and data do we have with the materials or configurations that you’re choosing? If you have very little, you’re going to need more development time. You’re going to need more proof points. So some of it is readiness, some of it is supply chain. Some of it is cost trade-offs.
Which approaches have you seen pulling any of those levers that seem riskiest to you?
It depends on what you mean by risky. I think all of them can be made safe, and so that means they can get through the regulatory process eventually. For some of them, getting the operations and maintenance pieces figured out is going to be a lot trickier. For example, one of these reactor designs where you have to do the maintenance at temperature, that’s going to be tricky, right? It doesn’t mean it’s impossible, but it’s going to take a lot of work to get there, and maybe will dramatically affect how long it takes you to get to a high capacity factor.
There’s also some supply chain things. Supply chain can be sorted out if there are a bunch of reactor designs that need the same supply chain to be developed as you. That’s a good sign. If you’re the only one that is trying to use a type of fuel or a type of coolant or whatever, it’s going to be a much tougher road. We saw a reactor design that wanted to use thorium and heavy water. It was like, “Well, no one else is trying to use thorium and heavy water in the United States. So where are you going to get a thorium and heavy water from?”
It’s a double-edged sword, isn’t it? You can go down the path where nobody else is doing what you’re doing, and then if it works, then maybe you have a more open playing field to compete on. But then if you take an approach that uses more common fuels or more common coolants, the supply chain piece will be easier, but then you might have a lot more competition going to market.
Yeah, but I think at this point, right now, the supply chains are so nascent, and the available expertise is not as broad. It’s not only the supply chain. It’s also who’s going to work at your company that has experience with this stuff. Maybe in 10 years from now, we’ll be in a well-enough populated industry that it makes more sense to go outside of some of these things, but right now you just need a little bit more commonality while things are getting started. If you want to do heavy water, go to Canada. There are people who know about heavy water in Canada.
It’s interesting you talk about this narrowness of expertise available out there. You’re not just competing for customers, you’re also competing for talent as a new startup. How do you think about the workforce and talent issue in the nuclear sector?
The good news is, on the nuclear part, it’s getting a lot better. My generation was the beginning of the repopulation of nuclear. I started undergrad in 2002, and at that time, the nuclear renaissance was about to happen. We were going to build all these new LWRs. And then that fell apart, because, as it turns out, we figured out fracking instead. So natural gas went from $8 to $3 and people didn’t want nuclear power plants anymore. But when I went to Penn State, my class had like 40 people in it. Two years ahead of me was about eight, but then three years behind me was a hundred. So it really was this first wave, and most people now are making the same choices I made: They’re going into nuclear energy because of climate change. It’s also now a more exciting and fast-growing industry. The American Nuclear Society meeting that just happened was the first meeting where there were more people under 40 than people over 60.
One of the bigger barriers is on actual execution, when we actually need to go build all this stuff. We need more welders. We need more skilled trades. That’s going to be the rub in about five years. There are some training programs that are being set up, but you can’t train this huge workforce right now and then be like, “Don’t worry, you’ll have a job five years from now.” So it’s a little bit of a later problem. I’m also hoping that, because there’s so much more interest in nuclear, we will get people from other fields who have more experience actually building stuff.
Part of why I was so excited about Radiant is that the leadership team has designed and built real things. They’ve translated new ideas into reality that are very complex. And because the nuclear industry didn’t build anything new for a long time, there aren’t that many people in nuclear who have ever done that. So we really need very talented people from other industries, and nuclear is really just a conglomeration of other engineering fields with radiation sprinkled on top.
I want to talk a little bit about Radiant. We’ve touched on them in a couple different places, but generally speaking, what about that team and that technology stood out to you as you were preparing for that Series C investment?
I have known Radiant since I was at ARPA-E. My second program at ARPA-E was about using digital twins and doing hardware-in-the-loop development, and I was really trying to bring that idea to the nuclear industry, because it was driving innovation in other industries. I made that whole program. And then I met Radiant, and they were doing exactly what I was trying to get everyone else to do. I actually had them guest-teach a class for me at Berkeley, because at the end of the year, I like to say, “Okay, you just learned all this stuff. But what do you actually do with it? What does it look like in reality?” So I had Radiant show their software-driven development, and then they asked me to be an independent board member when they did their Series A. They asked before I knew I was going into venture. So then when the Series C came around, it was the right stage for our climate fund. And so I said, “Hey, team, you all should really look at this company. They’re doing really well. They’ve actually stayed on schedule this whole time.”
Imagine that. Thinking about Kaleidos and that end product that they’re working towards and the market that they’re working towards, what’s interesting there?
They are taking a smart approach on finding a very clear market and a solution that is the right size and shape for that market. It’s not a big enough market to have hundreds of companies in it, but it’s a big enough market to have a few companies in it. And so if you’re one of the first ones and the one that can really deliver most effectively, you’re going to win that market. For me, it’s also compelling that it’s so much easier and faster and less expensive to get microreactors built and deployed than really big reactors. I think it’s a really great way to help get the industry rebooted. To some extent, you can actually get successes, and you can get people used to your reactors. I view it as the tip of the success spear. And with their products specifically, it’s TRISO fuel, it’s gas coolant. It’s so safe that you can put it in these remote locations. It can’t melt down. They’ve done the testing. And then they’re using supercritical CO2 Brayton cycle so that they don’t need water cooling, so they have a lot of flexibility. And then it’s a small size, but the whole thing fits in a shipping container, so that when you get it to site, set up and install is very easy and requires very little regulatory oversight, because you’re not assembling any of the nuclear parts of the system on site.
I thought it was interesting what you said in your Radiant blog post about how the nuclear industry has in the past looked to achieve economies of scale, and Radiant is looking to achieve more of an economy of series. What doors does that open, and do you think that’s representative of a shift in the nuclear sector?
I think it is, and it depends on what country you’re in. Some countries are great at building mega projects. The United States is terrible at building mega projects. We are like the worst in the world at building big projects. And so adding radiation does not solve that problem. But we are good at manufacturing things. And so if you can move it out of this thing that actually we’re pretty bad at, and then move it into something we’re pretty good at, it makes a lot of sense. Korea could build power plants all day long. There’s lots of reasons, mostly because we have a lot of subcontractors. They don’t work together in an integrated fashion.
Is that the core of it? A less integrated supply chain and workforce?
That is some of it. You’ll have contractors from a bunch of different companies on site, so it’s really difficult to have a unified schedule and plan. In nuclear, we’ve also never built the same reactor over and over again. We were always building different designs. So every project was a first of a kind. There’s a bunch of reasons, but if you have subcontractors suing each other while the project is going on, it’s not gonna go fast.
Now that we’re post-election, we’re looking forward to potential changes in nuclear policy and program development. What are your expectations for the second Trump presidency?
It’s hard to know. I think they will be pro-nuclear. I am hoping that we can move some of the bureaucracy out of the way. There’s been some action on helping unlock the HALEU supply chain, but it’s been very slow. I want to give the NRC credit. They’ve actually done a pretty good job of getting ready and starting to move things through the regulatory system. I suspect there’s probably more opportunity for efficiency. I think there’s an opportunity for permitting reform. I want to make sure that that is done smartly. Nuclear regulation is a good thing. We should regulate industry. The permitting process is a good thing. We should have a process before we build things. And getting things a little more streamlined and efficient, not deleting the processes, is, I think, a big opportunity.
What would be on your wishlist for the next four years?
I think those are the things that are most helpful. It probably will take more federal dollars, but we’re going to increasingly see private dollars come in, to meet the need that is help on the fuel supply chain. That is just a really big sticking point that companies can’t solve themselves.
Lead Reporter of Ignition
