April 4, 2023

Ep 389: Bret van den Akker - Director of Fuel Cycle Innovation, Ultra Safe Nuclear

Director of Fuel Cycle Innovation
Ultra Safe Nuclear
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Show notes

Sarah Howorth [00:01:31] Hi, my name is Sarah Howorth, and you're listening to the Titans of Nuclear Podcast. Today, I am here at the MIT CANES Nuclear Symposium, Nuclear Everywhere, in Cambridge, Massachusetts. And I'm here with Bret van den Akker, who is the Director of Fuel Cycle Innovation at Ultra Safe Nuclear, lovingly known as USNC. Bret, welcome. It's so nice to have you on.

Bret van den Akker [00:01:57] It's a tremendous pleasure to be on the podcast and I'm really looking forward to our conversation.

Sarah Howorth [00:02:01] Awesome. So, let's start off, like I mentioned, with the kind of classic Titans of Nuclear question, where did you grow up?

Bret van den Akker [00:02:08] I grew up in San Diego, California. My dad was a deputy sheriff there and my mom was a housewife. So, it was a pretty typical middle class upbringing. I have two older brothers. Shout out to John and Eric, wish you guys were here. And my little sister Carrie, so, my family. Father's Jack and Francine, so, hi guys.

Sarah Howorth [00:02:29] That's awesome. And where are you now currently located?

Bret van den Akker [00:02:31] So, right now I'm located in Sevierville, Tennessee, birthplace of Dolly Parton. It's about an hour and a half away from Oak Ridge, Tennessee, where we have our pilot fuel manufacturing facility. For your listeners, it's the first privately funded TRISO manufacturing facility in the United States, ever. And Ultra Safe is very, very proud that we are 100% privately-funded company.

Sarah Howorth [00:02:58] That's amazing. And where did you end up going to school?

Bret van den Akker [00:03:01] I did my undergrad in Physics and then I got my masters and Ph.D. in Nuclear Engineering, all from UC Berkeley.

Sarah Howorth [00:03:08] Okay, awesome. So, California to Tennessee pipeline for you.

Bret van den Akker [00:03:12] Yeah. So, nuclear engineering as a field is a little bit niche. It's a niche application of engineering. And then when you get a Ph.D, you tend to specialize further. So, it's niche within niche. And then, I specialize in the back end of the fuel cycle, radioactive waste management. And so, at that time, really I was looking at either Los Alamos National Laboratory or Oak Ridge. So, New Mexico or Tennessee, was my destination from Berkeley.

Sarah Howorth [00:03:44] Awesome. And so, let's back it up a little bit and kind of talk about how you sparked your interest in nuclear energy and fuel and all of that.

Bret van den Akker [00:03:52] Sure. Coming out of high school, I knew that I'd wanted to do physics. We had an alum that came and gave a week lecture on maglev trains. I thought that was really cool, the applications you could do. And so, I went into physics as an undergrad. I knew that I should probably have a undergraduate research position towards the end of my undergrad tenure, and I got a position. Basically it was an applied plasma physics laboratory, but it was run through the Nuclear Engineering Department. So, I did research there, and then after I graduated from undergrad. And through that connection, I got pulled into the Nuclear Engineering Department.

Bret van den Akker [00:04:40] While I was there, I met a tremendous researcher, Joonhong Ahn, who's no longer with us, unfortunately. He was a great mentor, a tremendous, tremendous scientist, and his area of specialty was the back end of the fuel cycle. I couldn't have asked for a better match from a mentor perspective. And really that is where I began to understand the importance of the back end the fuel cycle. And that's really what drew me into the nuclear industry.

Sarah Howorth [00:05:09] That's awesome. And so, for all of our nuclear undergrads who are listening right now, do you have a piece of advice that really stuck with you through your education into your current career?

Bret van den Akker [00:05:22] Well, I think that everyone is probably going to learn this at some point in their career no matter what they do. But I really can't overstate enough the importance of finding a good mentor and finding a good team to work with. I mean, you really can almost do anything if you have a good group of people around and you have someone, especially if you're doing something new, who's willing to guide you through that process. And I've had throughout the years better and worse mentors and bosses. But man, finding Joonhong Ahn was just a tremendous, tremendous mentor for me. For your listening audience, particularly the undergrads in nuclear engineering, if they can find that strong mentor that would be huge for them, I would say.

Sarah Howorth [00:06:07] That's great advice. And let's dive a little bit deeper into your career background and history before we get to your current work.

Bret van den Akker [00:06:16] Sure. So after after graduating from U.C. Berkeley, I did my postdoc at Oak Ridge National Laboratory and then spent a couple of years there in the used fuel group supporting the DOE as a staff scientist. Supporting the DOE's priorities on the back end of the fuel cycle. So, helping them think through how they're going to manage the commercial spent nuclear fuel. At that time, the Obama administration had just shut down Yucca Mountain. The Blue Ribbon Commission report had come out and not a lot of the recommendations were being followed. I was getting very, very discouraged supporting the federal government. To me as a young career scientist, it didn't look like there was going to be a lot of motion happening there. And so, I pivoted, actually.

Bret van den Akker [00:07:02] My intention was to leave nuclear forever. I pivoted out of nuclear, went into the commercial management consulting. With Boston Consulting Group first, and then on the federal side with Booz Allen Hamilton. And that actually brought me back into nuclear. Booz Allen was looking for a management consultant with a nuclear engineer background who could have a security clearance, and I checked all those boxes.

Bret van den Akker [00:07:27] I don't know who they wrote that job description for. I might have been the only one in the country to have that job description. But that brought me back into nuclear. I was doing cost cutting exercise at Y-12 National Security Complex first, and then the last two years before I joined Ultra Safe, I was working for RPE, which is the DOE's Advanced Research Agency, and helped them stand up the ONWARDS program, which is a $40 million R&D program to support the development of technologies to mitigate the impacts of waste from advanced reactor fuel cycles.

Sarah Howorth [00:08:06] Well, glad that you made your way back to nuclear and could be here with us today to talk a little more about it.

Bret van den Akker [00:08:10] I couldn't be happier to be back. I'm just tremendously excited and fulfilled with what I'm doing at Ultra Safe.

Sarah Howorth [00:08:18] That's great to hear. So, let's talk a little bit more about that. What does your position as Director of Fuel Cycle Innovation entail? What's your role within Ultra Safe?

Bret van den Akker [00:08:28] Sure. I think that it's a little bit of an interesting title that I have given the fact that what I functionally do is to plan for the back end of our fuel cycle. So, my area of responsibility is everything that begins with the defueling of the reactor through the storage and transportation of the used fuel and then the decommissioning of the reactor site and returning that to pre-operational conditions.

Bret van den Akker [00:08:55] I've had people say, "Well, how is that innovative?" To date, throughout all of our commercial nuclear fuel cycles, not one gram of spent commercial fuel has made it underground into a repository. So, if I can help plan and execute on the back end of our fuel cycle, I would consider that tremendously innovative.

Sarah Howorth [00:09:22] Okay. So, this might be a silly question, but if the fuel isn't going underground, where is it going?

Bret van den Akker [00:09:29] Well, let's stick with the current generation of nuclear reactors because nowhere in the world are there commercially deployed advanced reactors. Right now, choose the United States. The fuel is discharged from the reactors, will spend some time in a cooling pool to let the decay heat come down from the short-lived fission products. Then it's discharged from the pool into dry storage casks. And typically, it will sit on the reactor site at roughly 90 sites across the United States waiting for the DOE to fulfill their contractual obligation to pick it up. Unfortunately, the DOE, for circumstances which are outside of their control, is decades behind on their obligation to begin accepting fuel for disposal.

Sarah Howorth [00:10:27] Okay. And for those who haven't kept up to date on recent news from Ultra Safe, what have you all announced lately or been working on that's exciting to everyone involved?

Bret van den Akker [00:10:38] So, for your listeners, Ultra Safe is a micro modular reactor company. Our reactor is a high-temperature gas reactor which uses graphite as its moderators. That's different than your typical light-water reactor today, which uses water for both its coolant and its moderator. We are moving forward at light speed towards our initial deployment of our first MMR in Canada, the Chalk River Canadian Nuclear Laboratory site with a target date of the 2026-2027 window, is what we're shooting for. So that's coming up very, very soon. We also have a partnership, an agreement with the University of Illinois, Urbana-Champaign, to deploy a reactor on campus there as a research reactor in the '27-'28 window.

Bret van den Akker [00:11:36] This was hugely exciting for me to be able to actually be there for the entire evolution of it. But in August of last year, we had our ribbon cutting ceremony at our pilot fuel manufacturing facility in Oak Ridge, Tennessee. And that's where we're producing our own TRISO particles. And we're producing the pellets, which will fuel our fuel blocks themselves. Again, as I said, it's the only privately-funded TRISO manufacturing facility anywhere in the United States, unlike some of our competitors who have received tremendous amounts of government dollars. We are both privately funded and we are the only company in the United States that is actually producing our own fuel in our own facilities. All other TRISO is being produced in rented space, basically.

Sarah Howorth [00:12:30] Okay. So, that's definitely where the innovation part comes in a little bit.

Bret van den Akker [00:12:34] Well, I think that our CEO would be flabbergasted if I didn't mention our FCM fuel form. That's our fully ceramic, micro-encapsulated fuel. I wish I had brought a mockup of it. But basically there are two kinds of different TRISO fuel cycles. One is a pebble bed where you have graphite balls about the size of a bocce ball or larger that are embedded with TRISO particles. So what they do is you get your TRISO, so you mix it together with pitch and carbon filler, and then you'll hot press it together in order to have your graphite in balls. The reactor we have is a core that is made up of graphite blocks about the height of these tables. They're hexagonal, but you can imagine them as cylinders with the face about the size of a large dinner plate and then about three feet tall.

Bret van den Akker [00:13:39] About 180 of those fuel blocks make up our core. Those few blocks have channels that have been drilled in them that we fill with our pellets. And the pellets look very, very much like your typical uranium oxide pellets used for light-water reactors. Our innovation is that we additively manufacture silicon carbide cups. So, silicon carbide is a very robust ceramic. It's used for tank armor. So, it's very, very strong. We fill those cups then with the TRISO particles that we manufacture, and then also put in silicon carbide micro powder. And then through a process called chemical vapor infiltration, we densify that into a fully dense silicon carbide pellet.

Bret van den Akker [00:14:29] So, that's really novel because we're not using graphite pellets for our fuel form. The silicon carbide is extremely robust. It is very radiation-resistant. And the fact that we don't press it means that we can go to substantially higher fuel loading than you can achieve with a graphite fuel form. So, we can get more fuel into the reactor, which means we can run it at both higher powers and for longer core times.

Sarah Howorth [00:15:03] Okay, awesome. So, how do you see these innovations changing the nuclear landscape as they come to fruition?

Bret van den Akker [00:15:12] The FCM itself, as I said, we use an additive manufacturing process in order to make our cups, but they don't have to be pellets. In fact, we are using this technology to produce fuel for... We have a tech division which does space technology. So, nuclear propulsion, for example, or lunar nuclear modules, which can leverage the additive manufacturing capability that we've developed to produce different shapes of fuel, which are more relevant for those applications. Beyond that, as I said, the FCM being an extremely robust fuel form, it can also serve as a fuel form in light-water reactors. Because of its nature, both the TRISO and the silicon carbide, it's an extremely accident tolerant fuel. And so, it can provide an extra layer of safety for reactor operators that would be looking to leverage that technology.

Sarah Howorth [00:16:15] Okay, great. Yeah, that layer of safety is probably something that a lot of people are looking for as well, especially if they're looking into Ultra Safe.

Bret van den Akker [00:16:26] Absolutely.

Sarah Howorth [00:16:27] So, that definitely makes a lot of sense. I guess within the realm of what you're doing in the realm of nuclear, is this the most exciting project that you've been looking at or working on? What are your other passion projects in the nuclear space?

Bret van den Akker [00:16:44] The other part of my job as the Director of Innovation is to go out and to look for significant opportunities for funding to push forward our technology. I did work through Booz Allen as a federal contractor, ARPA-E. And shout out to everybody at Booz Allen and ARPA-E. They've been doing a tremendous job there at that agency. But ARPA-E is a very, very forward looking organization. They have put out some very, very interesting calls and we've put in, unfortunately, unsuccessful proposals for them. But interacting and putting together those proposal teams, trying to come up with the innovative and compelling ideas for the funding agencies, that has bee also a tremendous part of my job that I've really enjoyed.

Sarah Howorth [00:17:35] Yeah, that must be a really thorough exercise to go through as well and helping everyone involved kind of understand better what your mission and values are.

Bret van den Akker [00:17:45] Yeah, I think so. I don't want to say too much here, but I had the opportunity recently to collaborate with some folks out at Sandia around a cybersecurity effort. Being a micro reactor, one of our initial markets is to replace diesel fuel generation in remote locations. You know, rural communities or industrial sites where the CO2 is being emitted in sensitive areas and they have very high fuel costs.

Bret van den Akker [00:18:24] A significant value proposition, I think for us, and all small modular reactor developers is going to be enabling through cybersecurity efforts and through regulatory oversight the remote monitoring and operations of these facilities. I mean, it's already difficult enough to be trained up as a nuclear reactor operator, but then to have to say, "Well, not only that, but we're going to put you in remote northern Canada," or, "remote northern Alaska," it's going to be very, very challenging from a workforce point of view.

Bret van den Akker [00:19:00] So, if we can relocate those capabilities to urban centers where we can have them in a centralized location through some kind of a secure cyber infrastructure that would be tremendously enabling for both Ultra Safe from a workforce development point of view and for the broader nuclear industry and would tremendously reduce operational costs for these reactors. And I think it's particularly attractive for this next generation of reactors which are passively safe. That's the so-called walk-away safe reactor. And I think that given that layer of inherent safety, enabling remote monitoring operations is a real, real possibility.

Sarah Howorth [00:19:48] That's great. So, for those who maybe don't know, what makes them passively safe like that?

Bret van den Akker [00:19:54] There are a number of features of our reactor which make it passively safe. I think the fear that most people have with nuclear reactors is the meltdown scenario, right? As I said before, our fuel being TRISO and silicon carbide... Silicon carbide can withstand temperatures in excess of 1,000 degrees centigrade, which is well below our operating temperature or any temperature that we would reach in an accident scenario. What's tremendous about our reactor is that it has a negative temperature reactivity coefficient, which means that... I'm sure that most your listening audience knows a nuclear reactor is driven by the fission chain reaction. So, a neutron comes in, a uranium-235 atom will split it and that will release more than one additional neutrons, so you have a positive feedback loop.

Bret van den Akker [00:20:45] In our reactor, as the core heats up, the absorption spectrum broadens. And so, what happens is... You can have, basically, three kinds of interactions with the neutron. You can have an absorption event where you'll have a 235 absorb a neutron and become uranium-236. You can have a scattering event where that neutron will bounce off. Or, you can have a fission event, where it splits off. So, the bulk of the reactions shift when the core gets hot from being fission events, neutron fissions, to absorption events. And so, that shuts down the chain reaction and shuts down the reactor itself. So, we could have a complete loss of coolant in the reactor, total ejection of all of our control rods, and the reactor would come down into a safe state.

Sarah Howorth [00:21:47] And then for those who maybe aren't familiar, you talked about the fact that you're developing a micro reactor. What makes that different from a mini reactor or a small modular reactor, which is something we've been talking about at the symposium a little bit?

Bret van den Akker [00:22:02] There are a lot of these terms. I would say that there's no hard and fast rule what makes one versus the other. A small reactor is anything smaller than is currently deployed now. When you're talking about what makes micro or mini, in my mind, I think it would make sense to talk about mobile reactors. These are your very, very small reactors that can fit on the back of a pickup truck. Micro reactor, those are going to be in your single digit of megawatt electric. And so, to give your audience an idea, a large nuclear power plant now will produce about 1,000 megawatts of electricity, and that's enough to power a large city. Our reactors are five megawatts electric, so that's about 200 times smaller than your reactors now. Five megawatts electric is about enough to power 5,000 homes.

Bret van den Akker [00:23:06] We can also produce thermal. We can also do process heat. So, thermal we produce 50 megawatts thermal. And that, the processing could be used for things like cement manufacturing or steel foundries, things of that nature, where typically a lot of heat is required. And one of the benefits of using our reactor as a process heat generator is that the conversion efficiency from the nuclear reaction to the heat is about 80% efficient conversion. With our reactor, like most others, the conversion efficiency to electricity is 30 to 40%. So, you get a significant savings if you can directly tap into that process heat.

Sarah Howorth [00:23:47] So, let's take a bit of a look into the future. Where do you see these micro reactors being deployed? Where would they be best placed?

Bret van den Akker [00:23:56] Everywhere. Everywhere. Everywhere. So as I said, our initial markets that we're looking at are communities where they're paying high fuel costs and emitting in sensitive areas. We can also support the defensive infrastructure where they're looking to have grid resiliency and not to be reliant on an external grid network. But honestly, given the ultra safe nature of our reactors, the fact that the way that they're designed and how we're operating them are far away from any of the tolerances of any of the components, you really can deploy them anywhere. And I think that's one of the value propositions that we're showing by our research reactor on UIUC's campus.

Bret van den Akker [00:24:43] Our reactors can be deployed in multiple units, all the way up to about the 200 megawatt area, so enough to support a small city. One of the novel features of our reactor is that we have our gas coolant loop and then we couple that with an intermediary solar salt loop and then use thermal storage tanks to store that heat. That gives us the capacity, unlike so many other reactors... Nuclear is not great at meeting demand variation. It's a little bit difficult to ramp reactors up and down in power. But having that salt storage tank allows us to run our reactor in a steady state mode and then tap into that heat to meet the variability on a grid. Or, for example, to support intermittent renewables like wind and solar.

Bret van den Akker [00:25:34] One of the problems that you can run into with wind and solar as an energy sources is they tend to have to be supported by batteries because it's not always constant. Or, you can bring in one or more micro reactors like the MMR and tie that into the grid and use our reactor to provide that stability against the variation of the wind and solar on the grid. The other benefit I've not mentioned yet is that our flagship design is based on using HALEU uranium, although we can also use LEU+. The HALEU core is designed as a 20 year core. You run that core at 5 megawatts electric or 15 thermal for 20 years before you even have to think about refueling.

Sarah Howorth [00:26:24] Okay. So, as someone who understands a little bit about all of this now, that makes a lot of sense to me. But what would you say to someone who was hesitant to have a reactor like this deployed in their neighborhood?

Bret van den Akker [00:26:38] I think the first thing that I would want to do is to understand the nature of that hesitancy. I think there is a lot of misunderstanding around nuclear. As an industry, and rightfully so, we are held to a very, very high safety standard for operation and for disposal of the fuel. But I think trying to understand what that sensitivity, the nature of that sensitivity, that's really where you have the beginning of those conversations.

Bret van den Akker [00:27:06] So, if it's somebody who's hesitant about nuclear, maybe they saw the Fukushima footage and is saying, "I don't want that happening here. I don't want a meltdown," then the best you can do is try to have an honest conversation and to talk to them about the inherent safety features of our technology. But in the end, you can't force anybody to accept anything. And so, the best you can do is just have that open, honest conversation. Hopefully, you'll be able to demonstrate the value proposition that we have and the ultra safe nature of our technology.

Sarah Howorth [00:27:43] For someone who looks at the name Ultra Safe Nuclear and thinks, "Okay, so this nuclear is ultra safe, but what about all the other nuclear out there?" How would you respond to that?

Bret van den Akker [00:27:59] As I said before, as an industry on both the commercial end... And I'll speak to the United States, that's we're I'm most familiar, but this is broadly true internationally as well. In the regulatory environment and the legal framework which is set up to support the regulatory environment, we are held to extremely high standards. We have tremendously talented and intelligent individuals in the NRC that license these reactors and the DOE, which does the research to support the NRC, who are ensuring that as an industry we are not only able to provide a safe carbon-free energy, but that it's done in a way that is transparent and that is going to protect human health and safety and the environment.

Sarah Howorth [00:28:48] And so you're speaking today at the conference, actually, right after we record this. What will you be speaking about? Can you give the listeners a little sneak peek?

Bret van den Akker [00:29:00] This might be a little bit esoteric. I might come off as a little bit of a geek, too. Recently, I've been reading a lot of stoic philosophy. Marcus Aurelius lived about 2,000 years ago. He was the last so-called "great" Roman emperor. He was also a stoic philosopher. Now, he wrote a book... He would sit down, typically in the mornings, and write to himself meditations. And I'm not going to even try to quote it, but I will give the sentiment of it. The quote's in my slide. But basically, he was talking about dealing with difficult people. But he was just saying that often times, those things which are obstructing your path actually illuminate the path forward.

Bret van den Akker [00:29:55] Speaking from the perspective of someone who's done a lot of work in my professional career on the back end of the fuel cycle and the waste management, in that community, it is often portrayed as a significant burden that we have to meet. That the regulations are written to a safety standard that we have to meet for a million years. And that's codified as part of the regulations. And that's a tremendous challenge. How can you show a safety case for anything over a million years? The whole history of written human civilization is 10,000 or so years, right?

Bret van den Akker [00:30:38] So, I was reading this Marcus Aurelius quote. A million years is 1,000 times 1,000 years. Marcus Aurelius lived 2,000 years ago. And so, I was reflecting on this requirement, this obligation that we have. I started to think, "Is this really a burden on the industry or is it a tremendous benefit?" And I think that we need to start thinking of it as a tremendous benefit. Now, why is that? How could this possibly be a benefit?

Bret van den Akker [00:31:10] As a global society, we are actively moving away from a power cycle which has taken us from horse and buggy to the information age and beyond. That has put us on the moon and has allowed tremendous amounts of the increase in the quality of life across the globe. So, the hydrocarbon power cycle, right? Why are we now moving away from it? It's global warming. Global warming that was driven by a short-sighted view on waste management practices. And so, if we take this obligation seriously and handle it as a nuclear fission industry and really tackle it and solve it... The hydrocarbon power cycle, this is a multi-trillion dollar per year industry that has tremendous benefit. And if we'd done it right from the beginning, we could probably leverage it for another few hundred years, right?

Bret van den Akker [00:32:03] If we do this right as an industry, we will never have to move away from nuclear fission, at least for 1,000 years. So, I think that this is a tremendous benefit that we have as an industry and a real opportunity for us to do it right and to not only replace the hydrocarbon power cycle, but to really put a foundation on which human civilization can take its next step forward.

Sarah Howorth [00:32:32] Right. Yeah, I really like that optimism, and I think that's a great lesson to kind of take forward as so much development and innovation is going on right now. Yeah, that's awesome. So, did we forget to talk about anything today that you wanted to mention? Any more exciting news that's going on or anything else that's on your mind?

Bret van den Akker [00:32:52] No, we could have spent some time talking about the challenges of nuclear waste. But I think that I really had an optimistic message there, and I don't want to get down into the weeds now.

Sarah Howorth [00:33:02] All right, that sounds great. So, I'll go ahead and ask you one last question that I heard recently and really enjoyed the answer to. In this industry, years and years down the line, what would you want your legacy to be that you left behind?

Bret van den Akker [00:33:23] Honestly, it's not so important to me that I have a personal legacy. What I really would like is if I could in some small, or hopefully very large way, push forward the nuclear industry so that it really can be that foundation for the advancement of human civilization, that's is what I want. If I was forced to have a legacy, I would love to be the first person to put a piece of commercially spent fuel underground. If you had to force it on me. But honestly, I am more interested in being an agent for the change to a better, more resilient... to a human civilization where there's an abundance of energy. The abundance and the availability for reliable, resilient and affordable electricity is going to be game changing for the globe. So, that's my rambling answer to your question.

Sarah Howorth [00:34:25] No, no, agreed. And I think that's a great answer and a great way to sort of wrap up the conversation.

Bret van den Akker [00:34:33] Great. Sarah, thank you so much. It was a pleasure.

Sarah Howorth [00:34:34] Thank you. Such a pleasure to have you on.

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