011 Gerrit Bruhaug, Nuclear Energy Guru

011 Gerrit Bruhaug, Nuclear Energy Guru

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Gerrit Bruhaug: [00:00:00] But one of the really fun things I found in reading up on the aircraft nuclear reactors was the project ended in the early sixties and then in the seventies in the oil crisis. It got picked back up, but not by the military who was first pushing it, but by NASA who was tasked with looking at different ways to try and save the country energy.

And they were looking at the fact, they were like, we're, we use cargo airplanes and cargo ships, which burn a lot of oil. Can we use nuclear powered aircraft to haul cargo?

[00:01:00]

Mark Hinaman: All right. Welcome back to another episode of the Fire2Fission podcast. Today we've got an awesome guest, Gerrit Bruhaug. Gerrit, how are you doing, man?

Gerrit Bruhaug: Good. How are you, Mark?

Mark Hinaman: Fantastic. I'm gonna go ahead and let you give a quick 30 second overview or elevator pitch intro about yourself.

Gerrit Bruhaug: Yeah, so I am a PhD student out here at the University of Rochester Laboratory for laser energetics, where we have the biggest lasers [00:02:00] on this side of the country, third biggest in the world. And we do inertial confinement fusion and other exciting experiments with those large lasers. But before coming out here, I did my undergrad in nuclear engineering out at Idaho State University right next to INL very fission focused place.

I became a licensed reactor operator. I had my license still up on the wall from that. And I worked extensively on particle accelerators for isotope production out there. And then like many young nuclear engineers, I got the fusion bug and thought I would go chase that for a while. And yeah, hopefully I will finish up my time here in Rochester pretty soon.

And then who knows from there?

Mark Hinaman: Perfect. So, uh, It's pretty atypical, but I won't send a list of questions ahead of time to a guest, but I didn't with you because we had chatted before, actually just earlier this weekend. Just hearing stories and facts and figures that you'd put together was awesome.

And I was like, we just gotta have a conversation that we can record. Here we are. It's Friday, five in the [00:03:00] afternoon for me and seven for you. And I'm sip and kambucha and you've got some whiskey. And so we're just gonna BS about nuclear. It's pretty cool.

So I wanna focus on kind of some of your experience, your work with your PhD.

Talk a little bit about fusion. Talk a little bit about the future perspective reactors, like the most pragmatic solutions, a as well as some of the. Call it history of designs. I view you as a nuclear expert and I didn't give you the chance to brush up on anything cause I wanted it to be of straight from your expert, expert gray matter.

Which I'm sure you'll do a great job, and if you get something wrong, then we won't give you a quiz or hold you to it.

I was thinking about this question before we started, but

I don't know. And our audience is pretty broad. Some are very educated about nuclear and some are not, they come from outside of the energy space or maybe the upstream oil and gas space.

But thinking about just reactor types in the US, those that are operating and those that have been envision. Talk to us a little bit about the contrast in ver the variety, like historical variety and what's in [00:04:00] use

Gerrit Bruhaug: now. Yeah. So the two types of power reactors we have in the United States right now are what are called pressurized water reactors and boiling water reactors.

And these are both in the broad category of lightwater reactors. So they use the same water that you and I can drink. They use lightly enriched fuel. Although they can go all the way up to very high enrichment the Navy uses pressurized water reactors or PWRs to power their ships and subs. And these are a very old worn type of reactor and that's why we have so many of them in the United States and they're the dominant design around the world for power.

And I do want to emphasize power. When you get out of power, things get weird and there's all sorts of interesting stuff out there. But. In the early days of nuclear, no one really knew what we were going to jump into. There was a lot of different ideas and the lightwater reactors ended up dominating for a variety of different reasons.

Prob probably one of them comes down to the fact that we as a species understand how to boil water. And we're real comfortable with that.

Mark Hinaman: Pretty straightforward. Yep. We got a lot of time. It's comparison to realize how long think about how long it took us to realize that [00:05:00] you could turn heat into motion.

Yeah. When all it took was a pot lid boiling, right?

Gerrit Bruhaug: Yeah. Yeah. Or that the, there's it maybe a apocryphal story of some ancient Greek steam engines, but they just thought they were fun toys. No one thought maybe you could do something with it. Spinning around. Yeah. But yeah, the, you think about a lightwater reactor especially of.

A lightwater reactor has got very similar operating parameters from the power plant side as to a coal plant. So you think when you're starting to make power plants in the fifties and envisioning them in the forties, something that matches up with what you understand with boilers and pressure and water makes a lot of sense.

But from the very beginning, people knew there was a lot of different ways you could do this because nuclear obviously doesn't need any oxygen, and there's all sorts of interesting neutronic properties and people were thinking about very exciting designs right from the beginning, and they were building them.

There was a, an entire AEC, so that's Atomic Energy Commission. That's before the DOE and the NRC were generated. There was just one group and they made all these different reactors at power plant scale, but [00:06:00] about 30 megawatts, and they sent them all over the country. To try and get a feel for what was gonna be best for deployment as power reactors throughout the country.

Nick Turin's, what is nuclear website, has a wonderful history on all of these awesome websites. Yeah, just great, fantastic website. Definitely visited it. But we had just incredible stuff from the classic PWR built in shipping port. BWR there was a b, the first BWR was actually built in South Dakota of all places.

Most people don't know South Dakota had a nuclear power plant. These were all built about 30 megawatts for the power size, just to, it was big enough that it would work. And impact the local power grid, but not so big that it was a gigantic investment. There was sodium cooled, graphite moderated reactors.

There was, I think it was Nebraska, where they deployed one of those and they tried putting one on a submarine. There's the classic sodium called fast reactor that we all know and love, which allow operates in a completely different regime and lets you breed nuclear fuel. There's several of those built in various ways.

Mark Hinaman: Isn't that the [00:07:00] actually called experimental breeder reactor, EBR?

Gerrit Bruhaug: So there's EBR I and EBR II, which being educated in Idaho, I have to love, I'm legally required to love those reactors cuz they were invented there. But there was actually another one built in Michigan, which is a bit infamous called Firmi one, and it suffered a partial meltdown.

Actually kept running right after the partial meltdown. And the partial meltdown was, as is typical with the story of early nuclear failures due to just complete incompetence. Someone welded a part in that they weren't supposed to weld, didn't tell anybody, and then it broke off and plugged the coolant loop.

Mark Hinaman: That's right. Just, yeah. Yeah. And like the bottom of the drain tank.

Gerrit Bruhaug: Just complete stupidity. There was no reason that had to happen. But it's infamous because some anti-nuclear people bring it up as, we almost lost Detroit, but we didn't, there was nowhere close. Yeah, the reactor was fine.

It just sucked to have a partial meltdown and it made the power company not wanna play with it. There was also gas cooled, high temperature reactors. Peach bottom down in Florida had one. I wanna say there was at least a couple others. And these [00:08:00] were just of the power plant variety that people were playing with.

Right? There was other much more exciting things being built just at the labs for tests. This is when the molten Yeah, like the kilowatt scale, megawatt typically.

Mark Hinaman: But the, but a megawatt like test reactor these prototypes that they're building were significantly smaller than, We think of as nuclear power plants, but they're still producing megawatts, right?

This would be a huge diesel generator.

Gerrit Bruhaug: Oh yeah. So it's a fun thing with nuclear is those of us, we're all familiar with chemical fuels, so we know if you want more power, the engine's gotta get bigger. Those of us in America know there's no replacement for displacement. You just gotta increase the cylinder size.

But for nuclear, the question is heat extraction not core size. You can make core in theory, basically go to any power you want. So I could have something, oh, maybe not that big, but about this big, make as many, yeah.

Mark Hinaman: Holding up a coffee cup for just the audio folks. But yeah, hold up cup.

Gerrit Bruhaug: Yeah, a coffee cup.

I could make something that size. Make as many. Megawatts or gigawatts or whatever you [00:09:00] want. The problem is power extraction. You can't pull power, you can't pull the heat out fast enough. But there are, there have been very power dense cores made. The, I think the absolute most power dense nuclear core made, if I was to guess, was probably the Tori two reactor built.

I wanna say 1961 as part of the aircraft nuclear program. This was to power a nuclear missile, a nuclear powered nuclear cruise missile that would fly around the world at mock three. And just circle the Russians until they said, told it to go, and it would carry 20 nu thermonuclear weapons, fly at treetop level break just shattering windows and killing people with the sonic boom, spraying radioactive exhaust out the back and dropping nukes.

It was a terrifying, terrifying weapons program. And the really scary part is it all hinged on the reactor and the reactor worked. They did these tests out in the Nevada desert with the Tori two reactor. And they made a 500 megawatt [00:10:00] thermal reactor that was just tiny and it would power a nuclear cruise missile to any, and the limit was heating of the skin of the missile.

The reactor had all the juice he wanted to get out of it, but that's another good example of a very innovative design. That was some companies are looking at what was done back then. Like hos gen has referenced it as something to consider, not the exact. Set up, but the broad ethos of these just air cooled turbine style reactors, right?

There was other aircraft reactors that were built. There was one in Idaho meant to power a bomber. They fired up the, they had a full jet engine array in it. One of my old professors was part of this project, so I've heard quite a bit about it. You could actually go see the engine out in Idaho. They have it sitting there on the side of the road, and it's a relative of the gas cooled reactors that people are excited about today for high tempera.

And this thing ha was built around a jet engine and they actually fired up the jet engine on nuclear heat, which no one had ever done before. There had been [00:11:00] some basic tests with just trying to make like a ram jet or a rocket, but they actually got the full turbines to spin and everything just off nuclear heat.

They even melted the turbines cuz the reactor could really give it the heat. And the idea was they could fly, fly an airplane with this. But the right, the other fun thing that came outta that program is the famous molten salt reactor everyone loved. It's so popular, especially in the more common nuclear discourse.

Love it or hate it. It is very common to talk about the molten salt reactor. And that came out of wanting to make very power dense, very simple, very long-lived reactor cores to go on airplane. It was not meant to revolutionize the power world. It was entirely to power airplanes. There was talk of molten reactors, even back into the Manhattan project, but the actual first one built was to power a nuclear bomber, and there was designs on the board to make a nuclear bomber the size of a 747 That would fly at mach three using molten salt react.

And it looks very plausible based on [00:12:00] the performance of these things. And it's there, there's just a rich history of really innovative, unique reactor designs that we're, what? What's really mind boggling is we're so used to these paper reactors today, right? And someone draws something up and say, this is gonna be amazing.

And all they have is a computer model or a couple calculations. Back then computers were really bad and expensive. They just built.

Mark Hinaman: They just went like this and fantastic at yeah, just going out and doing it, which is incredible.

Gerrit Bruhaug: Yeah I heard a lot of stories of the early days in Idaho where they would talk about building a reactor, come up with a rough design in say, a week, and they would have it running in six months.

And it's just, yeah, some of those reactors are still around to this day they'll probably live forever. The ATR Reactor Advanced Test Reactor, which has got this infamous beautiful cloverleaf looking core. A lot of people know if you Google Rinko radiation, it's usually the first picture that comes up.

That thing is got some of the most advanced [00:13:00] neutronics you could ever consider from a nuclear engineering perspective. They built that in six months. And as far as I know, I think they designed it in a couple weeks. It started with a bar room napkin sketch and went from there.

Mark Hinaman: That's awesome. I, so I love that brain dump.

And the point of the question was to give listeners or viewers the, demonstration, we'll, we'll call it that, we only use really two types of reactors in the US and there's a couple of, there's a handful that are used for power for across the world, but we've built a bunch of different reactors in the history of nuclear, which was something that I didn't know when I, started restudying the topic and I feel like is not well known outside of called nuclear engineering Circle.

Gerrit Bruhaug: Yeah. And e even within nuclear engineering circles I find it so interesting. I finished my undergrad oh, fi almost five years ago, and I still learn about this stuff. There's, yeah, there's only so much you can jam into a, into an undergrad career, and you're of course focused [00:14:00] on learning about what exists and what we're building.

But there is an incredible, rich history of things that have been built, have been tested, have been thought of that all. Unique potential, especially when we're considering not just making a big electrical power station based on what we know how to make in the fifties, you know, it's 20, it's 2023. We gotta start thinking a little more exciting.

Mark Hinaman: I totally agree. So I wanna start with what we know with existing plants. And one, one thing that comes up is safety and really the, we'll call it radio phobia that results in, in my opinion, overregulation of nuclear and nuclear energy. So you live near a power plant in upstate New York?

Gerrit Bruhaug: Yep. Correct. R. E. Ginna, which is the oldest operating nuclear power plant in America.

Mark Hinaman: Yeah. And also the smallest. So tell, tell us a little bit about it. Yeah. Give us kind of an overview. I remember chatting about kind. Your experience with it.

Gerrit Bruhaug: Yeah, so this was the first nuclear power plan I'd ever visited.

So I should back up a little bit. I'm from [00:15:00] Montana. We have no nucl. The only nuclear thing we have is bombs. Yeah, so I had to leave to go do any of this exciting stuff. And in Idaho, my experience was all with research reactors. They don't have a power reactor in Idaho right now. Hopefully they'll have several pretty soon.

But I sadly was there when there was no operating power reactors, even at I n. And moving out to New York in upstate New York. They built a bunch of lar they started out with Ginna and then they built some larger and larger nuclear power plants up here on the lake. And then of course, Indian Point down near New York City, which is sadly now closed.

But Ginna is of the era where they were starting to scale up the reactors bigger and bigger and it was, I think probably in the very beginning of that, cuz it's 585 or something megawatts electric. So a little tiny PWR compared to these one gigawatt plus machines that we're used to. Uh, Plenty for Rochester though which is not that big of a town.

It used to be a larger town industrially, but has [00:16:00] shrunk since then. And one of the things I thought was really neat with this is when I finally gotta go get a tour of the reactor. It's right near town. It's just right up on the edge of the lake. And I never realized I had driven by it probably hundreds of times.

And did not know, I knew there was a reactor nearby. I didn't know where it was. There's no big sign, there's no big cooling towers. They did direct lake cooling. They ran all the power lines under the big power lines underground so that it wasn't obvious. And it, upstate New York's very pretty with all these big trees and orchards and everything like that.

And the designer of the power plant that this gentleman Ginna, who it's named for he was big on trying to integrate his designs into the community. So the reactor also, it doesn't have a big ugly concrete dome. They built everything up with this nice green color. This is a cup from Ginna. That's the color the reactor is.

It's got nice covers over all of it, and it just looks like a big building with a parking lot. And it's the exclusion zone around the reactor is all apple [00:17:00] orchards and you can buy Ginna grown apples and the people that work there can even hunt on the land where all the deer run around.

They used to be able to fish right off the edge of the reactors, but they told us. But that's been banned now. But if you go out into the water a couple hundred yards away where the, they cut off the exclusion zone, I guess the fishing's still very good because the heat from the reactor and it was just, it was so cool to go see integrated, this integrated thing into the community. I think more reactors need to be like that. And I think the only downside is that Ginna. Advertise, they should have billboards telling everyone, Hey, your city is powered absolutely by zero carbon energy and we make apples for you as well, just because we had something to do.

And they should do way more tours. But due to the restrictions on the site safety restrictions in the United States, it's very difficult to get a tour. One thing they were showing us was post nine 11. They did a lot of upgrades to the security there. There's tank traps. We're in upstate New York.[00:18:00]

I don't where-

Mark Hinaman: what are the Canadians gonna invade?

Gerrit Bruhaug: This doesn't make any sense. Right across. They'd have to come across the, oh, they gotta come from Maine, Connecticut. Yeah. Yeah. We also have a gigantic army base in upstate New York. Call the military if there's a tank. It makes no sense. Other waste of money.

Yeah, there's little sniper towers. The amount of mi hardware, military hardware we saw during the tour was wild to me. But one aside from those complaints, one really amazing thing I gotta do, and I don't know how common this is, but. Ginna was running, it was powering the city at the time.

They were coming up on a refuel. They actually did their record, I think the record for the United States fastest refuel ever right after we were there. Because they've just had so long. We were talking to the engineers about it and they said, we've just gotten so good. We actually plan where people park and we think about like where people stand when we start the refuel so we can do it faster.

But they had us, we were in the turbine.

Mark Hinaman: What are you thinking, man? Six Sigma. They figured that out.

Gerrit Bruhaug: Oh, yea. Just incredible thinking. But we're in the turbine hall and they had us walk up and they said, go put [00:19:00] your hand on the outside of the turbine and feel what 585 megawatts feels like. And I'm a muscle car guy.

I love, I the, the rumble of the engine. But man, nothing beats that, that was wild. That it you can you, because it's isolated, it's sitting in the floor. It's not really shaking anything. It's just loud in there and you go up and touch it and you go, oh my goodness. This is a whole city's worth of power.

Mark Hinaman: So I, I love your articulation of the beauty and the magic behind this power plant. But yeah, like you said, when people think of nuclear, even within the industry, they, that is not what comes to mind, but it's a demonstration of how you can beautify an industrial project. And when you originally described it to me, I was fascinated.

I was like, oh my goodness, the apple orchard and you can go and hunt. What a great idea. Now it's more expensive to bury the power lines and make some call it development decisions that were probably made that are probably more expensive to develop facilities like that. But if you wanna make it fit in my [00:20:00] opinion, it's a demonstration of how you can integrate an industrial facility into anywhere in the world and beautify it. Like really cool.

Gerrit Bruhaug: I totally agree. And one, just speaking of cost, one kind of painful thing too is, so this plant was built back when things were still happening fast and cheap. It was built in four years and for, I believe inflation adjusted, it was something like a hundred, probably not inflation adjusted today.

If inflation adjusted two years ago something like 190 million dollars.

Mark Hinaman: It's sad that, yeah, that's, impactful. Two years ago, in 2020, dollars were worth a lot more.

Gerrit Bruhaug: Yes. But still, even then, we're not talking a billion dollar power plant. We're not even talking half a billion dollars inflation.

Mark Hinaman: So 190 million you said for 550 megawatts, right?

Gerrit Bruhaug: Yeah. Something like that. Yeah.

Mark Hinaman: That's incredible. Wow. Wow.

Pausing here for half a second. I went back and checked this, and Gerrit was close, but off by about a factor of two. So he guessed $190 million. Um, It turns out in 2020 [00:21:00] dollars the power plant cost about $432 million to manufacture. Which, on a dollar per watt basis, is still absolutely incredible.

I mean, that's like 75 cents per watt. Which for reliable power, a beautiful power plant that's carbon free, is just unreal. So he said 190 million. I went back, fact checked, it was really $432 million in 2020 dollars. We won't hold him to it but still, remarkable to think about how cheap that is.

Gerrit Bruhaug: Yeah. And it's going to, it's licensed to run to, I want to say 20. It's at least 2028. Um, the, the bigger question is actually just the state of New York. They think they can keep running the power plant indefinitely.

Mark Hinaman: For forever. That's incredible. So that's what exists now. And I the industry needs to talk about it and promote it, and it's incredible, especially the fact that it was [00:22:00] built so cheaply. And we should be able to replicate that today. The safety upgrades from nine 11, like you said, make no sense.

I totally agree. And, I've heard a lot of people within the industry complain about them, and it just seems silly. But let's shift gears a little bit.

The NIF event, when I was listening, prepping for this interview, you chatted with Keifer on Decoupled podcast about two years ago, so it was January 6th, 2021 when that episode is released.

And you guys were contemplating about when NIF might have been energy positive. So NIF being the National Ignition Facility and it's happened and there's been a lot of buzz about it. I'm sure all of your friends have asked you, what does this mean? All of my friends have asked me what does it mean?

And mean, I'm sure we're still of the same mindset that neat science. Really tough engineering problem.

Gerrit Bruhaug: Yeah. So to, to real quick, to shill Keefer's podcast a bit more. I actually did a follow up with him I think a month ago on, on the NIF event. Yeah. Yeah. We don't think that one's been released yet, has it?

Yeah, I don't know. I don't know if it's been released. I can never listen to my [00:23:00] own voice, so I have no clue. Fair. But yeah the NIP event was very exciting. We were pumped. Obviously, I feel really happy, really blessed to be in this portion of fusion when this happened. It's pretty incredible to have to build, it's neat to be able to say, I was around and I was plugged in when that happened.

That we took that step. I really I'm gonna rip off Robert Zubrin's way of describing this, but it's like figuring out how to light a fire. It doesn't mean you can build. A beautiful diesel engine tomorrow, but the fact that you can light the fire is a huge step when you could not light the fire before.

Yeah. And it's good it's incredibly exciting to be at this point, I am hopeful that we will see a lot more development on that front. I wouldn't be shocked if we get other ignition or burning plasma events from other types of fusion concepts here in the next 10 or so years. But fusion's a big engineering challenge.

It's very difficult to get the power plants to work. There's been a lot of work on the physics of making it [00:24:00] happen. There has not been very much work on the power plant side, and it's going to be a big leap to get there. And on top of that, if we just look at the history of fission, there was a lot of learning to get to where we are now.

Yeah. Reactors weren't all that reliable. They, they didn't always have this 90 plus percent capacity factor and we had to figure it out and we had to have dumb failures. Fusion is going to have to go through that, and it's a more capital intensive project just based on the high tech equipment needed, and we're in a bad time for capital intensive things.

So it's gonna be challenging. The one thing that is nice, at least in the, in, in ICF, inertial confinement fusion, like what NIF does, And like what we do here in Rochester is we are connected to the national security world. So we are very liable to get future lasers that can do even better than NIF that can break the path towards a power plant.

And just similar to fission ride the backs of [00:25:00] the military industrial complex to figure it out. But that's gonna take a while and no one's talking about building a new NIF tomorrow. They're talking about, maybe 10 years from now we'll build a new one. It's not something I would bank on especially if we're talking climate change stuff, I would not bank on getting, turning a fusion reactor on fast enough to make it to really matter.

Mark Hinaman: Yeah, I agree Tragically I had investigated, NIF and inertial confinement fusion, as a young man and as even as a kid. Cause I was fascinated. I was like I can grow up and make this work. And then I went and got oil out of the ground instead unlike you who's actually out trying to do it and trying to make it work and studying it and that's really cool. I admire you and everyone else in the field for that.

I'm curious on your opinion about the MIT group, the Commonwealth Fusion Project, and, they've made a lot of bold claims coming out, or they think they'll have great or good success by the late 2020s. I dunno if [00:26:00] you've studied that project much or if you have, or if you've interfaced with any of those folks and Oh, yeah. What's your perspective?

Gerrit Bruhaug: Yeah. Yes. To both of those fusion's a small field. So I personally, so they're doing what's called a tomac, which is the kind of classic magnetic confinement solution for fusion.

It has, what they're doing too is a very obvious good way of going after a better tomac. The current Big Token Act project is the ITER project over in France. It is based on designs that were settled in the late eighties. It's just very old tech. It makes it very big. Very expensive.

It's running crazily over budget. For the amount of money that they'll spend on ITER. We could have built NIF something like 10 times at least. All that also of makes me feel good as an American with getting NIF and how it ca, it came in pretty good pretty fast and pretty good human being.

Mark Hinaman: How much have they spent? I know the number I have in my mind is 25 billion, but,

Gerrit Bruhaug: For ITER, it is not clear. It'll be somewhere in, it'll be at least [00:27:00] 25 billion. All said and done. The accounting is very opaque because it's an international project. There are doe estimates of 60 billion. Gotcha. By the time they get to burning plasma, specifically when they're injecting deuterium and tridium in and actually getting chain reactions, assuming it all works, there's been a lot of claims of fusion reactors.

That'll work instantly before it'll be a lot of money and it'll be at least 2035 at the absolute earliest.

Mark Hinaman: Okay. But the MIT guys have

Gerrit Bruhaug: these, so

Mark Hinaman: they're going super superconductors. Making the magnet better.

Gerrit Bruhaug: Yeah. So in, in the eighties around the time they were settling the design for ITER, we discovered what are called high temp superconductors.

They're not actually high temperature, they just work at higher temperatures than normal. They work at liquid nitrogen temperatures, but to get really high magnetic fields, you have to run them a lot colder. So what MIT, what the MIT group is doing is they are still running them. Same four Kelvin or two Kelvin temperatures, whatever, it ends up being very close to absolute zero.

But it lets them get a much, much [00:28:00] stronger magnetic field, which lets them make a smaller tomac which is definitely helpful. The down, there's a couple downsides with that whole approach though. The first being is that those superconductors are really expensive and really finicky. Classic superconductors are metal.

You can cast them into wires, you can cut them into shapes. You can do all this normal stuff you need to do, and it's not very hard. These are ceramics you can imagine. Making a cable out of a ceramic is tricky and they're made out of very expensive, rare earths and getting everything to bond correctly and get really solid superconducting connect electrical connections is very challenging.

But having said all of that, they have a lot of money. They have a lot of very smart people who have been doing Tomac work for a long time. They basically took the entire group that was working, that was running and developing MIT's personal Tomac, which the Department of Energy shut down about 10 years ago, I think.

And said, build another one and get private funding. Private and public, they're, they are [00:29:00] definitely getting public support and they are, they, I've seen pictures. They are pouring concrete, they're moving fast. It's exciting. I would not be shocked if they can get plasma to burn and get a fusion chain reaction out of it.

That's awesome. But similar to the story with n f it is hard to then go from there to a power. And I personally am not a fan of tocamacs. I have no doubt that you can eventually beat one into making net energy. But I think making one, make a power plant is much, much more challenging. There's a lot of challenges with.

The heat extraction and actually getting your power cycle to work. Yeah. There are actually interesting safety concerns. Those magnets store a lot of energy. They need to be kept very cold. If they are not kept cold and kept superconducting, they can violently fail. We saw that with the large Haydron Collider decade and a half ago.

Mark Hinaman: That's a fancy way of saying explode, right?

Gerrit Bruhaug: Yes. They can explode. There's ways to prevent it, but it is a risk. And it's and you're just [00:30:00] putting a lot of very expensive stuff in a very nasty radiation environment. And it's not built in a way that's easy to replace components. Fusion makes like a hundred x more neutrons than fission per unit energy.

Mark Hinaman: So I don't think you know that, that simple fact, I don't think people really appreciate. Meaning if you're blasting neutrons all over the place is there any residual radiation on some of the components? So this is something that nobody talks about especially, and everyone on the fusion side knows it, but they just ignore it when they're like there's no waste.

And it's but you just turned on this power generator. You created a ton of heat, but then you also blasted neutrons all over the place, which creates residual radioactive material, meaning everything that was in your reactor just became radioactive. And I'm ignorant on how long it might stay radioactive or remain dangerous or, so it's definitely shorter.

So you might educate me a little more on that.

Gerrit Bruhaug: Yeah. It's definitely shorter lived than than some of the things we talk about with fission. Although if you [00:31:00] invoke fuel recycling for fission, the comparison stops looking so good. Because the long-lived stuff in fission is primarily fuel, right?

It's things like plutonium, the fission,

Mark Hinaman: and actually I'm curious on, on one specific comparison, which is a fusion tomac versus a high temperature gas reactor. Like what they were trying to build for aircraft. And I dunno if you've ever thought of those.

Gerrit Bruhaug: In terms of waste or?

Mark Hinaman: In terms of radiated material that might be radioactive after you shut the machine off.

Gerrit Bruhaug: Oh the aircraft reactor will almost surely have less to, it will definitely have less total volume of material per unit energy. You probably end up about the same in ac in total activity, and the aircraft reactor will remain radioactive for longer unless you reprocess it and process things out.

Mark Hinaman: But is it fuel that remains radioactive or is it also the other components?

Gerrit Bruhaug: Because, and the,

it's almost entirely fuel. It's [00:32:00] both.

Mark Hinaman: But the tocamac, it's not just the fuel, it's the actual machine that becomes radioactive.

Gerrit Bruhaug: Yes. It's the low. It's the low. Again, that's the distinction. Yeah, so it's, you think all of these magnets are radioactive, the tungsten armor on the inside and so you'll find this kind of fun.

One particular issue that is being looked at for fusion reactors and especially tokamac or their related magnetic brethren is the inside becomes unbelievably radioactive in a short term. So you're thinking like on maintenance cycles, it's a problem, right? When you have to get in and replace burnt components because you have a, a star and a jar.

It's not very nice to things. And the who thought this was a good idea? It's hot in here. Yeah. In fission, of course, we also have really high activity, but the way that we cheat because we always keep everything underwater or under sodium or whatever, that absorbs all the radiation.

You can, famously you can walk right over an operating research reactor and the water shields you, you can swim in a spent fuel pool and be [00:33:00] fine. Fusion, we need to keep the inside. Maybe may. We can let air in, but we don't wanna flood it with water and the radiation from a shutdown.

Operating deuterium tridium reactor from activation is so high you can't send people in at power plant levels, not at test re reactor levels, but at power plant levels you can't send people in and most robots will die. So there's a whole development. The electronics just melt, right? Yeah, they just get fried.

And there's a whole development program as to how to make robots to do maintenance on shutdown fusion reactors because it's a big issue. And so actually circling all the way back to even NIF one of the advantages of inertial confinement fusion is we keep all the expensive stuff and doesn't have to be lasers.

There's a bunch of different ways to do icf, but lasers are what we like to use right now. We keep all the expensive stuff, the lasers really far. You can go walk next to the laser amplifiers and there's no radiation. You shouldn't be there for other safety reasons cuz there's a lot of energy flying around.

But [00:34:00] we can turn them off and you're fine. I've done it. I've walked along the laser amplifiers at the lab here in Rochester many times. They're beautiful, incredible pieces of machinery. The reactor vessel is just a big dumb chunk of metal and we, so we can let things get nice and hot in there and there's not that much in the way of maintenance that needs to happen in the reactor vessel.

But even then, the way when NIF got that ignition the ignition shots. They, the first one that happened last year, the one that didn't get over laser gained, but by was Physics Wise Ignition, the one that happened in August. They didn't have all their radiation shielding in place. All their armor, they have different levels of armor that they can put into place to protect portions of the facility, and they killed the lights in the building with the radiation wait on the successful n.

Yes. And they were so activated. By killed, you mean they, the lights didn't work anymore. The r radiation fry them. They damaged some [00:35:00] components because the shot was a surprise and things were so radioactive. We were wondering what the, so the way that we get the absolute yield measurement, how much fusion did you get?

Is they have these little copper pucks that are activated and then you go count them. You count how radioactive they got. You can back calculate to how many neutrons you made. They couldn't send the people in to go get the copper pucks for a week because they were, they had to cool off and, yeah.

Yeah, because they weren't ready for it and they didn't have all the armor in place. And this thing, it was a mega, the first good one was about a mega Juul and a half of fusion, of which a mega juul of that is neutrons. Think about a mega jewel of neutron. That is, some people don't understand what that is, but it's crazy.

Yeah. Yeah. It's a crazy number. Megajoule is like a tank cannon round, and it's just that energy in little tiny neutrons flying around. And fusion also has those really high energy. Yeah. It's wild. And so it, it makes for [00:36:00] a very uh, challenging operating environment and you have to be ready with your radiation shielding.

Mark Hinaman: So we've scoped kind of the fusion or we've stated some issues, engineering challenges that exist with Fusion. Let's circle back. You're interested in fission side now. I'm curious on your opinion. There's a lot of advanced nuclear designs, a lot of people trying different stuff.

Many people are getting funded. It's a really exciting time in nuclear. Now looking forward, in your opinion, what's the most pragmatic uh, solution for kind of developing new reactors? And I'll put some bounds on this, so size doesn't matter. Meaning if you were trying to say, get the most megawatts out or power out that doesn't really matter.

But whi which technology selection would you say stands the best chance? Potentially get licensed or fall in line or [00:37:00] be adapted by society first. And I mean you can cop out and say NuScale cuz I just got approved. But I'm cur curious if you think if there's some other advanced designs that, have other characteristics that might be first movers.

Gerrit Bruhaug: Yeah. So obviously the easy answer in the United States and it's always good to put that parameter in front of it. Caveat. Yep. Yeah, the caveat.

Mark Hinaman: Because in China and Russia, they're just building stuff like they don't care.

Gerrit Bruhaug: Even in Canada and Europe, things will be different. The US is a uniquely challenging environment.

And it's it's interesting cuz we have the best, I would say, we have the best.

Mark Hinaman: We're gonna change that, Gerrit. We're working to change that. We'll change it. So.

Gerrit Bruhaug: Fingers crossed. Yeah. have the best labs, we have the most knowledge on this, the most, the best r and d. But it's annoying that taking that step past is hard.

But in the United States, the obvious answer is PWRs. The classic Lightwater reactor. We already know and love PWRs, BWRS. I'm really partial, to, I have friends at NuScale, they're doing great stuff, and I can't wait to see their power plant get built. I really [00:38:00] like the GE BWR or BWX-300. I just really like the design philosophy that went into that, and I like how BWRs are very fast to ramp.

I'm angry that they're building it first in Canada with all of, with so much GE stuff being here in New York. It'd be nice and Sweden, new York.

Mark Hinaman: Just wait. So I participated in a conference just this morning that was put on in Sweden, in Stockholm, and you can, dial in virtually, but the lady in charge of nuclear in Sweden said, we're open for business.

If you have a design and you want to sell it to Sweden, come talk to us. And there's the ge Hitachi guys there today. The, he's like on camera, he is like, we'll come talk to you. Sounds great. So just watch. I bet it happens.

Gerrit Bruhaug: Yeah. I think they are, they have a compelling design. GEs got a long history of good nuclear production people like bws, they were, they're a bit spooky when you first learned some nuclear engineering as a young nuclear [00:39:00] engineer, you're like, ah, control routes from the bottom and boil and cool cooling.

Ooh, that sounds freaky. But they have a long, good history. They're well understood, and they there's this persistent myth that nuclear can't load follow. So dumb. If it couldn't load follow, we couldn't drive a submarine with it. But beyond that, there are,

Mark Hinaman: we'll just keep saying that people will catch on eventually.

Gerrit Bruhaug: I hope so. But BWR specifically are extremely fast and load following. It's a problem. The grid operators can actually force the reactor to load follow without the reactor operators being in charge. And they get very angry about that.

Mark Hinaman: And I that's last energy's design right with the Open- 100 project and

Gerrit Bruhaug: I think they're PWRs. I'm not sure though. I'd have to check. I thought it was a gen gen two BWR I'll challenge you to go check that out,

so Yeah. Yeah. I'll have to check it out. Either way, both of them can load follow just fine. It's just BWS are infamous for being so fast and love doing it. There's other nuclear economics and fuel damage reasons why we don't like to load follow with those reactors.[00:40:00]

They 100% can do it. And fuel is better now than it was in the eighties when people were complaining about load following. We have much tougher fuel. Anyways, those two are the obvious, easy answers. The other one I am very excited about the Natrium reactor from Terra Power. It's e b R two made big.

I love Ebr R two. I love a sodium fast reactor. I like their inclusion of thermal storage. I think that's, I like that they're building it in Wyoming and on an old coal fired power plant. Growing up in Montana, I've seen the impact of coal jobs. I would love to see a bunch of those built in Montana. I can think of many nice sites where they would go.

And I've actually heard a lot of conversation when I go home. People ask me about that. They said, why are we not building one here? How do we get that built here? We need those jobs. That looks like a great way to power the state. And the nice part is sodium, although the NRC is a challenging regulator to work through, large sodium cooled fast reactors, people have worked on licensing those before.

The n and one of the to [00:41:00] give the NRC some credit, one of the issues they have is they're pretty short staffed and they don't have people that know everything about every type of reactor that all these companies are trying to get licensed. But finding experts on sodium cooled fast reactors isn't that hard in the United States.

There's a heck of a lot of 'em. So the, it's more likely that one moves forward. It's got a nice heritage to sit on and man, you wanna talk about load following a sodium cooled fast reactor. They can do anything. Yeah. Yeah. Absolute lightning on the power grid. People will love it. And then, X energy with their high-temp gas reactor.

Both of those companies have big DOE support. That helps a lot. And both are working on these designs that have a lot of heritage and that helps you get through a a nervous regulator. Yeah, and they they have big customers, right? X energy's got Dow coming for them. Terra Powers,

Mark Hinaman: it's genius, right?

I imagine their sales cycle has been two to four years, if not longer, to get some of those contracts in [00:42:00] place. But once they've gotten 'em in place, like it's anchor tenants, it's great business, great big business, very impressed with them.

I feel like we've run the gamut, meaning we started very elementary at the beginning of this discussion and have just launched into kind of all, many of the advanced systems and jumped into the lingo, which is I feel like necessary, meaning anytime that you're recording stuff to, to make public, you wanna try and create something new and add to the conversation which is good.

And obviously, we're already coming up on hour and just gonna have to do this again or more often. Oh

yeah. So if anyone's listening and they are curious about those designs go start Googling cuz there's tons of information about all the designs that we've mentioned so far.

I'll say I'm most bullish on the opportunity for small, high temperature gas reactors. And I don't know. I've talked, I talk about that a lot, so we don't have to go into it now. But I do wanna segue with that into some of the applications that we talked about, right off the bat with nuclear meaning, there's space, there's power in space.

There's, the stuff that they tried to do in the fifties and sixties is [00:43:00] just incredible. The fact that they tried to power an airplane, And we just talked about emitting neutrons and radiation in a confined space, and we've now got these containment domes and trying to control radio nides.

But these guys were putting it on an airplane and then lit. They literally flew one, right?

Gerrit Bruhaug: They literally flew one and they were that that terrifying missile I was talking about was actually just one congressional approval from going, they had everything ready to go for a test flight. They were gonna launch from San Diego and circle it around in the ocean and then just dump it.

And it was actually the US military that said,

Mark Hinaman: this is hilarious, genius. Yeah,

Gerrit Bruhaug: the US military the Department of Defense said, no, this is too provocative. We're canceling the project, which is wild. But just talking about the radiation shielding. One other interesting thing I found diving into this aircraft reactor stuff.

I've told you this and I'll say it on camera now. A big part of this is I realized about midway through my graduate career that I feel like I wasted some of my time in Idaho. Not that I didn't have a good time or learn a lot, but I was around all these incredible older nuclear [00:44:00] engineers who had done incredible things and I didn't ask them questions about some of these projects.

So now I've been trying to read up myself.

Mark Hinaman: Shame Gerrit. Shame. You gotta always ask the older people. Ask the mentors. Yeah. Don't be afraid.

Gerrit Bruhaug: I think I just, part of it is I just didn't know enough to know what to ask. And now I have a million little questions and getting back in contact with them and learning about some of this stuff from people that were there that built it.

But one of the really fun things I found in reading up on the aircraft nuclear reactors was the project ended in the early sixties and then in the seventies in the oil crisis. It got picked back up, but not by the military who was first pushing it, but by NASA who was tasked with looking at different ways to try and save the country energy.

And they were looking at the fact, they were like, we're, we use cargo airplanes and cargo ships, which burn a lot of oil. Can we use nuclear powered aircraft to haul cargo? And because it's going to be a civilian thing, they had to think about how to make it ultra safe. You can't take the risks that you could with the military aircraft.

Yeah. And. [00:45:00] Looked at shielding, that would act as armor for the reactor as well. And the shielding would be so thick and powerful or good at stopping the radiation that you could sleep on it and there wouldn't be any issue with the reactor at full power. And then they said let's see how armored it is.

Can it survive a crash? And they made these little test dummy stand-ins. I think they were like one-tenth size and shot them on rocket sled. And proved that they could survive an aircraft coming in and crashing and the reactor wouldn't leak. And they even had one that's come off the rocket sled. I have these old black and white pictures of these things flying into walls and stuff, and they had one come off the rocket sled and go bouncing down the road and crush a car.

Oh. And they said the car is destroyed, but the reactor's fine.

Mark Hinaman: You gotta email a picture of one of those to Emmett Penny and have 'em included in Crom's Blessing in Grid Brief.

Gerrit Bruhaug: Oh yeah, I do. I should send that to Emmet.

Mark Hinaman: Yeah. He'll love that. I wanna finish on the [00:46:00] gas core reactor. So you just, you've, you have a Twitter thread about this, which is awesome, and you described it to me briefly. I'll give some background or context.

Most people, when they think about nuclear, Unless you've actually studied the industry and understand what Nu nuclear fuel is, don't actually have any idea. You might pic I pictured the blue glowing something or the green goo from the Simpsons. Which is totally inaccurate. All nuclear fuel is generally solids, meaning like it's metals uranium, right? There's atoms and elements of uranium that we've just separated isotopes. And then we combine it in such a way that An effect that when you change the geometry or modified the geometry of how you arrange these metals, then it creates a neutronics effect.

AMIThinking about that correctly? That, you've got more neutrons going out and create and colliding with other atoms, and then they fi, which is incredible, but essentially they're solids, right? And, You've studied or you [00:47:00] identified a system that didn't use solid uranium and had some interesting characteristics.

So let's give us kind of an overview of that.

Gerrit Bruhaug: Yeah. And I guess real quick, actually, in the United States, most of our reactor fuel is oxides. So a ceramic, but there's a big push back to metal. Metal is, yeah, it's a whole bait. I don't, I got those wrong. Yeah. No, I just wanted to point it out because it's fun to think that it's ma, the fuels like your plate I guess I meant they're not liquids or gases.

No, they're not liquids or gases. And there's of course the famous molten salt reactor, which is, does have liquid fuel, but we're. A step beyond. So this was thought up. Gas, a gas core reactor. It's not a gas cooled reactor, even though the, it's easy to mishear it. The idea is the classic thing you hear the molten salt guys say is the reactor can't melt down if it's already melted.

And the gas core, if there was any gas core guys are still around, would say the reactor can't boil if it's already boiled. And so the idea is they will have, they'll let the

Mark Hinaman: meaning the fuel, the uranium is literally in gaseous form.

Gerrit Bruhaug: It is in gaseous form. It can be gas pure [00:48:00] gaseous uranium itself, or more commonly uranium hexa fluoride, which it will turn into a gas actually at a pretty low temperature, which is good for experiments.

I think it's 50 degrees above. Background or above room temp or something like that. Anyways the, this whole thing, people were thinking about this even in the Manhattan project. Because they're moving a bunch of gaseous uranium around for enrichment, and they're going, you could totally make a critical reactor with this if you got your arrangements right, because they had to think about how to not make it critical.

And the Soviets first played around with this and they, they just had gaseous filled fuel rods, just trying to understand what you could even do. And then the United States, in classic fashion, went much further at Los Alamos, and then finally in Idaho, one of my old professors built this thing where they let, they just had a sphere of gaseous uranium in a cavity, and then they had reflectors on the outside.

And the big advantage here is that you can run that uranium gas or hexa fluoride gas. To just incredible [00:49:00] temperatures. You'll hear some people refer to it as a plasma core rather than a gas core, because it will act, it would, depending on how you wanna define it, it will become a plasma. Yeah.

And how hot. Give us a, how hot do you want it? They talked about 5,000 degrees Kelvin without even a blink. No one has done that. All the tests were much lower temperature, but it wouldn't be challenging to do. And the advantage there was the whole idea was to power rockets. Now, there's a lot of other challenges they found with making nuclear rockets used run with gas cores, but the idea never really went away because one big advan, there's two, two big advantages here, aside from the temperatures. The reactor is unbelievably responsive because of the fuel being liquid like that it or gaseous. It just responds instantly to changes in power and the poisons.

Naturally go out. So the burnup of the reactor, you can burn the fuel to 100% depletion. You just keep putting fuel in as you burn fuel. And the poisons, the fission fragments just leave You're naturally reprocessing. And there was [00:50:00] designs for all sorts of very interesting gas core reactors for power.

They talked about. Literally gas core reciprocating engines to power trains. These they looked into these really incredible kind of gas turbine like gas core reactors that would have crazy burnup, very high power output would be breeders. It's a really compelling concept and I think.

It's not something I would go put in my nickel down today, but man, there, there's something to be said for what you could get out of it. If you, if we put the r and d in there was very few ever made. The project ended in a whimper with the end of Apollo. But it seems like something that could be picked back up and some really exciting stuff done with it.

They even looked into it. You can actually use the gaseous core to directly act as a laser. So you can get a large amounts of industrial grade ultraviolet light, coherent. So you think like maybe a semiconductor fat, self-powered for instance. That would be an interesting [00:51:00] concept.

Mark Hinaman: That's awesome. So I know we, we threw shade at Fusion for having some engineering challenges.

But I did wanna end with this discussion on kind of an advance. Application and really core design, right? Of this incredible physical phenomena that is fission to give people hope and spark some optimism. And also like some curiosity because when you talk about this, it sounds like a technology that is science fiction.

When it was tested, it is real. And yet there's still so much unknown about it that the applications that could be realized and use of it and like the benefit is huge. I just think it's fun to think about. And that's just one case, you list it off to, to start this discussion.

Probably 10 to 20 different reactor types and models that have been built. And I think when I've counted 'em, it's like 50, 60 that prototypes that we had actually built and, there's [00:52:00] dozens more designs. So anyway, there's just so much opportunity in nuclear and with fission and to move forward and advance the science and the technology. So.

Gerrit Bruhaug: I 100% agree. I think we're in the very early stages of the nuclear era. And we're, there's so much more that we could do. It's talking about it like the designs are over are like people in 1820 saying, talking about they've solved how to burn coal.

Mark Hinaman: Yeah, exactly. Cool. Gerrit, thanks so much. We appreciate it.

Gerrit Bruhaug: Yeah, thanks for having me on.

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