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What's All the Fuss About Fusion?

Gerrit Bruhaug

Monday, January 9, 2023

Chris Keefer  0:00  

Welcome back to decouple. Today I'm joined by a returning guest Gerrit Bruhaug. Our in house fusion expert. Garrett is a decouple veteran. We'll be referencing back to our first podcast together the nuclear fusion energy delusion question mark. But in short, Garrett is a nuclear engineer with a background in fission and particle accelerators, now at the University of Rochester, working on his PhD, blasting things with huge lasers. And so I thought, you know, after hearing the announcement from the Lawrence Livermore Laboratory, where I think 172 lasers were blasted out a little fuel pellet, that I should talk to my man Garrett again. And he has been so gracious as to join us. So Garrett, welcome back to the couple men.


Gerrit Bruhaug  0:45  

Happy to be back, Chris, and happy to talk about the exciting news and maybe bring some clarity to it.


Chris Keefer  0:51  

That would be helpful. I'm not sure how you feel about, you know, fusion journalism as someone who's, you know, deep on the inside. But maybe we could just start with that, actually. I mean, what's your kind of reaction to the way that the public has been discussing what happened at we'll just start calling it Triple L. Lawrence Livermore Laboratory. I've also heard it referred to as lasers, lasers, lasers,


Gerrit Bruhaug  1:12  

we actually usually call it LOL, NL or just Livermore, or those goddamn guys in Livermore more often. But yeah, fusion journalism is possibly some of the worst journalism out there period, no matter which way you want to cut it. It's either hype to disgusting degree, even if you're a big fan of fusion, it kind of it gets overboard. Or there is almost pessimism to a disgusting degree. It's it feels like it takes every thing from the bad stuff with general energy journalism, and just turns it to 11.


Chris Keefer  1:48  

You were mentioning, you know those bastards down at at at Livermore. So you also shoot lasers? You know, I kind of did a real quick intro there. But just tell us, you know, for listeners that you know, haven't been with us for the last 100 episodes when we recorded our first fusion podcast. Just tell us a little bit more about yourself, before we dive into the exciting announcement from Triple L or Livermore, as you refer to it?


Gerrit Bruhaug  2:10  

Yeah. So like you said, my background is originally fission. I've actually operate a fission reactor worked on accelerators, and all that fun stuff out in Idaho, and then as many young nuclear engineers do, you catch the fusion bug, and get convinced that that's the thing to go do. And unlike many other people, I pretty quickly realized I didn't like the magnetic confinement method of fusion, which I'm sure we'll dive into shortly. I thought this laser thing sounded fun. And so I went out to the University of Rochester, which is, has the largest laser at any university in the world, its facility. So big, if you came out here, and I told you, it wasn't a national lab, you would think I'm a liar, but $90 million a year budget. And we have two enormous lasers, one of which does very similar work to the machine at Livermore. And it's kind of the little sister or the, or like the older sister, but also smaller, called omega, which has 60, lasers all aimed inwards, to implode targets and generate fusion conditions among many other exciting bits of science. And so I work with omega and its sister laser Omega EP, which is a different laser that we don't have to dive into that to study the physics involved in all of this. And specifically, my thesis work is on generating radiation sources to act as kind of like a flash bulb to look at what's going on in these experiments, because they are very messy, very fast, very small, very dense. So we don't really know what's happening beyond Oh, boy, a lot of energy goes in, and oh, boy, a lot of radiation comes out. We've gotten a lot better in the past 20 years, but it's, it's still hard.


Chris Keefer  3:40  

Yes, I really listened to our initial episode, and it really is a good one. You're an amazing guest. And I did a lot of research on that show and impressed myself, I have a pretty good short term memory. I think that's how I got into med school, I was able to, you know, memorize and crush those multiple choice, pre med courses pretty well. My long term memory, not so much. And as you know, we had to reschedule this episode because I got a bonk on the head recently. So I do want to, you know, revisit the basics. We always talk about Spaced Repetition as being a really key tool to finally learned something I remember it for those of us not bright enough to grasp it on the on the third on the first first time. But before we get to, I guess, maybe some kind of rapid fire stuff to get everybody up to base on some fusion basics. Want to clarify, clarify for me, this news out of triple Well, what happened? I heard they shot a big laser at a pellet and they got more energy out than they then they put in. But um, if you can expand on that slightly, that'd be helpful for us.


Gerrit Bruhaug  4:44  

Yeah. So before getting into the real specifics of types of fusion, what specifically happened at Livermore, and why everyone was so excited and I'm very excited. I mean, we were we were all just absolutely pumped when we heard the news being in the biz. I heard it a lot earlier than the rest of you. I got a text about two in the morning about what had happened. But they passed what's called the ignition threshold. And interestingly enough, we kind of did this last year, but there is a, the US government set a very specific legal limit on what counts as ignition, a scientist will argue back and forth as to what it is, but there was a specific number that they had to pass. And some of that has to do with some of the history with Livermore being a bit of a politically aggressive lab. And some of its just for clarity there, there can be no games, you just have to pass this number. And so the lasers themselves can generate two mega joules of laser energy, they consume a lot more, but two mega joules of laser energy goes in to actually affect the fusion fuel. And we got more than three mega joules out. And we call that ignition. That means that the fusion chain reaction was self sustaining, it was self heating. And more importantly, although there's two mega joules going in, there's just a bazillion in efficiencies. So when we actually look at how much heat went into the fusion fuel, it's more like 29 kilojoules of actual heat. And so almost all of the heat that was keeping the reaction going was generated by fusion itself, we have never done that in a lab ever. That is, that is completely new. We've only ever done that in thermonuclear weapons. And the reason that this is important, even with all the issues that we'll dive into about the system, you can think about this, like learning to light a fire. And I'm going to cribbed from a wonderful article from Robert Zubrin about this. If you're a caveman and you see our cave woman or see lightning coming in hitting things and lighting fires and go man, it'd be cool to be able to light that fire. But I don't have a lightning bolt, or in the case of humans, we don't want to use the lightning bolt we have. I want to be able to light it on a small scale. And so you sit there and you work and you work and you work and you work and work and you get a little bit of an Ember and a little bit of wood to burn. That's useless, that's utterly useless, except for the fact that you now know how to light the fire. And you can get better and better and better at it. And you can use that little bit of burning to light a bigger fire, to eventually, you know, 1000s of years later build a power plant or whatever. So this is, this is the very tiny little first step that had to happen, there can be no fusion power plants without reaching this there gonna be no fusion anything without reaching this point. And it has been the goal of decades and decades of work to reach ignition. So it is a big scientific deal. And that's the thing I want to emphasize scientific deal.


Chris Keefer  7:29  

And this is this is the National Ignition laboratory or ni F facility. You know, it was named ignition. And from what I heard, I think in a side conversation with you is that they were anticipating this was gonna happen a long time ago. This this lab was built some time ago, and, and it was little humbling how long it took. But again, just just to, to make sure I've got this right. The first time that humans ever succeeded with a fusion reaction, certainly ignition, a sustained reaction where the energy, you know, not wasn't just individual pulses, but it sustained itself was IV, Mike was was our hydrogen bomb explosion. And when you think about I mean, we're going to be making lots of fission fusion comparisons. But, you know, fishing being essentially getting a neutron to hit an already very unstable, enormous atom, which is relatively easy. And we saw that in the progress from the Chicago pile to, you know, to the Nautilus and to shipping port happening in a relatively short period of time, the amount of energy in to make fusion happen or sustain it is is crazy, it took fish and I took a fish and explosion, I believe in those thermonuclear bombs, fish and sets off the fusion, right. It just gives you a sense, I think of what a challenge this is, and what an accomplishment it is.


Gerrit Bruhaug  8:46  

Yeah, it's extremely challenging, and the what, specifically the kind of comparison to think of as the energy density or the or, more specifically, the power density, to be able to ignite that reaction. And this is part of why NIF was built, the way it was built. Those lasers mimic the power density of a fission explosive, wow, to be able to drive that same sort of system to happen. But fission gives us a cheat code, you know, we could I could just get nine kilos of plutonium and do it as well. But that's not a very productive way forward,


Chris Keefer  9:17  

might produce a little bit of follow up a little bit. So and maybe just maybe this isn't a jumping off point to just get a little bit into the theory and just some super basics here. But you know, fusion happens in the sun, and that happens quite easily. Why is it that it's so hard to do on Earth?


Gerrit Bruhaug  9:31  

So fusion has extreme conditions to reach when you look at the sun? Yes, it does happen easily. Although it happens rarely. It's, it's always fun to point out the power density of the Sun is equivalent to about a person. It's just the sun is really, really, really, really really big. So that adds up to a lot of power coming out in total. And the sun is doing the hardest kind of fusion called proton proton fusion, very very rare because of that has low power density very hard to make react but any kind of fusion the one done it and F is the quote unquote easiest called deuterium tritium fusion, where we use two isotopes of heavy hydrogen, both provided by Canada, thank you very much. To Yeah, oh, straight from Kansas. And those have the lowest requirements for fusion. But fusion by lowest, it's still very, very, very challenging. We have researchers,


Chris Keefer  10:23  

when you say the lowest requirements, you mean the lowest amount of energy in in order to initiate fusion.


Gerrit Bruhaug  10:27  

Yeah, so we, what we'd like to talk about is something called the Lawson criterion. And that's just a rough, weird random number to compare this URL to where we just multiply a bunch of different things together. But effectively, what you need to do is reach a certain temperature so that the cross section or probability of fusion becomes high enough to even matter, there's always a probability of fusion, there's probably a fusion event happening in the ocean right now. But it's so rare, it doesn't matter. But we need it to actually become high enough to start to matter. So that only happens at temperatures at hundreds of millions of degrees, or billions of degrees, pick any unit you want, it doesn't matter. It all ends up being hundreds of millions to billions. And then we need to hold that plasma that gets made. So at those temperatures, matter is no longer normal matter, all the electrons are stripped off, and they're just flea free flying around, we need to hold that stuff for a certain period of time to get the reactions to actually happen at a rate that matters. And we would specifically like to hold it long enough. So they start self heating, so that when the fusion reaction, heat goes off, it generates more heat to keep the whole thing together, so we don't have to keep heating it ourselves. And the reach of that loss and criterion, you have to reach you have to get very, very, very insanely high temperatures. And you have to either hold the plasma for a long period of time, or generate really crazy pressures, the sun does both at the National Ignition Facility, we reach very high temperatures, and we reach insane pressures, we the hydrogen at the National Ignition Facility is compressed so much, it is more like a kilo. So hydrogen is like point o seven grams per cc density. Normally, as of ice, we freeze it into an ice before we compress it, it goes up to more than a kilo per cc. So it's like 100 times lead density. And then it's also a billion degrees. So that's, that's the sort of insanity you need to reach. And that's for that easy fuel. It just gets harder from there.


Chris Keefer  12:29  

Wow. So this is kind of cool, because it's easy. Fusion is much easier in the sun because of the mass of the Sun and the gravity there. And the way in which that can force protons together from getting this correct. But we need to and I want to talk a little bit more which we mentioned the lasers which are depositing interesting energy, I think a lot of people can conceptualize what a laser is you've got laser pointers, etc. But I want to talk a bit more about these little pellets of deuterium and tritium, because I understand part of what took the NF so Gundam long to get this happening was perfecting that little, that little target. So you're creating that pressure by exploding and compressing something right? Tell us about the target and what that's like, because I think we're gonna get into a little bit about you know, what this would look like to sustain it? How many how long did the the reaction go on for was this like a microsecond thing that goes on for a few seconds a minute,


Gerrit Bruhaug  13:21  

the reaction only went on for about a 80 pico seconds, but it released more than three mega joules. But that this is something that kind of drives me nuts. A lot of people focus on the time and are like, Oh, well, it's useless, we have to make it go billions of times longer trillions or whatever. Completely ignoring that every day we get into a vehicle that is powered by tiny explosions that go off constantly. This is basically a diesel engine for fusion. That's what the niif is. And we because we just compress it really hard till till she burns. And this is it's completely copying how nuclear weapons initiate fusion as well. So that's that's the reason this path was chosen, there's two primary paths for fusion magnetic and inertial and inertial was picked because we knew it worked. It was the only one that you can 100% point to a real world example. And now we have two that we can point to where inertial works. But you're right, we need we have these little pellets, we had to make them very, very perfect. And the reasoning for that is in a nuclear weapon. If you've ever looked at the designs for how a thermo nuke works, you'll notice the whole thing is pretty crude and big and there's compression the nukes only on one side and the the hydrogen portions over here. How does that compress effectively when you hear that the NIF has to be so focused to make such good compression? And there's tricks there's super secret BS that I don't know and if I knew I couldn't tell you, but also you get a cheat with fission like that's the number one thing always come back to his vision is amazing and provides you just this stunning, incredible amount of power instantly. And so you can get around any imperfections by just being more powerful. It's the thing we talked about in the initial world a lot. That if we just had Bigger lasers than we don't need as much perfection. But the the nihf was built on the very ragged edge of what we thought could work for ignition. It was based on underground tests that were made meant to simulate ideas of how inertial confinement would work and based on smaller lasers that had been built. And the original proposal was we have to have a 10 mega joule laser. And we think that'll, that'll do it based on the nuclear weapons testing, and Congress went No way, we will not give you a 10 mega joule laser. So they went back and they reran their simulations and fusion simulations are the most untrustworthy things in the world, but they went at it. Sure, okay, two mega joules. If we're really, really, really good, and Congress went fine, well, fun to two mega joule laser. And you guys can do all this stockpile stewardship stuff with it and play with Fusion. That's, that's the most will fund. So because of that, they had to get really, really, really good not only with the laser radiation, the spots, the timing, pointing everything, but the targets had to be made perfect. So the actual little pellets themselves, you can imagine this little tiny thing the size of a period at the end of a sentence that is filled up with deuterium tritium ice. And the pellets are made out of things like diamond or beryllium, to build it make really perfect super strong surfaces. And then in the case of the niif, they're placed inside of a little tiny gold case called a hole round. And this is very similar to how a new quarks and the idea is the lasers hit the whole realm, they heat the whole realm up, and the whole realm of emits X rays, it gets so hot, like we've ever seen metal get white hot, imagine if it got X ray hot, and then the X rays ablate the outside of the pellet, or you get a rocket effect. And the pellet goes compressing in as all the stuffs flying off, and the pellet compresses in at 400 kilometers per second, I mean that everything in this is just unbelievably extreme. But the reason they went that way, because you'll you'll think like wait a second, the lasers don't even hit the pellet. And it's going to make X rays and a bunch of those x rays are gonna leak. And this has got to be so inefficient. And it is it's horribly inefficient. It's called indirect drive. The reason they did it is that's how nukes work. And once again, it was let's do it, the way we are sure is going to work. There's a billion different good ideas. For instance, in Rochester, we don't do indirect drive, well, we will, we will if people ask for it. But that's not our primary thing. We actually directly ablate the pellets with the lasers, which is a much more efficient way of doing it. But when they were designing the nihf, they didn't know how good lasers were going to be in the future. So they weren't, we're going to use the laser tech we have, which all the design was finalized in 1992. I got approved in 94 for construction. So that means they were using lasers that were a mature technology in maybe 1986. Maybe you always you always have to pick older technology because you need to build a build it right, you talked about this a lot on the show, you have to actually have a supply chain, you can't just pick something that some guy made in a lab on this big and says oh, I think it's going to be super efficient, magical, you have to pick something that you can contract to a company, and they'll you know, build 192 laser beams for you. So they that's what they ended up. That's that's how the end I ended up the way it did.


Chris Keefer  18:18  

So I love what you said earlier about, you know, people saying hey, it only lasted for a picosecond or a fraction of a picosecond. We've got to you know, make billions of these to actually sustain it for any amount of time that's going to be you know, congruent to running a power plant eventually. And you mentioned well that's what happens in a diesel engine. There's all these individual little hydrocarbon molecules that are oxidizing and you know, burning up essentially. But then when you describe, you know, these deuterium tritium pellets, each of them seem it seems like it's this. I don't even know what what analogy to use this like perfect jewel, this is like diamond, this this, this pearl that has just been polished, and of creating billions of those to go off sequentially. Seems seems bizarre, like as you mentioned, and you've been sort of teasing at this that a lot of this research, particularly at triple l has to do with stockpile stewardship. Maybe this is a moment to sort of talk a little bit more about Triple L as a facility. And and you know, you mentioned that this this path towards initial confinement had a lot to do with with nuclear weapons. So why don't why don't we chat about that a little bit.


Gerrit Bruhaug  19:26  

So, Lawrence Livermore National Labs is one of the younger national labs than all the other ones that we know the names of like Los Alamos and Oak Ridge are from the Manhattan Project days directly. Livermore was a spin off because there was a fight between weapons scientists, and it came out of work that was already happening at Berkeley sounds potentially messy. Yeah, well, if you ever heard of Edward Teller he wasn't friendly to a lot of people. And he went off and started Livermore. Hilariously enough, it was actually partially They driven by his want to make the hydrogen bombers they called it the super. And a lot of people at Los Alamos were not into the idea. But it took him so long and he had to burn so many bridges to get Livermore going that Los Alamos built the first hydrogen bomb before he could even get his lab going. And so let Livermore is famous for always being in tight competition with Los Alamos. And they had a lot of very young, bright scientists there right around the time the laser was invented, which is how they have always been the champion of inertial confinement fusion, because once we got hydrogen bombs, a lot of people started thinking panic if there was only a way to do fusion like this, but without a nuclear weapon, then it would, it might make sense we might build actually do it easily rather than these big magnetic monsters. And the moment, I think it's like two years after the laser gets invented, one of our best bomb designers, John knuckles, writes the seminal paper saying, Well, if you had lasers like this, you'll be able to do inertial confinement fusion, with lasers. And this is what we should pursue. And so Livermore has always had this, this big focus on developing lasers and developing inertial confinement fusion. And it was always closely tied with the weapons work, it was weapons designers that were involved with it, a lot of the stuff was classified. The actually the, from what I can tell the first fusion company ever was started about inertial confinement because of the same idea with lasers. And they had a huge fight with the AC. And you know, before before the NRC and the DoD were created the Atomic Energy Commission, they this massive classification fight. Because they said, you know, we're going to do this fusion thing. And AC said, hey, that's secret bomb tech. And these guys said, Well, what, you know, we came up with it ourselves. It's not our fault that it's secret bomb tech. And funnily enough, the first ever laser fusion experiment was not done at Livermore. And they are very bitter about that fact, it was done at a private company in Wisconsin. But the the physics from laser from the compression that we can do with lasers has always been very interesting. For bomb scientists, there's a lot of indications that design, some designs were updated based on things that they learned how to make better, smaller, more efficient bombs, blah, blah, blah, but then we get near the end of the Cold War. And it looks like we're going to stop doing underground testing entirely. That's, that's where everything's going. And everyone's getting pretty freaked out about that, because of two major things. One are bombs are old, the vast majority of them are from the 60s. And you ever think about if you had to go start a car from the 60s, would you trust it to turn on. So a lot of people were worried about that. And then the other thing is, we would lose the knowledge base. So you imagine, just like with building nuclear power plants, if you don't build any for 3040, however many years, you might not know how to do it later. Even if you have the paperwork in front of you for how to do it, you're gonna lose all the all the little things. And so this idea of stockpile stewardship came up that we're going to do research, we're going to build machines that allow us to do research on the conditions of nuclear weapons and better understand what's going on in them so that we can update our codes, make sure that all the little sub components still work properly, but also trained bomb scientists. So if you are designing inertial confinement experiments at the end, if you implicitly know a lot of things for how to design a nuclear weapon, even if you don't know that, even if it's not, it's like we're teaching you in secret. And it also is, this is a common thing in the DoD science world, it gives everyone a toy to play with. And you have to eat your vegetables and do a little bit of bomb work. And as a reward, you get a you get to do fun experiments with this giant laser we built for you.


Chris Keefer  23:35  

That's an interesting kind of Psych. It's an interesting kind of psychological mechanism, right? Because I imagined being a weapon scientist, if you're not a sociopath, is is kind of tricky to balance in your head. And there's lots of ways I'm sure you can sort of moralize and justify it. But probably it is nice to have what you're saying there. This this kind of toy to distract yourself with.


Gerrit Bruhaug  23:52  

I've also heard it's just incredibly boring. Not you got to think once again, we haven't set them off in a long time. What do you do all day? You probably just confirm things on codes and go Yup, I bet it still works. God, I hate my life. I'm working on weapons and it's boring.


Chris Keefer  24:07  

Right. Right. Right. And one other thing I heard and this is a bit of a sidebar, but you know, we hear about the massive amount of military spending. The US does, for instance, but I think Livermore is funded under the DOD and a lot of the stockpile stewardship research is doe. So in reality, the US military budgets even bigger when you


Gerrit Bruhaug  24:25  

saw no, this is actually a really fun side note, the the entire weapons related portion of the DoD which is called the NSA. They pay my check by the way they fund my entire the entire lab. I'm at I am funded under an NSA fellowship. What does that stand for and NSA National Nuclear Security Administration, so it's the the United States the nuclear weapons are technically owned and ran by civilians. Under the DOD. It's this weird sharing thing that's kind of been around forever. That goes back to the AC. The NSA is funded by the military. So the DoD is given a certain and budget by Congress, and then the NSA gets their budget from the Department of Defense. But like I said, we we do get these giant cool machines that do other things. So most of the time on say the NSF or the Omega laser here in Rochester is not doing fusion, and very, very, very few shots are ever classified or anything directly related to, to weapons work, we do a lot of just pure science with it. So honestly, I think it's like the best deal ever, we get, you know, a couple billion dollars from the military to do weapons work, of which most of it is just cool science. They they take you know, those lasers have other applications for scientifically that nothing practical, but like we can simulate the interior of planets and stars and understand astrophysics and, you know, on and on and on and on. And it all comes from the DoD writing a big check for a cool machine.


Chris Keefer  25:56  

So let's, let's dig in a little bit more. Again, I was sort of teasing at that issue of these pellets, how perfect they are. Of course, you know, in the popular press, people are saying this is a breakthrough moment, this is maybe the Kitty Hawk moment, you know, similar to when the Wright brothers got an engine, you know, lawnmower engine on their, on their proper wing shapes, and we're able to sustain flight for 14 seconds, this is the beginning of that, we're gonna see limitless clean power. You know, it's very reminiscent. And when people you know, wind and solar enthusiasts talk about sort of free energy from the sun and the wind, neglecting, of course, all of the steel and concrete and rare minerals within the actual weather harvesting machines. I want to I just wanna understand a little bit more the fuel, how it's made, and how we would potentially step up inertial confinement with lasers to actual power production? How many laser shots a day can you do at your lab? Or Can Can they do it Triple L? How efficient are the lasers? How much room is there to improve that, you know, how many of these little pellets can we build and sort of line up to, you know, set off these little Thermonuclear explosions? What do you see as as you know, the main rate limiting factors in turn a turn the announcement that they had and what they did into usable power for the grid?


Gerrit Bruhaug  27:15  

Yeah, so I'll start out with the that Kitty Hawk analogy first, I actually think it's fine to compare this to Kitty Hawk, because the Kitty Hawk airplane also sucked. But it proved we could fly. The difference being is we don't need to go from the Kitty Hawk plane to a Sopwith Camel, we need to go from the Kitty Hawk plane to a 747. The all the steps in between are basically useless. We have to we have to hit the 747. Before this becomes useful, doesn't mean the Kitty Hawk moment isn't a big deal. But it does kind of ignore that we're gonna we have a lot left. We'll start with the pellets. The pellets are always rightfully so focused on they're very expensive. They're custom made. However, the reasoning behind that is we can't shoot the lasers very often. So there's kind of this chicken and an egg problem. Why would you ever make a lot of pellets if you can't use them? There have been test programs where they've tried making a lot of pellets rapidly. And they can do it. And it's the the comparisons I've I've heard are, it's kind of like thinking about semiconductors, the first time someone ever made a computer chip, it was a custom made insane thing that you could never imagine mass producing. And now we make millions of them without a problem. But you have to have the large capital investment. And there's going to be a lot of r&d to get it to the point where you need it to where it's going to work. There is no just throw a million dollars and will already start making pellets at mass production. There's interest, there's projects, there's a lot of work that needs to be done. It's not happening tomorrow. It's not happening this decade.


Chris Keefer  28:48  

So how many Poles do we are we talking about? Say like, if we're to run this for a day? Are we talking about 1000s? millions? Billions there are


Gerrit Bruhaug  28:55  

Yeah, there are I should have that number, and I don't but there are, it depends on how fast you want to shoot the power plant. And that comes into there's an interesting design space with inertial confinement fusion because we can get what's called very high gain. In theory we've never


Chris Keefer  29:08  

shown game is during the queue is that what


Gerrit Bruhaug  29:12  

a lot of bad numbers being thrown around gain is when we talk about the recent experiment. We'll talk about scientific gain. So we had a scientific gain of 1.5. We got three mega joules out versus two mega joules in but we had an engineering gain of like point oh, something because the lasers consumed far too much electricity. Also, there's no ability to convert power at the NIF anyways,


Chris Keefer  29:35  

and when you when you say convert power, you're saying the three mega joules you got out running that through working fluid and turning Yeah, turbine and you'd be 40% efficient and lose about another half or something. Right. So okay, yeah, so


Gerrit Bruhaug  29:47  

you'd never you'd never get it back around that way. Now, all fusion systems have to have I like to think about as gain there's other different ways of talking about but it's you need more you need a it's a factor of energy out versus energy in And it's always worth talking about both scientific and engineering because sometimes you can get very high scientific gain very poor engineering gain, maybe they're middling it depends on all these different concepts. There's a million fusion concepts, but specifically with ICF, to one very important neat trick that we should be able to do a big emphasis on should but we're basing this off weapons experience is get very, very high gains. Because once the fusion burns starts happening, and a well compressed pellet, it should consume a lot of the fuel at once. MCF off the the magnetic systems often struggle with much lower gains, but they make up for that with trying to make more efficient overall systems. And ICF. There's a whole debate about do you try and make something with very, very high gain their their ideas that were there's basically no limit as to how high you could push it and deal with these massive explosions every couple of minutes? Or do you make something much lower gain and try and shoot it faster, but at minimum we're talking, you need to be throwing a pellet once every three or four seconds up to multiple times per second and firing. So you're gonna need a lot of them.


Chris Keefer  31:11  

Like the again, I think part of the journalism on fusion mobilephone frustrating is it's kind of like a lot of the, you know, the hype around using hydrogen. Now, like in where I'm at right now, they're going to be blending in homeopathic amounts of hydrogen into natural gas to you know, greenwash natural gas plant operation. But there's this idea with fusion that well, it basically turns water into energy. And deuterium and tritium are not h2o. They're very special forms of hydrogen. And, you know, while it's sort of framed as well, the fuel is limitless, and it's here, it's in a form that's really fucking hard to get into concentrate and purify and,


Gerrit Bruhaug  31:48  

well the deuterium isn't hard. That's, that's, that's a very easy thing to get a hold of,


Chris Keefer  31:52  

I mean, we run heavy heavy water reactors and that's a big uranium enrichment we don't have to do up here in Canada, but heavy water still is pretty expensive. Like I was just actually at the well this is a big tangent but I was at the dark matter Research Center at the Sudbury Neutrino Observatory and the you know, they ran a neutrino test in the in the 90s. And they had to borrow heavy water from from Atomic Energy of Canada Limited I believe. And it was $300 million worth of heavy water that they needed to pour into a tank for one of their sensors. So it's not I mean, it's not cheap cheap. My right yeah, you just saying it's cheap because tritium is so fucking expensive or is due to


Gerrit Bruhaug  32:30  

the it as with all nuclear things, so it's important to remember fusion is also nuclear so it gets the same fun benefit of you just don't need much fuel. So we need like 70 kilos of deuterium a year for a gigawatt power plant. It just doesn't matter if it ends up the fuel cost ends up being like nothing compared to the everything else in the power plant. It wouldn't. I think it would literally end up as a rounding error


Chris Keefer  32:52  

and much less than you need to fill a call Andrea can do up with a yes gobsmacking on heavy water. Okay, I got you there. Okay, so the amount in the pellets is quite small,


Gerrit Bruhaug  33:00  

oh, excruciating, like micrograms and each pellet. The tritium, on the other hand is the tricky one. So any any fusion power plant that wants to use dt, which once again, easiest fuel to try and do anything beyond di t is somewhere in the range of 30 times harder to potentially impossible. We do know that pure deuterium can be forced to fuse as well. Because IV Mike was a pure deuterium thermonuclear weapon. But once again, much much harder. So there's no one there's very few people looking directly at that. Di T is by far the favorite one. And just for everyone's reference, tritium is super heavy hydrogen, it's radioactive. It's got about 12 year half life, there's no supply on Earth worth mentioning. We have to make it right now all the lat Well, labs like mine get our supply from Canada from directly from Cantu's. There's also weapons supply that is used for things like the NRF that the US government, Russia, China, etc, breed their own tritium from lithium. So the plan for a future power plant this is where things get really, really tricky, like ignoring the pellets or anything else I would say just abstracting to a future fusion power plant of arbitrary type, we have to breed the tritium in situ. And every fusion reaction makes one neutron and that one neutron needs to go off and make more than one tritium. So we have to have a really, really efficient breeding blanket to make this happen. In theory, you can do it no one's ever done it. I assume there's probably going to be quite a bit of r&d, there was decades of r&d on fission breeders. They never quite reached the breeding ratios that they wanted to reach. And life's a lot easier for fission breeders than for fusion breeders because the reactor will just keep running even if it's not a breeder. In Fusion, you have to you have to make it happen. You have to cycle the tritium out in real time while other reactors running usually out of something like liquid lithium and lead mix together that'll be running through your walls, which is a whole different materials nightmare that people have to come up with how to handle cycle at the tritium efficiently put it into whatever form is going to be your fuel, and then feed it back in. And you also have to deal with the fact that tritium likes to soak in everything. So especially these magnetic confinement reactors, where you can imagine they're like a big doughnut that's just full of dt plasma everywhere. They have this problem with some of the experiments for the tritium just soaks into the walls, it just gets everywhere. So you have to have even more tritium to even start the reactor. It's just like a tax of tritium you have to pay so they talk about like the eater fusion plant fusion project and France, which is a giant token that will basically consume the entire world supply of tritium just to start up, because it's just got to soak the frickin walls with tritium. And then they have to try and breed more. And there was concern actually about your you're helping the fusion community, by the way by saving Pickering and things like that, because there is major concern that as candy was closed down, we will lose all tritium supply for experiments.


Chris Keefer  36:08  

Wow. Wow. You're welcome. You're welcome. Oh, really, that really helped there was there was a company that was going to detach create the water from Pickering. And now they've put that on hold and friends of people involved in that company. They were had mixed feelings. But yes, for the long term viability of the tritium supply, Pickering being around longer is a good thing. I this is a cool anecdote you might find interesting. We have a deep titration plant at Darlington, next to one of our this is one of our four unit sites. And they, as part of this process, they produce this interesting waste product, which they hadn't really monetized. I was talking to some guys that work there and just said the physics of that of that the titration planner are extraordinary. And I'm having this huge tank of helium three. And someone you know from the finance department had a look at it and said I think we're sitting on $4 billion of helium three right now, I might have been abroad, there's definitely billions, right. But helium three is another source I've heard I you know, I was in preparing for this. I don't want to go too much. Because I know there's all sorts of different forms of fusion I think it's simplest to think about inertial and magnetic on one side, there's some combinations there's Healy on I think which is experimenting with with helium fuels and maybe more of a I don't I don't think I really understood it. I watched one video on it, but maybe more of a particle accelerator approach to fusion. I'm losing track of my question here. We're talking about tritium.


Gerrit Bruhaug  37:31  

Well, you're talking about helium three, which I do want to point out I made a I made a Twitter thread, actually about this about how they can do is basically run the world on helium three if they if they actually pull the helium three out, whole world supply taking care of, but that's not for fusion, you'll find this little number fun because i we i talked about this with a friend of mine, they said well, you know, could the tritium supply just be handled by having like, candles and DT reactors, and they'll work together right? Each each PW R, or I'm sorry, all the P pH WR is in the world. So that's Canada, India and Romania, make about 4.5 kilos of tritium per year. But for a DT reactor, we need something like 70 kilos per year for a one gigawatt power plant. So there's no possible way all the candies in the world can't keep it going. And the same issue holds for the helium three, because helium three is the decay product of tritium. And it is it is a potential fusion fuel, we actually use it at omega. Sometimes we'll do helium three shots, not to try it and reach ignition because it's 30x Harder than dt. We use it because it produces a unique type of radiation. That's helpful for some experiments where we will have a fusion explosion, and then we'll take a picture of it with another fusion explosion. Which is pretty neat. One of the


Chris Keefer  38:49  

one of the things we talked about, I think, in our last conversation was particularly with DT reactions. You know, these are heavy isotopes of hydrogen, I guess when those protons fuse, some neutrons go zipping off. And those neutrons are just fucking bowling balls. I'm not sure what the right analogy is. But we were talking about how they knock all the you know, atoms out of a metal lattice 30 times I forget what time unit but they're just bashing everything when I looked at the some of the animations of the Triple L laser shots. I mean, there's a bunch of really finicky fancy looking equipment there. What's What's the implications in terms of the the kind of neutron damage to to those facilities in terms of an engineering challenge or a feasibility challenge we've talked about now I guess we've talked about the pellets themselves. Let's talk a little bit about neutrons and then we'll talk about lasers a bit more.


Gerrit Bruhaug  39:36  

Yeah, so the neutrons once again, abstracting to any kind of fusion reactor are of massive concern. Neutron damage is in a fusion reactor. It's just like nothing we've ever seen in the fission world. We can't even simulate it properly with a fission reactor because we just can't get the damage because the neutrons from DT fusion are 7x more energetic than the fastest neutrons from fission and you make away More of them 80% of the power from a DT fusion reactor is neutrons. Compare that to what's my number for fission 2.5% as neutrons from fission, and that's actually sandbagging fission, because most of those neutrons and fission have to go back into making more fission. Whereas in fusion, all of those neutrons come out maybe and they got to stop somewhere. And you're trying to stop them and lithium and lead so that you can make more tritium. But like you said, they're gonna hit other things. And they will do an unbelievable amount of damage not you know, knocking lattices, metal lattices out malt, you know, I think it's like 30 knocks per year or something crazy like that. It's like nothing we've ever had them, booboo. Yeah, just being beaten


Chris Keefer  40:47  

an inefficient plant. I mean, those neutrons are being generated inside a great big steel, you know, reactor pressure vessel, they're they're colliding with stuff. That's pretty simple. And when I looked at the, again, the animation from Triple L, it was just it, they're going to be colliding with some pretty high tech instrumentation, it looked like yeah,


Gerrit Bruhaug  41:03  

so But interestingly enough, that's actually one of the proposed advantages of any kind of ICF facility. And it's important to remember ICF can be abstracted away from just lasers, there's other ways to do the same trick. But lasers are favored for a variety of political and technical reasons, that'll take a whole different podcast to get into. But the nice part is most of the really expensive stuff is actually very far away, and well shielded. So like the laser amplifiers, which for the case of Livermore the size of three football fields, well, those are so safe from there's nothing, you know, radiation dose at all by those, you compare that to some other fusion facility fusion systems where they have to put say, a magnet, one foot away from the fusion plasma, they kind of get the crap beaten out of them. And so that's that's always been one of the arguments for ICF is, you don't have to put at least very much high tech equipment within the HAL radiation zone. What that ends up being in reality, I don't know, I think we kind of need to, I'm hoping that we can build future facilities and find out really what the damage looks like. But the National Ignition Facility when they read, they, they have done damage to themselves with with Fusion neutrons and other fusion reactor experiments have done similar things, we have to it's one of the 1000 Miracles, we have to get working for a real good, reliable fusion power plant.


Chris Keefer  42:32  

So let's let's talk about lasers now. And I think the way that you just mentioned there's other ways to kind of deposit that energy into the DI T to make it do something curious what those are. But we've talked about using efficient bomb as a way to get ignition happening, and now they've done it with lasers. You know, we talk about the kind of efficiency limits say of a solar panel. I think it's the Shockley Kaiser limit around 40%. maximum efficiency, the best limit for wind is around 40, I think as well. And you know, there's the what is it the car no limits for internal combustion or gas turbines? I forget what the lasers you mentioned at Lawrence Livermore are super old and super inefficient. And lasers have gotten a lot better is there? What's the kind of maximum efficiencies we're seeing with lasers? How cool are lasers? Tell me more about lasers. You love lasers? You know, they sound really awesome. Yeah.


Gerrit Bruhaug  43:21  

They're a neat piece of technology. So yeah, the the Livermore lasers are very old. And they're old and poor, poorly, poor efficiency, like I said, on purpose, because of the age and also cost, they picked a technology that was going to be cheap to build the system. I always think it's fun. People like to talk about the cost of Livermore, or the NIF, it was about $4 billion over budget. That's a lot of money. I'll agree. But it was also over a pretty long period of time. And you compare that to say eater, which is estimated to be between, I don't know, 30 and $60 billion, and it's still not finished, I think the US made the better investment. Yeah, that those lasers are something like point 1% electrically efficient, they use a flash lamp to put the energy into the laser. So think like an old timey camera with that big white powerful flash, that's how we put the energy in, most of that's heat that doesn't go that doesn't do anything for the laser because the laser needs one particular wavelength of light to get pumped up to the energy or to become a laser. I won't get into the laser physics, but it needs only one little portion of that white light spectrum similar to how a solar panel can't use very much of the Sun spectrum. We have way way better lasers. Nowadays we even had the back then. But it wasn't a good choice for a scientific facility that was so kind of pushing the limits anyways. So there's very, very efficient lasers like laser diodes that are getting up above 50% electrically efficient we cannot use so that's like a laser pointer. We can't use those for inertial confinement fusion. They don't have some of the right characteristics. When we look at lasers that actually have the correct characteristics so they can make big pulses of energy they need to be ultra violet, there's some beam quality stuff that you they have to have. There are two options. There are late basically a hyper modified version of what Livermore is using right now, which is very similar to what's also being tested for laser weapons. Before they become ICF usable, there's something like 40% electrically efficient. After we beat the laser hard enough to make it be useful for fusion, they're more like 15% electrically efficient, that's still a heck of a lot better than point o one. And those lasers also can fire a lot. So Livermore can only fire three times a day. And that's because of the heating of the laser and putting the targets in and all the other complexities that slow them down, because they're the targets are put in by hand and hand aligned and all this stuff that you can imagine ways to pretty easily do it better with just some modern techniques. So you know, 15% efficient with that type of laser. The other option is an excimer laser, which some people might be familiar with, because they're used for LASIK, I actually got that done a couple weeks ago, got shot right in the face for the UV laser works.


Chris Keefer  46:09  

That's cool. That's called informed consent. When you go to an ophthalmologist and they have to get your consent, you were truly informed. I think, knowing exactly what that I


Gerrit Bruhaug  46:17  

was a little too informed I was I was telling them to drug me up fast, because I knew a little too much about what was about to hit me. But those lasers are have been investigated for ICF for a long time by the Navy. And for other weapons related crap. And those are about 15 to 18% efficient, and also have already been built and shown to fire really rapidly. The Navy has a laser called Nike that does this, they did a bunch of testing to see could you ever even make ICF possible, you know, you had to this is I was telling you, they tried making a lot of little pellets. They did this whole program called hackles where they made pellets really fast, they didn't load them with fuel, they were just curious if you could make pellets fast, shoot them into a chamber and hit them with a laser at once a second. And they showed they could and they did it, I think it was like a million or 2 million times just to prove that it was at all even barely feasible. So the lasers are definitely looking better. Still, you know, we'd like to see more, and we have to build them. The lasers I'm talking about are at the kilojoule scale, we need to show hundreds of them to really make this work right all linked together to try and make some sort of power plant or power plant analog I I'm not thinking about power plants anytime soon, I'm thinking more like pilot facilities like those very first fission reactors way before shipping port things like EBR one, I think is the next phase we need to consider for fusion. But there's there's other options too, to deposit that energy. So lasers are one really good one, there's also particle beams. So we can use a particle accelerator like they have at the at CERN and Switzerland. Those are nice, because they're really electrically efficient. They're already built for high rep rate. So they fire really rapidly without a problem. But they're, you know, big. So you're you're talking that's that's kind of the end theme you might notice here is every time we're talking about something with Fusion, we're talking big, we're talking a machine that is going to take up some space is going to be it's going to end you have to think about it a gigawatt scale, you'll never it It blows me away when people talk about small fusion reactors and like what are you guys smoking, the amount of equipment and personnel and money? The only way it could ever make sense from what from what I can tell from my perspective is you you're gonna have to make a big, they're gonna have to be, you know, a three gigawatt power plant and doing r&d to get to that point is also challenging.


Chris Keefer  48:49  

So I think, conceptually, you know, I think we've explored some of the challenges here. You know, one being the fuel itself, making those little beads, the tritium sourcing that, in particular, another being neutron damage. And the third being the enormous amounts of energy that we need to sort of deposit in to get it going, what's been referred to, I think, is parasitic load. And that can either be all the energy to charge up your magnets at a magnetic magnetic confinement operation or to charge your lasers and, you know, whatever, whatever the source of energy is that you need to put in. On the on the fusion side or in the fishing side of things. There was a good episode on power hungry podcast, as always to Robert Bryce with Ray Roth rock, who's a venture capitalist with some interest in fusion and had some interesting things to say he was saying, listen on the fusion side, fusion gets past the issues of decay heat, which kind of haunt efficient in terms of, you know, managing decay, heat and the advent of, you know, loss of coolant and things like that. It gets around the problems of waste. And I'm not sure if he said this, but it seems like that fusion there's a lot of fusion research, a lot of prototypes, a lot of stuff happening in a way that you don't see happening with fishing and I'm not sure if fusion As under the provision for Visa or the regulation of the Nuclear Regulatory Commission in America, but it really seems like, you know, you hear about endless startups, I think there's $4.8 billion of private capital in Fusion projects. There's lots of, you know, workshops with people setting up their own lasers. You mentioned, they actually managed to do a laser shot outside of Lawrence Livermore Laboratory in a private facility first. You know, I think these these challenges of the two technologies are interesting. On the efficient side, I think what Ray was saying is a little overhyped. I mean, we've managed to K heat pretty well, there's been a couple accidents, they've been pretty inconsequential from a human health perspective. The waste, I think, has been overblown. But again, on on the on the fusion side, I guess I'm, I'm interested in the regulation and whether fusion falls under the arbitrage of the of the Nuclear Regulatory Commission, if there's regulatory hurdles, or not really


Gerrit Bruhaug  50:52  

so fusion does, it is under the NRC, but right now, it's basically treated like particle accelerators are regulated, which is very, very loosely, it's not nearly as much of a pain in the neck to handle you just kind of have to prove you're not going to kill someone with the radiation and you're okay. However, the tritium is heavily regulated by the NRC to, as you probably know about tritium regulations, unknowing and horrible, the US limits on tritium are very, very low. And all fusion reactors will make tritium just like all fission reactors. Well, even if you were doing a deuterium, deuterium, you know, ideal fusion reactor that just use sea water as its fuel. It, it'll still make tritium and it'll there'll be tritium to handle, you might be able to keep it all circulating in the reactor, but I would assume you're probably going to have tritium issues to deal with with the NRC. But also, the NRC is writing rules now, for fusion power plants, because you know, we might as well strangle the new industry right in the crib. Well, we'll see how that really works. But I don't know if you've seen the new advanced reactor rules from the NRC, I'm not hopeful that anything good will come out on the fusion side. But I want to address a couple of the other points also, from that I listened to the same episode from power hungry. And it's it kind of gets into some of the perpetual myths with Fusion as well, you write the decay, heat won't be as big of an issue, however, there will be decay heat, there will be prompt decay heat from the activation of the reactor that massive neutron flux will activate the heck out of the reactor. And there are actual concerns about partial melts of fusion reactors upon rough shutdown, it's, um, it's not likely to be as nearly big of a deal, it'll decay faster, blah, blah, blah, but you could definitely damage it, and you don't have this giant body of water, you know, the inside of a fusion reactors vacuum, really hard to get rid of heat and vacuum. So if you lose your cooling pumps, it wouldn't, it wouldn't be the craziest thing to imagine you're very, very, very expensive fusion reactor kind of slips over in a giant pile of super radioactive nastiness, because also the the decay activity is very, very high. And maintenance on fusion reactors is already a problem. Because once again, you you don't have that water cover. If you've you've been to a nuclear power plant, you see how they move the rods around, they're all covered by water, it's very easy, you bolt on to these things, and a guy can just move the crane himself in a fusion reactor, we can fill the inside backer with air and people can go inside. But then it's going to be extremely radioactive, it's already radioactive enough from simple experiments that we often wait days for the niif part of why they were waiting so long to make the announcements because they had to wait for the whole thing to get to lower in radioactivity enough to go pull some of the detectors out and check them. So the there's work on like robots to do maintenance and things like that. It's another another one of these challenges, but also on the waste front. Activation makes radioactive waste just like we there's radioactive waste from accelerators, there's radioactive waste from medicine. And a lot of the stuff from fusion is going to be in that kind of intermediate level that you know, it's not, it's not low level waste that you can immediately throw away we'll we'll have to actually have a decay time we'll have to manage it. And because of the high volumes of the machines, it's, it's considered an issue, I can send you some IEA papers where people are really thinking about decommissioning a large fusion reactor like eater, it's going to be a substantial volume of waste to handle. And it's one of the interesting comparisons to fission as you look at the total activities of the waste. Division is higher, but total activity, but then if you look at like waste per unit volume, fusion ends up being much worse. So you have to do at least these like intermediate, you know, we have to hold on to it for like 100 years until it decays down to the point where it'll be fine. And of course, we you and I know that that's actually not a big deal that's very easy to handle. But it is very annoying to see it bandied about as not a problem at all I am one of the things I'm perpetually worried about with Fusion is that If we get a working let's say we get a forking fusion reactor and all these promises are being made, we're building them and somehow we've sidestepped the NRC and Kung Fu our way to starting to make power plants. I'm worried about a lot of the same problems, reoccurring, that the fission industry, you know, the same, the same sort of kind of lying to people the same. Just general issues that really hurt the fission industry and kind of kneecapped it. And I think fusion advocates need to think about that. And they need to read their history of nuclear power, if they ever want to have real good fusion reactors on the grid and not just a one off government project. And maybe a big, you know, mothballed decommissioned facility somewhere.


Chris Keefer  55:44  

Okay, we're coming up on the hour. I think I've got most of the questions I had down here answered. Is there anything else that you feel we haven't touched on that you wanted to? Say your piece about?


Gerrit Bruhaug  55:55  

No, I think we've, we've covered just about everything. I just really wanted to kind of push the point that what happened at Livermore was was a very big deal, and we should all celebrate it, but it's not gonna it's not making infinite power tomorrow, and fusions neat, but maybe isn't everything you think it is?


Chris Keefer  56:12  

And the joke is always it's 20 years away. Do you have any guests on on timeframes? I mean, again, I thought that was really interesting, the, you know, the Kitty Hawk moment that you extended that further into, like, we're not just trying to build the next shitty airplane, we'll have to get up to a level of the other power generation sources that we have, we need to get a 737 out of this. I mean, there's certainly, like you mentioned that the journalism is either breathlessly too optimistic, or probably more in rare cases, just so pessimistic. And you're putting yourself somewhere in the middle there. I mean, I guess there's the possibility that this is just going to be too much of an engineering challenge to ever be viable. I mean, again, it's fishing is a lot easier to initiate, whatever, but yeah, where do you put yourself in that in that perspective, I guess, or I don't know, it's a silly question, I guess about about timeframes or, you know, the degree to which it's a tribute.


Gerrit Bruhaug  57:05  

It's always hard, right. But um, I think we're very liable to see EBR, one, maybe aebr to ask test fusion reactors, you know, that that'll make net energy and you'll you'll power arco, Idaho briefly with them or something like that. With within our lifetime, there's, there's a lot of money that we've we've solved a lot of problems, there's a lot of just inertia to make it happen. There's big, you know, it's a way for a government to brag, it's kind of like building a particle collider or something, you say I have a fusion power plant, I think stepping to I would call that within like, next 2030 years, I would almost guarantee we'll see one or two, you know, the US and China will each build one. And they'll brag about how amazing they are stepping on to, to actual commercial power, I don't really know it, like you said it could it could be like a lot of other niche sources of energy that it remains forever niche, or we never really step past the engineering challenges. And one of the difficult things with Fusion is, you know, unlike say, like a wave generator, that you can get a bunch of VC money and make a little test one and show it off. And everyone goes, that's great, but it's useless. You have to spend a lot of money and time and effort to get your your test fusion reactor going. So I don't know. It might never make commercial sense, or I but I am not highly optimistic for something within our lifetime barring, you know, a complete black swan out of left field event. It's just it's such it's challenging.


Chris Keefer  58:39  

So, you know, just a little extended edition for the truly loyalty couple listeners. You know, we've had a couple of episodes now we had BF Randall on I just had a great episode with Cal evil. And obviously, electrification is part of the picture of decarbonisation. But process heat is a really big deal. You know, I always say that the challenge is not making lots of clean energy, it's replacing fossil fuel services. Can fusion be used for things like process heat, you know, are we going to reactors are we going to see fusion reactors on submarines for propulsion? You got into Fusion? I think because you thought fusion rockets are super cool. So just just I guess, in closing, you know, answer those questions for me.


Gerrit Bruhaug  59:19  

Yeah. So fusion if you can make a fusion power plant work, it will be real good for process heat. It'll be hard to run it cold. You will, you will find it very easy to get those real high at least sodium cooled reactor temperatures, if not higher. The that'll be an easy one to get. So I guess if you want gigawatts of process heat, there you go. I don't know about ever shrinking down for a submarine submarines are very demanding as rod Adams likes to talk about the reactor that powered his submarine went under his desk. fusions got to find the shrinking down to those sizes much harder, but you know, maybe, and then yeah, for space propulsion. That's really where fusion shines. That's when you when you start to run the numbers on that if we ever if we ever get real sci fi with with humanity and going out to the stars, that's where fusion looks really, really good.


Chris Keefer  1:00:09  

All right, well, that's probably for a whole other episode to dive on that but we'll leave that hanging out there. Garrett, thanks again for coming back, man. It's, it's been great catching up. And you have just I can't think of a better guest to deep dive this this most recent announcement with so thank you for for making the time.


Gerrit Bruhaug  1:00:28  

Yeah, I really enjoyed it. Thanks for having me


Unknown Speaker  1:00:29  

on.



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