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Can molton salt reactors produce electricity safely? · Daniel and Kelly’s Extraordinary Universe

• 0:08
  Speaker 1: Hey, or hey, are you a fan of molecular gastronomy.
• 0:12
  Speaker 1: Molecular gastronomy is that like molecular astronomy, but you eat
• 0:15
  Speaker 1: it exactly. They used chemistry to like transform the texture
• 0:19
  Speaker 1: of your food into foams, so you might get like
• 0:22
  Speaker 1: burrito bubbles for example. I'm not sure burritos need to
• 0:26
  Speaker 1: give you more gas. Well, if you're not into spherical sandwiches,
• 0:29
  Speaker 1: then I've got an idea for a new frontier and
• 0:32
  Speaker 1: eating high energy physics gastronomy. What's that like proton pasta
• 0:38
  Speaker 1: or bosonic burritos? Did you already invest in this startup? No? No,
• 0:41
  Speaker 1: I'm thinking more about spices. What if you had a
• 0:44
  Speaker 1: device that accelerated and heated up your spices and shot
• 0:48
  Speaker 1: them out of a gun like the large any accelerator Exactly?
• 0:52
  Speaker 1: Would you like a little molten salt on your proton pasta?
• 0:56
  Speaker 1: I think you should get your money back, But I
• 0:57
  Speaker 1: wonder what's for dessert. Hi, I'm more handmade cartoonists and
• 1:15
  Speaker 1: the creator of PhD comics. Hi, I'm Daniel. I'm a
• 1:18
  Speaker 1: particle physicist and a professor you see Irvine, and I
• 1:21
  Speaker 1: am actually a big fan of toasted spices when it
• 1:24
  Speaker 1: was toasted spices like you pour spices on your toast raven. No,
• 1:30
  Speaker 1: when you're cooking, you're supposed to warm up your spices,
• 1:33
  Speaker 1: makes them volatile by toasting them in the pan, you know,
• 1:35
  Speaker 1: it like brings them to life. Oh I see, I see,
• 1:38
  Speaker 1: I see. Like if you don't put the spices at
• 1:40
  Speaker 1: the end, you cook with the spices. Yeah, you gotta
• 1:43
  Speaker 1: put the spices in the pan first so they warm
• 1:45
  Speaker 1: up and become alive, and then you eat them. And
• 1:49
  Speaker 1: then you eat them exactly interesting. Have you dug into
• 1:53
  Speaker 1: the physics of that. I've taken a big bite out
• 1:55
  Speaker 1: of it, But I wouldn't say I understood the science.
• 1:57
  Speaker 1: I see. It's more of an experimental thing. I guess.
• 2:00
  Speaker 1: Hands on so far, it's just exploratory. But I'm sure
• 2:03
  Speaker 1: my wife, the biochemist, could explain to you why volatile
• 2:05
  Speaker 1: molecules create better reactions in the news, why being volatiles tastier? Anyways,
• 2:10
  Speaker 1: Welcome to our podcast, Daniel and Jorge Explain the Universe,
• 2:13
  Speaker 1: a production of I Heart Radio in which we spice
• 2:16
  Speaker 1: up the universe by explaining all of it to you.
• 2:19
  Speaker 1: We go out there and dig into black holes to
• 2:21
  Speaker 1: understand what's going on on the inside. We take apart
• 2:24
  Speaker 1: the core of neutron stars. We dig deep into the
• 2:28
  Speaker 1: earth and into all the tiny particles that make it
• 2:30
  Speaker 1: up in order to tease them apart and spice up
• 2:33
  Speaker 1: your life with a little bit of understanding. That's right,
• 2:36
  Speaker 1: because it is a pretty tasty universe, full of amazing
• 2:38
  Speaker 1: flavors and colors and textures and deliciousness to discover, and
• 2:45
  Speaker 1: we like to serve it to you in a three
• 2:47
  Speaker 1: course meal. Here. I think there's an interesting and unexplored
• 2:50
  Speaker 1: philosophy question there. You know, some people ask is it
• 2:52
  Speaker 1: necessary for us to find the universe beautiful? But I
• 2:55
  Speaker 1: don't know if anybody has ever explored the question of
• 2:57
  Speaker 1: is it necessary for us to find the universe tasty?
• 3:00
  Speaker 1: Could we have evolved in the universe that we just
• 3:02
  Speaker 1: found kind of gross to eat? Well, I don't think
• 3:05
  Speaker 1: it's necessary, but it's certainly nicer that things taste good
• 3:10
  Speaker 1: and look nice. It would be kind of a bleak.
• 3:13
  Speaker 1: I guess if everything didn't look nice or taste good. Yeah,
• 3:16
  Speaker 1: what if we evolved in an ugly, bland universe? Boy,
• 3:20
  Speaker 1: I'm sure glad we didn't. Or maybe we just lower
• 3:22
  Speaker 1: our bar and start to appreciate the the ugliness of
• 3:26
  Speaker 1: the universe. Maybe maybe that's what happened. Maybe there's another
• 3:29
  Speaker 1: version of the universe where everything is more beautiful and
• 3:32
  Speaker 1: more delicious interesting. So you think aliens would come to
• 3:35
  Speaker 1: Earth and be like, boy, what a crappy place. Look
• 3:37
  Speaker 1: at all this blue stuff and call the sky gets
• 3:41
  Speaker 1: all red. That's disgusting. Yeah, there's another unexamined frontier. When
• 3:45
  Speaker 1: aliens do come, they wouldn't just teach us about the universe.
• 3:47
  Speaker 1: They might give us tips about how to cook, hopefully
• 3:50
  Speaker 1: not how to cook us, hopefully not a direct lesson
• 3:54
  Speaker 1: spices to serve to humanity, not new spices to serve
• 3:58
  Speaker 1: with you. Finally, get up humans really sort of makes
• 4:01
  Speaker 1: it more volatile, really activate activates their flavors. I don't
• 4:06
  Speaker 1: think we want to learn about that dry aged Yeah,
• 4:11
  Speaker 1: but anyways, it is a wonderful universe that we like
• 4:13
  Speaker 1: to talk about, and we'll hopefully we'll be here for
• 4:16
  Speaker 1: a long time to sort of appreciate how did walls
• 4:18
  Speaker 1: and how it changes and how it gets more and
• 4:20
  Speaker 1: more interesting and complex. And in order to stick around
• 4:23
  Speaker 1: a long time, we need to power our lifestyle. We
• 4:27
  Speaker 1: need to provide energy for our burners and for our
• 4:30
  Speaker 1: oven so that we can continue to cook and bake
• 4:33
  Speaker 1: delicious things to eat. As our society gets more and
• 4:36
  Speaker 1: more complex, we have a larger and larger appetite for energy. Yeah,
• 4:40
  Speaker 1: and so far in human history, we've basically resorted to
• 4:43
  Speaker 1: one source of energy for most of you know, our existence,
• 4:47
  Speaker 1: and that is to basically burn stuff. You know, take
• 4:50
  Speaker 1: wood and set it on fire, or find oil and
• 4:53
  Speaker 1: set it on fire. And it's kind of dirty and
• 4:56
  Speaker 1: not as efficient as it could be. It's really shockingly inefficient.
• 4:59
  Speaker 1: And the amount of energy you take out of coal
• 5:02
  Speaker 1: when you burn it or when you burn wood is
• 5:04
  Speaker 1: really a tiny, tiny fraction of the energy that's in there.
• 5:08
  Speaker 1: It's like you find Bill gates wallet and you just
• 5:10
  Speaker 1: take a single dollar out of there and then give
• 5:12
  Speaker 1: it back to him. That would be would be shocking
• 5:15
  Speaker 1: to you. That seems just like the right thing to be. No,
• 5:19
  Speaker 1: clearly you should give Bill Gates his wallet back with
• 5:22
  Speaker 1: all of his billions, but it's you know, maybe another
• 5:25
  Speaker 1: analogy is like we're thirsty and we're standing next to
• 5:28
  Speaker 1: a rushing river, but we're just like sucking droplets of
• 5:31
  Speaker 1: water from the grass nearby. Yeah, because I guess we've
• 5:34
  Speaker 1: only resorted to chemical means to extract energy out of matter, right,
• 5:39
  Speaker 1: We only sort of release the energy that's trapped in
• 5:42
  Speaker 1: the chemical bonds of materials. But it turns out that
• 5:44
  Speaker 1: if you go deeper and smaller, you can release a
• 5:46
  Speaker 1: whole bunch more energy. Yeah. At this sort of maximum
• 5:50
  Speaker 1: efficiency would be to take particles and antiparticles and annihilate
• 5:54
  Speaker 1: them into pure energy. If you had a huge source
• 5:58
  Speaker 1: of antimatter, for examp couple, you could generate energy very,
• 6:02
  Speaker 1: very efficiently. You turn a hundred of the energy stored
• 6:06
  Speaker 1: in matter into energy. But of course antimatter not very plentiful,
• 6:10
  Speaker 1: very expensive to make, and so not really a practical
• 6:14
  Speaker 1: choice for energy production. You're not pro antimatter. I love antimatter.
• 6:18
  Speaker 1: It's wonderful. I wish we had so much more of it,
• 6:20
  Speaker 1: so we could study it and do all sorts of
• 6:21
  Speaker 1: things with it, and we could fuel all of our
• 6:24
  Speaker 1: desires and charge up all of our bones with it.
• 6:26
  Speaker 1: But it costs more energy to make antimatter than you
• 6:29
  Speaker 1: get out of the antimatter afterwards, so it's not efficient
• 6:32
  Speaker 1: for commercial industries for example. Right, Well, I think what
• 6:34
  Speaker 1: you're saying is that if we could somehow take pure
• 6:37
  Speaker 1: matter and transform it into pure energy, there would be
• 6:40
  Speaker 1: a huge amount of energy, even just like a drop
• 6:42
  Speaker 1: of water or even a tiny little raisin. A single
• 6:46
  Speaker 1: raisin has more energy stored in it than a nuclear bomb.
• 6:51
  Speaker 1: It's an incredible amount of energy that's all around us.
• 6:54
  Speaker 1: It's just bound up. It's just tightly contained in the
• 6:57
  Speaker 1: atoms and the molecules that we are surrounded with. We
• 7:00
  Speaker 1: haven't been great at figuring out how to tap into
• 7:03
  Speaker 1: that energy, right because I guess the energy inside of
• 7:06
  Speaker 1: a raisin likes to stay there, right, Like a raisin
• 7:09
  Speaker 1: I didn't want to give up its energy, or it
• 7:11
  Speaker 1: doesn't want to turn into energy like it would take
• 7:14
  Speaker 1: a lot of energy just to unlock that energy. Raisins
• 7:17
  Speaker 1: are not like particles. They don't just decay, right, They
• 7:20
  Speaker 1: just hang out. You take a raisin and you leave
• 7:22
  Speaker 1: it in space, you come back a billion years later,
• 7:24
  Speaker 1: you'll still have a raisin most likely. So raisins are
• 7:27
  Speaker 1: stable elements of the universe exactly. This is energy locked
• 7:31
  Speaker 1: into a certain configuration. To release it, you have to
• 7:34
  Speaker 1: somehow pride apart. One way to do that is to
• 7:36
  Speaker 1: collide with an anti raisin, But without anti raisins floating around,
• 7:40
  Speaker 1: it's harder to crack open that raisin. Right, Well, I
• 7:43
  Speaker 1: guess you could eat the raisin and somehow convert that
• 7:47
  Speaker 1: to energy. Maybe you could, but humans are not very
• 7:50
  Speaker 1: efficient at extracting energy from stuff. You know, most of
• 7:53
  Speaker 1: the stuff in the raisin just passes right through you,
• 7:55
  Speaker 1: and the energy stored in its matter you don't even touch.
• 7:59
  Speaker 1: Humans do like a chemical rearrangement of some of the
• 8:02
  Speaker 1: bonds in the raisin extract a tiny, tiny little sliver
• 8:06
  Speaker 1: of that energy, which is why the matrix doesn't make
• 8:08
  Speaker 1: any sense. You know, humans and sources of energy. I mean,
• 8:11
  Speaker 1: come on, that's the part that doesn't make sense. That's
• 8:15
  Speaker 1: the part that drives me crazy. That's the physics of
• 8:17
  Speaker 1: it right there. You're like, you're so inefficient computers and
• 8:23
  Speaker 1: they have to power a hyper realistic simulated world. There's
• 8:26
  Speaker 1: no way they're doing that with human batteries. They should
• 8:30
  Speaker 1: have used raisins. Maybe, yes, yes, exactly. Raisins are more efficient,
• 8:34
  Speaker 1: So chemical means have a limit. So over the years,
• 8:38
  Speaker 1: humans have tried other things, right, more intricate physical ways
• 8:41
  Speaker 1: to do things, and that includes fusion. Yeah, we have
• 8:44
  Speaker 1: looked up into the sky and seeing a fusion reactor
• 8:47
  Speaker 1: at work. Right, Most of the energy that it is
• 8:50
  Speaker 1: here on Earth originally came here Rhea the sun, the
• 8:53
  Speaker 1: rays from the Sun, which are in the end the
• 8:56
  Speaker 1: output of a fusion reactor at the heart of the
• 8:58
  Speaker 1: star pushing high juging together to form helium. It's much
• 9:02
  Speaker 1: more efficient than chemical burning, although much less efficient still
• 9:06
  Speaker 1: than matter antimatter production. Interesting, and there's also fission, right,
• 9:10
  Speaker 1: I mean, we've sort of done both in terms of
• 9:13
  Speaker 1: at least nuclear weapons fusion and fission, but in terms
• 9:16
  Speaker 1: of making energy power plants, we've only really used fission plans, right,
• 9:20
  Speaker 1: that's right. Fusion has a lot of advantages. It's much
• 9:23
  Speaker 1: more efficient, it doesn't produce any waste. You can use
• 9:26
  Speaker 1: water essentially as fuel. But we haven't really managed to
• 9:30
  Speaker 1: make it work yet. There are a lot of efforts
• 9:32
  Speaker 1: in that direction, people working on it. We have a
• 9:34
  Speaker 1: couple of episodes on how to make fusion power possible.
• 9:37
  Speaker 1: But fusion is one of these technologies that always seems
• 9:40
  Speaker 1: to be about twenty five years off, whereas fission splitting
• 9:44
  Speaker 1: atoms in half and extracting the energy when a heavy
• 9:47
  Speaker 1: atom breaks up. That is something we have working that
• 9:49
  Speaker 1: is part of the electrons that you are probably using
• 9:53
  Speaker 1: come from fission power plants. Yeah, if you're in Europe,
• 9:56
  Speaker 1: most likely you're the energy you're using to listen to
• 9:59
  Speaker 1: this podcast came from a fission power plant. And you're
• 10:02
  Speaker 1: in the U. S. There's a pretty high likelihood also, right, Yeah,
• 10:05
  Speaker 1: it's a significant fraction depending on the country. In France,
• 10:08
  Speaker 1: for example, they have a very large fraction of their
• 10:10
  Speaker 1: energy comes from nuclear power plants. Yeah, and it's been
• 10:13
  Speaker 1: around for maybe like sixty years, right, a long time,
• 10:17
  Speaker 1: like this is old technology now, Yeah, the first power
• 10:19
  Speaker 1: plants were developed in the fifties, not long after we
• 10:22
  Speaker 1: cracked open the atom and developed the weapons technology in
• 10:25
  Speaker 1: the forties. So it's been around for a long long time.
• 10:28
  Speaker 1: Of course, there are significant drawbacks to vision reactors, yeah,
• 10:32
  Speaker 1: and so people are always looking for a new kind
• 10:35
  Speaker 1: of fission plants that could maybe be safer and cleaner.
• 10:38
  Speaker 1: And one such idea is the one we're going to
• 10:40
  Speaker 1: talk about today, which is this idea of molten salt reactors. Exactly.
• 10:45
  Speaker 1: They stole it from my heated spice accelerator. Maybe you
• 10:52
  Speaker 1: should have filed the pattern sooner, Daniel, and so let's
• 10:54
  Speaker 1: talk about that. So to be on the podcast, we'll
• 10:57
  Speaker 1: be tackling the question can molten salt reactors solve our
• 11:06
  Speaker 1: energy problems? Now, Daniel have to say, I'm not familiar
• 11:09
  Speaker 1: with molten salt. Is that the same as Morton salt.
• 11:11
  Speaker 1: That's a brand, right, that's a brand exactly. No, molten
• 11:17
  Speaker 1: means liquid like super hot, you know, like molten lead.
• 11:21
  Speaker 1: Heat up lead and it goes from being a solid
• 11:23
  Speaker 1: to being a liquid and it's all glowy. That's molten.
• 11:26
  Speaker 1: So in this case, molten salt refers to taking salts
• 11:30
  Speaker 1: and melting them down. Oh, I see, So it's like
• 11:32
  Speaker 1: melted salt, Like if you heat up salt, it'll melt
• 11:35
  Speaker 1: into a liquid. M hmm exactly. And we're not just
• 11:37
  Speaker 1: talking about like table salt. But there's a whole set
• 11:41
  Speaker 1: of compounds and elements that chemists call salts, and any
• 11:45
  Speaker 1: of those can be used. And so the idea is
• 11:48
  Speaker 1: to use these for a fission nuclear power reactor to
• 11:52
  Speaker 1: make them better. Yeah, there are these really interesting designs
• 11:55
  Speaker 1: for nuclear power plants that use molten salts, which sounds
• 11:59
  Speaker 1: you know, salty and dangerous and crazy, but it could
• 12:03
  Speaker 1: actually be much safer than traditional nuclear power plants. So
• 12:07
  Speaker 1: this is kind of a new idea, and so it's usual.
• 12:09
  Speaker 1: We were wondering how many people out there had heard
• 12:11
  Speaker 1: of melting salt for fission power. So Daniel went out
• 12:15
  Speaker 1: there into the internet to ask the question, how do
• 12:18
  Speaker 1: you think a molten salt reactor works? And thank you
• 12:21
  Speaker 1: again to all of our cadre of volunteers who answer
• 12:25
  Speaker 1: crazy physics questions without the opportunity to look anything up.
• 12:29
  Speaker 1: If that sounds fun to you and you'd like to
• 12:30
  Speaker 1: hear your voice on a future podcast, please don't be shy.
• 12:34
  Speaker 1: Email us at Questions at Daniel and Jorge dot com
• 12:37
  Speaker 1: for instructions about how to participate. So think about it
• 12:40
  Speaker 1: for a second. What would you use melted salt for?
• 12:44
  Speaker 1: Here's what people had to say. I honestly have no idea.
• 12:47
  Speaker 1: If I had to guess, I would say that it
• 12:50
  Speaker 1: uses some kind of molten salt mixture as a fuel source.
• 12:57
  Speaker 1: I don't know if that's even possible. After I'm done
• 13:00
  Speaker 1: answering this question, I'm definitely gonna look it up. Though
• 13:02
  Speaker 1: the word reactor makes me think of power generation, but
• 13:06
  Speaker 1: then molten sodium. The first thing that comes to mind
• 13:09
  Speaker 1: is the reaction between sodium and water and how violent
• 13:12
  Speaker 1: it is. So maybe it's a reactor that can harness
• 13:16
  Speaker 1: the power of the reaction between sodium and water. Somehow.
• 13:20
  Speaker 1: A molten salt reactor is a reactor that uses molten salt,
• 13:28
  Speaker 1: and maybe something to do with the salts ions to
• 13:31
  Speaker 1: help facilitate reactions. Well, I know that salts typically don't
• 13:37
  Speaker 1: get molten. They have to be very very hot to
• 13:41
  Speaker 1: become molten. Something to do with their conductivity probably. I'm
• 13:45
  Speaker 1: not sure how that would work, but I expect it
• 13:47
  Speaker 1: as something to do with the electrical conductivity of salts
• 13:53
  Speaker 1: when they are in a liquid rather than a solid state.
• 13:56
  Speaker 1: All Right, some pretty pretty cool answers here. A lot
• 13:59
  Speaker 1: of people it seemed like it seemed like they're chemists. Yeah,
• 14:03
  Speaker 1: people thinking about salt maybe as fuel, you know, But
• 14:07
  Speaker 1: none of these are actually even close at all to
• 14:10
  Speaker 1: the right answer. How we use molden salt inside a reactor.
• 14:13
  Speaker 1: And that's not a criticism because to me, the whole
• 14:15
  Speaker 1: design of a molten salt reactor is kind of bonkers.
• 14:19
  Speaker 1: I never would have guessed either it melts your mind
• 14:23
  Speaker 1: or at least the salt in your mind. Yeah, exactly.
• 14:25
  Speaker 1: I prefer the molten pepper reactors. I prefer the melted
• 14:29
  Speaker 1: oreganos because you know, I like my Italian energy compressed
• 14:35
  Speaker 1: cinnamon reactors. I mean, that's the way I'm gonna go.
• 14:37
  Speaker 1: It happens if you take like cinnamon and chocolate and
• 14:39
  Speaker 1: you fuse them together inside a reactor, you get some
• 14:42
  Speaker 1: new superspice. Interesting. I think you need to start a
• 14:45
  Speaker 1: new like think tank where it's just spices used for
• 14:49
  Speaker 1: making energy. Well, I think before I think about it.
• 14:51
  Speaker 1: I just want to build an accelerator so you can
• 14:53
  Speaker 1: shoot like cinnamon and chocolate particles at each other and
• 14:56
  Speaker 1: just see what happens. I mean, I'm an experimentalist, not
• 14:58
  Speaker 1: a theorist after all. You see, you just want to
• 15:01
  Speaker 1: make like anti cinnamon maybe or dark cinnamon. What is
• 15:06
  Speaker 1: anti cinnamon? Is that something you can add to your
• 15:08
  Speaker 1: food to make it taste less like cinnamon? I don't know.
• 15:12
  Speaker 1: It's intriguing though, right, Like what is anti chocolate taste? Like?
• 15:15
  Speaker 1: Oh man, it doesn't sound very good, but I am curious.
• 15:19
  Speaker 1: Or like anti salt, and speaking of salty situations, I
• 15:26
  Speaker 1: want to give a special birthday shout out to one
• 15:29
  Speaker 1: Salty listener, Happy birthday to Ben. His girlfriend Natasha tells
• 15:33
  Speaker 1: us that Ben is something of a salt afficionado, so
• 15:36
  Speaker 1: happy salty Birthday, Ben. All Right, this is an interesting
• 15:39
  Speaker 1: idea to use, Maybe melted salt. I guess that's Stadia right,
• 15:43
  Speaker 1: to melt salt because if you heat up so I've
• 15:45
  Speaker 1: never tried heating up salt, does it actually melt into
• 15:48
  Speaker 1: a liquid? Yeah? A lot of salts if you heat
• 15:50
  Speaker 1: them up hot enough and we're talking like four fifty c,
• 15:53
  Speaker 1: they'll melt into a transparent liquid. Can you said, like
• 15:57
  Speaker 1: salt on fire? Wow, that's something I want to type
• 16:01
  Speaker 1: into Google, but I don't want my university to have
• 16:04
  Speaker 1: seen me type that into Google. Silt, What do you mean?
• 16:07
  Speaker 1: He said, salt and fire. I think that's the kind
• 16:10
  Speaker 1: that's going to get you on the t s A
• 16:12
  Speaker 1: watch list, Like trying to think you're thinking of, like
• 16:14
  Speaker 1: can I make a bomb at a salt? Yeah, that's
• 16:16
  Speaker 1: the next thing to google, right exactly, salt bombs? Bombs?
• 16:22
  Speaker 1: Is that sort of like a bath bomb? You know,
• 16:23
  Speaker 1: like a salt bomb? Your I think that's that's what
• 16:26
  Speaker 1: I was thinking. I think those exist already bad salt
• 16:29
  Speaker 1: bombs are, Yeah, and then you can make a reactor.
• 16:33
  Speaker 1: You can convert yourself from a dirty person into a
• 16:35
  Speaker 1: clean person. Using a bath salt, you can make clean energy,
• 16:39
  Speaker 1: or at least a clean you. I wouldn't recommend dipping
• 16:41
  Speaker 1: your toes into four fifty molten salt, no matter how
• 16:45
  Speaker 1: much you want to get into the bath. Yeah, it
• 16:47
  Speaker 1: sounds like a bad idea, but this is all sort
• 16:49
  Speaker 1: of leading towards making maybe nuclear power more efficient, more clean,
• 16:54
  Speaker 1: and more clean. And so maybe we should start with that.
• 16:55
  Speaker 1: Let's start maybe recapping how a nuclear reactor works, like
• 16:59
  Speaker 1: the kind that we in our countries right now. You
• 17:01
  Speaker 1: have to understand why molten salt is an attractive idea.
• 17:05
  Speaker 1: You have to understand what it is doing in the
• 17:07
  Speaker 1: reactor and what it's replacing. A lot of current fission
• 17:10
  Speaker 1: reactors use water as an important element of it. Essentially,
• 17:14
  Speaker 1: molten salt will be replacing the water. But you might
• 17:17
  Speaker 1: not be familiar with the role of water in fission,
• 17:19
  Speaker 1: like why would you even need water? So, yeah, we
• 17:21
  Speaker 1: should probably break down exactly how fission operates. Yeah, and
• 17:24
  Speaker 1: so fishing is like splitting the nucleus of an atom,
• 17:27
  Speaker 1: and then when you do that, energy gets released. And
• 17:29
  Speaker 1: so if you do that in the right way, you
• 17:31
  Speaker 1: can just get energy from stuff. Yeah, I think it's
• 17:33
  Speaker 1: really quite interesting that for light elements hydrogen, helium, et cetera,
• 17:37
  Speaker 1: if you squeeze them together, you release energy, whereas for
• 17:41
  Speaker 1: heavy elements everything above iron, if you break them in
• 17:44
  Speaker 1: half you release energy. The reason for that is a
• 17:47
  Speaker 1: bunch of really interesting nuclear physics details, which, as usual,
• 17:50
  Speaker 1: we have planned for a future episode. But the point
• 17:52
  Speaker 1: is that when you do fishing, you need to use
• 17:54
  Speaker 1: heavy elements. Things like uranium or plutonium are good for
• 17:58
  Speaker 1: fishing because when they break up, they produced neutrons which
• 18:02
  Speaker 1: can then create more fission and they produce some energy.
• 18:05
  Speaker 1: And so the way a fission reaction works is you
• 18:08
  Speaker 1: have like a bunch of uranium, It splits up, shoots
• 18:11
  Speaker 1: off more neutrons, which hits more uranium, which split them up,
• 18:14
  Speaker 1: which shoot off more neutrons. And if you get enough
• 18:18
  Speaker 1: uranium together, then it's going to self sustain, it's going
• 18:21
  Speaker 1: to keep going, it's going to cause like a chain reaction. Right,
• 18:24
  Speaker 1: that's the idea. I mean, that's kind of how an
• 18:26
  Speaker 1: efficient bomb works, is that if you put enough of
• 18:28
  Speaker 1: it together, you break one atom one nucleus, and that
• 18:31
  Speaker 1: breaks other nuclei and then then you have a runaway explosion.
• 18:35
  Speaker 1: That's a bomb. But for a reactor you do the
• 18:37
  Speaker 1: same thing, but you do it in a I guess
• 18:38
  Speaker 1: more controlled way. Yeah, naturally occurring uranium will just spontaneously decay,
• 18:43
  Speaker 1: and that doesn't always start a chain reaction, although we
• 18:45
  Speaker 1: did have a fun episode about a dense depositive uranium
• 18:48
  Speaker 1: underground in Africa which did create a natural, self sustaining reaction.
• 18:53
  Speaker 1: But in general, naturally occurring uranium can't set off a
• 18:56
  Speaker 1: chain reaction. Those neutrons just go into whatever other material.
• 18:59
  Speaker 1: But you get uranium that's dense enough and you have
• 19:02
  Speaker 1: it pure enough, then it can reach critical mass and
• 19:05
  Speaker 1: so it sustains itself. And as you said, if you
• 19:07
  Speaker 1: have the right kind of fuel, it can create a
• 19:09
  Speaker 1: runaway explosion or very rapid release of energy. That's a bomb.
• 19:13
  Speaker 1: You can slow it down and moderate it a little
• 19:16
  Speaker 1: bit so that for example, every neutron creates one more
• 19:19
  Speaker 1: uranium that split, which creates one more and rather than
• 19:22
  Speaker 1: growing exponentially, it'll just keep going at the same level,
• 19:26
  Speaker 1: producing some heat. Right, because each time the atom splits,
• 19:29
  Speaker 1: it releases sort of like other particles or you know,
• 19:33
  Speaker 1: like light or heat in some way that you then
• 19:36
  Speaker 1: capture through another means exactly. Usually you capture that in
• 19:40
  Speaker 1: like water, which then you boil into steam and you
• 19:43
  Speaker 1: can feed it through some turbine and that generates electricity.
• 19:47
  Speaker 1: So that's the basic idea, but it turns out to
• 19:49
  Speaker 1: be a little bit more complicated in a crucial way
• 19:51
  Speaker 1: because there's different kinds of uranium, and the different kinds
• 19:54
  Speaker 1: of uranium some of them are really good to use
• 19:56
  Speaker 1: in fission and some of them are not very good
• 19:58
  Speaker 1: to use in fission. You got to get the right
• 20:00
  Speaker 1: blend and you've got to get the neutrons going at
• 20:02
  Speaker 1: just the right speed. So there are a couple of
• 20:04
  Speaker 1: details there. Yeah, and there have been a couple of
• 20:07
  Speaker 1: problems in history in making these things work. And so
• 20:10
  Speaker 1: let's get into all of those details and all of
• 20:13
  Speaker 1: that history. But first let's take a quick break. All right,
• 20:28
  Speaker 1: we're talking about melting salt to make fission power more efficient. Now,
• 20:34
  Speaker 1: is this sort of a new idea, Daniel, or something
• 20:36
  Speaker 1: you just came up with this morning, or has this
• 20:38
  Speaker 1: been around for a while. Now? This is fascinating history
• 20:41
  Speaker 1: because it's an idea that has been around for a while,
• 20:44
  Speaker 1: and it was explored early on, but then was put
• 20:47
  Speaker 1: aside because it didn't have enough weapons applications. It wasn't
• 20:52
  Speaker 1: good for developing fuel for nuclear weapons, so it's basically ignored.
• 20:56
  Speaker 1: And now that's actually an advantage and so it's being
• 21:00
  Speaker 1: looked at again, right, interesting, and it might make our
• 21:03
  Speaker 1: food tastier somehow. Exactly don't you want your kid to
• 21:06
  Speaker 1: have molten salt sprayers so they can shoot their own
• 21:09
  Speaker 1: eggs with molten salt? I want my kist sweet food
• 21:12
  Speaker 1: that's not glowing perfectly. But you said there are some
• 21:14
  Speaker 1: details here about fishing that are important to understand, and
• 21:17
  Speaker 1: they sort of have to do with the fact that
• 21:19
  Speaker 1: basically to do fishing and to make fission reactors, you
• 21:22
  Speaker 1: need uranium. Now, I guess maybe step me through here,
• 21:24
  Speaker 1: like why do we need uranium? Like, you know, everyone
• 21:27
  Speaker 1: has probably heard of uranium for movies or TV shows
• 21:29
  Speaker 1: because they know it's related to making nuclear energy, But
• 21:32
  Speaker 1: like why uranium? Why not the next material over? Or
• 21:35
  Speaker 1: why not iron or why not you know, chlorine? Well,
• 21:38
  Speaker 1: you can do fishing with lots of different kinds of stuff,
• 21:41
  Speaker 1: and we'll talk a little bit later in the program
• 21:43
  Speaker 1: about alternative fuels. You can use plutonium, you can use thorium,
• 21:46
  Speaker 1: you can use all sorts of different heavy elements. Uranium
• 21:49
  Speaker 1: has been used traditionally because it satisfies a lot of
• 21:51
  Speaker 1: the requirements, like it is fizzile, meaning if you hit
• 21:54
  Speaker 1: it with a neutron, it will split in half and
• 21:57
  Speaker 1: produce more neutrons. And also because it's abundant, like there's
• 22:01
  Speaker 1: a lot of uranium around. There's more uranium than plutonium,
• 22:05
  Speaker 1: for example, which is almost non existent in the Earth's core. Interesting,
• 22:09
  Speaker 1: so it's like, and is there a reason why it's
• 22:11
  Speaker 1: more abundant. It's really interesting and deep question actually about
• 22:14
  Speaker 1: just like why various elements exist in the universe in
• 22:17
  Speaker 1: their various proportions. Typically there's a trend that, like the
• 22:20
  Speaker 1: heavier elements, there's less of them because it's harder to
• 22:23
  Speaker 1: make them you need like collisions of neutron stars. And
• 22:26
  Speaker 1: also the heavier ones are less stable. So uranium is
• 22:28
  Speaker 1: a bit of a sweet spot there in terms of
• 22:30
  Speaker 1: being heavy enough to be fizzile, but also long lived
• 22:33
  Speaker 1: enough to still be around in the Earth's core. I
• 22:36
  Speaker 1: see maybe there were other kinds of material, physical materials,
• 22:39
  Speaker 1: but they just naturally split by themselves over time, and
• 22:42
  Speaker 1: so they're not that material anymore. Yeah, And some of
• 22:45
  Speaker 1: the heavier ones there's just harder to make because the
• 22:48
  Speaker 1: heavier they are, the more neutrons you need to get
• 22:50
  Speaker 1: together in the core of a neutron star to make them.
• 22:52
  Speaker 1: So there are just less of them. And so uranium
• 22:55
  Speaker 1: is around, and it's I guess there's enough of it
• 22:57
  Speaker 1: around right now that we use it for nuclear reactors
• 23:01
  Speaker 1: and so like, what's the process of using uranium for fission?
• 23:04
  Speaker 1: So uranium comes in two flavors in the Earth's core
• 23:08
  Speaker 1: is uranium two thirty five and uranium two thirty eight,
• 23:12
  Speaker 1: and there are the same element. They have the same
• 23:14
  Speaker 1: number of protons. Both of them have ninety two protons
• 23:17
  Speaker 1: in the nucleus, but uranium two thirty eight has three
• 23:20
  Speaker 1: more neutrons. So that doesn't change, you know, what element
• 23:23
  Speaker 1: you are, doesn't change the number of electrons. It just
• 23:26
  Speaker 1: changes how many neutrons are in the core. So it's
• 23:28
  Speaker 1: a different isotope. But uranium two thirty five and two
• 23:31
  Speaker 1: thirty eight are really quite different. Uranium two thirty five
• 23:34
  Speaker 1: is great for fusion, it splits nicely, it produces more neutrons.
• 23:38
  Speaker 1: It's excellent. But most of the uranium we find in
• 23:41
  Speaker 1: the Earth is uranium two thirty eight, the one that's
• 23:44
  Speaker 1: not good for fission. In fact, it's like more than
• 23:47
  Speaker 1: nine nine of the naturally occurring uranium. And I guess
• 23:50
  Speaker 1: for those of us who don't remember high school chemistry,
• 23:53
  Speaker 1: that the two thirty five and the two thirty eight means,
• 23:56
  Speaker 1: it's like the sum of the number of protons and
• 23:58
  Speaker 1: neutrons in the nucleus. Right, Like said, it has ninety
• 24:00
  Speaker 1: two protons and three neutrons. If you add those up,
• 24:04
  Speaker 1: that gives you the two thirty five, And so uranium
• 24:07
  Speaker 1: to thirty eight has just three more neutrons in it exactly,
• 24:10
  Speaker 1: And uranium two thirty five is the one that is
• 24:13
  Speaker 1: really good for fission. Wait, why is two thirty five better?
• 24:16
  Speaker 1: Like what is adding those just three neutrons to the
• 24:19
  Speaker 1: nucleus due to the whole thing, it makes it more
• 24:22
  Speaker 1: or less stable. So uranium two thirty five is a
• 24:25
  Speaker 1: little bit less stable. If you hit it with a neutron,
• 24:27
  Speaker 1: it's more likely to split up than uranium two thirty eight,
• 24:31
  Speaker 1: And that has to do with like how the neutrons
• 24:33
  Speaker 1: are arranged. Remember we talked once about super heavy elements
• 24:37
  Speaker 1: and how the protons and the neutrons inside the atom
• 24:40
  Speaker 1: arranged into these shells sort of the same way electrons
• 24:43
  Speaker 1: do in their orbits. And if you have the right number,
• 24:45
  Speaker 1: then they're much more stable. It's like completing an arch,
• 24:49
  Speaker 1: like a Roman arch. If you have all the pieces,
• 24:50
  Speaker 1: it's much more stable than if you're missing one or two.
• 24:54
  Speaker 1: So uranium two thirty eight is harder to split than
• 24:57
  Speaker 1: uranium two thirty five, right, which is weird because it
• 24:59
  Speaker 1: just had three more neutrons, which are you know, neutral,
• 25:04
  Speaker 1: but I guess they also sort of contribute to the
• 25:06
  Speaker 1: general stickiness of the nucleus, right, like through the gluons
• 25:10
  Speaker 1: and quirks. Yeah, neutrons are neutrals. They don't have electromagnetic forces,
• 25:14
  Speaker 1: but they do have the strong force because they're made
• 25:17
  Speaker 1: of quarks, and it's a strong force that holds the
• 25:19
  Speaker 1: nucleus together. So the fact that neutrons are neutral doesn't
• 25:22
  Speaker 1: mean they don't play a role in the strong force.
• 25:24
  Speaker 1: They totally participate just as much as protons. Both of
• 25:27
  Speaker 1: them have three quarks, and so just adding those three
• 25:30
  Speaker 1: makes a huge difference, and so that's why we prefer
• 25:32
  Speaker 1: uranium to thirty five. But it's like the minority in
• 25:35
  Speaker 1: the uranium we find it's the minority. And also uranium
• 25:39
  Speaker 1: two thirty five likes a very particular kind of neutron.
• 25:42
  Speaker 1: It likes slow moving neutrons. That's moving neutrons are much
• 25:45
  Speaker 1: less likely to cause uranium two thirty five to split.
• 25:48
  Speaker 1: So the problem with naturally existing uranium, as we find it,
• 25:51
  Speaker 1: is that there isn't enough uranium two thirty five, and
• 25:55
  Speaker 1: when it splits, it produces neutrons that are sort of
• 25:57
  Speaker 1: have too much energy. They're going too fast to be
• 26:00
  Speaker 1: effective to split more uranium two thirty five, right, So
• 26:04
  Speaker 1: it's rarer. So we that's why people could talk about
• 26:06
  Speaker 1: enriching uranium. Right, it's like you're sort of sifting through
• 26:09
  Speaker 1: the uranium and you're separating the two thirty five with
• 26:12
  Speaker 1: the exactly. So to solve these two problems, to like
• 26:15
  Speaker 1: get more uranium two thirty five and to fix the
• 26:18
  Speaker 1: neutron speed, we have two solutions. One is enrich it,
• 26:22
  Speaker 1: and so we use centrifuges and all sorts of other
• 26:24
  Speaker 1: technologies to get uranium two thirty five to be a
• 26:26
  Speaker 1: larger percentage so that there's enough in there to do
• 26:30
  Speaker 1: the fission. And then we do things to slow down
• 26:32
  Speaker 1: the neutrons that are produced so that they are much
• 26:35
  Speaker 1: better at causing fission. And that's where the water comes in.
• 26:39
  Speaker 1: In traditional reactors, we bathe these uranium rods in water,
• 26:43
  Speaker 1: which is really good at slowing down neutrons, so they
• 26:46
  Speaker 1: go from the fast speed to the slow speed where
• 26:49
  Speaker 1: they're much better at causing fission. Right, So you make
• 26:52
  Speaker 1: like a bar of this enriched uranium, and if you
• 26:54
  Speaker 1: just leave it there, it's gonna decay, right, It's gonna glow,
• 26:56
  Speaker 1: it's gonna give up heat. And so the idea is
• 26:58
  Speaker 1: that you sort of put a bunch of these bars
• 27:01
  Speaker 1: sort of together, and like the neutrons from one bar
• 27:04
  Speaker 1: then cause the atoms from the next bar to split up,
• 27:09
  Speaker 1: and then that one releases more stuff and that then
• 27:11
  Speaker 1: causes the atoms and the other bars to split up,
• 27:14
  Speaker 1: and that's how you get the chain reaction exactly. And
• 27:16
  Speaker 1: the water plays a crucial role between the bars there
• 27:19
  Speaker 1: and slowing down the neutrons, because slower neutrons are much
• 27:23
  Speaker 1: more likely to cause fission. You need to enrich the
• 27:26
  Speaker 1: YouTube thirty five component, and you need to slow down
• 27:28
  Speaker 1: those neutrons. And so that's called a light water thermal reactor.
• 27:32
  Speaker 1: Thermal there just means the neutrons are slow and water
• 27:35
  Speaker 1: means the thing you're using to moderate the neutrons and
• 27:38
  Speaker 1: also to provide coolant for the whole thing and to
• 27:41
  Speaker 1: suck off the heat to create electricity is water. So
• 27:44
  Speaker 1: that's the traditional structure of a fission reactor. Right. You
• 27:47
  Speaker 1: just take a bunch of rods of enriched uranium and
• 27:50
  Speaker 1: you dip them in water, basically, right. But it's interesting,
• 27:53
  Speaker 1: I think too, because the way they control the reaction
• 27:55
  Speaker 1: is they control how much do you dip the rods
• 27:57
  Speaker 1: in water? Right? Exactly? If you overmoderated, for example, then
• 28:02
  Speaker 1: you'll slow down the reaction. You'll slow all those neutrons
• 28:04
  Speaker 1: down so that they can't even provide fission anymore. Right,
• 28:07
  Speaker 1: And so what is it called light water thermal reactor? Oh?
• 28:10
  Speaker 1: As opposed to heavy water. Sometimes they use like deuterium
• 28:13
  Speaker 1: water and that has different Properties' is like a thousand
• 28:16
  Speaker 1: different varieties of these reactors. And this is the one
• 28:19
  Speaker 1: that uses like normal water, the kind of water that
• 28:21
  Speaker 1: we can drink. I see, all right, So then you
• 28:25
  Speaker 1: dip the rods and water. That's how you get a reactor.
• 28:27
  Speaker 1: But there are problems with that, right. There are a
• 28:29
  Speaker 1: bunch of problems with these reactors. Number one is that
• 28:32
  Speaker 1: you're only really burning the uranium two thirty five, which
• 28:36
  Speaker 1: is a tiny fraction of your fuel. So the uranium
• 28:39
  Speaker 1: two it's in there, you're just sort of wasting it
• 28:42
  Speaker 1: like it could maybe be turned into fission, but you
• 28:46
  Speaker 1: don't use it. And so uranium depleted uranium is uranium
• 28:49
  Speaker 1: where you've burned the uranium two thirty five, just like
• 28:52
  Speaker 1: leaving most of the uranium gone, sort of like you know,
• 28:55
  Speaker 1: you try to burn a camp fire and you only
• 28:58
  Speaker 1: burn the pine needles on the tree. You burn like
• 29:00
  Speaker 1: the real core of the tree. So most of the
• 29:02
  Speaker 1: energy is wasted. It's not even used. Wow, and then
• 29:05
  Speaker 1: that becomes nuclear waste, right because this stuff is still
• 29:08
  Speaker 1: like breaking down shooting off dangerous particles. And that's why
• 29:12
  Speaker 1: it's radioactive exactly that you two thirty eight doesn't burn,
• 29:15
  Speaker 1: it doesn't participate in fission, but all the neutrons that
• 29:18
  Speaker 1: are flying around will convert it into really dangerous stuff
• 29:22
  Speaker 1: like plutonium and all sorts of other stuff, and that
• 29:24
  Speaker 1: stuff has half lives of like tens of thousands of years.
• 29:28
  Speaker 1: So most of the stuff in your fuel doesn't contribute
• 29:30
  Speaker 1: in a useful way and then turns into like poison
• 29:33
  Speaker 1: which will kill people and ruin the environment for like
• 29:36
  Speaker 1: you know, thousands and thousands of years. Wow. Not good.
• 29:41
  Speaker 1: Definitely not good. Yeah, And it's also a little bit
• 29:43
  Speaker 1: you know, risky too, because if you don't control the
• 29:47
  Speaker 1: the reaction well enough, you can have a big meltdown. Yeah.
• 29:50
  Speaker 1: One problem with water is that it boils at a
• 29:52
  Speaker 1: pretty low temperature, right a hundred C, and so you
• 29:56
  Speaker 1: need to keep it at a very high pressure in
• 29:58
  Speaker 1: order to keep it liquid because it has to be
• 30:00
  Speaker 1: liquid to play this role to flow through your reactor
• 30:03
  Speaker 1: and to pull off the energy and to be a moderator.
• 30:05
  Speaker 1: And so a lot of these reactors operated extremely high temperatures,
• 30:09
  Speaker 1: like a hundred atmospheres, which is you know, dangerous, and
• 30:12
  Speaker 1: it means that these things are big and bulky. They
• 30:15
  Speaker 1: have to have like thick, thick layers of steel to
• 30:18
  Speaker 1: contain them, and it takes work to maintain this, you know,
• 30:20
  Speaker 1: to keep this thing flowing and to keep it under pressure.
• 30:22
  Speaker 1: And for it all to be safe, and you can
• 30:24
  Speaker 1: also have accidents which have happened in the past, right,
• 30:27
  Speaker 1: notably like Kushima and Chernobyl. Those were sort of like
• 30:31
  Speaker 1: failures in controlling the fission reaction exactly, And all those
• 30:35
  Speaker 1: failures are linked to the water. You know, in Chernobyl
• 30:37
  Speaker 1: that water boiled because it got too hot. In Fukushima,
• 30:41
  Speaker 1: the water pumps were knocked out by the tsunami. In
• 30:44
  Speaker 1: Three Mile Island and earlier disaster, the water hatch was
• 30:48
  Speaker 1: jammed and so the water didn't flow. And so like
• 30:50
  Speaker 1: this water, it can work. And you know, more modern
• 30:53
  Speaker 1: reactors have more and more layers of safety, but it's complicated.
• 30:57
  Speaker 1: It's interesting from an engineering point of view. I think
• 30:59
  Speaker 1: that as we learned to do fission reactors with water,
• 31:02
  Speaker 1: the time it takes to build and get one of
• 31:04
  Speaker 1: these things up and running gets longer, not shorter, right,
• 31:07
  Speaker 1: because we're learning how to do it safely. We're just
• 31:09
  Speaker 1: like adding layers and layers of precaution as we developed
• 31:13
  Speaker 1: new reactors, right, because I guess you know, when they
• 31:15
  Speaker 1: built Fukushima, they were probably didn't think, like, hey, what
• 31:18
  Speaker 1: if there's an earthquake in the middle of the ocean
• 31:20
  Speaker 1: and that causes a giant tsunami wave that then hits
• 31:22
  Speaker 1: our water pumps. Right, Like, you have to think of everything,
• 31:26
  Speaker 1: and that's really hard. Why didn't they think of that though?
• 31:29
  Speaker 1: Like who builds a nuclear power plant near an earthquake
• 31:32
  Speaker 1: line or near the ocean? You know, it doesn't make
• 31:34
  Speaker 1: any sense to me. You're expecting this thing to be
• 31:37
  Speaker 1: there for decades and decades, Like she's put it far
• 31:40
  Speaker 1: away from everything that could potentially cause it any damage.
• 31:43
  Speaker 1: But I guess there's always something unexpected. I guess, you know,
• 31:46
  Speaker 1: even if you put it in the middle of the mountain,
• 31:48
  Speaker 1: then something else is going to happen, right, There's always
• 31:50
  Speaker 1: something I expected. That's true. Yeah, And you know that's
• 31:52
  Speaker 1: the danger here. We're dealing with very high pressure, very
• 31:56
  Speaker 1: high temperature environment and it needs to maintain that or
• 31:59
  Speaker 1: it's going to melt on and cause a disaster. And
• 32:01
  Speaker 1: so it's a bit fragile, and I think that's one
• 32:04
  Speaker 1: main concern of these water reactors. All right, Well, um,
• 32:07
  Speaker 1: let's talk about then, how to make things better, how
• 32:10
  Speaker 1: to make them cleaner and safer. It seems like water
• 32:13
  Speaker 1: is kind of a problem here because water boils too
• 32:16
  Speaker 1: easily maybe, And so you have you have to be
• 32:18
  Speaker 1: very careful with it because if it evaporates, then you
• 32:21
  Speaker 1: don't have anything controlling the reaction. Yeah, and that's why
• 32:24
  Speaker 1: people think about using molten salt. Right. You take fluoride,
• 32:27
  Speaker 1: for example, and you heat it up to four hundred
• 32:30
  Speaker 1: and fifty c it melts into a transparent liquid. It
• 32:33
  Speaker 1: looks like water, right, It flows. It's clear, sort of
• 32:36
  Speaker 1: weird to think about it, but that's what happens. That's
• 32:38
  Speaker 1: the chemistry of it. And so you can use molten
• 32:41
  Speaker 1: salt in your reactor instead of water. And the advantage
• 32:45
  Speaker 1: is that this thing stays liquid at much higher temperatures,
• 32:49
  Speaker 1: that doesn't boil, right, and so so you don't need
• 32:51
  Speaker 1: really high pressure. You can keep it like one atmosphere
• 32:54
  Speaker 1: and you can still do the same job that water
• 32:57
  Speaker 1: does for you. So you're talking about like a salt
• 32:59
  Speaker 1: that uses four rain and then melting it and then
• 33:01
  Speaker 1: using that like bathing the uranium rods in that liquid. Yeah.
• 33:06
  Speaker 1: And here when we say salt again, we're talking about
• 33:08
  Speaker 1: in a chemical definition of what as salt is, right,
• 33:10
  Speaker 1: the same way that like astronomers consider everything heavier than
• 33:14
  Speaker 1: helium to be a metal chemists have a specific definition
• 33:17
  Speaker 1: of salt, and so fluoride is one example. And so yeah,
• 33:21
  Speaker 1: you melt it, and then you can use this to
• 33:23
  Speaker 1: cool your reactor, to pull the energy out of it.
• 33:26
  Speaker 1: And you don't even have to wrap your rods in it.
• 33:28
  Speaker 1: You can dissolve the fuel itself into the salt. So
• 33:32
  Speaker 1: you just have this like mixture of molten salt with
• 33:35
  Speaker 1: your fuel flowing around your reactor. Whoa, so you you
• 33:39
  Speaker 1: mix the fuel into the this salt that's at the
• 33:42
  Speaker 1: four and fifty degrees celsius? Is that the idea? So
• 33:45
  Speaker 1: you have this boiling hot stew of radioactive uranium and salt,
• 33:51
  Speaker 1: and and then how do you get the energy out?
• 33:53
  Speaker 1: Or like what happens to does it just stay hot forever?
• 33:56
  Speaker 1: Does it start to heat up if you leave it alone?
• 33:59
  Speaker 1: What do you get? What are you gotta do? Well,
• 34:00
  Speaker 1: you have the reactor and you pump some of this
• 34:03
  Speaker 1: salt out into a heat exchanger, so then you can
• 34:06
  Speaker 1: like you know, take the heat out and spin turbines, etcetera, etcetera.
• 34:09
  Speaker 1: And there you know, you could transfer it to water
• 34:11
  Speaker 1: or whatever you need to do. But there's lots of
• 34:13
  Speaker 1: really cool options because it's much hotter because molten salt
• 34:17
  Speaker 1: stays liquid at higher temperatures. It's much more efficient actually
• 34:20
  Speaker 1: for energy generation, and it gives you other options like
• 34:23
  Speaker 1: creating hydrogen fuel as like sort of chemical battery to
• 34:26
  Speaker 1: store all this energy. So, yeah, you have this molten
• 34:29
  Speaker 1: salt flowing around in your reactor and some of it
• 34:32
  Speaker 1: gets pumped out into a heat exchanger so that you
• 34:35
  Speaker 1: can pull the energy out. Well, it's intense because you
• 34:38
  Speaker 1: pump it out, but it's radioactive to right, Yeah, it
• 34:41
  Speaker 1: is radioactive. It still has your fuel in it, so
• 34:43
  Speaker 1: fission is happening in it. And so I guess what
• 34:45
  Speaker 1: happens if you just have a vat of this dissolved fuel.
• 34:49
  Speaker 1: Does it eventually just heat up to like a million
• 34:51
  Speaker 1: degrees or I guess it eventually would melt whatever container
• 34:55
  Speaker 1: it's in. Well, you're pulling the heat out of it, right,
• 34:57
  Speaker 1: because you're using it as a reactor. And there's also
• 35:00
  Speaker 1: sort of a safety valve which is at the bottom
• 35:02
  Speaker 1: of this thing. They have a plug which is made
• 35:04
  Speaker 1: out of another frozen salt, and so if the whole
• 35:07
  Speaker 1: thing overheats, if it gets too hot, then it will
• 35:09
  Speaker 1: melt this frozen plug and it'll just all sort of
• 35:12
  Speaker 1: like drip out of the reactor and it'll cool down
• 35:15
  Speaker 1: fast enough to become solid and then the reaction will stop.
• 35:18
  Speaker 1: The reaction only happens when it's liquid. Oh, that's a
• 35:22
  Speaker 1: good mechanism for safety. Like it, so if the salt solidifies,
• 35:26
  Speaker 1: then that stops the reaction, like the reaction only works
• 35:29
  Speaker 1: if the salt is melted. All right, Well, that's sort
• 35:31
  Speaker 1: of one idea to make fission safer and cleaner. And
• 35:34
  Speaker 1: so let's get into another one that it may or
• 35:37
  Speaker 1: may not be related to the Avengers. But first let's
• 35:39
  Speaker 1: take another quick break. All right, we're talking about making
• 35:54
  Speaker 1: fission energy safer by maybe some new ideas to make
• 35:59
  Speaker 1: the fission reactor process safer. And one of them we
• 36:02
  Speaker 1: talked about was melting salt or a kind of salt
• 36:05
  Speaker 1: as the sort of mediator between the field enrich uranium.
• 36:10
  Speaker 1: And so that's a pretty good idea, right, it seems safer,
• 36:13
  Speaker 1: it does exactly. It seems like a cool idea. Another
• 36:17
  Speaker 1: version of that is using molten metals, like you can
• 36:20
  Speaker 1: have liquid lead in your reactor instead of water, and
• 36:24
  Speaker 1: it's actually maybe even safer than water because again it
• 36:26
  Speaker 1: doesn't have to be at such high pressures, right, And
• 36:29
  Speaker 1: that's good because I guess high pressure of things that
• 36:32
  Speaker 1: are radioactive are kind of danger. Yeah, exactly. It's just
• 36:35
  Speaker 1: less likely to blow if it's not a high pressure,
• 36:37
  Speaker 1: all right, So melting salt is one way. Another way
• 36:40
  Speaker 1: is to use something called thorium exactly. And I'm desperate
• 36:43
  Speaker 1: to hear about your avenger's connection. Well, I'm just wondering
• 36:47
  Speaker 1: if it's related to holkium in in iron manium. Well,
• 36:51
  Speaker 1: I see thrium, right, How can I have missed that? No,
• 36:55
  Speaker 1: Thorium is an element. It's something that exists in the Earth.
• 36:59
  Speaker 1: It's actually more plentiful than uranium, and it's something that
• 37:03
  Speaker 1: we produce as a byproduct already of rare earth mining.
• 37:07
  Speaker 1: You know, when you're trying to get like cobalt or
• 37:09
  Speaker 1: namibium or whatever you need for your new batteries. When
• 37:13
  Speaker 1: you're doing the rare earth element mining, you already are
• 37:16
  Speaker 1: just like digging through lots of thorium to get it.
• 37:19
  Speaker 1: And so thorium is something we have a lot of,
• 37:22
  Speaker 1: and it turns out to be an excellent fuel for
• 37:24
  Speaker 1: nuclear reactors. Wait, what, so there's something else it's not
• 37:28
  Speaker 1: uranium that could also be used for fission reactors. Is
• 37:32
  Speaker 1: it like lighter or heavier or what's what's different about it?
• 37:35
  Speaker 1: The cool thing abou thorium is that it can't actually
• 37:37
  Speaker 1: do fission on its own, but when you hit it
• 37:39
  Speaker 1: with a neutron, it turns into uranium two thirty three.
• 37:44
  Speaker 1: So now another version of uranium. See it is kind
• 37:48
  Speaker 1: of like the Hulk. It turns green and more volatile.
• 37:52
  Speaker 1: Sounds like the Hulk. Yeah, and uranium two thirty three
• 37:55
  Speaker 1: is not something that exists in the Earth crust in
• 37:57
  Speaker 1: anything but trace amounts. But it's an slow fuel for
• 38:01
  Speaker 1: FISHI and it's very fiscile, and it can operate with
• 38:03
  Speaker 1: slow neutrons. If you just hit thorium with a neutron,
• 38:06
  Speaker 1: it turns into uranium, which is then fuel. So the
• 38:09
  Speaker 1: reactor can turn thorium into fuel four itself. Wait what like? Wait,
• 38:15
  Speaker 1: so you take thorium, you somehow bombarded with neutrons, it
• 38:18
  Speaker 1: becomes uranium two thirty three, and then when that splits,
• 38:22
  Speaker 1: it splits back into thorium. Is that the idea? Now,
• 38:24
  Speaker 1: when that splits, it splits into lighter stuff, releases energy
• 38:27
  Speaker 1: and neutrons and those neutrons. It produces enough neutrons not
• 38:31
  Speaker 1: just to split other uranium two thirty three atoms, but
• 38:34
  Speaker 1: also to hit thorium and turn it into uranium two
• 38:37
  Speaker 1: thirty three, So it like breeds its own fuel. Oh interesting,
• 38:42
  Speaker 1: I see, Like the process of the fission reaction would
• 38:45
  Speaker 1: actually make more fuel in the process if you put
• 38:47
  Speaker 1: more thorium in it. Like it's not making stuff out
• 38:50
  Speaker 1: of the blue. No, it's not just generating it. But
• 38:52
  Speaker 1: if you pour thorium into the reactor, it will turn
• 38:55
  Speaker 1: thorium into the fuel that it needs and then burn
• 38:57
  Speaker 1: that fuel, turning more thorium into the fuel that it needs.
• 39:01
  Speaker 1: So you need to keep adding thorium. But thorium by
• 39:03
  Speaker 1: itself is very stable. It's not fizzle, so it's not
• 39:06
  Speaker 1: like dangerous the way uranium, right, And it's also better
• 39:09
  Speaker 1: because it's not it's not as wasteful, right or dangerous
• 39:12
  Speaker 1: when it gets used exactly, it burns up a lot
• 39:14
  Speaker 1: of the uranium, and it doesn't produce crazy dangerous things
• 39:18
  Speaker 1: that last tens and thousands of years. I mean, it
• 39:20
  Speaker 1: produces very dangerous byproducts. Sum one thirty seven is very
• 39:25
  Speaker 1: very poisonous, but it has a half life of like
• 39:28
  Speaker 1: fifty issue years, not ten thousand years. So you need
• 39:32
  Speaker 1: to put this stuff in a barrel and wait a
• 39:33
  Speaker 1: couple hundred years before anybody goes near it. But you
• 39:36
  Speaker 1: don't need to wait fifty thousand years. Wow, this sounds great.
• 39:39
  Speaker 1: Why don't we use that? Like, why are we still
• 39:42
  Speaker 1: using uranium regular uranium? Let's switch to the avengers. Exactly,
• 39:47
  Speaker 1: it's a much better idea, but historically it hasn't been
• 39:49
  Speaker 1: pursued in the United States because it doesn't produce plutonium
• 39:53
  Speaker 1: and other heavy elements, those things which are very dangerous
• 39:56
  Speaker 1: and last forever. Those are also excellent for building nuclear weapons,
• 40:00
  Speaker 1: and so the Department of Energy, for example, Yeah, they
• 40:03
  Speaker 1: wanted to promote atomic power, but they also wanted to
• 40:06
  Speaker 1: develop facilities which would generate fuel for nuclear weapons. And
• 40:10
  Speaker 1: so burning uranium two thirty five was very inefficient. But
• 40:15
  Speaker 1: the uranium two thirty eight that was there, some of
• 40:17
  Speaker 1: it turned into plutonium, so you could make weapons grade fuel. Wait,
• 40:21
  Speaker 1: what are you saying that most nuclear power plants are
• 40:24
  Speaker 1: also secretly like weapons weapons and factories, not secretly. A
• 40:29
  Speaker 1: lot of nuclear power plants can produce plutonium, and it's
• 40:33
  Speaker 1: certainly an issue you need to also enrich it. Right,
• 40:35
  Speaker 1: it doesn't come out with pure plutonium, but a lot
• 40:38
  Speaker 1: of the uranium two thirty eight gets converted into very dangerous,
• 40:42
  Speaker 1: long lived waste, and some of that waste is excellent
• 40:45
  Speaker 1: fuel for weapons. Wow. So I guess maybe they saw
• 40:48
  Speaker 1: it as like a two for like a bonus, Like, Hey,
• 40:50
  Speaker 1: if we use this kind of fuel, this uranium two
• 40:53
  Speaker 1: thirty five to thirty eight, then as a byproduct, we
• 40:56
  Speaker 1: have kind of kind of a steady source of nuclear
• 40:58
  Speaker 1: weapons exactly. And so if, on the other hand, you
• 41:02
  Speaker 1: would like nuclear power without creating weapons fuel and without
• 41:07
  Speaker 1: creating environment poisoning waste that last tens and thousands of years,
• 41:11
  Speaker 1: you can do both at the same time by switching
• 41:13
  Speaker 1: to thorium. Wow. Well, it seems like countries that you
• 41:17
  Speaker 1: know don't have nuclear weapons, like does France have nuclear weapons? Like,
• 41:20
  Speaker 1: why wouldn't they switch to thorium. Well, it's just not
• 41:22
  Speaker 1: something that's been as developed. You know, we did some
• 41:25
  Speaker 1: research in the fifties and sixties and developed these reactors,
• 41:28
  Speaker 1: but uranium turned out to be kind of cheap and plentiful,
• 41:30
  Speaker 1: and people didn't really care about the fact that you
• 41:32
  Speaker 1: were wasting most of it, and it had these nuclear
• 41:35
  Speaker 1: weapons benefits. So it's largely just sort of abandoned for
• 41:39
  Speaker 1: decades and decades and just not really pursued. Oh I see,
• 41:42
  Speaker 1: So now it's maybe more of like a historical inertia
• 41:45
  Speaker 1: kind of like this is what we know what to do,
• 41:48
  Speaker 1: This is what we know how to do it. We
• 41:49
  Speaker 1: know how to make the safe. But thorium who knows, right, Like,
• 41:53
  Speaker 1: who knows? We don't know enough of it. Nobody has
• 41:55
  Speaker 1: done it enough to really kind of meet the same
• 41:57
  Speaker 1: safety standards. Maybe is that? Could that be an obstacle? Yeah,
• 42:01
  Speaker 1: it's a regulatory issues. You know, you're a company and
• 42:03
  Speaker 1: you're deciding to invest one billion dollars into a nuclear
• 42:07
  Speaker 1: power plant. What are you gonna do? You're gonna use
• 42:09
  Speaker 1: the plans for one that where was recently approved that
• 42:12
  Speaker 1: already sailed through the approval process and is working well,
• 42:14
  Speaker 1: instead of like, yeah, we're going to work on development
• 42:16
  Speaker 1: of some new technology. It requires the government to take
• 42:19
  Speaker 1: the lead in terms of research and developing and making
• 42:21
  Speaker 1: sure these things work. And so outside the United States,
• 42:24
  Speaker 1: some governments are doing this. China, for example, recently completed
• 42:28
  Speaker 1: a flora thorium reactor and they were supposed to turn
• 42:31
  Speaker 1: it on at the end of one. I haven't heard
• 42:34
  Speaker 1: if that thing has been turned on yet and works.
• 42:36
  Speaker 1: But you know, a lot of other countries are looking
• 42:38
  Speaker 1: into this. They can't find a thor's hammer to start
• 42:42
  Speaker 1: the reaction or something. Every time you gotta reboot it. Exactly,
• 42:46
  Speaker 1: you've gotta call thora um. And not just China, India. Also.
• 42:51
  Speaker 1: India is home to twenty five percent of the world's
• 42:54
  Speaker 1: thorium deposits, so it would be a great place to
• 42:56
  Speaker 1: rely on this kind of energy, and so they're developing
• 42:59
  Speaker 1: a the orium nuclear power program as well. Wow. Interesting,
• 43:03
  Speaker 1: I guess it just takes a long time, right, I mean,
• 43:06
  Speaker 1: you gotta you can't just like do this in a rush.
• 43:08
  Speaker 1: You gotta do this, do this very carefully. You do.
• 43:11
  Speaker 1: And there are some challenges to salt reactors that don't
• 43:14
  Speaker 1: exist for water reactors. For example, molten salt is kind
• 43:17
  Speaker 1: of corrosive. Like you have that in the inside of
• 43:20
  Speaker 1: a chamber for a long time, it's going to eat
• 43:22
  Speaker 1: away at the inside. So that was an obstacle a
• 43:25
  Speaker 1: long time ago. But these days we have fancy new
• 43:27
  Speaker 1: materials that can be basically hardened to the salt and
• 43:31
  Speaker 1: so it's no longer really a challenge. So with the
• 43:34
  Speaker 1: help of new technologies to overcome some of these technical challenges.
• 43:37
  Speaker 1: There's lots of places that are looking into this. There's
• 43:39
  Speaker 1: a company in Denmark actually called Copenhagen Atomics, and they
• 43:43
  Speaker 1: have a strategy to build one of these thorium reactors
• 43:46
  Speaker 1: and they want to make them into shipping containers. The
• 43:49
  Speaker 1: whole thing is just totally self contained. You never have
• 43:51
  Speaker 1: to open it up or do anything. You just turn
• 43:53
  Speaker 1: it on. It runs for like fifty years, produces energy
• 43:57
  Speaker 1: steadily for fifty years, and you can like them. You're like, oh,
• 44:00
  Speaker 1: we need ten of those. All we need five of those.
• 44:03
  Speaker 1: And to the self contained, what do you mean like
• 44:04
  Speaker 1: they produce the waste, But it's the wayt stays inside,
• 44:07
  Speaker 1: the waist stays inside, and you just like bury it
• 44:10
  Speaker 1: for two hundred years and then it's done. So that's
• 44:12
  Speaker 1: pretty cool idea. It's a company called Copenhagen Atomics. And
• 44:15
  Speaker 1: for the record, you're not you haven't invested in this
• 44:18
  Speaker 1: company heavy, You're not like Elon Musk trying to game
• 44:22
  Speaker 1: the markets. No, but you should buy Daniel coin. Really,
• 44:25
  Speaker 1: it's my new cryptocurrency, dan Coin, there you go, Exactly,
• 44:32
  Speaker 1: it's going to fund all of my heated spices for
• 44:36
  Speaker 1: your other the other arm of your subsidiary corporation, right,
• 44:39
  Speaker 1: spicy dan exactly working on development of anti chocolate technology.
• 44:45
  Speaker 1: All right, So those are two pretty interesting ideas using
• 44:48
  Speaker 1: melted salt molten salt and also maybe switching up the
• 44:52
  Speaker 1: fuel to do something that's maybe cleaner. And it sounds
• 44:54
  Speaker 1: like people are working on it, and maybe we should
• 44:56
  Speaker 1: too because it sounds like other countries are working on it.
• 44:59
  Speaker 1: It's definitely pro missing technology. And if you think that
• 45:02
  Speaker 1: nuclear power is an important part of a clean future,
• 45:05
  Speaker 1: then definitely thorium is a better choice than uranium. It's
• 45:09
  Speaker 1: a question, you know, whether or not even the waste
• 45:11
  Speaker 1: produced by thorm reactors is worth the risks, but it's
• 45:14
  Speaker 1: definitely all better than burning fossil fuels, right, and it's
• 45:17
  Speaker 1: much better than hawkeye. Um. Yeah, maybe you should just
• 45:19
  Speaker 1: take the avengers and grind them up into fuel. Well,
• 45:22
  Speaker 1: they definitely make enough money to self sustained. It's its
• 45:27
  Speaker 1: own reaction there, Yeah, exactly, will mint avenge coins at
• 45:31
  Speaker 1: a ground up avengers? There you go, marvel Coin, marvel Coin,
• 45:36
  Speaker 1: you might as well have their own economy, right, they're
• 45:39
  Speaker 1: basically just printing money, all right, Well, this is kind
• 45:42
  Speaker 1: of hopeful news to know that maybe they're people are
• 45:44
  Speaker 1: working on cleaner and more efficient energies and to get
• 45:47
  Speaker 1: humanity into the stars maybe and into the far future
• 45:51
  Speaker 1: so we can learn more about the universe and discover
• 45:55
  Speaker 1: more of it exactly. And it's always fascinating to learn
• 45:58
  Speaker 1: about the history of these things and how like political
• 46:00
  Speaker 1: choices that were made decades ago really changed the direction
• 46:04
  Speaker 1: of research. And it's not always for a good reason,
• 46:07
  Speaker 1: not always for reasons that we would agree with today,
• 46:10
  Speaker 1: And so the things that people are working on currently
• 46:13
  Speaker 1: are just sort of the things people have been working on,
• 46:15
  Speaker 1: and they're often really promising directions that were overlooked for
• 46:19
  Speaker 1: silly reasons. All right, Well, we hope you enjoyed that.
• 46:22
  Speaker 1: Thanks for joining us, See you next time. Thanks for listening,
• 46:33
  Speaker 1: and remember that Daniel and Jorge explained. The Universe is
• 46:36
  Speaker 1: a production of I Heart Radio. For more podcast from
• 46:39
  Speaker 1: my Heart Radio, visit the i Heart Radio app, Apple Podcasts,
• 46:43
  Speaker 1: or wherever you listen to your favorite shows.