Speaker 1: Get in touch with technology with tech Stuff from how
Speaker 1: stuff works dot com. Hey there, and welcome to tech Stuff.
Speaker 1: I'm your host, Jonathan Strickland. I'm an executive producer with
Speaker 1: how Stuff Works and I love all things tech, and
Speaker 1: recently I got some requests to talk about some subjects
Speaker 1: related to nuclear power. Specifically, I had a request to
Speaker 1: talk about cold fusion and whether there is any validity
Speaker 1: to cold fusion claims and research, and that's a very
Speaker 1: loaded subject and I will tackle it. But before I
Speaker 1: can handle that topic, I thought we would be good
Speaker 1: to do a couple of episodes about nuclear power to
Speaker 1: lead up to it, and that includes how nuclear power
Speaker 1: plants work today and how nuclear fusion reactors will work
Speaker 1: in the future if we ever suss out how to
Speaker 1: do them in a way that isn't a net loss
Speaker 1: on energy and is sustainable. So today's episode is going
Speaker 1: to be about new clear fission reactors. That's the kind
Speaker 1: that we use today to generate electricity. Their nuclear power
Speaker 1: plants all across the world, and all of the ones
Speaker 1: that are not just pure research facilities are fission based.
Speaker 1: And then fusion is something that is in a research
Speaker 1: stage in various places around the world, and then this
Speaker 1: is actually gonna be a nuclear power week because we're
Speaker 1: going to talk about cold fusion in the third episode.
Speaker 1: In the fourth episode, I think I'm going to take
Speaker 1: a really close look at some of the famous nuclear
Speaker 1: facility disasters, things like Three Mile Island, Chernobyl, and the
Speaker 1: Fukushima reactor and talk about what happened in each of
Speaker 1: those instances and what the consequences were, so that we
Speaker 1: can have a deep understanding. Now, this is not supposed
Speaker 1: to be a series that is meant to scare you
Speaker 1: about nuclear power. I actually believe that nuclear power, if
Speaker 1: performed responsibly, is a good alternative to fossil fuel based power.
Speaker 1: But the responsibly part is absolutely of paramount importance. And
Speaker 1: we'll get into why as I talk about this. But
Speaker 1: this is not an anti nuclear power or even a
Speaker 1: pro nuclear power episode. It's just to kind of give
Speaker 1: us the understanding of what it is, what's going on,
Speaker 1: what are the pros and the cons of it. So,
Speaker 1: fission means they use a process to generate energy that
Speaker 1: involves splitting one heavy atom into lighter atoms, and fusion
Speaker 1: is the opposite. You would take two or more lighter
Speaker 1: atoms and you squish them together real hard to make
Speaker 1: into a heavier atom, and both processes release energy, though
Speaker 1: a fusion reaction would release far more energy than a
Speaker 1: fission reaction. I'll explain how that is in the next episode.
Speaker 1: But first, fission, well, it happens naturally with certain large
Speaker 1: unstable atoms. Uranium, for example, It will spontaneously undergo fission
Speaker 1: uranium two specifically, but it does so at a very
Speaker 1: slow rate. But you can speed that rate up through
Speaker 1: a process called induced fission. And generally speaking, induced fission
Speaker 1: happens when you take a heavy and unstable atom and
Speaker 1: you pelt it really hard with neutrons. You accelerate the
Speaker 1: neutrons and you shoot them at these heavy isotopes, and
Speaker 1: those isotopes break up into smaller components. That process generates
Speaker 1: a lot of energy in the form of heat, and
Speaker 1: you can use that heat to heat up water, preferably
Speaker 1: in a separate, sealed system. Not all nuclear power plants
Speaker 1: work that way, but about two thirds of the US
Speaker 1: nuclear power plants do, And you convert the water into
Speaker 1: steam and use that steam to turn turbines conducted to
Speaker 1: generators to produce electricity. Now, in a way today's nuclear
Speaker 1: power plants are really not all that different from coal
Speaker 1: power plants or thermal plants that use solar power to
Speaker 1: heat up water. And in all these cases, you use
Speaker 1: a process to either generate or harness heat. And you know,
Speaker 1: you can burn cold to do that, you can harness
Speaker 1: solar power to do that, you can use nuclear power
Speaker 1: to do that. Use that heat to boil water, to
Speaker 1: convert water into high pressure steam, and you direct that
Speaker 1: steam to move turbines, and those turbines are electricity generators. Now,
Speaker 1: to be clear, the generators aren't generating energy because energy
Speaker 1: can be neither created nor destroyed. You can convert energy
Speaker 1: from one form to another. You can convert mass into energy,
Speaker 1: but you can't just create energy and of nothing. So
Speaker 1: electricity generators are converting some form of energy into electricity. Uh.
Speaker 1: With steam turbines, we're talking about converting kinetic energy, the
Speaker 1: energy of movement, into electrical energy. And here's how that works.
Speaker 1: In a nutshell. Generators have many parts typically, but a
Speaker 1: really important component is the alternator. And inside the alternator
Speaker 1: you have a statter and you have a rotor. The
Speaker 1: statter stays motionless with respect to the generator. It's remains
Speaker 1: stationary motionless. The rotor, as a name suggests, rotates on
Speaker 1: its axis. So it rotates. Uh. Typically the statter has
Speaker 1: an iron core and you have conductive wire or cable
Speaker 1: wrapped around that iron core. So you think about this,
Speaker 1: it sounds oh, it sounds like an electro magnet. Well, yeah,
Speaker 1: kind of. The rotor typically has permanent magnets or some
Speaker 1: other thing that generates a magnetic field, and as the
Speaker 1: rotor rotates, this magnetic field moves with the rotation. So
Speaker 1: this is essentially a fluctuating magnetic field. And as we know,
Speaker 1: when you have a fluctuation magnetic field and you've got
Speaker 1: a a conductive wire that's wrapped around an iron core,
Speaker 1: that can induce or it does induce a voltage difference
Speaker 1: in that conductive material and that wire, and that voltage
Speaker 1: difference produces alternating current or a c electricity. There are
Speaker 1: tons of different types of generators out there. Some of
Speaker 1: them burn fuel in a in an engine that creates
Speaker 1: the energy needed to move a motor, which in turn
Speaker 1: rotates the rotor. So you can take fuel, you can
Speaker 1: burn it in an engine and use that engine to
Speaker 1: work with a generator to produce electricity, so you just
Speaker 1: refill the uh that the engine whenever the fuel runs out,
Speaker 1: and you can keep on generating electricity this way, or
Speaker 1: you could use turbines that are turned by stuff like
Speaker 1: wind or water. So with a typical steam turbine, you
Speaker 1: have a closed system in which a heat source heats
Speaker 1: up water until it boils and creates high pressure steam.
Speaker 1: That high pressure means the steam has got a lot
Speaker 1: of energy behind it, and the steam encounters the first
Speaker 1: blades of the turbine. Typically turbines consist of multiple blades,
Speaker 1: and they start in a very kind of tight circle,
Speaker 1: and then as you go further into the turbine, the
Speaker 1: circles are getting bigger and bigger because steam expands as
Speaker 1: it's moving through this turbine system, and the fans are
Speaker 1: angled so that the push from the steam creates a
Speaker 1: rotational force on the turbine and it turns the rotor.
Speaker 1: So steam passes through the fan blades, it expands, it
Speaker 1: keeps pushing those next series of fans. This is what
Speaker 1: allows you to create a very efficient steam turbine design,
Speaker 1: and it helps you capture as much of the energy
Speaker 1: from the steam as you can. The turbines shaft, like
Speaker 1: I said, is connected to the rotor of the electrical
Speaker 1: generator that produces the rotational energy that creates the fluctuating
Speaker 1: magnetic field, etcetera, etcetera, etcetera. Now, the steam continues through
Speaker 1: the system after passing through the turbine, and it cools
Speaker 1: down as it does so typically through exposure to some
Speaker 1: other part of this system. And as it cools down,
Speaker 1: it condenses back into water and it flows back into
Speaker 1: the boiler where the whole process can start over again.
Speaker 1: But again, with nuclear power, you're using a different material
Speaker 1: and process to create the heat than you would with
Speaker 1: a coal power plant, and there's a need to make
Speaker 1: sure the systems in a nuclear power plant are secure
Speaker 1: and separate from each other to prevent contamination, or at
Speaker 1: least shielded very very well if you have a full
Speaker 1: implemented system. So if the water is actually passing through
Speaker 1: the reactor and that same water is the water that's
Speaker 1: converted into steam to pass with the turbine, you want
Speaker 1: to make sure that that facility is very well shielded.
Speaker 1: Most nuclear power plants have two water systems. They have
Speaker 1: one that's the coolant uh and then they have a
Speaker 1: secondary one where there's a heat exchanger that sends the
Speaker 1: heat from the coolant into this boiler, which then boils
Speaker 1: off the water and create steam. And the two systems
Speaker 1: are separate. They don't they don't come into direct contact
Speaker 1: with each other, so you don't pass radioactive contaminants from
Speaker 1: the coolant into the steam that you're using to turn
Speaker 1: the turbines. Now, the isotope most commonly associated with nuclear
Speaker 1: power is uranium two thirty five, but plutonium two thirty
Speaker 1: nine is also used in some reactors, and there are
Speaker 1: some nuclear power proponents who really advocate a thorium based
Speaker 1: power plant. More on that later in this episode. And
Speaker 1: I've said the word isotope a few times. Why does
Speaker 1: that actually mean. Well, isotopes are two or more forms
Speaker 1: of the same element, meaning uh, two or more forms
Speaker 1: that all have the same number of protons. Because if
Speaker 1: you have different number of protons and you have different elements,
Speaker 1: so you're looking at two different atoms that represent the
Speaker 1: same element, and they have the same number of protons,
Speaker 1: but they have different numbers of neutrons from each other.
Speaker 1: Neutrons are particles have a neutral charge. You find them
Speaker 1: in the nuclei of atoms. They don't affect the chemical
Speaker 1: properties of the element, but isotopes do have different atomic
Speaker 1: masses relative to one another, so they are chemically identical,
Speaker 1: but from a nuclear process perspective, they are different. So
Speaker 1: uranium two thirty five is as you would imagine an
Speaker 1: isotope of uranium. It is not the most commonly found
Speaker 1: form of uranium in nature. The most common form of
Speaker 1: uranium is uranium two thirty eight. Uranium two thirty eight
Speaker 1: has ninety two protons and one forty six neutrons. Uranium
Speaker 1: two thirty five has ninety two protons and one forty
Speaker 1: three neutrons. Uranium two thirty five makes up less than
Speaker 1: one percent of all naturally occurring uranium in the world,
Speaker 1: and it has a half life of nearly seven hundred
Speaker 1: four million years, which means if you have a qual
Speaker 1: unto ty of uranium to thirty five any given amount.
Speaker 1: Let's say that you have a pound of uranium two
Speaker 1: thirty five. That's an enormous amount of uranium two thirty five.
Speaker 1: But let's say you have a pound of it, it
Speaker 1: would take approximately seven four million years for that uranium
Speaker 1: two thirty five to reduce in half through radioactive decay,
Speaker 1: so you would end up with half a pound on
Speaker 1: average after seven four million years. More or less. This
Speaker 1: is essentially uh the rate of radioactive decay. But I
Speaker 1: think we could actually do a lot better than that
Speaker 1: if we really put our minds to it, And I'll
Speaker 1: explain how in just a second, but first let's take
Speaker 1: a quick break to thank our sponsor. Okay, So, uranium
Speaker 1: two thirty five will spontaneously decay and release energy in
Speaker 1: the process, and when it decay as uranium two thirty
Speaker 1: five will split to create an alpha particle that's technically
Speaker 1: two protons and two neutrons that are bound together. Interestingly,
Speaker 1: there's no standard equation we can use to represent spontaneous
Speaker 1: fission for uranium two thirty five because the results are unpredictable.
Speaker 1: But if you were to trace the chain of decay,
Speaker 1: the chain of decay goes like this. And pardon me,
Speaker 1: because this gets really kind of ridiculous to describe it all,
Speaker 1: but all right, you start with uranium two thirty five,
Speaker 1: and that decays into thorium two thirty one, which decays
Speaker 1: into protact tenium. And I'm sure I'm mispronouncing that two
Speaker 1: thirty one that decays into actinium to twenty seven, which
Speaker 1: decays into thorium to twenty seven, which then decays into
Speaker 1: radium to twenty three, which then decays into rate on
Speaker 1: to nineteen, and then to polonium to fifteen, and then
Speaker 1: to lead to eleven, to bismuth to eleven, to thallium
Speaker 1: two oh seven, and then finally to lead too oh seven.
Speaker 1: Lead to oh seven is a stable atom, so it
Speaker 1: will not decay at least not through any observable time
Speaker 1: frame that we can talk about, so that's a relief.
Speaker 1: But as I mentioned earlier, if uranium two thirty five
Speaker 1: gets hit with a high speed neutron, it can absorb
Speaker 1: that neutron and then undergo fission. So as the uranium
Speaker 1: two thirty five atom splits, it can release two or
Speaker 1: three more neutrons, which is also unpredictable. It all depends
Speaker 1: on how the uranium splits, but we cannot predict how
Speaker 1: many neutrons would be given off by any one reaction. However,
Speaker 1: those two or three neutrons can then go and get
Speaker 1: absorbed by other uranium two thirty five atoms. If you
Speaker 1: have enough uranium two thirty five atoms concentrated in the
Speaker 1: same space, then the decay of one can affect another one,
Speaker 1: and if a neutron from one decaying uranium two thirty
Speaker 1: five atom hits another, then that will prompt another reaction.
Speaker 1: So if you have the right concentration of uranium two
Speaker 1: thirty five, called a critical mass, you can have a
Speaker 1: sustained nuclear reaction. Now there has to be enough uranium
Speaker 1: two thirty five and the neutrons need to be moving
Speaker 1: at the right speed for that to happen. With lower
Speaker 1: concentrations of uranium two thirty five, you actually need to
Speaker 1: slow down the neutrons a bit in order to improve
Speaker 1: the chances that the existing uranium two thirty five atoms
Speaker 1: will absorb that incoming neutron. So you would typically use
Speaker 1: another material like graphite to act like kind of like
Speaker 1: a set of breaks. They slow down the neutrons enough
Speaker 1: for the uranium two thirty five atoms to take them
Speaker 1: in and then split apart. That type of material is
Speaker 1: called a moderator. Use a moderator to moderate the speed
Speaker 1: of the neutrons. That reaction will sustain itself until the
Speaker 1: amount of uranium two thirty five reduces below critical mass. Now,
Speaker 1: one atom of uran two thirty five will release about
Speaker 1: two hundred million electron volts worth of energy, which is
Speaker 1: actually not a very large amount of energy. So an
Speaker 1: electron vault is the amount of energy gained by the
Speaker 1: charge of an electron moved across an electric potential difference
Speaker 1: of one vault. So two hundred million electron volts sounds
Speaker 1: like a lot, because two hundred million is a really
Speaker 1: big number, But a mosquito in flight has the kinetic
Speaker 1: energy of about one trillion electron volts, so it's a
Speaker 1: fraction of the energy of a mosquito flying. However, I
Speaker 1: did say a single decaying atom of uranium two thirty
Speaker 1: five releases two hundred million electron volts. That's just one atom.
Speaker 1: If you've got a significant amount of uranium two thirty five,
Speaker 1: you're talking about billions or trillions of these atoms, and
Speaker 1: that adds up pretty darn fast. So individually the atoms
Speaker 1: don't have that much energy, but collectively they've got a
Speaker 1: whole bunch of it. In fact, in one hound of uranium,
Speaker 1: you have as much energy as three million pounds of coal,
Speaker 1: so very energy dense. When a uranium two thirty five
Speaker 1: atom splits, it also releases energy in the form of
Speaker 1: heat and gamma radiation. It's not just splitting neutrons off,
Speaker 1: it's also releasing heat and gamma radiation, which is a
Speaker 1: high energy photons. In addition, the two new atoms that
Speaker 1: result from the fission of uranium two thirty five will
Speaker 1: undergo beta radiation, which means they release super fast electrons,
Speaker 1: and they also release more gamma radiation. A gamma radiation
Speaker 1: is pretty dangerous stuff. It will not turn you into
Speaker 1: the hook, it will hurt you very badly. So let's
Speaker 1: talk about the innards of a nuclear reactor. So you've
Speaker 1: got to get a source of uranium two thirty five
Speaker 1: enriched uranium two thirty five. That means that there's a
Speaker 1: higher concentration of uranium two thirty five in your amount
Speaker 1: of uranium and you would find in nature. So if
Speaker 1: you went out in nature, you got yourself a pick,
Speaker 1: and you're going to an area that's rich in uranium.
Speaker 1: Can you mind yourself some uranium and you get a
Speaker 1: big chunk of uranium. Most of the atoms of that
Speaker 1: uranium are going to be you two thirty eight, almost
Speaker 1: all of them. Uranium two thirty five would make up
Speaker 1: about point seven two of all the atoms in that
Speaker 1: sample you collected. That is not enough for you to
Speaker 1: be able to hit critical mass. You need to be
Speaker 1: at around two or three percent uranium two thirty five
Speaker 1: in the overall sample in order to have that sustainable
Speaker 1: nuclear reaction, which means you have to have enriched uranium.
Speaker 1: You have to have uranium that has unnaturally high concentrations
Speaker 1: of uranium two thirty five. And you form these samples
Speaker 1: of enriched uranium into pellets. Now, each pellet is a
Speaker 1: cylinder that's about two and a half centimeters long or
Speaker 1: about an inch long, and they have a diameter of
Speaker 1: around eighteen millimeters round points seven inches, so in other words,
Speaker 1: they are about the diameter of a US dime. And
Speaker 1: you take these little cylindrical pellets and you put them
Speaker 1: end to end to form rods, uranium rods. You then
Speaker 1: collect bunches of those rods into what are called bundles.
Speaker 1: The bundles you put into a pressure vessel that's filled
Speaker 1: with water, and the water access you're coolant. These nuclear
Speaker 1: reactions generate a lot of heat, and without a coolant,
Speaker 1: that amount of heat would be high enough to actually
Speaker 1: melt the rods themselves. That rods would overheat through these
Speaker 1: reactions and we get hotter than the melting point for uranium.
Speaker 1: This is what we in the BIZ call a nuclear
Speaker 1: melt down, and it is a bad thing to have happen,
Speaker 1: so you have to have that coolant there. Another preventive
Speaker 1: measure against overheating are the control rods. Control rods are
Speaker 1: made out of a material that can absorb neutrons. Now, remember,
Speaker 1: the sustained nuclear reaction of a nuclear power plant involves
Speaker 1: uranium two thirty five emitting these neutrons and then absorbing
Speaker 1: incoming neutrons, emitting, splitting, and emitting more neutrons, and that's
Speaker 1: what keeps the reaction going. So if you put in
Speaker 1: material that can absorb those neutrons, you're taking away the
Speaker 1: trigger that would continue to allow this nuclear reaction to happen.
Speaker 1: So you can actually use these sort of robotic arms
Speaker 1: to lower or raise the control rods out of the
Speaker 1: bundles of uranium to and by uh by putting them
Speaker 1: into the bundles, you absorb more of those neutrons, so
Speaker 1: you can reduce the rate of nuclear reaction. You can
Speaker 1: even stop it completely if you if you leave it
Speaker 1: in there long enough and you have enough of the
Speaker 1: control rods there, or you can lift it out of
Speaker 1: the bundles to allow more of those reactions to occur,
Speaker 1: to increase the reactions, And it all depends on how
Speaker 1: things are going on in the core at any given time,
Speaker 1: and uh, if the reaction is ramping up too quickly
Speaker 1: lower a rod in the bundle soak up some neutrons
Speaker 1: prevent those YouTube thirty five atoms and the bundles from
Speaker 1: doing it and pushing the reaction even further. Now, in
Speaker 1: some reactors, the coolant isn't water at all, It might
Speaker 1: be something else. There are a few that use gas
Speaker 1: based coolants like carbon dioxide, or they might use liquid
Speaker 1: metals like sodium or potassium. That generally allows you to
Speaker 1: operate at a higher temperature than you would if you
Speaker 1: were using water, but that also could mean that you're
Speaker 1: burning through fuel a lot faster. So in some reactors,
Speaker 1: like the third of the ones that are in the
Speaker 1: United States, the coolant is in fact the water that
Speaker 1: gets converted into steam and eventually pushes a turbine. But
Speaker 1: again that can be risky because that coolant has been
Speaker 1: in direct contact with the radioactive materials. So if that
Speaker 1: steam were to escape him, then that could be a
Speaker 1: potential hazard for the surrounding environment. Generally, most of the
Speaker 1: power plants in the United States use pressurized water reactors
Speaker 1: and a secondary closed system of water for the purposes
Speaker 1: of turning the turbines. Two thirds of the power plants
Speaker 1: the United States use this approach. So you have the
Speaker 1: water the coolant that's inside your nuclear reactor under a
Speaker 1: tremendous amount of pressure, and that pressure prevents the water
Speaker 1: from boiling off. It remains liquid, so it's superheated liquid
Speaker 1: that cannot boil because of that pressure. But that superheated
Speaker 1: liquid is in contact with a heat exchanger, and the
Speaker 1: heat exchanger transfers heat to the water that's inside a boiler,
Speaker 1: and that water can boil off, turn into steam, and
Speaker 1: turn steam turbines, but it's in its own closed, parallel system,
Speaker 1: so the two systems don't actually share any water between
Speaker 1: the two of them, and that way you have one
Speaker 1: relatively clean system of water that's consistently being heated to steam,
Speaker 1: turning turbines, condensing back into water and starting over again,
Speaker 1: and then you have the other one that's acting as
Speaker 1: the coolant for your actual reactor. Two thirds of the
Speaker 1: power plants in the United States use that approach. The
Speaker 1: steam that powers the turbine has to cool off in
Speaker 1: order to condense back into water, so some plants will
Speaker 1: use water from natural resources like lakes or streams to
Speaker 1: cool that steam using another form of heat exchange. So
Speaker 1: the steam exchanges heat, it transfers heat to the water
Speaker 1: from the lake or stream, and then as a result,
Speaker 1: the steam itself starts to cool down because it's pushed
Speaker 1: that heat energy off to a different source and turns
Speaker 1: into water. Other nuclear power plants have those really tall
Speaker 1: cooling towers. Those are those iconic, enormous chimney like structures
Speaker 1: that we tend to associate with nuclear power plants. Like
Speaker 1: if you watch the Simpsons, you see that that iconic
Speaker 1: shape of the cooling towers next to the power plant
Speaker 1: in in Springfield. So for every unit of electricity produced
Speaker 1: by a power plant, it about two units of waste
Speaker 1: heat get transferred to the environment. But that's just heat.
Speaker 1: It's it is heat, but it's not greenhouse gas, so
Speaker 1: it's not something that contributes to climate change on a
Speaker 1: global scale. You get some regionalized heating, but it's temporary,
Speaker 1: So that's good. But nuclear power plants obviously create some
Speaker 1: real challenges. What are those Well, I'll tell you in
Speaker 1: just a second, but first let's take another quick break
Speaker 1: to thank our sponsor. Because the energy from a nuclear
Speaker 1: reactor includes stuff that can really cause harm to humans
Speaker 1: in various ways, the nuclear reactor itself has to be
Speaker 1: heavily shielded to prevent that radiation from getting out into
Speaker 1: the general environment. Typically, the reactor has a concrete liner
Speaker 1: to act as a radiation shield, and around that line
Speaker 1: inner so one layer out. Think of it as an onion.
Speaker 1: So you've got a reactor at the core of the
Speaker 1: onion that you've got a peel of the onion. Layer
Speaker 1: of the onion that is the concrete liner. Then you
Speaker 1: have another layer around that that's a steel containment vessel,
Speaker 1: and then the power plant itself is typically made out
Speaker 1: of very thick concrete that access sort of a final
Speaker 1: layer of protection between the reactor and the surrounding area
Speaker 1: if all else were to fail. In addition, the spent
Speaker 1: fuel in a fission reactor is itself radioactive. It contains
Speaker 1: a lot of different radioactive materials in it of various
Speaker 1: uh half life's so some of those half lives are
Speaker 1: on the matter of days or a couple of years,
Speaker 1: but others last a lot longer. The equipment and parts
Speaker 1: of a nuclear power plant can absorb energy and become
Speaker 1: radioactive as well. That is what we call low level
Speaker 1: radioactive material or radioactive waste. UH that is much lower
Speaker 1: in radioactivity and in potential danger than say, spent fuel is.
Speaker 1: But however, this all creates challenges when it comes to
Speaker 1: what do you do with that stuff? What do you
Speaker 1: do with this waste? It's still dangerous. It emits a
Speaker 1: lot of energy, It will eventually corrode whatever container you
Speaker 1: put it into, and it will stay dangerous for thousands
Speaker 1: of years, in some cases tens of thousands with high
Speaker 1: level radiation, and it decays very slowly into stable forms,
Speaker 1: but it'll do so long after we're gone. Keep in
Speaker 1: mind ten thousand years. That's the length of human history.
Speaker 1: So this waste, some of it will remain dangerously radioactive,
Speaker 1: as in the type of radiation it gives off could
Speaker 1: cause harm for thousands of years. The most dangerous stuff
Speaker 1: tends to decay much faster, but it's not really that reassuring,
Speaker 1: So we have to figure out what do we do
Speaker 1: with this stuff? Well, nuclear power plants produce about two
Speaker 1: thousand metric tons of nuclear waste every year. Back in
Speaker 1: the nineteen sixties, one plan for dealing with waste involved
Speaker 1: reprocessing the nuclear waste in order to produce new fuel,
Speaker 1: and one of those products of reprocessing is plutonium, and
Speaker 1: plutonium two thirty eight can be used as a nuclear fuel.
Speaker 1: You make it by bombarding uranium two thirty eight with neutrons,
Speaker 1: so uranium two thirty five. When you do that, that's
Speaker 1: what you have as a uh fission fuel. Uranium two
Speaker 1: thirty eight. You can't use that to create a sustainable
Speaker 1: fission reaction, but you can bombard it with neutrons to
Speaker 1: create plutonium two thirty eight, which in turn is a
Speaker 1: good source for fission fuel. So that was a possibility. However,
Speaker 1: plutonium two thirty eight can also be used to make
Speaker 1: nuclear weapons, and in the nineteen seventies, US President Jimmy
Speaker 1: Carter argued that reprocessing nuclear fuel presented a grave secure
Speaker 1: risk that the plutonium produced would be attempting target for
Speaker 1: agents that wish to create nuclear weapons. You could have
Speaker 1: terrorists or foreign net agents that we're trying to get
Speaker 1: hold of that plutonium. At least that was Carter's argument,
Speaker 1: and so reprocessing was kind of put on the shelf.
Speaker 1: It was said, well, we're not gonna allow that process
Speaker 1: to happen because it's too dangerous. In addition, on top
Speaker 1: of that, reprocessing fuel was seen as being really expensive,
Speaker 1: and it was generally thought that mining new uranium fuel
Speaker 1: made more economic sense. So you can kind of see
Speaker 1: this in other areas too, Like in recycling. There are
Speaker 1: certain materials where recycling makes incredible sense because the amount
Speaker 1: of energy and money you spend recycling that material is
Speaker 1: less than what it would take for you to mine
Speaker 1: and process new material. But some stuff like glass glass
Speaker 1: is so easy to make that re cycling it is
Speaker 1: a tough sell because the process of recycling glass takes
Speaker 1: about as much energy and effort as it would take
Speaker 1: to make brand new glass. Well, that was kind of
Speaker 1: the argument that the nuclear industry was making about reprocessing.
Speaker 1: They said, yeah, we could make more efficient use of
Speaker 1: this fuel, but it's not like it's super cheap to
Speaker 1: do compared to just getting new fuels, So why should
Speaker 1: we invest and these reprocessing facilities which will cost a
Speaker 1: huge amount of money to create and then maintain when
Speaker 1: we can just keep mining the stuff that's already there.
Speaker 1: So there are two big arguments against reprocessing in the seventies.
Speaker 1: But that would mean that we would have two different
Speaker 1: sets of nuclear power plants, because you would use one
Speaker 1: that has uranium two thirty five that would produce the
Speaker 1: neutrons that you could then use to create the plutonium
Speaker 1: two thirty nine. And uh so you've got the uranium
Speaker 1: two power plants. Those are generating a ectricity, and then
Speaker 1: you've got the plutonium two thirty nine power plants. Those
Speaker 1: are generating electricity to thirty five is feeding the fuel
Speaker 1: into the two thirty nine plutonium ones. So they would
Speaker 1: becomes what we would call a breeder plant. We call
Speaker 1: them breeders because they create the fuel that will be
Speaker 1: used in a different facility. So the idea was that, hey,
Speaker 1: you've got a much more efficient use of the material
Speaker 1: because you're you're able not actually to use it twice,
Speaker 1: but you're able to use more of the material you
Speaker 1: have mind to produce electricity, and that's how power plants
Speaker 1: in countries like France operate to this day. You have
Speaker 1: some that are essentially those breeders, and you have others
Speaker 1: that are plutonium two thirty nine plants, and so in
Speaker 1: France of their electricity comes from nuclear power, which means
Speaker 1: that if there's an oil crisis or even a uranium crisis,
Speaker 1: they're still in pretty good shape because most of their
Speaker 1: power plants depend on plutonium, and you don't need that
Speaker 1: much uranium to start producing plutonium in amounts large enough
Speaker 1: to create electricity. So France argues that their emphasis on
Speaker 1: nuclear power gives them more national security because they depend
Speaker 1: less on foreign countries to produce the fuel they need.
Speaker 1: Critics of Jimmy Carter's plan said that while plutonium might
Speaker 1: have presented attempting target, it would actually in practicality be
Speaker 1: very difficult to pull off a successful plutonium heist or
Speaker 1: an attack. But as of now in the United States,
Speaker 1: reprocessing is a moot point. So that still leaves the
Speaker 1: question what are we to do with nuclear waste at
Speaker 1: the moment. Various sites around the world are acting as
Speaker 1: temporary holding facilities. There's some permanent ones in other parts
Speaker 1: of the world, but in the United States, the plants
Speaker 1: that produce the waste are the ones that are storing
Speaker 1: the waste on site, so usually the first step is
Speaker 1: to store the way to what are called spent fuel
Speaker 1: cooling pools. Uh. These are enormous tanks filled with circulating water,
Speaker 1: and you put the spent fuel in there to keep
Speaker 1: the fuel from overheating through its own natural radioactive decay.
Speaker 1: But as those pools fill up, you gotta do something
Speaker 1: else with that spent fuel. So spent nuclear fuel at
Speaker 1: that point tends to be merged with glass. We we've
Speaker 1: vitrified in glass, and then we store that in steel
Speaker 1: and concrete casks, which are incredibly thick and secure, and
Speaker 1: in turn we put those in cooled, heavily shielded facilities. Now,
Speaker 1: there have been several sites suggested as long term storage facilities,
Speaker 1: since the stuff is going to be radioactive for tens
Speaker 1: of thousands of years, so we need to find a
Speaker 1: place to put it that's going to be far away
Speaker 1: from people, far away from other elements of the environment
Speaker 1: that could possibly contaminate, like sources of water, that kind
Speaker 1: of thing. But understandably, people living in the general area
Speaker 1: around those per post sites aren't too keen to have
Speaker 1: nuclear waste nearby, even if it is under tons of
Speaker 1: stone like beneath Yuck a mountain in Nevada. Now that
Speaker 1: particular site is the one that has been proposed as
Speaker 1: the long term storage facility of the United States. But
Speaker 1: Nevada does not have any nuclear power plants of its own,
Speaker 1: so the state would be accepting incoming spent nuclear fuel
Speaker 1: from other states. Now, that is to put it lightly
Speaker 1: a hard sell. I mean, imagine, let's say that we're
Speaker 1: talking about garbage instead. And let's say that the state
Speaker 1: has somehow managed to create a system where they are
Speaker 1: producing net zero garbage. Somehow they're able to process the
Speaker 1: garbage to the point where they don't need any garbage
Speaker 1: facilities because they're not generating any And then they get
Speaker 1: notifications from all these states nearby that say, hey, we
Speaker 1: want to put our garbage in your state. Well, most
Speaker 1: states are going to say, no, we we fixed our problem.
Speaker 1: We don't need to take your garbage. That's kind of
Speaker 1: the way it was with Nevada. And there's there are
Speaker 1: tons of different groups that oppose the storage of nuclear
Speaker 1: waste and yucka mountain for lots of different reasons. There
Speaker 1: are cultural groups that oppose it for that reason. There
Speaker 1: are state and regional groups that oppose it for kind
Speaker 1: of in that not in my backyard sort of approach.
Speaker 1: There are i'd say, there are people on the nuclear
Speaker 1: power proponents side who would describe some of these reactions
Speaker 1: as knee jerk. I think that's being a little unfair, because,
Speaker 1: for one, the concept of harm from nuclear waste is
Speaker 1: one that has been deeply ingrained in the American psyche
Speaker 1: through pop culture and through news reports. So the general
Speaker 1: American has a very negative view of what might happen
Speaker 1: with nuclear waste should something go wrong, So naturally you
Speaker 1: don't want it near you. Also, uh, you know, unless
Speaker 1: you're talking about significant economic uh support going into a
Speaker 1: state like Nevada, which does not have its own nuclear
Speaker 1: power plants, to say hey, you'll you'll be the site
Speaker 1: for this stuff. We're putting it in a place that
Speaker 1: nobody can go and it's far, far far away from anybody,
Speaker 1: so there's not going to be any issues with contamination.
Speaker 1: But in return, we're also going to give your state
Speaker 1: the x amount of money in federal funding for being
Speaker 1: the site of this. That might go a long way
Speaker 1: if you can make a very convincing argument that the
Speaker 1: whole process is safe and reliable. But getting past that
Speaker 1: hump is very difficult. To do, because again, people have
Speaker 1: a concept that nuclear waste is such a dangerous and
Speaker 1: undesirable thing that it's really hard to reassure them that
Speaker 1: there is a way to do this responsibly. Now, as
Speaker 1: of the recording of this podcast, Yuckum is essentially a
Speaker 1: no go. The Department of Energy and the Nuclear Regulatory
Speaker 1: Commission have both requested money from Congress to continue the
Speaker 1: work building out a repository, but both have encountered stiff
Speaker 1: resistance from the government. The Obama administration ended federal funding
Speaker 1: in two thousand eleven and launched a new review for
Speaker 1: potential long term storage sites. And we're kind of in
Speaker 1: a holding pattern because since then the answer has been
Speaker 1: the same. The government has sort of refused to entertain
Speaker 1: the idea of funding the Yucca Mountain repository. Meanwhile, the
Speaker 1: infrastructure for nuclear power plants is aging towards the projected
Speaker 1: end of their estimated lifespans, and facilities are having to
Speaker 1: store waste on site indefinitely. So these nuclear power plants,
Speaker 1: when they were built, they were built with the engineers saying,
Speaker 1: this facility, we're rating this facility for us, let's say
Speaker 1: forty years. We think this facility will be able to
Speaker 1: work at full capacity for forty years, and after that
Speaker 1: we're gonna have to build a new one. We're gonna
Speaker 1: have to renovate this one, we're gonna have to fix it,
Speaker 1: whatever it may be. And we're getting in on that time,
Speaker 1: and some of them are past that time, and unless
Speaker 1: more money comes into uh totally you know, refurbish or
Speaker 1: to build new facilities, those will be going offline one
Speaker 1: by one. We've seen quite a few go offline since
Speaker 1: the really since the eighties and moving forward. So uh,
Speaker 1: it's it's tough because we don't have a place to
Speaker 1: put the waste, and we're starting to shut down these
Speaker 1: nuclear power plants, and because we don't have an answer
Speaker 1: of what to do with that waste, it's really hard
Speaker 1: to build new nuclear power plants, uh, even though they
Speaker 1: currently produce about twenty of the electricity that the United
Speaker 1: States uses. So eventually, if those all those power plants
Speaker 1: go dark, you've got to figure out where that is
Speaker 1: going to come from. Because our demand for electricity isn't
Speaker 1: going down, it's going up every year. So that puts
Speaker 1: a huge pressure on us to figure out where else
Speaker 1: are we going to get this electricity? And the easiest
Speaker 1: answer is fossil fuels, but we already know fossil fuels
Speaker 1: contribute to climate change. They produce pollutants that are environmental
Speaker 1: and health hazards, So not a great story. Now it's
Speaker 1: easier to store low level waste. That stuff I was
Speaker 1: telling you about where it's the equipment or the uniforms
Speaker 1: is stuff like that stuff that was in the power
Speaker 1: plant and absorbed radiation over time. Uh, But those materials
Speaker 1: pose much less of a threat than spent nuclear fuel.
Speaker 1: They will tend to uh have their radiation completely diminished
Speaker 1: within three years, which is still a long time, but
Speaker 1: a heck of a lot shorter than tens of thousands
Speaker 1: of years. And again, like I said, some of the
Speaker 1: most hazardous radioactive materials have a half life of around
Speaker 1: ten years or less, but not all them do. And
Speaker 1: that's the problem. So telling someone, hey, within twenty years,
Speaker 1: most of the stuff won't even be a problem anymore
Speaker 1: isn't necessarily the biggest winning argument you can make to
Speaker 1: someone when you're trying to store nuclear waste. There. In
Speaker 1: addition to all that, building nuclear power plants became economically challenging.
Speaker 1: It's very expensive to build one, not just because the
Speaker 1: technology is sophisticated and complicated and you've got to have
Speaker 1: a lot of materials, but also there's a lot of
Speaker 1: bureaucracy surrounding the process. Not that the bureaucracy doesn't serve
Speaker 1: a purpose. They're very strict protections and regulations that are
Speaker 1: in place to require facilities to be built and operate
Speaker 1: under safe guidelines. Those are absolutely necessary. There's a history
Speaker 1: of of facilities that we're not operating up to those guidelines,
Speaker 1: and that is not just criminal, but potentially deadly. So
Speaker 1: those regulations and restrictions end up adding to the cost obviously,
Speaker 1: and while nuclear power has compelling positive arguments compared to
Speaker 1: a again like coal power plants, it might make more
Speaker 1: economic sense to look elsewhere if you're getting into the
Speaker 1: energy biz. And then of course we have the famous disasters,
Speaker 1: stuff like Three Mile Island, Chernobyl and Fukushima. And as
Speaker 1: I said, I'm going to do an episode soon that
Speaker 1: explains what happened in each of those three cases and
Speaker 1: what we learned as a result of those. But they
Speaker 1: certainly have gone a long way to discourage support for
Speaker 1: nuclear power. If you can point to a disaster that's
Speaker 1: a pretty powerful con argument, and earlier I mentioned thorium
Speaker 1: reactors as a proposed alternative to the traditional you two
Speaker 1: thirty five ones. These reactors wouldn't use thorium itself for fuel. Rather,
Speaker 1: a facility would process thorium two thirty two and create
Speaker 1: an isotope called uranium two thirty three. Uranium two thirty
Speaker 1: three is unstable, you will not find it out in nature,
Speaker 1: but it is fiscile, meaning like you two thirty five,
Speaker 1: you can create a sustained nuclear reaction using this fuel.
Speaker 1: In addition, proponents say thorium based plants would produce less
Speaker 1: nuclear waste, they would be more efficient at producing energy,
Speaker 1: and thorium is more plentiful than uranium. Now I'll have
Speaker 1: to do a full episode about thorium plants, but that
Speaker 1: that's further in the future. I'm not gonna do more
Speaker 1: than one week of nuclear power stories at a time.
Speaker 1: I'll revisit that. But here's one fun local fact, something
Speaker 1: that you guys can look forward to. I learned that,
Speaker 1: and I'm amazed that I'd never heard this before, But
Speaker 1: I live within an hour of a radiated site, and
Speaker 1: I learned about this in a book titled Atomic Awakening.
Speaker 1: By James Mahaffee, and the radiated site is now known
Speaker 1: as the Dawson Forest Wildlife Area. That's about fifty miles
Speaker 1: north of Atlanta, the city where I live, and formerly
Speaker 1: this was the Georgia Nuclear Aircraft Laboratory, which was a
Speaker 1: top secret R and D facility operated by the Air Force.
Speaker 1: And the story behind it is really interesting and I
Speaker 1: think I'm actually gonna take a little trip with guys
Speaker 1: from stuff they don't want you to know, and we're
Speaker 1: all going to visit it with Geiger counters. So stay
Speaker 1: tuned for that. I'm sure I'll give a glowing review.
Speaker 1: That about wraps it up for this episode of tech Stuff.
Speaker 1: In our next episode, I'll talk about fusion reactors. If
Speaker 1: you guys have any suggestions for future topics I should cover,
Speaker 1: whether it's a technology, a company, person in tech, whatever
Speaker 1: it may be, send me an email. The address is
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