How to pronounce “fission” in English

but also in chemistry and in chemical bonds, that in those chemical bonds, there is a change in mass.- ...fission side? So uranium, plutonium for the fission, and then hydrogen isotopes for the fusion? In terms of fuel, is that correct to say?- That's correct to say at today's power level. I think what's interesting is the idea that as we deploy the same power source that powers the

are also very safe. I think there's a perception that nuclear fission reactors are unsafe, they're dangerous.fission reactors are unsafe, they're dangerous. And if you just look empirically at the statistics, look empirically at the statistics, that the fear is not justified by the actual safety data.by the actual safety data. Can you just speak to that a little bit?

And then there were two others after me, before Obama.Fission weapons will do the job over there, but it's not enough for nuclear winter.

- Yeah, and I think fundamentally it's that in a lot of ways, fusion is hard and fission is easy.Nuclear fission happens at room temperature, that this uranium and plutonium is so likely to break apart already that simply the adding of one of these neutrons, one extraparticle will then break it apart and release energy.

Eventually there was a fission, the original bomb was a fission bomb.And fission was first shown by Lise Meitner who showed that a certain uranium, when you bombarded it with protons, broke into smaller pieces thatwere less than the uranium, right?

"When all thermonuclear sources of energy are exhausted, a sufficiently heavy star will collapse." That's an opener."Unless fission due to rotation, the radiation of mass, or the blowing off of mass by radiation, reduce the star's mass to orders of that of the sun,this contraction will continue indefinitely." And it goes on that way.

It gets some from-- and that isn't counted here.Nuclear fission, which we've already talked about, is what we use now to produce energy in our nuclear power plants.

mission. I prefer the nuclear fission pronunciation because America. So today's nuclear power plantsuse nuclear fission. They split apart heavy uranium atoms to release energy. Fusion does the opposite. It combines light hydrogen atoms together, the same reaction thatpowers the Sun and the stars. The result is that it's clean fuel from water, no long-lived radioactive waste, inherently safe because a fusion reactor can't melt down. If

...fission side? So uranium, plutonium for the fission, and then hydrogen isotopes for the fusion?- So for fission, uranium and plutonium, we don't make those nuclei. Those, right now for humanity, make those nuclei. Those, right now, for humanity,those have been made in the primordial universe through super-supernova and Big Bang and the initial formation of the universe where matter was created. And so we dig those up.

directly as quickly as possible. And some of the other alternatives, have an intermediate step, and those again, are technical details, but let me still linger on the difference between...fusion and fission. What are some advantages at a high level of nuclear fusion as a source of energy?- fundamentally as a source of energy. In fusion, you're taking these lightweight isotopes, you're bringing them together, you're releasing energy,

and produces electricity. Can you talk through this process in a nuclear fission reactor?process in a nuclear fission reactor?- In a nuclear fission reactor, you put enough of this fissile material, uranium or plutonium, together such that as these unstable molecules, these unstable atoms

process in a nuclear fission reactor?- In a nuclear fission reactor, you put enough of this fissile material, uranium or plutonium, together such that as these unstable molecules, these unstable atomscrack open and break apart, they release heat, that the component parts of those are actually quite hot. And so not only are the component parts that the uranium breaks into, and it's a whole spectrum of different atoms and atomic nuclei,

lay out the difference between nuclear fission power plants and nuclear fission weapons,power plants and nuclear fission weapons, and maybe also nuclear fusion power plants and nuclear fusion weapons. Like,what are the differences here?

things called fusion bombs, the H-bomb, the hydrogen bomb, the hydrogen bomb has uranium in it. It's still a fission bomb. So, fundamentally, this works because youhave a fission reaction, a primary, and that creates radiation that induces a fusion reaction with a small amount of fusion fuel thatthen boosts that uranium reaction again. And so most of the energy, in fact 90% of the energy in an H-bomb, is all still from the uranium reactions themselves.

It's the same technology, overcoming a critical mass, igniting thermonuclear fusion.Eventually there was a fission, the original bomb was a fission bomb.And fission was first shown by Lise Meitner who showed that a certain uranium, when you bombarded it with protons, broke into smaller pieces that

And that's particularly important nowadays when you need to do structural analysis of how receptors fit into molecules, and also, in the case of penicillin, creatingSo this is nuclear fission.

You know Congress defined it, they have politically motivated definitions that are like any reactor after a certain year I think usually when people saygeneration which is nuclear fission power plants out of the stack and making it challenging for them to be able to actually sell all their electricity so

They couldn't do it, even incrementally.And some of the fission products, like Xenon, tend to absorb neutrons and impede the reaction.

They couldn't do it, even incrementally.can release neutrons when fissioned and promote 232 thorium to becomes fissile U-233.

majority of atoms in the universe still are hydrogen.- So the basic fuel for fission is already in the ground, and then the basic fuel for fusion is everywhere.- Is everywhere, and we particularly use a type of hydrogen called deuterium, which is a heavier isotope of hydrogen. Hydrogen is typically one proton and one

So the Nuclear Regulatory Commission, the NRC, defines reactor as, I have it right here, "A nuclear reactor is an apparatus other than an atomic weapon,designed or used to sustain nuclear fission in a self-supporting chain reaction." And there's two big parts to that. That one, fission reaction. Obviously,fusion is not that, and we've talked about why, but also the self-sustaining part. In that a reactor is self-sustaining, you take

- Can you speak to those? So, maybe this is a good place to also lay out the difference between nuclear fissionlay out the difference between nuclear fission power plants and nuclear fission weapons,power plants and nuclear fission weapons, and maybe also nuclear fusion power plants and nuclear fusion weapons. Like,

So that's a promising piece of technology.The other is next generation nuclear fission, which we also sort of know how to do.And it raises a specter in people's minds of bombs and things.

There's going to be carbon capture.There's going to be next generation fission.Really the question is whether we develop this technology here and sell it abroad, or whether we're later forced to buy it from, say, the Chinese, who are developing

Above the layer with the stone tools was a layer of volcanic ash.The geologists used the Zircon Fission Track method to date that layer of ash.They got an age of 270,000 years.

And we use it-- we use uranium in reactors, where we trigger chain reactions in the uranium.And those chain reactions-- the uranium undergoes fission, and because I can never figure out the verbform that I would use there to say where it fizz-- fizzes-- fissions-- nothing sounds right, so I'm just

And ended up there.And if there were any fissionable materials inside the box, it would pick them up and alert the operator.

the path between where things are today and commercialization for something that's a little more out of the box?So what a thorium reactor is really fissioning is Uranium-233, which you breed, and then, you

And we have moved from-- the original American position was Iran could not have anyprinciple and any facilities to produce fissionable material, no reprocessing.We have now moved to agreeing that there are certain types of reprocessing and enrichment they could do, and that the

only thing that's a red line is the acquisition of nuclear weapons.Which if you have enough fissionable material, it's relatively easy to do.So I would say the probability is that Iran

atoms to fuse. That's why the joke in the past has been that fusion is 30 years away and always will be. Just in case you're not familiar, let meclarify the difference between nuclear fusion and nuclear fission. By the way, I believe according to the excellent subreddit post bypmgoodbeer on this, the preferred pronunciation of the latter in the US is nuclear fission, like vision. And in the UK and other countries is nuclear fission, like

these plants as designed, and then I believe they're safe. And that gets to some of the atomic weapons questions And that gets to some of the atomic weapons questions that I think are the other part around nuclear reactorsare the other part around nuclear reactors and fission reactors that are concerning for me.- Can you speak to those? So, maybe this is a good place to also lay out the difference between nuclear fission

up. By way of advice, what questions should I ask world leaders to figure out the geopolitics of nuclear, nuclear proliferation....nuclear weapons, nuclear fission power plants, and nuclear fusion power plants? What's the interesting, intricate complexity there that you could maybe speak to?- The question I would want to ask is, "What would you do if we could deliver for you low-cost, clean, industrial scale, tens or hundreds of megawatts of fusion power

it's not catastrophic, but you have a large coal fire for a long time releasing toxic fumes that you may have to deal with. And in nuclearpower, in a fission power plant, you may have several years of fuel sitting in the core. And in that case, if something bad happened, you have all that potentialenergy for things to happen. But in fusion, you have literally one second of fuel at any time in the system. And having a tank of deuterium, which we have around all the time,

She has a background working on solar vehicles natural gas oil refining and of course nuclear engineering and her company Oklois working on clean energy plants for microgrids where advanced fission reactors can pair and work along with renewables so it's pretty exciting.Tyler Ellis is founder and principal of Ellis, black Ellis partners pardon me he received a PhD, SM and SB degrees from MIT in nuclear science and engineering and

And then there were two others after me, before Obama.And they have only maybe 20 to 60 fission weapons.

He went to a lecture in the late '30s about nuclear physics, and as he was walking across the street, literally in mid-stride, he had this realizationabout how he could start a nuclear chain reaction using fission.Then we get Henri Poincare-- how'd I do, how'd I do?

They couldn't do it, even incrementally.At the top left is an example of a U-233 fission which releases neutrons.

pmgoodbeer on this, the preferred pronunciation of the latter in the US is nuclear fission, like vision. And in the UK and other countries is nuclear fission, likemission. I prefer the nuclear fission pronunciation because America. So today's nuclear power plantsuse nuclear fission. They split apart heavy uranium atoms to release energy. Fusion does the opposite. It combines light hydrogen atoms together, the same reaction that

questions, give feedback, and so on. And now, dear friends, here's David Kirtley. Let's start with the big picture. What is nuclearfusion, and maybe what is nuclear fission? Let's lay out the basics.- So fusion is what powers the universe. Fusion is what happens in stars and it's where the vast amount of energy

- I guess the flip side of that, just stating the obvious, but it's nice to lay it out.nice to lay it out. For nuclear fission, it's a chain reaction, so it's hard to shut off, reaction, so it's hard to shut off, and it works by boiling water into steam,by boiling water into steam, which spins turbines and produces electricity.

more heat and more of these neutrons. And that's how you have those reactions of a self-supporting chain reaction, those reactions of a self-supporting chain reaction, and that chain reaction then continues.and that chain reaction then continues. People design fission reactors such that you have just the right balance fission reactors such that you have just the right balance of enough neutrons are made such that the reaction is continuing,of enough neutrons are made such that the reaction is continuing, but not so many neutrons are made that it speeds up.

and output electricity through your steam turbine. You end up with complicated systems of flowing liquids and flowing water, up with complicated systems of flowing liquids and flowing water, balancing the heat.balancing the heat. A lot of fission reactor design comes from that thermal balance of keeping this reaction comes from that thermal balance of keeping this reaction going, making sure it doesn't speed up, because that'sgoing, making sure it doesn't speed up, because that's an uncontrolled chain reaction, which you would not want, an uncontrolled chain reaction, which you would not want, and balancing the cooling and the output of getting the water out of it.

You can just shut it off. But it should also be said that as far as I understand, the current fission nuclear reactorsas far as I understand, the current fission nuclear reactors are also very safe.are also very safe. I think there's a perception that nuclear fission reactors are unsafe, they're dangerous.

this from a nuclear engineer's point of view. I spent a lot of years studying these systems.studying these systems. And modern fission reactors, I believe, are engineered to be safe.believe, are engineered to be safe. They're engineered in ways where as those reactions maybe speed up where as those reactions maybe speed up and those systems get hotter,

Absolutely. I think a lot of us have had those people in our lives.And she's the one who figured out the theory of nuclear fission, which eventually led to, of course, the bomb, which she refused to be a part of.

And it has many manifestations, which I want to run through quickly.Nuclear reactions, whatever kind they are-- fission, nuclear fusion, radioactive decay-- produce millions of times more energy than chemical reactions,like burning fuels or metabolizing food.

place to start that's what I was going to say yeah we participated in this film because I feel like there isn't a great there's not like a single great sourceto point people to people are like hey I want to learn about advanced fission like what is it how does it differ from older plants what is nuclear at all umI'm not I don't have like a lot of resources I'm like oh this is a really great way and user friend not really technologically dense to

form that I would use there to say where it fizz-- fizzes-- fissions-- nothing sounds right, so I'm justavoiding saying that. It undergoes fission.It splits into chunks, and that releases energy which splits more of it and splits more of it.